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Sample records for hydrated magnesium sulfate

  1. Surface modification of magnesium hydroxide sulfate hydrate whiskers using a silane coupling agent by dry process

    Science.gov (United States)

    Zhu, Donghai; Nai, Xueying; Lan, Shengjie; Bian, Shaoju; Liu, Xin; Li, Wu

    2016-12-01

    In order to improve the compatibility of magnesium hydroxide sulfate hydrate (MHSH) whiskers with polymers, the surface of MHSH whiskers was modified using vinyltriethoxysilane (VTES) by dry process. The possible mechanism of the surface modification and the interfacial interactions between MHSH whiskers and VTES, as well as the effect of surface modification, were studied. Scanning electronic microscopy (SEM), transmission electron microscopy (TEM) and X-ray powder diffraction (XRD) analyses showed that the agglomerations were effectively separated and a thin layer was formed on the surface of the whiskers after modification. Fourier transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS) analyses showed that the VTES molecules were bound to the surface of MHSH whiskers after modification. Chemical bonds (Sisbnd Osbnd Mg) were formed by the reaction between Sisbnd OC2H5 or Sisbnd OH and the hydroxyl group of MHSH whiskers. The effect of surface modification was evaluated by sedimentation tests, contact angle measurements and thermogravimetric analysis (TGA). The results showed that the surface of MHSH whiskers was transformed from hydrophilic to hydrophobic, and the dispersibility and the compatibility of MHSH whiskers were significantly improved in the organic phase. Additionally, the thermal stability of the VTES-modified MHSH whiskers was improved significantly.

  2. 21 CFR 184.1443 - Magnesium sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium sulfate. 184.1443 Section 184.1443 Food... Specific Substances Affirmed as GRAS § 184.1443 Magnesium sulfate. (a) Magnesium sulfate (MgSO4·7H2O, CAS... magnesium oxide, hydroxide, or carbonate with sulfuric acid and evaporating the solution to...

  3. 21 CFR 582.5443 - Magnesium sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Magnesium sulfate. 582.5443 Section 582.5443 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5443 Magnesium sulfate. (a) Product. Magnesium sulfate. (b) Conditions of use....

  4. 碱式硫酸镁晶须水热过程结晶动力学研究%Hydrothermal Crystallization Kinetics of Magnesium Hydroxide Sulfate Hydrate Whiskers

    Institute of Scientific and Technical Information of China (English)

    高传慧; 王传兴; 许军; 武玉民; 李先国

    2012-01-01

    Magnesium hydroxide sulfate hydrate whiskers were prepared by a hydrothermal method and scanning electron microscope, transmission electron microscope, X-ray powder diffraction and energy dispersive X-ray spectroscopy were employed to investigate composition and morphology of the products. Crystallization kinetics of the whisker was studied by analyzing the change of SO42- ion concentration through the hydrothermal process at different temperatures. Experimental data were handled using software MATLAB and numerical solution of Runge-Kutta and crystallization kinetics equations at different temperatures were obtained according to the above mentioned analysis. The results showed that the mechanism for crystal growth was different when the whiskers were synthesized at different temperatures. When the reaction occurred at 170 ℃, 180 ℃ and 190 ℃, the crystallization was controlled by multi-core surface growth, and the dynamic models for the crystallization were MB-1, MB-2 and MB-3, respectively. While it changed to be controlled by single-core surface growth when the reaction temperature was 200 ℃ or 210 ℃ and the dynamic models became MC-2 and MC-3 correspondingly.%采用水热法合成了碱式硫酸镁晶须,利用扫描电镜、透射电镜、X射线能谱仪和X射线衍射仪等对产物的形貌和组成进行表征.通过考察不同温度下SO42-浓度随时间的变化,对碱式硫酸镁晶须的结晶动力学进行了研究.利用MATLAB软件和Runge-Kutta数值解法对实验数据进行处理,得出不同温度下晶须的结晶动力学方程.对晶须的几种生长机理模型进行分析发现,低温和高温的动力学模型不同,反应温度为170℃、180℃、190℃时的动力学模型分别为MB-1 、MB-2和MB-3,结晶机理为多核控制表面生长,结晶速率由表面反应控制;反应温度为200℃和210℃时,结晶机理发生了变化,为单核控制表面生长,结晶动力学模型分别为MC-2和MC-3.

  5. Temperature-dependent VNIR spectroscopy of hydrated Mg-sulfates

    Science.gov (United States)

    De Angelis, S.; Carli, C.; Tosi, F.; Beck, P.; Schmitt, B.; Piccioni, G.; De Sanctis, M. C.; Capaccioni, F.; Di Iorio, T.; Philippe, Sylvain

    2017-01-01

    We investigate two poly-hydrated magnesium sulfates, hexahydrite (MgSO4 · 6H2O) and epsomite (MgSO4 · 7H2O), in the visible and infrared (VNIR) spectral range 0.5/4.0 μm, as particulate for three different grain size ranges: 20-50 μm, 75-100 μm and 125-150 μm. All samples were measured in the 93-298 K temperature range. The spectra of these hydrated salts are characterized by strong OH absorption bands in the 1.0-1.5 μm region, and by H2O absorption bands near 2 and 3 μm. Other weak features show up at low temperatures near 1.75 μm (in both hexahydrite and epsomite) and 2.2 μm (only in hexahydrite). The spectral behavior of the absorption bands of these two minerals has been analyzed as a function of both grain size and temperature, deriving trends related to specific spectral parameters such as band center, band depth, band area, and band width. Hydrated minerals, in particular mono- and poly-hydrated sulfates, are present in planetary objects such as Mars and the icy Galilean satellites. Safe detection of these minerals shall rely on detailed laboratory investigation of these materials in different environmental conditions. Hence an accurate spectral analysis of such minerals as a function of temperature is key to better understand and constrain future observations.

  6. Intravenous magnesium sulfate therapy in severe asthma

    Directory of Open Access Journals (Sweden)

    Mohd. Al-Ajmi

    2007-01-01

    Full Text Available A 22-year-old female, known asthmatic since seven years, developed severe bronchospasm in the preop-erative period. Bronchospasm remained unresponsive to the inhaled beta-agonist plus anticholinergic, IV ami-nophylline and hydrocortisone but responded quickly with magnesium sulfate® ( PSI, KSA infusion 1.25gm in 100ml normal saline over 20 minutes and another 1.25 gm over next 30 minutes as the initial infusion showed improvement in her clinical symptoms. Within half an hour of administering the 1st infusion of magnesium sulfate (1.25 gm the respiratory rate started reducing, rhonchi became less, SpO 2 came upto 92% and re-mained always above 90%. Encouraged by this result IV magnesium sulfate 2.5 gm in 500 ml normal saline was infused over next 24 hours along with alternate salbutamol and ipratropium nebulization every 6 hourly. With this treatment regimen the patient became asymptomatic within next 24 hours with normal clinical parameters and FEV 1 value. Hence it may be concluded that IV magnesium sulfate can be considered for patients with acute severe asthma who do not respond to standard therapeutic medications.

  7. Phase equilibria of the magnesium sulfate-water system to 4 kbars

    Science.gov (United States)

    Hogenboom, D. L.; Kargel, J. S.; Ganasan, J. P.; Lee, L.

    1993-01-01

    Magnesium sulfate is the most abundant salt in carbonaceous chondrites, and it may be important in the low-temperature igneous evolution and aqueous differentiation of icy satellites and large chondritic asteroids. Accordingly, we are investigating high-pressure phase equilibria in MgSO4-H2O solutions under pressures up to four kbars. An initial report was presented two years ago. This abstract summarizes our results to date including studies of solutions containing 15.3 percent, 17 percent, and 22 percent MgSO4. Briefly, these results demonstrate that increasing pressure causes the eutectic and peritectic compositions to shift to much lower concentrations of magnesium sulfate, and the existence of a new low-density phase of magnesium sulfate hydrate.

  8. Effects of magnesium sulfate on traumatic brain edema in rats

    Institute of Scientific and Technical Information of China (English)

    冯东福; 朱志安; 卢亦成

    2004-01-01

    Objective: To investigate the effects of magnesium sulfate on traumatic brain edema and explore its possible mechanism.Methods: Forty-eight Sprague-Dawley ( SD ) rats were randomly divided into three groups: Control, Trauma and Treatment groups. In Treatment group, magnesium sulfate was intraperitoneally administered immediately after the induction of brain trauma. At 24 h after trauma, total tissue water content and Na + , K + , Ca2 + , Mg2+ contents were measured. Permeability of blood-brain barrier (BBB)was assessed quantitatively by Evans Blue (EB) dye technique. The pathological changes were also studied.Results: Water, Na + , Ca2 + and EB contents in Treatment group were significantly lower than those in Trauma group ( P < 0. 05 ). Results of light microscopy and electron microscopy confirmed that magnesium sulfate can attenuate traumatic brain injury and relieve BBB injury.Conclusions: Treatment with MgSO4 in the early stage can attenuate traumatic brain edema and prevent BBB injury.

  9. Sulfate Hydration States in Interpretation of Martian Mineral Assemblages

    Science.gov (United States)

    Vaniman, D. T.; Bish, D. L.

    2008-12-01

    Remote spectral data and surface-measured chemical associations with S indicate widespread distribution of Mg-, Ca-, and Fe-sulfate salts on Mars. These salts are identified at least in part as hydrates, but spectral data and the low temperatures and low pH2O of Mars suggest that hydration states vary with origin, latitude, and exposure history. An understanding of stability limits and dehydration/rehydration rates is vital to understanding occurrences that may be interpreted variously as lacustrine, alteration via groundwater or discharge with evaporation, surface weathering, thermal brine systems, eolian recycling, or others. Different sulfates on Mars have varied susceptibility to desiccation at relatively warm, low-RH conditions or to hydration at cold, high-RH conditions. This variability provides a potent tool for interpreting exposure history. Among Ca-sulfates, gypsum and insoluble anhydrite should be stable and remain, respectively, fully hydrated or water-free at most latitudes and through diurnal and seasonal cycles, but bassanite is more sensitive to transient hydration. Mg-sulfates may have various values of n in the formula MgSO4.nH2O, and rehydration of desiccated forms often produces metastable phases. At low pH2O, unlike Ca- sulfates, amorphous forms appear with low values of n dependent, in part, on temperature. Kieserite resists dehydration but may hydrate in conditions where ice is stable at the surface. Fe-sulfates have more complex dehydration and rehydration properties. Jarosite is very resilient because of the lack of H2O molecules and presence of OH. Other Fe-sulfates are not so durable, e.g., coquimbite (Fe2 (SO4)3.9H2O) has independent H2O and dehydration on heating to 30 °C produces an amorphous product that does not rehydrate. Copiapite is similarly susceptible to dehydration. Modest heating of many H2O-bearing ferric sulfates can be destructive, and degradation can produce both cemented solids and viscous liquids. Sulfate salt

  10. Thermodynamics of Ion Pair of Magnesium Sulfate in Mixed Solvent

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Introduction Magnesium sulfate is an archetypal 2-2 salt that plays a central role in defining the characteristics of higher valent electrolyte solutions and its solution has been widely used to test various theories of strong electrolyte behavior and to develop models of ion association in solution[1]. Up to now, the ion pairs of magnesium sulfate in an aqueous solution have been widely investigated by using different experimental techniques, such as conductometry[2] , cryoscopy[3] , potentiometry[4] ,solubility[5] and Raman spectrometry[6]. However, to our knowledge, no measurement of the standard association constant of the ion pairs, [MgSO4] 0 in a glucosewater mixed solvent is available.

  11. Role of magnesium sulfate in neuroprotection in acute ischemic stroke

    Directory of Open Access Journals (Sweden)

    Harpreet Singh

    2012-01-01

    Full Text Available Aims: To study the effect of intravenous magnesium sulfate infusion on clinical outcome of patients of acute stroke. Materials and Methods: Sixty consecutive cases of acute ischemic stroke hospitalised within 24 h of an episode of stroke were taken as subjects. All subjects underwent a computed tomography head, and those found to have evidence of bleed/space-occupying lesions were excluded from the study. The subjects taken up for the study were divided into two groups of 30 subjects each. Both the groups received the standard protocol management for acute ischemic stroke. Subjects of Group 1 additionally received intravenous magnesium sulfate as initial 4 g bolus dose over 15 min followed by 16 g as slow infusion over the next 24 h. In all the subjects of the two study groups, serum magnesium levels were estimated at the time of admission (Day 0, Day 1 and Day 2 of hospitalization using an atomic absorption spectrometer. Statistical Analysis Used: Scandinavian stroke scores were calculated on Day 3, day of discharge and Day 28. Paired t-test was employed for comparison of stroke scores on Day 3, day of discharge and Day 28 within the same group and the unpaired t-test was used for the intergroup comparison, i.e. comparison of stroke scores of control group with corresponding stroke scores of magnesium group. Results: Comparison of stroke scores on Day 3 and day of discharge, on the day of discharge and Day 28 and on Day 3 and Day 28 in the magnesium group produced a t-value of 5.000 and P 0.05, which was not significant. Conclusions: The study failed to document a statistical significant stroke recovery in spite of achieving a significant rise in serum magnesium level, more than that necessary for neuroprotection, with an intravenous magnesium sulfate regime.

  12. Attack of Limestone Cement-based Material Exposed to Magnesium Sulfate Solution at Low Temperature

    Institute of Scientific and Technical Information of China (English)

    ZHANG Fengchen; WU Shengxing; FANG Yonghao; ZHOU Jikai; LI Zhonghua

    2014-01-01

    Limestone in cement could be a source of CO32-needed for thaumasite formation which will result in thaumasite form of sulfate attack (TSA) probably. TSA has more deterioration than ettringite or gypsum form of sulfate attack because it targets the calcium silicate hydrates (C-S-H) which is the main binder phase in all Portland cement-based materials. By means of physical and mechanical property testing as well as erosion phases analysis, magnesium sulfate attack of cement-based material containing 35% limestone powder by mass at 5 ± 2℃is investigated. The compressive strength and flexural strength of mortar specimen immersed in MgSO4 solution increase firstly, then decrease rapidly with the immersing age. Relative dynamic elastic modulus of mortar specimen changes in a phased process. After immersing in MgSO4 solution for 15 weeks, the main erosion phases in paste specimen change from four phases compounds, three phases compounds to two phases compounds from surface to inside. Deterioration course of limestone cement-based material exposed to magnesium sulfate aggressive environment appears progressive damage layer by layer, and every layer probably suffers four stages, which are property strengthening stage, initial degradation stage, thaumasite formation stage and cementation loss stage, respectively.

  13. Progressive muscle weakness with respiratory insufficiency in a young patient with tetanus during magnesium sulfate infusion.

    Science.gov (United States)

    Mathew, Preethy Joseph; Muthurajan, Narayanan; Wig, Jyotsna

    2010-09-01

    Magnesium sulfate administered as an intravenous infusion is considered safe. However, there have been concerns about the neuromuscular blocking properties of magnesium that can cause respiratory insufficiency. We report a patient with mild tetanus who, after being started on magnesium infusion, developed progressive respiratory insufficiency, proximal muscle weakness and ptosis. On discontinuation of magnesium infusion, the muscular weakness improved and respiration became normal. The safety of magnesium sulfate infusion for the management of tetanus needs to be re-evaluated.

  14. Using Terrestrial Sulfate Efflorescences as an Analogue of Hydrated Sulfate Formation in Valles Marineris on Mars

    Science.gov (United States)

    Smith, P. C.; Szynkiewicz, A.

    2015-12-01

    Hydrated sulfate minerals provide conclusive evidence that a hydrologic cycle was once active on the surface of Mars. Two classes of hydrated sulfate minerals have been detected by robotic instruments on Mars: monohydrated sulfate minerals comprised of kieserite and gypsum, and various polyhydrated sulfates with Fe-Ca-Na-Mg-rich compositions. These minerals are found in various locations on Mars, including large surface exposures in valley settings of Valles Marineris. However, the sulfate sources and formation mechanisms of these minerals are not yet well understood.Recently, it has been suggested that the sulfate minerals in Valles Marineris might have formed in a manner similar to sulfate efflorescences found in dry environments on Earth. In this study, we use sulfate effloresences from the Rio Puerco Watershed, New Mexico as a terrestrial analogue to assess major factors that might have led to deposition of sulfate minerals in Valles Marineris. In different seasons indicative of dry and wet conditions, we collected field photographs and sediment samples for chemical and stable isotopic analyses (sulfur content, δ34S) to determine major sources of sulfate ions for efflorescences and to assess how the seasonal changes in surface/groundwater activity affect their formation. Preliminary sulfur isotope results suggest that oxidation of bedrock sulfides (0.01-0.05 wt. S %) is a major source of sulfate ion for efflorescences formation because their δ34S varied in negative range (-28 to -20‰) similar to sulfides (average -32‰). Using field photographs collected in Oct 2006, Feb and Nov 2012, May 2013, Mar and Oct 2014, we infer that the highest surface accumulation of sulfate efflorescences in the studied analog site was observed after summer monsoon seasons when more water was available for surface and subsurface transport of solutes from chemical weathering. Conversely, spring snow melt led to enhanced dissolution of sulfate efflorescences.

  15. Ab Initio Thermodynamic Model for Magnesium Carbonates and Hydrates

    Energy Technology Data Exchange (ETDEWEB)

    Chaka, Anne M.; Felmy, Andrew R.

    2014-03-28

    An ab initio thermodynamic framework for predicting properties of hydrated magnesium carbonate minerals has been developed using density-functional theory linked to macroscopic thermodynamics through the experimental chemical potentials for MgO, water, and CO2. Including semiempirical dispersion via the Grimme method and small corrections to the generalized gradient approximation of Perdew, Burke, and Ernzerhof for the heat of formation yields a model with quantitative agreement for the benchmark minerals brucite, magnesite, nesquehonite, and hydromagnesite. The model shows how small differences in experimental conditions determine whether nesquehonite, hydromagnesite, or magnesite is the result of laboratory synthesis from carbonation of brucite, and what transformations are expected to occur on geological time scales. Because of the reliance on parameter-free first principles methods, the model is reliably extensible to experimental conditions not readily accessible to experiment and to any mineral composition for which the structure is known or can be hypothesized, including structures containing defects, substitutions, or transitional structures during solid state transformations induced by temperature changes or processes such as water, CO2, or O2 diffusion. Demonstrated applications of the ab initio thermodynamic framework include an independent means to evaluate differences in thermodynamic data for lansfordite, predicting the properties of Mg analogs of Ca-based hydrated carbonates monohydrocalcite and ikaite which have not been observed in nature, and an estimation of the thermodynamics of barringtonite from the stoichiometry and a single experimental observation.

  16. Ab initio thermodynamic model for magnesium carbonates and hydrates.

    Science.gov (United States)

    Chaka, Anne M; Felmy, Andrew R

    2014-09-04

    An ab initio thermodynamic framework for predicting properties of hydrated magnesium carbonate minerals has been developed using density-functional theory linked to macroscopic thermodynamics through the experimental chemical potentials for MgO, water, and CO2. Including semiempirical dispersion via the Grimme method and small corrections to the generalized gradient approximation of Perdew, Burke, and Ernzerhof for the heat of formation yields a model with quantitative agreement for the benchmark minerals brucite, magnesite, nesquehonite, and hydromagnesite. The model shows how small differences in experimental conditions determine whether nesquehonite, hydromagnesite, or magnesite is the result of laboratory synthesis from carbonation of brucite, and what transformations are expected to occur on geological time scales. Because of the reliance on parameter-free first-principles methods, the model is reliably extensible to experimental conditions not readily accessible to experiment and to any mineral composition for which the structure is known or can be hypothesized, including structures containing defects, substitutions, or transitional structures during solid state transformations induced by temperature changes or processes such as water, CO2, or O2 diffusion. Demonstrated applications of the ab initio thermodynamic framework include an independent means to evaluate differences in thermodynamic data for lansfordite, predicting the properties of Mg analogues of Ca-based hydrated carbonates monohydrocalcite and ikaite, which have not been observed in nature, and an estimation of the thermodynamics of barringtonite from the stoichiometry and a single experimental observation.

  17. Inadvertent intrathecal injection of large dose magnesium sulfate

    Directory of Open Access Journals (Sweden)

    Atabak Najafi

    2013-01-01

    Full Text Available The case is a 35-year-old man who underwent spinal anesthesia for emergency strangulated inguinal hernia repair. About five minutes after 3 ml intrathecal drug injection, the patient suffered respiratory distress, bradycardia, hypotension and loss of consciousness. The patient was rapidly intubated and crystalloid infusion and epinephrine drip were established. Thereafter, he was admitted in intensive care unit. Search for the cause revealed us that 3 ml of magnesium sulfate (50% was injected mistakenly for spinal anesthesia. Two days later, he was extubated and on the fifth day, he was discharged from the hospital without an obvious evidence of complication.

  18. The analysis of magnesium oxide hydration in three-phase reaction system

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Xiaojia; Guo, Lin; Chen, Chen; Liu, Quan; Li, Tie; Zhu, Yimin, E-mail: ntp@dlmu.edu.cn

    2014-05-01

    In order to investigate the magnesium oxide hydration process in gas–liquid–solid (three-phase) reaction system, magnesium hydroxide was prepared by magnesium oxide hydration in liquid–solid (two-phase) and three-phase reaction systems. A semi-empirical model and the classical shrinking core model were used to fit the experimental data. The fitting result shows that both models describe well the hydration process of three-phase system, while only the semi-empirical model right for the hydration process of two-phase system. The characterization of the hydration product using X-Ray diffraction (XRD) and scanning electron microscope (SEM) was performed. The XRD and SEM show hydration process in the two-phase system follows common dissolution/precipitation mechanism. While in the three-phase system, the hydration process undergo MgO dissolution, Mg(OH){sub 2} precipitation, Mg(OH){sub 2} peeling off from MgO particle and leaving behind fresh MgO surface. - Graphical abstract: There was existence of a peeling-off process in the gas–liquid–solid (three-phase) MgO hydration system. - Highlights: • Magnesium oxide hydration in gas–liquid–solid system was investigated. • The experimental data in three-phase system could be fitted well by two models. • The morphology analysis suggested that there was existence of a peel-off process.

  19. Growth performance and root transcriptome remodeling of Arabidopsis in response to Mars-like levels of magnesium sulfate.

    Directory of Open Access Journals (Sweden)

    Anne M Visscher

    Full Text Available BACKGROUND: Martian regolith (unconsolidated surface material is a potential medium for plant growth in bioregenerative life support systems during manned missions on Mars. However, hydrated magnesium sulfate mineral levels in the regolith of Mars can reach as high as 10 wt%, and would be expected to be highly inhibitory to plant growth. METHODOLOGY AND PRINCIPAL FINDINGS: Disabling ion transporters AtMRS2-10 and AtSULTR1;2, which are plasma membrane localized in peripheral root cells, is not an effective way to confer tolerance to magnesium sulfate soils. Arabidopsis mrs2-10 and sel1-10 knockout lines do not mitigate the growth inhibiting impacts of high MgSO(4.7H(2O concentrations observed with wildtype plants. A global approach was used to identify novel genes with potential to enhance tolerance to high MgSO(4.7H(2O (magnesium sulfate stress. The early Arabidopsis root transcriptome response to elevated concentrations of magnesium sulfate was characterized in Col-0, and also between Col-0 and the mutant line cax1-1, which was confirmed to be relatively tolerant of high levels of MgSO(4.7H(2O in soil solution. Differentially expressed genes in Col-0 treated for 45 min. encode enzymes primarily involved in hormone metabolism, transcription factors, calcium-binding proteins, kinases, cell wall related proteins and membrane-based transporters. Over 200 genes encoding transporters were differentially expressed in Col-0 up to 180 min. of exposure, and one of the first down-regulated genes was CAX1. The importance of this early response in wildtype Arabidopsis is exemplified in the fact that only four transcripts were differentially expressed between Col-0 and cax1-1 at 180 min. after initiation of treatment. CONCLUSIONS/SIGNIFICANCE: The results provide a solid basis for the understanding of the metabolic response of plants to elevated magnesium sulfate soils; it is the first transcriptome analysis of plants in this environment. The results foster

  20. Comparison between magnesium sulfate and dexmedetomidine in controlled hypotension during functional endoscopic sinus surgery

    OpenAIRE

    Adnan Bayram; Ayse Ülgey; Isin Günes; Ibrahim Ketenci; Ayse Çapar; Aliye Esmaoglu; Adem Boyaci

    2015-01-01

    BACKGROUND AND OBJECTIVES: It is crucial to decrease bleeding during functional endoscopic sinus surgery. Our primary goal was to investigate the effects of magnesium sulfate and dexmedetomidine used for controlled hypotension on the visibility of the surgical site. METHODS: 60 patients aged between 18 and 65 years were enrolled. In the magnesium sulfate ...

  1. Formation of magnesium silicate hydrates (M-S-H)

    Science.gov (United States)

    Bernard, Ellina; Lothenbach, Barbara; Rentsch, Daniel; Pochard, Isabelle; Dauzères, Alexandre

    2017-06-01

    The formation of magnesium silicate hydrates (M-S-H) with MgO to SiO2 ratios from 0.7 to 1.6 has been studied at 20, 50 and 70 °C. TGA and XRD data reveal that initially brucite and M-S-H are formed while amorphous silica is still present as indicated by FT-IR and 29Si MAS NMR experiments. In this first step M-S-H with Mg/Si ∼1 with pH values ∼9.4 is formed independently of the total Mg/Si. Investigations by FT-IR and 29Si MAS NMR detail that the structure of that initial M-S-H evolved with time and M-S-H formed with Mg/Si ranging from ∼0.8 to ∼1.3 after 2 years at 20 °C and after 1 year at 50 and 70 °C. This implies that the composition of synthetic M-S-H depends strongly on temperature and equilibration time. At 50 and 70 °C the M-S-H formation occurs faster although it is thermodynamically slightly less stable. The solubility of M-S-H, talc and antigorite after 1 year or longer shows comparable trends.

  2. IV Magnesium Sulfate for Bronchiolitis: A Randomized Trial.

    Science.gov (United States)

    Alansari, Khalid; Sayyed, Rafah; Davidson, Bruce L; Al Jawala, Shahaza; Ghadier, Mohamed

    2017-07-01

    The goal of this study was to determine if IV magnesium, useful for severe pediatric asthma, reduces time to medical readiness for discharge in patients with bronchiolitis when added to supportive care. We compared a single dose of 100 mg/kg of IV magnesium sulfate vs placebo for acute bronchiolitis. Patients received bronchodilator therapy, nebulized hypertonic saline, and 5 days of dexamethasone if there was eczema and/or a family history of asthma. Time to medical readiness for discharge was the primary efficacy outcome. Bronchiolitis severity scores and need for infirmary or hospital admission and for clinic revisits within 2 weeks were secondary outcomes. Cardiorespiratory instability onset was the safety outcome. A total of 162 previously healthy infants diagnosed with bronchiolitis aged 22 days to 17.6 months (median, 3.7 months) were enrolled. Approximately one-half of patients had eczema and/or a family history of asthma; 86.4% had positive findings on nasopharyngeal virus swabs. Geometric mean time until medical readiness for discharge was 24.1 h (95% CI, 20.0-29.1) for the 78 magnesium-treated patients and 25.3 h (95% CI, 20.3-31.5) for the 82 patients receiving placebo (ratio, 0.95 [95% CI, 0.52-1.80]; P = .91). Mean bronchiolitis severity scores over time were similar for the two groups. The frequency of clinic visits in the subsequent 2 weeks (33.8% and 27.2%, respectively) was also similar. Fifteen magnesium recipients (19.5%) vs five placebo recipients (6.2%) were readmitted to the infirmary or hospital within 2 weeks (P = .016). No acute cardiorespiratory side effects were reported. IV magnesium did not provide benefit for patients with acute bronchiolitis and may be harmful. ClinicalTrials.gov; No.: NCT02145520; URL: www.clinicaltrials.gov. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

  3. The analysis of magnesium oxide hydration in three-phase reaction system

    Science.gov (United States)

    Tang, Xiaojia; Guo, Lin; Chen, Chen; Liu, Quan; Li, Tie; Zhu, Yimin

    2014-05-01

    In order to investigate the magnesium oxide hydration process in gas-liquid-solid (three-phase) reaction system, magnesium hydroxide was prepared by magnesium oxide hydration in liquid-solid (two-phase) and three-phase reaction systems. A semi-empirical model and the classical shrinking core model were used to fit the experimental data. The fitting result shows that both models describe well the hydration process of three-phase system, while only the semi-empirical model right for the hydration process of two-phase system. The characterization of the hydration product using X-Ray diffraction (XRD) and scanning electron microscope (SEM) was performed. The XRD and SEM show hydration process in the two-phase system follows common dissolution/precipitation mechanism. While in the three-phase system, the hydration process undergo MgO dissolution, Mg(OH)2 precipitation, Mg(OH)2 peeling off from MgO particle and leaving behind fresh MgO surface.

  4. Dry Climate as Major Factor Controlling Formation of Hydrated Sulfate Minerals in Valles Marineris on Mars

    Science.gov (United States)

    Szynkiewicz, A.

    2016-12-01

    In this study, a model for the formation of hydrated sulfate salts (Mg-Ca-Na sulfates) in the Rio Puerco watershed of New Mexico, a terrestrial analog site from the semi-arid Southwest U.S., was used to assess the origin and climate condition that may have controlled deposition of hydrated sulfates in Valles Marineris on Mars. In this analog site, the surface accumulation of sulfate minerals along canyon walls, slopes and valley surfaces closely resemble occurrences of hydrated sulfates in Valles Marineris on Mars. Significant surface accumulations of Mg-Ca-Na sulfates are a result of prevailing semiarid conditions and a short-lived hydrological cycle that mobilizes sulfur present in the bedrock as sulfides, sulfate minerals, and atmospheric deposition. Repeating cycles of salt dissolution and re-precipitation appear to be the underpinning processes that serve to transport sulfate from bedrock to sulfate salts (e.g., efflorescences) and into surface water. This process occurs in the shallow surface environment and is not accompanied by deep groundwater flow because of prevailing dry conditions and low annual precipitation. Generally, close resemblance of surface occurrence and mineralogical composition of sulfate salts between the studied terrestrial analog and Valles Marineris suggest that a similar sulfate cycle, involving limited water activity during formation of hydrated sulfates, was once present in Valles Marineris. Measured as efflorescence, the distributed surface mass of hydrated sulfates in Valles Marineris is relatively small (4 to 42%) when compared to terrestrial settings with higher surface accumulation of sulfate minerals such as the White Sands gypsum dune field. Under semi-arid conditions similar to the studied analog in the Rio Pueurco watershed, it would take only 100 to 1,000 years to activate an equivalent flux of aqueous sulfate in Valles Marineris, when comparing terrestrial annual sulfate fluxes from the Rio Puerco watershed with the amount

  5. ACTION DURATION OF ATRACURIUM IN HYPERTENSIVE PREGNANT PATIENTS WHO RECEIVED MAGNESIUM SULFATE

    Directory of Open Access Journals (Sweden)

    P SAJEDI

    2000-03-01

    Full Text Available Introduction. Usually, infusion of intermittent doses of succinylcholin is used for relaxation of muscles in the preeclamptic pregnant women treated with magnesium sulfate during cesarian. section This drug has complications such as hyperkalemia, phase 11block, etc. On the other hand non depolarizing muscle relaxant in these patients should be used only in the presence of nerve stimulator and with careful titration. Methods. Duration of clinical action of a medium acting non depolarizing muscle relaxant "atracurium" with succinylcolin's infusion was studied in 86 preeclamptic pregnant women who received therapeutic doses of magnesium sulfate. Findings. Magnesium sulfate did not prolong clinical action of atracurium. Conclusion. Based on this study it can be concluded that administration of atracurium in the pregnant women who received therapeutic dose of magnesium sulfate in the absence of peripheral nerve stimulator is not contraindicated.

  6. Comparison of efficacy and safety of nifedipine versus magnesium sulfate in treatment of preterm labor

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    Ali Akbar Taherian

    2007-07-01

    Full Text Available

    BACKGROUND: Preterm labor with intact membrane is responsible for approximately one-third of preterm births, which account for about 70-80% of all neonatal deaths among normally formed neonates. Premature delivery is the leading cause of perinatal morbidity and mortality. In this study we have compared the safety and efficacy of nifedipine and magnesium sulfate in treatment of preterm labor.
    METHODS: In this study, 120 pregnant women experiencing preterm labor at 26-36 weeks gestation were randomly selected to receive either oral nifedipine or intravenous magnesium sulfate. The efficacy and side effects related to nifedipine or magnesium sulfate were recorded and all data was analyzed with SPSS software, using t student, chisquire and fisher exact tests.
    RESULTS: Twenty two of 57 (38.6% patients in the nifedipine group and 31 of 63 (49.2% patients in the magnesium sulfate group were delivered before discharge. In 25 (43.8% patients in the nifedipine group and 24 (38% patients in the magnesium sulfate group, pregnancy was continued until the 34th-36th week, at which time the patients were delivered. No significant difference has been found concerning any of the following: delivery postponement, drug side effects or neonatal outcomes between nifedipine and magnesium sulfate groups (P>0.05.
    CONCLUSIONS: Oral nifedipine may be a suitable alternative to magnesium sulfate, with the same efficacy and side effects.
    KEYWORDS: Nifedipine, magnesium sulfate, preterm labor.

  7. Gas chromatographic thermodynamics on hydration processes of magnesium chloride with low water

    Institute of Scientific and Technical Information of China (English)

    陈建军; 陈关城; 马培华; 保积庆; 马玉涛; 陈丰秋

    2003-01-01

    The dehydration and hydration processes of magnesium chloride hydrates were studied by means of frontal chromatography analysis, calorimetry, thermogravimetry and chemical analysis. The mathematical imitation for the adsorption isotherms of MgCl2*4H2O and MgCl2*2H2O at different temperatures indicates that Boltzmann Function is the ideal equation to describe those adsorption isotherms. Its adsorption heat is -13.06kJ/mol and -16.11kJ/mol, respectively. The adsorption equilibrium constants are also given. From the data obtained, there is a thermodynamical possibility to use partial dehydrated magnesium chloride hydrates as an absorbance to clean water vapor contained in bischophite dehydration equipment and let the protection gas HCl recycle in the fluid bed reaction system.

  8. A Dose – Response Study of Magnesium Sulfate in Suppressing Cardiovascular Responses to Laryngoscopy & Endotracheal Intubation

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    K Montazeri

    2005-03-01

    Full Text Available Background: The effects of pretreatment with magnesium on cardiovascular responses associated with intubation have been studied previously. In this study we wanted to find optimal dose of magnesium that causes decreased cardiovascular responses after laryngoscopy & endotracheal intubation. Methods: In a double-blind , randomized, clinical trial ,120 ASA-1 patients with ages between 15-50 years old , who were candidates for elective surgery, were selected and classified in 6 groups (20 patients in each . The pulse rate and arterial blood pressure were measured and recorded at 5 minutes before taking any drug then, according to different groups, patients took magnesium sulfate (10, 20, 30, 40, 50mg/kg and lidocaine (1.5 mg/kg. The induction of anesthesia was same in all groups and the pulse rate and arterial blood pressure were measured and recorded just before intubation and also at 1, 3 , and 5 minutes after intubation (before surgical incision . Statistical analysis was performed by use of ANOVA, Post Hoc test (Duncan, Pearson correlation, and Chi square test. Results: there were no statistically significant differences in blood pressure, pulse rate, Train Of Four (TOF, and complications between groups who received magnesium but the significant differences in these parameters were seen between magnesium and lidocaine groups. Conclusion: We concluded that pretreatment with different doses of magnesium sulfate have a safe decreasing effect on cardiovascular responses that is more effective than pretreatment with lidocaine. Keywords: magnesium sulfate, cardiovascular responses, lidocaine.

  9. Influence of recycled fine aggregates on the resistance of mortars to magnesium sulfate attack.

    Science.gov (United States)

    Lee, Seung-Tae

    2009-08-01

    The influence of recycled fine aggregates, which had been reclaimed from field-demolished concretes, on the resistance of mortar specimens to magnesium sulfate attack was investigated. Mortar specimens were prepared with recycled fine aggregates at different replacement levels (0%, 25%, 50%, 75% and 100% of natural fine aggregate by mass). The mortar specimens were exposed to 4.24% magnesium sulfate solution for about 1 year at ambient temperature, and regularly monitored for visual appearance, compressive strength loss and expansion. Additionally, in order to identify products of magnesium sulfate attack, mortar samples incorporating 0%, 25% and 100% replacement levels of the recycled fine aggregates were examined by X-ray diffraction (XRD) technique. Experimental results confirmed that the use of recycled fine aggregates up to a maximum 50% replacement level is effective under severe magnesium sulfate environment, irrespective of type of recycled fine aggregates. However, the worse performance was observed in mortar specimens incorporating 100% replacement level. It was found that the water absorption of recycled fine aggregates affected deterioration of mortar specimens, especially at a higher replacement level. XRD results indicated that the main cause of deterioration of the mortar specimens was primarily due to the formation of gypsum and thaumasite by magnesium sulfate attack. In addition, it appeared that the conversion of C-S-H into M-S-H by the attack probably influenced mechanical deterioration of mortar specimens with recycled fine aggregates.

  10. Experimental study and modelling of sulfate sorption on calcium silicate hydrates; Etude experimentale et modelisation de l'adsorption de sulfates sur des silicates de calcium hydrates

    Energy Technology Data Exchange (ETDEWEB)

    Barbarulo, R.; Peycelon, H. [CEA Saclay, Dept. de Physico-Chimie DPC/SCCME/LECBA, 91 - Gif sur Yvette (France); Prene, St. [Electricite de France, Dept. MMC, 77 - Moret sur Loing (France)

    2003-07-01

    A detailed study of the interactions between Calcium Silicate Hydrates (C-S-H) and sulfate is reported in this paper. C-S-H of Ca/Si ratio w 0.7-1.6 were synthesized from CaO and SiO{sub 2} in suspension, and Na{sub 2}SO{sub 4} was added to the system, kept at 20 or 85 deg C. The results of sulfate sorption show that the capacity of C-S-H to bind sulfate increases with the Ca/Si ratio of the C-S-H, and that temperature seems to have little influence for a given Ca/Si ratio. From these results, a modeling of sulfate binding on C-S-H is proposed. (authors)

  11. Interventional effect of magnesium sulfate on nitric oxide synthase activity after acute craniocerebral injury

    Institute of Scientific and Technical Information of China (English)

    Ximin Yang; Jiangong Zhu; Zongchun Tang

    2007-01-01

    BACKGROUND: Abnormal changes in magnesium ion are closely related to cerebral injury. At present,some evidence indicates that magnesium reagent can improve nerve function and prognosis of patients with cerebral injury.OBJECTIVE: To observe the effect of magnesium sulfate on changes in nitric oxide synthase (NOS)activity in brain tissue of rats with acute craniocerebral injury.DESIGN: Completely randomized grouping design and randomly controlled study.SETTING: Laboratory of Neurosurgery, the Third Hospital of Chinese PLA.MATERIALS: Fifty-four male SD rats of clean grade and weighing 220 - 250 g were randomly divided into normal control group (n =6), cerebral injury group (n =24) and magnesium sulfate group (n =24). Especially,rats in cerebral injury group and magnesium sulfate group were equally divided into four subgroups and observed at 0.5, 2, 6 and 24 hours after model establishment. A solution of 125 g/L of magnesium sulfate was provided by the Seventh Pharmaceutical Factory of Wuxi and the NOS assay kit by Nanjing Jiancheng Bioengineering Institute.METHODS: The experiment was carried out in the Institute of Neurosurgery, the Third Hospital of Chinese PLA from August 2000 to August 2002. ① Rats in the cerebral injury group and magnesium sulfate group were anesthetized to establish cerebral injury models based on modified Feeney technique; magnesium sulfate group were intraperitoneally injected 600 mg/kg magnesium sulfate (125 g/L), but rats in the normal control group remained untreated. ② At 0.5, 2, 6 and 24 hours after cerebral injury, rats in cerebral injury group and magnesium sulfate group were decapitated and brains were dissected. Cerebral cortex of rats in cerebral injury group was selected for NOS assay; in addition, at 0.5 hour after cerebral injury, a portion of the parietal lobe was selected from the brains of rats in the normal control group. Brain samples were homogenized, the homogenated centrifuged and the supernatants were used to measure

  12. [A comparative study of antiarrhythmic and antihypoxic effects of magnesium sulfate, its prolonged form and blockers of calcium channels].

    Science.gov (United States)

    Samsonia, M D; Kandelaki, M A

    2013-01-01

    The aim of the study is the comparative study of treatment of heart and brain damages during the hypoxia with magnesium sulfate, verapamil, diltiazem. As a result of the experiment carried out on rats it was proved that magnesium sulfate and its prolonged form are not less active than the blockers of calcium channels, such as verapamil and diltiazem. It is possible to avoid lethal fibrillations caused by calcium chloride with the help of 25% magnesium sulfate solution (after intraperitoneal administration with the dose of 1000 mg/kg) in case we make arrythmogenic injection 5 minutes after inputting magnesium sulfate solution. During the arrhythmia induced by calcium chloride prolonged form of magnesium sulfate is also effective only if we inject the drug subcutaneous 30 minutes before the arrythmogenic injection. If the interval is 5 minutes lethal fibrillations cant be avoided as the release of magnesium ions from the drug form is slowed down. The drugs containing magnesium ions also displayed cytoprotective activity on the model of normobaric hypoxia. This was resulted in the increase of protective index. Neuroprotective action of magnesium ions (in the condition of hypoxia) is caused by maintaining homeostasis of calcium ions and by inhibition of exocytosis of neuromediators in the synaptic cleft. Thus, magnesium sulfate and its prolonged form can be used with the purpose of pharmacocorrection of heart and brain injuries during hypoxic conditions.

  13. Use of magnesium sulfate before 32 weeks of gestation

    DEFF Research Database (Denmark)

    Wolf, H T; Huusom, L; Weber, T

    2017-01-01

    OBJECTIVES: The use of magnesium sulfate (MgSO4) in European obstetric units is unknown. We aimed to describe reported policies and actual use of MgSO4 in women delivering before 32 weeks of gestation by indication. METHODS: We used data from the European Perinatal Intensive Care in Europe (EPICE...

  14. Effect of nickel and magnesium on zinc electrowinning using sulfate solutions

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    V. F. C Lins

    2011-09-01

    Full Text Available Zinc electrowinning is performed with the application of a current through insoluble electrodes (Pb - Ag, causing the electrolysis of zinc sulfate, with or without impurities, and zinc deposition on the cathode of aluminum. The impurities can reduce the current efficiency and increase the energy consumption in zinc electrolysis. In this work, the effect of nickel and magnesium on zinc electrodeposition was studied using the electrochemical techniques of galvanostatic deposition and cyclic voltammetry. Additions of nickel, magnesium or both cations in zinc sulfate electrolyte resulted in a marginal increase in current efficiency. Addition of nickel or magnesium polarizes the cathode; however, the extent of polarization in the presence of magnesium is more than that of nickel. Addition of magnesium to the zinc electrolyte caused zinc reduction at a more negative potential. The addition of nickel to the zinc electrolyte increased the current density of the anodic peaks, thus increasing the dissolution of zinc and hydrogenated phases. The addition of nickel to the zinc and magnesium solutions decreased the nucleation loop, facilitating zinc deposition.

  15. The effects of magnesium sulfate therapy after severe diffuse axonal injury

    Directory of Open Access Journals (Sweden)

    Zhao L

    2016-09-01

    Full Text Available Ling Zhao,1 Wei Wang,1 Jiwen Zhong,1 YaYun Li,1 YanZi Cheng,1 Zhenjiao Su,1 Wei Zheng,1 Xiang-Dong Guan2 1Department of Critical Care Medicine, Zhuhai People’s Hospital, Zhuhai, Guangdong, 2Department of Critical Care Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, People’s Republic of China Purpose: To evaluate the clinical effects of magnesium sulfate in the treatment of diffuse axonal injury (DAI.Patients and methods: This study was a randomized, double-blind, placebo-controlled trial conducted in the First Affiliated Hospital of Sun Yat-sen University, Guangzhou and Zhuhai People’s Hospital, Zhuhai, two trauma center hospitals. A total of 128 patients suffered from DAI, with initial Glasgow coma scale (GCS scores of 3–8. They were randomly divided into two groups: magnesium sulfate treatment (MST group (n=64 and control group (n=64. The MST group received 250 µmol/kg magnesium sulfate intravenously 20 minutes after admission, followed by 750 µmol/kg magnesium sulfate intravenously daily for 5 days. The control group received standard management without MST. GCS scores and serum neuron-specific enolase values were measured and recorded at admission, and on days 3 and 7 after injury. Outcomes were determined by Glasgow outcome scale scores at discharge and at 3 months’ follow-up, respectively.Results: After the 7-day treatment, patients in the MST group, compared with those in the control group, had a lower serum neuron-specific enolase level (25.40±6.66 vs 29.58±7.32, respectively, P=0.001 and higher GCS score (8.23±2.72 vs 7.05±2.64, respectively, P=0.016. Although the length of stay and mortality did not differ between the groups in the intensive care unit, Glasgow outcome scale score was significantly lower in the MST group at discharge (3.30±1.35 vs 3.90±1.10, P=0.004 and 3 months after discharge (2.95±1.48 vs 3.66±1.44, P=0.009.Conclusion: Early treatment with magnesium sulfate

  16. Calculated plasma medial effective concentration of propofol with and without magnesium sulfate at loss of consciousness

    Institute of Scientific and Technical Information of China (English)

    WU Hong-liang; YE Tie-hu; SUN Li

    2011-01-01

    Background Perioperative disorder of magnesium,an important cation in the human body,may affect clinical anesthesia. The pharmacological data of propofol use,which is popularly used in the anesthesiology department and intensive care unit,is incomplete in Chinese patients. This study aimed to assess the effect of magnesium sulfate on the calculated plasma medial effective concentration (Cp50cal) of propofol at loss of response to command in Chinese females.Methods Fifty patients undergoing gynecological laparoscopic surgery were randomly divided into the control group and the magnesium group. Before induction,magnesium sulfate (30 mg/kg) or placebo (equal volume of 0.9% saline)was given to patients in the magnesium group or the control group,respectively. Propofol was infused using a target-controlled infusion system,with a target concentration for each patient decided by up-and-down sequential allocation. After the equilibration between target plasma concentration and effective-site concentration,the state of consciousness was assessed. For determination of serum magnesium and calcium concentration,blood samples were taken before induction,after induction and at the end of surgery.Results The Cp50cal was 2.52 μg/ml (2.47-2.57 μg/ml) for patients in the control group,and 2.46 μg/ml (2.41-2.51μg/ml) for those in the magnesium group. A significant reduction of Cp50cal was observed (P=0.021). There was a significant difference between the serum magnesium concentrations after induction and at the end of the surgery (P <0.05). In the magnesium group,there was a trend toward decreasing after surgery,while in the control group,Cp50cal decreased significantly (P <0.01).Conclusions Cp50cal of propofol at loss of response to command was 2.52 μg/ml (2.47-2.57 μg/ml) for Chinese female adults in this study. Infusion of 30 mg/kg magnesium sulfate may reduce the Cp50cal of propofol at loss of consciousness,which implies that magnesium may enhance the pharmacological

  17. Formation of magnesium silicate hydrate (M-S-H) cement pastes using sodium hexametaphosphate

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Tingting [Faculty of Infrastructure Engineering, Dalian University of Technology, Dalian 116024 (China); Department of Materials, Centre for Advanced Structural Ceramics, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Vandeperre, Luc J. [Department of Materials, Centre for Advanced Structural Ceramics, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Cheeseman, Christopher R., E-mail: c.cheeseman@imperial.ac.uk [Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom)

    2014-11-15

    Magnesium silicate hydrate (M-S-H) gel is formed by the reaction of brucite with amorphous silica during sulphate attack in concrete and M-S-H is therefore regarded as having limited cementing properties. The aim of this work was to form M-S-H pastes, characterise the hydration reactions and assess the resulting properties. It is shown that M-S-H pastes can be prepared by reacting magnesium oxide (MgO) and silica fume (SF) at low water to solid ratio using sodium hexametaphosphate (NaHMP) as a dispersant. Characterisation of the hydration reactions by x-ray diffraction and thermogravimetric analysis shows that brucite and M-S-H gel are formed and that for samples containing 60 wt.% SF and 40 wt.% MgO all of the brucites react with SF to form M-S-H gel. These M-S-H cement pastes were found to have compressive strengths in excess of 70 MPa.

  18. Structural characterization of magnesium silicate hydrate: towards the design of eco-sustainable cements.

    Science.gov (United States)

    Tonelli, M; Martini, F; Calucci, L; Fratini, E; Geppi, M; Ridi, F; Borsacchi, S; Baglioni, P

    2016-02-28

    Magnesium-based cement is one of the most interesting eco-sustainable alternatives to standard cementitious binders. The reasons for the interest towards this material are twofold: (i) its production process, using magnesium silicates, brine or seawater, dramatically reduces CO2 emissions with respect to Portland cement production, and (ii) it is very well suited to applications in radioactive waste encapsulation. In spite of its potential, assessment of the structural properties of its binder phase (magnesium silicate hydrate or M-S-H) is far from complete, especially because of its amorphous character. In this work, a comprehensive structural characterization of M-S-H was obtained using a multi-technique approach, including a detailed solid-state NMR investigation and, in particular, for the first time, quantitative (29)Si solid-state NMR data. M-S-H was prepared through room-temperature hydration of highly reactive MgO and silica fume and was monitored for 28 days. The results clearly evidenced the presence in M-S-H of "chrysotile-like" and "talc-like" sub-nanometric domains, which are approximately in a 1 : 1 molar ratio after long-time hydration. Both these kinds of domains have a high degree of condensation, corresponding to the presence of a small amount of silanols in the tetrahedral sheets. The decisive improvement obtained in the knowledge of M-S-H structure paves the way for tailoring the macroscopic properties of eco-sustainable cements by means of a bottom-up approach.

  19. Direct electroless Ni-P deposition on AM50 magnesium alloy from sulfate bath

    Institute of Scientific and Technical Information of China (English)

    LI Guang-yu; NIU Li-yuan; JIANG Zhong-hao; GU Chang-dong; LIAN Jian-she

    2006-01-01

    A bright electroless Ni-P deposition on AM50 magnesium alloy in a sulfate plating bath was proposed by using direct plating process with non-chromate pretreatment. The electroless Ni-P plating on AM50 magnesium alloy has an admirable appearance and good adhesion. The results indicate that the electroless Ni-P deposition with non-chromate pretreatment has better adhesion than that of zinc immersion coating. Anodic polarization curves indicate that the electroless Ni-P deposition obtained from the sulfate bath has similar corrosion-resistance to that obtained from basic nickel carbonate bath. The deposition process generates less pollutant by a non-chromate plating bath and is suitable for the magnesium alloys manufacture because of its low cost. The hardness of the electroless Ni-P plated AM50 is about HV 720.6 and HV 969.7 after heat treatments at 180 ℃ for 2 h. The wear resistance of Ni-P plated magnesium alloy specimens is about 5 to 9 times as high as that of bare magnesium alloys.

  20. The Effect of Magnesium Sulfate on Renal Colic Pain Relief; a Randomized Clinical Trial

    Directory of Open Access Journals (Sweden)

    Abolfazl Jokar

    2017-01-01

    Full Text Available Introduction: Renal colic can be managed by preventing the contraction movements of ureter muscles. By reducing acetylcholine in the nerve terminals, magnesium sulfate could be effective in this regard. The aim of this study is to investigate the effect of magnesium sulfate on acute renal colic pain relief. Method: The present study was a double-blind clinical trial in which the patients suffering from acute renal colic were randomly divided into 2 groups of who either received standard protocol (intravenous infusion of 0.1 mg/Kg morphine sulfate, 30 mg of Ketorolac, and 100 ml normal saline as placebo/15 minutes or standard protocol plus 15 mg/Kg of intravenous magnesium sulfate 50%/100 ml normal saline/15 minutes. Severity of patients’ pain was measured by visual analogue scale (VAS at baseline, and 30 and 60 minutes after infusion. The collected data were analyzed using STATA statistical software. Results: 100 cases were randomly allocated to intervention or control group. The two groups were similar in baseline pain score and demographic characteristics. At 30 and 60 minutes, mean pain score was less in the intervention group compared to the control group. Moreover, the difference between the two groups was statistically significant regarding the additional amount of morphine, suggesting that the intervention group needed less additional morphine than the control group. Conclusion: The results of this study showed that Magnesium sulfate can be used as an adjunct drug in treatment of patients suffering from renal colic. It not only alleviates the pain in the patients, but also diminishes the need for pain medications.

