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Sample records for mg amlodipine besylate

  1. Efficacy and safety of olmesartan medoxomil and hydrochlorothiazide compared with benazepril and amlodipine besylate.

    Science.gov (United States)

    Kereiakes, Dean J; Neutel, Joel M; Punzi, Henry A; Xu, Jianbo; Lipka, Leslie J; Dubiel, Robert

    2007-01-01

    Most patients with stage 2 hypertension require two or more antihypertensive agents in order to achieve the BP goals recommended in current treatment guidelines. Accordingly, combinations of two drugs with different mechanisms of antihypertensive action are widely used. The aim of this randomized, double-blind, multicenter 12-week study was to compare the efficacy, safety, and tolerability of a combination of olmesartan medoxomil/hydrochlorothiazide (HCTZ) with that of benazepril plus amlodipine besylate in patients with stage 2 hypertension. Patients were eligible for randomization following a 3- to 4-week placebo run-in period if they had either (i) mean seated DBP>or=90 mm Hg butor=160 mm Hg but or=100 mm Hg butor=95 mm Hg and145 mm Hg andbenazepril (10 mg/day for 2 weeks; then 20 mg/day for 2 weeks; then benazepril 20 mg/day plus amlodipine besylate 5 mg/day for 4 weeks; then benazepril 20 mg/day plus amlodipine besylate 10 mg/day for 4 weeks). The primary endpoint was change from baseline in mean SBP at the end of week 12 (end of study). Secondary endpoints included DBP after completion of monotherapy and combination therapy at the end of weeks 4 and 12, SBP at the end of week 4, and percentage of patients attaining BP goals ofbenazepril plus amlodipine besylate (least square [LS] mean change: -32.5 vs -26.5 mm Hg, p=0.024; LS mean treatment difference -6.0 mm Hg; 95% CI -11.1, -0.8 mm Hg). The LS mean change for reduction in DBP approached statistical significance with olmesartan medoxomil/HCTZ compared with the benazepril-based regimen (p=0.056) at week 12 (end of study). BP reductions showed statistically significant differences between treatment groups favoring olmesartan medoxomil/HCTZ in both SBP and DBP at week 8. The percentage of patients achieving goal rates at the end of the study for olmesartan medoxomil/HCTZ and benazepril plus amlodipine besylate, respectively, were 66.3% versus 44.7% (p=0.006) forbenazepril plus amlodipine besylate 20/5 and 20

  2. Microneedle-assisted delivery of verapamil hydrochloride and amlodipine besylate.

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    Kaur, Monika; Ita, Kevin B; Popova, Inna E; Parikh, Sanjai J; Bair, Daniel A

    2014-02-01

    The aim of this project was to study the effect of stainless steel solid microneedles and microneedle rollers on percutaneous penetration of verapamil hydrochloride and amlodipine besylate. Verapamil, 2-(3,4-dimethooxyphenyl)-5-[2-(3,4 dimethoxyphenyl)ethyl-methyl-amino]-2-propan-2-yl-pentanenitrile is a calcium channel blocker agent that regulates high blood pressure by decreasing myocardial contractilty, heart rate and impulse conduction. Amlodipine, (R, S)-2-[(2-aminoethoxy) methyl]-4-(2-chlorophenyl)-3-ethoxycarbonyl-5-methoxycarbonyl-6-methyl-1, 4-dihydropyridine, is a calcium channel blocker that is used for the management of hypertension and ischemic heart disease. Passive penetration of verapamil and amlodipine across the skin is low. In vitro studies were performed with microneedle-treated porcine ear skin using vertical static Franz diffusion cells (PermeGear, Hellertown, PA, USA). The receiver chamber contained 5ml of PBS (pH7.4) and was constantly maintained at 37°C temperature with a water circulation jacket. The diffusion area of the skin was 1.77cm(2). The donor compartment was loaded with 1ml of the solution containing 2.5mg/ml of amlodipine besylate. The donor chamber was covered with parafilm to avoid evaporation. Passive diffusion across untreated porcine skin served as control. Aliquots were taken every 2h for 12h and analyzed by liquid chromatography-mass spectrometry. Transcutaneous flux of verapamil increased significantly from 8.75μg/cm(2)/h to 49.96μg/cm(2)/h across microneedle-roller treated porcine skin. Percutaneous flux of amlodipine besylate following the use of stainless steel microneedles was 22.39μg/cm(2)/h. Passive flux for the drug was 1.57μg/cm(2)/h. This enhancement of amlodipine flux was statistically significant. Transdermal flux of amlodipine with microneedle roller was 1.05μg/cm(2)/h in comparison with passive diffusion flux of 0.19μg/cm(2)/h. The difference in flux values was also statistically significant. Stainless

  3. Investigation of forced and total degradation products of amlodipine besylate by liquid chromatography and liquid chromatography-mass spectrometry

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    Stoiljković Zora Ž.

    2014-01-01

    Full Text Available An isocratic, reversed-phase liquid chromatographic method was applied for the investigation of the degradation products of amlodipine besylate under the stressed conditions in solution. Amlodipine besylate stock solutions were subjected to acid and alkali hydrolysis, chemical oxidation and photodegradation as well as to the electrochemical degradation by cyclic voltammetry in 0.05 mol/L NaHCO3 on gold electrode. The total degradation of amlodipine besylate was achieved in 5 mol/L NaOH at 80°C for 6 h and the compound with molecular formula C15H16NOCl was identified as a main degradation product. Under acidic (5 mol/L HCl at 80°C for 6 h stress conditions 75.2% of amlodipine besylate degradation was recorded. Oxidative degradation in the solution of 3% H2O2-methanol 80:20 at 80°C for 6 h showed that amlodipine besylate degraded to 80.1%. After 14 days of expose in photostability chamber amlodipine besylate solution showed degradation of 32.2%. In electrochemical degradation after 9 hours of cyclization the beginning of amlodipine oxidation was shifted for 200 mV to more negative potentials, with the degradation of 66.5%. Mass spectrometry analysis confirmed the presence of dehydro amlodipine derivate with molecular formula C20H23N2O5Cl in oxidative and acidic conditions while in electrochemical degradation was detected in traces. [Projekat Ministarsva nauke Republike Srbije, br. 172013

  4. Design and stability study of an oral solution of amlodipine besylate for pediatric patients.

    Science.gov (United States)

    van der Vossen, A C; van der Velde, I; Smeets, O S N M; Postma, D J; Vermes, A; Koch, B C P; Vulto, A G; Hanff, L M

    2016-09-20

    Amlodipine is an antihypertensive agent recommended for the management of hypertension in children and adolescents. The commercially available tablets of 5 and 10mg do not provide the necessary flexibility in dosing needed for treating children. Our goal was to develop a pediatric oral solution of amlodipine, using a robust manufacturing process suitable for ex-tempora and larger scale production. The parameters API and preservative content, related substances, appearance and pH were studied under four different storage conditions. Samples were analyzed up to 12months. Microbiological quality was studied in an 18-week in-use test based on a two-times daily dosing schedule. The stability of the formulation was influenced by storage conditions and composition. A formulation containing amlodipine besylate, sucrose syrup and methyl paraben remained physically stable for 12months at 4°C with no loss of amlodipine content. Related substances increased during the study but remained below 0.5%. In-use stability was proven up to 18weeks. Storage under refrigerated conditions was necessary to prevent precipitation and to obtain an acceptable shelf-life. In conclusion, we have developed and validated an amlodipine oral solution, suitable for the pediatric population. This liquid formulation is preferred over manipulated commercial dosage forms or non-standardized extemporaneously compounded formulations. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Efficacy and safety of long-term treatment with the combination of amlodipine besylate and olmesartan medoxomil in patients with hypertension.

    Science.gov (United States)

    Chrysant, Steven G; Oparil, Suzanne; Melino, Michael; Karki, Sulekha; Lee, James; Heyrman, Reinilde

    2009-09-01

    J Clin Hypertens (Greenwich). 2009;11:475-482. (c) 2009 Wiley Periodicals, Inc.The authors report on the 44-week open-label extension of the 8-week, double-blind Combination of Olmesartan Medoxomil and Amlodipine Besylate in Controlling High Blood Pressure (COACH) trial in 1684 patients. Initial therapy was amlodipine (AML) plus olmesartan medoxomil (OM) 5+40 mg/d, up-titrated to AML+OM 10+40 mg/d plus hydrochlorothiazide (HCTZ) 12.5 mg then 25 mg if patients did not achieve blood pressure (BP) goal (<140/90 mm Hg or <130/80 mm Hg in patients with diabetes). Baseline mean BP decreased from 164/102 mm Hg to 131/82 mm Hg at end of study, with an overall 66.7% of patients, including those with diabetes, achieving BP goal. The BP goal achievement was 80% for AML+OM 5+40 mg/d, 70.6% for AML+OM 10+40 mg/d, 66.6% for AML+OM+HCTZ 10+40+12.5 mg/d, and 46.3% for AML+OM+HCTZ 10+40+25 mg/d. Study medication was safe and well tolerated. Combination antihypertensive therapy with AML+OM+/-HTCZ, up-titrated as necessary, allowed a majority of patients to achieve BP goal.

  6. VERIFICATION HPLC METHOD OF QUANTITATIVE DETERMINATION OF AMLODIPINE IN TABLETS

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    Khanin V. A

    2014-10-01

    Full Text Available Introduction. Amlodipine ((±-2-[(2-aminoetoksimethyl]-4-(2-chlorophenyl-1,4-dihydro-6-methyl-3,5-pyridine dicarboxylic acid 3-ethyl 5-methyl ester as besylate and small tally belongs to the group of selective long-acting calcium channel blockers, dihydropyridine derivatives. In clinical practice, as antianginal and antihypertensive agent for the treatment of cardiovascular diseases. It is produced in powder form, substance and finished dosage forms (tablets of 2.5, 5 and 10 mg. The scientific literature describes methods of quantitative determination of the drug by spectrophotometry – by his own light absorption and by reaction product with aloksan, chromatography techniques, kinetic-spectrophotometric method in substances and preparations and methods chromatomass spectrometry and stripping voltammetry. For the quantitative determination of amlodipine besylate British Pharmacopoeia and European Pharmacopoeia recommend the use of liquid chromatography method. In connection with the establishment of the second edition of SPhU and when it is comprised of articles on the finished product, we set out to analyze the characteristics of the validation of chromatographic quantitative determination of amlodipine besylate tablets and to verify the analytical procedure. Material & methods. In conducting research using substance amlodipine besylate series number AB0401013. Analysis subject pill “Amlodipine” series number 20113 manufacturer of “Pharmaceutical company “Zdorovye”. Analytical equipment used is: 2695 chromatograph with diode array detector 2996 firms Waters Corp. USA using column Nova-Pak C18 300 x 3,9 mm with a particle size of 4 μm, weight ER-182 company AND Japan, measuring vessel class A. Preparation of the test solution. To accurately sample powder tablets equivalent to 50 mg amlodipine, add 30 ml of methanol, shake for 30 minutes, dilute the solution to 50.0 ml with methanol and filtered. 5 ml of methanol solution adjusted to

  7. Development and Validation of a Chromatography Method Using Tandem UV/Charged Aerosol Detector for Simultaneous Determination of Amlodipine Besylate and Olmesartan Medoxomil: Application to Drug-Excipient Compatibility Study

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    Ariadne M. Brondi

    2017-01-01

    Full Text Available A study was carried out to investigate compatibility of amlodipine besylate and olmesartan medoxomil with a variety of pharmaceutical excipients. Both drugs are antihypertensive agents that can be administered alone, in monotherapy, or in pharmaceutical association. The studies were performed using binary and ternary mixtures, and samples were stored for 3 and 6 months at 40°C under 75% relative humidity and dry conditions. For this study, a method based on high-performance liquid chromatography (HPLC was developed and validated for the simultaneous determination of amlodipine besylate and olmesartan medoxomil in samples from pharmaceutical preformulation studies using diode array detector (DAD and charged aerosol detector (CAD. The runtime per sample was 10 min with retention time of 7.926 min and 4.408 min for amlodipine and olmesartan, respectively. The validation was performed according to ICH guidelines. The calibration curve presents linear dynamic range from 12 to 250 μg mL−1 for amlodipine and from 25 to 500 μg mL−1 for olmesartan with coefficient of determination (R2 ≥ 0.9908 while repeatability and reproducibility (expressed as relative standard deviation were lower than 1.0%. The excipients such as corn starch, croscarmellose sodium, magnesium stearate, polyvinyl alcohol, talc, polyvinylpyrrolidone, lactose monohydrate, and polyethylene glycol showed potential incompatibilities after accelerated stability testing.

  8. Development of dissolution test method for a telmisartan/amlodipine besylate combination using synchronous derivative spectrofluorimetry

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    Panikumar Durga Anumolu

    2014-04-01

    Full Text Available The dissolution process is considered an important in vitro tool to evaluate product quality and drug release behavior. Single dissolution methods for the analysis of combined dosage forms are preferred to simplify quality control testing. The objective of the present work was to develop and validate a single dissolution test for a telmisartan (TEL and amlodipine besylate (AML combined tablet dosage form. The sink conditions, stability and specificity of both drugs in different dissolution media were tested to choose a discriminatory dissolution method, which uses an USP type-II apparatus with a paddle rotating at 75 rpm, with 900 mL of simulated gastric fluid (SGF without enzymes as the dissolution medium. This dissolution methodology provided good dissolution profiles for both TEL and AML and was able to discriminate changes in the composition and manufacturing process. To quantify both drugs simultaneously, a synchronous first derivative spectrofluorimetric method was developed and validated. Drug release was analyzed by a fluorimetric method at 458 nm and 675 nm for AML and TEL, respectively. The dissolution method was validated as per ICH guidance.

  9. Development and Evaluation of Mouth Dissolving Films of Amlodipine Besylate for Enhanced Therapeutic Efficacy

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    K. M. Maheswari

    2014-01-01

    Full Text Available The present investigation was undertaken with an objective of formulating mouth dissolving films (MDFs of Amlodipine Besylate (AMLO to enhance convenience and compliance of the elderly and pediatric patients for better therapeutic efficacy. Film formers like hydroxy propyl methyl cellulose (HPMC and methyl cellulose (MC along with film modifiers like poly vinyl pyrrolidone K30 (PVP K30, and sodium lauryl sulphate (SLS as solubilizing agents were evaluated. The prepared MDFs were evaluated for in vitro dissolution characteristics, in vitro disintegration time, and their physicomechanical properties. All the prepared MDFs showed good mechanical properties like tensile strength, folding endurance, and % elongation. MDFs were evaluated by means of FTIR, SEM, and X-RD studies. MDFs with 7.5% (w/w of HPMC E3 gave better dissolution properties when compared to HPMC E5, HPMC E15, and MC. MDFs with PVP K30 and SLS gave superior dissolution properties when compared to MDFs without PVP K30 and SLS. The dissolution properties of MDFs with PVP K30 were superior when compared to MDFs with SLS. In the case of F3 containing 7.5% of HPMC E3 and 0.04% of PVP K30, complete and faster release was observed within 60 sec when compared to other formulations. Release kinetics data reveals diffusion is the release mechanism.

  10. Multiway analysis methods applied to the fluorescence excitation-emission dataset for the simultaneous quantification of valsartan and amlodipine in tablets

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    Dinç, Erdal; Ertekin, Zehra Ceren; Büker, Eda

    2017-09-01

    In this study, excitation-emission matrix datasets, which have strong overlapping bands, were processed by using four different chemometric calibration algorithms consisting of parallel factor analysis, Tucker3, three-way partial least squares and unfolded partial least squares for the simultaneous quantitative estimation of valsartan and amlodipine besylate in tablets. In analyses, preliminary separation step was not used before the application of parallel factor analysis Tucker3, three-way partial least squares and unfolded partial least squares approaches for the analysis of the related drug substances in samples. Three-way excitation-emission matrix data array was obtained by concatenating excitation-emission matrices of the calibration set, validation set, and commercial tablet samples. The excitation-emission matrix data array was used to get parallel factor analysis, Tucker3, three-way partial least squares and unfolded partial least squares calibrations and to predict the amounts of valsartan and amlodipine besylate in samples. For all the methods, calibration and prediction of valsartan and amlodipine besylate were performed in the working concentration ranges of 0.25-4.50 μg/mL. The validity and the performance of all the proposed methods were checked by using the validation parameters. From the analysis results, it was concluded that the described two-way and three-way algorithmic methods were very useful for the simultaneous quantitative resolution and routine analysis of the related drug substances in marketed samples.

  11. Catalytic degradation of Amlodipine Besylate using ZnO, Cu doped ZnO, and Fe doped ZnO nanoparticles from an aqueous solution: Investigating the effect of different parameters on degradation efficiency

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    Alizadeh, Elahe; Baseri, Hadi

    2018-04-01

    Some common nanoparticles, such as Zinc Oxide have been used as nanocatalysts in many processes, but they also have an important application in water purification processes. In this research, ZnO based nanoparticles were used for the degradation of Amlodipine Besylate (AMB) and the effect of some main parameters, e.g. initial concentration of AMB, nanocatalysts dose, pH of the solution, temperature of the solution, H2O2 dose, and the time of visible light irradiation, were investigated. The destruction amount was determined by UV-Vis spectroscopy. The synthesized nanoparticles were characterized by FE-SEM, XRD, FT-IR, BET, BJH, EDS, XRF and UV-Vis techniques. The maximum degradation of AMB was about 90% in 60 min of visible light irradiation with 100 μL of H2O2.

  12. Analytical method development and Validation of Aml odipine Besylate and Nebivolol in their Dosage Form

    OpenAIRE

    Patel Jignesh; Patel Mandev

    2014-01-01

    This work is concerned with application of simple, economical, precise, accurate and reproducible reverse phase high performance liquid chromatographic (RP-HPLC) method for simultaneous estimation of Nebivolol hydrochloride(NBH) and S-Amlodipine besylate (AMB) on thermo Hypersil C18 (Thermo Electron Corporation) (250 x 4.6 mm, 5 μm) using Acetonitrile and Phosphate buffer (pH 2.5 ± 0.1) in ratio of 60:40 as mobile phase. pH of buffer adjusted to 2.5 ± 0.1 with O-phosphoric acid. The flow rate...

  13. Combined Treatment with Amlodipine and Atorvastatin Calcium Reduces Circulating Levels of Intercellular Adhesion Molecule-1 and Tumor Necrosis Factor-α in Hypertensive Patients with Prediabetes.

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    Huang, Zhouqing; Chen, Chen; Li, Sheng; Kong, Fanqi; Shan, Peiren; Huang, Weijian

    2016-01-01

    To assess the effect of amlodipine and atorvastatin on intercellular adhesion molecule (ICAM)-1 and tumor necrosis factor (TNF)-α expression, as endothelial function and inflammation indicators, respectively, in hypertensive patients with and without prediabetes. Forty-five consecutive patients with hypertension, diagnosed according to JNC7, were divided into two groups based on the presence (HD group, n = 23) or absence (H group, n = 22) of prediabetes, diagnosed according to 2010 ADA criteria, including impaired glucose tolerance (IGT) and fasting glucose tests. All patients simultaneously underwent 12-week treatment with daily single-pill amlodipine besylate/atorvastatin calcium combination (5/10 mg; Hisun-Pfizer Pharmaceuticals Co. Ltd). Serum isolated before and after treatment from overnight fasting blood samples was analyzed by ELISA. In the HD and H groups after vs. before 12-week amlodipine/atorvastatin treatment, there were significantly (all P atorvastatin improved endothelial function and inflammation, as reflected by lower circulating levels of ICAM-1 and TNF-α, more prominently in hypertensives with than without prediabetes. Starting statin treatment before overt diabetes in hypertensives might thus improve cardiovascular outcomes.

  14. Dgroup: DG01925 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available amlodipine besilate mixt ... D07569 ... Candesartan cilexetil and anmlodipine besylate tablets (JP17) ... D10286 ... Amlodipine - valsartan... -hydrochlorothiazide mixt ... D10287 ... Aliskiren hemifumarate - valsartan... mixt D10288 ... Olmesartan medoxomil - amlodipine besylate - hydrochlorothiazide mixt ... D10226 ... Sacubitril valsartan

  15. Atorvastatin calcium plus amlodipine for the treatment of hypertension.

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    Delgado-Montero, Antonia; Zamorano, Jose L

    2012-12-01

    Hypertension (HTN) and dyslipemia (DYL) are two of the major modifiable cardiovascular (CV) risk factors, determinants in the development of cerebrovascular and coronary heart disease (CHD). Many patients have both risk factors which increase their total CV risk compared with patients with only one risk factor. Treatment guideline recommendations are poorly implemented in real practice, in part due to numerous and complicated drug regimes which hamper patient´s adherence. In this article the authors describe the first combined fixed-dose pill of an antihypertensive and a lipid-lowering agent, the single-pill combination of amlodipine besylate and atorvastatin calcium (SPAA). They summarize the pharmacokinetic and pharmacodynamic properties of both compounds and the main randomized clinical studies, as well as real-world observational studies, made with the new combined formulation. The use of the single-pill amlodipine and atorvastatin is an adequate option for the clinician to treat hypertensive patients with DYL or high CV risk burden, with proven efficacy, tolerability, cost-effectiveness, and the advantage of improving patient treatment compliance.

  16. The effects of high-dose amlodipine/benazepril combination therapies on blood pressure reduction in patients not adequately controlled with amlodipine monotherapy.

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    Chrysant, Steven G; Sugimoto, Daniel H; Lefkowitz, Marty; Salko, Thomas; Khan, Mahmudul; Arora, Vipin; Shi, Victor

    2007-03-01

    This study compared the efficacy and safety of amlodipine/benazepril (10/40 mg/day and 10/20 mg/day) with amlodipine 10 mg/day in patients whose blood pressure (BP) was not adequately controlled with amlodipine monotherapy. After a lead-in period with amlodipine monotherapy, 812 non-responder patients (mean sitting diastolic BP > or =95 mmHg) were randomized to one of three treatment groups. Ambulatory BP monitoring was conducted in 276 patients. Treatment with amlodipine/benazepril 10/40 mg/day and 10/20 mg/day resulted in a decrease of mean sitting systolic and mean sitting diastolic BP by 13.3/12.7 mmHg and 12.1/11.6 mmHg, respectively, compared with monotherapy (6.6/8.5 mmHg) (p benazepril 10/40 mg/day and 10/20 mg/day decreased ambulatory systolic and diastolic BP by 9.9/6.7 mmHg and 7.4/5.2 mmHg compared with monotherapy (p benazepril combinations compared with monotherapy (4.5%, 5.5% vs. 9.2%, respectively, p=NS). No significant metabolic side-effects were noted among the combination groups. Amlodipine/benazepril combinations were well tolerated and resulted in significant BP reductions and better BP responder rates than amlodipine monotherapy.

  17. Pharmacokinetics of repeated oral doses of amlodipine and amlodipine plus telmisartan in healthy volunteers.

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    Stangier, J; Su, C A

    2000-12-01

    This open-label, crossover study was performed to establish if there is evidence for interaction between telmisartan, an angiotensin II antagonist, and amlodipine, a class II (dihydropyridine) calcium channel antagonist, on the basis of pharmacokinetics and safety. In a two-way crossover trial, 12 healthy Caucasian males were randomized to receive once daily for 9 days oral amlodipine 10 mg with or without oral telmisartan 120 mg. After a washout period of > or = 13 days, the subjects were switched to the other medication regimen. The geometric means of the primary pharmacokinetic parameters at steady state (day 9) for amlodipine when given alone were the following: maximum plasma concentration (Cmax) 17.7 ng/mL, area under the plasma concentration-time curve (AUC) 331 ng.h/mL, and renal clearance 39.5 mL/min, with 8% of the total amlodipine dose being excreted. When concomitant telmisartan was given, the respective values were 18.7 ng/mL, 352 ng.h/mL, and 43.0 mL/min, with 9.4% of the total amlodipine dose being excreted renally. The limits of the 90% confidence intervals (CIs) for the ratios of these steady-state parameters were 0.97 to 1.14 for Cmax and 0.98 to 1.16 for AUC; both were within the predefined reference range (0.8 to 1.25) for bioequivalence. The high intersubject variability in urinary amlodipine excretion resulted in bioequivalence not being demonstrated for renal clearance. Adverse effects were few, mild to moderate in intensity, and transient whether amlodipine was given alone or with telmisartan. Vital signs, except for blood pressure, and clinical laboratory values were unaffected by either medication. The findings of this study show that concomitant telmisartan and amlodipine may be administered as there is no clinically significant variation in primary pharmacokinetic parameters of amlodipine in the presence of telmisartan, and the safety of the combination is comparable to that of amlodipine alone.

  18. Pharmacokinetics of a telmisartan, amlodipine and ...

    African Journals Online (AJOL)

    Conclusion: A formulated FDC tablet containing a telmisartan/amlodipine/HCTZ combination (80/10/25mg) was bioequivalent to a co-administrated commercially available telmisartan/amlodipine combination and HCTZ tablets at equivalent concentrations. Keywords: Fixed-dose combination, Hypertension, Telmisartan, ...

  19. The antihypertensive effect of amlodipine in cats

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    D. Morar,

    2011-06-01

    Full Text Available The purpose of the study was to evaluate the effect of amlodipine on blood pressure and renal function in cats with arterial hypertension secondary to chronic renal failure. The research was conducted on 11 cats, aged between 7 and 14.5 years, diagnosed with arterial hypertension secondary to chronic renal failure. Systolic blood pressure (SBP, diastolic blood pressure (DBP, mean arterial pressure (MBP and pulse rate were determined by oscillometric method, before and after 7, 30 or 120 days of treatment with amlodipine. At the beginning of treatment, all cats were receiving 0.625 mg amlodipine once daily and after 7 days oftreatment, in five cats, the dose was increased to 1.25 mg amlodipine, once daily. Before amlodipine administration the mean values of SBP/DBP were 175 ± 13.2 mmHg/119 ± 7.2 mmHg and after 30 days of treatment, the mean values of the SBP/DBP were reduced by 27.9/25.4 mmHg (p<0,001. After 120 days of treatment with amlodipine mean values of SBP/DBP were lower with 32/31 mmHg compared with baseline values (p<0.001. The treatment with amlodipine did not significantly affect the values of blood biochemical parameters of renal profile.

  20. Prospective direct comparison of antihypertensive effect and safety between high-dose amlodipine or indapamide in hypertensive patients uncontrolled by standard doses of angiotensin receptor blockers and amlodipine.

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    Okamura, Keisuke; Shirai, Kazuyuki; Totake, Nao; Okuda, Tetsu; Urata, Hidenori

    2018-01-01

    When hypertension is uncontrolled by routine treatment with an angiotensin II receptor blocker (ARB) and the calcium channel blocker amlodipine (5 mg), the dose of amlodipine can be increased or a diuretic can be added. We investigated the more effective option in a prospective multicenter open-label study. Hypertensive patients were recruited if the target blood pressure (BP) in The Japanese Society of Hypertension 2009 guideline could not be achieved with standard-dose ARB therapy and amlodipine (5 mg). Patients were divided into three groups. Group-1 was switched to a combination of irbesartan (100 mg) and amlodipine (10 mg). Group-2A was changed to a combination of irbesartan (100 mg), amlodipine (5 mg), and indapamide, while Group-2B received a standard-dose ARB and amlodipine (5 mg) plus indapamide. Patients were assigned by their attending physicians and were followed for 6 months. The primary endpoint was the antihypertensive effect of each regimen. Group-1 contained 85 patients, Group-2A had 49 patients, and Group-2B had 4 patients. We only analyzed Group-1 and Group-2A due to the small size of Group-2B. In both groups, systolic BP and diastolic BP were significantly decreased up to 6 months (all p < 0.001). Reduction of systolic BP was greater in Group-1 than Group-2A after 1 month and 6 months (both p < 0.05). Uric acid was increased in Group-2A after 3 months, but not at 6 months. Although both regimens were effective for reducing BP, increasing amlodipine to 10 mg daily controlled hypertension without elevation of serum uric acid.

  1. Blood pressure control with amlodipine add-on therapy in patients with hypertension and diabetes: results of the Amlodipine Diabetic Hypertension Efficacy Response Evaluation Trial.

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    Kloner, Robert A; Neutel, Joel; Roth, Eli M; Weiss, Robert; Weinberger, Myron H; Thakker, Kamlesh M; Schwartz, Brian; Shi, Harry; Gregg, Anne-Marie

    2008-11-01

    Attainment of blood pressure (BP) goals in patients with diabetes is critical both to reduce the risk of cardiovascular events and to delay the progression of renal disease. While therapeutic guidelines advise initial therapy with an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker, monotherapy with these agents may not be sufficient to attain target BP. The ADHT (Amlodipine Diabetic Hypertension Efficacy Response Evaluation Trial) evaluated the efficacy and safety of adding amlodipine to the treatment regimen of patients with hypertension and diabetes who were already receiving either quinapril or losartan as monotherapy. ADHT was a double-blind, double-dummy, 22-week trial conducted in the US. After a washout period of 7-13 days, patients (aged 30-75 y) with hypertension and diabetes were randomized to receive quinapril 20 mg/day plus placebo or losartan 50 mg/day plus placebo for 4 weeks, titrated to 40 mg or 100 mg (if required), respectively, for an additional 4 weeks to achieve their BP goals (<130/80 mm Hg). At week 8, either amlodipine 5 mg/day or placebo was added for an additional 12 weeks, with titration to 10 mg at week 14 if the BP goal was not achieved. Efficacy of add-on therapy was evaluated in 411 patients (amlodipine 211, placebo 200). BP goal was reached by 27.5% of patients when amlodipine was added to quinapril or losartan monotherapy, compared with 12.5% when placebo was added (OR 2.73; 95% CI 1.61 to 4.64; p < 0.001). When added to quinapril or losartan monotherapy, amlodipine reduced BP by 8.1/5.4 mm Hg, compared with a 1.6/0.7 mm Hg decrease with add-on placebo (p < 0.001). Amlodipine, quinapril, and losartan were well tolerated. Amlodipine is safe and effective when added to quinapril or losartan monotherapy to help lower BP toward therapeutic targets in patients with hypertension and diabetes.

  2. AMLODIPINE ADVANTAGES IN ARTERIAL HYPERTENSION THERAPY

    Directory of Open Access Journals (Sweden)

    V. M. Tsareva

    2008-01-01

    Full Text Available Aim. To study effects of calcium channel blocker, amlodipine on indices of ambulatory blood pressure monitoring (ABPM, heart rate variability, corrected QT-interval and its dispersion, structural and functional heart indices, microcirculation in patients with arterial hypertension (HT.Material and methods. 48 patients with HT of 1-2 stages were involved in the study. After 2 week wash-out period amlodipine (5-10 mg/day therapy was started. ABPM, 24 hour electrocardiogram monitoring, echocardiography, laser Doppler flowmetry was performed initially and in 24 weeks of therapy.Results. Amlodipine therapy increased microcirculation efficacy, reduced repolarization nonhomogeneity, contributed to myocardial electrophysiological stability. Besides it improved structural and functional heart indices, decreased systolic and diastolic blood pressure (BP, reduced indices of BP load during a day.Conclusion. Amlodipine is effective antihypertensive medicine, having prominent cardio- and vasoprotective effects and good tolerability.

  3. ASSESSMENT OF AMLODIPINE ANTIHYPERTENSIVE EFFECT HOMOGENEITY IN CONTROLLED TRIAL

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    V. M. Gorbunov

    2016-01-01

    Full Text Available Aim. To compare influence of amlodipine and spirapril on ambulatory blood pressure profile, including antihypertensive effect smoothness in patients with arterial hypertension (HT.Methods. 39 patients (aged 53,7±10,0 y.o. with HT were included in the open, randomized, cross-over study, 30 patients completed study. The duration of every therapies was 4 weeks, initial control period and wash-out period between therapies lasted 1 week. The initial daily dose of amlodipine was 5 mg, standard dose of spirapril (6 mg/daily was not changed during the trial. After 1-2 weeks of treatment amlodipine dose was increased up to 10 mg/daily as well as dihydrochlorothiazide was added, if necessary. Ambulatory blood pressure monitoring (ABPM was performed initially and at the end of both therapies.Results. Both drugs demonstrated good antihypertensive effect according to ABPM data. Decrease of systolic/diastolic blood pressure was 11,2±1,8/7,6±1,2 mm Hg in amlodipine therapy and 10,0±1,8/7,1±1,2 in spirapril therapy (p<0,0001. The smoothness indexes (SI were 0,65/0,45 and 0,55/0,45, respectively, differences between two therapies were not significant. However the individual analysis of the SI distribution (with SI=0,5 as a satisfactory criterion, showed that antihypertensive effect smoothness is better in amlodipine therapy than this in spirapril one.Conclusion. Amlodipine has prominent as well as smooth antihypertensive effect, that gives it advantages in the long-term antihypertensive therapy.

  4. Amlodipine reduces the antimigratory effect of diclofenac in spontaneously hypertensive rats.

    Science.gov (United States)

    Rodrigues, Stephen Fernandes; Dossantos, Rosangela Aparecida; de Oliveira, Maria Aparecida; Rastelli, Viviani Milan; Nucci, Gilberto de; Tostes, Rita de Cássia; Nigro, Dorothy; Carvalho, Maria Helena; Fortes, Zuleica B

    2008-05-01

    Amlodipine, an antihypertensive drug, and diclofenac, an antiinflammatory drug, may generally be combined, particularly in elderly patients; therefore, the potential for their interaction is high. We aim to determine if amlodipine interferes with the antimigratory effect of diclofenac. For this, male spontaneously hypertensive rats (SHRs) were treated with either diclofenac (1 mg.kg.d, 15 d) alone or combined with amlodipine (10 mg.kg.d, 15 d). Leukocyte rolling, adherence, and migration were studied by intravital microscopy. Diclofenac did not change (180.0 +/- 2.3), whereas amlodipine combined (163.4 +/- 5.1) or not (156.3 +/- 4.3) with diclofenac reduced the blood pressure (BP) levels in SHR (183.1 +/- 4.4). Diclofenac and amlodipine reduced leukocyte adherence, migration, and ICAM-1 expression, whereas only diclofenac reduced rolling leukocytes as well. Combined with amlodipine, the effect of the diclofenac was reduced. Neither treatment tested increased the venular shear rate or modified the venular diameters, number of circulating leukocytes, P-selectin, PECAM-1, L-selectin, or CD-18 expressions. No difference could be found in plasma concentrations of both drugs given alone or in association. In conclusion, amlodipine reduces leukocyte migration in SHR, reducing endothelial cell ICAM-1 expression. Amlodipine reduces the effect of the diclofenac, possibly by the same mechanism. A pharmacokinetic interaction as well as an effect on the other adhesion molecules tested could be discarded.

  5. EFFECTS OF AMLODIPINE, FOSINOPRIL AND METOPROLOL ON HEMODYNAMICS IN HYPERTENSIVE PATIENTS

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    A. L. Hohlov

    2007-01-01

    Full Text Available Aim. To assess an efficacy of antihypertensive therapy with calcium antagonist, angiotensin converting enzyme inhibitor and β-blocker in patients with arterial hypertension (AH taking into account influence on central and peripheral hemodynamics.Material and methods. 60 patients with AH of I-II stage, 1-2 grade were studied. They were split in 3 groups. Patients of the first group received amlodipine (Tenox, 5-10 mg/d, the second group – fosinopril (Monopril, 10-20 mg/d and the third group – metoprolol (Metocard, 50-200 mg/d.Diuretics were added when necessary. Ambulatory blood pressure (BP monitoring, echocardiography, ultrasound investigation of brachiocephalic and main cerebral arteries, test on reactive hyperemia and nitroglycerine were conducted before and after 6 months of therapy.Results. Amlodipine, fosinopril and metoprolol had similar antihypertensive effect. Amlodipine was more effective in comparison with fosinopril and metoprolol in reduction of left ventricular (LV myocardial mass and improving of LV diastolic function. Amlodipine and fosinopril had positive effect on vascular remodeling. Metoprolol reduced in BP morning elevation and heart rate, but had no effect on systolic BP variability.Conclusion. Amlodipine, fosinopril and metoprolol have similar antihypertensive effect but different influence on the heart, arteries, BP variability and hemodinamics.

  6. Olmesartan/amlodipine/hydrochlorothiazide in participants with hypertension and diabetes, chronic kidney disease, or chronic cardiovascular disease: a subanalysis of the multicenter, randomized, double-blind, parallel-group TRINITY study

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    Kereiakes Dean J

    2012-10-01

    Full Text Available Abstract Background Patients with hypertension and cardiovascular disease (CVD, diabetes, or chronic kidney disease (CKD usually require two or more antihypertensive agents to achieve blood pressure (BP goals. Methods The efficacy/safety of olmesartan (OM 40 mg, amlodipine besylate (AML 10 mg, and hydrochlorothiazide (HCTZ 25 mg versus the component dual-combinations (OM 40/AML 10 mg, OM 40/HCTZ 25 mg, and AML 10/HCTZ 25 mg was evaluated in participants with diabetes, CKD, or chronic CVD in the Triple Therapy with Olmesartan Medoxomil, Amlodipine, and Hydrochlorothiazide in Hypertensive Patients Study (TRINITY. The primary efficacy end point was least squares (LS mean reduction from baseline in seated diastolic BP (SeDBP at week 12. Secondary end points included LS mean reduction in SeSBP and proportion of participants achieving BP goal ( Results At week 12, OM 40/AML 10/HCTZ 25 mg resulted in significantly greater SeBP reductions in participants with diabetes (−37.9/22.0 mm Hg vs −28.0/17.6 mm Hg for OM 40/AML 10 mg, −26.4/14.7 mm Hg for OM 40/HCTZ 25 mg, and −27.6/14.8 mm Hg for AML 10/HCTZ 25 mg, CKD (−44.3/25.5 mm Hg vs −39.5/23.8 mm Hg for OM 40/AML 10 mg, −25.3/17.0 mm Hg for OM 40/HCTZ 25 mg, and −33.4/20.6 mm Hg for AML 10/HCTZ 25 mg, and chronic CVD (−37.8/20.6 mm Hg vs −31.7/18.2 mm Hg for OM 40/AML 10 mg, −30.9/17.1 mm Hg for OM 40/HCTZ 25 mg, and −27.5/16.1 mm Hg for AML 10/HCTZ 25 mg (P Conclusions In patients with diabetes, CKD, or chronic CVD, short-term (12 weeks and long-term treatment with OM 40/AML 10/HCTZ 25 mg was well tolerated, lowered BP more effectively, and enabled more participants to reach BP goal than the corresponding 2-component regimens. Trial Identification Number NCT00649389

  7. A Rare Case Report of Amlodipine-Induced Gingival Enlargement and Review of Its Pathogenesis

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    Sanjeev Joshi

    2013-01-01

    Full Text Available Gingival enlargement is a common clinical feature of gingival and periodontal diseases. It is an unwanted side effect of certain systemic drugs given for nondental treatment. It is being reported with three main groups of drugs like calcium channel blockers (CCBs, immunosuppressants, and anticonvulsants. Among calcium channel blockers, nifedipine causes gingival hyperplasia in about 10% of patients, whereas the incidence of amlodipine-, a third generation calcium channel blocker, induced gingival hyperplasia is very limited. There are very few reports of amlodipine-induced gingival enlargement at a dose of 5 mg. We report a case of amlodipine-induced gingival enlargement in a 45-year-old hypertensive patient taking amlodipine at a dose of 5 mg.

  8. Blood pressure effects of high-dose amlodipine-benazepril combination in Black and White hypertensive patients not controlled on monotherapy.

    Science.gov (United States)

    Chrysant, Steven G

    2012-06-01

    Black hypertensive patients are more resistant to angiotensin-converting enzyme (ACE) inhibitor monotherapy than White patients. This resistance can be overcome with the combination of ACE inhibitors with diuretics or calcium-channel blockers (CCBs). The objective of this clinical investigation was to evaluate the antihypertensive effectiveness of monotherapy with the ACE inhibitor benazepril or the CCB amlodipine and their combination in Black and White hypertensive patients in two separate studies. This was a post hoc analysis of data from two separate studies, pooled because of their similarities, to increase the sample size. Outpatient Black and White hypertensive patients were selected for these studies. In study H2303, 201 patients of both sexes and races, whose mean seated diastolic blood pressure (MSDBP) was ≥95 mmHg after 4 weeks of single-blind treatment with benazepril 40 mg/day, were randomized into two groups. Group 1 received benazepril 40 mg/day and group 2 received amlodipine/benazepril 5/40 mg/day, which was uptitrated to amlodipine/benazepril 10/40 mg/day at week 4 of the study. In study H2304, 812 similar patients, whose MSDBP was ≥95 mmHg after 4 weeks of single-blind treatment with amlodipine 10 mg/day, were randomized into three groups. Group 1 received amlodipine/benazepril 10/20 mg/day, uptitrated to amlodipine/benazepril 10/40 mg/day after 2 weeks. Group 2 received amlodipine/benazepril 10/20 mg/day. Group 3 received amlodipine 10 mg/day. All three groups were followed up for 6 additional weeks. This report presents the results of post hoc analysis of pooled data from two separate but similar studies. Combination therapy resulted in greater lowering of MSDBP and mean seated systolic blood pressure (MSSBP) than monotherapy with either benazepril or amlodipine (p benazepril 10/20 mg/day resulted in greater blood pressure (BP) reductions in White patients than in Black patients (p benazepril 10/40 mg

  9. Three different spectrophotometric methods manipulating ratio spectra for determination of binary mixture of Amlodipine and Atorvastatin

    Science.gov (United States)

    Darwish, Hany W.; Hassan, Said A.; Salem, Maissa Y.; El-Zeiny, Badr A.

    2011-12-01

    Three simple, specific, accurate and precise spectrophotometric methods manipulating ratio spectra are developed for the simultaneous determination of Amlodipine besylate (AM) and Atorvastatin calcium (AT) in tablet dosage forms. The first method is first derivative of the ratio spectra ( 1DD), the second is ratio subtraction and the third is the method of mean centering of ratio spectra. The calibration curve is linear over the concentration range of 3-40 and 8-32 μg/ml for AM and AT, respectively. These methods are tested by analyzing synthetic mixtures of the above drugs and they are applied to commercial pharmaceutical preparation of the subjected drugs. Standard deviation is <1.5 in the assay of raw materials and tablets. Methods are validated as per ICH guidelines and accuracy, precision, repeatability and robustness are found to be within the acceptable limit.

  10. Micellar Enhanced Three-Dimensional Excitation-Emission Matrix Fluorescence for Rapid Determination of Antihypertensives in Human Plasma with Aid of Second-Order Calibration Methods

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    Hai-Yan Fu

    2015-01-01

    Full Text Available A highly sensitive three-dimensional excitation-emission fluorescence method was proposed to determine antihypertensives including valsartan and amlodipine besylate in human plasma with the aid of second-order calibration methods based on parallel factor analysis (PARAFAC and alternating trilinear decomposition (ATLD algorithms. Antihypertensives with weak fluorescent can be transformed into a strong fluorescent property by changing microenvironment in samples using micellar enhanced surfactant. Both the adopted algorithms with second-order advantage can improve the resolution and directly attain antihypertensives concentration even in the presence of potential strong intrinsic fluorescence from human plasma. The satisfactory results can be achieved for valsartan and amlodipine besylate in complicated human plasma. Furthermore, some statistical parameters and figures of merit were evaluated to investigate the performance of the proposed method, and the accuracy and precision of the proposed method were also validated by the elliptical joint confidence region (EJCR test and repeatability analysis of intraday and interday assay. The proposed method could not only light a new avenue to directly determine valsartan or amlodipine besylate in human plasma, but also hold great potential to be extended as a promising alternative for more practical applications in the determination of weak fluorescent drugs.

  11. Effect of combination tablets containing amlodipine 10 mg and irbesartan 100 mg on blood pressure and cardiovascular risk factors in patients with hypertension

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    Yagi S

    2015-01-01

    Full Text Available Shusuke Yagi,1 Akira Takashima,1 Minoru Mitsugi,2 Toshihiro Wada,2 Junko Hotchi,1 Ken-ichi Aihara,3 Tomoya Hara,1 Masayoshi Ishida,1 Daiju Fukuda,4 Takayuki Ise,1 Koji Yamaguchi,1 Takeshi Tobiume,1 Takashi Iwase,1 Hirotsugu Yamada,1 Takeshi Soeki,1 Tetsuzo Wakatsuki,1 Michio Shimabukuro,4 Masashi Akaike,5 Masataka Sata11Department of Cardiovascular Medicine, Graduate School of Health Biosciences, University of Tokushima, Tokushima, 2Department of Internal Medicine, Shikoku Central Hospital, Shikokuchuo, 3Department of Medicine and Bioregulatory Sciences, 4Department of Cardio-Diabetes Medicine, 5Department of Medical Education, Graduate School of Health Biosciences, University of Tokushima, Tokushima, JapanBackground: Hypertension is one of the major risk factors for cardiovascular and cerebrovascular disease and mortality. Patients who receive insufficient doses of antihypertensive agents or who are poorly adherent to multidrug treatment regimens often fail to achieve adequate blood pressure (BP control. The aim of this study was to determine the efficacy of an angiotensin II receptor blocker (ARB and calcium channel blocker (CCB combination tablet containing a regular dose of irbesartan (100 mg and a high dose of amlodipine (10 mg with regard to lowering BP and other risk factors for cardiovascular disease.Methods: We retrospectively evaluated data from 68 patients with essential hypertension whose treatment regimen was changed either from combination treatment with an independent ARB and a low-dose or regular-dose CCB or from a combination tablet of ARB and a low-dose or regular-dose CCB to a combination tablet containing amlodipine 10 mg and irbesartan 100 mg, because of incomplete BP control. Previous treatments did not include irbesartan as the ARB.Results: The combination tablet decreased systolic and diastolic BP. In addition, it significantly decreased serum uric acid, low-density lipoprotein cholesterol, and increased high

  12. Less adrenergic response to mental task during verapamil compared to amlodipine treatment in hypertensive subjects

    NARCIS (Netherlands)

    Sevre, K; Lefrandt, JD; Eide, [No Value; Smit, AJ; Rostrup, M

    2001-01-01

    We compared the effects of amlodipine and verapamil slow release on autonomic responses to a 5-min mental arithmetic test (MST) in patients with mild to moderate hypertension. Twenty subjects received 8 weeks of verapamil slow release 240 mg or amlodipine 10 mg in a double-blind crossover design,

  13. Beneficial effect of low dose Amlodipine vs Nifedipine on serum cholesterol profile of rabbits receiving standard diet.

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    Bavane DS, Rajesh CS, Gurudatta Moharir, Bharatha Ambadasu

    2013-01-01

    Full Text Available To investigate the effect of low dose amlodipine v/s nifedipine on serum cholesterol profile of rabbits receiving standard diet. Methods: Fourty Newzealand rabbits were selected for the study. Their cholesterol profile was estimated at the beginning of the study. Rabbits were grouped into 4 groups receiving standard diet (control group, standard diet + vehicle propylene glycol, standard diet + nifedipine dissolved in propylene glycol and standard diet + amlodipine dissolved in propylene glycol. Along with standard diet they were treated with respective drugs for ten weeks. At the end of ten weeks serum cholesterol profile was estimated. Results: The cholesterol profile was estimated at the beginning and at the end of ten weeks. Total cholesterol in the amlodipine group decreased from 97±4.06 mg/dl to 90±4.2 mg/dl and HDL-Cholesterol increased from 32.01±4.40 mg/dl to 37±4.60 mg/dl after 10 week treatment but these changes were not significant. LDL cholesterol decreased significantly in rabbits with low dose of amlodipine from 55.42±3.32 mg/dl to 32.40±3.22 mg/dl and. In the nifedipine group there was a slight increase in total cholesterol from 102.49±5.16 mg/dl to 106±5.39 mg/dl, HDL cholesterol from 34.10±2.80 to 35.16±2.82 mg/dl and LDL cholesterol also increased from 56.20±2.20 mg/dl to 59.00±2.20 mg/dl after 10 week treatment. Conclusion: The study shows amlodipine produces favorable alterations in serum cholesterol profile

  14. Amlodipine decreases fibrosis and cardiac hypertrophy in spontaneously hypertensive rats: persistent effects after withdrawal.

    Science.gov (United States)

    Sevilla, María A; Voces, Felipe; Carrón, Rosalía; Guerrero, Estela I; Ardanaz, Noelia; San Román, Luis; Arévalo, Miguel A; Montero, María J

    2004-07-02

    Our objective was to examine the effect of chronic treatment with amlodipine on blood pressure, left ventricular hypertrophy, and fibrosis in spontaneously hypertensive rats and the persistence of such an effect after drug withdrawal. We investigated the effects of treatment with 2, 8 and 20 mg/kg/day of amlodipine given orally for six months and at three months after drug withdrawal. Systolic blood pressure was measured using the tail-cuff method. At the end of the study period, the heart was excised, the left ventricle was isolated, and the left ventricle weight/body weight ratio was calculated as a left ventricular hypertrophy index. Fibrosis, expressed as collagen volume fraction, was evaluated using an automated image-analysis system on sections stained with Sirius red. Age-matched untreated Wistar-Kyoto and SHR were used as normotensive and hypertensive controls, respectively. Systolic blood pressure was reduced in the treated SHR in a dose-dependent way and after amlodipine withdrawal it increased progressively, without reaching the values of the hypertensive controls. Cardiac hypertrophy was reduced by 8 and 20 mg/kg/day amlodipine, but when treatment was withdrawn only the group treated with 8 mg/kg/day maintained significant differences versus the hypertensive controls. All three doses of amlodipine reduced cardiac fibrosis and this regression persisted with the two highest doses after three months without treatment. We concluded that antihypertensive treatment with amlodipine is accompanied by a reduction in left ventricular hypertrophy and regression in collagen deposition. Treatment was more effective in preventing fibrosis than in preventing ventricular hypertrophy after drug withdrawal. Copyright 2004 Elsevier Inc.

  15. Amlodipine and Atorvastatin Improved Hypertensive Cardiac Remodeling through Regulation of MMPs/TIMPs in SHR Rats

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    Jingchao Lu

    2016-06-01

    Full Text Available Background: MMPs/TIMPs system is well known to play important roles in pressure overload-induced cardiac remodeling, and Amlodipine and Atorvastatin have been showed to exert favourable protective effects on cardiovascular disease, however, it is not clear whether Amlodipine and Atorvastatin can improve hypertensive cardiac remodeling and whether the MMPs/TIMPs system is involved. The present study aims to answer these questions. Methods: 36 weeks old male spontaneous hypertension (SHR rats were randomly divided into four groups: 1. SHR control group, 2. Amlodipine alone (10 mg/kg/d group, 3. Atorvastatin alone (10 mg/kg/d group, 4.Combination of Amlodipine and Atorvastatin (10 mg/kg/d for each group. Same gender, weight and age of Wistar-Kyoto (WKY rats with normal blood pressure were used as normal control. Drugs were administered by oral gavage over 12 weeks. The blood pressure and left ventricle mass index were measured. Enzyme activity of MMP-2 and MMP-9 was assessed with Gelatin zymography. MMP-2, MMP-9, TIMP-1 and TIMP-2 mRNA and protein expression was studied by RT-PCR and Western blot. Single factor ANOVA and LSD-t test were used in statistical analysis. Results: Treatment with Amlodipine alone or combination with atorvastatin significantly decreased blood pressure, left ventricle mass index in SHR rats (P Conclusion: Amlodipine and Atorvastatin could improve ventricular remodeling in SHR rats through intervention with the imbalance of MMP-2/TIMP-2 and MMP-9/TIMP-1 system.

  16. Targeting Hypertension with Valsartan: Lessons Learned from the Valsartan/HCTZ Versus Amlodipine in Stage II Hypertensive Patients (VAST Trial

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    Luis M Ruilope

    2006-03-01

    Full Text Available Many patients with hypertension, especially those at increased risk because of additional cardiovascular risk factors, require treatment with more than one antihypertensive agent to achieve target blood pressure (BP goals. Many different classes of antihypertensive agents are available: a renin-angiotensin-aldosterone system (RAAS blocker and a diuretic are widely used in combination.Here we report the results of the recently completed Valsartan/HCTZ versus Amlodipine in STage II hypertensive patients (VAST trial. In this 24-week study, patients with moderate hypertension and at least one other cardiovascular risk factor were treated with a combination of valsartan 160 mg and hydrochlorothiazide (HCTZ 12.5 or 25 mg once daily (o.d., or with amlodipine monotherapy (10 mg o.d.. Overall, valsartan plus HCTZ 25 mg reduced systolic BP significantly more than amlodipine monotherapy, and with fewer adverse events. In addition, combination therapy resulted in a trend towards more favourable outcomes with respect to pro-thrombotic and proinflammatory markers than amlodipine alone.

  17. Targeting Hypertension with Valsartan: Lessons Learned from the Valsartan/HCTZ Versus Amlodipine in Stage II Hypertensive Patients (VAST Trial

    Directory of Open Access Journals (Sweden)

    Luis M Ruilope

    2006-03-01

    Full Text Available Many patients with hypertension, especially those at increased risk because of additional cardiovascular risk factors, require treatment with more than one antihypertensive agent to achieve target blood pressure (BP goals. Many different classes of antihypertensive agents are available: a renin-angiotensin-aldosterone system (RAAS blocker and a diuretic are widely used in combination. Here we report the results of the recently completed Valsartan/HCTZ versus Amlodipine in STage II hypertensive patients (VAST trial. In this 24-week study, patients with moderate hypertension and at least one other cardiovascular risk factor were treated with a combination of valsartan 160 mg and hydrochlorothiazide (HCTZ 12.5 or 25 mg once daily (o.d., or with amlodipine monotherapy (10 mg o.d.. Overall, valsartan plus HCTZ 25 mg reduced systolic BP significantly more than amlodipine monotherapy, and with fewer adverse events. In addition, combination therapy resulted in a trend towards more favourable outcomes with respect to pro-thrombotic and pro-inflammatory markers than amlodipine alone.

  18. Development and Validation of Reversed Phase High Performance ...

    African Journals Online (AJOL)

    All rights reserved. Available online ... Methods: Standards and samples were prepared by dissolving amlodipine besylate standard or ... Tropical Journal of Pharmaceutical Research is indexed by Science Citation Index (SciSearch), Scopus,.

  19. Quantitative model for the blood pressure‐lowering interaction of valsartan and amlodipine

    Science.gov (United States)

    Heo, Young‐A; Holford, Nick; Kim, Yukyung; Son, Mijeong

    2016-01-01

    Aims The objective of this study was to develop a population pharmacokinetic (PK) and pharmacodynamic (PD) model to quantitatively describe the antihypertensive effect of combined therapy with amlodipine and valsartan. Methods PK modelling was used with data collected from 48 healthy volunteers receiving a single dose of combined formulation of 10 mg amlodipine and 160 mg valsartan. Systolic (SBP) and diastolic blood pressure (DBP) were recorded during combined administration. SBP and DBP data for each drug alone were gathered from the literature. PKPD models of each drug and for combined administration were built with NONMEM 7.3. Results A two‐compartment model with zero order absorption best described the PK data of both drugs. Amlodipine and valsartan monotherapy effects on SBP and DBP were best described by an I max model with an effect compartment delay. Combined therapy was described using a proportional interaction term as follows: (D1 + D2) +ALPHA×(D1 × D2). D1 and D2 are the predicted drug effects of amlodipine and valsartan monotherapy respectively. ALPHA is the interaction term for combined therapy. Quantitative estimates of ALPHA were −0.171 (95% CI: −0.218, −0.143) for SBP and −0.0312 (95% CI: −0.07739, −0.00283) for DBP. These infra‐additive interaction terms for both SBP and DBP were consistent with literature results for combined administration of drugs in these classes. Conclusion PKPD models for SBP and DBP successfully described the time course of the antihypertensive effects of amlodipine and valsartan. An infra‐additive interaction between amlodipine and valsartan when used in combined administration was confirmed and quantified. PMID:27504853

  20. Improved oral absorption of cilostazol via sulfonate salt formation with mesylate and besylate

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    Seo JH

    2015-07-01

    Full Text Available Jae Hong Seo, Jung Bae Park, Woong-Kee Choi, Sunhwa Park, Yun Jin Sung, Euichaul Oh, Soo Kyung Bae College of Pharmacy and Integrated Research Institute of Pharmaceutical Sciences, The Catholic University of Korea, Bucheon, South Korea Objective: Cilostazol is a Biopharmaceutical Classification System class II drug with low solubility and high permeability, so its oral absorption is variable and incomplete. The aim of this study was to prepare two sulfonate salts of cilostazol to increase the dissolution and hence the oral bioavailability of cilostazol.Methods: Cilostazol mesylate and cilostazol besylate were synthesized from cilostazol by acid addition reaction with methane sulfonic acid and benzene sulfonic acid, respectively. The salt preparations were characterized by nuclear magnetic resonance spectroscopy. The water contents, hygroscopicity, stress stability, and photostability of the two cilostazol salts were also determined. The dissolution profiles in various pH conditions and pharmacokinetic studies in rats were compared with those of cilostazol-free base.Results: The two cilostazol salts exhibited good physicochemical properties, such as nonhygroscopicity, stress stability, and photostability, which make it suitable for the preparation of pharmaceutical formulations. Both cilostazol mesylate and cilostazol besylate showed significantly improved dissolution rate and extent of drug release in the pH range 1.2–6.8 compared to the cilostazol-free base. In addition, after oral administration to rats, cilostazol mesylate and cilostazol besylate showed increases in Cmax and AUCt of approximately 3.65- and 2.87-fold and 3.88- and 2.94-fold, respectively, compared to cilostazol-free base.Conclusion: This study showed that two novel salts of cilostazol, such as cilostazol mesylate and cilostazol besylate, could be used to enhance its oral absorption. The findings warrant further preclinical and clinical studies on cilostazol mesylate and

  1. The efficacy and safety of fixed-dose combination of amlodipine/benazepril in Chinese essential hypertensive patients not adequately controlled with benazepril monotherapy: a multicenter, randomized, double-blind, double-dummy, parallel-group clinical trial.

    Science.gov (United States)

    Yan, Pingping; Fan, Weihu

    2014-01-01

    This double-blind, double-dummy clinical trial evaluated the efficacy and safety of two strengths of fixed-dose combination of amlodipine/benazepril in Chinese hypertensive patients not adequately controlled with benazepril. Of 442 patients who received treatment with benazepril 10 mg for 4 weeks, 341 patients failed to achieve to diastolic blood pressure (DBP) benazepril 2.5/10 mg, or amlodipine/benazepril 5/10 mg, or benazepril 10 mg for 8 weeks. BP reductions with amodipinel/benazepril 2.5/10 mg (15.2/11.8 mmHg) or amlodipine/benazepril 5/10 mg (15.4/12.4 mmHg) were significantly greater than that with benazepril 10 mg (9.88/9.46 mmHg) at study end (p benazepril). BP control rate was 83.8% with amlodipine/benazepril 2.5/10 mg, 80.2% with amlodipine/benazepril 5/10 mg, 64.9% with benazepril 10 mg at study end (p benazepril). Three groups were generally well tolerated. Our study indicated that amlodipine/benazepril fixed-dose combination offered significant additional BP reductions and BP control rate compared with the continuation of benazepril monotherapy. No significant differences were observed in both BP reductions and BP control rate between amlodipine/benazepril 2.5/10 mg and amlodipine/benazepril 5/10 mg.

  2. Pharmacokinetic and bioequivalence study of a telmisartan/S-amlodipine fixed-dose combination (CKD-828) formulation and coadministered telmisartan and S-amlodipine in healthy subjects.

    Science.gov (United States)

    Kang, Woo Youl; Seong, Sook Jin; Ohk, Boram; Gwon, Mi-Ri; Kim, Bo Kyung; La, Sookie; Kim, Hyun-Ju; Cho, Seungil; Yoon, Young-Ran; Yang, Dong Heon; Lee, Hae Won

    2018-01-01

    A new fixed-dose combination (FDC) formulation of telmisartan 80 mg and S-amlodipine 5 mg (CKD-828) has been developed to increase convenience (as only one tablet is required per day) and improve treatment compliance. The pharmacokinetic characteristics and tolerability of an FDC of telmisartan and S-amlodipine were compared to those after coadministration of the individual agents in this randomized, open-label, single-dose, two-way, four-period, crossover study. To analyze the telmisartan and S-amlodipine plasma concentrations using a validated liquid chromatography-tandem mass spectrometry method, serial blood samples were collected up to 48 hours post-dose for telmisartan and 144 hours post-dose for S-amlodipine, in each period. Forty-eight healthy subjects were enrolled, and 43 completed the study. The mean peak plasma concentration (C max ) and the area under the plasma concentration-time curve from time 0 to the last measurement (AUC 0-t ) values of telmisartan were 522.29 ng/mL and 2,475.16 ng·h/mL for the FDC, and 540.45 ng/mL and 2,559.57 ng·h/mL for the individual agents concomitantly administered, respectively. The mean C max and AUC 0-t values of S-amlodipine were 2.71 ng/mL and 130.69 ng·h/mL for the FDC, and 2.74 ng/mL and 129.81 ng·h/mL for the individual agents concomitantly administered, respectively. The geometric mean ratio (GMR) and 90% confidence interval (CI) for the telmisartan C max and AUC 0-t (FDC of telmisartan and S-amlodipine/concomitant administration) were 0.8509 (0.7353-0.9846) and 0.9431 (0.8698-1.0226), respectively. The GMR and 90% CI for the S-amlodipine C max and AUC 0-t (FDC/concomitant administration) were 0.9829 (0.9143-1.0567) and 0.9632 (0.8798-1.0546), respectively. As the intrasubject variability of the C max for telmisartan administered individually was 42.94%, all 90% CIs of the GMRs fell within the predetermined acceptance range. Both treatments were well tolerated in this study. CKD-828 FDC tablets were shown to

  3. Comparative effects of amlodipine and benazepril on left atrial pressure in dogs with experimentally-induced mitral valve regurgitation.

    Science.gov (United States)

    Suzuki, Shuji; Fukushima, Ryuji; Ishikawa, Taisuke; Yamamoto, Yuta; Hamabe, Lina; Kim, Soomin; Yoshiyuki, Rieko; Machida, Noboru; Tanaka, Ryou

    2012-09-18

    One of the purposes of treatment for dogs with mitral regurgitation (MR) is lowering left atrial pressure (LAP). There has been few study of the amlodipine in dogs with MR and amlodipine's effect on LAP has not been fully evaluated in a quantitative manner because of difficulties in directly measuring LAP. The objective of our study was to compare the short-term effects of amlodipine (0.2 mg/kg PO q12h) vs benazepril (0.5 mg/kg PO q12h), on LAP and echocardiographic parameters in five beagle dogs with experimentally-induced MR. LAP of eight dogs that has own control were measured using radiotelemetry system at baseline and again on days 1, 2, 3, 4, 5, 6, 7 of the drug administration. Mean LAP decreased significantly after amlodipine (11.20 ± 4.19 mmHg vs 14.61 ± 3.81 mmHg at baseline, p benazepril treatment (13.19 ± 3.47 mmHg, p > .05). LAP was lower after 7 days of amlodipine treatment than after 7 days of benazepril treatment. Significant reduction was seen for the first time 4 days after the administration amlodipine. The rate of the maximal area of the regurgitant jet signals to the left atrium area (ARJ/LAA) of the amlodipine treatment was significantly lower (p benazepril treatment. Although this study did not focus on adverse effects, amlodipine may be an effective drug for helping the patients with acute onset of severe MR, such as rupture of chordae tendinae or end stage patients were the LAP is likely to be elevated. Additional studies in clinical patients with degenerative mitral valve disease and acute chordal rupture are warranted because the blood-pressure lowering effects of amlodipine can decrease renal perfusion and this can further activate the RAAS.

  4. Functional Vascular Study in Hypertensive Subjects with Type 2 Diabetes Using Losartan or Amlodipine

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    Cesar Romaro Pozzobon

    2014-07-01

    Full Text Available Background: Antihypertensive drugs are used to control blood pressure (BP and reduce macro- and microvascular complications in hypertensive patients with diabetes. Objectives: The present study aimed to compare the functional vascular changes in hypertensive patients with type 2 diabetes mellitus after 6 weeks of treatment with amlodipine or losartan. Methods: Patients with a previous diagnosis of hypertension and type 2 diabetes mellitus were randomly divided into 2 groups and evaluated after 6 weeks of treatment with amlodipine (5 mg/day or losartan (100 mg/day. Patient evaluation included BP measurement, ambulatory BP monitoring, and assessment of vascular parameters using applanation tonometry, pulse wave velocity (PWV, and flow-mediated dilation (FMD of the brachial artery. Results: A total of 42 patients were evaluated (21 in each group, with a predominance of women (71% in both groups. The mean age of the patients in both groups was similar (amlodipine group: 54.9 ± 4.5 years; losartan group: 54.0 ± 6.9 years, with no significant difference in the mean BP [amlodipine group: 145 ± 14 mmHg (systolic and 84 ± 8 mmHg (diastolic; losartan group: 153 ± 19 mmHg (systolic and 90 ± 9 mmHg (diastolic]. The augmentation index (30% ± 9% and 36% ± 8%, p = 0.025 and augmentation pressure (16 ± 6 mmHg and 20 ± 8 mmHg, p = 0.045 were lower in the amlodipine group when compared with the losartan group. PWV and FMD were similar in both groups. Conclusions: Hypertensive patients with type 2 diabetes mellitus treated with amlodipine exhibited an improved pattern of pulse wave reflection in comparison with those treated with losartan. However, the use of losartan may be associated with independent vascular reactivity to the pressor effect.

  5. Pharmacokinetic interaction of telmisartan with s-amlodipine: an open-label, two-period crossover study in healthy Korean male volunteers.

    Science.gov (United States)

    Noh, Yook-Hwan; Lim, Hyeong-Seok; Kim, Mi Jo; Kim, Yo Han; Choi, Hee Youn; Sung, Hye Ryoung; Jin, Seok-Joon; Lim, Jonglae; Bae, Kyun-Seop

    2012-07-01

    Telmisartan belongs to a class of orally active angiotensin II receptor blockers (ARBs), and S-amlodipine is an enantiomer of amlodipine. Amlodipine is a racemic mixture and the calcium channel blocking (CCB) effect is confined to S-amlodipine, whereas R-amlodipine has a 1000-fold lower activity and no racemization occurs in vivo in human plasma. Combination therapy of ARBs with CCBs provides advantages for blood pressure control and vascular protection over monotherapy. To investigate the effects of coadministration of telmisartan and S-amlodipine on the steady-state pharmacokinetic properties of each drug as a drug-drug interaction study required before developing the fixed-dose combination agent. This study comprised 2 separate parts, A and B; each was a multiple-dose, open-label, 2-sequence, 2-period, crossover study in healthy male Korean volunteers. In part A, volunteers were administered 80 mg of telmisartan, either alone or with 5 mg of S-amlodipine. In part B, volunteers were administered 5 mg of S-amlodipine, either alone or with 80 mg of telmisartan. Blood samples were taken on days 9 and 37, following the final dose of each treatment, and at 0 (predose), 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8, 10, 12, and 24 hours after administration in part A, and were taken at 0 (predose), 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, and 24 hours after administration in part B. Plasma concentrations were determined using LC-MS/MS. The pharmacokinetic properties of each drug after coadministration of telmisartan and S-amlodipine were compared with those of each drug administered alone. Tolerability was assessed using measurements of vital signs, clinical chemistry tests, and interviews. Fifty-six volunteers were enrolled (32 in part A and 24 in part B), and all completed except 4 volunteers (3 withdrawn in part A and 1 withdrawn in part B). The geometric mean ratios (GMRs) (90% CI) for the C(max,ss) and AUC(τ,ss) of telmisartan (with or without S-amlodipine) were 1.039 (0

  6. Effects of amlodipine on bone metabolism in male albino Wistar rats

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    Iveta Gradošová

    2011-01-01

    Full Text Available Amlodipine (dihydropyridine-type calcium channel blocker is a widely used agent for the treatment of hypertension in human and veterinary medicine but detailed information about its effects on bone metabolism are missing. Therefore, the aim of our study was to investigate the effect of amlodipine on bone metabolism in male albino Wistar rats. Amlodipine (0.3 mg/100 g body weight; gavage was administered to 8 rats for 8 weeks. Control group (n = 8 received aqua pro inj. (0.2 ml/100 g body weight; gavage. Bone marker concentrations of carboxy-terminal cross-linking telopeptide of type I collagen (CTX-I and aminoterminal propeptide of procollagen type I in serum, and of bone alkaline phosphatase (BALP in both serum and bone homogenate were measured by enzyme immunoassay. We investigated the expression of bone morphogenetic protein 2 (BMP-2 in proximal tibia using Western blotting, and bone mineral density was measured by Dual-energy X-ray Absorptiometry in lumbar and caudal vertebrae and in femoral areas. Mechanical properties of the femurs were measured by three-point bending of the shaft and compression testing of the femoral neck. After 8 weeks of amlodipine administration there was a significant decrease in serum concentrations of BALP (p = 0.0009 and CTX-I (p = 0.003, and the content of BALP in bone homogenate (p = 0.026 compared to the control. In addition, Western blot analysis indicated increased BMP-2 protein concentration after amlodipine administration. Our findings suggest that amlodipine has a retarding influence on bone metabolism in rats by decreasing bone turnover, which probably in consequence increases expression of BMP-2.

  7. S-Amlodipine: An Isomer with Difference—Time to Shift from Racemic Amlodipine

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    Jamshed Dalal

    2018-01-01

    Full Text Available Calcium channel blockers are among the first-line drugs for treatment of hypertension (HTN. S-amlodipine (S-AM, an S-enantiomer of amlodipine, is available in India and in other countries like China, Korea, Russia, Ukraine, and Nepal. Being clinically researched for nearly two decades, we performed in-depth review of S-AM. This review discusses clinical evidence from total 42 studies (26 randomized controlled trials, 14 observational studies, and 2 meta-analyses corroborating over 7400 patients treated with S-AM. Efficacy and safety of S-AM in HTN in comparison to racemic amlodipine, used as monotherapy and in combination with other antihypertensives, efficacy in angina, and pleiotropic benefits with S-AM, are discussed in this review.

  8. Comparative effects of amlodipine and benazepril on Left Atrial Pressure in Dogs with experimentally-induced Mitral Valve Regurgitation

    Directory of Open Access Journals (Sweden)

    Suzuki Shuji

    2012-09-01

    Full Text Available Abstract Background One of the purposes of treatment for dogs with mitral regurgitation (MR is lowering left atrial pressure (LAP. There has been few study of the amlodipine in dogs with MR and amlodipine’s effect on LAP has not been fully evaluated in a quantitative manner because of difficulties in directly measuring LAP. The objective of our study was to compare the short-term effects of amlodipine (0.2 mg/kg PO q12h vs benazepril (0.5 mg/kg PO q12h, on LAP and echocardiographic parameters in five beagle dogs with experimentally-induced MR. LAP of eight dogs that has own control were measured using radiotelemetry system at baseline and again on days 1, 2, 3, 4, 5, 6, 7 of the drug administration. Results Mean LAP decreased significantly after amlodipine (11.20 ± 4.19 mmHg vs 14.61 ± 3.81 mmHg at baseline, p  .05. LAP was lower after 7 days of amlodipine treatment than after 7 days of benazepril treatment. Significant reduction was seen for the first time 4 days after the administration amlodipine. The rate of the maximal area of the regurgitant jet signals to the left atrium area (ARJ/LAA of the amlodipine treatment was significantly lower (p  Conclusions LAP was significantly decreased after amlodipine treatment in dogs with surgically-induced MR but not after benazepril treatment. Although this study did not focus on adverse effects, amlodipine may be an effective drug for helping the patients with acute onset of severe MR, such as rupture of chordae tendinae or end stage patients were the LAP is likely to be elevated. Additional studies in clinical patients with degenerative mitral valve disease and acute chordal rupture are warranted because the blood-pressure lowering effects of amlodipine can decrease renal perfusion and this can further activate the RAAS.

  9. Steroidogenesis in amlodipine treated purified Leydig cells

    Energy Technology Data Exchange (ETDEWEB)

    Latif, Rabia, E-mail: rabialatif08@hotmail.com [Department of Physiology, Army Medical College, National University of Sciences and Technology, Islamabad (Pakistan); Lodhi, Ghulam Mustafa, E-mail: drmustafa786@gmail.com [Department of Physiology, Wah Medical College, Wah (Pakistan); Hameed, Waqas, E-mail: waqham@hotmail.com [Department of Physiology, Rehman Medical College, Peshawar (Pakistan); Aslam, Muhammad, E-mail: professormaslam@yahoo.com [Department of Physiology, Shifa College of Medicine, Islamabad (Pakistan)

    2012-01-01

    Drugs have been shown to adversely affect male fertility and recently anti-hypertensive drugs were added to the list. The anti-fertility effects of amlodipine, a calcium channel blocker, are well-illustrated in in vivo experiments but lack an in vitro proof. The present study was designed to experimentally elucidate the effects of amlodipine on Leydig cell steroidogenesis and intracellular calcium in vitro. Leydig cells of Sprague–Dawley rats were isolated and purified by Percoll. Cells were incubated for 3 h with/without amlodipine in the presence/absence of LH, dbcAMP, Pregnenolone and 25-Hydroxycholesterol. Cytosolic calcium was measured in purified Leydig cells by fluorometric technique. The results showed significantly reduced (P < 0.05) steroidogenesis and intracellular calcium in amlodipine exposed rats. The site of amlodipine induced steroidogenic inhibition seems to be prior to the formation of Pregnenolone at the level of StAR protein. -- Highlights: ► Inhibition of steroidogenesis in isolated and purified Leydig cells by amlodipine. ► Site of inhibition was before Pregnenolone formation, at the level of StAR protein. ► Inhibition of LH stimulated rise in cytosolic calcium by amlodipine.

  10. Simultaneous Determination of Amlodipine and Valsartan

    OpenAIRE

    Mohamed, Nashwah Gadallah

    2011-01-01

    A spectrophotometric method was developed for simultaneous determination of amlodipine (Aml) and valsartan (Val) without previous separation. In this method amlodipine in methanolic solution was determined using zero order UV spectrophotometry by measuring its absorbency at 360.5 nm without any interference from valsartan. Valsartan spectrum in zero order is totally overlapped with that of amlodipine. First, second and third derivative could not resolve the overlapped peaks. The first derivat...

  11. Simultaneous Detemination of Atorvastatin Calcium and Amlodipine Besylate by Spectrophotometry and Multivariate Calibration Methods in Pharmaceutical Formulations

    Directory of Open Access Journals (Sweden)

    Amir H. M. Sarrafi

    2011-01-01

    Full Text Available Resolution of binary mixture of atorvastatin (ATV and amlodipine (AML with minimum sample pretreatment and without analyte separation has been successfully achieved using a rapid method based on partial least square analysis of UV–spectral data. Multivariate calibration modeling procedures, traditional partial least squares (PLS-2, interval partial least squares (iPLS and synergy partial least squares (siPLS, were applied to select a spectral range that provided the lowest prediction error in comparison to the full-spectrum model. The simultaneous determination of both analytes was possible by PLS processing of sample absorbance between 220-425 nm. The correlation coefficients (R and root mean squared error of cross validation (RMSECV for ATV and AML in synthetic mixture were 0.9991, 0.9958 and 0.4538, 0.2411 in best siPLS models respectively. The optimized method has been used for determination of ATV and AML in amostatin commercial tablets. The proposed method are simple, fast, inexpensive and do not need any separation or preparation methods.

  12. Is Time an Important Problem in Management of Hypertension and Hypercholesterolemia by Using an Amlodipine-Atorvastatin Single Pill Combination?

    Science.gov (United States)

    Zeng, Rui; Wang, Mian; Zhang, Li

    2016-07-26

    BACKGROUND Is the timing of dosing for amlodipine and atorvastatin important with regard to therapeutic efficacy? To answer this question, we designed an outpatient, practice-based, case-control study lasting 8 weeks. MATERIAL AND METHODS Two hundred patients were divided into 2 groups: in Group I, patients were provided with a single pill containing amlodipine/atorvastatin (5/20 mg) to be taken each night at 10 pm, and in Group II, patients were taking amlodipine (5 mg) and atorvastatin (20 mg) each morning at 7 am. RESULTS Our results indicated no obvious difference in blood pressure control between the 2 groups. Taking amlodipine at night not only lowered blood pressure, but it also provided better control during the peak blood pressure in the morning. Hypercholesterolemia control in the 2 groups was also not significantly different, taking atorvastatin in the morning was as effective as dosing at night in patients with hypercholesterolemia. While the carotid IMT, hs-CRP, and LVMI were significantly lower after treatment, no differences were found between the 2 groups. Although no obvious difference was found in adverse drug reactions between the 2 groups, compliance was much better in the single-pill group than in patients taking the 2 medications separately. CONCLUSIONS In conclusion, single-pill amlodipine-atorvastatin taken at night can lower blood pressure and reduce the morning peak blood pressure levels the next day. Additionally, this dosing method could improve patient adherence to the therapy.

  13. Amlodipine and valsartan as components of a rational and effective fixed-dose combination

    Directory of Open Access Journals (Sweden)

    Bernard Waeber

    2009-03-01

    Full Text Available Bernard Waeber1, Luis M Ruilope21Division of Clinical Pathophysiology, University Hospital, Faculty of Biology and Medicine, University of Lausanne, Switzerland; 2Hypertension Unit, Hospital 12 de Octubre, Madrid, SpainAbstract: Pharmacological treatment of hypertension is effective in preventing cardiovascular and renal complications. Calcium antagonists and blockers of the renin-angiotensin system are widely used today to initiate antihypertensive therapy but, when given as monotherapy, do not suffice in most patients to normalize blood pressure. Combining the two types of agents considerably increases the antihypertensive efficacy, but not at the expense of a deterioration of tolerability. This is exemplified by the experience accumulated with the recently developed fixed dose combination containing the AT1-receptor blocker valsartan (160 mg and the dihydropyridine amlodipine (5 or 10 mg. In a randomized trial, an 8-week treatment normalized blood pressure (<140/90 mmHg within 8 weeks in a large fraction of hypertensive patients (78.4% and 85.2% using the 5/160 [n = 371] and 10/160 mg [n = 377] dosage, respectively. Like all AT1-receptor blockers valsartan has a placebo-like tolerability. Valsartan prevents to a large extent the occurrence amlodipine-induced peripheral edema. Both amlodipine and valsartan have beneficial effects on cardiovascular morbidity and mortality, as well as protective effects on renal function. The co-administration of these two agents is therefore very attractive, as it enables a rapid and sustained blood pressure control in hypertensive patients. The availability of a fixed-dose combination based on amlodipine and valsartan is expected therefore to facilitate the management of hypertension, to improve long-term adherence with antihypertensive therapy and, ultimately, to have a positive impact on cardiovascular and renal outcomes.Keywords: antihypertensive therapy, fixed-dose combination, calcium antagonists

  14. Pharmacokinetic and bioequivalence study of a telmisartan/S-amlodipine fixed-dose combination (CKD-828 formulation and coadministered telmisartan and S-amlodipine in healthy subjects

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    Kang WY

    2018-03-01

    Full Text Available Woo Youl Kang,1,2,* Sook Jin Seong,1,* Boram Ohk,1,2 Mi-Ri Gwon,1,3 Bo Kyung Kim,1,2 Sookie La,4 Hyun-Ju Kim,3 Seungil Cho,1 Young-Ran Yoon,1,2 Dong Heon Yang,5 Hae Won Lee1 1Clinical Trial Center, Kyungpook National University Hospital, Daegu, Republic of Korea; 2Department of Biomedical Science, BK21 Plus KNU Bio-Medical Convergence Program for Creative Talent, Kyungpook National University Graduate School, Daegu, Republic of Korea; 3Department of Molecular Medicine, Cell and Matrix Research Institute, Kyungpook National University School of Medicine, Daegu, Republic of Korea; 4Analytical Research Division, Biocore Co Ltd, Seoul, Republic of Korea; 5Division of Cardiology, Department of Internal Medicine, Kyungpook National University School of Medicine & Hospital, Daegu, Republic of Korea *These authors contributed equally to this work Purpose: A new fixed-dose combination (FDC formulation of telmisartan 80 mg and S-amlodipine 5 mg (CKD-828 has been developed to increase convenience (as only one tablet is required per day and improve treatment compliance.Methods: The pharmacokinetic characteristics and tolerability of an FDC of telmisartan and S-amlodipine were compared to those after coadministration of the individual agents in this randomized, open-label, single-dose, two-way, four-period, crossover study. To analyze the telmisartan and S-amlodipine plasma concentrations using a validated liquid chromatography–tandem mass spectrometry method, serial blood samples were collected up to 48 hours post-dose for telmisartan and 144 hours post-dose for S-amlodipine, in each period.Results: Forty-eight healthy subjects were enrolled, and 43 completed the study. The mean peak plasma concentration (Cmax and the area under the plasma concentration–time curve from time 0 to the last measurement (AUC0–t values of telmisartan were 522.29 ng/mL and 2,475.16 ng⋅h/mL for the FDC, and 540.45 ng/mL and 2,559.57 ng⋅h/mL for the individual agents

  15. Comparison of the efficacy of dihydropyridine calcium channel blockers in African American patients with hypertension. ISHIB Investigators Group. International Society on Hypertension in Blacks.

    Science.gov (United States)

    Hall, W D; Reed, J W; Flack, J M; Yunis, C; Preisser, J

    1998-10-12

    Hypertension is a prevalent disease among African Americans, and successful treatment rates are low. Since calcium channel blockers are well-tolerated and efficacious in African Americans, we undertook this study to compare the efficacy, safety, and tolerability of 3 commonly prescribed calcium channel blockers: amlodipine besylate (Norvasc), nifedipine coat core (CC) (Adalat CC), and nifedipine gastrointestinal therapeutic system (GITS) (Procardia XL). One hundred ninety-two hypertensive patients across 10 study centers were randomly assigned to double-blind monotherapy with amlodipine besylate (5 mg/d), nifedipine CC (30 mg/d), or nifedipine GITS (30 mg/d) for 8 weeks. Patients not achieving therapeutic response after 4 weeks had their dose doubled for the next 4 weeks. The primary end point was a comparison of the average reduction (week 8 minus baseline) in 24-hour ambulatory diastolic blood pressure (DBP). Secondary end points included a comparison of average 24-hour ambulatory systolic blood pressure (SBP), office SBP or DBP reduction, responder rates, safety, and tolerability. One hundred sixty-three patients were evaluable for efficacy after 8 weeks. There was no significant difference in the average 24-hour ambulatory DBP (-8.5, -9.0, and -6.1 mm Hg, respectively) or SBP (-14.3, -15.7, and -11.8 mm Hg, respectively) reduction. Average office SBP and DBP were reduced to a comparable degree (19-22 mm Hg [P =.50] and 12-14 mm Hg [P =.51], respectively). Responder rates (DBP or = 10 mm Hg) were similar (P = .38). Discontinuation rates and adverse event frequency were distributed similarly across the 3 treatment groups. The efficacy, safety, and tolerability of the 3 dihydropyridine calcium channel blockers are equivalent in African Americans with stages 1 and 2 hypertension.

  16. Author Details

    African Journals Online (AJOL)

    Evaluation of the Release Profiles of Ibuprofen Formulated from Carnuba Wax and Homolipid Capra hircus. Abstract PDF · Vol 4, No 1 (2011) - Articles In Vitro Assessment of Quality Control Parameters of Some Commercially Available Generics of Amlodipine Besylate in Nigerian Drug Market Abstract PDF. ISSN: 1596- ...

  17. [Comparison of benazepril monotherapy to amlodipine plus benazepril in the treatment of patients with mild and moderate hypertension: a multicentre, randomized, double-blind, parallel-controlled study].

    Science.gov (United States)

    Fan, Chao-mei; Yan, Li-rong; Tao, Yong-kang; Wang, Li; Li, Yu-qing; Gao, Ming-ming; Wang, Yan-ni; Li, Cheng-xiang; Wang, Xiao-wan; Lu, Xiao-lei; Pang, Hui-min; Li, Yi-shi

    2011-01-01

    To evaluate the efficacy and tolerability of the fixed combination of amlodipine 5 mg/benazepril 10 mg once-daily therapy, compared with benazepril, 10 mg, monotherapy in patients with mild and moderate hypertension, and to evaluate the 24 h antihypertensive efficacy and the duration of action by ambulatory blood pressure monitoring. In a multicenter, randomized, double-blind, parallel controlled trial, 356 cases of hypertensive patients after 2 weeks wash-out, and then given 4 weeks of benazepril 10 mg monotherapy, 220 patients with mean seated diastolic blood pressure (SeDBP) remained ≥ 90 mm Hg (1 mm Hg = 0.133 kPa) were randomly divided into benazepril 10 mg/amlodipine 5 mg (BZ10/AML5) fixed-dose combination therapy group (once a day, n = 113), and benazepril monotherapy group (daily 20 mg, n = 107). In the two groups the patients with SeDBP ≥ 90 mm Hg were doubled the dosage of the initial regimen at the end of 4-week treatment for additional 4 weeks, and the patients with SeDBP benazepril/amlodipine (10 mg/5 mg) and benazepril (20 mg) alone were 83.1%/76.0% and 85.8%/79.5%, respectively. Adverse events rates were 16.8% in the combination therapy group and 35.5% in the monotherapy group (P benazepril/amlodipine was superior to benazepril monotherapy and was well tolerated in patients with essential hypertension and allowing a satisfactory BP control for 24 hours.

  18. Lack of effect of long-term amlodipine on insulin sensitivity and plasma insulin in obese patients with essential hypertension

    DEFF Research Database (Denmark)

    de Courten, Maximilian; Ferrari, P; Schneider, M

    1993-01-01

    Method of Bergman, fasting plasma insulin and glucose concentrations, serum total triglyceride and lipoprotein cholesterol fractions, and blood pressure in 20 obese, non-diabetic patients with essential hypertension before and after 6 weeks of placebo and again after 6 months of amlodipine. Ten patients......To evaluate the effects of long-term treatment antihypertensive with the dihydropyridine calcium antagonist amlodipine on insulin sensitivity, plasma insulin, and lipoprotein metabolism in obese hypertensive patients. We measured the insulin sensitivity index (SI), determined by the Minimal Model...... [mean body mass index (BMI) 30.2 kg.m-2] had been on prior treatment with a thiazide diuretic in low dosage and/or a beta-adrenoceptor blocker (group A), and 10 matched patients [BMI 31.8 kg.m-2] had been previously untreated (group B). Amlodipine was started in a dose of 5 mg and was increased to 10 mg...

  19. Amlodipine-induced gingival hyperplasia in chronic renal failure: a ...

    African Journals Online (AJOL)

    Amlodipine is a dihydropyridine calcium channel blocker that is used in the management of both hypertension and angina. Amlodipine induced side effects are headache, dizziness, edema, flushing, palpitations, and rarely gingival hyperplasia. The exact reason of amlodipine-induced gingival hyperplasia is not known.

  20. Benazepril combined with either amlodipine or hydrochlorothiazide is more effective than monotherapy for blood pressure control and prevention of end-organ injury in hypertensive Dahl rats.

    Science.gov (United States)

    Zhou, Ming-Sheng; Jaimes, Edgar A; Raij, Leopoldo

    2006-07-01

    We studied the effect of hydrochlorothiazide (HCTZ), the angiotensin-converting enzyme inhibitor benazepril, the calcium channel blocker amlodipine, or a combination of benazepril/amlodipine or benazepril/HCTZ on systolic blood pressure (BP) and end-organ injury (left ventricular hypertrophy, proteinuria, and endothelium-dependent relaxation to acetylcholine) in hypertensive Dahl salt-sensitive rats fed either a normal-salt (0.5% NaCl) or high-salt (4% NaCl) diet for 6 weeks. Rats fed a high-salt diet developed hypertension and significant end-organ injury. Monotherapy with HCTZ (75 mg/L in drinking water) or amlodipine (10 mg/kg/day by gavage) reduced systolic BP and proteinuria; benazepril (40 mg/kg/day by gavage) decreased proteinuria without significantly lowering systolic BP. In rats receiving a high-salt diet, only HCTZ reduced left ventricular hypertrophy, whereas endothelium-dependent relaxation was improved by amlodipine and benazepril but not by HCTZ. Combining benazepril with either amlodipine or HCTZ dramatically reduced systolic BP and end-organ injury. These data clearly support clinical studies suggesting that combination therapy is more effective than monotherapy for systolic BP control and prevention of end-organ injury. Complementary mechanisms of action of agents from different antihypertensive classes appear to facilitate the greater benefit on BP and end-organ injury.

  1. A Comparative Study of the Management of Stage 2 hypertension by Combined therapy with Losartan, Amlodipine and Hydrochlorothiazide

    Directory of Open Access Journals (Sweden)

    Reza Jafarzadeh Esfehani

    2012-09-01

    Full Text Available Background: The most effective and accurate treatment of hypertensive patients reduces cardiovascular events and improves the quality of life. Objective: This study compared the efficacy and safety of combined (combination therapy with an angiotensin-receptor blocker (ARB a calcium-channel blocker (CCB (Losartan / Amloidipine 50/10mg vs maximal combination doses of ARB with hydrochlorothiazide (Losartan /HCTZ 100/25 mg and maximal combination doses of CCB with HCTZ (Amlodipine /HCTZ 10/25 mg in the management of stage 2 hypertension. Methods: This randomized clinical trial (RTC comprised 478 hypertensive patients with mean age 50.5±5.21 years, and took place between January 2010 and December 2011 in Vasei Hospital clinic in Sabzevar. Antihypertensive drugs were washed out after 5 days of discontinuation of drugs and the patients with mean blood pressure in sitting position ≥ 160 and <200 mmHg in systole and ≥ 100 and <110 mmHg in diastole were randomized into three groups: Losartan / Amlodipine 50/10 mg (n =164 , Losartan / HCTZ 100/25 mg (n =155 and Amlodipine / HCTZ 10/25 mg (n =159. The end point was reaching the blood pressure below 140/90 within 56 days of treatment in each group. Results: There was a significant difference in systolic blood pressure reductions between treatment groups (P<0.001 and also there was a significant difference between groups in reducing diastolic blood pressure (P<0.01. The highest systolic and diastolic blood pressure reduction respectively was found in Amlodipine/losartane and losartane/HTCZ group. The ANCOVA analysis revealed that only treatment regimen had a significant effect (P=0.01 and other factor including Age, Gender, Diabetes Mellitus, Smoking and High serum cholesterol didn’t have significant effect on blood pressure reduction. Conclusion: ARB/CCB combination therapy reduced blood pressure more effectively than the maximal doses of ARB or CCB with HCTZ in stage 2 hypertensive patients within

  2. Comparative pharmacokinetics of a fixed-dose combination vs concomitant administration of telmisartan and S-amlodipine in healthy adult volunteers.

    Science.gov (United States)

    Oh, Minkyung; Park, Sung-Eun; Ghim, Jong-Lyul; Choi, Young-Kyung; Shim, Eon-Jeong; Shin, Jae-Gook; Kim, Eun-Young

    2017-01-01

    This study compared the pharmacokinetic (PK) and safety profiles of a fixed-dose combination (FDC) formulation of telmisartan and S-amlodipine with those of concomitant administration of the two drugs. This was an open-label, randomized, crossover study in healthy male Koreans. All subjects were administered an FDC tablet containing 40 mg telmisartan and 5 mg S-amlodipine and were also coadministered the same dose of both drugs given separately. The crossover study design included a 14-day washout period between the two treatments. Blood samples were collected up to 168 h following drug administration. The plasma concentrations of telmisartan and S-amlodipine were determined by liquid chromatography tandem mass spectrometry. PK parameters and plasma concentration-time curves were compared. Safety was assessed by measuring vital signs, clinical laboratory tests, physical examinations, and patient interviews. The geometric mean ratios and 90% CIs for the maximum plasma concentration (C max ) and area under the curve from time zero to the last sampling time (AUC t ) were 0.8782 (0.8167-0.9444) and 0.9662 (0.9210-1.0136) for telmisartan and 1.0069 (0.9723-1.0427) and 1.0324 (0.9969-1.0690) for S-amlodipine, respectively. A total of 36 adverse events (AEs) were reported by 23 subjects, but no statistical differences were observed between the two treatments. The most frequently reported AE was a mild-to-moderate headache that was generally self-limiting. For both telmisartan and S-amlodipine, the C max and AUC t 90% CIs were between ln (0.8) and ln (1.25). These results suggest that the FDC formulation is pharmacokinetically bioequivalent and has a similar safety profile to the coadministration of these drugs.

  3. The potential role of amlodipine on experimentally induced bacterial rhinosinusitis

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    Arzu Tatar

    Full Text Available Abstract Introduction: Antibiotics are frequently used for the treatment of rhinosinusitis. Concerns have been raised regarding the adverse effects of antibiotics and growing resistance. The lack of development of new antibiotic compounds has increased the necessity for exploration of non-antibiotic compounds that have antibacterial activity. Amlodipine is a non-antibiotic compound with anti-inflammatory activity. Objective: In this study we aimed to investigate the potential role of amlodipine in the treatment of rhinosinusitis by evaluating its effects on tissue oxidative status, mucosal histology and inflammation. Methods: Fifteen adult albino guinea pigs were inoculated with Staphylococcus aureus and treated with saline, cefazolin sodium, or amlodipine for 7 days. The control group was composed by five healthy guinea pigs. Animals were sacrificed after the treatment. Histopathological changes were identified using Hematoxylin-Eosin staining. Inflammation was assessed by Polymorphonuclear Leukocyte infiltration density. Tissue levels of antioxidants (superoxide dismutase, glutathione and an oxidative product (malondialdehyde were determined. Results: In rhinosinusitis induced animals, amlodipine reduced loss of cilia, lamina propria edema and collagen deposition compared to placebo (saline and although not superior to cefazolin, amlodipine decreased polymorphonuclear leukocyte infiltration. The superoxide dismutase activity and glutathione levels were reduced, whereas the malondialdehyde levels were increased significantly in all three-treatment groups compared to the control group. Amlodipine treated group showed significantly increased superoxide dismutase and glutathione levels and decreased malondialdehyde levels compared to all treatment groups. Conclusion: The non-antibiotic compound amlodipine may have a role in acute rhinosinusitis treatment through tissue protective, antioxidant and anti-inflammatory mechanisms.

  4. Quality by Design (QbD) approach to optimize the formulation of a bilayer combination tablet (Telmiduo®) manufactured via high shear wet granulation.

    Science.gov (United States)

    Lee, Ah Ram; Kwon, Seok Young; Choi, Du Hyung; Park, Eun Seok

    2017-12-20

    A bilayer tablet, which consisted of telmisartan and amlodipine besylate, was formulated based on a Quality by Design (QbD) approach. The control and response factors were determined based on primary knowledge and the target values of the control tablet (Twynsta ® ). A D-optimal mixture design was used to obtain the optimal formulations in terms of D-mannitol, crospovidone, and MCC for the telmisartan layer, and CCM-Na, PVP K25, and Prosolv for the amlodipine layer. The quantitative effects of the different formulation factors on the response factors were accurately predicted using the equations of best fit and a strong linearity was observed between the predicted and actual values of the response factors. The optimized bilayer tablet was obtained using a numeric optimization technique and was characterized compared with a control (Twynsta ® ) by using various physical evaluations and in vivo pharmacokinetic parameters. The physical stability of Telmiduo ® was greater than that of Twynsta ® owing to the improvement of formulation factors. The in vivo pharmacokinetic parameters suggested that Telmiduo ® might have pharmaceutical equivalence and bioequivalence with Twynsta ® . Therefore, the bilayer tablet that consisted of telmisartan and amlodipine besylate could be produced using a more economical and simpler method than that used to produce Twynsta ® . Moreover, the suitability of QbD for effective product development in the pharmaceutical industry was shown. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Phlebitis as a consequence of peripheral intravenous administration of cisatracurium besylate in critically ill patients.

    Science.gov (United States)

    Meeder, Annelijn M; van der Steen, Marijke S; Rozendaal, Annemieke; van Zanten, Arthur R H

    2016-10-03

    This case report series describes 3 cases of cisatracurium besylate associated phlebitis after an infusion period of 14-20 hours. No similar cases have been reported in the literature. Association of phlebitis with another neuromuscular blocking agent, atracurium, has been described in the literature. The acidity of atracurium is thought to be the main cause. It is recommended that atracurium is administered only via central venous catheters when indicated to infuse over prolonged periods of time due to the acidity. Cisatracurium is a stereoisomer of atracurium and as such has the same molecular weight. Although cisatracurium also has a similar acidity as atracurium, a recommendation concerning infusion via a central venous catheter is lacking. We suggest prolonged administration of cisatracurium besylate only via centrally placed venous catheters or if not possible to careful monitor relevant peripheral intravenous sites to diminish the risks of phlebitis and associated complications or other cutaneous reactions. 2016 BMJ Publishing Group Ltd.

  6. Comparative pharmacokinetics of a fixed-dose combination vs concomitant administration of telmisartan and S-amlodipine in healthy adult volunteers

    Directory of Open Access Journals (Sweden)

    Oh M

    2017-12-01

    Full Text Available Minkyung Oh,1,2,* Sung-Eun Park,3,* Jong-Lyul Ghim,1–3 Young-Kyung Choi,1 Eon-Jeong Shim,1–3 Jae-Gook Shin,1–3 Eun-Young Kim1–3 1Department of Pharmacology, 2PharmacoGenomics Research Center, Inje University College of Medicine, Busan, 3Department of Clinical Pharmacology, Inje University Busan Paik Hospital, Busan, Republic of Korea *These authors contributed equally to this work Objective: This study compared the pharmacokinetic (PK and safety profiles of a fixed-dose combination (FDC formulation of telmisartan and S-amlodipine with those of concomitant administration of the two drugs.Materials and methods: This was an open-label, randomized, crossover study in healthy male Koreans. All subjects were administered an FDC tablet containing 40 mg telmisartan and 5 mg S-amlodipine and were also coadministered the same dose of both drugs given separately. The crossover study design included a 14-day washout period between the two treatments. Blood samples were collected up to 168 h following drug administration. The plasma concentrations of telmisartan and S-amlodipine were determined by liquid chromatography tandem mass spectrometry. PK parameters and plasma concentration–time curves were compared. Safety was assessed by measuring vital signs, clinical laboratory tests, physical examinations, and patient interviews.Results: The geometric mean ratios and 90% CIs for the maximum plasma concentration (Cmax and area under the curve from time zero to the last sampling time (AUCt were 0.8782 (0.8167–0.9444 and 0.9662 (0.9210–1.0136 for telmisartan and 1.0069 (0.9723–1.0427 and 1.0324 (0.9969–1.0690 for S-amlodipine, respectively. A total of 36 adverse events (AEs were reported by 23 subjects, but no statistical differences were observed between the two treatments. The most frequently reported AE was a mild-to-moderate headache that was generally self-limiting.Conclusion: For both telmisartan and S-amlodipine, the Cmax and AUCt 90% CIs

  7. Development and validation of an rp-hplc method for simultaneous determination of Ramipril and Amlodipine in tablets

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    Shi-Ying Dai

    2013-12-01

    Full Text Available An rp-hplc method for the simultaneous determination of Ramipril (RP and Amlodipine (AL in tablets was developed and validated by Chinese Pharmacopoeia 2010. The linearity of the proposed method was investigated in the range of 0.01–0.25 mg/mL (r2=0.9998 for RP and 0.014–0.36 mg/mL (r2=0.9997 for AL. The limits of detection (LOD were 0.06 μg/mL and 0.02 μg/mL for RP and AL, and the limits of quantitation (LOQ were 0.2 μg/mL and 0.07 μg/mL, respectively. Some major impurities and degradation products did not disturb the detection of RP and AL and the assay can thus be considered stability-indicating. Keywords: Ramipril, Amlodipine, RP-HPLC, Stability-indicating

  8. Comparative efficacy of amlodipine and hydrochlorthiazide-amiloride in cases of mild essential hypertension in outdoor patients at Combined Military Hospital Multan

    International Nuclear Information System (INIS)

    Ullah, M.U.; Khan, M.B.; Tahir, M.; Alamgir, W.; Yousif, M.A.

    2010-01-01

    To compare antihypertensive effect of fixed dose combination Hydrochlorothiazide-Amiloride and Amlodipine in patients of mild essential hypertension. After fulfilling the inclusion criteria of mild essential hypertension, defined as per recommendations of Seventh Joint National Committee (JNC 7) for treatment of Hypertension as stage 1 hypertension, systolic blood pressure (SBP) amlodipine and hydrochlorthiazide-amiloride 140-159-mmHg and Diastolic blood pressure(DBP) greater or equal to 90-99-mmHg, 100 patients were randomized into two study groups using a table of random numbers. Group 1 received tab amlodipine (5 mg) and Group 2 received tab hydrocholrthiazide-amiloride (25 mg-2.5mg). Informed written consent was taken. The patients were followed on subsequent visits (6 in total) for five months and systolic and diastolic blood pressure was recorded carefully. All the data thus obtained were processed and analyzed using SPSS version 10.0. Mean and standard deviation (SD) were calculated for age, diastolic and systolic blood pressure. In group 1 the drop in mean SBP between first and last visit was 15.42 mm Hg. In group 2 the drop in mean SBP between first and last visit was 18.34 mm Hg. In group 1, the drop in mean DBP between first and last visit was 10.08 mm Hg. In group 2 the drop in mean DBP between first and last visit was 14.65 mmHg. Mean drop in SBP of both the groups were compared with each other and found to be significantly different (P=0.003). Similarly mean drop in DBP of both the groups were compared with each other and found to be significant statistically (P=0.001). Hydrochlorothiazide-Amiloride had significantly better antihypertensive effect than Amlodipine in patients of mild essential hypertension at the end of five months therapy. (author)

  9. Cyclodextrine Screening for the Chiral Separation of Amlodipine Enantiomers by Capillary Electrophoresis

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    Gabriel Hancu

    2015-03-01

    Full Text Available Purpose: Amlodipine is a long acting, dihydropyridine type calcium channel blocker frequently used in the treatment of hypertension and coronary insufficiency. The calcium channel blocking activity resides primarily in the S-amlodipine enantiomer, while R-amlodipine is a potent inhibitor of smooth muscle cell migration. Methods: In this study capillary electrophoresis was applied for the enantiomeric separation of amlodipine using different native and derivatized; neutral and charged cyclodextrines as chiral selectors. The effects of pH and composition of the background electrolyte, concentration and type of chiral selector, capillary temperature, running voltage and injection parameters have been investigated. Results: Stereoselective interactions were observed when using α-CD, β-CD, HP-β-CD, RAMEB, CM-β-CD and SBE-β-CD. Optimized separation conditions consisted on a 50 mM phosphate buffer, pH – 3.0, 20 mM RAMEB as chiral selector, + 25 kV applied voltage, 15°C temperature and UV detection at 238 nm. Using the optimized electrophoretic conditions we succeeded the chiral separation of amlodipine enantiomers in approximately 6 minute, the order of migration being R-amlodipine followed by S-amlodipine. The method was successfully applied for the determination of amlodipine enantiomers from commercially available pharmaceuticals. The linearity range, limits of detection and quantification, precision and accuracy were determined and the results obtained confirmed that the method was suitable for this purpose. Conclusion: It can be concluded that the proposed capillary electrophoresis methods can be useful for routine pharmaceutical applications with benefits of its effectivity, simplicity, short analysis time and low consumption of analytes, solvents and chiral selectors.

  10. Amlodipine and the Successful Management of Post-Electroconvulsive Therapy Agitation.

    Science.gov (United States)

    Shahriari, Ali; Khooshideh, Maryam; Sheikh, Mahdi

    2016-01-01

    Electroconvulsive therapy (ECT) is a highly effective nonpharmacologic treatment for the management of depression and some other psychiatric disorders. Post-ECT agitation occurs in up to 12% of ECT treatments and is characterized by motor restlessness, irritability, disorientation, and panic-like behaviors. The severity of post-ECT agitation ranges from mild and self-limited to serious and severe forms requiring prompt medical intervention to protect the patient and the medical staff. In severe agitation medical management may be necessary which consists of using sedative agents, either benzodiazepines or propofol. The side-effects of these sedative agents, especially in the elderly population, necessitate finding ways that could help the prevention of the occurrence of agitation after ECT treatments. We report a 68-year-old female with major depression who was referred for ECT. She experienced severe post-ECT agitation requiring medical intervention after all ECT treatments. Administering of oral amlodipine (5 mg) one hour before ECT treatment successfully prevented the occurrence of post-ECT agitation in this patient. We briefly discuss the possible underlying mechanisms and pathophysiology of amlodipine in the prevention of post-ECT agitation.

  11. Amlodipine and the Successful Management of Post-Electroconvulsive Therapy Agitation

    Directory of Open Access Journals (Sweden)

    Ali Shahriari

    2016-01-01

    Full Text Available Electroconvulsive therapy (ECT is a highly effective nonpharmacologic treatment for the management of depression and some other psychiatric disorders. Post-ECT agitation occurs in up to 12% of ECT treatments and is characterized by motor restlessness, irritability, disorientation, and panic-like behaviors. The severity of post-ECT agitation ranges from mild and self-limited to serious and severe forms requiring prompt medical intervention to protect the patient and the medical staff. In severe agitation medical management may be necessary which consists of using sedative agents, either benzodiazepines or propofol. The side-effects of these sedative agents, especially in the elderly population, necessitate finding ways that could help the prevention of the occurrence of agitation after ECT treatments. We report a 68-year-old female with major depression who was referred for ECT. She experienced severe post-ECT agitation requiring medical intervention after all ECT treatments. Administering of oral amlodipine (5 mg one hour before ECT treatment successfully prevented the occurrence of post-ECT agitation in this patient. We briefly discuss the possible underlying mechanisms and pathophysiology of amlodipine in the prevention of post-ECT agitation.

  12. The significance of amlodipine on autonomic nervous system adjustment (ANSA method: A new approach in the treatment of hypertension

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    Milovanović Branislav

    2009-01-01

    Full Text Available Introduction. Cardiovascular autonomic modulation is altered in patients with essential hypertension. Objective To evaluate acute and long-term effects of amlodipine on cardiovascular autonomic function and haemodynamic status in patients with mild essential hypertension. Methods. Ninety patients (43 male, mean age 52.12 ±10.7 years with mild hypertension were tested before, 30 minutes after the first 5 mg oral dose of amlodipine and three weeks after monotherapy with amlodipine. A comprehensive study protocol was done including finger blood pressure variability (BPV and heart rate variability (HRV beat-to-beat analysis with impedance cardiography, ECG with software short-term HRV and nonlinear analysis, 24-hour Holter ECG monitoring with QT and HRV analysis, 24-hour blood pressure (BP monitoring with systolic and diastolic BPV analysis, cardiovascular autonomic reflex tests, cold pressure test, mental stress test. The patients were also divided into sympathetic and parasympathetic groups, depending on predominance in short time spectral analysis of sympathovagal balance according to low frequency and high frequency values. Results. We confirmed a significant systolic and diastolic BP reduction, and a reduction of pulse pressure during day, night and early morning hours. The reduction of supraventricular and ventricular ectopic beats during the night was also achieved with therapy, but without statistical significance. The increment of sympathetic activity in early phase of amlodipine therapy was without statistical significance and persistence of sympathetic predominance after a few weeks of therapy detected based on the results of short-term spectral HRV analysis. All time domain parameters of long-term HRV analysis were decreased and low frequency amongst spectral parameters. Amlodipne reduced baroreflex sensitivity after three weeks of therapy, but increased it immediately after the administration of the first dose. Conclusion. The results

  13. Phototransformation of amlodipine: degradation kinetics and identification of its photoproducts.

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    Anna Jakimska

    Full Text Available Nowadays, monitoring focuses on the primary compounds and does not include degradation products formed during various biological and chemical processes. Transformation products may have the same effects to human health and the environment or sometimes they can be more toxic than the parent compound. Unfortunately, knowledge about the formation of degradation products is still limited, however, can be very important for the environmental risk assessment. Firstly, the photodegradation kinetic of amlodipine was investigated in two experimental conditions: during the exposure to solar radiation and during the exposure to the light emitted by the xenon lamp. In all cases degradation of amlodipine followed a pseudo-first-order kinetics. In the next step, identification of transformation products of amlodipine formed during the exposure to xenon lamp irradiation was performed using ultra high performance liquid chromatography quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS. As a result sixteen photoproducts were identified, their structures were elucidated and ultimately the transformation pathway was proposed. Fifteen compounds (out of 16 photoproducts were newly identified and reported here for the first time; some of those compounds were formed from the first photoproduct, amlodipine pyridine derivative. Several analytes were formed only in acidic or basic conditions. Furthermore, the occurrence of amlodipine and its identified degradation products was investigated in environmental waters. Only one out of 16 compounds was found in wastewater effluent. The possibility of the sorption of examined analytes to sewage sludge particles was discussed based on QSAR.

  14. Cardioprotective effect of amlodipine in oxidative stress induced by experimental myocardial infarction in rats

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    Sudhira Begum

    2007-12-01

    Full Text Available The present study investigated whether the administration of amlodipine ameliorates oxidative stress induced by experimental myocardial infarction in rats. Adrenaline was administered and myocardial damage was evaluated biochemically [significantly increased serum aspertate aminotransferase (AST, lactate dehydrogenase (LDH and malondialdehyde (MDA levels of myocardial tissue] and histologically (morphological changes of myocardium. Amlodipine was administered as pretreatment for 14 days in adrenaline treated rats. Statistically significant amelioration in all the biochemical parameters supported by significantly improved myocardial morphology was observed in amlodipine pretreatment. It was concluded that amlodipine afforded cardioprotection by reducing oxidative stress induced in experimental myocardial infarction of catecholamine assault.

  15. Comparative effect of fixed dose combination of Amlodipine + Bisoprolol versus Amlodipine and Bisoprolol alone on blood pressure in stage-2 essential hypertensive patients.

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    Shirure PA,Tadvi NA, Bajait CS, Baig MS, Gade PR

    2012-09-01

    Full Text Available Background: Employment of low dose combinations of two antihypertensives, with different mode of action has gained acceptance worldwide for the treatment of mild to moderate hypertension. However, most studies in hypertensive disease have focused on monotherapy. The combination therapy in the treatment of hypertension is largely extrapolated from these monotherapy studies. Objectives: To study and compare the effect of amlodipine, bisoprolol and fixed dose combination of amlodipine + bisoprolol on blood pressure in stage-2 essential hypertensive patients. Methods: The present study was carried out in Department of Pharmacology in collaboration with Department of Medicine at Government Medical College and Hospital, Aurangabad. Results and Conclusion : Amlodipine + bisoprolol in fixed dose combination have showed significant blood pressure control in patients of stage-2 essential hypertension and the antihypertensive effect was greater than individual monotherapy study groups.

  16. Efficacy and safety of olmesartan/amlodipine/hydrochlorothiazide in patients with hypertension not at goal with mono, dual or triple drug therapy: results of the CHAMPiOn study.

    Science.gov (United States)

    Punzi, Henry A

    2014-02-01

    To assess the efficacy and safety of once daily olmesartan medoxomil (OM)/amlodipine besylate (AM)/hydrochlorothiazide (HCTZ) 40/10/25 mg in patients with hypertension not at goal with mono, dual or triple drug therapy. This was a single-center, prospective, open-label, blinded-endpoint study. After a 1-week screening visit, 40 patients were enrolled into the study and given once daily treatment with OM/AM/HCTZ after the patients underwent baseline ambulatory blood pressure monitoring (ABPM) on their original therapy. The primary endpoint was changes from baseline in mean 24 h ABPM [systolic blood pressure (SBP)] after the first day of therapy with OM/AM/HCTZ 40/10/25 mg. Secondary endpoints were changes from baseline in mean 24 h ABPM [diastolic blood pressure (DBP)] after the first day of therapy with OM/AM/HCTZ 40/10/25 mg; mean changes from baseline in trough seated SBP (SeSBP) at day 1 and SeSBP at weeks 1, 2, 3 and 4; mean changes from baseline in trough seated DBP (SeDBP) at day 1 and SeDBP at weeks 1, 2, 3 and 4; and the percentage of subjects achieving mean 24 h, daytime and night-time ABPM BP goals. The baseline paired t-test systolic ABPM was 134.0 ± 2.77 mmHg and day 1 was 128.6 ± 2.47 mmHg with a treatment difference of -5.55 ± 1.3 mmHg (pABPM SBP reduction was 117.7 ± 2.0 mmHg with a treatment difference of -16.5 ± 1.8 mmHg (p ABPM SBP reduction was 115.8 ± 1.8 mmHg with a treatment difference of -18.4 ± 2.0 mmHg (p ABPM SBP reduction was 115.5 ± 1.9 mmHg with a treatment difference of -18.6 ± 2.0 mmHg (p ABPM SBP reduction was 115.5 ± 1.8 mmHg with a treatment difference of -18.6 ± 2.2 mmHg (p ABPM reductions compared with mono, dual or triple drug therapy, resulting in all patients achieving systolic ABPM goal without ABPM documented hypotension.

  17. A high throughput platform for understanding the influence of excipients on physical and chemical stability

    DEFF Research Database (Denmark)

    Raijada, Dhara; Cornett, Claus; Rantanen, Jukka

    2013-01-01

    The present study puts forward a miniaturized high-throughput platform to understand influence of excipient selection and processing on the stability of a given drug compound. Four model drugs (sodium naproxen, theophylline, amlodipine besylate and nitrofurantoin) and ten different excipients were...... for chemical degradation. The proposed high-throughput platform can be used during early drug development to simulate typical processing induced stress in a small scale and to understand possible phase transformation behaviour and influence of excipients on this....

  18. Amlodipine induced plasma cell granuloma of the gingiva: A novel case report.

    Science.gov (United States)

    Vishnudas, Bhandari; Sameer, Zope; Shriram, Bansode; Rekha, Kardile

    2014-07-01

    Drug-induced gingival overgrowth (DIGO) can be a serious concern for both patients and clinicians. DIGO is a well-documented side-effect of some pharmacologic agents, including, but not limited to, calcium channel blockers, phenytoin, and cyclosporine. Plasma cell granulomas (pseudotumors) are exceedingly rare, non-neoplastic, reactive tumor-like proliferation, primarily composed of plasma cells that manifest primarily in the lungs, but may occur in various anatomic locations. Intraoral plasma cell granulomas involving the lip, oral mucosa, tongue, and gingiva have been reported in the past. This is the first case report of amlodipine induced plasma cell granuloma of the gingiva in the medical literature presenting a 54 year-old female patient with hypertension, who received amlodipine (10 mg/day, single dose orally) for 2 years, sought medical attention because of developing maxillary anterior massive gingival overgrowth causing functional and esthetic problem, which was treated by excisional biopsy. Histologically, these lesions were composed of mature plasma cells, showing polyclonality for both lambda and kappa light chains and fibrovascular connective tissue stroma confirming a diagnosis of plasma cell granuloma. This case also highlights the need to biopsy for unusual lesions to rule out potential neoplasms.

  19. Amlodipine Ameliorates Ischemia-Induced Neovascularization in Diabetic Rats through Endothelial Progenitor Cell Mobilization

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    Jiayin Sun

    2016-01-01

    Full Text Available Objectives. We investigated whether amlodipine could improve angiogenic responses in a diabetic rat model of acute myocardial infarction (AMI through improving bone marrow endothelial progenitor cell (EPC mobilization, in the same way as angiotensin converting enzyme inhibitors. Methods. After induction of AMI by coronary artery ligation, diabetic rats were randomly assigned to receive perindopril (2 mgkg−1 day−1, amlodipine (2.5 mgkg−1 day−1, or vehicle by gavage (n=20 per group. Circulating EPC counts before ligation and on days 1, 3, 5, 7, 14, and 28 after AMI were measured in each group. Microvessel density, cardiac function, and cardiac remodeling were assessed 4 weeks after treatment. The signaling pathway related to EPC mobilization was also measured. Results. Circulating EPC count in amlodipine- and perindopril-treated rats peaked at day 7, to an obvious higher level than the control group peak which was reached earlier (at day 5. Rats treated with amlodipine showed improved postischemia neovascularization and cardiac function, together with reduced cardiac remodeling, decreased interstitial fibrosis, and cardiomyocyte apoptosis. Amlodipine treatment also increased cardiac SDF-1/CXCR4 expression and gave rise to activation of VEGF/Akt/eNOS signaling in bone marrow. Conclusions. Amlodipine promotes neovascularization by improving EPC mobilization from bone marrow in diabetic rats after AMI, and activation of VEGF/Akt/eNOS signaling may in part contribute to this.

  20. THE ROLE OF S-AMLODIPINE IN ARTERIAL HYPERTENSION THERAPY WITH COMBINATION OF CALCIUM CHANNEL BLOCKERS AND BETA-BLOCKERS

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    M. A. Maksimova

    2013-01-01

    Full Text Available Aim. To study efficacy and safety of calcium channel blocker, S-amlodipine, in combination with β-blocker, atenolol, in patients with arterial hypertension (HT 1-2 degree com- pared to fixed combination of racemic amlodipine and atenolol.Material and methods. Patients (n=31, 7 men and 24 women with HT 1–2 degree were included into the study. The patients were randomized into two groups by the com- binations sequence. Treatment with each combination lasted 4 weeks. Office blood pressure (BP was assessed at baseline and at the end of the treatment periods, possible side effects were registered.Results. All patients completed the study. Both combination of S-amlodipine+atenolol and fixed combination of racemic amlodipine+atenolol reduced systolic (in average, -15.9 and -12.7 mm Hg, respectively and diastolic (in average, -7.3 and -5.3 mmHg, respectively BP significantly. Heart rate also decreased during therapy (in average, -3 and -4 bt/min, respectively. The differences between combinations BP and heart rate effects were not significant. 8 and 16 adverse events were registered during S-amlodipine+atenolol and racemic amlodipine+atenolol therapies, respectively Conclusion. Combination of S-amlodipine+atenolol, as well as combination of racemic amlodipine+atenolol are effective in the treatment of patients with HT 1-2 degree, however combination with S-amlodipine has less number of adverse events.

  1. In-vitro displacement interaction of atenolol and amlodipine on binding with bovine serum albumin when co-administered

    Directory of Open Access Journals (Sweden)

    Md. Ashraful Alam, Md. Abdul Awal, Mahbub Mostofa, Md. Kamrul Islam and Nusrat Subhan

    2007-06-01

    Full Text Available The binding of atenolol (selective β1-blocker and amlodipine (calcium channel blocker to bovine serum albumin (BSA was studied by equilibrium dialysis method in order to have an insight into the binding chemistry of these two to BSA. Free atenolol concentration was increased due to addition of amlodipine which reduced the binding of the compounds to BSA. However, the free fraction was increased to a level as it was expected from direct competitive displacement while the free atenolol concentration was increased according to increasing the amlodipine concentration when only the BSA was present. The result obtained when the binding site was blocked by sufficient amount of amlodipine was that the increment of free concentration of atenolol was prominent. When no amlodipine was added the free concentration of atenolol was only 28% whereas this release was 93 % to 98.01% when amlodipine was added with increasing concentration.

  2. Original Research Monotherapy with amlodipine or ...

    African Journals Online (AJOL)

    hypertension is the most common cardiovascular disease ... on the electrolyte profile of Nigerians with mild to moderate hypertension. Methods ... sphygmomanometer. ... Figure 1: Systolic blood pressure measurements following treatment with amlodipine and ..... above, the age of the subjects may be a contributing factor;.

  3. Can combining different risk interventions into a single formulation contribute to improved cardiovascular disease risk reduction? The single pill of amlodipine/atorvastatin

    Directory of Open Access Journals (Sweden)

    FD Richard Hobbs

    2007-11-01

    Full Text Available FD Richard HobbsUniversity of Birmingham, Edgbaston, Birmingham B15 2TT, UK.Abstract: In order to prevent cardiovascular events, it is essential to effectively manage overall risk of cardiovascular disease. However, despite guideline recommendations to this effect, current management of the major, modifiable cardiovascular risk factors such as hypertension and dyslipidemia is disconnected and patient adherence to therapy is poor. This is particularly important for patients with multiple cardiovascular risk factors, who are often prescribed multiple medications. The JEWEL study program investigated the use of single-pill amlodipine/atorvastatin as a strategy to improve management of these patients. The JEWEL program consisted of two 16-week, international, openlabel, multicenter, titration-to-goal studies in patients with hypertension and dyslipidemia. The two studies differed based on country of enrollment and certain tertiary endpoints, but the overall designs were very similar. Patients were enrolled from 255 centers across Canada and 13 European countries. The study was designed to assess the efficacy, safety, and utility of amlodipine/atorvastatin single pill therapy in a real-world setting. Patients were initiated at a dose of amlodipine 5 mg/atorvastatin 10 mg, unless previously treated, and were uptitrated as necessary. The primary efficacy parameter was the percentage of patients, at different levels of cardiovascular risk, achieving country-specific guideline-recommended target levels for blood pressure and lipids. A secondary analysis of efficacy measured attainment of the same single goal for blood pressure across all study participants (JEWEL I and II and the same single goal for LDL-C across all study participants (JEWEL I and II. The program utilized a newly developed questionnaire to gain better understanding of participants’ beliefs and behaviors towards medical treatment of their multiple risk factors. Approximately 2850

  4. Antihypertensive treatment with telmisartan in a cat with amlodipine-induced gingival hyperplasia

    Directory of Open Access Journals (Sweden)

    Lien Desmet

    2017-12-01

    Full Text Available Case summary Systemic arterial hypertension is commonly reported in middle-aged-to-older cats. Amlodipine is recommended as the initial antihypertensive drug in cats. In this case report, gingival hyperplasia secondary to the use of amlodipine in a cat is described. Benazepril as a monotherapy was unsuccessful in reducing blood pressure in this cat. After replacement of benazepril by telmisartan, gingival hyperplasia disappeared and blood pressure was well controlled. Relevance and novel information This case report describes the first reported case of reversible gingival hyperplasia as a result of the treatment with amlodipine. It also contains the first published data on the effect of telmisartan in a hypertensive cat.

  5. Noncardiogenic Pulmonary Edema after Amlodipine Overdose without Refractory Hypotension and Bradycardia

    Directory of Open Access Journals (Sweden)

    M. Hedaiaty

    2015-01-01

    Full Text Available Amlodipine overdose can be life-threatening when manifesting as noncardiogenic pulmonary edema. Treatment remains challenging. We describe a case of noncardiogenic pulmonary edema without refractory hypotension and bradycardia after ingestion of 500 milligram amlodipine with suicidal intent. Mechanical ventilation, dexamethasone, atrovent HFA (ipratropium, pulmicort inhalation, and antibiotic therapy were used for the management. Length of hospital stay was 11 days. The patient was discharged with full recovery.

  6. Benazepril plus amlodipine or hydrochlorothiazide for hypertension in high-risk patients.

    Science.gov (United States)

    Jamerson, Kenneth; Weber, Michael A; Bakris, George L; Dahlöf, Björn; Pitt, Bertram; Shi, Victor; Hester, Allen; Gupte, Jitendra; Gatlin, Marjorie; Velazquez, Eric J

    2008-12-04

    The optimal combination drug therapy for hypertension is not established, although current U.S. guidelines recommend inclusion of a diuretic. We hypothesized that treatment with the combination of an angiotensin-converting-enzyme (ACE) inhibitor and a dihydropyridine calcium-channel blocker would be more effective in reducing the rate of cardiovascular events than treatment with an ACE inhibitor plus a thiazide diuretic. In a randomized, double-blind trial, we assigned 11,506 patients with hypertension who were at high risk for cardiovascular events to receive treatment with either benazepril plus amlodipine or benazepril plus hydrochlorothiazide. The primary end point was the composite of death from cardiovascular causes, nonfatal myocardial infarction, nonfatal stroke, hospitalization for angina, resuscitation after sudden cardiac arrest, and coronary revascularization. The baseline characteristics of the two groups were similar. The trial was terminated early after a mean follow-up of 36 months, when the boundary of the prespecified stopping rule was exceeded. Mean blood pressures after dose adjustment were 131.6/73.3 mm Hg in the benazepril-amlodipine group and 132.5/74.4 mm Hg in the benazepril-hydrochlorothiazide group. There were 552 primary-outcome events in the benazepril-amlodipine group (9.6%) and 679 in the benazepril-hydrochlorothiazide group (11.8%), representing an absolute risk reduction with benazepril-amlodipine therapy of 2.2% and a relative risk reduction of 19.6% (hazard ratio, 0.80, 95% confidence interval [CI], 0.72 to 0.90; Pbenazepril-amlodipine combination was superior to the benazepril-hydrochlorothiazide combination in reducing cardiovascular events in patients with hypertension who were at high risk for such events. (ClinicalTrials.gov number, NCT00170950.) 2008 Massachusetts Medical Society

  7. Efficacy of fix dose combination (atorvastatin and amlodipine) in treatment of uncontrolled hypertension and dyslipidemia

    International Nuclear Information System (INIS)

    Bashir, S.; Sherwani, M.U.K.; Batool, A.

    2012-01-01

    The fixed-dose combination containing the antihypertensive agent amlodipine and the statin, atorvastatin, is the first combination of its kind designed to treat two risk factors for cardiovascular disease (CVD), i.e., hypertension and dyslipidemia. in this study, blood pressure and lipid lowering effects of combination of amlodipine and atorvastatin were evaluated in uncontrolled hypertensive patients. Methods: Thirty patients both male and female in the age group 35-60 years attending the hypertensive clinic of PMRC FJMC suffering from uncontrolled hypertension were selected. baseline blood pressure was checked after half hour rest in sitting and standing position using mercury sphygmomanometer. Blood sample was collected from all patients after overnight fasting for assessment of serum cholesterol, triglycerides, LDL and HDL cholesterol levels. they were prescribed with fixed dose combination of 5 mg amlodipine and 10 mg atorvastatin. Patients were followed for their blood pressure measurement after every 4 weeks up to 12 weeks. At the end of 12 weeks their fasting blood sample was taken again for determination of serum cholesterol, triglyceride, IDL and HDL cholesterol levels. Results: Systolic blood pressure after 4, 8 and 12 weeks was significantly lower at all intervals from baseline. when systolic blood pressure after 8 and 12 weeks was compared with 4 weeks, the effect was again significant (p=0.024, p=0.002 respectively). There was no significant reduction seen in 8 versus 12 weeks (p=0.493). Diastolic blood pressure at 4, 8 and 12 weeks was significantly lower from baseline. Diastolic blood pressure after 4 and 8 weeks when compared with 8 and 12 weeks was not significantly low (p=0.99 and 0.91 respectively). Lipid profile of the patients was significantly reduced from baseline after twelve weeks of fixed dose combination of treatment (p<0.000). Conclusion: Combination therapy proved to be effective in controlling hypertension and dyslipidemia than single

  8. Efficacy of fix dose combination (atorvastatin and amlodipine) in treatment of uncontrolled hypertension and dyslipidemia

    Energy Technology Data Exchange (ETDEWEB)

    Bashir, S; Sherwani, M U.K.; Batool, A [Fatima Jinnah Medical College, Lahore (Pakistan)

    2012-07-15

    The fixed-dose combination containing the antihypertensive agent amlodipine and the statin, atorvastatin, is the first combination of its kind designed to treat two risk factors for cardiovascular disease (CVD), i.e., hypertension and dyslipidemia. in this study, blood pressure and lipid lowering effects of combination of amlodipine and atorvastatin were evaluated in uncontrolled hypertensive patients. Methods: Thirty patients both male and female in the age group 35-60 years attending the hypertensive clinic of PMRC FJMC suffering from uncontrolled hypertension were selected. baseline blood pressure was checked after half hour rest in sitting and standing position using mercury sphygmomanometer. Blood sample was collected from all patients after overnight fasting for assessment of serum cholesterol, triglycerides, LDL and HDL cholesterol levels. they were prescribed with fixed dose combination of 5 mg amlodipine and 10 mg atorvastatin. Patients were followed for their blood pressure measurement after every 4 weeks up to 12 weeks. At the end of 12 weeks their fasting blood sample was taken again for determination of serum cholesterol, triglyceride, IDL and HDL cholesterol levels. Results: Systolic blood pressure after 4, 8 and 12 weeks was significantly lower at all intervals from baseline. when systolic blood pressure after 8 and 12 weeks was compared with 4 weeks, the effect was again significant (p=0.024, p=0.002 respectively). There was no significant reduction seen in 8 versus 12 weeks (p=0.493). Diastolic blood pressure at 4, 8 and 12 weeks was significantly lower from baseline. Diastolic blood pressure after 4 and 8 weeks when compared with 8 and 12 weeks was not significantly low (p=0.99 and 0.91 respectively). Lipid profile of the patients was significantly reduced from baseline after twelve weeks of fixed dose combination of treatment (p<0.000). Conclusion: Combination therapy proved to be effective in controlling hypertension and dyslipidemia than single

  9. [Pharmacogenetic approaches to predicting the efficiency and safety of amlodipine in patients with arterial hypertension].

    Science.gov (United States)

    Sychev, D A; Shih, N V; Kalle, E G; Ryzhikova, K A; Morozova, T E

    2017-10-01

    An open, non-comparative, prospective clinical study was conducted to evaluate the antihypertensive efficacy and tolerability of amlodipine, a calcium antagonist, in patients with arterial hypertension (AH) I-II stages, depending on the genotype for the polymorphic marker C3435T of the ABCB1 gene. The study included 100 patients with AH I-II stages, aged from 45 to 58 years. The initial dose of amlodipine was 5 mg, duration of treatment was 12 weeks. General clinical examination methods, office measurement and daily blood pressure monitoring, tolerance evaluation, and genotyping using the ABCB1 polymorphic marker C3435T by the PCR-RFLP method (polymerase chain reaction and restriction fragment length polymorphism) were used. The statistical analysis of results was carried out using the Mann-Whitney U test for quantitative variables, Kruskal-Wallis one-way analysis of variance (ANOVA) for three independent groups of quantitative data. Excellent antihypertensive efficacy with the CC genotype was found in 11.8% patients, with CT - 33.9%, with TT - 43.3%; good - 35.3%, 32.1%, and 33.3% respectively, satisfactory - 52.9%, 34,0% and 23.4% respectively. Six patients with the CT genotype and nine patients with the CC genotype required the increase in the dose to 10 mg. The number of patients with Adverse drug reactions (ADR) were found in 35.3% of patients with the CC genotype, 6.7% with the TT genotype and 11.3% with the CT genotype. The Kruskal-Wallis test revealed significant differences between CC and TT genotypes in the degree of decrease in SBP (p=0.02), antihypertensive efficacy parameter (p=0.02), an increase in dose requirements (p = 0.04) and the incidence of ADR(p=0.05). In AH patients (I-II stage) with the TT genotype of the C3435T gene polymorphism one can expect higher rates of antihypertensive efficacy of amlodipine in combination with a good safety profile and the lowest ADR percentage, while patients with the CC genotype more likely to develop ADR and

  10. Amlodipine-induced gingival hyperplasia in chronic renal

    African Journals Online (AJOL)

    Administrator

    Keywords: Amlodipine, gingival hyperplasia, chronic renal failure. African Health ... for the treatment of hypertension and angina. Pharmacokinetic ... patient appealed to the dentist at first. ... Am Heart J. 1989 Nov; 118(5 Pt 2):. 1100-1103. 2.

  11. The effect of captopriland amlodipine on C-reactive protein concentrations in type 2 diabetic hypertensive patients

    International Nuclear Information System (INIS)

    Mahmood, I.H.

    2008-01-01

    To compare the effects of the ACE inhibitor captopril with the calcium channel blocker amlodipine on serum CRP concentrations in hypertensive type 2 diabetic patients. This is a case control study conducted in Al-Wafa Diabetic Center in Mosul. Serum CRP concentrations were measured in two groups of hypertensive type 2 diabetic patients before and after drug administration (group 1 on captopril therapy, group two on amlodipine therapy). A significant reduction of serum CRP level was demonstrated after treatment with captopril but not with amlodipine. Mean CRP concentration of the control group was statistically lower than those of captopril and amlodipine groups. The present study showed that hypertensive type 2 diabetic patients are associated with increased level of CRP and therapy with captopril but not amlodipine significantly reduced CRP, suggesting a possible anti-inflammatory action of captopril in addition to its BP lowering effects thus captopril may be regarded as the drug of choice in the treatment of BP in diabetic hypertensive patients. (author)

  12. Impact of Statin Therapy on the Blood Pressure-Lowering Efficacy of a Single-Pill Perindopril/Amlodipine Combination in Hypertensive Patients with Hypercholesterolemia.

    Science.gov (United States)

    Sirenko, Yuriy; Radchenko, Ganna

    2017-03-01

    Several lines of research indicate that statins can lower blood pressure (BP) independently of their lipid-lowering effects when used as monotherapy and in combination with antihypertensive agents. This short-term, open-label study examined whether statin therapy had a synergistic effect on the BP-lowering efficacy of perindopril/amlodipine in a subgroup of patients in the PERSPECTIVA study with concomitant hypertension and hypercholesterolemia, with or without statin at baseline. The PERSPECTIVA study recruited 732 adults with untreated or uncontrolled hypertension. This subgroup analysis of PERSPECTIVA included 587 patients with concomitant hypertension and hypercholesterolemia (mean age 56.7 years) of whom 226 were receiving a statin at baseline (statin [+] group) and 361 were not (statin [-] group). All patients received treatment with single-pill combination perindopril/amlodipine at a dose of 5/5, 10/5 or 10/10 mg/day. The study duration was 60 days with follow-up visits for BP monitoring at 7, 15, 30 and 60 days. At day 60, BP control (statin [+] vs statin [-] group: 73 vs 64% respectively (+14%, P statin [+] group, the single-pill perindopril/amlodipine combination significantly reduced BP in patients previously untreated (n = 18), or treated with monotherapy (n = 97), dual therapy (n = 93), or triple therapy (n = 18): -38.8/-20.0, -39.1/-20.1, -38.0/-19.4, -39.9/-18.3 mmHg respectively (P statin [+] group (0.9%) vs the statin [-] group (2.5%). BP control rates in patients with uncontrolled hypertension and concomitant hypercholesterolemia are significantly improved with a treatment regimen that combines perindopril/amlodipine with statin therapy, regardless of previous antihypertensive therapy. This subanalysis of the PERSPECTIVA study supports the synergistic BP-lowering effect of statins and perindopril/amlodipine.

  13. Comparison of efficacy and tolerability of different brands of amlodipine in patients with mild to moderate hypertension

    Directory of Open Access Journals (Sweden)

    Molouk Hadjibabaie

    2015-10-01

    Full Text Available Background: The efficacy of amlodipine, a calcium channel blocker, in treating systemic hypertension is well established but the most efficacious brand of this drug is still uncertain. The cost of different brands of amlodipine is tremendously different which may affect decision-making in hypertension treatment. The purpose of this study was to compare the efficacy and safety of different brands of amlodipine (Amlodipine, Amlopress, and Norvasc in the treatment of hypertension in adult patients.Methods: This was a double-blind, randomized, three-sequence crossover study. Ambulatory patients with hypertension who had the inclusion criteria were enrolled. Patients were randomized and entered into three groups to receive either brand of amlodipine in a crossover method. After every four weeks of treatment completed, the other brand of drug was prescribed. The total period of the study was 12 weeks for all three drugs including four weeks for each brand.Results: A total of 20 patients entered to the study, 15 completed the 12-week treatment schedule. The absolute reductions in seated and supine systolic blood pressure (SBP and diastolic blood pressure (DBP were similar with all three brands during the 4 weeks of treatment. Headache, malaise and weakness were the most common reported adverse effects (AE with all three drugs. Generic amlodipine had the most AE as compared with other brands. These AE were mild and did not require withdrawal of the drug. Conclusion: There is no statistical difference in lowering blood pressure by three different brands of amlodipine thus everyone which has the lowest price can be the first choice.

  14. Beneficial effects of combined benazepril-amlodipine on cardiac nitric oxide, cGMP, and TNF-alpha production after cardiac ischemia.

    Science.gov (United States)

    Siragy, Helmy M; Xue, Chun; Webb, Randy L

    2006-05-01

    The aim of this study was to determine if myocardial inflammation is increased after myocardial ischemia and whether angiotensin-converting enzyme inhibitors, calcium channel blockers, or diuretics decrease mediators of inflammation in rats with induced myocardial ischemia. Changes in cardiac interstitial fluid (CIF) levels of nitric oxide metabolites (NOX), cyclic guanosine 3',5'-monophosphate (cGMP), angiotensin II (Ang II), and tumor necrosis factor-alpha (TNF-alpha) were monitored with/without oral administration of benazepril, amlodipine, combined benazepril-amlodipine, or hydrochlorothiazide. Using a microdialysis technique, levels of several mediators of inflammation were measured after sham operation or 30-minute occlusion of the left anterior descending coronary artery. Compared with sham animals, levels of CIF NOX and cGMP were decreased in animals with ischemia (P Benazepril or amlodipine significantly increased NOX levels (P benazepril significantly increased cGMP (P benazepril-amlodipine further increased CIF NOX and cGMP (P benazepril alone, or combined benazepril-amlodipine significantly reduced TNF-alpha (P benazepril-amlodipine may be beneficial for managing cardiac ischemia.

  15. [Fixed drug combinations in hypertension: a budget impact analysis for the Spanish Health System on the marketing of a fixed combination of olmesartan/amlodipine].

    Science.gov (United States)

    Belén Ferro-Rey, M; Roca-Cusachs, Alex; Sicras-Mainar, Antoni; Alvarez-Martín, Carlos; de Salas-Cansado, Marina

    2011-07-01

    To carry out a budget impact analysis (BIA) of olmesartan/amlodipine (20/5, 40/5 and 40/10mg) marketed as a fixed combination (FC) in its approved indication for the National Health System (NHS). We developed a decision tree model in order to estimate usual hypertension treatment algorithm in Spanish clinical practice. The BIA has been developed from the perspective of the NHS for a period of 3 years (years 2010-2012). Spanish hypertensive population ≥ 35 years old. Introduction into the market of a fixed combination (FC) olmesartan/amlodipine in Spain. Expected costs to be assumed by the Spanish NHS (RRP-VAT) for hypertensive population able to be treated with the FC versus currently assumed costs by the NHS with free combination olmesartan and amlodipine. Estimated pharmaceutical costs in hypertensive population treated with olmesartan and amlodipine (2 pills) would be €25.2M (1(st) year), €26.4M (2011), €27.6M (2012), with a total 3-year period of €79.2M. According to patient tree model, the population able to be treated with FC would be 71,283 patients (2010), with a growth rate of 4.8% in the successive years, which supposes an annual cost of €21.2M (2010), €21.8M (2011) and €22.4M (2012), with a total 3-year period of €65.4M. The BIA shows savings of €13.8M in a total 3-year period. The BIA of FC olmesartan/amlodipine could generate net savings of €13.8M for the NHS in the period ranging from years 2010 to 2012. Copyright © 2010 Elsevier España, S.L. All rights reserved.

  16. amlodipine besylate impairs the morphology of bone marrow in ...

    African Journals Online (AJOL)

    2017-07-01

    Jul 1, 2017 ... rats were fed with standard pellet diet (Bendel. Feeds Limited, Nigeria) and received water ad libitum. The rats were acclimatized for seven days before the ... flexible feeding tube long enough to reach the stomach through the oesophagus. The average weight of rats employed in the study was measured as ...

  17. Comparative evaluation of capillary electrophoresis and high-performance liquid chromatography for the separation of cis-cis, cis-trans, and trans-trans isomers of atracurium besylate.

    Science.gov (United States)

    de Moraes, M de L; Polakiewicz, B; Mattua, M F; Tavares, M F

    1998-01-01

    Atracurium besylate is a highly selective nondepolarizing neuromuscular blocking agent routinely used during anesthetic procedures. The commercial presentation of this drug is a mixture of positional isomers, cis-cis, cis-trans, and trans-trans. Reversed-phase high-performance liquid chromatography has been the technique of choice for the analysis of atracurium besylate formulations at the quality control laboratory of Núcleo de Desenvolvimento Cristália (São Paulo, Brazil), a local pharmaceutical company. HPLC analysis is usually conducted under gradient elution using acetonitrile/0.1 M phosphate buffer eluent mixture as mobile phase and an octadecyl silica (ODS)-packed column. The complete elution of the three isomers takes about 1 hr. In this work, an alternative capillary electrophoresis methodology was developed. The complete resolution of all three isomers was accomplished in about 13 min (+20 kV/72 cm, 211 nm direct detection) using a 60-mM phosphate buffer solution (pH 4) containing 20 mM beta-cyclodextrin and 4 M urea. The isomer ratio was found to be 59.1% cis-cis, 35.9% cis-trans, and 5.02% trans-trans (expected ratio: 59:35:6). Laudanosine, a major metabolite of atracurium besylate, was identified in two commercially available formulations, Tracur (Núcleo de Desenvolvimento Cristália) and Tracrium (Glaxo Wellcome, S.A., Rio de Janeiro, Brazil). Its concentration increases considerably during storage of the product, even if the product is stored at low temperatures.

  18. [Simultaneous determination of amlodipine, benazepril and benazeprilat in human plasma by LC-HESI/MS/MS method].

    Science.gov (United States)

    Pan, Hua-Ling; Lin, Li-Shan; Ding, Jue-Fang; Chen, Xiao-Yan; Zhong, Da-Fang

    2014-01-01

    The study aims to develop a rapid, sensitive and specified method of liquid chromatography with heated electrospray ionization tandem mass spectrometry (LC-HESI/MS/MS) for simultaneous determination of amlodipine, benazepril and benazeprilat in human plasma using amlodipine-d4 and ubenimex as internal standards (ISs). Selected reaction monitoring (SRM) with heated electrospray ionization (HESI) was used in the positive mode for mass spectrometric detection. Analytes and ISs were extracted from plasma by simple protein precipitation. The reconstituted samples were chromatographed on a C18 (100 mm x 4.6 mm, 5 microm) column with mixture of methanol-acetonitrile-5 mmol.L- ammonium acetate-formic acid (30 : 30 : 40 : 0.1) as mobile phase at a flow rate of 0.6 mL.min-1. The standard curves were demonstrated to be linear in the range of 0.02 to 6.00 ng.mL-1 for amlodipine, 0.2 to 1,500 ng.mL-1 for benazepril and benazeprilat with r2>0.99 for each analyte. The lower limit of quantitation was identifiable and reproducible at 0.02, 0.2 and 0.2 ng mL-1 for amlodipine, benazepril and benazeprilat, respectively. The intra-day and inter-day precision and accuracy results were within the acceptable limit across all concentrations. The plasma samples were stable after four freeze-thaw cycles and being stored for 93 days at -20 degrees C. The method was applied to a pharmacokinetic study of a fixed-dose combination of amlodipine and benazepril on Chinese healthy volunteers.

  19. PATHOGENESIS OF IMMUNE ALTERATIONS AND CORRECTIVE ROLE OF AMLODIPINE IN EXPERIMENTAL CHRONIC RENAL FAILURE

    Directory of Open Access Journals (Sweden)

    M. V. Osikov

    2016-01-01

    Full Text Available The purpose of this study was to assess some mechanisms of changes in immune state, and to evaluate a role of amlodipine, a known calcium channel blocker, as a potential corrective drug in experimental chronic renal failure (CRF. An animal CRF model was produced in rats by a two-stage operative resection of 5/6 of the renal tissue. Amlodipine is used per os at a daily dose of 0.25 mg/kg for 7 days. Flow cytofluorimetric approach was used to discern peripheral blood lymphocytes: CD3+ (mainly, T lymphocytes, CD45RA+ (mainly, B cells, as well as the following cell markers: Annexin 5-FITC+/7-AAD- (early apoptosis, Annexin 5-FITC+/7-AAD+ (late apoptosis and, in part, necrotic cells. Moreover, we have measured serum concentrations of urea, creatinine, phosphate, total calcium, parathyroid hormone (PTH, IL-1β, IL-4, interferon-γ, superoxide dismutase (SOD and catalase activities. Evaluation of Th1- and Th2-dependent immune response was carried out, respectively, by detection of delayed-type hypersensitivity, and scoring the antibody-forming cells in rat spleen induced by immunization with allogeneic erythrocytes. Primary, secondary and final products of lipid peroxidation were evaluated in lipid extracts from peripheral blood lymphocytes. Changes of immune state in CRF included depression of Th1 and Th2 dependent immune response, reduced number of lymphocytes bearing T and В cell markers, increased IL-1β concentrations in blood, along with decreased amounts of IFNγ and IL-4. Probable pathogenesis of the altered immune state may be associated with increased number of peripheral lymphocytes being at early and late stages of apoptosis/necrosis, elevated blood levels of IL-1β, total calcium, parathyroid hormone, reduced concentrations of IFNγ, and increased contents of primary, secondary and final peroxidation products in peripheral blood lymphocytes, being accompanied by inhibition of the SOD and catalase activity in blood plasma

  20. Zero crossing and ratio spectra derivative spectrophotometry for the dissolution tests of amlodipine and perindopril in their fixed dose formulations

    Directory of Open Access Journals (Sweden)

    Maczka Paulina

    2014-06-01

    Full Text Available Dissolution tests of amlodipine and perindopril from their fixed dose formulations were performed in 900 mL of phosphate buffer of pH 5.5 at 37°C using the paddle apparatus. Then, two simple and rapid derivative spectrophotometric methods were used for the quantitative measurements of amlodipine and perindopril. The first method was zero crossing first derivative spectrophotometry in which measuring of amplitudes at 253 nm for amlodipine and 229 nm for perindopril were used. The second method was ratio derivative spectrophotometry in which spectra of amlodipine over the linearity range were divided by one selected standard spectrum of perindopril and then amplitudes at 242 nm were measured. Similarly, spectra of perindopril were divided by one selected standard spectrum of amlodipine and then amplitudes at 298 nm were measured. Both of the methods were validated to meet official requirements and were demonstrated to be selective, precise and accurate. Since there is no official monograph for these drugs in binary formulations, the dissolution tests and quantification procedure presented here can be used as a quality control test for amlodipine and perindopril in respective dosage forms.

  1. Development and validation of RP-HPLC and UV-spectrophotometric methods for rapid simultaneous estimation of amlodipine and benazepril in pure and fixed dose combination

    Directory of Open Access Journals (Sweden)

    Abhi Kavathia

    2017-05-01

    Full Text Available High-performance liquid chromatographic (HPLC and UV spectrophotometric methods were developed and validated for the quantitative determination of amlodipine besylate (AM and benazepril hydrochloride (BZ. Different analytical performance parameters such as linearity, precision, accuracy, specificity, limit of detection (LOD and limit of quantification (LOQ were determined according to International Conference on Harmonization ICH Q2B guidelines. The RP-HPLC method was developed by the isocratic technique on a reversed-phase Shodex C-18 5e column. The retention time for AM and BZ was 4.43 min and 5.70 min respectively. The UV spectrophotometric determinations were performed at 237 nm and 366 nm for AM and at 237 nm for BZ. Correlation between absorbance of AM at 237 nm and 366 nm was established and based on developed correlation equation estimation of BZ at 237 nm was carried out. The linearity of the calibration curves for each analyte in the desired concentration range was good (r2 > 0.999 by both the HPLC and UV methods. The method showed good reproducibility and recovery with percent relative standard deviation less than 5%. Moreover, the accuracy and precision obtained with HPLC co-related well with the UV method which implied that UV spectroscopy can be a cheap, reliable and less time consuming alternative for chromatographic analysis. The proposed methods are highly sensitive, precise and accurate and hence successfully applied for determining the assay and in vitro dissolution of a marketed formulation.

  2. Studying structurally-mechanical characteristics suppositories with amlodipine

    Directory of Open Access Journals (Sweden)

    Fadi Al Zedan

    2013-02-01

    Full Text Available Rheological behaviour suppositories with amlodipine on lypofiles to a basis are studied and character of temperature effect on their structurally-mechanical properties is positioned. It is revealed that the temperature of carrying out of technological operations of homogenization and overflow suppositories 50-55ºС is optimum, providing necessary fluidity suppositories masses at hypodispersion in it reacting and aids.

  3. Synergistic anticonvulsant effects of pregabalin and amlodipine on acute seizure model of epilepsy in mice.

    Science.gov (United States)

    Qureshi, Itefaq Hussain; Riaz, Azra; Khan, Rafeeq Alam; Siddiqui, Afaq Ahmed

    2017-08-01

    Status epilepticus is a life threatening neurological medical emergency. It may cause serious damage to the brain and even death in many cases if not treated properly. There is limited choice of drugs for the short term and long term management of status epilepticus and the dugs recommended for status epilepticus possess various side effects. The present study was designed to investigate synergistic anticonvulsant effects of pregabalin with amlodipine on acute seizure model of epilepsy in mice. Pentylenetetrazole was used to induce acute seizures which mimic status epilepticus. Pregabalin and amlodipine were used in combination to evaluate synergistic anti-seizure effects on acute seizure model of epilepsy in mice. Diazepam and valproate were used as reference dugs. The acute anti-convulsive activity of pregabalin with amlodipine was evaluated in vivo by the chemical induced seizures and their anti-seizure effects were compared with pentylenetetrazole, reference drugs and to their individual effects. The anti-seizure effects of tested drugs were recorded in seconds on seizure characteristics such as latency of onset of threshold seizures, rearing and fallings and Hind limbs tonic extensions. The seizure protection and mortality to the animals exhibited by the drugs were recorded in percentage. Combination regimen of pregabalin with amlodipine exhibited dose dependent significant synergistic anticonvulsant effects on acute seizures which were superior to their individual effects and equivalent to reference drugs.

  4. Clinical Utility of Amlodipine/Valsartan Fixed-Dose Combination in the Management of Hypertension in Chinese Patients

    Directory of Open Access Journals (Sweden)

    Wenbo He, MD

    2017-02-01

    Full Text Available Amlodipine/valsartan (Aml/Val single-pill combination (SPC therapy has been widely used and studied in clinical practice in recent years. This article reviews the Chinese and English literature on the clinical use of Aml/Val SPC therapy in Chinese hypertensive patients. According to five studies concerning the efficacy and safety of this treatment, Aml/Val SPC therapy was more efficacious than monotherapy with valsartan, amlodipine, or the nifedipine gastrointestinal therapeutic system. This treatment showed greater blood pressure-lowering effects, a higher blood pressure control rate, and a higher response rate. Aml/Val SPC treatment was well tolerated, with adverse event rates similar to those of monotherapy with valsartan or amlodipine and significantly rarer adverse events compared with the nifedipine gastrointestinal therapeutic system. Aml/Val SPC is a highly efficacious and well-tolerated antihypertensive treatment in Chinese hypertensive patients.

  5. [Blood pressure lowering efficacy of telmisartan and amlodipine taking on the morning or at bedtime: ABPM results].

    Science.gov (United States)

    Peng, Gui-cheng; Wang, Yi-fang; Xiao, Yong; Chen, Jian-fu; Yang, Yu; Ye, Yu-liang; Sai, Shuang-qiao; Huang, Jin-xiang

    2013-06-01

    To observe the blood lowering effect of telmisartan and amlodipine taking on the morning or at bedtime in hypertensive patients. A total of 108 individuals with hypertension (grade 2 or above) were randomized to receive telmisartan and amlodipine in one of the following four therapeutic schemes: Group A (26 cases): both medications taken on the morning; Group B (28 cases): both medication taken at bedtime; Group C (27 cases): telmisartan on the morning and amlodipine at bedtime; or Group D (27 cases): amlodipine on the morning and telmisartan at bedtime. ABPM was performed before and after 8 weeks treatment. BP was significantly reduced in 4 groups and the value of 24 hours SBP/DBP decline for each group after treatment was 29.94/16.32, 31.37/18.35, 29.49/17.30 and 25.80/15.51 mm Hg (1 mm Hg = 0.133 kPa) respectively (P 0.05). The night-time BP decline and the distributive difference of dipper, non-dipper, extreme dipper and reverse dipper pattern were similar among groups at both baseline and after various treatment regimens (all P > 0.05) . Morning blood pressure surge (MBPS) after treatment in group B declined more significantly than other groups (P < 0.05). Telmisartan/amlodipine administered either on the morning or at bedtime can effectively reduce blood pressure. The efficacy of BP lowering is independent of the drug taking time. There is a trend both in better BP lowering and less BP variability when two medications are administered at bedtime.

  6. Efficacy of an amlodipine/olmesartan treatment algorithm in patients with or without type 2 diabetes and hypertension (a secondary analysis of the BP-CRUSH study).

    Science.gov (United States)

    Nesbitt, S D; Shojaee, A; Maa, J-F; Weir, M R

    2013-07-01

    A prespecified subgroup analysis of an open-label, multicenter, single-arm, dose-titration study is presented. The efficacy and safety of 20-week treatment with an amlodipine (AML)/olmesartan medoxomil (OM)±hydrochlorothiazide (HCTZ) algorithm were assessed in patients with hypertension and type 2 diabetes mellitus (T2DM) who were uncontrolled by antihypertensive monotherapy. Eligible patients received AML/OM 5/20 mg for 4 weeks, followed by stepwise uptitration to AML/OM 5/40 mg, AML/OM 10/40 mg, AML/OM 10/40 mg+HCTZ 12.5 mg and AML/OM 10/40 mg+HCTZ 25 mg at 4-week intervals if blood pressure (BP) remained uncontrolled. The primary end point was the achievement of the seated cuff systolic BP (SeSBP) goal (hypertension and T2DM.

  7. 4-Aminopyridine (fampridine) effectively treats amlodipine poisoning: A case report

    NARCIS (Netherlands)

    Wilffert, B.; Boskma, R.J.; Van Der Voort, P.H.J.; Uges, D.R.A.; Van Roon, E.N.; Brouwers, J.R.B.J.

    2007-01-01

    A case of a serious poisoning with the calcium entry blocker amlodipine is described, which was treated effectively with 4-aminopyridine. Calcium is suggested as general treatment of poisoning with calcium entry blockers in many guidelines. The use of intravenous 4-aminopyridine is theoretically

  8. 4-Aminopyridine (fampridine) effectively treats amlodipine poisoning : a case report

    NARCIS (Netherlands)

    Wilffert, B.; Boskma, R. J.; van der Voort, P. H. J.; Uges, D. R. A.; van Roon, E. N.; Brouwers, J. R. B. J.

    2007-01-01

    A case of a serious poisoning with the calcium entry blocker amlodipine is described, which was treated effectively with 4-aminopyridine. Calcium is suggested as general treatment of poisoning with calcium entry blockers in many guidelines. The use of intravenous 4-aminopyridine is theoretically

  9. Comparison of effects of valsartan and amlodipine on cognitive functions and auditory p300 event-related potentials in elderly hypertensive patients.

    Science.gov (United States)

    Katada, Eiichi; Uematsu, Norihiko; Takuma, Yuko; Matsukawa, Noriyuki

    2014-01-01

    We compared the antihypertensive effect of valsartan (VAL) and amlodipine (AML) treatments in elderly hypertensive patients by examining the long-term changes in cognitive function and auditory P300 event-related potentials. We enrolled 20 outpatients, including 12 men and 8 women in the age group of 56 to 81 years who had mild to moderate essential hypertension. The subjects were randomly allocated to receive either 80 mg VAL once a day (10 patients) or 5 mg AML once a day (10 patients). Neuropsychological assessment and auditory P300 event-related potentials were obtained before initiation of VAL or AML treatment and after 6 months of the treatment with VAL or AML. Neuropsychological assessment was evaluated by conducting the Mini-Mental State Examination, the verbal fluency, word-list memory, word-list recall test, word-list recognition, and Trails B tests. Both the groups showed significantly reduced-blood pressure after 6 months of treatment, and the intergroup difference was not significant. The mean baseline Mini-Mental State Examination scores of the VAL and AML groups were not significantly different. Amlodipine treatment did not significantly affect any test score, but VAL treatment significantly increased the word-list memory and word-list recall test scores. Valsartan, and not AML, significantly reduced the mean P300 latency after 6 months. These results suggest that VAL exerts a positive effect on cognitive functions, independent of its antihypertensive effect.

  10. Effect of amlodipine, lisinopril and allopurinol on acetaminophen-induced hepatotoxicity in rats

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    Nesreen E.M. Mohammed

    2016-11-01

    Conclusion: Amlodipine, lisinopril or allopurinol can protect against acetaminophen-induced hepatotoxicity, showing mechanistic roles of calcium channels, angiotensin converting enzyme and xanthine oxidase enzyme in the pathogenesis of hepatotoxicity induced by acetaminophen.

  11. Simultaneous determination of telmisartan and amlodipine in dog plasma by LC-MS-MS.

    Science.gov (United States)

    Wang, Baolian; Sheng, Li; Li, Yan

    2015-01-01

    A simple, rapid and sensitive method was established for the simultaneous determination of telmisartan and amlodipine in dog plasma by a HPLC-MS-MS analysis. The plasma sample preparation was a simple deproteinization by the addition of three volumes of methanol/acetonitrile mixture followed by centrifugation. The analytes and internal standard diphenhydramine were separated on a Zorbax SB-C18 column with a mobile phase of acetonitrile : water (45 : 55, v/v) at a flow rate of 0.2 mL/min with an operating temperature of 25°C. Detection was carried out by electrospray ionization in positive-ion multiple reaction monitoring mode. The calibration plots in dog plasma were linear over the ranges of 0.5-2,000 ng/mL for telmisartan and 0.5-500 ng/mL for amlodipine. The lower limit of quantification was 0.5 ng/mL for two analytes. The intra- and interday precisions (RSD%) were within 9.0%. The average recoveries of analytes were >85.0%. The method was successfully applied to the pharmacokinetic study of the two compounds after oral administration of telmisartan-amlodipine combination preparation to dogs. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Efficacy and duration of benazepril plus amlodipine or hydrochlorothiazide on 24-hour ambulatory systolic blood pressure control.

    Science.gov (United States)

    Jamerson, Kenneth A; Devereux, Richard; Bakris, George L; Dahlöf, Björn; Pitt, Bertram; Velazquez, Eric J; Weir, Matthew; Kelly, Roxzana Y; Hua, Tsushung A; Hester, Allen; Weber, Michael A

    2011-02-01

    The combination of benazepril plus amlodipine was shown to be more effective than benazepril plus hydrochlorothiazide in reducing cardiovascular events in the Avoiding Cardiovascular Events through Combination Therapy in Patients Living with Systolic Hypertension (ACCOMPLISH) trial. There was a small difference in clinic systolic blood pressure between the treatment arms favoring benazepril plus amlodipine. Ambulatory blood pressure monitoring provides a more rigorous estimate of blood pressure effects. A subset of 573 subjects underwent ambulatory blood pressure monitoring during year 2. Readings were obtained every 20 minutes during a 24-hour period. Between-treatment differences (benazepril plus amlodipine versus benazepril plus hydrochlorothiazide) in mean values were analyzed using ANOVA. Treatment comparisons with respect to categorical variables were made using Pearson's χ². At year 2, the treatment groups did not differ significantly in 24-hour mean daytime or nighttime blood pressures (values of 123.9, 125.9, and 118.1 mm Hg for benazepril plus amlodipine group versus 122.3, 124.1, and 116.9 for the benazepril plus hydrochlorothiazide group), with mean between-group differences of 1.6, 1.8, and 1.2 mm Hg, respectively. Blood pressure control rates (24-hour mean systolic blood pressure <130 mm Hg on ambulatory blood pressure monitoring) were greater than 80% in both groups. Nighttime systolic blood pressure provided additional risk prediction after adjusting for the effects of drugs. The 24-hour blood pressure control was similar in both treatment arms, supporting the interpretation that the difference in cardiovascular outcomes favoring a renin angiotensin system blocker combined with amlodipine rather than hydrochlorothiazide shown in the ACCOMPLISH trial was not caused by differences in blood pressure, but instead intrinsic properties (metabolic or hemodynamic) of the combination therapies.

  13. Reduction of cerebral injury in stroke-prone spontaneously hypertensive rats by amlodipine

    NARCIS (Netherlands)

    Blezer, E.L.A.; Nicolaij, K.; Goldschmeding, R.C.; Koomans, H.A.; Joles, Jaap

    2002-01-01

    Dihydropyridine Ca2+ channel antagonists, initiated together with high salt intake, prevent the development of hypertension and subsequent cerebral damage in stroke-prone spontaneously hypertensive rats (SHRSP). We hypothesized that the dihydropyridine Ca2+ channel antagonist amlodipine

  14. Therapeutic drug monitoring of amlodipine and the Z-FHL/HHL ratio ...

    African Journals Online (AJOL)

    Globally, high blood pressure (BP) is the leading single risk factor for ... concentrations and clinical effect or toxicity and those with a narrow therapeutic ..... The pharmacokinetics of amlodipine in healthy volunteers after. 120 ... revealed by high-performance liquid chromatography-tandem mass spectrometry (HP LC-MS/MS).

  15. Role of triple fixed combination valsartan, amlodipine and hydrochlorothiazide in controlling blood pressure

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    Monica Doménech

    2010-04-01

    Full Text Available Monica Doménech, Antonio CocaHypertension Unit, Department of Internal Medicine, Institute of Internal Medicine and Dermatology, Hospital Clinic (IDIBAPS, University of Barcelona, SpainAbstract: Hypertension is one of the main risk factors for the development of cardiovascular diseases and the search for new therapeutic strategies aimed at optimizing its control remains an ongoing research and clinical challenge. In recent years, there has been a marked increase in the use of combinations of antihypertensive drugs with complementary mechanisms of action, with the aims of reducing blood pressure levels more rapidly and vigorously than strategies employing monotherapy and improving treatment compliance and adhesion. Therefore, as recommended by the 2009 reappraisal of the European Society of Hypertension/European Society of Cardiology Guidelines, the use of a triple combination that combines a calcium channel blocker, an angiotensin II receptor blocker and a thiazide diuretic seems a reasonable and efficacious combination for the management of hypertensive patients with moderate, high or very high risk. This article reviews the clinical trials carried out with the fixed combination of amlodipine/valsartan/hydrochlorothiazide at the doses recommended for each drug in monotherapy. The data show that this combination achieved greater reductions in mean sitting diastolic and systolic blood pressure than amlodipine, valsartan or hydrochlorothiazide in monotherapy, with favorable pharmacodynamic and pharmacokinetic profiles. The triple combination at high single doses should be used with caution in elderly patients and those with renal or liver failure. Although the tolerability and safety of the triple combination are good, the mostfrequently reported adverse effects were peripheral edema, headache and dizziness. Analytical alterations were consistent with the already-known biochemical effects of amlodipine, valsartan or hydrochlorothiazide in

  16. Effects of hypertension and ovariectomy on rat hepatocytes. Are amlodipine and lacidipine protective? (A stereological and histological study).

    Science.gov (United States)

    Dursun, Hakan; Albayrak, Fatih; Uyanik, Abdullah; Keleş, Nuri Osman; Beyzagül, Polat; Bayram, Ednan; Halici, Zekai; Altunkaynak, Zuhal Berrin; Süleyman, Halis; Okçu, Nihat; Ünal, Bünyamin

    2010-12-01

    Calcium channel blockers are increasingly used for the treatment of hypertension. Menopause and hypertension are both important risk factors for liver damage and several other circulatory abnormalities. The aim of this study was to determine the effects of amlodipine and lacidipine in an ovariectomy-induced postmenopausal period model and a deoxycorticosterone acetate-salt-induced hypertensive model in rats. In this study, animals were divided into six groups as follows: control (Group 1), hypertension (Group 2), ovariectomy (Group 3), ovariectomy and hypertension (Group 4), ovariectomy, hypertension and amlodipine-treated (Group 5), and ovariectomy, hypertension and lacidipine-treated (Group 6). At the end of the experiment, the livers were removed and tissue samples were histologically and stereologically examined. The numerical densities of the hepatocytes according to group were 0.000422, 0.00329, 0.000272, 0.00259, 0.00374 and 0.000346 μm3, respectively. Significant differences were found between values of all groups (phypertension in Groups 5 and 6. Our experimental results show that both hypertension and the postmenopausal period have negative effects on the number of hepatocytes and histological structure of the liver. Both amlodipine and lacidipine appear to ameliorate the hypertension and/or postmenopausal period-related decrease in hepatocyte number. We thus suggest that lacidipine and particularly amlodipine have important protective and recovering effects on the liver.

  17. Treatment with triple combination of atorvastatin, perindopril, and amlodipine in patients with stable coronary artery disease: A subgroup analysis from the PAPA-CAD study.

    Science.gov (United States)

    Dézsi, Csaba András

    2018-01-01

    Background In patients with stable coronary artery disease, aspirin, a statin, and an angiotensin-converting enzyme inhibitor are recommended as first-line agents for secondary prevention. Subgroup analyses of the previously published Hungarian Perindopril plus Amlodipine in PAtients with Coronary Artery Disease (PAPA-CAD) non-interventional trial demonstrated that the addition of the metabolically beneficial, fixed combination of perindopril + amlodipine to atorvastatin further improves the patient's lipid profile. Methods The PAPA-CAD study, a 6-month open-label, prospective, multicenter, observational/non-interventional survey evaluated data accumulated from patients with hypertensive patients with stable coronary artery disease. The herein-reported subgroup analysis was conducted using the findings from those 1130 patients, who were taking atorvastatin in addition to the fixed combination of perindopril + amlodipine at the time of all four study visits (i.e., at baseline and 1, 3, and 6 months later). Results In the subgroup of patients taking atorvastatin as an add-on agent, 82.5% reached the target blood pressure of 140/90 mmHg compared with 78.8% of those not taking a statin. The addition of atorvastatin to the fixed combination of perindopril + amlodipine resulted in further significant improvements of key metabolic parameters. Conclusion This subgroup analysis confirmed that favorable synergism exists among perindopril, amlodipine, and atorvastatin.

  18. EFFECTS OF AMLODIPIN AND METOPROLOL ON AUTONOMIC SYSTEM IN EMOTIONAL AND COLD TESTS IN HYPERTENSIVE PATIENTS WITH DIFFERENT PSYCHOLOGICAL PROFILE

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    M. P. Rubanova

    2006-01-01

    Full Text Available Aim. To asses effects of amlodipin and metoprolol on autonomic system in emotional and cold tests in hypertensive patients with different psychological profile (PP Material and methods. 61 patients with arterial hypertension of II grade were observed. Therapy with amlodipin or metoprolol was prescribed and allowed to reach target blood pressure (BP level in all the patients. Patients were divided into 2 groups: 1-st one – patients with normal PP, 2-nd group – patients with subclinical depression. Patients were examined before and 30 days after therapy. Examination included ambulatory BP monitoring, assessment of autonomic status by variational intervalometry and spectral analysis of heart rate variability (HRV in cold and emotional tests. Depression and anxiety levels were determined with Bek’s and HADS scales.  Results. Treatment with amlodipin  and metoprolol can result in improvement, worsening or unchanging of PP.  In hypertensive patients with subclinical depression improving their PP resulted in autonomic reaction change: sympathetic activity increases and reaction on stress becomes more adequate. If subclinical depression occurred in hypertensive patients because of amlodipin and metoprolol therapy, sympathetic system stress-reaction decreased and parasympathetic influence increased. Conclusion. The study results show necessity of psychometric examination of hypertensive patients in order to reveal subclinical depression and anxiety.  

  19. Evaluation of palatability of 10 commercial amlodipine orally disintegrating tablets by gustatory sensation testing, OD-mate as a new disintegration apparatus and the artificial taste sensor.

    Science.gov (United States)

    Uchida, Takahiro; Yoshida, Miyako; Hazekawa, Mai; Haraguchi, Tamami; Furuno, Hiroyuki; Teraoka, Makoto; Ikezaki, Hidekazu

    2013-09-01

    The purpose of this study was to evaluate and compare the palatability of 10 formulations (the original manufacturer's formulation and nine generics) of amlodipine orally disintegrating tablets (ODTs) by means of human gustatory sensation testing, disintegration/dissolution testing and the evaluation of bitterness intensity using a taste sensor. Initially, the palatability, dissolution and bitterness intensity of the ODTs were evaluated in gustatory sensation tests. Second, the disintegration times of the ODTs were measured using the OD-mate, a newly developed apparatus for measuring the disintegration of ODTs, and lastly, the bitterness intensities were evaluated using an artificial taste sensor. Using factor analysis, the factors most affecting the palatability of amlodipine ODTs were found to be disintegration and taste. There was high correlation between the disintegration times of the 10 amlodipine ODTs estimated in human gustatory testing and those found using the OD-mate. The bitterness intensities of amlodipine ODTs 10, 20 and 30 s after starting the conventional brief dissolution test and the values determined by the taste sensor were highly correlated with the bitterness intensities determined in gustatory sensation testing. The OD-mate and the taste sensor may be useful for predicting the disintegration and bitterness intensity of amlodipine ODTs in the mouth. © 2013 Royal Pharmaceutical Society.

  20. Disparate effects of eplerenone, amlodipine and telmisartan on podocyte injury in aldosterone-infused rats

    NARCIS (Netherlands)

    Liang, Wei; Chen, Cheng; Shi, Jing; Ren, Zhilong; Hu, Fengqi; van Goor, Harry; Singhal, Pravin C.; Ding, Guohua

    Background. Several studies in patients with primary aldosteronism (PA) have suggested that aldosterone (ALD) is directly contributing to albuminuria. However, there are limited data pertaining to the direct role of ALD in (EPL), telmisartan (TEL) and amlodipine (AML) on ALD-induced renal structural

  1. Validated HPTLC methods for determination of some selected antihypertensive mixtures in their combined dosage forms

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    Rasha A. Shaalan

    2014-12-01

    Full Text Available Simple and selective HPTLC methods were developed for the simultaneous determination of the antihypertensive drugs; carvedilol and hydrochlorothiazide in their binary mixture (Mixture I and amlodipine besylate, valsartan, and hydrochlorothiazide in their combined ternary formulation (Mixture II. Effective chromatographic separation was achieved on Fluka TLC plates 20 × 20 cm aluminum cards, 0.2 mm thickness through linear ascending development. For Mixture I, the mobile phase composed of chloroform–methanol in the ratio 8:2 v/v. Detection was performed at 254 nm for both carvedilol and hydrochlorothiazide. For Mixture II, the mobile phase was chloroform–methanol–ammonia in the volume ratio 8:2:0.1. Detection was performed at 254 nm for valsartan and hydrochlorothiazide, and at 365 nm for amlodipine. Quantification was based on spectrodensitometric analysis. Analytical performance of the proposed HPTLC procedures was statistically validated with respect to linearity, ranges, precision, accuracy, specificity, robustness, detection and quantification limits. The linearity ranges were 0.05–1.0 and 0.1–2.0 μg/spot for carvedilol and hydrochlorothiazide, respectively in Mixture I, 0.1–2.0, 0.1–2.0 and 0.2–4.0 μg/spot for amlodipine, hydrochlorothiazide and valsartan, respectively in Mixture II, with correlation coefficients >0.9992. The validated HPTLC methods were applied to the analysis of the cited antihypertensive drugs in their combined pharmaceutical tablets. The proposed methods confirmed peak identity and purity.

  2. ACHIEVEMENT OF TARGET BLOOD PRESSURE LEVEL IN HYPERTENSIVE PATIENTS WITH AMLODIDINE: ORIGINAL DRUG VERSUS GENERIC

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    S. Yu. Martsevich

    2009-01-01

    Full Text Available Aim. To evaluate antihypertensive effects of new generic amlodipine (Stamlo M in comparison with original amlodipine (Norvasc in monotherapy and in combination with angiotensin converting enzyme (ACE inhibitor and diuretic in patients with arterial hypertension (HT of 1-2 degree.Material and methods. 60 patients with HT of 1-2 degree were included in the open randomized parallel comparative study. Patients were split into 2 groups. Study duration was 10 weeks. Efficacy control, dose correction, addition of ACE inhibitor and diuretic was performed each 2 weeks.Results. The significant antihypertensive effect of monotherapy was observed in both groups already by the 2-4 weeks of therapy. Significant differences between amlodipines in influence on blood pressure (BP level and heart rate was not found. Monotherapy with generic amlodipine (10 mg OD provided target BP level more than in half of patients. Achievement of target BP levels was found in 89% and 96% of patients treated with generic and original amlodipine, respectively, when they were combined with lisinopril (10 mg OD and hydrochlorothiazide (12,5 mg OD.Conclusion. New generic amlodipine (Stamlo M is an effective and safe antihypertensive drug comparable with original amlodipine in clinical efficacy.

  3. Combinação de anlodipino e enalaprila em pacientes hipertensos com doença coronariana Combinación de amlodipino y enalapril en pacientes hipertensos con enfermedad coronaria Combination of amlodipine and enalapril in hypertensive patients with coronary disease

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    Marcos Rienzo

    2009-03-01

    Full Text Available FUNDAMENTO: Pacientes (pts com doença coronariana (DAC estável podem se beneficiar de menor pressão arterial (PA, conforme estudos recentes. OBJETIVO: Avaliar a eficácia e a tolerabilidade da combinação fixa anlodipino + enalaprila, comparada a anlodipino na normalização da PA diastólica (PAD ( 90 e 110 mmHg durante o wash-out de quatro semanas, em uso só de atenolol. Após wash-out randomizamos para combinação (A ou anlodipino (B e seguimos de quatro em quatro semanas até 98 dias. As doses (mg iniciais foram, respectivamente: A- 2,5/10 e B- 2,5, sendo incrementadas se PAD> 85mmHg, nas visitas. Estatística com χ2, Fischer e análise de variância, para pFUNDAMENTO: Pacientes (pts con enfermedad coronaria (EAC estable pueden beneficiarse con una menor presión arterial (PA, de acuerdo con estudios recientes. OBJETIVO: Evaluar la eficacia y la tolerancia de la combinación fija amlodipino + enalapril, comparada a el amlodipino en la normalización de la PA diastólica (PAD (90 y 110 mmHg durante el wash-out de cuatro semanas, en uso sólo de atenolol. Después del wash-out randomizamos para combinación (A o amlopidino (B y seguimos de cuatro en cuatro semanas hasta 98 días. Las dosis (mg iniciales fueron, respectivamente: A- 2,5/10 y B- 2,5, siendo incrementadas si PAD> 85mmHg, en las visitas. Estadística con χ2, Fischer y análisis de varianza, para pBACKGROUND: Patients (pts with stable coronary artery disease (CAD can benefit from a decrease in the blood pressure (BP, according to recent studies. OBJECTIVE: To evaluate the efficacy and tolerability of the fixed combination: amlodipine + enalapril, when compared to amlodipine in the normalization of the diastolic arterial pressure (DAP (90 and 110 mmHg during the four-week wash-out with atenolol treatment alone, were excluded. After the wash-out, pts were randomly distributed for the use of the combination (A or amlodipine (B and were followed every four weeks up to 98 days

  4. Sequential Spectrophotometric Method for the Simultaneous Determination of Amlodipine, Valsartan, and Hydrochlorothiazide in Coformulated Tablets

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    Hany W. Darwish

    2013-01-01

    Full Text Available A new, simple and specific spectrophotometric method was developed and validated in accordance with ICH guidelines for the simultaneous estimation of Amlodipine (AML, Valsartan (VAL, and Hydrochlorothiazide (HCT in their ternary mixture. In this method three techniques were used, namely, direct spectrophotometry, ratio subtraction, and isoabsorptive point. Amlodipine (AML was first determined by direct spectrophotometry and then ratio subtraction was applied to remove the AML spectrum from the mixture spectrum. Hydrochlorothiazide (HCT could then be determined directly without interference from Valsartan (VAL which could be determined using the isoabsorptive point theory. The calibration curve is linear over the concentration ranges of 4–32, 4–44 and 6–20 μg/mL for AML, VAL, and HCT, respectively. This method was tested by analyzing synthetic mixtures of the above drugs and was successfully applied to commercial pharmaceutical preparation of the drugs, where the standard deviation is <2 in the assay of raw materials and tablets. The method was validated according to the ICH guidelines and accuracy, precision, repeatability, and robustness were found to be within the acceptable limits.

  5. Preparation and preclinical evaluation of 68Ga-DOTA-amlodipine for L-type calcium channel imaging

    Science.gov (United States)

    Firuzyar, Tahereh; Jalilian, Amir Reza; Aboudzadeh, Mohammad Reza; Sadeghpour, Hossein; Shafiee-Ardestani, Mahdi; Khalaj, Ali

    2016-01-01

    Aim: In order to develop a possible tracer for L-type calcium channel imaging, we here report the development of a Ga-68 amlodipine derivative for possible PET imaging. Materials and Methods: Amlodipine DOTA conjugate was synthesized, characterized and went through calcium channel blockade, toxicity, apoptosis/necrosis tests. [68Ga] DOTA AMLO was prepared at optimized conditions followed by stability tests, partition coefficient determination and biodistribution studies using tissue counting and co incidence imaging up to 2 h. Results: [68Ga] DOTA AMLO was prepared at pH 4–5 in 7–10 min at 95°C in high radiochemical purity (>99%, radio thin layer chromatography; specific activity: 1.9–2.1 GBq/mmol) and was stable up to 4 h with a log P of −0.94. Calcium channel rich tissues including myocardium, and tissues with smooth muscle cells such as colon, intestine, and lungs demonstrated significant uptake. Co incidence images supported the biodistribution data up to 2 h. Conclusions: The complex can be a candidate for further positron emission tomography imaging for L type calcium channels. PMID:27833311

  6. Development and validation of different methods manipulating zero order and first order spectra for determination of the partially overlapped mixture benazepril and amlodipine: A comparative study

    Science.gov (United States)

    Hemdan, A.

    2016-07-01

    Three simple, selective, and accurate spectrophotometric methods have been developed and then validated for the analysis of Benazepril (BENZ) and Amlodipine (AML) in bulk powder and pharmaceutical dosage form. The first method is the absorption factor (AF) for zero order and amplitude factor (P-F) for first order spectrum, where both BENZ and AML can be measured from their resolved zero order spectra at 238 nm or from their first order spectra at 253 nm. The second method is the constant multiplication coupled with constant subtraction (CM-CS) for zero order and successive derivative subtraction-constant multiplication (SDS-CM) for first order spectrum, where both BENZ and AML can be measured from their resolved zero order spectra at 240 nm and 238 nm, respectively, or from their first order spectra at 214 nm and 253 nm for Benazepril and Amlodipine respectively. The third method is the novel constant multiplication coupled with derivative zero crossing (CM-DZC) which is a stability indicating assay method for determination of Benazepril and Amlodipine in presence of the main degradation product of Benazepril which is Benazeprilate (BENZT). The three methods were validated as per the ICH guidelines and the standard curves were found to be linear in the range of 5-60 μg/mL for Benazepril and 5-30 for Amlodipine, with well accepted mean correlation coefficient for each analyte. The intra-day and inter-day precision and accuracy results were well within the acceptable limits.

  7. Predictors of systolic BP benazepril plus amlodipine or hydrochlorothiazide) in the ACCOMPLISH Study.

    Science.gov (United States)

    Kjeldsen, Sverre E; Jamerson, Kenneth A; Bakris, George L; Pitt, Bertram; Dahlöf, Björn; Velazquez, Eric J; Hua, Tsushung A; Kelly, Roxzana Y; Zappe, Dion; Hester, Allen; Tuomilehto, Jaakko; Ostergren, Jan; Ibsen, Hans; Weber, Michael

    2012-04-01

    The ACCOMPLISH Trial investigated intensive antihypertensive combination treatment with benazepril + amlodipine (B+A) or benazepril + hydrochlorothiazide (B+H) on cardiovascular outcomes in patients with systolic hypertension. We analyzed the baseline predictors of achieving a systolic blood pressure (SBP) Nordic region) and Caucasian ethnicity in both randomization arms. A higher diastolic BP and the use of lipid lowering agents indicated favorable effects in the B+H arm only. The predictors of uncontrolled SBP were: (i) higher baseline SBP values, (ii) higher number of previous antihypertensive medications in both arms, (iii) the previous use of insulin in the B+A arm, and (iv) pre-trial calcium channel blocker (CCB) use in the B+H arm. Additionally, pre-trial use of thiazides and electrocardiogram (ECG)-left ventricular hypertrophy (LVH) at baseline predicted higher, and smoking lower absolute SBP in the B+A arm and the use of thiazides and proteinuria a higher SBP in the B+H arm. Irrespective of treatment, patients in the USA and Caucasians achieved better SBP control, whereas higher baseline SBP and more previous antihypertensive medications indicated less control. Concomitant use of lipid lowering treatment indicated a better SBP control in the benazepril + hydrochlorothiazide arm. Lastly, insulin use and ECG-LVH in the benazepril + amlodipine arm and proteinuria in the benazepril + hydrochlorothiazide arm indicated poor control.