  1. The effects of magnesium sulfate therapy after severe diffuse axonal injury

    Science.gov (United States)

    Zhao, Ling; Wang, Wei; Zhong, Jiwen; Li, YaYun; Cheng, YanZi; Su, Zhenjiao; Zheng, Wei; Guan, Xiang-Dong

    2016-01-01

    Purpose To evaluate the clinical effects of magnesium sulfate in the treatment of diffuse axonal injury (DAI). Patients and methods This study was a randomized, double-blind, placebo-controlled trial conducted in the First Affiliated Hospital of Sun Yat-sen University, Guangzhou and Zhuhai People’s Hospital, Zhuhai, two trauma center hospitals. A total of 128 patients suffered from DAI, with initial Glasgow coma scale (GCS) scores of 3–8. They were randomly divided into two groups: magnesium sulfate treatment (MST) group (n=64) and control group (n=64). The MST group received 250 μmol/kg magnesium sulfate intravenously 20 minutes after admission, followed by 750 μmol/kg magnesium sulfate intravenously daily for 5 days. The control group received standard management without MST. GCS scores and serum neuron-specific enolase values were measured and recorded at admission, and on days 3 and 7 after injury. Outcomes were determined by Glasgow outcome scale scores at discharge and at 3 months’ follow-up, respectively. Results After the 7-day treatment, patients in the MST group, compared with those in the control group, had a lower serum neuron-specific enolase level (25.40±6.66 vs 29.58±7.32, respectively, P=0.001) and higher GCS score (8.23±2.72 vs 7.05±2.64, respectively, P=0.016). Although the length of stay and mortality did not differ between the groups in the intensive care unit, Glasgow outcome scale score was significantly lower in the MST group at discharge (3.30±1.35 vs 3.90±1.10, P=0.004) and 3 months after discharge (2.95±1.48 vs 3.66±1.44, P=0.009). Conclusion Early treatment with magnesium sulfate resulted in a significant improvement in DAI outcome. Further studies are needed to confirm the clinical significance of treatment of DAI patients with magnesium sulfate. PMID:27729796

  2. Efficacy of nebulized magnesium sulfate in the treatment of acute exacerbation of asthma in children

    Directory of Open Access Journals (Sweden)

    Mohammed Ataul Haqq

    2006-06-01

    Full Text Available A double-blind randomized controlled trial was conducted to examine the efficacy of nebulized magnesium sulfate in the treatment of acute exacerbation of asthma in children. Thirty patients received nebulized salbutamol (0.15 mg/kg; minimum dose 2.5 mg with 2.0 ml of isotonic magnesium sulfate solution and another 30 patients received same dose of salbutamol with 2.0 ml of normal saline on 3 occasions at 20 minute intervals. Mean percent of predicted peak expiratory flow rate (PEFR detected in both group at 0 minute were not significantly different. But from 10 minute up to 60 minute, the values were significantly different among the groups. Mean respiratory rate at 0 and 10 minute were similar in both groups and from 20 up to 60 minute, respiratory rate improvement were significantly different. Arterial oxygen saturation (SaO2 at presentation was not significantly different. But from 10 min up to 60 minute differences were significant. With single dose of nebulization, in the magnesium sulfate with salbutamol group, by 20 minute almost all (29 out of 30 patient achieved at least 60% of predicted PEFR. Within this 20 minute, from control group none could achieve 60% of predicted PEFR. After 2nd dose of nebulization control group started achieving 60% PEFR value. Regarding response criteria, with 2nd dose of nebulization, at 30 and 40 minute 9 (30.0% and 17 (56.7% patient from magnesium sulfate with salbutamol group showed good response (PEFR ≥ 70% predicted. But within this first 40 minutes time, none could show good response in control group. With 3rd dose of nebulization all from magnesium sulfate group showed good response but even at 60 minute, 4 (13.3% patient in control group failed to be included as good responder. So, it is evident that nebulization by isotonic magnesium sulfate solution with salbutamol provide early and better response as compared to conventional approach (salbutamol plus normal saline in acute exacerbation of asthma

  3. The efficacy of magnesium sulfate loading on microalbuminuria following SIRS: One step forward in dosing.

    Science.gov (United States)

    Mirrahimi, Bahador; Hamishehkar, Hadi; Ahmadi, Arezo; Mirjalili, Mohamad Reza; Aghamohamadi, Mostafa; Najafi, Atabak; Abdollahi, Mohammad; Mojtahedzahed, Mojtaba

    2012-10-31

    Magnesium has been known for its antioxidative and antiinflammatory properties in many studies. In this study two dosing regimens of magnesium were compared with a placebo control group in order to investigate safety and efficacy of high doses of intravenous magnesium sulfate infusion on critically ill trauma patients. Inflammatory and oxidative factors were measured in this trial. 45 trauma patients with systemic inflammatory response syndromes (SIRS) were randomly assigned into 2 treatment and one placebo groups. The high dose group received 15 g MgSO4, low dose group received 7.5 g of MgSO4 over 4 hour infusion, and placebo group received saline alone. The initial and post magnesium sulfate injections levels of tumor necrosis factor alpha (TNF-α), total antioxidant power and lipid peroxidation were measured after 6, 18 and 36 hours. The pre-infusion along with 6 and 36 hour level of microalbuminuria were also determined. Repeated measurements illustrated that there was no significant difference in TNF-α, total antioxidant power and lipid peroxidation levels among groups during the period of analysis. The microalbuminuria at 36 hour post infusion of high dose group was lower than that of control group (p = 0.024). Patient's mortality (28 day) was similar among all treatment groups. Both magnesium infusion groups tolerated the drug without experiencing any complications. No evidence for antioxidative and antiinflammatory effects of magnesium in traumatic SIRS positive patients was found. Magnesium in high doses may be recommended for traumatic patients with SIRS status to prevent microalbuminuria.

  4. The Efficacy of Magnesium Sulfate Loading on Microalbuminuria Following SIRS:One Step forward in Dosing

    Directory of Open Access Journals (Sweden)

    Atabak Najafi

    2012-10-01

    Full Text Available Backgrounds:Magnesium has been known for its antioxidative and antiinflammatory properties in many studies. In this study two dosing regimens of magnesium were compared with a placebocontrol group in order to investigate safety and efficacy of high doses of intravenous magnesium sulfate infusion on critically ill trauma patients. Inflammatory and oxidative factors were measured in this trial.Methods:45 trauma patients with systemic inflammatory response syndromes (SIRS were randomly assigned into 2 treatment and one placebo groups. The high dose group received 15 g MgSO4, low dose group received 7.5 g of MgSO4 over 4 hour infusion, and placebo groupreceived saline alone. The initial and post magnesium sulfate injections levels of tumor necrosis factor alpha (TNF-α, total antioxidant power and lipid peroxidation were measured after 6, 18 and 36 hours. The pre-infusion along with 6 and 36 hour level ofmicroalbuminuria were also determined.Results:Repeated measurements illustrated that there was no significant difference in TNF-α, total antioxidant power and lipid peroxidation levels among groups during the period of analysis.The microalbuminuria at 36 hour post infusion of high dose group was lower than that of control group (p = 0.024. Patient’s mortality (28 day was similar among all treatment groups. Both magnesium infusion groups tolerated the drug without experiencing anycomplications.Conclusion:No evidence for antioxidative and antiinflammatory effects of magnesium in traumatic SIRS positive patients was found. Magnesium in high doses may be recommended for traumaticpatients with SIRS status to prevent microalbuminuria.

  5. Utilization of Magnesium Hydroxide Produced by Magnesia Hydration as Fire Retardant for Nylon 6-6,6

    Directory of Open Access Journals (Sweden)

    Rocha Sônia D.F.

    2001-01-01

    Full Text Available The present work investigates the use of magnesium hydroxide, produced by magnesia hydration, as a fire retardant in polymers. The hydration was carried out in an autoclave, at temperature of 130°C for 1 hour, and the product was further submitted to cominution in a jet mill. The solids were characterized with regard to their chemical composition, particle size distribution, surface area and morphology. The performance evaluation of the hydroxide as a flame retardant for a copolymer of nylon 6-6,6 was carried out according to the UL94 specifications for vertical burning tests. V-0 flammability rating at 1.6 mm (60% magnesium hydroxide-filled nylon composite and at 3.2 mm (40% magnesium hydroxide filled nylon composite were achieved. Mechanical properties were maintained at the desired values. These results indicate that the hydroxide obtained from magnesia hydration can be successfully employed as a fire retardant for nylon 6-6,6.

  6. Effect of magnesium sulfate administration for neuroprotection on latency in women with preterm premature rupture of membranes.

    LENUS (Irish Health Repository)

    Horton, Amanda L

    2015-03-01

    This study aims to evaluate whether magnesium sulfate administration for neuroprotection prolongs latency in women with preterm premature rupture of membranes (PPROM) between 24 and 31(6\\/7) weeks\\' gestation.

  7. Quickly Identification of Magnesium Sulfate Uixed into Glutamate%快速鉴别味精中的硫酸镁

    Institute of Scientific and Technical Information of China (English)

    张丽华; 李君; 马春颖; 励建荣

    2012-01-01

    Glutamate is a common condiment which is white granular crystal. It is reported that magnesium sulfate is mixed into glutamate to reduce costs in recent years. Magnesium sulfate is similar to glutamate and it is hard to be distinguished through naked eyes. A quick and convenient method for detecting glutamate mixed with magnesium sulfate was developed based on the characteristic that sulphate could enable solidification of soybean protein. This method can be used to evaluate whether glutamate is mixed with magnesium sulfate.%MgSO4与味精极其相似,肉眼很难分辨,利用硫酸盐能使大豆蛋白凝固的特点,从而寻找一种快速简便的鉴别味精中MgSO4的方法,以便初步判断味精中是否掺入MgSO4.

  8. Effect of magnesium sulfate with propofol induction of anesthesia on succinylcholine-induced fasciculations and myalgia

    Directory of Open Access Journals (Sweden)

    Mahendra Kumar

    2012-01-01

    Full Text Available Background: Magnesium sulfate and propofol have been found to be effective against succinylcholine-induced fasciculations and myalgia, respectively, in separate studies. A prospective randomized double blind controlled study was designed to assess the effect of a combination of magnesium sulfate with propofol for induction of anesthesia on succinylcholine-induced fasciculations and myalgia. Materials and Methods: Randomly selected 60 adult patients scheduled for elective surgery under general anesthesia were allocated to one of the two equal groups by draw of lots. The patients of MG Group were pretreated with magnesium sulfate 40 mg/kg body weight in 10 ml volume, while patients of NS group were given isotonic saline 0.9% in the same volume (10 ml intravenously slowly over a period of 10 min. Anesthesia was induced with fentanyl 1.5 mcg/kg and propofol 2 mg/kg, followed by administration of succinylcholine 2 mg/kg intravenously. Muscle fasciculations were observed and graded as nil, mild, moderate, or severe. Postoperative myalgia was assessed after 24 h of surgery and graded as nil, mild, moderate, or severe. Observations were made in double blind manner. Results: Demographic data of both groups were comparable (P> 0.05. Muscle fasciculations occurred in 50% patients of MG group versus in 100% patients of NS group with a significant difference (P< 0.001. After 24 h of surgery, no patient of MG group and 30% patients of NS group had myalgia with a significant difference (P< 0.002. Conclusion: Magnesium sulfate 40 mg/kg intravenously may be used with propofol for induction of anesthesia to control succinylcholine-induced fasciculations and myalgia.

  9. Thermal stability and hydration behavior of ritonavir sulfate: A vibrational spectroscopic approach

    Directory of Open Access Journals (Sweden)

    Kaweri Gambhir

    2015-12-01

    Full Text Available Ritonavir sulfate is a protease inhibitor widely used in the treatment of acquired immunodeficiency syndrome. In order to elucidate the inherent stability and sensitivity characteristics of ritonavir sulfate, it was investigated under forced thermal and hydration stress conditions as recommended by the International Conference on Harmonization guidelines. In addition, competency of vibrational (infrared and Raman spectroscopy was assessed to identify structural changes of the drug symbolizing its stress degradation. High performance liquid chromatography was used as a confirmatory technique for both thermal and hydration stress study, while thermogravimetric analysis/differential thermal analysis and atomic force microscopy substantiated the implementation of vibrational spectroscopy in this framework. The results exhibited high thermal stability of the drug as significant variations were observed in the diffuse reflectance infrared Fourier transform spectra only after the drug exposure to thermal radiations at 100 °C. Hydration behavior of ritonavir sulfate was evaluated using Raman spectroscopy and the value of critical relative humidity was found to be >67%. An important aspect of this study was to utilize vibrational spectroscopic technique to address stability issues of pharmacological molecules, not only for their processing in pharmaceutical industry, but also for predicting their shelf lives and suitable storage conditions.

  10. Thermal stability and hydration behavior of ritonavir sulfate:A vibrational spectroscopic approach

    Institute of Scientific and Technical Information of China (English)

    Kaweri Gambhir; Parul Singh; Deepak K Jangir; Ranjana Mehrotra

    2015-01-01

    abstract Ritonavir sulfate is a protease inhibitor widely used in the treatment of acquired immunodeficiency syndrome. In order to elucidate the inherent stability and sensitivity characteristics of ritonavir sulfate, it was investigated under forced thermal and hydration stress conditions as recommended by the Inter-national Conference on Harmonization guidelines. In addition, competency of vibrational (infrared and Raman) spectroscopy was assessed to identify structural changes of the drug symbolizing its stress de-gradation. High performance liquid chromatography was used as a confirmatory technique for both thermal and hydration stress study, while thermogravimetric analysis/differential thermal analysis and atomic force microscopy substantiated the implementation of vibrational spectroscopy in this frame-work. The results exhibited high thermal stability of the drug as significant variations were observed in the diffuse reflectance infrared Fourier transform spectra only after the drug exposure to thermal ra-diations at 100 °C. Hydration behavior of ritonavir sulfate was evaluated using Raman spectroscopy and the value of critical relative humidity was found to be 4 67%. An important aspect of this study was to utilize vibrational spectroscopic technique to address stability issues of pharmacological molecules, not only for their processing in pharmaceutical industry, but also for predicting their shelf lives and suitable storage conditions.

  11. Direct Electroless Nickel Plating on AZ91D Magnesium Alloy from a Sulfate Solution and its Deposition Mechanism

    Institute of Scientific and Technical Information of China (English)

    GU Chang-dong; LIAN Jian-she; LI Guang-yu; NIU Li-yuan; JIANG Zhong-hao

    2004-01-01

    A bath of electroless plating Ni on the AZ91D magnesium alloy, containing sulfate nickel, was given in this paper. The nucleation mechanism of Ni-P deposits on the AZ91D magnesium alloy was studied by using XRD and SEM.The electroless Ni-P deposits were preferentially nucleated on the β (Mg17Al12) phase and extended to the primary and eutectic α phases of the AZ91D magnesium alloy.

  12. Direct Electroless Nickel Plating on AZ91D Magnesium Alloy from a Sulfate Solution and its Deposition Mechanism

    Institute of Scientific and Technical Information of China (English)

    GUChang-dong; LIANJian-she; LIGuang-yu; NIULi-yuan; JIANGZhong-hao

    2004-01-01

    A bath of electroless plating Ni on the AZ91D magnesium alloy, containing sulfate nickel, was given in this paper. The nucleation mechanism of Ni-P deposits on the AZ91D magnesium alloy was studied by using XRD and SEM. The electroless Ni-P deposits were preferentially nucleated on the β(Mg17Al12) phase and extended to the primary and eutectic α phases of the AZ91D magnesium alloy.

  13. TREATMENT AND PREVENTION OF ATRIAL TACHYARRHYTHMIAS IN CRITICALLY ILL PATIENT: THE ROLEOF MAGNESIUM SULFATE

    Directory of Open Access Journals (Sweden)

    M. MOJTAHEDZADEH

    1999-09-01

    Full Text Available In this prospective, randomized study, in the general intensive care unit at Shanatee teaching hospital, we evaluated twenty patients, mean age 52+18 years and mean acute physiology and chronic health evaluation II score of 20±8, who were experiencing atrial tachyarrhythmias for more than 1 hour. After correction of their plasma potassium concentration to more than 4.0 mmof/1, patients were randomized to receive either 40 mg/kg magnesium sulfate bolus followed by 30 mg/kg/hr or 5mg/kg amiodarone bolus and 10 mg/kg/24hr infusion. Therapeutic end point was conversion to sinus rhythm over 24 hours. By logistic regression, the probability of conversion to sinus rhythm was significantly better for magnesium than for amiodarone at time 0-4 (0.6 vs.0.4, 12 (0.72 vs 0.45, and 24 (0.72vs.0.45 hours. In patients not converting to sinus rhythm, a significant decrease in ventricular response rate occurred at time zero to 0.5 hour (mean decrease 22 beats/min, P=0.0001, but there was no specific treatment effect between the magnesium and the amiodarone groups. Magnesium sulfate is superior to amiodarone in the conversion of acute atrial tachyarrhythmias, while initial slowing of ventricular response rate in non-converters appears equally efficacious with both agents.

  14. Magnesium sulfate enhances non-depolarizing muscle relaxant vecuronium action at adult muscle-type nicotinic acetylcholine receptor in vitro

    Institute of Scientific and Technical Information of China (English)

    Hong WANG; Qi-sheng LIANG; Lan-ren CHENG; Xiao-hong LI; Wei FU; Wen-tao DAI; Shi-tong LI

    2011-01-01

    To investigate the effect of magnesium sulfate and its interaction with the non-depolarizing muscle relaxant vecuronium at adult muscle-type acetylcholine receptors in vitro.Methods:Adult muscle-type acetylcholine receptors were expressed in HEK293 cells.Drug-containing solution was applied via a gravity-driven perfusion system.The inward currents were activated by brief application of acetylcholine (ACh),and recorded using whole-cell voltage-clamp technique.Results:Magnesium sulfate (1-100 mmol/L) inhibited the inward currents induced ACh (10 μmol/L) in a concentration-dependent manner (IC5o=29.2 mmol/L).The inhibition of magnesium sulfate was non-competitive.In contrast,vecuronium produced a potent inhibition on the adult muscle-type acetylcholine receptor (IC50=8.7 nmol/L) by competitive antagonism.Magnesium sulfate at the concentrations of 1,3,and 6 mmol/L markedly enhanced the inhibition of vecuronium (10 nmol/L) on adult muscle-type acetylcholine receptors.Conclusion:Clinical enhancement of vecuronium-induced muscle relaxation by magnesium sulfate can be attributed partly to synergism between magnesium sulfate and non-depolarizing muscle relaxants at adult muscle-type acetylcholine receptors.

  15. Effects of magnesium sulfate on brain mitochondrial respiratory function in rats after experimental traumatic brain injury

    Institute of Scientific and Technical Information of China (English)

    许民辉; 代文光; 邓洵鼎

    2002-01-01

    Objective: To study the effects of magnesium sulfate on brain mitochondrial respiratory function in rats after experimental traumatic brain injury and the possible mechanism.Methods: The middle degree brain injury in rats was made by BIM-III multi-function impacting machine. The brain mitochondrial respiratory function was measured with oxygen electrode and the ultra-structural changes were observed with transmission electron microscope (TEM).Results: 1. The brain mitochondrial respiratory stage III and respiration control rate reduced significantly in the untreated groups within 24 and 72 hours. But treated Group A showed certain degree of recovery of respiratory function; treated Group B showed further improvement. 2. Untreated Group, treated Groups A and B had different degrees of mitochondrial ultra-structural damage respectively, which could be attenuated after the treatment with magnesium sulfate.Conclusions: The mitochondrial respiratory function decreases significantly after traumatic brain injury. But it can be apparently improved after magnesium sulfate management along with the attenuated damage of mitochondria discovered by TEM. The longer course of treatment can obtain a better improvement of mitochondrial respiratory function.

  16. Electroless Ni-P Deposition on Magnesium Alloy from a Sulfate Bath

    Institute of Scientific and Technical Information of China (English)

    LI Guangyu; NIU Liyuan; JIANG Qing; JIANG Zhonghao; LIAN Jianshe

    2008-01-01

    A technology for electroless Ni-P deposition on AZ91D from a low cost plating bath containing sulfate nickel was proposed.The seal pretreatment was employed before the electroless Ni-P deposition for the sake of occluding the micro holes of the cast magnesium alloy and interdicting the bubble formation in the Ni-P coating during plating process.And pickling pretreatment can provide a better adhesion between the Ni-P deposition and AZ91D substrate.The deposition speed of the Ni-P coating is 29 um/h.The technology is employed to AZ91D magnesium alloy automobile parts and can provide high hardness and high wear-resistant.The weight losses of Ni-P plated and heat-treated Ni-P plated magnesium alloy specimen are only about I/6 and 1/10 that of bare magnesium alloy specimen after l0 min abrasion wear,respectively.The hardness of the electroless Ni-P plated brake pedal support brackets is 674.1 VHN and 935.7 VHN after 2 hours heat treatments at 180 C.The adhesion of Ni-P coatings on magnesium alloy substrates meets the demands of ISO Standards 2819.The technology is environment friendly and cannot cause hazard to environment because of absence of chromate in the whole process.

  17. Comparative study of intravenously administered clonidine and magnesium sulfate on hemodynamic responses during laparoscopic cholecystectomy

    Directory of Open Access Journals (Sweden)

    Nand Kishore Kalra

    2011-01-01

    Full Text Available Background: Both magnesium and clonidine are known to inhibit catecholamine and vasopressin release and attenuate hemodynamic response to pneumoperitoneum. This randomized, double blinded, placebo controlled study has been designed to assess which agent attenuates hemodynamic stress response to pneumoperitoneum better. Materials and Methods: 120 patients undergoing elective laparoscopic cholecystectomy were randomized into 4 groups of 30 each. Group K patients received 50 ml normal saline over a period of 15 min after induction and before pneumoperitoneum, group M patients received 50 mg/kg of magnesium sulfate in normal saline (total volume 50 ml over same time duration. Similarly group C1 patients received 1 μg/kg clonidine and group C2 1.5 μg/kg clonidine respectively in normal saline (total volume 50 ml. Blood pressure and heart rate were recorded before induction (baseline value, at the end of infusions and every 5 min after pneumoperitoneum. Statistical Analysis: Paired t test was used for intra-group comparison and ANOVA for inter-group comparison. Results: Systolic blood pressure was significantly higher in control group as compared to all other groups during pneumoperitoneum. On comparing patients in group M and group C1, no significant difference in systolic BP was found at any time interval. Patients in group C2 showed best control of systolic BP. As compared to group M and group C1, BP was significantly lower at 10, 30 and 40 min post pneumoperitoneum. No significant episodes of hypotension were found in any of the groups. Extubation time and time to response to verbal command like eye opening was significantly longer in group M as compared to other groups. Conclusion: Administration of magnesium sulfate or clonidine attenuates hemodynamic response to pneumoperitoneum. Although magnesium sulfate 50 mg/kg produces hemodynamic stability comparable to clonidine 1 μg/kg, clonidine in doses of 1.5μg/kg blunts the hemodynamic response

  18. Effect of Low-Dose (Single-Dose Magnesium Sulfate on Postoperative Analgesia in Hysterectomy Patients Receiving Balanced General Anesthesia

    Directory of Open Access Journals (Sweden)

    Arman Taheri

    2015-01-01

    Full Text Available Background and Aim. Aparallel, randomized, double blinded, placebo-controlled trial study was designed to assess the efficacy of single low dose of intravenous magnesium sulfate on post-total abdominal hysterectomy (TAH pain relief under balanced general anesthesia. Subject and Methods. Forty women undergoing TAH surgery were assigned to two magnesium sulfate (N=20 and normal saline (N=20 groups randomly. The magnesium group received magnesium sulfate 50 mg·kg−1 in 100 mL of normal saline solution i.v as single-dose, just 15 minutes before induction of anesthesia whereas patients in control group received 100 mL of 0.9% sodium chloride solution at the same time. The same balanced general anesthesia was induced for two groups. Pethidine consumption was recorded over 24 hours precisely as postoperative analgesic. Pain score was evaluated with Numeric Rating Scale (NRS at 0, 6, 12, and 24 hours after the surgeries. Results. Postoperative pain score was lower in magnesium group at 6, 12, and 24 hours after the operations significantly (P<0.05. Pethidine requirement was significantly lower in magnesium group throughout 24 hours after the surgeries (P=0.0001. Conclusion. Single dose of magnesium sulfate during balanced general anesthesia could be considered as effective and safe method to reduce postoperative pain and opioid consumption after TAH.

  19. The effect of sulfate activation on the early age hydration of BFS:PC composite cement

    Energy Technology Data Exchange (ETDEWEB)

    Collier, N.C., E-mail: nick.collier@sheffield.ac.uk; Li, X.; Bai, Y.; Milestone, N.B.

    2015-09-15

    Blast furnace slag/Portland cement composites are routinely used for immobilising intermediate level nuclear wastes in the UK. Using high cement replacement levels reduces hydration exotherm and lowers pH. Although a lower grout pH will be beneficial in reducing the corrosion of certain encapsulated reactive metals such as aluminium, the degree of slag reaction will also be lower which may result in the formation of less hydration products and which in turn may reduce the capacity to immobilise waste ions. Adding neutral salts such as calcium and sodium sulfate to the composite cement can potentially increase slag activation without significantly altering the pH of the cement matrix. Thus the corrosion of any encapsulated metals would not be affected. This paper describes some of the properties of a hydrated 9:1 blast furnace slag:Portland cement matrix containing added sulfates of calcium and sodium. The findings show that all additives caused an increase in the amount of slag that reacted when cured for up to 28 days. This produced more material able to chemically bind waste ions. Activation with gypsum produced the highest rate of slag reaction.

  20. Effect of agglomeration during coprecipitation: Delayed spinellization of magnesium aluminate hydrate

    Indian Academy of Sciences (India)

    Soumen Pal; A K Bandyopadhyay; S Mukherjee; B N Samaddar; P G Pal

    2010-08-01

    Precipitation of magnesium aluminate hydrate with faster addition of ammonia at desired pH causes agglomeration. Agglomerated powder, without any further treatment, on calcination forms intermediate compounds at low temperatures (≤ 900°C). The intermediate compounds on further heat treatment (≥ 1000°C) decompose into MgO, MgAl2O4 and -Al2O3. Effect of agglomeration and absorption of foreign ions such as Cl–, SO$^{2-}_{4}$, and NH$^{+}_{4}$ in complex compounds probably cause loss of Al3+ and Mg2+ ions during heat treatment, and stoichiometry changes. Powders prepared by continuous method with better control of process parameters than batch process yields better spinellization.

  1. The Impact of Magnesium Oxide on the Hydratation and Features of Mechanicaly Activated Phosphogypsum

    Directory of Open Access Journals (Sweden)

    Andrejus Jefimovas

    2011-04-01

    Full Text Available Extractive hemihydrate phosphogypsum (E-PG is the most popular mineral waste in Lithuania. The dumps of that are rapidly growing and the question of possible use still remains open. Phosphogypsum is obtained during the process of extracting phosphoric acid from apatite using sulphuric acid. Due to low activity and contamination with acidic mineral admixtures (phosphorus and fluorine compounds, this technogenic product cannot be used for producing construction materials. Instead of present energy consuming processes used for neutralisation, another method – mechanical activation neutralizing acid admixtures with cement and opoka mix is offered. Whereas cement and opoka are grey, the items made of phosphogypsum (neutralised using these admixtures are dark. Research was made trying to find out the possibility of gaining the white binder from phosphogypsum. In order to achieve that magnesium oxide was chosen to neutralise phosphogypsum and its impact on E-PG, hydratation and features were studied.Article in Lithuanian

  2. Effect of parenteral magnesium sulfate on pulmonary functions in bronchial asthma.

    Science.gov (United States)

    Sharma, S K; Bhargava, A; Pande, J N

    1994-01-01

    Eighteen patients with bronchial asthma were studied in a single-blind fashion. Each patient received an infusion of magnesium sulfate (MgSO4.7H2O 50% W/V) in a dose equivalent to 10 mmol of elemental magnesium. The airways resistance showed a significant decrease (p significantly (p V50 (p statistically significant increase (p Significant changes in Raw (p significant side effects were observed with MgSO4 infusion. It is concluded that modest improvement in airways resistance and specific conductance and only small improvement in maximal expiratory flow rates is consistent with a predominant effect of MgSO4 on large airways in patients with bronchial asthma.

  3. Comparison between magnesium sulfate and dexmedetomidine in controlled hypotension during functional endoscopic sinus surgery

    Directory of Open Access Journals (Sweden)

    Adnan Bayram

    2015-02-01

    Full Text Available BACKGROUND AND OBJECTIVES: It is crucial to decrease bleeding during functional endoscopic sinus surgery. Our primary goal was to investigate the effects of magnesium sulfate and dexmedetomidine used for controlled hypotension on the visibility of the surgical site. METHODS: 60 patients aged between 18 and 65 years were enrolled. In the magnesium sulfate group (Group M, patients were administered 40 mg/kg magnesium sulfate in 100 mL saline solution over 10 min as the intravenous loading dose 10 min before induction, with a subsequent 10-15 µg/kg/h infusion during surgery. In the dexmedetomidine group (Group D, patients were administered 1 µg/kg dexmedetomidine in 100 mL saline solution as the loading dose 10 min before surgery and 0.5-1 µg/kg/h dexmedetomidine during surgery. Deliberate hypotension was defined as a mean arterial pressure of 60-70 mmHg. RESULTS: Bleeding score was significantly decreased in Group D (p = 0.002. Mean arterial pressure values were significantly decreased in Group D compared to that in Group M, except for the initial stage, after induction and 5 min after intubation (p < 0.05. The number of patients who required nitroglycerine was significantly lower in Group D (p = 0.01 and surgeon satisfaction was significantly increased in the same group (p = 0.001. Aldrete recovery score ≥9 duration was significantly shorter in Group D (p = 0.001. There was no difference between the two groups in terms of recovery room verbal numerical rating scale. CONCLUSIONS: Dexmedetomidine can provide more effective controlled hypotension and thus contribute to improved visibility of the surgical site.

  4. A facile synthesis of phenazine and quinoxaline derivatives using magnesium sulfate heptahydrate as a catalyst

    Directory of Open Access Journals (Sweden)

    BAHADOR KARAMI

    2011-09-01

    Full Text Available Convenient and simple procedures for the synthesis of phenazine and quinoxaline derivatives were developed via a reaction of o-phenylenediamines and 1,2-dicarbonyl compounds. In addition, the synthesis of two new 1,4-benzodiazine derivatives and the catalytic activity of magnesium sulfate heptahydrate (MgSO4·7H2O in the room temperature condensation of o-phenylenediamines and 1,2-dicarbonyl compounds in ethanol as solvent are reported. This method has many appealing attributes, such as excellent yields, short reaction times, and simple work-up procedures.

  5. Bioactive calcium sulfate/magnesium phosphate cement for bone substitute applications

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Guangyong [Department of Orthopaedics, Taizhou Hospital of Zhejiang Province, Linhai Zhejiang, 317000 (China); Department of Orthopaedic Surgery, Second Affiliated Hospital of Wenzhou Medical College, Wenzhou, Zhejiang, 325000 (China); Liu, Jianli [Trauma Center, Affiliated Hospital of Hainan Medical University, Haikou, Hainan, 570206 (China); Division of Functional Materials and Nanodevices, Ningbo Institute of Materials Technology and Engineering (NIMTE), Chinese Academy of Sciences (CAS), Ningbo, Zhejiang, 315201 (China); Li, Fan; Pan, Zongyou; Ni, Xiao; Shen, Yue [Department of Orthopaedic Surgery, Second Affiliated Hospital of Wenzhou Medical College, Wenzhou, Zhejiang, 325000 (China); Xu, Huazi, E-mail: spinexu@163.com [Department of Orthopaedic Surgery, Second Affiliated Hospital of Wenzhou Medical College, Wenzhou, Zhejiang, 325000 (China); Huang, Qing, E-mail: huangqing@nimte.ac.cn [Division of Functional Materials and Nanodevices, Ningbo Institute of Materials Technology and Engineering (NIMTE), Chinese Academy of Sciences (CAS), Ningbo, Zhejiang, 315201 (China)

    2014-02-01

    A novel calcium sulfate/magnesium phosphate cement (CSMPC) composite was prepared and studied in the present work. The physical properties including the phases, the microstructures, the setting properties and the compressive strengths of the CSMPCs were studied. The bio-performances of the CSMPCs were comprehensively evaluated using in vitro simulated body fluid (SBF) method and in vitro cell culture. The dependence of the physical and chemical properties of the CSMPC on its composition and microstructure was studied in detail. It is found that the CSMPC composites exhibited mediate setting times (6–12 min) compared to the calcium sulfate (CS) and the magnesium phosphate cement (MPC). They showed an encapsulation structure in which the unconverted hexagonal prism CSH particles were embedded in the xerogel-like MPC matrix. The phase compositions and the mechanical properties of the CSMPCs were closely related to the content of MPC and the hardening process. The CSMPCs exhibited excellent bioactivity and good biocompatibility to support the cells to attach and proliferate on the surface. The CSMPC composite has the potential to serve as bone grafts for the bone regeneration. - Highlights: • The mechanical strength and degradation rate of CSMPC composites are discussed. • The CSMPC composites exhibited good bioactivity to form bone-like apatite. • The CSMPC composites also show good biocompatibility.

  6. Bioactive calcium sulfate/magnesium phosphate cement for bone substitute applications.

    Science.gov (United States)

    Yang, Guangyong; Liu, Jianli; Li, Fan; Pan, Zongyou; Ni, Xiao; Shen, Yue; Xu, Huazi; Huang, Qing

    2014-02-01

    A novel calcium sulfate/magnesium phosphate cement (CSMPC) composite was prepared and studied in the present work. The physical properties including the phases, the microstructures, the setting properties and the compressive strengths of the CSMPCs were studied. The bio-performances of the CSMPCs were comprehensively evaluated using in vitro simulated body fluid (SBF) method and in vitro cell culture. The dependence of the physical and chemical properties of the CSMPC on its composition and microstructure was studied in detail. It is found that the CSMPC composites exhibited mediate setting times (6-12 min) compared to the calcium sulfate (CS) and the magnesium phosphate cement (MPC). They showed an encapsulation structure in which the unconverted hexagonal prism CSH particles were embedded in the xerogel-like MPC matrix. The phase compositions and the mechanical properties of the CSMPCs were closely related to the content of MPC and the hardening process. The CSMPCs exhibited excellent bioactivity and good biocompatibility to support the cells to attach and proliferate on the surface. The CSMPC composite has the potential to serve as bone grafts for the bone regeneration.

  7. The lithification of ultramafic dominated till with magnesium silicate hydrate: a new green concrete

    Science.gov (United States)

    de Ruiter, Lisa; Olav Austrheim, Håkon; Hu, Depan; Dysthe, Dag Kristian; Ulven, Ole Ivar

    2016-04-01

    The Feragen Ultramafic Body located near the town of Røros in Eastern Norway gives rise to a unique phenomenon: A lithification process involving natural cement of magnesium silicate hydrate (M-S-H). The ultramafic body is covered with moraine deposits that form tills throughout the area. The tills consist mainly of variably serpentinized ultramafic rock fragments, with additional quartz and feldspar grains transported to the area with the glaciers that formed the till. This provides the exceptional combination of ultramafic and Si-rich rocks. Throughout the area, multiple spots can be found where natural cement has resulted in the lithification of the till, forming tillite. This mainly occurs close to mine tailings of ancient chromium mines, as the mine tunnels provide air flow that increases the evaporation and thus the precipitation of the cement. The Weichselian glaciation constrains the age of the moraines to less than 10 ka and the formation of the concrete related to mine tailings suggests that the lithification took place after the termination of the mining activity in 1927. Thus, the cement is formed in-situ at its current location, indicating that it forms in a subarctic climate. EMP and SEM analysis indicate that the cement is a hydrated magnesium silicate phase, cementing together quartz, feldspar and serpentine grains to form a natural concrete. The cement consist of 31 wt% of MgO and 49 wt% of SiO2. Quartz and feldspar grains are partly dissolved in the concrete while the resulting pore space is filled with cement, indicating that the Si in the cement originated from the quartz and feldspar phases. Weathering of the ultramafic body involves the dissolution of brucite to create a high pH, Mg-rich fluid, which subsequently can dissolve the quartz and be the source for the M-S-H cement. A dissolution-precipitation process involving the dissolution of both brucite and quartz thus results in the formation of the cement. Future TEM analysis should give

  8. [Evaluation of the efficacy of ligustrazine collaborated with magnesium sulfate in the treatment of pregnancy-induced hypertension in rats].

    Science.gov (United States)

    Fang, Ma Rong; Li, Ji Cheng

    2005-02-01

    The aim of this study was to evaluate the outcome of treatment of pregnancy--induced hypertension (PIH) in rats by Ligustrazine collaborated with magnesium sulfate. PIH rat models were induced with Nomega-nitro-L-arginine methyl ester (L-NAME) infusing at 7 mg/kg per day via caudal vein for four days, then treated with Ligustrazine, magnesium sulfate, or both for three days. Rat blood pressure level was measured by the tail-cuff method, 24 hours urine protein was also assayed. The blood pressure and urine proteins of grouped PIH rats were recorded before the start and after the termination of therapy. The body length and the weight of fetal rats, the weight of placentals from pregnant rats were measured. The placental tissues, livers, kidneys of rats were investigated with integrated methods such as histopathologic observation with light microscopy, ultrastructural observation with transmission electron microscopy. L-NAME administration in pregnancy rats during the late pregnancy period had resulted in an rise of blood pressure, an increasing of urine protein, death rate of rat fetus, incidence of teratogenesis, and so on. Three groups of PIH rats treated with single magnesium sulfate, Ligustrazine, or Ligustrazine combined with magnesium sulfate showed an obvious dropping of the proteinuria, decompression of blood pressure (p<0.01, p<0.001), especially the treatment efficacy in the group of Ligustrazine combined with magnesium sulfate was more significant effective than other two groups (p<0.01, p<0.001). The treatment with both Ligustrazine and magnesium sulfate could increase the body length of newly born rats, the body weight of tomites and the placental weight, furthermore, reduce the rate of the teratosis of hindlimb-shortness (p<0.001). There were diffuse focal necrosis areas in the livers of PIH rats, their glomerular basement membrane had thickened extensively, the glomerular endothelium had swelled, extensive edema in the epithelia of renal tubule was

  9. Function of magnesium aluminate hydrate and magnesium nitrate as MgO addition in crystal structure and grain size control of -Al2O3 during sintering

    Indian Academy of Sciences (India)

    Soumen Pal; A K Bandyopadhyay; S Mukherjee; B N Samaddar; P G Pal

    2010-02-01

    Chemically pure reactive alumina (-Al2O3) which is commercially available was used for densification study in presence of widely accepted dopant MgO as additive. MgO was added both as spinel (MgAl2O4) forming precursor i.e. magnesium aluminate hydrate, and magnesium nitrate. Sintering investigations were conducted in the temperature range 1500–1600°C with 2 h soaking. Structural study of sintered pellets was carried out by extensive XRD analysis. Scanning electron mode SEM images of the specimens were considered to understand the effect of both types of additions. Addition of MgO within and beyond optimum amount had some effect on development of microstructure of sintered bodies. Densification, around 99% ρth, with fine grain microstructure was achieved. These different types of additions caused two distinct changes in crystal structure of alumina-one small contraction and the other expansion of unit cell parameters.

  10. Ganymede's internal structure including thermodynamics of magnesium sulfate oceans in contact with ice

    Science.gov (United States)

    Vance, Steve; Bouffard, Mathieu; Choukroun, Mathieu; Sotin, Christophe

    2014-06-01

    The large icy moons of Jupiter contain vast quantities of liquid water, a key ingredient for life. Ganymede and Callisto are weaker candidates for habitability than Europa, in part because of the model-based assumption that high-pressure ice layers cover their seafloors and prevent significant water-rock interaction. Water-rock interactions may occur, however, if heating at the rock-ice interface melts the high pressure ice. Highly saline fluids would be gravitationally stable, and might accumulate under the ice due to upward migration, refreezing, and fractionation of salt from less concentrated liquids. To assess the influence of salinity on Ganymede's internal structure, we use available phase-equilibrium data to calculate activity coefficients and predict the freezing of water ice in the presence of aqueous magnesium sulfate. We couple this new equation of state with thermal profiles in Ganymede's interior-employing recently published thermodynamic data for the aqueous phase-to estimate the thicknesses of layers of ice I, III, V, and VI. We compute core and silicate mantle radii consistent with available constraints on Ganymede's mass and gravitational moment of inertia. Mantle radii range from 800 to 900 km for the values of salt and heat flux considered here (4-44 mW m-2 and 0 to 10 wt% MgSO4). Ocean concentrations with salinity higher than 10 wt% have little high pressure ice. Even in a Ganymede ocean that is mostly liquid, achieving such high ocean salinity is permissible for the range of likely S/Si ratios. However, elevated salinity requires a smaller silicate mantle radius to satisfy mass and moment-of-inertia constraints, so ice VI is always present in Ganymede's ocean. For lower values of heat flux, oceans with salinity as low as 3 wt% can co-exist with ice III. Available experimental data indicate that ice phases III and VI become buoyant for salinity higher than 5 wt% and 10 wt%, respectively. Similar behavior probably occurs for ice V at salinities

  11. Comparison of Usefulness of Ketamine and Magnesium Sulfate Nebulizations for Attenuating Postoperative Sore Throat, Hoarseness of Voice, and Cough.

    Science.gov (United States)

    Rajan, Sunil; Malayil, George Jacob; Varghese, Rekha; Kumar, Lakshmi

    2017-01-01

    Postoperative sore throat (POST) is a complication that is unresolved in patients undergoing endotracheal intubation. To compare the effects of ketamine and magnesium sulfate nebulizations in two strengths, on the incidence and severity of POST, hoarseness, and cough. Sixty surgical patients undergoing elective abdominal and lower limb surgeries under combined epidural and general anesthesia were included in this prospective, randomized, double-blinded study. Patients in each group were nebulized with the respective study drug 15 min prior to the surgery, i.e., ketamine in Group K, magnesium sulfate 250 mg, and 500 mg in Group M1 and Group M2, respectively, and normal saline as control in Group C. A standardized anesthesia protocol was followed for all patients. After extubation, the patients were asked to grade POST, hoarseness, and cough at 0, 2, 4, 12, and 24 h. One-way analysis of variance, Chi-square test, Fisher's exact test, paired t-tests, and Wilcoxon's signed-rank test as applicable. Ketamine and magnesium sulfate 500 mg demonstrated a statistically significant decrease in POST at 0, 2, and 4 h, and postoperative hoarseness at 0 h. There was decrease in the incidence and severity of sore throat, hoarseness, and cough at all periods in the study groups as compared with control. Nebulization with ketamine 50 mg and magnesium sulfate 500 mg, 15 min before induction of general anesthesia and intubation, reduce the incidence and severity of POST and hoarseness of voice.

  12. Effect of pancreatic kallikrein combined with magnesium sulfate therapy on disease severity of patients with severe preeclampsia

    Institute of Scientific and Technical Information of China (English)

    Yi Yang

    2016-01-01

    Objective:To study the clinical effect of pancreatic kallikrein combined with magnesium sulfate therapy on severe preeclampsia.Methods: A total of 47 patients with severe preeclampsia treated in our hospital from May 2013 to October 2015 were retrospectively analyzed, patients who received pancreatic kallikrein combined with magnesium sulfate therapy were selected as observation group, patients who received magnesium sulfate therapy were selected as control group, and then blood pressure level, renal function, uterine artery and umbilical artery blood flow state, and hypoxia indexes in serum and placenta were compared between two groups.Results: After treatment, systolic pressure and diastolic pressure levels as well as serum CysC level and 24 h urine protein level of observation group were significantly lower than those of control group, the uterine artery and umbilical artery S/D and PI were significantly lower than those of control group, PIGF and NO levels in serum as well as Xiap and Survivin levels in placenta were significantly higher than those of control group, and sVEGFR1 level in serum as well as Caspase-3 and Caspase-7 levels in placenta was significantly lower than those of control group.Conclusions:Pancreatic kallikrein combined with magnesium sulfate therapy can alleviate the disease severity, lower blood pressure and vascular resistance, and improve renal function and the apoptosis caused by placental hypoxia in patients with severe preeclampsia.

  13. Effect of Magnesium Sulfate on Doppler Parameters of Fetal Umbilical and Middle Cerebral Arteries in Women with Severe Preeclampsia

    Directory of Open Access Journals (Sweden)

    Nazanin Farshchian

    2012-01-01

    Full Text Available Objective: To assess the effect of injecting magnesium sulfate on Doppler parameters of fetal umbilical and middle cerebral arteries (MCA in women with severe preeclampsia. Materials and Methods: A total of 21 patients with severe preeclampsia admitted to Imam Reza Hospital, Kermanshah (Iran, were evaluated. Before and after administration of magnesium sulfate, Doppler ultrasound scan was carried out to measure fetal middle cerebral artery and umbilical artery blood flow. Paired t-test was used for statistical analysis. Results: After injection of magnesium sulfate, the mean resistivity index (RI-umbilical, and pulsatility index (PI-cerebral showed a statistically significant reduction ( P < 0.001. The cerebroumbilical C/U ratio increased after the intervention ( P < 0.001. The PI-umbilical ( P = 0.1 and pre- and post-RI-cerebral ( P = 0.96 did not have statistically significant changes. Conclusions: Infusion of magnesium sulfate significantly decreases the flow in the fetus RI-umbilical and PI-MCA, and it increases C/U ratio indices in color Doppler ultrasound.

  14. Hydration state of calcium sulfates in Gale crater, Mars: Identification of bassanite veins

    Science.gov (United States)

    Rapin, W.; Meslin, P.-Y.; Maurice, S.; Vaniman, D.; Nachon, M.; Mangold, N.; Schröder, S.; Gasnault, O.; Forni, O.; Wiens, R. C.; Martínez, G. M.; Cousin, A.; Sautter, V.; Lasue, J.; Rampe, E. B.; Archer, D.

    2016-10-01

    In-situ analyses reveal the presence of hydrogen within calcium sulfate veins crosscutting the sediments found in Gale crater. Laboratory experiments were performed to calibrate the hydrogen signal measured by laser induced breakdown spectroscopy (LIBS) in a range applicable to martian data. The analyses indicate that all veins targeted so far at Gale consist predominantly of bassanite which most likely formed by dehydration of gypsum. This scenario suggests that the percolating water produced gypsum, possibly by hydration of anhydrite in aqueous solution, and remained at temperatures below ∼60 °C at that time. Desiccating conditions followed, consistent with a hyperarid climate and favored by burial or impacts. Additionally, anhydrite with lesser bassanite has been found by XRD in samples of sediments hosting the veins. Our result suggests bassanite is likely found in the veins and anhydrite may be more common as a fine-grained component within the sediments.

  15. Preparation of Adsorbent with Magnesium Sulfate and Straw Pulp Black Liquor and Its Phenol Adsorption Properties

    Institute of Scientific and Technical Information of China (English)

    GUO Lugang; WANG Haizeng

    2009-01-01

    A magnesia adsorbent was prepared from straw pulp black liquor and magnesium sulfate for the first time, and its adsorption of phenol from aqueous solution was examined. The characteristics of the adsorbent were tested through chemical analysis,surface analysis, X-ray diffraction and FT-IR spectroscopy. The effects of various factors, such as dose, adsorption time and adsorption temperature, on phenol adsorption behavior were studied. The results show that the adsorption processes can be fitted to the isotherm Langmuir model very well. It was found that the adsorption process was strongly influenced by temperature and the optimal temperature for phenol removal was 40 ℃. The optimum adsorption time was 10 min, and desorption would happen afterwards. Between the models of Langmuir and Freundlich, the adsorption process of phenol onto magnesia fitted the Langmuir equation better.

  16. Intravenous Magnesium Sulfate to Deliberate Hypotension and Bleeding after Bimaxillary Orthognathic Surgery; A Randomized Double-blind Controlled Trial.

    Science.gov (United States)

    Modanlou Juibari, Hamed; Eftekharian, Hamid Reza; Arabion, Hamid Reza

    2016-09-01

    The preoperative or intraoperative administration of intravenous magnesium sulfate has been approved as an accepted medication for stabilizing hemodynamic indices during surgeries. Intraoperative blood loss during orthognathic surgery is frequently abundant and sometimes requires blood transfusion. The present trial addressed the efficacy of intravenous magnesium sulfate on deliberating hypotension and bleeding reduction in patients undergoing bimaxillary orthognathic surgery. This randomized double-blinded placebo controlled trial was conducted on 52 consecutive patients who underwent orthognathic surgery. The participants were randomly assigned to two groups receiving intravenous magnesium sulfate 30 mg/kg body weight bolus for 15 minutes immediately before anesthesia induction, followed by 10 mg/kg/hr dissolved in saline via pump infusion (n=26) and the second group received placebo as same bolus volume of normal saline in a 15-minute intravenous infusion which was continued until the end of operation (n=26). Both systolic and diastolic blood pressures were measured before anesthesia induction at baseline, during surgery, and at the end of the surgery. Intraoperative blood loss was also determined. Systolic and diastolic blood pressures did not differ between the two groups at baseline. Although a downward trend of both systolic and diastolic blood pressures was seen during the operation in both groups, the decrease in blood pressures occurred with greater gradient in the group administered magnesium sulfate. Assessing difference in the trend of the changes in systolic and diastolic blood pressures between the two study groups (adjusted for gender, age, mean body mass index, and time of surgery) showed different trends in the changes of blood pressures. No differences were observed in blood loss or blood product requirement between the two groups. The administration of intravenous magnesium sulfate can attenuate both systolic and diastolic blood pressures during

  17. The effect of magnesium sulfate administration for neuroprotection on latency in women with preterm premature rupture of membranes

    Science.gov (United States)

    Horton, Amanda L.; Lai, Yinglei; Rouse, Dwight J.; Spong, Catherine Y.; Leveno, Kenneth J.; Varner, Michael W.; Mercer, Brian M.; Iams, Jay D.; Wapner, Ronald J.; Sorokin, Yoram; Thorp, John M.; Ramin, Susan M.; Malone, Fergal D.; O'Sullivan, Mary J.; Hankins, Gary D. V.; Caritis, Steve N.

    2015-01-01

    Objective To evaluate whether magnesium sulfate administration for neuroprotection prolongs latency in women with preterm premature rupture of membranes between 24 and 31 6/7 weeks' gestation. Study Design This is a secondary analysis of a randomized controlled trial of magnesium sulfate for prevention of cerebral palsy. Gravid women with a singleton pregnancy between 24 and 31 6/7 weeks' gestation with preterm premature rupture of membranes (pPROM) without evidence of labor were randomized to receive magnesium sulfate, administered intravenously as a 6-g bolus followed by a constant infusion of 2 g per hour up to 12 hours, or placebo. Maternal outcomes for this analysis were delivery in less than 48 hours and in less than 7 days from randomization. Neonatal outcomes included a composite of respiratory distress, interventricular hemorrhage grades 3 or 4, periventricular leukomalacia, sepsis, necrotizing enterocolitis, retinopathy of prematurity, or death. Results A total of 1259 women were included. The rate of delivery < 48 hours was not different in the magnesium sulfate and the placebo groups (22.2% and 20.7%, p=0.51). Delivery < 7 days was similar between groups (55.4% and 51.4%, p=0.16). Median latency was also similar between groups (median [interquartile range] 6.0 days [2.4–13.8] and 6.6 days [2.4–15.1], p =0.29). Composite neonatal outcomes did not differ between groups. Conclusion: Magnesium sulfate administration given for neuroprotection in women with a singleton gestation with preterm premature rupture of membranes and without labor before 32 weeks does not impact latency. PMID:25241107

  18. Mg2+-induced vesicles of tetradecyldimethylamine oxide and magnesium dodecyl sulfate.

    Science.gov (United States)

    Teng, Minmin; Song, Aixin; Hao, Jingcheng

    2009-10-15

    A Mg2+-induced vesicle phase was prepared from a mixture of tetradecyldimethylamine oxide (C14DMAO) and magnesium dodecyl sulfate [Mg(DS)2] in aqueous solution. Study of the phase behavior shows that at the appropriate mixing ratios, Mg2+-ligand coordination between C14DMAO and Mg(DS)2 results in the formation of molecular bilayers, in which Mg2+ can firmly bind to the head groups of the two surfactants. The area of the head group can be reduced because of the complexation. In this case, no counterions exist in aqueous solution because of the fixation of Mg2+ ions to the bilayer membranes. Therefore, the charges of the bilayer membranes are not shielded by salts. The birefringent solutions of Mg(DS)2 and C14DMAO mixtures consist of vesicles which were determined by transmission electron microscopy (TEM) images and rheological measurements. Magnesium oxide (MgO) nanoplates were obtained via the decomposition of Mg(OH)2 which were synthesized in Mg2+-induced vesicle phase which was used as the microreactor under the existence of ammonia hydroxide. The morphologies and structures of the obtained MgO nanoplates have been characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results indicate that the crystal growth is along the (111) direction which can be affected by the presence of a vesicle phase having a fixation of Mg2+ ions to the bilayer membranes.

  19. A comparative study of magnesium sulfate vs dexmedetomidine as an adjunct to epidural bupivacaine

    Science.gov (United States)

    Shahi, Vaibhav; Verma, Anil Kumar; Agarwal, Apurva; Singh, Chandra Shekhar

    2014-01-01

    Background and Aims: This prospective, randomized, double-blind study was undertaken to establish the effect of addition of magnesium or dexmedetomidine, as an adjuvant, to epidural bupivacaine in lower limb surgeries. Materials and Methods: One hundred and twenty ASA (American Society of Anesthesiologists) class I and II patients undergoing lower limb surgeries were enrolled to receive either magnesium sulfate (Group M) or dexmedetomidine (Group D) along with epidural bupivacaine for surgical anesthesia. All the study subjects received an epidural anesthesia with 14 ml of 0.5% bupivacaine along with either MgSO4 50 mg (Group M) or dexmedetomidine 0.5 μg/kg (Group D) or saline (Group C). The onset of motor and sensory block, duration of block, hemodynamic parameters, and any adverse events were monitored. Results: Analgesia in the postoperative period was better in Group D, duration of sensory and motor blockade was significantly prolonged in Group D and incidence of sedation was more in Group D. Conclusion: Hence, addition of dexemedetomidine to epidural bupivacaine can be advantageous with respect to increased duration of motor and sensory blockade and arousable sedation. PMID:25425781

  20. The Effects of Magnesium Sulfate on Fetal Rats of FGR and the Expression of Caspase-3 in the Placenta of Maternal Rat

    Institute of Scientific and Technical Information of China (English)

    GAO Hui; ZOU Li

    2005-01-01

    To investigate the effect of magnesium sulfate on the fetal rats of FGR and the expression of caspase-3 in the placenta of maternal rat; To explore the mechanism of using magnesium sulfate to cure the FGR. Establish model of FGR by a way of passive smoking: giving the maternal rats different agent of magnesium sulfate by subcutaneous injection: low agent group (300 mg/kg),high agent group (600 mg/kg). Concentration of magnesium sulfate was monitored. The expres sion of caspase-3 was measured by RT-PCR and immunohistochemistry technology. Both of the concentrations of magnesium sulfate in high and low agents group are higher than the FGR group (P<0. 01); the weight of the placenta and fetal rat in high agent group are higher than the FGR group (P<0.05 and P<0.01); the expression of mRNA and protein of caspase-3 in the two agent group is higher than the FGR group (P<0.05 respectively); concentration of magnesium sulfate in the maternal rat blood correlate to the weight of fetal rat (r=0. 899, P=0. 038) and the expression of caspase-3 in the placenta of maternal rat (r= 0.747, P 0.033; r=-0. 915, P=0.001).The research suggests that the weight of fetal rat could be increased by treatment of magnesium sulfate. Because it would imfrmove the placental function by depressing the expression of caspase-3.

  1. Situational analysis of facilitators and barriers to availability and utilization of magnesium sulfate for eclampsia and severe preeclampsia in the public health system in Brazil.

    Science.gov (United States)

    Lotufo, Fátima Aparecida; Parpinelli, Mary Angela; Osis, Maria José; Surita, Fernanda Garanhani; Costa, Maria Laura; Cecatti, José Guilherme

    2016-08-30

    Eclampsia is the main cause of maternal death in Brazil. Magnesium sulfate is the drug of choice for seizure prevention and control in the management of severe preeclampsia and eclampsia. Despite scientific evidence demonstrating its effectiveness and safety, there have been delays in managing hypertensive disorders, including timely access to magnesium sulfate. To conduct a general situational analysis on availability and use of magnesium sulfate for severe preeclampsia and eclampsia in the public health system. A situational analysis was conducted with two components: a documental analysis on information available at the official websites on the policy, regulation and availability of the medication, plus a cross sectional study with field analysis and interviews with local managers of public obstetric health services in Campinas, in the southeast of Brazil. We used the fishbone cause and effect diagram to organize study components. Interviews with managers were held during field observations using specific questionnaires. There was no access to magnesium sulfate in primary care facilities, obstetric care was excluded from urgency services and clinical protocols for professional guidance on the adequate use of magnesium sulfate were lacking in the emergency mobile care service. Magnesium sulfate is currently only administered in referral maternity hospitals. The lack of processes that promote the integration between urgency/emergency care and specialized obstetric care possibly favors the untimely use of magnesium sulfate and contributes to the high maternal morbidity/mortality rates.

  2. The use of magnesium peroxide for the inhibition of sulfate-reducing bacteria under anoxic conditions.

    Science.gov (United States)

    Chang, Yu-Jie; Chang, Yi-Tang; Hung, Chun-Hsiung

    2008-11-01

    Sulfate-reducing bacteria (SRB), which cause microbiologically influenced material corrosion under anoxic conditions, form one of the major groups of microorganisms responsible for the generation of hydrogen sulfide. In this study, which is aimed at reducing the presence of SRB, a novel alternative approach involving the addition of magnesium peroxide (MgO2) compounds involving the use of reagent-grade MgO2 and a commercial product (ORC) was evaluated as a means of inhibiting SRB in laboratory batch columns. Different concentrations of MgO2 were added in the columns when black sulfide sediment had appeared in the columns. The experimental results showed that MgO2 is able to inhibit biogenic sulfide. The number of SRB, the sulfide concentration and the sulfate reducing rate (SRR) were decreased. ORCtrade mark as an additive was able to decrease more effectively the concentration of sulfide in water and the SRB-control effect was maintained over a longer time period when ORCtrade mark was used. The level of oxidation-reduction potential (ORP), which has a linear relationship to the sulfide/sulfate ratio, is a good indicator of SRB activity. As determined by fluorescence in-situ hybridization (FISH), most SRB growth was inhibited under increasing amounts of added MgO2. The concentration of sulfide reflected the abundance of the SRB. Utilization of organic matter greater than the theoretical SRB utilization rate indicated that facultative heterotrophs became dominant after MgO2 was added. The results of this study could supply the useful information for further study on evaluating the solution to biocorrosion problems in practical situations.

  3. Magnesium

    Science.gov (United States)

    ... by limiting the amount lost in urine. Low magnesium intakes for a long period of time, however, can ... is important for healthy bones. People with higher intakes of magnesium have a higher bone mineral density, which is ...

  4. Effect of Compounding of Sodium Tripolyphosphate and Super Plasticizers on the Hydration of α-calcium Sulfate Hemihydrate

    Institute of Scientific and Technical Information of China (English)

    PAN Wei; WANG Peiming

    2011-01-01

    The inhibition and its mechanism of sodium tripolyphosphate(STP)composited with super plasticizers(SPs)on hydration of α-calcium sulfate hemihydrate were studied by setting time,strength,hydration heat,X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),electronic probe micro analysis (EPMA),scanning electron microscopy(SEM)and differential scanning calorimeter(DSC)measurements.The experimental results show that compared with STP addition,compositing STP with polycarboxylate(PC)plasticizer,the final setting time is prolonged from 0.5h to 2hs.While formulating STP with naphthalene-based plasticizer(NAP)or sulfonate melamine formaldehyde plasticizer(SMF),the final setting time is reduced to quarter of an hour Similar changes can also be found in the rate of exothermic hydration and hydration degree.Formulating STP with suitable addition of PC can enhance the strength,while compositing STP and NAP or SMF weakens the strength.Besides,adding STP or STP and SMF,obvious movement(more than lev)of binding energy of Ca2p1/2 and Ca2p3/2 is detected.Compared with STP addition,content of the characteristic element(P)of STP is cut down form 1.1% to 0.49% by compositing STP with SMF.Furthermore,as hydration age increases,hydration inhibition in the presence of admixtures weakens and even disappears within 56 h.

  5. The efficacy of nebulized magnesium sulfate alone and in combination with salbutamol in acute asthma

    Directory of Open Access Journals (Sweden)

    Sarhan HA

    2016-06-01

    Full Text Available Hatem A Sarhan,1 Omar H EL-Garhy,1 Mohamed A Ali,2 Nouran A Youssef1 1Department of Pharmaceutics, Faculty of Pharmacy, 2Department of Chest Diseases, Faculty of Medicine, Minia University, Minia, Egypt Objective: Evaluation of the efficacy of nebulized magnesium sulfate (MgSO4 alone and in combination with salbutamol in acute asthma.Methods: A double-blind randomized controlled study was conducted in Chest and Emergency Departments. Thirty patients of acute attack of bronchial asthma were randomized into three groups: MgSO4 nebulization (group A, salbutamol nebulization (group B, and their combination (group C. All patients were monitored before and after nebulization (each 20 minutes for peak expiratory flow rate (PEFR, respiratory rate (RR, heart rate (HR, blood pressure, pulsus paradoxus, oxygen saturation, clinical examination, and Fischl index.Results: A highly significant improvement in PEFR, PEFR percentage, and Fischl index and significant decrease in RR and HR was observed in all groups. A similar improvement in PEFR was observed in group A and group B (P=0.389. The difference in peak expiratory flow (PEF improvement was insignificant between group B and group C (P=0.101, while there was a significant differ­ence between group A and group C (P=0.014 in favor of group C.Conclusion: Nebulized MgSO4 alone or combined with salbutamol has a clinically significant bronchodilator effect in acute asthma and leads to clinical improvement, increase in PEFR, reduction in HR, and reduction in RR. The response to nebulized MgSO4 alone (PEFR improvement 54±35.6 L/min, P=0.001 is comparable (P=0.389 to that of nebulized salbutamol (PEFR improvement 67.0±41.9 L/min, P=0.001 and is significantly less than (P=0.014 that of nebulized combination (PEFR improvement 92.0±26.9 L/min, P=0.000. Keywords: nebulized magnesium sulfate, salbutamol, acute asthma, peak expiratory flow rate, Fischl index

  6. A Novel Injectable Magnesium/Calcium Sulfate Hemihydrate Composite Cement for Bone Regeneration

    Directory of Open Access Journals (Sweden)

    Shanchuan Zhang

    2015-01-01

    Full Text Available Objective. A novel injectable magnesium/calcium sulfate hemihydrate (Mg/CSH composite with improved properties was reported here. Methods. Composition, setting time, injectability, compressive strength, and bioactivity in simulated body fluid (SBF of the Mg/CSH composite were evaluated. Furthermore, the cellular responses of canine bone marrow stromal cells (cBMSCs and bone formation capacity after the implantation of Mg/CSH in tibia defects of canine were investigated. Results. Mg/CSH possessed a prolonged setting time and markedly improved injectability and mechanical property p<0.05. Mg/CSH samples showed better degradability than CSH in SBF after 21 days of soaking p<0.05. Moreover, the degrees of cell attachment, proliferation, and capability of osteogenic differentiation on the Mg/CSH specimens were higher than those on CSH, without significant cytotoxicity and with the increased proliferation index, ALP activity, and expression levels of integrin β1 and Coll I in cBMSCs p<0.05. Mg/CSH enhanced the efficiency of new bone formation at the tibia defect area, including the significantly elevated bone mineral density, bone area fraction, and Coll I expression level p<0.05. Conclusions. The results implied that this new injectable bone scaffold exhibited promising prospects for bone repair and had a great potential in bone tissue engineering.

  7. Magnesium sulfate treatment for juvenile ferrets following induction of hydrocephalus with kaolin.

    Science.gov (United States)

    Di Curzio, Domenico L; Turner-Brannen, Emily; Mao, Xiaoyan; Del Bigio, Marc R

    2016-04-27

    Previous work with 3-week hydrocephalic rats showed that white matter damage could be reduced by the calcium channel antagonist magnesium sulfate (MgSO4). We hypothesized that MgSO4 therapy would improve outcomes in ferrets with hydrocephalus induced with kaolin at 15 days. MRI was performed at 29 days to assess ventricle size and stratify ferrets to treatment conditions. Beginning at 31 days age, they were treated daily for 14 days with MgSO4 (9 mM/kg/day) or sham saline therapy, and then imaged again before sacrifice. Behavior was examined thrice weekly. Histological and biochemical ELISA and myelin enzyme activity assays were performed at 46 days age. Hydrocephalic ferrets exhibited some differences in weight and behavior between treatment groups. Those receiving MgSO4 weighed less, were more lethargic, and displayed reduced activity compared to those receiving saline injections. Hydrocephalic ferrets developed ventriculomegaly, which was not modified by MgSO4 treatment. Histological examination showed destruction of periventricular white matter. Glial fibrillary acidic protein content, myelin basic protein content, and myelin enzyme activity did not differ significantly between treatment groups. The hydrocephalus-associated disturbances in juvenile ferret brains are not ameliorated by MgSO4 treatment, and lethargy is a significant side effect.

  8. The role of magnesium sulfate in prevention of seizures induced by pentylenetetrazole in rats

    Directory of Open Access Journals (Sweden)

    L D B Oliveira

    2011-01-01

    Full Text Available Magnesium sulfate (MgSO4 has been used to prevent seizures in eclampsia. This study examined the central effects of MgSO4 on different types of pentylenetetrazole (PTZ-induced seizures. Male Wistar rats were submitted to intracerebroventricular (ICV administration of MgSO4 at different doses followed by intraperitoneal administration of PTZ. The latency to the onset of the first seizure induced by PTZ was significantly increased by ICV administration of MgSO4 at a dose of 100 µg compared to the control treatment. In addition, the total period during which animals presented with seizures was significantly reduced at this dose of MgSO4. Furthermore, the latency to the onset of the first partial complex seizure was significantly increased by the lowest dose of MgSO4. However, a high dose of MgSO4 had no effect or even potentiated the effect of PTZ. These results suggest that, depending on the dose, MgSO4 may be important in prevention of epileptic seizures.

  9. Liquid-liquid equilibrium of water + PEG 8000 + magnesium sulfate or sodium sulfate aqueous two-phase systems at 35°C: experimental determination and thermodynamic modeling

    Directory of Open Access Journals (Sweden)

    B. D. Castro

    2005-09-01

    Full Text Available Liquid-liquid extraction using aqueous two-phase systems is a highly efficient technique for separation and purification of biomolecules due to the mild properties of both liquid phases. Reliable data on the phase behavior of these systems are essential for the design and operation of new separation processes; several authors reported phase diagrams for polymer-polymer systems, but data on polymer-salt systems are still relatively scarce. In this work, experimental liquid-liquid equilibrium data on water + polyethylene glycol 8000 + magnesium sulfate and water + polyethylene glycol 8000 + sodium sulfate aqueous two-phase systems were obtained at 35°C. Both equilibrium phases were analyzed by lyophilization and ashing. Experimental results were correlated with a mass-fraction-based NRTL activity coefficient model. New interaction parameters were estimated with the Simplex method. The mean deviations between the experimental and calculated compositions in both equilibrium phases is about 2%.

  10. Using Demonstrations Involving Combustion and Acid-Base Chemistry to Show Hydration of Carbon Dioxide, Sulfur Dioxide, and Magnesium Oxide and Their Relevance for Environmental Climate Science

    Science.gov (United States)

    Shaw, C. Frank, III; Webb, James W.; Rothenberger, Otis

    2016-01-01

    The nature of acidic and basic (alkaline) oxides can be easily illustrated via a series of three straightforward classroom demonstrations for high school and general chemistry courses. Properties of carbon dioxide, sulfur dioxide, and magnesium oxide are revealed inexpensively and safely. Additionally, the very different kinetics of hydration of…

  11. Using Demonstrations Involving Combustion and Acid-Base Chemistry to Show Hydration of Carbon Dioxide, Sulfur Dioxide, and Magnesium Oxide and Their Relevance for Environmental Climate Science

    Science.gov (United States)

    Shaw, C. Frank, III; Webb, James W.; Rothenberger, Otis

    2016-01-01

    The nature of acidic and basic (alkaline) oxides can be easily illustrated via a series of three straightforward classroom demonstrations for high school and general chemistry courses. Properties of carbon dioxide, sulfur dioxide, and magnesium oxide are revealed inexpensively and safely. Additionally, the very different kinetics of hydration of…

  12. An integrative review of the side effects related to the use of magnesium sulfate for pre-eclampsia and eclampsia management

    Directory of Open Access Journals (Sweden)

    Smith Jeffrey Michael

    2013-02-01

    Full Text Available Abstract Background Pre-eclampsia/eclampsia is one of the most common causes of maternal and perinatal morbidity and mortality in low and middle income countries. Magnesium sulfate is the drug of choice for prevention of seizures as part of comprehensive management of the disease. Despite the compelling evidence for the effectiveness of magnesium sulfate, concern has been expressed about its safety and potential for toxicity, particularly among providers in low- and middle-income countries. The purpose of this review was to determine whether the literature published in these global settings supports the concerns about the safety of use of magnesium sulfate. Methods An integrative review of the literature was conducted to document the known incidences of severe adverse reactions to magnesium sulphate, and specific outcomes of interest related to its use. All types of prospective clinical studies were included if magnesium sulfate was used to manage pre-eclampsia or eclampsia, the study was conducted in a low- or middle-income country, and the study included the recording of the incidence of any adverse side effect resulting from magnesium sulfate use. Results A total of 24 studies that compared a magnesium sulfate regimen against other drug regimens and examined side effects among 34 subject groups were included. The overall rate of absent patellar reflex among all 9556 aggregated women was 1.6%, with a range of 0-57%. The overall rate of respiratory depression in 25 subject groups in which this outcome was reported was 1.3%, with a range of 0–8.2%. Delay in repeat administration of magnesium sulfate occurred in 3.6% of cases, with a range of 0-65%. Calcium gluconate was administered at an overall rate of less than 0.2%. There was only one maternal death that was attributed by the study authors to the use of magnesium sulfate among the 9556 women in the 24 studies. Conclusion Concerns about safety and toxicity from the use of magnesium sulfate

  13. Experience of use of magnesium sulfate in the treatment of tetanus in a tertiary referral Infectious Disease Hospital, Kolkata, India

    Directory of Open Access Journals (Sweden)

    Alakes Kumar Kole

    2013-01-01

    Full Text Available Background: Tetanus is still a public health problem in developing countries with high morbidity and mortality. Aims and Objectives: To evaluate the effects of magnesium sulfate in the treatment of moderate to very severe tetanus cases. Patients and Methods: Eighty-six patients suffering from of moderate to very severe tetanus, treated with injection magnesium sulphate in combination with injection diazepam were evaluated and compared to the tetanus patients from the hospital record (treated with only diazepam regarding outcomes. Results: The average duration of reflex spasm was 12 vs. 8 days in moderate group, 18 vs. 15 days in severe group and 21 vs. 17 days in very severe group in the previous and study year respectively. Average duration of hospital stay was 20 vs. 17 days in moderate group, 27 vs. 22 days in severe group and 36 vs. 30 days in very severe group in the previous and study year respectively. It had been observed that in both severe and very severe tetanus cases, occurrence of autonomic instability, respiratory depression, aspiration pneumonia, cardiac arrhythmia and total death - all were decreased in the study period than previous year. Conclusion: Magnesium sulfate in combination with diazepam may be a better option in the treatment of tetanus particularly in developing countries with limited intensive care facility because of morbidity and mortality benefits.

  14. Effect of magnesium sulfate and thyroxine on inflammatory markers in a rat model of hypothyroidism.

    Science.gov (United States)

    Abbas, Amr M; Sakr, Hussein F

    2016-04-01

    Inflammation is a major risk factor for cardiovascular complications. Magnesium sulfate (MgSO4) has anti-inflammatory actions. Therefore we investigated the effects of levothyroxine and MgSO4 on inflammatory markers as C-reactive protein (CRP), interleukin-6, tumor necrosis factor-α (TNF-α), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) in hypothyroid rats. Sixty male rats were divided into 6 groups; normal, normal + MgSO4, hypothyroidism, hypothyroidism + levothyroxine, hypothyroidism + MgSO4, and hypothyroidism + levothyroxine + MgSO4. Thyroxine, triiodothyronine, and thyroid-stimulating hormone (TSH), CRP, interleukin-6, TNF-α, ICAM-1, and VCAM-1 were measured in all rats. Hypothyroidism significantly increased TSH, CRP, interleukin-6, TNF-α, ICAM-1, and VCAM-1 and decreased triiodothronine and thyroxine. Treatment of hypothyroid rats with levothyroxine or MgSO4 significantly decreased CRP, interleukin-6, TNF-α, ICAM-1, and VCAM-1. Combined therapy of hypothyroid rats with levothyroxine and MgSO4 significantly decreased CRP, interleukin-6, TNF-α, ICAM-1, and VCAM-1 compared with hypothyroid rats either untreated or treated with levothyroxine or MgSO4. This study demonstrates that hypothyroid rats have chronic low grade inflammation, which may account for increased risk of cardiovascular diseases. Combined levothyroxine and MgSO4 is better than levothyroxine or MgSO4 alone in alleviating the chronic low grade inflammatory status and therefore reducing the risk of cardiovascular diseases in hypothyroid animals.

  15. Influence of magnesium sulfate on HCO3/Cl transmembrane exchange rate in human erythrocytes.

    Science.gov (United States)

    Chernyshova, Ekaterina S; Zaikina, Yulia S; Tsvetovskaya, Galina A; Strokotov, Dmitry I; Yurkin, Maxim A; Serebrennikova, Elena S; Volkov, Leonid; Maltsev, Valeri P; Chernyshev, Andrei V

    2016-03-21

    Magnesium sulfate (MgSO4) is widely used in medicine but molecular mechanisms of its protection through influence on erythrocytes are not fully understood and are considerably controversial. Using scanning flow cytometry, in this work for the first time we observed experimentally (both in situ and in vitro) a significant increase of HCO3(-)/Cl(-) transmembrane exchange rate of human erythrocytes in the presence of MgSO4 in blood. For a quantitative analysis of the obtained experimental data, we introduced and verified a molecular kinetic model, which describes activation of major anion exchanger Band 3 (or AE1) by its complexation with free intracellular Mg(2+) (taking into account Mg(2+) membrane transport and intracellular buffering). Fitting the model to our in vitro experimental data, we observed a good correspondence between theoretical and experimental kinetic curves that allowed us to evaluate the model parameters and to estimate for the first time the association constant of Mg(2+) with Band 3 as KB~0.07mM, which is in agreement with known values of the apparent Mg(2+) dissociation constant (from 0.01 to 0.1mM) that reflects experiments on enrichment of Mg(2+) at the inner erythrocyte membrane (Gunther, 2007). Results of this work partly clarify the molecular mechanisms of MgSO4 action in human erythrocytes. The method developed allows one to estimate quantitatively a perspective of MgSO4 treatment for a patient. It should be particularly helpful in prenatal medicine for early detection of pathologies associated with the risk of fetal hypoxia.

  16. Microstructure and Physical Properties of Sulfate Hydrate/Ice Eutectic Aggregates in the Binary System Sodium-Sulfate/Water at Planetary Conditions

    Science.gov (United States)

    McCarthy, C. M.; Kirby, S.; Durham, W.; Stern, L.

    2004-12-01

    Reflectance spectra data from Mars Odyssey, Galileo and potentially from Cassini suggest the presence of hydrated salts on numerous satellites in environments such as evaporate beds or combined with water ice. Improved mission data on these occurrences indicate that grain structures and properties of such materials merit a closer look using laboratory methods. Here we report the synthesis of a two-phase aggregate of sodium sulfate hydrate and water ice made by eutectic solidification from solution, characterization of its microstructure using cryogenic SEM, and comparison of its physical properties to those of its end-member components. Samples are crystallized from solution using a precision cryobath and seeded growth. The reaction is a "simple" one meaning that there is no solid solution formation in either of the two solid phases. The eutectic composition we studied for the sodium sulfate hydrate is 4wt% Na2SO4, which corresponds to about .06 volume fraction of Na2SO4ṡ10H2O, mirabilite, and .94 ice I. The eutectic microstructure observed with this volume fraction, which is termed "broken lamellar", consists of fairly uniform blade-like mirabilite grains arranged in roughly parallel columns within a water ice matrix. The blades and matrix material form a lamella that alternates with lamellae of pure ice. Energy dispersive spectroscopy of these eutectic mixtures confirms the presence of the two crystalline phases. Also, we find that lamellar spacing decreases with increasing growth rate. Constant-strain-rate tests in compression are carried out in the cryogenic gas deformation apparatus at LLNL in a pressure-temperature range appropriate to the icy satellites. We report the rheology of the two-phase aggregate and compare it to the strength properties of pure water ice and pure mirabilite. With the aid of numerous studies on similar structures in the literature on metals, we analyze the deformation mechanics from the perspective of defect and crack propagation

  17. Anti-hyperalgesic effect of systemic magnesium sulfate in carrageenan-induced inflammatory pain in rats: influence of the nitric oxide pathway.

    Science.gov (United States)

    Srebro, Dragana P; Vučković, Sonja; Vujović, Katarina Savić; Prostran, Milica

    2014-01-01

    This study investigated whether systemic magnesium sulfate (an antagonist at the glutamate subtype of N-methyl-D-aspartate receptor) affects inflammatory pain, and whether the nitric oxide pathway is involved. Carrageenan (0.5%, 0.1 mL, intraplantar)-induced mechanical hyperalgesia was evaluated using the electronic von Frey test in male Wistar rats. Magnesium sulfate had no effect when injected locally into the inflamed rat paw. However, subcutaneous magnesium sulfate, at doses of 0.5, 5, 15 and 30 mg/kg, reduced the hyperalgesia by 44.4 ± 8.8, 68 ± 8.4, 24.6 ± 6.9 and 45.3 ± 6.7% respectively. N-nitro-L-arginine methyl ester hydrochloride (L-NAME) (3 and 5 mg/kg, intraperitoneal), a non-selective nitric oxide synthase inhibitor, significantly reduced the effects of magnesium sulfate. Also, L-arginine (0.4 mg/kg, subcutaneously) significantly reversed the effect of L-NAME in the magnesium sulfate-treated rats. A selective inhibitor of neuronal or inducible nitric oxide synthase, N-ω-Propyl-L-arginine hydrochloride (L-NPA) (0.5, 1 and 2 mg/kg, intraperitoneal) and S-methylisothiourea (SMT) (0.005, 0.01 and 0.015 mg/kg, intraperitoneal) reduced the effect of magnesium sulfate significantly only at the highest doses tested. When given alone, L-NAME (3 and 5 mg/kg) L-NPA (2 mg/kg) and SMT (0.015 mg/kg) did not have any influence on carrageenan-induced hyperalgesia. The present study revealed that magnesium sulfate is effective against inflammatory pain after systemic, but not after local peripheral administration, and activation of the nitric oxide pathway is probably involved in the anti-hyperalgesic effect of magnesium sulfate. Low doses of systemic magnesium sulfate given as a pretreatment or a treatment might have a beneficial effect in patients with inflammatory somatic pain.

  18. Effects of calcium sulfate and magnesium sulfate whiskers on Vickers Hardness of dental composite resin%硫酸钙和硫酸镁晶须对复合树脂维氏硬度的影响

    Institute of Scientific and Technical Information of China (English)

    何峰; 张莘; 王晓菲; 章非敏; 谢海峰

    2011-01-01

    Objects The aim of this study was to evalue the effects of calcium sulphate and magnesium sulfate whiskers on the Vickers Hardness of dental composite resin. Methods Calcium suffate and magnesium sulfate whiskers were prepared and were surface modified by sodium stearate. Eight groups of composite resin specimens were prepared: one control group, and seven groups using either surface modified calcium sulfate whiskers or magnesium sulfate whiskers comprising 1%, 10% , 20%, 30% of the material by weight. The standard resin samples were prepared, and their Vickers Hardness values were measured. Results With 20% and 30% calcium sulphate or magnesium sulfate whiskers, surface hardness improved. The more magnesium sulfate whiskers was added, the higher surface hardness values presented. Conclusons Appropriate proportions of calcium sulphate and magnesium sulfate whisker would increase the surface hardness of dental composite resin.%目的 探讨硫酸钙和硫酸镁晶须对复合树脂的维氏硬度的影响.方法 制备硫酸钙和硫酸镁晶须,以硬脂酸钠改性剂表面改性,随后分别按1%、10%、20%、30%的比例混合入复合树脂中,固化后测量各组试件表面维氏硬度.结果 两种晶须的添加比例为20%和30%时,树脂的表面维氏硬度均增加,硫酸镁晶须添加量多时树脂表面硬度相应增加.结论 添加适当比例的硫酸钙和硫酸镁镁晶须可以提高复合树脂的表面硬度.

  19. Influence of Calcium Sulfate State and Fineness of Cement on Hydration of Portland Cements Using Electrical Measurement

    Institute of Scientific and Technical Information of China (English)

    WEI Xiaosheng; LI Zongjin; XIAO Lianzhen; THONG Wangfai

    2006-01-01

    The influence of calcium sulfate state and fineness of cement on hydration of Portland cement was studied using electrical resistivity measurement. The bulk resistivity curve of the paste from the abnormal cement mainly with hemihydrate had a characteristic abnormal peak and rapid increase in early period. The resistivity measurement technique can be used to discriminate abnormal setting. For normal cement with gypsum, the increase in fineness of the Portland cement decreases the minimum resistivity due to a higher ionic concentration and increases the 24 hour resistivity due to a reduction in macroscopic pore size. Thesetting time, compressive strength, pore structure of pastes made from different cements were carried out to compare the influence of water to cement ratio, calcium sulfate state and fineness. It is found that the electrical and mechanical properties are strongly affected by the initial porosity, the presence of hemihydrate or gypsum, and the fineness of cement.

  20. Effects of Thaumasite Formation on the Performance of Portland-limestone Concrete Stored in Magnesium Sulfate Solution

    Institute of Scientific and Technical Information of China (English)

    GAO Lixiong; YAO Yan; WANG Ling

    2005-01-01

    The influence of thaumasite formation on the performance of Portland- limestone cement concrete stored in magnesium sulfate solution was studied. The experimental results show that the deterioration of Portlandlimestone cement concrete is higher than that of Portland cement concrete. The more the content of limestone, the more serious the deterioration of concrete, and also the lower the temperature, the earlier the deterioration of concrete. Thaumasite was detected to form in the Portland-limestone pastes when stored in 10wt% MgSO4 solution at 3- 10 ℃ and it was easy to form at lower temperatures.

  1. The Influence of the MRSP on the Freezing and Evaporation Processes of the Magnesium Sulfate Subtype Salt Lake Brine

    Directory of Open Access Journals (Sweden)

    Qinghai Li

    2016-01-01

    Full Text Available We have developed a new concept, which is the mass fraction ratio of sulfate and potassium ions (MRSP, for the magnesium sulfate subtype salt lake, which is calculated using the metastable phase diagram. We also studied the trend of the MRSP values with the temperature and the influence of the MRSP values on the evaporation process. The experimental results indicated that the MRSP value showed significantly negative trend with decrease of refrigerated temperature. Moreover, when the MRSP value of the objective brine is reduced to less than or equal to the Specific Value by freezing operation, the great changes of crystal morphology and stage of K+ and SO42- will take place, which makes the sequence of salts precipitation of the freezing-evaporation different from the direct-evaporation.

  2. The analgesic effect of Magnesium Sulfate in postoperative pain of inguinal hernia repair

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    Mehraein A

    2007-08-01

    Full Text Available Background: Magnesium Sulfate (MgSO4 has been used as a pharmacologic agent in different situations for many years in the treatment of tachyarrhythmias, myocardial ischemia, preeclampsia, and tocolysis among others. The analgesic effect of MgSO4 for postoperative pain has been used since the 1990s. Postoperative pain is one of the most common complications in the perioperative period and can result in serious consequences in different organs if left untreated. Inguinal herniorrhaphy is among the most common surgeries and is almost always accompanied by severe pain. The object of this study is to determine the effect of a pre-induction infusion of MgSO4 on the reduction of postsurgical pain after herniorrhaphy. Methods: This double-blind, randomized clinical trial included 105 ASA class I and class II herniorrhaphy patients at Shariati Hospital in years 2004 and 2005. For statistical analysis, the 2 and T tests were used. The patients were divided into three groups based on block randomization. Patients in the following groups received: Group A, 200 ml of normal saline infusion (placebo; Group B, 25 mg/kg MgSO4 in 200 ml of normal saline; Group C, 50 mg/kg MgSO4 in 200 ml of normal saline. All groups were infused twenty minutes before induction of anesthesia using identical methods and dosage in all three groups. Heart rate and mean arterial pressure (MAP at pre- and postintubation and so at skin incision time were charted. Visual analog scale (VAS pain score, nausea, vomiting and the amount of morphine used before recovery room discharge and in six, twelve and twenty-four hours after recovery discharge was recorded. Results: The average age for the different groups was as follows: Group A: 33.6, Group B: 37.37, Group C: 32.74. Nausea and vomiting between the case and control groups were not statistically different (60% vs. 71.4%, p=0.0499, nor was the amount of Morphine used. On recovery room discharge, the VAS scores were 8.1, 7.2, and 5

  3. Magnesium sulfate treatment reverses seizure susceptibility and decreases neuroinflammation in a rat model of severe preeclampsia.

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    Abbie Chapman Johnson

    Full Text Available Eclampsia, defined as unexplained seizure in a woman with preeclampsia, is a life-threatening complication of pregnancy with unclear etiology. Magnesium sulfate (MgSO4 is the leading eclamptic seizure prophylactic, yet its mechanism of action remains unclear. Here, we hypothesized severe preeclampsia is a state of increased seizure susceptibility due to blood-brain barrier (BBB disruption and neuroinflammation that lowers seizure threshold. Further, MgSO4 decreases seizure susceptibility by protecting the BBB and preventing neuroinflammation. To model severe preeclampsia, placental ischemia (reduced uteroplacental perfusion pressure; RUPP was combined with a high cholesterol diet (HC to cause maternal endothelial dysfunction. RUPP+HC rats developed symptoms associated with severe preeclampsia, including hypertension, oxidative stress, endothelial dysfunction and fetal and placental growth restriction. Seizure threshold was determined by quantifying the amount of pentylenetetrazole (PTZ; mg/kg required to elicit seizure in RUPP + HC ± MgSO4 and compared to normal pregnant controls (n = 6/group; gestational day 20. RUPP+HC rats were more sensitive to PTZ with seizure threshold being ∼ 65% lower vs. control (12.4 ± 1.7 vs. 36.7 ± 3.9 mg/kg PTZ; p<0.05 that was reversed by MgSO4 (45.7 ± 8.7 mg/kg PTZ; p<0.05 vs. RUPP+HC. BBB permeability to sodium fluorescein, measured in-vivo (n = 5-7/group, was increased in RUPP+HC vs. control rats, with more tracer passing into the brain (15.9 ± 1.0 vs. 12.2 ± 0.3 counts/gram ×1000; p<0.05 and was unaffected by MgSO4 (15.6 ± 1.0 counts/gram ×1000; p<0.05 vs. controls. In addition, RUPP+HC rats were in a state of neuroinflammation, indicated by 35 ± 2% of microglia being active compared to 9 ± 2% in normal pregnancy (p<0.01; n = 3-8/group. MgSO4 treatment reversed neuroinflammation, reducing microglial activation to 6 ± 2% (p<0.01 vs. RUPP+HC. Overall, RUPP+HC rats were in a state of augmented

  4. Facilitation of fiberoptic nasotracheal intubation with magnesium sulfate: A double-blind randomized study

    Science.gov (United States)

    Elgebaly, Ahmed Said; Eldabaa, Ahmed Ali

    2014-01-01

    Background: A double-blinded, prospective, and randomized study was designed to determine the efficacy and tolerability of intravenous (IV) magnesium sulfate (MgSO4) to facilitate fiberoptic bronchoscopic (FOB) nasotracheal intubations. Patients and Methods: A total of 120 patients scheduled to undergo elective awake fiberoptic nasotracheal intubation, while they were anesthetized for elective surgery were randomly allocated to one of three groups: The control Group S (n = 40) received 100 ml (50 ml 0.9% saline + 50 ml paracetamol) was infused in 10 min and direct IV 5 ml 0.9% normal saline, Group MD (n = 40): Received midazolam IV in a dose of 0.07 mg/kg in 5 ml 0.9% normal saline and 100 ml 0.9% was infused in 10 min and Group MS (n = 40): IV 45 mg/kg MgSO4 10 min in 100 ml of 0.9% normal saline through 10 min and direct IV 5 ml 0.9% normal saline. Results: Time required for nasotracheal intubation was significantly less in group Groups MD and MS, as compared with the control group, but not significant between the two groups. (Group MD: 9.05 + 1.95 min, Group MS 3.75 + 0.75 min and Group S 16.85 + 1.7 min). However, the number of fiberoptic intubation was significantly more in the MD and MS groups, as compared with the control group. Easy intubation (control group: 0, Group MD: 25 and Group MS: 35), moderate difficulty (control group: 5, Group MD: 12 and Group MS: 4) and difficult (control group: 35, Group MD: 3 and Group MS: 1). Procedure adverse events were significantly lower in Group MS. None of the patients in Group MS had procedure hypoxia, but it occurred in 10 patients of Group MD and 20 patients in Group S. Six patients in Group S and two in Group MD had procedure apnea whereas, none of the patients in the MS group experienced this. After medication and just before intubation heart rate and mean arterial pressure were significantly less in Groups MD and MS, as compared to the control group (Group MD: 77 + 7.7 beat/min, Group MS: 70 + 5.6 beat/min and

  5. Relationship between small bowel transit time and absorption of a solid meal. Influence of metoclopramide, magnesium sulfate, and lactulose.

    Science.gov (United States)

    Holgate, A M; Read, N W

    1983-09-01

    The times taken for a radiolabeled solid meal to empty from the stomach and terminal ileum and the absorption of the components of that meal were measured in 14 patients with terminal ileostomies under control conditions and after administration of either lactulose (40 g) or metoclopramide (20 mg tds), or magnesium sulfate (0.1 g/kg body weight). Absorption of each of the components of the meal was determined by chemical analysis of the ileostomy effluent. The radioisotope proved an excellent marker for the delivery of fat, protein, and carbohydrate residues. All three agents significantly reduced the time taken for the meal to empty from the ileum. This was associated with significant reductions in the absorption of fat, carbohydrate, protein, water, and electrolytes in the case of lactulose and magnesium sulfate. Although metoclopramide reduced transit time to the same degree as the other agents, its effect on absorption of fat, fluid, and electrolytes was much less, and absorption of protein and carbohydrate was unaffected. We therefore conclude that, although agents that accelerate postprandial transit of a meal may diminish absorption of the component of that meal in the small bowel, the extent to which this occurs cannot be predicted by a knowledge of transit kinetics alone and depends on the means by which transit is altered. The action of lactulose on the small intestine causes fluid and fat losses, sufficient to result in diarrhea and steatorrhea in a normal subject.

  6. Reinforcement of calcium sulfate and magnesium sulfate whiskers to dental composite resin%CaSO4和MgSO4晶须填料对牙科复合树脂抗弯强度的影响

    Institute of Scientific and Technical Information of China (English)

    何峰; 徐玲玲; 谢海峰; 朱烨; 章非敏

    2010-01-01

    目的 观察CaSO4晶须和MgSO4晶须对复合树脂的抗弯强度的影响.方法 制备CaSO4晶须和MgSO4晶须,以硬脂酸钠改性剂表面改性,随后分别按质量分数为1%、10%、20%、30%混合添加到复合树脂中,固化后评价其三点抗弯强度,扫描电镜观察断面形态.结果 添加2种晶须的质量分数在10%及以下时,复合树脂的三点抗弯强度均下降,质量分数为20%和30%时,MgsO4晶须组的三点抗弯强度增加.结论 添加适当比例的MgSO4晶须可以提高复合树脂的三点抗弯强度.%Objective The aim of this study was to evaluate the effect of calcium sulphate and magnesium sulfate whiskers on the flexture strengths of dental composite resin.Methods Calcium sulfate whiskers and magnesium sulfate whiskers were prepared.Seven groups of composite resin specimens were prepared including one control group and six groups using either calcium sulfate whiskers or magnesium sulfate whiskers comprising 1%,10%,20%,30% of the material by weight.Before mixing with resin,both whiskers were surface modified by Sodium stearate.The standard resin samples with dimensions of 25 mm×2 mm×2 mm were prepared according to the ISO-10477 criterion(eight for each group),and their flexure strengths were measured by a universal testing machine.The fracture surfaces of selected specimens were examined by a scan electron microscope.Results Neither mixture improved the flexure strength of composite resin when the adding proportions of calcium sulfate and whiskers magnesium sulfate whiskers were under 10%.However,when the adding proportions were 20 wt % and 30 wt%,magnesium sulfate whiskers excerted positive effects.Concluson Appropriate proportions of magnesium sulfate crystal whisker would increase the flexure strength of dental composite resin.

  7. EFFICACY OF SINGLE LOADING DOSE OF MAGNESIUM SULFAT E IN ECLAMPSIA

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    Meenakshi

    2013-02-01

    Full Text Available ABSTRACT: BACKGROUND: Eclampsia is a life threatening condition and it va ries from countries to countries .The incidence in our countr y varies from 5-10%. The first and foremost thing in management of eclampsia is control of conv ulsions. Magnesium sulphate has established itself as the drug of choice for the an ticonvulsant management of eclampsia but the question as to what constitutes the Minimum effecti ve dose remains unanswered which is evident from the different regimens used in clinica l practice. Its narrow therapeutic range mandates that it only be used in the minimum doses which gives efficient control of convulsions and helps in improving maternal and fetal outcome. Ai ms: To study the efficacy and safety of single loading dose of magnesium sulphate in control ling and prevention of recurrence of convulsion in eclampsia, to reduce the adverse affec ts of magnesium sulphate and improve the maternal and fetal outcome with single loading dose . Methods: Prospective study of 100 cases with clinical diagnosis of eclampsia were given sing le loading dose of magnesium sulphate [4 g of 20% IV and 10 g of 50 % IM], there was no mainte nance dose. The effect of singe loading dose of magnesium sulphate in controlling convulsions, th e recurrence rates, toxicity and the maternal and fetal outcome was studied. Results: Th e results showed a favorable outcome with the reduction of the dose and duration of magnesium sulphate therapy. The primary outcomes were comparable with all other regimens in use. Wit h recurrence rate of 9% its efficacy was comparable with the other regimens in use. The cases that were on single dose regimen had a significantly lower incidence of cesarean section w ith up to 74% of the patients having vaginal deliveries. The maternal mortality was 3% and perina tal mortality was 29%. Conclusions: Single loading dose of magnesium sulphate is effecti ve in controlling and prevention of recurrence of convulsions in eclampsia

  8. Comparative study of the hydration systems formed during interactions of hydrogen phosphate dianions with putrescine, nor-putrescine and magnesium dications

    Science.gov (United States)

    Figlerowicz, M.; Utzig, E.; Alejska, M.; Bratek-Wiewiórowska, M. D.; Wiewiórowski, M.

    1997-10-01

    A comparative study of hydration systems, formed as a result of the interaction between hydrogen phosphate dianions and three naturally occurring cations (putrescine (Put), its nor-homologue (nPut) and magnesium), is presented. On the basis of X-ray data and IR, NMR and calorimetric measurements, we have determined how the structure and physicochemical properties of the cations influence the system of phosphate residue hydration. Our study demonstrates that the stability of the hydration systems depends not only on the character of the bonds used by water to link with other salt components (coordinate or hydrogen bonds), but also on the location of the water molecules in the crystal lattice. In addition, contrary to magnesium salts, the dehydration of diamine (Put and nPut) hydrogen phosphates is reversible. Both dehydration and rehydration processes take place in the solid state. During rehydration, the crystalline anhydrous salt absorbs water molecules from the atmosphere. This leads to the reconstruction of the hydrated salt structure; this means that the salt which is the product of rehydration is identical with that obtained by crystallization from water solution.

  9. Magnesium sulfate in femoral nerve block, does postoperative analgesia differ? A comparative study

    Directory of Open Access Journals (Sweden)

    Hossam A. ELShamaa

    2014-04-01

    Conclusion: The current study concluded that the admixture of magnesium to bupivacaine provides a profound prolongation of the femoral nerve block, in addition to a significant decrease in postoperative pain scores and total dose of rescue analgesia, with a longer bearable pain periods in the first postoperative day.

  10. Extraction of compositional and hydration information of sulfates from laser-induced plasma spectra recorded under Mars atmospheric conditions - Implications for ChemCam investigations on Curiosity rover

    Energy Technology Data Exchange (ETDEWEB)

    Sobron, Pablo, E-mail: pablo.sobron@asc-csa.gc.ca [Department of Earth and Planetary Sciences and McDonnell Center for the Space Sciences, Washington University, St. Louis, MO 63130 (United States); Wang, Alian [Department of Earth and Planetary Sciences and McDonnell Center for the Space Sciences, Washington University, St. Louis, MO 63130 (United States); Sobron, Francisco [Unidad Asociada UVa-CSIC a traves del Centro de Astrobiologia, Parque Tecnologico de Boecillo, Parcela 203, Boecillo (Valladolid), 47151 (Spain)

    2012-02-15

    Given the volume of spectral data required for providing accurate compositional information and thereby insight in mineralogy and petrology from laser-induced breakdown spectroscopy (LIBS) measurements, fast data processing tools are a must. This is particularly true during the tactical operations of rover-based planetary exploration missions such as the Mars Science Laboratory rover, Curiosity, which will carry a remote LIBS spectrometer in its science payload. We have developed: an automated fast pre-processing sequence of algorithms for converting a series of LIBS spectra (typically 125) recorded from a single target into a reliable SNR-enhanced spectrum; a dedicated routine to quantify its spectral features; and a set of calibration curves using standard hydrous and multi-cation sulfates. These calibration curves allow deriving the elemental compositions and the degrees of hydration of various hydrous sulfates, one of the two major types of secondary minerals found on Mars. Our quantitative tools are built upon calibration-curve modeling, through the correlation of the elemental concentrations and the peak areas of the atomic emission lines observed in the LIBS spectra of standard samples. At present, we can derive the elemental concentrations of K, Na, Ca, Mg, Fe, Al, S, O, and H in sulfates, as well as the hydration degrees of Ca- and Mg-sulfates, from LIBS spectra obtained in both Earth atmosphere and Mars atmospheric conditions in a Planetary Environment and Analysis Chamber (PEACh). In addition, structural information can be potentially obtained for various Fe-sulfates. - Highlights: Black-Right-Pointing-Pointer Routines for LIBS spectral data fast automated processing. Black-Right-Pointing-Pointer Identification of elements and determination of the elemental composition. Black-Right-Pointing-Pointer Calibration curves for sulfate samples in Earth and Mars atmospheric conditions. Black-Right-Pointing-Pointer Fe curves probably related to the crystalline

  11. Bathing in a magnesium-rich Dead Sea salt solution improves skin barrier function, enhances skin hydration, and reduces inflammation in atopic dry skin.

    Science.gov (United States)

    Proksch, Ehrhardt; Nissen, Hans-Peter; Bremgartner, Markus; Urquhart, Colin

    2005-02-01

    Magnesium salts, the prevalent minerals in Dead Sea water, are known to exhibit favorable effects in inflammatory diseases. We examined the efficacy of bathing atopic subjects in a salt rich in magnesium chloride from deep layers of the Dead Sea (Mavena(R) Dermaline Mg(46) Dead Sea salt, Mavena AG, Belp, Switzerland). Volunteers with atopic dry skin submerged one forearm for 15 min in a bath solution containing 5% Dead Sea salt. The second arm was submerged in tap water as control. Before the study and at weeks 1-6, transepidermal water loss (TEWL), skin hydration, skin roughness, and skin redness were determined. We found one subgroup with a normal and one subgroup with an elevated TEWL before the study. Bathing in the Dead Sea salt solution significantly improved skin barrier function compared with the tap water-treated control forearm in the subgroup with elevated basal TEWL. Skin hydration was enhanced on the forearm treated with the Dead Sea salt in each group, which means the treatment moisturized the skin. Skin roughness and redness of the skin as a marker for inflammation were significantly reduced after bathing in the salt solution. This demonstrates that bathing in the salt solution was well tolerated, improved skin barrier function, enhanced stratum corneum hydration, and reduced skin roughness and inflammation. We suggest that the favorable effects of bathing in the Dead Sea salt solution are most likely related to the high magnesium content. Magnesium salts are known to bind water, influence epidermal proliferation and differentiation, and enhance permeability barrier repair.

  12. Reversal with sugammadex for rocuronium-induced deep neuromuscular block after pretreatment of magnesium sulfate in rabbits.

    Science.gov (United States)

    Kang, Woon Seok; Kim, Kyo Sang; Song, Shin Mi

    2017-04-01

    Magnesium sulfate (MgSO4) has been used in the treatment of pre-eclampsia, hypertension and arrhythmia. Magnesium enhances the neuromuscular block of rocuronium. This study has been conducted to evaluate the reversal efficacy of sugammadex from deep rocuronium-induced neuromuscular block (NMB) during consistent pretreatment of MgSO4 in rabbits. Twenty-eight rabbits were randomly assigned to four groups, a control group or study groups (50% MgSO4 150-200 mg/kg and 25 mg/kg/h IV), and received rocuronium 0.6 mg/kg. When post-tetanic count 1-2 appeared, sugammadex 2, 4, and 8 mg/kg was administered in the 2-mg group, control and 4-mg group, and 8-mg group, respectively. The recovery course after reversal of sugammadex administration was evaluated in each group. The mean serum concentration of magnesium was maintained at more than 2 mmol/L in the study groups, and the total dose of MgSO4 was more than 590 mg. The reversal effect of sugammadex on rocuronium-induced NMB in pretreated MgSO4 was not different from that in the group without MgSO4. The recovery time to train-of-four ratio 0.9 after sugammadex administration in the 2-mg group was longer than in the other groups (P sugammadex from a deep rocuronium-induced NMB during large pretreatment of MgSO4 was not affected. However, we should consider that the reversal effect of sugammadex varied depending on the dose.

  13. [High-dose magnesium sulfate in the treatment of aconite poisoning].

    Science.gov (United States)

    Clara, A; Rauch, S; Überbacher, C A; Felgenhauer, N; Drüge, G

    2015-05-01

    This article reports the case of a 62-year-old male patient who ingested the roots of Monkshood (Aconitum napellus) and white hellebore (Veratrum album) dissolved in alcohol with a suicidal intention and suffered cardiotoxic and neurotoxic symptoms. After contacting the Poison Information Centre ventricular arrhythmia was treated with high-dose magnesium sulphate as the only antiarrhythmic agent and subsequently a stable sinus rhythm could be established after approximately 3 h. Aconitum napellus is considered the most poisonous plant in Europe and it is found in gardens, the Alps and the Highlands. Poisoning is mainly caused by the alkaloid aconite that leads to persistent opening and activation of voltage-dependent sodium channels resulting in severe cardiac and neurological toxicity. As no specific antidote is known so far, poisoning is associated with a high mortality. The therapy with high-dose magnesium sulphate is based on in vitro and animal experiments as well as limited clinical case reports.

  14. Effects of lidocaine and magnesium sulfate in attenuating hemodynamic response to tracheal intubation: single-center, prospective, double-blind, randomized study.

    Science.gov (United States)

    Mendonça, Fabricio Tavares; de Queiroz, Lucas Macedo da Graça Medeiros; Guimarães, Cristina Carvalho Rolim; Xavier, Alexandre Cordeiro Duarte

    Hemodynamic response to airway stimuli is a common phenomenon and its management is important to reduce the systemic repercussions. The objective of this study is to compare the efficacy of intravenous magnesium sulfate versus lidocaine on this reflex hemodynamics after laryngoscopy and tracheal intubation. This single-center, prospective, double-blind, randomized study evaluated 56 patients ASA 1 or 2, aged 18-65 years, scheduled for elective surgeries under general anesthesia with intubation. The patients were allocated into two groups: Group F received 30mg·kg(-1) of magnesium sulphate and Group L, 2mg·kg(-1) of lidocaine, continuous infusion, immediately before the anesthetic induction. Blood pressure (BP), heart rate (HR), and bispectral index (BIS) were measured in both groups at six different times related to administration of the study drugs. In both groups there was an increase in HR and BP after laryngoscopy and intubation, compared to baseline. Group M showed statistically significant increase in the values of systolic and diastolic blood pressure after intubation, which was clinically unimportant. There was no difference in the BIS values between groups. Among patients receiving magnesium sulfate, three (12%) had high blood pressure versus only one among those receiving lidocaine (4%), with no statistical difference. Magnesium sulfate and lidocaine have good efficacy and safety for hemodynamic management in laryngoscopy and intubation. Copyright © 2016 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

  15. Magnesium sulfate salts and historic building materials: experimental simulation of limestone flaking by relative humidity cycling and crystallization of salts

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    Pinchin, S.

    2008-06-01

    Full Text Available Magnesium sulfate salts often result from the combination of incompatible construction materials, such as stone or mortar with high magnesium content and sulfates from adjacent mortars or polluted air. When combined with a source of moisture, these materials react to form soluble salts, often leading to significant damage by flaking of the stone, as the magnesium sulfate responds to fluctuating environmental conditions. Several laboratory experiments were performed to reproduce surface flaking on different types of limestone from Spain and the UK to evaluate the effects of humidity cycling on the damage of stone by salt crystallization. The two salt solutions used for the experiments were a single salt of magnesium sulfate and a mixture of magnesium sulfate, calcium sulfate and sodium chloride, a typical salt mixture found in damaged stone at the site of Howden Minster (UK. A climate chamber with precise and programmable temperature and humidity control was used to test the hypothesis that salt damage in the stone can be readily caused by humidity fluctuations. Damage was monitored using Linear Variable Differential Transformer (LVDT, which measure transducers displacement by dimensional change on the order of microns. In addition, Ion Chromatography, Environmental Scanning Electron Microscopy with energy dispersive X-ray spectroscopy (ESEM-EDX and X-ray Diffraction analyses (XRD were also carried out to analyze salt behavior. Damage by flaking took place in two types of magnesian limestone cubes impregnated with the salt mixture, from Cadeby quarry and York Minster, apparently by deliquescent salts of low equilibrium relative humidity (RHeq, while the rest of the samples developed a salt crust over the surface, but no damage was observed in the stone. It is important to verify hypotheses developed from field observations with laboratory experiments. By combining both field and laboratory data, a clearer understanding the different mechanisms of

  16. Dietary Supplementation of Magnesium Sulfate during Late Gestation and Lactation Affects the Milk Composition and Immunoglobulin Levels in Sows.

    Science.gov (United States)

    Hou, W X; Cheng, S Y; Liu, S T; Shi, B M; Shan, A S

    2014-10-01

    This experiment was conducted to investigate the effects of dietary supplementation of magnesium sulfate (MgSO4) during late gestation and lactation on sow and litter performance, fecal moisture, blood biochemistry parameters, immunoglobulin levels and milk composition in sows. Forty-eight sows (Yorkshire×Landrace, 4th to 5th parity) were randomly allocated to 1 of 4 dietary treatments supplemented with 0, 200, 400, or 600 mg/kg MgSO4 (n = 12). The experiment started on day 90 of gestation and continued through day 21 of lactation. Blood samples were collected on day 107 of gestation, day 0 (farrowing) and 21 (weaning) of lactation for the analyses of the blood biochemistry parameters and immunoglobulin levels. The colostrum and milk samples were obtained on day 0 and 14 of lactation, respectively. Fecal samples were collected from the sows on day 107 of gestation as well as day 7 and 20 of lactation to determine fecal moisture content. The results showed that the survival percentage of piglets and the litter weight at weaning were decreased linearly (p0.05) by MgSO4 supplementation. The fecal moisture content of the sows were increased (pplasma magnesium (Mg) level linearly (p0.05 and pplasma on day of farrowing and immunoglobulin A (IgA) level in colostrum (quadratic, p<0.05) and milk (linear, p<0.05) of the sows. These results indicated that supplementation with MgSO4 during late gestation and lactation may have the potential to prevent sow constipation, but may also result in some negative effects.

  17. Effect of magnesium sulfate on hyperthermia and pentylen-tetrazol-induced seizure in developing rats

    Science.gov (United States)

    Ghadimkhani, Maryam; Saboory, Ehsan; Roshan-Milani, Shiva; Mohammdi, Sedra; Rasmi, Yousef

    2016-01-01

    Objective(s): Febrile seizures (FS) are the most common type of convulsive events among children. Its prevalence has been estimated to be 2-5% in children between 3 months and 5 years old. Also, blood and CSF magnesium levels have been demonstrated to be reduced in children with FS. This study investigates the effect of MgSo4 pretreatment on the behaviors caused by hyperthermia (HT) and effect of these two on pentylen-tetrazol (PTZ)-induced seizure later in life. Materials and Methods: Thirty two Wistar rats were assigned to 2 groups: saline-hyperthermia-pentylentetrazol (SHP) and magnesium-hyperthermia-pentylentetrazol (MHP). In both groups, HT was induced at the age of 18-19 days old. Before the HT, MHP group received MgSo4 and SHP group received normal saline intraperitoneally (IP). Behaviors of the rats were recorded during the HT. Then, in half of each group (n=8) at the age of 25-26 days old and in other half at the age of 78-79 days, seizure was induced by PTZ. Results: The HT successfully caused convulsive behaviors in the rats and pretreatment with MgSo4 before HT attenuated HT-induced convulsive behaviors. PTZ-induced seizures a week later was more severe than those of 2 months later. Conclusion: It can be concluded that pretreatment with MgSO4 inhibits HT-induced seizure and, in a long run, this intervention reduced PTZ-induced seizure later in life. PMID:27482341

  18. INVESTIGATION FOR THE INFLUENCE OF DIFFERENT MAGNESIUM SULFATE DOSES ON THE CONTENT OF CALCIUM AND CHLORIDE IN BLOOD SERUM OF RATS OF BOTH GENDERS

    Directory of Open Access Journals (Sweden)

    A. V. Voronkov

    2016-01-01

    Full Text Available We have conducted an investigation for the influence of different magnesium sulfate doses on the content of calcium and chloride in blood serum of rats of both genders. As the result of the study, we have established that peroral administration of magnesium sulfate at dose 1.7 g/kg leads to the significant decrease of chlorides content in blood serum of male rats, concerning the control group of animals, and at dose 5 g/kg to the decrease of concentration, chloride as well as calcium in rats of both genders.