  8. Cost Minimization Analysis of Antihypertensive Therapy with Captopril-Hydrochlorothiazide and Amlodipine-Hydrochlorothiazide in One of Hospitals in Bandung

    Directory of Open Access Journals (Sweden)

    Andini Faramitha

    2017-09-01

    Full Text Available The successful therapy of stage 2 hypertension can be supported by the administration of antihypertensive. Existence of various antihypertensive alternative, making pharmacoeconomics study is needed in order to have an effective and efficient therapy. Purpose of this study is to find the antihypertensive group therapy which is more efficient in cost (cost minimization which used in the treatment of stage 2 hypertension in patients at one hospital in Bandung from 2011 until 2013. This study is an observational reserach with retrospective data collection. Data retrieval is done by taking the medical records of hospitalized patients who received therapy of stage 2 hypertension antihypertensive, captopril-hydrochlorothiazide or amlodipin-hydrochlorothiazide. Components that are collected include the cost of antihypertensive, supportive therapy costs, the cost of action, administrative expenses and cost of hospitalization. The result of the study cost minimization analysis showed that the total cost of treatment with the antihypertensive captopril-hydrochlorothiazide is lower compared to amlodipin- hydrochlorothiazide, with the difference amounting to Rp126,798.

  9. A randomized, controlled study evaluating effects of amlodipine addition to chelators to reduce iron loading in patients with thalassemia major.

    Science.gov (United States)

    Eghbali, Aziz; Kazemi, Hamideh; Taherahmadi, Hassan; Ghandi, Yazdan; Rafiei, Mohammad; Bagheri, Bahador

    2017-12-01

    Cardiomyopathy due to iron overload can be fatal in patients with thalassemia major. Calcium channel blockers seem to be effective to reduce iron loading. Our goal was to study effects of amlodipine addition to chelators on iron loading in patients with thalassemia major. This randomized, controlled, and single-center trial was performed on 56 patients with thalassemia major. Patients were randomized 1:1 to combined group (iron chelator plus amlodipine) or control group (iron chelator) for 1 year. Iron content was measured by magnetic resonance imaging; heart T2*, and liver T2*. Serum ferritin was also measured. After 12 months of treatment, myocardial T2* values had significant improvement in combined group (21.9 ± 8.0 ms to 24.5 ± 7.6 ms; P < .05); Difference between two groups was significant (P = .02). Combined treatment had no effect on hepatic T2* value (9.6 ± 2.8 ms to 9.5 ± 3.6 ms); difference between two groups was not significant (P = .2). In addition, a significant reduction was seen in serum ferritin levels in two groups. Mild gastrointestinal upset was the most common untoward effect. Addition of amlodipine to iron chelators has beneficial effects for reduction of iron loading in patients with thalassemia major. This combination therapy seems safe. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. Powerful vascular protection by combining cilnidipine with valsartan in stroke-prone, spontaneously hypertensive rats

    OpenAIRE

    Takai, Shinji; Jin, Denan; Aritomi, Shizuka; Niinuma, Kazumi; Miyazaki, Mizuo

    2012-01-01

    Cilnidipine is an L- and N-type calcium channel blocker (CCB), and amlodipine is an L-type CCB. Valsartan (10?mg?kg?1), valsartan (10?mg?kg?1) and amlodipine (1?mg kg?1), and valsartan (10?mg?kg?1) and cilnidipine (1?mg?kg?1) were administered once daily for 2 weeks to stroke-prone, spontaneously hypertensive rats (SHR-SPs). Blood pressure was significantly reduced by valsartan, and it was further reduced by the combination therapies. Vascular endothelial dysfunction was significantly attenua...

  11. Combination With Low-dose Dextromethorphan Improves the Effect of Amlodipine Monotherapy in Clinical Hypertension

    Science.gov (United States)

    Yin, Wei-Hsian; Chen, Pei; Yeh, Hung-I; Wang, Kuo-Yang; Hung, Yi-Jen; Tseng, Wei-Kung; Wen, Ming-Shien; Wu, Tao-Cheng; Wu, Chau-Chung; Cheng, Shu-Meng; Chen, Jaw-Wen

    2016-01-01

    Abstract The combination of low rather than high dose of dextromethorphan (DXM) with amlodipine (AM) could improve blood pressure (BP) reduction in hypertensive animals. The study aimed to evaluate the feasibility of different doses of DXM combined with standard AM treatment in clinical hypertension. This was a prospective, 14-week, dose-escalation, multicenter study. After 2-week run-in period with AM 5 mg/day, hypertensive patients who got the BP goal of 140/90 mmHg kept receiving AM monotherapy for another 12 weeks. The nonresponders, while kept on AM 5 mg/day, received additional DXM treatment for 3 sequential dose-titrated periods with initially 2.5 mg/day, followed by 7.5 mg/day, and finally 30 mg/day. Each period was for 4 weeks. The patients at BP goal after each treatment period were defined as the responders and kept on the same combination till the end of the study. The responder rate of each treatment period was recorded. The changes of BP and serum antioxidant/endothelial markers between week 14 and week 2 were evaluated. Of the 103 patients initially enrolled, 89 entered the treatment period. In the 78 patients completing the study, 31 (40%) at BP goal after 2-week AM run-in kept on AM monotherapy (DXM0). The addition of 2.5 (DXM2.5) and 7.5 mg/day (DXM7.5) of DXM enabled BP goal achievement in 22 (47%) nonresponders to AM monotherapy including 16 (29%) with DXM2.5 and 6 (18%) with DXM7.5. Only 4 patients (16%) reached BP goal with the combination of DXM 30 mg/day (DXM30). Overall, 73% of the 78 patients reached BP goal at the end of the 14-week study. Mean systolic BP was reduced by 7.9% ± 7.0% with DXM2.5 (P < 0.001) and by 5.4% ± 2.4% with DXM7.5 (P = 0.003) respectively at week 14 from that at week 2, which was unchanged in either DXM0 or DXM30 group. Besides, the effects of combination treatment were particularly significant in the patients with impaired endothelial function suggested by reduced serum NOx level

  12. Preparation and preliminary biological evaluation of radiogallium-labeled DTPA-amlodipine complex for possible L-type calcium channel imaging

    Energy Technology Data Exchange (ETDEWEB)

    Firuzyar, Tahereh; Shafiee-Ardestani, Mehdi; Khalaj, Ali [Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of). Faculty of Pharmacy; Jalilian, Amir R.; Fazaeli, Yousef; Aboudzadeh, Mohammad Reza [Nuclear Science and Technology Research Institute (NSTRI), Tehran (Iran, Islamic Republic of). Radiopharmacy Research Group

    2014-07-01

    A DTPA-conjugated amlodipine analog (DTPA-AMLO) 3, was prepared for possible voltage gated calcium channel imaging after radiolabeling with Ga-67. [{sup 67}Ga]-DTPA-AMLO complex was prepared starting [{sup 67}Ga]gallium chloride and DTPA-AMLO in 60-90 min at 50-60 C in phosphate buffer. The partition co-efficient and stability of the tracer was determined in final solution (25 C) and presence of human serum (37 C) up to 24 h. The biodistribution of the labeled compound in wild-type rats were determined up to 72 h using organ counting and SPECT. The radiolabled complex was prepared in high radiochemical purity (>96%, RTLC and >98% HPLC) and significant specific activity (7-10 GBq/mmol). The log P for the complex was calculated as -0.594, consistent with a water soluble complex. The tracer is mostly washed out through kidneys which were in full compliance with the amlodipine metabolism and imaging studies demonstrated the same behavior. The tracer uptake in organs with smooth muscles was observed in stomach, colon as well as intestine.

  13. Investigation of the Relationship of Some Antihypertensive Drugs with Oxidant/Antioxidant Parameters and DNA Damage on Rat Uterus Tissue

    OpenAIRE

    Mustafa Talip Sener; Hamit Hakan Alp; Beyzagul Polat; Bunyamin Borekci; Yakup Kumtepe; Nesrin Gursan; Serkan Kumbasar; Suleyman Salman; Halis Suleyman

    2011-01-01

    Background In this study, we investigated the effects of treatment with chronic antihypertensive drugs (clonidine, methyldopa, amlodipine, ramipril and rilmenidine) on oxidant-antioxidant parameters and toxic effects on DNA in rat uterus tissue. In addition, uterus tissues were examined histopathologically. Materials and Methods A total of 36 albino Wistar rats were divided into the following six groups: 0.075 mg/kg clonidine group; 100 mg/kg methyldopa group; 2 mg/kg amlodipine group; 2.5 mg...

  14. Differential effects of amlodipine and atorvastatin treatment and their combination on atherosclerosis in ApoE*3-Leiden transgenic mice

    NARCIS (Netherlands)

    Delsing, D.J.; Jukema, J.W.; van de Wiel, M.A.; Emeis, J.; van der Laarse, A.; Havekes, L.M.; Princen, H.M.G.

    2003-01-01

    This study was designed to investigate the potential antiatherosclerotic effects of the calcium antagonist amlodipine as compared with the HMG-CoA reductase inhibitor atorvastatin and the combination of both in ApoE*3-Leiden transgenic mice. Four groups of 15 ApoE*3-Leiden mice were put on a

  15. Design and monitoring of photostability systems for amlodipine dosage forms.

    Science.gov (United States)

    Ragno, G; Cione, E; Garofalo, A; Genchi, G; Ioele, G; Risoli, A; Spagnoletta, A

    2003-10-20

    Photostability of amlodipine (AML) has been monitored in several pharmaceutical inclusion systems characterized by plurimolecular aggregation of the drug and excipients with high molecular weight. Several formulations including cyclodextrins, liposomes and microspheres have been prepared and characterized. The photodegradation process has been monitored according to the conditions suggested by the ICH Guideline for photostability testing, by using a light cabinet equipped with a Xenon lamp and monitored by spectrophotometry. The formulations herein tested have been found to be able to considerably increase drug stability, when compared with usual pharmaceutical forms. The residual concentration detected in the inclusion complexes with cyclodextrins and liposomes was 90 and 77%, respectively, while a very good value of 97% was found for microspheres, after a radiant exposure of 11,340 kJm(-2).

  16. Comparison of the efficacy and safety profiles of two fixed-dose combinations of antihypertensive agents, amlodipine/benazepril versus valsartan/hydrochlorothiazide, in patients with type 2 diabetes mellitus and hypertension: a 16-week, multicenter, randomized, double-blind, noninferiority study.

    Science.gov (United States)

    Lee, I-Te; Hung, Yi-Jen; Chen, Jung-Fu; Wang, Chih-Yuan; Lee, Wen-Jane; Sheu, Wayne Huey-Herng

    2012-08-01

    Hypertension is a prevalent condition that is closely associated with chronic complications in patients with diabetes. Fixed-dose combination therapy is currently recommended for the treatment of hypertension due to the advantage of reducing the pill burden. However, the effects of combination therapy may be diverse because of the different components. We examined blood pressure reduction and metabolic alterations after amlodipine/benazepril and valsartan/hydrochlorothiazide treatment in patients with type 2 diabetes mellitus and hypertension and microalbuminuria. This randomized, double-blind, parallel comparison, noninferiority clinical trial included patients with type 2 diabetes mellitus and hypertension and microalbuminuria detected within the past year. After a 2-week, placebo run-in period, patients were assigned to treatment with amlodipine/benazepril or valsartan/hydrochlorothiazide for 16 weeks. The primary end point was mean change in diastolic blood pressure. The prespecified boundary for noninferiority was 3.5 mm Hg of the mean change in diastolic blood pressure between treatments (amlodipine/benazepril minus valsartan/hydrochlorothiazide). If the upper limit of the 95% CI fell within 3.5 mm Hg, amlodipine/benazepril would be considered noninferior to valsartan/hydrochlorothiazide. Of the 226 patients assessed for eligibility, 169 satisfied the inclusion/exclusion criteria and were assigned to a treatment group; 83 patients (54.2% male, mean age of 60.5 [10.0] years) in the amlodipine/benazepril group and 84 patients (64.3% male, mean age of 59.0 [10.6] years) in the valsartan/hydrochlorothiazide group received at least 1 dose of study medication and were included in the intention-to-treat population. In the per-protocol population, amlodipine/benazepril (n = 74) was noninferior to valsartan/hydrochlorothiazide (n = 78) with regard to the mean change in diastolic blood pressure (difference, -0.9 mm Hg; 95% CI, -3.5 to 1.6). The mean change in systolic

  17. Comparison of valsartan and amlodipine on ambulatory blood pressure variability in hypertensive patients.

    Science.gov (United States)

    Eguchi, Kazuo; Imaizumi, Yuki; Kaihara, Toshiki; Hoshide, Satoshi; Kario, Kazuomi

    We tested the hypothesis that calcium channel blockers (CCBs: amlodipine group, n = 38)) are superior to angiotensin receptor blockers (ARBs: valsartan group, n = 38) against ambulatory blood pressure variability (BPV) in untreated Japanese hypertensive patients. Both drugs significantly reduced ambulatory systolic and diastolic BP values. With regard to BPV, standard deviation (SD) in SBP did not change with the administration of either drug, but the ARB significantly increased SD in awake DBP (12 ± 4-14 ± 4 mmHg). The ARB also significantly increased the coefficients of variation (CVs)in awake and 24-h SBP/DBP (all P valsartan, especially in reducing maximum BP levels.

  18. A qualitative study of amlodipine and its related compounds by electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Gibbons, John; Pugh, Jonathan; Dimopoulos-Italiano, Gina; Pike, Richard

    2006-01-01

    A comprehensive structural analysis of amlodipine and certain related compounds was performed by electrospray ionization tandem mass spectrometry. Triple quadrupole and quadrupole time-of-flight instruments were used to provide collision-induced dissociation and accurate mass measurement for selected product and second-generation product ions. A unique ion rearrangement was observed, which was found to be characteristic of certain dihydropyridines. This study provides a fundamental understanding of the fragmentation of these compounds. The structural elucidation of an unknown impurity is presented as an example. Copyright (c) 2006 John Wiley & Sons, Ltd.

  19. DYNAMICS OF STRUCTURAL AND FUNCTIONAL STATUS OF MYOCARDIUM DUE TO COMBINATION THERAPY WITH AMLODIPINE AND BISOPROLOL IN PATIENTS WITH ARTERIAL HYPERTENSION

    Directory of Open Access Journals (Sweden)

    I. L. Zapesochnaya

    2015-09-01

    Full Text Available Aim. To evaluate the effect of 6-month therapy with combination of amlodipine and bisoprolol on the structural and functional status of the myocardium in hypertensive patients who work in the Far North.Material and methods. 140 hypertensive patients who live in the Khanty-Mansiysk Autonomous District - Yugra were divided into two groups depending on arrangement of working time. The first group included 72 patients who work only day shift; the second group – 68 patients who work alternate (day/night shifts. Combination therapy with amlodipine and bisoprolol assigned to all patients. Echocardiography was performed at baseline, after 12 weeks, and after 6 months of therapy.Results. The target blood pressure (BP level in group 1 was achieved in 92.9%. A share of patients with normal left ventricular (LV geometry increased from 37.5 to 44.8%; a share of patients with concentric and eccentric LV hypertrophy (LVH decreased from 30.6 to 23.9% and 19.4 to 19.2%, respectively. Target BP level in group 2 was achieved in 87.9%. A share of patients with normal LV geometry increased from 23.5 to 33.3%; while share of patients with concentric and eccentric LVH decreased from 45.6 to 38.1% and from 19.1 to 17.4%, respectively. A positive correlation between LV myocardial index and average daily systolic and diastolic BP was found.Conclusion. Revealed changes in BP and in LV structure and function due to treatment with amlodipine and bisoprolol can be considered as cardioprotective effect of this combination in hypertensive patients who work in the Far North. This effect was more pronounced in hypertensive patients working alternate (day/night shifts.

  20. DYNAMICS OF STRUCTURAL AND FUNCTIONAL STATUS OF MYOCARDIUM DUE TO COMBINATION THERAPY WITH AMLODIPINE AND BISOPROLOL IN PATIENTS WITH ARTERIAL HYPERTENSION

    Directory of Open Access Journals (Sweden)

    I. L. Zapesochnaya

    2014-01-01

    Full Text Available Aim. To evaluate the effect of 6-month therapy with combination of amlodipine and bisoprolol on the structural and functional status of the myocardium in hypertensive patients who work in the Far North.Material and methods. 140 hypertensive patients who live in the Khanty-Mansiysk Autonomous District - Yugra were divided into two groups depending on arrangement of working time. The first group included 72 patients who work only day shift; the second group – 68 patients who work alternate (day/night shifts. Combination therapy with amlodipine and bisoprolol assigned to all patients. Echocardiography was performed at baseline, after 12 weeks, and after 6 months of therapy.Results. The target blood pressure (BP level in group 1 was achieved in 92.9%. A share of patients with normal left ventricular (LV geometry increased from 37.5 to 44.8%; a share of patients with concentric and eccentric LV hypertrophy (LVH decreased from 30.6 to 23.9% and 19.4 to 19.2%, respectively. Target BP level in group 2 was achieved in 87.9%. A share of patients with normal LV geometry increased from 23.5 to 33.3%; while share of patients with concentric and eccentric LVH decreased from 45.6 to 38.1% and from 19.1 to 17.4%, respectively. A positive correlation between LV myocardial index and average daily systolic and diastolic BP was found.Conclusion. Revealed changes in BP and in LV structure and function due to treatment with amlodipine and bisoprolol can be considered as cardioprotective effect of this combination in hypertensive patients who work in the Far North. This effect was more pronounced in hypertensive patients working alternate (day/night shifts.

  1. Role of valsartan, amlodipine and hydrochlorothiazide fixed combination in blood pressure control: an update

    Directory of Open Access Journals (Sweden)

    Maurizio Destro

    2010-04-01

    Full Text Available Maurizio Destro1, Francesca Cagnoni1, Antonio D’Ospina1, Alessandra Rossi Ricci1, Elena Demichele1, Emmanouil Peros1, Augusto Zaninelli2, Paola Preti31Internal Medicine, Ospedale Unificato Broni-Stradella, Stradella (PV, Italy; 2General Medicine, School of Medicine, University of Florence, Florence, Italy; 3Internal Medicine, University of Pavia, Pavia, ItalyAbstract: The treatment of moderate or severe hypertension in most cases requires the contemporaneous use of multiple antihypertensive agents. The most available two-drug combinations have an agent that addresses renin secretion and another one that is statistically more effective in renin-independent hypertension. The practice of combining agents that counteract different mechanisms is the most likely explanation for the fact that most available two-drug combinations have an agent that addresses renin secretion (beta-blocker, angiotensin converting enzyme inhibitor, angiotensin II receptor blocker or direct renin inhibitor and another one that is more effective in renin-independent hypertension (diuretic, dihydropyridine or non-dihydropyridine calcium channel blocker. Based on these considerations, addition of hydrochlorothiazide to the combination of an antagonist of the renin-angiotensin system with a calcium channel blocker would constitute a logical approach. Inclusion of a diuretic in the triple combination is based on the evidence that these agents are effective and cheap, enhance the effect of other antihypertensive agents, and add a specific effect to individuals with salt-sensitivity of blood pressure. The benefit of triple combination therapy with amlodipine, valsartan and hydrochlorothiazide over its dual component therapies has been demonstrated, and the use of a single pill will simplify therapy resulting in better blood pressure control.Keywords: valsartan, amlodipine, hydrochlorothiazide, HCTZ, blood pressure, hypertension

  2. Long-term efficacy of a combination of amlodipine and olmesartan medoxomil ± hydrochlorothiazide in patients with hypertension stratified by age, race and diabetes status: a substudy of the COACH trial.

    Science.gov (United States)

    Oparil, S; Chrysant, S G; Melino, M; Lee, J; Karki, S; Heyrman, R

    2010-12-01

    A prespecified subgroup analysis of a 44-week open-label extension study is presented. The efficacy and safety of the combination of amlodipine (AML) + olmesartan medoxomil (OM), with and without the addition of hydrochlorothiazide (HCTZ), were investigated in patients aged ≥65 and <65 years, Blacks and non-Blacks and patients with and without type 2 diabetes. After an 8-week double-blind, placebo-controlled portion of the study, patients initiated therapy on AML 5 + OM 40 mg per day, were uptitrated stepwise to AML 10 + OM 40 mg per day, with the addition of HCTZ 12.5 mg, and 25 mg if blood pressure (BP) goal was not achieved (<140/90 or <130/80 mm Hg for patients with diabetes). Endpoints included the change from baseline in mean seated systolic BP, mean seated diastolic BP and achievement of BP goal. BP decreased from baseline for all treatments in each prespecified subgroup. By the end of the study, BP goal was achieved in 61.0% of patients aged ≥65 years, 68.1% of patients aged <65 years, 63.3% of Blacks, 67.8% of non-Blacks, 26.9% of patients with diabetes and 72.9% of patients without diabetes. The combination of AML + OM ± HCTZ was efficacious, safe and well tolerated by these subgroups.

  3. Adherence to Treatment, Safety, Tolerance, and Effectiveness of Perindopril/Amlodipine Fixed-Dose Combination in Greek Patients with Hypertension and Stable Coronary Artery Disease: A Pan-Hellenic Prospective Observational Study of Daily Clinical Practice.

    Science.gov (United States)

    Liakos, Charalampos I; Papadopoulos, Dimitrios P; Kotsis, Vasilios T

    2017-10-01

    Initiation of antihypertensive therapy with a two-drug fixed-dose combination (FDC) in a single tablet may be recommended in patients at high risk of cardiovascular events to improve adherence and effectiveness. Preferred combinations include an angiotensin-converting enzyme inhibitor with a dihydropyridine calcium antagonist. This study assessed adherence to and the safety, tolerance, and effectiveness of the perindopril/amlodipine FDC in Greek patients with hypertension and stable coronary artery disease (CAD) over a 4-month period. A total of 1907 patients with hypertension and CAD (59.1% males) who had recently (≤2 weeks) commenced treatment with the perindopril/amlodipine FDC (5/5, 5/10, 10/5, or 10/10 mg) were studied at baseline and at 1 and 4 months. Adherence to treatment was assessed with the Morisky Medication-taking Adherence Scale (MMAS). Seven patients (0.4%) did not attend the scheduled visits. In total, 1607 (84.6%) patients received a constant treatment dose throughout the study. High adherence (MMAS score = 0) was reported by 1592 (83.6%), 1628 (85.7%), and 1477 (77.7%) patients at the second and the third visit and at both visits, respectively. Adverse reactions were reported by only 13 (0.7%) patients, were all minor, and did not result in treatment discontinuation. Office blood pressure (BP) was significantly decreased at the third visit (130.8 ± 8.4/78.2 ± 6.4 mmHg) compared with baseline (156.5 ± 15.0/89.9 ± 9.6 mmHg; p < 0.001), regardless of previous antihypertensive treatment. Patients with grade 1, 2, and 3 hypertension at baseline showed a reduction in BP of 19.3/9.4, 31.5/13.5, and 47.8/22.2 mmHg, respectively (p < 0.001). Uncontrolled hypertension (≥140/90 mmHg) was notably reduced from 90.3% at baseline to 18.5% at the third visit. The perindopril/amlodipine FDC is characterized by high adherence and effectiveness, regardless of previous treatment. Degree of BP reduction was related to baseline BP levels

  4. Ambulatory blood pressure monitoring after 1 year on valsartan or amlodipine-based treatment: a VALUE substudy

    DEFF Research Database (Denmark)

    Pedersen, Ole Lederballe; Mancia, Giuseppe; Pickering, Thomas

    2007-01-01

    OBJECTIVE: The ambulatory blood pressure (ABP) monitoring substudy of the Valsartan Antihypertensive Long-term Use Evaluation (VALUE) trial was carried out in a subset of patients from USA, Italy and Denmark. ABP was measured after 1 year in the trial, with the aim of evaluating comparability...... of ABP levels on valsartan (VAL) and amlodipine (AML)-based regimens. METHODS: ABP was measured every 20 min during a 25-h period after morning administration of medicine; 659 patients were available for intention-to-treat analysis. RESULTS: Office blood pressure (BP) differences were smaller than...

  5. Investigation of the Relationship of Some Antihypertensive Drugs with Oxidant/Antioxidant Parameters and DNA Damage on Rat Uterus Tissue

    Directory of Open Access Journals (Sweden)

    Mustafa Talip Sener

    2011-01-01

    Full Text Available Background: In this study, we investigated the effects of treatment with chronic antihypertensivedrugs (clonidine, methyldopa, amlodipine, ramipril and rilmenidine on oxidant-antioxidantparameters and toxic effects on DNA in rat uterus tissue. In addition, uterus tissues were examinedhistopathologically.Materials and Methods: A total of 36 albino Wistar rats were divided into the following six groups:0.075 mg/kg clonidine group; 100 mg/kg methyldopa group; 2 mg/kg amlodipine group; 2.5 mg/kgramipril group; 0.5 mg/kg rilmenidine group; and the healthy group. Rats underwent chronic drugadministration for 30 days and at the end, biochemical and histopathological examinations wereperformed. All data were subjected to one-way ANOVA test.Results: We divided these drugs into the following three groups according to their effects on ratuteri: (I mild negative effects (clonidine, (II moderate negative effects (rilmenidine, methyldopaand (III drugs which had severe negative effects (amlodipine, ramipril.Conclusion: These data may help with selection of antihypertensive drugs, in order to determinewhich drugs have the lowest toxicity in pregnant and non-pregnant (pre-pregnancy women.

  6. Comparison of benazepril plus amlodipine or hydrochlorothiazide in high-risk patients with hypertension and coronary artery disease.

    Science.gov (United States)

    Bakris, George; Briasoulis, Alexandros; Dahlof, Bjorn; Jamerson, Kenneth; Weber, Michael A; Kelly, Roxzana Y; Hester, Allen; Hua, Tsushung; Zappe, Dion; Pitt, Bertram

    2013-07-15

    Combination therapy with benazepril 40 mg and amlodipine 10 mg (B+A) has been shown to be more effective than benazepril 40 mg and hydrochlorothiazide (HCTZ) 25 mg (B+H) in reducing cardiovascular (CV) events in high-risk patients with stage 2 hypertension with similar blood pressure reductions. In the present post hoc analysis, we evaluated whether B+A is more effective than B+H for reducing CV events in patients with known coronary artery disease (CAD) at baseline in a subgroup analysis of the Avoiding Cardiovascular events through COMbination therapy in Patients LIving with Systolic Hypertension (ACCOMPLISH) study. The main trial randomized 11,506 patients. Of those, 5,744 received B+A and 5,762 received B+H. Of the 11,506 patients, 5,314 (46%) were classified as having CAD at baseline. The mean patient follow-up period was 35.7 months for the B+A group and 35.6 months for the B+H group. The primary end point was the interval to the first event of composite CV morbidity and mortality. At baseline, significant differences were present between the 5,314 with CAD and the 6,192 without CAD. The patients with CAD had a lower systolic blood pressure and heart rate, a lower incidence of diabetes, and greater incidence of dyslipidemia. However, no baseline differences were found between the randomized B+A and B+H groups. In the patients with CAD, an 18% reduction occurred in the hazard ratio for CV events (primary end point) with B+A versus B+H (p = 0.0016). In a prespecified secondary analysis of the composite end point, including only CV death, myocardial infarction, and stroke, the hazard ratio in the patients with CAD was reduced by 25% (p = 0.0033) in the B+A group compared with the B+H group. B+A was more effective than B+H at comparable blood pressure reductions for reducing CV events in patients, regardless of the presence of CAD. In conclusion, our findings suggest that the combination of B+A should be preferentially used for older patients with high

  7. Assessment of Glomerular Filtration Rate Based on Alterations of Serum Brain-Derived Neurotrophic Factor in Type 2 Diabetic Subjects Treated with Amlodipine/Benazepril or Valsartan/Hydrochlorothiazide

    Directory of Open Access Journals (Sweden)

    I-Te Lee

    2015-01-01

    Full Text Available Background. Brain-derived neurotrophic factor (BDNF is associated with sympathetic activation. However, the effects of BDNF on diabetic nephropathy are unknown. The aim of this study was to assess the estimated glomerular filtration rates (eGFRs and changes in serum BDNF levels in type 2 diabetic subjects treated with antihypertensive medications. Methods. In this randomized, double-blind clinical trial, type 2 diabetic subjects with hypertension were assigned to either the benazepril/amlodipine or valsartan/hydrochlorothiazide treatment groups for a 16-week period. The post hoc analyses were based on increased or decreased serum BDNF levels. Results. Of the 153 enrolled subjects, the changes in eGFR were significantly and inversely correlated with those in BDNF in the 76 subjects treated with valsartan/hydrochlorothiazide (r=-0.264, P=0.021 but not in the 77 subjects treated with benazepril/amlodipine (r=-0.025, P=0.862. The 45 subjects with increased BDNF following valsartan/hydrochlorothiazide treatment exhibited a significantly reduced eGFR (-8.8±14.9 mL/min/1.73 m2; P<0.001. Multivariate regression analysis revealed that increased serum BDNF represents an independent factor for reduced eGFR (95% confidence interval between −0.887 and −0.076, P=0.020. Conclusions. Increased serum BDNF is associated with reduced eGFR in type 2 diabetic subjects treated with valsartan/hydrochlorothiazide but not with amlodipine/benazepril.

  8. Efficacy and safety of a therapeutic interchange from high-dose calcium channel blockers to a fixed-dose combination of amlodipine/benazepril in patients with moderate-to-severe hypertension.

    Science.gov (United States)

    Hilleman, D E; Reyes, A P; Wurdeman, R L; Faulkner, M

    2001-08-01

    Recent hypertension trials have demonstrated the importance of achieving goal blood pressures to reduce the risk of target organ damage. In patients with moderate to severe hypertension, the use of high-dose monotherapy and/or combinations of drugs are necessary to achieve these goals. Fixed-dose combination products may be useful in these patients by reducing the number of daily doses required to control blood pressure. The objective of the present study was to evaluate the efficacy and safety of a therapeutic interchange between high-dose calcium channel blocker therapy and a fixed-dose combination of amlodipine/ benazepril (Lotrel; Novartis Pharmaceuticals, USA) in patients with moderate to severe hypertension. A total of 75 patients were switched from amlodipine (n = 25), felodipine (n = 25), and nifedipine-GITS (n = 25) to amlodipine/benazepril. Twenty-eight of the 75 patients (37%) were taking either a beta-blocker or a diuretic in addition to the high-dose calcium channel blocker prior to the switch. Blood pressure control, side effects and the cost of the therapeutic interchange were evaluated in the year following the therapeutic interchange. Sixty-six of the 75 (88%) patients were successfully switched with maintenance of blood pressure control and without the development of new dose-limiting side effects. Reasons for treatment failure after the therapeutic interchange included loss of blood pressure control in five patients and the development of new dose-limiting side effects in four patients. These side effects included cough in three patients and rash in one patient. After accounting for differences in drug acquisition cost and costs related to the switch (clinic and emergency room and laboratory tests), a cost savings of $16030 for all 75 patients was realised in the first year. The per patient-per year cost savings was $214. Our data indicate that a therapeutic interchange from selected high-dose calcium channel blockers to a fixed-dose combination

  9. Simultaneous determination of amlodipine, valsartan and hydrochlorothiazide by LC–ESI-MS/MS and its application to pharmacokinetics in rats

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    Shankar Ganesh Gadepalli

    2014-12-01

    Full Text Available Polypill is a fixed-dose combination that contains three or more active ingredients used as a single daily pill to achieve a large effect in preventing cardiovascular disease with minimal adverse effects. A novel and accurate liquid chromatography tandem mass spectrometry method using electrospray ionization mode has been developed and validated for the simultaneous determination of amlodipine (AMD, valsartan (VAL using losartan (LOS as an internal standard (IS, and hydrochlorothiazide (HCT using furosemide (FSD as an IS. The separation was carried on Aquasil C18 (50 mm×2.1 mm, 5 µm reversed phase column using acetonitrile and water containing 0.1% formic acid (50:50, v/v as the mobile phase. The method was validated in terms of linearity, accuracy and precision over the concentration range of 1–1000 ng/mL. The intra and inter-day precision and accuracy, stability and extraction recoveries of all the analytes were in the acceptable range. This method can be successfully applied to the pharmacokinetic study of AMD, VAL and HCT when given as a polypill. Keywords: Amlodipine, Valsartan, Hydrochlorothiazide, Exforge HCT, Polypill

  10. Application of an LC–MS/MS method for the analysis of amlodipine, valsartan and hydrochlorothiazide in polypill for a bioequivalence study

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    Jaivik V. Shah

    2017-10-01

    Full Text Available A sensitive and selective method has been proposed for the simultaneous determination of amlodipine (AML, valsartan (VAL and hydrochlorothiazide (HCTZ in human plasma by liquid chromatography–tandem mass spectrometry (LC–MS/MS. The analytes and their deuterated analogs were quantitatively extracted from 100 µL human plasma by solid phase extraction on Oasis HLB cartridges. The chromatographic separation of the analytes was achieved on a Chromolith RP18e (100 mm × 4.6 mm analytical column within 2.5 min. The resolution factor between AML and VAL, AML and HCTZ, and VAL and HCTZ was 2.9, 1.5 and 1.4, respectively, under isocratic conditions. The method was validated over a dynamic concentration range of 0.02–20.0 ng/mL for AML, 5.00–10,000 ng/mL for VAL and 0.20–200 ng/mL for HCTZ. Ion-suppression/enhancement effects were investigated by post-column infusion technique. The mean IS-normalized matrix factors for AML, VAL and HCTZ were 0.992, 0.994 and 0.998, respectively. The intra-batch and inter-batch precision (% CV across quality control levels was ≤ 5.56% and the recovery was in the range of 93.4%–99.6% for all the analytes. The method was successfully applied to a bioequivalence study of 5 mg AML + 160 mg VAL + 12.5 mg HCTZ tablet formulation (test and reference in 18 healthy Indian males under fasting. The mean log-transformed ratios of Cmax, AUC0–120h and AUC0-inf and their 90% CIs were within 90.2%–102.1%. The assay reproducibility was demonstrated by reanalysis of 90 incurred samples.

  11. Evaluation of safety and efficacy of telmisartan-amlodipine combination in treating hypertension.

    Science.gov (United States)

    Faruqui, Arif A

    2008-09-01

    The objective of this open, non-comparative, prospective postmarketing surveillance (PMS) study was to identify, validate and quantify the safety and efficacy associated with the use of fixed dose combination (FDC) of telmisartan 40 mg + amlodipine 5 mg (T40+A5) in hypertensive patients with or without concomitant diabetes. The data was collected from 72 centres from all over India during the period of June 2007 to February 2008. A total of 251 patients of either sex and those who were newly diagnosed stage II hypertension, or those who were uncontrolled on monotherapy with or without diabetes mellitus were included in this study. Patients were prescribed with T40+A5 combination orally. Systolic BP (SBP), diastolic BP (DBP) and heart rate (HR) were measured at the start and at the end of 2, 4 and 8 weeks of treatment. Primary efficacy end points were reduction in clinical SBP/ DBP from baseline to study end and number of patients achieving JNC VII goals. Tolerability was assessed by treatment-emergent adverse events. Out of 251 patients, 208 patients had completed the study (120 males and 88 females), 42 were lost to follow-up the study and one patient was withdrawn due to adverse effects. The mean age of the patients was 54.5 +/- 0.98 years for males and 52.94 +/- 1.078 years for females. Diabetes mellitus was seen in 64.9% of cases, dyslipidaemia in 2.88%, previous IHD in 7.2% cases and chronic obstructive pulmonary disease (COPD) in 0.50% of cases. Reduction in the mean SBP was found to be 12.08%, 18.92% and 22.90% at the end of 2, 4 and 8 weeks respectively (p hypertensive patients and 70% diabetic hypertensive patients achieved the JNC VII recommended goals. The overall incidence of ADRs was 7.69% with headache (1.92%) and vertigo (1.44%), as the commonest side-effect. According to physician's assessment of efficacy and tolerability 99.5% of total cases showed good to excellent response. In the treatment of stage II hypertensive patient the FDC of T40+A5

  12. Bilateral blindness secondary to optic nerve ischemia from severe amlodipine overdose: a case report.

    Science.gov (United States)

    Kao, Raymond; Landry, Yves; Chick, Genevieve; Leung, Andrew

    2017-08-03

    Calcium channel blockers are commonly prescribed medications; calcium channel blocker overdose is becoming increasingly prevalent. The typical presentation of a calcium channel blocker overdose is hypotension and decreased level of consciousness. We describe a case of a calcium channel blocker overdose that led to bilateral cortical blindness, a presentation that has not previously been reported. A 49-year-old white woman with known bilateral early optic atrophy presented to our hospital with hypotension and obtundation following a known ingestion of 150 mg of amlodipine. She was transferred to our intensive care unit where she was intubated, mechanically ventilated, and required maximal vasopressor support (norepinephrine 40 mcg/minute, epinephrine 40 mcg/minute, and vasopressin 2.4 units/hour) along with intravenously administered crystalloid boluses. Despite these measures, she continued to deteriorate with persistent hypotension and tachycardia, as well as anuria. Intralipid emulsion therapy was subsequently administered to which no initial response was observed. A chest X-ray revealed diffuse pulmonary edema; intravenous diuresis as well as continuous renal replacement therapy was initiated. Following the initiation of continuous renal replacement therapy, her oxygen requirements as well as urine output began to improve, and 3 days later she was liberated from mechanical ventilation. Following extubation, she complained of new onset visual impairment, specifically seeing only red-green colors, but no objects. An ophthalmologic examination revealed that this was due to bilateral optic atrophy from prolonged hypotension during the first 24 hours after the overdose. Persistent hypotension in the setting of a calcium channel blocker overdose can lead to worsening optic atrophy resulting in bilateral cortical blindness.

  13. Clinical utility of fixed-combination telmisartan–amlodipine in the treatment of hypertension

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    Segura J

    2011-05-01

    Full Text Available Julian Segura, Luis M RuilopeHypertension Unit, Hospital 12 de Octubre, Madrid, SpainAbstract: The majority of hypertensive patients, especially those with target organ damage, are likely to require multiple-drug therapy in order to reach blood pressure (BP targets and reduce their risk of adverse vascular outcomes. The rationale for combination therapy with agents that block the renin–angiotensin system (RAS and a calcium channel blocker (CCB or diuretic is well founded in growing evidence. Recent published trials have shown that the combination of an RAS suppressor and a dihydropiridinic CCB would offer additional benefits independently of BP reduction. A telmisartan–amlodipine combination has demonstrated significantly greater BP reductions compared with each monotherapy component in the overall population, and in particular in patients with moderate to severe hypertension and high-risk patients. This combination is well tolerated with a safety profile similar to placebo and is consistent with the known safety profile of its monotherapy components.Keywords: hypertensive patients, monotherapy, stroke, antihypertensive

  14. Antihypertensive and cardioprotective effects of pumpkin seed oil.

    Science.gov (United States)

    El-Mosallamy, Aliaa E M K; Sleem, Amany A; Abdel-Salam, Omar M E; Shaffie, Nermeen; Kenawy, Sanaa A

    2012-02-01

    Pumpkin seed oil is a natural product commonly used in folk medicine for treatment of prostatic hypertrophy. In the present study, the effects of treatment with pumpkin seed oil on hypertension induced by the nitric oxide synthase inhibitor N(ω)-nitro-L-arginine methyl ester hydrochloride (L-NAME) (50 mg /kg/day) in rats were studied and compared with those of the calcium channel blocker amlodipine. Pumpkin seed oil (40 or 100 mg/kg), amlodipine (0.9 mg/kg), or vehicle (control) was given once daily orally for 6 weeks. Arterial blood pressure (BP), heart rate, electrocardiogram (ECG) changes, levels of serum nitric oxide (NO) (the concentrations of nitrite/nitrate), plasma malondialdehyde (MDA), blood glutathione, and erythrocytic superoxide dismutase activity were measured. Histopathological examination of heart and aorta was conducted as well. L-NAME administration resulted in a significant increase in BP starting from the second week. Pumpkin seed oil or amlodipine treatment significantly reduced the elevation in BP by L-NAME and normalized the L-NAME-induced ECG changes-namely, prolongation of the RR interval, increased P wave duration, and ST elevation. Both treatments significantly decreased the elevated levels of MDA and reversed the decreased levels of NO metabolites to near normal values compared with the L-NAME-treated group. Amlodipine also significantly increased blood glutathione content compared with normal (but not L-NAME-treated) rats. Pumpkin seed oil as well as amlodipine treatment protected against pathological alterations in heart and aorta induced by L-NAME. In conclusion, this study has shown that pumpkin seed oil exhibits an antihypertensive and cardioprotective effects through a mechanism that may involve generation of NO.

  15. Assessment of glomerular filtration rate based on alterations of serum brain-derived neurotrophic factor in type 2 diabetic subjects treated with amlodipine/benazepril or valsartan/hydrochlorothiazide.

    Science.gov (United States)

    Lee, I-Te; Sheu, Wayne Huey-Herng; Hung, Yi-Jen; Chen, Jung-Fu; Wang, Chih-Yuan; Lee, Wen-Jane

    2015-01-01

    Brain-derived neurotrophic factor (BDNF) is associated with sympathetic activation. However, the effects of BDNF on diabetic nephropathy are unknown. The aim of this study was to assess the estimated glomerular filtration rates (eGFRs) and changes in serum BDNF levels in type 2 diabetic subjects treated with antihypertensive medications. In this randomized, double-blind clinical trial, type 2 diabetic subjects with hypertension were assigned to either the benazepril/amlodipine or valsartan/hydrochlorothiazide treatment groups for a 16-week period. The post hoc analyses were based on increased or decreased serum BDNF levels. Of the 153 enrolled subjects, the changes in eGFR were significantly and inversely correlated with those in BDNF in the 76 subjects treated with valsartan/hydrochlorothiazide (r = -0.264, P = 0.021) but not in the 77 subjects treated with benazepril/amlodipine (r = -0.025, P = 0.862). The 45 subjects with increased BDNF following valsartan/hydrochlorothiazide treatment exhibited a significantly reduced eGFR (-8.8 ± 14.9 mL/min/1.73 m(2); P benazepril.

  16. MODERN PHARMACOTHERAPY OF THE STABLE ANGINA: POSSIBILITIES AND PROSPECTS OF NICORANDIL IMPLEMENTATION

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    Z. M. Sizova

    2010-01-01

    Full Text Available Aim. To evaluate antianginal efficacy and safety of nicorandil for angina attack prevention and relief in patients with ischemic heart disease (IHD and symptoms of stable angina class 2-3.Material and methods. 30 patients with stable angina class 2-3 (17 men, 13 women; aged 58.6±5.8 y.o. were included into the study. All patients received amlodipine 10 mg QD within 2 weeks. For angina attack relief patients used nicorandil 10-20 mg and in case of its inefficacy — nitroglycerin. In 2 weeks all patients were randomized in 2 groups. Patients of the 1st group (n=15 received nicorandil 20 mg TID, patients of the 2nd group (n=15 — amlodipine 10 mg QD. The study duration was 3 months. The efficiency evaluation was based on the analysis of hemodynamic indicators (heart rate, blood pressure, bioelectric heart activity (electrocardiogram, velocity exercise tolerance test, ambulatory blood pressure monitoring indicators. The pain severity was defined with Borg's scale, and the quality of life — with General Health Questionnaire (GHQ-28. Therapy safety was evaluated in according to laboratory tests results.Results. Frequency of angina attacks reduced by 60% (р<0.05 and 47% (р<0.05 in 12 weeks of nicorandil and amlodipine therapy, respectively. Duration of angina decreased by 38% and 37% (р<0.05 in 12 weeks of nicorandil and amlodipine therapy, respectively. Eexercise duration before angina attack onset increased by 56% (р<0.05 in 1 month of nicorandil therapy. A number of myocardial ischemia episodes reduced by 64% (р<0.05 and 54% (р<0.05 due to nicorandil and amlodipine therapy, respectively. General GHQ-28 score decreased by 54% (р<0.05 and 44% (р<0.05 in patients of the 1st and the 2nd groups, respectively. Tolerability of nicorandil was good in 13 (86.7% and satisfactory in 2 (13.3% patients.Conclusion. Nicorandil can be prescribed both for the prevention and for relief of angina attacks in IHD patients.

  17. Phototransformation of Amlodipine in Aqueous Solution: Toxicity of the Drug and Its Photoproduct on Aquatic Organisms

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    Marina DellaGreca

    2007-01-01

    Full Text Available The phototransformation of amlodipine in water was investigated under various conditions. A quantum yield ΦS2.2×10−4 and a half-life time t1/2 0.419 days were calculated when the drug in water (10−4 M was exposed to sunlight. The only photoproduct found was its pyridine derivative. Formation of this product was explained on the basis of a radical cation intermediate. The acute and chronic toxicity of the drug and its photoproduct were evaluated on different organisms of the freshwater chain (Brachionus calyciflorus, Thamnocephalus platyurus, Daphnia magna, Ceriodaphnia dubia. The photoproduct exhibited a stronger toxic potential than the parent drug on the long time for C. dubia.

  18. A review of the benefits of early treatment initiation with single-pill combinations of telmisartan with amlodipine or hydrochlorothiazide

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    Segura J

    2013-09-01

    Full Text Available Julian Segura, Luis Miguel Ruilope Department of Nephrology, Hospital 12 de Octubre, Madrid, Spain Abstract: This review discusses the rationale for earlier use of single-pill combinations (SPCs of antihypertensive drugs, with a focus on telmisartan/amlodipine (T/A and telmisartan/hydrochlorothiazide (T/H SPCs. Compared with the respective monotherapies, the once-daily T/A and T/H SPCs have been shown to result in significantly higher blood pressure (BP reductions, BP goal rates, and response rates in patients at all stages of hypertension. As expected, BP reductions are highest with the highest dose (T80/A10 and T80/H25 SPCs. Subgroup analyses of the telmisartan trials have reported the efficacy of both SPCs to be consistent, regardless of the patients' age, race, and coexisting diabetes, obesity, or renal impairment. In patients with mild-to-moderate hypertension, the T/A combination provides superior 24-hour BP-lowering efficacy compared with either treatment administered as monotherapy. Similarly, the T/H SPC treatment provides superior 24-hour BP-lowering efficacy, especially in the last 6 hours relative to other renin–angiotensin system inhibitor-based SPCs. The T/A SPC is associated with a lower incidence of edema than amlodipine monotherapy, and the T/H SPC with a lower incidence of hypokalemia than hydrochlorothiazide monotherapy. Existing evidence supports the use of the T/A SPC for the treatment of hypertensive patients with prediabetes, diabetes, or metabolic syndrome, due to the metabolic neutrality of both component drugs, and the use of the T/H SPC for those patients with edema or in need of volume reduction. Keywords: calcium-channel blocker, essential hypertension, diuretic, primary care physician, renin-angiotensin system inhibitor

  19. Host-Guest Inclusion Complexes between Amlodipine Enantiomers in Biphasic Recognition Chiral Extraction System using Tartaric Acid and β-Cyclodextrin Derivatives as Positive Confirmation Using of their Enantioselective Extraction

    OpenAIRE

    AZZAM, Khaldun; ABDALLAH, Hassan; HALIM, Hairul; AHMAD, Maizatul; SHAIBAH, Hassan

    2015-01-01

    The current work reports an extended theoretical study from our previous experimental work for the enantioselective extraction of amlodipine enantiomers in a biphasic recognition chiral extraction system (BRCES) consisting of hydrophobic D-diisopropyl tartrate dissolved in organic phase (n-decanol) and hydrophilic hydroxypropyl-?-cyclodextrin (HP-?-CD) in aqueous phase (acetate buffer) which preferentially recognize the R-enantiomer and S-enantiomer, respectively. The calculations were simula...

  20. Comparative study between derivative spectrophotometry and multivariate calibration as analytical tools applied for the simultaneous quantitation of Amlodipine, Valsartan and Hydrochlorothiazide

    Science.gov (United States)

    Darwish, Hany W.; Hassan, Said A.; Salem, Maissa Y.; El-Zeany, Badr A.

    2013-09-01

    Four simple, accurate and specific methods were developed and validated for the simultaneous estimation of Amlodipine (AML), Valsartan (VAL) and Hydrochlorothiazide (HCT) in commercial tablets. The derivative spectrophotometric methods include Derivative Ratio Zero Crossing (DRZC) and Double Divisor Ratio Spectra-Derivative Spectrophotometry (DDRS-DS) methods, while the multivariate calibrations used are Principal Component Regression (PCR) and Partial Least Squares (PLSs). The proposed methods were applied successfully in the determination of the drugs in laboratory-prepared mixtures and in commercial pharmaceutical preparations. The validity of the proposed methods was assessed using the standard addition technique. The linearity of the proposed methods is investigated in the range of 2-32, 4-44 and 2-20 μg/mL for AML, VAL and HCT, respectively.

  1. Comparative study between derivative spectrophotometry and multivariate calibration as analytical tools applied for the simultaneous quantitation of Amlodipine, Valsartan and Hydrochlorothiazide.

    Science.gov (United States)

    Darwish, Hany W; Hassan, Said A; Salem, Maissa Y; El-Zeany, Badr A

    2013-09-01

    Four simple, accurate and specific methods were developed and validated for the simultaneous estimation of Amlodipine (AML), Valsartan (VAL) and Hydrochlorothiazide (HCT) in commercial tablets. The derivative spectrophotometric methods include Derivative Ratio Zero Crossing (DRZC) and Double Divisor Ratio Spectra-Derivative Spectrophotometry (DDRS-DS) methods, while the multivariate calibrations used are Principal Component Regression (PCR) and Partial Least Squares (PLSs). The proposed methods were applied successfully in the determination of the drugs in laboratory-prepared mixtures and in commercial pharmaceutical preparations. The validity of the proposed methods was assessed using the standard addition technique. The linearity of the proposed methods is investigated in the range of 2-32, 4-44 and 2-20 μg/mL for AML, VAL and HCT, respectively. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. ECONOMIC BENEFITS OF LEFT VENTRICULAR HYPERTROPHY REGRESSION IN PATIENTS WITH ARTERIAL HYPERTENSION

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    E. I. Tarlovskaya

    2011-01-01

    Full Text Available Aim. To evaluate by modelling the economic benefits of left ventricular hypertrophy (LVH regression in patients with arterial hypertension (HT due to therapy with fixed combination of valsartan/amlodipine.  Material and methods. 20 patients (15 females and 5 males, aged 18 to 70 years with essential HT accompanied by metabolic syndrome with a history of previous ineffective antihypertensive therapy were included into the study. All patients were treated with fixed combination of amlodipine/valsartan in doses of 5/160 and 10/160 mg depending on blood pressure (BP level. Treatment duration was 24 weeks. Changes in BP level, LVH regression were assessed. Economic evaluation was performed on the basis of modelling with the specialized software Decision Tree 4.xla. Results. Effect of fixed amlodipine/valsartan combination therapy on LVH was used to estimate treatment effectiveness and to build the model. Patients were distributed according to left ventricular (LV mass (at baseline and after 24 weeks of therapy. Significant decrease in LV mass from 205.8±50.4 to 181.9±45.1 g (p<0.05 was revealed. The model took into account economic and frequency factors for 10 year prognosis: this therapy prevents 36 deaths, 6 strokes, 24 myocardial infarction per 1000 patients. Absence of need in treatment of these prevented events can save 2 516 772.42 RUR for every 1 000 patients. It would reduce the total costs per patient during 10 years. Conclusion. Treatment with amlodipine/valsartan single pill combination has not only clinical advantages, but also pharmacoeconomic benefits. This combination reduces risk of acute myocardial infarction and death more effectively. Treatment with fixed valsartan/amlodipine combination saves maximum years of life with less cost during 10 years. Despite of higher pharmacotherapy costs, fixed valsartan/amlodipine combination reduces total costs due to prevention of fatal and nonfatal cardiovascular events.

  3. Host-Guest Inclusion Complexes between Amlodipine Enantiomers in the Biphasic Recognition Chiral Extraction System using Tartaric Acid and β-Cyclodextrin Derivatives as Positive Confirmation by using their Enantioselective Extraction.

    Science.gov (United States)

    Al Azzam, Khaldun M; Abdallah, Hassan H; Halim, Hairul N Abdul; Ahmad, Maizatul Akmam; Shaibah, Hassan

    2015-01-01

    The current work reports an extended theoretical study from our previous experimental work for the enantioselective extraction of amlodipine enantiomers in a biphasic recognition chiral extraction system (BRCES) consisting of hydrophobic D-diisopropyl tartrate dissolved in organic phase (n-decanol) and hydrophilic hydroxypropyl-β-cyclodextrin (HP-β-CD) in aqueous phase (acetate buffer) which preferentially recognize the R-enantiomer and S-enantiomer, respectively. The calculations were simulated using a semi-empirical PM3 method as a part of the Gaussian09 software package and were used to optimize the structures of the hosts, guests, and host-guest complexes in the gas phase without any restrictions. It was found that HP-β-CD has the strongest recognition ability among the three β-CD derivatives studied, namely HP-β-CD, hydroxyethyl-β-cyclodextrin (HE-β-CD), and methylated-β-cyclodextrin (Me-β-CD), due to the large interaction energies (Ecomp = -14.3025 kcal/ mol), while D-diisopropyl tartrate has the strongest ability among the four tartaric acid derivatives studied namely; L-diisopropyl tartrate, D-diisopropyl tartrate, L-diethyl tartrate, and D-diethyl tartrate (Ecomp = -5.9964 kcal/ mol). The computational calculations for the enantioselective partitioning of amlodipine enantiomers rationalized the reasons for the different behaviors for this extraction. The present theoretical results may be informative to scientists who are devoting themselves to developing models for their experimental parts or for enhancing the hydrophobic drug solubility in drug delivery systems.

  4. Host-Guest Inclusion Complexes between Amlodipine Enantiomers in the Biphasic Recognition Chiral Extraction System using Tartaric Acid and β-Cyclodextrin Derivatives as Positive Confirmation by using their Enantioselective Extraction

    Science.gov (United States)

    Al Azzam, Khaldun M.; Abdallah, Hassan H.; Halim, Hairul N. Abdul; Ahmad, Maizatul Akmam; Shaibah, Hassan

    2015-01-01

    The current work reports an extended theoretical study from our previous experimental work for the enantioselective extraction of amlodipine enantiomers in a biphasic recognition chiral extraction system (BRCES) consisting of hydrophobic D-diisopropyl tartrate dissolved in organic phase (n-decanol) and hydrophilic hydroxypropyl-β-cyclodextrin (HP-β-CD) in aqueous phase (acetate buffer) which preferentially recognize the R-enantiomer and S-enantiomer, respectively. The calculations were simulated using a semi-empirical PM3 method as a part of the Gaussian09 software package and were used to optimize the structures of the hosts, guests, and host-guest complexes in the gas phase without any restrictions. It was found that HP-β-CD has the strongest recognition ability among the three β-CD derivatives studied, namely HP-β-CD, hydroxyethyl-β-cyclodextrin (HE-β-CD), and methylated-β-cyclodextrin (Me-β-CD), due to the large interaction energies (Ecomp = −14.3025 kcal/ mol), while D-diisopropyl tartrate has the strongest ability among the four tartaric acid derivatives studied namely; L-diisopropyl tartrate, D-diisopropyl tartrate, L-diethyl tartrate, and D-diethyl tartrate (Ecomp = −5.9964 kcal/ mol). The computational calculations for the enantioselective partitioning of amlodipine enantiomers rationalized the reasons for the different behaviors for this extraction. The present theoretical results may be informative to scientists who are devoting themselves to developing models for their experimental parts or for enhancing the hydrophobic drug solubility in drug delivery systems. PMID:26839848

  5. Gender difference in the response to valsartan/amlodipine single-pill combination in essential hypertension (China Status II): An observational study.

    Science.gov (United States)

    Wang, Huan; Chen, Hui

    2016-01-01

    The China STATUS II is a prospective, multicentre, open-label, post-marketing, observational study including Chinese adults (aged ⩾ 18 years) with essential hypertension who were prescribed once-daily valsartan/amlodipine (Val/Aml 80/5 mg) single-pill combination. In order to examine gender differences in treatment response to Val/Aml, we further analysed data from the China STATUS II study. A total of 11,312 patients (6456 (57%) men and 4856 (43%) women) received the Val/Aml treatment for 8 weeks. After the treatment, we compared the proportion of patients not achieving the target systolic blood pressure (SBP: < 140 mm Hg) or diastolic blood pressure (DBP: < 90 mm Hg) in different age groups (by Fisher exact probability test) and estimated the changes in blood pressure (BP) according to age and gender, using a mixed model. At enrolment, mean SBP was higher in the female versus the male patients (160.0 ± 12.71 versus 159.3 ± 12.31 mm Hg; p = 0.003), whereas the mean DBP was higher in the male versus the female patients (96.4 ± 10.65 versus 94.5 ± 10.72 mm Hg; p < 0.001). The overall proportion of women not achieving the target BP was less than that of men (57.41% versus 59.59%; p < 0.05) at 4 weeks and (22.22% versus 23.78%; p < 0.05) at 8 weeks after the Val/Aml treatment. Among both men and women, the proportion of patients not achieving the target SBP increased with age; however, the proportion not achieving the target DBP decreased with age. The mixed-model analysis showed that the changes in SBP were closely related to gender, indicating that the SBP-lowering effect after Val/Aml treatment might be better in women. In addition, the changes in DBP were closely related to age. Gender might be a factor for consideration in the decision-making process of individualised antihypertensive therapy, in the future. © The Author(s) 2016.

  6. Use of multiattribute utility theory for formulary management in a health system.

    Science.gov (United States)

    Chung, Seonyoung; Kim, Sooyon; Kim, Jeongmee; Sohn, Kieho

    2010-01-15

    The application, utility, and flexibility of the multiattribute utility theory (MAUT) when used as a formulary decision methodology in a Korean medical center were evaluated. A drug analysis model using MAUT consisting of 10 steps was designed for two drug classes of dihydropyridine calcium channel blockers (CCBs) and angiotensin II receptor blockers (ARBs). These two drug classes contain the most diverse agents among cardiovascular drugs on Samsung Medical Center's drug formulary. The attributes identified for inclusion in the drug analysis model were effectiveness, safety, patient convenience, and cost, with relative weights of 50%, 30%, 10%, and 10%, respectively. The factors were incorporated into the model to quantify the contribution of each attribute. For each factor, a utility scale of 0-100 was established, and the total utility score for each alternative was calculated. An attempt was made to make the model adaptable to changing health care and regulatory circumstances. The analysis revealed amlodipine besylate to be an alternative agent, with the highest total utility score among the dihydropyridine CCBs, while barnidipine hydrochloride had the lowest score. For ARBs, losartan potassium had the greatest total utility score, while olmesartan medoxomil had the lowest. A drug analysis model based on the MAUT was successfully developed and used in making formulary decisions for dihydropyridine CCBs and ARBs for a Korean health system. The model incorporates sufficient utility and flexibility of a drug's attributes and can be used as an alternative decision-making tool for formulary management in health systems.

  7. Estudo "LOTHAR": avaliação de eficácia e tolerabilidade da combinação fixa de anlodipino e losartana no tratamento da hipertensão arterial primária The "LOTHAR" study: evaluation of efficacy and tolerability of the fixed combination of amlodipine and losartan in the treatment of essential hypertension

    Directory of Open Access Journals (Sweden)

    Osvaldo Kohlmann Jr

    2006-01-01

    Full Text Available OBJETIVO: O estudo LOTHAR avaliou a eficácia, tolerabilidade e os efeitos metabólicos em médio e longo prazo (um ano da combinação fixa de anlodipino e losartana versus anlodipino e losartana isoladamente. MÉTODOS: Estudo multicêntrico brasileiro, randomizado, duplo-cego e comparativo realizado com 198 pacientes com hipertensão arterial primária em estágios 1 e 2. RESULTADOS: A combinação fixa apresenta alta eficácia anti-hipertensiva que se mantém em longo prazo com percentual reduzido de escape do controle pressórico, inferior a dos dois regimes monoterápicos de comparação. Em longo prazo, mais de 60% dos pacientes tratados com a combinação fixa permaneceram com níveis da PAD OBJECTIVE: The LOTHAR study evaluated medium and long term (one year efficacy, tolerability and metabolic effects of the fixed combination of amlodipine and losartan compared to amlodipine or losartan alone. METHODS: Brazilian multicenter, randomized, double-blind and comparative trial performed with 198 patients in stage 1 and 2 essential hypertension. RESULTS: The fixed combination has a high antihypertensive efficacy that is sustained in the long term with very low percentage of loss of blood pressure control. This percentage is incidentally lower than that of the two monotherapy comparative regimens. In the long term, more than 60% of the patients treated with the fixed combination remained with DBP < 85 mmHg, and the antihypertensive effect, when assessed by ABPM persisted for 24 hours with a trough-to-peak ratio of 76.7%. The frequency of adverse events was quite low in this group, and the long-term incidence of leg edema was approximately four-fold lower than that observed with amlodipine alone. The fixed combination did not change glucose and lipid metabolism in the medium or in the long term. CONCLUSION: Based on these results, we can say that the combination of amlodipine and losartan - the first fixed combination of a calcium channel

  8. [Intervention of systolic pressure and left ventricular hypertrophy in rats under cold stress].

    Science.gov (United States)

    Sun, C F; Wang, S G; Peng, Y G; Shi, Y; Du, Y P; Shi, G X; Wen, T; Wang, Y K; Su, H

    2016-06-20

    To investigate the effects of different drugs on systolic blood pressure (SBP) and left ventricular hypertrophy (LVH) in spontaneously hypertensive rats under cold stress. A total of 40 male spontaneously hypertensive rats aged 10 weeks (160~200 g) were given adaptive feeding for 7 days at a temperature of 20±1°C and then randomly divided into control group, cold stress group, metoprolol group, amlodipine group, and benazepril group, with 8 rats in each group. SBP, body weight, and heart rate were measured once a week. After the rats were sacrificed by exsanguination, left ventricular weight (LVW) was measured, and left ventricular weight index (LVWI; mg/g) was calculated. Radioimmunoassay was used to measure the concentrations of endothelin-1 (ET-1) and angiotensin-II (Ang-II) in plasma and myocardium, and the chemical method was used to measure the concentrations of nitric oxide (NO) in plasma and myocardium. RT-PCR was used to measure the mRNA expression of endothelin-A receptor. Compared with the cold stress group, all medication groups showed significant reductions in SBP since week 5 (Pcold stress group showed a significant increase in LVWI compared with the control group (3.38±0.27 mg/g vs 2.89±0.19 mg/g, Pcold stress group (2.98±0.28 mg/g vs 3.38±0.27 mg/g, Pcold stress group showed a significant reduction in plasma NO concentration compared with the control group (104.9±19.5 μmol/L vs 129.3±17.8 μmol/L, Pcold stress group, all the medication groups showed significant increases in blood NO concentration (Pcold stress group showed a significant increase in myocardial ET-1 concentration compared with the control group (6.3±1.5 pg/100 mg vs 4.5±1.9 pg/100 mg, Pcold stress group, the amlodipine group showed a significant reduction in myocardial ET-1 concentration (4.4±1.0 pg/100 mg vs 6.3±1.5 pg/100 mg, Pcold stress group had significantly higher mRNA expression of endothelin-A receptor than the control group (0.86±0.23 vs 0.45±0.16, Pcold

  9. Antidepressant-selective gynecomastia.

    Science.gov (United States)

    Kaufman, Kenneth R; Podolsky, Dina; Greenman, Danielle; Madraswala, Rehman

    2013-01-01

    To describe what we believe is the first reported case of synergistic gynecomastia during treatment of depressive and anxiety disorders when sertraline was added to a stable medication regimen including duloxetine, rosuvastatin, and amlodipine. A 67-year-old male with major depression, dysthymia, obsessive-compulsive disorder, social anxiety, hypertension, diabetes, and hyperlipidemia presented with new-onset gynecomastia and breast tenderness. Mammography revealed bilateral gynecomastia (fibroglandular tissue posterior to the nipples bilaterally) without suspicious mass, calcification, or other abnormalities. These new symptoms developed after sertraline was added to his stable medication regimen (duloxetine, alprazolam, rosuvastatin, metoprolol, amlodipine, hydrochlorothiazide/triamterene, metformin, and sitagliptin). These symptoms were dose-dependent, with gynecomastia and breast tenderness more severe as sertraline was titrated from 25 mg/day to 50 mg/day and then to 75 mg/day. When sertraline was discontinued, gynecomastia and breast tenderness rapidly resolved. Mammoplasia and gynecomastia are associated with altered dopamine neurotransmission and/or perturbations in sexual hormones. These adverse effects may be medication induced. Selective serotonin reuptake inhibitors (sertraline), serotonin-norepinephrine reuptake inhibitors (duloxetine), rosuvastatin, and amlodipine have been reported to cause these adverse effects. This case was unique, since the patient had been on both sertraline and duloxetine previously as independent psychotropics without the development of gynecomastia. In the context of an additive drug adverse effect, the probability of sertraline as the precipitant drug was determined by both the Naranjo probability scale and the Horn drug interaction probability scale as probable. Gynecomastia is associated with antidepressants and other medications but is rarely addressed. Gynecomastia may be antidepressant selective or may be the result of

  10. An evaluation of the effect of atorvastatin on memory and psychomotor functions in hypertensive patients

    Directory of Open Access Journals (Sweden)

    S Prajapati

    2011-01-01

    Full Text Available Background : The effect of statins on memory and psychomotor function has been controversial and needs further evaluation. Aims : To evaluate the effect of atorvastatin on memory and psychomotor functions in hypertensive patients treated with enalapril or amlodipine. Settings and Design : Prospective, comparative, non-randomized, before-after, open-label clinical study conducted at a tertiary care hospital in Western India. Materials and Methods : Memory was evaluated with PGI (Post Graduate Institute, Chandigarh Memory Scale, while psychomotor functions were evaluated with Digit Letter Substitution test, Six Letter Cancellation test, and Finger Tapping test at baseline, 1 week, 1 month, and 3 months of starting atorvastatin in 74 hypertensive patients who were prescribed either enalapril or amlodipine with or without atorvastatin 10 mg/day. Scores obtained in patients receiving enalapril or amlodipine were compared with those receiving these drugs along with atorvastatin. Memory and psychomotor functions of 12 healthy volunteers were also evaluated and compared with those of the patients at respective time periods. Statistical Analysis : Student′s t test, Wilcoxon Signed Rank test, and Mann Whitney U test were used to compare the pre- and post-treatment scores of memory and psychomotor functions in various groups. Statistical significance was considered at P<0.05. Results : A statistically significant improvement in scores of memory and psychomotor functions was observed in both healthy volunteers (P=0.009 and P=0.016 and hypertensive patients (P=0.008 and P=0.031 throughout the study period. Memory and psychomotor function in hypertensive patients remained significantly inferior to those of healthy volunteers (P=0.01 and P=0.018. There was no significant difference in the scores of memory and psychomotor functions between patients receiving atorvastatin and those not receiving this drug. Conclusion : Atorvastatin, at 10 mg/day dose, does not

  11. Metoprolol Increases Uric Acid and Risk of Gout in African Americans With Chronic Kidney Disease Attributed to Hypertension.

    Science.gov (United States)

    Juraschek, Stephen P; Appel, Lawrence J; Miller, Edgar R

    2017-09-01

    There is little evidence guiding selection of nondiuretic, antihypertensive agents with a goal of lowering uric acid (SUA) and minimizing gout risk. In the African American Study of Kidney Disease and Hypertension (AASK) trial, African Americans with chronic kidney disease were randomly assigned to metoprolol (a beta-blocker), ramipril (an angiotensin-converting enzyme inhibitors [ACEi]), or amlodipine (a dihydropyridine calcium-channel blocker). SUA was measured at baseline and 12 months. Gout-related hospitalizations were based on ICD9 codes. Gout-related medication use (GRMs) was based on active prescriptions of allopurinol, colchicine, or probenecid during the baseline visit of the AASK cohort phase. We examined the effect of drug assignment on 12-month SUA (linear regression), gout-related hospitalization (Cox regression), and GRM (logistic regression). Of the 630 participants, 40% were female with a mean age of 55 years (SD, 10), mean SUA of 8.2 mg/dl (2.0), and mean serum creatinine of 1.8 mg/dl (0.6). After 12 months, metoprolol increased SUA by 0.3 mg/dl, while ramipril or amlodipine had no effect on SUA. Compared to ramipril, metoprolol significantly increased 12-month SUA (0.40; 0.10, 0.70 mg/dl; P = 0.009), nonsignificantly increased risk of gout-related hospitalization (hazard ratio: 3.87; 0.82, 18.26; P = 0.09), and significantly increased the odds of GRM (odds ratio: 1.62; 1.03, 2.54; P = 0.04). While metoprolol was associated with a higher 12-month SUA compared with amlodipine (0.57; 0.18, 0.95; P = 0.004), there was no difference in gout-related hospitalizations or GRM. Metoprolol increased SUA and GRM in African American adults. Health professionals treating patients with kidney disease at risk for gout should avoid metoprolol and possibly consider an ACEi. Trial Number NCT00582777. © American Journal of Hypertension, Ltd 2017. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  12. The therapeutic advantage of combination antihypertensive drug therapy using amlodipine and irbesartan in hypertensive patients: Analysis of the post-marketing survey data from PARTNER (Practical combination therapy of Amlodin and angiotensin II Receptor blocker; safety and efficacy in patients with hypertension) study.

    Science.gov (United States)

    Ishimitsu, Toshihiko; Fukuda, Hirofumi; Uchida, Masako; Ishibashi, Kazushi; Sato, Fusako; Nukui, Kazuhiko; Nagao, Munehiko

    2015-01-01

    Two-thirds of hypertensive patients need a combination antihypertensive therapy to achieve the target blood pressure (BP). The PARTNER (Practical combination therapy of Amlodin and angiotensin II Receptor blocker; Safety and efficacy in paTieNts with hypERtension) study is a prospective specific clinical use survey examining the efficacy and safety of 12-week treatment with amlodipine (AML) and Angiotensin II Receptor Blocker (ARB) in 5900 hypertensive patients. The current analysis was performed as to the BP control, adverse reactions, and the effects on laboratory data in patients treated with the combination of AML and irbesartan (IRB), namely the patients added AML to already taking IRB (AML add-on group, n = 1202) and the patients added IRB to AML (IRB add-on group, n = 1050). Both study groups showed distinct decreases in office BP at 4 week (p 7 mg/dl. The incidence of adverse reactions was as few as 1.11% and there were no severe adverse reactions which hampered the continuation of combination therapy. In conclusion, combination antihypertensive therapy with AML and IRB effectively lowers BP without particular safety problems, reduces serum uric acid especially in patients with hyperuricemia and exhibits renoprotective effects in patients with chronic kidney disease.

  13. Gateways to clinical trials.

    Science.gov (United States)

    Bayés, M; Rabasseda, X; Prous, J R

    2007-12-01

    Gateways to Clinical Trials are a guide to the most recent clinical trials in current literature and congresses. The data in the following tables has been retrieved from the Clinical Trials Knowledge Area of Prous Science Intergrity, the drug discovery and development portal, http://integrity.prous.com. This issue focuses on the following selection of drugs: 249553, 2-Methoxyestradiol; Abatacept, Adalimumab, Adefovir dipivoxil, Agalsidase beta, Albinterferon alfa-2b, Aliskiren fumarate, Alovudine, Amdoxovir, Amlodipine besylate/atorvastatin calcium, Amrubicin hydrochloride, Anakinra, AQ-13, Aripiprazole, AS-1404, Asoprisnil, Atacicept, Atrasentan; Belimumab, Bevacizumab, Bortezomib, Bosentan, Botulinum toxin type B, Brivaracetam; Catumaxomab, Cediranib, Cetuximab, cG250, Ciclesonide, Cinacalcet hydrochloride, Curcumin, Cypher; Darbepoetin alfa, Denosumab, Dihydrexidine; Eicosapentaenoic acid/docosahexaenoic acid, Entecavir, Erlotinib hydrochloride, Escitalopram oxalate, Etoricoxib, Everolimus, Ezetimibe; Febuxostat, Fenspiride hydrochloride, Fondaparinux sodium; Gefitinib, Ghrelin (human), GSK-1562902A; HSV-tk/GCV; Iclaprim, Imatinib mesylate, Imexon, Indacaterol, Insulinotropin, ISIS-112989; L-Alanosine, Lapatinib ditosylate, Laropiprant; Methoxy polyethylene glycol-epoetin-beta, Mipomersen sodium, Motexafin gadolinium; Natalizumab, Nimotuzumab; OSC, Ozarelix; PACAP-38, Paclitaxel nanoparticles, Parathyroid Hormone-Related Protein-(1-36), Pasireotide, Pegfilgrastim, Peginterferon alfa-2a, Peginterferon alfa-2b, Pemetrexed disodium, Pertuzumab, Picoplatin, Pimecrolimus, Pitavastatin calcium, Plitidepsin; Ranelic acid distrontium salt, Ranolazine, Recombinant human relaxin H2, Regadenoson, RFB4(dsFv)-PE38, RO-3300074, Rosuvastatin calcium; SIR-Spheres, Solifenacin succinate, Sorafenib, Sunitinib malate; Tadalafil, Talabostat, Taribavirin hydrochloride, Taxus, Temsirolimus, Teriparatide, Tiotropium bromide, Tipifarnib, Tirapazamine, Tocilizumab; UCN-01, Ularitide

  14. Olmesartan medoxomil combined with hydrochlorothiazide for the treatment of hypertension

    Directory of Open Access Journals (Sweden)

    Mark Greathouse

    2006-12-01

    Full Text Available Mark GreathouseSouth Hills Cardiology Associates of Pittsburgh, Pittsburgh, PA, USAAbstract: In most patients with hypertension, especially Stage 2 hypertension, adequate control of blood pressure (BP is only achieved with combination drug therapy. When using combination therapy, antihypertensive agents with complementary mechanisms of action are recommended, for example, an angiotensin receptor blocker (ARB in combination with hydrochlorothiazide (HCTZ, a β-blocker + HCTZ, an ACE inhibitor + HCTZ, or a calcium channel blocker + an ACE inhibitor. One such combination is olmesartan medoxomil + HCTZ, which is available as fixed-dose, single-tablet combinations for once-daily administration. In clinical trials, olmesartan medoxomil/HCTZ reduced systolic BP (SBP and diastolic BP (DBP to a greater extent than either component as monotherapy. A clinical study in patients with Stage 1 or 2 hypertension showed that olmesartan medoxomil/HCTZ achieved a similar mean reduction in DBP, but a significantly greater mean reduction in SBP and higher rate of BP control (<140/90 mmHg than observed with losartan/HCTZ, at US/European-approved starting doses. In a non-inferiority trial, the antihypertensive efficacy of olmesartan medoxomil/HCTZ was comparable to that of atenolol/HCTZ. Furthermore, indirect comparisons have shown that olmesartan medoxomil/HCTZ compares favorably with other antihypertensive combination therapies, including other ARB/HCTZ combinations and amlodipine besylate/benazepril. Olmesartan medoxomil/HCTZ is generally well tolerated. In conclusion, olmesartan medoxomil/HCTZ is an effective and well-tolerated combination antihypertensive therapy that results in significant BP reductions and BP control in many patients. Keywords: olmesartan medoxomil, hydrochlorothiazide, angiotensin II receptor blocker, hypertension

  15. Different approaches in Partial Least Squares and Artificial Neural Network models applied for the analysis of a ternary mixture of Amlodipine, Valsartan and Hydrochlorothiazide

    Science.gov (United States)

    Darwish, Hany W.; Hassan, Said A.; Salem, Maissa Y.; El-Zeany, Badr A.

    2014-03-01

    Different chemometric models were applied for the quantitative analysis of Amlodipine (AML), Valsartan (VAL) and Hydrochlorothiazide (HCT) in ternary mixture, namely, Partial Least Squares (PLS) as traditional chemometric model and Artificial Neural Networks (ANN) as advanced model. PLS and ANN were applied with and without variable selection procedure (Genetic Algorithm GA) and data compression procedure (Principal Component Analysis PCA). The chemometric methods applied are PLS-1, GA-PLS, ANN, GA-ANN and PCA-ANN. The methods were used for the quantitative analysis of the drugs in raw materials and pharmaceutical dosage form via handling the UV spectral data. A 3-factor 5-level experimental design was established resulting in 25 mixtures containing different ratios of the drugs. Fifteen mixtures were used as a calibration set and the other ten mixtures were used as validation set to validate the prediction ability of the suggested methods. The validity of the proposed methods was assessed using the standard addition technique.

  16. MODERN PHARMACOTHERAPY OF THE STABLE ANGINA: POSSIBILITIES AND PROSPECTS OF NICORANDIL IMPLEMENTATION

    OpenAIRE

    Z. M. Sizova; E. V. Shikh; V. L. Zakharova; E. V. Smirnova

    2010-01-01

    Aim. To evaluate antianginal efficacy and safety of nicorandil for angina attack prevention and relief in patients with ischemic heart disease (IHD) and symptoms of stable angina class 2-3.Material and methods. 30 patients with stable angina class 2-3 (17 men, 13 women; aged 58.6±5.8 y.o.) were included into the study. All patients received amlodipine 10 mg QD within 2 weeks. For angina attack relief patients used nicorandil 10-20 mg and in case of its inefficacy — nitroglycerin. In 2 weeks a...

  17. MANAGEMENT OF HYPERTENSION- INSIGHTS INTO REAL-WORLD CLINICAL PRACTICE FOR DIFFERENTIAL USAGE OF CALCIUM CHANNEL BLOCKERS (CCBS

    Directory of Open Access Journals (Sweden)

    Arup Dasbiswas

    2017-05-01

    Full Text Available BACKGROUND Calcium channel blockers (CCB like amlodipine, S (- amlodipine and cilnidipine, etc. have established place in the treatment of hypertension (HTN. As perceived by most of the physicians, they have comparative antihypertensive efficacy. However, available evidences suggest varied differences in incidence of pedal oedema. Aim- This survey was planned to understand real-world clinical practice pattern of Indian physicians for usage of various antihypertensive agents with emphasis on CCBs and whether differential incidence of oedema with CCBs is encountered in their clinical practice. MATERIALS AND METHODS Survey questionnaire consisting of 10 questions about preferred antihypertensive choice for different subsets of patients with HTN and efficacy and safety of S (- amlodipine was prepared and validated in small group of physicians. Overall, 494 general physicians and cardiologists practising in India were approached for seeking their opinion on usage of various CCBs. Statistical Analysis- Data were expressed in percentage. Design- Prospective, cross sectional, questionnaire-based survey. RESULTS Amongst various anti-hypertensive agents, majority of the physicians preferred CCB as their initial drug of choice for patients with HTN (53.8%, HTN with CKD (41.1%, elderly (55.3%, and young (30.8% patients. Though amlodipine was preferred by 75.7% physicians, pedal oedema was observed in >10% patients by 40.5% physicians. Most of the physicians rated S (- amlodipine to have better efficacy (79.4% and safety profile (88.3% with decreased incidence of pedal oedema than racemic Amlodipine. CONCLUSION Available evidences suggest comparative efficacy of S (- amlodipine and racemic amlodipine with varied differences in incidence of pedal oedema. However, our survey suggests better efficacy and safety of S (- amlodipine over racemic amlodipine as opined by most of the physicians of India. The survey findings need to be further evaluated in randomised

  18. Comparative study between univariate spectrophotometry and multivariate calibration as analytical tools for quantitation of Benazepril alone and in combination with Amlodipine.

    Science.gov (United States)

    Farouk, M; Elaziz, Omar Abd; Tawakkol, Shereen M; Hemdan, A; Shehata, Mostafa A

    2014-04-05

    Four simple, accurate, reproducible, and selective methods have been developed and subsequently validated for the determination of Benazepril (BENZ) alone and in combination with Amlodipine (AML) in pharmaceutical dosage form. The first method is pH induced difference spectrophotometry, where BENZ can be measured in presence of AML as it showed maximum absorption at 237nm and 241nm in 0.1N HCl and 0.1N NaOH, respectively, while AML has no wavelength shift in both solvents. The second method is the new Extended Ratio Subtraction Method (EXRSM) coupled to Ratio Subtraction Method (RSM) for determination of both drugs in commercial dosage form. The third and fourth methods are multivariate calibration which include Principal Component Regression (PCR) and Partial Least Squares (PLSs). A detailed validation of the methods was performed following the ICH guidelines and the standard curves were found to be linear in the range of 2-30μg/mL for BENZ in difference and extended ratio subtraction spectrophotometric method, and 5-30 for AML in EXRSM method, with well accepted mean correlation coefficient for each analyte. The intra-day and inter-day precision and accuracy results were well within the acceptable limits. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Dose Uniformity of Scored and Unscored Tablets: Application of the FDA Tablet Scoring Guidance for Industry.

    Science.gov (United States)

    Ciavarella, Anthony B; Khan, Mansoor A; Gupta, Abhay; Faustino, Patrick J

    world. Tablets are often split to modify dose strength, make swallowing easier, and reduce cost to the consumer. To better address product quality for this widely used practice, the U.S. Food and Drug Administration (FDA) published a Guidance for Industry that addresses tablet splitting. The guidance provides testing criteria for scored tablets, which is a part of the FDA review process for drugs. The model drugs selected for this study were amlodipine and gabapentin, which have different sizes, shapes, and tablet scores. Whole and split amlodipine tablets were tested for drug content because of a concern that the low-dose strength may cause greater variability. Whole and split gabapentin tablets were tested for weight variation because of their higher dosage strength of 600 mg. All whole tablets met the acceptance criteria for the Uniformity of Dosage Units based on the guidance recommendations. When unscored amlodipine tablets were split by a splitter, all formulations did not meet the acceptance criteria. When fully scored gabapentin tablets were split by hand and by splitter, they met the acceptance criteria. The findings of this FDA study indicated physical characteristics such as size, shape, and tablet score can affect the uniformity of split tablets. © PDA, Inc. 2016.

  20. Quantification of amlodipine and atorvastatin in human plasma by UPLC-MS/MS method and its application to a bioequivalence study.

    Science.gov (United States)

    Rezk, Mamdouh R; Badr, Kamal A

    2018-07-01

    A robust, rapid and sensitive UPLC-MS/MS method has been developed, optimized and validated for the determination of amlodipine (AML) and atorvastatin (ATO) in human plasma using eplerenone as an internal standard (IS). Multiple-reaction monitoring in positive electrospray ionization mode was utilized in Xevo TQD LC-MS/MS. Double extraction was used in sample preparation using diethyl ether and ethyl acetate. The prepared samples were analyzed using an Acquity UPLC BEH C 18 (50 × 2.1 mm, 1.7 μm) column. Ammonium formate and acetonitrile, pumped isocraticaly at a flow rate of 0.25 mL/min, were used as a mobile phase. Method validation was done as per the US Food and Drug Administration guidelines. Linearity was achieved in the range of 0.1-10 ng/mL for AML and 0.05-50 ng/mL for ATO. Intra-day and inter-day accuracy and precision were calculated and found to be within the acceptable range. A short run time, of <1.5 min, permits analysis of a large number of plasma samples per batch. The developed and validated method was applied to estimate AML and ATO in a bioequivalence study in healthy human volunteers. Copyright © 2018 John Wiley & Sons, Ltd.

  1. Biointerfacial phenomena of amlodipine buccomucosal tablets of HPMC matrix system containing polyacrylate polymer/β-cyclodextrin: Correlation of swelling and drug delivery performance.

    Science.gov (United States)

    Panda, Brajabihari; Subhadarsini, Rajalaxmi; Mallick, Subrata

    2016-01-01

    This study focuses on the development of amlodipine bilayer buccal tablets of hydroxypropyl methylcellulose (HPMC) matrix system containing polyacrylate polymer (Carbopol(®))/β-cyclodextrin as the drug layer and ethylcellulose as the non-swellable backing layer, and their biointerfacial phenomena. Tablets were evaluated for swelling, erosion and mucoadhesion using buccal mucosal tissue ex vivo. In vitro drug release and ex vivo drug transport across mucosal tissue were also performed in phosphate buffer (pH 6.8). The relationship of swelling with buccoadhesion and buccal permeation of various bilayer tablet formulations containing HPMC alone and in combination with Carbopol or drug-β-cyclodextrin complex has been prepared. Overall buccoadhesion of the tablet with combination of HPMC and Carbopol was increased significantly compared with that of HPMC alone. Presence of cyclodextrin did not change bioadhesion force and swelling behavior significantly. Ex vivo permeation was increased with the increase of HPMC proportion in other formulations as observed in in vitro dissolution. Drug-cyclodextrin complexes in the tablet improved permeation due to its improved dissolution at the site of biointerface of tablet and buccomucosa. Correlations of ex vivo and in vitro data have been established to predict the buccomucosal permeation from the swelling index or drug release alone.

  2. Comparison between general anesthesia and spinal anesthesia in attenuation of stress response in laparoscopic cholecystectomy: A randomized prospective trial

    Directory of Open Access Journals (Sweden)

    Writuparna Das

    2015-01-01

    Full Text Available Background: Laparoscopy though minimally invasive produces significant hemodynamic surge and neuroendocrine stress response. Though general anesthesia (GA is the conventional technique, now-a-days, regional anesthesia has been accepted for laparoscopic diagnostic procedures, and its use is also being extended to laparoscopic surgeries. Objective: The aim was to compare the hemodynamic surge and neuroendocrine stress response during laparoscopic cholecystectomy (LC under GA and spinal anesthesia (SA in American Society of Anesthesiologists (ASA PS 1 patients. Materials and Methods: Thirty ASA physical status I patients, aged 18-65 years were randomly allocated into two equal groups of 15 each. Group A received GA with controlled ventilation. Patients were preoxygenated for 5 min with 100/5 oxygen, premedicated with midazolam 0.03 mg/kg intravenous (i.v, fentanyl 2 mcg/kg i.v; induction was done with thiopentone 3-5 mg/kg i.v; intubation was achieved after muscle relaxation with 0.5 mg/kg atracurium besylate i.v. Anesthesia was maintained with 1-2% sevoflurane and N2O:O2 (60:40 and intermittent i.v injection of atracurium besylate. Group B SA with 0.5% hyperbaric bupivacaine and 25 μg fentanyl along with local anesthetic instillation in the subdiaphragmatic space. Mean arterial pressure, heart rate (HR, oxygen saturation, end tidal carbon-dioxide were recorded. Venous blood was collected for cortisol assay before induction and 30 min after pneumoperitoneum. All data were collected in Microsoft excel sheet and statistically analyzed using SPSS software version 16 (SPSS Inc., Chicago, IL, USA. All numerical data were analyzed using Student′s t-test and paired t-test. Any value <0.05 was taken as significant. Results: Mean arterial pressure and mean HR and postpneumoperitoneum cortisol level were lower in group B than group A though the difference was not statistically significant in hemodynamic parameters but significant in case of cortisol

  3. Dgroup: DG01918 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available litinib ... D09689 ... Varlitinib (USAN/INN) ... D09690 ... Varlitinib tosylate (USAN) ... DG01361 ... Crenolanib ... D10102 ... Crenolan...ib (USAN) ... D10103 ... Crenolanib besylate (USAN) ... DG01363 ... Toceranib ... D085

  4. Discharge behaviour of Mg-Al-Pb and Mg-Al-Pb-In alloys as anodes for Mg-air battery

    International Nuclear Information System (INIS)

    Wang, Naiguang; Wang, Richu; Peng, Chaoqun; Peng, Bing; Feng, Yan; Hu, Chengwang

    2014-01-01

    Highlights: • We investigate the effect of indium on the discharge behaviour of Mg-Al-Pb alloy. • We evaluate the performance of Mg-air batteries with Mg-Al-Pb and Mg-Al-Pb-In anodes. • We analyze the activation mechanism of Mg-Al-Pb-In alloy in the discharge process. - Abstract: The discharge behaviour of Mg-Al-Pb and Mg-Al-Pb-In alloys in 3.5 wt.% NaCl solution is investigated by electrochemical techniques, and compared with that of pure magnesium. The results show that Mg-Al-Pb-In alloy provides a more negative potential and exhibits a higher utilization efficiency in contrast with Mg-Al-Pb alloy and pure magnesium during the half-cell test at a large current density, and gives desirable discharge performance when used as anode for Mg- air battery. The peak power density of the Mg-air battery with Mg-Al-Pb-In anode is 94.5 mW cm −2 , which is comparable with those of Mg-H 2 O 2 semi-fuel batteries. Moreover, the activation mechanism of Mg-Al-Pb-In alloy during the discharge process is also analyzed

  5. The effect of the MgO buffer layer thickness on magnetic anisotropy in MgO/Fe/Cr/MgO buffer/MgO(001)

    Energy Technology Data Exchange (ETDEWEB)

    Kozioł-Rachwał, Anna, E-mail: a.koziolrachwal@aist.go.jp [National Institute of Advanced Industrial Science and Technology, Spintronics Research Center, Tsukuba, Ibaraki 305-8568 (Japan); AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, al. Mickiewicza 30, 30-059 Kraków (Poland); Nozaki, Takayuki; Zayets, Vadym; Kubota, Hitoshi; Fukushima, Akio; Yuasa, Shinji [National Institute of Advanced Industrial Science and Technology, Spintronics Research Center, Tsukuba, Ibaraki 305-8568 (Japan); Suzuki, Yoshishige [National Institute of Advanced Industrial Science and Technology, Spintronics Research Center, Tsukuba, Ibaraki 305-8568 (Japan); Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan)

    2016-08-28

    The relationship between the magnetic properties and MgO buffer layer thickness d was studied in epitaxial MgO/Fe(t)/Cr/MgO(d) layers grown on MgO(001) substrate in which the Fe thickness t ranged from 0.4 nm to 1.1 nm. For 0.4 nm ≤ t ≤ 0.7 nm, a non-monotonic coercivity dependence on the MgO buffer thickness was shown by perpendicular magneto-optic Kerr effect magnetometry. For thicker Fe films, an increase in the buffer layer thickness resulted in a spin reorientation transition from perpendicular to the in-plane magnetization direction. Possible origins of these unusual behaviors were discussed in terms of the suppression of carbon contamination at the Fe surface and changes in the magnetoelastic anisotropy in the system. These results illustrate a method to control magnetic anisotropy in MgO/Fe/Cr/MgO(d) via an appropriate choice of MgO buffer layer thickness d.