  19. Similarities and peculiarities between the crystal structures of the hydrates of sodium sulfate and selenate.

    Science.gov (United States)

    Kamburov, Stoyan; Schmidt, Horst; Voigt, Wolfgang; Balarew, Christo

    2014-08-01

    The crystal structures of the two hydrates Na2SeO4·10H2O and Na2SeO4·7.5H2O are studied for the first time. The structures of Na2SO4·10H2O and Na2SO4·7H2O are reinvestigated as a function of temperature with respect to the degree of disorder of the O atoms of SO4(2-) in the decahydrate and the O atom of water in the heptahydrate. For Na2SO4·10H2O, the unit site occupancy factor (SOF) of O atoms of SO4(2-) was determined at 120 K. After the temperature dependence of the lattice parameters was studied from 120 to 260 K, it was shown that SOF decreased from 1.0 at 120 K to 0.247 at room temperature. The interesting fact that two salts with different chemical compositions and different crystal structures (Na2SO4·7H2O, tetragonal, space group P4(1)2(1)2 and Na2SeO4·7.5H2O, monoclinic, space group C2/c) can act mutually as a crystal nucleus is accounted for by similarities in certain fragments of their crystal structures. This phenomenon is attributed to similarities between particular elements of their structures.

  20. 温度对MgCl2与Na2CO3反应制备碳酸镁水合物的影响%Effects of Temperature on the Preparation of Magnesium Carbonate Hydrates by Reaction of MgCI2 with Na2CO3

    Institute of Scientific and Technical Information of China (English)

    程文婷; 李志宝; George P. Demopoulos

    2009-01-01

    Homogeneous (unseeded) precipitation of magnesium carbonate hydrates by the reaction of MgCI2 with Na2CO3 in supersaturated solutions between 273 and 363 K was investigated. The compositions, morphologies and filtration characteristics of the precipitates were studied in detail. The magnesium carbonate hydrates obtained at 313 K and in the range of 343-363 K showed good morphologies and filtration characteristics. Magnesium oxides (MgO) with high purity (97.6%-99.4%) were obtained by calcining magnesium carbonate hydrates at 1073 K.

  1. The influence of calcium, magnesium, phosphorus and silica in vanadium precipitation in acidic sulfate solutions

    Energy Technology Data Exchange (ETDEWEB)

    Martins, A.H. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Engenharia Metalurgica e de Materiais. E-mail: ahmartin@demet.ufmg.br

    2000-06-01

    The experimental research work was carried out in accordance with the Factorial Design Statistical Method to evaluate and analyze the influence of calcium, magnesium, silica and phosphorus on the precipitation of vanadates. precipitation was performed by neutralization with H{sub 2} SO{sub 4} of alkaline aqueous solutions containing vanadium pentoxide (V{sub 2} O{sub 5}) at 60 {+-} 2 deg C. The experimental responses measured were percent of vanadium recovery and vanadium pentoxide content in the precipitate. These impurities are considered representative of those present in a leach liquor from the ore obtained at Campo Alegre de Lourdes (Brazil). The operational variables in this work were used optimum conditions as determined by the statistical approach. Among the impurities under study, phosphorus exhibited the highest negative influence on the experimental responses. Phosphorus diminished the percent of vanadium recovered from 98.9 to 34.5 and the vanadium oxide content in the precipitate from 91.2% to 39.3%. (author)

  2. Dexmedetomidine versus Magnesium Sulfate as Adjunct during Anesthesia for Laparoscopic Colectomy

    Directory of Open Access Journals (Sweden)

    Pierre Zarif

    2016-01-01

    Full Text Available Objectives. To compare dexmedetomidine versus magnesium during laparoscopic colectomy. Patients and Methods. 51 patients were randomly allocated into 3 groups: group C (control received saline infusion, group D dexmedetomidine 1 g/kg and then 0.4 g/kg/hr, and group M MgSO4 2 g and then 15 g/kg/min. Intraoperative hemodynamics were measured before and 1 min after intubation (T1 and T2, before and 5 min after peritoneal insufflation (T3 and T4, before and 5 min after 30° Trendelenburg position (T5 and T6, 5 min after resuming flat position (T7, 5 min after peritoneal deflations (T8, after extubation (T9, and at time of admission to PACU (T10. Recovery time and degree of sedation were assessed. Results. HR and MAP were significantly higher in T2, T4, and T6 compared to T1, T3, and T5, respectively, in all groups with lower measurements in groups D and M compared to group C. Mean of collective measurements was significantly higher in group C. Recovery time and sedation score were significantly higher in groups D and M. Time to Aldrete score of ≥9 was significantly longer in groups D and M. Conclusion. Both drugs ameliorate the pressor responses during LC with a nonsignificant difference. This study is registered with PACTR201602001481308.

  3. Dexmedetomidine versus Magnesium Sulfate as Adjunct during Anesthesia for Laparoscopic Colectomy

    Science.gov (United States)

    Zarif, Pierre; Abdelhaq, Mohamed Mohamed; Mikhail, Hany M. S.; Farag, Ahmed

    2016-01-01

    Objectives. To compare dexmedetomidine versus magnesium during laparoscopic colectomy. Patients and Methods. 51 patients were randomly allocated into 3 groups: group C (control) received saline infusion, group D dexmedetomidine 1 g/kg and then 0.4 g/kg/hr, and group M MgSO4 2 g and then 15 g/kg/min. Intraoperative hemodynamics were measured before and 1 min after intubation (T1 and T2), before and 5 min after peritoneal insufflation (T3 and T4), before and 5 min after 30° Trendelenburg position (T5 and T6), 5 min after resuming flat position (T7), 5 min after peritoneal deflations (T8), after extubation (T9), and at time of admission to PACU (T10). Recovery time and degree of sedation were assessed. Results. HR and MAP were significantly higher in T2, T4, and T6 compared to T1, T3, and T5, respectively, in all groups with lower measurements in groups D and M compared to group C. Mean of collective measurements was significantly higher in group C. Recovery time and sedation score were significantly higher in groups D and M. Time to Aldrete score of ≥9 was significantly longer in groups D and M. Conclusion. Both drugs ameliorate the pressor responses during LC with a nonsignificant difference. This study is registered with PACTR201602001481308. PMID:27051421

  4. The influence of calcium, magnesium, phosphorus and silica on vanadium precipitation in acidic sulfate solutions

    Directory of Open Access Journals (Sweden)

    A. H. Martins

    2000-06-01

    Full Text Available The experimental research work was carried out in accordance with the Factorial Design Statistical Method to evaluate and analyze the influence of calcium, magnesium, silica and phosphorus on the precipitation of vanadates. Precipitation was performed by neutralization with H2SO4 of alkaline aqueous solutions containing vanadium pentoxide (V2O5 at 60± 2ºC. The experimental responses measured were percent of vanadium recovery and vanadium pentoxide content in the precipitate. These impurities are considered representative of those present in a leach liquor from the ore obtained at Campo Alegre de Lourdes (Brazil. The operational variables in this work were used under optimum conditions as determined by the statistical approach. Among the impurities under study, phosphorus exhibited the highest negative influence on the experimental responses. Phosphorus diminished the percent of vanadium recovered from 98.9 to 34.5 and the vanadium oxide content in the precipitate from 91.2 % to 39.3 %.

  5. Study on the influent factors of magnesium phosphate cement hydration heat%磷酸镁水泥水化热的影响因素研究∗

    Institute of Scientific and Technical Information of China (English)

    汪宏涛; 丁建华; 张时豪; 齐召庆

    2015-01-01

    Micro calorimeter of eight channels was used to study the influent law of different M/P ratio (quality ratio of magnesium and potassium dihydrogen phosphate),the ratio of water and binder (W/B ratio),borax content,dosage of fly ash and phosphate species on the magnesium phosphate cement hydration heat.The re-sults show that the magnesium phosphate cement hydration was an endothermic and exothermic process.It has one endothermic valley and two exothermic peaks.The endothermic valley arises from the dissolution of phos-phate,the exothermic peaks associate with the dissolution of magnesia in acid solution and the formation of product.The release rate of heat and heat quantity of magnesium phosphate cement hydration was reduced by improving the M/P ratio,the W/B ratio,borax content and dosage of fly ash.The hydration exothermic peak and heat of magnesium phosphate cement of ammonium dihydrogen phosphate,sodium dihydrogen phosphate, potassium dihydrogen phosphate was 0.430714,0.145677,0.1 94626 W and 1 1 98.949,452.798,902.872 J,re-spectively,which not only indicates that phosphate species have significant influence on hydration heat,but also was related to their the solubility and pH value.%采用八通道微量热仪研究了不同 m (M)/m (P)(氧化镁和磷酸二氢钾质量比)比值、水胶比(W/B)、硼砂掺量、粉煤灰掺量和磷酸盐种类对磷酸镁水泥水化热的影响规律.实验结果表明,磷酸镁水泥的水化存在吸热和放热两个过程,包含一个吸热谷和两个放热峰,吸热谷产生于磷酸盐的溶解,放热峰与氧化镁溶于酸性溶液及产物的形成有关;提高 m (M)/m (P)比值、水胶比、硼砂掺量和粉煤灰掺量都会降低磷酸镁水泥水化的放热速率和放热量;以磷酸二氢铵、磷酸二氢钠、磷酸二氢钾为磷酸盐所制备的磷酸镁水泥的水化放热峰峰值和放热量分别达到了0.430714,0.145677,0.194626 W 和1198.949,452.798,902.872 J,表明了磷酸

  6. Comparison of the analgesic effects of intravenous magnesium sulfate infusion versus intrathecal fentanyl in patients with severe pre-eclampsia undergoing caesarean section

    Directory of Open Access Journals (Sweden)

    Ahmed Said Elgebaly

    2011-01-01

    Full Text Available Background : A double-blinded, prospective, randomized, controlled study was designed to determine the analgesic efficacy and tolerability of intravenous magnesium sulfate versus intrathecal fentanyl, in patients with severe pre-eclampsia, scheduled for caesarean section, under spinal anaesthesia. Materials and Methods : One hundred and five patients were randomly allocated to one of the three groups; the control group B received spinal anaesthesia with 10 mg of 0.5% heavy bupivacaine, the test group FB received spinal anaesthesia with 10 mg of 0.5% heavy bupivacaine plus 25 ΅g of preservative-free fentanyl and the test group MB received spinal anaesthesia with 10 mg of 0.5% heavy bupivacaine along with intravenous magnesium sulfate (6 gm iv as a loading dose over 20-30 minutes, followed by infusion of magnesium sulfate 2 gm per hour for 24 hours. Results : The time required for the first postoperative analgesic requirement was significantly more in groups FB and MB, as compared to the control group. (Group FB: 6.85 + 1.7 hours, group MB: 7.05 + 1.95 hours and Group B: 3.75 + 0.75 hours. This difference, however, was not significant between group FB and group MB. The frequency of postoperative analgesic requirement was significantly less in the FB and MB groups, as compared to the control group. (Control group: 3.9 + 0.5, group FB 2.3 + 0.25 and group MB: 2.5 + 0.4. Perioperative sedation was significantly higher in group FB as compared to group B and group MB. Nine patients in group FB had postoperative nausea and vomiting, whereas, none of the patients in the control group or group MB experienced this. This difference too was statistically significant. Conclusion : Intravenous magnesium sulfate and intrathecal fentanyl in the doses mentioned, increased the duration of postoperative analgesia in severely pre-eclamptic patients undergoing caesarean section under spinal anaesthesia; however, patients who received intravenous magnesium sulfate

  7. Determination of thermodynamic parameters for complexation of calcium and magnesium with chondroitin sulfate isomers using isothermal titration calorimetry: Implications for calcium kidney-stone research

    Science.gov (United States)

    Rodgers, Allen L.; Jackson, Graham E.

    2017-04-01

    Chondroitin sulfate (CS) occurs in human urine. It has several potential binding sites for calcium and as such may play an inhibitory role in calcium oxalate and calcium phosphate (kidney stone disease by reducing the supersaturation (SS) and crystallization of these salts. Urinary magnesium is also a role player in determining speciation in stone forming processes. This study was undertaken to determine the thermodynamic parameters for binding of the disaccharide unit of two different CS isomers with calcium and magnesium. These included the binding constant K. Experiments were performed using an isothermal titration calorimeter (ITC) at 3 different pH levels in the physiological range in human urine. Data showed that interactions between the CS isomers and calcium and magnesium occur via one binding site, thought to be sulfate, and that log K values are 1.17-1.93 and 1.77-1.80 for these two metals respectively. Binding was significantly stronger in Mg-CS than in Ca-CS complexes and was found to be dependent on pH in the latter but not in the former. Furthermore, binding in Ca-CS complexes was dependent on the location of the sulfate binding site. This was not the case in the Mg-CS complexes. Interactions were shown to be entropy driven and enthalpy unfavourable. These findings can be used in computational modeling studies to predict the effects of the calcium and magnesium CS complexes on the speciation of calcium and the SS of calcium salts in real urine samples.

  8. Examining the Use of Magnesium Sulfate to Treat Pregnant Women with Preeclampsia and Eclampsia: Results of a Program Assessment of Emergency Obstetric Care (EmOC) Training in India.

    Science.gov (United States)

    Budhwani, Henna; Shivkumar, Poonam; Purandare, Chittaranjan Narhari; Cataldo, Nicholas A; Desai, Sadhana; Bhatt, Prakash; Baswal, Dinesh; Bhardwaj, Ajey

    2017-10-01

    The aim of this study is to examine rates of magnesium sulfate utilization by emergency obstetric care trainees to treat preeclampsia-eclampsia in India. Secondarily, structural barriers are identified which limit the use of magnesium sulfate, highlighting limitations of emergency obstetric care training, which is a commonly implemented intervention in resource-poor settings. Trainees' curriculum specified magnesium sulfate treatment for eclampsia and severe preeclampsia. Case records were analyzed for preeclampsia-eclampsia diagnosis, magnesium sulfate utilization, delivery route, and maternal and neonatal outcomes from 13,238 reported deliveries between 2006 and 2012 across 75 district hospitals in 12 Indian states. Of 1320 cases of preeclampsia-eclampsia, 322 (24.4%) had eclampsia. Magnesium sulfate was given to 12.9% of preeclamptic and 54.3% of eclamptic women, with lower usage rates in rural communities. Among the 1308 women with preeclampsia-eclampsia, only 24 deaths occurred (1.8%). In contrast, among the 17,179 women without preeclampsia-eclampsia, there were 95 reported deaths (0.6%). Both maternal mortality ratios were found to be much higher than the Millennium Development Goal target of 0.15%. Magnesium sulfate administration was associated with a higher death rate in preeclamptic but not eclamptic women, representing possible confounding by severity. To optimize resources spent on emergency obstetric care training, the consistent availability of magnesium sulfate should be improved in India. Increasing drug availability, implementing clinical guidelines around its administration, and training health-care providers on the identification and treatment of preeclampsia-eclampsia could lead to notable improvements in maternal and infant mortality.

  9. Effect of heparin in combined with magnesium sulfate on the blood gas and blood viscosity in patients with pulmonary heart failure

    Institute of Scientific and Technical Information of China (English)

    Rui Deng; Hong-Wei Liang; Jun-Hong Liao; Jun-Hua Chen; Hai-Yan Liu

    2016-01-01

    Objective:To observe the effect of heparin in combined with magnesium sulfate on the blood gas indicators and blood viscosity in patients with pulmonary heart disease merged with respiratory failure.Methods: A total of 80 patients with pulmonary heart disease merged with respiratory failure who were admitted in our hospital were included in the study and randomized into the observation group (n=40) and the control group (n=40). The patients in the control group were given routine symptomatic treatments of pulmonary heart disease. On the above basis, the patients in the observation group were given intravenous drip of heparin and magnesium sulfate. The patients in the two groups were treated for 2 weeks. The blood gas indicators, blood viscosity indicators, PAPs, SBP, and DBP in the two groups were compared. The clinical efficacy in the two groups was evaluated.Results:After 2-week treatment, PaO2 and PaCO2 in the two groups were improved, pH value was not significantly changed, PaO2 in the observation group was significantly higher than that in the control group, while PaCO2 was significantly lower than that in the control group. The hemorheology indicators after treatment in the two groups were significantly reduced when compared with before treatment, among which the comparison of WBV, PV, Hct, and EAI between the two groups was statistically significant, and PAPs after treatment in the observation group was significantly reduced when compared with the control group. SBP and DBP after treatment in the two groups were not significantly changed.Conclusions: Heparin in combined with magnesium sulfate in the treatment of pulmonary heart disease merged with respiratory failure can improve the blood gas indicators and blood viscosity indicators, and reduce SBP of pulmonary artery, with a higher efficacy; therefore, it deserves to be widely recommended in the clinic.

  10. Effects of salbutamol aerosol combined with magnesium sulfate on T-lymphocyte subgroup and Th1/Th2 cytokines of pediatric asthma

    Science.gov (United States)

    Diao, Min; Min, Jie; Guo, Fei; Zhang, Chong-Lin

    2017-01-01

    The aim of the study was to analyze the effects of the intravenous infusion of salbutamol aerosol combined with magnesium sulfate in the treatment of pediatric asthma and the subsequent effects on the levels of T-lymphocyte subgroups and Th1/Th2 cytokines. A total of 86 patients with pediatric asthma, first diagnosed and treated at the Xuzhou Children's Hospital, were continuously selected and randomly divided into an observation group of 44 cases and control group of 42 cases. The patients in the control group were treated with budesonide atomization inhalation, while the children in the observation group were treated with intravenous infusion of salbutamol aerosol combined with magnesium sulfate. The therapeutic effects in the groups were compared. After treatment, the levels of serum CD3+ and CD8+ decreased when compared to before treatment; the levels of CD4+ and CD4+/CD8+ also increased, but the observation group had more significant improvement. Differences were statistically significant (P<0.05). After treatment, the levels of serum interleukin-2 (IL-2) and interferon-γ (IFN-γ) increased when compared to before, while levels of IL-4 and IL-6 decreased, and the observation group had more significant improvement. The differences were statistically significant (P<0.05). After treatment, the levels of VT, t-PTEF/t-E, MTIF/MTEF and TEF75/PTEF increased when compared to before; the observation group had more significant improvement. The differences were statistically significant (P<0.05). The effective rate and degree of treatment for the observation group were significantly higher than those of the control group and differences were statistically significant (P<0.05). The intravenous infusion of salbutamol aerosol combined with magnesium sulfate in the treatment of pediatric asthma can significantly improve therapeutic effects and lung functions, improve immune functions and relieve inflammatory reactions. Therefore, it indicates better clinical application and

  11. Compatibility and stability of potassium chloride and magnesium sulfate in 0.9% sodium chloride injection and 5% dextrose injeciton solutions.

    Science.gov (United States)

    Quay, I; Tan, E

    2001-01-01

    The compatibility and stability of 80 mmol/L potassium chloride and 16 mmol/L magnesium sulfate in 0.9% sodium chloride injection and in 5% dextrose injection solutions at 22 deg C have been studied by means of a Beckman Clinical Chemistry Analyzer Synchron CX5 Delta. The infusions were stable for 24 hours at 22 deg C. The results from both diluents showed an average of +/-5% fluctuations in concentration. None of the samples appeared to form visible precipitation or to change in color or clarity.

  12. Use of magnesium sulfate before 32 weeks of gestation: a European population-based cohort study

    Science.gov (United States)

    Wolf, H T; Huusom, L; Weber, T; Piedvache, A; Schmidt, S; Norman, M; Zeitlin, J

    2017-01-01

    Objectives The use of magnesium sulfate (MgSO4) in European obstetric units is unknown. We aimed to describe reported policies and actual use of MgSO4 in women delivering before 32 weeks of gestation by indication. Methods We used data from the European Perinatal Intensive Care in Europe (EPICE) population-based cohort study of births before 32 weeks of gestation in 19 regions in 11 European countries. Data were collected from April 2011 to September 2012 from medical records and questionnaires. The study population comprised 720 women with severe pre-eclampsia, eclampsia or HELLP and 3658 without pre-eclampsia delivering from 24 to 31 weeks of gestation in 119 maternity units with 20 or more very preterm deliveries per year. Results Among women with severe pre-eclampsia, eclampsia or HELLP, 255 (35.4%) received MgSO4 before delivery. 41% of units reported use of MgSO4 whenever possible for pre-eclampsia and administered MgSO4 more often than units reporting use sometimes. In women without pre-eclampsia, 95 (2.6%) received MgSO4. 9 units (7.6%) reported using MgSO4 for fetal neuroprotection whenever possible. In these units, the median rate of MgSO4 use for deliveries without severe pre-eclampsia, eclampsia and HELLP was 14.3%. Only 1 unit reported using MgSO4 as a first-line tocolytic. Among women without pre-eclampsia, MgSO4 use was not higher in women hospitalised before delivery for preterm labour. Conclusions Severe pre-eclampsia, eclampsia or HELLP are not treated with MgSO4 as frequently as evidence-based medicine recommends. MgSO4 is seldom used for fetal neuroprotection, and is no longer used for tocolysis. To continuously lower morbidity, greater attention to use of MgSO4 is needed. PMID:28132012

  13. Promotion of in vivo degradability, vascularization and osteogenesis of calcium sulfate-based bone cements containing nanoporous lithium doping magnesium silicate

    Science.gov (United States)

    Cao, Liehu; Weng, Weizong; Chen, Xiao; Zhang, Jun; Zhou, Qirong; Cui, Jin; Zhao, Yuechao; Shin, Jung-Woog; Su, Jiacan

    2017-01-01

    Nanoporous lithium doping magnesium silicate (nl-MS) was introduced into calcium sulfate hemihydrate to prepare calcium sulfate composite (nl-MSC) bone cements. The introduction of nl-MS improved the in vitro degradability of nl-MSC cements, which could neutralize acidic degradable products of calcium sulfate and prevented the pH from dropping. The cements were implanted into the bone defects of femur bone of rabbits, and the results of histological and immunohistochemical analysis revealed that massive new bone tissue formed in the defects while the cements were degradable, indicating that the osteogenesis and degradability of the nl-MSC cements were much better than the control calcium sulfate dihydrate (CSD) cements. Furthermore, the positive expression of vascular endothelial growth factor and collagen type I for nl-MSC cements was higher than CSD, indicating that addition of nl-MS into the cements enhanced vascularization and osteogenic differentiation. The results suggested that the nl-MSC cements with good biocompatibility and degradability could promote vascularization and osteogenesis, and had great potential to treat bone defects. PMID:28260883

  14. 硫铝酸盐水泥混凝土抗高浓度硫酸镁侵蚀性能研究%Study on the Resistance to High Concentration of Magnesium Sulfate Attack on Sulfate Aluminate Cement Concrete

    Institute of Scientific and Technical Information of China (English)

    刘向楠; 唐新军; 苏建彪; 张涛; 张傲齐

    2015-01-01

    In some part of the drought and salinity region in the south of Xinjiang ,concrete buildings are confronted with double erosion problems of sulphate and magnesium salt in high concentrations .In this study ,the influence of water/ce-ment ratio ,erosion of solution concentration and erosion time on the erosion resistance of sulfate aluminium cement con-crete were studied with“the concrete resistance to sulfate erosion experiment method”(method K ) .What’s more ,both of the macroscopic and microscopic observation methods such as scanning electron microscope (SEM ) and energy spectrum analysis (EDS ) were used to analyze and reveal the mechanism of sulfate attack resistance .It is found that lowering the water/cement ratio can effectively increase the erosion resistance of sulphate aluminium cement in magnesium sulfate ero-sion environment;the double erosion damage of erosion solution to sulphate aluminium cement mortar specimens has obvi-ous correlation with the concentration of sulfate ions;gypsum which generates in large numbers is the main reason of the surface erosion on the surface of the mortar specimens .%新疆南疆部分干旱多盐碱地区混凝土建筑物面临高浓度硫酸盐、镁盐双重侵蚀破坏问题。通过水泥抗硫酸盐侵蚀试验方法(K法)研究了水灰比、侵蚀溶液浓度、侵蚀龄期等对硫铝酸盐水泥混凝土抗硫酸盐侵蚀能力的影响,并采用宏观观测和扫描电镜(SEM )、能谱(EDS )等微观观测方法,分析和揭示其抗硫酸盐侵蚀机理。结果表明,降低水胶比能有效提高硫铝酸盐水泥胶砂试件抗高浓度硫酸盐、镁盐侵蚀性能;在镁离子浓度一定时,侵蚀溶液对硫铝酸盐水泥胶砂试件的双重侵蚀破坏作用与硫酸根离子浓度具有明显的相关性;石膏的大量生成是造成胶砂试件表面剥蚀破坏的主要原因。

  15. The Effect of Intravenous Magnesium Sulfate Infusion on Sensory Spinal Block and Postoperative Pain Score in Abdominal Hysterectomy

    Directory of Open Access Journals (Sweden)

    Fatih Kahraman

    2014-01-01

    Full Text Available Aim. The aim of this study was to investigate the effect of i.v. infusion of magnesium sulphate during spinal anesthesia on duration of spinal block and postoperative pain. Methods. Forty ASA physical status I and status II, aged between 18 and 65, female patients undergoing abdominal hysterectomy under spinal anesthesia were enrolled in this study. Patients in the magnesium group (Group M, n = 20 received magnesium sulphate 65 mg kg−1 infusion in 250 mL 5% dextrose at 3.5 mL/min rate, and control group (Group C, n = 20 received at the same volume of saline during operation in a double-blind randomized manner. Duration of sensory and motor block, systolic, diastolic, and mean arterial blood pressures, heart rates, pain scores (VAS values, and side effects were recorded for each patient. Blood and CSF samples were taken for analysis of magnesium concentrations. Results. Regression of sensorial block was longer in Group M when compared with that in Group C (175 ± 39 versus 136 ± 32 min (P < 0.01. The VAS scores were lower in Group M than those in Group C at the 2 time points postoperatively (P < 0.01. Conclusion. 65 mg kg−1 of magnesium sulphate i.v. infusion under spinal anesthesia prolongs spinal sensorial block duration and decreases pain VAS scores without complication in patients undergoing abdominal hysterectomy.

  16. Effect of magnesium sulfate in the treatnent of 482 children with asthma%硫酸镁治疗儿童哮喘482例分析

    Institute of Scientific and Technical Information of China (English)

    王顺培

    2011-01-01

    Objective To explore a safe and effective treatment for asthma in children. Methods 482 children with asthma admitted in our hospital from Jan. 2008 to Dec. 2010 were treated by magnesium sulfate based on conventional treatment. The treatment was performed until the disappearance of clinical symptoms or the remission of the symptoms for 2 to 3 days. Results Twelve to Forty-eight hours after treatment with magnesium sulfate, 176 cases (36.5%) achieved clinical control, 281 cases (58.3%) were markedly effective, and 25 cases (5.2%) were improved. The total effective rate was 100%. Of the 482 cases, 14 cases (2.9%) showed mild reactions, which disappeared without special treatment. Conclusion Treatment with magnesium sulfate is safe and effective for asthma in Children, which should be popularized clinically.%目的 探讨迅速缓解儿童哮喘安全、有效的治疗方法.方法 我院儿科2008年1月至2010年12月收治482例哮喘患儿,在常规治疗的基础上,加用静脉点滴硫酸镁治疗,直至临床症状消失或减轻后2~3 d停药.结果硫酸镁治疗后,482例均在12~48h内起效,其中临床控制176例(36.5%),显效281例(58.3%),好转25例(5.2%),总有效率为100%;其中仅14例(2.9%)发生轻微反应,未经特殊处理症状消失.结论 硫酸镁治疗儿童哮喘安全、有效,值得临床推广应用.

  17. Infrared Spectra of Hydrated Magnesium Salts and their Role in the Search for Possible Life Conditions on Jupiter Moons

    Science.gov (United States)

    Chaban, Galina; Huo, Winifred M.; Lee, Timothy J.; Kwak, Dochan (Technical Monitor)

    2002-01-01

    Recent observations from the Galileo satellite indicate that three of the Jupiter moons, Europa, Ganymede, and Callisto, may have subsurface oceans. Possible existence of such ocean and the nature of its composition are of great interest to astrobiologists. Data from Galileo's NIMS spectrometer indicate the possibility of hydrated salts on Europa's surface. To aid in the design of future missions, we investigated infrared spectra of MgSO4-nH20, n=1-3 using ab initio calculations. Geometry, energetics, dipole moments, vibrational frequencies and infrared intensities of pure and hydrated MgSO4 salts were determined. Significant differences are found between vibrational spectra of water molecules in complexes with MgSO4 and pure water. Some of the O-H stretching frequencies in the complexes are shifted to the red by up to 1,500 - 2,000 per cm. In addition, the SO2 stretching vibrations are found at lower frequency regions than the water vibrations. The calculated bands of water and SO2 fragments can serve as markers for the existence of the salt-water complexes on the surface of Jupiter's moon.

  18. 硫酸镁联合硝苯地平治疗妊娠期高血压的临床分析%Clinical Analysis of Magnesium Sulfate Combined With Nifedipine in Treatment of Hypertension in Pregnancy

    Institute of Scientific and Technical Information of China (English)

    常淑英

    2015-01-01

    目的:分析硫酸镁联合硝苯地平治疗妊娠期高血压的效果。方法比较单用硫酸镁与硫酸镁联合硝苯地平治疗妊娠期高血压的疗效。结果治疗后观察组收缩压、舒张压以及Apgar评分、24 h尿蛋白定量、随机尿蛋白肌酐比值、血液粘度与对照组差异显著。结论硫酸镁联合硝苯地平治疗妊娠期高血压效果显著。%Objective To analyze the effect of magnesium sulfate combined with nifedipine in the treatment of hypertension in pregnancy.Methods Compared the curative effect of single magnesium sulfate and magnesium sulfate combined with nifedipine in the treatment of hypertension in pregnancy.Results After treatment,the observation group systolic blood pressure,diastolic blood pressure and Apgar score,24 h urinary protein,urinary albumin creatinine ratio,blood viscosity were significantly better than the control group.ConclusionThere are good effect in the treatment of gestational hypertension using magnesium sulfate combined with nifedipine.

  19. Gas hydrates

    Digital Repository Service at National Institute of Oceanography (India)

    Ramprasad, T.

    and the role it plays in the global climate and the future of fuels. Russia, Japan, Nigeria, Peru, Chile, Pakistan, Indonesia, Korea, etc are various countries who are perusing the gas hydrates studies as a future resource for fuel. Indian Initiative..., 1993, Free gas at the base of the gas hydrate zone in the vicinity of the Chile Triple junction: Geology, v. 21, pp. 905-908. Borowski, W.S., C.K. Paull, and U. William, III, 1999, Global and local variations of interstitial sulfate gradients...

  20. Melt-compounded composites of ethylene vinyl acetate with magnesium sulfate as flexible EPR dosimeters: Mechanical properties, manufacturing process feasibility and dosimetric characteristics.

    Science.gov (United States)

    Suman, S K; Kadam, R M; Mondal, R K; Murali, S; Dubey, K A; Bhardwaj, Y K; Natarajan, V

    2017-03-01

    Novel polymeric composites for radiation dosimetry were developed. The composites were prepared by solvent-free melt compounding of ethylene vinyl acetate (EVA) (40% vinyl) and magnesium sulfate (MgSO4). Mechanical properties, melt flow characteristics and dosimetric properties were investigated. The composites with up to 50% (wt) of MgSO4 were flexible and capable of flow. The dose response of the EPR signal of the composites was studied in the dose range 3Gy-4kGy and found to be linear between 18Gy and 4kGy. The reproducibility of dose measurements was good. The signal fading rate and the energy dependence of the dose response were found to be acceptable.

  1. Mecanismos de hidratação do óxido de magnésio Mechanisms of magnesium oxide hydration

    Directory of Open Access Journals (Sweden)

    L. F. Amaral

    2007-12-01

    Full Text Available O óxido de magnésio, MgO, é uma importante matéria-prima para a indústria de refratários por ser um material de elevada refratariedade (ponto de fusão próximo a 2800 °C, resistente a escórias básicas, e de custo competitivo. No entanto, em presença de água, o MgO rapidamente se hidrata formando hidróxido de magnésio, Mg(OH2. Essa reação leva a uma expansão volumétrica de até três vezes, limitando sua aplicação em concretos refratários. Para desenvolver soluções que minimizem este problema, torna-se necessário um melhor entendimento do mecanismo pelo qual o MgO se hidrata e quais as principais variáveis envolvidas. Dois mecanismos distintos para esta reação foram propostos: a dissolução seguida de precipitação e b reação em uma única etapa ocorrendo diretamente na superfície das partículas. Este trabalho apresenta uma revisão crítica com relação aos mecanismos propostos e sua potencial aplicação em concretos refratários contendo MgO. Suspensões aquosas de MgO e diferentes técnicas de caracterização (ensaios reológicos oscilatórios, medidas de expansão volumétrica aparente e condutividade iônica permitiram correlacionar os mecanismos apresentados, principalmente com respeito à cinética da reação de hidratação.Magnesium oxide, MgO, is an important raw material for refractories industry due to its high refractoriness (melting point of approximately 2800 ºC, corrosion resistance in basic environment and competitive cost. Nevertheless, MgO presents a great tendency to react with water producing magnesium hydroxide, Mg(OH2. This reaction generates a threefold volumetric expansion and could lead to material breakdown inhibiting its application in refractory castables. In order to develop solutions to minimize this effect, a further understanding of the magnesia hydration mechanism and the main variables involved in this reaction is required. Two different mechanisms were proposed: a

  2. Physicochemical Study on the Interface Zone of Concrete Exposed to Different Sulfate Solutions

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper reports the results of the visual observations and micro-analysis of concrete core samples after 6 and 12 months of their exposure to sodium, ammonium and magnesium sulfate solutions with the same concentration of sulfate ions. XRD, SEM and EDS were used for micro-analysis of the microstructure and the composition of the interface zone in the samples. The results indicate that the deterioration of concrete by different sulfate solutions could proceed differently with regard to the mechanism and the mode of damage caused. The damage of concrete exposed to sodium sulfate solution is mainly caused by the gypsum crystals formed in the interface zone, which lead to expansion and cracking. In the case of concrete immersed in magnesium sulfate solutions, a layer of brucite (magnesium hydroxide) and gypsum was produced in the interface zone, which reduces the cohesiveness of the interface zone in concrete. For the concrete immersed in ammonium sulfate solutions, the conversation of mortar to some mush mass by ammonium ions and the formation of a large of gypsum occurred in the interface zone, consequently, serious softening of hydrated cement pastes and expansion and cracking of concrete are the characteristics of the attack by ammonium sulfate solutions. Also, it is considered that using drilled concrete core as samples to evaluate the sulfate resistance of concrete is a good and accelerated method.

  3. 21 CFR 184.1428 - Magnesium hydroxide.

    Science.gov (United States)

    2010-04-01

    ... hydration of reactive grades of magnesium oxide. (b) The ingredient meets the specifications of the Food... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium hydroxide. 184.1428 Section 184.1428 Food... Specific Substances Affirmed as GRAS § 184.1428 Magnesium hydroxide. (a) Magnesium hydroxide (Mg(OH)2,...

  4. The influence of magnesium hydroxide sulfate whisker on the properties of liquid silicone rubber%碱式硫酸镁晶须对液体硅橡胶性能影响研究

    Institute of Scientific and Technical Information of China (English)

    张晓颖; 王国辉; 李倩; 邓新华

    2012-01-01

    以双组份加成型液体硅橡胶(LSR)为基胶,白炭黑为补强填料,通过测试分析,对比氢氧化铝、氢氧化镁、碱式硫酸镁晶须、经硬脂酸钠表面处理的碱式硫酸镁晶须4种阻燃剂复合液体硅橡胶的燃烧性能和力学性能.结果表明,经表面处理后的碱式硫酸镁晶须提高了LSR的拉伸强度,并在改善LSR的防火性能方面具有独特的优势.%Taking two-component additional liquid silicone rubber (LSR) as base rubber, silica white carbon black was as reinforcing packing material. Analyzis and comparison of the combustion performance and mechanical properties of four flame retardant liquid silicone rubber compound, including aluminum hydroxide, magnesium hydroxide, magnesium hydroxide sulfate whisker,and the stearic acid sodium surface treatment of magnesium hydroxide sulfate whisker. The results showed that the stearic acid sodium surface treatment of magnesium hydroxide sulfate whisker could improve the tensile strength of LSR, and had a unique advantage in improving the flame resistance of LSR.

  5. Reactions Involving Calcium and Magnesium Sulfates as Potential Sources of Sulfur Dioxide During MSL SAM Evolved Gas Analyses

    Science.gov (United States)

    McAdam, A. C.; Knudson, C. A.; Sutter, B.; Franz, H. B.; Archer, P. D., Jr.; Eigenbrode, J. L.; Ming, D. W.; Morris, R. V.; Hurowitz, J. A.; Mahaffy, P. R.; Navarro-Gonzalez, R.

    2016-01-01

    The Sample Analysis at Mars (SAM) and Chemistry and Mineralogy (CheMin) instruments on the Mars Science Laboratory (MSL) have analyzed several subsamples of 860 C). Sulfides or Fe sulfates were detected by CheMin (e.g., CB, MJ, BK) and could contribute to the high temperature SO2 evolution, but in most cases they are not present in enough abundance to account for all of the SO2. This additional SO2 could be largely associated with x-ray amorphous material, which comprises a significant portion of all samples. It can also be attributed to trace S phases present below the CheMin detection limit, or to reactions which lower the temperatures of SO2 evolution from sulfates that are typically expected to thermally decompose at temperatures outside the SAM temperature range (e.g., Ca and Mg sulfates). Here we discuss the results of SAM-like laboratory analyses targeted at understanding this last possibility, focused on understanding if reactions of HCl or an HCl evolving phase (oxychlorine phases, chlorides, etc.) and Ca and Mg sulfates can result in SO2 evolution in the SAM temperature range.

  6. Rietveld 全谱拟合方法对磷酸镁水泥水化产物的定量分析研究%Quantitative Analysis of Hydration Products in Magnesium Phosphate Cement with Rietveld Whole Pattern Fitting

    Institute of Scientific and Technical Information of China (English)

    赖振宇; 邹秋林; 卢忠远; 李倩

    2014-01-01

    在 X 射线衍射定性分析的基础上,结合 Rietveld 全谱拟合方法对不同龄期磷酸镁水泥样品的水化产物晶相含量进行了定量研究。结果表明,龄期为10 min、1 h 及1 d 的磷酸镁水泥样品中水化产物 MgKPO4·6H2 O 的相对含量分别为12.39%、15.77%和18.38%,拟合的 Rwp因子为9.73%~12.8%,说明该方法能准确、直观、快速的确定不同龄期样品中各晶相的组成及相对含量,并获得各相的相关晶体学结构参数,同时结合相关理论对磷酸镁水泥的水化及性能作出客观分析,为加深对水泥材料的认识提供了一种可行的研究方法。%Based on the qualitative analysis of X-ray diffraction,combined with the rietveld whole pattern fitting method,the quantitative research for content of hydration products crystalline phase in magnesium phosphate cement at different hydration time was achieved. Results showed that the relative content of hydration products MgKPO4 ·6H2 O in magnesium phosphate cement at hydration time 10 min,1 h and 1 d were 12. 39% ,15. 77% and 18. 38% ,respectively. The Rwp factor changed from 9. 73% to 12. 8% ,which indicated that the method could confirm the crystalline phase composition and relative content in magnesium phosphate cement accurately,intuitively and rapidly. It could obtain the crystallography parameters of every crystalline phase. Also in combination with the related theory,the hydration and performance of magnesium phosphate cement could be analysised objectively,thus provided a feasible method to deepen the understanding of cement materials.

  7. The Effect of Systemic and Regional Use of Magnesium Sulfate on Postoperative Tramadol Consumption in Lumbar Disc Surgery

    Directory of Open Access Journals (Sweden)

    Melek Demiroglu

    2016-01-01

    Full Text Available Aim. To investigate the effect of magnesium administered to the operative region muscle and administered systemically on postoperative analgesia consumption after lumbar disc surgery. Material and Method. The study included a total of 75 ASA I-II patients aged 18–65 years. The patients were randomly allocated into 1 of 3 groups of 25: the Intravenous (IV Group, the Intramuscular (IM Group, and the Control (C Group. At the stage of suturing the surgical incision site, the IV Group received 50 mg/kg MgSO4 intravenously in 150 mL saline within 30 mins. In the IM Group, 50 mg/kg MgSO4 in 30 mL saline was injected intramuscularly into the paraspinal muscles. In Group C, 30 mL saline was injected intramuscularly into the paraspinal muscles. After operation patients in all 3 groups were given 100 mg tramadol and 10 mg metoclopramide and tramadol solution was started intravenously through a patient-controlled analgesia device. Hemodynamic changes, demographic data, duration of anesthesia and surgery, pain scores (NRS, the Ramsay sedation score (RSS, the amount of analgesia consumed, nausea- vomiting, and potential side effects were recorded. Results. No difference was observed between the groups. Nausea and vomiting side effects occurred at a rate of 36% in Group C, which was a significantly higher rate compared to the other groups (p<0.05. Tramadol consumption in the IM Group was found to be significantly lower than in the other groups (p<0.05. Conclusion. Magnesium applied to the operative region was found to be more effective on postoperative analgesia than systemically administered magnesium.

  8. TRPA1, NMDA receptors and nitric oxide mediate mechanical hyperalgesia induced by local injection of magnesium sulfate into the rat hind paw.

    Science.gov (United States)

    Srebro, Dragana P; Vučković, Sonja M; Savić Vujović, Katarina R; Prostran, Milica Š

    2015-02-01

    Previous studies have shown that while magnesium, an antagonist of the glutamate subtype of N-methyl-D-aspartate receptors, possesses analgesic properties, it can induce writhing in rodents. The aim of this study was to determine the effect and mechanism of action of local (intraplantar) administration of magnesium sulfate (MS) on the paw withdrawal threshold (PWT) to mechanical stimuli. The PWT was evaluated by the electronic von Frey test in male Wistar rats. Tested drugs were either co-administered intraplantarly (i.pl.) with MS or given into the contralateral paw to exclude systemic effects. MS at doses of 0.5, 1.5, 3 and 6.2 mg/paw (i.pl.) induced a statistically significant (as compared to 0.9% NaCl) and dose-dependent mechanical hyperalgesia. Only isotonic MS (250 mmol/l or 6.2% or 6.2 mg/paw) induced mechanical hyperalgesia that lasted at least six hours. Isotonic MS-induced mechanical hyperalgesia was reduced in a dose-dependent manner by co-injection of camphor, a non-selective TRPA1 antagonist (0.3, 1 and 2.5 μg/paw), MK-801, a NMDA receptor antagonist (0.001, 0.025 and 0.1 μg/paw), L-NAME, a non-selective nitric oxide (NO) synthase inhibitor (20, 50 and 100 μg/paw), ARL 17477, a selective neuronal NOS inhibitor (5.7 and 17 μg/paw), SMT, a selective inducible NOS inhibitor (1 and 2.78 μg/paw), and methylene blue, a guanylate cyclase inhibitor (5, 20 and 125 μg/paw). Drugs injected into the contralateral hind paw did not produce significant effects. These results suggest that an i.pl. injection of MS produces local peripheral mechanical hyperalgesia via activation of peripheral TRPA1 and NMDA receptors and peripheral production of NO.

  9. Glycine zinc sulfate penta­hydrate: redetermination at 10 K from time-of-flight neutron Laue diffraction

    Science.gov (United States)

    Fortes, A. Dominic; Howard, Christopher M.; Wood, Ian G.; Gutmann, Matthias J.

    2016-01-01

    Single crystals of glycine zinc sulfate penta­hydrate [systematic name: hexa­aqua­zinc tetra­aquadiglycinezinc bis­(sulfate)], [Zn(H2O)6][Zn(C2H5NO2)2(H2O)4](SO4)2, have been grown by isothermal evaporation from aqueous solution at room temperature and characterized by single-crystal neutron diffraction. The unit cell contains two unique ZnO6 octa­hedra on sites of symmetry -1 and two SO4 tetra­hedra with site symmetry 1; the octa­hedra comprise one [tetra­aqua-diglycine zinc]2+ ion (centred on one Zn atom) and one [hexa­aqua­zinc]2+ ion (centred on the other Zn atom); the glycine zwitterion, NH3 +CH2COO−, adopts a monodentate coordination to the first Zn atom. All other atoms sit on general positions of site symmetry 1. Glycine forms centrosymmetric closed cyclic dimers due to N—H⋯O hydrogen bonds between the amine and carboxyl­ate groups of adjacent zwitterions and exhibits torsion angles varying from ideal planarity by no more than 1.2°, the smallest values for any known glycine zwitterion not otherwise constrained by a mirror plane. This work confirms the H-atom locations estimated in three earlier single-crystal X-ray diffraction studies with the addition of independently refined fractional coordinates and Uij parameters, which provide accurate inter­nuclear X—H (X = N, O) bond lengths and consequently a more accurate and precise depiction of the hydrogen-bond framework. PMID:27746937

  10. 酚妥拉明与硫酸镁联合湿敷治疗新生儿输液渗漏%Phentolamine Combined with Magnesium Sulfate Wet Compress for Neonates with Permeation of the Vein Importation

    Institute of Scientific and Technical Information of China (English)

    巩清梅; 赵崟; 立晓霞; 罗琳

    2012-01-01

      Objective:To investigate the effect of Phentolamine combined with magnesium sulfate wet compress for neonates with permeation of the vein importation.Methods:68 neonates with permeation of the vein importation were assigned to treatment and control groups randomly.MgSO4 wet and cold compress was administered in control group.Treatment group were tredted by Phentolamine combined with magnesium sulfate wet compress. Results:The overall effective rate of 100.0%in the treatment group was superior to that in the control group(85.3%),and there was statistical difference(P0.05).结论:酚妥拉明与硫酸镁联合湿敷治疗输液外渗消肿效果好,值得临床推广应用.

  11. Nifedipine and magnesium sulfate combined treatment of pregnancy the analysis of the high character%硝苯地平与硫酸镁联用治疗妊娠期高血压疾病的分析

    Institute of Scientific and Technical Information of China (English)

    游颖

    2016-01-01

    ObjectiveTo explore the nifedipine the clinical effect of combined therapy with magnesium sulfate used in pregnancy,high character.Methodswill be perfect in our high tax treatment of 96 patients were randomly divided into observation group 48 cases(nifedipine combined therapy with magnesium sulfate)and control group 48 cases)(magnesium sulfate treatment,compared two groups of treatment effect.Resultscompared two groups of treatment effectiveness difference is significant(P<0.05).ConclusionMagnesium sulfate and nifedipine combined treatment can improve myocardial blood oxygen at the same time also can ensure patients' myocardial function,avoid the occurrence of complications,reduce the incidence of hypertension,ensure the life and health of pregnant women and infants.%目的:探讨硝苯地平联合硫酸镁用于妊娠期高血压疾病治疗的临床效果。方法将我院收治的妊娠期高血压疾病患者96例随机分成观察组48例(硝苯地平联合硫酸镁治疗)和对照组48例(硫酸镁治疗),对比2组的治疗效果。结果2组治疗有效率相比差异具有显著性(P<0.05)。结论硫酸镁和硝苯地平联合治疗能够在改善患者心肌血氧的同时保护心肌功能,避免并发症的出现,减少高血压发病率,保障孕妇和婴儿的生命健康。

  12. The effect of magnesium sulfate on the convulsion and mortality rate in lidocaine-poisoned mice%硫酸镁对利多卡因中毒小鼠惊厥和死亡率的影响

    Institute of Scientific and Technical Information of China (English)

    邱有波; 杨拯; 袁梦郎

    2012-01-01

    OBJECTIVE Using the model of seizure induced by lidocaine hydrochloride to investigate the effect of magnesium sulfate on the convulsions and mortality rate of mice with lidocaine poisoning. METHODS 210 Kunming mice weighing 18-25g were randomly divided into 5 groups: control group, 50mg/kg magnesium sulfate, 100mg/kg magnesium sulfate, 200mg/kg magnesium sulfate, 400mg/kg magnesium sulfate group, 42 mice in each group, and received intraperitoneal injections of magnesium sulfate of four different doses or the same volume of normal saline, respectively. 15 minutes later, all the mice received an intraperitoneal injection of 100mg/kg lidocaine hydrochloride, convulsion latency, duration, seizures incidence, death time and mortality in mice were observed. RESULTS ① Compared with control group, magnesium sulfate extended incubation period of lidocaine induced convulsions, shortened the duration of convulsions induced by lidocaine, extended the time of death of lidocaine induced convulsions. ② Magnesium sulfate could reduce the incidence of seizures induced by lidocaine, 200 and 400mg/kg magnesium group compared with the control group, the incidence of lidocaine induced convulsions had significant differences (P<0.05); could reduce mortality of convulsions induced by lidocaine, 50, 100, 200 mg/kg magnesium group compared with the control group, lidocaine induced convulsions were significant differences in mortality (P < 0.01, P< 0.05). ③ Magnesium sulfate could reduce the intensity convulsions caused by lidocaine. Increased with the dose of magnesium sulfate, the level of induced convulsions by lidocaine decreased. CONCLUSION In this experimental condition, magnesium sulfate could be antagonized by convulsive effects of lidocaine to reduce the toxicity of lidocaine.%目的 应用盐酸利多卡因致小鼠中毒惊厥模型,探讨硫酸镁对利多卡因中毒小鼠惊厥和死亡率的影响.方法 210只昆明小鼠,体重18~25 g,按照

  13. Effect of lead ion on the hydration of compound phosphate based magnesium phosphate cement%铅离子对复合磷酸盐磷酸镁水泥水化硬化特性的影响∗

    Institute of Scientific and Technical Information of China (English)

    石军兵; 赖振宇; 卢忠远; 黄陈程; 廖其龙

    2015-01-01

    In this paper,the effect of lead ion on the hydration of compound phosphate based magnesium phos-phate cement and its leaching properties was studied.The results show that the compressive strength of com-pound phosphate based magnesium phosphate cement decrease with the increase of lead ion content.High con-tent of lead ion has no significant effect on the setting time of magnesium phosphate cement.During the hydra-tion of compound phosphate based magnesium phosphate cement,lead ion has no significant effect on the pH of the system,but the hydration exothermic peak is delayed by lead ion adding.The lead ion also reduced the amount of hydration heat and affected the degree of crystallization of the main hydration products.In the late hydration reaction of composite magnesium phosphate cement,when the content of lead nitrate is 10% or more the obvious Pb2 P2 O7 diffraction peak can be found.The leaching toxicity of lead ion is 43μg/L and it is lower than the national standard.%研究了铅离子对复合磷酸盐磷酸镁水泥水化硬化特性的影响及其在复合磷酸盐磷酸镁水泥中的稳定性。实验结果表明,复合磷酸盐磷酸镁水泥抗压强度随着铅离子掺量的增加而降低,其中硝酸铅掺量达到10%时,复合磷酸盐磷酸镁水泥的各个龄期的抗压强度发生明显下降。铅离子对复合磷酸盐磷酸镁水泥凝结时间没有明显影响。在复合磷酸盐磷酸镁水泥水化过程中,铅离子对水泥体系的 pH 值影响不大,但能够造成水泥水化放热峰出现的时间延迟,水化放热的总量减少并影响主要水化产物的结晶程度。在复合磷酸盐磷酸镁水泥水化反应后期,当硝酸铅掺量达到10%以上时,在水化产物中出现了较为明显的 Pb2 P2 O7的衍射峰。复合磷酸盐磷酸镁水泥固化铅离子的浸出毒性试验结果(43μg/L)远低于国家标准要求(5 mg/L)。

  14. Hydration and Leaching Toxicity of Magnesium Phosphate Cement with Lead Nitrate%硝酸铅对磷酸镁水泥水化的影响及浸出毒性

    Institute of Scientific and Technical Information of China (English)

    马保国; 王景然; 李相国; 蹇守卫; 谭洪波

    2011-01-01

    重金属铅污染是重大的环境问题,利用磷酸镁水泥体系可对重金属铅进行稳定/固化.研究了不同硝酸铅掺量对磷酸镁水泥水化进程的影响,并对水化产物的晶体形貌、浸出毒性进行了探讨.研究表明:硝酸铅掺量的增加(最大掺量2.5%)对磷酸镁水泥的凝结时间影响不大,对水化产物种类(MgKPO4·6H2O和Mg3 (PO4)2)无影响,但水化产物形貌有所变化.磷酸镁水泥对硝酸铅进行固化的浸出毒性试验结果(0.5 mg/L左右)比国家标准要求(5 mg/L)低一个数量级.EDS检测出Pb元素存在于水泥水化产物中.%Lead pollution is one of the significant environmental problems. Different contents lead nitrate stabilization/solidification by the magnesium phosphate cement was studied. The influence of lead nitrate on hydration process of phosphate magnesium cement and the crystal behaviors and leaching toxicity of the samples were investigated. The results show that:the increase of the lead nitrate (maximum dosage for 2, 5%) would not take obviously effect on phosphate magnesium cement setting time and the hydration products (MgKPO4 · 6HZO and Mg3 (PO4)2) except morphology. Solidification/solidification of lead nitrate was good on magnesium phosphate cement. Its leaching toxicity testing results (0. 5 mg/L)were controlled under the national standard (5 mg/L). EDS shows Pb exists in the form of hydration products.

  15. 脱除硫酸锰溶液中杂质镁的研究%Study on Magnesium Removal in Manganese Sulfate Solution

    Institute of Scientific and Technical Information of China (English)

    杨超; 王文磊; 曾德文; 阳海棠; 陈聪; 陈启元

    2012-01-01

    Magnesium impurity was removed by recrystallization and fluoride precipitation in manganese sulfate solution, respectively. The solubility isotherms of binary systems MgSO4-H2O, MnSO4~H2O and ternary system MgSO4-MnSO4-H2O were simulated and predicted with Pitzer thermodynamic model, and the distribution ratio of MgSO4 and MnSO4 in solid phase-liquid phase was verified via recrystallization experiment. Magnesium was also removed by fluoride precipitation compared with the former. The results show that recrystallization exerts quite limited effect on the separation of Mg and Mn by recrystallization due to constant distribution ratio, and the efficiency is improved by adding MgF2 crystal seed in fluorina-tion. The removal rate of Mg is 94. 3% at 95 "C with 0. 3 g MgF2 and 250% NH4F for 1 h.%分别采用重结晶法和氟化沉淀法脱除硫酸锰溶液中的杂质镁.用Pitzer热力学模型对二元系MgSO4 - H2O、MnSO4- H2O和三元系MgSO4-MnSO4-H2O的溶解度相图进行模拟预测,并结合溶解度相图对三元系的固溶体用重结晶法验证其分配比.同时采用氟化沉淀法进行对比试验.结果表明,由于固定分配比,重结晶法对镁锰分离作用十分有限,而加入MgF2晶种的氟化沉淀除镁新方法能够有效提高氟化沉淀法的效率,在95℃下,加入0.3g氟化镁晶种和250%理论用量的NH4F搅拌1h,能使镁的除去率达到94.3%.

  16. 海水淡化浓盐水石灰法制备氢氧化镁的研究%Research on Preparation of Magnesium Hydrate Through Lime Method with Concentrated Saltwater Obtained from Seawater Desalination

    Institute of Scientific and Technical Information of China (English)

    陈侠; 马俊涛; 周秀云; 于博

    2012-01-01

    The experiment study on the process conditions of preparation of magnesium hydrate through lime method, using the concentrated slatwater obtained from Seawater Desalination as raw material. According to the single factor and orthogonal tests, the effects of reaction aging time, molar ratio of calcium hydroxide and magnesium ions, the flow rate of calcium hydroxide and agitation rate on the purity of magnesium hydrate and calcium content in the production are investigated to optimize the reaction conditions. The results show that the order of the factors is molar ratio of calcium hydroxide and magnesium ions, the flow rate of calcium hydroxide and the reaction aging time follow. The optimal react conditions are: molar ratio of calcium hydroxide and magnesium ions is 0.9, the flow rate of calcium hydroxide is 10 x 10 "3 mol/min, and the reaction aging time is 120 min.%以海水淡化获得的浓盐水为原料,进行石灰法制备氢氧化镁的实验研究.通过单因素实验和正交实验,考察了反应陈化时间、Ca(OH)2与Mg2摩尔比、Ca(OH)2加料速率和反应器搅拌速率对氢氧化镁纯度及钙含量的影响,优化了反应条件.实验结果表明,影响氢氧化镁纯度及钙含量的各因素大小依次为:Ca(OH)2与Mg2摩尔比、Ca(OH)2加料速率、反应陈化时间.并确定了氢氧化镁制备的优化条件为:Ca( OH)2与Mg2+摩尔比0.9、Ca(OH)2的加料速率10 mmol/min,反应陈化时间120 min.

  17. Real-time high-resolution X-ray imaging and nuclear magnetic resonance study of the hydration of pure and Na-doped C3A in the presence of sulfates

    Energy Technology Data Exchange (ETDEWEB)

    Kirchheim,, A. P.; Dal Molin, D.C.; Emwas, Abdul-Hamid; Provis, J.L.; Fischer, P.; Monteiro, P.J.M.

    2010-12-01

    This study details the differences in real-time hydration between pure tricalcium aluminate (cubic C{sub 3}A or 3CaO {center_dot} Al{sub 2}O{sub 3}) and Na-doped tricalcium aluminate (orthorhombic C{sub 3}A or Na{sub 2}Ca{sub 8}Al{sub 6}O{sub 18}), in aqueous solutions containing sulfate ions. Pure phases were synthesized in the laboratory to develop an independent benchmark for the reactions, meaning that their reactions during hydration in a simulated early age cement pore solution (saturated with respect to gypsum and lime) were able to be isolated. Because the rate of this reaction is extremely rapid, most microscopy methods are not adequate to study the early phases of the reactions in the early stages. Here, a high-resolution full-field soft X-ray imaging technique operating in the X-ray water window, combined with solution analysis by {sup 27}Al nuclear magnetic resonance (NMR) spectroscopy, was used to capture information regarding the mechanism of C{sub 3}A hydration during the early stages. There are differences in the hydration mechanism between the two types of C{sub 3}A, which are also dependent on the concentration of sulfate ions in the solution. The reactions with cubic C{sub 3}A (pure) seem to be more influenced by higher concentrations of sulfate ions, forming smaller ettringite needles at a slower pace than the orthorhombic C{sub 3}A (Na-doped) sample. The rate of release of aluminate species into the solution phase is also accelerated by Na doping.

  18. Real-time high-resolution X-ray imaging and nuclear magnetic resonance study of the hydration of pure and Na-doped C3A in the presence of sulfates

    KAUST Repository

    Kirchheim, A. P.

    2011-02-21

    This study details the differences in real-time hydration between pure tricalcium aluminate (cubic C3A or 3CaO·Al2O 3) and Na-doped tricalcium aluminate (orthorhombic C3A or Na2Ca8Al6O18), in aqueous solutions containing sulfate ions. Pure phases were synthesized in the laboratory to develop an independent benchmark for the reactions, meaning that their reactions during hydration in a simulated early age cement pore solution (saturated with respect to gypsum and lime) were able to be isolated. Because the rate of this reaction is extremely rapid, most microscopy methods are not adequate to study the early phases of the reactions in the early stages. Here, a high-resolution full-field soft X-ray imaging technique operating in the X-ray water window, combined with solution analysis by 27Al nuclear magnetic resonance (NMR) spectroscopy, was used to capture information regarding the mechanism of C3A hydration during the early stages. There are differences in the hydration mechanism between the two types of C3A, which are also dependent on the concentration of sulfate ions in the solution. The reactions with cubic C3A (pure) seem to be more influenced by higher concentrations of sulfate ions, forming smaller ettringite needles at a slower pace than the orthorhombic C3A (Na-doped) sample. The rate of release of aluminate species into the solution phase is also accelerated by Na doping. © 2011 American Chemical Society.

  19. 掺复合缓凝剂的磷酸钾镁水泥浆体的水化硬化特性%Hydration and Hardening Characteristics of Magnesium Potassium Phosphate Cement Paste Containing Composite Retarders

    Institute of Scientific and Technical Information of China (English)

    杨建明; 史才军; 常远; 杨楠

    2013-01-01

    测试和分析了掺复合缓凝剂(CR)的磷酸钾镁水泥(MKPC)浆体的凝结时间、水化热、液相pH值、抗压强度、物相组成和微观结构,将其与掺硼砂(NB)的MKPC浆体进行比较,研究了掺CR的MKPC浆体的水化硬化特性.结果表明:CR通过控制MKPC水化体系液相pH值,使MKPC浆体的凝结时间延长、早期水化反应速度减慢、水化体系最高温度降低、总水化放热量减少;掺CR的MKPC硬化体中主要水化产物磷酸钾镁晶体(MKP)的生成量增加、晶体生长完好、稳定性好,MKPC硬化体的微观结构更完善,后期抗压强度显著提高.%Hydration and hardening properties of magnesium potassium phosphate cement paste(MKPC) containing composite retarders(CR) were investigated by testing and analyzing its setting time, hydration heat, compressive strength,phase component and microstructure, which were compared with those of MKPC paste with borax(NB) added. The results show that there are two heat releasing peaks on hydration temperature curve of MKPC paste with CR, and the setting time of MKPC paste is prolonged, the early hydration rate of MKPC paste is lowered, the highest temperature and total heat release of MKPC paste are decreased. The hardened MKPC paste with CR generates more main hydrates magnesium potassium phosphate hexahydrate(MgKPO4 · 6H2OMKP), which grows more perfectly and stably with few defects and cracks resulting in more perfect microstructure and high late compressive strength of hardened MKPC paste.

  20. Clinical experience of labetalol combined with magnesium sulfate in the treatment of hypertension in pregnancy%拉贝洛尔联合硫酸镁治疗妊娠期高血压的临床体会

    Institute of Scientific and Technical Information of China (English)

    张美娟

    2013-01-01

    目的观察拉贝洛尔联合硫酸镁治疗妊娠期高血压临床疗效。方法回顾性分析经临床诊断为妊娠期高血压的孕妇127例,分为治疗组和对照组,对照组给予硫酸镁注射液,治疗组在此基础上给予拉贝洛尔注射液。结果治疗组患者治疗后总显效65例(94.2%),对照组49例(84.5%),两组比较有统计学意义(P<0.05)。结论拉贝洛尔联合硫酸镁治疗妊娠期高血压避免了硫酸镁的血压控制不理想、容易反跳和镁中毒的不良反应,而且疗效显著,降压作用快,稳定时间长,临床应用前景广阔。%Objective To observe the clinical curative effect of labetalol combined with magnesium sulfate in the treatment of hypertension in pregnancy. Methods 127 cases of pregnant women with gestational hypertension were selected and divided into the treatment group and the control group. The control group was treated with magnesium sulfate injection, the treatment group were given labetalol injection on this basis. Results The total effect in treatment group was 65 cases(94.2%).It was 49 cases in control group(84.5%).There was statistically significant in two groups (P<0.05). Conclusion Labetalol combined with magnesium sulfate in the treatment of hypertension in pregnancy can avoid the adverse reaction of magnesium sulfate on not ideal blood pressure control, easy to rebound and magnesium intoxication. The curative effect is remarkable, the antihypertensive effect of fast, stable and long time, wide prospect of clinical application.

  1. Health system barriers to access and use of magnesium sulfate for women with severe pre-eclampsia and eclampsia in Pakistan: evidence for policy and practice.

    Science.gov (United States)

    Bigdeli, Maryam; Zafar, Shamsa; Assad, Hafeez; Ghaffar, Adbul

    2013-01-01

    Severe pre-eclampsia and eclampsia are rare but serious complications of pregnancy that threaten the lives of mothers during childbirth. Evidence supports the use of magnesium sulfate (MgSO4) as the first line treatment option for severe pre-eclampsia and eclampsia. Eclampsia is the third major cause of maternal mortality in Pakistan. As in many other Low- and Middle-Income Countries (LMIC), it is suspected that MgSO4 is critically under-utilized in the country. There is however a lack of information on context-specific health system barriers that prevent optimal use of this life-saving medicine in Pakistan. Combining quantitative and qualitative methods, namely policy document review, key informant interviews, focus group discussions and direct observation at health facility, we explored context-specific health system barriers and enablers that affect access and use of MgSO4 for severe pre-eclampsia and eclampsia in Pakistan. Our study finds that while international recommendations on MgSO4 have been adequately translated in national policies in Pakistan, the gap remains in implementation of national policies into practice. Barriers to access to and effective use of MgSO4 occur at health facility level where the medicine was not available and health staff was reluctant to use it. Low price of the medicine and the small market related to its narrow indications acted as disincentives for effective marketing. Results of our survey were further discussed in a multi-stakeholder round-table meeting and an action plan for increasing access to this life-saving medicine was identified.

  2. Health system barriers to access and use of magnesium sulfate for women with severe pre-eclampsia and eclampsia in Pakistan: evidence for policy and practice.

    Directory of Open Access Journals (Sweden)

    Maryam Bigdeli

    Full Text Available Severe pre-eclampsia and eclampsia are rare but serious complications of pregnancy that threaten the lives of mothers during childbirth. Evidence supports the use of magnesium sulfate (MgSO4 as the first line treatment option for severe pre-eclampsia and eclampsia. Eclampsia is the third major cause of maternal mortality in Pakistan. As in many other Low- and Middle-Income Countries (LMIC, it is suspected that MgSO4 is critically under-utilized in the country. There is however a lack of information on context-specific health system barriers that prevent optimal use of this life-saving medicine in Pakistan. Combining quantitative and qualitative methods, namely policy document review, key informant interviews, focus group discussions and direct observation at health facility, we explored context-specific health system barriers and enablers that affect access and use of MgSO4 for severe pre-eclampsia and eclampsia in Pakistan. Our study finds that while international recommendations on MgSO4 have been adequately translated in national policies in Pakistan, the gap remains in implementation of national policies into practice. Barriers to access to and effective use of MgSO4 occur at health facility level where the medicine was not available and health staff was reluctant to use it. Low price of the medicine and the small market related to its narrow indications acted as disincentives for effective marketing. Results of our survey were further discussed in a multi-stakeholder round-table meeting and an action plan for increasing access to this life-saving medicine was identified.

  3. Bonding Analysis on the Crystallization of Magnesium Carbonate Hydrates%基于水合碳酸镁结晶过程的化学键分析

    Institute of Scientific and Technical Information of China (English)

    闫小星; 李云飞; 薛冬峰; 晏成林; 王雷

    2007-01-01

    基于晶体学结构,将化学键理论定量地应用到水合碳酸镁Mg5(CO3)4(OH)2·4H2O和MgOgO3·3H2O的结晶行为研究中,以此指导和控制实际晶体的生长行为.根据所选晶面的化学键数目和强度,可以计算出该晶面的垂直生长速率,从而方便地预测出Mg5(CO3)4(OH)2·4H2O和MMgO3·3H2O晶体的理想形貌.Mg5(CO3)4(OH)2·4H2O晶体表现出六方片状的结晶习性,MgCO3·3H2O则具有六方柱的理想形貌.在实验中,六方片状的Mg5(CO3)4(OH)2-114心O和MgO3·3H2O六方柱可以通过简单的液相反应获得,证明我们的理论计算与实验结果完全相符.目前研究结果表明,单晶生长可以通过热力学意义上调整组成原子或离子的成键方式获得本质上的改进,这一过程为我们从动力学角度优化实验策略提供了更广阔的空间.%The chemical bonding theory is used to investigate the fundamental crystallization behaviours of magnesium carbonate hydrate crystals Mg5(CO3)4OH)2·4H2O and MgCO3·3H2O in terms of crystallographic structure, with the aim to guide and control the practical crystal growth. The ideal morphology of Mg5(CO3)4(OH)2·4H2O and MgCO3·3H2O crystals has readily been predicted, by calculating the vertical growth rate of selected planes in terms of the bond number and bond strength. Theoretically,Mg5 (CO3)4(OH)2·4H2O crystal exhibits hexagonal plate-shaped characteristics, while MgCO3·3H2O crystal possesses a hexagonal prism morphology. Experimentally, the hexagonal Mg5(CO3)4(OH)2·4H2O micro-platelets and MgCO3 ·3H2O micro-prisms with reproducible shape can be obtained by a simple liquid phase reaction. Theoretical results are in a good agreement with our experimental observations. Single crystal growth can be improved by tuning the bonding modification of constituent atoms or ions, such a process can leave us a great space to kinetically maximize our experimental strategies.

  4. 苦土—硫酸铵循环法制备氢氧化镁的研究%Study on Preparation of Magnesium Hydroxide from Bitter Earth-Ammonium Sulfate by Circulation Method

    Institute of Scientific and Technical Information of China (English)

    杨定明; 石荣铭; 王清成; 白进伟

    2001-01-01

    本文对苦土—硫酸铵循环法制备氢氧化镁的工艺条件进行了试验研究,找到了提高产品质量以及镁和氨的回收率的适宜工艺条件,对苦土资源合理利用具有参考价值。%In this paper,the technological conditions for preparation of magnesium hydroxide from bitter earth-ammonium sulfate by circulation method have been studied,and the suitable conditions to increase quality of product and recovery of ammonia and magnesium oxide have been found.It has important significance for rational utilization of bitter earth resources.

  5. Tratamento da Eclâmpsia: Estudo Comparativo entre o Sulfato de Magnésio e a Fenitoína Treatment of Eclampsia: Comparative Study on the Use of Magnesium Sulfate and Phenytoin

    Directory of Open Access Journals (Sweden)

    João de Deus Valadares Neto

    2000-10-01

    Full Text Available Objetivos: comparar a eficácia do sulfato de magnésio e da fenitoína no controle das convulsões em pacientes com eclâmpsia e avaliar os efeitos de sulfato de magnésio e da fenitoína sobre o prognóstico materno e perinatal em pacientes com eclâmpsia. Métodos: estudo prospectivo, randômico e controlado no qual foram analisados, de forma comparativa, os resultados obtidos no tratamento anticonvulsivante da eclâmpsia em 77 mulheres tratadas com sulfato de magnésio ou fenitoína. As drogas que constituíram os dois esquemas terapêuticos foram distribuídas, na proporção de um para um, em caixas numeradas aleatoriamente que apresentavam características semelhantes. À medida que cada paciente era admitida, uma caixa era aberta e o esquema nela contido administrado à paciente. Resultados: observou-se que, no grupo tratado com sulfato de magnésio, 19,5% das pacientes apresentaram recidiva de convulsões, ao passo que no grupo que usou fenitoína, 36,1% manifestaram novas crises (p0,05. Conclusões: o sulfato de magnésio mostrou-se mais eficaz que a fenitoína no controle e prevenção da recidiva de convulsões em pacientes com eclâmpsia, embora sua utilização esteja associada a maior prevalência materna de hemorragia pós-parto e desconforto respiratório neonatal. A fenitoína apresenta-se como droga alternativa para o tratamento de eclâmpsia nos casos em que houver contra-indicação ao uso do sulfato de magnésio.Purpose: to compare the efficiency between magnesium sulfate and phenytoin in the control of convulsions in patients with eclampsia and to evaluate the effects of magnesium sulfate and phenytoin on the maternal and perinatal prognosis in patients with eclampsia. Methods: this is a prospective, randomized and controlled study in which the results obtained with the use of anticonvulsive treatment in 77 women with eclampsia, treated with either magnesium sulfate or phenytoin, were analyzed comparatively. The drugs

  6. 硫酸镁联合酚妥拉明治疗妊高症临床疗效研究%Magnesium Sulfate Combined with Phentolamine in the Treatment of Pregnancy Induced Hypertension Clinical Research

    Institute of Scientific and Technical Information of China (English)

    徐春梅

    2015-01-01

    ObjectiveTo research the clinical effect of Magnesium sulfate combined with phentolamine in the treatment of pregnancy induced hypertension. MethodsThe pregnancy induced hypertension in our hospital for treatment of 96 cases of patients with comprehensive, it wil be randomly observation group and control group, each with 48 cases. The observation group were given Magnesium sulfate combined with phentolamine treatment, control group was given conventional treatment.Results After the treatment of diastolic and systolic blood pressure has significant difference (P < 0.05). Conclusion The clinical curative effect is better Magnesium sulfate combined with phentolamine in the treatment of pregnancy induced hypertension, can effectively improve the patients blood pressure, can be popularized in clinical.%目的:研究硫酸镁联合酚妥拉明治疗妊高症临床疗效。方法选取在我院接受治疗的妊娠高血压综合征患者96例,将其随机观察组与对照组,各有患者48例。给予观察组患者硫酸镁联合酚妥拉明治疗,给予对照组患者常规治疗。结果接受治疗后舒张压和收缩压具有显著性差异(P <0.05)。结论硫酸镁联合酚妥拉明治疗妊高症临床疗效较好,能够有效的改善患者血压情况,可在临床中推广。

  7. Clinical Efficacy Observation on Combined Treatment of Anpo and Magnesium Sulfate for Premature Rupture Membrane%安宝与硫酸镁联合治疗早产胎膜早破的疗效观察

    Institute of Scientific and Technical Information of China (English)

    李海东

    2012-01-01

    目的 探讨安宝与硫酸镁联合治疗早产胎膜早破的临床疗效.方法 90例早产胎膜早破孕妇按随机数字表法分为三组,各30例.对照Ⅰ组给予硫酸镁,对照Ⅱ组给予安宝,观察组联合安宝与硫酸镁.观察三组的疗效、显效时间、起效时间、延长妊娠时间及不良反应.结果 对照Ⅰ组总有效率低于对照Ⅱ组和观察组(P<0.05);对照Ⅰ组显效时间、起效时间晚于对照Ⅱ组和观察组,延长妊娠时间小于对照Ⅱ组和观察组(P<0.05);对照Ⅱ组不良反应发生率显著高于对照Ⅰ组(P<0.05).结论 安宝与硫酸镁联合治疗早产胎膜早破显效快,延长妊娠时间长,疗效好,不良反应少,值得临床推广应用.%Objective To study the clinical efficacy of Anpo and magnesium sulfate as a combined treatment for premature rupture membrane. Methods 90 pregnant women with premature rupture membrane were randomized into three groups,30 patients per group. The three groups were respectively regarded as the control group Ⅰ ( treated with magnesium sulfate ),the control group Ⅱ ( treated with Anpo )and the observation group( treated with Anpo and magnesium sulfate ). The clinical efficacy, the excellent effective time, the effective time, prolonged pregnancy time and adverse reactions were observed. Results Compared with control group Ⅱ and the observation group, the total effective rate was obviously lower in control Ⅰ group( P < 0. 05 ). Compared with the control group Ⅱ and the observation group,the excellent effective time and the effective time were obviously longer and the prolonged pregnancy time was significantly lower in control Ⅰ group( P<0.05 ). The adverse reactions were significantly higher in control group Ⅱ than control group Ⅰ ( P <0. 05 ). Conclusion The clinical efficacy of the combination treatment of Anpo and magnesium sulfate for premature rupture memherane is featured with fast, longer prolonged pregnancy time, good

  8. The effect of magnesium sulfate in the treatment of pregnancy induced hypertension and nursing experience%硫酸镁治疗妊高症的疗效及护理体会

    Institute of Scientific and Technical Information of China (English)

    申丽红

    2015-01-01

    OBJECTIVE: to analyze the clinical effect and nursing method of magnesium sulfate in the treatment of pregnancy induced hypertension.. Methods: in January 2013 to January 2014 to hospital treatment of pregnancy induced hypertension (PiH) in 48 cases as the object of study, were given magnesium sulfate treatment, and take effective nursing measures and the clinical effect was observed and analyzed. Results: in this group, 48 cases of pregnancy hypertension patients treatment with magnesium sulfate and take scienti c and reasonable nursing measures, achieved good results, after a period of time after the systematic nursing, except for 2 cases of neonatal transfer pediatric treatment, the rest were recovered and discharged. Conclusion: the treatment of the patients with pregnancy induced hypertension by magnesium sulfate treatment of the comprehensive system of nursing measures can improve the effect of treatment.%目的:分析硫酸镁治疗妊高症的临床疗效及护理方法。方法选取于2013年1月—2014年1月来院治疗的妊高症患者48例作为研究对象,均给予硫酸镁治疗,并采取有效的护理措施,观察分析其临床效果。结果本组48例妊高症患者经硫酸镁治疗并采取科学合理的护理措施后,取得较好效果,经一段时间的系统护理后,除有2例新生儿转儿科治疗外,其余均康复出院。结论对采取硫酸镁治疗妊高症患者实施全面系统的护理措施,可提高其治疗效果。

  9. 硫酸镁对杂种犬急性肺动脉高压模型抗炎机制研究%Study on the anti-inflammatory mechanism of magnesium sulfate in mongrel dog with acute pulmonary hypertension

    Institute of Scientific and Technical Information of China (English)

    卢宏志; 刘翠萍; 张冰

    2013-01-01

    Objective To investigate the effect of magnesium sulfate on acute pulmonary hypertension and its anti-inflammatory mechanism in mongrel dogs .Methods 18 mongrel dogs were randomly divided into three groups:blank group,control group and magnesium sulfate group (2.0mm/kg),with 6 dogs in each group.The dogs in blank group were not given any treatment ,the dogs in control group were operated to induce acute pulmonary hypertension,and the dogs in magnesium sulfate group were given magnesium sulfate 2.0mm/kg by intravenous infusion for 10 minutes after the animal models with acute pulmonary hypertension were established .The mean pulmonary artery pressure ( MPAP) and circulation mean arterial pressure ( MAP) were detected by pulmonary artery and femoral artery cannulation , IL-6 and TNF-αlevels in serum were detected by enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay,respectively,and MCP-1 protein expression was determined by Western blot .Results The MPAP in control group was significantly higher than that in blank group;however MPAP in magnesium sulfate group was significantly lower than that in control group ( P <0.05 or P <0.01).The MAP in control group was significantly lower than that in blank group ,however,MAP in magnesium sulfate group was significantly higher than that in control group ( P <0.05 or P <0.01).The serum levels of TNF-αand IL-6 in control group were significantly higher that those in blank group , however , which in magnesium sulfate group were significantly lower than those in control group ( P <0.05 or P <0.01).The MCP-1 protein expression levels in control group were significantly higher than those in blank group ,however ,which in magnesium sulfate group was significantly lower than those in control group ( P <0.05 or P <0.01).Conclusion Magnesium sulfate can significantly reduce acute pulmonary hypertension ,which may be related to its effects of inhibiting the expression of MCP-1 in lung tissue,decrease TNF-αand IL-6 levels

  10. Magnesium Gluconate

    Science.gov (United States)

    Magnesium gluconate is used to treat low blood magnesium. Low blood magnesium is caused by gastrointestinal disorders, prolonged vomiting or ... disease, or certain other conditions. Certain drugs lower magnesium levels as well.This medication is sometimes prescribed ...

  11. Investigating and Modeling the Thermo-dynamic Impact of Electrolyte Solutions of Sodium Chloride and Sodium Sulfate on Prevention of the Formation of Methane Hydrate

    Directory of Open Access Journals (Sweden)

    M. Manteghian

    2013-07-01

    Full Text Available Devising methods to prevent hydrate formation is of the important issues in natural gas industry. Since a great deal of money is annually spent on using hydrate inhibitors, identification of new inhibitors with higher degrees of efficacy is economically justifiable. Bearing in mind the significant role of hydrate inhibitors in prevention of natural gas pipelines’ getting blocked, the present study attempts to investigate two compounds of NaCl and Na2SO4 as inhibitors of hydrate methane’s formation so as to respond to “what is the inhibitive thermo-dynamic impact of electrolyte compounds of NaCl and Na2SO4 on the formation of methane hydrate?” To do so, this study not only measures the equilibrium temperature and pressure of methane hydrate formation in the presence of electrolyte solutions of NaCl and Na2SO4 and compares the results obtained with the state lacking such inhibitors, but it also assesses the regression and mathematical modeling are utilized within a basic virtual environment in order to propose a model for prediction of thermo-dynamic equilibrium temperature and pressure of methane hydrate formation.

  12. Hidratação do óxido de magnésio em presença de alumina hidratável Magnesium oxide hydration in presence of hydratable alumina

    Directory of Open Access Journals (Sweden)

    R. Salomão

    2010-07-01

    Full Text Available Aluminas hidratáveis são compostos obtidos a partir da calcinação incompleta da gibsita Al(OH3, que podem reagir com água e possuem ação ligante em suspensões cerâmicas. A substituição do cimento de aluminato de cálcio pelas aluminas hidratáveis em concretos refratários contendo óxido de magnésio (MgO pode gerar diversos benefícios em relação às propriedades termomecânicas e refratariedade. No entanto, os efeitos da combinação desses materiais e suas conseqüências para a hidratação do MgO ainda não foram investigados sistemicamente. Neste trabalho, quatro fontes de MgO e aluminas hidratáveis foram combinadas em diferentes proporções e hidratados simultaneamente. Após investigações utilizando difração de raios X, termogravimetria e expansão volumétrica aparente, verificou-se que a relação MgO/Al2O3 e as diferenças de reatividade de cada matéria prima podem afetar significativamente o processo de hidratação. Além disso, foi observado que essa combinação pode ser utilizada como uma interessante técnica anti-hidratação para o MgO.The substitution of calcium aluminate cement by hydratable aluminas in MgO-containing refractory castables can afford several benefits for these materials mechanical properties and refractoriness. Nevertheless, the way that hydratable aluminas affects MgO hydration and its consequences were not yet systemically explored. In the present work, four sources of magnesia and alumina were combined at different ratios and hydrated simultaneously. They were investigated by X-ray diffraction, thermogravimetry and apparent volumetric expansion measurements. It was found that the magnesia/alumina ratio and the differences of reactivity of each raw material can greatly affect both hydration processes, generating different hydrated compounds. It was also verified that this combination can be suitably used as powerful MgO anti-hydration technique.

  13. Calcining Serpentine with Ammonium Sulfate for Preparation of Ultrafine Magnesium Hydroxide%用蛇纹石硫酸铵焙烧法制备超细氢氧化镁的研究

    Institute of Scientific and Technical Information of China (English)

    宋贝; 刘超; 郑水林; 戴瑞; 侯会丽

    2013-01-01

    Calcining serpentine with ammonium sulfate to extract magnesium for preparaion of ultrafine magnesium hydroxide. This paper studies the effect of temperature on the performance of the preparation of ultrafine magnesium hydroxide, which come to the conclusion the appropriate reaction temperature is 40℃. The results show that superfine magnesium hydroxide particles occur agglomeration and have large specific surface area. In order to overcome the agglomeration of the magnesium hydroxide and decrease the surface area, the magnesium hydroxide hydrothermal reaction is carried on and the appropriate condition of hydrothermal time is 3 h. Through analysis of their chemical composition, particle size distribution, surface area and SEM, it shows that after the hydrothermal reaction magnesium hydroxide specific surface area is 13.79 m2/g, the content of MgO is 68.23%, and has good crystalline form.%  以蛇纹石为原料,通过硫酸铵焙烧法提取蛇纹石中的镁,并制备超细氢氧化镁。研究了温度对制备超细氢氧化镁性能的影响,得出适宜反应温度为40℃,SEM测试结果表明,制备的超细氢氧化镁颗粒间发生了较多团聚,比表面积较大。为克服氢氧化镁的团聚现象,降低比表面积,将氢氧化镁在反应釜中进行水热反应,得出适宜水热时间为3 h。化学分析以及粒度、比表面积、SEM测试结果表明,水热反应后氢氧化镁比表面积为13.79 m2/g,MgO含量为68.23%,晶型较好。

  14. Investigation on Gas Storage in Methane Hydrate

    Institute of Scientific and Technical Information of China (English)

    Zhigao Sun; Rongsheng Ma; Shuanshi Fan; Kaihua Guo; Ruzhu Wang

    2004-01-01

    The effect of additives (anionic surfactant sodium dodecyl sulfate (SDS), nonionic surfactant alkyl polysaccharide glycoside (APG), and liquid hydrocarbon cyclopentane (CP)) on hydrate induction time and formation rate, and storage capacity was studied in this work. Micelle surfactant solutions were found to reduce hydrate induction time, increase methane hydrate formation rate and improve methane storage capacity in hydrates. In the presence of surfactant, hydrate could form quickly in a quiescent system and the energy costs of hydrate formation were reduced. The critical micelle concentrations of SDS and APG water solutions were found to be 300× 10-6 and 500× 10-6 for methane hydrate formation system respectively. The effect of anionic surfactant (SDS) on methane storage in hydrates is more pronounced compared to a nonionic surfactant (APG). CP also reduced hydrate induction time and improved hydrate formation rate, but could not improve methane storage in hydrates.

  15. Magnesium sulfate and montelukast for treatment of asthma in adult:a meta-analysis%孟鲁司特与硫酸镁联合治疗成人支气管哮喘的meta分析

    Institute of Scientific and Technical Information of China (English)

    马康; 赵宇

    2016-01-01

    Objective To systemically review the efficacy and safety of magnesium sulfate for asthma.Methods Such databases as Pubmed,Cochrane Library,CNKI,VIP from inception to January 201 6 for randomized controlled trials (RCTs)concerning magnesium sulfate and montelukast for adult asthma.Two reviewers screened literature according to the inclusion and exclusion criteria,extracted data,and assessed methodological quality of included studies.Then meta-analysis was performed using RevMan 5.3 software.Results A total of 12 RCTs involving 1 992 patients were included.The results of meta-analysis showed that magnesium sulfate and montelukast had higher remission rate of clinical signs compared with control group (OR = 5.50,95% CI = 3.73-8.1 1,P < 0.01 ).And magnesium sulfate and montelukast could significantly reduce the relief time of cough (SMD = -1.66,95% CI =-1.92--1.40,P <0.01),gasp (SMD =-1.42,95% CI =-1.68--1.16,P <0.01),chest congestion (SMD =-1.54,95% CI = -1.73--1.34,P < 0.01 ).Compared with control group,magnesium sulfate and montelukast could obviously reduce the recurrence rate of asthma (OR =0.26,95% CI =0.1 5-0.43,P <0.01).And magnesium sulfate and montelukast could significantly improve lung function index:PEF (SMD =0.85,95% CI =0.11-1.59,P <0.01),FEV1 % (SMD =7.65,95% CI =2.60-12.71,P <0.01),FEV1/FVC% (SMD =6.31,95% CI =5.47-7.14,P <0.01).Magnesium sulfate and montelukast could cause more adverse drug reactions (OR =4.43,95% CI =1.87-10.49,P =0.0007).Funnel plot of the remission rate of clinical signs is asymmetric that indicates publication bias.Conclusion Magnesium sulfate and montelukast can obviously improve the clinical signs,pulmonary function of patients with asthma,and reduce the recurrence rate,but increase adverse drug reactions.Due to limited quantity and quality of the included studies,the above conclusion should be further verified by conducting more high quality,large scale,multicentre RCTs.%目的:系统评价孟鲁司特与硫酸镁联合治

  16. The neuroprotective effect of magnesium sulfate in treatment of patients with acute cerebral ischemic stroke%硫酸镁对急性缺血性脑卒中的神经保护作用

    Institute of Scientific and Technical Information of China (English)

    麦辉

    2011-01-01

    Objective To explore the neuroprotective effect of magnesium sulfate in tretment of patients with cerebral ischemic stroke. Methods 40 patients with cerebral ischemic stroke were selected and randomly divided into experimental group(20 cases) and control group(20 cases). Among those two groups,the magnesium sulfate therapeutic measure was carried out in the experimental group and the control group was treated without magnesium sulfate. The difference rangeability of level of serum myelin basic protein pre and pro-therapy of both groups was compared. Results For the experimental group, the mean level of serum myelin basic protein in the first day pre-therapy was (8.3 + 2.5) μg/L, and (4.2 ± 1.7) μg/L in 10 days pro-therapy. the csrtrol group was ( 8.0 ± 3.0) μg/L for tite first day pre-therapy,and (6.0 ± 1.4) μg/L in 10 days pro-therapy. The difference rangeability of level of serum myelin basic protein pre and pro-therapy of both groups had statistical significance, compared with the controlled group,the experimental group had lower level of serum myelin basic protein ( t = 1. 231, P = 0. 041 ).Conclusion Magnesium sulfate could significantly decrease the serum level of myelin basic protein for patients with cerebral ischemic stroke,which irdicate that the magnesium sulfate should have neuroprotective effect on patients with cerebral ischemic stroke.%目的 探讨硫酸镁对急性缺血性脑卒中患者的神经保护作用。方法 采用髓鞘碱性蛋白量化分析方法,分析急性缺血性脑卒中患者硫酸镁治疗前后血清髓鞘碱性蛋白水平变化的幅度,并与对照组对比。结果 治疗组20例患者治疗前第1天血清髓鞘碱性蛋白平均水平为(8.3±2.5) μg/L,治疗后第10天为(4.2±1.7) μg/L;对照组20例患者治疗前第1天血清髓鞘碱性蛋白平均水平为(8.0±3.0)μg/L,治疗后第10天为(6.0±1.4) μg/L。两组患者治疗前后血清髓鞘碱性蛋白水平变化幅度的

  17. Protective effects of magnesium sulfate on renal ischemia-reperfusion injury in mice%硫酸镁对小鼠肾缺血再灌注损伤保护作用

    Institute of Scientific and Technical Information of China (English)

    李祖成; 李淑翠; 亢泽春; 王垣芳

    2012-01-01

    目的 观察硫酸镁对小鼠肾缺血再灌注损伤的抗氧化保护作用.方法 雄性小鼠随机分为假手术组、模型组和硫酸镁高、低剂量(120、60 mg/kg)组,无创动脉夹夹闭左肾蒂45 min和再灌注3h制备急性肾缺血再灌注损伤模型,检测肾脏指数、血清尿素氮(BUN)和肌酐含量、肾组织丙二醛(MDA)含量以及超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)活力,HE染色观察肾组织学变化.结果 硫酸镁高、低剂量组小鼠肾指数分别为(0.72±0.05)和(0.74±0.07)、血清BUN含量为(12.36±2.24)和(15.58±1.92) mmol/L、血清肌酐水平为(98.23±4.37)和(114.63±6.24) μmol/L、肾组织MDA含量为(2.11±0.24)和(2.27±0.21) nmol/(mg·prot),肾组织SOD活力为(4.03±0.68)和(3.51±0.58) U/(mg·prot),硫酸镁高剂量组肾组织GSH-Px活力为(323.90±23.50)U/( mg· prot),与模型组比较,差异均有统计学意义(P<0.05),且肾组织病理变化较轻.结论 硫酸镁对小鼠急性肾缺血再灌注损伤具有保护作用,其机制可能与抑制脂质过氧化反应有关.%Objective To investigate whether magnesium sulfate could protect kidney against ischemia/reperfusion (I/R) injury. Methods Kunming male mice were randomly divided into sham group and model group and treated with magnesium sulfate (120 mg/kg and 60 mg/kg). I/R were induced by occlusion of left renal pedicle for 45 minutes followed by a three hours of reperfusion except sham group. After the reperfusion, the blood samples were collected and blood urea nitrogen(BUN) and serum creatinine were measured for the evaluation of renal function. The content of ma-londialdehyde( MDA),superoxide dismutase( SOD) activity,and glutathione peroxidase( GSH-Px) activity in left kidney tissues were detected,and histological examination was carried out. Results Compared with the model group,renal dysfunction of the mice treated with magnesium sulfate was improved; the content of MDA in the kidney tissues was

  18. 硝苯地平联合硫酸镁对妊娠期高血压疾病的临床疗效分析%Clinical Efficacy Analysis of Nifedipine Combined with Magnesium Sulfate on Pregnancy-Induced Hypertension

    Institute of Scientific and Technical Information of China (English)

    肖琼; 孙丽萍

    2014-01-01

    Objective:To investigate clinical efficacy of Nifedipine combined with magnesium sulfate on pregnancy-induced hypertension. Method:80 cases of patients with pregnancy-induced hypertension in our hospital from March 2012 to March 2014 were selected and randomly divided into control group and observation group,40 cases in each group. Patients in control group were given magnesium sulfate treatment,and patients in observation group were given nitrate benzene horizon combined magnesium sulfate. The blood pressure,birth outcomes,and adverse reactions of two groups were analyzed and compared. Result:Compared with before treatment,systolic and diastolic blood pressure of two groups were significantly reduced,and the reduce of observation group were more significantly(P<0.05).The natural childbirth rate of observation group was 65.0%(26/40),which was significantly higher than 37.5%(15/40)of control group(P<0.05). There was no serious adverse reactions in two groups. Conclusion:Nifedipine combined magnesium sulfate can effectively treat pregnancy-induced hypertension,with advantages of significantly blood pressure change and high natural childbirth compared with magnesium sulfate,worthy of promotion and application.%目的:探讨硝苯地平联合硫酸镁对妊娠期高血压疾病的临床疗效,为临床应用提供参考和依据。方法:选取2012年3月-2014年3月间入住本院的妊娠期高血压疾病患者80例,随机分成对照组和观察组,每组40例,对照组给予硫酸镁治疗,观察组给予硝苯地平联合硫酸镁治疗。对两组患者的血压、分娩结局以及不良反应发生情况进行分析比较。结果:与治疗前相比,两组患者治疗后的收缩压与舒张压均显著降低,而且观察组患者的降低更显著(P<0.05);观察组自然分娩率65.0%(26/40),显著高于对照组的37.5%(15/40)(P<0.05);两组患者均没有发生严重的不良反应。结论:硝苯地平联合硫

  19. 硫酸镁联合硝苯地平控释片治疗妊高征临床分析%Magnesium Sulfate in Combination with Nifedipine Controlled Release Tablets in Treatment of Pregnancy-induced Hypertension

    Institute of Scientific and Technical Information of China (English)

    韩力

    2015-01-01

    目的:分析硫酸镁联合硝苯地平控释片治疗妊高征的临床疗效。方法:将我院收治的78例妊高征患者随机分为观察组39例和对照组39例。观察组患者在常规治疗的基础上行硫酸镁联合硝苯地平控释片治疗,对照组患者在常规治疗的基础上行单纯的硫酸镁治疗。评价两组患者的临床治疗效果,监测患者治疗前后的相关生化指标,并对母婴预后进行随访观察。结果:治疗后,观察组患者的SBP、DBP 指标值均低于对照组(P 均<0.05),尿蛋白减少率高于对照组(P<0.05),且患者的BUN、UA、CysC指标值均低于对照组( P均<0.05)。同时,观察组患者母婴死亡率及提早终止妊娠、子痫、胎盘早剥、子宫过度收缩等并发症的总发生率为12.81%,对照组为25.65%,两组比较,差异具有统计学意义( P<0.05)。结论:硫酸镁联合硝苯地平控释片治疗妊高征的临床疗效要优于单纯的硫酸镁治疗,能有效改善患者血压、肾功能及母婴预后。%Objective:To analyse curative effect magnesium sulfate in combination with nifedipine con-trolled release tablets clinical on pregnancy-induced hypertension .Method:78 cases patients were dividedinto observation group (39 cases) and control group (39 cases).On the basis of routine therapy , patients of observation group were treated by magnesium sulfate with ifedipine controlled release tablets , the control group patients were treated by magnesium sulfate .Effect of patients between two groups was assessed , related biochemical indexes was monitored , maternal and infant prognosis was observed .Result: After treatment , SBP, DBP, parameter values the patients observation group were lower than the control group (P <0.05), urinary protein loss was higher than the control group (P <0.05), and the patient's BUN, UA, CysC pa-rameter values were lower than the control group ( P <0.05) .At

  20. 硫酸镁对伊布利特转复心房颤动/心房扑动疗效的影响%Influence of magnesium sulfate on conversion effect of ibutilide on atrial fibrillation or flutter

    Institute of Scientific and Technical Information of China (English)

    吕薇; 牛铁生; 曹乾

    2013-01-01

    AIM To investigate the influence of pre-injected magnesium sulfate on the conversion effect of ibutilide on atrial fibrillation or flutter. METHODS Sixty -four patients who has atrial fibrillation or flutter were randomized to give placebo plus ibutilide group (control group) or magnesium sulfate plus ibutilide group (trial group) , receive either an infusion of 100 mL of 0.9% sodium chloride or the same amount of sodium chloride with 20 mL of 25% magnesium sulfate in one hour. After 10 min, ibutilide was infused. The conversion rate of atrial fibrillation or flutter and adverse events were observed. RESULTS Conversion rate of ibutilide for atrial fibrillation or flutter in the control group and the trial group is 50% and 84% respectively (P < 0.05). Adverse events are not significantly different between the two groups. CONCLUSION Pre - injection of mag -nesium sulfate enhances the ability of ibutilide for the conversion of atrial fibrillation or flutter.%目的 观察预先静脉给予硫酸镁对伊布利特转复心房颤动/心房扑动的影响.方法 选择符合条件的心房颤动/心房扑动患者64例,随机单盲法分为安慰剂+伊布利特组(对照组)和硫酸镁+伊布利特组(试验组),分别在1h内静脉滴注氯化钠注射液100 mL或氯化钠注射液100 mL加25%硫酸镁20 mL,10 min后给予伊布利特静脉注射,观察两组患者的心房颤动/心房扑动转复率及不良事件发生情况.结果 对照组与试验组对于心房颤动/心房扑动的转复率分别为50%及84%,两组比较差异显著(P<0.05);两组间不良反应发生率无显著差异(P>0.05).结论 预先静脉给予硫酸镁可显著提高伊布利特转复心房颤动/心房扑动的成功率.

  1. PART II. HYDRATED CEMENTS

    Directory of Open Access Journals (Sweden)

    Milan Drabik

    2014-09-01

    Full Text Available Essential focus of the study has been to acquire thermoanalytical events, incl. enthalpies of decompositions - ΔH, of technological materials based on two types of Portland cements. The values of thermoanalytical events and also ΔH of probes of technological compositions, if related with the data of a choice of minerals of calcium-silicate-sulfate-aluminate hydrates, served as a valued input for the assessment of phases present and phase changes due to the topical hydraulic processes. The results indicate mainly the effects of "standard humidity" or "wet storage" of the entire hydration/hydraulic treatment, but also the presence of cement residues alongside calcium-silicate-sulfate-aluminate hydrates (during the tested period of treatment. "A diluting" effect of unhydrated cement residues upon the values of decomposition enthalpies in the studied multiphase system is postulated and discussed

  2. Water Resistance, Hydration Product and Microstructure of Glass Fiber Reinforced Magnesium Oxychloride Cement Exterior Wall Cladding%玻镁外墙挂板的抗水性、水化产物和微观结构

    Institute of Scientific and Technical Information of China (English)

    董金美; 余红发; 刘倩倩; 李颖; 林启红

    2011-01-01

    Bending mechanical properties and deformations in natural state and wet state under water of common and high-performance glass fiber reinforced magnesium oxychloride cement ( GRMC ) exterior wall cladding were tested in this study. Hydration product components and microstructure were observed by X-ray diffraction ( XRD ) and scanning electron microscopy ( SEM). The results indicated that, in wet state under water, the main hydration product 5 ·1 ·8 was hydrolysed, microstructure is destroyed and bending strength is decreased for common GRMC exterior wall cladding. For high-performance GRMC exterior wall cladding with a complex water-repellent admixture and mixed minerals, the main hydration product 3 ·1 ·8 is stable existing in cement matrix and microstructure has been changed little. The sample reveals high water resistance. So, hydration product components and microstructure stability of GRMC exterior wall cladding are important prerequisites for high water resistance.%试验测定了普通玻镁外墙挂板、掺加复合抗水外加剂和矿物掺合料的高性能玻镁外墙挂板在自然和浸水状态下的弯曲力学性能和变形性能,并运用X射线衍射仪(XRD)和扫描电镜(SEM)分析了水化产物的组成和微观结构特征.结果表明:在浸水条件下,普通玻镁外墙挂板的主要水化产物5 ·1·8相发生了分解,破坏了微观结构,导致其抗弯强度降低;而掺加复合抗水外加剂和矿物掺合料的高性能玻镁外墙挂板的水化产物5·1·8相保持稳定,微观结构未发生变化,显示出较高的抗水性.因此,玻镁外墙挂板的水化产物组成和微观结构的稳定性是确保其抗水性的重要前提.

  3. plasma magnesium in adult asthmatics at the lagos university ...

    African Journals Online (AJOL)

    hi-tech

    2003-09-09

    Sep 9, 2003 ... Subjects: Forty stable asthmatics and thirty five apparently healthy controls. Methods: Detailed ... Plasma magnesium, albumin, calcium and phosphorus were measured ... management of asthma and magnesium sulfate in.

  4. Effect of magnesium sulfate on remifentanil-induced hyperalgesia%硫酸镁对瑞芬太尼引起痛觉过敏的影响

    Institute of Scientific and Technical Information of China (English)

    姚维娜; 崔松勤; 吴晓丽; 马正良; 顾小萍

    2011-01-01

    Objective To observe the effect of magnesium sulfate ( MgSO4 ) on remifentanil-induced hyperalgesia in rats model of incision pain. Methods Forty-two male Sprague Dawley(SD) rats were randomly divided into seven groups(n = 6): group C (control), group I (incision pain), group R (remifentanil + incision pain), group Mgl (incision pain+MgSO4 1 000 mg/kg), group MgR1 (remifentanil+incision pain+MgSO4 250 mg/kg), group MgR2 (remifentanil+ incision pain + MgSO4 500 mg/kg), MgR3 group (remifentanil + incision pain+MgSQ4 1 000 mg/kg). MgSO4 contained in 4 ml volume was administered intraperitoneally ten minutes before anesthesia in MgSO4 treatment groups, while saline was administered subcutaneously in group C, group I and group R. All groups except group C received incision pain model. Paw Withdrawal Thermal latency ( PWTL) and Paw Mechanical Withdrawal Threshold (PMW) were detected on the rats' right hind paw at T0(24 h before operation), T1 (6 h after operation), T2 (24 h after operation), and T3 (48 h after operation) in all groups. Results The PWTL and PMW of group R were significantly shorter at T1 ,T2 ,T3, when compared with group I (P<0. 05). The decrement of PMW and PWTL was alleviated by MgSO4 (P <0. 05). The PWTL and PMW of group MgR1, MgR2, and MgR3 were significantly longer when compared with group R (P<0. 05). Conclusion MgSO4 can relieve the incision pain and alleviate remifentanil-induced hyperalgesia in rats.%目的 研究大鼠切口痛模型中硫酸镁对瑞芬太尼诱发的痛觉过敏的影响.方法 42只雄性SD大鼠,随机均分为七组:切口痛组(Ⅰ组)、瑞芬太尼组(R组)、切口痛十硫酸镁组(MgI组)、切口痛十瑞芬太尼十硫酸镁( 250、500、1 000 mg/kg)组(MgR1、MgR2、MgR3组)、对照组(C组).MgI、MgR组均于麻醉前10 min腹腔注射硫酸镁稀释液4ml,余组给予相应生理盐水4ml.除C组外,各组均制作切口痛模型.各组均测定并计算出术前24 h(T0),术后6、24、48 h(T1、T2、T3)大鼠

  5. Cold bupivacaine versus magnesium sulfate added to room temperature bupivacaine in sonar-guided femoral and sciatic nerve block in arthroscopic anterior cruciate ligament reconstruction surgery

    Science.gov (United States)

    Alzeftawy, Ashraf Elsayed; El-Daba, Ahmad Ali

    2016-01-01

    Background: Cooling of local anesthetic potentiates its action and increases its duration. Magnesium sulfate (MgSo4) added to local anesthetic prolongs the duration of anesthesia and postoperative analgesia with minimal side effects. Aim: The aim of this prospective, randomized, double-blind study was to compare the effect of cold to 4°C bupivacaine 0.5% and Mg added to normal temperature (20–25°C) bupivacaine 0.5% during sonar-guided combined femoral and sciatic nerve blocks on the onset of sensory and motor block, intraoperative anesthesia, duration of sensory and motor block, and postoperative analgesia in arthroscopic anterior cruciate ligament (ACL) reconstruction surgery. Patients and Methods: A total of 90 American Society of Anesthesiologists classes I and II patients who were scheduled to undergo elective ACL reconstruction were enrolled in the study. The patients were randomly allocated to 3 equal groups to receive sonar-guided femoral and sciatic nerve blocks. In Group I, 17 ml of room temperature (20–25°C) 0.5% bupivacaine and 3 ml of room temperature saline were injected for each nerve block whereas in Group II, 17 ml of cold (4°C) 0.5% bupivacaine and 3 ml of cold saline were injected for each nerve block. In Group III, 17 ml of room temperature 0.5% bupivacaine and 3 ml of MgSo4 5% were injected for each nerve block. The onset of sensory and motor block was evaluated every 3 min for 30 min. Surgery was started after complete sensory and motor block were achieved. Intraoperatively, the patients were evaluated for heart rate and mean arterial pressure, rescue analgesic and sedative requirements plus patient and surgeon satisfaction. Postoperatively, hemodynamics, duration of analgesia, resolution of motor block, time to first analgesic, total analgesic consumption, and the incidence of side effects were recorded. Results: There was no statistically significant difference in demographic data, mean arterial pressure, heart rate, and duration of

  6. Magnesium Oxide

    Science.gov (United States)

    Magnesium is an element your body needs to function normally. Magnesium oxide may be used for different reasons. Some ... to relieve heartburn, sour stomach, or acid indigestion. Magnesium oxide also may be used as a laxative ...

  7. Chemical and Mineralogical Characterization of Acid-Sulfate Alteration of Basaltic Material on Mauna Kea Volcano, Hawaii: Jarosite and Hydrated Halloysite

    Science.gov (United States)

    Graff, Trevor G.; Morris, R. V.; Archilles C. N.; Agresti, D. G.; Ming, D. W.; Hamilton, J. C.; Mertzman, S. A.; Smith, J.

    2012-01-01

    Sulfates have been identified on the martian surface during robotic surface exploration and by orbital remote sensing. Measurements at Meridiani Planum (MP) by the Alpha-Particle X-ray Spectrometer (APXS) and Mossbauer (MB) instruments on the Mars Exploration Rover Opportunity document the presence of a ubiquitous sulfate-rich outcrop (20-40% SO3) that has jarosite as an anhydrous Fe3+-sulfate [1- 3]. The presence of jarosite implies a highly acidic (pH volcano, Hawaii) resulted in jarosite and alunite as sulfate-bearing alteration products [11-14]. Other, more soluble, sulfates may have formed, but were leached away by rain and melting snow. Acidsulfate processes on Puu Poliahu also formed hematite spherules similar (except in size) to the hematite spherules observed at MP as an alteration product [14]. Phyllosilicates, usually smectite }minor kaolinite are also present as alteration products [13]. We discuss here an occurrence of acid-sulfate alteration on Mauna Kea Volcano (Hawaii). We report VNIR spectra (0.35-2.5 microns ASD spectrometer), Mossbauer spectra (MER-like ESPI backscatter spectrometer), powder XRD (PANalytical), and major element chemical compositions (XRF with LOI and Fe redox) for comparison to similar data acquired or to be acquired by MRO-CRISM and MEx OMEGA, MERMB, MSL-CheMin, and MER and MSL APXS, respectively.

  8. Determination Method of Content of Calcium Ion, Magnesium Ion and Sulfate Ion in Agricultural Potassium Sulfate%农用硫酸钾中钙离子、镁离子和硫酸根离子含量的测定方法

    Institute of Scientific and Technical Information of China (English)

    郭峰

    2016-01-01

    The agricultural potassium sulfate is a common high quality potash fertilizer , which quality is related to the safety of national agricultural production .Through repeated trial and error , the determination method suitable for detecting calcium ion , magnesium ion and sulfate ion content in agricultural potassium sulfate is obtained , which can provide theoretical basis and data foundation for determination of content of these ions in agricultural potassium sulfate .%农用硫酸钾是常用的优质钾肥,其质量优劣关系着我国农业生产的安全。通过反复试验摸索,得出了适合测定硫酸钾中钙离子、镁离子和硫酸根离子含量的测定方法,以期为农用硫酸钾中这些离子含量的测定提供理论依据与数据基础。

  9. 硫酸镁治疗妊娠期高血压综合征的临床效果分析%Clinical effect analysis of treatment of hypertension during pregnancy with magnesium sulfate

    Institute of Scientific and Technical Information of China (English)

    柴光兰; 李辉

    2013-01-01

    Objective To explore effects of treatment of hypertension during pregnancy with magnesium sulfate. Methods Totally 86 patients with hypertension during pregnancy treated from November 2009 to November 2012 were divided into control group and observation group. The control group was treated with aspirin, and the observation group was treated with magnesium sulfate. The clinical effects were analyzed. Results The effective rate of treatment and the effect on blood pressure control in the observation group were significantly higher than that of the control group ( P < 0. 05). The complication rate in the observation group was lower than that of the control group. Conclusions The effect that hypertension during pregnancy was treated with magnesium sulfate is significant, lower complication rate, effective and safe, so the method is worth popularizing.%目的 对应用硫酸镁对妊娠期高血压综合征进行治疗的临床效果进行分析探讨.方法 随机抽取在2009年11月-2012年11月间潍坊市妇幼保健院收治的妊娠期高血压综合征临床患者病例86例,将其分成对照组和观察组,分别常规应用阿司匹林和硫酸镁进行治疗,而后对比分析治疗效果.结果 观察组患者治疗有效率、血压控制效果明显优于对照组(P<0.05),并发症发生率较对照组低(P<0.05).结论 采取硫酸镁对妊娠期高血压综合征患者展开治疗的临床疗效显著,并发症发生率低,安全有效,值得推广.