  6. Microstructural evolution in Mg-rich Mg-Zn-Y alloys

    International Nuclear Information System (INIS)

    Biswas, T.; Ranganathan, S.; Nair, S.; Bajargan, G.

    2005-01-01

    Mg-rich Mg-Zn-Y alloys with nominal compositions Mg 97 Zn 1 Y 2 , Mg 97 Zn 2 Y 1 , Mg 92 Zn 6.5 Y 1.5 and Mg 97-x Zn 1 Y 2 Zr x have been chosen for the present study. These alloys are prepared by using sand casting mold. The sand cast alloys are remelted and subjected to copper mold casting and melt spinning techniques. The effect of cooling rate on microstructures was studied. It is observed that the size of the precipitates decreases with an increase of cooling rate. The formation of nano precipitates results in higher strength of the alloy as compared to the conventional alloys. The microstructures of melt spun ribbons are compared with RS/PM (rapidly solidified power metallurgy) Mg 97 Zn 1 Y 2 alloy, obtained from a different source. (author)

  7. Semisolid matrix-filled hard gelatin capsules for rapid dissolution of amlodipine besilate: Development and assessment

    Directory of Open Access Journals (Sweden)

    Vijay K Tyagi

    2013-01-01

    Full Text Available The objective of the study was to prepare semisolid capsules (SSCs of poorly water-soluble drug amlodipine besilate (AB using a combination of technologies involving solid dispersion (SD preparation and converting it into semisolid matrix filled in hard gelatin capsules (termed as SSCs with the aim of reducing lag time in drug release and to improve the dissolution rate. AB is used for its anti-arrhythmic, anti-anginal, and anti-hypertensive activity. These are the emergency activities which should be treated as fast as possible like in the case of angina attack (heart attack. Any lag time that is generated due to its poor dissolution can add on in this emergency and that can be avoided by developing a readily dissolvable formulation: SDs of AB. SD of AB was prepared by fusion method using varying combinations of Poloxamer 407 and Plasdone S630. A total of nine batches (SD1−SD9 were characterized for the in vitro dissolution behavior in phosphate buffer pH7.4. SD8 with 95.8% cumulative drug release in 60 min, t50% = 4.1 min and DE 30 Min = 84.2% were selected for the development of the semisolid matrix. Differential scanning calorimetry of SD8 revealed molecular dispersion of AB and Plasdone S630 in Poloxamer 407. SD8 was then formulated as SSCs using gelucire 44/14 and PEG 400 as semisolid components and PEG 6000 as a suspending agent to achieve the reduction in lag time for drug release. A total of seven SSC formulations were prepared and evaluated for drug release. Formulation of SSC4 showed maximum cumulative drug release (CDR of 98.9% within 20 min that was almost a threefold reduction in the time required to achieve similar CDR by SD of AB. Thus, SSCs present an excellent approach to enhance the dissolution as well as to reduce the lag time of dissolution for poor water-soluble drugs especially to those therapeutic classes that are intended for faster onset of action.

  8. Amlodipine+benazepril is superior to hydrochlorothiazide+benazepril irrespective of baseline pulse pressure: subanalysis of the ACCOMPLISH trial.

    Science.gov (United States)

    Skoglund, Per H; Svensson, Per; Asp, Joline; Dahlöf, Björn; Kjeldsen, Sverre E; Jamerson, Kenneth A; Weber, Michael A; Jia, Yan; Zappe, Dion H; Östergren, Jan

    2015-02-01

    Pulse pressure (PP) is an independent risk factor for cardiovascular (CV) disease and death but few studies have investigated the effect of antihypertensive treatments in relation to PP levels before treatment. The Avoiding Cardiovascular Events Through Combination Therapy in Patients Living With Systolic Hypertension (ACCOMPLISH) trial showed that the combination of benazepril+amlodipine (B+A) is superior to benazepril+hydrochlorothiazide (B+H) in reducing CV events. We aimed to investigate whether the treatment effects in the ACCOMPLISH trial were dependent on baseline PP. High-risk hypertensive patients (n=11,499) were randomized to double-blinded treatment with single-pill combinations of either B+A or B+H and followed for 36 months. Patients were divided into tertiles according to their baseline PP and events (CV mortality/myocardial infarction or stroke) were compared. Hazard ratios (HRs) for the treatment effect (B+A over B+H) were calculated in a Cox regression model with age, coronary artery disease, and diabetes mellitus as covariates and were compared across the tertiles. The event rate was increased in the high tertile of PP compared with the low tertile (7.2% vs 4.4% P<.01). In the high and medium PP tertiles, HRs were 0.75 (95% confidence interval [CI], 0.60-0.95; P=.018) and 0.74 (CI, 0.56-0.98, P=.034), respectively, in favor of B+A. There was no significant difference between the treatments in the low tertile and no significant differences in treatment effect when comparing the HRs between tertiles of PP. B+A has superior CV protection over B+H in high-risk hypertensive patients independent of baseline PP although the absolute treatment effect is enhanced in the higher tertiles of PP where event rates are higher. © 2014 Wiley Periodicals, Inc.

  9. Role of dopants in LiF:Mg,Cu, LiF:Mg,P and LiF:Mg,Cu,P detectors

    International Nuclear Information System (INIS)

    Mohammadi, Kh.; Moussavi Zarandi, A.; Afarideh, H.; Shahmaleki, S.

    2013-01-01

    In this study, electronic structure of LiF crystal doped with Mg,Cu,P impurities was studied with WIEN2k code on the basis of FPLAPW+lo method. Results show that in Mg-doped LiF composition, an electronic trap was created with impurity concentration of 1.56% and 3.125%. In this condition, the electronic trap with increasing the percentage of the impurities up to 4.687% is annihilated. It was found, that by doping of Mg and Cu or P simultaneously, a hole-trap is created in valence band. It was realized that in LiF:Mg,Cu, LiF:Mg,P and LiF:Mg,Cu,P, Cu impurity and Li atom, have a key role in creation of levels which lead to create electronic and hole traps. Mg impurity and F atom, only have a role in creation of electronic traps. In addition, P impurity has a main role in creation of the electronic and hole traps in LiF:Mg,Cu,P. The activation energy of electronic and hole trap in LiF:Mg,Cu, LiF:Mg,P and LiF:Mg,Cu,P crystalline lattice were obtained as 0.3 and 5.5 eV, 0.92 and 3.4 eV and 0.75 and 3.1 eV, respectively. - Graphical abstract: Figure (a) and (b) shows changes in electronic structure and band gap energy of LiF crystal due to presence of Mg and Cu, Mg and P ions respectively. - Highlights: • Electronic structure of LiF, LiF:Mg,Cu, LiF:Mg,P and LiF:Mg,Cu,P materials were studied with WIEN2K code. • In LiF:Mg,Cu and LiF:Mg,Cu,P, Li atom and Cu impurity have a key role in creation of levels. • F atom and Mg impurity only have a role in creation of electronic traps. • In LiF:Mg,Cu,P, P impurity has a main role in creation of electronic and hole traps

  10. Preparation and Hydrogen Storage Properties of Mg-Rich Mg-Ni Ultrafine Particles

    Directory of Open Access Journals (Sweden)

    Jianxin Zou

    2012-01-01

    Full Text Available In the present work, Mg-rich Mg-Ni ultrafine powders were prepared through an arc plasma method. The phase components, microstructure, and hydrogen storage properties of the powders were carefully investigated. It is found that Mg2Ni and MgNi2 could be obtained directly from the vapor state reactions between Mg and Ni, depending on the local vapor content in the reaction chamber. A nanostructured MgH2 + Mg2NiH4 hydrogen storage composite could be generated after hydrogenation of the Mg-Ni ultrafine powders. After dehydrogenation, MgH2 and Mg2NiH4 decomposed into nanograined Mg and Mg2Ni, respectively. Thermogravimetry/differential scanning calorimetry (TG/DSC analyses showed that Mg2NiH4 phase may play a catalytic role in the dehydriding process of the hydrogenated Mg ultrafine particles.

  11. Dgroup: DG01917 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available anib phosphate (JAN) DG01357 ... Varlitinib ... D09689 ... Varlitinib (USAN/INN) ... D09690 ... Varlitinib tosylate (USAN) DG01361 ... Crenolan...ib ... D10102 ... Crenolanib (USAN) ... D10103 ... Crenolanib besylate (USAN) DG01363 ... Toceranib ... D0850

  12. Calcium channel blockers, angiotensin receptor blockers, and angiotensin-converting enzyme inhibitors: Effectiveness in combination with diuretics or β-blockers for treating hypertension

    Directory of Open Access Journals (Sweden)

    John D Bisognano

    2007-11-01

    Full Text Available John D Bisognano1, Trent McLaughlin2, Craig S Roberts3, Simon SK Tang31Internal Medicine Department, Cardiology Division, the University of Rochester Medical Center, Rochester, NY, USA; 2NDC Health, Phoenix, Arizona, USA; 3Pfizer Inc, New York, NY, USAAbstract: This retrospective database analysis compared the effectiveness of dihydropyridine calcium channel blockers (DHPs, angiotensin-converting enzyme (ACE inhibitors, and angiotensin receptor blockers (ARBs added to diuretics or β-blockers. Adults with hypertension treated with diuretic or β-blocker monotherapy between 1998 and 2001 were identified from a large US electronic medical records database of primary care practices. Patients were required to have a baseline blood pressure (BP ≥140/90 mmHg (≥130/80 mmHg for diabetes mellitus and recorded BP measurements within 6 months before and 1–12 months following index date. Patients were matched 1:1:1 by propensity score to correct for differences in baseline characteristics. 1875 patients met study criteria and 660 (220 in each cohort were matched based on propensity scores. Matched cohorts had no significant differences in baseline characteristics. Mean changes in systolic/diastolic BP were –17.5/–8.8, –15.7/–6.3, and –13.0/–8.0 mmHg with DHPs, ACE inhibitors, and ARBs, respectively. Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High BP 6/7 goal attainment for each regimen was 47.3%, 40.0%, and 32.2%, respectively. DHPs, ACE inhibitors, and ARBs improved BP when added to patients’ β-blocker or diuretic therapy. The greatest benefits were observed with DHPs, followed by ACE inhibitors, then ARBs.Keywords: hypertension, amlodipine besylate, lisinopril, valsartan, Joint National Committee (JNC 6 and 7

  13. Application and validation of superior spectrophotometric methods for simultaneous determination of ternary mixture used for hypertension management

    Science.gov (United States)

    Mohamed, Heba M.; Lamie, Nesrine T.

    2016-02-01

    Telmisartan (TL), Hydrochlorothiazide (HZ) and Amlodipine besylate (AM) are co-formulated together for hypertension management. Three smart, specific and precise spectrophotometric methods were applied and validated for simultaneous determination of the three cited drugs. Method A is the ratio isoabsorptive point and ratio difference in subtracted spectra (RIDSS) which is based on dividing the ternary mixture of the studied drugs by the spectrum of AM to get the division spectrum, from which concentration of AM can be obtained by measuring the amplitude values in the plateau region at 360 nm. Then the amplitude value of the plateau region was subtracted from the division spectrum and HZ concentration was obtained by measuring the difference in amplitude values at 278.5 and 306 nm (corresponding to zero difference of TL) while the total concentration of HZ and TL in the mixture was measured at their isoabsorptive point in the division spectrum at 278.5 nm (Aiso). TL concentration is then obtained by subtraction. Method B; double divisor ratio spectra derivative spectrophotometry (RS-DS) and method C; mean centering of ratio spectra (MCR) spectrophotometric methods. The proposed methods did not require any initial separation steps prior the analysis of the three drugs. A comparative study was done between the three methods regarding their; simplicity, sensitivity and limitations. Specificity was investigated by analyzing the synthetic mixtures containing different ratios of the three studied drugs and their tablets dosage form. Statistical comparison of the obtained results with those found by the official methods was done, differences were non-significant in regard to accuracy and precision. The three methods were validated in accordance with ICH guidelines and can be used for quality control laboratories for TL, HZ and AM.

  14. Re-examining the 26Mg(α ,α')26Mg reaction: Probing astrophysically important states in 26Mg

    Science.gov (United States)

    Adsley, P.; Brümmer, J. W.; Li, K. C. W.; Marín-Lámbarri, D. J.; Kheswa, N. Y.; Donaldson, L. M.; Neveling, R.; Papka, P.; Pellegri, L.; Pesudo, V.; Pool, L. C.; Smit, F. D.; van Zyl, J. J.

    2017-11-01

    Background: The 22Ne(α ,n )25Mg reaction is one of the neutron sources for the s process in massive stars. The properties of levels in 26Mg above the α -particle threshold control the strengths of the 22Ne(α ,n )25Mg and 22Ne(α ,γ )26Mg reactions. The strengths of these reactions as functions of temperature are one of the major uncertainties in the s process. Purpose: Information on the existence, spin, and parity of levels in 26Mg can assist in constraining the strengths of the 22Ne(α ,γ )26Mg and 22Ne(α ,n )25Mg reactions, and therefore in constraining s -process abundances. Methods: Inelastically scattered α particles from a 26Mg target were momentum-analyzed in the K600 magnetic spectrometer at iThemba LABS, South Africa. The differential cross sections of states were deduced from the focal-plane trajectory of the scattered α particles. Based on the differential cross sections, spin and parity assignments to states are made. Results: A newly assigned 0+ state was observed in addition to a number of other states, some of which can be associated with states observed in other experiments. Some of the deduced Jπ values of the states observed in the present study show discrepancies with those assigned in a similar experiment performed at RCNP Osaka. The reassignments and additions of the various states can strongly affect the reaction rate at low temperatures. Conclusion: The number, location, and assignment of levels in 26Mg that may contribute to the 22Ne+α reactions are not clear. Future experimental investigations of 26Mg must have an extremely good energy resolution to separate the contributions from different levels. Coincidence experiments of 26Mg provide a possible route for future investigations.

  15. Optical absorption and thermoluminescence in Mg O, Mg O:Ni and Mg O:Li irradiated at room temperature; Absorcion optica y termoluminiscencia en MgO, MgO:Ni y MgO:Li irradiados a temperatura ambiente

    Energy Technology Data Exchange (ETDEWEB)

    Delgado, L

    1984-07-01

    Optical absorption and thermoluminescence (TL) studies in Mg O, Mg O:Ni and Mg O:Li irradiated at room temperature are presented. In pure Mg O the thermal annihilation of Fe3+ by recombination with thermally released electrons at {approx} 90 and 175 degree centigree and the V center annealing by hole release up to 100 degree centigree cause the observed glow peaks at these temperatures. The TL excitation spectrum shows two maxima at 245 nm (electron center) and 288 nm (Fe3+). In Mg O:Ni X irradiation induces Fe{sup 2}+ {yields}- Fe{sup 3}+ and Ni{sup 2}+ {yields} Ni{sup 3}+ oxidations. Two TL emission bands centered at 110 degree centigree (red) and 80 o{sup C} (green) are assigned to electron release and their recombination at Fe{sup 3}+ and Ni{sup 3}+ respectively. In Mg O:Li two TL emission bands, one blue (430 nm) and the other red (730 nm) with excitation maxima at 245 nm (electron center) and 200 nm (hole center) respectively are observed. No V-center formation was detected in both Ni and Li doped samples. (Author) 42 refs.

  16. Systemic arterial hypertension secondary to chronic kidney disease in two captive-born large felids.

    Science.gov (United States)

    Leclerc, A; Trehiou-Sechi, E; Greunz, E M; Damoiseaux, C; Bouvard, J; Chetboul, V

    2017-06-01

    Systemic arterial hypertension (SHT) has been widely described in the domestic cat (Felis catus). In these feline patients, SHT is considered as the most common vascular disorder of middle-aged to older animals, and secondary SHT related to chronic kidney disease (CKD) represents the most common form of the disease. We describe here the first two cases of spontaneous SHT in large felids, i.e. one 18-year old, 34.4 kg, male North-Chinese leopard (Panthera pardus japonensis, case #1) and one 20-year old, 28.7 kg, female snow leopard (Panthera uncia, case #2), both captive-bred and previously diagnosed with CKD. Both animals underwent complete echocardiographic examination under general anesthesia due to abnormal cardiac auscultation (heart murmur and/or gallop sound), and recurrent lethargy in case #1. The combination of left ventricular remodeling with moderate aortic regurgitation of high velocity was highly suggestive of SHT, which was confirmed by indirect blood pressure measurement (systolic arterial blood pressure of 183 mmHg for case #1 and 180 mmHg for case #2). Amlodipine was prescribed (0.35-0.70 mg/kg/day orally) for 31 and 6 months respectively after the initial diagnosis. In case #1, concurrent amlodipine and benazepril treatment was associated with decreased heart murmur grade and reduced aortic insufficiency severity. These reports illustrate that, similarly to domestic cats, SHT should be suspected in old large felids with CKD and that amlodipine is a well-tolerated antihypertensive drug in these species. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Modeling and stabilities of Mg/MgH2 interfaces: A first-principles investigation

    Directory of Open Access Journals (Sweden)

    Jia-Jun Tang

    2014-07-01

    Full Text Available We have theoretically investigated the modeling and the structural stabilities of various Mg/MgH2 interfaces, i.e. Mg(101¯0/MgH2(210, Mg(0001/MgH2(101 and Mg(101¯0/MgH2(101, and provided illuminating insights into Mg/MgH2 interface. Specifically, the main factors, which impact the interfacial energies, are fully considered, including surface energies of two phases, mutual lattice constants of interface model, and relative position of two phases. The surface energies of Mg and MgH2, on the one hand, are found to be greatly impacting the interfacial energies, reflected by the lowest interfacial energy of Mg(0001/MgH2(101 which is comprised of two lowest energy surfaces. On the other hand, it is demonstrated that the mutual lattice constants and the relative position of two phases lead to variations of interfacial energies, thus influencing the interface stabilities dramatically. Moreover, the Mg-H bonding at interface is found to be the determinant of Mg/MgH2 interface stability. Lastly, interfacial and strain effects on defect formations are also studied, both of which are highly facilitating the defect formations. Our results provide a detailed insight into Mg/MgH2 interface structures and the corresponding stabilities.

  18. Transformation of Mg-bearing amorphous calcium carbonate to Mg-calcite - In situ monitoring

    Science.gov (United States)

    Purgstaller, Bettina; Mavromatis, Vasileios; Immenhauser, Adrian; Dietzel, Martin

    2016-02-01

    The formation of Mg-bearing calcite via an amorphous precursor is a poorly understood process that is of relevance for biogenic and abiogenic carbonate precipitation. In order to gain an improved insight on the controls of Mg incorporation in calcite formed via an Mg-rich amorphous calcium carbonate (Mg-ACC) precursor, the precipitation of Mg-ACC and its transformation to Mg-calcite was monitored by in situ Raman spectroscopy. The experiments were performed at 25.0 ± 0.03 °C and pH 8.3 ± 0.1 and revealed two distinct pathways of Mg-calcite formation: (i) At initial aqueous Mg/Ca molar ratios ⩽ 1:6, Mg-calcite formation occurs via direct precipitation from solution. (ii) Conversely, at higher initial Mg/Ca molar ratios, Mg-calcite forms via an intermediate Mg-rich ACC phase. In the latter case, the final product is a calcite with up to 20 mol% Mg. This Mg content is significant higher than that of the Mg-rich ACC precursor phase. Thus, a strong net uptake of Mg ions from the solution into the crystalline precipitate throughout and also subsequent to ACC transformation is postulated. Moreover, the temporal evolution of the geochemical composition of the reactive solution and the Mg-ACC has no significant effect on the obtained ;solubility product; of Mg-ACC. The enrichment of Mg in calcite throughout and subsequent to Mg-ACC transformation is likely affected by the high aqueous Mg/Ca ratio and carbonate alkalinity concentrations in the reactive solution. The experimental results have a bearing on the formation mechanism of Mg-rich calcites in marine early diagenetic environments, where high carbonate alkalinity concentrations are the rule rather than the exception, and on the insufficiently investigated inorganic component of biomineralisation pathways in many calcite secreting organisms.

  19. Lowering blood pressure effect of Apium graviolens (seledri and Orthosipleon stamineus benth (kumis kucing in mild and moderate hypertension

    Directory of Open Access Journals (Sweden)

    Siti Supari

    2002-12-01

    Full Text Available In Indonesia Apium graviolens and Orthosiphon stamineus benth have been used to as traditional medicines to lower blood pressure. Since at present time is avaiLable as a combination of those phytopharmaca in the market, therefore, it is necessary to conduct a study to evaLtnte the ffictivity and side effects of those phytopharmaca toward hypertensive subjects. A randomized double blind conftolled trial was conducted at area of Monica - Jakarta in South of Jalarta from July-untiL 29 October 2001 toward mild and moderate hypertensive subjects. The first group (72 subjects received phytophanmaca (Tensigard® /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} which contains Apium graviolens and Orthosiphon stamineus benth 3 x 250 mg, whiLe the second grottp (70 subjects had Amlodipine I x 5 mg. Obseruation were conducted for 12 weelcs, and the parameter observed wère systolic and diastolic blood pressure (SBP and DBP, plasma lipid, blood glucose before and after treatment, and electrolyte with nvo week intervals. The Resuhs revealed that the phytopharmaca treatment for 12 weelAmlodipine (SBP 24.72 t 1.63 mm4g vs 26.27 + 2.18 mmHg; P > 0,05; DBP 10.00 t0.96 mmHg vs 9.49 t 1.37 ntmHg; P> 0.05. Phytopharmaca treatment for 12

  20. Stability-Indicating RP-UPLC Method for the Simultaneous Determination of Potential Degradation and Process Impurities of Amlodipine Basylate and Benazepril HCl in Pharmaceutical Dosage Form

    Directory of Open Access Journals (Sweden)

    Gajanan B. Kasawar

    2014-10-01

    Full Text Available A stability-indicating RP-UPLC method was developed for the quantification of related impurities of amlodipine basylate (AB and Benazepril hydrochloride (BH in solid pharmaceutical dosages form. The chromatographic separation employs a C18 column using a gradient elution, being solvent-A (1.36 g of potassium dihydrogen phosphate dissolved in one liter of water, adjusted to pH 3.0 with orthophosphoric acid and solvent-B (acetonitrile delivered at a flow rate of 0.3 mL min-1. The analytes were detected and quantified at 217 nm and 240 nm using photo diode-array detector. The method was validated demonstrating to be accurate and precise within the corresponding linear range of all components. The stability of the method was investigated under different stress conditions including hydrolytic, oxidative, exposed to photolytic, humidity and thermal as recommended by ICH guidelines. Relevant degradation was found under hydrolytic and oxidative conditions. Robustness against small modification in mobile phase pH, column oven temperature, flow rate and percentage of the mobile phase composition was ascertained. Lower limit of quantification and detection was also determined. The peak purity indices (purity angle < purity threshold obtained with the aid of PDA detector and satisfactory resolution between related impurities established the specificity of the determination.

  1. Mg Incorporation Efficiency in Pulsed MOCVD of N-Polar GaN:Mg

    Science.gov (United States)

    Marini, Jonathan; Mahaboob, Isra; Hogan, Kasey; Novak, Steve; Bell, L. D.; Shahedipour-Sandvik, F.

    2017-10-01

    We report on the effect of growth polarity and pulsed or δ -doped growth mode on impurity incorporation in metalorganic chemical vapor deposition-grown GaN. In Ga-polar orientation, up to 12× enhancement in Mg concentration for given Mg flow rate is observed, resulting in enhanced p-type conductivity for these samples. In contrast, this enhancement effect is greatly diminished for N-polar samples, falling off with increasing Mg flow and showing maximum enhancement of 2.7× at 30 nmol/min Mg flow. At higher Mg flow rates, Mg incorporation at normal levels did not correspond to p-type conductivity, which may be due to Mg incorporation at nonacceptor sites. Concentrations of C, O, and Si were also investigated, revealing dependence on Mg flow in N-polar pulsed samples. Carbon incorporation was found to decrease with increasing Mg flow, and oxygen incorporation was found to remain high across varied Mg flow. These effects combine to result in N-polar samples that are not p-type when using the pulsed growth mode.

  2. Hyponatremia induced by hyperinsulinemia-euglycemia therapy.

    Science.gov (United States)

    Beavers, Jennifer R; Stollings, Joanna L; Rice, Todd W

    2017-07-15

    A case of symptomatic hyponatremia induced by hyperinsulinemia-euglycemia (HIE) therapy is reported. A 59-year-old, 81.65-kg woman with hypertension, major depressive disorder, and anxiety arrived at a tertiary medical center 1.5 hours after an intentional overdose of oral amlodipine 200 mg, metoprolol tartrate 2,000 mg, and isosorbide mononitrate 1,200 mg. Upon arrival, her pulse was 63 beats/min and blood pressure was 106/56 mm Hg. The patient's blood pressure was refractory to fluids, calcium gluconate, and norepinephrine, resulting in initiation of HIE therapy. She had recurrent episodes of hypoglycemia, which required increases of the dextrose infusion and resulted in the patient receiving a total of 6.9 L of dextrose with free water. Seventeen hours into the hospitalization, the patient became obtunded due to hyponatremia (serum sodium concentration, 121 mmol/L). HIE therapy was discontinued, an infusion of 5% dextrose injection with sodium bicarbonate added was started, and a bolus of 3% sodium chloride was administered. Nine hours after the presentation of hyponatremia, the patient's serum sodium concentration normalized (137 mmol/L), and her symptoms resolved. The patient's blood pressure, pulse, and mental status continued to improve, and the patient was transferred out of the medical intensive care unit 41 hours after her arrival at the hospital. A woman who overdosed on amlodipine, metoprolol tartrate, and isosorbide mononitrate was treated with HIE therapy and developed symptomatic hyponatremia. Hyponatremia resolved after administration of dextrose with sodium bicarbonate infusion and 3% sodium chloride infusion and cessation of HIE therapy. Copyright © 2017 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

  3. Intra-individual comparison of different contrast media concentrations (300 mg, 370 mg and 400 mg iodine) in MDCT

    Energy Technology Data Exchange (ETDEWEB)

    Behrendt, Florian F.; Keil, Sebastian; Plumhans, Cedric; Guenther, Rolf W. [RWTH Aachen University, Department of Diagnostic Radiology, University Hospital, Aachen (Germany); Pietsch, Hubertus; Jost, Gregor; Sieber, Martin A.; Seidensticker, Peter [Bayer Schering Pharma AG, Berlin (Germany); Mahnken, Andreas H. [RWTH Aachen University, Department of Diagnostic Radiology, University Hospital, Aachen (Germany); RWTH Aachen University, Applied Medical Engineering, Helmholtz-Institute for Biomedical Engineering, Aachen (Germany)

    2010-07-15

    To compare intra-individual contrast enhancement in multi-detector-row computed tomography (MDCT) using contrast media (CM) containing 300, 370 and 400 mg iodine per ml (mgI/ml). Six pigs underwent repeated chest MDCT using three different CM (iopromide 300, iopromide 370, iomeprol 400). An identical iodine delivery (IDR) rate of 1.5 gI/s and a constant total iodine dose of 300 mg/kg body weight were used. Dynamic CT were acquired at the level of the pulmonary artery, and the ascending and descending aorta. After the time enhancement curves were computed, the pulmonary and aortic peak enhancement, time to peak and plateau time above 300 HU were calculated. Intra-individual peak contrast enhancement was significantly higher for the 300 mgI/ml contrast medium compared with the 370 and 400 mgI/ml media: pulmonary trunk 595 HU vs 516 HU (p = 0.0093) vs 472HU (p = 0.0005), and aorta 505 HU vs 454 HU (p = 0.0008) vs 439 HU (p = 0.0001), respectively. Comparison of time to peaks showed no significant difference. Plateau times were significantly longer for the 300 mgI/ml than for the 370 and 400 mgI/ml CM at all anatomical sites. Given normalised IDR and total iodine burden, the use of CM with a standard concentration with 300 mg iodine/ml provides improved contrast enhancement compared with highly concentrated CM in the chest. (orig.)

  4. Quasicrystal-reinforced Mg alloys.

    Science.gov (United States)

    Kyun Kim, Young; Tae Kim, Won; Hyang Kim, Do

    2014-04-01

    The formation of the icosahedral phase (I-phase) as a secondary solidification phase in Mg-Zn-Y and Mg-Zn-Al base systems provides useful advantages in designing high performance wrought magnesium alloys. The strengthening in two-phase composites (I-phase + α -Mg) can be explained by dispersion hardening due to the presence of I-phase particles and by the strong bonding property at the I-phase/matrix interface. The presence of an additional secondary solidification phase can further enhance formability and mechanical properties. In Mg-Zn-Y alloys, the co-presence of I and Ca 2 Mg 6 Zn 3 phases by addition of Ca can significantly enhance formability, while in Mg-Zn-Al alloys, the co-presence of the I-phase and Mg 2 Sn phase leads to the enhancement of mechanical properties. Dynamic and static recrystallization are significantly accelerated by addition of Ca in Mg-Zn-Y alloy, resulting in much smaller grain size and more random texture. The high strength of Mg-Zn-Al-Sn alloys is attributed to the presence of finely distributed Mg 2 Sn and I-phase particles embedded in the α -Mg matrix.

  5. Hydriding and dehydriding rates of Mg, Mg-10TaF5, and Mg-10NbF5 prepared via reactive mechanical grinding

    Science.gov (United States)

    Song, Myoung Youp; Kwak, Young Jun; Lee, Seong Ho; Park, Hye Ryoung

    2015-01-01

    In this work, TaF5 and NbF5 were chosen as additives to enhance the hydriding and dehydriding rates of Mg. Mg, Mg-10TaF5, and Mg-10NbF5 samples were prepared by reactive mechanical grinding. The hydriding and dehydriding properties of the samples were then examined. Mg-10TaF5 had the largest amount of hydrogen absorbed for 30 min and the highest initial dehydriding rate after incubation period, followed in order by Mg-10NbF5, and Mg. At 593 K under 12 bar H2 at the first cycle, Mg-10TaF5 absorbed 3.63 wt% H for 5 min and 4.53 wt% H for 30 min. At 593 K under 1.0 bar H2 at the first cycle, Mg-10TaF5 desorbed 0 wt% H for 2.5 min, 0.59 wt% H for 5 min, 3.42 wt% H for 30 min, and 4.24 wt% H for 60 min. The reactive mechanical grinding of Mg with TaF5 or NbF5 is believed to have facilitated the nucleation and to have decreased the diffusion distances of hydrogen atoms. These two effects are believed to have increased the hydriding and dehydriding rates of Mg. The MgF2 and Ta2H formed in Mg-10TaF5, and the MgF2, NbH2, and NbF3 formed in Mg-10NbF5 are considered to have enhanced both of these effects.

  6. Superconducting properties of MgB2 particle impregnated with Mg-based alloys

    International Nuclear Information System (INIS)

    Shimizu, Yusuke; Matsuda, Kenji; Mizutani, Manabu; Nishimura, Katsuhiko; Kawabata, Tokimasa; Ikeno, Susumu; Hishinuma, Yoshimitsu; Aoyama, Shigeki

    2011-01-01

    The three-dimensional penetration method combined with semi-solid casting (SS-3DPC) was utilized to prepare magnesium diboride (MgB 2 ) powder composite materials with various host materials of Mg, Mg-3%Al, Mg-3%Al-1%Zn, Mg-9%Al, and Mg-9%Al-1%Zn. X-ray diffraction measurements indicated predominant peak patterns of MgB 2 and a host alloy, implying that the host material tightly bonded MgB 2 grains without melting the MgB 2 powder. This was confirmed by SEM images. Measured electrical resistivity and magnetization versus temperature showed clear signals of superconducting transition temperature of 27-38 K for all the samples cut out from the billets. Magnetic hysteresis loop observed at 5 K enabled us to estimate a critical current density (J c ) based on the extended Bean model. Additions of aluminum and zinc elements to magnesium host-matrix were found to enhance J c and increase residual resistivity (ρ 0 ) suggesting that aluminum and zinc have an effect on pinning magnetic flux flow for J c enhancement, and scattering conduction electrons for increase of ρ 0 . (author)

  7. Optical absorption and thermoluminescence in Mg O, Mg O:Ni and Mg O:Li irradiated at room temperature

    International Nuclear Information System (INIS)

    Delgado, L.

    1984-01-01

    Optical absorption and thermoluminescence (TL) studies in Mg O, Mg O:Ni and Mg O:Li irradiated at room temperature are presented. In pure Mg O the thermal annihilation of Fe3+ by recombination with thermally released electrons at ∼ 90 and 175 degree centigree and the V center annealing by hole release up to 100 degree centigree cause the observed glow peaks at these temperatures. The TL excitation spectrum shows two maxima at 245 nm (electron center) and 288 nm (Fe3+). In Mg O:Ni X irradiation induces Fe 2 + →- Fe 3 + and Ni 2 + → Ni 3 + oxidations. Two TL emission bands centered at 110 degree centigree (red) and 80 o C (green) are assigned to electron release and their recombination at Fe 3 + and Ni 3 + respectively. In Mg O:Li two TL emission bands, one blue (430 nm) and the other red (730 nm) with excitation maxima at 245 nm (electron center) and 200 nm (hole center) respectively are observed. No V-center formation was detected in both Ni and Li doped samples. (Author) 42 refs

  8. The Influence of MgH2 on the Assessment of Electrochemical Data to Predict the Degradation Rate of Mg and Mg Alloys

    Directory of Open Access Journals (Sweden)

    Wolf-Dieter Mueller

    2014-06-01

    Full Text Available Mg and Mg alloys are becoming more and more of interest for several applications. In the case of biomaterial applications, a special interest exists due to the fact that a predictable degradation should be given. Various investigations were made to characterize and predict the corrosion behavior in vitro and in vivo. Mostly, the simple oxidation of Mg to Mg2+ ions connected with adequate hydrogen development is assumed, and the negative difference effect (NDE is attributed to various mechanisms and electrochemical results. The aim of this paper is to compare the different views on the corrosion pathway of Mg or Mg alloys and to present a neglected pathway based on thermodynamic data as a guideline for possible reactions combined with experimental observations of a delay of visible hydrogen evolution during cyclic voltammetry. Various reaction pathways are considered and discussed to explain these results, like the stability of the Mg+ intermediate state, the stability of MgH2 and the role of hydrogen overpotential. Finally, the impact of MgH2 formation is shown as an appropriate base for the prediction of the degradation behavior and calculation of the corrosion rate of Mg and Mg alloys.

  9. Structural characteristics and corrosion behavior of biodegradable Mg-Zn, Mg-Zn-Gd alloys.

    Science.gov (United States)

    Kubásek, J; Vojtěch, D

    2013-07-01

    In this research, binary Mg-Zn (up to 3 wt% Zn) and ternary Mg-Zn-Gd (up to 3 wt% Gd, 3 wt% Zn) alloys were prepared by induction melting in an argon atmosphere. The structures of these alloys were characterized using light and scanning electron microscopy, energy dispersive spectrometry, X-ray diffraction and X-ray fluorescence. In addition, Brinell hardness measurements were taken to supplement these studies. Corrosion behavior was evaluated by immersion tests and potentiodynamic measurements in a physiological solution (9 g/l NaCl). Depending on the composition, structures of the as-cast alloys contained α-Mg dendrites, MgZn, Mg5Gd and Mg3Gd2Zn3 phases. Compared to pure Mg, zinc improved the corrosion resistance of binary Mg-Zn. Gadolinium also improved the corrosion resistance in the case of Mg-1Zn-3Gd alloy. The highest corrosion rate was observed for Mg-3Zn-3Gd alloy. Our results improve the understanding of the relationships between the structure and corrosion behavior of our studied alloy systems.

  10. Coherent interface structures and intergrain Josephson coupling in dense MgO/Mg{sub 2}Si/MgB{sub 2} nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, Katsuya; Takahashi, Kazuyuki; Uchino, Takashi, E-mail: uchino@kobe-u.ac.jp [Department of Chemistry, Graduate School of Science, Kobe University, Nada, Kobe 657-8501 (Japan); Nagashima, Yukihito [Nippon Sheet Glass Co., Ltd., Konoike, Itami 664-8520 (Japan); Seto, Yusuke [Department of Planetology, Graduate School of Science, Kobe University, Nada, Kobe 657-8501 (Japan); Matsumoto, Megumi; Sakurai, Takahiro [Center for Support to Research and Education Activities, Kobe University, Nada, Kobe 657-8501 (Japan); Ohta, Hitoshi [Molecular Photoscience Research Center, Kobe University, Nada, Kobe 657-8501 (Japan)

    2016-07-07

    Many efforts are under way to control the structure of heterointerfaces in nanostructured composite materials for designing functionality and engineering application. However, the fabrication of high-quality heterointerfaces is challenging because the crystal/crystal interface is usually the most defective part of the nanocomposite materials. In this work, we show that fully dense insulator (MgO)/semiconductor(Mg{sub 2}Si)/superconductor(MgB{sub 2}) nanocomposites with atomically smooth and continuous interfaces, including epitaxial-like MgO/Mg{sub 2}Si interfaces, are obtained by solid phase reaction between metallic magnesium and a borosilicate glass. The resulting nanocomposites exhibit a semiconductor-superconducting transition at 36 K owing to the MgB{sub 2} nanograins surrounded by the MgO/Mg{sub 2}Si matrix. This transition is followed by the intergrain phase-lock transition at ∼24 K due to the construction of Josephson-coupled network, eventually leading to a near-zero resistance state at 17 K. The method not only provides a simple process to fabricate dense nanocomposites with high-quality interfaces, but also enables to investigate the electric and magnetic properties of embedded superconducting nanograins with good intergrain coupling.

  11. Relativistic quasiparticle band structures of Mg2Si, Mg2Ge, and Mg2Sn: Consistent parameterization and prediction of Seebeck coefficients

    Science.gov (United States)

    Shi, Guangsha; Kioupakis, Emmanouil

    2018-02-01

    We apply density functional and many-body perturbation theory calculations to consistently determine and parameterize the relativistic quasiparticle band structures of Mg2Si, Mg2Ge, and Mg2Sn, and predict the Seebeck coefficient as a function of doping and temperature. The quasiparticle band gaps, including spin-orbit coupling effects, are determined to be 0.728 eV, 0.555 eV, and 0.142 eV for Mg2Si, Mg2Ge, and Mg2Sn, respectively. The inclusion of the semicore electrons of Mg, Ge, and Sn in the valence is found to be important for the accurate determination of the band gaps of Mg2Ge and Mg2Sn. We also developed a Luttinger-Kohn Hamiltonian and determined a set of band parameters to model the near-edge relativistic quasiparticle band structure consistently for all three compounds that can be applied for thermoelectric device simulations. Our calculated values for the Seebeck coefficient of all three compounds are in good agreement with the available experimental data for a broad range of temperatures and carrier concentrations. Our results indicate that quasiparticle corrections are necessary for the accurate determination of Seebeck coefficients at high temperatures at which bipolar transport becomes important.

  12. Separate and simultaneous binding effects of aspirin and amlodipine to human serum albumin based on fluorescence spectroscopic and molecular modeling characterizations: A mechanistic insight for determining usage drugs doses

    International Nuclear Information System (INIS)

    Abdollahpour, Nooshin; Asoodeh, Ahmad; Saberi, Mohammad Reza; Chamani, JamshidKhan

    2011-01-01

    The binding of aspirin (ASA) and amlodipine (AML) to human serum albumin (HSA) in aqueous solution was investigated by multiple techniques such as fluorescence quenching, resonance light scattering (RLS), three-dimensional fluorescence spectroscopy, FT-IR and zeta-potential measurements in an aqueous solution at pH=7.4. For the protein-ligand association reaction, fluorescence measurements can give important clues as to the binding of ligands to proteins, e.g., the binding mechanism, binding mode, binding constants, binding sites, etc. Fluorescence spectroscopy showed that ASA and AML could quench the HSA fluorescence spectra, and this quenching effect became more significant when both ASA and AML coexisted. The results pointed at the interaction between HSA and both drugs as ternary systems decreasing the binding constant and binding stability of the HSA-drug complex as a binary system. Therefore, by reducing the amount of drugs transported to their targets, the free drug concentration of the target would be reduced, lowering the efficacy of the drugs. It was demonstrated that there exists antagonistic behavior between the two drugs when it comes to binding of HSA. Furthermore, the fluorescence results also showed that the quenching mechanism of HSA-drug complexes as binary and ternary systems is a static procedure. The number of binding sites of HSA-ASA, (HSA-AML)ASA, HSA-AML and (HSA-ASA) AML were 1.31, 0.92, 1 and 0.93, respectively. Due to the existence of the antagonistic action between ASA and AML, the binding distance r was reduced. The results of synchronous fluorescence and three-dimensional fluorescence spectra showed that the antagonistic action between ASA and AML would alter the micro-environment around Trp and Tyr residues. Moreover, the simultaneous presence of ASA and AML during binding to HSA should be taken into account in multidrug therapy, as it induces the necessity of a monitoring therapy owing to the possible increase of uncontrolled toxic

  13. Separate and simultaneous binding effects of aspirin and amlodipine to human serum albumin based on fluorescence spectroscopic and molecular modeling characterizations: A mechanistic insight for determining usage drugs doses

    Energy Technology Data Exchange (ETDEWEB)

    Abdollahpour, Nooshin [Department of Biology, Faculty of Sciences, Mashhad Branch, Islamic Azad University, Mashhad (Iran, Islamic Republic of); Asoodeh, Ahmad [Department of Chemistry, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of); Saberi, Mohammad Reza [Department of Medical Chemistry, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad (Iran, Islamic Republic of); Chamani, JamshidKhan, E-mail: chamani@ibb.ut.ac.ir [Department of Biology, Faculty of Sciences, Mashhad Branch, Islamic Azad University, Mashhad (Iran, Islamic Republic of)

    2011-09-15

    The binding of aspirin (ASA) and amlodipine (AML) to human serum albumin (HSA) in aqueous solution was investigated by multiple techniques such as fluorescence quenching, resonance light scattering (RLS), three-dimensional fluorescence spectroscopy, FT-IR and zeta-potential measurements in an aqueous solution at pH=7.4. For the protein-ligand association reaction, fluorescence measurements can give important clues as to the binding of ligands to proteins, e.g., the binding mechanism, binding mode, binding constants, binding sites, etc. Fluorescence spectroscopy showed that ASA and AML could quench the HSA fluorescence spectra, and this quenching effect became more significant when both ASA and AML coexisted. The results pointed at the interaction between HSA and both drugs as ternary systems decreasing the binding constant and binding stability of the HSA-drug complex as a binary system. Therefore, by reducing the amount of drugs transported to their targets, the free drug concentration of the target would be reduced, lowering the efficacy of the drugs. It was demonstrated that there exists antagonistic behavior between the two drugs when it comes to binding of HSA. Furthermore, the fluorescence results also showed that the quenching mechanism of HSA-drug complexes as binary and ternary systems is a static procedure. The number of binding sites of HSA-ASA, (HSA-AML)ASA, HSA-AML and (HSA-ASA) AML were 1.31, 0.92, 1 and 0.93, respectively. Due to the existence of the antagonistic action between ASA and AML, the binding distance r was reduced. The results of synchronous fluorescence and three-dimensional fluorescence spectra showed that the antagonistic action between ASA and AML would alter the micro-environment around Trp and Tyr residues. Moreover, the simultaneous presence of ASA and AML during binding to HSA should be taken into account in multidrug therapy, as it induces the necessity of a monitoring therapy owing to the possible increase of uncontrolled toxic

  14. Chondrogenic differentiation of ATDC5-cells under the influence of Mg and Mg alloy degradation

    Energy Technology Data Exchange (ETDEWEB)

    Martinez Sanchez, Adela H., E-mail: adela.martinez@hzg.de [Helmholtz-Zentrum Geesthacht, Institute of Material Research, Department for Structural Research on Macromolecules, Geesthacht (Germany); Feyerabend, Frank; Laipple, Daniel; Willumeit-Römer, Regine [Helmholtz-Zentrum Geesthacht, Institute of Material Research, Department for Structural Research on Macromolecules, Geesthacht (Germany); Weinberg, Annelie [Department of Orthopedics and Orthopedic Surgery, Medical University of Graz (Austria); Luthringer, Bérengère J.C. [Helmholtz-Zentrum Geesthacht, Institute of Material Research, Department for Structural Research on Macromolecules, Geesthacht (Germany)

    2017-03-01

    Biodegradable magnesium (Mg)-based materials are a potential alternative to permanent implants for application in children. Nevertheless effects of those materials on growth plate cartilage and chondrogenesis have not been previously evaluated. In vitro differentiation of ATDC5 cells was evaluated under the influence of pure Mg (PMg), Mg with 10 wt% of gadolinium (Mg-10Gd) and Mg with 2 wt% of silver (Mg-2Ag) degradation products (extracts) and direct cell culture on the materials. Gene expression showed an inhibitory effect on ATDC5 mineralization with the three extracts and a chondrogenic potential of Mg-10Gd. Cells cultured in Mg-10Gd and Mg-2Ag extracts showed the same proliferation and morphology than cells cultured in growth conditions. Mg-10Gd induced an increase in production of ECM and a bigger cell size, similar to the effects found with differentiation conditions. An increased metabolic activity was observed in cells cultured under the influence of Mg-10Gd extracts, indicated by an acidic pH during most of the culture period. After 7 days of culture on the materials, ATDC5 growth, distribution and ECM synthesis were higher on Mg-10Gd samples, followed by Mg-2Ag and PMg, which was influenced by the homogeneity and composition of the degradation layer. This study confirmed the tolerance of ATDC5 cells to Mg-based materials and a chondrogenic effect of Mg-10Gd. Further studies in vitro and in vivo are necessary to evaluate cell reactions to those materials, as well as the effects on bone growth and the biocompatibility of the alloying system in the body. - Highlights: • Degradation of PMg, and Mg-2Ag do not influence ATDC5 cells growth and chondrogenic redifferentiation. • Mg-10Gd enhances fast chondrogenic redifferentiation and expression of hyperthrophic markers on ATDC5 cells. • Further evaluation of the effects of PMg, Mg-10Gd and Mg-2Ag in vivo are necessary to confirm its potential for application in growing bones.

  15. Chondrogenic differentiation of ATDC5-cells under the influence of Mg and Mg alloy degradation

    International Nuclear Information System (INIS)

    Martinez Sanchez, Adela H.; Feyerabend, Frank; Laipple, Daniel; Willumeit-Römer, Regine; Weinberg, Annelie; Luthringer, Bérengère J.C.

    2017-01-01

    Biodegradable magnesium (Mg)-based materials are a potential alternative to permanent implants for application in children. Nevertheless effects of those materials on growth plate cartilage and chondrogenesis have not been previously evaluated. In vitro differentiation of ATDC5 cells was evaluated under the influence of pure Mg (PMg), Mg with 10 wt% of gadolinium (Mg-10Gd) and Mg with 2 wt% of silver (Mg-2Ag) degradation products (extracts) and direct cell culture on the materials. Gene expression showed an inhibitory effect on ATDC5 mineralization with the three extracts and a chondrogenic potential of Mg-10Gd. Cells cultured in Mg-10Gd and Mg-2Ag extracts showed the same proliferation and morphology than cells cultured in growth conditions. Mg-10Gd induced an increase in production of ECM and a bigger cell size, similar to the effects found with differentiation conditions. An increased metabolic activity was observed in cells cultured under the influence of Mg-10Gd extracts, indicated by an acidic pH during most of the culture period. After 7 days of culture on the materials, ATDC5 growth, distribution and ECM synthesis were higher on Mg-10Gd samples, followed by Mg-2Ag and PMg, which was influenced by the homogeneity and composition of the degradation layer. This study confirmed the tolerance of ATDC5 cells to Mg-based materials and a chondrogenic effect of Mg-10Gd. Further studies in vitro and in vivo are necessary to evaluate cell reactions to those materials, as well as the effects on bone growth and the biocompatibility of the alloying system in the body. - Highlights: • Degradation of PMg, and Mg-2Ag do not influence ATDC5 cells growth and chondrogenic redifferentiation. • Mg-10Gd enhances fast chondrogenic redifferentiation and expression of hyperthrophic markers on ATDC5 cells. • Further evaluation of the effects of PMg, Mg-10Gd and Mg-2Ag in vivo are necessary to confirm its potential for application in growing bones.

  16. Performance of Mg-14Li-1Al-0.1Ce as anode for Mg-air battery

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Yibin; Li, Deyu [School of Chemical Engineering and Technology, Harbin Institute of Technology, West Street No. 92, Harbin 150001 (China); Li, Ning [School of Chemical Engineering and Technology, Harbin Institute of Technology, West Street No. 92, Harbin 150001 (China); Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, Harbin Engineering University, Harbin 150001 (China); Zhang, Milin; Huang, Xiaomei [Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, Harbin Engineering University, Harbin 150001 (China)

    2011-02-15

    In this research, a new Mg-air battery based on Mg-14Li-1Al-0.1Ce was prepared and the battery performance was investigated by constant current discharge test. The corrosion behavior of Mg, AZ31 and Mg-Li-Al-Ce were studied by self-corrosion rate measurement and potentiodynamic polarization measurement. The characteristics of Mg-Li-Al-Ce after discharge were investigated by electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results show that Mg-Li-Al-Ce is more active than Mg and AZ31. The self-corrosion rate is found to be in the order: Mg-Li-Al-Ce < Mg < AZ31. It has been observed that the Mg-air battery based on Mg-Li-Al-Ce offers higher operating voltage, anodic efficiency and capacity than those with Mg and AZ31. SEM and EIS results show that the discharge product of Mg-Li-Al-Ce is loosely adhered to the alloy surface, and thus Mg-Li-Al-Ce could keep high discharge activity during discharge. (author)

  17. Mifepristone 5 mg versus 10 mg for emergency contraception: double-blind randomized clinical trial

    Directory of Open Access Journals (Sweden)

    Carbonell JL

    2015-01-01

    Full Text Available Josep Lluis Carbonell,1 Ramon Garcia,2 Adriana Gonzalez,2 Andres Breto,2 Carlos Sanchez2 1Mediterranea Medica Clinic, Valencia, Spain; 2Eusebio Hernandez Gynecology and Obstetrics Teaching Hospital, Havana, Cuba Purpose: To estimate the efficacy and safety of 5 mg and 10 mg mifepristone for emergency contraception up to 144 hours after unprotected coitus. Methods: This double-blind randomized clinical trial was carried out at Eusebio Hernandez Hospital (Havana, Cuba. A total of 2,418 women who requested emergency contraception after unprotected coitus received either 5 mg or 10 mg mifepristone. The variables for assessing efficacy were the pregnancies that occurred and the fraction of pregnancies that were prevented. Other variables assessed were the side effects of mifepristone, vaginal bleeding, and changes in the date of the following menstruation. Results: There were 15/1,206 (1.2% and 9/1,212 (0.7% pregnancies in the 5 mg and 10 mg group, respectively (P=0.107. There were 88% and 93% prevented pregnancies in the 5 mg and 10 mg group, respectively. The side effect profiles were similar in both groups. Delayed menstruation ≥7 days was experienced by 4.9% and 11.0% of subjects in the 5 mg and 10 mg group, respectively (P=0.001. There was a significant high failure rate for women weighing >75 kg in the 5 mg group. Conclusion: It would be advisable to use the 10 mg dose of mifepristone for emergency contraception as there was a trend suggesting that the failure rate of the larger dose was lower. Keywords: mifepristone, emergency contraception

  18. Chondrogenic differentiation of ATDC5-cells under the influence of Mg and Mg alloy degradation.

    Science.gov (United States)

    Martinez Sanchez, Adela H; Feyerabend, Frank; Laipple, Daniel; Willumeit-Römer, Regine; Weinberg, Annelie; Luthringer, Bérengère J C

    2017-03-01

    Biodegradable magnesium (Mg)-based materials are a potential alternative to permanent implants for application in children. Nevertheless effects of those materials on growth plate cartilage and chondrogenesis have not been previously evaluated. In vitro differentiation of ATDC5 cells was evaluated under the influence of pure Mg (PMg), Mg with 10wt% of gadolinium (Mg-10Gd) and Mg with 2wt% of silver (Mg-2Ag) degradation products (extracts) and direct cell culture on the materials. Gene expression showed an inhibitory effect on ATDC5 mineralization with the three extracts and a chondrogenic potential of Mg-10Gd. Cells cultured in Mg-10Gd and Mg-2Ag extracts showed the same proliferation and morphology than cells cultured in growth conditions. Mg-10Gd induced an increase in production of ECM and a bigger cell size, similar to the effects found with differentiation conditions. An increased metabolic activity was observed in cells cultured under the influence of Mg-10Gd extracts, indicated by an acidic pH during most of the culture period. After 7days of culture on the materials, ATDC5 growth, distribution and ECM synthesis were higher on Mg-10Gd samples, followed by Mg-2Ag and PMg, which was influenced by the homogeneity and composition of the degradation layer. This study confirmed the tolerance of ATDC5 cells to Mg-based materials and a chondrogenic effect of Mg-10Gd. Further studies in vitro and in vivo are necessary to evaluate cell reactions to those materials, as well as the effects on bone growth and the biocompatibility of the alloying system in the body. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Electronic structure of ferromagnet-insulator interfaces: Fe/MgO and Co/MgO

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, M.

    2007-07-11

    In this thesis the electronic structure of Fe/MgO{sub x} and Co/MgO{sub x} ferromagnet-insulator interfaces, representing material systems which are widely used in magnetic tunnel junctions, is studied by means of spin- and angle-resolved photoemission spectroscopy. The photoemission studies focus particularly on the response of the ferromagnetic electronic system in contact with MgO of varying stoichiometries, as this reflects the mechanisms of metal-oxide bonding at real ferromagnet-insulator interfaces. The correlation between chemical bonding and electronic structure formation is analyzed by combining information from core- and valence-band photoemission spectroscopy. The spectral features are compared to band structure calculations, which are performed using the SPR-KKR method. The Fe/MgO and Co/MgO systems are prepared by molecular beam epitaxy under ultrahigh vacuum conditions on well-defined (4 x 6) GaAs(001) substrates. A structural analysis by means of low-energy electron diffraction (LEED) reveals their body-centered cubic crystalline structure, whereas the chemical characterization by Auger electron spectroscopy is used to quantify the chemical environment at the sample surfaces. The magnetic analysis, using the magneto-optical Kerr effect, reveals the uniaxial anisotropy of the ferromagnetic layers. A crucial parameter is given by the MgO degree of oxidation, which is addressed by means of core-level spectroscopy and quantified by suitable fitting procedures of the Mg 2p core level. The results of the photoemission experiments show, that the electronic structure of the Fe/MgO and Co/MgO ferromagnet/insulator interfaces and, consequently, the interfacial spin polarization are sensitively controlled by the interface chemistry. In particular, three distinct scenarios are identified: the nearly stoichiometric, the oxygen-deficient and the over-oxidized ferromagnet/MgO interface. Each case is defined by innate characteristics of the electronic structure at

  20. FRACTIONAL RECRYSTALLIZATION KINETICS IN DIRECTLY COLD ROLLED Al-Mg, Al-Mg-Sc AND Al-Mg-Sc-Zr ALLOY

    Directory of Open Access Journals (Sweden)

    M. S. Kaiser

    2014-12-01

    Full Text Available The evaluation of texture as a function of recrystallization has been characterized for directly cold rolled Al-6Mg, Al-6Mg-0.4Sc and Al-6Mg-0.4Sc-0.2Zr alloys. Samples were annealed isothermally at 400 °C for 1 to 240 minutes to allow recrystallization. Recrystallization kinetics of the alloys is analyzed from the micro-hardness variation. Isothermally annealed samples of aluminum alloys were also studied using JMAK type analysis to see if there exists any correlation between the methods. Recrystallization fraction behavior between two methods the scandium added alloys show the higher variation due to precipitation hardening and higher recrystallization behavior. The scandium and zirconium as a combined shows the more variation due to formation of Al3(Sc, Zr precipitate. From the microstructure it is also observed that the base Al-Mg alloy attained almost fully re-crystallized state after annealing at 400 °C for 60 minutes

  1. Investigation of the 26Mg(d, p)27Mg reaction

    NARCIS (Netherlands)

    Meurders, F.; Steld, A. van der

    1974-01-01

    The angular distributions of 31 protons groups from the 26Mg(d, p)27Mg reaction have been measured at Ed = 12.0 MeV with a split-pole magnetic spectrograph. Excitation energies have been determined for 29 bound states. Three new levels have been found. A DWBA analysis yields ln values for 19 levels;

  2. Preliminary study of the characteristics of a high Mg containing Al-Mg-Si alloy

    International Nuclear Information System (INIS)

    Yan, F; McKay, B J; Fan, Z; Chen, M F

    2012-01-01

    An Al-20Mg-4Si high Mg containing alloy has been produced and its characteristics investigated. The as-cast alloy revealed primary Mg 2 Si particles evenly distributed throughout an α-Al matrix with a β-Al 3 Mg 2 fully divorced eutectic phase observed in interdendritic regions. The Mg 2 Si particles displayed octahedral, truncated octahedral, and hopper morphologies. Additions of Sb, Ti and Zr had a refining influence reducing the size of the Mg 2 Si from 52 ± 4 μm to 25 ± 0.1 μm, 35 ± 1 μm and 34 ± 1 μm respectively. HPDC tensile test samples could be produced with a 0.6 wt.% Mn addition which prevented die soldering. Solution heating for 1 hr was found to dissolve the majority of the Al 3 Mg 2 eutectic phase with no evidence of any effect on the primary Mg 2 Si. Preliminary results indicate that the heat treatment has a beneficial effect on the elongation and the UTS.

  3. A Computational Investigation of Precipitates in Mg-RE Alloys With Applications To Mg-X Systems

    Science.gov (United States)

    Issa, Ahmed

    Increasing fuel efficiency in transportation vehicles is a major policy goal for both government and auto and aerospace manufacturers. Lightweight structural materials, such as magnesium alloys, hold great promise in enabling such fuel efficiency gains. Understanding the controlling factors in Mg alloy strengthening is crucial for the rational design of structurally strong and inexpensive Mg alloys. In this work, we seek to understand the energetic underpinnings giving rise to a class of remarkably strong Mg alloys: Mg-RE systems. We use first-principles methods to efficiently explore seventeen Mg-RE systems, drawing out broad patterns and distilling our knowledge into simple design rules for Mg alloys. We begin by investigating the controlling factors for the Mg-strengthening prismatic plate precipitates in Mg-RE systems, discovering the critical role of strain in such systems. We then proceed to investigate the surprising role of interfacial energies in determining the course of the Mg-RE precipitation reactions. Using strain and interfacial energies, we construct a phase-field model which accurately depicts the precipitate morphology as a function of time and size in a Mg-Nd system. Finally, we combine our gained insights to implement a computational alloy design scheme on a large portion of the periodic table where we seek Mg-strengthening solutes. Our work advances the understanding of strengthening in Mg alloys and lays the groundwork for full scale computational alloy design.

  4. The role of MgO content in ex situ MgB2 wires

    DEFF Research Database (Denmark)

    Kovac, P.; Hugek, I.; Meligek, T.

    2004-01-01

    An experimental study of the effect of MgO content in the MgB2 powder used for ex situ made composite wires was carried out. Two single-core MgB2/Fe/Cu wires were made using commercial MgB2 powders from Alfa Aesar containing different fraction of MgO. Critical temperature and critical currents of...

  5. Investigation of the 24Mg(d, p)25Mg reaction

    NARCIS (Netherlands)

    Meurders, F.; Korte, G. de

    1975-01-01

    Abstract Proton angular distributions from the 24Mg(d, p)25Mg reaction at Ed = 12.0 MeV have been measured with a split-pole magnetic spectrograph for Ex < 6 MeV at an average resolution (FWHM) of 7 keV. New ln values have been determined for three levels. A DWBA analysis yielded spectroscopic

  6. Formation and Corrosion Resistance of Mg-Al Hydrotalcite Film on Mg-Gd-Zn Alloy

    Science.gov (United States)

    Ba, Z. X.; Dong, Q. S.; Kong, S. X.; Zhang, X. B.; Xue, Y. J.; Chen, Y. J.

    2017-06-01

    An environment-friendly technique for depositing a Mg-Al hydrotalcite (HT) (Mg6Al2(OH)16-CO3ṡ4H2O) conversion film was developed to protect the Mg-Gd-Zn alloy from corrosion. The morphology and chemical compositions of the film were analyzed by scanning electronic microscope (SEM) equipped with energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and Raman spectroscopy (RS), respectively. The electrochemical test and hydrogen evolution test were employed to evaluate the biocorrosion behavior of Mg-Gd-Zn alloy coated with the Mg-Al HT film in the simulated body fluid (SBF). It was found that the formation of Mg-Al HT film was a transition from amorphous precursor to a crystalline HT structure. The HT film can effectively improve the corrosion resistance of magnesium alloy. It indicates that the process provides a promising approach to modify Mg-Gd-Zn alloy.

  7. Melting relations in the MgO-MgSiO3 system up to 70 GPa

    Science.gov (United States)

    Ohnishi, Satoka; Kuwayama, Yasuhiro; Inoue, Toru

    2017-06-01

    Melting experiments in a binary system MgO-MgSiO3 were performed up to 70 GPa using a CO2 laser heated diamond anvil cell. The quenched samples were polished and analyzed by a dualbeam focused ion beam (FIB) and a field emission scanning electron microscope (FE-SEM), respectively. The liquidus phase and the eutectic composition were determined on the basis of textual and chemical analyses of sample cross sections. Our experimental results show that the eutectic composition is the Si/Mg molar ratio of 0.76 at 35 GPa and it decreases with increasing pressure. Above 45 GPa, it becomes relatively constant at about 0.64-0.65 Si/Mg molar ratio. Using our experimental data collected at a wide pressure range up to 70 GPa together with previous experimental data, we have constructed a thermodynamic model of the eutectic composition of the MgO-MgSiO3 system. The eutectic composition extrapolated to the pressure and temperature conditions at the base of the mantle is about 0.64 Si/Mg molar ratio. The modeled eutectic composition is quite consistent with a previous prediction from ab initio calculations (de Koker et al. in Earth Planet Sci Lett 361:58-63, 2013), suggesting that the simple assumption of a non-ideal regular solution model can well describe the melting relation of the MgO-MgSiO3 system at high pressure. Our results show that the liquidus phase changes from MgO-periclase to MgSiO3-bridgmanite at 35 GPa for the simplified pyrolite composition ( 0.7 Si/Mg molar ratio), while MgSiO3-bridgmanite is the liquidus phase at the entire lower mantle conditions for the chondritic composition ( 0.84 Si/Mg molar ratio).

  8. Effects of limestone, N, K and Mg fertilizers on Mg absorption by oats and barley

    Energy Technology Data Exchange (ETDEWEB)

    Alston, A M

    1966-01-01

    Oats grown in a pot experiment on two sandy loams were sampled at four stages of growth. Neither KCl nor MgSO/sub 4/. 7H/sub 2/O had any effect on yield but % Mg and total Mg uptake were consistently decreased by applying K and increased by applying Mg. Ca(NO/sub 3/)/sub 2/ increased % Mg more than did (NH/sub 4/)/sub 2/SO/sub 4/, but yield and total Mg uptake were higher where (NH/sub 4/)/sub 2/SO/sub 4/ was applied. The effects of fertilizers were similar on both soils. The effects of applying (NH/sub 4/)/sub 2/SO/sub 4/ and NaNO/sub 2/ to the soil on % Mg in barley were compared in a field experiment on an acid loam to which several rates of limestone had been applied. Treatments had no effect on the % Mg in grain or straw at maturity. At four earlier stages of growth (NH/sub 4/)/sub 2/SO)/sub 4/ increased % Mg in the plants more than did NaNO/sub 2/. Limestone slightly increased % Mg. Nitrification of NH/sub 4/ in the soil was rapid.

  9. Effect of different seawater Mg

    NARCIS (Netherlands)

    Mewes, A.; Langer, G.; de Nooijer, L.J.; Bijma, J.; Reichart, G.J.

    2014-01-01

    Magnesium, incorporated in foraminiferal calcite (Mg/CaCC), is used intensively to reconstruct past seawater temperatures but, in addition to temperature, the Mg/CaCC of foraminiferal tests also depends on the ratio of Mg and Ca in seawater (Mg/CaSW). The physiological mechanisms responsible for

  10. Decay of a Jπ=36+ Resonance in the 24Mg+24Mg Reaction

    International Nuclear Information System (INIS)

    Salsac, M.-D.; Haas, F.; Courtin, S.

    2005-01-01

    For the 24 Mg+ 24 Mg reaction, striking narrow and correlated resonance structures have been observed previously in the excitation functions of the elastic and low-lying channels. In our study we have decided to focus on the resonance at E C M =45.7 MeV, which is known to have J π =36 + . Despite the very high excitation energy(∼60 MeV) in the 48 Cr composite system, this resonance has a narrow total width of 170 keV. To determine precisely which states in the inelastic 24 Mg channels carry away the resonance flux, an experiment, on the 24 Mg + 24 Mg reaction at energies On and OFF resonance, has been performed at the Legnaro Tandem accelerator using the Prisma fragment spectrometer associated with the CLARA γ array

  11. Mg-Ca Alloys Produced by Reduction of CaO: Understanding of ECO-Mg Alloy Production

    Science.gov (United States)

    Jung, In-Ho; Lee, Jin Kyu; Kim, Shae K.

    2017-04-01

    There have been long debates about the environment conscious (ECO) Mg technology which utilizes CaO to produce Ca-containing Mg alloys. Two key process technologies of the ECO-Mg process are the chemical reduction of CaO by liquid Mg and the maintenance of melt cleanliness during the alloying of Ca. Thermodynamic calculations using FactSage software were performed to explain these two key issues. In addition, an experimental study was performed to compare the melt cleanliness of the Ca-containing Mg alloys produced by the conventional route with metallic Ca and the ECO-Mg route with CaO.

  12. Positron annihilation study of formation of Mg vacancy in MgO

    International Nuclear Information System (INIS)

    Mizuno, M.; Araki, H.; Shirai, Y.; Inoue, Y.; Sugita, K.; Mizoguchi, T.; Tanaka, I.; Adachi, H.

    2004-01-01

    We have investigated the formation of Mg vacancy induced by ultra-dilute trivalent impurities in MgO by a combination of positron annihilation measurement and theoretical calculations of positron lifetimes. The undoped MgO yields the shortest positron lifetime of 130 ps that is shorter than that of 166 ps previously reported using a single crystal sample. The positron lifetime of the doped samples increases with the increase of the Al or Ga dopant concentration and is saturated at around 170 ps. This result indicates that the previously reported value of 166 ps is ascribed to not the bulk but the vacancy state induced by impurities. The experimental bulk lifetime of 130 ps, which is obtained by employing trapping model, is well reproduced by the theoretical calculation using the semiconductor model. The calculated defect lifetime is about 20 ps longer than the experimental value. This may be due to the lattice relaxation around Mg vacancy associated with the trapping of positrons. (orig.)

  13. Positron annihilation study of formation of Mg vacancy in MgO

    Energy Technology Data Exchange (ETDEWEB)

    Mizuno, M.; Araki, H.; Shirai, Y. [Science and Technology Center for Atoms, Molecules and Ions Control, Osaka Univ., Osaka (Japan); Inoue, Y.; Sugita, K. [Dept. of Materials Science and Engineering, Osaka Univ., Osaka (Japan); Mizoguchi, T.; Tanaka, I.; Adachi, H. [Dept. of Materials Science and Engineering, Kyoto Univ., Kyoto (Japan)

    2004-07-01

    We have investigated the formation of Mg vacancy induced by ultra-dilute trivalent impurities in MgO by a combination of positron annihilation measurement and theoretical calculations of positron lifetimes. The undoped MgO yields the shortest positron lifetime of 130 ps that is shorter than that of 166 ps previously reported using a single crystal sample. The positron lifetime of the doped samples increases with the increase of the Al or Ga dopant concentration and is saturated at around 170 ps. This result indicates that the previously reported value of 166 ps is ascribed to not the bulk but the vacancy state induced by impurities. The experimental bulk lifetime of 130 ps, which is obtained by employing trapping model, is well reproduced by the theoretical calculation using the semiconductor model. The calculated defect lifetime is about 20 ps longer than the experimental value. This may be due to the lattice relaxation around Mg vacancy associated with the trapping of positrons. (orig.)

  14. Synthesis of Mg(OH)2, MgO, and Mg nanoparticles using laser ablation of magnesium in water and solvents

    Energy Technology Data Exchange (ETDEWEB)

    Tran, P.X.; Howard, B.H.; Martello, D.V.; Soong, Y.; Chyu, M.K.

    2008-01-01

    laser ablation of magnesium in deionized water (OW), solutions of OW and sodium dodecyl sulfate (50S) with different concentrations, acetone and 2-propanol has been conducted, The results showed that ablation in acetone and 2-propanol yielded MgO and Mg nanocrystallites as isolated particles and agglomerated chains probably intermixed with organic residues resulting from the alterationj decomposition of the solvents under the high-energy conditions. Brucite-like Mg(OH)2 particles were mainly produced by laser ablation of Mg in either OW or OW~SOS solutions. Ablation in OW yielded particles of fiber-like shapes having a diameter of about 5-lOnm and length as long as 150nm. Materials produced in DW-SOS solutions were composed of various size and shape particles, Some had rough surfaces with irregular shapes. Small particles were about 20-30nm and larger particles were about 120 nm. Particles with rod-like, triangular, and plate-like shapes were also observed.

  15. Synthesis of Mg(OH) 2, MgO, and Mg nanoparticles using laser ablation of magnesium in water and solvents

    Science.gov (United States)

    Phuoc, Tran X.; Howard, Bret. H.; Martello, Donald V.; Soong, Yee; Chyu, Minking K.

    2008-11-01

    Laser ablation of magnesium in deionized water (DW), solutions of DW and sodium dodecyl sulfate (SDS) with different concentrations, acetone and 2-propanol has been conducted. The results showed that ablation in acetone and 2-propanol yielded MgO and Mg nanocrystallites as isolated particles and agglomerated chains probably intermixed with organic residues resulting from the alteration/decomposition of the solvents under the high-energy conditions. Brucite-like Mg(OH) 2 particles were mainly produced by laser ablation of Mg in either DW or DW-SDS solutions. Ablation in DW yielded particles of fiber-like shapes having a diameter of about 5-10 nm and length as long as 150 nm. Materials produced in DW-SDS solutions were composed of various size and shape particles. Some had rough surfaces with irregular shapes. Small particles were about 20-30 nm and larger particles were about 120 nm. Particles with rod-like, triangular, and plate-like shapes were also observed.

  16. Antibacterial biodegradable Mg-Ag alloys

    Directory of Open Access Journals (Sweden)

    D Tie

    2013-06-01

    Full Text Available The use of magnesium alloys as degradable metals for biomedical applications is a topic of ongoing research and the demand for multifunctional materials is increasing. Hence, binary Mg-Ag alloys were designed as implant materials to combine the favourable properties of magnesium with the well-known antibacterial property of silver. In this study, three Mg-Ag alloys, Mg2Ag, Mg4Ag and Mg6Ag that contain 1.87 %, 3.82 % and 6.00 % silver by weight, respectively, were cast and processed with solution (T4 and aging (T6 heat treatment.The metallurgical analysis and phase identification showed that all alloys contained Mg4Ag as the dominant β phase. After heat treatment, the mechanical properties of all Mg-Ag alloys were significantly improved and the corrosion rate was also significantly reduced, due to presence of silver. Mg(OH2 and MgO present the main magnesium corrosion products, while AgCl was found as the corresponding primary silver corrosion product. Immersion tests, under cell culture conditions, demonstrated that the silver content did not significantly shift the pH and magnesium ion release. In vitro tests, with both primary osteoblasts and cell lines (MG63, RAW 264.7, revealed that Mg-Ag alloys show negligible cytotoxicity and sound cytocompatibility. Antibacterial assays, performed in a dynamic bioreactor system, proved that the alloys reduce the viability of two common pathogenic bacteria, Staphylococcus aureus (DSMZ 20231 and Staphylococcus epidermidis (DSMZ 3269, and the results showed that the killing rate of the alloys against tested bacteria exceeded 90%. In summary, biodegradable Mg-Ag alloys are cytocompatible materials with adjustable mechanical and corrosion properties and show promising antibacterial activity, which indicates their potential as antibacterial biodegradable implant materials.

  17. Hydrodechlorination of Tetrachloromethane over Palladium Catalysts Supported on Mixed MgF2-MgO Carriers

    Directory of Open Access Journals (Sweden)

    Magdalena Bonarowska

    2016-11-01

    Full Text Available Pd/MgO, Pd/MgF2 and Pd/MgO-MgF2 catalysts were investigated in the reaction of CCl4 hydrodechlorination. All the catalysts deactivated in time on stream, but the degree of deactivation varied from catalyst to catalyst. The MgF2-supported palladium with relatively large metal particles appeared the best catalyst, characterized by good activity and selectivity to C2-C5 hydrocarbons. Investigation of post-reaction catalyst samples allowed to find several details associated with the working state of hydrodechlorination catalysts. The role of support acidity was quite complex. On the one hand, a definite, although not very high Lewis acidity of MgF2 is beneficial for shaping high activity of palladium catalysts. The MgO-MgF2 support characterized by stronger Lewis acidity than MgF2 contributes to very good catalytic activity for a relatively long reaction period (~5 h but subsequent neutralization of stronger acid centers (by coking eliminates them from the catalyst. On the other hand, the role of acidity evolution, which takes place when basic supports (like MgO are chlorided during HdCl reactions, is difficult to assess because different events associated with distribution of chlorided support species, leading to partial or even full blocking of the surface of palladium, which plays the role of active component in HdCl reactions.

  18. Intrinsic Conductivity in Magnesium-Oxygen Battery Discharge Products: MgO and MgO2

    DEFF Research Database (Denmark)

    Smith, Jeffrey G.; Naruse, Junichi; Hiramatsu, Hidehiko

    2017-01-01

    Nonaqueous magnesium–oxygen (or “Mg-air”) batteries are attractive next generation energy storage devices due to their high theoretical energy densities, projected low cost, and potential for rechargeability. Prior experiments identified magnesium oxide, MgO, and magnesium peroxide, MgO2...

  19. Corrosion analysis of AlMg2 and AlMgSi using electrochemical method

    International Nuclear Information System (INIS)

    Dian A; Maman Kartaman; Rosika K; Yanlinastuti

    2014-01-01

    Corrosion test of cladding materials and structures of research reactor fuel, AlMgSi and AlMg2 have been performed in demineralized water of pH 2 and 6.7 using an electrochemical method. Corrosion phenomenon is affected by several factor such as composition and condition of solution. The purpose of this activity is to investigate the corrosion phenomena through the determination of the parameters of corrosion and polarization curve. The materials used are AlMg2 and AlMgSi alloy in circular dish shape with an area of 1 Cm"2. Preparation of the test sample is performed through several stages polishing, cleaning and drying procedures followed ASTM G3. The electrochemical method is done by measuring the open circuit potential (OCP), polarization resistance and potentiodynamic in demineralized water of pH 2 and pH 6.7 at temperature of 25°C. The results of the OCP is the corrosion potential (Ecorr) of AlMg2 and AlMgSi each of -906.1 mV and -619.8 mV at pH 2 and -868.6 and -756.7 mV at pH 6.7 mV. The results of measurements by polarization resistance technique showed that the corrosion rate of AlMg2 and AlMgSi in safe category (<2 mpy) at pH 6.7 and at pH 2 corrosion rate increased significantly, but still in the lightweight category (<20 mpy). Potentiodynamic curves showed that the passivation at pH 6.7 is very low while the passivation at pH 2 occurs within a relatively short range potential and followed events corroded. (author)

  20. Constraints on the ^22Ne(α,n)^25Mg reaction rate from ^natMg+n Total and ^25Mg(n,γ ) Cross Sections

    Science.gov (United States)

    Koehler, Paul

    2002-10-01

    The ^22Ne(α,n)^25Mg reaction is the neutron source during the s process in massive and intermediate mass stars as well as a secondary neutron source during the s process in low mass stars. Therefore, an accurate determination of this rate is important for a better understanding of the origin of nuclides heavier than iron as well as for improving s-process models. Also, because the s process produces seed nuclides for a later p process in massive stars, an accurate value for this rate is important for a better understanding of the p process. Because the lowest observed resonance in direct ^22Ne(α,n)^25Mg measurements is considerably above the most important energy range for s-process temperatures, the uncertainty in this rate is dominated by the poorly known properties of states in ^26Mg between this resonance and threshold. Neutron measurements can observe these states with much better sensitivity and determine their parameters much more accurately than direct ^22Ne(α,n)^25Mg measurements. I have analyzed previously reported Mg+n total and ^25Mg(n,γ ) cross sections to obtain a much improved set of resonance parameters for states in ^26Mg in this region, and an improved estimate of the uncertainty in the ^22Ne(α,n)^25Mg reaction rate. This work was supported by the U.S. DOE under contract No. DE-AC05-00OR22725 with UT-Battell, LLC.

  1. Corrosion behaviour of Mg-Cu and Mg-Mo composites in 3.5% NaCl

    International Nuclear Information System (INIS)

    Budruk Abhijeet, S.; Balasubramaniam, R.; Gupta, M.

    2008-01-01

    The corrosion behaviour of pure magnesium, Mg-Cu (0.3, 0.6, and 1 vol.%) and Mg-Mo (0.1, 0.3, and 0.6 vol.%) composites has been studied in 3.5% NaCl solution by weight loss and polarisation methods. Corrosion rates determined by weight loss method were considerably higher than that determined by polarisation method. The corrosion rate increased with increasing volume fraction of reinforcement in Mg-Cu and Mg-Mo composites. At the same volume fraction of reinforcement, molybdenum reinforced composite corroded faster than copper reinforced composite. The galvanic current density between Mg-Cu and Mg-Mo couples has been experimentally measured using zero resistance ammeter technique. The experimentally observed galvanic current densities were in close agreement with those obtained using mixed potential theory analysis. SEM observation of corroded samples confirmed microgalvanic activity at the matrix/reinforcement interfaces. The poor corrosion resistance of composites has been attributed to microgalvanic effects between the matrix and reinforcements and inferior quality of surface films

  2. Structural and electronic properties of Mg and Mg-Nb co-doped TiO2 (101) anatase surface

    International Nuclear Information System (INIS)

    Sasani, Alireza; Baktash, Ardeshir; Mirabbaszadeh, Kavoos; Khoshnevisan, Bahram

    2016-01-01

    Highlights: • Formation energy of Mg and Mg-Nb co-doped TiO_2 anatase surface (101) is studied. • Effect of Mg defect to the TiO_2 anatase (101) surface and bond length distribution of the surface is studied and it is shown that Mg defects tend to stay far from each other. • Effect of Mg and Nb to the bond length distribution of the surface studied and it is shown that these defects tend to stay close to each other. • Effects of Mg and Mg-Nb defects on DSSCs using TiO_2 anatase hosting these defects are studied. - Abstract: In this paper, by using density functional theory, Mg and Nb-Mg co-doping of TiO_2 anatase (101) surfaces are studied. By studying the formation energy of the defects and the bond length distribution of the surface, it is shown that Mg defects tend to stay as far as possible to induce least possible lattice distortion while Nb and Mg defects stay close to each other to cause less stress to the surface. By investigating band structure of the surface and changes stemmed from the defects, potential effects of Mg and Mg-Nb co-doping of TiO_2 surface on dye-sensitized solar cells are investigated. In this study, it is shown that the Nb-Mg co-doping could increase J_S_C of the surface while slightly decreasing V_O_C compared to Mg doped surface, which might result in an increase in efficiency of the DSSCs compared to Nb or Mg doped surfaces.

  3. The structural, electrical and optical properties of Mg-doped ZnO with different interstitial Mg concentration

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Yonghong, E-mail: hchyh@njust.edu.cn [School of Nuclear Technology and Chemistry & Biology, Hubei University of Science and Technology, Xianning 437100 (China); Institute of Optoelectronics & Nanomaterials, College of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Zeng, Haibo [Institute of Optoelectronics & Nanomaterials, College of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Du, Jifu [School of Nuclear Technology and Chemistry & Biology, Hubei University of Science and Technology, Xianning 437100 (China); Hu, Ziyu [Beijing Computational Science Research Center, Beijing 100084 (China); Zhang, Shengli [Institute of Optoelectronics & Nanomaterials, College of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China)

    2016-10-01

    Through first principle calculations, we studied the structural, electronic and optical properties of ZnO doped by interstitial Mg. With the increase of Mg content (x), the derivations of lattice parameters from the wurtzite ZnO become more and more significant. The Mg-doped ZnO with x below 15.79% is found to be n-type semiconductor. The minimum of energy band gap and light transmittance in high energy region (7.5–25 eV) decrease while the conductivity and refractive index increase with increasing x. Further increasing x up to 20%, the Mg-doped ZnO is found to be direct-band-gap semiconductor with great structural derivation from wurtzite phase. The light transmittance increases while the refractive index decreases with the increase of x due to the change of geometry and electronic structure. So, it’s concluded that the electronic and optical properties of ZnO doped by interstitial Mg may be greatly influenced by Mg content. - Graphical abstract: The minimum of energy gap decreases while the corresponding relative number of electrons into the conduction bands increases when the interstitial Mg content x in Mg-doped ZnO increases (0 ≤ x ≤ 15.79%). - Highlights: • The energy band gap decreases with the increase of interstitial Mg content from 5.88% to 15.79%. • The conductivity increases with the increase of interstitial Mg content from 5.88% to 15.79%. • The Mg{sub x}Zn{sub 1-x}O (interstitial Mg content x= 20%) is found to be a direct-band-gap semiconductor. • The light transmittance decreases with the increase of interstitial Mg content from 5.88% to 15.79%. • The refractive index increases with the increase of interstitial Mg content from 5.88% to 15.79%.

  4. Phase diagrams of aluminium alloys of Al-Cu-Mg, Al-Mg-Si-Cu, and Al-Mg-Li system

    International Nuclear Information System (INIS)

    Ber, L.B.; Kaputkin, E.Ya.

    2001-01-01

    Isothermal diagrams of phase transformations (DPT) and temperature-time charts (TTC) of variation of electric conductivity and of mechanical features at tension were plotted following thermal treatment according to the pattern of direct hardening and ageing and according to the pattern of normal aging for D16 commercial alloy, Al-Cu-Mg model alloy of the same system, AD37 commercial alloys of Al-Mg-Si-Cu and 1424 one of Al-Li-Mg system. Phase transformations were studied by means of fluorescence electron microscopy, micro-X-ray spectral analysis, X-ray phase analysis of single crystals and polycrystals and differential scanning calorimetry. For every alloy comparison of TTC and DPT enables to clarity the mechanism of phase composition effect on features and to optimize conditions of hardening cooling and ageing [ru

  5. The dependence of Raman scattering on Mg concentration in Mg-doped GaN grown by MBE

    International Nuclear Information System (INIS)

    Flynn, Chris; Lee, William

    2014-01-01

    Magnesium-doped GaN (GaN:Mg) films having Mg concentrations in the range 5 × 10 18 –5 × 10 20 cm −3 were fabricated by molecular beam epitaxy. Raman spectroscopy was employed to study the effects of Mg incorporation on the positions of the E 2 and A 1 (LO) lines identifiable in the Raman spectra. For Mg concentrations in excess of 2 × 10 19 cm −3 , increases in the Mg concentration shift both lines to higher wave numbers. The shifts of the Raman lines reveal a trend towards compressive stress induced by incorporation of Mg into the GaN films. The observed correlation between the Mg concentration and the Raman line positions establish Raman spectroscopy as a useful tool for optimizing growth of Mg-doped GaN. (papers)

  6. Applications of thermodynamic calculations to Mg alloy design: Mg-Sn based alloy development

    International Nuclear Information System (INIS)

    Jung, In-Ho; Park, Woo-Jin; Ahn, Sang Ho; Kang, Dae Hoon; Kim, Nack J.

    2007-01-01

    Recently an Mg-Sn based alloy system has been investigated actively in order to develop new magnesium alloys which have a stable structure and good mechanical properties at high temperatures. Thermodynamic modeling of the Mg-Al-Mn-Sb-Si-Sn-Zn system was performed based on available thermodynamic, phase equilibria and phase diagram data. Using the optimized database, the phase relationships of the Mg-Sn-Al-Zn alloys with additions of Si and Sb were calculated and compared with their experimental microstructures. It is shown that the calculated results are in good agreement with experimental microstructures, which proves the applicability of thermodynamic calculations for new Mg alloy design. All calculations were performed using FactSage thermochemical software. (orig.)

  7. In vitro degradation and electrochemical corrosion evaluations of microarc oxidized pure Mg, Mg-Ca and Mg-Ca-Zn alloys for biomedical applications.

    Science.gov (United States)

    Pan, Yaokun; He, Siyu; Wang, Diangang; Huang, Danlan; Zheng, Tingting; Wang, Siqi; Dong, Pan; Chen, Chuanzhong

    2015-02-01

    Calcium phosphate (CaP) ceramic coatings were fabricated on pure magnesium (Mg) and self-designed Mg-0.6Ca, Mg-0.55Ca-1.74Zn alloys by microarc oxidation (MAO). The coating formation, growth and biomineralization mechanisms were discussed. The coating degradability and bioactivity were evaluated by immersion tests in trishydroxymethyl-aminomethane hydrochloric acid (Tris-HCl) buffer and simulated body fluid (SBF) solutions, respectively. The coatings and corrosion products were characterized by scanning electron microscope (SEM), X-ray diffractometer (XRD), X-ray photoelectron spectrometer (XPS) and fourier transform infrared spectrometer (FT-IR). The electrochemical workstation was used to investigate the electrochemical corrosion behaviors of substrates and coatings. Results showed that Mg-0.55Ca-1.74Zn alloy exhibits the highest mechanical strength and electrochemical corrosion resistance among the three alloys. The MAO-coated Mg-0.55Ca-1.74Zn alloy has the potential to be served as a biodegradable implant. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Synthesis, crystal growth and structure of Mg containing β-rhombohedral boron: MgB17.4

    International Nuclear Information System (INIS)

    Adasch, Volker; Hess, Kai-Uwe; Ludwig, Thilo; Vojteer, Natascha; Hillebrecht, Harald

    2006-01-01

    For the first time, single crystals of Mg containing β-rhombohedral boron MgB 17.4 were synthesised from the elements in a Mg/Cu melt at 1600deg. C. The crystal structure determined by the refinement of single crystal data (space group R-3m, a=10.991(2)A, c=24.161(4)A, 890 reflections, 123 variables, R 1 (F)=0.049, wR 2 (I)=0.122) improves and modifies the former structure model derived from earlier investigations on powder samples. Mg is located on four different positions with partial occupation. While the occupation of the sites D (53.3%), E (91%) and F (7.2%) is already known from other boron-rich borides related to β-rhombohedral boron, the occupation of the fourth position (18h, 6.7%) is observed for the first time. Two boron positions show partial occupation. The summation reveals the composition MgB 17.4 and Mg 5.85 B 101.9 , respectively, confirmed by WDX measurements. The single crystals of MgB 17.4 show the highest Mg content ever found. Preliminary measurements indicate no superconductivity

  9. Structural and electronic properties of Mg and Mg-Nb co-doped TiO2 (101) anatase surface

    Energy Technology Data Exchange (ETDEWEB)

    Sasani, Alireza [Department of Science, Karaj Islamic Azad University, Karaj, Alborz, P.O. Box 31485-313 (Iran, Islamic Republic of); Baktash, Ardeshir [Institute of Nano Science and Nano Technology, University of Kashan, Kashan, P.O. Box 87317-51167 (Iran, Islamic Republic of); Mirabbaszadeh, Kavoos, E-mail: mirabbas@aut.ac.ir [Department of Energy Engineering and Physics, Amirkabir University of Technology, Tehran, P. O. Box 15875-4413 (Iran, Islamic Republic of); Khoshnevisan, Bahram [Institute of Nano Science and Nano Technology, University of Kashan, Kashan, P.O. Box 87317-51167 (Iran, Islamic Republic of)

    2016-10-30

    Highlights: • Formation energy of Mg and Mg-Nb co-doped TiO{sub 2} anatase surface (101) is studied. • Effect of Mg defect to the TiO{sub 2} anatase (101) surface and bond length distribution of the surface is studied and it is shown that Mg defects tend to stay far from each other. • Effect of Mg and Nb to the bond length distribution of the surface studied and it is shown that these defects tend to stay close to each other. • Effects of Mg and Mg-Nb defects on DSSCs using TiO{sub 2} anatase hosting these defects are studied. - Abstract: In this paper, by using density functional theory, Mg and Nb-Mg co-doping of TiO{sub 2} anatase (101) surfaces are studied. By studying the formation energy of the defects and the bond length distribution of the surface, it is shown that Mg defects tend to stay as far as possible to induce least possible lattice distortion while Nb and Mg defects stay close to each other to cause less stress to the surface. By investigating band structure of the surface and changes stemmed from the defects, potential effects of Mg and Mg-Nb co-doping of TiO{sub 2} surface on dye-sensitized solar cells are investigated. In this study, it is shown that the Nb-Mg co-doping could increase J{sub SC} of the surface while slightly decreasing V{sub OC} compared to Mg doped surface, which might result in an increase in efficiency of the DSSCs compared to Nb or Mg doped surfaces.

  10. [Changes of twenty-four-hour profile blood pressure and its correction of patients with arterial hypertension on the background of combined antihypertensive therapy application].

    Science.gov (United States)

    Solomennchuk, T M; Slaba, N A; Prots'ko, V V; Bedzaĭ, A O

    2014-01-01

    The aim of this research was the study of efficiency and endurance antihypertensive therapy on the basis of fixed combination of enalapril and hydrochlorothiazide (HCTZ) and enalapril and HCTZ in combination with amlodipine according to the twenty-four-hour (? day-and-night) monitoring of blood pressure (? 24H BPM) of patients with arterial hypertension (AH) 2-3 severity. The study included 33 patients with 2-3 grade of hypertension (average age--54,40 ± 3.45 years). All patients performed ? 24H BPM before treatment and after 12 weeks of therapy. The combination of enalapril and HCTZ allowed to achieve target levels of blood pressure in 79% of patients, amlodipine additional purpose--in 86% of patients. We found that this therapy has a corrective effect on daily blood pressure profile, significantly reducing the load pressure and blood pressure variability. During treatment with the combination of enalapril and HCTZ combination of enalapril, HCTZ with amlodipine optimal daily profile of blood pressure after 12 weeks of reaching respectively 63.1% and 71.4% of patients. The treatment with combination of enalapril and HCTZ and adding of amlodipine is characterized by good endurance and high adherence to treatment.

  11. Effect of sterilization process on surface characteristics and biocompatibility of pure Mg and MgCa alloys

    International Nuclear Information System (INIS)

    Liu, X.L.; Zhou, W.R.; Wu, Y.H.; Cheng, Y.; Zheng, Y.F.

    2013-01-01

    The aim of this work was to investigate the effect of various sterilization methods on surface characteristics and biocompatibility of MgCa alloy, with pure Mg as a comparison, including steam autoclave sterilization (SA), ethylene oxide steam sterilization (EO), glutaraldehyde sterilization (GD), dry heat sterilization (DH) and Co60 γ ray radiation sterilization (R) technologies. The surface characterizations were performed by environmental scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, grazing incidence X-ray diffraction, water contact angle and surface free energy measurement, whereas the cytotoxicity and hemocompatibility were evaluated by cellular adhesive experiment, platelet adhesion and hemolysis test. The results showed that the five sterilization processes caused more changes on the surface of MgCa alloy than that on the surface of pure Mg. The GD sterilization caused the most obvious changes on the surface of the pure Mg, and the SA sterilization made the largest alteration on the MgCa alloy surface. The GD and DH sterilization processes could cause increases on surface free energy for both pure Mg and MgCa alloys, while the other three sterilization processes reduced the surface free energy. The DH and GD sterilization processes caused the least alteration on the cell adhesion on pure Mg surface, whereas the EO sterilization performed the greatest impact on the cell adhesion on the Mg–Ca alloy surface. The hemolysis percentage of pure Mg and MgCa alloys were reduced by SA sterilization, meanwhile the other four sterilization processes increased their hemolysis percentages significantly, especially for the EO sterilization. - Highlights: • The effect of sterilization on surface chemistry and biocompatibility was studied. • Sterilization caused more surface changes on MgCa alloy than pure Mg. • Co60 γ ray radiation is the most appropriate sterilization process

  12. A study on preparation and hydriding of β-Mg2Al3 and γ-Mg17Al12

    International Nuclear Information System (INIS)

    Hadi Suwarno

    2009-01-01

    The mechanism of the synthetic formation of β-Mg 2 Al 3 and γ-Mg 17 Al 12 has been studied. Mechanical alloying of Mg and Al powders with the atomic ratio of Mg:Al = 2:3 in toluene solution yields β-Mg 2 Al 3 compound after milling for 30 h. The γ-Mg 17 Al 12 can be formed by heating the β-Mg 2 Al 3 at 430°C under high vacuum. The measured hydrogen capacities of β-Mg 2 Al 3 and γ-Mg 17 Al 12 as hydride at 300°C are 3.2 and 4.9 wt%, respectively. Microstructure of the Mg-Al specimen shows that on hydriding at 300°C the polygonal shape of the γ-Mg 17 Al 12 changes into irregular shapes which are composed of γ-MgH 2 and Al. (author)

  13. Mg concentration profile and its control in the low temperature grown Mg-doped GaN epilayer

    Science.gov (United States)

    Liu, S. T.; Yang, J.; Zhao, D. G.; Jiang, D. S.; Liang, F.; Chen, P.; Zhu, J. J.; Liu, Z. S.; Liu, W.; Xing, Y.; Zhang, L. Q.; Wang, W. J.; Li, M.; Zhang, Y. T.; Du, G. T.

    2018-01-01

    In this work, the Cp2Mg flux and growth pressure influence to Mg doping concentration and depth profiles is studied. From the SIMS measurement we found that a transition layer exists at the bottom region of the layer in which the Mg doping concentration changes gradually. The thickness of transition layer decreases with the increases of Mg doping concentration. Through analysis, we found that this is caused by Ga memory effect which the Ga atoms stay residual in MOCVD system will react with Mg source, leading a transition layer formation and improve the growth rate. And the Ga memory effect can be well suppressed by increasing Mg doping concentration and growth pressure and thus get a steep Mg doping at the bottom region of p type layer.

  14. Solid-liquid stable phase equilibria of the ternary systems MgCl2 + MgB6O10+ H2O AND MgSO4 + MgB6O10 + H2O at 308.15 K

    Directory of Open Access Journals (Sweden)

    Lingzong Meng

    2014-03-01

    Full Text Available The solubilities and the relevant physicochemical properties of the ternary systems MgCl2 + MgB6O10 + H2O and MgSO4 + MgB6O10 + H2O at 308.15 K were investigated using an isothermal dissolution method. It was found that there is one invariant point, two univariant curves, and two crystallization regions of the systems. The systems belong to a simple co-saturated type, and neither double salts nor solid solutions were found. Based on the extended HW model and its temperature-dependent equations, the single-salt Pitzer parameters β(0, β(1, β(2 and CØ for MgCl2, MgSO4, and Mg(B6O7(OH6, the mixed ion-interaction parameters θCl,B6O10, θSO4,B6O10, ΨMg,Cl,B6O10, ΨMg,SO4,B6O10 of the systems at 308.15 K were fitted, In addition, the average equilibrium constants of the stable equilibrium solids at 308.15 K were obtained by a method using the activity product constant. Then the solubilities of the ternary systems are calculated. The calculated solubilities agree well with the experimental values.

  15. Structural and optical properties of ZnMgO nanostructures formed by Mg in-diffused ZnO nanowires

    International Nuclear Information System (INIS)

    Pan, C.-J.; Hsu, H.-C.; Cheng, H.-M.; Wu, C.-Y.; Hsieh, W.-F.

    2007-01-01

    ZnMgO nanostructures with wurtzite phase were prepared by thermal diffusion of Mg into the ZnO nanowires. As ZnO light-emitting devices have been operated by using ZnMgO layers as energy barrier layers to confine the carriers, it is essential to realize the characterization of ZnMgO particularly. In this work, the Mg content in Zn 1 -x Mg x O alloy determined by X-ray diffraction (XRD) and photoluminescence (PL) shows a good coincidence. The variation of lattice constant and the blueshift of near-band-edge emission indicate that Zn 2+ ions are successfully substituted by Mg 2+ ions in the ZnO lattice. In Raman-scattering studies, the change of E 2 (high) phonon line shape in ZnO:Mg nanostructures reveals the microscopic substitutional disorder. In addition to the host phonons of ZnO, two additional bands around 383 and 510 cm -1 are presumably attributed to the Mg-related vibrational modes. - Graphical abstract: We reported the synthesis of the ZnMgO nanostructures prepared by a simple vapor transport method. Magnesium-related anomalous modes are observed by Raman spectra for the first time in ZnMgO system

  16. Hydrogen absorption kinetics and structural properties of Mg85Ni10Ca5 and Mg90Ni10

    International Nuclear Information System (INIS)

    Aoki, Masakazu; Saito, Katsushi; Towata, Shin-ichi

    2005-01-01

    Mg 85 Ni 10 Ca 5 and Mg 90 Ni 10 were prepared by melting mixtures of the elements in mild steel crucibles and pouring them into copper molds. Hydrogen absorption kinetics and structural properties of the alloys were characterized by the volumetric method using a Sievert's apparatus, X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The crystallite size of Mg in Mg 85 Ni 10 Ca 5 , which is evaluated by XRD peak broadening, is about 50% smaller than that in Mg 90 Ni 10 . In addition, the nanometer-scale structure composed of Mg, Mg 2 Ni, Mg 2 Ca was observed in Mg 85 Ni 10 Ca 5 . Mg 85 Ni 10 Ca 5 shows better hydrogen absorption kinetics than Mg 90 Ni 10 in the temperature range of room temperature to 573 K. The better absorption kinetics of Mg 85 Ni 10 Ca 5 is mainly attributed to the nanometer-scale structure

  17. Enhanced post-annealing stability of perpendicular Ta/CoFeB/Mg/MgO multilayers by inhibiting Ta diffusion

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xu-Jing; Jiang, Shao-Long; Zhang, Jing-Yan; Liu, Qian-Qian; Liu, Yi-Wei; Zhao, Jian-Cheng [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China); Wu, Zheng-Long [Analytical and Testing Center, Beijing Normal University, Beijing 100875 (China); Feng, Chun, E-mail: fengchun@ustb.edu.cn [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China); Li, Ming-Hua [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China); Yu, Guang-Hua, E-mail: ghyu@mater.ustb.edu.cn [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China)

    2016-03-01

    Graphical abstract: To reveal the underlying mechanism of Mg influence on the enhanced post-annealing stability of perpendicular Ta/CoFeB/Mg/MgO multilayers, the X-ray photoelectron spectroscopy analysis have been performed. It is found that a certain amount of Mg interlayer at the CoFeB/MgO interface could prevent the Ta oxidation to some extent due to the oxygen deficit MgO{sub x} (x < 1), and consequently lower the diffusion motivation of Ta from the bottom layer to the CoFeB/MgO interfaces to some extent during the annealing process. The prevention of Ta diffusion realizes the effective hybridization of Fe and O at the CoFeB/MgO interface and maintains interfacial magnetic anisotropy (K{sub CoFeB/MgO}). As a result, the perpendicular magnetic anisotropy at high annealing temperatures was maintained. - Highlights: • High annealing stability of perpendicular Ta/CoFeB/Mg/MgO multilayers was realized. • X-ray photoelectron spectroscopy analysis has been performed to explore the reasons. • The prevention of Ta diffusion was realized by introducing Mg at the CoFeB/MgO interface. - Abstracts: To reveal the underlying mechanism of Mg influence on the enhanced post-annealing stability of perpendicular Ta/CoFeB/Mg/MgO multilayers, the X-ray photoelectron spectroscopy analysis has been performed. It is found that a certain amount of Mg interlayer at the CoFeB/MgO interface could prevent the Ta oxidation, and consequently lower the diffusion motivation of Ta from the bottom layer to the CoFeB/MgO interfaces to some extent in the annealing process. The prevention of Ta diffusion realizes the effective hybridization of Fe and O at the CoFeB/MgO interface and maintains interfacial magnetic anisotropy (KCoFeB/MgO). As a result, the perpendicular magnetic anisotropy at high annealing temperatures is maintained.

  18. In vivo and in vitro degradation comparison of pure Mg, Mg-10Gd and Mg-2Ag: a short term study

    Directory of Open Access Journals (Sweden)

    I Marco

    2017-02-01

    Full Text Available The purpose of this study was to compare short term in vitro and in vivo biodegradation studies with low purity Mg (> 99.94 %, Mg-10Gd and Mg-2Ag designed for biodegradable implant applications. Three in vitro testing conditions were applied, using (i phosphate buffered saline (PBS, (ii Hank’s balanced salt solution (HBSS and (iii Dulbecco’s modified eagle medium (DMEM in 5 % CO2 under sterile conditions. Gas evolution and mass loss (ML were assessed, as well as the degradation layer, by elemental mapping and scanning electron microscopy (SEM. In vivo, implantations were performed on male Sprague-Dawley rats evaluating both, gas cavity volume and implant volume reduction by micro-computed tomography (µCT, 7 d after implantation. Samples were produced by casting, solution heat treatment and extrusion in disc and pin shape for the in vitro and in vivo experiments, respectively. Results showed that when the processing of the Mg sample varied, differences were found not only in the alloy impurity content and the grain size, but also in the corrosion behaviour. An increase of Fe and Ni or a large grain size seemed to play a major role in the degradation process, while the influence of alloying elements, such as Gd and Ag, played a secondary role. Results also indicated that cell culture conditions induced degradation rates and degradation layer elemental composition comparable to in vivo conditions. These in vitro and in vivo degradation layers consisted of Mg hydroxide, Mg-Ca carbonate and Ca phosphate.

  19. Respiratory outcomes following 100 mg/kg v. 200 mg/kg of poractant ...

    African Journals Online (AJOL)

    In keeping with current evidence, the initial dose of poractant alpha was increased from 100 mg/kg to 200 mg/kg. e outcomes of newborns requiring treatment with surfactant before and aer this change were reviewed. Methods. Electronic clinical records were reviewed of infants admitted to ACH who received surfactant ...

  20. Mg/Ca ratio in fertilization and agricultural soils, Mg percent of liming ...

    African Journals Online (AJOL)

    Strong increase of NPK (nitrogen, phosphorus and potassium) in mineral fertilization (fm) included relative delay in Mg supplementation and dilution in plant available silicon (Si) via recycled nutrients (rcl). (Silicon is not included in essential fertilizers in Finland.) Methods: We have assessed old data on Ca and Mg in ...

  1. Enhanced post-annealing stability of perpendicular Ta/CoFeB/Mg/MgO multilayers by inhibiting Ta diffusion

    International Nuclear Information System (INIS)

    Li, Xu-Jing; Jiang, Shao-Long; Zhang, Jing-Yan; Liu, Qian-Qian; Liu, Yi-Wei; Zhao, Jian-Cheng; Wu, Zheng-Long; Feng, Chun; Li, Ming-Hua; Yu, Guang-Hua

    2016-01-01

    Graphical abstract: To reveal the underlying mechanism of Mg influence on the enhanced post-annealing stability of perpendicular Ta/CoFeB/Mg/MgO multilayers, the X-ray photoelectron spectroscopy analysis have been performed. It is found that a certain amount of Mg interlayer at the CoFeB/MgO interface could prevent the Ta oxidation to some extent due to the oxygen deficit MgO_x (x < 1), and consequently lower the diffusion motivation of Ta from the bottom layer to the CoFeB/MgO interfaces to some extent during the annealing process. The prevention of Ta diffusion realizes the effective hybridization of Fe and O at the CoFeB/MgO interface and maintains interfacial magnetic anisotropy (K_C_o_F_e_B_/_M_g_O). As a result, the perpendicular magnetic anisotropy at high annealing temperatures was maintained. - Highlights: • High annealing stability of perpendicular Ta/CoFeB/Mg/MgO multilayers was realized. • X-ray photoelectron spectroscopy analysis has been performed to explore the reasons. • The prevention of Ta diffusion was realized by introducing Mg at the CoFeB/MgO interface. - Abstracts: To reveal the underlying mechanism of Mg influence on the enhanced post-annealing stability of perpendicular Ta/CoFeB/Mg/MgO multilayers, the X-ray photoelectron spectroscopy analysis has been performed. It is found that a certain amount of Mg interlayer at the CoFeB/MgO interface could prevent the Ta oxidation, and consequently lower the diffusion motivation of Ta from the bottom layer to the CoFeB/MgO interfaces to some extent in the annealing process. The prevention of Ta diffusion realizes the effective hybridization of Fe and O at the CoFeB/MgO interface and maintains interfacial magnetic anisotropy (KCoFeB/MgO). As a result, the perpendicular magnetic anisotropy at high annealing temperatures is maintained

  2. Effect of amorphous Mg50Ni50 on hydriding and dehydriding behavior of Mg2Ni alloy

    International Nuclear Information System (INIS)

    Guzman, D.; Ordonez, S.; Fernandez, J.F.; Sanchez, C.; Serafini, D.; Rojas, P.A.; Aguilar, C.; Tapia, P.

    2011-01-01

    Composite Mg 2 Ni (25 wt.%) amorphous Mg 50 Ni 50 was prepared by mechanical milling starting with nanocrystalline Mg 2 Ni and amorphous Mg 50 Ni 50 powders, by using a SPEX 8000 D mill. The morphological and microstructural characterization of the powders was performed via scanning electron microscopy and X-ray diffraction. The hydriding characterization of the composite was performed via a solid gas reaction method in a Sievert's-type apparatus at 363 K under an initial hydrogen pressure of 2 MPa. The dehydriding behavior was studied by differential thermogravimetry. On the basis of the results, it is possible to conclude that amorphous Mg 50 Ni 50 improved the hydriding and dehydriding kinetics of Mg 2 Ni alloy upon cycling. A tentative rationalization of experimental observations is proposed. - Research Highlights: → First study of the hydriding behavior of composite Mg 2 Ni (25 wt.%) amorphous Mg 50 Ni 50 . → Microstructural characterization of composite material using XRD and SEM was obtained. → An improved effect of Mg 50 Ni 50 on the Mg 2 Ni hydriding behavior was verified. → The apparent activation energy for the hydrogen desorption of composite was obtained.

  3. Synthesis of Mg(OH)2, MgO, and Mg nanoparticles using laser ablation of magnesium in water and solvents

    Energy Technology Data Exchange (ETDEWEB)

    Phuoc, Tran X. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Howard, Bret. H. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Martello, Donald V. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Soong, Yee [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Chyu, Minking K. [Univ. of Pittsburgh, PA (United States)

    2008-11-01

    Laser ablation of magnesium in deionized water (DW), solutions of DW and sodium dodecyl sulfate (SDS) with different concentrations, acetone and 2-propanol has been conducted. The results showed that ablation in acetone and 2-propanol yielded MgO and Mg nanocrystallites as isolated particles and agglomerated chains probably intermixed with organic residues resulting from the alteration/decomposition of the solvents under the high-energy conditions. Brucite-like Mg(OH)2 particles were mainly produced by laser ablation of Mg in either DW or DW-SDS solutions. Ablation in DW yielded particles of fiber-like shapes having a diameter of about 5-10nm and length-as long as 150 nm. Materials produced in DW-SDS solutions were composed of various size and shape particles. Some had rough surfaces with irregular shapes. Small particles were about 20-30 nm and larger particles were about 120 nm. Particles with rodlike, triangular, and plate-like shapes were also observed.

  4. Mg-MOF-74/MgF₂ Composite Coating for Improving the Properties of Magnesium Alloy Implants: Hydrophilicity and Corrosion Resistance.

    Science.gov (United States)

    Liu, Wei; Yan, Zhijie; Ma, Xiaolu; Geng, Tie; Wu, Haihong; Li, Zhongyue

    2018-03-07

    Surface modification on Mg alloys is highly promising for their application in the field of bone repair. In this study, a new metal-organic framework/MgF₂ (Mg-MOF-74/MgF₂) composite coating was prepared on the surface of AZ31B Mg alloy via pre-treatment of hydrofluoric acid and in situ hydrothermal synthesis methods. The surface topography of the composite coating is compact and homogeneous, and Mg-MOF-74 has good crystallinity. The corrosion resistance of this composite coating was investigated through Tafel polarization test and immersion test in simulated body fluid at 37 °C. It was found that Mg-MOF-74/MgF₂ composite coating significantly slowed down the corrosion rate of Mg alloy. Additionally, Mg-MOF-74/MgF₂ composite coating expresses super-hydrophilicity with the water contact angle of nearly 0°. In conclusion, on the basis of MgF₂ anticorrosive coating, the introduction of Mg-MOF-74 further improves the biological property of Mg alloys. At last, we propose that the hydrophilicity of the composite coating is mainly owing to the large number of hydroxyl groups, the high specific surface area of Mg-MOF-74, and the rough coating produced by Mg-MOF-74 particles. Hence, Mg-MOF-74 has a great advantage in enhancing the hydrophilicity of Mg alloy surface.

  5. Effect of Mg content on microstructure and corrosion behavior of hot dipped Zn–Al–Mg coatings

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Caizhen; Lv, Haibing [Research Centre of Laser Fusion, CAEP, P.O.Box 919-988-5, Mianyang, Sichuan 621900 (China); Zhu, Tianping [Department of Chemical and Materials Engineering, The University of Auckland, PB 92019, Auckland 1142 (New Zealand); Zheng, Wanguo [Research Centre of Laser Fusion, CAEP, P.O.Box 919-988-5, Mianyang, Sichuan 621900 (China); Yuan, Xiaodong, E-mail: xdyuan@caep.cn [Research Centre of Laser Fusion, CAEP, P.O.Box 919-988-5, Mianyang, Sichuan 621900 (China); Gao, Wei, E-mail: w.gao@auckland.ac.nz [Department of Chemical and Materials Engineering, The University of Auckland, PB 92019, Auckland 1142 (New Zealand)

    2016-06-15

    In this article, Zn–Al–Mg coatings were prepared by hot dipping method. The surface morphology, cross–section microstructure, microhardness, composition, corrosion behaviour of ZAM coatings were investigated by using X–ray diffraction (XRD), Optical microscope, Environmental scanning electron microscopy equipped with EDS (FESEM–EDS), Microhardness tester and Electrochemical analysis respectively. Corrosion test was also performed in a standard salt fog spray chamber. Microstructure studies indicates that Zn grain size was refined and eutectic areas at Zn grain boundary areas increased with increasing Mg content. ZA5M1.5 and ZA5M2 coatings have two distinct layers. Mg tends to exist in the outer layer while Al is in the inner layer. The inner layer is composed of Al{sub 5}Fe{sub 2}Zn{sub 0.4} intermetallic, which may to contribute to the microhardness. The outer layer is Zn grains surrounded by Zn–Mg etutectics, which may improve the corrosion resistance. The microhardness is more than 700 HV{sub 50g} for Al-rich layer and around 151 HV{sub 25g} for Mg-rich layer. The improved corrosion resistance of Zn–5%Al-1.5%Mg coating comes from the corrosion product of flocculent type simonkolleite, which prolongs the micro-path and impedes the movement of O{sub 2} and H{sub 2}O, ultimately retards the overall corrosion process. - Highlights: • Two-layer structured Zn–Al–Mg coatings were prepared by hot dipping method. • Mg exists in the outer layer while Al exists in the inner layer of Zn–Al–Mg coating. • Zn–Al–Mg coating has better protective ability than Zn and Zn–Al coatings. • The Mg-modified simonkolleite is the reason of the enhanced corrosion resistance.

  6. Green emission from ZnO–MgO nanocomposite due to Mg diffusion at the interface

    International Nuclear Information System (INIS)

    Sowri Babu, K.; Ramachandra Reddy, A.; Venugopal Reddy, K.

    2015-01-01

    The origin and electronic transitions responsible for green emission observed from ZnO–MgO nanocomposite are investigated. The photoluminescence (PL) spectrum of ZnO–MgO nanocomposite annealed at 600 °C showed only a sharp and intense UV emission peak centered at 396 nm. As the annealing temperature increased from 600 °C to 1000 °C, the green emission positioned at 503 nm is emerged and its intensity enhanced gradually and reached maximum value at 900 °C and then decreased at 1000 °C. It is observed that both UV and green emission intensities are enhanced with variation of atomic ratio (Zn/Mg=1.52, 0.50, 0.30, 0.21, 0.15). Our experiments confirmed that the enhancement of green emission intensity is due to the formation of oxygen vacancies (V o ) due to Mg doping at the interface of ZnO and MgO. This experimental observation is in good agreement with the recent theoretical predictions which states that Mg doping in ZnO lowers the formation energies of oxygen vacancies (V o ) and zinc interstitials (Zn i ) significantly. PL excitation and emission spectra analysis reveals that excited state for both UV and green emissions is same and lies 0.24 eV below the conduction band of ZnO. Hence, the green emission is attributed to the transition of an electron form the shallow donor (defect level of Zn i ) to the deep acceptor (defect level of V o ). - Highlights: • It is found that the UV emission intensity from ZnO–MgO nanocomposite enhanced with increase of Mg concentration. • The intensity of the green emission is enhanced gradually as the temperature increased from 600 °C to 900 °C and then decreased at 1000 °C. • The effect of Mg concentration, MgO, strain at the interface on green emission is investigated. • These experiments confirmed that green emission is due to the oxygen vacancies created in ZnO due to the Mg doping at the interface and it is in good agreement with the theoretical predictions. • The decrease of green emission intensity is

  7. Phase formation in Mg-Sn-Si and Mg-Sn-Si-Ca alloys

    Energy Technology Data Exchange (ETDEWEB)

    Kozlov, A.; Groebner, J. [Institute of Metallurgy, Clausthal University of Technology, Robert-Koch-Str. 42, D-38678 Clausthal-Zellerfeld (Germany); Schmid-Fetzer, R., E-mail: schmid-fetzer@tu-clausthal.de [Institute of Metallurgy, Clausthal University of Technology, Robert-Koch-Str. 42, D-38678 Clausthal-Zellerfeld (Germany)

    2011-02-17

    Research highlights: > The solidification paths of ternary and quaternary alloys are analyzed in detail, using the tool of thermodynamic calculations. > The precipitation sequence of phases and their amounts compare well with the microstructure of alloys. > The most efficient comparison to the experimental thermal analysis data is done by calculation of the enthalpy variation with temperature. > The viability of a procedure for the selection of multicomponent key samples is demonstrated for the development of the Mg-Ca-Si-Sn phase diagram. - Abstract: Experimental work is done and combined with the Calphad method to generate a consistent thermodynamic description of the Mg-Ca-Si-Sn quaternary system, validated for Mg-rich alloys. The viability of a procedure for the selection of multicomponent key samples is demonstrated for this multicomponent system. Dedicated thermal analysis with DTA/DSC on sealed samples is performed and the microstructure of slowly solidified alloys is analyzed using SEM/EDX. The thermodynamic description and phase diagram of the ternary Mg-Si-Sn system, developed in detail also in this work, deviates significantly from a previous literature proposal. The phase formation in ternary and quaternary alloys is analyzed using the tool of thermodynamic equilibrium and Scheil calculations for the solidification paths and compared with present experimental data. The significant ternary/quaternary solid solubilities of pertinent intermetallic phases are quantitatively introduced in the quaternary Mg-Ca-Si-Sn phase diagram and validated by experimental data.

  8. Mg/Ca of Continental Ostracode Shells

    Science.gov (United States)

    Ito, E.; Forester, R. M.; Marco-Barba, J.; Mezquita, F.

    2007-12-01

    Marine ionic chemistry is thought to remain constant. This, together with the belief that marine calcifiers partition Mg/Ca in a systematic manner as functions of temperature (and Mg/Ca) of water forms the basis of the Mg/Ca thermometer. In continental settings both of these assumptions are usually not true. Continental waters contain a wide variety of solutes in absolute and relative ion concentrations. Hence, waters with identical Mg/Ca may have very different concentrations of Mg and Ca and very different anions. Here we use two examples to focus on the effects of ion chemistry on Mg/Ca partitioning in continental ostracode shells and we ignore the complexities of solute evolution, which can change Mg/Ca over timescales of minutes to millennia. Palacios-Fest and Dettman (2001) conducted a monthly study of ,Cypridopsis vidua at El Yeso Lake in Sonora, Mexico. They established a relation between temperature and average shell Mg/Ca using regression analyses on averaged data. When their Mg/Ca-temperature relation is applied to monthly ,C. vidua data from Page Pond near Cleveland, Ohio, water temperatures of -8 to -1°C are obtained. The observed Mg/Ca ranges for El Yeso Lake (0.31 to 0.46) and Page Pond (0.33 to 0.46) are similar, as are their specific conductivities (700 to 850μS for El Yeso Lake; 400 to 600μS for Page Pond). However, [Ca] is 140-260 mg/L for El Yeso, but only 70-90 mg/L for Page Pond. Page Pond data, in fact, shows a good temperature shell Mg/Ca relation for .C. vidua, but the relation is different from that at El Yeso. Hence, shell Mg/Ca is a multi-valued, family of curves function of temperature and Mg/Ca of water that depends on the [Mg] and [Ca] values in water and perhaps other factors. Our second example comes from sites near Valencia, Spain and involves shell data for ,Cyprideis torosa, an estuarine ostracode that is tolerant of a wide range of salinity and can live in continental waters as long as the carbonate alkalinity to Ca ratio is

  9. Single crystal structures of the new vanadates CuMgVO{sub 4} and AgMgVO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Ben Yahia, Hamdi, E-mail: Hyahia@qf.org.qa [Research Institute of Electrochemical Energy, National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan); Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Qatar Foundation, PO Box 5825, Doha (Qatar); Shikano, Masahiro, E-mail: shikano.masahiro@aist.go.jp [Research Institute of Electrochemical Energy, National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan); Essehli, Rachid; Belharouak, Ilias [Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Qatar Foundation, PO Box 5825, Doha (Qatar)

    2016-08-01

    The new compounds CuMgVO{sub 4} and AgMgVO{sub 4} have been synthesized by a solid state reaction route. Their crystal structures were determined from single-crystal X-ray diffraction data. CuMgVO{sub 4} crystallizes with Na{sub 2}CrO{sub 4}-type structure with space group Cmcm, a = 5.6932 (10), b = 8.7055 (15), c = 6.2789 (10) Å, V = 311.20 (9) Å{sup 3}, and Z = 4, whereas AgMgVO{sub 4} crystallizes in the maricite-type structure with space group Pnma, a = 9.4286 (14), b = 6.7465 (10), c = 5.3360 (8) Å, V = 339.42 (9) Å{sup 3}, and Z = 4. Both structures of CuMgVO{sub 4}, and AgMgVO{sub 4} contain MgO{sub 4} chains made up of edge-sharing MgO{sub 6} octahedra. In CuMgVO{sub 4} the MgO{sub 4} chains are interconnected through CuVO{sub 4} double chains made up of VO{sub 4} and CuO{sub 4} tetrahedra sharing corners and edges, however in AgMgVO{sub 4} the chains are interlinked by the VO{sub 4} and AgO{sub 4} tetrahedra sharing only corners. - Highlights: • We have been able to grow CuMgVO{sub 4} and AgMgVO{sub 4} single crystals. • We solved their crystal structures using single crystal data. • We compared the crystal structures of CuMgVO{sub 4} and AgMgVO{sub 4}.

  10. Experimental investigation and thermodynamic calculation of the Fe-Mg-Mn and Fe-Mg-Ni systems

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Peisheng; Zhao, Jingrui; Xu, Honghui; Liu, Shuhong; Ouyang, Hongwu [Central South Univ., Hunan (China). State Key Lab. of Powder Metallurgy; Du, Yong [Central South Univ., Hunan (China). State Key Lab. of Powder Metallurgy; Harbin Institute of Technology (China). State Key Lab. of Advanced Welding Production Technology; Gang, Tie; Fen, Jicai [Harbin Institute of Technology (China). State Key Lab. of Advanced Welding Production Technology; Zhang, Lijun [Central South Univ., Hunan (China). State Key Lab. of Powder Metallurgy; Bochum Univ. (Germany). ICAMS Inst.; He, Cuiyun [Guangxi Univ. (China). College of Physical Science and Technology

    2011-01-15

    Based on the thermodynamic calculations extrapolated from the corresponding binary sub-systems, four decisive alloys in the Fe-Mg-Mn system and three in the Fe-Mg-Ni system were selected and prepared using a powder metallurgy method to measure the isothermal sections at 500 C in both systems. The prepared samples were annealed at 500 C, and then subjected to X-ray diffraction, optical microscopy, scanning electron microscopy with energy-dispersive X-ray spectrometry as well as electron probe microanalysis. Taking into account the presently obtained experimental data and the experimental data available in the literature, thermodynamic modeling was performed for the above systems. It was found that a direct extrapolation from the corresponding three binary systems can well reproduce all the experimental data in the Fe-Mg-Mn system, while two thermodynamic parameters are needed in the Fe-Mg-Ni system to fit all the experimental data. The liquidus projections and reaction schemes for the Fe-Mg-Mn and Fe-Mg-Ni systems are also presented. (orig.)

  11. Proton resonance elastic scattering of $^{30}$Mg for single particle structure of $^{31}$Mg

    CERN Multimedia

    The single particle structure of $^{31}$Mg, which is located in the so-called “island of inversion”, will be studied through measuring Isobaric Analog Resonances (IARs) of bound states of $^{31}$Mg. They are located in the high excitation energy of $^{31}$Al. We are going to determine the spectroscopic factors and angular momenta of the parent states by measuring the excitation function of the proton resonance elastic scattering around 0 degrees in the laboratory frame with around 3 MeV/nucleon $^{30}$Mg beam. The present study will reveal the shell evolution around $^{32}$Mg. In addition, the spectroscopic factor of the (7/2)$^{−}$ state which was not yet determined experimentally, may allow one to study the shape coexistence in this nucleus.

  12. Mechanism of magnetoresistance ratio enhancement in MgO/NiFe/MgO heterostructure by rapid thermal annealing

    Science.gov (United States)

    Zhao, Chong-Jun; Liu, Yang; Zhang, Jing-Yan; Sun, Li; Ding, Lei; Zhang, Peng; Wang, Bao-Yi; Cao, Xing-Zhong; Yu, Guang-Hua

    2012-08-01

    To reveal thermal effects on the film quality/microstructure evolution and the resulted magnetoresistance (MR) ratio in MgO/NiFe/MgO heterostructures, positron annihilation spectroscopy studies have been performed. It is found that the ionic interstitials in the MgO layers recombine with the nearby vacancies at lower annealing temperatures (200-300 °C) and lead to a slow increase in sample MR. Meanwhile, vacancy defects agglomeration/removal and ordering acceleration in MgO will occur at higher annealing temperatures (450-550 °C) and the improved MgO and MgO/NiFe interfaces microstructure are responsible for the observed significant MR enhancement.

  13. Alterations of Mg2+ After Hemorrhagic Shock.

    Science.gov (United States)

    Lee, Mun-Young; Yang, Dong Kwon; Kim, Shang-Jin

    2017-11-01

    Hemorrhagic shock is generally characterized by hemodynamic instability with cellular hypoxia and diminishing cellular function, resulting from an imbalance between systemic oxygen delivery and consumption and redistribution of fluid and electrolytes. Magnesium (Mg) is the fourth most abundant cation overall and second most abundant intracellular cation in the body and an essential cofactor for the energy production and cellular metabolism. Data for blood total Mg (tMg; free-ionized, protein-bound, and anion-bound forms) and free Mg 2+ levels after a traumatic injury are inconsistent and only limited information is available on hemorrhagic effects on free Mg 2+ as the physiologically active form. The aim of this study was to determine changes in blood Mg 2+ and tMg after hemorrhage in rats identifying mechanism and origin of the changes in blood Mg 2+ . Hemorrhagic shock produced significant increases in blood Mg 2+ , plasma tMg, Na + , K + , Cl - , anion gap, partial pressures of oxygen, glucose, and blood urea nitrogen but significant decreases in RBC tMg, blood Ca 2+ , HCO 3 - , pH, partial pressures of carbon dioxide, hematocrit, hemoglobin, total cholesterol, and plasma/RBC ATP. During hemorrhagic shock, K + , anion gap, and BUN showed significant positive correlations with changes in blood Mg 2+ level, while Ca 2+ , pH, and T-CHO correlated to Mg 2+ in a negative manner. In conclusion, hemorrhagic shock induced an increase in both blood-free Mg 2+ and tMg, resulted from Mg 2+ efflux from metabolic damaged cell with acidosis and ATP depletion.

  14. Bioequivalence of a single 400-mg dose of imatinib 100-mg oral tablets and a 400-mg tablet in healthy adult Korean volunteers.

    Science.gov (United States)

    Lee, Hae Won; Seong, Sook Jin; Park, Sung Min; Lee, Joomi; Gwon, Mi-Ri; Kim, Hyun-Ju; Lim, Sung Mook; Lim, Mi-Sun; Kim, Woomi; Yang, Dong Heon; Yoon, Young-Ran

    2015-06-01

    Imatinib mesylate (IM) is a selective tyrosine kinase inhibitor for the treatment of chronic myeloid leukemia and gastrointestinal stromal tumors. A new once-daily 400-mg film-coated tablet of imatinib has been developed by a pharmaceutical company in Korea. The present study was designed to assess and compare the PK parameters, bioavailability, and bioequivalence of the new imatinib 400-mg formulation (test) versus the conventional 100-mg formulation (reference) administered as a single 400-mg dose in healthy adult male volunteers. This randomized, open-label, single-dose, two-way crossover study was conducted in healthy Korean male volunteers. Eligible subjects were randomly assigned in a 1 : 1 ratio to receive 400 mg of the test (one 400-mg tablet) or reference (four 100-mg tablets) formulation, followed by a 2-week washout period and administration of the alternate formulation. Serial blood samples were collected at 0 (predose), 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12, 24, 48, and 72 hours after administration. Plasma imatinib concentrations were determined using liquid chromatography coupled with tandem mass spectrometry. The formulations were to be considered bioequivalent if the 90% confidence intervals (CIs) of the adjusted geometric mean ratios for Cmax, AUC(0-t), and AUC(0-∞)ž were within the predetermined range of 0.80 - 1.25. In total, 35 subjects completed the study. No serious adverse event was reported during the study. The 90% CIs of the adjusted geometric mean ratios of the test formulation to the reference formulation for C(max), AUC(0-t) and AUC(0-∞)ž of imatinib were all within the bioequivalence criteria range of 0.8 - 1.25. The test formulation of imatinib met the Korean regulatory requirements for bioequivalence. Both imatinib formulations were well-tolerated in all subjects.

  15. Ab-initio calculations of semiconductor MgGeP{sub 2} and MgGeAs{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Kocak, B.; Ciftci, Y.O., E-mail: yasemin@gazi.edu.tr

    2016-05-15

    Highlights: • MgGeP{sub 2} and MgGeAs{sub 2} are semiconductor compounds. • MgGeP{sub 2} and MgGeAs{sub 2} are energetically, mechanically and dynamically stable. • The electronic charge density contour plot shows that the nature of bonding is a mixture of ionic-covalent. - Abstract: In this study, we focus on structural, electronic, elastic, lattice dynamic and optic properties of MgGeP{sub 2} and MgGeAs{sub 2} using ab-initio density-functional theory (DFT) within Armiento-Mattson 2005 (AM05) scheme of the generalized gradient approximation (GGA) for the exchange-correlation potential. Our computed structural results are in reasonable agreement with the literature. The band gap of these compounds is predicted to be direct. Our elastic results prove that these compounds are mechanically stable. The obtained phonon spectra of MgGeP{sub 2} and MgGeAs{sub 2} do not exhibit any significant imaginary branches using GGA-AM05 for the exchange-correlation approximation. Further analysis of the optical response of the dielectric functions, optical reflectivity, refractive index, extinction coefficient and electron energy loss delves into for the energy range of 0–22.5 eV. It motivated that there exists an optical polarization anisotropy of these compounds for optoelectronic device applications.

  16. Sorption of selenium on Mg-Al and Mg-Al-Eu layered double hydroxides

    International Nuclear Information System (INIS)

    Curtius, H.; Paparigas, Z.; Kaiser, G.

    2008-01-01

    Salt domes represent deep geological formations which are under consideration as final repositories for irradiated research reactor fuel elements. For long-term safety aspects the mobilisation of the radionuclides due to a water ingress is intensively investigated. At the Institute of Energy Research (IEF-6), leaching experiments were performed in a hot cell facility with UAl x -Al and U 3 Si 2 -Al dispersed research reactor fuel elements in repository-relevant MgCl 2 -rich salt brines under anaerobic conditions. The fuel plates corroded completely within one year and a Mg-Al-layered double hydroxide (LDH) with chloride as interlayer anion was identified as one crystalline phase component of the corrosion products (secondary phases). This Mg-Al-LDH was synthesized, characterized, and the ability to retard europium by an incorporation process was investigated. Europium, as a representative for lanthanides, was identified to be one of the radionuclides which were found in the corrosion products. We could show that europium was incorporated in the lattice structure. LDHs have high anion exchange capacities that enhance their potential to remove anionic contaminants from aqueous systems. In this work the sorption behaviour of selenium in the chemical form as selenite (SeO 3 2- ) on Mg-Al-LDH and on Mg-Al-Eu-LDH was investigated. Especially the influence of the larger europium-III ion was of interest. It represents in the Mg-Al-Eu-LDH about 10% of the molar aluminium amount. The sorption has been experimentally studied in a wide range of pH, ionic strength, radionuclide and sorbent concentration. Both LDHs with chloride as interlayer anion were synthesized by a coprecipitation method under controlled conditions, and their main physico-chemical properties were analyzed prior to the sorption experiments. The sorption kinetics of selenite on the LDHs in water and in MgCl 2 -rich brine were rapid using a LDH concentration of 10 g/L. Equilibrium, indicated by stable p

  17. Adsorption of arginine, glycine and aspartic acid on Mg and Mg-based alloy surfaces: A first-principles study

    Science.gov (United States)

    Fang, Zhe; Wang, Jianfeng; Yang, Xiaofan; Sun, Qiang; Jia, Yu; Liu, Hairong; Xi, Tingfei; Guan, Shaokang

    2017-07-01

    Studying the adsorption behaviors of biomolecules on the surface of Mg and Mg-based alloy has a fundamental and important role for related applications in biotechnology. In the present work, we systematically investigate and compare the adsorption properties of three typical amino acids, i.e., Arg (arginine), Gly (glycine) and Asp (aspartic acid), which form RGD tripeptide, on the Mg (0 0 0 1) surface with various doping (Zn, Y, and Nd), and aim to realize proper binding between biomolecules and Mg and Mg-based biomedical materials. Our results show that flat adsorption configurations of the functional groups binding to the surfaces are favored in energy for all the three selected amino acids. In specific, for the amino acids adsorped on clean Mg (0 0 0 1) surface, the adsorption energy (Eads) of Arg is found to be -1.67 eV for the most stable configuration, with amino and guanidyl groups binding with the surface. However, Gly (Asp) is found to binding with the surface through amino and carboxyl groups, with a -1.16 eV (-1.15 eV) binding energy. On the 2% Zn doped Mg (0 0 0 1) alloy surface (Mg-Zn (2%)), the Eads are significantly increased to be -1.91 eV, -1.32 eV and -1.35 eV for Arg, Gly and Asp, respectively. While the Mg-Y (1%) and Mg-Nd (1%) slightly weaken the adsorption of three amino acids. Moreover, we have performed detail discussions of the binding properties between amino acids and surfaces by projected density of states (PDOS) combined with charge transfer analyses. Our studies provide a comprehensive understanding on the interactions between amino acids and Mg and Mg-based alloy surfaces, with respect to facilitate the applications of Mg and Mg-based biomedical alloys in biosensing, drug delivery, biomolecule coating and other fields in biotechnology.

  18. Single-crystalline MgAl2O4 spinel nanotubes using a reactive and removable MgO nanowire template

    International Nuclear Information System (INIS)

    Fan Hongjin; Knez, Mato; Scholz, Roland; Nielsch, Kornelius; Pippel, Eckhard; Hesse, Dietrich; Goesele, Ulrich; Zacharias, Margit

    2006-01-01

    Using MgO nanowires as a reactive template, we fabricated for the first time single-crystal MgAl 2 O 4 spinel nanotubes through an interfacial solid-state reaction of MgO-Al 2 O 3 core-shell nanowires. Single-crystal MgO nanowires are coated with a conformal thin layer of amorphous Al 2 O 3 via atomic layer deposition. Subsequent annealing at 700 deg. C activates the interfacial reaction between MgO and Al 2 O 3 , transforming the alumina shell into a spinel shell. Finally, after etching away the remaining MgO core in ammonia sulfuric solution, MgAl 2 O 4 spinel nanotubes are obtained. As a transition from conventional planar spinel layers via thin-film interface reactions, our result might open a window for the fabrication of a wide variety of MgO-based spinel one-dimensional nanostructures

  19. EFFICACY OF COMBINED ANTIHYPERTENSIVE THERAPY IN ACHIEVEMENT OF TARGET BLOOD PRESSURE IN DIABETIC PATIENTS

    Directory of Open Access Journals (Sweden)

    O. A. Koshel'skaya

    2015-12-01

    Full Text Available Aim. To evaluate the efficacy of long-term combined antihypertensive therapy (AHT based on renin-angiotensin-aldosterone system (RAAS blockers, indapamide and calcium channel blocker (CCB in hypertensive patients with diabetes mellitus (DM in accordance with target blood pressure (BP <130/80 mm Hg achievement rate, dynamics of 24-hour BP profile, metabolic indices, and local stiffness of the main arteries. Besides, to study the effects of the CCB addition to dual therapy on these parameters. Material and methods. Patients (16 men, 31 women, 57.2±6.6 years old with arterial hypertension degrees 1–3 and mild to moderate DM type 2 were included into the study. The patients were treated with perindopril (5–10 mg/day or valsartan (80–160 mg/day in combination with indapamide SR (1.5 mg/day and amlodipine (5–10 mg/day. Examination included office BP measurement and ambulatory BP monitoring (ABPM, common carotid arteries sonarography , evaluation of serum levels of potassium, creatinine, uric acid, glucose metabolism and lipid profile parameters, calculation of insulin resistance index (HOMA at baseline and after 30–32 weeks of treatment. Results. Target BP was achieved in 86.7% of patients. Evenly reduction of day and night BP without reflex tachycardia and hypotension episodes was observed. Office BP decreased from 149.5±12.0/90.0±8.3 to 125.0±7.6/76.8±4.9 mm Hg (p<0.05 and average daily BP (ABPM decreased to 120.1±10.0/71.7±6.9 mmHg. Three drugs were needed to achieve target BP in baseline systolic BP >150 mm Hg (office or >134 mmHg (ABPM. Marked beneficial effect on the morphological and functional characteristics of the vascular wall and its elastic properties, improvement of glycemic control, tissue insulin sensitivity and lipids profile were found. These effects were associated mainly with amlodipine inclusion into the therapy. Conclusion. The combined AHT based on RAAS blockers, indapamide SR and CCB provides achievement of

  20. EFFICACY OF COMBINED ANTIHYPERTENSIVE THERAPY IN ACHIEVEMENT OF TARGET BLOOD PRESSURE IN DIABETIC PATIENTS

    Directory of Open Access Journals (Sweden)

    O. A. Koshel'skaya

    2012-01-01

    Full Text Available Aim. To evaluate the efficacy of long-term combined antihypertensive therapy (AHT based on renin-angiotensin-aldosterone system (RAAS blockers, indapamide and calcium channel blocker (CCB in hypertensive patients with diabetes mellitus (DM in accordance with target blood pressure (BP <130/80 mm Hg achievement rate, dynamics of 24-hour BP profile, metabolic indices, and local stiffness of the main arteries. Besides, to study the effects of the CCB addition to dual therapy on these parameters. Material and methods. Patients (16 men, 31 women, 57.2±6.6 years old with arterial hypertension degrees 1–3 and mild to moderate DM type 2 were included into the study. The patients were treated with perindopril (5–10 mg/day or valsartan (80–160 mg/day in combination with indapamide SR (1.5 mg/day and amlodipine (5–10 mg/day. Examination included office BP measurement and ambulatory BP monitoring (ABPM, common carotid arteries sonarography , evaluation of serum levels of potassium, creatinine, uric acid, glucose metabolism and lipid profile parameters, calculation of insulin resistance index (HOMA at baseline and after 30–32 weeks of treatment. Results. Target BP was achieved in 86.7% of patients. Evenly reduction of day and night BP without reflex tachycardia and hypotension episodes was observed. Office BP decreased from 149.5±12.0/90.0±8.3 to 125.0±7.6/76.8±4.9 mm Hg (p<0.05 and average daily BP (ABPM decreased to 120.1±10.0/71.7±6.9 mmHg. Three drugs were needed to achieve target BP in baseline systolic BP >150 mm Hg (office or >134 mmHg (ABPM. Marked beneficial effect on the morphological and functional characteristics of the vascular wall and its elastic properties, improvement of glycemic control, tissue insulin sensitivity and lipids profile were found. These effects were associated mainly with amlodipine inclusion into the therapy. Conclusion. The combined AHT based on RAAS blockers, indapamide SR and CCB provides achievement of

  1. Mechanochemical Synthesis of Nanostructured MgXNi1-XO Compound by Mg-NiO Mixture

    Directory of Open Access Journals (Sweden)

    Nader Setoudeh

    2017-06-01

    Full Text Available Synthesis of magnesium nickel oxide phase such as MgxNi1-xO solid solutions has been studied in this research article using mechnochmical reaction between magnesium and nickel oxide. Mixtures of magnesium powder and nickel oxide (Mg+NiO with stoichiometric compositions were milled for different times in a planetary ball mill. Reduction reaction of nickel oxide by magnesium via a mechanically induced self-sustaining reaction (MSR was confirmed in the XRD measurements of the as-milled samples. Formation of nanostructured magnesium nickel oxide phases (such as Mg0.4Ni0.6O or MgNiO2 was observed after isothermal heating of the 30 minutes milled samples at 1000°C where nickel phase seems to disappear in XRD patterns. The traces of phases such as Mg0.4Ni0.6O or MgNiO2 were also observed in the as-milled mixtures. Therefore, the XRD results of the as-milled samples suggested that the formation of magnesium nickel oxide phases could be possible even after prolonged milling. The XRD and SEM results of both as-milled and isothermally heated samples indicated that the crystallite size and particle size of the final products reached to nanoscale after milling. Morphological and compositional evolution of the samples after heat treatment was monitored through SEM imaging and elemental analyses. The results confirmed that the composition of final product is close to Mg0.4Ni0.6O compound.

  2. Enhanced voltage-controlled magnetic anisotropy in magnetic tunnel junctions with an MgO/PZT/MgO tunnel barrier

    Science.gov (United States)

    Chien, Diana; Li, Xiang; Wong, Kin; Zurbuchen, Mark A.; Robbennolt, Shauna; Yu, Guoqiang; Tolbert, Sarah; Kioussis, Nicholas; Khalili Amiri, Pedram; Wang, Kang L.; Chang, Jane P.

    2016-03-01

    Compared with current-controlled magnetization switching in a perpendicular magnetic tunnel junction (MTJ), electric field- or voltage-induced magnetization switching reduces the writing energy of the memory cell, which also results in increased memory density. In this work, an ultra-thin PZT film with high dielectric constant was integrated into the tunneling oxide layer to enhance the voltage-controlled magnetic anisotropy (VCMA) effect. The growth of MTJ stacks with an MgO/PZT/MgO tunnel barrier was performed using a combination of sputtering and atomic layer deposition techniques. The fabricated MTJs with the MgO/PZT/MgO barrier demonstrate a VCMA coefficient, which is ˜40% higher (19.8 ± 1.3 fJ/V m) than the control sample MTJs with an MgO barrier (14.3 ± 2.7 fJ/V m). The MTJs with the MgO/PZT/MgO barrier also possess a sizeable tunneling magnetoresistance (TMR) of more than 50% at room temperature, comparable to the control MTJs with an MgO barrier. The TMR and enhanced VCMA effect demonstrated simultaneously in this work make the MgO/PZT/MgO barrier-based MTJs potential candidates for future voltage-controlled, ultralow-power, and high-density magnetic random access memory devices.

  3. Comparing the Electrochemical Performance of LiFePO4/C Modified by Mg Doping and MgO Coating

    Directory of Open Access Journals (Sweden)

    Jianjun Song

    2013-01-01

    Full Text Available Supervalent cation doping and metal oxide coating are the most efficacious and popular methods to optimize the property of LiFePO4 lithium battery material. Mg-doped and MgO-coated LiFePO4/C were synthesized to analyze their individual influence on the electrochemical performance of active material. The specific capacity and rate capability of LiFePO4/C are improved by both MgO coating and Mg doping, especially the Mg-doped sample—Li0.985Mg0.015FePO4/C, whose discharge capacity is up to 163 mAh g−1, 145.5 mAh g−1, 128.3 mAh g−1, and 103.7 mAh g−1 at 1 C, 2 C, 5 C, and 10 C, respectively. The cyclic life of electrode is obviously increased by MgO surface modification, and the discharge capacity retention rate of sample LiFePO4/C-MgO2.5 is up to 104.2% after 100 cycles. Comparing samples modified by these two methods, Mg doping is more prominent on prompting the capacity and rate capability of LiFePO4, while MgO coating is superior in terms of improving cyclic performance.

  4. Formation of Al3Ti/Mg composite by powder metallurgy of Mg-Al-Ti system.

    Science.gov (United States)

    Yang, Zi R; Qi Wang, Shu; Cui, Xiang H; Zhao, Yu T; Gao, Ming J; Wei, Min X

    2008-07-01

    An in situ titanium trialuminide (Al 3 Ti)-particle-reinforced magnesium matrix composite has been successfully fabricated by the powder metallurgy of a Mg-Al-Ti system. The reaction processes and formation mechanism for synthesizing the composite were studied by differential scanning calorimetry (DSC), x-ray diffractometry (XRD), scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS). Al 3 Ti particles are found to be synthesized in situ in the Mg alloy matrix. During the reaction sintering of the Mg-Al-Ti system, Al 3 Ti particles are formed through the reaction of liquid Al with as-dissolved Ti around the Ti particles. The formed intermetallic particles accumulate at the original sites of the Ti particles. As sintering time increases, the accumulated intermetallic particles disperse and reach a relatively homogeneous distribution in the matrix. It is found that the reaction process of the Mg-Al-Ti system is almost the same as that of the Al-Ti system. Mg also acts as a catalytic agent and a diluent in the reactions and shifts the reactions of Al and Ti to lower temperatures. An additional amount of Al is required for eliminating residual Ti and solid-solution strengthening of the Mg matrix.

  5. Ab initio calculations of half-metallic ferromagnetism in Cr-doped MgSe and MgTe semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Noor, N.A. [Department of Physics, University of the Punjab, Quaid-e-Azam Campus, 54590 Lahore (Pakistan); Alay-e-Abbas, S.M. [Department of Physics, University of Sargodha, Sargodha 40100 (Pakistan); Department of Physics, GC University Faisalabad, Allama Iqbal Road, Faisalabad 38000 (Pakistan); Sohaib, M.U. [Lahore Development Authority, 54590 Lahore (Pakistan); Ghulam Abbas, S.M. [Department of Chemistry, University of Agriculture, Faisalabad 38040 (Pakistan); Shaukat, A., E-mail: schaukat@gmail.com [Department of Physics, University of Sargodha, Sargodha 40100 (Pakistan)

    2015-01-15

    The full-potential linear-augmented-plane-waves plus local-orbitals (FP-LAPW+lo) method has been employed for investigation of half-metallic ferromagnetism in Cr-doped ordered zinc-blende MgSe and MgTe semiconductors. Calculations of exchange and correlation (XC) effects have been carried out using generalized gradient approximation (GGA) and orbital independent modified Becke–Johnson potential coupled with local (spin) density approximation (mBJLDA). The thermodynamic stability of the compounds and their preferred magnetic orders have been analyzed in terms of the heat of formation and minimum total energy difference in ferromagnetic (FM) and anti-ferromagnetic (AFM) ordering, respectively. Calculated electronic properties reveal that the Cr-doping induces ferromagnetism in MgSe and MgTe which gives rise to a half-metallic (HM) gap at Fermi level (E{sub F}). Further, the electronic band structure is discussed in terms of s (p)–d exchange constants that are consistent with typical magneto-optical experiment and the behavior of charge spin densities is presented for understanding the bonding nature. Our results demonstrate that the higher effective potential for the spin-down case is responsible for p–d exchange splitting. Total magnetic moment (mainly due to Cr-d states) of these compounds is 4µ{sub B}. Importantly, the electronic properties and HM gap obtained using mBJLDA show remarkable improvement as compared to the results obtained using standard GGA functional. - Highlights: • Spin effect theoretical study on Cr-doped MgSe and MgTe is performed. • Half-metallic ferromagnetism in Cr{sub x}Mg{sub 1−x}Se and Cr{sub x}Mg{sub 1−x}Te is established. • Results of WC-GGA and mBJLDA are compared for performance. • HM gaps for Cr{sub x}Mg{sub 1−x}Se and Cr{sub x}Mg{sub 1−x}Te show nonlinear variation with x. • Important values of exchange splitting/constants and moments are reported.

  6. Mg-lattice associations in red coralline algae

    Science.gov (United States)

    Kamenos, N. A.; Cusack, M.; Huthwelker, T.; Lagarde, P.; Scheibling, R. E.

    2009-04-01

    Recent investigations have shown red coralline algae to record ambient temperature in their calcite skeletons. Temperature recorded by variation in Mg concentrations within algal growth bands has sub-annual resolution and high accuracy. The conversion of Mg concentration to temperature is based on the assumption of Ca replacement by Mg within the algal calcite skeleton at higher temperatures. While Mg-temperature relationships in coralline algae have been calibrated for some species, the location of Mg within the calcite lattice remains unknown. Critically, if Mg is not a lattice component but associated with organic components this could lead to erroneous temperature records. Before coralline algae are used in large scale climate reconstructions it is therefore important to determine the location of Mg. Synchrotron Mg-X-ray absorbance near edge structure (XANES) indicates that Mg is associated with the calcite lattice in Lithothamnion glaciale (contemporary free-living, contemporary encrusting and sub-fossil free-living) and Phymatolithon calcareum (contemporary free-living) coralline algae. Mg is deposited within the calcite lattice in all seasons ( L. glaciale & P. calcareum) and thallus areas ( P. calcareum). These results suggest L. glaciale and P. calcareum are robust Mg-palaeotemperature proxies. We suggest that similar confirmation be obtained for Mg associations in other species of red coralline algae aiding our understanding of their role in climate reconstruction at large spatial scales.

  7. The role of Mg interface layer in MgO magnetic tunnel junctions with CoFe and CoFeB electrodes

    Directory of Open Access Journals (Sweden)

    Hyunsoo Yang

    2012-03-01

    Full Text Available The tunneling spin polarization (TSP is directly measured from reactively sputter deposited crystalline MgO tunnel barriers with various CoFe(B compositions using superconducting tunneling spectroscopy. We find that the Mg interface layer thickness dependence of TSP values for CoFeB/Mg/MgO junctions is substantially different from those for CoFe/Mg/MgO especially in the pre-annealed samples due to the formation of boron oxide at the CoFeB/MgO interface. Annealing depletes boron at the interface thus requiring a finite Mg interface layer to prevent CoFeOx formation at the CoFeB/MgO interface so that the TSP values can be optimized by controlling Mg thickness.

  8. Raman-spectroscopic (Fe/Fe+Mg, CO2) and Structural studies of Mg-Fe cordierites

    International Nuclear Information System (INIS)

    Haefeker, U.

    2013-01-01

    In the course of this dissertation synthetic hexagonal and orthorhombic Mg-Fe-cordierites have been investigated with Raman-spectroscopy and XRD methods. Cordierite´s Mg- and Fe-end-members as well as their Mg-Fe solid solutions with the chemical formula (Mg, Fe 2+ ) 2 Al 4 Si 5 O 18 *nH 2 O have been synthesized. Raman-data of synthetic hydrous Mg- and Fe-cordierites have been obtained in the wavenumber-region 100-1250 cm-1 and the experimental data were then compared with the results of quantum-mechanical calculations. 86 theoretical bands could be related to specific vibrational modes of the tetrahedral and octahedral sites of the cordierite structure. Maximum and mean deviation between experimentally-derived bands and calculated modes were ±7 cm -1 for Mg-cordierite and ±19 cm -1 for Fe-cordierite. Spectra comparison revealed a trend of peak downshifting as a consequence of Fe-incorporation. The calculations now allow more accurate interpretation of the Raman spectra with respect to structural changes of cordierite, resulting from Al-Si ordering and Mg-Fe exchange. Atomic motions in cordierite have been compared with those of the structurally similar mineral beryl. Investigations of 16 H 2 O-bearing synthetic well-ordered Mg-Fe-cordierites (XFe =0-1) with micro-Raman spectroscopy revealed a linear correlation between the Fe/Mg ratio and the position of certain Raman peaks. The peaks (wave-number Mg-/Fe-cordierite) at 122/111, 262/257, 430/418, 579/571, 974/967, and 1012/1007 cm -1 were selected for a detailed deconvolution analysis . The shifts of these peaks were then plotted vs. XFe and regression of the data lead to the formulation of a set of linear equations. In addition, the effect of different H 2 O contents and the degree of Al-Si ordering on the Fe/Mg determination were also investigated. Testing the calibration against data from six well-characterized natural cordierite samples yielded excellent agreement. Existing calibration diagrams for CO 2

  9. EFFECT OF THE COMBINED ANTIHYPERTENSIVE THERAPY WITH TARGET BLOOD PRESSURE ACHIEVEMENT ON INTRARENAL BLOOD FLOW IN PATIENTS WITH TYPE 2 DIABETES

    Directory of Open Access Journals (Sweden)

    O. A. Koshel'skaya

    2012-01-01

    Full Text Available Aim. To compare the dynamics of intrarenal vascular resistance (IRVR, circadian blood pressure (BP profile and glomerular filtration rate (GFR in patients with arterial hypertension (HT and type 2 diabetes mellitus (DM who achieved the target BP levels (<130/80 mmHg due to long-term combined antihypertensive therapy with or without renin-angiotensin-aldosterone system (RAAS inhibitors. Material and methods. Patients (n=61 with HT and DM without clinical symptoms of nephroangiopathy were included into the open randomized study , 59 of these patients completed study. Patients of Group 1 (n=41 received therapy with valsartan (n=20, 80–160 mg/day , or perindopril (n=21, 5–10 mg/day , in combination with indapamide retard, 1.5 mg/day , and amlodipine, 5–10 mg/day. Patients of Group 2 (n=18 received amlodipine (5–10 mg/day in combination with indapamide retard (1.5 mg/day and metoprolol succinate (50–100 mg/day. Initially and after 30–32 weeks of therapy the following examinations were performed: duplex ultrasound scanning of the main renal (MRA and intrarenal arteries (IRA with resistive index (RI calculation, ambulatory BP monitoring (ABPM, GFR calculation (by Cockcroft-Gault formula. Results. The target BP levels were achieved in all patients of both groups. Patient’s baseline characteristics including age, sex, duration of disease, office BP , GFR, RI in MRA and IRA did not differ in the groups as well as decrease in office BP due to treatment. However patients of Group 2 had higher levels of systolic BP and systolic BP load at night time than these in patients of Group 1 during all period of the treatment. In patients of Group 2 RI in MRA and arcuate IRA were increased from 0.67±0.06 to 0.69±0.06 (p=0.02 and from 0.62±0.07 to 0.64±0.06 (p=0.02, respectively. The increase in IRA was positively associated with systolic BP at night time in these patients (r=0.6; p=0.01. There were no significant changes of IRA in Group 1 totally

  10. EFFECT OF THE COMBINED ANTIHYPERTENSIVE THERAPY WITH TARGET BLOOD PRESSURE ACHIEVEMENT ON INTRARENAL BLOOD FLOW IN PATIENTS WITH TYPE 2 DIABETES

    Directory of Open Access Journals (Sweden)

    O. A. Koshel'skaya

    2015-12-01

    Full Text Available Aim. To compare the dynamics of intrarenal vascular resistance (IRVR, circadian blood pressure (BP profile and glomerular filtration rate (GFR in patients with arterial hypertension (HT and type 2 diabetes mellitus (DM who achieved the target BP levels (<130/80 mmHg due to long-term combined antihypertensive therapy with or without renin-angiotensin-aldosterone system (RAAS inhibitors. Material and methods. Patients (n=61 with HT and DM without clinical symptoms of nephroangiopathy were included into the open randomized study , 59 of these patients completed study. Patients of Group 1 (n=41 received therapy with valsartan (n=20, 80–160 mg/day , or perindopril (n=21, 5–10 mg/day , in combination with indapamide retard, 1.5 mg/day , and amlodipine, 5–10 mg/day. Patients of Group 2 (n=18 received amlodipine (5–10 mg/day in combination with indapamide retard (1.5 mg/day and metoprolol succinate (50–100 mg/day. Initially and after 30–32 weeks of therapy the following examinations were performed: duplex ultrasound scanning of the main renal (MRA and intrarenal arteries (IRA with resistive index (RI calculation, ambulatory BP monitoring (ABPM, GFR calculation (by Cockcroft-Gault formula. Results. The target BP levels were achieved in all patients of both groups. Patient’s baseline characteristics including age, sex, duration of disease, office BP , GFR, RI in MRA and IRA did not differ in the groups as well as decrease in office BP due to treatment. However patients of Group 2 had higher levels of systolic BP and systolic BP load at night time than these in patients of Group 1 during all period of the treatment. In patients of Group 2 RI in MRA and arcuate IRA were increased from 0.67±0.06 to 0.69±0.06 (p=0.02 and from 0.62±0.07 to 0.64±0.06 (p=0.02, respectively. The increase in IRA was positively associated with systolic BP at night time in these patients (r=0.6; p=0.01. There were no significant changes of IRA in Group 1 totally

  11. Nicotine chewing gum (2 mg, 4 mg) and cigarette smoking: comparative effects upon vigilance and heart rate.

    Science.gov (United States)

    Parrott, A C; Winder, G

    1989-01-01

    Sixteen male smokers, abstinent the morning before testing, were assessed under four conditions: placebo chewing gum, 2 mg nicotine chewing gum, 4 mg nicotine gum, and cigarette smoking. Placebo gum was administered in the cigarette condition, while sham smoking occurred in the gum conditions. Pre-drug administration and post-drug difference scores were calculated for each assessment measure: rapid visual information processing (RVIP), memory for new information, and heart rate. Nicotine raised heart rate in a significant monotonic dose-related manner (P less than 0.001): placebo +0.2; 2 mg gum +5.1; 4 mg gum +9.8; cigarette +17.5 bpm. Rapid visual information processing target detections were also significantly related to dose (P less than 0.01), with this increased vigilance significant under 4 mg nicotine gum and cigarette smoking. Memory task performance was not significantly affected. Self-reported feelings of alertness/energy were higher while smoking than under placebo or 4 mg gum. Complaints about the taste of the 4 mg nicotine gum were frequent.

  12. Ab initio study of MgH2 formation

    International Nuclear Information System (INIS)

    Novakovic, Nikola; Matovic, Ljiljana; Novakovic, Jasmina Grbovic; Manasijevic, Miodrag; Ivanovic, Nenad

    2009-01-01

    Even if there is considerable literature dealing with structure and properties of MgH 2 compound there are still some uncertain details about nature of bonding governing its formation and decomposition. In order to better understand the processes essential for absorption and desorption of MgH 2 , ab initio DFT based calculations of rutile MgH 2 compound, elemental hcp-Mg, and three different hypothetical hcp-Mg-derived hydrides are performed. Our findings show that all structures are unstable, and that MgH (Wurtzite) is a closest possible candidate for intermediate phase between the hcp-Mg and MgH 2 at 1:1 stoichiometry. An alternative hydration pathway is suggested, including promotion of hcp-Mg to bcc-Mg and consecutive transformation to rutile MgH 2 by means of hydrogen incorporation into Mg matrix. Rutile MgH 2 calculations with various hydrogen vacancies concentration are performed. Calculation shows that at high hydrogen concentration close to 1:2, stable substoichiometric hydride is possible. Calculation also shows that high vacancy (low hydrogen) concentration favors bcc-Mg 2 H over rutile Mg 2 H structure.

  13. In-situ thermal analysis and macroscopical characterization of Mg-xCa and Mg-0.5Ca-xZn alloy systems

    Energy Technology Data Exchange (ETDEWEB)

    Farahany, Saeed [Department of Materials Engineering, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Bakhsheshi-Rad, Hamid Reza, E-mail: Rezabakhsheshi@gmail.com [Department of Materials Engineering, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Idris, Mohd Hasbullah [Department of Materials Engineering, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Abdul Kadir, Mohammed Rafiq [Medical Implants Technology Group, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Department of Biomechanics and Biomedical Materials, Faculty of Biomedical Engineering and Health Sciences, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Lotfabadi, Amir Fereidouni [Department of Manufacturing and Industrial Engineering, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Ourdjini, Ali [Department of Materials Engineering, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia)

    2012-01-10

    Highlights: Black-Right-Pointing-Pointer The effect of Ca and Zn addition on Mg-Ca and Mg-Ca-Zn were investigated. Black-Right-Pointing-Pointer Ca and Zn addition decreased solid fraction at coherency point. Black-Right-Pointing-Pointer T{sub N}-T{sub DCP} increased by adding Ca and Zn in Mg-Ca and Mg-Ca-Zn, respectively. Black-Right-Pointing-Pointer Three reactions were detected when Zn/Ca atomic ratio less than 1.25 in Mg-Ca-Zn. Black-Right-Pointing-Pointer A new peak Mg{sub 51}Zn{sub 20} was identified in Mg-0.5Ca-9Zn in addition of other peaks. - Abstract: This research described the identification phases by thermal analysis and microscopy inspection of Mg-xCa and Mg-0.5%Ca-xZn alloys that were solidified at slow cooling rate. Analysis of cooling curve after Ca addition shows the evolution of the Mg{sub 2}Ca intermetallic phase at around 520 Degree-Sign C in addition to {alpha}-Mg phase. First derivative curves of alloys after the addition of Zn to Mg-0.5Ca alloy reveals three peaks related to {alpha}-Mg, Mg{sub 2}Ca and Ca{sub 2}Mg{sub 6}Zn{sub 3} for alloys that have Zn/Ca atomic ratio less than 1.23. The peak of Mg{sub 2}Ca reaction on the first derivative curves disappeared for alloys containing Zn/Ca ratio more than 1.23. A new peak was also observed at 330 Degree-Sign C for Mg-0.5Ca-9Zn which was identified as Mg{sub 51}Zn{sub 20}. Solid fraction at coherency point decreased with increasing Ca and Zn elements. However, coherency time and difference between the nucleation and coherency temperatures (T{sub N}-T{sub DCP}) increased by adding Ca and Zn in Mg-Ca and Mg-Ca-Zn systems.

  14. First-principles study of the (0001)-MgB2 surface finished in Mg and B

    International Nuclear Information System (INIS)

    Segura, Sully; Martínez, Jairo Arbey Rodríguez; Moreno-Armenta, María Guadalupe

    2014-01-01

    We present a study based on Density Functional Theory (DFT) of the volume and two surfaces (0001) of MgB 2 , one of them terminated in Mg and the other one terminated in B. Each one of the surface was relaxed and their electronic properties were determined. From calculation of the enthalpy of formation we found that the Mg-terminated surface is energetically favored. The bands seem to present a formation similar to the Dirac's cone as that are presented in graphene, but in MgB 2 is above of the Fermi level. In the three cases, volume and the two surfaces, the behaviour is boron-metallic, because there are strong presence of B orbital's in the neighborhood of the Ferm level

  15. Effect of Mg on the Microstructure and Corrosion Resistance of the Continuously Hot-Dip Galvanizing Zn-Mg Coating

    Directory of Open Access Journals (Sweden)

    Anping Dong

    2017-08-01

    Full Text Available The microstructure of continuously hot-dip galvanizing Zn-Mg coating was investigated in order to obtain the mechanism of the effects of Mg on the corrosion resistance. In this paper, the vertical section of the Zn-0.20 wt % Al-Mg ternary phase diagram near the Al-low corner was calculated. The results indicates that the phase composition of the Zn-0.20 wt % Al-Mg ternary phase diagram near the Al-low corner is the same as Zn-Mg binary phase diagram, suggesting Al in the Zn-Mg (ZM coatings mainly concentrates on the interfacial layer between the coating and steel substrate. The microstructure of continuously hot-dip galvanizing ZM coatings with 0.20 wt % Al containing 1.0–3.0 wt % Mg was investigated using tunneling electron microscopy (TEM. The morphology of Zn in the coating changes from bulk to strip and finally to mesh-like, and the MgZn2 changes from rod-like to mesh-like with the Mg content increasing. Al in the ZM coatings mainly segregates at the Fe2Al5 inhibition layer and the Mg added to the Zn bath makes this inhibition layer thinner and uneven. Compared to GI coating, the time of the first red rust appears increases by more than two-fold and expansion rate of red rust reduces by more than four-fold in terms of salt spray experiment. The ZM coating containing 2.0 wt % Mg has the best corrosion resistance. The enhanced corrosion resistance of ZM coatings mainly depends on different corrosion products.

  16. Hydroxyapatite and zirconia composites: Effect of MgO and MgF2 on the stability of phases and sinterability

    International Nuclear Information System (INIS)

    Evis, Zafer; Usta, Metin; Kutbay, Isil

    2008-01-01

    Composites of hydroxyapatite with cubic zirconia with MgO or MgF 2 were pressureless sintered at temperatures from 1000 to 1300 deg. C. The reactions and transformations of phases were monitored with X-ray diffraction. For the hydroxyapatite and zirconia composites with MgO, calcium diffused from hydroxyapatite into the zirconia, and hydroxyapatite decomposed to tri-calcium phosphate at sintering temperatures higher than 1000 deg. C. Above about 1200 deg. C, CaZrO 3 was formed. Composites containing the MgF 2 decomposed slower than the composites with MgO which was verified by the changes in the lattice volume of the hydroxyapatite left in the composites. Fluorine ions in MgF 2 diffused into hydroxyapatite which resulted in thermal stability at high sintering temperatures. Composites with MgF 2 had higher hardness than those with MgO. The lowest porosity was found in a composite initially containing 10 wt% cubic zirconia and 5 wt% MgF 2

  17. Photodissociation spectroscopy of the Mg+-acetic acid complex

    Science.gov (United States)

    Abate, Yohannes; Kleiber, P. D.

    2006-11-01

    We have studied the structure and photodissociation of Mg+-acetic acid clusters. Ab initio calculations suggest four relatively strongly bound ground state isomers for the [MgC2H4O2]+ complex. These isomers include the cis and trans forms of the Mg+-acetic acid association complex with Mg+ bonded to the carbonyl O atom of acetic acid, the Mg+-acetic acid association complex with Mg+ bonded to the hydroxyl O atom of acetic acid, or to a Mg+-ethenediol association complex. Photodissociation through the Mg+-based 3p←3s absorption bands in the near UV leads to direct (nonreactive) and reactive dissociation products: Mg+, MgOH+, Mg(H2O )+, CH3CO+, and MgCH3+. At low energies the dominant reactive quenching pathway is through dehydration to Mg(H2O)+, but additional reaction channels involving C-H and C-C bond activation are also open at higher energies.

  18. Corrosion and Discharge Behaviors of Mg-Al-Zn and Mg-Al-Zn-In Alloys as Anode Materials

    Directory of Open Access Journals (Sweden)

    Jiarun Li

    2016-03-01

    Full Text Available The Mg-6%Al-3%Zn and Mg-6%Al-3%Zn-(1%, 1.5%, 2%In alloys were prepared by melting and casting. Their microstructures were investigated via metallographic and energy-dispersive X-ray spectroscopy (EDS analysis. Moreover, hydrogen evolution and electrochemical tests were carried out in 3.5 wt% NaCl solution aiming at identifying their corrosion mechanisms and discharge behaviors. The results suggested that indium exerts an improvement on both the corrosion rate and the discharge activity of Mg-Al-Zn alloy via the effects of grain refining, β-Mg17Al12 precipitation, dissolving-reprecipitation, and self-peeling. The Mg-6%Al-3%Zn-1.5%In alloy with the highest corrosion rate at free corrosion potential did not perform desirable discharge activity indicating that the barrier effect caused by the β-Mg17Al12 phase would have been enhanced under the conditions of anodic polarization. The Mg-6%Al-3%Zn-1.0%In alloy with a relative low corrosion rate and a high discharge activity is a promising anode material for both cathodic protection and chemical power source applications.

  19. Combinatorial search for hydrogen storage alloys: Mg-Ni and Mg-Ni-Ti

    Energy Technology Data Exchange (ETDEWEB)

    Oelmez, Rabia; Cakmak, Guelhan; Oeztuerk, Tayfur [Dept. of Metallurgical and Materials Engineering, Middle East Technical University, 06531 Ankara (Turkey)

    2010-11-15

    A combinatorial study was carried out for hydrogen storage alloys involving processes similar to those normally used in their fabrication. The study utilized a single sample of combined elemental (or compound) powders which were milled and consolidated into a bulk form and subsequently deformed to heavy strains. The mixture was then subjected to a post annealing treatment, which brings about solid state reactions between the powders, yielding equilibrium phases in the respective alloy system. A sample, comprising the equilibrium phases, was then pulverized and screened for hydrogen storage compositions. X-ray diffraction was used as a screening tool, the sample having been examined both in the as processed and the hydrogenated state. The method was successfully applied to Mg-Ni and Mg-Ni-Ti yielding the well known Mg{sub 2}Ni as the storage composition. It is concluded that a partitioning of the alloy system into regions of similar solidus temperature would be required to encompass the full spectrum of equilibrium phases. (author)

  20. Thermoluminescence kinetic analysis and dosimetry features of MgSO4:Dy and MgSO4:Cu nano-rods

    International Nuclear Information System (INIS)

    Zahedifar, M.; Almasifard, F.; Sadeghi, E.; Biroon, M. Kashefi; Ramazani- Moghaddam-Arani, A.

    2016-01-01

    MgSO 4 :Dy and MgSO 4 :Cu nano-rods (NRs) were synthesized for the first time by semi co- precipitation method. X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) were utilized for sample characterization. The optimum amount of dysprosium and copper concentrations were obtained both at 0.1 mol% in MgSO 4 :Dy and MgSO 4 :Cu NRs. T m -T stop and computerized glow curve deconvolution (CGCD) methods were used for identifying the number of component glow peaks and kinetic parameters of the synthesized NRs. Initial rise and variable heating rate methods were also used to ensure the reliability of obtained kinetic parameters. Results show that the TL sensitivity of MgSO 4 :Dy is about 7 times more than that of magnesium sulfate doped with Cu. The TL dose response of MgSO 4 :Dy and MgSO 4 :Cu NRs are linear up to absorbed dose of 10 KGy. Other TL dosimetry characteristics of the produced NRs are also presented and discussed. - Highlights: • MgSO4:Dy and MgSO4:Cu nano-rods were synthesized for the first time. • Thermoluminescence dosimetry properties were studied. • The nano-phosphors showed linear dose response up to very high dose levels. • The synthesized nano-rods have potential application for high dose dosimetry.

  1. Porous composite materials ZrO2(MgO)-MgO for osteoimplantology

    International Nuclear Information System (INIS)

    Buyakov, Ales; Litvinova, Larisa; Shupletsova, Valeria; Kulbakin, Denis; Kulkov, Sergey

    2016-01-01

    The pore structure and phase composition of ceramic composite material ZrO 2 (Mg)-MgO at different sintering temperatures were studied. The main mechanical characteristics of the material were determined and it was shown that they are close to the characteristics of natural bone tissues. It was shown that material structure has a positive effect on the pre-osteoblast cells proliferation. In-vitro studies of pre-osteoblast cells, cultivation on material surface showed a good cell adhesion, proliferation and differentiation of MMSC by osteogenic type.

  2. A study of stability of MgH{sub 2} in Mg-8at%Al alloy powder

    Energy Technology Data Exchange (ETDEWEB)

    Tanniru, Mahesh; Ebrahimi, Fereshteh [Materials Science and Engineering Department, University of Florida, Gainesville, FL 32611 (United States); Slattery, Darlene K. [Florida Solar Energy Center (FSEC), Cocoa, FL (United States)

    2010-04-15

    To investigate the effect of Al addition on the stability of magnesium hydride, the hydrogenation characteristics of a Mg-8at%Al alloy powder synthesized using the electrodeposition technique were evaluated. The characterization of the hydrogenation behavior within the 180 C-280 C temperature range and the subsequent microstructural analysis elucidated that the amount of Al present in the hydride decreased with increasing temperature. This observation suggests that Al has very low solubility in magnesium hydride but Al can be accommodated in MgH{sub 2} by processing under non-equilibrium conditions. Pressure-composition isotherms were developed at different temperatures for the Mg-Al powder as well as pure Mg powder. The results indicate that the enthalpy of formation was slightly lower for the Mg-8at%Al powder while the enthalpy of dissociation did not change. The absence of noticeable influence of Al addition on the stability of magnesium hydride is attributed to its lack of solubility. (author)

  3. Defect kinetics in spinels: Long-time simulations of MgAl2O4, MgGa2O4, and MgIn2O4

    International Nuclear Information System (INIS)

    Uberuaga, B. P.; Voter, A. F.; Sickafus, K. E.; Bacorisen, D.; Smith, Roger; Ball, J. A.; Grimes, R. W.

    2007-01-01

    Building upon work in which we examined defect production and stability in spinels, we now turn to defect kinetics. Using temperature accelerated dynamics (TAD), we characterize the kinetics of defects in three spinel oxides: magnesium aluminate MgAl 2 O 4 , magnesium gallate MgGa 2 O 4 , and magnesium indate MgIn 2 O 4 . These materials have varying tendencies to disorder on the cation sublattices. In order to understand chemical composition effects, we first examine defect kinetics in perfectly ordered, or normal, spinels, focusing on point defects on each sublattice. We then examine the role that cation disorder has on defect mobility. Using TAD, we find that disorder creates local environments which strongly trap point defects, effectively reducing their mobility. We explore the consequences of this trapping via kinetic Monte Carlo (KMC) simulations on the oxygen vacancy (V O ) in MgGa 2 O 4 , finding that V O mobility is directly related to the degree of inversion in the system

  4. Density functional theory (DFT) study on the hydrolysis behavior of degradable Mg/Mg alloys for biomedical applications

    Science.gov (United States)

    Nezafati, Marjan

    Magnesium-based (Mg and/or Mg alloys) materials possess many advantageous physicochemical/biological characteristics such as good biocompatibility and similarity of the mechanical properties to the human bone tissue, which renders this material a promising candidate for the biomedical and implant applications. One of the most attractive features of Mg-based materials is the degradability in the physiological environment. With the burst of research on the biodegradable materials for the healthcare device applications, Mg and its alloys attracted a strong attention in the bioengineering field in recent years. However, the major limitation of applying Mg-based materials to biomedical applications is the fast degradation/corrosion rate with regards to the healing process time-span. In the present thesis, an atomistic model employing the density-functional theory (DFT) has been developed to study the hydrolysis process by understanding the influences of commonly used alloying elements (zinc (Zn), calcium (Ca), aluminum (Al), and yttrium (Y)) and the crystallographic orientation of the dissolution surfaces (basal (0001), prism (1010), and pyramidal (1011) planes) on the corrosion behavior. These parameters are known to strongly impact the initial hydrolysis phenomena of Mg-based materials. To develop the atomistic computational model, we have implemented the Dmol3 software package in conjunction with PBE (Perdew, Burke and Ernzerhof) correlation energy functional in the GGA (generalized gradient approximation) scheme. Throughout the thesis, we performed three sets of calculations, i) surface energy, ii) dissolution potential, and iii) water adsorption computations, to examine the hydrolysis mechanism and the subsequent corrosion/degradation of Mg/Mg alloys. The total energy changes of various Mg-based systems in different conditions for these surface energies, dissolution behavior, and tendency of the system for adsorbing the water molecule were quantified. The results

  5. Biocompatibility Assessment of Novel Bioresorbable Alloys Mg-Zn-Se and Mg-Zn-Cu for Endovascular Applications: In- Vitro Studies.

    Science.gov (United States)

    Persaud-Sharma, Dharam; Budiansky, Noah; McGoron, Anthony J

    2013-01-01

    Previous studies have shown that using biodegradable magnesium alloys such as Mg-Zn and Mg-Zn-Al possess the appropriate mechanical properties and biocompatibility to serve in a multitude of biological applications ranging from endovascular to orthopedic and fixation devices. The objective of this study was to evaluate the biocompatibility of novel as-cast magnesium alloys Mg-1Zn-1Cu wt.% and Mg-1Zn-1Se wt.% as potential implantable biomedical materials, and compare their biologically effective properties to a binary Mg-Zn alloy. The cytotoxicity of these experimental alloys was evaluated using a tetrazolium based- MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay and a lactate dehydrogenase membrane integrity assay (LDH). The MTS assay was performed on extract solutions obtained from a 30-day period of alloy immersion and agitation in simulated body fluid to evaluate the major degradation products eluted from the alloy materials. Human foreskin fibroblast cell growth on the experimental magnesium alloys was evaluated for a 72 hour period, and cell death was quantified by measuring lactate dehydrogenase concentrations. Both Mg-Zn-Se and Mg-Zn-Cu alloys exhibit low cytotoxicity levels which are suitable for biomaterial applications. The Mg-Zn-Cu alloy was found to completely degrade within 72 hours, resulting in lower human foreskin fibroblast cell viability. The Mg-Zn-Se alloy was shown to be less cytotoxic than both the Mg-Zn-Cu and Mg-Zn alloys.

  6. Interlayer exchange coupling, dipolar coupling and magnetoresistance in Fe/MgO/Fe trilayers with a subnanometer MgO barrier

    Energy Technology Data Exchange (ETDEWEB)

    Kozioł-Rachwał, A. [AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, al. Mickiewicza 30, 30-059 Kraków (Poland); National Institute of Advanced Industrial Science and Technology, Spintronics Research Center, Tsukuba, Ibaraki 305-8568 (Japan); Skowroński, W.; Frankowski, M. [AGH University of Science and Technology, Department of Electronics, al. Mickiewicza 30, 30-059 Kraków (Poland); Chęciński, J. [AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, al. Mickiewicza 30, 30-059 Kraków (Poland); AGH University of Science and Technology, Department of Electronics, al. Mickiewicza 30, 30-059 Kraków (Poland); Ziętek, S.; Rzeszut, P. [AGH University of Science and Technology, Department of Electronics, al. Mickiewicza 30, 30-059 Kraków (Poland); Ślęzak, M.; Matlak, K.; Ślęzak, T. [AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, al. Mickiewicza 30, 30-059 Kraków (Poland); Stobiecki, T. [AGH University of Science and Technology, Department of Electronics, al. Mickiewicza 30, 30-059 Kraków (Poland); Korecki, J. [AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, al. Mickiewicza 30, 30-059 Kraków (Poland); Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, ul. Niezapominajek 8, 30-239 Kraków (Poland)

    2017-02-15

    Fe/MgO/Fe trilayers with a subnanometer MgO tunnel barrier were grown by molecular beam epitaxy. Longitudinal magnetooptic Kerr effect measurements confirmed the existence of the antiferromagnetic interlayer exchange coupling (IEC) between the Fe layers for 2 ÅMgO}<6 Å. The coupling was enhanced for the trilayer grown on a homoepitaxial MgO buffer layer, and its IEC constant was estimated to be −3.3 erg/cm{sup 2} at a MgO thickness of 2.7 Å. After magnetic characterization, the sample was patterned into circular-shaped pillars with diameters ranging from 200 nm to 520 nm. We showed that the dipolar coupling that appeared after the nanofabrication process modified the effective coupling between layers, and we determined dependence of the dipolar coupling on the pillar diameter. Finally, magnetoresistance (MR) was measured as a function of MgO thickness (d{sub MgO}), and a non-zero MR was found for the MgO as thin as 3.4 Å. Extrapolation of the MR (d{sub MgO}) dependence to MR=0 allowed us to determine the length of the pinholes in our sample, which was estimated to be (3.2±0.5) Å. - Highlights: • Strong antiferromagnetic (AFM) interlayer exchange coupling (IEC) between Fe layers in Fe/MgO/Fe. • After nanofabrication the effective AFM IEC is enhanced due to the dipolar coupling. • The dipolar coupling that appeared after the nanofabrication process modified the effective coupling between layers. • Non-zero magnetoresistance values registered for the Fe/MgO/Fe trilayers with the MgO spacers as thin as 3.4 Å.

  7. Facile fabrication of hydrophobic surfaces on mechanically alloyed-Mg/HA/TiO{sub 2}/MgO bionanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Khalajabadi, Shahrouz Zamani [Medical Devices and Technology Group (MEDITEG), Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Abdul Kadir, Mohammed Rafiq, E-mail: rafiq@biomedical.utm.my [Medical Devices and Technology Group (MEDITEG), Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Izman, Sudin; Mohd Yusop, Mohd Zamri [Department of Materials, Manufacturing and Industrial Engineering, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia)

    2015-01-01

    Highlights: • Mg/HA/TiO{sub 2}-based nanocomposite was produced using mechanical alloying. • The hydrophobic surface coverage was fabricated on the mechanical alloyed samples by annealing. • The morphological characteristics, phase evolution and wettability of nanocomposites and the hydrophobic surface coverage were investigated. • The activation energies and reaction kinetic of the powder mixture of nanocomposites were calculated. - Abstract: The effect of mechanical alloying and post-annealing on the phase evolution, microstructure, wettability and thermal stability of Mg–HA–TiO{sub 2}–MgO composites was investigated in this study. Phase evolution and microstructure analysis were performed using X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy and atomic force microscopy, as well as the wettability determined by contact angle measurements with SBF. The 16-h mechanical alloying resulted in the formation of MgTiO{sub 3}, CaTiO{sub 3}, Mg{sub 3}(PO{sub 4}){sub 2} and Mg(OH){sub 2} phases and a decrease in wettability of the nanocomposites. A hydrophobic film with hierarchical structures comprising nanoflakes of MgTiO{sub 3}, nano-cuboids of CaTiO{sub 3}, microspheres of Mg{sub 3}(PO{sub 4}){sub 2} and Mg(OH){sub 2} was successfully constructed on the surface of the Mg-based nanocomposites substrates as a result of the post-annealing process. After 1-h annealing at 630 °C, the synthesized hydrophobic surface on the nanocomposite substrates decreased the wettability, as the 8-h-mechanically alloyed samples exhibited a contact angle close to 93°. The formation activation energies and reaction kinetics of the powder mixture were investigated using differential thermal analysis and thermal gravimetric analysis. The released heat, weight loss percentage and reaction kinetics increased, while the formation activation energies of the exothermic reactions decreased following an increase in the milling time.