  10. Clinical Analysis of Magnesium Sulfate and Phentolamine on Pulmonary Heart Disease in 32 Cases%硫酸镁与酚妥拉明联合治疗肺心病心衰32例临床分析

    Institute of Scientific and Technical Information of China (English)

    陈谷

    2015-01-01

    目的硫酸镁与酚妥拉明联合治疗肺心病心衰的疗效观察。方法2010年~2013年来,我院在综合治疗基础上应用硫酸镁联合酚妥拉明治疗肺心病(CPHD)心衰32例,同时以30例使用常规综合治疗作为对照,分析疗效。结果治疗组治愈9例,好转1例,无效6例,总有效率81.3%;对照组治愈1例,好转13例,无效16例,总有效率46.7%。结论小剂量的硫酸镁与酚妥拉明静滴,确能改善CPHD心衰患者呼吸衰竭和心力衰竭的临床状况,且疗效优于文献报道的单独使用任何一种药,比较安全且疗效肯定。%Objective To observe the curative ef ect of Magnesium sulfate combined with phentolamine in treatment of heart failure of pulmonary heart disease. Methods 2010~2013 years, my col ege application Magnesium sulfate combined with phentolamine in the treatment of pulmonary heart disease on the basis of the comprehensive treatment of heart failure (CPHD) in 32 cases, and 30 cases used routine treatment as a control, ef ect analysis. Results The treatment group 9 cases were cured, 1 cases improved, 6 cases inef ective, the total ef iciency of 81.3%;control group 1 cases were cured, 13 cases improved, 16 cases inef ective, the total ef iciency of 46.7%. Conclusion A smal dose of Magnesium sulfate and phentolamine intravenous drip, the clinical condition can improve the respiratory failure and heart failure in patients with CPHD heart failure, and the curative ef ect is bet er than those reported in the literature of any kind of drug used alone, compared the safety and curative ef ect af irmation.

  11. 硫酸镁联合细辛脑治疗毛细支气管炎139例临床观察%Magnesium Sulfate Joint Asarone Treatment for 139 Cases with Bronchiolitis

    Institute of Scientific and Technical Information of China (English)

    邓志洲

    2013-01-01

      目的:观察硫酸镁联合细辛脑治疗毛细支气管炎的疗效.方法:将139例毛细支气管炎患儿随机分为两组,对照组采用常规治疗加用氨茶碱治疗,治疗组在常规治疗的基础上加用硫酸镁联合细辛脑治疗,全部以7 d为1个疗程,观察疗效.结果:1个疗程后,治疗组总有效率为95.7%,对照组总有效率为78.2%,治疗组疗效明显优于对照组,比较差异有统计学意义(P<0.05).结论:硫酸镁联合细辛脑治疗毛细支气管炎疗效显著,值得临床推广应用.%Objective:To observe curative effect of magnesium sulfate joint asarone treatment for bronchiolitis. Method:The 139 children with bronchiolitis were randomly divided into two groups,the control group received routine treatment plus with aminophylline treatment,the treatment group received the conventional treatment on the basis of add a magnesium sulfate joint asarone treatment with all the 7 d for a period of treatment. To observe the curative effect. Result:After a period of treatment,the total effective rate of the treatment group was 95.7%,and that of the control group was 78.2%. The curative effect of the treatment group was better than that of the control group(P<0.05). Conclusion:The curative effect of magnesium sulfate joint asarone treatment for bronchiolitis is distinct,which is worth clinical application.

  12. Clinical observation of Magnesium sulfate on 46 cases of bronchiolitis%硫酸镁治疗毛细支气管炎46例疗效观察

    Institute of Scientific and Technical Information of China (English)

    林小娜

    2009-01-01

    Objective: To investigate the therapeutic effect and safety of magnesium sulfate on bronchiolitis. Methods: 92 children with bronchiolitis were randomly divided into the treatment group(n=46) and the control group(n=46). Two groups received routine therapy, while the control group was treated with aminophylline, the treatment group was treated with magnesium sulfate. Results: The resolution time of clinical wheezing and hospitalize were obviously shortened in the treatment group compared with the control group (P<0.01).The improving rate of treatment group was significantly higher than that of control group,the figures were 76.1% and 45.7%, P<0.01. The total effectiveness rate of treatment group was higher than that of control group too,the figures were 93.5% and 73.9%, P<0.05. Treatment group had few side reaction occurred. Conclusion: Magnesium sulfate is cheap and have effect in the treatment of bronchiolitis, it has few side reaction and can be widely used in clinic.%目的:探讨硫酸镁治疗毛细支气管炎的临床疗效及安全性.方法:将92例毛细支气管炎患儿随机分为治疗组和对照组各46例,两组均给予常规治疗,在此基础上,治疗组加用硫酸镁,对照组加用氨茶碱静脉滴注.结果:治疗组在喘憋缓解、哮鸣音消失及住院时间方面均明显优于对照组(P<0.01).治疗组的显效率76.1%和总有效率93.5%,均高于对照组,分别为45.7%和73.9%(P<0.01和P<0.05).治疗组未见明显副作用.结论:硫酸镁治疗毛细支气管炎疗效好,价格便宜,不良反应少,值得临床推广应用.

  13. Isotopic Zonation Within Sulfate Evaporite Mineral Crystals Reveal Quantitative Paleoenvironment Details

    Science.gov (United States)

    Coleman, M.; Rhorssen, M.; Mielke, R. E.

    2008-12-01

    Isotopic variations measured within a single crystal of hydrated magnesium sulfate are greater than 30 permil for delta 2-H, almost 10 permil for δ18O in water of hydration; and greater than 3 permil in sulfate oxygen. These results are interpreted to indicate the relative humidity of the system during evaporation (15 to 20 percent in this test case) and constrain the volume of water involved. The theoretical basis of this system is the isotopic fractionation between the species in solution and those precipitated as evaporite salts. Precipitation preferentially accumulates more of the heavy isotopes of sulfur and oxygen in mineral sulfate, relative to sulfate in solution. During the course of mineral growth this leads to successive depletion of the respective heavier isotopes in the residual brine reflected in a parallel trend in successive precipitates or even in successive zones within a single crystal. The change in isotopic composition at any one time during the process, relative to the initial value, can be described by an isotopic version of the Rayleigh Fractionation equation, depending only on the extent of the completion of the process and the relevant fractionation factor. Evaporation preferentially removes isotopically lighter hydrogen and oxygen leading to successive extents of enrichment in the respective heavier isotopes in the residual water. However, the relative effects on hydrogen and oxygen isotopes differs as function of relative humidity [1]. ALL OF THESE CHANGES ARE PRESERVED IN THE MINERAL ISOTOPE COMPOSITIONS. We precipitated barium sulfate from epsomite or gypsum samples, which was reduced at 1450°C in the presence of graphite and glassy carbon in a Finnigan TC/EA to produce CO for O isotopic analysis in a Finnigan 253 mass spectrometer, while a separate subsample was oxidized to SO2 in a Costech Elemental Analyzer. However, to make progress with this approach we needed to make a large number of measurements of hydration water and so we

  14. Mechanical property and hydration mechanism of slag blended magnesium phosphate cement%矿渣磷酸镁水泥的力学性能和水化机理

    Institute of Scientific and Technical Information of China (English)

    侯磊; 李金洪; 王浩林

    2011-01-01

    以高炉矿渣作为磷酸镁水泥(MPC)的活性混合材料,研究了MPC的凝固时间、力学性能、物相组成和显微结构,并探讨了矿渣MPC的作用机理.实验固定磷镁比为25%,硼镁比为7.5%,矿渣掺量分别为磷镁总质量的0%、10%、20%、30%和40%.结果表明,矿渣参与了水化反应并提高了MPC的胶凝性能,随着矿渣掺量增大,矿渣MPC的抗压强度提高,但矿渣水化产生的膨胀应力会破坏MPC的内部结构,因此其抗折强度随矿渣掺量增大而降低.矿渣MPC的主要水化产物为六水合磷酸镁铵(MgNH4PO4·6 H2O),矿渣的掺入使凝胶相增加,并有部分Ca2+进入MgNH4PO4·6 H2O品格,使水化产物的形貌、大小发生变化.样品中剩余较多死烧镁和矿渣颗粒,可起骨料作用.%Blast-furnace slag was used as an active addition of magnesium phosphate cement. The influence of blast-furnace slag on the setting time, mechanical property, mineral phase and microstucture of slag blended magnesium phosphate cement (MPC) was studied. The prescription was designed as follows: the ratio of monoammonium phosphate to magnesia was 25% in mass, the borax additive amount to magnesia was 7.5% , the additive amount of blast-furnace slag was 0% , 10%, 20%, 30% and 40% separately in the ratio of total amount of dead burned magnesia and monoammonium phosphate to MPC. The results show that slag might participate the hydration, which improves the bonding of MPC, and the compressive strength of slag-blended MPC is improved with the increasing additive amount of slag. However, slag might results in expansion stress during hydration process, which causes lattice disturbance in hardened MPC, so the flexual strength decreases with the increasing additive amount of slag at the same time. The main hydration product of slag blended MPC is struvite (MgNH4PO4·6 H2O), the content of amorphous phase might increase after being mixed with slag in MPC, and Ca2+ ions in slag can result

  15. Obsidian hydration profiles measured by sputter-induced optical emission.

    Science.gov (United States)

    Tsong, I S; Houser, C A; Yusef, N A; Messier, R F; White, W B; Michels, J W

    1978-07-28

    The variation of concentrations of hydrogen, sodium, potassium, lithium, calcium, magnesium, silicon, and aluminum as a function of depth in the hydration layer of obsidian artifacts has been determined by sputter-induced optical emission. The surface hydration is accompanied by dealkalization, and there is a buildup of alkaline earths, calcium and magnesium in the outermost layers. These results have clarified the phenomena underlying the obsidian hydration dating technique.

  16. 硫酸镁对创伤性脑损伤大鼠血清NSE含量的影响%The effection of magnesium sulfate on neuron specific enolase of traumatic brain injury in rats

    Institute of Scientific and Technical Information of China (English)

    夏冬剑

    2014-01-01

    Objective To explore the effect of magnesium sulfate on neuron specific enolase ( NSE) in traumatic brain injuried rats blood.Methods Healthy Sprague-Dawley ( SD) rats were randomly divided into magnesium sulfate administration group ,trau-matic brain injury but without drug administration group and sham-injury group.And then prepare the brain injury model of free-fall, administration of magnesium sulfate at a dose of 140mg/kg,intraperitoneal injection after the injury ,24 hours after the traumatic brain injury ,the brain edemas was evaluated ,and expression of NSE level was determined in rats blood by radioimmunoassay meth -od.Results Compared with sham-injury group,24 hours after traumatic brain injury ,the brain edemas of rats increase (P<0.05), NSE level increase in blood (P<0.05).Compared with the group with traumatic brain injury but without drug administration ,mag-nesium sulfate pretreatment group improved the brain edemas of rats ( P<0.05 ) , and reduce NSE level in the rats blood ( P<0.05).Conclusion MgSO4 can decrease the brain edemas of traumatic brain injury rats ,lower NSE level in brain blood,MgSO4 has neuroprotective effect against traumatic brain injury in rats.%目的:探讨硫酸镁对创伤性脑损伤大鼠血清神经元特异性烯醇化酶( neuron specific enolase ,NSE)水平的影响。方法选用健康Sprague-Dawley(SD)大鼠,随机分为假损伤组、单纯脑损伤组、损伤给药组。然后制备自由落体脑损伤模型,损伤给药组大鼠在致伤后5分钟予25%硫酸镁(MgSO4)140mg/kg,腹腔注射,损伤24小时后分别测定脑组织含水量、放射免疫分析法测定大鼠血清NSE水平。结果与假损伤组比较,脑损伤24小时大鼠脑组织含水量明显增高(P<0.01),血清NSE水平升高(P<0.05)。与单纯脑损伤组比较,损伤给药组可降低脑组织含水量(P<0.05),降低血清NSE水平(P<0.05)。结论 MgSO4可以改善大鼠急性脑

  17. Tetromethylpyrazine combined with magnesium sulfate in treatment of hypertension during pregnancy%中药川芎嗪联合硫酸镁治疗妊娠高血压

    Institute of Scientific and Technical Information of China (English)

    孙君侠; 李建芬; 尹金丽; 卓会芳; 王娜; 高辉; 毕淑洁

    2015-01-01

    Objective To explore the efficacy of traditional Chinese medicine Tetromethylpyrazine combined with magnesium in the treatment of hypertension during pregnancy ,provide the basis for the clinical treatment of hypertension in pregnancy . Methods Selected 90 cases of pregnancy induced hypertension in patients treated in our hospital between September 2010 and December 2013 .The 90 patients were divided into a control group and observation group depending on the method of treatment ,and 45 patients in each group .Observation group were treated with traditional Chinese medicine Chuan Qiong piperazine combined with magnesium sulfate injection in the treatment ,and control group patients using magnesium sulfate injection therapy alone .Observe the clinical effect of the treatment and the two groups of patients'efficient and plasma vis-cosity before and after treatment .Results The results showed that patients in the observation group total efficiency (97 .8% ) was significantly higher than patients in control group (86 .7% ) ,in addition ,the observation group were stable blood pressure and protein in urine was significantly better than the control group in patients with conditions ( P<0 .05 ) , observed group only had 1 patient with nausea ,vomiting ,significantly less than the control patients ( P<0 .05 ) .Plasma vis-cosity observed group of patients decreased significantly ,and significantly lower than the control patients ( P<0 .05 ) .Con-clusion Application Tetromethylpyrazine combined with magnesium sulfate injection in the treatment of pregnancy induced hypertension to good effect can stable blood pressure and reduce nausea ,vomiting etc .%目的:探究中药川芎嗪联合硫酸镁在妊娠高血压治疗过程中的疗效,为临床治疗妊娠高血压提供依据。方法选取2010年9月—2013年12月间在我院住院治疗的妊娠高血压患者90例,根据治疗方法的不同分为对照组及观察组各45例,其中观察组患者采用中药

  18. 磷酸镁水泥固化Pb2+、Zn2+、Cu2+及其水化产物研究%The solidification and hydration products of magnesium phosphate cement with Pb2+,Zn2+and Cu2+

    Institute of Scientific and Technical Information of China (English)

    王景然; 马保国; 李相国; 李海南; 田振

    2014-01-01

    利用磷酸镁水泥对Pb2+、Zn2+、Cu2+重金属硝酸盐进行固化,研究其浸出率变化规律,并对不同种类重金属对磷酸镁水泥水化产物种类、形貌及其微区元素进行了探讨.研究表明,磷酸镁水泥对重金属进行固化效果Pb2+>Cu2+>Zn2+,浸出毒性数值远低于国家标准要求.Pb2+促进了水化产物的生成,Cu2+和Zn2+抑制水化.采用 EDS 能谱分别检测水化产物中Pb、Zn和Cu,分析磷酸镁水泥对重金属硝酸盐稳定/固化效果.%The leaching rate of magnesium phosphate cement with Pb2+,Zn2+,Cu2+ were studied.The kind, morphology and micro area elements of hydration products of magnesium phosphate cement added heavy met-als,were discussed in this paper.Research shows that:the magnesium phosphate cement on heavy metal solidi-fication effect of Pb2+>Cu2+> Zn2+,while the value of leaching toxicity was far lower than the national stand-ard requirements.Pb2+ could promote the formation of hydration products,while Cu2+ and Zn2+ were opposite. Pb,Cu and Zn were respectively detected used the EDS spectrum detection,which was proved that it cans or not stabilization/solidification of heavy metals in the hydration products of magnesium phosphate cement.

  19. Aspectos da hidratação de óxido de magnésio em formulações de concretos refratários Aspects of magnesium oxide hydration in refractory castables compositions

    Directory of Open Access Journals (Sweden)

    R. Salomão

    2006-06-01

    Full Text Available Óxido de magnésio (MgO ou magnésia é uma das matérias primas mais importantes para a indústria de refratários. Graças à sua elevada refratariedade (ponto de fusão da ordem de 2800 ºC e resistência à corrosão me meios básicos, associadas a custos relativamente baixos, sua utilização em tijolos permitiu um significativo aumento no desempenho e durabilidade desses materiais. No entanto, como uma seqüência natural da utilização desse material, seu uso em concretos refratários não obteve o mesmo impacto em aplicações industriais devido à sua elevada tendência em reagir com água e a decorrente expansão volumétrica gerada. Desse modo, adições de magnésia em concretos têm sido restritas a baixos teores (> 10% peso e ao uso de partículas grosseiras (> 100 µm. Neste trabalho, foram analisados criteriosamente os diversos estudos referentes à hidratação do MgO em concretos refratários, o impacto gerado nas diferentes etapas de processamento desses materiais e as técnicas empregadas para evitá-la.Magnesium oxide (MgO or magnesia is one of the most important raw materials for the refractories industry. Because of high refractoriness (melting point of 2800 ºC, corrosion resistance in basic environments and relatively low costs, its use in bricks has allowed a significant increase in the performance and service life of these materials. However, its use in refractory castables did not attain the same impact in industrial applications because of its great tendency in react with water and the consequent volumetric expansion generated. Therefore, magnesia additions in castables has been kept in small amounts (bellow 10 wt% and restricted to large particles (> 100 µm. In the present work, several reports on magnesia hydration in refractory castables, its effects on the castables processing and the anti-hydration techniques were critically reviewed.

  20. 硫酸镁对早产胎儿神经保护作用的Meta分析%Effects of Antenatal Exposure to Magnesium Sulfate on Neuroprotection in Preterm Infants:A Meta-analysis

    Institute of Scientific and Technical Information of China (English)

    杨春艳; 胡小平; 韩凤珍; 杜娟

    2014-01-01

    Objective To review the evidence regarding neuroprotective effects of antenatal exposure to magnesium sulfate. Methods We conducted database searches of PubMed, Cochrane library, EMBASE, China Journal Full-text Database, Chinese Biomedical Database, Chinese Scientific Journals Full-text Database. Randomized controlled trials comparing Magnesium Sulfate with placebo/other treatment in patients at risk of preterm labor were evaluated for inclusion and methodological quality. The data was analyzed by RevMan 5.0. The outcomes were death with cerebral palsy by 18~24 months corrected age , death , cerebral palsy , moderate-severe cerebral palsy , and death with moderate-severe cerebral palsy. Result Five randomized controlled trials were included (5 235 fetuses/ infants). When analyzed by GA(gestational age) at randomization, in utero exposure to magnesium sulfate during 30~34 weeks did not reduce the rate of death or cerebral palsy (RR 0.93, 95%CI 0.79~1.09). However, cerebral palsy (RR 0.70, 95%CI 0.54~0.90), moderate-severe cerebral palsy (RR 0.61, 95%CI 0.44~0.84), and death with moderate-severe cerebral palsy were significantly reduced, without an evident increase in risk death (RR 0.99, 95%CI 0.82~1.19). Similar results were obtained when the GA at randomization was less than 30 weeks. When only neuroprotection trials (four trials, 4 324 fetuses/infants) are analyzed, in utero exposure to Magnesium Sulfate additionally reduced the outcome of cerebral palsy. Conclusion Fetal exposure to Magnesium Sulfate in women at risk of preterm delivery significantly reduces the risk of cerebral palsy without increasing the risk of death.%目的:系统分析产前使用硫酸镁对胎儿神经的保护作用。方法检索 PubMed、Cochrane 图书馆、EMBASE、中国期刊全文数据库、中国生物医学文献数据库、中文科技期刊全文数据库收录的公开发表与研究目的相关的随机对照研究文献,对满足条件的

  1. Effects of Magnesium and Ferric Ions on Crystallization of Calcium Sulfate Dihydrate Under the Simulated Conditions of Wet Flue-gas Desulfurization

    Institute of Scientific and Technical Information of China (English)

    GAO Xiang; HUO Wang; ZHONG Yi; LUO Zhong-yang; CEN Ke-fa; NI Ming-jiang; CHEN Le-ming

    2008-01-01

    The influences of magnesium and ferric ions in their different ratios on the rate of gypsum crystallization were studied under the conditions similar to those of wet flue-gas desulfurization(WFGD).The results show thataddition of both Mg2+ and Fe3+ increased induction time and decreased the growth efficiency up to 50% compared with the baseline(without impurities) depending on the concentration and the type of impurity.The effects of Mg2+ and Fe3+ on the surface energy and the rate of nucleation were estimated by employing the classical nucleation theory.The surface energy decreased by 8% and 14% with the addition of 0.02 mol/L magnesium or ferric ions,respectively,compared to the baseline.Mg2+ and Fe3+ made the growth rate of the (020),(021) and (040) faces of gypsum crystal a much greater reduction,which leads to the formation of needle crystals compared to the baseline which favors the formation of plate or flakes.Furthermore,an edge detection program was developed to quantify the effects of impurities on the filtration rate of gypsum product.The results show that the inhibition efficiency of the presence of 0.02 mol/L Mg2+ and Fe3+ on the filtration rate of gypsum crystal ranges from 22% to 39%.

  2. Influence of sulfate ion concentration and pH on the corrosion of Mg-Al-Zn-Mn (GA9 magnesium alloy

    Directory of Open Access Journals (Sweden)

    Sudarshana Shetty

    2015-09-01

    Full Text Available The corrosion behavior of Mg-Al-Zn-Mn (GA9 alloy in sodium sulfate solutions was studied over a range of concentrations and solution temperatures at different pH conditions by electrochemical techniques like Tafel extrapolation and electrochemical impedance spectroscopy (EIS. The studies were carried out in solutions with sodium sulfate concentrations 0.1M, 0.5M, 1M, 1.5M and 2M; and at five different temperatures of 30, 35, 40, 45 and 50 °C in a pH range of 3–12. As per the experimental data, the corrosion rate of the alloy increased with the increase in temperature, and also with the increase in concentration of sodium sulfate in the medium. It was observed that the rate of corrosion decreased with the increase in pH. The activation parameters like activation energy, enthalpy of activation and entropy of activation for the corrosion process were calculated. The surface morphology of the alloy was examined before and after corrosion using scanning electron microscopy (SEM.

  3. Luminescence investigation of Dy2O2S and Dy2O2SO4 obtained by thermal decomposition of sulfate hydrate

    Institute of Scientific and Technical Information of China (English)

    RV Rodrigues; L Marciniak; LU Khan; JR Matos; HF Brito; W Strk

    2016-01-01

    The yellow emitting dysprosium oxysulfide (Dy2O2S) and dysprosium oxysulfate (Dy2O2SO4) compounds were prepared from the thermal decomposition of hydrated dysprosium sulphate. The materials were characterized by using thermogravimetry (TG/DTG), X-ray powder diffraction (XRD), Fourier transform infrared (FTIR) and Raman spectroscopies. The thermal stability temperatures at around 1151 and 1313 K were determined for the Dy2O2S and Dy2O2SO4 materials, respectively. The photolumines-cence properties of the dysprosium oxysulfide were investigated, showing narrow emission bands assigned to the 4F9/2→6HJ intracon-figurational transitions of the Dy3+ion. The yellow emission color of this phosphor suggests that the Dy2O2S is a promising material for applications in LEDs.

  4. Magnesium Test

    Science.gov (United States)

    ... be limited. Home Visit Global Sites Search Help? Magnesium Share this page: Was this page helpful? Also known as: Mg; Mag Formal name: Magnesium Related tests: Calcium , Potassium , Phosphorus , PTH , Vitamin D ...

  5. Magnesium Hydroxide

    Science.gov (United States)

    Magnesium hydroxide is used on a short-term basis to treat constipation.This medication is sometimes prescribed ... Magnesium hydroxide come as a tablet and liquid to take by mouth. It usually is taken as ...

  6. Research of Magnesium Extracted from Asbestos Tailings by Ammonium Sulfate Calcination Method%硫酸铵焙烧活化石棉尾矿提取镁实验研究

    Institute of Scientific and Technical Information of China (English)

    曾丽; 孙红娟; 彭同江

    2012-01-01

    本实验采用硫酸铵与石棉尾矿用高温炉焙烧的方法提取镁.首先利用差热-热重法分析石棉尾矿与硫酸铵混合物的热分解和化学反应的热效应,得出石棉尾矿与硫酸铵混合物在240~ 500℃下产生分解、失重.将石棉尾矿与硫酸铵混合均匀后在320℃、400℃和460℃下焙烧1h,用XRD分析焙烧产物,得出在320℃时石棉尾矿和硫酸铵反应主要生成(NH4)2Mg(SO4)2和(NH4)2Mg2(SO4)3;在400℃时主要生成(NH4)2Mg2(SO4)3;在460℃时主要生成MgSO4,由于吸水变为MgSO4·6H2O.研究了硫酸铵与石棉尾矿不同物质的量的配比、焙烧温度和焙烧时间对镁浸取率的影响,得出当硫酸铵与石棉尾矿物质的量之比为2∶1、焙烧温度为460℃、焙烧时间为60 min时,镁的浸取率为83.1%.%In this paper, magnesium was extracted from asbestos tailings by ammonium sulfate calcination method. First the thermal behavior and the chemical calorific effect of the blend of asbestos tailings and ammonium sulfate were characterized by TG-DTA, it showed that asbestos tailings and ammonium sulfate were decompounded at 240~500 ℃. Then the asbestos tailings were uniform mixed with ammonium sulfate and calcined at 320 ℃, 400 ℃, and 460 ℃ for 1 h respectively and the calcinated products were studied by XRD. The results indicated that asbestos tailings and ammonium sulfate react each other to generate (NH4)2Mg(SO4)2 and (NH4)2Mg2(SO4)3 at 320 °C; the main product was (NH4)2Mg2(SO4)3 at 400 ℃ and MgSO4 at 460℃ respectively. Then the influence of the molar ratio of ammonium sulfate and asbestos tailings, the calcination temperature, the calcination time were studied. The results indicated that when the molar ratio of ammonium sulfate and asbestos tailings is 2 : 1, the calcination temperature is 460 ℃, the calcination time is 60 min, the leaching rate of Mg is 83.1%.

  7. REFINEMENT OF THE CRYSTAL STRUCTURE OF GUANIDINIUM ALUMINUM SULFATE HEXAHYDRATE.

    Science.gov (United States)

    FERROELECTRIC CRYSTALS, * CRYSTAL STRUCTURE ), (*GUANIDINES, CRYSTAL STRUCTURE ), (*ALUMINUM COMPOUNDS, CRYSTAL STRUCTURE ), SULFATES, HYDRATES, X RAY DIFFRACTION, CHROMIUM COMPOUNDS, CRYSTAL LATTICES, CHEMICAL BONDS

  8. 硫酸镁对全麻术后疼痛和并发症影响的Meta分析%Effects of Magnesium Sulfate on Postoperative Pain and Complications after General Anesthesia: A Meta-Analysis

    Institute of Scientific and Technical Information of China (English)

    尹秀茹; 裴凌

    2012-01-01

    Objective To systematically evaluate the effects of magnesium sulfate on postoperative pain and complications after general anesthesia. Methods A literature search was conducted in following databases as The Cochrane Library, Embase, PubMed, EBSCO, Springer, Ovid, CNKI and CBM from the date of establishment to September 2011 to identify randomized controlled trials (RCTs) about intravenous infusion of magnesium sulfate during general anesthesia. All included RCTs were assessed and the data were extracted according to the standard of Cochrane systematic review. The homogenous studies were pooled using RevMan 5.1 software. Results A total of 11 RCTs involving 905 patients were included. The results of meta-analyses showed that compared with the control group, intravenous infusion of magnesium sulfate during general anesthesia significantly reduced the visual analog scale (VAS) scores at the time-points of 2, 4, 6, 8,16, and 24 hours, respectively, after surgery, the postoperative 24 hours morphine requirements, and the incidents of postoperative nausea and vomiting (RR=0.61, 95%CI 0.40 to 0.91, P=0.02) and chilling (RR=0.29, 95%CI 0.14 to 0.59, P=0.000 7). Although the incidents of bradycardia (RR=1.93, 95%CI 1.05 to 3.53, P=0.03) increased, there were no adverse events or significant differences in the incidents of hypotension and serum concentration changes of magnesium. Conclusion Intravenous infusion of magnesium sulfate during general anesthesia may obviously decrease the pain intensity, and the incidents of nausea and vomiting and chilling after surgery, without increasing cardiovascular adverse events and risk of hypermagnesemia. The results still need to be confirmed by more high-quality and large-sample RCTs.%目的 系统评价硫酸镁对全麻术后疼痛和并发症的影响.方法 计算机检索Cochrane图书馆、EMbase、PubMed、EBSCO、Springer、Ovid、CNKI、CBM等数据库,收集从建库至2011年9月间关于全身麻醉中静脉应用硫酸

  9. The Effectiveness of Magnesium Sulfate in Treatment of Intractable Epilepsy:A report of 72 Cases%硫酸镁辅助治疗顽固性癫癎72例

    Institute of Scientific and Technical Information of China (English)

    李德香; 闫士广; 李学松; 李仁祧; 李茂绪; 车峰远

    2001-01-01

    目的:探讨硫酸镁辅助治疗顽固性癫癎的剂量、方法及疗效。方法:治疗组72例,用25%硫酸镁10 mL静脉滴注,或用16.5%硫酸镁10 mL口服。对照组36例给予常规抗癫癎药物,卡马西平或苯妥英钠加苯巴比妥或氯硝西泮加用γ-氨基丁酸等治疗。结果:治疗组有效率87.5%,对照组有效率44.4%,两组比较经统计学分析P<0.01,差异极显著。结论:硫酸镁联合一线抗癫癎药治疗顽固性癫癎的方法简单易行,具有良好效果。%Objective:To determine the dosage,method and effectiveness of using magnesium sulfate for treating the intractable epilepsy.Methods:72 cases were allocated to treatment group and 36 to control group. For those in the treatment group,either 10 mL of 25% MgSO4 was administered by intravenous drip or 10 mL of 16.5% MgSO4 by oral intake once per day,in addition to the use of the commonly used antiepilepsy drugs. For those in the control group,the commonly used antiepilepsy drugs such as tegretol,sodium phenytoin,luminal or γ-Aminobutyric Acid were employed.Results:The improvement rate in the treatment group was 87.50%,higher than that (44.44%) in the control group (P<0.01).Conclusion:Using magnesium sulfate in conjunction with the antiepilepsy drugs is a simple yet effective regime for the treatment of the intractable epilepsy.

  10. 离子色谱法测定奥美拉唑镁原料药中硫酸盐的含量%Determination of sulfate omeprazole magnesium in raw medicine by Ion Chromatography

    Institute of Scientific and Technical Information of China (English)

    赵昌军; 高新贞

    2016-01-01

    Objective: to determine the content of sulfate omeprazole magnesium in raw medicine established by ion chromatography. Methods:thermo IonPac AS19 (50mm×4mm)anion exchange column and IonPac AG19 (50mm×4mm)anion protective column, eluent:3.6mmol/L sodium carbonate and 6 mmol / L sodium bicarbonate solution and velocity: 1.0mL/min, the column temperature: 30℃, the conductance pool temperature: 35℃, anion suppressor current 40mA, sample volume: 25μL. Results: The linear range of Sulfate was 0.1~40.0μg/mL (r=0.9996), the recovery rate was 100.3%. Conclusion: the method is accurate and reliable, and can be used for determination of omeprazole magnesium sulphate impurity in raw medicine.%目的:建立离子色谱法测定奥美拉唑镁原料药中硫酸盐的含量。方法:用Thermo IonPac AS19(250mm×4mm)阴离子交换柱和IonPac AG19(50mm×4mm)阴离子保护柱,淋洗液:3.6mmol/L碳酸钠和6mmol/L碳酸氢钠溶液,流速:1.0mL/min,柱温:30℃,电导池温度:35℃,阴离子抑制器电流40mA,进样量:25μL。结果:硫酸根酸根离子在0.1~40.0μg/mL范围内线性关系良好(r为0.9996),回收率为100.3%。结论:该方法准确可靠,可用于奥美拉唑镁原料药中硫酸盐杂质的测定。

  11. INFLUENCE OF CHEMICAL ADDITIVES ON GAS HYDRATE FORMATION

    Institute of Scientific and Technical Information of China (English)

    TANG Cuiping; FAN Shuanshi

    2003-01-01

    One surfactant as sodium dodecyl sulfate (SDS) and one synthesized sample as gas hydrate inhibitor are introduced in this paper. Through experiments we prove sodium dodecyl sulfate can accelerate the formation rate of gas hydrate and the synthesized sample can inhibit the formation and growth.

  12. Experimental Study of Natural Gas Storage in Hydrates

    Institute of Scientific and Technical Information of China (English)

    孙志高; 王如竹; 郭开华; 樊栓狮

    2004-01-01

    Hydrate formation rate plays an important role in the making of hydrates for natural gas storage. The effect of sodium dodecyl sulfate (SDS), alkyl polysaccharide glycoside (APG) and cyclopentane (CP) on natural gas hydrate formation rate, induction time and storage capacity was studied. Micellar surfactant solutions were found to increase hydrate formation rate in a quiescent system and improve hydrate formation rate and natural gas storage capacity. The process of hydrate formation includes two stages with surfactant presence. Hydrate forms quickly in the first stage, and then the formation rate is slowed down. Surfactants (SDS or APG) reduce the induction time of hydrate formation. The effect of an anionic surfactant (SDS) on gas storage in hydrates is more pronounced compared to a nonionic surfactant (APG). CP also reduces the induction time of hydrate formation, but can not improve the natural gas storage capacity in hydrates.

  13. Combined liquid helium neon laser with magnesium sulfate and lidocaineNursing experience of treating phlebitis%硫酸镁与利多卡因混合液联合氦氖激光治疗静脉炎的护理体会

    Institute of Scientific and Technical Information of China (English)

    叶秀珍

    2015-01-01

    目的:观察硫酸镁与利多卡因混合液联合多功能氦氖激光治疗静脉炎的效果。方法将67例静脉炎患者随机分为实验组和对照组两组。实验组使用硫酸镁与利多卡因混合液联合氦氖激光治疗;对照组使用硫酸镁与利多卡因混合液外敷。结果实验组治疗静脉炎的效果明显高于对照组﹙P<0.05﹚。结论使用硫酸镁与利多卡因混合液联合氦氖激光治疗静脉炎的效果好,值得临床推广。%ObjectiveTo observe the Magnesium sulfate and lidocaine combined multifunctional He-Ne laser treatment of phlebitis.Method67 patients with phlebitis were randomLy divided into experimental group and control group two groups.The experimental group used Magnesium sulfate and lidocaine combined with helium neon laser treatment;The control group used Magnesium sulfate and lidocaine ointment.ResultExperimental treatment of phlebitis is obviously higher than that of the control group (P<0.05).Conclusion The use of Magnesium sulfate and lidocaine combined with helium neon laser for the treatment of phlebitis, It is worthy of clinical promotion.

  14. Observation Curative Effect on Magnesium Sulfate and Benzene Three Phenol in the treatment of Acute Gastroenteritis Spastic Abdominal Pain%硫酸镁联合间苯三酚治疗急性胃肠炎痉挛性腹痛疗效观察

    Institute of Scientific and Technical Information of China (English)

    周丽华

    2016-01-01

    目的:观察硫酸镁联合间苯三酚治疗急性胃肠炎痉挛性腹痛的效果。方法随机将70例急性胃肠炎痉挛性腹痛患者平均分为两组,对照组行间苯三酚治疗,观察组在对照组的基础上行硫酸镁治疗,比较两组临床疗效。结果观察组治疗总有效率、VAS 评分等均优于对照组(P<0.05)。结论硫酸镁联合间苯三酚治疗急性胃肠炎痉挛性腹痛效果理想。%Objective To analyze the benzene three phenol and magnesium sulfate in the treatment of acute gastroenteritis spastic abdominal pain. Methods Random 70 cases of acute gastroenteritis spasm of abdominal pain in patients divided into two groups, control group interline phloroglucinol treatment, observe group in the control group based uplink magnesium sulfate treatment, compared two groups of clinical curative effect. Results The total effective rate and VAS score of the observation group were better than those of the control group (P<0.05). Conclusion Magnesium sulfate combined with benzene three phenol treatment of acute gastroenteritis spastic abdominal pain effect.

  15. Methane Flux and Authigenic Carbonate in Shallow Sediments Overlying Methane Hydrate Bearing Strata in Alaminos Canyon, Gulf of Mexico

    Directory of Open Access Journals (Sweden)

    Joseph P. Smith

    2014-09-01

    Full Text Available In June 2007 sediment cores were collected in Alaminos Canyon, Gulf of Mexico across a series of seismic data profiles indicating rapid transitions between the presence of methane hydrates and vertical gas flux. Vertical profiles of dissolved sulfate, chloride, calcium, magnesium, and dissolved inorganic carbon (DIC concentrations in porewaters, headspace methane, and solid phase carbonate concentrations were measured at each core location to investigate the cycling of methane-derived carbon in shallow sediments overlying the hydrate bearing strata. When integrated with stable carbon isotope ratios of DIC, geochemical results suggest a significant fraction of the methane flux at this site is cycled into the inorganic carbon pool. The incorporation of methane-derived carbon into dissolved and solid inorganic carbon phases represents a significant sink in local carbon cycling and plays a role in regulating the flux of methane to the overlying water column at Alaminos Canyon. Targeted, high-resolution geochemical characterization of the biogeochemical cycling of methane-derived carbon in shallow sediments overlying hydrate bearing strata like those in Alaminos Canyon is critical to quantifying methane flux and estimating methane hydrate distributions in gas hydrate bearing marine sediments.

  16. Recorrência da Crise Convulsiva após Terapia Anticonvulsivante com Sulfato de Magnésio em Pacientes com Eclâmpsia Recurrence of Seizures after Anticonvulsant Therapy with Magnesium Sulfate in Patients with Eclampsia

    Directory of Open Access Journals (Sweden)

    Melania Maria Ramos de Amorim

    2000-04-01

    Full Text Available Objetivos: determinar a freqüência de recorrência das crises convulsivas após tratamento com sulfato de magnésio, avaliando o tratamento adotado e o prognóstico materno. Casuística e Métodos: analisaram-se todos os casos de eclâmpsia atendidos no IMIP entre janeiro de 1995 e junho de 1998. Sulfato de magnésio e oxigenoterapia foram administrados para todas as pacientes, interrompendo-se a gravidez após estabilização do quadro clínico. Determinou-se a freqüência de complicações maternas de acordo com a presença ou não de recorrência da crise convulsiva, utilizando-se o teste chi² de associação, a um nível de significância de 5%. Resultados: doze pacientes apresentaram recorrência da eclâmpsia após sulfato de magnésio (10%, repetindo-se então metade da dose de ataque. Em 4 destas verificou-se nova recorrência, administrando-se então diazepam endovenoso. Depois do diazepam, uma paciente ainda teve crises repetidas, sendo então realizada infusão de fenitoína e, posteriormente, indução do coma barbitúrico (tionembutal. Essa paciente foi submetida a tomografia computadorizada, constatando-se hemorragia intracraniana. As complicações maternas foram significativamente mais freqüentes no grupo com recorrência: coma (16,7% versus 0,9%, acidose (50% versus 2,9%, edema agudo de pulmão (16,7% versus 2,9%, hemorragia cerebral (16,7% versus 0% e insuficiência renal aguda (16,7% versus 1,9%. Ocorreram 3 casos de morte materna no grupo com recorrência (25% e 2 no grupo sem recorrência (1,9%. Conclusões: a recorrência da crise convulsiva é pouco freqüente após uso do sulfato de magnésio (10%, porém associa-se a aumento da morbimortalidade materna, requerendo acompanhamento em UTI e realização de tomografia para exclusão de hemorragia cerebral.Purpose: to determine the frequency of recurrence of seizures after anticonvulsant therapy with magnesium sulfate and to evaluate treatment and maternal prognosis

  17. 20%的硫酸镁在成人重症破伤风中的治疗作用%The 20 % magnesium sulfate for the treatment of the adult severe tetanus

    Institute of Scientific and Technical Information of China (English)

    魏刚; 章希; 张必翔; 刘文; 陈孝平; 张应天

    2012-01-01

    目的 探讨20%的硫酸镁治疗成人重症破伤风的安全性及有效性.方法 对2005年4月- 2010年10月收治的27例成人重症破伤风住院病例行回顾性分析.结果 血镁超过4 mmol/L者2例(2/27,7.4%);气管切开者25例(25/27,92.6%),机械通气22例(22/25,88.0%),机械通气时间为4~16d,平均(7.5±3.7)d;肺部感染25例(25/27,92.6%);死亡4例(4/27,14.8%);治愈23例(23/27,85.2%),住院时间25~48 d,平均(32.2±18.8)d.结论 20%的硫酸镁治疗成人重症破伤风安全,可有效控制肌肉强直、抽搐和自律性不稳定,以减少安定和氯丙嗪等镇静药的用量,操作简单,价格便宜,易于在临床推广.%Objective To study the efficacy and safety magnesium sulfate for the treatment of adult severe tetanus.Methods Twenty-seven inpatients with adult severe tetanus during April 2005 - October 2010 were retrospectively analysed.Results The total serum magnesium more than 4 mmol/L was found in 2 patients ( 2/27,7.40% ).The tracheotomy was performed in 25 Patients (25/27,92.6%),22 of which (22/25,88.0%) run mechanical ventilation with the mean mechanical ventilation time (7.5 ± 3.7 ) days,(4 to 16 days).Pulmonary infection occurred in 25 cases (25/27,92.6%).Twenty-three of 27 (23/27,85.2% ) cases were cured except 4 cases died,and the mean hospital stay was (32.22 ± 18.78) days,(25to 48) days.Conclusions 20% magnesium sulfate is safe for treatment of the patients of adult severe tetanus.It can control not only muscle rigidity and spasms but also autonomic instability efficaciously,and lower the dosage of sedative such as diazepam and chlorpromazine.This method is worth popularizing in clinical practice for its easy operation and low cost.

  18. The Clinical Efficacy of Nifedipine Combined with Phentolamine and Magnesium Sulfate Treatment on Gestational Hypertension%硝苯地平联合酚妥拉明及硫酸镁治疗妊娠高血压疾病的临床疗效

    Institute of Scientific and Technical Information of China (English)

    石国素; 路运华

    2016-01-01

    目的 探究硝苯地平联合酚妥拉明及硫酸镁的临床疗效. 方法 选取2010 年8 月至2015年1月在邢台市第三医院治疗的妊娠高血压疾病的孕妇共140例,根据随机数字表法分为联合治疗组、硫酸镁+酚妥拉明组、硫酸镁+硝苯地平组、酚妥拉明+硝苯地平组,各35 例. 联合治疗组采用硝苯地平+酚妥拉明+硫酸镁治疗,口服硝苯地平,每次10 mg,每日3 次,静脉滴注酚妥拉明5 mg和硫酸镁4 g,以1周为1个疗程. 硫酸镁+酚妥拉明组、硫酸镁+硝苯地平组、酚妥拉明 +硝苯地平组用药方法同联合治疗组. 记录4组患者治疗前后的收缩压与舒张压,观察治疗后的临床疗效. 结果 治疗后,联合治疗组血压低于硫酸镁+酚妥拉明组、硫酸镁+硝苯地平组、酚妥拉明 +硝苯地平组[收缩压( 112 ±8 ) mmHg ( 1 mmHg =0.133 kPa )比( 134 ±8 ) mmHg、( 132 ±10 ) mmHg、(135 ±9) mmHg,舒张压(68 ±5) mmHg 比(87 ±8) mmHg、(83 ±7) mmHg、(77 ±6) mmHg,P <0.05]. 联合治疗组总有效率高于硫酸镁+酚妥拉明组、硫酸镁+硝苯地平组、酚妥拉明 +硝苯地平组[100%(35/35)比77.1%(27/35)、82.8%(29/35)、74.3%(26/35)],差异有统计学意义(P <0.05). 结论 对于患有妊娠高血压疾病的孕妇,应用硝苯地平联合酚妥拉明及硫酸镁治疗能够达到更好的效果,值得更多的探索与应用.%Objective To explore the clinical efficacy on nifedipine joint phentolamine and magnesium sulfate treatment on gestational hypertension .Methods Total of 140 cases of gestational hypertension admit-ted to Xingtai City Third Hospital from Aug .2010 to Jan.2015 were divided according to random number table method into combination therapy group,magnesium sulfate +phentolamine group,magnesium sulfate+nifedipine group,phentolamine +nifedipine group,each group of 35 patients.The combination therapy group was treated with nifedipine joint phentolamine and magnesium sulfate therapy ,oral nifedipine,10 mg

  19. Thermodynamic Properties of Magnesium Chloride Hydroxide Hydrate (Mg3Cl(OH)5:4H2O, Phase 5), and Its importance to Nuclear Waste Isolation in Geological Repositories in Salt Formations

    Science.gov (United States)

    Xiong, Y.; Deng, H.; Nemer, M. B.; Johnsen, S.

    2009-12-01

    MgO (bulk, pure MgO corresponding to the mineral periclase) is the only engineered barrier certified by the Environmental Protection Agency for emplacement in the Waste Isolation Pilot Plant (WIPP) in the US, and an Mg(OH)2-based engineered barrier (bulk, pure Mg(OH)2 corresponding to brucite) is to be employed in the Asse repository in Germany. Both the WIPP and the Asse are located in salt formations. The WIPP is a U.S. Department of Energy geological repository being used for the permanent disposal of defense-related transuranic waste (TRU waste). The repository is 655 m below the surface, and is situated in the Salado Formation, a Permian salt bed mainly composed of halite, and of lesser amounts of polyhalite, anhydrite, gypsum, magnesite, clays and quartz. The WIPP Generic Weep Brine (GWB), a Na-Mg-Cl dominated brine, is associated with the Salado Formation. The previous vendor for MgO for the WIPP was Premier Chemicals and the current vendor is Martin Marietta Materials. Experimental studies of both Premier MgO and Martin Marietta MgO with the GWB at SNL indicate the formation of magnesium chloride hydroxide hydrate, Mg3Cl(OH)5:4H2O, termed as phase 5. However, this important phase is lacking in the existing thermodynamic database. In this study, the solubility constant of phase 5 is determined from a series of solubility experiments in MgCl2-NaCl solutions. The solubility constant at 25 oC for the following reaction, Mg3Cl(OH)5:4H2O + 5H+ = 3Mg2+ + 9H2O(l) + Cl- is recommended as 43.21±0.33 (2σ) based on the Specific Interaction Theory (SIT) model for extrapolation to infinite dilution. The log K obtained via the Pitzer equations is identical to the above value within the quoted uncertainty. The Gibbs free energy and enthalpy of formation for phase 5 at 25 oC are derived as -3384±2 (2σ) kJ mol-1 and -3896±6 (2σ) kJ mol-1, respectively. The standard entropy and heat capacity of phase 5 at 25 oC are estimated as 393±20 J mol-1 K-1 and 374±19 J mol-1 K

  20. Effect of Paraffin/Expanded Graphite Composite Phase Change Materials on the Hydration Performances of Magnesium Phosphate Cement%石蜡/膨胀石墨复合相变材料对磷酸镁水泥水化性能的影响

    Institute of Scientific and Technical Information of China (English)

    李云涛; 晏华; 汪宏涛; 王群; 赵思勰

    2016-01-01

    The thermal effect of paraffin/expanded graphite composite phase change materials ( CPCM ) was proposed to control the hydration heat of magnesium phosphate cement ( MPC) .By testing the setting time, fluidity, hydration temperature, compressive strength and thermal conductivity of CPCM , the effect of CPCM on the hydration properties of MPC was explored .The results showed that the hydration heat of MPC was controlled by the phase change .The hydration system temperature was reduced , and the hydration reaction rate was slowed down and the goal of reducing the hydration heat was accomplished .At the same time , the degree of crystallinity of MgKPO 4 · 6 H2 O was decreased lightly , and it made the compressive strength of MPC change small .CPCM did not participate in the hydration reaction of MPC , but combined by the physical effect with MPC , maintained their excellent performance , and ensured the stability and performance of the MPC system .%提出了利用石蜡/膨胀石墨复合相变材料( CPCM)的热效应调控磷酸镁水泥( MPC)水化热的方法,通过测试加入CPCM的凝结时间、流动性、水化温度、抗压强度和导热系数等性能的变化,研究了CPCM对MPC水化性能的影响。结果表明,可以通过CPCM相变吸放热来调控MPC的水化热,使其水化体系温度降低,水化反应速度减慢,达到降低水化热的目的;但是会使MPC的抗压强度下降,加入钢纤维会大幅度提高其抗压强度;机理分析表明CPCM不参与MPC的水化反应,而是与MPC物理结合,保持了各自的优良性能,保证了MPC体系的结构稳定和性能优良。

  1. Drug: D01108 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available D01108 Drug Magnesium sulfate hydrate (JP16); Magnesium sulfate (USP); Magnesium sulfate heptahydr...1AX05 V04CC02 Therapeutic category of drugs in Japan [BR:br08301] 1 Agents affect...Magnesium salts D01108 Magnesium sulfate hydrate (JP16); Magnesium sulfate (USP) 2 Agents affecting individu... D01108 Magnesium sulfate hydrate (JP16); Magnesium sulfate (USP) Anatomical Therapeutic Chemical (ATC) clas...TION A06AD Osmotically acting laxatives A06AD04 Magnesium sulfate D01108 Magnesium sulfate hydr

  2. Effect of Hydroxyapatite and Shell on Cement Hydration and Sulfate Resistance%羟基磷灰石和贝壳对水泥水化和抗侵蚀性能的影响

    Institute of Scientific and Technical Information of China (English)

    王桂芸; 芦令超; 王守德; 赵丕琪

    2011-01-01

    Coastal cement concrete engineering has been eroded for a long time, and cant achieve their expected service lives. One solution was to just cultivate the ocean living beings on the surface of cement concrete engineering to resist the corrosion. The influences of hydroxyapatite, shell powder and calcium carbonate on the durability of 42.5R ordinary Portland cement and sulphoaluminate cement were investigated. The sulfate corrosion resistance coefficients of the cement would increase to some extent when appropriate content of hydroxyapatite, shell powder and calcium carbonate were added. When the content of calcium carbonate in the sulphoaluminate cement was 10%, the corrosion resistance coefficient was 1.16; and when the content of calcium carbonate in the ordinary Portland cement was 15%, the corrosion resistance coefficient reached 1.34, the performance of resistance to sulfate attack was best.When the hydroxyapatite was added into the ordinary Portland cement and the sulphoaluminate cement,the hydration heat was lower than that of the cement containing shell powder and calcium carbonate.When the hydroxyapatite, shell powder and calcium carbonate were added into the ordinary Portland cement, each hydration heat was lower than that of the ordinary Portland cement; this was helpful for the durability of the cement concrete engineering.%沿海水泥混凝土工程长期受到腐蚀,很难达到预期服役寿命.本文分析其中的原因,希望采用水泥混凝土表面生长海洋生物的方法来抵抗腐蚀.研究羟基磷灰石、贝壳和碳酸钙对硅酸盐42.5R水泥和硫铝酸盐水泥抗硫酸盐侵蚀性能的影响.结果表明:硅酸盐水泥和硫铝酸盐水泥中掺人适萤的羟基磷灰石、贝壳和碳酸钙时,其抗侵蚀系数有一定程度增加.当硫铝酸盐水泥中碳酸钙掺量为10%时,其抗侵蚀系数为1.16,硅酸盐水泥中碳酸钙掺量为15%时,其抗侵蚀系数达到1.34,抗硫酸盐侵蚀能力最强.硅酸盐

  3. MORPHOFUNCTIONAL CHARACTERISTICS OF FIBROBLASTS (MCCOY CELL LINE CULTURED WITH MAGNESIUM PREPARATIONS

    Directory of Open Access Journals (Sweden)

    L. V. Didenko

    2015-01-01

    Full Text Available Aim. To study the effect of magnesium orotate, magnesium/pyridoxine combination and magnesium sulfate on fibroblast morphofunctional characteristics in cell culture of fibroblasts (McCoy line.Material and methods. The study of fibroblasts (McCoy line with the addition of magnesium-containing preparations (magnesium orotate, magnesium/pyridoxine combination, magnesium sulphate to the culture medium was performed using scanning and transmission electron microscopy.Results. When adding into the media magnesium orotate or magnesium/pyridoxine combination, significant changes in morphofunctional state of fibroblasts were noted, which were absent when adding magnesium sulfate. At that fibroblasts significantly promoted synthetic and secretory activity. This was expressed in the formation of amorphous and fibrous components in well-formed cell layers.Conclusion. Stimulation by magnesium ions of the proliferative activity of fibroblasts is shown in the morphological analysis of the effect of magnesium orotate or magnesium in combination with pyridoxine and magnesium sulfate on morphological and functional organization of fibroblasts. Revealed the predominant influence of magnesium orotate, and a less pronounced effect of magnesium in combination with pyridoxine on biosynthetic processes in the cells, including the synthesis of amorphous and fibrous components (protocollagen and elastin of the extracellular matrix founded.