  8. The in vitro biocompatibility and macrophage phagocytosis of Mg17Al12 phase in Mg-Al-Zn alloys.

    Science.gov (United States)

    Liu, Chen; He, Peng; Wan, Peng; Li, Mei; Wang, Kehong; Tan, Lili; Zhang, Yu; Yang, Ke

    2015-07-01

    Mg alloys are gaining interest for applications as biodegradable medical implant, including Mg-Al-Zn series alloys with good combination of mechanical properties and reasonable corrosion resistance. However, whether the existence of second phase particles in the alloys exerts influence on the biocompatibility is still not clear. A deeper understanding of how the particles regulate specific biological responses is becoming a crucial requirement for their subsequent biomedical application. In this work, the in vitro biocompatibility of Mg17Al12 as a common second phase in biodegradable Mg-Al-Zn alloys was investigated via hemolysis, cytotoxicity, cell proliferation, and cell adhesion tests. Moreover, osteogenic differentiation was evaluated by the extracellular matrix mineralization assay. The Mg17Al12 particles were also prepared to simulate the real situation of second phase in the in vivo environment in order to estimate the cellular response in macrophages to the Mg17Al12 particles. The experimental results indicated that no hemolysis was found and an excellent cytocompatibility was also proved for the Mg17Al12 second phase when co-cultured with L929 cells, MC3T3-E1 cells and BMSCs. Macrophage phagocytosis co-culture test revealed that Mg17Al12 particles exerted no harmful effect on RAW264.7 macrophages and could be phagocytized by the RAW264.7 cells. Furthermore, the possible inflammatory reaction and metabolic way for Mg17Al12 phase were also discussed in detail. © 2014 Wiley Periodicals, Inc.

  9. Surface treatments for controlling corrosion rate of biodegradable Mg and Mg-based alloy implants

    International Nuclear Information System (INIS)

    Uddin, M S; Hall, Colin; Murphy, Peter

    2015-01-01

    Due to their excellent biodegradability characteristics, Mg and Mg-based alloys have become an emerging material in biomedical implants, notably for repair of bone as well as coronary arterial stents. However, the main problem with Mg-based alloys is their rapid corrosion in aggressive environments such as human bodily fluids. Previously, many approaches such as control of alloying materials, composition and surface treatments, have been attempted to regulate the corrosion rate. This article presents a comprehensive review of recent research focusing on surface treatment techniques utilised to control the corrosion rate and surface integrity of Mg-based alloys in both in vitro and in vivo environments. Surface treatments generally involve the controlled deposition of thin film coatings using various coating processes, and mechanical surfacing such as machining, deep rolling or low plasticity burnishing. The aim is to either make a protective thin layer of a material or to change the micro-structure and mechanical properties at the surface and sub-surface levels, which will prevent rapid corrosion and thus delay the degradation of the alloys. We have organised the review of past works on coatings by categorising the coatings into two classes—conversion and deposition coatings—while works on mechanical treatments are reviewed based on the tool-based processes which affect the sub-surface microstructure and mechanical properties of the material. Various types of coatings and their processing techniques under two classes of coating and mechanical treatment approaches have been analysed and discussed to investigate their impact on the corrosion performance, biomechanical integrity, biocompatibility and cell viability. Potential challenges and future directions in designing and developing the improved biodegradable Mg/Mg-based alloy implants were addressed and discussed. The literature reveals that no solutions are yet complete and hence new and innovative approaches

  10. Surface treatments for controlling corrosion rate of biodegradable Mg and Mg-based alloy implants

    Science.gov (United States)

    Uddin, M S; Hall, Colin; Murphy, Peter

    2015-01-01

    Due to their excellent biodegradability characteristics, Mg and Mg-based alloys have become an emerging material in biomedical implants, notably for repair of bone as well as coronary arterial stents. However, the main problem with Mg-based alloys is their rapid corrosion in aggressive environments such as human bodily fluids. Previously, many approaches such as control of alloying materials, composition and surface treatments, have been attempted to regulate the corrosion rate. This article presents a comprehensive review of recent research focusing on surface treatment techniques utilised to control the corrosion rate and surface integrity of Mg-based alloys in both in vitro and in vivo environments. Surface treatments generally involve the controlled deposition of thin film coatings using various coating processes, and mechanical surfacing such as machining, deep rolling or low plasticity burnishing. The aim is to either make a protective thin layer of a material or to change the micro-structure and mechanical properties at the surface and sub-surface levels, which will prevent rapid corrosion and thus delay the degradation of the alloys. We have organised the review of past works on coatings by categorising the coatings into two classes—conversion and deposition coatings—while works on mechanical treatments are reviewed based on the tool-based processes which affect the sub-surface microstructure and mechanical properties of the material. Various types of coatings and their processing techniques under two classes of coating and mechanical treatment approaches have been analysed and discussed to investigate their impact on the corrosion performance, biomechanical integrity, biocompatibility and cell viability. Potential challenges and future directions in designing and developing the improved biodegradable Mg/Mg-based alloy implants were addressed and discussed. The literature reveals that no solutions are yet complete and hence new and innovative approaches

  11. Relationship between insulin resistance and plasma endothelin in hypertension patients

    International Nuclear Information System (INIS)

    Duan Yongqiang; Wang Zuobing; Yu Hui; Cao Wei; Wang Jing; Li Xiaoqin

    2011-01-01

    To explore the relationship between plasma endothelin and hypertension insulin resistance, and the improvement of insulin resistance in hypertension patients treated with captopril and l-amlodipine, 25 patients with primary hypertension and impaired glucose tolerance were selected and treated by captopril and l-amlodipine. Systolic pressure, diastolic pressure, fasting blood glucose, insulin and insulin antibody were measured before and after treatment and compared with healthy controls. The results showed that the plasma ET-1 level in hypertension group was significantly higher than that of healthy controls (P<0.01), and he plasma ET-1 level was positively correlated with FPG, FINS, Anti-INS, HOMA-IR. The systolic pressure, diastolic pressure, fasting blood glucose, insulin, insulin antibody and insulin resistance index in hypertension patients were decreased significantly after treatment (P<0.05). There is a good correlation between endothelin and insulin resistance index in hypertension patients. Captopril and l-amlodipine had obvious improvement effect on insulin resistance in hypertension patients. (authors)

  12. Strength of FePd/MgO and FePt/MgO interfaces from first principles

    Science.gov (United States)

    Černý, M.

    2018-04-01

    Cleavage characteristics such as the cleavage energy and the cleavage stress of FePd/MgO and FePt/MgO interfaces are computed from first principles. Considering several possible cleavage planes, the weakest link in these systems is found as the plane with the lowest cleavage stress. This weakest plane is identified in both systems with the interface plane, where the cohesion is reduced by 30% compared to the MgO bulk. Two distinct models of tensile test are employed to verify the results and convergence of computed values with respect to size of the simulation cell is discussed.

  13. Structurally characterized 1,1,3,3-tetramethylguanidine solvated magnesium aryloxide complexes: [Mg(mu-OEt)(DBP)(H-TMG)]2, [Mg(mu-OBc)(DBP)(H-TMG)]2, [Mg(mu-TMBA)(DBP)(H-TMG)]2, [Mg(mu-DPP)(DBP)(H-TMG)]2, [Mg(BMP)2(H-TMG)2], [Mg(O-2,6-Ph2C6H3)2 (H-TMG)2].

    Science.gov (United States)

    Monegan, Jessie D; Bunge, Scott D

    2009-04-06

    The synthesis and structural characterization of several 1,1,3,3-tetramethylguanidine (H-TMG) solvated magnesium aryloxide complexes are reported. Bu(2)Mg was successfully reacted with H-TMG, HOC(6)H(3)(CMe(3))(2)-2,6 (H-DBP), and either ethanol, a carboxylic acid, or diphenyl phosphate in a 1:1 ratio to yield the corresponding [Mg(mu-L)(DBP)(H-TMG)](2) where L = OCH(2)CH(3) (OEt, 1), O(2)CC(CH(3))(3) (OBc, 2), O(2)C(C(6)H(2)-2,4,6-(CH(3))(3)) (TMBA, 3), or O(2)P(OC(6)H(5))(2) (DPP, 4). Bu(2)Mg was also reacted with two equivalents of H-TMG and HOC(6)H(3)(CMe(3))-2-(CH(3))-6 (BMP) or HO-2,6-Ph(2)C(6)H(3) to yield [Mg(BMP)(2)(H-TMG)(2)] (5) and [Mg(O-2,6-Ph(2)C(6)H(3))(2)(H-TMG)(2)] (6). Compounds 1-6 were characterized by single-crystal X-ray diffraction. Polymerization of l- and rac-lactide with 1 was found to generate polylactide (PLA). A discussion concerning the relevance of compounds 2 - 4 to the structure of Mg-activated phosphatase enzymes is also provided. The bulk powders for all complexes were found to be in agreement with the crystal structures based on elemental analyses, FT-IR spectroscopy, and (1)H, (13)C and (31)P NMR studies.

  14. Lattice stability and formation energies of intrinsic defects in Mg2Si and Mg2Ge via first principles simulations

    International Nuclear Information System (INIS)

    Jund, Philippe; Viennois, Romain; Tédenac, Jean-Claude; Colinet, Catherine; Hug, Gilles; Fèvre, Mathieu

    2013-01-01

    We report an ab initio study of the semiconducting Mg 2 X (with X = Si, Ge) compounds and in particular we analyze the formation energies of the different point defects with the aim of understanding the intrinsic doping mechanisms. We find that the formation energy of Mg 2 Ge is 50% larger than that of Mg 2 Si, in agreement with the experimental tendency. From a study of the stability and the electronic properties of the most stable defects, taking into account the growth conditions, we show that the main cause of the n doping in these materials comes from interstitial magnesium defects. Conversely, since other defects acting like acceptors such as Mg vacancies or multivacancies are more stable in Mg 2 Ge than in Mg 2 Si, this explains why Mg 2 Ge can be of n or p type, in contrast to Mg 2 Si. The finding that the most stable defects are different in Mg 2 Si and Mg 2 Ge and depend on the growth conditions is important and must be taken into account in the search for the optimal doping to improve the thermoelectric properties of these materials.

  15. Excited states in 22Mg via the 12C(12C,2n)22Mg reaction

    International Nuclear Information System (INIS)

    Jewett, Cybele; Baktash, Cyrus; Bardayan, Daniel W.; Blackmon, Jeff C.; Chipps, K.; Galindo-Uribarri, Alfredo; Greife, U.; Gross, Carl J.; Jones, K. L.; Liang, Junjien; Livesay, Jake; Kozub, R. L.; Nesaraja, Caroline D; Radford, David C.; Sarazin, F.; Smith, Michael Scott; Thomas, J. S.; Yu, Chang-Hong

    2007-01-01

    The 12C(12C, 2n)22Mg reaction was measured with the CLARION array and the RMS separator at the Holifield Facility of Oak Ridge National Laboratory. This experiment was performed to gather more information on the excited states in 22Mg, which might be of relevance to recent radioactive ion beam measurements of the astrophysically important 21Na(p,γ)22Mg reaction. The results are compared to direct measurements, transfer experiments and a competing experiment performed with Gammasphere

  16. Efficacy of 5MG and 10MG rosuvastatin in type-2 diabetes mellitus with hypercholesteroalemia

    International Nuclear Information System (INIS)

    Ullah, F.; Rahim, F.; Rahman, S.U.; Ashfaq, M.; Afridi, A.K.

    2015-01-01

    Background: Coronary Heart Disease (CHD) is the most important complication and the leading cause of death in patients with type 2 diabetes mellitus (T2DM). Hypercholesterolemia is an important modifiable risk factor for CHD. Statins are the first line drugs for the treatment of hypercholesterolemia in DM. Comparative studies between different statins are available but different doses of the same statin have not been compared in our population. The objective of this study is to compare mean reduction in serum LDL-C level after using 5mg and 10mg of rosuvastatin among T2DM patients with hypercholesterolemia. This study will help finding lowest effective dose of rosuvastatin to achieve internationally set low density lipoprotein cholesterol (LDL-C) goals. Method: A total of 82 patients with T2DM having fasting LDL-C levels equal or more than 100mg/dl were randomly allocated into two groups with 41 patients in each group. Baseline fasting serum LCL-C levels were obtained in all patients. Group A received 5mg while group B received 10mg of rosuvastatin daily at night. After 6 weeks, fasting LDL-C levels were obtained and analysed to compare the mean±SD reduction of LDL-C levels in both groups. Results: Baseline mean±SD LDL-C levels in group A and group B were 134.12±30.02 and 143.49±32.01 respectively (p 0.176). Follow up mean ± SD LDL-C levels were 81.59±28.47 and 83.24±36.06 respectively (p 0.818). Mean ± SD reduction in LDL-C levels from baseline levels in group A and group B were 52.51±19.49 and 60.20±24.09 (p 0.116). Conclusion: Rosuvastatin 5mg is as effective as 10mg in reducing the LDL-C levels in type 2 diabetic patients with hypercholesterolemia. (author)

  17. Comparison of effects of ATP-MgCl2 and adenosine-MgCl2 on renal function following ischemia

    International Nuclear Information System (INIS)

    Sumpio, B.E.; Hull, M.J.; Baue, A.E.; Chaudry, I.H.

    1987-01-01

    ATO-MgCl 2 administration had been shown to accelerate the recovery of renal function following warm ischemia. However, since the major breakdown product of ATP is adenosine, the relative contribution of ATP vs. adenosine in improving renal function following ischemia remains to be determined. To study this, kidneys were subjected to 45 min of normothermic ischemia and then perfused at 100 mmHg with oxygenated Krebs-HCO 3 buffer containing albumin, [ 3 H]inulin, substrates, and either 0.3 mM ATP-MgCl 2 or adenosine-MgCl 2 for 110 min. Perfusate and timed urine samples were collected and analyzed for radioactivity and [Na + ]. The functional parameters indicated that although adenosine-MgCl 2 treatment provided a transient improvement, it failed to provided a sustained improvement in renal function or attain control valued compared with ATP-MgCl 2 treatment. Thus, the salutary effects of ATP-MgCl 2 following warm ischemia in the kidney are not mediated by adenosine

  18. Catalytic activity of Co-Mg-Al, Cu-Mg-Al and Cu-Co-Mg-Al mixed oxides derived from hydrotalcites in SCR of NO with ammonia

    Energy Technology Data Exchange (ETDEWEB)

    Chmielarz, Lucjan; Kustrowski, Piotr; Rafalska-Lasocha, Alicja [Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow (Poland); Majda, Dorota; Dziembaj, Roman [Regional Laboratory for Physicochemical Analyses and Structural Research, Ingardena 3, 30-060 Krakow (Poland)

    2002-01-10

    M-Mg-Al hydrotalcites (where M=Cu{sup 2+}, Co{sup 2+} and Cu{sup 2+}+Co{sup 2+}) with M ranging from 5 to 20% (as atomic ratio) were prepared by co-precipitation method. Obtained samples were characterised by XRD and TGA techniques. The influence of transition metal content on thermal decomposition of hydrotalcites was observed. Calcination of the hydrotalcites at 600C resulted in the formation of mixed oxides with surface areas in the range 71-154m{sup 2}/g. Calcined hydrotalcites were tested as catalysts in the selective reduction of NO with ammonia (NO-SCR). The catalytic activity depends on the kind of transition metal, as well as its content. For the NO-SCR the following reactivity order was found: Cu-Mg-Al>Cu-Co-Mg-Al>Co-Mg-Al. Temperature-programmed methods (TPD, TPSR, stop flow-TPD), as well as FT-IR spectroscopy have been applied to determine interaction of NO and NH{sub 3} molecules with the catalyst surface.

  19. Effect of amorphous Mg{sub 50}Ni{sub 50} on hydriding and dehydriding behavior of Mg{sub 2}Ni alloy

    Energy Technology Data Exchange (ETDEWEB)

    Guzman, D., E-mail: danny.guzman@uda.cl [Departamento de Ingenieria en Metalurgia, Facultad de Ingenieria, Universidad de Atacama y Centro Regional de Investigacion y Desarrollo Sustentable de Atacama (CRIDESAT), Av. Copayapu 485, Copiapo (Chile); Ordonez, S. [Departamento de Ingenieria Metalurgica, Facultad de Ingenieria, Universidad de Santiago de Chile, Av. Lib. Bernardo O' Higgins 3363, Santiago (Chile); Fernandez, J.F.; Sanchez, C. [Departamento de Fisica de Materiales, Facultad de Ciencias, Universidad Autonoma de Madrid, Cantoblanco 28049, Madrid (Spain); Serafini, D. [Departamento de Fisica, Facultad de Ciencias, Universidad de Santiago de Chile and Center for Interdisciplinary Research in Materials, CIMAT, Av. Lib. Bernardo O' Higgins 3363, Santiago (Chile); Rojas, P.A. [Escuela de Ingenieria Mecanica, Facultad de Ingenieria, Av. Los Carrera 01567, Quilpue, Pontificia Universidad Catolica de Valparaiso, PUCV (Chile); Aguilar, C. [Departamento de Ingenieria Metalurgica y Materiales, Universidad Tecnica Federico Santa Maria, Av. Espana 1680, Valparaiso (Chile); Tapia, P. [Departamento de Ingenieria en Metalurgia, Facultad de Ingenieria, Universidad de Atacama, Av. Copayapu 485, Copiapo (Chile)

    2011-04-15

    Composite Mg{sub 2}Ni (25 wt.%) amorphous Mg{sub 50}Ni{sub 50} was prepared by mechanical milling starting with nanocrystalline Mg{sub 2}Ni and amorphous Mg{sub 50}Ni{sub 50} powders, by using a SPEX 8000 D mill. The morphological and microstructural characterization of the powders was performed via scanning electron microscopy and X-ray diffraction. The hydriding characterization of the composite was performed via a solid gas reaction method in a Sievert's-type apparatus at 363 K under an initial hydrogen pressure of 2 MPa. The dehydriding behavior was studied by differential thermogravimetry. On the basis of the results, it is possible to conclude that amorphous Mg{sub 50}Ni{sub 50} improved the hydriding and dehydriding kinetics of Mg{sub 2}Ni alloy upon cycling. A tentative rationalization of experimental observations is proposed. - Research Highlights: {yields} First study of the hydriding behavior of composite Mg{sub 2}Ni (25 wt.%) amorphous Mg{sub 50}Ni{sub 50}. {yields} Microstructural characterization of composite material using XRD and SEM was obtained. {yields} An improved effect of Mg{sub 50}Ni{sub 50} on the Mg{sub 2}Ni hydriding behavior was verified. {yields} The apparent activation energy for the hydrogen desorption of composite was obtained.

  20. Prussian Blue Mg-Li Hybrid Batteries.

    Science.gov (United States)

    Sun, Xiaoqi; Duffort, Victor; Nazar, Linda F

    2016-08-01

    The major advantage of Mg batteries relies on their promise of employing an Mg metal negative electrode, which offers much higher energy density compared to graphitic carbon. However, the strong coulombic interaction of Mg 2+ ions with anions leads to their sluggish diffusion in the solid state, which along with a high desolvation energy, hinders the development of positive electrode materials. To circumvent this limitation, Mg metal negative electrodes can be used in hybrid systems by coupling an Li + insertion cathode through a dual salt electrolyte. Two "high voltage" Prussian blue analogues (average 2.3 V vs Mg/Mg 2+ ; 3.0 V vs Li/Li + ) are investigated as cathode materials and the influence of structural water is shown. Their electrochemical profiles, presenting two voltage plateaus, are explained based on the two unique Fe bonding environments. Structural water has a beneficial impact on the cell voltage. Capacities of 125 mAh g -1 are obtained at a current density of 10 mA g -1 (≈C/10), while stable performance up to 300 cycles is demonstrated at 200 mA g -1 (≈2C). The hybrid cell design is a step toward building a safe and high density energy storage system.

  1. An Asian regional analysis of cost-effectiveness of early irbesartan treatment versus conventional antihypertensive, late amlodipine, and late irbesartan treatments in patients with type 2 diabetes, hypertension, and nephropathy.

    Science.gov (United States)

    Annemans, Lieven; Demarteau, Nadia; Hu, Shanlian; Lee, Tae-Jin; Morad, Zaher; Supaporn, Thanom; Yang, Wu-Chang; Palmer, Andrew J

    2008-01-01

    The prevalence of type 2 diabetes, often leading to diabetic nephropathy, has increased globally, especially in Asia. Irbesartan treatment delays the progression of kidney disease at the early (microalbuminuria) and late (proteinuria) stages of nephropathy in hypertensive type 2 diabetics. This treatment has proven to be cost-effective in Western countries. This study assessed the cost-effectiveness of early irbesartan treatment in Asian settings. An existing lifetime model was reprogrammed in Microsoft Excel to compare irbesartan started at an early stage to irbesartan or amlodipine started at a late stage, and standard treatments from a health-care perspective in China, Malaysia, Thailand, South Korea, and Taiwan. The main effectiveness parameters were incidences of end-stage renal disease, time in dialysis, and life expectancy. All costs were converted to 2004 US$ using official purchasing power parity. Local data were obtained for costs, transplantation,dialysis, and mortality rates. Probabilities regarding disease progression after treatment with the investigated drugs were extracted from two published clinical trials. A probabilistic sensitivity analysis was performed. Early use of irbesartan yielded the largest clinical and economic benefits reducing need for dialysis by 61% to 63% versus the standard treatment, total costs by 9% (Thailand) to 42% (Taiwan), and increasing life expectancy by 0.31 to 0.48 years. Early irbesartan had a 66% (Thailand) to 95% (Taiwan) probability of being dominant over late irbesartan. Although the absolute results varied in different settings, reflecting differences in epidemiology, management, and costs, early irbesartan treatment was a cost-effective alternative in the Asian settings.

  2. Loss of Endothelial Barrier in Marfan Mice (mgR/mgR Results in Severe Inflammation after Adenoviral Gene Therapy.

    Directory of Open Access Journals (Sweden)

    Philipp Christian Seppelt

    Full Text Available Marfan syndrome is an autosomal dominant inherited disorder of connective tissue. The vascular complications of Marfan syndrome have the biggest impact on life expectancy. The aorta of Marfan patients reveals degradation of elastin layers caused by increased proteolytic activity of matrix metalloproteinases (MMPs. In this study we performed adenoviral gene transfer of human tissue inhibitor of matrix metalloproteinases-1 (hTIMP-1 in aortic grafts of fibrillin-1 deficient Marfan mice (mgR/mgR in order to reduce elastolysis.We performed heterotopic infrarenal transplantation of the thoracic aorta in female mice (n = 7 per group. Before implantation, mgR/mgR and wild-type aortas (WT, C57BL/6 were transduced ex vivo with an adenoviral vector coding for human TIMP-1 (Ad.hTIMP-1 or β-galactosidase (Ad.β-Gal. As control mgR/mgR and wild-type aortas received no gene therapy. Thirty days after surgery, overexpression of the transgene was assessed by immunohistochemistry (IHC and collagen in situ zymography. Histologic staining was performed to investigate inflammation, the neointimal index (NI, and elastin breaks. Endothelial barrier function of native not virus-exposed aortas was evaluated by perfusion of fluorescent albumin and examinations of virus-exposed tissue were performed by transmission electron microscopy (TEM.IHC and ISZ revealed sufficient expression of the transgene. Severe cellular inflammation and intima hyperplasia were seen only in adenovirus treated mgR/mgR aortas (Ad.β-Gal, Ad.hTIMP-1 NI: 0.23; 0.43, but not in native and Ad.hTIMP-1 treated WT (NI: 0.01; 0.00. Compared to native mgR/mgR and Ad.hTIMP-1 treated WT aorta, the NI is highly significant greater in Ad.hTIMP-1 transduced mgR/mgR aorta (p = 0.001; p = 0.001. As expected, untreated Marfan grafts showed significant more elastolysis compared to WT (p = 0.001. However, elastolysis in Marfan aortas was not reduced by adenoviral overexpression of hTIMP-1 (compared to untreated

  3. Resetting of Mg isotopes between calcite and dolomite during burial metamorphism: Outlook of Mg isotopes as geothermometer and seawater proxy

    Science.gov (United States)

    Hu, Zhongya; Hu, Wenxuan; Wang, Xiaomin; Lu, Yizhou; Wang, Lichao; Liao, Zhiwei; Li, Weiqiang

    2017-07-01

    Magnesium isotopes are an emerging tool to study the geological processes recorded in carbonates. Calcite, due to its ubiquitous occurrence and the large Mg isotope fractionation associated with the mineral, has attracted great interests in applications of Mg isotope geochemistry. However, the fidelity of Mg isotopes in geological records of carbonate minerals (e.g., calcite and dolomite) against burial metamorphism remains poorly constrained. Here we report our investigation on the Mg isotope systematics of a dolomitized Middle Triassic Geshan carbonate section in eastern China. Magnesium isotope analysis was complemented by analyses of Sr-C-O isotopic compositions, major and trace element concentrations, and petrographic and mineralogical features. Multiple lines of evidence consistently indicated that post-depositional diagenesis of carbonate minerals occurred to the carbonate rocks. Magnesium isotope compositions of the carbonate rocks closely follow a mixing trend between a high δ26Mg dolomite end member and a low δ26Mg calcite end member, irrespective of sample positions in the section and calcite/dolomite ratio in the samples. By fitting the measured Mg isotope data using a two-end member mixing model, an inter-mineral Δ26Mgdolomite-calcite fractionation of 0.72‰ was obtained. Based on the experimentally derived Mg isotope fractionation factors for dolomite and calcite, a temperature of 150-190 °C was calculated to correspond to the 0.72‰ Δ26Mgdolomite-calcite fractionation. Such temperature range matches with the burial-thermal history of the local strata, making a successful case of Mg isotope geothermometry. Our results indicate that both calcite and dolomite had been re-equilibrated during burial metamorphism, and based on isotope mass balance of Mg, the system was buffered by dolomite in the section. Therefore, burial metamorphism may reset Mg isotope signature of calcite, and Mg isotope compositions in calcite should be dealt with caution in

  4. Effect of amorphous lamella on the crack propagation behavior of crystalline Mg/amorphous Mg-Al nanocomposites

    Science.gov (United States)

    Hai-Yang, Song; Yu-Long, Li

    2016-02-01

    The effects of amorphous lamella on the crack propagation behavior in crystalline/amorphous (C/A) Mg/Mg-Al nanocomposites under tensile loading are investigated using the molecular dynamics simulation method. The sample with an initial crack of orientation [0001] is considered here. For the nano-monocrystal Mg, the crack growth exhibits brittle cleavage. However, for the C/A Mg/Mg-Al nanocomposites, the ‘double hump’ behavior can be observed in all the stress-strain curves regardless of the amorphous lamella thickness. The results indicate that the amorphous lamella plays a critical role in the crack deformation, and it can effectively resist the crack propagation. The above mentioned crack deformation behaviors are also disclosed and analyzed in the present work. The results here provide a strategy for designing the high-performance hexagonal-close-packed metal and alloy materials. Project supported by the National Natural Science Foundation of China (Grant Nos. 11372256 and 11572259), the 111 Project (Grant No. B07050), the Program for New Century Excellent Talents in University of Ministry of Education of China (Grant No. NCET-12-1046), and the Program for New Scientific and Technological Star of Shaanxi Province, China (Grant No. 2012KJXX-39).

  5. Porous composite materials ZrO{sub 2}(MgO)-MgO for osteoimplantology

    Energy Technology Data Exchange (ETDEWEB)

    Buyakov, Ales, E-mail: alesbuyakov@gmail.com [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation); National Research Tomsk State University, Tomsk, 634050 (Russian Federation); Litvinova, Larisa, E-mail: larisalitvinova@yandex.ru; Shupletsova, Valeria, E-mail: vshupletsova@mail.ru [Immanuel Kant Baltic Federal University, Kaliningrad (Russian Federation); Kulbakin, Denis, E-mail: kulbakin2012@gmail.com [Tomsk Cancer Research Institute, Tomsk, 634050 (Russian Federation); Kulkov, Sergey, E-mail: kulkov@ispms.ru [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation); National Research Tomsk State University, Tomsk, 634050 (Russian Federation); National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation)

    2016-08-02

    The pore structure and phase composition of ceramic composite material ZrO{sub 2}(Mg)-MgO at different sintering temperatures were studied. The main mechanical characteristics of the material were determined and it was shown that they are close to the characteristics of natural bone tissues. It was shown that material structure has a positive effect on the pre-osteoblast cells proliferation. In-vitro studies of pre-osteoblast cells, cultivation on material surface showed a good cell adhesion, proliferation and differentiation of MMSC by osteogenic type.

  6. Role of 3d-ions for radiation defect production in MgO and MgAl2O4

    International Nuclear Information System (INIS)

    Mironova, N.A.; Grinvald, G.A.; Skvortsova, V.N.

    1985-01-01

    Optical properties of MgO and MgAl 2 O 4 crystals containing chromium and manganese impurity ions were studied by exposure to but all types of radiation. Complicated defects of the ''impurity-intrinsic matrix defect'' type were preferably considered. It has been shown that different symmetry center forming chromium ions in MgO:Crsup(3+) change their valency with various efficiency being exposed to external action. Besides, the compensating vacancy does not participate in the hole center formation. For MgOxAl 2 O 3 single crystals the presence of octahedrally coordinated manganese ions suppresses the hole center creation by gamma-irradiation. Studying luminescence spectra of Crsup(3+) ions in MgAl 2 O 4 it has been states that neutron irradiation increases the degree of inversion for the magnesium-aluminium spinel

  7. Mg2BIV: Narrow Bandgap Thermoelectric Semiconductors

    Science.gov (United States)

    Kim, Il-Ho

    2018-05-01

    Thermoelectric materials can convert thermal energy directly into electric energy and vice versa. The electricity generation from waste heat via thermoelectric devices can be considered as a new energy source. For instance, automotive exhaust gas and all industrial processes generate an enormous amount of waste heat that can be converted to electricity by using thermoelectric devices. Magnesium compound Mg2BIV (BIV = Si, Ge or Sn) has a favorable combination of physical and chemical properties and can be a good base for the development of new efficient thermoelectrics. Because they possess similar properties to those of group BIV elemental semiconductors, they have been recognized as good candidates for thermoelectric applications. Mg2Si, Mg2Ge and Mg2Sn with an antifluorite structure are narrow bandgap semiconductors with indirect band gaps of 0.77 eV, 0.74 eV, and 0.35 eV, respectively. Mg2BIV has been recognized as a promising material for thermoelectric energy conversion at temperatures ranging from 500 K to 800 K. Compared to other thermoelectric materials operating in the similar temperature range, such as PbTe and filled skutterudites, the important aspects of Mg2BIV are non-toxic and earth-abundant elements. Based on classical thermoelectric theory, the material factor β ( m* / m e)3/2μκ L -1 can be utilized as the criterion for thermoelectric material selection, where m* is the density-of-states effective mass, me is the mass of an electron, μ is the carrier mobility, and κL is the lattice thermal conductivity. The β for magnesium silicides is 14, which is very high compared to 0.8 for iron silicides, 1.4 for manganese silicides, and 2.6 for silicon-germanium alloys. In this paper, basic phenomena of thermoelectricity and transport parameters for thermoelectric materials were briefly introduced, and thermoelectric properties of Mg2BIV synthesized by using a solid-state reaction were reviewed. In addition, various Mg2BIV compounds were discussed

  8. Centrifugally cast Zn-27Al-xMg-ySi alloys and their in situ (Mg2Si + Si)/ZA27 composites

    International Nuclear Information System (INIS)

    Wang Qudong; Chen Yongjun; Chen Wenzhou; Wei Yinhong; Zhai Chunquan; Ding Wenjiang

    2005-01-01

    Effects of composition, mold temperature, rotating rate and modification on microstructure of centrifugally cast Zn-27Al-xMg-ySi alloys have been investigated. In situ composites of Zn-27Al-6.3Mg-3.7Si and Zn-27Al-9.8Mg-5.2Si alloys were fabricated by centrifugal casting using heated permanent mold. These composites consist of three layers: inner layer segregates lots of blocky primary Mg 2 Si and a litter blocky primary Si, middle layer contains without primary Mg 2 Si and primary Si, outer layer contains primary Mg 2 Si and primary Si. The position, quantity and distribution of primary Mg 2 Si and primary Si in the composites are determined jointly by alloy composition, solidification velocity under the effect of centrifugal force and their floating velocity inward. Na salt modifier can refine grain and primary Mg 2 Si and make primary Mg 2 Si distribute more evenly and make primary Si nodular. For centrifugally cast Zn-27Al-3.2Mg-1.8Si alloy, the microstructures of inner layer, middle layer and outer layer are almost similar, single layer materials without primary Mg 2 Si and primary Si are obtained, and their grain sizes increased with the mold temperature increasing

  9. Comparison of initial loading doses of 5 mg and 10 mg for warfarin therapy

    Directory of Open Access Journals (Sweden)

    Sidnei Lastória

    2014-03-01

    Full Text Available CONTEXT: The question of what is the best loading dosage of warfarin when starting anticoagulant treatment has been under discussion for ten years. We were unable to find any comparative studies of these characteristics conducted here in Brazil. OBJECTIVE: To compare the safety and efficacy of two initial warfarin dosage regimens for anticoagulant treatment. METHODS: One-hundred and ten consecutive patients of both sexes, with indications for anticoagulation because of venous or arterial thromboembolism, were analyzed prospectively. During the first 3 days of treatment, these patients were given adequate heparin to keep aPTT (activated partial thromboplastin time between 1.5 and 2.5, plus 5 mg of warfarin. From the fourth day onwards, their warfarin doses were adjusted using International Normalized Ratios (INR; target range: 2 to 3. This prospective cohort was compared with a historical series of 110 patients had been given 10 mg of warfarin on the first 2 days and 5 mg on the third day with adjustments based on INR thereafter. Outcomes analyzed were as follows: recurrence of thromboembolism, bleeding events and time taken to enter the therapeutic range. RESULTS: Efficacy, safety and length of hospital stay were similar in both samples. The sample that were given 10 mg entered the therapeutic range earlier (means: 4.5 days vs. 5.8 days, were on lower doses at discharge and had better therapeutic indicators at the first return appointment. CONCLUSIONS: The 10 mg dosage regimen took less time to attain the therapeutic range and was associated with lower warfarin doses at discharge and better INR at first out-patients follow-up visit.

  10. Renoprotective effects of benazepril: current perspective.

    Science.gov (United States)

    Stompór, Tomasz; Napora, Maria; Olszewski, Artur

    2011-06-01

    Cardiovascular (CV) disease, its associated risk factors and continued progression run in parallel with renal deterioration (cardio-renal syndrome). Most guidelines promote early treatment, including the use of ACE inhibitors to control CV risk in patients with chronic renal failure. The renoprotective effects of the ACE inhibitor, benazepril, independent of blood pressure control, have been demonstrated, as monotherapy or in combination with amlodipine or hydrochlorothiazide, in large clinical trials: Avoiding Cardiovascular Events through Combination Therapy in Patients Living with Systolic Hypertension (ACCOMPLISH) and Gauging Albuminuria Reduction with Lotrel in Diabetic Patients with Hypertension (GUARD) in patients with mild-to-severe chronic kidney disease. In the ACCOMPLISH trial, CV outcomes and renoprotective effects were greater in patients receiving benazepril in combination with amlodipine; the GUARD trial demonstrated that combined benazepril/hydrochlorothiazide was more effective than amlodipine combined with benazepril in reducing baseline urinary albumin:creatinine ratio and normalizing urinary albumin:creatinine ratio in patients with baseline microalbuminuria, although this effect was accompanied with a greater decrease in glomerular filtration rate than with benazepril/amlodipine. While this is not a study in patients with overt renal disease (patients had severe CV diseases), the ACCOMPLISH trial is the first large study to date to show the added benefit of combining ACE inhibitors and calcium-channel blockers in renal protection. Future large, well-controlled trials, designed to evaluate hard renal outcomes, are required to identify which patients will benefit most from particular combination treatment strategies in renoprotection.

  11. Effect of solution concentration on sealing treatment of Mg-Al hydrotalcite film on AZ91D Mg alloy

    Directory of Open Access Journals (Sweden)

    Qiangsheng Dong

    2017-09-01

    Full Text Available Cerium-based sealing treatment was developed for Mg-Al hydrotalcite film on AZ91D Mg alloy, and the influence of cerium salt solution was investigated to modify the surface integrity and corrosion resistance. Scanning electron microscope (SEM and X-ray diffraction (XRD measurements were carried out to analyze the surface morphology and phase composition. The corrosion resistance of Mg-Al hydrotalcite film after sealing treatment was evaluated by the polarization curve and electrochemical impedance spectroscopy (EIS tests. The results showed that lower concentration of Ce-containing solution was beneficial to seal the micro-cracks on Mg-Al hydrotalcite film, and improve the surface integrity and corrosion resistance; higher concentration of Ce-containing solution could seal fewer micro-cracks, and the corrosion resistance was decreased owing to the disintegration of Mg-Al hydrotalcite film.

  12. Uncovering the Local Magnesium Environment in the Metal–Organic Framework Mg 2 (dobpdc) Using 25 Mg NMR Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jun; Blaakmeer, E. S. Merijn [Institute; Lipton, Andrew S. [Environmental; McDonald, Thomas M.; Liu, Yifei Michelle; Smit, Berend [Laboratory; Long, Jeffrey R. [Materials; Kentgens, Arno P. M. [Institute; Reimer, Jeffrey A. [Materials

    2017-09-06

    The incorporation of N,N'-dimethylethylenediamine into an expanded MOF-74 framework has yielded a material (mmen-Mg2(dobpdc)) exhibiting “step-shaped” CO2 adsorption isotherms. The coordination of mmen at the Mg open metal center is essential for the unique cooperative adsorption mechanism elucidated for this material. Despite its importance for carbon capture, there is as yet no experimental structure determination available for the underlying metal– organic framework Mg2(dobpdc). Our 25Mg solid-state NMR data unravel the local Mg environments in several Mg2(dobpdc) samples, unambiguously confirming the formation of fivecoordinate Mg centers in the activated material and six-coordinate Mg centers in the solvent- or diamine-loaded samples, such as mmen-Mg2(dobpdc). A fraction of the Mg centers are locally disordered due to the framework deformation accompanied by the guest distributions and dynamics.

  13. Behavior of methyl orange and orange 10 (orange G) in the presence of hydrotalcite type compounds of Mg/Al and Mg/Fe; Comportamiento de naranja de metilo y naranja 10 (orange G) en presencia de compuestos tipo hidrotalcita de mg/Al y Mg/Fe

    Energy Technology Data Exchange (ETDEWEB)

    Cruz N, G.

    2015-07-01

    This work is focused on studying the sorption capacity of methyl orange dye (Nm) and orange 10 (N-10) in the presence of hydrotalcite type compounds of Mg/Al and Mg/Fe uncalcined and calcined previously at 500 degrees Celsius. Sorption isotherms were determined and the study of the kinetics of sorption was performed. The materials were characterized before and after sorption processes of these dyes by X-ray diffraction, scanning electron microscopy, the specific surface area determination by the Brunauer-Emmett-Teller method, thermogravimetry coupled to mass and infrared spectrometry. The hydrotalcite type compounds reported in this paper were prepared in the laboratory and their acronyms are: HTMgAlG1, HTMgAlMO, HTMgFeG1 and HTMgFeG2. Note that in this work the best conditions for preparing compounds of Mg/Fe were found. From patterns of X-ray diffraction was identified the typical crystal structure of the hydrotalcite type compounds. By scanning electron microscopy the morphology could be determined in the form of flakes characteristics of these compounds. Likewise with elemental analysis of energy dispersive X-ray spectroscopy the presence of Mg, Al, Fe and C, elements of interest for this study was determined. The compounds presented a specific surface area relatively high from 80 to 120 m{sup 2}/g. Thermogravimetry results presented spectra of mass loss very characteristic associated to water losses, dehydroxylation and decarboxylation. The characteristic bands of water and carbonate were assigned by infrared spectroscopy and the bands corresponding to the dyes sulfonates were identified only for the calcined materials. The sorption capacities found of these compounds were as follows: for Nm in the compound HTMgAlG1 uncalcined was 17.82 mg/g for an initial concentration of 200 mg/L and for calcined (HTMgAlMOcal) of 99.8 mg/g with and initial concentration of 1000 mg/L. Moreover, the sorption capacity of the dye N-10 in this same material was 17.92 mg/g and 99

  14. Exploring the island of inversion with the d({sup 30}Mg,p){sup 31}Mg reaction

    Energy Technology Data Exchange (ETDEWEB)

    Bildstein, Vinzenz

    2010-12-07

    In this thesis the results of a d({sup 30}Mg,p){sup 31}Mg experiment at REX-ISOLDE are presented. {sup 31}Mg is located directly on the border of the so-called ''Island of Inversion'', a region of the nuclear chart around {sup 32}Mg where deformed intruder states of the fp shell form the ground states of the nuclei instead of the normal spherical states of the sd shell. A recent experiment has shown the ground state of {sup 31}Mg to be a 1/2{sup +} state and indicates more than 90% intruder configuration. The question whether the low-lying excited states of {sup 31}Mg are deformed intruder states as well or rather spherical states from the sd shell, indicating shape coexistence, is still open. The d({sup 30}Mg,p) {sup 31}Mg reaction is thus a good tool to gain more insight into the nature of the Island of Inversion. In the framework of this thesis the angular distribution of protons was measured for the second excited state at 221 keV in coincidence with de-excitation {gamma}-rays. The angular distribution was compared to DWBA calculations for different transferred orbital momenta, identifying the state for the first time as an l=1 state. The experiment was performed with the new charged particle detector setup T-REX. The setup is optimized for transfer reactions with radioactive beams in inverse kinematics. T-REX was developed, built, installed, and used for this first one neutron transfer experiment in the context of this thesis. The T-REX setup consists of {delta}E-E{sub Rest} telescopes made out of position sensitive silicon detectors that cover almost 4{pi} of the solid angle and can be combined with the MINIBALL {gamma}-ray detector array. It has a large solid angle for the detection and identification of the light recoils from transfer reactions. T-REX allows in combination with the MINIBALL Germanium detector array the tagging of the excited states by their characteristic {gamma}-rays. The combination of T-REX and MINIBALL achieves an

  15. The difference of contrast effects of myelography in normal dogs: Comparison of iohexol (180 mgI/ml), iohexol (240 mgI/ml) and iotrolan (240 mgI/ml)

    International Nuclear Information System (INIS)

    Shimizu, J.; Yamada, K.; Kishimoto, M.; Iwasaki, T.; Miyake, Y.

    2008-01-01

    The contrast effects of three different contrast media preparations (iohexol 180 mgI/ml, iohexol 240 mgI/ml and iotrolan 240 mgI/ml) in conventional and CT myelography were compared. Three beagle dogs were used and the study employed a cross-over method (total of 9) for each contrast media. The result of CT myelography showed that the contrast effect of iohexol (180 mgI/ml), which had low viscosity, was highest in cranial sites, and the contrast effect of high-viscosity iotrolan (240 mgI/ml) was highest in caudal sites 5 min after injection of the contrast media preparations. This shows that the diffusion of contrast media preparations in the subarachnoid space is influenced by viscosity. The results of conventional myelography also showed that the diffusion of contrast media preparations is influenced by viscosity. Therefore, it is important to identify the location of spinal lesions in veterinary practice, and low viscosity contrast medium preparation with wide spread contrast effects is considered suitable for myelography

  16. Defect structure of ultrafine MgB2 nanoparticles

    International Nuclear Information System (INIS)

    Bateni, Ali; Somer, Mehmet; Repp, Sergej; Erdem, Emre; Thomann, Ralf; Acar, Selçuk

    2014-01-01

    Defect structure of MgB 2 bulk and ultrafine particles, synthesized by solid state reaction route, have been investigated mainly by the aid of X-band electron paramagnetic resonance spectrometer. Two different amorphous Boron (B) precursors were used for the synthesis of MgB 2 , namely, boron 95 (purity 95%–97%, <1.5 μm) and nanoboron (purity >98.5%, <250 nm), which revealed bulk and nanosized MgB 2 , respectively. Scanning and transmission electron microscopy analysis demonstrate uniform and ultrafine morphology for nanosized MgB 2 in comparison with bulk MgB 2 . Powder X-ray diffraction data show that the concentration of the by-product MgO is significantly reduced when nanoboron is employed as precursor. It is observed that a significant average particle size reduction for MgB 2 can be achieved only by using B particles of micron or nano size. The origin and the role of defect centers were also investigated and the results proved that at nanoscale MgB 2 material contains Mg vacancies. Such vacancies influence the connectivity and the conductivity properties which are crucial for the superconductivity applications

  17. Effects of graphite doping on critical current density and microstructure of MgB2 bulks by an improved Mg-diffusion method

    International Nuclear Information System (INIS)

    Pan, X.F.; Zhao, Y.; Feng, Y.; Yang, Y.; Cheng, C.H.

    2008-01-01

    abstract: A series of graphite-doped MgB 2 bulks with high density have been successfully prepared by an improved Mg-diffusion method in ambient pressure. The effects of graphite doping on lattice parameters, T c , J c and microstructure of MgB 2 have been investigated. The results show that compared to the nano-C-doped or CNTs-doped MgB 2 , C is not easy to substitute B in graphite-doped MgB 2 . However, at the same C content, the graphite-doped MgB 2 has a higher J c . At 10 K and self-field, the J c for MgB 1.985 C 0.015 reaches 0.58 MA/cm 2 . For the MgB 1.945 C 0.055 , at 5 K, 7 T and 10 K, 6 T the J c achieves 10,000 A/cm 2 which is two orders of magnitude higher than that for the undoped sample. In addition to improving electron scattering and intergranular connectivity, the unreacted graphite in the graphite-doped MgB 2 is proposed to be responsible to the excellent J c properties of MgB 2 in high fields, due to depressed grain growth and enhanced grain boundary flux pinning

  18. Atorvastatin 10 mg plus ezetimibe 10mg compared with atorvastatin 20 mg: impact on the lipid profile in Japanese patients with abnormal glucose tolerance and coronary artery disease.

    Science.gov (United States)

    Uemura, Yusuke; Watarai, Masato; Ishii, Hideki; Koyasu, Masayoshi; Takemoto, Kenji; Yoshikawa, Daiji; Shibata, Rei; Matsubara, Tatsuaki; Murohara, Toyoaki

    2012-01-01

    Oxidized low-density lipoprotein (LDL) cholesterol is a sensitive lipid marker for predicting atherosclerosis. Ezetimibe and statins are reported to decrease both LDL cholesterol and oxidized LDL cholesterol. This prospective randomized open-label crossover study compared combination therapy with atorvastatin plus ezetimibe versus high-dose atorvastatin monotherapy. Changes in serum lipids, including malondialdehyde-modified LDL (MDA-LDL) as a representative form of oxidized LDL cholesterol, and glucose metabolism were assessed. The subjects were 39 Japanese patients with coronary artery disease and type 2 diabetes or impaired glucose tolerance who were taking 10 mg/day of atorvastatin (30 men and 9 women with a mean age of 67.8 years). They were randomized to a group that first received add-on ezetimibe (10 mg/day) or a group that first received atorvastatin monotherapy at a higher dose of 20 mg/day. Both treatments were given for 12 weeks each in a crossover fashion. Add-on ezetimibe significantly decreased MDA-LDL (109.0 ± 31.9 mg/dl to 87.7 ± 29.4 mg/dl, p=0.0009), while up-titration of atorvastatin did not. The decrease with add-on ezetimibe was significantly greater than with up-titration of atorvastatin (p=0.0006). Total cholesterol and LDL cholesterol were significantly decreased by both treatments, but the percent reduction with add-on ezetimibe was significantly greater (pHigh-density lipoprotein cholesterol was significantly increased by both treatments and there was no significant difference between them. The apolipoprotein B/apolipoprotein A-I ratio and remnant-like particle cholesterol were only significantly decreased by add-on ezetimibe. Both treatments caused similar elevation of hemoglobin A(1c). In Japanese patients with type 2 diabetes or impaired glucose tolerance and coronary artery disease, adding ezetimibe (10 mg/day) to atorvastatin (10 mg/day) significantly improved the lipid profile compared with atorvastatin monotherapy at 20 mg

  19. Fabrication of sandwich-type MgB{sub 2}/Boron/MgB{sub 2} Josephson junctions with rapid annealing method

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Song; Wang, Xu; Ma, Junli; Cui, Ruirui; Deng, Chaoyong, E-mail: cydeng@gzu.edu.cn

    2015-11-15

    Sandwich-type MgB{sub 2}/Boron/MgB{sub 2} Josephson junctions were fabricated using magnetron sputtering system. The rapid-anneal process was adopted to replace traditional way of annealing, trying to solve the problem of interdiffusion and oxidation with multilayer films. The boron film was used as barrier layer to avoid the introduction of impurities and improve reproducibility of the junctions. The bottom MgB{sub 2} thin films deposited on c-plane sapphire substrate exhibits a critical temperature T{sub C} of 37.5 K and critical current density J{sub C} at 5 K of 8.7 × 10{sup 6} A cm{sup −2}. From the XRD pattern, the bottom MgB{sub 2} thin film shows c-axis orientation, whereas the top MgB{sub 2} became polycrystalline as Boron barrier layer grown thicker. Therefore, all junction samples show lower T{sub C} than single MgB{sub 2} thin film. The junctions exhibit excellent quasiparticle characteristics with ideal dependence on temperature and Boron barrier thickness. Subharmonic gap structure was appeared in conductance characteristics, which was attributed to the multiple Andreev reflections (MAR). The result demonstrates great promise of this new fabrication technology for MgB{sub 2} Josephson junction fabrication. - Highlights: • Sandwich-type MgB{sub 2}/Boron/MgB{sub 2} Josephson junctions were fabricated. • The junctions were annealed after deposition with the rapid-anneal process. • The highest critical current is 25.3 mA at 5 K and remains non-zero near 25 K. • Subharmonic gap features can be observed in the dI/dV – V curves.

  20. Ipilimumab 10 mg/kg versus ipilimumab 3 mg/kg in patients with unresectable or metastatic melanoma

    DEFF Research Database (Denmark)

    Ascierto, Paolo A; Del Vecchio, Michele; Robert, Caroline

    2017-01-01

    of ipilimumab 10 mg/kg versus 3 mg/kg. METHODS: This randomised, double-blind, multicentre, phase 3 trial was done in 87 centres in 21 countries worldwide. Patients with untreated or previously treated unresectable stage III or IV melanoma, without previous treatment with BRAF inhibitors or immune checkpoint...

  1. Pinning in high performance MgB{sub 2} thin films and bulks: Role of Mg-B-O nano-scale inhomogeneities

    Energy Technology Data Exchange (ETDEWEB)

    Prikhna, Tatiana, E-mail: prikhna@mail.ru [Institute for Superhard Materials of the National Academy of Sciences of Ukraine , 2, Avtozavodskaya Str. , Kiev 07074 (Ukraine); Shapovalov, Andrey [Institute for Superhard Materials of the National Academy of Sciences of Ukraine , 2, Avtozavodskaya Str. , Kiev 07074 (Ukraine); Eisterer, Michael [Atominstitut, Vienna University of Technology, Stadionallee 2, 1020 Vienna (Austria); Shaternik, Vladimir [G.V. Kurdyumov Institute for Metal Physics of the National Academy of Sciences of Ukraine, 36 Academician Vernadsky blvd., Kiev, 03680 (Ukraine); Goldacker, Wilfried [Karlsruhe Institute of Technology (KIT), 76344 Eggenstein (Germany); Weber, Harald W. [Atominstitut, Vienna University of Technology, Stadionallee 2, 1020 Vienna (Austria); Moshchil, Viktor; Kozyrev, Artem; Sverdun, Vladimir [Institute for Superhard Materials of the National Academy of Sciences of Ukraine , 2, Avtozavodskaya Str. , Kiev 07074 (Ukraine); Boutko, Viktor [Donetsk Institute for Physics and Engineering named after O.O. Galkin of the National Academy of Sciences of Ukraine, R. Luxemburg str.72, Donetsk-114, 83114 (Ukraine); Grechnev, Gennadiy [B. Verkin Institute for Low Temperature Physics of the National Academy of Sciences of Ukraine, 47, Prospekt Nauky, Kharkiv 61103 (Ukraine); Gusev, Alexandr [Donetsk Institute for Physics and Engineering named after O.O. Galkin of the National Academy of Sciences of Ukraine, R. Luxemburg str.72, Donetsk-114, 83114 (Ukraine); Kovylaev, Valeriy; Shaternik, Anton [Institute for Superhard Materials of the National Academy of Sciences of Ukraine , 2, Avtozavodskaya Str. , Kiev 07074 (Ukraine)

    2017-02-15

    Highlights: • Pinning in MgB{sub 2} depends on the Mg-B-O nano-scaled inhomogeneities. • Finer oxygen-enriched inhomogeneities is the reason of the higher J{sub c} in MgB{sub 2} thin films as compared to bulk. • The results of DOS calculations for MgB{sub 2-x}O{sub x} compounds demonstrate that they have metal-like behavior. • Ordered oxygen distribution in MgB{sub 2} (in pairs or zigzags) reduces binding energy. - Abstract: The comparison of nano-crystalline MgB{sub 2} oxygen-containing thin film (140 nm) and highly dense bulk materials showed that the critical current density, J{sub c}, depends on the distribution of Mg-B-O nano-scale inhomogeneities. It has been shown that MgB{sub 2} bulks with high J{sub c} in low (∼10{sup 6} A/cm{sup 2} in 0-1 T at 10 K) and medium magnetic fields contain MgB{sub 0.6-0.8}O{sub 0.8-0.9} nano-inclusions, where δT{sub c} or a combined δT{sub c} (dominant) / δ{sub l} pinning mechanism prevails, while in bulk MgB{sub 2} with high J{sub c} in high magnetic fields (B{sub irr}(18.5 K) = 15 T, B{sub c2}(0 K) = 42.1 T) MgB{sub 1.2-2.7}O{sub 1.8-2.5} nano-layers are present and δ{sub l} pinning prevails. The structure of oxygen-containing films with high J{sub c} in low and high magnetic fields (J{sub c} (0 T) = 1.8 × 10{sup 7} A/cm{sup 2} and J{sub c} (5 T) = 2 × 10{sup 6} A/cm{sup 2} at 10 K) contains very fine oxygen-enriched Mg-B-O inhomogeneities and δ{sub l} pinning is realized. The results of DOS calculations in MgB{sub 2-x}O{sub x} cells for x = 0, 0.125, 0.25, 0.5, 1 demonstrate that all compounds are conductors with metal-like behaviour. In the case of ordered oxygen substitution for boron the binding energy, E{sub b}, does not increase sufficiently as compared with that for MgB{sub 2}, while when oxygen atoms form zigzag chains the calculated E{sub b} is even lower (E{sub b} = −1.15712 Ry).

  2. Transport properties and exponential n-values of Fe/MgB2 tapes with various MgB2 particle sizes

    International Nuclear Information System (INIS)

    Lezza, P.; Abaecherli, V.; Clayton, N.; Senatore, C.; Uglietti, D.; Suo, H.L.; Fluekiger, R.

    2004-01-01

    Fe/MgB 2 tapes have been prepared starting with pre-reacted binary MgB 2 powders. As shown by resistive and inductive measurements, the reduction of particle size to a few microns by ball milling has little influence on B c2 , while the superconducting properties of the individual MgB 2 grains are essentially unchanged. Reducing the particle size causes an enhancement of B irr from 14 to 16 T, while J c has considerably increased at high fields, its slope J c (B) being reduced. At 4.2 K, values of 5.3 x 10 4 and 1.2 x 10 3 A/cm 2 were measured at 3.5 and 10 T, respectively, suggesting a dominant role of the conditions at the grain interfaces. A systematic variation of these conditions at the interfaces is undertaken in order to determine the limit of transport properties for Fe/MgB 2 tapes. The addition of 5% Mg to MgB 2 powder was found to affect neither J c nor B c2 . For the tapes with the highest J c values, very high exponential n factors were measured: n=148, 89 and 17 at 3.5, 5 and 10 T, respectively and measurements of critical current versus applied strain have been performed. The mechanism leading to high transport critical current densities of filamentary Fe/MgB 2 tapes based on MgB 2 particles is discussed

  3. A double-blind study comparing ibuprofen 1800 mg or 2400 mg daily and placebo in sports injuries.

    Science.gov (United States)

    Hutson, M A

    1986-01-01

    In a double-blind, placebo-controlled study of forty-six patients with acute ligamentous damage of the knee, ibuprofen in dosages 1800 mg and 2400 mg produced significant improvements in joint mobility, weight bearing ability and match fitness. Joint effusion, pain on stress and pain severity was significantly improved by all three treatments. Only two patients reported side-effects (one while taking placebo and one taking ibuprofen 2400 mg). The study confirmed the efficacy and excellent tolerance to ibuprofen in patients with sports injuries to the knee.

  4. Cathodoluminescence study of Mg activation in non-polar and semi-polar faces of undoped/Mg-doped GaN core-shell nanorods

    Science.gov (United States)

    Hortelano, V.; Martínez, O.; Cuscó, R.; Artús, L.; Jiménez, J.

    2016-03-01

    Spectrally and spatially resolved cathodoluminescence (CL) measurements were carried out at 80 K on undoped/Mg-doped GaN core-shell nanorods grown by selective area growth metalorganic vapor phase epitaxy in order to investigate locally the optical activity of the Mg dopants. A study of the luminescence emission distribution over the different regions of the nanorods is presented. We have investigated the CL fingerprints of the Mg incorporation into the non-polar lateral prismatic facets and the semi-polar facets of the pyramidal tips. The amount of Mg incorporation/activation was varied by using several Mg/Ga flow ratios and post-growth annealing treatment. For lower Mg/Ga flow ratios, the annealed nanorods clearly display a donor-acceptor pair band emission peaking at 3.26-3.27 eV and up to 4 LO phonon replicas, which can be considered as a reliable indicator of effective p-type Mg doping in the nanorod shell. For higher Mg/Ga flow ratios, a substantial enhancement of the yellow luminescence emission as well as several emission subbands are observed, which suggests an increase of disorder and the presence of defects as a consequence of the excess Mg doping.

  5. Thermoluminescence responses of photon- and electron-irradiated lithium potassium borate co-doped with Cu+Mg or Ti+Mg

    International Nuclear Information System (INIS)

    Alajerami, Y.S.M.; Hashim, S.; Ramli, A.T.; Saleh, M.A.; Saripan, M.I.; Alzimami, K.; Min Ung, Ngie

    2013-01-01

    New glasses Li 2 CO 3 –K 2 CO 3 –H 3 BO 3 (LKB) co-doped with CuO and MgO, or with TiO 2 and MgO, were synthesized by the chemical quenching technique. The thermoluminescence (TL) responses of LKB:Cu,Mg and LKB:Ti,Mg irradiated with 6 MV photons or 6 MeV electrons were compared in the dose range 0.5–4.0 Gy. The standard commercial dosimeter LiF:Mg,Ti (TLD-100) was used to calibrate the TL reader and as a reference in comparison of the TL properties of the new materials. The dependence of the responses of the new materials on 60 Co dose is linear in the range of 1–1000 Gy. The TL yields of both of the co-doped glasses and TLD-100 are greater for electron irradiation than for photon irradiation. The TL sensitivity of LKB:Ti,Mg is 1.3 times higher than the sensitivity of LKB:Cu,Mg and 12 times less than the sensitivity of TLD-100. The new TL dosimetric materials have low effective atomic numbers, good linearity of the dose responses, excellent signal reproducibility, and a simple glow curve structure. This combination of properties makes them suitable for radiation dosimetry. - Highlights: • Enhancement of about three times has been shown with the increment of MgO. • A comparison was carried out between the TL responses of the prepared dosimeters and TLD-100. • The prepared dosimeters show simple glow curve, low Z material and excellent reproducibility. • The TL measurements show a linear dose response in a long span of exposures. • The electron response shows 1.18 times greater than photon response for the prepared dosimeters

  6. Comparison of the effects of esomeprazole 40 mg, rabeprazole 20 mg, lansoprazole 30 mg, and pantoprazole 40 mg on intragastrıc pH in extensive metabolizer patients with gastroesophageal reflux disease.

    Science.gov (United States)

    Çelebi, Altay; Aydın, Dinçer; Kocaman, Orhan; Konduk, Buğra Tolga; Şentürk, Ömer; Hülagü, Sadetin

    2016-09-01

    Studies on the therapeutic efficacy of proton pump inhibitors (PPIs) in patients with gastroesophageal reflux disease (GERD) have been recently published. In most of these studies, comparison of only two PPIs have been made. There are few studies on the comparison of four or more PPIs. We aimed to compare the acid inhibitory effects of esomeprazole 40 mg, rabeprazole 20 mg, lansoprazole 30 mg, and pantoprazole 40 mg on days 1 and 5 of treatment in patients with GERD, who were extensive metabolizers in regard to the CYP2C19 genotype. Helicobacter pylori-negative with typical symptoms of GERD patients were randomly divided into four treatment groups. Efficacy analysis on days 1 and 5 were performed on the four groups which comprised 10 (esomeprazole), 11 (rabeprazole), 10 (lansoprazole), and 10 (pantoprazole) patients. On day 1 of PPI treatment, the mean percentage of time with intragastric Ph>4 were 54%, 58%, 60%, and 35% for the groups, respectively, and on day 5, these values were 67%, 60%, 68%, and 59%, respectively. Esomeprazole, rabeprazole, and lansoprazole were found to be superior to pantoprazole on the first day of treatment. Pantoprazole is a less potent proton pump inhibitor than the other PPIs tested on the first day of treatment. When the time needed to raise the intragatric pH to over 4 was evaluated, esomeprazole was found to have the most rapid action, followed by lansoprazole and rabeprazole.

  7. Superconducting tunnel junctions on MgB{sub 2} using MgO and CaF{sub 2} as a barrier

    Energy Technology Data Exchange (ETDEWEB)

    Sakoda, Masahito, E-mail: sakoda@cc.tuat.ac.jp [Department of Applied Physics, Tokyo University of Agriculture and Technology, 2-24-16, Koganei, Tokyo 184-8588 (Japan); Aibara, Masato; Mede, Kazuya; Kikuchi, Motoyuki; Naito, Michio [Department of Applied Physics, Tokyo University of Agriculture and Technology, 2-24-16, Koganei, Tokyo 184-8588 (Japan)

    2016-11-15

    Highlights: • We have revised the manuscript according to reviewer's comments. The details are in “Response to Reviewers”. • Superconducting junctions with MgO and CaF{sub 2} barrier were fabricated in order to improve the quality of junctions. • In SIN junctions with MgO barrier, clear superconducting gap was observed. (). • In SIS junctions with CaF2 barrier, Josephson current was observed over 30 K. (). • The compatibility of each barrier material at the upper and lower interfaces was clarified. (). - Abstract: We report the fabrication of superconducting tunnel junctions, both of superconductor–insulator-normal metal (SIN) and superconductor–insulator-superconductor (SIS), on MgB{sub 2} using MgO and CaF{sub 2} as a barrier. The SIN junctions fabricated using an MgO barrier showed excellent quasi-particle characteristics, including a large superconducting gap (Δ) of 2.5–3 meV and a low zero-bias conductance. We have also fabricated SIS junctions with an MgO barrier, but the quasi-particle characteristics of the SIS junctions are not as good as those of the SIN junctions, namely a reduced superconducting gap and a high zero-bias conductance. It appears that top MgB{sub 2} electrodes do not grow well on an MgO barrier, which is also suggested from in-situ RHEED observation. The SIN junctions fabricated using a CaF{sub 2} barrier showed less sharp quasi-particle characteristics than using an MgO barrier. However, the SIS junctions using a CaF{sub 2} barrier showed a fairly large I{sub c}R{sub N} value at 4.2 K over 1 mV and also exhibited finite Josephson current up to almost the film's T{sub c} (∼30 K). The RHEED observation revealed that top MgB{sub 2} electrodes grow well on a CaF{sub 2} barrier.

  8. Comparison of 1 mg and 2 mg overnight dexamethasone suppression tests for the screening of Cushing's syndrome in obese patients.

    Science.gov (United States)

    Sahin, Mustafa; Kebapcilar, Levent; Taslipinar, Abdullah; Azal, Omer; Ozgurtas, Taner; Corakci, Ahmet; Akgul, Emin Ozgur; Taslipinar, Mine Yavuz; Yazici, Mahmut; Kutlu, Mustafa

    2009-01-01

    Obesity is currently a major public health problem and one of the potential underlying causes of obesity in a minority of patients is Cushing's syndrome (CS). Traditionally, the gold standard screening test for CS is 1 mg dexamethasone overnight suppression test. However, it is known that obese subjects have high false positive results with this test. We have therefore compared the 1 mg and 2 mg overnight dexamethasone suppression tests in obese subjects. Patients whose serum cortisol after ODST was >50 nM underwent and a low-dose dexamethasone suppression test (LDDST); 24-hour urine cortisol was collected for basal urinary free cortisol (UFC). For positive results after overnight 1-mg dexamethasone suppression test we also performed the overnight 2-mg dexamethasone suppression test. We prospectively evaluated 100 patients (22 men and 78 women, ranging in age from 17 to 73 years with a body mass index (BMI) >30 kg/m2 who had been referred to our hospital-affiliated endocrine clinic because of simple obesity. Suppression of serum cortisol to suppression. Thyroid function tests, lipid profiles, homocysteine, antithyroglobulin, anti-thyroid peroxidase antibody levels, vitamin B12, folate levels, insulin resistance [by homeostasis model assessment (HOMA)] and 1.0 mg postdexamethasone (postdex) suppression cortisol levels were measured. We found an 8% false-positive rate in 1 mg overnight test and 2% in 2 mg overnight test (p=0.001). There was no correlation between the cortisol levels after ODST and other parameters. Our results indicate that the 2 mg overnight dexamethasone suppression test (ODST) is more convenient and accurate than 1-mg ODST as a screening test for excluding CS in subjects with simple obesity.

  9. Lubrication performance and mechanisms of Mg/Al-, Zn/Al-, and Zn/Mg/Al-layered double hydroxide nanoparticles as lubricant additives

    International Nuclear Information System (INIS)

    Li, Shuo; Bhushan, Bharat

    2016-01-01

    Highlights: • Mg/Al-, Zn/Al- and Zn/Mg/Al-layered double hydroxide were synthesized. • Mg/Al-LDH had superior tribological performance compared to other LDHs. • The best thermal stability of Mg/Al-LDH was responsible for its friction property. - Abstract: Solid lubricant particles are commonly used as oil additives for low friction and wear. Mg/Al-, Zn/Al-, and Zn/Mg/Al-layered double hydroxides (LDH) were synthesized by coprecipitation method. The benefits of LDH nanoparticles are that they can be synthesized using chemical methods where size and shape can be controlled, and can be modified organically to allow dispersal in fluids. The LDH nanoparticles were characterized by X-ray diffraction, scanning electron microscope, thermogravimetry, and differential scanning calorimetry. A pin-on-disk friction and wear tester was used for evaluating the friction and wear properties of LDH nanoparticles as lubricant additives. LDH nanoparticles have friction-reducing and anti-wear properties compared to oil without LDHs. Mg/Al-LDH has the best lubrication, possibly due to better thermal stability in severe conditions.

  10. Lubrication performance and mechanisms of Mg/Al-, Zn/Al-, and Zn/Mg/Al-layered double hydroxide nanoparticles as lubricant additives

    Energy Technology Data Exchange (ETDEWEB)

    Li, Shuo [School of Materials Science and Technology, China University of Geosciences (Beijing), 29 Xueyuan Road, Haidian Distract, Beijing 100083 (China); Nanoprobe Laboratory for Bio- & Nanotechnology and Biomimetics (NLBB), The Ohio State University, 201 W. 19th Avenue Columbus, OH 43210-1142 (United States); Bhushan, Bharat, E-mail: bhushan.2@osu.edu [Nanoprobe Laboratory for Bio- & Nanotechnology and Biomimetics (NLBB), The Ohio State University, 201 W. 19th Avenue Columbus, OH 43210-1142 (United States)

    2016-08-15

    Highlights: • Mg/Al-, Zn/Al- and Zn/Mg/Al-layered double hydroxide were synthesized. • Mg/Al-LDH had superior tribological performance compared to other LDHs. • The best thermal stability of Mg/Al-LDH was responsible for its friction property. - Abstract: Solid lubricant particles are commonly used as oil additives for low friction and wear. Mg/Al-, Zn/Al-, and Zn/Mg/Al-layered double hydroxides (LDH) were synthesized by coprecipitation method. The benefits of LDH nanoparticles are that they can be synthesized using chemical methods where size and shape can be controlled, and can be modified organically to allow dispersal in fluids. The LDH nanoparticles were characterized by X-ray diffraction, scanning electron microscope, thermogravimetry, and differential scanning calorimetry. A pin-on-disk friction and wear tester was used for evaluating the friction and wear properties of LDH nanoparticles as lubricant additives. LDH nanoparticles have friction-reducing and anti-wear properties compared to oil without LDHs. Mg/Al-LDH has the best lubrication, possibly due to better thermal stability in severe conditions.

  11. A comparison of amorphous calcium carbonate crystallization in aqueous solutions of MgCl2 and MgSO4: implications for paleo-ocean chemistry

    Science.gov (United States)

    Han, Mei; Zhao, Yanyang; Zhao, Hui; Han, Zuozhen; Yan, Huaxiao; Sun, Bin; Meng, Ruirui; Zhuang, Dingxiang; Li, Dan; Liu, Binwei

    2018-04-01

    Based on the terminology of "aragonite seas" and "calcite seas", whether different Mg sources could affect the mineralogy of carbonate sediments at the same Mg/Ca ratio was explored, which was expected to provide a qualitative assessment of the chemistry of the paleo-ocean. In this work, amorphous calcium carbonate (ACC) was prepared by direct precipitation in anhydrous ethanol and used as a precursor to study crystallization processes in MgSO4 and MgCl2 solutions having different concentrations at 60 °C (reaction times 240 and 2880 min). Based on the morphology of the aragonite crystals, as well as mineral saturation indices and kinetic analysis of geochemical processes, it was found that these crystals formed with a spherulitic texture in 4 steps. First, ACC crystallized into columnar Mg calcite by nearly oriented attachment. Second, the Mg calcite changed from columnar shapes into smooth dumbbell forms. Third, the Mg calcite transformed into rough dumbbell or cauliflower-shaped aragonite forms by local dissolution and precipitation. Finally, the aragonite transformed further into spherulitic radial and irregular aggregate forms. The increase in Ca2+ in the MgSO4 solutions compared with the MgCl2 solutions indicates the fast dissolution and slow precipitation of ACC in the former solutions. The phase transition was more complete in the 0.005 M MgCl2 solution, whereas Mg calcite crystallized from the 0.005 M MgSO4 solution, indicating that Mg calcite could be formed more easily in an MgSO4 solution. Based on these findings, aragonite and Mg calcite relative to ACC could be used to provide a qualitative assessment of the chemistry of the paleo-ocean. Therefore, calcite seas relative to high-Mg calcite could reflect a low concentration MgSO4 paleo-ocean, while aragonite seas could be related to an MgCl2 or high concentration of MgSO4 paleo-ocean.

  12. Low-energy radioactive ion beam production of 22Mg

    International Nuclear Information System (INIS)

    Duy, N.N.; Kubono, S.; Yamaguchi, H.; Kahl, D.; Wakabayashi, Y.; Teranishi, T.; Iwasa, N.; Kwon, Y.K.; Khiem, L.H.; Kim, Y.H.; Song, J.S.; Hu, J.; Ayyad, Y.

    2013-01-01

    The 22 Mg nucleus plays an important role in nuclear astrophysics, specially in the 22 Mg(α,p) 25 Al and proton capture 22 Mg(p,γ) 23 Al reactions. It is believed that 22 Mg is a waiting point in the αp-process of nucleosynthesis in novae. We proposed a direct measurement of the 22 Mg+α resonance reaction in inverse kinematics using a radioactive ion (RI) beam. A 22 Mg beam of 3.73 MeV/u was produced at CRIB (Center for Nuclear Study (CNS) low-energy RI Beam) facility of the University of Tokyo located at RIKEN (Japan) in 2011. In this paper we present the results about the production of the 22 Mg beam used for the direct measurement of the scattering reaction 22 Mg(α,α) 22 Mg, and the stellar reaction 22 Mg(α,p) 25 Al in the energy region concerning an astrophysical temperature of T 9 =1–3 GK

  13. Effects of Sacubitril/Valsartan Versus Olmesartan on Central Hemodynamics in the Elderly With Systolic Hypertension: The PARAMETER Study.

    Science.gov (United States)

    Williams, Bryan; Cockcroft, John R; Kario, Kazuomi; Zappe, Dion H; Brunel, Patrick C; Wang, Qian; Guo, Weinong

    2017-03-01

    Effective treatment of systolic hypertension in elderly patients remains a major therapeutic challenge. A multicenter, double-blind, randomized controlled trial with sacubitril/valsartan (LCZ696), a first-in-class angiotensin receptor neprilysin inhibitor, was conducted to determine its effects versus olmesartan (angiotensin receptor blocker) on central aortic pressures, in elderly patients (aged ≥60 years) with systolic hypertension and pulse pressure >60 mm Hg, indicative of arterial stiffness. Patients (n=454; mean age, 67.7 years; mean seated systolic blood pressure, 158.6 mm Hg; mean seated pulse pressure, 69.7 mm Hg) were randomized to receive once-daily sacubitril/valsartan 200 mg or olmesartan 20 mg, force titrated to double the initial doses after 4 weeks, before primary assessment at 12 weeks. The study extended double-blind treatment for 12 to 52 weeks, during which amlodipine (2.5-5 mg) and subsequently hydrochlorothiazide (6.25-25 mg) were added-on for patients not achieving blood pressure target (secondary assessments at week 12 (central aortic pulse pressure, -2.4 mm Hg, P blood pressure and central aortic systolic pressure, -4.1 mm Hg and -3.6 mm Hg, respectively, both P blood pressure parameters were similar between treatments ( P hypertension and stiff arteries. © 2017 American Heart Association, Inc.

  14. Energetic prediction on the stability of A2Mg12Si7, A2Mg4Si3, and AMgSi in the A2Si–Mg2Si system (A = Ca, Sr and Ba) and their calculated electronic structures

    International Nuclear Information System (INIS)

    Imai, Yoji; Mori, Yoshihisa; Nakamura, Shigeyuki; Takarabe, Ken-ichi

    2014-01-01

    Highlights: • Formation energies of A 2 Mg 4 Si 3 , A 2 Mg 12 Si 7 , and AMgSi (A = Ca,Sr,Ba) were calculated. • All AMgSi are quite stable compared to mixture of A 2 Si and Mg 2 Si. • Ba 2 Mg 4 Si 3 and Sr 2 Mg 4 Si 3 are predicted to be stable, but Ca 2 Mg 4 Si 3 is not. • Ca 2 Mg 12 Si 7 and Sr 2 Mg 12 Si 7 are energetically unstable. • Stability of Ba 2 Mg 12 Si 7 is a tender subject. -- Abstract: In order to evaluate the relative stability of A 2 Mg 4 Si 3 , A 2 Mg 12 Si 7 , and AMgSi (A = Ca, Sr, and Ba) in the A 2 Si–Mg 2 Si system, electronic energy changes in the formation of these compounds were calculated using a density-functional theory with the Perdew–Wang generalized gradient approximations. It was found that (1) AMgSi’s are quite stable compared to equi-molar mixture of A 2 Si and Mg 2 Si, (2) Ba 2 Mg 4 Si 3 and Sr 2 Mg 4 Si 3 are also stable, (3) Ca 2 Mg 4 Si 3 and Ca 2 Mg 12 Si 7 are less stable than the mixture of CaMgSi and Mg 2 Si, and (4) Stability of Ba 2 Mg 12 Si 7 is a tender subject and Sr 2 Mg 12 Si 7 is energetically unstable compared to the mixture of Sr 2 Mg 4 Si 3 (or, SrMgSi) and Mg 2 Si. The presence of Sr 2 Mg 12 Si 7 may be due to the vibrational and/or configurational entropy, which are not treated in the present study. From the calculated electronic densities of state, complex compounds of SrMgSi and Mg 2 Si have both p-type and n-type character, depending on the ratio of SrMgSi and Mg 2 Si in that compound

  15. Synthesis and crystal structure of MgB12

    International Nuclear Information System (INIS)

    Adasch, Volker; Hess, Kai-Uwe; Ludwig, Thilo; Vojteer, Natascha; Hillebrecht, Harald

    2006-01-01

    Single crystals of MgB 12 were synthesized from the elements in a Mg/Cu melt at 1600deg. C. MgB 12 crystallizes orthorhombic in space group Pnma with a=16.632(3)A, b=17.803(4)A and c=10.396(2)A. The crystal structure (Z=30, 5796 reflections, 510 variables, R 1 (F)=0.049, wR 2 (I)=0.134) consists of a three dimensional net of B 12 icosahedra and B 21 units in a ratio 2:1. The B 21 units are observed for the first time in a solid compound. Mg is on positions with partial occupation. The summation reveals the composition MgB 12.35 or Mg 0.97 B 12 , respectively. This is in good agreement with the value of MgB 11.25 as expected by electronic reasons to stabilize the boron polyhedra B 12 2- and B 21 4-

  16. Role of olmesartan in combination therapy in blood pressure control and vascular function

    Directory of Open Access Journals (Sweden)

    Carlos M Ferrario

    2010-08-01

    Full Text Available Carlos M Ferrario, Ronald D SmithWake Forest University School of Medicine, Winston-Salem, North Carolina, USAAbstract: Angiotensin receptor blockers have emerged as a first-line therapy in the management of hypertension and hypertension-related comorbidities. Since national and international guidelines have stressed the need to control blood pressure to <140/90 mmHg in uncomplicated hypertension and <130/80 mmHg in those with associated comorbidities such as diabetes or chronic kidney disease, these goal blood pressures can only be achieved through combination therapy. Of several drugs that can be effectively combined to attain the recommended blood pressure goals, fixed-dose combinations of angiotensin receptor blockers and the calcium channel blocker amlodipine provide additive antihypertensive effects associated with a safe profile and increased adherence to therapy. In this article, we review the evidence regarding the beneficial effects of renin–angiotensin system blockade with olmesartan medoxomil and amlodipine in terms of blood pressure control and improvement of vascular function and target organ damage.Keywords: amlodipine, angiotensin receptor blockers, angiotensin-converting enzyme 2, hypertension, renin–angiotensin system

  17. Ethylbenzene dehydrogenation over FeOx/(Mg,Zn)(Al)O catalysts derived from hydrotalcites: Role of MgO as basic sites

    KAUST Repository

    Balasamy, Rabindran J.; Tope, Balkrishna B.; Khurshid, Alam; Al-Ali, Ali A S; Atanda, Luqman A.; Sagata, Kunimasa; Asamoto, Makiko; Yahiro, Hidenori; Nomura, Kiyoshi; Sano, Tsuneji; Takehira, Katsuomi; Al-Khattaf, Sulaiman S.

    2011-01-01

    A series of Mg3-xZnxFe0.5Al0.5 mixed oxide catalysts derived from hydrotalcites were tested in the ethylbenzene dehydrogenation to styrene in He atmosphere at 550 °C. The catalysts were prepared by coprecipitation from the nitrates of metal components followed by calcination to mixed oxides at 550 °C. A part of Mg2+ in Mg 3Fe0.5Al0.5 mixed oxide was replaced with Zn2+ to test the effect of MgO as the support. The mixed oxides were composed of periclase and spinel-type compounds with a high surface area of 100-180m2gcat-1. Mössbauer and XPS measurements indicated the presence of Fe3+ on the catalysts and H2-TPR measurement suggested that the dehydrogenation reaction is catalyzed by the reduction-oxidation between Fe3+/Fe2+. The activity of Mg3-xZnxFe0.5Al0.5 mixed oxide decreased with increasing x, indicating an important role of MgO on the activity. Both CO2-TPD measurements as well as IR measurements of adsorbed CO2 clearly indicated the presence of basic sites of Mg 2+O2- on the catalysts. It seems that the combination of Mg2+O2- and Fe3+ was essential for the catalytic activity. It is concluded that the surface base sites generated on O2- bound Mg2+ near Fe3+ sites are responsible for H+-abstraction; the dehydrogenation of ethylbenzene was initiated by the H+ abstraction on Mg2+O2- basic sites, and accelerated by the reduction-oxidation of Fe3+/Fe2+ active species. © 2011 Elsevier B.V.

  18. Ethylbenzene dehydrogenation over FeOx/(Mg,Zn)(Al)O catalysts derived from hydrotalcites: Role of MgO as basic sites

    KAUST Repository

    Balasamy, Rabindran J.

    2011-05-01

    A series of Mg3-xZnxFe0.5Al0.5 mixed oxide catalysts derived from hydrotalcites were tested in the ethylbenzene dehydrogenation to styrene in He atmosphere at 550 °C. The catalysts were prepared by coprecipitation from the nitrates of metal components followed by calcination to mixed oxides at 550 °C. A part of Mg2+ in Mg 3Fe0.5Al0.5 mixed oxide was replaced with Zn2+ to test the effect of MgO as the support. The mixed oxides were composed of periclase and spinel-type compounds with a high surface area of 100-180m2gcat-1. Mössbauer and XPS measurements indicated the presence of Fe3+ on the catalysts and H2-TPR measurement suggested that the dehydrogenation reaction is catalyzed by the reduction-oxidation between Fe3+/Fe2+. The activity of Mg3-xZnxFe0.5Al0.5 mixed oxide decreased with increasing x, indicating an important role of MgO on the activity. Both CO2-TPD measurements as well as IR measurements of adsorbed CO2 clearly indicated the presence of basic sites of Mg 2+O2- on the catalysts. It seems that the combination of Mg2+O2- and Fe3+ was essential for the catalytic activity. It is concluded that the surface base sites generated on O2- bound Mg2+ near Fe3+ sites are responsible for H+-abstraction; the dehydrogenation of ethylbenzene was initiated by the H+ abstraction on Mg2+O2- basic sites, and accelerated by the reduction-oxidation of Fe3+/Fe2+ active species. © 2011 Elsevier B.V.

  19. Nanostructured Layered Cathode for Rechargeable Mg-Ion Batteries.

    Science.gov (United States)

    Tepavcevic, Sanja; Liu, Yuzi; Zhou, Dehua; Lai, Barry; Maser, Jorg; Zuo, Xiaobing; Chan, Henry; Král, Petr; Johnson, Christopher S; Stamenkovic, Vojislav; Markovic, Nenad M; Rajh, Tijana

    2015-08-25

    Nanostructured bilayered V2O5 was electrochemically deposited within a carbon nanofoam conductive support. As-prepared electrochemically synthesized bilayered V2O5 incorporates structural water and hydroxyl groups, which effectively stabilizes the interlayers and provides coordinative preference to the Mg(2+) cation in reversible cycling. This open-framework electrode shows reversible intercalation/deintercalation of Mg(2+) ions in common electrolytes such as acetonitrile. Using a scanning transmission electron microscope we demonstrate that Mg(2+) ions can be effectively intercalated into the interlayer spacing of nanostructured V2O5, enabling electrochemical magnesiation against a Mg anode with a specific capacity of 240 mAh/g. We employ HRTEM and X-ray fluorescence (XRF) imaging to understand the role of environment in the intercalation processes. A rebuilt full cell was tested by employing a high-energy ball-milled Sn alloy anode in acetonitrile with Mg(ClO4)2 salt. XRF microscopy reveals effective insertion of Mg ions throughout the V2O5 structure during discharge and removal of Mg ions during electrode charging, in agreement with the electrode capacity. We show using XANES and XRF microscopy that reversible Mg intercalation is limited by the anode capacity.

  20. Interplay of Mg2+, ADP, and ATP in the cytosol and mitochondria: unravelling the role of Mg2+ in cell respiration.

    Science.gov (United States)

    Gout, Elisabeth; Rébeillé, Fabrice; Douce, Roland; Bligny, Richard

    2014-10-28

    In animal and plant cells, the ATP/ADP ratio and/or energy charge are generally considered key parameters regulating metabolism and respiration. The major alternative issue of whether the cytosolic and mitochondrial concentrations of ADP and ATP directly mediate cell respiration remains unclear, however. In addition, because only free nucleotides are exchanged by the mitochondrial ADP/ATP carrier, whereas MgADP is the substrate of ATP synthase (EC 3.6.3.14), the cytosolic and mitochondrial Mg(2+) concentrations must be considered as well. Here we developed in vivo/in vitro techniques using (31)P-NMR spectroscopy to simultaneously measure these key components in subcellular compartments. We show that heterotrophic sycamore (Acer pseudoplatanus L.) cells incubated in various nutrient media contain low, stable cytosolic ADP and Mg(2+) concentrations, unlike ATP. ADP is mainly free in the cytosol, but complexed by Mg(2+) in the mitochondrial matrix, where [Mg(2+)] is tenfold higher. In contrast, owing to a much higher affinity for Mg(2+), ATP is mostly complexed by Mg(2+) in both compartments. Mg(2+) starvation used to alter cytosolic and mitochondrial [Mg(2+)] reversibly increases free nucleotide concentration in the cytosol and matrix, enhances ADP at the expense of ATP, decreases coupled respiration, and stops cell growth. We conclude that the cytosolic ADP concentration, and not ATP, ATP/ADP ratio, or energy charge, controls the respiration of plant cells. The Mg(2+) concentration, remarkably constant and low in the cytosol and tenfold higher in the matrix, mediates ADP/ATP exchange between the cytosol and matrix, [MgADP]-dependent mitochondrial ATP synthase activity, and cytosolic free ADP homeostasis.

  1. Effect of Mg Doping on the Photoluminescence of GaN:Mg Films by Radio-Frequency Plasma-Assisted Molecular Beam Epitaxy

    International Nuclear Information System (INIS)

    Sui Yan-Ping; Yu Guang-Hui

    2011-01-01

    We investigate undoped GaN and Mg-doped GaN grown by rf plasma-assisted molecular beam epitaxy (MBE) with different Mg concentrations by photoluminescence (PL) at low temperature, Hall-effect and XRD measurements. In the PL spectra of lightly Mg-doped GaN films, a low intensity near band edge (NBE) emission and strong donor-acceptor pair (DAP) emission with its phonon replicas are observed. As the Mg concentration is increased, the DAP and NBE bands become weaker and a red shift of these bands is observed in the PL spectra. Yellow luminescence (YL) is observed in heavily Mg-doped GaN. The x-ray diffraction is employed to study the structure of the films. Hall measurement shows that there is a maximum value (3.9 × 10 18 cm −3 ) of hole concentration with increasing Mg source temperature for compensation effect. PL spectra of undoped GaN are also studied under N-rich and Ga-rich growth conditions. Yellow luminescences of undoped Ga-rich GaN and heavily Mg-doped GaN are compared, indicating the different origins of the YL bands. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  2. Influence of particle size of Mg powder on the microstructure and critical currents of in situ powder-in-tube processed MgB_2 wires

    International Nuclear Information System (INIS)

    Kumakura, Hiroaki; Ye, Shujun; Matsumoto, Akiyoshi; Nitta, Ryuji

    2016-01-01

    We fabricated in situ powder-in-tube(PIT) MgB_2 wires using three kinds of Mg powders with particle size of ∼45 μm, ∼150 μm and 212∼600 μm. Mg particles were elongated to filamentary structure in the wires during cold drawing process. Especially, long Mg filamentary structure was obtained for large Mg particle size of 212∼600 μm. Critical current density, J_c, increased with increasing Mg particle size for 1 mm diameter wires. This is due to the development of filamentary structure of high density MgB_2 superconducting layer along the wires. This MgB_2 structure is similar to that of the internal Mg diffusion (IMD) processed MgB_2 wires. However, J_c of the wires fabricated with 212∼600 μm Mg particle size decreased and the scattering of J_c increased with decreasing wire diameter, while the J_c of the wires with ∼45 μm Mg particle was almost independent of the wire diameter. The cross sectional area reduction of the Mg particles during the wire drawing is smaller than that of the wire. When using large size Mg particle, the number of Mg filaments in the wire cross section is small. These two facts statistically lead to the larger scattering of Mg areal fraction in the wire cross section with proceeding of wire drawing process, resulting in smaller volume fraction of MgB_2 in the wire and lower J_c with larger scattering along the wire. SiC nano powder addition is effective in increasing J_c for all Mg particle sizes. (author)

  3. Amlodipine and Benazepril

    Science.gov (United States)

    ... or pharmacist if you are taking valsartan and sacubitril (Entresto) or if you have stopped taking it ... benazepril, if you are also taking valsartan and sacubitril. Also, tell your doctor if you have diabetes ...

  4. Fate of half-metallicity near interfaces: The case of NiMnSb/MgO and NiMnSi/MgO

    KAUST Repository

    Zhang, Ruijing

    2014-08-27

    The electronic and magnetic properties of the interfaces between the half-metallic Heusler alloys NiMnSb, NiMnSi, and MgO have been investigated using first-principles density-functional calculations with projector augmented wave potentials generated in the generalized gradient approximation. In the case of the NiMnSb/MgO (100) interface, the half-metallicity is lost, whereas the MnSb/MgO contact in the NiMnSb/MgO (100) interface maintains a substantial degree of spin polarization at the Fermi level (∼60%). Remarkably, the NiMnSi/MgO (111) interface shows 100% spin polarization at the Fermi level, despite considerable distortions at the interface, as well as rather short Si/O bonds after full structural optimization. This behavior markedly distinguishes NiMnSi/MgO (111) from the corresponding NiMnSb/CdS and NiMnSb/InP interfaces. © 2014 American Chemical Society.

  5. Enhanced mechanical properties of an Al–Si–Cu–Mg alloy at 300 °C: Effects of Mg and the Q-precipitate phase

    International Nuclear Information System (INIS)

    Farkoosh, A.R.; Pekguleryuz, M.

    2015-01-01

    Strategies to improve the strength of Al–Si alloys at elevated temperatures can follow two routes: (i) improving the age-hardening behavior and/or (ii) producing effective dispersoid strengthening. In this study, the influence of Mg (in the range of 0.3–0.7 wt%) on the precipitation characteristics and mechanical properties of the Al–7Si–0.5Cu–(Mg) alloy was investigated. Thermodynamic calculations were performed via the CALPHAD method which showed that Q-Al 5 Mg 8 Cu 2 Si 6 is the main thermodynamically stable precipitate at 300 °C. The calculations were validated by transmission electron microscopy and differential scanning calorimetry analyses. Increasing the Mg level from 0.3 wt% to the maximum solubility limit of ∼0.5 wt% increased the amount of the Q-Al 5 Mg 8 Cu 2 Si 6 precipitates at 300 °C by ∼60 wt% and significantly improved the tensile strength and creep resistance at the expense of some ductility. Mg in excess of the solubility limit was seen to remain within the microstructure in the form of the large π-Al 8 FeMg 3 Si 6 and β-Mg 2 Si intermetallics after solution treatment at 530 °C. Cracking of the brittle π-Al 8 FeMg 3 Si 6 intermetallics during deformation was accounted for the decreased ductility of the alloys at high Mg levels. It is concluded that the Mg level can be increased to 0.5 wt% in the A–7Si–0.5Cu alloys to improve strength. However, for elevated temperature applications in which both strength and ductility are required (e.g. Diesel engine), modification of the π-Al 8 FeMg 3 Si 6 intermetallics would be required to improve the ductility of the alloys with high Mg contents

  6. Fabrication of seven-core multi-filamentary MgB2 wires with high critical current density by an internal Mg diffusion process

    International Nuclear Information System (INIS)

    Togano, K; Hur, J M; Matsumoto, A; Kumakura, H

    2009-01-01

    We found that the reaction between a Mg core and a B powder layer in an internal Mg diffusion (IMD)-processed multi-filamentary wire can proceed rapidly even at a furnace temperature lower than the melting point of Mg (650 deg. C), resulting in the formation of a reacted layer with a fine composite structure and, hence, excellent in-field critical current properties. The multi-filamentary wire is composed of an outermost Cu-Ni sheath and seven filaments with a Ta sheath, a Mg core, and B+SiC powder filled in the space between the Ta sheath and the Mg core. Heat treatment at 645 deg. C for 1 h produced a reacted layer with dense composite structure along the inner wall of the Ta sheath and a hole at the center of each core. This reaction probably initiated from the heat generation at the B/Mg interface, resulting in a temperature rise of the Mg core and the occurrence of liquid Mg infiltration. The J c value at 4.2 K for the reacted layer exceeds 10 5 cm -2 at 9 T, which is the highest reported so far for MgB 2 wire, including powder-in-tube (PIT)-processed wires. These results indicate that the IMD process can compete in terms of practical wire fabrication with the conventional PIT process.

  7. Influences of the quantity of Mg2Sn phase on the corrosion behavior of Mg-7Sn magnesium alloy

    International Nuclear Information System (INIS)

    Liu Xianbin; Shan Dayong; Song Yingwei; Chen Rongshi; Han Enhou

    2011-01-01

    The influence of the quantity of the Mg 2 Sn phase on the corrosion behavior of different solution temperature treated Mg-7Sn magnesium alloy has been investigated by electrochemical measurements, scanning electron microscope (SEM) observation, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis. With the increase of solution temperature, the quantity of Mg 2 Sn phase decreased and the tin concentration of matrix increased. The dissolved tin in Mg matrix took part in the film formation and the constituent of film was magnesium oxide and stannic oxide. The corrosion mode and corrosion rate were associated with the quantity of Mg 2 Sn phases and tin concentration of the matrix. If most of tin was present as Mg 2 Sn, the corrosion mode was pitting corrosion and it accelerated the corrosion rate. If most of tin was dissolved in matrix, the corrosion mode was filiform corrosion and it decreased the corrosion rate. The experiment evidences demonstrated that the corrosion resistance can be improved by increasing the tin concentration of matrix and the lowest corrosion rate was observed for sample solution treated at 540 o C.

  8. Comparative study of 250 mg/day terbinafine and 100 mg/day itraconazole for the treatment of cutaneous sporotrichosis.

    Science.gov (United States)

    Francesconi, Glaucia; Francesconi do Valle, Antonio Carlos; Passos, Sonia Lambert; de Lima Barros, Mônica Bastos; de Almeida Paes, Rodrigo; Curi, André Luiz Land; Liporage, José; Porto, Cássio Ferreira; Galhardo, Maria Clara Gutierrez

    2011-05-01

    Itraconazole is currently used for the treatment of cutaneous sporotrichosis. Terbinafine at a daily dose of 250 mg has been successfully applied to the treatment of cutaneous sporotrichosis. To compare the efficacy of 250 mg/day terbinafine and 100 mg/day itraconazole for the treatment of cutaneous sporotrichosis. A bidirectional cohort study was conducted on 55 patients receiving 250 mg/day terbinafine and 249 patients receiving 100 mg/day itraconazole. The latter patients were matched for age and clinical form to the terbinafine group at a ratio of 5:1. Sporothrix schenckii was isolated by culture from all patients (age range: 18-70 years), who were submitted to the standard care protocol consisting of clinical and laboratory evaluation and periodic visits. Cure was observed in 51 (92.7%) patients of the terbinafine group and 229 (92%) of the itraconazole group within a similar mean period of time (11.5 and 11.8 weeks, respectively). An increase in the terbinafine dose to 500 mg was necessary in two patients due to the lack of a response, and one patient presented recurrence. In the itraconazole group, two patients required a dose increase and three presented recurrence. Adverse events were equally frequent among patients receiving terbinafine (n = 4, 7.3%) and itraconazole (n = 19, 7.6%) and were generally mild without the need for drug discontinuation, except for two patients of the itraconazole group. Terbinafine administered at a daily dose of 250 mg is an effective and well-tolerated option for the treatment of cutaneous sporotrichosis.

  9. Stability of rapidly quenched and hydrogenated Mg-Ni-Y and Mg-Cu-Y alloys in extreme alkaline medium

    International Nuclear Information System (INIS)

    Gebert, A.; Khorkounov, B.; Wolff, U.; Mickel, Ch.; Uhlemann, M.; Schultz, L.

    2006-01-01

    Amorphous-nanocrystalline Mg 50 Ni 30 Y 20 and Mg 63 Ni 30 Y 7 and amorphous Mg 65 Cu 25 Y 10 alloys were produced by melt-spinning and characterized regarding their microstructure and thermal behaviour using XRD, TEM and DSC. Their electrochemical behaviour in the as-quenched state and after hydrogen charging at -25 mA/cm 2 for up to 20 h was studied in electrolytes with pH 5-7 and 13, but mainly in a battery electrolyte: 6 M KOH with pH 14.8 by means of anodic and cathodic polarization measurements. In the as-quenched state, the highest alloys stability was observed at pH 13. At pH 14.8, gradual oxidation and dissolution of copper or nickel governs the anodic behaviour before a passive state is attained. The dissolution of nickel is much more inhibited than that of copper due to its lower tendency to form soluble oxidized ions and to a stabilizing effect of higher fractions of yttrium in the alloy on the passivation. By galvanostatic charging, the Mg 65 Cu 25 Y 10 alloy shows the highest hydrogen absorption capacity followed by Mg 50 Ni 30 Y 20 and Mg 63 Ni 30 Y 7 . During the charging process, the alloys exhibit a change in the surface state chemistry, i.e. an enrichment of nickel- or copper-rich species, causing preferential oxidation and dissolution during subsequent exposure under free corrosion and anodic conditions. Mg-Ni-Y alloys demonstrate a higher stability during this treatment in extreme alkaline medium. The reasons for this and consequences regarding the use as electrode materials are discussed in detail

  10. First-principle Calculations of Mechanical Properties of Al2Cu, Al2CuMg and MgZn2 Intermetallics in High Strength Aluminum Alloys

    Directory of Open Access Journals (Sweden)

    LIAO Fei

    2016-12-01

    Full Text Available Structural stabilities, mechanical properties and electronic structures of Al2Cu, Al2CuMg and MgZn2 intermetallics in Al-Zn-Mg-Cu aluminum alloys were determined from the first-principle calculations by VASP based on the density functional theory. The results show that the cohesive energy (Ecoh decreases in the order MgZn2 > Al2CuMg > Al2Cu, whereas the formation enthalpy (ΔH decreases in the order MgZn2 > Al2Cu > Al2CuMg. Al2Cu can act as a strengthening phase for its ductile and high Young's modulus. The Al2CuMg phase exhibits elastic anisotropy and may act as a crack initiation point. MgZn2 has good plasticity and low melting point, which is the main strengthening phase in the Al-Zn-Mg-Cu aluminum alloys. Metallic bonding mode coexists with a fractional ionic interaction in Al2Cu, Al2CuMg and MgZn2, and that improves the structural stability. In order to improve the alloys' performance further, the generation of MgZn2 phase should be promoted by increasing Zn content while Mg and Cu contents are decreased properly.

  11. Effect of excess Mg and Excess Nb incorporation into the B-site of pyrochlore in the Pb-Mg-Nb-O system

    Directory of Open Access Journals (Sweden)

    Mergen, A.

    2002-12-01

    Full Text Available In the Pb-Mg-Nb-O system, excess Mg and excess Nb incorporation into the B-site of PMN pyrochlore were investigated along the compositons of Pb1.83Mg0.29+xNb1.71-xO6.39-1.5x where x=0.1, 0.2, 0.3, 0.4, 0.522 and Pb1.83Mg0.29-xNb1.71+xO6.39+1.5x where x=0.1, 0.2, 0.29 respectively. Excess Mg incorporation led to the formation of perovskite and excess Nb resulted in formation of Pb2Nb2O7 monoclinic pyrochlore. The densities of the PMN pyrochlore-PMN perovskite mixtures decreased with an increase in Mg concentration. The relative permittivity of the mixtures increased with decreasing pyrochlore content. The effect of pyrochlore on the permittivity follows the Weiner’s mixture rule up to a pyrochlore content of 50 vol%.

    Se investigó la incorporación en lugares B de pirocloro PMN de un exceso de Mg y un exceso de Nb. En el sistema Pb-Mg-Nb-O2 las composiciones analizadas fueron Pb1.83Mg0.29+xNb1.71-xO6.39-1.5x donde x=0.1, 0.2, 0.3, 0.4, 0.522 y en Pb1.83Mg0.29-xNb1.71+xO6.39+1.5x donde x= 0.1, 0.2,0.29. El exceso de Mg condujo a la formación de perovskita y el exceso de Nb resultó en la formación del pirocloro monolínico, Pb2Nb2O7. La densidad de la mezcla de PMN pirocloro-perovskita dismunuye con el aumento de la concentración de Mg. La permitividad dieléctrica de las mezclas aumenta con la disminución del contenido de pirocloro. El efecto del pirocloro sobre la permitividad sigue la regla de mezclas de Weiner hasta conenidos de pirocloro del 50%.

  12. LOW Mg/Si PLANETARY HOST STARS AND THEIR Mg-DEPLETED TERRESTRIAL PLANETS

    Energy Technology Data Exchange (ETDEWEB)

    Carter-Bond, Jade C.; O' Brien, David P. [Planetary Science Institute, 1700 E. Fort Lowell, Tucson, AZ 85719 (United States); Delgado Mena, Elisa; Israelian, Garik; Gonzalez Hernandez, Jonay I. [Instituto de Astrofisica de Canarias, 38200 La Laguna, Tenerife (Spain); Santos, Nuno C., E-mail: j.bond@unsw.edu.au [Centro de Astrofisica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal)

    2012-03-15

    Simulations have shown that a diverse range of extrasolar terrestrial planet bulk compositions are likely to exist based on the observed variations in host star elemental abundances. Based on recent studies, it is expected that a significant proportion of host stars may have Mg/Si ratios below 1. Here we examine this previously neglected group of systems. Planets simulated as forming within these systems are found to be Mg-depleted (compared to Earth), consisting of silicate species such as pyroxene and various feldspars. Planetary carbon abundances also vary in accordance with the host star C/O ratio. The predicted abundances are in keeping with observations of polluted white dwarfs, lending validity to this approach. Further studies are required to determine the full planetary impacts of the bulk compositions predicted here.

  13. Comparative Effects of an Angiotensin II Receptor Blocker (ARB)/Diuretic vs. ARB/Calcium-Channel Blocker Combination on Uncontrolled Nocturnal Hypertension Evaluated by Information and Communication Technology-Based Nocturnal Home Blood Pressure Monitoring - The NOCTURNE Study.

    Science.gov (United States)

    Kario, Kazuomi; Tomitani, Naoko; Kanegae, Hiroshi; Ishii, Hajime; Uchiyama, Kazuaki; Yamagiwa, Kayo; Shiraiwa, Toshihiko; Katsuya, Tomohiro; Yoshida, Tetsuro; Kanda, Kiyomi; Hasegawa, Shinji; Hoshide, Satoshi

    2017-06-23

    Nocturnal blood pressure (BP) is an independent risk factor of cardiovascular events. The NOCTURNE study, a multicenter, randomized controlled trial (RCT) using our recently developed information and communication technology (ICT) nocturnal home BP monitoring (HBPM) device, was performed to compare the nocturnal HBP-lowering effects of differential ARB-based combination therapies in 411 Japanese patients with nocturnal hypertension (HT).Methods and Results:Patients with nocturnal BP ≥120/70 mmHg at baseline even under ARB therapy (100 mg irbesartan daily) were enrolled. The ARB/CCB combination therapy (irbesartan 100 mg+amlodipine 5 mg) achieved a significantly greater reduction in nocturnal home systolic BP (primary endpoint) than the ARB/diuretic combination (daily irbesartan 100 mg+trichlormethiazide 1 mg) (-14.4 vs. -10.5 mmHg, P<0.0001), independently of urinary sodium excretion and/or nocturnal BP dipping status. However, the change in nocturnal home systolic BP was comparable among the post-hoc subgroups with higher salt sensitivity (diabetes, chronic kidney disease, and elderly patients). This is the first RCT demonstrating the feasibility of clinical assessment of nocturnal BP by ICT-nocturnal HBPM. The ARB/CCB combination was shown to be superior to ARB/diuretic in patients with uncontrolled nocturnal HT independently of sodium intake, despite the similar impact of the 2 combinations in patients with higher salt sensitivity.

  14. Phase-field simulations of dendrite morphologies and selected evolution of primary {alpha}-Mg phases during the solidification of Mg-rich Mg-Al-based alloys

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Mingyue [Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Jing, Tao; Liu, Baicheng [Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China)

    2009-10-15

    A formulation of solid-liquid interfacial thermodynamic and kinetic anisotropic characteristics for hexagonal close-packed metals is proposed. The two- and three-dimensional dendritic growth of primary Mg in undercooled Mg-Al alloy melts is modeled using the phase-field method, based on a combination of crystallographic lattice symmetry and experimental observations. The morphologies of three-dimensional dendrites are obtained and the calculated results show intricately hierarchical branched structures. The excess free energy of the solution system is based on the Redlich-Kister model.

  15. Phase-field simulations of dendrite morphologies and selected evolution of primary α-Mg phases during the solidification of Mg-rich Mg-Al-based alloys

    International Nuclear Information System (INIS)

    Wang, Mingyue; Jing, Tao; Liu, Baicheng

    2009-01-01

    A formulation of solid-liquid interfacial thermodynamic and kinetic anisotropic characteristics for hexagonal close-packed metals is proposed. The two- and three-dimensional dendritic growth of primary Mg in undercooled Mg-Al alloy melts is modeled using the phase-field method, based on a combination of crystallographic lattice symmetry and experimental observations. The morphologies of three-dimensional dendrites are obtained and the calculated results show intricately hierarchical branched structures. The excess free energy of the solution system is based on the Redlich-Kister model.

  16. Effects of graphite doping on critical current density and microstructure of MgB{sub 2} bulks by an improved Mg-diffusion method

    Energy Technology Data Exchange (ETDEWEB)

    Pan, X.F. [Key Laboratory of Magnetic Levitation and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Zhao, Y. [Key Laboratory of Magnetic Levitation and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); School of Materials Science and Engineering, University of New South Wales, Sydney 2052, NSW (Australia)], E-mail: yshao@home.swjtu.edu.cn; Feng, Y. [Northwest Institute for Nonferrous Metal Research, P.O. Box 51, Xi' an, Shaanxi 710016 (China); Western Superconductivity Technology Company, Xi' an (China); Yang, Y. [Key Laboratory of Magnetic Levitation and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Cheng, C.H. [Key Laboratory of Magnetic Levitation and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); School of Materials Science and Engineering, University of New South Wales, Sydney 2052, NSW (Australia)

    2008-09-15

    abstract: A series of graphite-doped MgB{sub 2} bulks with high density have been successfully prepared by an improved Mg-diffusion method in ambient pressure. The effects of graphite doping on lattice parameters, T{sub c}, J{sub c} and microstructure of MgB{sub 2} have been investigated. The results show that compared to the nano-C-doped or CNTs-doped MgB{sub 2}, C is not easy to substitute B in graphite-doped MgB{sub 2}. However, at the same C content, the graphite-doped MgB{sub 2} has a higher J{sub c}. At 10 K and self-field, the J{sub c} for MgB{sub 1.985}C{sub 0.015} reaches 0.58 MA/cm{sup 2}. For the MgB{sub 1.945}C{sub 0.055}, at 5 K, 7 T and 10 K, 6 T the J{sub c} achieves 10,000 A/cm{sup 2} which is two orders of magnitude higher than that for the undoped sample. In addition to improving electron scattering and intergranular connectivity, the unreacted graphite in the graphite-doped MgB{sub 2} is proposed to be responsible to the excellent J{sub c} properties of MgB{sub 2} in high fields, due to depressed grain growth and enhanced grain boundary flux pinning.

  17. Interstitial Fe in MgO

    CERN Document Server

    Mølholt, T E; Gunnlaugsson, H P; Svane, A; Masenda, H; Naidoo, D; Bharuth-Ram, K; Fanciulli, M; Gislason, H P; Johnston, K; Langouche, G; Ólafsson, S; Sielemann, R; Weyer, G

    2014-01-01

    Isolated Fe-57 atoms were studied in MgO single-crystals by emission Mossbauer spectroscopy following implantation of Mn-57 decaying to Fe-57. Four Mossbauer spectral components were found corresponding to different Fe lattice positions and/or charge states. Two components represent Fe atoms substituting Mg as Fe2+ and Fe3+, respectively; a third component is due to Fe in a strongly implantation-induced disturbed region. The fourth component, which is the focus of this paper, can be assigned to Fe at an interstitial site. Comparison of its measured isomer shift with ab initio calculations suggests that the interstitial Fe is located on, or close to, the face of the rock-salt MgO structure. To harmonize such an assignment with the measured near-zero quadrupole interaction a local motion process (cage motion) of the Fe has to be stipulated. The relation of such a local motion as a starting point for long range diffusion is discussed.

  18. Conductivity, XRD, and FTIR studies of New Mg2+-ion-conducting solid polymer electrolytes: [PEG: Mg(CH3COO)2

    International Nuclear Information System (INIS)

    Polu, Anji Reddy; Kumar, Ranveer; Causin, Valerio; Neppalli, Ramesh

    2011-01-01

    Solid polymer electrolytes based on poly (ethylene glycol) (PEG) doped with Mg(CH 3 COO) 2 have been prepared by using the solution-casting method. The X-ray diffraction patterns of PEG with Mg(CH 3 COO) 2 salt indicated a decrease in the degree of crystallinity with increasing concentration of the salt. The complexation of Mg(CH 3 COO) 2 salt with the polymer was confirmed by using Fourier transform infrared spectroscopy (FTIR) studies. The ionic conductivity was measured for the [PEG: Mg(CH 3 COO) 2 ] system in the frequency range 50 Hz - 1 MHz. The addition of Mg salt was found to improve the ionic conductivity significantly. The 15-wt-% Mg(CH 3 COO) 2 -doped system had a maximum conductivity of 1.07 x 10 -6 S/cm at 303 K. The conductance spectrum shows two distinct regions: a dc plateau and a dispersive region. The temperature dependence of the ionic conductivity reveals the conduction mechanism to be an Arrhenius-type thermally activated process.

  19. Determination of the Mg occupation site in MOCVD- and MBE-grown Mg-doped InN using X-ray absorption fine-structure measurements

    Energy Technology Data Exchange (ETDEWEB)

    Miyajima, Takao; Uemura, Shigeaki; Kudo, Yoshihiro [Materials Laboratories, Sony Corporation, Atsugi, Kanagawa (Japan); Kitajima, Yoshinori [Photon Factory, High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan); Yamamoto, Akio [Graduate School of Engineering, University of Fukui, Fukui (Japan); Muto, Daisuke; Nanishi, Yasushi [Department of Photonics, Ritsumeikan University, 1-1-1 Noji-Higashi, Kusatsu, Shiga 525-8577 (Japan)

    2008-07-01

    We analyzed the atomic structure around Mg atoms in MOCVD- and MBE-grown Mg-doped InN using Mg K-edge X-ray absorption fine-structure (XAFS) measurements. Our experimental data closely fit to the simulated data in which Mg atoms occupy the substitutional sites of In atoms. From this result, we conclude that Mg atoms essentially occupy not N atoms sites but In atoms sites, meaning that Mg atoms can act as acceptors in InN. We believe that observations of p-type conductivity are prevented by problems such as carrier compensation and electron accumulation at the surface. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  20. Enhanced mechanical properties of an Al–Si–Cu–Mg alloy at 300 °C: Effects of Mg and the Q-precipitate phase

    Energy Technology Data Exchange (ETDEWEB)

    Farkoosh, A.R., E-mail: amir.rezaeifarkoosh@mail.mcgill.ca; Pekguleryuz, M., E-mail: mihriban.pekguleryuz@mcgill.ca

    2015-01-05

    Strategies to improve the strength of Al–Si alloys at elevated temperatures can follow two routes: (i) improving the age-hardening behavior and/or (ii) producing effective dispersoid strengthening. In this study, the influence of Mg (in the range of 0.3–0.7 wt%) on the precipitation characteristics and mechanical properties of the Al–7Si–0.5Cu–(Mg) alloy was investigated. Thermodynamic calculations were performed via the CALPHAD method which showed that Q-Al{sub 5}Mg{sub 8}Cu{sub 2}Si{sub 6} is the main thermodynamically stable precipitate at 300 °C. The calculations were validated by transmission electron microscopy and differential scanning calorimetry analyses. Increasing the Mg level from 0.3 wt% to the maximum solubility limit of ∼0.5 wt% increased the amount of the Q-Al{sub 5}Mg{sub 8}Cu{sub 2}Si{sub 6} precipitates at 300 °C by ∼60 wt% and significantly improved the tensile strength and creep resistance at the expense of some ductility. Mg in excess of the solubility limit was seen to remain within the microstructure in the form of the large π-Al{sub 8}FeMg{sub 3}Si{sub 6} and β-Mg{sub 2}Si intermetallics after solution treatment at 530 °C. Cracking of the brittle π-Al{sub 8}FeMg{sub 3}Si{sub 6} intermetallics during deformation was accounted for the decreased ductility of the alloys at high Mg levels. It is concluded that the Mg level can be increased to 0.5 wt% in the A–7Si–0.5Cu alloys to improve strength. However, for elevated temperature applications in which both strength and ductility are required (e.g. Diesel engine), modification of the π-Al{sub 8}FeMg{sub 3}Si{sub 6} intermetallics would be required to improve the ductility of the alloys with high Mg contents.

  1. Evaluation of a single-dose of intravenous magnesium sulphate for prevention of postoperative pain after inguinal surgery

    Directory of Open Access Journals (Sweden)

    Shashi Kiran

    2011-01-01

    Full Text Available This study was undertaken to study efficacy of single dose of intravenous magnesium sulphate to reduce post-operative pain in patients undergoing inguinal surgery. One hundred patients undergoing inguinal surgery were divided randomly in two groups of 50 each. The patients of magnesium sulphate group (Group-I received magnesium sulphate 50 mg/kg in 250 ml of isotonic sodium chloride solution IV whereas patients in control group (Group-II received same volume of isotonic sodium chloride over 30 minutes preoperatively. Anaesthesia was induced with propofol (2 mg/kg and pethidine (1 mg/kg. Atracurium besylate (0.5 mg/kg was given to facilitate insertion of LMA. Pain at emergence from anaesthesia and 2, 4, 6, 12 and 24 hours after surgery was evaluated. The timing and dosage of rescue analgesic during first 24 hrs after operation was noted. Pain in postop period was significantly lower in magnesium sulphate group in comparison to control group at emergence from anaesthesia and 2, 4, 6, 12 and 24 hrs postop [1.86 vs. 1.96 (P=0.138, 1.22 vs. 1.82 (P=0.001, 1.32 vs. 1.88 (P=0.000, 2.74 vs. 3.84 (P=0.000, 1.36 vs. 2.00 (P=0.000 and 0.78 vs 1.30 (P=0.000, respectively]. Patients in group-I were more sedated as compared to group-II [sedation score 1.86 vs. 1.40 (P=0.000]. Rescue analgesia requirement postoperatively in first 4, 8 and 16 hrs was significantly lower in patients of group-1 than in group- II [1.9 vs. 3.8 (P<0.05, 25.50 vs. 52.50 (P<0.05 and 0.000 vs. 7.5 (P<0.05]. Preoperative magnesium sulphate infusion decreases postop pain and requirement of rescue analgesia.

  2. Structural and transport properties of Sn-Mg alloys

    International Nuclear Information System (INIS)

    Meydaneri, F.; Saatci, E.; Oezdemir, M.; Ari, M.; Durmus, S.

    2010-01-01

    The structural and temperature dependence transport of Sn-Mg alloys have been investigated for five different samples (Pure Sn, Sn-1.0 wt % Mg , Sn-2.0 wt % Mg , Sn-6.0 wt.% Mg and Pure Mg). Scanning Electron Microscopy (SEM), x-ray diffraction (XRD) and Energy Dispersive x-ray Analysis (EDX) measurements were carried out in order to clarify the structural properties of the samples. It has been found that, the samples have tetragonal crystal symmetry except the pure Mg which has hexagonal crystal symmetry. The cell parameters decrease slightly with addition of Mg element. The SEM micrographs of the samples show that, the samples have smooth surfaces with clear grain boundary. There is no crack, porosity or defects on the surfaces. The electrical resistivity of the samples increases almost linearly with the increasing temperature, which were measured by four-point probe technique. The thermal conductivity values are in between 0.60-1.00 W/Km, which are decrease slightly with temperature and increase with composition of Mg. The thermal conductivity values of the alloys are in between the values of the pure samples. Thermal conductivity results of the alloys have been compared with available other studies and a good agreement has been seen between the results. In addition, the temperature coefficients of electrical resistivity and thermal conductivity have been determined, which are independent with the compositions of alloying elements

  3. MgB{sub 2} superconductors for applications

    Energy Technology Data Exchange (ETDEWEB)

    Glowacki, B A; Majoros, M; Eisterer, M; Toenies, S; Weber, H W; Fukutomi, M; Komori, K; Togano, K

    2003-05-01

    The paper presents up to date results on MgB{sub 2} filamentary conductors and coated conductors from the point of view of their possible applications. Basic physical parameters of MgB{sub 2} compound relevant to conductor design are introduced. The correlation between the slope of the irreversibility line, critical temperature and critical current density is discussed with respect to the conductor performance and applicability. The possible origin of the observed anomalous decrease of ac susceptibility at 50 K in copper clad in situ powder-in-tube MgB{sub 2} wires is presented. Some numerical results on critical currents, thermal stability and ac losses of the MgB{sub 2} multifilamentary and coated conductors with magnetic cladding of their filaments are given.

  4. Comparison of characteristics of LiF:Mg,Ti e LiF:Mg,Cu,P thermoluminescent dosemeters; Comparacao das caracteristicas dos dosimetros termoluminescentes LiF:Mg,Ti e LiF:Mg,Cu,P

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, M.S.; Filipov, D., E-mail: dfilipov@utfpr.edu.br [Universidade Tecnologica Federal do Parana (UTFPR/DAFIS), Curitiba, PR (Brazil). Departamento Academicao de Fisica; Schelin, H.R. [Instituto de Pesquisa Pele Pequeno Principe (IPPPP), Curitiba, PR (Brazil)

    2014-07-01

    The aim of the current study was to compare the thermoluminescent dosimeters LiF:Mg,Ti (TLD-100) and LiF:Mg,Cu,P (MCP) data, which were acquired by the Federal Technological University - Parana. Tests were realized, for this purpose, such as: sensitivity (only one MCP TLD did not present results within the limit range), linearity (whose MCP result was better than the TLD-100 one), energy dependence (TLD-100 presented lower variation than MCP TLD) and reproducibility (whose TLD-100 results were better than the MCP ones). The results from both dosimeters show that these TLDs attend radiodiagnostic dosimetry criteria, however MCP had more satisfactory results. (author)

  5. Industrial production of MgH2 and its application

    International Nuclear Information System (INIS)

    Uesugi, H.; Sugiyama, T.; Nii, H.; Ito, T.; Nakatsugawa, I.

    2011-01-01

    Research highlights: → Tablet and powder Mg were hydrogenated in a 50 kg batch furnace based on thermal equilibrium method. → Compression of Mg tablet improved the hydrogenation yield. → Hydrolysis of MgH 2 using citric acid generated hydrogen under 373 K. → A MgH 2 -hydrogen reactor utilizing hydraulic head pressure was developed. → - Abstract: A process for the industrial production of magnesium hydride (MgH 2 ) based on a thermal equilibrium method and its application to portable hydrogen sources is proposed. Mg powders and tablets compressed with mechanically ground Mg ribbons were successfully hydrogenated in a 50-kg-batch furnace. The resultant MgH 2 showed a hydrogen yield of around 96% with good reproducibility. The compression ratio of Mg tablets was found to be an important factor in the hydrogenation yield. A hydrolysis technique using citric acid as an additive was employed to generate hydrogen under 373 K. Increasing the concentration of citric acid and the temperature accelerated the hydrolysis reactivity. A hydrogen reactor utilizing hydraulic head pressure was developed. It generated hydrogen continuously for 1 h at a flow rate of 100 ml min -1 with hydrolysis of 5 g of tablet-form MgH 2 . The conversion yield was around 70%, regardless of the flow rate.

  6. Corrosion behavior of Mg/graphene composite in aqueous electrolyte

    International Nuclear Information System (INIS)

    Selvam, M.; Saminathan, K.; Siva, P.; Saha, P.; Rajendran, V.

    2016-01-01

    In the present work, the electrochemical corrosion behavior of magnesium (Mg) and thin layer graphene coated Mg (Mg/graphene) are studied in different salt electrolyte such as NaCl, KCl and Na_2SO_4. The phase structure, crystallinity, and surface morphology of the samples are investigated using X-ray diffraction (XRD) analysis, scanning electron microscopy coupled with energy dispersive X-ray analysis (SEM/EDAX), and Raman spectroscopy techniques. The electrochemical corrosion behavior of the Mg and graphene coated Mg are also investigated using Electrochemical Impedance Spectroscopy (EIS) analysis. The tafel plot reveals that the corrosion of Mg drastically drops when coated with thin layer graphene (Mg/graphene) compared to Mg in KCl electrolyte. Moreover, the EIS confirms that Mg/graphene sample shows improve corrosion resistance and lower corrosion rate in KCl solution compare to all other electrolytes studied in the present system. - Highlights: • The corrosion behavior of magnesium alloy (AZ91) was investigated in three different electrolyte solution. • To study the anti-corrosion behavior of graphene coated with magnesium alloy. • To improve the corrosion resistance for magnesium alloy. • Nyquist plots confirms that MgG shows better corrosion resistance and lower corrosion rate in KCl solution.

  7. Corrosion behavior of Mg/graphene composite in aqueous electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Selvam, M. [Centre for Nano Science and Technology, KS Rangasamy College of Technology, Tiruchengode, 637215, Tamil Nadu (India); Saminathan, K., E-mail: ksaminath@gmail.com [Centre for Nano Science and Technology, KS Rangasamy College of Technology, Tiruchengode, 637215, Tamil Nadu (India); Siva, P. [Centre for Nano Science and Technology, KS Rangasamy College of Technology, Tiruchengode, 637215, Tamil Nadu (India); Saha, P. [Department of Ceramic Engineering, National Institute of Technology, Rourkela, India-769008 (India); Rajendran, V. [Centre for Nano Science and Technology, KS Rangasamy College of Technology, Tiruchengode, 637215, Tamil Nadu (India)

    2016-04-01

    In the present work, the electrochemical corrosion behavior of magnesium (Mg) and thin layer graphene coated Mg (Mg/graphene) are studied in different salt electrolyte such as NaCl, KCl and Na{sub 2}SO{sub 4}. The phase structure, crystallinity, and surface morphology of the samples are investigated using X-ray diffraction (XRD) analysis, scanning electron microscopy coupled with energy dispersive X-ray analysis (SEM/EDAX), and Raman spectroscopy techniques. The electrochemical corrosion behavior of the Mg and graphene coated Mg are also investigated using Electrochemical Impedance Spectroscopy (EIS) analysis. The tafel plot reveals that the corrosion of Mg drastically drops when coated with thin layer graphene (Mg/graphene) compared to Mg in KCl electrolyte. Moreover, the EIS confirms that Mg/graphene sample shows improve corrosion resistance and lower corrosion rate in KCl solution compare to all other electrolytes studied in the present system. - Highlights: • The corrosion behavior of magnesium alloy (AZ91) was investigated in three different electrolyte solution. • To study the anti-corrosion behavior of graphene coated with magnesium alloy. • To improve the corrosion resistance for magnesium alloy. • Nyquist plots confirms that MgG shows better corrosion resistance and lower corrosion rate in KCl solution.

  8. Thermal behaviour of Cu-Mg-Mn and Ni-Mg-Mn layered double hydroxides and characterization of formed oxides

    Czech Academy of Sciences Publication Activity Database

    Kovanda, F.; Grygar, Tomáš; Dorničák, V.; Rojka, T.; Bezdička, Petr; Jirátová, Květa

    2005-01-01

    Roč. 28, 1-4 (2005), s. 121-136 ISSN 0169-1317 Institutional research plan: CEZ:AV0Z40320502 Keywords : Cu-Mg-Mn basic carbonates * Ni-Mg-Mn hydrotalcite Subject RIV: CA - Inorganic Chemistry Impact factor: 1.324, year: 2005

  9. Decomposition of supersaturated solid solutions Mg-Ho and Mg-Gd

    International Nuclear Information System (INIS)

    Sukhanov, V.D.; Dobromyslov, A.V.; Rokhlin, L.L.; Dobatkina, T.V.

    2002-01-01

    Methods of electron microscopy and X-ray diffraction analysis are applied to study ageing magnesium base alloys with holmium and gadolinium. It is shown that the precipitation of supersaturated Mg base solid solutions goes through several subsequent stages and is accompanied by a considerable precipitation hardening effect at the stage of metastable phase precipitation. The influence of aging time and temperature on precipitation kinetics is established [ru

  10. Low-power, high-uniform, and forming-free resistive memory based on Mg-deficient amorphous MgO film with rough surface

    Science.gov (United States)

    Guo, Jiajun; Ren, Shuxia; Wu, Liqian; Kang, Xin; Chen, Wei; Zhao, Xu

    2018-03-01

    Saving energy and reducing operation parameter fluctuations remain crucial for enabling resistive random access memory (RRAM) to emerge as a universal memory. In this work, we report a resistive memory device based on an amorphous MgO (a-MgO) film that not only exhibits ultralow programming voltage (just 0.22 V) and low power consumption (less than 176.7 μW) but also shows excellent operative uniformity (the coefficient of variation is only 1.7% and 2.2% for SET and RESET voltage, respectively). Moreover, it also shows a forming-free characteristic. Further analysis indicates that these distinctive properties can be attributed to the unstable local structures and the rough surface of the Mg-deficient a-MgO film. These findings show the potential of using a-MgO in high-performance nonvolatile memory applications.

  11. Research on MgLi and a specifically German consequence. MgLi-Forschung und ihre spezifisch deutsche Konsequenz

    Energy Technology Data Exchange (ETDEWEB)

    Hehmann, F [Office National d' Etudes et de Recherches Aerospatiales (ONERA), 92 - Chatillon (France)

    1994-05-01

    When light weight structural applications are of prime concern, magnesium cannot be ignored. When magnesium is of prime concern, of course, the research cannot be ignored, either. Since there is not much to be ignored (or not), however, it is the research on MgLi that takes the lead in the German press. ''Rock-solid as Kruppstahl'' was it meant to be, though MgLi-alloys soften quite appreciable already at ambient temperature. A hydrogen treatment of the MgLi melt was the phenomenon that was naturally astounded. In the meantime, however, it became very tranquilly around the contest for the selection of the species from the ''MgLi-Born''. Has the hot air already escaped Warm wind is not bad in each case. Daily discipline, however, has scaled ever since with the natural beauty of the more concrete results by working. What follows is an article that looks upon this particular German variant at the ''histoire parallele'' in the field of metallic innovations as well as upon the sound base of such deliberately outbalanced renaissances. (orig.)

  12. Microstructure and properties of Mg-Al binary alloys

    Directory of Open Access Journals (Sweden)

    ZHENG Wei-chao

    2006-11-01

    Full Text Available The effects of different amounts of added Al, ranging from 1 % to 9 %, on the microstructure and properties of Mg-Al binary alloys were investigated. The results showed that when the amount of added Al is less than 5%, the grain size of the Mg-Al binary alloys decreases dramatically from 3 097 μm to 151 μm with increasing addition of Al. Further addition of Al up to 9% makes the grain size decrease slowly to 111 μm. The α-Mg dendrite arms are also refined. Increasing the amount of added Al decreases the hot cracking susceptibility of the Mg-Al binary alloys remarkably, and enhances the micro-hardness of the α-Mg matrix.

  13. MgB2 and Mg1-xAlxB2 single crystals: high pressure growth and physical properties

    International Nuclear Information System (INIS)

    Karpinski, J.; Kazakov, S.M.; Jun, J.; Zhigadlo, N.D.; Angst, M.; Puzniak, R.; Wisniewski, A.

    2004-01-01

    Single crystals of MgB 2 have been grown with a high pressure cubic anvil technique. They grow via the peritectic decomposition of the MgNB 9 ternary nitride. The crystals are of a size up to 2 x 1 x 0.1 mm 3 with a weight up to 230 μg. Typically they have transition temperatures between 38 and 38.6 K with a width of 0.3-0.5 K. Investigations of the P-T phase diagram prove that the MgB 2 phase is stable at least up to 2190 deg. C at high hydrostatic pressure in the presence of Mg vapor under high pressure. Substitution of aluminum for magnesium in single crystals leads to stepwise decrease of T c . This indicates a possible appearance of superstructures or phases with different T c 's. The upper critical field decreases with Al doping

  14. Examination of the Mg-Zn phase formation in hot-dip galvanized steel sheet; Untersuchung der Mg-Zn-Phasenbildung in feuerverzinktem Stahlblech

    Energy Technology Data Exchange (ETDEWEB)

    Zywitzki, Olaf; Modes, Thomas; Scheffel, Bert; Metzner, Christoph [Fraunhofer-Institut fuer Elektronenstrahl- und Plasmatechnik, Dresden (Germany)

    2012-07-01

    Zinc-magnesium layers have been produced by a combination of conventional hot-dip galvanizing and PVD magnesium coating. A subsequent short heat treatment causes the diffusion of magnesium into the zinc layer. The influence of the maximum temperature of the heat treatment on the diffusion of magnesium and on the type and distribution of the formed intermetallic Mg-Zn phases has been examined in detail in a temperature range from 300 to 400 C by means of X-ray phase analyses and metallographic cross sections. With increasing temperature a sequential intermetallic Mg-Zn phase formation has been detected. At 300 C, an initial magnesium rich, intermetallic MgZn{sub 2} surface layer is formed, which, at higher temperatures from 335 to 379 C, is progressively transformed into a zinc rich Mg{sub 2}Zn{sub 11} layer by interdiffusion. In this context, the nucleation of the Mg{sub 2}Zn{sub 11} phase takes place on the interface between the MgZn{sub 2} and the Zn phase. Above the peritectic temperature of 381 C, the microstructure is composed of a zinc matrix in which precipitated MgZn{sub 2} is dispersed. (orig.)

  15. Effect of MgCl2 addition on the sintering behavior of MgAl2O4 spinel and formation of nano-particles

    Directory of Open Access Journals (Sweden)

    Mohammadi F.

    2014-01-01

    Full Text Available In this paper, the effect of MgCl2 addition on the sintering behavior of MgAl2O4 spinel produced via oxide mixture method was investigated. For this reason, the stoichiometric mixture of magnesite and calcined alumina as raw materials was calcined at 1100°C. The calcined mixture was milled, pressed and then, fired at 1300 and 1500°C after addition of various amounts of MgCl2. Besides, the physical properties, phase composition and microstructure of fired samples were investigated. The results showed that MgCl2 addition has great effect on the densification and particle size of spinel. Besides, MgCl2 addition increases the amount of spinel phase at all firing temperatures. Due to the decomposition of MgCl2 and then formation of ultra-fine MgO particles, the nano-sized spinel is formed on the surface of the larger spinel particles.

  16. Powder metallurgical low-modulus Ti-Mg alloys for biomedical applications.

    Science.gov (United States)

    Liu, Yong; Li, Kaiyang; Luo, Tao; Song, Min; Wu, Hong; Xiao, Jian; Tan, Yanni; Cheng, Ming; Chen, Bing; Niu, Xinrui; Hu, Rong; Li, Xiaohui; Tang, Huiping

    2015-11-01

    In this work, powder metallurgical (PM) Ti-Mg alloys were prepared using combined techniques of mechanical alloying and spark plasma sintering. The alloys mainly consist of super saturations of Mg in Ti matrix, and some laminar structured Ti- and Mg-rich phases. The PM Ti-Mg alloys contain a homogeneous mixtures of nanocrystalline Mg and Ti phases. The novel microstructures result in unconventional mechanical and biological properties. It has been shown that the PM Ti-Mg alloys have a much lower compression modulus (36-50GPa) compared to other Ti alloys, but still remain a very high compressive strength (1500-1800MPa). In addition, the PM Ti-Mg alloys show good biocompatibility and bioactivity. Mg can dissolve in the simulated body fluids, and induce the formation of the calcium phosphate layer. The compression modulus of PM Ti-Mg alloys decreases with the amount of Mg, while the bioactivity increases. Although the corrosion resistance of Ti-Mg alloys decreases with the content of Mg, the alloys still show good stability in simulated body fluid under electrochemical conditions. The indirect and direct cytotoxicity results show that PM Ti-Mg alloys have a good biocompatibility to NIH-3T3 cells. Therefore, the PM Ti-Mg alloys are promising candidates in biomedical applications. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. The Effects of Arterial Blood Pressure Reduction on Endocan and Soluble Endothelial Cell Adhesion Molecules (CAMs and CAMs Ligands Expression in Hypertensive Patients on Ca-Channel Blocker Therapy

    Directory of Open Access Journals (Sweden)

    Refmir Tadzic

    2013-04-01

    Full Text Available Background/Aims: To determine the effect of arterial blood pressure (BP reduction on endocan and soluble cell adhesion molecules' (sCAM plasma concentration and expression of their ligands on circulatory leukocyte subpopulations. Methods: 24 hypertensive subjects of both sexes (age: 53±8 yrs were treated with Ca-channel blocker, amlodipin (5-10 mg/day for 8 weeks; to reach BP≤139/89mmHg. The serum sCAMs and endocan concentrations were determined by ELISA kits. Level of ICAM/VCAM ligands on leukocytes was assessed by flow cytometry. Paired t-test, or t-test were used as appropriate, with Pearson's correlation calculated; pResults: sICAM-1 and sVCAM-1 were decreased (p≤0.001 and p=0.002, respectively, while E-selectin concentration was increased after amlodipin treatment (P=0.014. CD11a/LFA-1 (ICAM-1 and endocan ligand was significantly increased in all three cell types with BP decrease. CD15 and CD49d/VLA-4 (VCAM-1 ligand did not change after the treatment. There was significant positive correlation of systolic and diastolic BP with ICAM-1 and VCAM-1, and significant negative correlation of systolic BP with CD11a/LFA-1. Endocan significantly positively correlated with ICAM-1. Conclusions: The increased expression of ICAM/VACM ligands, together with decrease of sCAMs and endocan suggests the de-activation of endothelium with reduction in BP, decreasing the adherence of circulatory leukocytes to endothelium; subsequently decreasing the risk for development of atherosclerosis.

  18. The role of Mg in the crystallization of monohydrocalcite

    Science.gov (United States)

    Rodriguez-Blanco, Juan Diego; Shaw, Samuel; Bots, Pieter; Roncal-Herrero, Teresa; Benning, Liane G.

    2014-02-01

    Monohydrocalcite is a member of the carbonate family which forms in Mg-rich environments at a wide range of Mg/Ca ratios Mg2+aq/Ca2+aq≥0.17stock solutions. However, its crystallite and particle size are inversely proportional to these parameters. At high supersaturations (SIMHC = 3.89) nanometer-sized single crystals of monohydrocalcite form, while at low values (SIMHC = 2.43) the process leads to low-angle branching spherulites. Many carbonates produced during biomineralization form at similar conditions to most synthetic monohydrocalcites, and thus we hypothesize that some calcite or aragonite deposits found in the geologic record that have formed at high Mg/Ca ratios could be secondary in origin and may have originally formed via a metastable monohydrocalcite intermediate. High-Mg monohydrocalcite (χMgCO3 > 0.06) consists of individual nanometer-sized crystals (500 °C (Fig. 9b). Such high-Mg monohydrocalcites are uncommon in nature, but can be synthesized in the laboratory at high initial supersaturation levels (SI > 3.25). Low-Mg monohydrocalcite (χMgCO3 bonded to Mg, so it fully dehydrates at low temperatures (150-200 °C). They have the same composition as natural monohydrocalcites reported in the literature, and can be synthesized in the laboratory at lower supersaturation levels (SI relationships. Firstly, our on-line experiment shows an increase in nanocrystal sizes during the secondary crystallization of monohydrocalcite, which is coupled with a significant decrease in χMgCO3 (from ˜0.26 to ˜0.065). This corresponds to the transition from high- to low-Mg monohydrocalcite, suggesting that the former would be metastable and rapidly transforming to the latter, possibly triggered by the removal of Mg from aqueous solution. Secondly, Davis et al. (2000) determined that the solubility of Mg-calcite (Ca1-xMgxCO3; x = 0-0.20) varies by approximately half an order of magnitude depending on the Mg content of the solid (Ksp = 10-8.0-10-8.5). A similar

  19. Wound healing effect of bioactive ion released from Mg-smectite.

    Science.gov (United States)

    Sasaki, Yu; Sathi, Gulsan Ara; Yamamoto, Osamu

    2017-08-01

    Bioactive ions like Mg 2+ and Si 4+ have been known as promotion factors of tissue regeneration. In the present work, Mg-smectite, consisting of Mg 2+ and Si 4+ ions, was synthesized by a solution process, and evaluated for the efficiency of the powder on wound healing in rats. White precipitates were obtained by mixing a magnesium chloride hexahydrate solution and a sodium silicate hexahydrate solution at room temperature. The precipitates mixed with a NaOH aqueous solution were subjected to hydrothermal reaction, and finally crystalline Mg-smectite powder was obtained. The crystal and molecular structure of Mg-smectite was identified by X-ray diffractometry (XRD) and Fourier-transform infrared spectroscopy (FT-IR). The synthesized material was determined to be crystalline Mg-smectite. The amount of Mg 2+ and Si 4+ ions released from Mg-smectite in physiological saline was analyzed by inductively coupled plasma mass spectroscopy (ICP-MS). The total amount of Si 4+ ion released from Mg-smectite was greater than that of Mg 2+ ion. To evaluate the wound healing effect of Mg-smectite, Mg-smectite powder was applied to a full-thickness surgical wound reaching the subcutaneous tissue in the rat's abdomen. At 1 and 2weeks, skin tissue was collected and subjected to histological analysis. The results for skin regeneration showed no significant difference in wound size between the control and Mg-smectite group. However, it was found that the neovascularization, collagen deposition, and maturation were notedly accelerated by applying Mg-smectite powder in comparison with the control. Mg-smectite can then be hypothesized to stimulate the regeneration of skin tissue by releasing Mg 2+ and Si 4+ ions. These results suggested that Mg-smectite could offer great potential as a wound dressing material. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Recovery of SO2 and MgO from By-Products of MgO Wet Flue Gas Desulfurization.

    Science.gov (United States)

    Yan, Liyun; Lu, Xiaofeng; Wang, Quanhai; Guo, Qiang

    2014-11-01

    An industrial demonstration unit using natural gas as a heat source was built to calcine the by-products of MgO wet flue gas desulfurization from power plants; influencing factors on the SO 2 content in calciner gas were comprehensively analyzed; and an advantageous recycling condition of MgO and SO 2 from by-products was summarized. Results showed that the SO 2 content in the calciner gas was increased by more than 10 times under a lower excess air coefficient, a higher feed rate, a lower crystal water in by-products, and a higher feed port position. For the tests conducted under the excess air coefficient above and below one, the effect of the furnace temperature on the SO 2 content in the calciner gas was reversed. Results of activity analysis indicate that particles of MgO generated under the calcination temperature of 900-1,000°C had a high activity. In contrast, due to the slight sintering, MgO generated under the calcination temperature of 1,100°C had a low activity. To recycle SO 2 as well as MgO, a temperature range of 900-927°C for TE103 is proposed. These studies will prompt the desulfurization market diversification, reduce the sulfur's dependence on imports for making sulfuric acid, be meaningful to balance the usage of the natural resource in China, and be regarded as a reference for the development of this technology for other similar developing countries.

  1. Behavior of methyl orange and orange 10 (orange G) in the presence of hydrotalcite type compounds of Mg/Al and Mg/Fe

    International Nuclear Information System (INIS)

    Cruz N, G.

    2015-01-01

    This work is focused on studying the sorption capacity of methyl orange dye (Nm) and orange 10 (N-10) in the presence of hydrotalcite type compounds of Mg/Al and Mg/Fe uncalcined and calcined previously at 500 degrees Celsius. Sorption isotherms were determined and the study of the kinetics of sorption was performed. The materials were characterized before and after sorption processes of these dyes by X-ray diffraction, scanning electron microscopy, the specific surface area determination by the Brunauer-Emmett-Teller method, thermogravimetry coupled to mass and infrared spectrometry. The hydrotalcite type compounds reported in this paper were prepared in the laboratory and their acronyms are: HTMgAlG1, HTMgAlMO, HTMgFeG1 and HTMgFeG2. Note that in this work the best conditions for preparing compounds of Mg/Fe were found. From patterns of X-ray diffraction was identified the typical crystal structure of the hydrotalcite type compounds. By scanning electron microscopy the morphology could be determined in the form of flakes characteristics of these compounds. Likewise with elemental analysis of energy dispersive X-ray spectroscopy the presence of Mg, Al, Fe and C, elements of interest for this study was determined. The compounds presented a specific surface area relatively high from 80 to 120 m 2 /g. Thermogravimetry results presented spectra of mass loss very characteristic associated to water losses, dehydroxylation and decarboxylation. The characteristic bands of water and carbonate were assigned by infrared spectroscopy and the bands corresponding to the dyes sulfonates were identified only for the calcined materials. The sorption capacities found of these compounds were as follows: for Nm in the compound HTMgAlG1 uncalcined was 17.82 mg/g for an initial concentration of 200 mg/L and for calcined (HTMgAlMOcal) of 99.8 mg/g with and initial concentration of 1000 mg/L. Moreover, the sorption capacity of the dye N-10 in this same material was 17.92 mg/g and 99.4 mg

  2. Hydrothermal replacement of calcite by Mg-carbonates

    Science.gov (United States)

    Jonas, Laura; Mueller, Thomas; Dohmen, Ralf

    2014-05-01

    The transport of heat and mass through the Earth's crust is coupled to mineral reactions and the exchange of isotopes and elements between different phases. Carbonate minerals are a major constituent of the Earth's crust and play an important role in different physical, chemical and even biological processes. In this experimental study, the element exchange reaction between calcite (CaCO3) and a Mg-rich fluid phase is investigated under hydrothermal conditions. Single crystals of calcite (2x2x2 mm) react with 1 ml of a 1 M MgCl2 solution at 200° C in a Teflon-lined steel autoclave for different times between one day and four weeks. The reaction leads to the formation of a porous reaction front and the pseudomorphic replacement of calcite by dolomite [CaMg(CO3)2] and magnesite (MgCO3). Scanning electron microscopy revealed that the reaction rim consists of small Mg-carbonate rhombs closely attached to each other, suggesting that the replacement reaction takes place by a dissolution-precipitation mechanism. Typically, the observed reaction front can be divided into two different domains. The outer part of the reaction rim, i.e. from the mineral surface in contact to the fluid inwards, consists of magnesite, whereas the inner part of the rim surrounding the unreacted calcite core consists of Ca-rich dolomite. The formation of a porous microstructure that varies in different parts of the reaction rim is a direct result of the large molar volume change induced by the replacement of calcite by magnesite and dolomite. The developing porosity therefore creates fluid pathways that promote the progress of the reaction front towards the unreacted core of the single crystal. Compositional profiles measured perpendicular to the mineral surface across the reactions rims using electron microprobe (EMPA) further revealed a compositional gradient within the reaction rim with regard to the structure-forming elements Mg and Ca. Here, the amount of Mg incorporated in both product

  3. Study of some Mg-based ferrites as humidity sensors

    International Nuclear Information System (INIS)

    Rezlescu, N; Rezlescu, E; Doroftei, C; Popa, P D

    2005-01-01

    The micostructure and humidity sensitivity of MgFe 2 O 4 + CaO, Mg 0.5 Cu 0.5 Fe 1.8 Ga 0.2 O 4 , Mg 0.5 Zn 0.5 Fe 2 O 4 + KCl and MgMn 0.2 Fe 1.8 O 4 ferrites were investigated. We have found that the humidity sensitivity largely depends on composition, crystallite size, surface area and porosity. The best results concerning humidity sensitivity were obtained for MgMn 0.2 Fe 1.8 O 4 ferrite

  4. Phototransfered thermoluminescence for dose reassessment in LiF:mg,ti , LiF: mg,Cu,p TL detectors

    International Nuclear Information System (INIS)

    Rodriguez Otazo, M.; Baly, L.

    2001-01-01

    Phototransfered Thermoluminescence (PTTL) from LiF:Mg,Ti (TLD-100) and LiF: Mg,Cu,P (GR-200) was studied at different conditions using different sources of UV light for dose reassessment purposes. The TL dosimeters were irradiated with 137Cs in the range 2 mGy to 100 mGy. The convenience of using PTTL for dose reassessment was analyzed

  5. Atomistic study on the interaction of nitrogen and Mg lattice and the nitride formation in nanocrystalline Mg alloys synthesized using cryomilling process

    International Nuclear Information System (INIS)

    Nezafati, Marjan; Giri, Anit; Hofmeister, Clara; Cho, Kyu; Schneider, Matthew M.; Zhou, Le; Sohn, Yongho; Kim, Chang-Soo

    2016-01-01

    Cryomilling is a broadly applied technique to synthesize nanostructured alloys and composites through powder metallurgy (PM) processing. Understanding the interactions between liquid nitrogen and the nanostructured metal powder is important as it can potentially impact the mechanical performance of these materials. In this study, we performed a series of ab initio density functional theory (DFT) computations to examine the interactions of liquid nitrogen and Mg-based matrices and the formation of Mg-nitrides. The diffusion energy barriers of nitrogen in the Mg and/or Mg-Al alloys were systematically quantified by calculating the transition state (TS) for the displacement of nitrogen between two neighboring equivalent positions. The TS calculation results indicate that diffusion of N atoms is much easier than that of N 2  molecule in the Mg matrix. It is predicted that at least ∼0.4 eV is required to overcome the diffusion energy barrier in the Mg matrix. We also quantified the formation energy of Mg nitride in the matrix. The presence of Mg nitride was demonstrated experimentally using transmission electron microscopy (TEM) and electron energy-loss spectroscopy (EELS). In conjunction with the DFT computations and TEM/EELS analysis, we performed analytical calculations for the strain energy introduced during cryomilling to examine the impacts of processing parameters.

  6. Theoretical Limiting Potentials in Mg/O2 Batteries

    DEFF Research Database (Denmark)

    Smith, Jeffrey G.; Naruse, Junichi; Hiramatsu, Hidehiko

    2016-01-01

    A rechargeable battery based on a multivalent Mg/O2 couple is an attractive chemistry due to its high theoretical energy density and potential for low cost. Nevertheless, metal-air batteries based on alkaline earth anodes have received limited attention and generally exhibit modest performance....... In addition, many fundamental aspects of this system remain poorly understood, such as the reaction mechanisms associated with discharge and charging. The present study aims to close this knowledge gap and thereby accelerate the development of Mg/O2 batteries by employing first-principles calculations...... by the presence of large thermodynamic overvoltages. In contrast, MgO2-based cells are predicted to be much more efficient: superoxide-terminated facets on MgO2 crystallites enable low overvoltages and round-trip efficiencies approaching 90%. These data suggest that the performance of Mg/O2 batteries can...

  7. Catalytically Enhanced Hydrogen Sorption in Mg-MgH2 by Coupling Vanadium-Based Catalyst and Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Atikah Kadri

    2015-06-01

    Full Text Available Mg (MgH2-based composites, using carbon nanotubes (CNTs and pre-synthesized vanadium-based complex (VCat as the catalysts, were prepared by high-energy ball milling technique. The synergistic effect of coupling CNTs and VCat in MgH2 was observed for an ultra-fast absorption rate of 6.50 wt. % of hydrogen per minute and 6.50 wt. % of hydrogen release in 10 min at 200 °C and 300 °C, respectively. The temperature programmed desorption (TPD results reveal that coupling VCat and CNTs reduces both peak and onset temperatures by more than 60 °C and 114 °C, respectively. In addition, the presence of both VCat and CNTs reduces the enthalpy and entropy of desorption of about 7 kJ/mol H2 and 11 J/mol H2·K, respectively, as compared to those of the commercial MgH2, which ascribe to the decrease of desorption temperature. From the study of the effect of CNTs milling time, it is shown that partially destroyed CNTs (shorter milling time are better to enhance the hydrogen sorption performance.

  8. Aliskiren: a clinical profile

    Directory of Open Access Journals (Sweden)

    Roland E Schmieder

    2006-06-01

    Full Text Available Aliskiren is a novel oral antihypertensive agent, and the first in the new class of direct renin inhibitors. Here we review the key criteria that a new antihypertensive drug should possess, notably effective blood pressure lowering as monotherapy and combination therapy, 24-hour blood pressure control, safety and tolerability, end-organ protective effects, minimal drug interaction and efficacy during long-term use.Aliskiren fulfils key criteria for a new antihypertensive agent.The drug demonstrates effective blood lowering in a number of studies as monotherapy and in combination with a thiazide diuretic (hydrochlorothiazide, an angiotensin-converting enzyme inhibitor (ramipril and a calcium channel blocker (amlodipine. Other studies applying ambulatory blood pressure monitoring show that aliskiren maintains blood pressure control for more than 24 hours. Aliskiren, 150 mg and 300 mg have demonstrated a placebo-like safety and tolerability profile, with no interactions with a wide range of commonly used drugs. Three studies (AVOID, ALOFT and ALLAY are ongoing properties. with aliskiren to assess end-organ protective properties.

  9. Influence of elemental diffusion on low temperature formation of MgH2 in TiMn1.3T0.2-Mg (T = 3d-transition elements)

    International Nuclear Information System (INIS)

    Yamamoto, K.; Tanioka, S.; Tsushio, Y.; Shimizu, T.; Morishita, T.; Orimo, S.; Fujii, H.

    1996-01-01

    In order to examine the influence of the elemental diffusion from the host compound into the Mg region on low temperature formation of MgH 2 , we have investigated the hydriding properties and the microstructures of the composite materials TiMn 1.3 T 0.2 -Mg (T = V, Cr, Mn, Fe, Co, Ni and Cu). MgH 2 is formed at 353 K in all composite materials. Of all the substitutions, the amount of MgH 2 is the largest in the case of the Cu substitution, which originates from the existence of the Mg-Mg 2 Cu eutectic formed by Cu diffusion from the host compound TiMn 1.3 Cu 0.2 into the Mg region during the liquid phase sintering. In addition, the hydrogen capacity of TiMn 1.3 Cu 0.2 -Mg (that is TiMn 1.3 Cu 0.1 -(Mg+Mg 2 Cu) after the sintering) easily saturates in comparison with TiMn 1.5 -(Mg+Mg 2 Cu) without Cu diffusion. It is concluded that Cu diffusion promotes the mobility of hydrogen atoms at the complex interface between the host compound and the Mg region. (orig.)

  10. Incorporation of Mg, Sr, Ba, U, and B in High-Mg Calcite Benthic Foraminifers Cultured Under Controlled pCO2

    Science.gov (United States)

    Not, C.; Thibodeau, B.; Yokoyama, Y.

    2018-01-01

    Measurement of elemental ratios (E/Ca) has been performed in two symbiont-bearing species of high-Mg calcite benthic foraminifers (hyaline, Baculogypsina sphaerulata and porcelaneous, Amphisorus hemprichii), cultured under five pCO2 levels, representing preindustrial, modern, and three predicted future values. E/Ca ratios were analyzed by Laser Ablation coupled with Inductively Coupled Plasma Mass Spectrometer (LA-ICP-MS). We measured several E/Ca, such as Mg/Ca, Sr/Ca, Ba/Ca, U/Ca, and B/Ca simultaneously. We observed that high-Mg calcite benthic foraminifers possess higher E/Ca than low-Mg calcite foraminifers, irrespective of their calcification mode (hyaline or porcelaneous). In both modes of calcification, Mg, Sr, Ba, U, and B incorporation could be controlled by Rayleigh fractionation. However, more data are needed to validate and quantify the relative importance of this process and closely investigate the presence/absence of other mechanism. Therefore, it highlights the need for a multielemental approach when looking at trace element incorporation. Finally, no significant relationship was observed between the different ratios and the pCO2 of the water, suggesting that none of the Mg/Ca, Sr/Ca, Ba/Ca, U/Ca, and B/Ca is sensitive to bottom water pCO2 or pH for these species.

  11. Is periodontal health a predictor of drug-induced gingival overgrowth? A cross-sectional study

    Directory of Open Access Journals (Sweden)

    Ruchi Banthia

    2014-01-01

    Full Text Available Background: Gingival overgrowth is a common side-effect of amlodipine regimen on the oral cavity. There is controversy regarding the cause and effect relationship of periodontal health and drug induced gingival overgrowth. Therefore, this study was conducted to investigate and to assess the relationship between the periodontal health and the onset and severity of gingival overgrowth in hypertensive patients receiving amlodipine. Materials and Methods: A total of 99 known hypertensive patients on amlodipine regimen were included in this study. Probing pocket depth (PPD and clinical attachment loss (CAL were noted on four sites of maxillary and mandibular anterior teeth. Gingival enlargement scores were assessed for each patient by employing the hyperplastic index. Oral hygiene status was evaluated using the calculus index (CI. Patients were divided into H, E and L groups based on their periodontal status and responders and non-responders based on their hyperplastic index scores. Differences in means of different periodontal variables in different groups were tested for significance by using ANOVA and unpaired Student t-test. Pearson′s correlation coefficient was calculated to assess the correlation between different variables. For all analyses, P < 0.05 was considered to be significant. Results: All the periodontal parameters were statistically highly significant (P = 0.00 amongst H, E and L groups and between responders and non-responders. Statistically highly significant Pearson correlation coefficients were found between mean PPD and mean hyperplastic score, mean CAL and mean hyperplastic score and mean calculus and mean hyperplastic score. Conclusion: The results of this study indicated a definite association between periodontal health and development and severity of amlodipine-induced gingival overgrowth

  12. Development of Sustained Release "NanoFDC (Fixed Dose Combination" for Hypertension - An Experimental Study.

    Directory of Open Access Journals (Sweden)

    Anjuman Arora

    Full Text Available The present study was planned to formulate, characterize and evaluate the pharmacokinetics of a novel "NanoFDC" comprising three commonly prescribed anti-hypertensive drugs, hydrochlorothiazide (a diuretic, candesartan (ARB and amlodipine (a calcium channel blocker.The candidate drugs were loaded in Poly (DL-lactide-co-gycolide (PLGA by emulsion- diffusion-evaporation method. The formulations were evaluated for their size, morphology, drug loading and in vitro release individually. Single dose pharmacokinetic profiles of the nanoformulations alone and in combination, as a NanoFDC, were evaluated in Wistar rats.The candidate drugs encapsulated inside PLGA showed entrapment efficiencies ranging from 30%, 33.5% and 32% for hydrochlorothiazide, candesartan and amlodipine respectively. The nanoparticles ranged in size from 110 to 180 nm. In vitro release profile of the nanoformulation showed 100% release by day 6 in the physiological pH 7.4 set up with PBS (phosphate buffer saline and by day 4-5 in the intestinal pH 1.2 and 8.0 set up SGF (simulated gastric fluid and SIF (simulated intestinal fluid respectively. In pharmacokinetic analysis a sustained-release for 6 days and significant increase in the mean residence time (MRT, as compared to the respective free drugs was noted [MRT of amlodipine, hydrochlorothiazide and candesartan changed from 8.9 to 80.59 hours, 11 to 69.20 hours and 9 to 101.49 hours respectively].We have shown for the first time that encapsulating amlodipine, hydrochlorothiazide and candesartan into a single nanoformulation, to get the "NanoFDC (Fixed Dose Combination" is a feasible strategy which aims to decrease pill burden.

  13. From $^{27}$Mg to ${33}$Mg transition to the "Island of inversion"

    CERN Document Server

    Yordanov, Deyan

    Since introduced in nuclear physics, the concept of shell structure and magic numbers has governed our understanding of nuclear matter in atomic nuclei close to stability. Nuclear species with a magic number of protons and/or neutrons are known to be more stable and close to spherical in shape. Experimental studies of 30Ne, 31Na and 32Mg, systems with a closed neutron sd shell (N=20), provide evidence for a ground-state deformation in these nuclei. The observed phenomenon is understood as an inversion of the normal spherical ground-state configuration, expected according to the traditional shell model, with deformed states governed by particle-hole excitations over the N=20 shell gap. The properties of nuclei in this Island of inversion are of particular importance for the theoretical modeling of the region. The present doctoral dissertation reports on the first determination of the nuclear ground-state spins and magnetic moments of 31,33Mg, obtained by means of laser spectroscopy in combination with nuclear...

  14. Revisiting Mg–Mg2Ni System from Electronic Perspective

    Directory of Open Access Journals (Sweden)

    Zhao Qian

    2017-11-01

    Full Text Available Both Mg and Mg2Ni are promising electrode materials in conversion-type secondary batteries. Earlier studies have shown their single-phase prospects in electro-devices, while in this work, we have quantitatively reported the electronic properties of their dual-phase materials, that is, Mg–Mg2Ni alloys, and analyzed the underlying reasons behind the property changes of materials. The hypoeutectic Mg–Mg2Ni alloys are found to be evidently more conductive than the hypereutectic Mg–Mg2Ni system. The density functional theory (DFT calculations give the intrinsic origin of electronic structures of both Mg2Ni and Mg. The morphology of quasi-nanoscale eutectics is another factor that can affect the electronic properties of the investigated alloy system; that is, the electrical property change of the investigated alloys system is due to a combination of the intrinsic property difference between the two constituting phases and the change of eutectic microstructures that affect electron scattering. In addition, regarding the Mg–Mg2Ni alloy design for device applications, the electronic property and mechanical aspect should be well balanced.

  15. Bulk and surface properties of magnesium peroxide MgO2

    Science.gov (United States)

    Esch, Tobit R.; Bredow, Thomas

    2016-12-01

    Magnesium peroxide has been identified in Mg/air batteries as an intermediate in the oxygen reduction reaction (ORR) [1]. It is assumed that MgO2 is involved in the solid-electrolyte interphase on the cathode surface. Therefore its structure and stability play a crucial role in the performance of Mg/air batteries. In this work we present a theoretical study of the bulk and low-index surface properties of MgO2. All methods give a good account of the experimental lattice parameters for MgO2 and MgO bulk. The reaction energies, enthalpies and free energies for MgO2 formation from MgO are compared among the different DFT methods and with the local MP2 method. A pronounced dependence from the applied functional is found. At variance with a previous theoretical study but in agreement with recent experiments we find that the MgO2 formation reaction is endothermic (HSE06-D3BJ: ΔH = 51.9 kJ/mol). The stability of low-index surfaces MgO2 (001) (Es = 0.96 J/m2) and (011) (Es = 1.98 J/m2) is calculated and compared to the surface energy of MgO (001). The formation energy of neutral oxygen vacancies in the topmost layer of the MgO2 (001) surface is calculated and compared with defect formation energies for MgO (001).

  16. Application in the STRATHE trial of a score system to compare the efficacy and the tolerability of different therapeutic strategies in the management of hypertension

    Directory of Open Access Journals (Sweden)

    Bernard Waeber

    2008-02-01

    Full Text Available Bernard Waeber1, Jean-Jacques Mourad21Division de Physiopathologie Clinique, Centre Hospitalier Universitaire Vaudois et Université de Lausanne, Lausanne, Switzerland; 2Hôpital Avicienne, Bobigny, FranceAbstract: A score system integrating the evolution of efficacy and tolerability over time was applied to a subpopulation of the STRATHE trial, a trial performed according to a parallel group design, with a double-blind, random allocation to either a fixed-dose combination strategy (perindopril/indapamide 2 mg/0.625 mg, with the possibility to increase the dose to 3 mg/0.935 mg, and 4 mg/1.250 mg if needed, n = 118, a sequential monotherapy approach (atenolol 50 mg, followed by losartan 50 mg and amlodipine 5 mg if needed, n = 108, or a stepped-care strategy (valsartan 40 mg, followed by valsartan 80 mg and valsartan 80 mg+ hydrochlorothiazide 12.5 mg if needed, n = 103. The aim was to lower blood pressure below 140/90 mmHg within a 9-month period. The treatment could be adjusted after 3 and 6 months. Only patients in whom the study protocol was strictly applied were included in this analysis. At completion of the trial the total score averaged 13.1 ± 70.5 (mean ± SD using the fixed-dose combination strategy, compared with –7.2 ± 81.0 using the sequential monotherapy approach and –17.5 ± 76.4 using the stepped-care strategy. In conclusion, the use of a score system allows the comparison of antihypertensive therapeutic strategies, taking into account at the same time efficacy and tolerability. In the STRATHE trial the best results were observed with the fixed-dose combination containing low doses of an angiotensin enzyme converting inhibitor (perindopril and a diuretic (indapamide.Keywords: antihypertensive therapy, tolerability, antihypertensive efficacy, fixed-dose combination, sequential monotherapy, stepped-care treatment

  17. MgO monolayer epitaxy on Ni (100)

    Science.gov (United States)

    Sarpi, B.; Putero, M.; Hemeryck, A.; Vizzini, S.

    2017-11-01

    The growth of two-dimensional oxide films with accurate control of their structural and electronic properties is considered challenging for engineering nanotechnological applications. We address here the particular case of MgO ultrathin films grown on Ni (100), a system for which neither crystallization nor extended surface ordering has been established previously in the monolayer range. Using Scanning Tunneling Microscopy and Auger Electron Spectroscopy, we report on experiments showing MgO monolayer (ML) epitaxy on a ferromagnetic nickel surface, down to the limit of atomic thickness. Alternate steps of Mg ML deposition, O2 gas exposure, and ultrahigh vacuum thermal treatment enable the production of a textured film of ordered MgO nano-domains. This study could open interesting prospects for controlled epitaxy of ultrathin oxide films with a high magneto-resistance ratio on ferromagnetic substrates, enabling improvement in high-efficiency spintronics and magnetic tunnel junction devices.

  18. Soluble salts addition modifies MgO hydration

    International Nuclear Information System (INIS)

    Santos, A.M.; Pandolfelli, V.C.; Salomao, R.

    2012-01-01

    Magnesium oxide (MgO) show great technological interest on refractories due to its high refractoriness, basic slag corrosion resistance and competitive cost. However, the hydration reaction of MgO produces magnesium hydroxide. This reaction generates a significant volumetric expansion that can lead to material breakdown inhibiting its use in refractory castables. This reaction can be affected by several factors such as magnesia source, purity, calcination temperature, pH, CaO/SiO 2 ratio and agitation speed. In the present work, soluble salts (CaCl 2 and MgCl 2 ) were used in MgO aqueous suspensions (caustic and sinter). The results were evaluated by means of techniques of degree of hydration (termogravimetric), Scanning electron microscopy, apparent volumetric expansion and x-ray Diffraction which showed that the degree of hydration was noticeably less to sinter aqueous and the expansive effects were less with the addition of CaCl 2 . (author)

  19. Pharmacokinetic characterization of three novel 4-mg nicotine lozenges
.

    Science.gov (United States)

    Sukhija, Manpreet; Srivastava, Reena; Kaushik, Aditya

    2018-03-01

    Nicotine replacement therapy (NRT) increases the probability of smoking cessation. This study was conducted to determine if three prototype 4-mg nicotine lozenges produced locally in India were bioequivalent to a globally marketed reference product, Nicorette® 4-mg nicotine lozenge. Healthy adult smokers (N = 39) were treated with three prototype 4-mg nicotine lozenges in comparison with a reference 4-mg lozenge in this single-center, randomized, open-label, single-dose, 4-way crossover study. Pharmacokinetic sampling was obtained to test for bioequivalence using maximal plasma concentration (Cmax) and extent of absorption (AUC0-t). Secondarily, AUC;0-∞, time to maximal plasma concentration (tmax), half-life (T1/2), elimination rate constant (Kel), and safety of the prototype lozenges versus the reference lozenge were compared. Each prototype 4-mg nicotine lozenge was found to be bioequivalent to the reference 4-mg nicotine lozenge based on the ratio of geometric means and 90% confidence intervals for Cmax, AUC0-t, and AUC;0-∞. Although tmax; was significantly longer for prototype III, all four lozenges achieved maximum plasma nicotine concentrations at a median of 1.5 hours. The safety profiles of the three prototype 4-mg lozenges did not differ from that of the 4-mg reference product. Each prototype 4-mg nicotine lozenge was bioequivalent to the reference 4-mg nicotine lozenge and was well tolerated. Furthermore, as these bioequivalent prototypes differed in in-vitro dissolution profiles, these data suggest that performance from the in -vitro method deployed is not a firm predictor of pharmacokinetic behavior.
.

  20. Influence of a transition metal atom on the geometry and electronic structure of Mg and Mg-H clusters

    International Nuclear Information System (INIS)

    Siretskiy, M.Yu.; Shelyapina, M.G.; Fruchart, D.; Miraglia, S.; Skryabina, N.E.

    2009-01-01

    We report on the study of (MgH 2 ) n + M complexes (M = Ti or Ni) carried out within the framework of the cluster density functional theory (DFT) method. The influence of such transition metal atoms on the cluster geometry and electronic structure is discussed considering the stability of MgH 2 hydride.

  1. Predictive calculation of phase formation in Al-rich Al-Zn-Mg-Cu-Sc-Zr alloys using a thermodynamic Mg-alloy database

    International Nuclear Information System (INIS)

    Groebner, J.; Rokhlin, L.L.; Dobatkina, T.V.; Schmid-Fetzer, R.

    2007-01-01

    Three series of Al-rich alloys in the system Al-Zn-Mg-Cu-Sc-Zr and the subsystems Al-Zn-Mg-Cu-Sc and Al-Zn-Mg-Sc were studied by thermodynamic calculations. Phase formation was compared with experimental data obtained by DTA and microstructural analysis. Calculated phase diagrams, phase amount charts and enthalpy charts together with non-equilibrium calculations under Scheil conditions reveal significant details of the complex phase formation. This enables consistent and correct interpretation of thermal analysis data. Especially the interpretation of liquidus temperature and primary phase is prone to be wrong without using this tool of computational thermodynamics. All data are predictions from a thermodynamic database developed for Mg-alloys and not a specialized Al-alloy database. That provides support for a reasonable application of this database for advanced Mg-alloys beyond the conventional composition ranges

  2. Predictive calculation of phase formation in Al-rich Al-Zn-Mg-Cu-Sc-Zr alloys using a thermodynamic Mg-alloy database

    Energy Technology Data Exchange (ETDEWEB)

    Groebner, J. [Institute of Metallurgy, Clausthal University of Technology, Robert-Koch Strasse 42, D-38678 Clausthal-Zellerfeld (Germany); Rokhlin, L.L. [Baikov Institute of Metallurgy and Materials Science, Leninsky prosp. 49, 119991 GSP-1, Moscow (Russian Federation); Dobatkina, T.V. [Baikov Institute of Metallurgy and Materials Science, Leninsky prosp. 49, 119991 GSP-1, Moscow (Russian Federation); Schmid-Fetzer, R. [Institute of Metallurgy, Clausthal University of Technology, Robert-Koch Strasse 42, D-38678 Clausthal-Zellerfeld (Germany)]. E-mail: schmid-fetzer@tu-clausthal.de

    2007-05-16

    Three series of Al-rich alloys in the system Al-Zn-Mg-Cu-Sc-Zr and the subsystems Al-Zn-Mg-Cu-Sc and Al-Zn-Mg-Sc were studied by thermodynamic calculations. Phase formation was compared with experimental data obtained by DTA and microstructural analysis. Calculated phase diagrams, phase amount charts and enthalpy charts together with non-equilibrium calculations under Scheil conditions reveal significant details of the complex phase formation. This enables consistent and correct interpretation of thermal analysis data. Especially the interpretation of liquidus temperature and primary phase is prone to be wrong without using this tool of computational thermodynamics. All data are predictions from a thermodynamic database developed for Mg-alloys and not a specialized Al-alloy database. That provides support for a reasonable application of this database for advanced Mg-alloys beyond the conventional composition ranges.

  3. Hydrogen sorption properties of ball-milled Mg-C nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Spassov, Tony; Zlatanova, Zlatina; Spassova, Maya; Todorova, Stanislava [Faculty of Chemistry, University of Sofia ' ' St.Kl.Ohridski' ' , 1 James Bourchier str. 1164 Sofia (Bulgaria)

    2010-10-15

    MgH{sub 2} 75 at.%-C 25 at.% composites are synthesized by ball milling using different kinds of carbon additives: carbon black (CB), nanodiamonds (ND) and amorphous carbon soot (AC). X-ray diffraction analysis showed that the MgH{sub 2} phase in the as-obtained composite powders is nanocrystalline (80-100 nm). The SEM observations revealed that the samples consist of 5-15 {mu}m MgH{sub 2} particles, surrounded and in some cases coated by carbon flakes. The composite containing nanodiamonds revealed strong decrease of the MgH{sub 2} decomposition temperature with more than 100 C, compared to ball-milled pure MgH{sub 2}. Important issue of the present study is also the low temperature hydriding of the ball-milled Mg-C nanocomposites, investigated by high-pressure DSC. The process starts at about 200 C for all materials studied, but the hydriding mechanism looks different for the composites with different kinds of carbon additives. Whereas for Mg-carbon black it takes place in a relatively narrow temperature range, expressed by a single exothermic peak (200-300 C) for the other two composites the hydriding is a multi-step process, featured by two overlapped exothermic peaks for Mg-nanodiamonds and by two well separated exothermic effects (at about 300 C and 400 C) for Mg-amorphous carbon soot. The observed difference in the hydriding behavior of the Mg-C composites is attributed to the different kind of carbon component, which is supposed to play a catalytic role as well as protects magnesium from oxidation. The incorporation of carbon into the MgH{sub 2} particles results in the formation of high density of defects (dislocations and grain boundaries), which is supposed to be among the most possible reasons for the decreased hydride decomposition temperature. The Mg-C nanocomposites show reproducible hydriding/dehydriding behavior (thermodynamics and kinetics) during multiple cycling. Among the composites in the present study ''Mg-carbon black

  4. The Abundance of Mg in the Interstellar Medium

    Science.gov (United States)

    Fitzpatrick, Edward L.

    1997-06-01

    An empirical determination of the f-values of the far-UV Mg II λλ1239, 1240 lines is reported. The strong near-UV Mg II λλ2796, 2803 lines are generally highly saturated along most interstellar sight lines outside the local interstellar medium (ISM) and usually yield extremely uncertain estimates of Mg+ column densities in interstellar gas. Since Mg+ is the dominant form of Mg in the neutral ISM, and since Mg is expected to be a significant constituent of interstellar dust grains, the far-UV lines are critical for assessing the role of this important element in the ISM. This study consists of complete component analyses of the absorption along the lines of sight toward HD 93521 in the Galactic halo and ξ Persei and ζ Ophiuchi in the Galactic disk, including all four UV Mg+ lines and numerous other transitions. The three analyses yield consistent determinations of the λλ1239, 1240 f-values, with weighted means of (6.4 +/- 0.4) × 10-4 and (3.2 +/- 0.2) × 10-4, respectively. These results are a factor of ~2.4 larger than a commonly used theoretical estimate, and a factor of ~2 smaller than a recently suggested empirical revision. The effects of this result on gas- and dust-phase abundance measurements of Mg are discussed. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, under NASA contract NAS5-2655. This Letter is dedicated to the memory of Professor Lyman Spitzer Jr. He was a great guy.

  5. Thermoelectric properties and microstructure of Mg3Sb2

    International Nuclear Information System (INIS)

    Condron, Cathie L.; Kauzlarich, Susan M.; Gascoin, Franck; Snyder, G. Jeffrey

    2006-01-01

    Mg 3 Sb 2 has been prepared by direct reaction of the elements. Powder X-ray diffraction, thermal gravimetric, differential scanning calorimetery, and microprobe data were obtained on hot pressed samples. Single phase samples of Mg 3 Sb 2 were prepared and found to contain oxygen at the grain boundaries and to lose Mg and oxidize at temperatures above 900 K. Thermoelectric properties were characterized by Seebeck, electrical resistivity, and thermal conductivity measurements from 300 to 1023 K, and the maximum zT was found to be 0.21 at ∼875 K. - Graphical abstract: Dimensionless figure of merit for Mg 3 Sb 2 hot pressed and sintered at 873 K. The inset illustrates the crystal structure of Mg 3 Sb 2 along the [100] direction (white=Mg, black=Sb)

  6. Mechanical Properties and Fabrication of Nanostructured Mg_2SiO_4-MgAl_2O_4 Composites by High-Frequency Induction Heated Combustion

    International Nuclear Information System (INIS)

    Shon, In-Jin; Kang, Hyun-Su; Hong, Kyung-Tae; Doh, Jung-Mann; Yoon, Jin-Kook

    2011-01-01

    Nanopowders of MgO, Al_2O_3 and SiO_2 were made by high energy ball milling. The rapid sintering of nanostructured MgAl_2O_4-Mg_2SiO_4 composites was investigated by a high-frequency induction heating sintering process. The advantage of this process is that it allows very quick densification to near theoretical density and inhibition of grain growth. Nanocrystalline materials have received much attention as advanced engineering materials with improved physical and mechanical properties. As nanomaterials possess high strength, high hardness, excellent ductility and toughness, undoubtedly, more attention has been paid for the application of nanomaterials. Highly dense nanostructured MgAl_2O_4-Mg_2SiO_4 composites were produced with simultaneous application of 80 MPa pressure and induced output current of total power capacity (15 kW) within 2 min. The sintering behavior, gain size and mechanical properties of MgAl_2O_4-Mg_2SiO_4 composites were investigated.

  7. Photoluminescence of Mg_2Si films fabricated by magnetron sputtering

    International Nuclear Information System (INIS)

    Liao, Yang-Fang; Xie, Quan; Xiao, Qing-Quan; Chen, Qian; Fan, Meng-Hui; Xie, Jing; Huang, Jin; Zhang, Jin-Min; Ma, Rui; Wang, Shan-Lan; Wu, Hong-Xian; Fang, Di

    2017-01-01

    Highlights: • High quality Mg_2Si films were grown on Si (111) and glass substrates with magnetron sputtering, respectively. • The first observation of Photoluminescence (PL) of Mg_2Si films was reported. • The Mg_2Si PL emission wavelengths are almost independence on temperature in the range of 77–300 K. • The strongest PL emissions may be attributed to interstitial Mg donor level to valence band transitions. • The activation energy of Mg_2Si is determined from the quenching of major luminescence peaks. - Abstract: To understand the photoluminescence mechanisms and optimize the design of Mg_2Si-based light-emitting devices, Mg_2Si films were fabricated on silicon (111) and glass substrates by magnetron sputtering technique, and the influences of different substrates on the photoelectric properties of Mg_2Si films were investigated systematically. The crystal structure, cross-sectional morphology, composition ratios and temperature-dependent photoluminescence (PL) of the Mg_2Si films were examined using X-ray diffraction (XRD), Scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS) and PL measurement system, respectively. XRD results indicate that the Mg_2Si film on Si (111) displays polycrystalline structure, whereas Mg_2Si film on glass substrate is of like-monocrystalline structure.SEM results show that Mg_2Si film on glass substrate is very compact with a typical dense columnar structure, and the film on Si substrate represents slight delamination phenomenon. EDS results suggest that the stoichiometry of Mg and Si is approximately 2:1. Photoluminescence (PL) of Mg_2Si films was observed for the first time. The PL emission wavelengths of Mg_2Si are almost independence on temperature in the range of 77–300 K. The PL intensity decreases gradually with increasing temperature. The PL intensity of Mg_2Si films on glass substrate is much larger than that of Mg_2Si film on Si (111) substrate. The activation energy of 18 meV is

  8. Comparison of the Effect of 800 mg Ibuprofen and 30 mg Predenisolone on Relief of Post Endodontic Pain

    Directory of Open Access Journals (Sweden)

    S.M. Jalalzadeh

    2009-04-01

    Full Text Available Introduction & Objective: One of the important problems in dentistry is post endodontic pains .The purpose of this study was comparison of the effect of prophylactic oral ibuprofen 800mg and oral predenisolone 30mg on prevention of post endodontic pain.Materials & Methods: The present study is a double-blind, randomized and controlled trial. It was conducted on 60 patient (16men and 44 women between the ages of 18-63 who needed endodontic treatment. Inclusive criteria for selecting of patients were: need for root canal therapy in one of the posterior teeth, having no systemic problem, no evidence of abscess; not taking analgesic or similar drug for at least 6 hours before treatment. Patients were divided into three experimental groups randomly taking one of the drugs before the treatment {ibuprofen 800 mg, prednisolone30mg and placebo (oral dextrose}. Patients completed VAS at 6,12 and 24 hours post root canal therapy and analyzed using the spss15 by chi-square, ANOVA test and Tukey test.Results: During 24 hours after treatment post endodontic pain is 95%- 100% in the placebo group. The prevalence of no-pain was not significant 6, 12 and 24 hours after treatment between the ibuprofen and predenisolone groups. The mean scale of pain in ibuprofen and predenisolone groups was significantly lower than placebo group 6, 12 and 24 hours after treatment. Differences between the drug groups are significant only on 6 and 12 hours after treatment.Conclusion: Post endodontic pains are present 24 hours after treatment. 6 and 12 hours after treatment 30 mg predenisolone are significantly better for pain relief than 800 mg ibuprofen. But after 24 hours it is not significant.

  9. A submillimetre-wave SIS mixer using NbN/MgO/NbN trilayers grown epitaxially on an MgO substrate

    CERN Document Server

    Uzawa, Y; Saito, A; Takeda, M; Wang, Z

    2002-01-01

    We have designed, fabricated and tested a quasi-optical superconductor-insulator-superconductor (SIS) mixer employing distributed NbN/MgO/NbN tunnel junctions and NbN/MgO/NbN microstriplines at submillimetre-wave frequencies. These trilayers were fabricated by dc- and rf-magnetron sputtering on an MgO substrate at ambient temperature so that the NbN and MgO films were grown epitaxially. Our SIS mixer consists of an MgO hyperhemispherical lens with an antireflection cap and a self-complementary log-periodic antenna made of a single-crystal NbN film, on which the distributed SIS junctions and the two-section impedance transformers were mirror-symmetrically placed at the feed point of the antenna. As designed, the junctions are 0.6 mu m wide and 15.5 mu m long, which is sufficient to absorb the incoming signal along this lossy transmission line, assuming a current density of 10 kA cm sup - sup 2. The mixer showed good I-V characteristics, with subgap-to-normal resistance ratios of about 13, although weak-link br...

  10. Nanostructure characterization of Ni and B layers as artificial pinning centers in multilayered MgB2/Ni and MgB2/B superconducting thin films

    International Nuclear Information System (INIS)

    Sosiati, H.; Hata, S.; Doi, T.; Matsumoto, A.; Kitaguchi, H.; Nakashima, H.