  4. 高性能混杂纤维增强膨胀混凝土在硫酸镁溶液中的抗腐蚀性能%Resistance of High Performance Hybrid Fibers Reinforced Expansive Concrete Exposed to Magnesium Sulfate Solution

    Institute of Scientific and Technical Information of China (English)

    杨礼明; 余红发; 麻海燕; 白康; 曹文涛

    2011-01-01

    采用自然浸泡和于湿循环的方法,研究了粉煤灰混凝土(FAC)、高性能混凝土(HPc)和高性能混杂纤维增强膨胀混凝土(mPHFREC)在5%硫酸镁溶液中的相对动弹性模量变化和质量损失规律.实验结果表明:硫酸镁环境对混凝土具有严重腐蚀性;干湿循环加速混凝土的表面剥落,对混凝土的抗硫酸镁腐蚀性能有劣化作用.在5%硫酸镁中自然浸泡,HPHFREC2具有优良的抗腐蚀性能,三元纤维混杂起到良好的增韧阻裂作用;在干湿循环+硫酸镁双重破坏因素作用下,HPC有较好的抗腐蚀性能,而HPHFREC的纤维增强效果不佳,表面剥落严重,抗腐蚀性能不理想.%In this paper, the relative dynamic modulus of elasticity (RDME) and mass loss of fly ash concrete (FAC), high performance concrete ( HPC), and high performance hybrid fibers reinforced expansive concrete (HPHFREC) exposed to 5% magnesium sulfate solution was investigated. Two corrosion regimes were conducted in natural immersion and dry-wet cycles. The results show that the erosion of concrete in magnesium sulfate environment is severe and the dry-wet cycles accelerates the surface peeling of concrete and has the negative effect to the resistance of concrete to magnesium sulfate attack. HPHFREC2 shows the outstanding resistance of concrete in the natural immersion of 5% magnesium solution and gets an obvious reinforced effect of three type hybrid fiber. Subjected to the combined action of dry-wet cycles and magnesium sulfate, HPC has the best resistance, oppositely, the resistance of HPHFREC is unexpected of which the surface peeling is severe and the reinforced effect of the fiber is not available.

  5. Performance analysis of magnesium phosphate cement mortar containing grinding dust

    OpenAIRE

    2009-01-01

    Magnesium phosphate cement materials are formed by reacting magnesium oxide with water-soluble phosphates such as monoammonium dihydrogen phosphate (ADP), which solidifies at ambient temperature through the formation of hydrated phases in the material. Cylindrical specimens of magnesium phosphate cement were molded and varying amounts (0 to 30% weight) of grinding dust were added to the ceramic matrices. The influence of the addition of grinding dust on the characteristics of the mortars in t...

  6. Usos do sulfato de magnésio em obstetrícia e em anestesia Usos del sulfato de magnesio en obstetricia y en anestesia Applications of Magnesium Sulfate in Obstetrics and Anesthesia

    Directory of Open Access Journals (Sweden)

    Fabiano Timbó Barbosa

    2010-02-01

    : Magnesium sulfate has been used in obstetrics with good results, inhibiting premature labor a

  7. Maternal magnesium sulfate fetal neuroprotective effects to the fetus: inhibition of neuronal nitric oxide synthase and nuclear factor kappa-light-chain-enhancer of activated B cells activation in a rodent model.

    Science.gov (United States)

    Beloosesky, Ron; Khatib, Nizar; Ginsberg, Yuval; Anabosy, Saja; Shalom-Paz, Einat; Dahis, Masha; Ross, Michael G; Weiner, Zeev

    2016-09-01

    Maternal magnesium administration has been shown to protect the preterm fetus from white- and gray-matter injury, although the mechanism is unknown. The purpose of the study is to test the following hypotheses: (1) maternal infections/inflammation activate fetal neuronal N-methyl-D-aspartate receptors that up-regulate neuronal nitric oxide synthase and nuclear factor kappa-light-chain-enhancer of activated B cells pathways; and (2) maternal magnesium sulfate attenuates fetal brain neuronal nitric oxide synthase and nuclear factor kappa-light-chain-enhancer of activated B cells activation through N-methyl-D-aspartate receptors. Pregnant rats at embryonic day 16 and embryonic day 18 (n = 6, 48 total) received injections of intraperitoneal lipopolysaccharide 500 μg/kg or saline at time 0. Dams were randomized for treatment with subcutaneous magnesium sulfate (270 mg/kg) or saline for 2 hours prior to and following lipopolysaccharide/saline injections. At 4 hours after lipopolysaccharide administration, fetal brains were collected from the 4 treatment groups (lipopolysaccharide/saline, lipopolysaccharide/magnesium sulfate, saline/magnesium sulfate, saline/saline), and phosphoneuronal nitric oxide synthase, nuclear factor kappa-light-chain-enhancer of activated B cells p65, and chemokine (C-C motif) ligand 2 protein levels were determined by Western blot. An additional group of pregnant rats (n = 5) received N-methyl-D-aspartate-receptor antagonist following the lipopolysaccharide injection to study magnesium sulfate protective mechanism. Lipopolysaccharide (lipopolysaccharide/saline) significantly increased fetal brain phosphoneuronal nitric oxide synthase, nuclear factor kappa-light-chain-enhancer of activated B cells p65, and chemokine (C-C motif) ligand 2 protein levels compared to the saline/saline group at both embryonic day 16 (phosphoneuronal nitric oxide synthase 0.23 ± 0.01 vs 0.11 ± 0.01 U; nuclear factor kappa-light-chain-enhancer of activated B cells

  8. Uso do sulfato de magnésio por via venosa e nebulização para o tratamento da asma aguda na emergência Use of the intravenous and nebulized magnesium sulfate for the treatment of the acute asthma in the emergence

    Directory of Open Access Journals (Sweden)

    Fabiano Timbó Barbosa

    2007-09-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: Tem sido mostrado que o sulfato de magnésio apresenta benefícios em adultos e crianças asmáticos, com fraca resposta aos agentes beta-agonistas e corticóides sistêmicos no departamento de emergência. O objetivo deste estudo foi realizar uma revisão não sistemática acerca do tratamento da asma aguda com sulfato de magnésio por via venosa e nebulização na emergência. CONTEÚDO: As primeiras investigações que demonstraram benefício no uso do sulfato de magnésio na asma são de 1938. Os efeitos do sulfato de magnésio podem ser mediados através da ação antagonista do cálcio ou através da função de co-fator em sistemas enzimáticos envolvendo o fluxo iônico através da membrana celular. Foi realizada uma revisão de literatura através da base de dados MedLine nos últimos seis anos (2000 a 2006 e incluídos os artigos publicados na língua inglesa, através do cruzamento dos unitermos asma e sulfato de magnésio. CONCLUSÕES: A administração de rotina do sulfato de magnésio por via venosa e nebulização em pacientes com asma aguda grave que se apresentam no serviço de emergência não é recomendado; entretanto, como um tratamento adjuvante obtém-se algum benefício.BACKGROUND AND OBJECTIVES: Magnesium sulfate has been shown to benefit asthmatic children and adults with poor responses to initial beta-agonist therapy and systemic corticoids in the emergency department. The aim of this study was to realize a no systematic review about the treatment of the acute asthma with intravenous and nebulized magnesium sulfate in the emergence. CONTENTS: The first investigations that demonstrate the benefit in the use of the magnesium sulfate in asthma date to 1938. The effects of magnesium sulfate may be mediated through its action as a calcium antagonist or through its function as a cofactor in enzyme systems involving ion flux across cell membranes. We realized a literature review using Med

  9. 喜辽妥软膏和硫酸镁治疗化疗所致静脉炎的临床疗效比较%Comparative study of treatment efficacy between hirudoid cream and magnesium sulfate for chemotherapy induced phlebitis

    Institute of Scientific and Technical Information of China (English)

    贺红; 李聪聪

    2015-01-01

    目的:观察喜辽妥与50%硫酸镁治疗化疗性静脉炎的疗效。方法:将60例静脉炎患者随机分为A、B两组。A组局部涂以喜辽妥软膏,B组给予50%硫酸镁湿敷,比较两组总有效率。结果:A组总有效率为96.7%,B组总有效率为80.0%,两组比较差异有统计学意义(P<0.05)。结论:喜辽妥软膏治疗化疗性静脉炎的疗效明显优于50%硫酸镁。%Objective:To investigate the difference of treatment efficacy between hiru induced phlebitis.Method:60 patient with phlebitis were randomly divided into A and B groups.The A group were treated with hirudoid cream,;the B group were treated with 50% magnesium sulfate.The treatment total effective rate were compared. Results:The total effective rate of A group was 96.7%; the total effective rate of B group was 80.0%, and the difference was significant in the total doid cream and magnesium sulfate for chemotherapy effective rate (P<0.05). Conclusion:The curative effect of hirudoid cream for chemotherapy induced phlebitis is better than 50%magnesium sulfate.

  10. Production of magnesium metal

    Science.gov (United States)

    Blencoe, James G [Harriman, TN; Anovitz, Lawrence M [Knoxville, TN; Palmer, Donald A [Oliver Springs, TN; Beard, James S [Martinsville, VA

    2010-02-23

    A process of producing magnesium metal includes providing magnesium carbonate, and reacting the magnesium carbonate to produce a magnesium-containing compound and carbon dioxide. The magnesium-containing compound is reacted to produce magnesium metal. The carbon dioxide is used as a reactant in a second process. In another embodiment of the process, a magnesium silicate is reacted with a caustic material to produce magnesium hydroxide. The magnesium hydroxide is reacted with a source of carbon dioxide to produce magnesium carbonate. The magnesium carbonate is reacted to produce a magnesium-containing compound and carbon dioxide. The magnesium-containing compound is reacted to produce magnesium metal. The invention further relates to a process for production of magnesium metal or a magnesium compound where an external source of carbon dioxide is not used in any of the reactions of the process. The invention also relates to the magnesium metal produced by the processes described herein.

  11. EXPERIMENTAL INVESTIGATION ON GAS HYDRATE FORMATION IN PRESENCE OF ADDITIVE COMPONENTS

    Institute of Scientific and Technical Information of China (English)

    SUN Zhigao; FAN Shuanshi; GUO Kaihua

    2003-01-01

    Additives were used to increase gas hydrate formation rate and storage capacity. Experimental tests of methane hydrate formation were carried out in surfactant water solutions in a high-pressure cell.Sodium dodecyl sulfate (SDS) and alkyl polysaccharide glycoside (APG) were used to increase hydrate formation. The effect of SDS on hydrate formation is more pronounced compared APG. Cyclopentane (CP) also improves hydrate formation rates while it cannot increase methane gas storage capacity.

  12. 碳酸盐沉淀法分离硫酸盐溶液中的锰与钙和镁%Separation of manganese from calcium and magnesium in sulfate solutions via carbonate precipitation

    Institute of Scientific and Technical Information of China (English)

    林清泉; 顾帼华; 王晖; 王重庆; 刘有才; 朱仁锋; 符剑刚

    2016-01-01

    The separation of manganese from sulfate solutions containing 14.59 g/L Mn2+, 1.89 g/L Mg2+ and 1.54 g/L Ca2+ was preformed successfully by carbonate precipitation. The results of thermodynamic analysis and tests indicate that carbonate precipitation holds better selectivity for manganese over magnesium than hydroxide precipitation and the feeding method is the most critical factor for minimizing the co-precipitation of calcium and magnesium. Furthermore, with adding MnSO4 solution to NH4HCO3 solution, the effects of the initial NH4HCO3 concentration, NH4HCO3 amount, solution pH value, reaction temperature and time on carbonate precipitation were evaluated and the optimum precipitation conditions were obtained. Under the optimum conditions, the precipitation rates of Mn2+, Ca2+ and Mg2+ are 99.75%, 5.62% and 1.43%, respectively. Moreover, the prepared manganese carbonate was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDX). The results demonstrate that the product can be indexed to the rhombohedral structure of MnCO3.%以含14.59 g/L Mn2+、1.89 g/L Mg2+和1.54 g/L Ca2+的硫酸盐溶液为原料,利用碳酸盐沉淀法实现了锰与钙和镁的有效分离。热力学分析与实验结果表明,碳酸盐沉淀体系中锰对镁的选择性明显优于水解沉淀体系,而且加料方式是减少钙、镁共沉淀的主要因素。因而以硫酸锰加入碳酸氢铵的方式,研究碳酸氢铵初始浓度和用量、溶液 pH 值、反应温度及时间对沉淀过程的影响,并得到最优沉淀条件。结果表明:最优条件下锰、钙和镁离子的沉淀率分别为99.75%、5.62%和1.43%。另外,制得的产品经 X 射线衍射和能谱扫描电镜分析,结果表明该产品为菱形碳酸锰。

  13. Effects of Foliar Spraying of Magnesium-potassium Sulfate Fertilizer on Absorption of Magnesium, Potassium and Calcium in Different-position Tobacco Leaves%叶面喷施硫酸钾镁肥对不同部位烟叶镁、钾、钙吸收的影响

    Institute of Scientific and Technical Information of China (English)

    周敏; 周绍松; 郑波; 鲁耀; 段宗颜; 王建新; 张忠武; 杨景华

    2014-01-01

    design were adopted in this research. The group without Mg fertilization was treated as control. There were 3 treatment groups for foliar spraying of magnesium-potassium sulfate fertilizer and 2 treatment groups for soil application + foliar spraying of magnesium-potassium sulfate fertilizer. The tobac-co roots, stems, lower leaves, middle leaves and upper leaves were dried and weighed. They were grinded for the determination of K, Ca and Mg content. The total K, Ca and Mg content in upper (B2F), middle (C3F) and lower (X2F) flue-cured tobacco leaves in each plot was measured. [Result] The foliar spraying and soil application + foliar spraying al increased the absorption of Mg and K in middle and lower tobacco leaves and the absorption of Ca in lower tobacco leaves, but de-creased the absorption of Mg, K and Ca in upper leaves and the absorption of Ca in middle leaves. Among the positions, the accumulated distribution of Mg, K and Ca ranked as middle leaves > lower leaves > upper leaves. With the application of Mg fertilizer, the Ca/Mg ratio and K/Mg ratio al decreased in middle and upper to-bacco leaves; while the Ca/Mg ratio increased in the lower tobacco leaves, and the K/Mg ratio showed no significant difference among treatment groups. [Conclusion] The foliar spraying and soil application + foliar spraying of magnesium-potassium sulfate fertilizer affected the Ca/Mg ratio and K/Mg ratio in tobacco leaves mainly through affecting the absorption of Mg.

  14. Growth Habit of the Basic Oxysulfate Magnesium Whisker

    Institute of Scientific and Technical Information of China (English)

    WU Jiansong; GAO Yimin

    2016-01-01

    The growth habit of the basic magnesium oxysulfate whisker was investigated based on the theoretical model of anion coordination polyhedron growth units. It is found that typical basic magnesium oxysulfate whisker growth is consistent with anion tetrahedral coordination incorporation rules. The growth units of basic magnesium oxysulfate whiskers are [Mg-(OH)4]2- and HSO4-. [Mg-(OH)4]2- is the favorable growth unit and whisker growth is in the direction of the [Mg-(OH)4]2- combination. A plurality of [Mg-(OH)4]2- s combine and become a larger dimensional growth unit in a one-dimensional direction. Then HSO4-and larger dimensional growth units connect as basic magnesium sulfate whiskers, according to the structural characteristics of the basic magnesium sulfate whisker, which can guide the synthesis of magnesium hydroxide whisker.

  15. Sulfates on Mars: Indicators of Aqueous Processes

    Science.gov (United States)

    Bishop, Janice L.; Lane, Melissa D.; Dyar, M. Darby; Brown, Adrian J.

    2006-01-01

    Recent analyses by MER instruments at Meridiani Planum and Gusev crater and the OMEGA instrument on Mars Express have provided detailed information about the presence of sulfates on Mars [1,2,3]. We are evaluating these recent data in an integrated multi-disciplinary study of visible-near-infrared, mid-IR and Mossbauer spectra of several sulfate minerals and sulfate-rich analog sites. Our analyses suggest that hydrated iron sulfates may account for features observed in Mossbauer and mid-IR spectra of Martian soils [4]. The sulfate minerals kieserite, gypsum and other hydrated sulfates have been identified in OMEGA spectra in the layered terrains in Valles Marineris and Terra Meridiani [2]. These recent discoveries emphasize the importance of studying sulfate minerals as tracers of aqueous processes. The sulfate-rich rock outcrops observed in Meridiani Planum may have formed in an acidic environment similar to acid rock drainage environments on Earth [5]. Because microorganisms typically are involved in the oxidation of sulfides to sulfates in terrestrial sites, sulfate-rich rock outcrops on Mars may be a good location to search for evidence of past life on that planet. Whether or not life evolved on Mars, following the trail of sulfate minerals will lead to a better understanding of aqueous processes and chemical weathering.

  16. Performance analysis of magnesium phosphate cement mortar containing grinding dust

    Directory of Open Access Journals (Sweden)

    Daniel Véras Ribeiro

    2009-03-01

    Full Text Available Magnesium phosphate cement materials are formed by reacting magnesium oxide with water-soluble phosphates such as monoammonium dihydrogen phosphate (ADP, which solidifies at ambient temperature through the formation of hydrated phases in the material. Cylindrical specimens of magnesium phosphate cement were molded and varying amounts (0 to 30% weight of grinding dust were added to the ceramic matrices. The influence of the addition of grinding dust on the characteristics of the mortars in terms of microstructure (SEM, mechanical strength and capillary water absorption was verified. The results obtained proved very satisfactory for the use of this waste as an additive in magnesium phosphate mortars.

  17. Magnesium compounds

    Science.gov (United States)

    Kramer, D.A.

    2012-01-01

    Seawater and natural brines accounted for about 57 percent of magnesium compounds produced in the United States in 2011. Dead-burned magnesia was produced by Martin Marietta Magnesia Specialties LLC from well brines in Michigan. Caustic-calcined magnesia was recovered from seawater by Premier Magnesia LLC in Florida, from well brines in Michigan by Martin Marietta and from magnesite in Nevada by Premier Magnesia. Intrepid Potash Wendover LLC and Great Salt Lake Minerals Corp. recovered magnesium chloride brines from the Great Salt Lake in Utah. Magnesium hydroxide was produced from seawater by SPI Pharma Inc. in Delaware and Premier Magnesia in Florida, and by Martin Marietta from its brine operation in Michigan.

  18. 利托君联合针对性护理治疗先兆早产91例%Observation on Efficacy of Albuterol Sulfate Combined with Magnesium Sulfate and Ritodrine in Treating Threatened Premature Labor and Its Nursing in 91 Cases

    Institute of Scientific and Technical Information of China (English)

    马飞娥

    2014-01-01

    Objective To explore the efficacy of albuterol sulfate combined with magnesium sulfate and ritodrine in treating threatened premature labor and its nursing countermeasures. Methods 182 cases of threatened premature labor in our hospital from May 2010 to July 2013 were selected and divided into the treatment group and the control group according to the stratified randomization method, 91 cases in each group. The treatment group was given ritodrine and the targeted nursing countermeasure for conducting treatment, while the control group was given albuterol sulfate combined with magnesium sulfate and the routine nursing care for conducting treatment. Results In the treatment group, the excellent effective time after treatment was ( 3. 82 ± 1. 63 ) h, the total medication time was ( 7. 93 ± 3. 15 ) d, the volume of postpartum hemorrhage was ( 249. 06 ± 47. 62 ) mL, neonatal diseases in 3 cases ( 3. 30% ) and neonatal death in 0 case, which in the control group was ( 4. 76 ± 2. 01 ) h, ( 9. 12 ± 3. 98 ) d, ( 285. 7 ± 51. 31 ) mL, neonatal disease in 10 cases ( 10. 99% ) and neonatal death in 4 cases ( 4. 40%) respectively, the differences showing the statistical significance;the time of prolonged pregnancy, heart rate, antenatal fetal biparietal diameter ( BPD ) , birth weight, Apgar score at 1 min and the curative effect rate in the treatment group were significantly higher than those in the control group with statistical differences ( P<0. 05 ) . Conclusion Adopting ritodrine hydrochlo-ride and the targeted nursing countermeasure in treating threatened preterm labor can significantly increase the tocolytic success rate, improve the neonatal level;but the existing adverse reactions such as increased heart rate need to be dealt accordingly.%目的:探讨利托君治疗先兆早产患者的疗效及护理对策。方法选取2010年5月至2013年7月就诊的先兆早产患者182例,依据分层随机分组法分为治疗组与对照组,各91例

  19. A Copper-Sulfate-Based Inorganic Chemistry Laboratory for First-Year University Students That Teaches Basic Operations and Concepts.

    Science.gov (United States)

    Rodriguez, Emilio; Vicente, Miguel Angel

    2002-01-01

    Presents a 10-hour chemistry experiment using copper sulfate that has three steps: (1) purification of an ore containing copper sulfate and insoluble basic copper sulfates; (2) determination of the number of water molecules in hydrated copper sulfate; and (3) recovery of metallic copper from copper sulfate. (Author/YDS)

  20. 碱式硫酸锌转化法制备ZnO多孔片及其光致发光性能%Porous ZnO Sheets Transformed from Zinc Sulfate Hydroxide Hydrate and Their Photoluminescence Performance

    Institute of Scientific and Technical Information of China (English)

    何朋; 高相东; 吴历斌; 蒋正武; 王彩露; 李效民

    2013-01-01

      采用化学浴沉积法制备了碱式硫酸锌(ZSH)纳米片,并经1000°C煅烧处理得到了ZnO多孔片。详细研究了ZSH在Zn2+-六亚甲基四胺前驱体溶液体系中的形成机理、ZSH的热解过程、ZnO的结晶性、微结构以及光致发光性能。结果表明,所得ZnO多孔片呈规则六角形状,其尺寸为10-50μm,厚度为200-500 nm,由于高温固相反应中传质等因素的限制,构成薄片的ZnO晶粒呈多边形或不规则形貌,晶粒间的孔为亚微米孔,尺寸在100-500 nm范围。 ZnO多孔薄片结晶性良好,在388 nm处表现出较强紫外发光,无可见光区的缺陷发光。机理分析表明, SO2-4与Zn2+的高亲和力是Zn2+-六亚甲基四胺体系中ZSH生成的根本原因,而ZSH的热分解过程对ZnO多孔片的形貌和微结构影响显著。本研究提出了一种制备高结晶质量ZnO多孔材料的新方法,所得ZnO多孔片可望在催化、染料敏化太阳能电池、紫外光电器件等领域得到应用。%Highly crystal ine, porous ZnO sheets were prepared from chemical y-deposited zinc sulfate hydroxide hydrate (ZSH) sheets by sintering at 1000 °C. The formation mechanism of ZSH in Zn2+-hexamethyltetramine (HMT) precursor system, the transformation process of ZSH to ZnO, and the crystal ine, microstructural and optical properties of the ZnO sheets were investigated. The porous ZnO sheets possessed a wel-defined hexagonal shape with control able size (10-50 μm) and thickness (200-500 nm), high crystal inity, and strong ultraviolet photoluminescence without detectable defect-related visible emission. Submicron-sized pores (100-500 nm) and polygonal or irregular ZnO particles resulting from the limited mass transport during high temperature sintering were observed in the ZnO sheets. Analysis of the formation mechanism indicated that the high affinity of SO2-4 for Zn2+was responsible for the formation of ZSH in the Zn2 +-HMT precursor system, and the thermolysis of ZSH affected

  1. Anaerobic oxidation of methane above gas hydrates at Hydrate Ridge, NE Pacific Ocean

    DEFF Research Database (Denmark)

    Treude, T.; Boetius, A.; Knittel, K.;

    2003-01-01

    At Hydrate Ridge (HR), Cascadia convergent margin, surface sediments contain massive gas hydrates formed from methane that ascends together with fluids along faults from deeper reservoirs. Anaerobic oxidation of methane (AOM), mediated by a microbial consortium of archaea and sulfate-reducing...... bacteria, generates high concentrations of hydrogen sulfide in the surface sediments. The production of sulfide supports chemosynthetic communities that gain energy from sulfide oxidation. Depending on fluid flow, the surface communities are dominated either by the filamentous sulfur bacteria Beggiatoa...

  2. Na2HPO4·12H2O对磷酸镁水泥水化硬化特性的影响%Effect of Na2HPO4 · 12H2O on Hydration and Hardening Properties of Potassium and Magnesium Phosphate Cement Paste

    Institute of Scientific and Technical Information of China (English)

    杨建明; 钱春香; 焦宝祥; 王玉琴

    2011-01-01

    A small amount of NazHPO4 ? 12H2O was mixed into magnesium phosphate cement (MPC) paste to investigate its effect on pH value, fluidity, hydration temperature and strength development of MKPC paste and on mineralogical composition and microstructural morphology of hydration products of hardened MKPC paste. Results indicate that, Na2HPO4 ? 12H2O absorbs a great deal of heat of dissolution and transformation in MKPC paste, thus the initial temperature and the temperature rise rate of MKPC paste is decreased. The pH value of MKPC paste is raised by adding Na2HPO4 ? 12H2O. The solubility and ion release rate of KH2PO4(K) and MgO(M) is decreased by above factors, and this effectively delays the setting time and the early hydration rate of MKPC paste and increases the fluidity of MKPC paste. Na2HPO4 ? 12H2O also participates in hydration reaction resulting in the sustainable growth of late strength of hardened MKPC paste.%研究了适量掺加Na2 HPO4·12H2O对新型磷酸镁水泥(MKPC)浆体水化硬化过程中的pH值、体系温度、凝结时间、流动性以及强度发展等的影响.结果表明:Na2HPO4·12H2O在MKPC浆体中的溶解和相变过程吸收了大量热量,从而降低了MKPC浆体的初始温度,延缓了浆体的温度上升速度,提高了MKPC浆体的pH值;上述因素导致MKPC浆体中KH2 PO4和MgO的溶解度以及离子溶出速度降低,从而有效地控制了MKPC浆体的凝结时间和早期水化反应速度,改善了MKPC浆体的流动性;Na2 HPO4·12H2O还参与了系统的水化反应,使MKPC硬化体后期强度稳定增长.

  3. Ligantes hidráulicos e a hidratação de óxido de magnésio em concretos refratários Hydraulic binders and magnesium oxide hydration in refractory castables

    Directory of Open Access Journals (Sweden)

    R. Salomão

    2010-07-01

    Full Text Available A presença de cimento de aluminato de cálcio e alumina hidratável pode afetar significativamente o comportamento de hidratação do óxido de magnésio (MgO em suspensões aquosas. Entre outros efeitos, destaca-se a formação do composto conhecido como hidrotalcita (Mg6Al2(CO3(OH16·(4H2O, que pode potencializar ou inibir os danos causados pela hidratação do MgO, dependendo da quantidade em que é gerado. Este trabalho investigou como a presença desses ligantes afeta a hidratação do MgO e suas conseqüências em formulações de concretos refratários usando testes de hidratação-desidratação, medidas de pH, expansão volumétrica aparente, resistência à tração por compressão diametral e porosidade. Por meio de comparações com composições de referência sem-ligante e sem-ligante-e-sem-MgO, foi verificado que os efeitos danosos da hidratação do MgO podem ser significativamente reduzidos por meio do ajuste do tipo e do teor de ligante aos concretos.The presence of calcium aluminate cement and hydratable alumina can significantly modify the magnesia sinter hydration behavior in aqueous suspensions. As a consequence of these studies, the present paper investigates how these binders content could affect magnesia hydration in refractory castables using hydration-dehydration tests, pH, AVE, mechanical strength and porosity measurements. Besides this, because for these materials the aspects related to mechanical strength, porosity and refractoriness also must be taken into account, binder-free, magnesia-free and magnesia-and-binder-free samples were also tested as references. It was found out that the deleterious effects of magnesia hydration can be greatly minimized by the binder content.

  4. 丹红、硫酸镁注射液联用治疗慢性肺心病急性加重期疗效观察%Observation of curative effect on Danhong Injection and Magnesium Sulfate Injection in the treatment of chronic cor pulmonale in acute exacerbation

    Institute of Scientific and Technical Information of China (English)

    董芳; 杨钦清; 马瑞斌; 柯颖

    2011-01-01

    Objective: To observe the effect of Danhong Injection and Magnesium Sulfate Injection in the treatment of chronic cor pulmonale in acute exacerbation. Methods: 78 patients with chronic cor pulmonale in acute exacerbation of our hospital were randomly divided into treatment group (n=39) and control group (n=39). The control group was treated with routine western medicine, the treatment group was additionally given Danhong Injection combined with Magnesium Sulfate Injection, 2 weeks as a course. The effects and blood gas analysis and pulmonary artery pressure before and after treatment were compared between the two groups. Results: Both groups had obvious effects. Compared with the control group, patients in the treatment group had a better improvement in pulmonary function and blood gas analysis, as well as a more marked decline in pulmonary artery pressure. All these measurements had significant differences between the two groups (P<0.05). Conclusion: There is an obvious therapeutic effect of Danhong Injection and Magnesium Sulfate Injection in the treatment of chronic cor pulmonale in acute exacerbation.%目的:观察丹红和硫酸镁注射液联用对慢性肺心病急性加重期的疗效.方法:选择我院78例慢性肺心病急性加重期患者,将其随机分为治疗组(n=39)和对照组(n=39).两组均给予常规西医综合治疗,治疗组在常规治疗基础上加用丹红和硫酸镁注射液静脉滴注,2周为1个疗程.比较两组患者的疗效及治疗前后血气分析、肺动脉压方面有无差异.结果:两组都有明显疗效,但与对照组比较,治疗组在肺功能及血气结果的改善更加显著,肺动脉压的下降更明显,差异有统计学意义(P<0.05).结论:丹红和硫酸镁注射液联用对治疗慢性肺心病急性加重期有显著疗效.

  5. TDP irradiation plus Magnesium Sulfate wet compress for patients with type 2 diabetes mellitus and urarthritis%TDP照射协同硫酸镁湿敷治疗2型糖尿病合并痛风性关节炎临床观察

    Institute of Scientific and Technical Information of China (English)

    罗叶昕; 阳仁美

    2011-01-01

    目的 探讨TDP照射协同硫酸镁湿敷对2型糖尿病合并痛风性关节炎的治疗效果.方法 采用随机数字表法将63例2型糖尿病合并痛风性关节炎患者分为两组,对照组仅给予规律药物治疗和饮食控制,治疗组在此基础上每日关节红肿处行3次硫酸镁湿热敷和TDP灯照射.结果 治疗组在缩短疼痛持续时间、住院时间、控制血糖等方面明显优于对照组(P<0.05或P<0.01).结论 硫酸镁湿热敷和TDP灯照射是2型糖尿病合并痛风性关节炎患者的重要治疗手段,能有效缓解疼痛,控制血糖水平,缩短住院时间.%Objective To investigate the efficacy of TDP irradiation plus Magnesium Sulfate wet compress for patients with type 2 diabetes mellitus and urarthritis.Methods Sixty-three patients with type 2 diabetes mellitus and urarthritis were divided into two groups,the observation group (32 cases) and the control group (31cases).The control group was treated by drug therapy and diet control The observation group was treated by partial irradiation of TDP light three times a day ( 15 minutes/time) and hot-wet compression with Magnesium Sulfate in addition to drug therapy and diet control.Results The observation group was significantly superior to the control group in the control of durante dolors ,hospital stay and blood glucose level.( P < 0.05 or P < 0.01 ).Conclusion The therapy of TDP irradiation plus Magnesium Sulfate wet compress is easier for patients to relieve pain, control blood glucose level and shorten hospital stay.

  6. Methods to determine hydration states of minerals and cement hydrates

    Energy Technology Data Exchange (ETDEWEB)

    Baquerizo, Luis G., E-mail: luis.baquerizoibarra@holcim.com [Innovation, Holcim Technology Ltd., CH-5113 Holderbank (Switzerland); Matschei, Thomas [Innovation, Holcim Technology Ltd., CH-5113 Holderbank (Switzerland); Scrivener, Karen L. [Laboratory of Construction Materials, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne (Switzerland); Saeidpour, Mahsa; Thorell, Alva; Wadsö, Lars [Building Materials, Lund University, Box 124, 221 000 Lund (Sweden)

    2014-11-15

    This paper describes a novel approach to the quantitative investigation of the impact of varying relative humidity (RH) and temperature on the structure and thermodynamic properties of salts and crystalline cement hydrates in different hydration states (i.e. varying molar water contents). The multi-method approach developed here is capable of deriving physico-chemical boundary conditions and the thermodynamic properties of hydrated phases, many of which are currently missing from or insufficiently reported in the literature. As an example the approach was applied to monosulfoaluminate, a phase typically found in hydrated cement pastes. New data on the dehydration and rehydration of monosulfoaluminate are presented. Some of the methods used were validated with the system Na{sub 2}SO{sub 4}–H{sub 2}O and new data related to the absorption of water by anhydrous sodium sulfate are presented. The methodology and data reported here should permit better modeling of the volume stability of cementitious systems exposed to various different climatic conditions.

  7. Sulfate Resistance of Alkali Activated Pozzolans

    OpenAIRE

    Bondar, Dali

    2015-01-01

    The consequence of sulfate attack on geopolymer concrete, made from an alkali activated natural pozzolan (AANP) has been studied in this paper. Changes in the compressive strength, expansion and capillary water absorption of specimens have been investigated combined with phases determination by means of X-ray diffraction. At the end of present investigation which was to evaluate the performance of natural alumina silica based geopolymer concrete in sodium and magnesium sulfate solution, the l...

  8. Magnesium in diet

    Science.gov (United States)

    ... sources of magnesium: Fruits or vegetables (such as bananas, dried apricots, and avocados) Nuts (such as almonds ... Supplements, National Institutes of Health. Dietary Supplement Fact Sheet: Magnesium . ods.od.nih.gov/factsheets/Magnesium-Consumer . ...

  9. The curative effect of nicardipine combined with magnesium sulfate in the treatment of patients with pregnancy-induced hypertension%尼卡地平联合硫酸镁治疗妊娠期高血压患者53例的疗效分析

    Institute of Scientific and Technical Information of China (English)

    高丽华; 袁珍; 林芳

    2014-01-01

    目的:探讨尼卡地平联合硫酸镁治疗妊娠期高血压的疗效。方法:选取2008年2月-2012年5月期间在我院确诊并治疗的妊娠期高血压患者106例,依据随机分配原则分为尼卡地平治疗组和对照组。对尼卡地平治疗组患者给予尼卡地平联合硫酸镁治疗,对对照组患者仅给予硫酸镁治疗。比较和分析两组患者的治疗效果以及分娩的新生儿结局和分娩时并发症发生情况。结果:治疗后,尼卡地平治疗组患者的收缩压和舒张压均显著低于对照组(P均<0.05);尼卡地平治疗组患者分娩的新生儿体重、胎盘重量均显著高于对照组,妊娠延长天数也显著长于对照组(P均<0.05);尼卡地平治疗组患者分娩时的并发症发生率显著低于对照组(P<0.05)。结论:尼卡地平联合硫酸镁治疗能有效降低妊娠期高血压患者的血压并改善新生儿结局,值得临床进一步研究。%Objective:To discuss the curative effect of nicardipine combined with magnesium sulfate in the treatment of patients with pregnancy-induced hypertension. Methods:One hundred and six patients, who were diagnosed as pregnancy-induced hypertension and treated in our hospital from February, 2008 to May, 2012, were selected and randomly divided into a nicardipine group and a control group. Patients were treated with nicardipine combined with magnesium sulfate in the nicardipine group while only magnesium sulfate in the control group. The curative effect, neonatal outcome and the incidence of complications were analyzed and compared between two groups after treatment. Results:Systolic and diastolic blood pressure and the incidence of childbirth complications of patients were signiifcantly lower in the nicardipine group than in the control group after treatment (P<0.05). The placenta weight and neonatal body weight were signiifcantly heavier in the nicardipine group than in the control group and the

  10. 地奥司明、50%硫酸镁溶液联合氦氖激光照射治疗混合痔术后创面水肿与疼痛的疗效观察%Efficacy of Diosmin and Magnesium Sulfate Combined with Helium Neon Laser Irradiation for Patients with Mixed Hemorrhoids

    Institute of Scientific and Technical Information of China (English)

    崔伟; 王丹; 魏智钧; 陈纲; 于波

    2015-01-01

    OBJECTIVE:To evaluate the efficacy of diosmin and magnesium sulfate combined with helium -neon laser irradiation therapy in patients with mixed hemorrhoids .METHODS: A total of 102 patients with hemorrhoid receiving external dissection and internal ligation surgery in our hospital between January 2013 and July 2014 were randomized to either control group or observation group of 51 cases each .The patients in the observation group were treated with diosmin, 50%magnesium sulfate solution combined helium-neon laser irradiation , whereas the control group were only given diosmin and 50% magnesium sulfate solution .Surgical wound edema and pain score in the two groups were followed and compared at 2, 4, 6 postoperative days .RESULTS: Surgical wound edema and pain scores at 4 and 6 postoperative days were significant lower in the observation group than in the control group , and the mean time to edema relief and pain relief were also significant less in the observation group than in the control group ( P <0.05 ) . CONCLUSIONS:Diosmin and magnesium sulfate combined with helium neon laser irradiation therapy can effectively relieve the postoperative edema and wound pain and promote rapid recovery of patients with mixed hemorrhoids .%目的:观察地奥司明、50%硫酸镁溶液联合氦氖激光照射治疗混合痔术后创面水肿与疼痛的疗效。方法:采用随机数字表法,将2013年1月—2014年7月北京军区总医院102例接受外剥内扎术的混合痔患者分为观察组和对照组各51例。观察组患者给予地奥司明、50%硫酸镁溶液联合氦氖激光照射治疗,对照组患者仅给予地奥司明、50%硫酸镁溶液治疗,记录2组患者术后第2、4、6d手术创面水肿与疼痛情况并进行比较。结果:观察组患者术后第4日和第6日创面水肿与疼痛评分均显著低于对照组,平均水肿与疼痛缓解时间也显著短于对照组,差异均有统计学意义( P<0.05

  11. 亚低温状态下大剂量硫酸镁治疗弥漫性轴索损伤的临床研究%The effects of combined mild hypothermia and high dose of magnesium sulfate in the treatment of diffuse axonal injury

    Institute of Scientific and Technical Information of China (English)

    赵灵; 林小华; Boyce C; 欧兴义; 梁小兵; 兰蒙; 招建华; 丁轩

    2005-01-01

    Objective To observe the clinical effects of combined mild hypothermia and high dose of magnesium sulfate (MHMS) in treatment of diffuse axonal injury (DAI).Methods 64 patients suffered from DAI and had Glasgow Coma Scale (GCS) scores of 3 to 8.They were randomly divided into two groups: MHMS treatment group (n=32) and control group (n=32).MHMS treatment group: mild hypothermia was used to keep the rectal temperature at 33 to 35℃ and received 24 mmol magnesium sulfate intravenously at 20 minutes after admission,followed by 80 mmol magnesium sulfate intravenously everyday for 3 to 5 days.Control group: patients were only treated with common method without MHMS.Serum neuron specific enolase (NSE),GCS and GOS of all the patients were measured.GCS score was recorded at admission,at 3 days,7 days,and 2 weeks;serum NSE values was measured at admission,at 3 days and 7 days.Outcome was determined by Glasgow Outcome Scale (GOS) score at discharge and after 3 months.The data were analyzed statistically.Results The serum NSE,GCS and GOS in the MHMS group were (24.8±19.2)g/L,12.3±3.3 and 4.6±1.3,respectively;while in control group were (49.7±23.1) g/L,9.8±2.8 and 3.0±1.5,respectively.There was significant difference between the two groups in serum NSE,GCS and GOS (P<0.01).Conclusion Mild hypothermia combined with high dose of magnesium sulfate therapy is effective in the treatment of patients with DAI.%目的观察联合使用亚低温及大剂量硫酸镁治疗弥漫性轴索损伤的临床效果.方法64例诊断为弥漫性轴索损伤,GCS评分为3~8的患者被随机分为治疗组和对照组.治疗组的患者入院20 min后给予静注24 mmol硫酸镁,再用80 mmol持续24 h静滴,同时自伤后6 h开始联合用亚低温治疗,使直肠温度控制在33~35 ℃,治疗时间为3~5 d,对照组按普通常规治疗.两组患者均于入院当天、治疗后3d和7d测血清神经元特异性异烯醇化酶(NSE)和GCS,出院和3个月后测GOS.结果 治

  12. Clinical Observation on Nifedipine,Phentolamine and Magnesium Sulfate in Treatting with Gestational Hypertension%硝苯地平联合酚妥拉明及硫酸镁治疗妊娠期高血压的临床疗效观察

    Institute of Scientific and Technical Information of China (English)

    买苗; 张晓莹; 冯瑞; 宋芳霞

    2013-01-01

    Objective:To observe clinical curative effects of using nifedipine,phentolamine and magnesium sulfate these three together to treat gestational hypertension.Methods:Chose 92 cases of those gestational hypertension patients who have been treated at our hospital from March 2011 to February 2012,divided them into experimental group and control group randomly through computer grouping way,each group has 46 cases.Gave nifedipine,phentolamine and magnesium sulfate these three together as treatment to those who in experimental group,while just adopted magnesium sulfate as treatment to those who in control group,observed these two groups’ patients’decreasing situations of blood pressure,plasma viscosity changes and these two groups’ overall effective conditions after treatment.Results:Experimental group's total effective cases were 44(95.65%),control group's were 37(80.43%),experimental group's overall effective rate was obviously higher than control group's,and experimental group's decresing degree of blood pressure,plasma viscosity was evidently higher than control group's,P<0.05,it has statistics value.Conclusion:Nifedipine,phentolamine and magnesium sulfate these three methods together have significant curative effects on treatment of gestational hypertension,it is worthy of clinical promotion.%目的::观察硝苯地平联合酚妥拉明及硫酸镁治疗妊娠期高血压的临床疗效。方法:选取2011年3月~2012年2月来我院接受治疗的妊娠期高血压患者92例,通过计算机随机分组的方式将其随机分为实验组和对照组,每组46例。其中实验组患者给予硝苯地平联合酚妥拉明及硫酸镁进行治疗,而对照组仅采用硫酸镁进行治疗,观察两组患者经过治疗后的血压下降情况、血浆黏度变化情况、两组的总体治疗有效情况。结果:实验组患者的总体有效例数为44例(95.65%),对照组的为37例(80.43%),实验组的总有效率要显著高于对照组,同时实

  13. To observe the clinical curative effect of magnesium sulfate in the treatment of pregnancy induced hypertension syndrome:a report of 39 cases%硫酸镁治疗妊高症39例的临床疗效观察

    Institute of Scientific and Technical Information of China (English)

    康庆福

    2013-01-01

    目的观察硫酸镁治疗妊高症的临床疗效。方法选取2011年4月至2012年7月在本院妇产科治疗的39例妊高症患者,给予硫酸镁治疗,观察比较治疗前后患者的血压及临床症状,统计并发症的发生率。结果给予硫酸镁治疗后,患者的血压下降明显(收缩压下降40.1±3.4mmHg;舒张压下降30.9±3.2mmHg),治疗前后患者血压值比较,差异具有统计学意义(P<0.05);头痛、头晕等症状的发生率较治疗前明显下降,治疗前后患者临床症状发生率比较,差异具有统计学意义(P<0.05)。治疗后出现产后出血1例,出现产后子痫1例,并发症的发生率为5.1%。结论硫酸镁治疗妊高症临床疗效显著,可有效降低产后并发症的发生率,具有重要的临床应用价值。%Objective To observe the clinical curative effect of magnesium sulfate in the treatment of pregnant high disease. Methods From 2011 April ~2012 year in July 39 cases of pregnancy induced hypertension patients in this hospital were given, Magnesium sulfate intravenous combined with intramuscular injection treatment, and clinical symptoms were observed before and after treatment in patients with hypertension, The incidence of complications of statistics.Results After the treatment with magnesium sulfate, blood pressure decreased signiifcantly (systolic blood pressure dropped to 40.1 ± 3.4mmHg; diastolic blood pressure was 30.9 ± 3.2mmHg), Before and after treatment in patients with blood pressure value, The difference was statistically significant (P<0.05); headache, dizziness and other symptoms were significantly decreased than that before treatment, The clinical symptoms before and after treatment in patients with rate comparison, the difference was statistically signiifcant (P<0.05). After the treatment of 1 cases of postpartum hemorrhage, postpartum eclampsia in 1 cases, the complication rate was 5.1%. Conclusion The therapeutic effect of

  14. Neuroprotective effects of Magnesium Sulfate and Citicoline in rats undergoing cerebral ischemia reperfusion injury%大鼠全脑缺血再灌注损伤后硫酸镁及胞二磷胆碱的脑保护作用

    Institute of Scientific and Technical Information of China (English)

    董亚茹; 由凤秋; 杨震

    2012-01-01

    Objective: To investigate neuroprotective effects of Magnesium Sulfate and Citicoline in rats undergoing cerebral ischemia reperfusion injury. Methods: Four-vessel occlusion was used to establish the model of global brain ischemia in rats. Animals were randomly and blindly assigned to one of the following treatment groups: placebo, MgsO, (90mg/kg) , Citicoline(250mg/kg) , and the combination of both. After cerebral ischemia reperfusion ld、3d、7d the change in the expression of Bcl-2 and pathological were observed. Results;Compared with placebo , other groups could increase expression of the Bcl-2 and pathological changes. The combination groups could significantly improve the behavior deficits and pathological changes. Conclusion:These results demonstrate neuroprotective effects of Magnesium Sulfate and Citicoline in experimental focal ischemia.%目的:探讨硫酸镁+胞二磷胆碱联合应用对大鼠脑缺血再灌注损伤后脑组织的保护作用.方法:建立大鼠全脑缺血模型后60只大鼠分为:缺血组、硫酸镁组、胞二磷组、联合组,观察治疗后1、3、7日各组大鼠神经行为学、病理学的改变和Bcl-2表达的变化.结果:联合组较缺血组及单一用药组神经行为异常显著改善、脑组织病理损害减轻、Bcl-2表达增多.结论:硫酸镁及胞二磷胆碱对脑组织均有保护作用,两者联合应用后效果更明显.

  15. Preparation and Characterization of Anhydrous Magnesium Chloride in Organic Solvent%有机溶剂法无水氯化镁的制备与表征

    Institute of Scientific and Technical Information of China (English)

    周宁波; 陈白珍; 何新快; 李义兵

    2005-01-01

    Ammonium carnallite was synthesized by hydrated magnesium chloride in salt lake and ammonium chloride solution. Dehydrated ammonium carnallite was dissolved in methanol under low temperature by feeding ammonia, to prepare anhydrous magnesium chloride. The results show that anhydrous magnesium chloride contains magnesium oxide in an amount less than 0.1% by weight, the yield of magnesium chloride was above 99.5%. Ammonium carnallite, ammoniation magnesium chloride and anhydrous magnesium chloride were characterized by thermoanalysis, X-ray powder diffraction and scanning electron microscopy.

  16. Clathrate hydrates in nature.

    Science.gov (United States)

    Hester, Keith C; Brewer, Peter G

    2009-01-01

    Scientific knowledge of natural clathrate hydrates has grown enormously over the past decade, with spectacular new findings of large exposures of complex hydrates on the sea floor, the development of new tools for examining the solid phase in situ, significant progress in modeling natural hydrate systems, and the discovery of exotic hydrates associated with sea floor venting of liquid CO2. Major unresolved questions remain about the role of hydrates in response to climate change today, and correlations between the hydrate reservoir of Earth and the stable isotopic evidence of massive hydrate dissociation in the geologic past. The examination of hydrates as a possible energy resource is proceeding apace for the subpermafrost accumulations in the Arctic, but serious questions remain about the viability of marine hydrates as an economic resource. New and energetic explorations by nations such as India and China are quickly uncovering large hydrate findings on their continental shelves.

  17. The specific surface area of methane hydrate formed in different conditions and manners

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The specific surface area of methane hydrates, formed both in the presence and absence of sodium dodecyl sulfate (SDS) and processed in different manners (stirring, compacting, holding the hydrates at the formation conditions for different periods of time, cooling the hydrates for different periods of time before depressurizing them), was measured under atmospheric pressure and temperatures below ice point. It was found that the specific surface area of hydrate increased with the decreasing temperature. The methane hydrate in the presence of SDS was shown to be of bigger specific surface areas than pure methane hydrates. The experimental results further demonstrated that the manners of forming and processing hydrates affected the specific surface area of hydrate samples. Stirring or compacting made the hydrate become finer and led to a bigger specific surface area.

  18. Magnesium in disease

    OpenAIRE

    Geiger, Helmut; Wanner, Christoph

    2012-01-01

    Although the following text will focus on magnesium in disease, its role in healthy subjects during physical exercise when used as a supplement to enhance performance is also noteworthy. Low serum magnesium levels are associated with metabolic syndrome, Type 2 diabetes mellitus (T2DM) and hypertension; consequently, some individuals benefit from magnesium supplementation: increasing magnesium consumption appears to prevent high blood pressure, and higher serum magnesium levels are associated ...

  19. Final report on the safety assessment of aluminum silicate, calcium silicate, magnesium aluminum silicate, magnesium silicate, magnesium trisilicate, sodium magnesium silicate, zirconium silicate, attapulgite, bentonite, Fuller's earth, hectorite, kaolin, lithium magnesium silicate, lithium magnesium sodium silicate, montmorillonite, pyrophyllite, and zeolite.

    Science.gov (United States)

    Elmore, Amy R

    2003-01-01

    This report reviews the safety of Aluminum, Calcium, Lithium Magnesium, Lithium Magnesium Sodium, Magnesium Aluminum, Magnesium, Sodium Magnesium, and Zirconium Silicates, Magnesium Trisilicate, Attapulgite, Bentonite, Fuller's Earth, Hectorite, Kaolin, Montmorillonite, Pyrophyllite, and Zeolite as used in cosmetic formulations. The common aspect of all these claylike ingredients is that they contain silicon, oxygen, and one or more metals. Many silicates occur naturally and are mined; yet others are produced synthetically. Typical cosmetic uses of silicates include abrasive, opacifying agent, viscosity-increasing agent, anticaking agent, emulsion stabilizer, binder, and suspending agent. Clay silicates (silicates containing water in their structure) primarily function as adsorbents, opacifiers, and viscosity-increasing agents. Pyrophyllite is also used as a colorant. The International Agency for Research on Cancer has ruled Attapulgite fibers >5 microm as possibly carcinogenic to humans, but fibers mining and processing of Aluminum Silicate, Calcium Silicate, Zirconium Silicate, Fuller's Earth, Kaolin, Montmorillonite, Pyrophyllite, and Zeolite. The Cosmetic Ingredient Review (CIR. The Cosmetic Ingredient Review (CIR) Expert Panel concluded that the extensive pulmonary damage in humans was the result of direct occupational inhalation of the dusts and noted that lesions seen in animals were affected by particle size, fiber length, and concentration. The Panel considers that most of the formulations are not respirable and of the preparations that are respirable, the concentration of the ingredient is very low. Even so, the Panel considered that any spray containing these solids should be formulated to minimize their inhalation. With this admonition to the cosmetics industry, the CIR Expert Panel concluded that these ingredients are safe as currently used in cosmetic formulations. The Panel did note that the cosmetic ingredient, Talc, is a hydrated magnesium silicate

  20. Magnesium and Ketamine Gargle and Postoperative Sore Throat

    OpenAIRE

    Teymourian, Houman; Mohajerani, Seyed Amir; Farahbod, Alireza

    2015-01-01

    Background: Postoperative sore throat is one of the most common complications after endotracheal intubation. Both Ketamine and magnesium can block N-methyl-D-aspartic acid (NMDA) receptors and provide central and local analgesia. Objectives: To compare the effect of magnesium sulfate and ketamine gargle on the incidence and severity of postoperative sore throat. Patients and Methods: A total of 100 patients candidate for emergency acute appendicitis surgery were enrolled in the study. Patient...

  1. Surfactant effects on SF6 hydrate formation.

    Science.gov (United States)

    Lee, Bo Ram; Lee, Ju Dong; Lee, Hyun Ju; Ryu, Young Bok; Lee, Man Sig; Kim, Young Seok; Englezos, Peter; Kim, Myung Hyun; Kim, Yang Do

    2009-03-01

    Sulfur hexafluoride (SF(6)) has been widely used in a variety of industrial processes, but it is one of the most potent greenhouse gases. For this reason, it is necessary to separate or collect it from waste gas streams. One separation method is through hydrate crystal formation. In this study, SF(6) hydrate was formed in aqueous surfactant solutions of 0.00, 0.01, 0.05, 0.15 and 0.20 wt% to investigate the effects of surfactants on the hydrate formation rates. Three surfactants, Tween 20 (Tween), sodium dodecyl sulfate (SDS) and linear alkyl benzene sulfonate (LABS), were tested in a semi-batch stirred vessel at the constant temperature and pressures of 276.2 K and 0.78 MPa, respectively. All surfactants showed kinetic promoter behavior for SF(6) hydrate formation. It was also found that SF(6) hydrate formation proceeded in two stages with the second stage being the most rapid. In situ Raman spectroscopy analysis revealed that the increased gas consumption rate with the addition of surfactant was possibly due to the increased gas filling rate in the hydrate cavity.

  2. Hydrothermal Synthesis of a-calcium Sulfate Hemihydrate Particles Modified with Hydroxyapatite%水热合成羟基磷灰石表面修饰α-半水石膏复合颗粒

    Institute of Scientific and Technical Information of China (English)

    程逵; 章华勇; 翁文剑; 李坚; 黄海生

    2013-01-01

    The a-calcium sulfate hemihydrate particles modified with hydroxyapatite (HA) were prepared with calcium sulfate di-hydrate and HA in a mixed electrolyte solution of citric acid and magnesium sulfate by a co-hydrothermal method. The crystalline phase, morphology and microstructure of the HA modified a-calcium sulfate hemihydrate particles were characterized by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, differential scanning calorimetry and thermogravimetry, respectively. The results indicate that the composite particles after surface modification can be prepared by the co-hydrothermal synthesis method. The more HA could be deposited on the surface of a-calcium sulfate hemihydrate particles when the content of HA in the electrolyte was increased.%在柠檬酸和硫酸镁溶液中同时直接引入二水石膏与羟基磷灰石(hydroxyapatite,HA)共水热合成,获得了一种具有HA表面修饰的α-半水石膏的复合颗粒,并分析了该复合颗粒的成分、形貌、微观结构.结果表明:水热合成的颗粒是以α-半水石膏为主体,有HA在其表面修饰;随着HA的添加量的增加,HA表面修饰层的覆盖范围明显增加.