    2013-01-01

    Highlights: ► Nanostructure characterization of Ni and B layers as artificial pinning centers (APCs). ► Relationship between nanostructure and J c property. ► Enhanced J c in parallel field by parallel APCs within the MgB 2 film. -- Abstract: Research on the MgB 2 /Ni and MgB 2 /B multilayer films fabricated by an electron beam (EB) evaporation technique have been extensively carried out. The critical current density, J c of MgB 2 /Ni and MgB 2 /B multilayer films in parallel fields has been suggested to be higher than that of monolayer MgB 2 film due to introducing the artificial pinning centers of nano-sized Ni and B layers. Nanostructure characterization of the artificial pinning centers in the multilayer films were examined by transmission electron microscopy (TEM) and scanning TEM (STEM-energy dispersive X-ray spectroscopy (STEM-EDS))–EDS to understand the mechanism of flux pinning. The growth of columnar MgB 2 grains along the film-thickness direction was recognized in the MgB 2 /Ni multilayer film, but not in the MgB 2 /B multilayer film. Nano-sized Ni layers were present as crystalline epitaxial layers which is interpreted that Ni atoms might be incorporated into the MgB 2 lattice to form (Mg,Ni)B 2 phase. On the other hand, nano-sized B layers were amorphous layers. Crystalline (Mg,Ni)B 2 layers worked more effectively than amorphous B-layers, providing higher flux-pinning force that resulted in higher J c of the MgB 2 /Ni multilayer film than the MgB 2 /B multilayer film

  11. EXAFS investigations of Cu-Mg-O compound

    CERN Document Server

    Sidorenko, A F; Babanov, Y A; Naumov, S V; Samokhvalov, A A

    2001-01-01

    The interest to systems containing copper oxide is connected with the problem of high-temperature superconductivity because of the closeness of its basic physical properties and properties of superconductor mother Cu-compounds. In this work, EXAFS study of the Cu sub 0 sub . sub 2 Mg sub 0 sub . sub 8 O compound is presented. A new iterative algorithm of the solution of ill-posed problem on determining three partial pair correlation functions from one EXAFS-data set near the Cu K-edge is described. The results of X-ray scattering study of a given sample show a presence of a single phase with the MgO structure and a lattice parameter of 4.219 A instead of 4.208 A for pure MgO. From the EXAFS investigations, we find the local distortion of the lattice. We revealed that the short range order differs both from a hypothetical alloy with the MgO structure and from copper oxide.

  12. Mg doping of GaN by molecular beam epitaxy

    International Nuclear Information System (INIS)

    Lieten, R R; Buchowicz, G; Dubon, O; Motsnyi, V; Zhang, L; Cheng, K; Leys, M; Degroote, S; Borghs, G

    2011-01-01

    We present a systematic study on the influence of growth conditions on the incorporation and activation of Mg in GaN layers grown by plasma-assisted molecular beam epitaxy. We show that high quality p-type GaN layers can be obtained on GaN-on-silicon templates. The Mg incorporation and the electrical properties have been investigated as a function of growth temperature, Ga : N flux ratio and Mg : Ga flux ratio. It was found that the incorporation of Mg and the electrical properties are highly sensitive to the Ga : N flux ratio. The highest hole mobility and lowest resistivity were achieved for slightly Ga-rich conditions. In addition to an optimal Ga : N ratio, an optimum Mg : Ga flux ratio was also observed at around 1%. We observed a clear Mg flux window for p-type doping of GaN : 0.31% 17 cm -3 and a mobility of 15 cm 2 V -1 s -1 . Temperature-dependent Hall effect measurements indicate an acceptor depth in these samples of 100 meV for a hole concentration of 5.5 x 10 17 cm -3 . The corresponding Mg concentration is 5 x 10 19 cm -3 , indicating approximately 1% activation at room temperature. In addition to continuous growth of Mg-doped GaN layers we also investigated different modulated growth procedures. We show that a modulated growth procedure has only limited influence on Mg doping at a growth temperature of 800 deg. or higher. This result is thus in contrast to previously reported GaN : Mg doping at much lower growth temperatures of 500 deg. C.

  13. Isopiestic Investigation of the Osmotic and Activity Coefficients of {yMgCl2 + (1 - y)MgSO4}(aq) and the Osmotic Coefficients of Na2SO4.MgSO4(aq) at 298.15 K

    Energy Technology Data Exchange (ETDEWEB)

    Miladinovic, J; Ninkovic, R; Todorovic, M; Rard, J A

    2007-06-06

    Isopiestic vapor pressure measurements were made for {l_brace}yMgCl{sub 2} + (1-y)MgSO{sub 4}{r_brace}(aq) solutions with MgCl{sub 2} ionic strength fractions of y = 0, 0.1997, 0.3989, 0.5992, 0.8008, and (1) at the temperature 298.15 K, using KCl(aq) as the reference standard. These measurements for the mixtures cover the ionic strength range I = 0.9794 to 9.4318 mol {center_dot} kg{sup -1}. In addition, isopiestic measurements were made with NaCl(aq) as reference standard for mixtures of {l_brace}xNa{sub 2}SO{sub 4} + (1-x)MgSO{sub 4}{r_brace}(aq) with the molality fraction x = 0.50000 that correspond to solutions of the evaporite mineral bloedite (astrakanite), Na{sub 2}Mg(SO{sub 4}){sub 2} {center_dot} 4H{sub 2}O(cr). The total molalities, m{sub T} = m(Na{sub 2}SO{sub 4}) + m(MgSO{sub 4}), range from m{sub T} = 1.4479 to 4.4312 mol {center_dot} kg{sup -1} (I = 5.0677 to 15.509 mol {center_dot} kg{sup -1}), where the uppermost concentration is the highest oversaturation molality that could be achieved by isothermal evaporation of the solvent at 298.15 K. The parameters of an extended ion-interaction (Pitzer) model for MgCl2(aq) at 298.15 K, which were required for an analysis of the {l_brace}yMgCl{sub 2} + (1-y)MgSO{sub 4}{r_brace}(aq) mixture results, were evaluated up to I = 12.025 mol {center_dot} kg{sup -1} from published isopiestic data together with the six new osmotic coefficients obtained in this study. Osmotic coefficients of {l_brace}yMgCl{sub 2} + (1-y)MgSO{sub 4}{r_brace}(aq) solutions from the present study, along with critically-assessed values from previous studies, were used to evaluate the mixing parameters of the extended ion-interaction model.

  14. The natural aging and precipitation hardening behaviour of Al-Mg-Si-Cu alloys with different Mg/Si ratios and Cu additions

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Lipeng [College of Materials Science and Engineering, Chongqing University, Chongqing 400044 China (China); Jia, Zhihong, E-mail: zhihongjia@cqu.edu.cn [College of Materials Science and Engineering, Chongqing University, Chongqing 400044 China (China); Zhang, Zhiqing; Sanders, Robert E.; Liu, Qing [College of Materials Science and Engineering, Chongqing University, Chongqing 400044 China (China); Yang, Guang [Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education and International Centre for Dielectric Research, Xi’an Jiaotong University, Xi’an 710049 (China)

    2015-03-11

    The natural aging and artificial aging behaviours of Al-Mg-Si-Cu alloys with different Mg/Si ratios and Cu additions were investigated using Vickers microhardness measurements, differential scanning calorimetry (DSC) analysis and transmission electron microscopy (TEM) characterisation. Excess Si and Cu additions enhanced the alloy hardening ability during natural (NA) and artificial aging (AA). Alloys with low Cu and high Si contents exhibited higher precipitation hardening than alloys rich in Mg during artificial aging. In contrast, the alloys with high amounts of Cu were less dependent on the Mg/Si ratio during precipitation hardening due to their similar aging kinetics. The main precipitate phases that contributed to the peak-aging hardness were the L, Q′ and β″ phases. In the over-aging conditions, the alloys rich in Mg and Cu had finer and more numerous precipitates than their Si-rich equivalents due to the preferential precipitation of the L phase. The combination of excess Mg and high Cu resulted in an alloy with a relatively low hardness in T4 temper and a relatively higher hardness after the paint baking cycle. Thus, this alloy has good potential for use in auto body panel applications.

  15. Influence of secondary ageing temperature on hardening and residual elastic stresses in AlMgSi and AlMgSiCu alloys

    International Nuclear Information System (INIS)

    Milosavlevich, A.Ya.; Shiyachki-Zheravchich; Rogulin, M.Ya.; Milenkovich, V.M.; Prokich-Tsvetkovich, R.M.

    1993-01-01

    The investigations were conducted on samples of AlMgSi and AlMgSiCu alloys quenched, aged and cold worked with 20, 40, 60 and 85 % reduction in area. Secondary ageing was carried out at 200 and 250 deg C. Residual stresses wee determined by X-ray diffraction method. It was shown that cold deformation effect on hardness and residual stresses is dependent on alloy composition. The hardening due to secondary ageing is more pronounced for AlMgSi alloy at 200 deg C and for AlMgSiCu alloy at 250 deg C. Positive residual stresses increase with secondary ageing temperature

  16. Progress in the deposition of MgB2 thin films

    International Nuclear Information System (INIS)

    Xi, X X; Pogrebnyakov, A V; Zeng, X H; Redwing, J M; Xu, S Y; Li, Qi; Liu, Zi-Kui; Lettieri, J; Vaithyanathan, V; Schlom, D G; Christen, H M; Zhai, H Y; Goyal, A

    2004-01-01

    An MgB 2 thin film deposition technology is the first critical step in the development of superconducting electronics utilizing the 39 K superconductor. It turned out to be a challenging task due to the volatility of Mg and phase stability of MgB 2 , the low sticking coefficients of Mg at elevated temperatures, and the reactivity of Mg with oxygen. A brief overview of current deposition techniques is provided here from a thermodynamic perspective, with an emphasis on a very successful technique for high quality in situ epitaxial MgB 2 films, the hybrid physical-chemical vapour deposition. Examples of heterostructures of MgB 2 with other materials are also presented

  17. Multifunctional MgO Layer in Perovskite Solar Cells.

    Science.gov (United States)

    Guo, Xudong; Dong, Haopeng; Li, Wenzhe; Li, Nan; Wang, Liduo

    2015-06-08

    A multifunctional magnesium oxide (MgO) layer was successfully introduced into perovskite solar cells (PSCs) to enhance their performance. MgO was coated onto the surface of mesoporous TiO(2) by the decomposition of magnesium acetate and, therefore, could block contact between the perovskite and TiO(2). X-ray photoelectron spectroscopy and infrared spectroscopy showed that the amount of H(2)O/hydroxyl absorbed on the TiO(2) decreased after MgO modification. The UV/Vis absorption spectra of the perovskite with MgO modification revealed an enhanced photoelectric performance compared with that of unmodified perovskite after UV illumination. In addition to the photocurrent, the photovoltage and fill factor also showed an enhancement after modification, which resulted in an increase in the overall efficiency of the cell from 9.6 to 13.9 %. Electrochemical impedance spectroscopy (EIS) confirmed that MgO acts as an insulating layer to reduce charge recombination. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. A high resolution atlas of Mg II profiles

    Science.gov (United States)

    Ewald, R.; Nichols-Bohlin, Joy Y.; Kondo, Yoji

    1990-01-01

    An atlas of high dispersion Mg II profiles for standard stars of spectral types B0 through G9 is presented. The atlas contains plots of the Mg II profiles for approximately 65 stars and associated equivalent width measurements for both absorption and emission components, and the subordinate lines. The atlas is used to investigate systematic behavior of the Mg II profiles and correlation of the behavior with spectral classification.

  19. Pseudopotential approach to superconductivity in MgB2

    International Nuclear Information System (INIS)

    Sharma, K.S.; Bhargava, Nidhi; Jain, Ritu; Goyal, Varsha; Sharma, Ritu; Sharma, Smita

    2010-01-01

    Superconductivity in MgB 2 has been re-examined in BCS-Eliashberg framework by employing Mc-Millan's T c -equation and form factors of MgB 2 computed from the form factors of component metals (Model-I). The empty core model pseudopotential due to Ashcroft and random phase approximation form of dielectric screening due to Gellmann and Brueckner are used in the present work. An excellent agreement between the present values and other theoretically computed values of T c and with the relevant experimental data for MgB 2 confirms the validity of the present approach. The explicit dependence of λ and T c on the isotopic masses of Mg and B, as revealed from the present work, confirms the role of lattice vibrations in the superconducting behaviour of MgB 2 and the high value of T c in it may be attributed to the phonon mediated e-e interaction coupled with higher values of phonon frequencies due to light mass of B atoms. It has also been observed that the pseudo-atom model (Model-II) with appropriate choice of the potential parameter r c successfully explains high value of T c and isotope effect in MgB 2 , confirming the prominent role played by electron-phonon interaction in the high-T c superconductivity observed in MgB 2 . The isotope effect exponent α-values obtained from the two models are in complete agreement with each other and the present value α = 0.46 is also much closer to the BCS value of 0.5. Interaction strength N 0 V values obtained from the two models are also in perfect agreement with each other and the present value N 0 V = 0.48 suggests that MgB 2 is a strong coupling superconductor. (author)

  20. Microstructure and fatigue properties of Mg-to-steel dissimilar resistance spot welds

    International Nuclear Information System (INIS)

    Liu, L.; Xiao, L.; Chen, D.L.; Feng, J.C.; Kim, S.; Zhou, Y.

    2013-01-01

    Highlights: ► Mg/steel dissimilar spot weld had the same fatigue strength as Mg/Mg similar weld. ► Crack propagation path of Mg/Mg and Mg/steel welds was the same. ► Penetration of Zn into the Mg base metal led to crack initiation of Mg/steel weld. ► HAZ weakening and stress concentration led to crack initiation of Mg/Mg weld. -- Abstract: The structural application of lightweight magnesium alloys in the automotive industry inevitably involves dissimilar welding with steels and the related durability issues. This study was aimed at evaluating the microstructural change and fatigue resistance of Mg/steel resistance spot welds, in comparison with Mg/Mg welds. The microstructure of Mg/Mg spot welds can be divided into: base metal, heat affected zone and fusion zone (nugget). However, the microstructure of Mg/steel dissimilar spot welds had three different regions along the joined interface: weld brazing, solid-state joining and soldering. The horizontal and vertical Mg hardness profiles of Mg/steel and Mg/Mg welds were similar. Both Mg/steel and Mg/Mg welds were observed to have an equivalent fatigue resistance due to similar crack propagation characteristics and failure mode. Both Mg/steel and Mg/Mg welds failed through thickness in the magnesium sheet under stress-controlled cyclic loading, but fatigue crack initiation of the two types of welds was different. The crack initiation of Mg/Mg welds was occurred due to a combined effect of stress concentration, grain growth in the heat affected zone (HAZ), and the presence of Al-rich phases at HAZ grain boundaries, while the penetration of small amounts of Zn coating into the Mg base metal stemming from the liquid metal induced embrittlement led to crack initiation in the Mg/steel welds.

  1. Influence of the core-hole effect on optical properties of magnesium oxide (MgO) near the Mg L-edge region.

    Science.gov (United States)

    Sinha, Mangalika; Modi, Mohammed H; Ghosh, Haranath; Yadav, P K; Gupta, R K

    2018-05-01

    The influence of the core-hole effect on optical properties of magnesium oxide (MgO) is established through experimental determination of optical constants and first-principles density functional theory studies. Optical constants (δ and β) of MgO thin film are measured in the spectral region 40-300 eV using reflectance spectroscopy techniques at the Indus-1 synchrotron radiation source. The obtained optical constants show strong core exciton features near the Mg L-edge region, causing significant mismatch with Henke's tabulated values. On comparing the experimentally obtained optical constants with Henke's tabulated values, an edge shift of ∼3.0 eV is also observed. Distinct evidence of effects of core exciton on optical constants (δ and β) in the near Mg L-edge absorption spectra are confirmed through first-principles simulations.

  2. Impact of interface manipulation of oxide on electrical transport properties and low-frequency noise in MgO/NiFe/MgO heterojunctions

    International Nuclear Information System (INIS)

    Li, Jian-wei; Zhao, Chong-jun; Feng, Chun; Yu, Guang-hua; Zhou, Zhongfu

    2015-01-01

    Low-frequency noise and magnetoresistance in sputtered-deposited Ta(5 nm)/MgO (3 nm)/NiFe(10 nm)/MgO(3 nm)/Ta(3 nm) films have been measured as a function of different annealing times at 400°C. These measurements did not change synchronously with annealing time. A significant increase in magnetoresistance is observed for short annealing times (of the order of minutes) and is correlated with a relatively small reduction in 1/f noise. In contrast, a significant reduction in 1/f noise is observed for long annealing times (of the order of hours) accompanied by a small change in magnetoresistance. After annealing for 2 hours, the 1/f noise decreases by three orders of magnitude. Transmission electron microscopy and slow positron annihilation results implicate the cause being micro-structural changes in the MgO layers and interfaces following different annealing times. The internal vacancies in the MgO layers gather into vacancy clusters to reduce the defect density after short annealing times, whereas the MgO/NiFe and the NiFe/MgO interfaces improve significantly after long annealing times with the amorphous MgO layers gradually crystallizing following the release of interfacial stress

  3. Impact of interface manipulation of oxide on electrical transport properties and low-frequency noise in MgO/NiFe/MgO heterojunctions

    Science.gov (United States)

    Li, Jian-wei; Zhao, Chong-jun; Feng, Chun; Zhou, Zhongfu; Yu, Guang-hua

    2015-08-01

    Low-frequency noise and magnetoresistance in sputtered-deposited Ta(5 nm)/MgO (3 nm)/NiFe(10 nm)/MgO(3 nm)/Ta(3 nm) films have been measured as a function of different annealing times at 400°C. These measurements did not change synchronously with annealing time. A significant increase in magnetoresistance is observed for short annealing times (of the order of minutes) and is correlated with a relatively small reduction in 1/f noise. In contrast, a significant reduction in 1/f noise is observed for long annealing times (of the order of hours) accompanied by a small change in magnetoresistance. After annealing for 2 hours, the 1/f noise decreases by three orders of magnitude. Transmission electron microscopy and slow positron annihilation results implicate the cause being micro-structural changes in the MgO layers and interfaces following different annealing times. The internal vacancies in the MgO layers gather into vacancy clusters to reduce the defect density after short annealing times, whereas the MgO/NiFe and the NiFe/MgO interfaces improve significantly after long annealing times with the amorphous MgO layers gradually crystallizing following the release of interfacial stress.

  4. Impact of interface manipulation of oxide on electrical transport properties and low-frequency noise in MgO/NiFe/MgO heterojunctions

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jian-wei [School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China); School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Zhao, Chong-jun; Feng, Chun; Yu, Guang-hua [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Zhou, Zhongfu [School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China)

    2015-08-15

    Low-frequency noise and magnetoresistance in sputtered-deposited Ta(5 nm)/MgO (3 nm)/NiFe(10 nm)/MgO(3 nm)/Ta(3 nm) films have been measured as a function of different annealing times at 400°C. These measurements did not change synchronously with annealing time. A significant increase in magnetoresistance is observed for short annealing times (of the order of minutes) and is correlated with a relatively small reduction in 1/f noise. In contrast, a significant reduction in 1/f noise is observed for long annealing times (of the order of hours) accompanied by a small change in magnetoresistance. After annealing for 2 hours, the 1/f noise decreases by three orders of magnitude. Transmission electron microscopy and slow positron annihilation results implicate the cause being micro-structural changes in the MgO layers and interfaces following different annealing times. The internal vacancies in the MgO layers gather into vacancy clusters to reduce the defect density after short annealing times, whereas the MgO/NiFe and the NiFe/MgO interfaces improve significantly after long annealing times with the amorphous MgO layers gradually crystallizing following the release of interfacial stress.

  5. Thermoelectric power of PrMg3

    Science.gov (United States)

    Isikawa, Yosikazu; Somiya, Kazuya; Koyanagi, Huruto; Mizushima, Toshio; Kuwai, Tomohiko; Tayama, Takashi

    2010-01-01

    PrMg3 is supposed to be one of the strongly correlated electron systems originated from the hybridization between the Pr 4f and conduction electrons, because the gigantic electronic specific heat coefficient C/T was observed at low temperatures. However, a typical behaviour of - ln T dependence was not observed in the temperature dependence of the electrical resistivity. The thermoelectric power S is a powerful tool to investigate the density of states at the Fermi energy. We measured carefully the thermoelectric power of PrMg3 in the temperature range between 2 and 300 K. S is extremely small, ranged within ±1 μV/K over the whole temperature. The value of S/T at low temperature limit was also significantly smaller than expected from the specific heat results. We therefore conclude that the density of state at the Fermi level is not enhanced in PrMg3.

  6. Thermoelectric power of PrMg3

    International Nuclear Information System (INIS)

    Isikawa, Yosikazu; Somiya, Kazuya; Koyanagi, Huruto; Mizushima, Toshio; Kuwai, Tomohiko; Tayama, Takashi

    2010-01-01

    PrMg 3 is supposed to be one of the strongly correlated electron systems originated from the hybridization between the Pr 4f and conduction electrons, because the gigantic electronic specific heat coefficient C/T was observed at low temperatures. However, a typical behaviour of - ln T dependence was not observed in the temperature dependence of the electrical resistivity. The thermoelectric power S is a powerful tool to investigate the density of states at the Fermi energy. We measured carefully the thermoelectric power of PrMg 3 in the temperature range between 2 and 300 K. S is extremely small, ranged within ±1 μV/K over the whole temperature. The value of S/T at low temperature limit was also significantly smaller than expected from the specific heat results. We therefore conclude that the density of state at the Fermi level is not enhanced in PrMg 3 .

  7. Simulation of precipitation and strengthening in MG-RE alloys

    OpenAIRE

    Liu, Hong

    2017-01-01

    Magnesium - rare earth (Mg-RE) alloys have received considerable attention in the past decades for wider applications in the aerospace industry due to their relatively high strength and excellent creep resistance. Most rare-earth containing magnesium alloys, such as Mg-Y, Mg-Gd, and Mg-Y-Nd, are precipitation hardenable. A technical barrier to the wider applications of such alloys is the lack of a sufficiently large age hardening response. To further improve this response, an improved underst...

  8. Randomized clinical trial of dexketoprofen/tramadol 25 mg/75 mg in moderate-to-severe pain after total hip arthroplasty.

    Science.gov (United States)

    McQuay, H J; Moore, R A; Berta, A; Gainutdinovs, O; Fülesdi, B; Porvaneckas, N; Petronis, S; Mitkovic, M; Bucsi, L; Samson, L; Zegunis, V; Ankin, M L; Bertolotti, M; Pizà-Vallespir, B; Cuadripani, S; Contini, M P; Nizzardo, A

    2016-02-01

    The aim was to evaluate the analgesic efficacy and safety of the dexketoprofen/tramadol 25 mg/75 mg fixed-dose combination vs dexketoprofen (25 mg) and tramadol (100 mg) in moderate-to-severe acute pain after total hip arthroplasty. This was a randomized, double-blind, parallel-group study in patients experiencing pain of at least moderate intensity on the day after surgery, compared with placebo at first administration to validate the pain model. The study drug was administered orally every 8 h throughout a 5 day period. Rescue medication, metamizole 500 mg, was available during the treatment period. The evaluation of efficacy was based on patient assessments of pain intensity and pain relief. The primary end point was the mean sum of the pain intensity difference values throughout the first 8 h (SPID8). Overall, 641 patients, mean age 62 (range 29-80) yr, were analysed; mean (sd) values of SPID8 were 247 (157) for dexketoprofen/tramadol, 209 (155) for dexketoprofen, 205 (146) for tramadol, and 151 (159) for placebo. The primary analysis confirmed the superiority of the combination over dexketoprofen 25 mg (P=0.019; 95% confidence interval 6.4-73) and tramadol 100 mg (P=0.012; 95% confidence interval 9.5-76). The single components were superior to placebo (P<0.05), confirming model sensitivity. Most secondary analyses supported the superiority of the combination. The incidence of adverse drug reactions was low and similar among active treatment groups. The efficacy results confirmed the superiority of dexketoprofen/tramadol over its single components, even at higher doses (tramadol), with a safety profile fully in line with that previously known for these agents in monotherapy. EudraCT 2012-004548-31 (https://www.clinicaltrialsregister.eu/ctr-search/search?query=eudract_number:2012-004548-31);ClinicalTrials.gov NCT01902134 (https://www.clinicaltrials.gov/ct2/show/NCT01902134?term=NCT01902134&rank=1). © The Author 2016. Published by Oxford University Press on

  9. Thermodynamic investigation of the ternary mixed aqueous electrolyte (MgCl{sub 2} + MgSO{sub 4}) system by potentiometric method at T = 298.15 K

    Energy Technology Data Exchange (ETDEWEB)

    Bagherinia, Mohammad A., E-mail: mabagherinia@yahoo.com [Department of Chemistry, Faculty of Science, Lahijan Branch, Islamic Azad University, Lahijan (Iran, Islamic Republic of); Giahi, Masoud; Pournaghdy, Mohammad; Vaghar, Gholam R. [Department of Chemistry, Faculty of Science, Lahijan Branch, Islamic Azad University, Lahijan (Iran, Islamic Republic of)

    2012-01-15

    Highlights: > In this study we investigated the thermodynamic properties of MgCl{sub 2} + MgSO{sub 4} + H{sub 2}O. > The method used in this work was potentiometric method. > Mg-ISE and the Ag/AgCl electrodes used in this work had a good Nernst response. > The experimental results obeyed the Harned rule. > The Pitzer model could be used to describe this ternary system satisfactorily. - Abstract: This work reports the results of thermodynamic investigation of the ternary mixed-electrolyte system (MgCl{sub 2} + MgSO{sub 4} + H{sub 2}O). The investigation was performed based on Pitzer ion interaction model by using the potentiometric technique at T = 298.15 K. The mean activity coefficients of MgCl{sub 2} in the mixed aqueous electrolyte system were determined on the galvanic cell without liquid junction of the type: Mg-ISE|MgCl{sub 2} (m{sub A}), MgSO{sub 4} (m{sub B}), H{sub 2}O|Ag/AgCl over total ionic strengths from (0.001 to 8.000) mol . kg{sup -1} for different series of salt ratio r (r=m{sub MgCl{sub 2}}/m{sub MgSO{sub 4}}=2.5,5.0,7.5,10.0,15.0 and pure MgCl{sub 2}). The PVC based magnesium ion-selective electrode (Mg-ISE) and the Ag/AgCl electrode used in this work were made in our laboratory and had a reasonably good Nernst response. The experimental results obeyed the Harned rule, and the Pitzer model could be used to describe this ternary system satisfactorily. Pitzer ion-interaction parameters for mixed salts were determined for this system. Then, these parameters ({theta}{sub ClSO{sub 4}}=0.0252{+-}0.0042, {psi}{sub MgClSO{sub 4}}=-0.0049{+-}0.0003) were used to calculate the values of the mean activity coefficients of MgSO{sub 4}, the osmotic coefficients of water ({phi}) and the excess Gibbs free energies of solution (G{sup E}) for the whole series of the studied electrolyte systems.

  10. Catalytic effect of Ni, Mg2Ni and Mg2NiH4 upon hydrogen desorption from MgH2

    Czech Academy of Sciences Publication Activity Database

    Čermák, Jiří; David, Bohumil

    2011-01-01

    Roč. 36, č. 21 (2011), s. 13614-13620 ISSN 0360-3199 R&D Projects: GA ČR GA106/09/0814; GA ČR(CZ) GAP108/11/0148 Institutional research plan: CEZ:AV0Z20410507 Keywords : MgH2 * Hydrogen storage * Hydrogen desorption * Catalysis Subject RIV: JG - Metallurgy Impact factor: 4.054, year: 2011

  11. Characterization of Mg-containing hydroxyapatites synthesized by combustion method

    Science.gov (United States)

    Kaygili, Omer; Keser, Serhat; Bulut, Niyazi; Ates, Tankut

    2018-05-01

    In the present paper, Mg-substituted hydroxyapatites with the morphology, composed of the stacked plate- and rod-like structures, were prepared at the temperature of 600 °C by combustion method using glycerine as a fuel. A significant decrease in the crystallite size values calculated for both Scherrer and Williamson-Hall methods is found. The crystallinity, lattice parameter of a, stress and anisotropic energy density values decreased by adding of Mg, whereas the lattice strain increased. The amount of HAp phase decreases with increasing amount of Mg and the β-tricalcium phosphate content increases. Mg incorporation the apatitic structure was detected. Depending on the increase in Mg content, Ca-deficiency was observed.

  12. Selective antibacterial effects of mixed ZnMgO nanoparticles

    International Nuclear Information System (INIS)

    Vidic, Jasmina; Stankic, Slavica; Haque, Francia; Ciric, Danica; Le Goffic, Ronan; Vidy, Aurore; Jupille, Jacques; Delmas, Bernard

    2013-01-01

    Antibiotic resistance has impelled the research for new agents that can inhibit bacterial growth without showing cytotoxic effects on humans and other species. We describe the synthesis and physicochemical characterization of nanostructured ZnMgO whose antibacterial activity was compared to its pure nano-ZnO and nano-MgO counterparts. Among the three oxides, ZnO nanocrystals—with the length of tetrapod legs about 100 nm and the diameter about 10 nm—were found to be the most effective antibacterial agents since both Gram-positive (B. subtilis) and Gram-negative (E. coli) bacteria were completely eradicated at concentration of 1 mg/mL. MgO nanocubes (the mean cube size ∼50 nm) only partially inhibited bacterial growth, whereas ZnMgO nanoparticles (sizes corresponding to pure particles) revealed high specific antibacterial activity to Gram-positive bacteria at this concentration. Transmission electron microscopy analysis showed that B. subtilis cells were damaged after contact with nano-ZnMgO, causing cell contents to leak out. Our preliminary toxicological study pointed out that nano-ZnO is toxic when applied to human HeLa cells, while nano-MgO and the mixed oxide did not induce any cell damage. Overall, our results suggested that nanostructured ZnMgO, may reconcile efficient antibacterial efficiency while being a safe new therapeutic for bacterial infections.

  13. Stabilization of Reactive MgO Surfaces by Ni Doping

    Science.gov (United States)

    Mazheika, Aliaksei; Levchenko, Sergey V.

    Ni-MgO solid solutions are promising materials for catalytic reduction of CO2 and dry reforming of CH4. To explain the catalytic activity, an ab initio study of Ni-substitutional defects in MgO (NiMg) has been performed. At first, the validation of the theory level was done. We compared results of CCSD(T) embedded-cluster calculations of NiMg formation energies and adsorption energies of CO, CO2 and H2 on them to the HSE(α) hybrid DFT functional with the fraction of the exact exchange α varied between 0 and 1. HSE(0.3) was found to be the best compromise in this study. Our periodic HSE(0.3) calculations show that NiMg defects are most stable at corner sites, followed by steps, and are least stable at (001) terraces. Thus, Ni-doping stabilizes stepped MgO surfaces. The dissociative adsorption of H2 on the terrace is found to be endothermic (+ 1 . 1 eV), whereas on (110) surface with NiMg it is highly exothermic (- 1 . 6 eV). Adsorbed CO2 is also significantly stabilized (- 0 . 6 vs. - 2 . 2 eV). These findings explain recent microcalorimetry measurements of H2 and CO2 adsorption at doped Ni-MgO samples. partially supported by UniCat (Deutsche Forschungsgemeinschaft).

  14. Selective antibacterial effects of mixed ZnMgO nanoparticles

    Science.gov (United States)

    Vidic, Jasmina; Stankic, Slavica; Haque, Francia; Ciric, Danica; Le Goffic, Ronan; Vidy, Aurore; Jupille, Jacques; Delmas, Bernard

    2013-05-01

    Antibiotic resistance has impelled the research for new agents that can inhibit bacterial growth without showing cytotoxic effects on humans and other species. We describe the synthesis and physicochemical characterization of nanostructured ZnMgO whose antibacterial activity was compared to its pure nano-ZnO and nano-MgO counterparts. Among the three oxides, ZnO nanocrystals—with the length of tetrapod legs about 100 nm and the diameter about 10 nm—were found to be the most effective antibacterial agents since both Gram-positive ( B. subtilis) and Gram-negative ( E. coli) bacteria were completely eradicated at concentration of 1 mg/mL. MgO nanocubes (the mean cube size 50 nm) only partially inhibited bacterial growth, whereas ZnMgO nanoparticles (sizes corresponding to pure particles) revealed high specific antibacterial activity to Gram-positive bacteria at this concentration. Transmission electron microscopy analysis showed that B. subtilis cells were damaged after contact with nano-ZnMgO, causing cell contents to leak out. Our preliminary toxicological study pointed out that nano-ZnO is toxic when applied to human HeLa cells, while nano-MgO and the mixed oxide did not induce any cell damage. Overall, our results suggested that nanostructured ZnMgO, may reconcile efficient antibacterial efficiency while being a safe new therapeutic for bacterial infections.

  15. Selective antibacterial effects of mixed ZnMgO nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Vidic, Jasmina, E-mail: jasmina.vidic@jouy.inra.fr [VIM, Institut de la Recherche Agronomique (France); Stankic, Slavica, E-mail: slavica.stankic@insp.jussieu.fr; Haque, Francia [CNRS, Institut des Nanosciences de Paris, UMR 7588 (France); Ciric, Danica; Le Goffic, Ronan; Vidy, Aurore [VIM, Institut de la Recherche Agronomique (France); Jupille, Jacques [CNRS, Institut des Nanosciences de Paris, UMR 7588 (France); Delmas, Bernard [VIM, Institut de la Recherche Agronomique (France)

    2013-05-15

    Antibiotic resistance has impelled the research for new agents that can inhibit bacterial growth without showing cytotoxic effects on humans and other species. We describe the synthesis and physicochemical characterization of nanostructured ZnMgO whose antibacterial activity was compared to its pure nano-ZnO and nano-MgO counterparts. Among the three oxides, ZnO nanocrystals-with the length of tetrapod legs about 100 nm and the diameter about 10 nm-were found to be the most effective antibacterial agents since both Gram-positive (B. subtilis) and Gram-negative (E. coli) bacteria were completely eradicated at concentration of 1 mg/mL. MgO nanocubes (the mean cube size {approx}50 nm) only partially inhibited bacterial growth, whereas ZnMgO nanoparticles (sizes corresponding to pure particles) revealed high specific antibacterial activity to Gram-positive bacteria at this concentration. Transmission electron microscopy analysis showed that B. subtilis cells were damaged after contact with nano-ZnMgO, causing cell contents to leak out. Our preliminary toxicological study pointed out that nano-ZnO is toxic when applied to human HeLa cells, while nano-MgO and the mixed oxide did not induce any cell damage. Overall, our results suggested that nanostructured ZnMgO, may reconcile efficient antibacterial efficiency while being a safe new therapeutic for bacterial infections.

  16. Electrochemical deposition of La-Mg alloys in LaCl3-MgCl2-KCl system with molten salt electrolysis process

    Directory of Open Access Journals (Sweden)

    Sahoo Kumar D.

    2014-01-01

    Full Text Available La-Mg alloys of different compositions were prepared by electrolysis of LaCl3-MgCl2-KCl melts. Different phases of La-Mg alloys were characterized by X-ray diffraction (XRD and Scanning Electron Microscopy (SEM. Energy dispersive spectrometry (EDS and Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES analyses showed that chemical compositions of La-Mg alloys were consistent with phase structures of XRD pattern, and magnesium content in the alloy could be controlled by electrolysis parameters. The effects of various process parameters such as concentration of magnesium chloride in the bath, temperature of electrolysis and cathode current density on the current efficiency have been investigated. A maximum current efficiency of 85% and yield of 80% was obtained from the bath at 12.5A/cm2 current density at an operating temp 850°C.

  17. Properties of thymidylate synthetase from Ehrlich ascites carcinoma cells. Effect of Mg2/ and MgATP2-.

    Science.gov (United States)

    Jastreboff, M; Kedzierska, B; Rode, W

    1982-01-15

    Ehrlich ascites carcinoma thymidylate synthetase was purified to electrophoretic homogeneity by affinity chromatography on 10-formyl-5,8-dideazofolate-ethyl-Sepharose. Electrophoretic analysis of the formation of the enzyme-5-fluorodeoxyuridylate-5,10-methylenetetrahydrofolate complexes showed the presence of two binding sites for 5-fluorodeoxyuridylate on the enzyme molecule. Molecular weight of the native enzyme was found to be 78,5000, whereas that of its monomer was 38, 500. The apparent Michaelis constants for dUMP and (+/-)-L-5,10-methylenetetrahydrofolate were 1.3 +/- 0.4 and 32.2 +/- 0.7 micrometers respectively. Phosphate acted as a weak inhibitor, competitive toward dUMP. The enzyme reaction exhibited a temperature-dependent change of activation energy, reflected in the binding affinity of dUMP, with a transitional temperature of 35.8 degrees. Both Mg2+ and MgATP2- were strong activators of the enzyme, MgATP2- being more effective.

  18. Reducing Mg acceptor activation-energy in Al(0.83)Ga(0.17)N disorder alloy substituted by nanoscale (AlN)₅/(GaN)₁ superlattice using Mg(Ga) δ-doping: Mg local-structure effect.

    Science.gov (United States)

    Zhong, Hong-xia; Shi, Jun-jie; Zhang, Min; Jiang, Xin-he; Huang, Pu; Ding, Yi-min

    2014-10-23

    Improving p-type doping efficiency in Al-rich AlGaN alloys is a worldwide problem for the realization of AlGaN-based deep ultraviolet optoelectronic devices. In order to solve this problem, we calculate Mg acceptor activation energy and investigate its relationship with Mg local structure in nanoscale (AlN)5/(GaN)1 superlattice (SL), a substitution for Al(0.83)Ga(0.17)N disorder alloy, using first-principles calculations. A universal picture to reduce acceptor activation energy in wide-gap semiconductors is given for the first time. By reducing the volume of the acceptor local structure slightly, its activation energy can be decreased remarkably. Our results show that Mg acceptor activation energy can be reduced significantly from 0.44 eV in Al(0.83)Ga(0.17)N disorder alloy to 0.26 eV, very close to the Mg acceptor activation energy in GaN, and a high hole concentration in the order of 10(19) cm(-3) can be obtained in (AlN)5/(GaN)1 SL by Mg(Ga) δ-doping owing to GaN-monolayer modulation. We thus open up a new way to reduce Mg acceptor activation energy and increase hole concentration in Al-rich AlGaN.

  19. Reducing Mg Acceptor Activation-Energy in Al0.83Ga0.17N Disorder Alloy Substituted by Nanoscale (AlN)5/(GaN)1 Superlattice Using MgGa δ-Doping: Mg Local-Structure Effect

    Science.gov (United States)

    Zhong, Hong-Xia; Shi, Jun-Jie; Zhang, Min; Jiang, Xin-He; Huang, Pu; Ding, Yi-Min

    2014-10-01

    Improving p-type doping efficiency in Al-rich AlGaN alloys is a worldwide problem for the realization of AlGaN-based deep ultraviolet optoelectronic devices. In order to solve this problem, we calculate Mg acceptor activation energy and investigate its relationship with Mg local structure in nanoscale (AlN)5/(GaN)1 superlattice (SL), a substitution for Al0.83Ga0.17N disorder alloy, using first-principles calculations. A universal picture to reduce acceptor activation energy in wide-gap semiconductors is given for the first time. By reducing the volume of the acceptor local structure slightly, its activation energy can be decreased remarkably. Our results show that Mg acceptor activation energy can be reduced significantly from 0.44 eV in Al0.83Ga0.17N disorder alloy to 0.26 eV, very close to the Mg acceptor activation energy in GaN, and a high hole concentration in the order of 1019 cm-3 can be obtained in (AlN)5/(GaN)1 SL by MgGa δ-doping owing to GaN-monolayer modulation. We thus open up a new way to reduce Mg acceptor activation energy and increase hole concentration in Al-rich AlGaN.

  20. Experimental investigation and thermodynamic calculation of the Mg-Sr-Zr system

    International Nuclear Information System (INIS)

    Zhou, Hua; Chen, Chong; Du, Yong; Central South Univ., Hunan; Gong, Haoran

    2016-01-01

    Both experimental investigation and thermodynamic calculation were performed for the Mg-Sr-Zr system. Four decisive alloys were firstly selected and prepared using a powder metallurgy method to measure the isothermal section at 400 C via a combination of X-ray diffraction and electron probe microanalysis. No ternary compound has been observed for this ternary system. Four three-phase regions, (Mg) + (αZr) + Mg 17 Sr 2 , Mg 17 Sr 2 + (αZr) + Mg 38 Sr 9 , Mg 38 Sr 9 + (αZr) + Mg 23 Sr 6 , and Mg 23 Sr 6 + (αZr) + Mg 2 Sr, have been identified at 400 C. No appreciable ternary solubility has been detected in the binary Mg-Sr compounds. Phase transition temperatures of the Mg-Sr-Zr alloys were measured by means of differential scanning calorimetry. The thermodynamic calculations match well with the experimental data in the present work, indicating that no ternary thermodynamic parameters are needed for the thermodynamic description of this ternary system. In order to verify the reliability of the current thermodynamic calculations of the Mg-Sr-Zr system, eight as-cast alloys in the Mg-rich corner were also prepared. The calculated liquidus projection is consistent with the observed primary phase regions. The present thermodynamic calculations are reliable and can be used in the development of Mg alloys.

  1. Magnesium balances and 28Mg studies in man

    International Nuclear Information System (INIS)

    Spencer, H.; Schwartz, R.; Osis, D.

    1988-01-01

    The intestinal absorption of magnesium was determined under strictly controlled dietary conditions in patients with normal renal function and also in patients with chronic renal failure. The average net absorption of magnesium of patients with normal renal function, expressed as percent of the magnesium intake, was 48.5%, while that of patients with chronic renal failure was significantly lower, 17%. Increasing the calcium intake from a low calcium intake of 200 mg/day to different higher intake levels up to 2000 mg/day did not change the magnesium balance nor the net absorption of magnesium of both types of patients. The lack of effect of the higher calcium intake on the absorption of magnesium was confirmed in 28 Mg studies in which an oral dose of 28 Mg, as the chloride, was given. The excretion of the absorbed magnesium into the intestine, the endogenous fecal magnesium, was low. Also, increasing the phosphorus intake up to 2000 mg/day in subjects with normal renal function did not affect the magnesium balance, regardless of the calcium intake

  2. Dry cryomagnetic system with MgB2 coil

    Science.gov (United States)

    Abin, D. A.; Mineev, N. A.; Osipov, M. A.; Pokrovskii, S. V.; Rudnev, I. A.

    2017-12-01

    MgB2 may be the future superconducting wire material for industrial magnets due to it’s higher operation temperature and potentially lower cost than low temperature superconductors (LTS) have. We designed a compact cryomagnetic system with the use of MgB2. The possibility of creating a magnet with a central field of 5 T from a commercial MgB2 wire by the “react and wound” method was investigated. The magnetic system is cooled by a cryocooler through a copper bus. The magnet has a warm bore diameter of 4 cm. The design of a magnet consisting of three concentric solenoids is proposed: an internal one of high-temperature superconductor (HTS), an average of MgB2, and an external of NbTi. The operating current of the system is 100 A. Two pairs of current leads are used. A separate pair of current leads for power supplying NbTi coil allows testing of MgB2 and HTS coils in an external field. The load curves for each of the magnets are calculated.

  3. Composition and properties tailoring in Mg.sup.2+./sup. codoped non-stoichiometric LuAG:Ce,Mg scintillation ceramics

    Czech Academy of Sciences Publication Activity Database

    Liu, S.; Mareš, Jiří A.; Babin, Vladimir; Hu, C.; Kou, H.; D'Ambrosio, C.; Li, J.; Pan, Y.; Nikl, Martin

    2017-01-01

    Roč. 37, č. 4 (2017), s. 1689-1694 ISSN 0955-2219 R&D Projects: GA ČR GA16-15569S Institutional support: RVO:68378271 Keywords : non-stoichiometric ceramic s * LuAG:Ce * Mg scintillator * Mg 2+ codopant * antisite defects * afterglow Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 3.411, year: 2016

  4. SIMS and Raman studies of Mg-doped InN

    International Nuclear Information System (INIS)

    Davydov, V.Yu.; Kitaev, Yu.E.; Smirnov, A.N.; Lundina, E.Y.; Klochikhin, A.A.; Smirnov, M.B.; Lu, Hai; Schaff, William J.; Lee, H.M.; Lin, H.W.; Hong, Y.L.; Gwo, S.

    2008-01-01

    Raman and SIMS studies of Mg-doped InN films with a Mg content from N Mg =3.3 x 10 19 to 5.5 x 10 21 cm -3 are reported. Lattice dynamics of hexagonal InN with substitutional impurities and vacancies has been investigated theoretically and calculated Raman spectra were compared with experimental ones. It is concluded that Raman spectroscopy is a good tool for quantitative characterization of Mg-doped InN. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  5. Catalysis and Downsizing in Mg-Based Hydrogen Storage Materials

    Directory of Open Access Journals (Sweden)

    Jianding Li

    2018-02-01

    Full Text Available Magnesium (Mg-based materials are promising candidates for hydrogen storage due to the low cost, high hydrogen storage capacity and abundant resources of magnesium for the realization of a hydrogen society. However, the sluggish kinetics and strong stability of the metal-hydrogen bonding of Mg-based materials hinder their application, especially for onboard storage. Many researchers are devoted to overcoming these challenges by numerous methods. Here, this review summarizes some advances in the development of Mg-based hydrogen storage materials related to downsizing and catalysis. In particular, the focus is on how downsizing and catalysts affect the hydrogen storage capacity, kinetics and thermodynamics of Mg-based hydrogen storage materials. Finally, the future development and applications of Mg-based hydrogen storage materials is discussed.

  6. Room temperature ferromagnetism in Mg-doped ZnO nanoparticles

    International Nuclear Information System (INIS)

    Singh, Jaspal; Vashihth, A.; Gill, Pritampal Singh; Verma, N. K.

    2015-01-01

    Zn 1-x Mg x O (x = 0, 0,10) nanoparticles were successfully synthesized using sol-gel method. X-ray diffraction (XRD) confirms that the synthesized nanoparticles possess wurtzite phase having hexagonal structure. Morphological analysis was carried out using transmission electron microscopy (TEM) which depicts the spherical morphology of ZnO nanoparticles. Energy dispersive spectroscopy (EDS) showed the presence of Mg in ZnO nanoparticles. Electron spin resonance (ESR) signal was found to be decreasing with increasing of Mg-doping concentration. The room temperature ferromagnetism was observed in undoped and Mg-doped ZnO nanoparticles. The increase of Mg-doping concentration resulted in decrease of saturation magnetization value which could be attributed to decrease of oxygen vacancies present in host nanoparticles

  7. Refinement of Mg2Si reinforcement in a commercial Al–20%Mg2Si in-situ composite with bismuth, antimony and strontium

    International Nuclear Information System (INIS)

    Nordin, Nur Azmah; Farahany, Saeed; Ourdjini, Ali; Abu Bakar, Tuty Asma; Hamzah, Esah

    2013-01-01

    Refinement by addition elements of Al–Mg 2 Si alloys is known to result in a change of primary Mg 2 Si morphology. In this paper, the effects of Bi, Sb and Sr on the characteristic parameters of Al–20%Mg 2 Si in-situ composite have been investigated by computer aided cooling curve thermal analysis and microstructural inspection. Size, density and aspect ratio measurements showed that additions of 0.4 wt.% Bi, 0.8 wt.% Sb and 0.01 wt.% Sr refined the Mg 2 Si reinforcement. Exceeding these concentrations, however, resulted in coarsening of Mg 2 Si particles with no change in the morphology. The results also showed that addition elements caused a decrease in the nucleation and growth temperatures of Mg 2 Si particles. The refining effect of Bi, Sb and Sr is likely to be related to the effect of oxide bifilms suspended in the composite melt as favored nucleation substrates for Mg 2 Si particles. - Highlight: • 0.4 wt.%, 0.8 wt.% and 0.01 wt.% is the optimum content for Bi, Sb and Sr addition. • Exceeding optimum concentration resulted in the coarsening of reinforcements. • Nucleation and growth temperatures decrease with addition of Bi, Sb and Sr. • The refining effect of Bi, Sb and Sr is likely to be related to the oxide bifilms

  8. Improved Mg-based alloys for hydrogen storage

    Energy Technology Data Exchange (ETDEWEB)

    Sapru, K.; Ming, L.; Stetson, N.T.; Evans, J. [Energy Conversion Devices, Inc., Troy, MI (United States)

    1998-08-01

    The overall objective of this on-going work is to develop low temperature alloys capable of reversibly storing at least 3 wt.% hydrogen, allowing greater than for 2 wt.% at the system level which is required by most applications. Surface modification of Mg can be used to improve its H-sorption kinetics. The authors show here that the same Mg-transition metal-based multi-component alloy when prepared by melt-spinning results in a more homogeneous materials with a higher plateau pressure as compared to preparing the material by mechanical grinding. They have also shown that mechanically alloyed Mg{sub 50}Al{sub 45}Zn{sub 5} results in a sample having a higher plateau pressure.

  9. Theoretical and experimental study of the intrinsic physical properties of the Mg-MgH{sub 2} system

    Energy Technology Data Exchange (ETDEWEB)

    Puszkiel, Julian A.; Gervasoni, Juana L. [Centro Atomico Bariloche (CAB) - Instituto Balseiro (IB) - Comision Nacional de Energia Atomica (CNEA), Av. Bustillo km 9.5, R8402 AGP S.C. de Bariloche (Argentina)

    2010-06-15

    Due to the fundamental problems of energy source limitations and environmental pollution, hydrogen has become an attractive clean energy source for the future. Despite the fact that the incentive to switch to a hydrogen economy has increased, there are many problems which must be solved. One of the main unsolved issues is hydrogen storage. Among the potential materials to store hydrogen in a safe way, Mg has drawn interest owing to its high hydrogen capacity (7.6 wt%), light weight and low cost. In order to improve the hydrogen capacity of potential storage materials such as Mg, it is important to understand the site preferences of hydrogen atoms in the metal. Such behavior depends mainly on the screening charge density ({delta}n(r)) of the system proton-metallic host, from which all the physical macroscopic properties (viz. V{sub H}, {delta}H{sub S}, B, etc.) and IDOS are determined. In the present work we study the interaction between a proton and Mg as host metal via ab initio calculations, using the Jellium model, based on the density-functional theory (DFT). The macroscopic properties are determined and compared with experimental results and values found in the bibliography. Furthermore, in order to obtain information about the electronic distribution of hydrogen and the nature of the Mg-H bonding, the IDOS is described. (author)

  10. Equilibrium between (Li,Na,K,Mg)-carbonate melt, gaseous CO

    NARCIS (Netherlands)

    Velden, P.F. van

    1967-01-01

    Considerable amounts of MgCO3 may appear in alkali metal carbonate melts in contact with MgO and carbon dioxide gas. The equilibrium between dissolved MgCO3, MgO and carbon dioxide gas has been studied. The results satisfactorily obey thermodynamic theory based upon a melt

  11. Randomised clinical trial: daily pantoprazole magnesium 40 mg vs. esomeprazole 40 mg for gastro-oesophageal reflux disease, assessed by endoscopy and symptoms.

    Science.gov (United States)

    Moraes-Filho, J P; Pedroso, M; Quigley, E M M

    2014-01-01

    Pantoprazole magnesium (pantoprazole-Mg) may display extended inhibition of the proton pump with the potential for improved clinical efficacy in gastro-oesophageal reflux disease (GERD). To compare the efficacy of pantoprazole-Mg and esomeprazole in GERD. Gastro-oesophageal reflux disease (Los Angeles grades A-D) patients were randomised to 4 weeks of treatment with pantoprazole-Mg (n = 290) or esomeprazole (n = 288), both 40 mg once daily, in this multicentre (14 Brazilian sites in 9 cities), double-blind study, with an additional 4 weeks' treatment in nonresponding patients. Severity of oesophagitis (at endoscopy) and GERD-related symptoms (ReQuest-GI) were assessed. The primary end point was the proportion of patients in complete remission (ReQuest-GI score <1.73 plus endoscopic healing) at week 4. Complete remission occurred in 61% of patients in each treatment group at 4 weeks (primary endpoint) and in 81% and 79% of patients in the pantoprazole-Mg and esomeprazole groups at 8 weeks, with no significant differences. Mucosal healing rates were high and not significantly different. At 8 weeks, symptom relief with pantoprazole-Mg was significantly greater than that with esomeprazole (91.6% vs. 86.0%, P = 0.0370) because of continued improvement in symptoms with pantoprazole-Mg from week 4 to week 8 (P = 0.0206). Pantoprazole-Mg 40 mg was at least as effective as esomeprazole 40 mg for complete remission and the mucosal healing rate was high. Symptom relief with pantoprazole-Mg continued to improve from 4 to 8 weeks and was greater than that with esomeprazole at week 8, suggesting an extended period of treatment effect (ClinicalTrials.gov identifier: NCT01132638). © 2013 John Wiley & Sons Ltd.

  12. Investigation of Mg(OH)2 nanoparticles as an antibacterial agent

    International Nuclear Information System (INIS)

    Dong Chunxu; Cairney, John; Sun Qunhui; Maddan, Orville Lee; He Gaohong; Deng Yulin

    2010-01-01

    Our experimental results of using Mg(OH) 2 nanoparticles as an antibacterial agent are reported in this study. The antibacterial behavior of Mg(OH) 2 nanoparticles in liquid culture and in paper sheets was investigated. The colony forming units (CFU) counting and the headspace gas chromatography (HS-GC) measurement were used to determine the cell viability. Results indicate that Mg(OH) 2 nanoparticles are effective antibacterial agent against Escherichia coli (E. coli) and Burkholderia phytofirmans, and the OH - and Mg 2+ ions in Mg(OH) 2 water suspension were found not to be the reason for killing the bacteria. Mg(OH) 2 nanoparticles could be added directly to wood pulp to make paper sheets, whose antibacterial efficiency increased with the increase of the nanoparticle amount. The possible mechanism of antibacterial effect of Mg(OH) 2 nanoparticles is discussed.

  13. Global investigation of the Mg atom and ion layers using SCIAMACHY/Envisat observations between 70 and 150 km altitude and WACCM-Mg model results

    Directory of Open Access Journals (Sweden)

    M. P. Langowski

    2015-01-01

    Full Text Available Mg and Mg+ concentration fields in the upper mesosphere/lower thermosphere (UMLT region are retrieved from SCIAMACHY/Envisat limb measurements of Mg and Mg+ dayglow emissions using a 2-D tomographic retrieval approach. The time series of monthly mean Mg and Mg+ number density and vertical column density in different latitudinal regions are presented. Data from the limb mesosphere–thermosphere mode of SCIAMACHY/Envisat are used, which cover the 50 to 150 km altitude region with a vertical sampling of ≈3.3 km and latitudes up to 82°. The high latitudes are not observed in the winter months, because there is no dayglow emission during polar night. The measurements were performed every 14 days from mid-2008 until April 2012. Mg profiles show a peak at around 90 km altitude with a density between 750 cm−3 and 1500 cm−3. Mg does not show strong seasonal variation at latitudes below 40°. For higher latitudes the density is lower and only in the Northern Hemisphere a seasonal cycle with a summer minimum is observed. The Mg+ peak occurs 5–15 km above the neutral Mg peak altitude. These ions have a significant seasonal cycle with a summer maximum in both hemispheres at mid and high latitudes. The strongest seasonal variations of Mg+ are observed at latitudes between 20 and 40° and the density at the peak altitude ranges from 500 cm−3 to 4000 cm−3. The peak altitude of the ions shows a latitudinal dependence with a maximum at mid latitudes that is up to 10 km higher than the peak altitude at the equator. The SCIAMACHY measurements are compared to other measurements and WACCM model results. The WACCM results show a significant seasonal variability for Mg with a summer minimum, which is more clearly pronounced than for SCIAMACHY, and globally a higher peak density than the SCIAMACHY results. Although the peak density of both is not in agreement, the vertical column density agrees well, because SCIAMACHY and WACCM profiles have different

  14. Mg{sub 2}Sn heterostructures on Si(111) substrate

    Energy Technology Data Exchange (ETDEWEB)

    Dózsa, L., E-mail: dozsa@mfa.kfki.hu [Institute of Technical Physics and Materials Science, Centre for Energy Research, Hungarian Academy of Sciences, 1525 Budapest Pf, 49 (Hungary); Galkin, N.G. [Institute of Automation and Control Processes of FEB RAS, 5 Radio St., Vladivostok 690041 (Russian Federation); Far Eastern Federal University, 8 Sukhanova St., Vladivostok 690950 (Russian Federation); Pécz, B.; Osváth, Z.; Zolnai, Zs. [Institute of Technical Physics and Materials Science, Centre for Energy Research, Hungarian Academy of Sciences, 1525 Budapest Pf, 49 (Hungary); Németh, A. [Wigner Research Centre for Physics, Institute for Particle and Nuclear Physics, 1525 Budapest, P.O.B. 49 (Hungary); Galkin, K.N.; Chernev, I.M. [Institute of Automation and Control Processes of FEB RAS, 5 Radio St., Vladivostok 690041 (Russian Federation); Dotsenko, S.A. [Institute of Automation and Control Processes of FEB RAS, 5 Radio St., Vladivostok 690041 (Russian Federation); Far Eastern Federal University, 8 Sukhanova St., Vladivostok 690950 (Russian Federation)

    2017-05-31

    Highlights: • Investigations show that the nanostructures have significant changes during the applied regular experimental investigations. • It is especially true for transmittance electron microscopy, where the investigated layers have to be thinned near to the nanostructure size. • The time order of the applied experimental investigation has a dominant effect on the experimetal results. - Abstract: Thin un-doped and Al doped polycrystalline Mg-stannide films consisting mainly of Mg{sub 2}Sn semiconductor phase have been grown by deposition of Sn-Mg multilayers on Si(111) p-type wafers at room temperature and annealing at 150 °C. Rutherford backscattering measurement spectroscopy (RBS) were used to determine the amount of Mg and Sn in the structures. Raman spectroscopy has shown the layers contain Mg{sub 2}Sn phase. Cross sectional transmission electron microscopy (XTEM) measurements have identified Mg{sub 2}Sn nanocrystallites in hexagonal and cubic phases without epitaxial orientation with respect to the Si(111) substrate. Significant oxygen concentration was found in the layer both by RBS and TEM. The electrical measurements have shown laterally homogeneous conductivity in the grown layer. The undoped Mg{sub 2}Sn layers show increasing resistivity with increasing temperature indicating the scattering process dominates the resistance of the layers, i.e. large concentration of point defects was generated in the layer during the growth process. The Al doped layer shows increase of the resistance at low temperature caused by freeze out of free carriers in the Al doped Mg{sub 2}Sn layer. The measurements indicate the necessity of protective layer grown over the Mg{sub 2}Sn layers, and a short time delay between sample preparation and cross sectionalTEM analysis, since the unprotected layer is degraded by the interaction with the ambient.

  15. Enhancement of Two-Dimensional Electron-Gas Properties by Zn Polar ZnMgO/MgO/ZnO Structure Grown by Radical-Source Laser Molecular Beam Epitaxy

    Directory of Open Access Journals (Sweden)

    Li Meng

    2015-01-01

    Full Text Available A Zn polar ZnMgO/MgO/ZnO structure with low Mg composition Zn1-xMgxO layer (x = 0.05 grown on a-plane (11–20 sapphire by radical-source laser molecular beam epitaxy was reported. The insertion of a thin (1 nm MgO layer between ZnMgO and ZnO layers in the ZnMgO/ZnO 2DEG structures results in an increase of 2DEG sheet density and affects electron mobility slightly. The carrier concentration reached a value as high as 1.1 × 1013 cm−2, which was confirmed by C-V measurements. A high Hall mobility of 3090 cm2/Vs at 10 K and 332 cm2/Vs at RT was observed from Zn0.95Mg0.05O/MgO/ZnO heterostructure. The choice of the thickness of MgO was discussed. The dependence of carrier sheet density of 2DEG on ZnMgO layer thickness was calculated in theory and the theoretical prediction and experimental results agreed well.

  16. IMPACT OF A REVISED {sup 25}Mg(p, {gamma}){sup 26}Al REACTION RATE ON THE OPERATION OF THE Mg-Al CYCLE

    Energy Technology Data Exchange (ETDEWEB)

    Straniero, O.; Cristallo, S. [INAF-Osservatorio Astronomico di Collurania, Teramo (Italy); Imbriani, G.; DiLeva, A.; Limata, B. [INFN Sezione di Napoli, Napoli (Italy); Strieder, F. [Institut fuer Experimentalphysik, Ruhr-Universitaet Bochum, Bochum (Germany); Bemmerer, D. [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400 (Germany); Broggini, C.; Caciolli, A. [Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Padova, via Marzolo 8, I-35131 Padova (Italy); Corvisiero, P.; Costantini, H.; Lemut, A. [Universita di Genova and INFN Sezione di Genova, Genova (Italy); Formicola, A.; Gustavino, C.; Junker, M. [INFN, Laboratori Nazionali del Gran Sasso (LNGS), Assergi (AQ) (Italy); Elekes, Z.; Fueloep, Zs.; Gyuerky, Gy. [Institute of Nuclear Research (ATOMKI), Debrecen (Hungary); Gervino, G. [Dipartimento di Fisica Universita di Torino and INFN Sezione di Torino, Torino (Italy); Guglielmetti, A., E-mail: straniero@oa-teramo.inaf.it [Universita degli Studi di Milano and INFN, Sezione di Milano (Italy); and others

    2013-02-15

    Proton captures on Mg isotopes play an important role in the Mg-Al cycle active in stellar H-burning regions. In particular, low-energy nuclear resonances in the {sup 25}Mg(p, {gamma}){sup 26}Al reaction affect the production of radioactive {sup 26}Al{sup gs} as well as the resulting Mg/Al abundance ratio. Reliable estimations of these quantities require precise measurements of the strengths of low-energy resonances. Based on a new experimental study performed at the Laboratory for Underground Nuclear Astrophysics, we provide revised rates of the {sup 25}Mg(p, {gamma}){sup 26}Al{sup gs} and the {sup 25}Mg(p, {gamma}){sup 26}Al {sup m} reactions with corresponding uncertainties. In the temperature range 50-150 MK, the new recommended rate of {sup 26}Al {sup m} production is up to five times higher than previously assumed. In addition, at T = 100 MK, the revised total reaction rate is a factor of two higher. Note that this is the range of temperature at which the Mg-Al cycle operates in a H-burning zone. The effects of this revision are discussed. Due to the significantly larger {sup 25}Mg(p, {gamma}){sup 26}Al {sup m} rate, the estimated production of {sup 26}Al{sup gs} in H-burning regions is less efficient than previously obtained. As a result, the new rates should imply a smaller contribution from Wolf-Rayet stars to the galactic {sup 26}Al budget. Similarly, we show that the asymptotic giant branch (AGB) extra-mixing scenario does not appear able to explain the most extreme values of {sup 26}Al/{sup 27}Al, i.e., >10{sup -2}, found in some O-rich presolar grains. Finally, the substantial increase of the total reaction rate makes the hypothesis of self-pollution by massive AGBs a more robust explanation for the Mg-Al anticorrelation observed in globular-cluster stars.

  17. Scattering effect of the well-ordered MgB{sub 4} impurity phase in two-step sintered polycrystalline MgB{sub 2} with glycine addition

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Qi; Liu, Yongchang; Guo, Qianying; Ma, Zongqing [Tianjin University, State Key Lab of Hydraulic Engineering Simulation and Safety, School of Materials Science and Engineering, Tianjin (China)

    2017-04-15

    Glycine-doped MgB{sub 2} bulk was prepared by two-step sintering in this study, first at 750 C and then 900 C. The MgB{sub 4} particles are induced to precipitate where the dislocations concentrated after C substitution or along the steps of screw dislocation during crystal growth, forming ordered MgB{sub 4} arrays throughout the MgB{sub 2} grain. By means of atomic force microscope, the detected magnetic domains are arranged in agreement with the ordered MgB{sub 4} particles after the measurement of magnetic hysteresis loop, which supported that the nano-scale MgB{sub 4} domain structure brought strong scattering effects and indicated that atomic force microscopy could test the role of the impurities. As a result, the extrapolating upper critical field H{sub c2}(0 K) is enhanced to 22.8 T for the sample with ordered MgB{sub 4}, while only 18.1 T for the un-doped sample underwent the same sintering program. Besides, carbon substitution contributed to the enhancement of H{sub c2} as well. (orig.)

  18. Ultraviolet spectra of Mg in liquid helium

    International Nuclear Information System (INIS)

    Moriwaki, Y.; Morita, N.

    1999-01-01

    Emission and absorption spectra of Mg atoms implanted in liquid helium have been observed in the ultraviolet region. We have presented a model of exciplex formation of Mg-He 10 and found that this model is more suitable for understanding the dynamics in the 3s3p 1 P→3s 21 S transition than the bubble model. (orig.)

  19. Reusability enhancement of combustion synthesized MgO/MgAl_2O_4 nanocatalyst in biodiesel production by glow discharge plasma treatment

    International Nuclear Information System (INIS)

    Rahmani Vahid, Behgam; Haghighi, Mohammad; Alaei, Shervin; Toghiani, Javad

    2017-01-01

    Graphical abstract: MgO/MgAl_2O_4 nanocatalyst synthesized by impregnation/combustion methods and treated by plasma. FESEM, XRD, EDX, BET-BJH, TG and FTIR analyses were used to investigate the physicochemical characteristics of the nanocatalysts. The nanocatalysts were used in biodiesel production to evaluate and compare their activity. The obtained results from reactor test showed almost similar conversion (higher than 95%) for both treated and untreated nanocatalysts. However, in reusability performance, the plasma treated sample indicated better stability. - Highlights: • Efficient dispersion of MgO on combustion synthesized MgAl_2O_4 spinel nanocatalyst. • Enhanced effect of plasma treatment on nanocatalyst synthesis and its structure. • Successful production of biodiesel using nanocatalyst that treated with plasma. • Increasing the nanocatalyst reusability in biodiesel production by plasma treatment. - Abstract: In this study, plasma technology was used to prepare the catalysts for biodiesel production. The base of MgO/MgAl_2O_4 particles was prepared by combustion synthesis method to attain suitable porosity for large molecules of triglyceride and then active phase of MgO was dispersed on the samples by impregnation method. The nanocatalysts were characterized by XRD, FESEM, EDX, BET-BJH, FTIR, TGA and Particle size distribution analyses. In order to evaluation the catalytic activity of the samples in biodiesel production, the transesterification reaction was performed under these conditions: reaction temperature = 110 °C, methanol-to-oil molar ratio = 12, catalyst concentration = 3 wt.% and reaction time = 3 h. XRD and FTIR results confirm successful synthesis of MgO/MgAl_2O_4. Meanwhile, XRD and EDX analyses indicated that MgO in modified sample by plasma has suitable size distribution. FESEM and BET-BJH analyses reveal proper morphology in both samples and showed higher surface area and pore size in plasma treated sample. TG analysis showed that

  20. Superconducting properties of in situ powder-in-tube-processed MgB2 tapes fabricated with sub-micrometre Mg powder prepared by an arc-plasma method

    International Nuclear Information System (INIS)

    Yamada, H; Uchiyama, N; Matsumoto, A; Kitaguchi, H; Kumakura, H

    2007-01-01

    We fabricated in situ powder-in-tube-processed MgB 2 /Fe tapes using sub-micrometre Mg powder prepared by applying an arc-plasma method. We found that the use of this sub-micrometre Mg powder was very effective in increasing the J c values. The transport J c value of 10 mol% SiC-added tapes fabricated with this sub-micrometre Mg powder reached 275 A mm -2 at 4.2 K and 10 T. This value was about six times that of 5 mol% SiC-added tapes fabricated with commercial Mg powder. Microstructure analyses suggest that this J c enhancement is primarily due to the smaller MgB 2 grain size

  1. The impact of Mg contents on Sr partitioning in benthic foraminifers

    NARCIS (Netherlands)

    Mewes, Antje; Langer, Gerald; Reichart, Gert Jan; de Nooijer, L.J.; Nehrke, Gernot; Bijma, Jelle

    2015-01-01

    Foraminiferal calcite Mg/Ca (Mg/CaCC) is used in paleoceanographic studies to reconstruct temperature. Furthermore, the Mg/CaCC is influenced by different seawater Mg/Ca (Mg/CaSW). Foraminiferal calcite Sr/Ca (Sr/CaCC) can potentially be used to reconstruct Sr/Ca ratios of seawater (Sr/CaSW). As

  2. Behaviour of Fe4O5-Mg2Fe2O5 solid solutions and their relation to coexisting Mg-Fe silicates and oxide phases

    Science.gov (United States)

    Uenver-Thiele, Laura; Woodland, Alan B.; Miyajima, Nobuyoshi; Ballaran, Tiziana Boffa; Frost, Daniel J.

    2018-03-01

    Experiments at high pressures and temperatures were carried out (1) to investigate the crystal-chemical behaviour of Fe4O5-Mg2Fe2O5 solid solutions and (2) to explore the phase relations involving (Mg,Fe)2Fe2O5 (denoted as O5-phase) and Mg-Fe silicates. Multi-anvil experiments were performed at 11-20 GPa and 1100-1600 °C using different starting compositions including two that were Si-bearing. In Si-free experiments the O5-phase coexists with Fe2O3, hp-(Mg,Fe)Fe2O4, (Mg,Fe)3Fe4O9 or an unquenchable phase of different stoichiometry. Si-bearing experiments yielded phase assemblages consisting of the O5-phase together with olivine, wadsleyite or ringwoodite, majoritic garnet or Fe3+-bearing phase B. However, (Mg,Fe)2Fe2O5 does not incorporate Si. Electron microprobe analyses revealed that phase B incorporates significant amounts of Fe2+ and Fe3+ (at least 1.0 cations Fe per formula unit). Fe-L2,3-edge energy-loss near-edge structure spectra confirm the presence of ferric iron [Fe3+/Fetot = 0.41(4)] and indicate substitution according to the following charge-balanced exchange: [4]Si4+ + [6]Mg2+ = 2Fe3+. The ability to accommodate Fe2+ and Fe3+ makes this potential "water-storing" mineral interesting since such substitutions should enlarge its stability field. The thermodynamic properties of Mg2Fe2O5 have been refined, yielding H°1bar,298 = - 1981.5 kJ mol- 1. Solid solution is complete across the Fe4O5-Mg2Fe2O5 binary. Molar volume decreases essentially linearly with increasing Mg content, consistent with ideal mixing behaviour. The partitioning of Mg and Fe2+ with silicates indicates that (Mg,Fe)2Fe2O5 has a strong preference for Fe2+. Modelling of partitioning with olivine is consistent with the O5-phase exhibiting ideal mixing behaviour. Mg-Fe2+ partitioning between (Mg,Fe)2Fe2O5 and ringwoodite or wadsleyite is influenced by the presence of Fe3+ and OH incorporation in the silicate phases.

  3. Interaction of hydrogen with an Mg-Al alloy

    International Nuclear Information System (INIS)

    Andreasen, A.; Sorensen, M.B.; Burkarl, R.; Moller, B.; Molenbroek, A.M.; Pedersen, A.S.; Andreasen, J.W.; Nielsen, M.M.; Jensen, T.R.

    2005-01-01

    The interaction of hydrogen with an Mg-Al alloy pre-exposed to air have been studied with in situ time resolved X-ray powder diffraction. Phase fractions as a function of time are derived from series of consecutive diffraction patterns allowing kinetic analysis. The apparent activation energy for dehydrogenation of the Mg-Al alloy is found to be 160 kJ/mol. This is not significantly higher than for pure and fully activated Mg. It is suggested that the addition of Al improves the resistance towards oxygen contamination

  4. CO{sub 2} capture in Mg oxides doped with Fe and Ni; Captura de CO{sub 2} en oxidos de Mg dopados con Fe y Ni

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez S, I. F.

    2016-07-01

    In this work the CO{sub 2} capture-desorption characteristics in Mg oxides doped with Fe and Ni obtained by the direct oxidation of Mg-Ni and Mg-Fe mixtures are presented. Mixtures of Mg-Ni and Mg-Fe in a different composition were obtained by mechanical milling in a Spex-type mill in a controlled atmosphere of ultra high purity argon at a weight / weight ratio of 4:1 powder using methanol as a lubricating agent, for 20 h. The powders obtained by mechanical milling showed as main phase, the Mg with nanocrystalline structure. Subsequently, the mixtures of Mg-Ni and Mg-Fe were oxidized within a muffle for 10 min at 600 degrees Celsius. By means of X-ray diffraction analysis, the Mg O with nano metric grain size was identified as the main phase, which was determined by the Scherrer equation. In the Mg O doped with Ni, was identified that as the Ni amount 1 to 5% by weight dispersed in the Mg O matrix was increased, the main peak intensity of the Ni phase increased, whereas in the Mg O doped with Fe was observed by XRD, that the Fe{sub 2}O{sub 3} phase was present and by increasing the amount of Fe (1 to 5% by weight) dispersed in the crystalline phase of Mg O, the intensity of this impurity also increased. Sem-EDS analysis showed that the Ni and Fe particles are dispersed homogeneously in the Mg O matrix, and the particles are porous, forming agglomerates. Through energy dispersive spectroscopy analysis, the elemental chemical composition obtained is very close to the theoretical composition. The capture of CO{sub 2} in the Mg O-1% Ni was carried out in a Parr reactor at different conditions of pressure, temperature and reaction time. Was determined that under the pressure of 0.2 MPa at 26 degrees Celsius for 1 h of reaction, the highest CO{sub 2} capture of 7.04% by weight was obtained, while in Mg O-1% Fe the CO{sub 2} capture was 6.32% by weight. The other magnesium oxides doped in 2.5 and 5% by weight Ni and Fe showed lower CO{sub 2} capture. The different stages

  5. Effect of Adding Elements on Microstructure of Mg-3Si Alloy

    Directory of Open Access Journals (Sweden)

    CUI Bin

    2017-03-01

    Full Text Available The microstructure of alloy Mg-3Si(mass fraction/%, same as below after successive additions with different elements of Zn, Nd, Gd and Y was observed and the microstructure evolution was investigated by scanning electron microscopy and X-ray diffraction. The results show the primary Mg2Si particles co-exist with eutectic Mg2Si particles in binary alloy Mg-Si. With minor addition of Zn element, only primary Mg2Si can be found in ternary Mg-3Si-3Zn system while eutectic Mg2Si particles disappear. In quaternary alloy Mg-2.0Nd-3.0Zn-3.0Si, the addition of Nd element can effectively refine the primary Mg2Si particles and form some Mg41Nd5 particles. After continuous adding of Gd and Y elements into quaternary system, Gd5Si3 and YSi particles increase significantly in the alloy Mg-8.0Gd-4.0Y-2.0Nd-3.0Zn-3.0Si, while volume fraction of primary Mg2Si decrease significantly. Thermo-Calc calculation predicts that the Gibbs free energy for primary particles Gd5Si3, YSi is lower, and therefore Gd, Y atom and Si are more likely to form compounds. In Mg-8Gd-4Y-2Nd-3Zn-3Si alloy, room temperature Gibbs free energy for primary particles Mg2Si, Gd5Si3, YSi is -9.56×104, -8.72×104, -2.83×104J/mol, respectively, and the mass fraction of these particles is 8.07%, 5.27%, 1.40% respectively.

  6. WIPP Magnesium Oxide (MgO) - Planned Change Request

    Science.gov (United States)

    On April 10, 2006, the DOE submitted a planned change request pertaining to the amount of MgO emplaced in the WIPP repository. MgO is an engineered barrier that DOE included as part of the original WIPP Certification Decision.

  7. A Raman spectroscopic study of the structural aspects of K2MgCl4 and Cs2MgCl4 as solid single crystals and molten salts

    International Nuclear Information System (INIS)

    Brooker, M.H.

    1975-01-01

    Polarized Raman spectra have been obtained for oriented single crystals of K 2 MgCl 4 and Cs 2 MgCl 4 at 77 and 298 K. The data are in excellent agreement with factor group analyses based on the space groups I 4 /mmm (D 17 4 /subh/) and Pnma (D 16 2 /subh/) for the K 2 MgCl 4 and Cs 2 MgCl 4 crystals. In K 2 MgCl 4 the magnesium is surrounded by six chloride ions in a distorted octahedral arrangement with a network structure such that neighboring octahedra share corners. In Cs 2 MgCl 4 a discrete tetrahedral MgCl 4 2- species is present. The 35 Cl-- 37 Cl isotopic splitting of the symmetric stetching mode of the tetrahedral MgCl 4 2- species has been resolved at 77 K and is similar to that observed for CCl 4 . Raman spectra for the high temperature solids and molten salts suggest that the coordination number of magnesium changes from six in solid K 2 MgCl 4 to four in the melt, whereas Cs 2 MgCl 4 melts with retention of the MgCl 4 2- tetrahedral complex. Additional evidence is presented to support previous reports that the MgCl 4 2- tetrahedral species is the principal complex ion in the melts, although a fraction of the magnesium appears to be present in a polynuclear complex, perhaps Mg 2 Cl 6 2-

  8. A randomized comparison of daunorubicin 90 mg/m2 vs 60 mg/m2 in AML induction

    DEFF Research Database (Denmark)

    Burnett, A. K.; Russell, N. H.; Hills, R. K.

    2015-01-01

    Modifying induction therapy in acute myeloid leukemia (AML) may improve the remission rate and reduce the risk of relapse, thereby improving survival. Escalation of the daunorubicin dose to 90 mg/m(2) has shown benefit for some patient subgroups when compared with a dose of 45 mg/m(2), and has been...... = .15). In an exploratory subgroup analysis, there was no subgroup that showed significant benefit, although there was a significant interaction by FLT3 ITD mutation. This trial is registered at http://www.isrctn.com as #ISRCTN55675535....

  9. Significance of tear β2-MG radioimmunoassay in herpes simplex keratitis

    International Nuclear Information System (INIS)

    Feng Zhuxu; Zhao Suzhen; Zhang Qiliang; Chen Fengfen; Tang Baoyi

    1994-01-01

    Levels of tear and serum β 2 -MG are determined with radioimmunoassay in 35 patients with herpes simplex keratitis and 40 normal subjects. The results show that tear β 2 -MG levels of patients with herpes simplex keratitis (13.21 +- 6.15 mg/l) and normal subjects (8.43 +- 1.52 mg/l) are significantly different (P 2 -MG levels of tear and that of serum in normal subjects (P 2 -MG levels of tear and that of serum in patients with herpes simplex keratitis (P 2 -MG levels of patients with herpes simplex keratitis and that of normal subjects (P>0.05). The β 2 -MG levels of tear is higher than that of serum in normal subjects which reflects more correctly immune condition of patients with herpes simplex keratitis than that of serum

  10. Mg and Ca isotope fractionation during CaCO3 biomineralisation

    International Nuclear Information System (INIS)

    Chang, Veronica T.-C.; Williams, R.J.P.; Makishima, Akio; Belshawl, Nick S.; O'Nions, R. Keith

    2004-01-01

    The natural variation of Mg and Ca stable isotopes of carbonates has been determined in carbonate skeletons of perforate foraminifera and reef coral together with Mg/Ca ratios to assess the influence of biomineralisation processes. The results for coral aragonite suggest its formation, in terms of stable isotope behaviour, approximates to inorganic precipitation from a seawater reservoir. In contrast, results for foraminifera calcite suggest a marked biological control on Mg isotope ratios presumably related to its low Mg content compared with seawater. The bearing of these observations on the use of Mg and Ca isotopes as proxies in paleoceanography is considered

  11. A new approach to MgB2 superconducting magnet fabrication

    International Nuclear Information System (INIS)

    Miyazoe, A; Ando, T; Wada, H; Abe, H; Hirota, N; Sekino, M

    2008-01-01

    Fabrication of MgB 2 -based superconducting magnets has been attempted by a new approach using film coated on symmetric tubes. Superconducting MgB 2 films have been prepared on iron substrates by electroplating in molten electrolytes. The critical current (I c ) of the MgB 2 electroplating films at 4.2 K and at self-field was 15 A on the basis of 1 μV/cm of I c criterion. A model calculation has shown that MgB 2 -based superconducting magnets based on MgB 2 electroplating films have the potential to generate magnetic fields over 0.5 T

  12. The Microstructure and Tensile Properties of a Newly Developed Mg-Al/Mg3Sb2 In Situ Composite in As-Cast and Extruded Conditions

    Science.gov (United States)

    Montajabnia, A.; Pourbahari, B.; Emamy, M.

    2018-04-01

    The microstructures and tensile properties of Mg-x wt%Al-y wt%Sb alloys have been studied where x/y ratio was 1 and Sb(Al) contents were 5, 10, 15 and 20 wt%, respectively. The results indicated that by increasing Sb(Al) content, not only the crystals of primary Mg3Sb2 alter from small flake-like particles to polygonal or needle-like morphology, but also the eutectic structure changes from semi-continuous network in Mg-5Al-5Sb to continuous network in Mg-20Sb-20Al alloy. The results obtained from thermal analysis revealed different peaks related to the formation of Mg3Sb2 as primary phase and eutectic structure containing Mg17Al12 + Al3Mg2 intermetallic phases. Further results also revealed that Sb(Al) additions change the solidification performance of the material by depressing the Mg3Sb2 nucleation temperature, reducing solidification range and widening eutectic area. Tensile testing results showed that with the increase in Sb (Al) content, ultimate tensile strength (UTS) and elongation values of the alloys are decreased in as-cast condition. But, significant improvement in the UTS and elongation values of the extruded specimens was attributed to the severe fragmentation of intermetallic phases and well distributed fine particles in the matrix which provided proper obstacles for dislocation motion. It was interesting to note that the fracture behavior of intermetallic particles was found to be different, while Mg3Sb2 was ductile, intermetallic compounds in eutectic regions were brittle.

  13. The relationship between visfatin and HOMA-IR in hypertensive patients, and the effect of antihypertensive drugs on visfatin and HOMA-IR in hypertensive patients with insulin resistance.

    Science.gov (United States)

    Lan, Jianjun; Chen, Xiaoni; Chen, Xiaoping; Wang, Si; Zhang, Xin; Wu, Kai; He, Sen; Peng, Yong; Jiang, Lingyun; Li, Longxin; Wan, Liyan

    2011-10-01

    To investigate the correlation between serum visfatin and insulin resistance (IR) in non-diabetic essential hypertensive (EH) patients with and without IR, and to evaluate the effect of antihypertensive treatment on serum visfatin and IR in these patients. A total of 81 non-diabetic EH patients, including 54 with IR and 27 without IR, were enrolled. After two weeks wash-out, patients with IR were randomly assigned to telmisartan (group T) or amlodipine (group A) for 6 months. Blood samples were taken before and after treatment for measurement of routine biochemical parameters, visfatin and insulin resistance (measured by HOMA-IR). Visfatin was independently correlated with HOMA-IR (r=0.845, P=0.000). After 6 months of treatment, both drugs lowered HOMA-IR, more significantly so in group T than group A (P=0.010). Serum visfatin levels increased in group T but decreased in group A. Serum visfatin levels were higher in non-diabetic EH patients with IR compared with those without IR. Visfatin is independently correlated with HOMA-IR. Telmisartan lowers HOMA-IR to a greater extent than amlodipine. Interestingly, serum visfatin increased with telmisartan yet decreased with amlodipine treatment. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  14. Comparison of hydrogen storage properties of pure Mg and milled ...

    Indian Academy of Sciences (India)

    Administrator

    increase the hydriding and dehydriding rates, pure Mg was ground under hydrogen atmosphere (reactive .... Hydrogen storage properties of pure Mg and milled pure Mg. 833. Figure 3. ... elongated and flat shapes via collisions with the steel.

  15. Hydrogen incorporation in high hole density GaN:Mg

    Science.gov (United States)

    Zvanut, M. E.; Uprety, Y.; Dashdorj, J.; Moseley, M.; Doolittle, W. Alan

    2011-03-01

    We investigate hydrogen passivation in heavily doped p-type GaN using electron paramagnetic resonance (EPR) spectroscopy. Samples include both conventionally grown GaN (1019 cm-3 Mg, 1017 cm-3 holes) and films grown by metal modulation epitaxy (MME), which yielded higher Mg (1- 4 x 1020 cm-3) and hole (1- 40 x 1018 cm-3) densities than found in conventionally grown GaN. The Mg acceptor signal is monitored throughout 30 minute annealing steps in N2 :H2 (92%:7%)) and subsequently pure N2 . N2 :H2 heat treatments of the lower hole density films begin to reduce the Mg EPR intensity at 750 o C, but quench the signal in high hole density films at 600 o C. Revival of the signal by subsequent N2 annealing occurs at 800 o C for the low hole density material and 600 o C in MME GaN. The present work highlights chemical differences between heavily Mg doped and lower doped films; however, it is unclear whether the difference is due to changes in hydrogen-Mg complex formation or hydrogen diffusion. The work at UAB is supported by the NSF.

  16. A new reversible Mg3Ag–H2 system for hydrogen storage

    International Nuclear Information System (INIS)

    Si, T.Z.; Zhang, J.B.; Liu, D.M.; Zhang, Q.A.

    2013-01-01

    Highlights: •Mg 3 Ag compound with high-purity was prepared by hydrogen metallurgy. •Mg 3 Ag is first employed for reversible hydrogen storage with altered thermodynamics. •The enhanced cyclic stability is due to the prevention of MgH 2 sintering by MgAg. -- Abstract: For the first time, the compound Mg 3 Ag was employed as a medium for hydrogen storage. It has been demonstrated that the hydriding/dehydriding process of Mg 3 Ag is reversible through the reaction Mg 3 Ag + 2H 2 ↔ 2MgH 2 + MgAg with obtaining altered thermodynamics. An enhanced cycling stability is also achieved by the capacity retention of 95% after 30 cycles, much higher than 70% for the pure Mg sample, which can be explained that the agglomeration and sintering of the resulting MgH 2 are efficiently prevented by the formation of hard and brittle MgAg phase upon multi-cycling

  17. Myasthenia Gravis (MG): Medical Management

    Science.gov (United States)

    ... take effect, prior to surgery or for myasthenic crisis. However, some people receive regular plasmapheresis or IVIg as a supplement to immunosuppressant drugs. Pregnancy In rare cases, pregnancy appears to trigger the onset of MG. ...

  18. Mecanismo de corrosión a refractarios de MgO-C y MgO-C-Al en horno eléctrico

    Directory of Open Access Journals (Sweden)

    Guerrero Barranco, M.

    2010-06-01

    Full Text Available This article presents the results of a post-mortem study of various MgO-C and MgO-C-Al pieces that are used in the electric furnaces at the Acerinox factory in Cádiz. From the chemical, thermal, mineralogical and microstructural characterization of the materials prior to use and post-mortem it has been established that, in both types of refractories, the corrosion has lead to the formation of reaction layers with different chemical and mineralogical composition, as a function of temperature and oxygen partial pressure, ranging from the hot to the cold face and strongly depending on the zone of the electric furnace where the piece is situated. Changes in graphite content have been observed in both types of materials by X-ray diffraction. These changes have been quantified by Differential Thermal Analysis. In MgO-C-Al refractories it has been observed the formation of small amounts of C3Al4 inside the pieces and MgAl2O4 in the refractories’ hot face. Keeping in mind the obtained results and the phase equilibrium diagram of Mg-C-Al-O it has been established a corrosion mechanism for both types of materials. It cannot be established by the present results that additions of Al (≈ 2 % in weight improve the performance of MgO-C materials.

    Se describen los resultados del estudio post-mortem de diversas piezas de MgO-C y MgO-C-Al utilizadas en los hornos eléctricos de la factoría de Acerinox en Cádiz. De la caracterización química, térmica, mineralógica y microestructural de los materiales sin usar y post-mortem se ha establecido que la corrosión ha dado lugar, en ambos tipos de refractarios, a la formación de capas de reacción con distinta composición química y mineralógica, en función de la temperatura y presión parcial de oxígeno en la pieza, que varían desde la cara caliente a la cara fría y dependen fuertemente de la zona del horno eléctrico en que está situada la pieza. En

  19. Significance of serum and urine β2-MG abnormality for diabetes

    International Nuclear Information System (INIS)

    Yu Fengling; Zhang Qiliang; Feng Zhixu; Hou Xiangzhen

    1995-01-01

    Levels of serum and urine β 2 -MG are determined in 114 patients with diabetes. It is found that levels of serum and urine β 2 -MG in diabetes are significantly higher than that of normal contrasts (P 2 -MG are increased with diabetes progress, especially urine β 2 -MG. There is no difference in levels of serum and urine β 2 -MG between non-insulin dependent diabetes mellitus (NIDDM) and insulin dependent diabetes mellitus (IDDM, P>0.05). Urine β 2 -MG levels of diabetes are relatively increased with the increase of serum β 2 -MG levels. Both are obviously positive correlation. While diabetes progressing, both are gradually increased. It can be shown that the longer diabetes process, the more renal function was damaged. Therefore, determination of β 2 -MG is very important for early diagnosing, preventing and treating diabetic nephropathy

  20. Synthesis and optical properties of ZnO/MgO nanocomposite

    International Nuclear Information System (INIS)

    Chawla, Santa; Jayanthi, K.; Chander, Harish; Haranath, D.; Halder, S.K.; Kar, M.

    2008-01-01

    ZnO and its ternary alloy ZnMgO offer an excellent material system with potential in applications related to quantum well and photonic devices in UV and visible. ZnO and ZnO/MgO composite were prepared by solid-state mixing and sintering at high temperature in reducing atmosphere. ZnO/MgO nanocomposites up to 50% Mg content could be prepared by this method. The resultant sample was in powder form and has distribution of grain sizes. X-ray diffraction showed hexagonal ZnO structure with small signature of cubic MgO, which increased with increasing Mg content. Particle size estimated from Scherrer formula was in the range of 40 nm, which reflected the average crystallite size. Photoluminescence (PL) studies showed excitation peak around 290 nm (4.3 eV) and 350 nm (3.5 eV). Pure ZnO nanophosphor showed emission peak around 508 nm, which blue shifted with increasing Mg content. Time resolved decay of PL indicated decay time in the microsecond time scale. Optical absorption spectra showed bandgap about 5.6 eV for ZnO/MgO nanocomposite with 50% Mg content. The optical absorption measurement was done in the colloidal suspension form and it is expected that only nanoparticles of very small grain size were effectively contributing to the optical absorption process. The large bandgap could then be manifestation of quantum size effect