  3. Advances in understanding hydration of Portland cement

    Energy Technology Data Exchange (ETDEWEB)

    Scrivener, Karen L., E-mail: Karen.scrivener@epfl.ch [Laboratory of Construction Materials, Ecole Polytechnique Fédérale de Lausanne, 1015 (Switzerland); Juilland, Patrick [Sika Technology AG, Zürich (Switzerland); Monteiro, Paulo J.M. [Department of Civil and Environmental Engineering, University of California at Berkeley (United States)

    2015-12-15

    Progress in understanding hydration is summarized. Evidence supports the geochemistry dissolution theory as an explanation for the induction period, in preference to the inhibiting layer theory. The growth of C–S–H is the principal factor controlling the main heat evolution peak. Electron microscopy indicates that C–S–H “needles” grow from the surface of grains. At the peak, the surface is covered, but deceleration cannot be attributed to diffusion control. The shoulder peak comes from renewed reaction of C{sub 3}A after depletion of sulfate in solution, but release of sulfate absorbed on C–S–H means that ettringite continues to form. After several days space becomes the major factor controlling hydration. The use of new analytical technique is improving our knowledge of the action of superplasticizers and leading to the design of molecules for different applications. Atomistic modeling is becoming a topic of increasing interest. Recent publications in this area are reviewed.

  4. Standard test method for laboratory evaluation of magnesium sacrificial anode test specimens for underground applications

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1997-01-01

    1.1 This test method covers a laboratory procedure that measures the two fundamental performance properties of magnesium sacrificial anode test specimens operating in a saturated calcium sulfate, saturated magnesium hydroxide environment. The two fundamental properties are electrode (oxidation potential) and ampere hours (Ah) obtained per unit mass of specimen consumed. Magnesium anodes installed underground are usually surrounded by a backfill material that typically consists of 75 % gypsum (CaSO4·2H2O), 20 % bentonite clay, and 5 % sodium sulfate (Na2SO4). The calcium sulfate, magnesium hydroxide test electrolyte simulates the long term environment around an anode installed in the gypsum-bentonite-sodium sulfate backfill. 1.2 This test method is intended to be used for quality assurance by anode manufacturers or anode users. However, long term field performance properties may not be identical to property measurements obtained using this laboratory test. Note 1—Refer to Terminology G 15 for terms used ...

  5. Authigenic gypsum found in gas hydrate-associated sediments from Hydrate Ridge, the eastern North Pacific

    Institute of Scientific and Technical Information of China (English)

    WANG; Jiasheng; Erwin; Suess; Dirk; Rickert

    2004-01-01

    Characteristic gypsum micro-sphere and granular mass were discovered by binocular microscope in the gas hydrate-associated sediments at cores SO143-221 and SO143/TVG40-2A respectively on Hydrate Ridge of Cascadia margin, the eastern North Pacific. XRD patterns and EPA analyses show both micro-sphere and granular mass of the crystals have the typical peaks and the typical main chemical compositions of gypsum, although their weight percents are slightly less than the others in the non-gas hydrate-associated marine regions. SEM pictures show that the gypsum crystals have clear crystal boundaries, planes, edges and cleavages of gypsum in form either of single crystal or of twin crystals. In view of the fact that there are meanwhile gas hydrate-associated authigenic carbonates and SO42(-rich pore water in the same sediment cores, it could be inferred reasonably that the gypsums formed also authigenically in the gas hydrate-associated environment too, most probably at the interface between the downward advecting sulfate-rich seawater and the below gas hydrate, which spilled calcium during its formation on Hydrate Ridge. The two distinct forms of crystal intergrowth, which are the granular mass of series single gypsum crystals at core SO143/TVG40-2A and the microsphere of gypsum crystals accompanied with detrital components at core SO143-221 respectively, indicate that they precipitated most likely in different interstitial water dynamic environments. So, the distinct authigenic gypsums found in gas hydrate-associated sediments on Hydrate Ridge could also be believed as one of the parameters which could be used to indicate the presence of gas hydrate in an unknown marine sediment cores.

  6. Effect of Reactivity of Quick Lime on the Properties of Hydrated Lime Sorbent for SO2 Removal

    Institute of Scientific and Technical Information of China (English)

    H.G.Shin; H.Kim; Y.N.Kim; H.S.Lee

    2009-01-01

    The hydration of quick lime and the sulfation of hydrated lime were carried out for verification of relationship between the reactivity of quick lime and the properties of hydrated lime as a sorbent.The effect of reactivity of quick lime was investigated with the change of calcination temperature and time.Results obtained showed that the temperature rise during the hydration of quick limes varied from 31 to 69℃ with the variation of calcination temperature and time.The specific surface area and the sulfation ability of hydrated lime prepared by hydration of quick lime showed a proportional relationship with the reactivity of quick lime.The hydrated lime which was prepared by hydration of quick lime calcined at 1100℃ had the highest reactivity and showed 41.53 m2/g of the specific surface area, 0.16 cm3/g of the pore volume and 87% of the removal efficiency for SO2 removal.

  7. Magnesium induces neuronal apoptosis by suppressing excitability

    OpenAIRE

    Dribben, W H; Eisenman, L N; Mennerick, S

    2010-01-01

    In clinical obstetrics, magnesium sulfate (MgSO4) use is widespread, but effects on brain development are unknown. Many agents that depress neuronal excitability increase developmental neuroapoptosis. In this study, we used dissociated cultures of rodent hippocampus to examine the effects of Mg++ on excitability and survival. Mg++-induced caspase-3-associated cell loss at clinically relevant concentrations. Whole-cell patch-clamp techniques measured Mg++ effects on action potential threshold,...

  8. Corrosion behavior of magnesium and magnesium alloys

    Institute of Scientific and Technical Information of China (English)

    I.M.Baghni; WU Yin-shun(吴荫顺); LI Jiu-qing(李久青); ZHANG Wei(张巍)

    2004-01-01

    The automotive industry has crossed the threshold from using magnesium alloys in interior applications such as instrument panels and steering wheels to unprotected environment such as oil pan, cylinder head and wheels. The expanding territory of magnesium leads to new challenges: mainly environmental degradation of the alloys used and how they can be protected. The present critical review is aimed at understanding the corrosion behavior of magnesium and magnesium alloys in industrial and marine environments, and the effect of microstructure, additive elements and inhibitors on the corrosion mechanism.

  9. Research of magnesium phosphosilicate cement

    Science.gov (United States)

    Ding, Zhu

    Magnesium phosphosilicate cement (MPSC) is a novel phosphate bonded cement, which consists mainly of magnesia, phosphate and silicate minerals. The traditional magnesium phosphate cements (MPCs) usually composed by ammonium phosphate, and gaseous ammonia will emit during mixing and in service. There is no noxious ammonia released from MPSC, furthermore, it can recycle a large volume of the non-hazardous waste. The goal of this research is to investigate the composition, reaction products, reaction mechanism, microstructure, properties, durability and applications of the MPSC. MPSC sets rapidly and has high early strength. It reacts better with solid industrial waste when compared to Portland cement. Many solid industrial wastes, such as fly ash, steel slag, coal gangue, red coal gangue, red mud, barium-bearing slag, copper slag, silica fume, and ground granulated blast furnace slag, have been used as the main component (40% by weight) in MPSC. The research has found that these aluminosilicate (or ironsilicate, or calciumsilicate) minerals with an amorphous or glass structure can enhance the performance of MPSC. The disorganized internal structure of amorphous materials may make it possess higher reactivity compared to the crystalline phases. Chemical reaction between phosphate and these minerals may form an amorphous gel, which is favorable to the cementing. Borax, boric acid and sodium tripolyphosphate have been used as retardants in the MPSC system. It is found that boric acid has a higher retarding effect on the setting of cement, than borax does. However, sodium polyphosphate accelerates the reaction of MPSC. The hydration of MPSC is exothermic reaction. The heat evolution may prompt hydrates formation, and shorten the setting process. Modern materials characterization techniques, XRD, DSC, TG-DTA FTIR, XPS, MAS-NMR, SEM, TEM, MIP, etc. were used to analyze the phase composition, micro morphology, and microstructure of hardened MPSC. The main hydration product

  10. Threshold collision-induced dissociation of hydrated magnesium: experimental and theoretical investigation of the binding energies for Mg(2+)(H2O)x complexes (x=2-10).

    Science.gov (United States)

    Carl, Damon R; Armentrout, Peter B

    2013-03-18

    The sequential bond energies of Mg(2+)(H2O)x complexes, in which x=2-10, are measured by threshold collision-induced dissociation in a guided ion beam tandem mass spectrometer. From an electrospray ionization source that produces an initial distribution of Mg(2+)(H2O)x complexes in which x=7-10, complexes down to x=3 are formed by using an in-source fragmentation technique. Complexes smaller than Mg(2+)(H2O)3 cannot be formed in this source because charge separation into MgOH(+)(H2O) and H3O(+) is a lower-energy pathway than simple water loss from Mg(2+)(H2O)3. The kinetic energy dependent cross sections for dissociation of Mg(2+)(H2O)x complexes, in which x=3-10, are examined over a wide energy range to monitor all dissociation products and are modeled to obtain 0 and 298 K binding energies. Analysis of both primary and secondary water molecule losses from each sized complex provides thermochemistry for the sequential hydration energies of Mg(2+) for x=2-10 and the first experimental values for x=2-4. Additionally, the thermodynamic onsets leading to the charge-separation products from Mg(2+)(H2O)3 and Mg(2+)(H2O)4 are determined for the first time. Our experimental results for x=3-7 agree well with quantum chemical calculations performed here and previously calculated binding enthalpies, as well as previous measurements for x=6. The present values for x=7-10 are slightly lower than previous experimental results and theory, but within experimental uncertainties.

  11. 联合应用硫酸镁、TDP、低频脉冲治疗急性乳腺炎效果观察%Effect observation of combined treatment by magnesium sulfate, TDP, and low frequency impulse for acute mastitis

    Institute of Scientific and Technical Information of China (English)

    杨建丽

    2015-01-01

    目的:探讨联合应用硫酸镁、TDP、低频脉冲治疗急性乳腺炎的临床疗效,进一步指导临床。方法160例急性乳腺炎患者,随机分为观察组和对照组,各80例,对照组患者采用硫酸镁湿热敷同步 TDP 照射,观察组在对照组基础上协同低频脉冲治疗急性乳腺炎。对两组的临床治疗效果、治疗时间、体温恢复时间、肿块消除时间等进行对比分析。结果观察组的临床总有效率96.25%明显高于对照组的77.50%,差异具有统计学意义(P<0.05),观察组治疗时间、体温恢复时间、肿块消除时间明显短于对照组,差异具有统计学意义(P<0.05)。结论联合应用硫酸镁、TDP、低频脉冲治疗急性乳腺炎临床疗效确切,值得进一步推广应用。%Objective To investigate the clinical effect of combined treatment by magnesium sulfate, TDP, and low frequency impulse for acute mastitis, in order to provide further clinical guide. Methods A total of 160 acute mastitis patients were randomly divided into observation group and control group, with 80 cases in each group. The control group received magnesium sulfate hot-wet compression combined with TDP irradiation. The observation group received additional low frequency impulse for acute mastitis treatment. Clinical effects, treatment time, recovery time of body temperature, and eliminate time of lump of the two groups were comparatively analyzed. Results The observation group had much higher clinical totally effective rate as 96.25% than 77.50%the control group, and their difference had statistical significance (P<0.05). It also had obviously shorter treatment time, recovery time of body temperature, and eliminate time of lump than the control group, and their difference had statistical significance (P<0.05). Conclusion Combination of magnesium sulfate, TDP, and low frequency impulse has precise effect for treating acute mastitis, and it is worthy of further promotion and

  12. 低分子肝素钙联合硫酸镁与酚妥拉明治疗肺源性心脏病急性加重期的效果%Clinical effect of low molecular heparin calcium combined with magnesium sulfate and phentolamine on acute exacerbation of pulmonary heart disease

    Institute of Scientific and Technical Information of China (English)

    李良玉

    2015-01-01

    Objective To observe the clinical effect of low molecular heparin calcium combined with magnesium sulfate and phentolamine on acute exacerbation of pulmonary heart disease.Methods One hundred and eight pulmonary heart disease patients in acute aggravating period were randomly divided into two groups:the treatment group with 54 cases and the control with 54 cases.The two groups were routinely given anti-infection,oxygen,cough expectorant,spasmolysis and asthma,strong heart,diuresis,correct electrolyte disturbances and so on.In addition,the patients in the treatment group were given low molecular heparin calcium,magnesium sulfate and phentolamine injection,taken 10 d as a course of treatment.The therapeutic effect,the difference of hemorrheology and blood gas analysis indexes before and after treatment between the two groups were observed.Results The total effectiveness of the treatment group was 88.9%,and the total effectiveness of the control group was 70.4%,the curative effect of the treatment group was better than that of the control group (P < 0.05) ; the improvement of blood gas analysis indexes in the treatment group were much better than those in the control group (all P < 0.05).Conclusions There is a good synergistic effect when low molecular heparin calcium combined with magnesium sulfate and phentolamine in the treatment of patients with acute exacerbation of pulmonary heart disease.It can improve the cardiopulmonary function and the prognosis of patients with pulmonary heart disease,and can be popularized in clinical application.%目的 观察低分子肝素钙联合硫酸镁、酚妥拉明治疗肺源性心脏病急性加重期的临床效果.方法 选择商丘市第四人民医院收治的符合入选标准的肺源性心脏病急性加重期患者108例,随机分为治疗组54例和对照组54例,两组患者均常规给予抗感染、吸氧、止咳祛痰、解痉平喘、强心利尿、纠正电解质紊乱等治疗,治疗组在常规治疗

  13. Observation of clinical effect by magnesium sulfate combined with nifedipine and phentolamine in the treatment of pregnancy-induced hypertension%硫酸镁联合硝苯地平和酚妥拉明治疗妊高症临床疗效观察

    Institute of Scientific and Technical Information of China (English)

    钟燕珍; 林凤琼; 谭小平

    2015-01-01

    目的:观察硫酸镁联合硝苯地平和酚妥拉明治疗妊娠高血压综合征(妊高症, PIH)的临床疗效。方法105例PIH患者,随机分为观察组(联合用药)53例,对照组(单一用药)52例。其中对照组单用25%硫酸镁静脉滴注;观察组采用联合用药治疗,即在对照组静脉滴注25%硫酸镁的基础上,给予酚妥拉明同时口服硝苯地平控释片治疗。两组患者均治疗7 d。观察治疗效果。结果治疗7 d后,观察组总有效率96.2%,对照组总有效率75.0%,观察组临床疗效明显优于对照组,组间比较差异具有统计学意义(P<0.05),两组治疗后平均动脉压(MAP)、红细胞比容(HCT)、24 h尿蛋白定量(PRO-U)及脐动脉血流速度峰谷比(S/D)较治疗前均有明显改善,组内比较差异有统计学意义(P<0.05),两组治疗后各观察指标组间比较,差异具有统计学意义(P<0.05)。结论硫酸镁联合硝苯地平和酚妥拉明治疗PIH,降压平稳,解痉作用强,临床疗效显著,可有效减少围生期并发症的发生。%ObjectiveTo observe clinical effect by magnesium sulfate combined with nifedipine and phentolamine in the treatment of pregnancy-induced hypertension (PIH).MethodsA total of 105 PIH patients were randomly divided into observation group (combined medication) with 53 cases and control group (single medication) with 52 cases. The control group received 25% magnesium sulfate by intravenous drip. The observation group received additional phentolamine and oral administration of nifedipine tablets. Treatment for both groups lasted for 7 d. Their curative effects were observed.ResultsAfter 7 d of treatment, the total effective rate was 96.2% in the observation group, and 75.0% in the control group. The observation group had much better clinical effect than the control group, and their difference had statistical significance (P<0.05). Both groups had improved mean arterial pressure (MAP), hematocrit value (HCT), 24 h urine protein

  14. Clinical analysis of phentolamine magnesium sulfate combining with nifedipine in treatment of pregnancy induced hypertension%硫酸镁联合酚妥拉明及硝苯地平治疗妊娠高血压综合征的临床效果分析

    Institute of Scientific and Technical Information of China (English)

    余晓梅; 桂定清

    2012-01-01

    OBJECTIVE To explore the clinical effects of magnesium sulfate combined with phentolamine and nifedipine in the treatment of pregnancy induced hypertension. METHODS Selected 100 cases of pregnancy induced hypertension patients in our hospital from July 2009 to December 2011. Depending on the medication of the patients during hospitalization, all patients were divided into control group (re = 50) and the observation group (n = 50). The control group was given magnesium sulfate treatment, based on this, the observation group was given phentolamine and nifedipineamlodipine treatment, clinical efficacies in two groups were compared. RESULTS The clinical efficacy of the observation group was significantly better than the control group, a statistically significant difference (P < 0.05); the end of treatment, various clinical indicators demonstrated greater improvement than the control group, the differences were statistically significant (P< 0.05) ; the main complications of uterine inertia, fetal distress, neonatal asphyxia, postpartum hemorrhage during delivery period in the observation group were less than the control group, the differences were statistically significant (P < 0.05). CONCLUSION Magnesium sulfate combined with phentolamine and nifedipine in the treatment of pregnancy induced hypertension can significantly improve the clinical efficacy and reduce the incidence of a variety of complications.%目的 探讨硫酸镁联合酚妥拉明及硝苯地平治疗妊娠高血压综合征的临床效果.方法 入选2009年7月~2011年12月在某院住院的妊娠期高血压综合征患者100例,根据患者在住院期间用药的不同将所有患者分为对照组(n=50)和观察组(n=50),对照组给予硫酸镁治疗,观察组在此基础上增加酚妥拉明及硝苯地平治疗,比较两组患者临床疗效.结果 观察组患者临床疗效显著优于对照组,差异具有统计学意义(P<0.05);治疗结束后,观察组患者各项临床指标改善

  15. Meta analysis of the comparison of the effects between external application with Aloe vera and wet dressings with Magnesium sulfate in the treatment of phlebitis%芦荟外敷与硫酸镁湿敷治疗静脉炎效果比较Meta分析

    Institute of Scientific and Technical Information of China (English)

    李娜

    2011-01-01

    目的:评价芦荟外敷治疗静脉炎的效果及安全性.方法:通过检索中国期刊全文数据库(CNKI)、中文科技期刊数据库(VIP)和万方数据库截至2010年8月公开发表的、报道芦荟与常规硫酸镁湿敷治疗静脉炎的随机对照试验和临床对照试验文献,运用Cochrane系统评价方法的质量评价标准和RevMan4.2分析软件进行纳入研究的分析.结果:共纳入7 篇文献,共712例,芦荟组369例,硫酸镁组343例,合并相对危险度(RR)值及95%可信区间(CI)为1.24(1.17,1.32),总的效应检验Z=6.80(P<0.000 01).结论:芦荟外敷治疗静脉炎优于传统的硫酸镁湿敷,可作为临床证据,但今后需要更多大样本、严格设计的随机对照试验进一步验证与支持.%Objective: To evaluate the efficacy and safety of the external application with Aloe vera in the treatment of phlebitis. Methods: By researching the literatures ( published up to August 2010 ) concerning the randomized controlled trials and clinical controlled trials in the treatment of phlebitis with Aloe vera and by wet dressings with Magnesium sulfate from Chinese National Knowledge Infrastructure ( CNKI ), VIP Database for Chinese Technical Periodicals ( VIP ) and Wanfang Database, the quality evaluation criteria of Cochrane systematic review methods and RevMan 4. 2 analysis software were adopted to make the a-nalysis of included study. Results: 7 documents were included in the study ( 712 cases ), including 369 cases treated with Aloe vera and 343 cases with Magnesium sulfate. The combined relative risk ( RR ) value and 95% confidence interval ( CI) was 1. 24 ( 1. 17 , 1. 32 ); the total effects of test was Z = 6. 80 ( P <0. 000 01 ). Conclusion: The effect of external application with Aloe vera was better than that of wet dressings with Magnesium sulfate in the treatment of phlebitis, which can be used as the clinical evidence. But the results need to be further validated by a large sample and the strictly

  16. Serum magnesium in the first week of life in extremely low birth weight infants.

    LENUS (Irish Health Repository)

    Noone, D

    2012-01-01

    Evidence that antenatal administration of magnesium sulfate (MgSO(4)) to women in preterm labor may confer fetal neuroprotection is growing. MgSO(4) crosses the placenta and can affect the neonate. Magnesium homeostasis in extremely low birth weight (ELBW) infants remains to be clarified.

  17. Choline Magnesium Trisalicylate

    Science.gov (United States)

    Choline magnesium trisalicylate is used to relieve the pain, tenderness, inflammation (swelling), and stiffness caused by arthritis and painful ... used to relieve pain and lower fever. Choline magnesium trisalicylate is in a class of nonsteroidal anti- ...

  18. Low magnesium level

    Science.gov (United States)

    Treating the condition that is causing low magnesium can help. If you play sports or do other vigorous activity, drink fluids such as sports drinks that contain electrolytes to keep your magnesium level in a healthy range.

  19. Clinical Effect Evaluation for Magnesium Sulfate in Combination With Nifedipine for the Treatment of Pregnancy-induced Hypertension Syndrome%硫酸镁联合硝苯地平治疗妊娠高血压综合征的临床效果评价

    Institute of Scientific and Technical Information of China (English)

    高洪艳

    2015-01-01

    Objective To investigate the focusing on patients with pregnancy induced hypertension syndrome, to observe the clinical effect of magnesium sulfate + nifedipine selected to obtained after completion of therapy. Methods 102 cases of patients with hypertension syndrome in our hospital from Feb.2012 to Feb.2015. The average divided into two groups, the clinical Magnesium sulfate + nifedipine treatment. The blood pressure and blood pressure of two groups of patients with pregnancy induced hypertension were compared. Results After treatment, the blood pressure of the two groups was significantly lower, and the B1 group was significantly lower than that of the patients with B2 (P<0.05). Conclusion The clinical value of combined medication in the treatment of patients with pregnancy induced hypertension was the clinical value of the combination therapy for patients with pregnancy induced hypertension.%目的探讨针对妊娠高血压综合征患者,观察选择硫酸镁+硝苯地平完成治疗后获得的临床效果。方法选取我院2012年2月~2015年2月妊娠高血压综合征患者102例。平均分为两组,临床选择硫酸镁+硝苯地平进行治疗。对比两组妊高症患者完成治疗后在血压水平等方面。结果两组患者完成治疗后,患者的血压表现为显著降低,并且 B1组低于 B2组(P <0.05)。结论针对患者自身以及胎儿进行有效保护,联合用药治疗妊高症患者有临床价值。

  20. Magnesium protects cognitive functions and synaptic plasticity in streptozotocin-induced sporadic Alzheimer's model.

    Directory of Open Access Journals (Sweden)

    Zhi-Peng Xu

    Full Text Available Alzheimer's disease (AD is characterized by profound synapse loss and impairments of learning and memory. Magnesium affects many biochemical mechanisms that are vital for neuronal properties and synaptic plasticity. Recent studies have demonstrated that the serum and brain magnesium levels are decreased in AD patients; however, the exact role of magnesium in AD pathogenesis remains unclear. Here, we found that the intraperitoneal administration of magnesium sulfate increased the brain magnesium levels and protected learning and memory capacities in streptozotocin-induced sporadic AD model rats. We also found that magnesium sulfate reversed impairments in long-term potentiation (LTP, dendritic abnormalities, and the impaired recruitment of synaptic proteins. Magnesium sulfate treatment also decreased tau hyperphosphorylation by increasing the inhibitory phosphorylation of GSK-3β at serine 9, thereby increasing the activity of Akt at Ser473 and PI3K at Tyr458/199, and improving insulin sensitivity. We conclude that magnesium treatment protects cognitive function and synaptic plasticity by inhibiting GSK-3β in sporadic AD model rats, which suggests a potential role for magnesium in AD therapy.

  1. Hydration of Portland cement with additions of calcium sulfoaluminates

    Energy Technology Data Exchange (ETDEWEB)

    Le Saout, Gwenn, E-mail: gwenn.le-saout@mines-ales.fr [Empa, Swiss Federal Laboratories for Materials Science and Technology, Concrete and Construction Chemistry Laboratory, Ueberlandstrasse 129, CH-8600 Duebendorf (Switzerland); Lothenbach, Barbara [Empa, Swiss Federal Laboratories for Materials Science and Technology, Concrete and Construction Chemistry Laboratory, Ueberlandstrasse 129, CH-8600 Duebendorf (Switzerland); Hori, Akihiro [DENKA Chemicals GmbH, Wehrhahn-Center, Cantadorstr. 3, D-40211 Duesseldorf (Germany); Higuchi, Takayuki [Denki Kagaku Kogyo Kabushiki Kaisha (DENKA), Omi, Itoigawa, Niigata, 949-0393 (Japan); Winnefeld, Frank [Empa, Swiss Federal Laboratories for Materials Science and Technology, Concrete and Construction Chemistry Laboratory, Ueberlandstrasse 129, CH-8600 Duebendorf (Switzerland)

    2013-01-15

    The effect of mineral additions based on calcium aluminates on the hydration mechanism of ordinary Portland cement (OPC) was investigated using isothermal calorimetry, thermal analysis, X-ray diffraction, scanning electron microscopy, solid state nuclear magnetic resonance and pore solution analysis. Results show that the addition of a calcium sulfoaluminate cement (CSA) to the OPC does not affect the hydration mechanism of alite but controls the aluminate dissolution. In the second blend investigated, a rapid setting cement, the amorphous calcium aluminate reacts very fast to ettringite. The release of aluminum ions strongly retards the hydration of alite but the C-S-H has a similar composition as in OPC with no additional Al to Si substitution. As in CSA-OPC, the aluminate hydration is controlled by the availability of sulfates. The coupling of thermodynamic modeling with the kinetic equations predicts the amount of hydrates and pore solution compositions as a function of time and validates the model in these systems.

  2. Magnesium and Space Flight.

    Science.gov (United States)

    Smith, Scott M; Zwart, Sara R

    2015-12-08

    Magnesium is an essential nutrient for muscle, cardiovascular, and bone health on Earth, and during space flight. We sought to evaluate magnesium status in 43 astronauts (34 male, 9 female; 47 ± 5 years old, mean ± SD) before, during, and after 4-6-month space missions. We also studied individuals participating in a ground analog of space flight (head-down-tilt bed rest; n = 27 (17 male, 10 female), 35 ± 7 years old). We evaluated serum concentration and 24-h urinary excretion of magnesium, along with estimates of tissue magnesium status from sublingual cells. Serum magnesium increased late in flight, while urinary magnesium excretion was higher over the course of 180-day space missions. Urinary magnesium increased during flight but decreased significantly at landing. Neither serum nor urinary magnesium changed during bed rest. For flight and bed rest, significant correlations existed between the area under the curve of serum and urinary magnesium and the change in total body bone mineral content. Tissue magnesium concentration was unchanged after flight and bed rest. Increased excretion of magnesium is likely partially from bone and partially from diet, but importantly, it does not come at the expense of muscle tissue stores. While further study is needed to better understand the implications of these findings for longer space exploration missions, magnesium homeostasis and tissue status seem well maintained during 4-6-month space missions.

  3. Nutrition and magnesium absorption.

    NARCIS (Netherlands)

    Brink, E.J.

    1992-01-01

    The influence of various nutrients present in dairy products and soybean-based products on absorption of magnesium has been investigated. The studies demonstrate that soybean protein versus casein lowers apparent magnesium absorption in rats through its phytate component. However, true magnesium abs

  4. Magnesium and Space Flight

    Science.gov (United States)

    Smith, Scott M.; Zwart, Sara R.

    2016-01-01

    Magnesium is an essential nutrient for muscle, cardiovascular, and bone health on Earth, and during space flight. We sought to evaluate magnesium status in astronauts before, during, and after space missions, in 43 astronauts (34 male, 9 female) on 4-6 month space flight missions. We also studied individuals participating in a ground analog of space flight, (head-down tilt bed rest, n=27, 35 +/- 7 y). We evaluated serum concentration and 24-hour urinary excretion of magnesium along with estimates of tissue magnesium status from sublingual cells. Serum magnesium increased late in flight, while urinary magnesium excretion was higher over the course of 180-d space missions. Urinary magnesium increased during flight but decreased significantly at landing. Neither serum nor urinary magnesium changed during bed rest. For flight and bed rest, significant correlations existed between the area under the curve of serum and urinary magnesium and the change in total body bone mineral content. Tissue magnesium concentration was unchanged after flight and bed rest. Increased excretion of magnesium is likely partially from bone and partially from diet, but importantly, it does not come at the expense of muscle tissue stores. While further study is needed to better understand the implications of these findings for longer space exploration missions, magnesium homeostasis and tissue status seem well maintained during 4- to 6-month space missions.

  5. Use of quartz crystal microbalance to study the effect of chloride, sulphate and magnesium ions on the scaling rate; Apport de la microbalance a quartz dans l'etude de l'influence des ions sulfate, chlorure et magnesium sur la cinetique d'entartrage

    Energy Technology Data Exchange (ETDEWEB)

    Ben Amor, Y.; Triki, E. [Ecole Nationale d' Ingenieurs de Tunis, Unite de Recherche Corrosion et Protection des Metalliques (Tunisia); Bousselmi, I. [Institut National de Recherche Scientifique et Technologique, Lab. des Eaux et Environnement, Hammam-Lif (Tunisia); Sutter, E.; Labbe, J.P.; Fiaud, C. [Universite Pierre et Marie Curie, Lab. de Genie des Procedes Plasmas et Traitements de Surface, 75 - Paris (France)

    2004-07-01

    In this work, an electrochemical quartz crystal microbalance was used to study the effect of chloride, sulphate and magnesium ions on the scaling rate of gold in synthesized water. The chrono-electro-gravimetric results allow the evaluation of the nucleation and crystal growth steps. Infrared analysis of deposits was used to interpret the kinetic data, particularly in SO{sub 4}{sup 2-} and Mg{sup 2+} containing. Threshold effects were identified in each situation and essentially attributed to adsorption phenomena of ions on the metal and/or on the scale layers, as indicated by the influence of electrode potential and concentration of ions in solutions. (authors)

  6. Controls on Gas Hydrate Formation and Dissociation

    Energy Technology Data Exchange (ETDEWEB)

    Miriam Kastner; Ian MacDonald

    2006-03-03

    The main objectives of the project were to monitor, characterize, and quantify in situ the rates of formation and dissociation of methane hydrates at and near the seafloor in the northern Gulf of Mexico, with a focus on the Bush Hill seafloor hydrate mound; to record the linkages between physical and chemical parameters of the deposits over the course of one year, by emphasizing the response of the hydrate mound to temperature and chemical perturbations; and to document the seafloor and water column environmental impacts of hydrate formation and dissociation. For these, monitoring the dynamics of gas hydrate formation and dissociation was required. The objectives were achieved by an integrated field and laboratory scientific study, particularly by monitoring in situ formation and dissociation of the outcropping gas hydrate mound and of the associated gas-rich sediments. In addition to monitoring with the MOSQUITOs, fluid flow rates and temperature, continuously sampling in situ pore fluids for the chemistry, and imaging the hydrate mound, pore fluids from cores, peepers and gas hydrate samples from the mound were as well sampled and analyzed for chemical and isotopic compositions. In order to determine the impact of gas hydrate dissociation and/or methane venting across the seafloor on the ocean and atmosphere, the overlying seawater was sampled and thoroughly analyzed chemically and for methane C isotope ratios. At Bush hill the pore fluid chemistry varies significantly over short distances as well as within some of the specific sites monitored for 440 days, and gas venting is primarily focused. The pore fluid chemistry in the tub-warm and mussel shell fields clearly documented active gas hydrate and authigenic carbonate formation during the monitoring period. The advecting fluid is depleted in sulfate, Ca Mg, and Sr and is rich in methane; at the main vent sites the fluid is methane supersaturated, thus bubble plumes form. The subsurface hydrology exhibits both

  7. Magnesium and the Athlete.

    Science.gov (United States)

    Volpe, Stella Lucia

    2015-01-01

    Magnesium is the fourth most abundant mineral and the second most abundant intracellular divalent cation in the body. It is a required mineral that is involved in more than 300 metabolic reactions in the body. Magnesium helps maintain normal nerve and muscle function, heart rhythm (cardiac excitability), vasomotor tone, blood pressure, immune system, bone integrity, and blood glucose levels and promotes calcium absorption. Because of magnesium's role in energy production and storage, normal muscle function, and maintenance of blood glucose levels, it has been studied as an ergogenic aid for athletes. This article will cover the general roles of magnesium, magnesium requirements, and assessment of magnesium status as well as the dietary intake of magnesium and its effects on exercise performance. The research articles cited were limited from those published in 2003 through 2014.

  8. Estudo controlado do uso endovenoso de sulfato de magnésio ou de salbutamol no tratamento precoce da crise de asma aguda grave em crianças Randomized clinical trial of intravenous magnesium sulfate versus salbutamol in the early management of severe acute asthma in children

    Directory of Open Access Journals (Sweden)

    João Carlos Santana

    2001-08-01

    Full Text Available OBJETIVOS: estudar os efeitos da administração endovenosa de sulfato de magnésio (MgEV ou de salbutamol (SalbEV em crianças com crise de asma aguda. MÉTODOS: estudo randomizado, duplo-cego e controlado por placebo. Incluídas crianças maiores de 2 anos admitidas em sala de observação com crise de asma aguda grave (refratária a três nebulizações com beta-adrenérgicos. Após a admissão, recebiam tratamento convencional (oxigênio, corticóides, nebulizações com beta-adrenérgicos e eram alocadas a receber uma de três soluções indistinguíveis entre si: a MgEV (50 mg/kg; b SalbEV (20 µg/kg; ou c solução salina, que eram administradas em 20 minutos (1ml/kg/hora. Avaliações clínicas, dosagens de eletrólitos e gases arteriais foram registrados antes e 1 hora após a infusão das drogas. RESULTADOS: foram estudados 50 pacientes (+ 4,5 anos e 53% de meninas, sem diferenças significativas entre os 3 grupos. No grupo MgEV, observou-se redução da pressão arterial durante a infusão, que retornou ao normal 1 hora após, associado com aumento (p OBJECTIVE: To study the efficacy of intravenous magnesium sulfate and intravenous salbutamol in the treatment of severe asthma in children. METHODS: Randomized, double-blind, placebo-controlled clinical trial, including children above 2 years of age with severe acute asthma admitted to the observation ward of the Pediatric Intensive Care Unit of Hospital São Lucas. All patients received conventional treatment (oxygen, corticoids, beta-adrenergics on admission, and later received one of the following solutions: a IVMg (50 mg/kg; b intravenous salbutamol (20 µg/kg; c saline solution (1 ml/kg/min. Clinical assessments, electrolyte concentration, and arterial blood gas analyses were recorded before intravenous infusion and one hour after that. RESULTS: Fifty patients participated in this study (of whom 53% were females, mean age = 4.5 years. There were no significant differences among the

  9. Magnesium and Osteoporosis

    Directory of Open Access Journals (Sweden)

    Ferda Özdemir

    2004-03-01

    Full Text Available Osteoporosis (OP is a condition of bone fragility resulting from micro-architectural deterioration and decreased bone mass. OP depends on the interaction of genetic, hormonal, environmental and nutritional factors. Chronic low intakes of vitamin D and possibly magnesium, zinc, fluoride and vitamins K, B12, B6 and folic acid may predispose to osteoporosis. Magnesium is a mineral needed by every cell of your body. It helps maintain normal muscle and nerve function, keeps heart rhythm steady, and bones strong. Mg serves as co-factors for enzymes that help build bone matrix. Magnesium deficiency occurs due to excessive loss of magnesium in urine, gastrointestinal system disorders that cause a loss of magnesium or limit magnesium absorption, or a chronic low intake of magnesium. Signs of magnesium deficiency include confusion, disorientation, loss of appetite, depression, muscle contractions and cramps, tingling, numbness, abnormal heart rhythms, coronary spasm, and seizures. Magnesium deficiency alters calcium metabolism and the hormones that regulates calcium. Several studies have suggested that magnesium supplementation may improve bone mineral density and prevent fractures.

  10. Origins of hydration lubrication.

    Science.gov (United States)

    Ma, Liran; Gaisinskaya-Kipnis, Anastasia; Kampf, Nir; Klein, Jacob

    2015-01-14

    Why is friction in healthy hips and knees so low? Hydration lubrication, according to which hydration shells surrounding charges act as lubricating elements in boundary layers (including those coating cartilage in joints), has been invoked to account for the extremely low sliding friction between surfaces in aqueous media, but not well understood. Here we report the direct determination of energy dissipation within such sheared hydration shells. By trapping hydrated ions in a 0.4-1 nm gap between atomically smooth charged surfaces as they slide past each other, we are able to separate the dissipation modes of the friction and, in particular, identify the viscous losses in the subnanometre hydration shells. Our results shed light on the origins of hydration lubrication, with potential implications both for aqueous boundary lubricants and for biolubrication.

  11. Polyethylene Glycol Drilling Fluid for Drilling in Marine Gas Hydrates-Bearing Sediments: An Experimental Study

    OpenAIRE

    Lixin Kuang; Yibing Yu; Yunzhong Tu; Ling Zhang; Fulong Ning; Guosheng Jiang; Tianle Liu

    2011-01-01

    Shale inhibition, low-temperature performance, the ability to prevent calcium and magnesium-ion pollution, and hydrate inhibition of polyethylene glycol drilling fluid were each tested with conventional drilling-fluid test equipment and an experimental gas-hydrate integrated simulation system developed by our laboratory. The results of these tests show that drilling fluid with a formulation of artificial seawater, 3% bentonite, 0.3% Na 2 CO 3 , 10% polyethylene glycol, 20% NaCl, 4% SMP-2, 1% ...

  12. Sulfate inhibition effect on sulfate reducing bacteria

    Directory of Open Access Journals (Sweden)

    Sulaiman Al Zuhair

    2008-12-01

    Full Text Available There is an increasing interest in the potential of bacterial sulfate reduction as an alternative method for sulfate removal from wastewater. Under anaerobic conditions, sulfate-reducing bacteria (SRB utilize sulfate to oxidize organic compounds and generate sulfide (S2-. SRB were successfully isolated from sludge samples obtained from a local petroleum refinery, and used for sulfate removal. The effects of initial sulfate concentration, temperature and pH on the rate of bacterial growth and anaerobic sulfate removal were investigated and the optimum conditions were identified. The experimental data were used to determine the parameters of two proposed kinetic model, which take into consideration substrate inhibition effect. Keywords: Sulfate Reducing Bacteria, Sulfate, Kinetic Model, Biotreatement, Inhibition Received: 31 August 2008 / Received in revised form: 18 September 2008, Accepted: 18 September 2008 Published online: 28 September 2008

  13. Preparation of magnesium phosphate cement by recycling the product of thermal transformation of asbestos containing wastes

    OpenAIRE

    2014-01-01

    Asbestos containing wastes have been employed for the first time in the formulation of magnesium phosphate cements. Two samples were mixed with magnesium carbonate and calcined at 1100 and 1300 C. Under these conditions, complete destruction of asbestos minerals is known to occur. The product, containing MgO, after reaction with water-soluble potassium di-hydrogen phosphate, led to the formation of hydrated phases at room temperature. Crystalline and amorphous reaction products were detected,...

  14. Magnesium for neuroprotection in birth asphyxia

    Directory of Open Access Journals (Sweden)

    Geeta Gathwala

    2010-01-01

    Full Text Available Background : Magnesium ion gates the N-methyl-D-aspartate (NMDA receptor and may protect the brain from NMDA receptor-mediated asphyxial injury. The present study evaluated the neuroprotective role of magnesium in birth asphyxia. Material and Methods : Forty term neonates with severe birth asphyxia were randomized to either the study group or the control group. Neonates in the study group received magnesium sulfate in a dose of 250 mg/kg initially within half an hour of birth followed by 125 mg/kg at 24 and 48 h of birth. Cranial computed tomography (CT scan and electroencephalography (EEG were performed for all the babies. Denver II was used for developmental assessment at the age of 6 months. Results : Two babies in each group died of severe hypoxic ischemic encephalopathy. EEG abnormalities occurred in 43.75% of the cases in the control group compared with 31.25% in the study group. CT scan abnormalities were present in 62.5% of the control group compared with 37.5% of the cases in the study group. The Denver II assessment at 6 months revealed that there were five babies that were either abnormal or suspect in the control group compared with three in the study group. Conclusion : Magnesium is well tolerated and does appear to have beneficial effects in babies with severe asphyxia. More data is however needed and a large multicenter trial should be conducted.

  15. Hydration Assessment of Athletes

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ KEY POINTS · Although there is no scientific consensus for 1 ) howbest to assess the hydration status of athletes, 2)what criteria to use as acceptable outcome measurements, or 3) the best time to apply practical assessment methods, there are methods that can be used toprovide athletes with useful feedback about their hydration status

  16. Magnesium for Hydrogen Storage

    DEFF Research Database (Denmark)

    Vigeholm, B.; Kjøller, John; Larsen, Bent

    1980-01-01

    The reaction of hydrogen with commercially pure magnesium powder (above 99.7%) was investigated in the temperature range 250–400 °C. Hydrogen is readily sorbed above the dissociation pressure. During the initial exposure the magnesium powder sorbs hydrogen slowly below 400 °C but during the second...

  17. 硫酸镁联合硝苯地平对妊娠高血压综合征的治疗效果分析%Analysis of effect of magnesium sulfate in combination with nifedipine in treatment of pregnancy - induced hy-pertension syndrome

    Institute of Scientific and Technical Information of China (English)

    梁雅倩

    2015-01-01

    Objective To study effect of the magnesium sulfate combined nifedipine were selected and treatment of pregnancy - induced hypertension syndrome. Method 172 cases of pregnancy - induced hypertension syndrome were selected and randomly divided into obser-vation group and control group,86 cases in each group. The control group given magnesium sulfate treatment,on the basis of the observation group was given nifedipine treatment. On two groups of clinical curative effect,systolic pressure,diastolic blood pressure before and after treatment and the 24 h urine protein quantity change and pregnancy outcomes were observed. Results The observation group treatment ef-fective rate of 95. 35% ,82. 56% of high significantly shorter than the control group(P < 0. 05);Observation group after treatment respec-tively systolic and diastolic blood pressure(85. 73 ± 5. 42)mm Hg(1 mm Hg = 0. 1333 kPa),(130. 83 ± 9. 24)mm Hg,were significantly lower than in the control group[(94. 63 ± 5. 48)mm Hg,(152. 11 ± 9. 30)]mm Hg(P < 0. 05);Observation group after treatment for 24 h urine protein total(0. 97 ± 0. 16)g/ L,significantly lower than the control group(1. 78 ± 0. 32)g/ L(P < 0. 05);Observation group of preterm labor,placental abruption,the cause of postpartum hemorrhage,and neonatal respiratory distress and death rate were significantly lower than control group(P < 0. 05). Conclusion Magnesium sulfate in combination with nifedipine can significantly alleviate the symp-toms in patients with pregnancy - induced hypertension syndrome,has good curative effect,significantly improve the pregnancy outcome,is worthy of promotion and use.%目的:探讨硫酸镁联合硝苯地平对妊娠高血压综合征的治疗效果。方法:选取妊娠高血压综合征或者172例,数字随机分为观察组和对照组,每组86例。对照组给予硫酸镁治疗,在此基础上观察组给予硝苯地平治疗。对两组临床疗效,治疗前后收缩压、舒张压和24 h 尿蛋白

  18. Hydration rate of obsidian.

    Science.gov (United States)

    Friedman, I; Long, W

    1976-01-30

    The hydration rates of 12 obsidian samples of different chemical compositions were measured at temperatures from 95 degrees to 245 degrees C. An expression relating hydration rate to temperature was derived for each sample. The SiO(2) content and refractive index are related to the hydration rate, as are the CaO, MgO, and original water contents. With this information it is possible to calculate the hydration rate of a sample from its silica content, refractive index, or chemical index and a knowledge of the effective temperature at which the hydration occurred. The effective hydration temperature can be either measured or approximated from weather records. Rates have been calculated by both methods, and the results show that weather records can give a good approximation to the true EHT, particularly in tropical and subtropical climates. If one determines the EHT by any of the methods suggested, and also measures or knows the rate of hydration of the particular obsidian used, it should be possible to carry out absolute dating to +/- 10 percent of the true age over periods as short as several years and as long as millions of years.

  19. Limestone reaction in calcium aluminate cement–calcium sulfate systems

    Energy Technology Data Exchange (ETDEWEB)

    Bizzozero, Julien, E-mail: julien.bizzozero@gmail.com; Scrivener, Karen L.

    2015-10-15

    This paper reports a study of ternary blends composed of calcium aluminate cement, calcium sulfate hemihydrate and limestone. Compressive strength tests and hydration kinetics were studied as a function of limestone and calcium sulfate content. The phase evolution and the total porosity were followed and compared to thermodynamic simulation to understand the reactions involved and the effect of limestone on these binders. The reaction of limestone leads to the formation of hemicarboaluminate and monocarboaluminate. Increasing the ratio between sulfate and aluminate decreases the extent of limestone reaction.

  20. Magnesium and Ketamine Gargle and Postoperative Sore Throat.

    Science.gov (United States)

    Teymourian, Houman; Mohajerani, Seyed Amir; Farahbod, Alireza

    2015-06-01

    Postoperative sore throat is one of the most common complications after endotracheal intubation. Both Ketamine and magnesium can block N-methyl-D-aspartic acid (NMDA) receptors and provide central and local analgesia. To compare the effect of magnesium sulfate and ketamine gargle on the incidence and severity of postoperative sore throat. A total of 100 patients candidate for emergency acute appendicitis surgery were enrolled in the study. Patients in ketamine group received ketamine gargle (0.5 mg/kg) and magnesium group received magnesium sulfate gargle (20 mg/kg up to 30 mL dextrose water 20%) 15 minutes before the operation. Patient complaint of postoperative sore throat, and its severity measured by visual analogue scale (VAS) were recorded at baseline in recovery room, and then 2, 4, and 24 hours after operation. There were no significant differences between age, sex, and body mass index (BMI) between two groups of patients. Hemodynamics of patients, including blood pressure, respiratory rate, oxygen saturation %, and conscious state were not significantly different (P > 0.05). Number of patients with sore throat were significantly lower in magnesium group compared to ketamine group at 2 (P = 0.032), 4 (P = 0.02), and 24 hours (P = 0.01) after the operation. Sore throat pain score (VAS) was significantly lower in magnesium group compared to ketamine group at 2 (P = 0.019), 4 (P = 0.028), and 24 hours (P = 0.014) after the operation. Magnesium at low dose decreases sore throat and pain severity more effectively compared to ketamine gargle.

  1. Discussion about magnesium phosphating

    Directory of Open Access Journals (Sweden)

    P. Pokorny

    2016-07-01

    Full Text Available The paper describes results from recently published research focused on production of non-conventional magnesium phosphate Mg3(PO42・4H2O – bobierrite, or MgHPO4・3H2O – newberyite coating for both magnesium alloys and/or mild steel. This new kind of coating is categorized in the context of current state of phosphating technology and its potential advantages and crystal structure is discussed. At the same time, the suitable comparison techniques for magnesium phosphate coating and conventional zinc phosphate coating are discussed.

  2. Hydrate morphology: Physical properties of sands with patchy hydrate saturation

    Science.gov (United States)

    Dai, S.; Santamarina, J.C.; Waite, William F.; Kneafsey, T.J.

    2012-01-01

    The physical properties of gas hydrate-bearing sediments depend on the volume fraction and spatial distribution of the hydrate phase. The host sediment grain size and the state of effective stress determine the hydrate morphology in sediments; this information can be used to significantly constrain estimates of the physical properties of hydrate-bearing sediments, including the coarse-grained sands subjected to high effective stress that are of interest as potential energy resources. Reported data and physical analyses suggest hydrate-bearing sands contain a heterogeneous, patchy hydrate distribution, whereby zones with 100% pore-space hydrate saturation are embedded in hydrate-free sand. Accounting for patchy rather than homogeneous hydrate distribution yields more tightly constrained estimates of physical properties in hydrate-bearing sands and captures observed physical-property dependencies on hydrate saturation. For example, numerical modeling results of sands with patchy saturation agree with experimental observation, showing a transition in stiffness starting near the series bound at low hydrate saturations but moving toward the parallel bound at high hydrate saturations. The hydrate-patch size itself impacts the physical properties of hydrate-bearing sediments; for example, at constant hydrate saturation, we find that conductivity (electrical, hydraulic and thermal) increases as the number of hydrate-saturated patches increases. This increase reflects the larger number of conductive flow paths that exist in specimens with many small hydrate-saturated patches in comparison to specimens in which a few large hydrate saturated patches can block flow over a significant cross-section of the specimen.

  3. Wet hydrate dissolution plant

    OpenAIRE

    Stanković Mirjana S.; Kovačević Branimir T.; Pezo Lato L.

    2003-01-01

    The IGPC Engineering Department designed basic projects for a wet hydrate dissolution plant, using technology developed in the IGPC laboratories. Several projects were completed: technological, machine, electrical, automation. On the basis of these projects, a production plant with capacity of 50,000 t/y was manufactured, at "Zeolite Mira", Mira (VE), Italy, in 1997, for increasing detergent zeolite production from 50,000 to 100,000 t/y. Several goals were realized by designing a wet hydrate ...

  4. Theoretical study on the reactivity of sulfate species with hydrocarbons

    Science.gov (United States)

    Ma, Q.; Ellis, G.S.; Amrani, A.; Zhang, T.; Tang, Y.

    2008-01-01

    used in the laboratory, with most of the dissolved sulfate occurring as SO42 -, aqueous calcium sulfate ([CaSO4](aq)), and aqueous magnesium sulfate ([MgSO4](aq)). Our calculations indicate that TSR reactions that occur in natural environments are most likely to involve bisulfate ions (HSO4-) and/or magnesium sulfate contact ion-pairs ([MgSO4]CIP) rather than 'free' sulfate ions (SO42 -) or solvated sulfate ion-pairs, and that water chemistry likely plays a significant role in controlling the rate of TSR. ?? 2008 Elsevier Ltd. All rights reserved.

  5. Hydrated salt minerals on Europa's Surface from the Galileo near-infrared mapping spectrometer (NIMS) investigation

    Science.gov (United States)

    McCord, T.B.; Hansen, G.B.; Matson, D.L.; Johnson, T.V.; Crowley, J.K.; Fanale, F.P.; Carlson, R.W.; Smythe, W.D.; Martin, P.D.; Hibbitts, C.A.; Granahan, J.C.; Ocampo, A.

    1999-01-01

    We reported evidence of heavily hydrated salt minerals present over large areas of Europa's surface from analysis of reflectance spectra returned by the Galileo mission near infrared mapping spectrometer (NIMS) [McCord et al., 1997a, b, 1998a, b]. Here we elaborate on this earlier evidence, present spatial distributions of these minerals, examine alternate water-ice interpretations, expand on our hydrated-salts interpretation, consider salt mineral stability on Europa, and discuss the implications. Extensive well-defined areas on Europa show distinct, asymmetric water-related absorption bands in the 1 to 2.5-??m region. Radiative transfer modeling of water ice involving different particle sizes and layers at Europa temperatures does not reproduce the distinctive Europa water bands. However, ice near its melting temperature, such as in terrestrial environments, does have some characteristics of the Europa spectrum. Alternatively, some classes of heavily hydrated minerals do exhibit such water bands. Among plausible materials, heavily hydrated salt minerals, such as magnesium and sodium sulfates, sodium carbonate and their mixtures, are preferred. All Europa spectral features are present in some salt minerals and a very good match to the Europa spectrum can be achieved by mixing several salt spectra. However, no single or mix of salt mineral spectra from the limited library available has so far been found to perfectly match the Europa spectrum in every detail. The material is concentrated at the lineaments and in chaotic terrain, which are technically disrupted areas on the trailing side. Since the spectrum of the material on Europa is nearly the same everywhere so-far studied, the salt or salt-mixture composition may be nearly uniform. This suggests similar sources and processes over at least a near-hemispheric scale. This would suggest that an extensive subsurface ocean containing dissolved salts is the source, and several possible mechanisms for deposit

  6. Magnesium blood test

    Science.gov (United States)

    Magnesium - blood ... A blood sample is needed. ... When the needle is inserted to draw blood, some people feel slight pain. Others feel a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon ...

  7. Magnesium Aluminate Spinel

    Institute of Scientific and Technical Information of China (English)

    Yu Lingyan

    2012-01-01

    1 ScopeThis standard specifies the terms, definitions,classifications,technical requirements,test methods,inspection rules, packing, marking, transportation,storage,and quality certificate of magnesium aluminate spinel.

  8. Magnesium Alloy for Repair of Lateral Tibial Plateau Defect in Minipig Model

    Institute of Scientific and Technical Information of China (English)

    Qiang Zhang; Xiao Lin; Zhengrong Qi; Lili Tan; Ke Yang; Zhuangqi Hu; Yan Wang

    2013-01-01

    Bone graft substitutes are widely-studied as alternatives to bone grafts in the clinic.The currently available products are mostly ceramics and polymers.Considerable progress has been made in the study of the biodegradable magnesium alloys,which possess the necessary attributions of a suitable substitute,including an excellent mechanical property.In the present study,a minipig model of a lateral tibial plateau defect was used to evaluate the effectiveness of a magnesium alloy in the repair of a critical-sized defect.The micro-arc oxidation (MAO)-coated ZK60 alloy tablets and medical-grade calcium sulfate pellets were used as the test and control materials,respectively.Bone morphology was monitored by computed tomography after the implantation for 2 and 4 months.It was found that the bone morphology in minipigs following magnesium treatment was similar to that of the normal bone,whereas an abnormal and concave morphology was displayed following the calcium sulfate treatment.The average bone healing rate for the magnesium-treated defects was higher than that of the calcium sulfate-treated defects at the first 4 months following the implantation.Overall,magnesium treatment appeared to improve the defect repair as compared with the calcium sulfate treatment.Thus,the MAO-coated ZK60 alloy appears to be a useful biocompatible bone graft substitute,and further research on its biological activity in vivo is needed.

  9. Effect of magnesium sulfate combined with calcium channel blockers on cystatin C,uric acid, alpha fetal protein and urinary transferrin levels in patients with hypertension pregnancy%硫酸镁联合钙离子通道拮抗剂对妊娠期高血压患者血清胱抑素C、尿酸、甲胎蛋白及尿转铁蛋白水平的影响

    Institute of Scientific and Technical Information of China (English)

    蔡安利; 宋飞銮; 秦洁; 戴洁; 潘倩若; 吕杰强

    2015-01-01

    目的:探讨硫酸镁联合钙离子通道拮抗剂对妊娠期高血压患者血清胱抑素C( cystatin C)、尿酸、甲胎蛋白( alpha fetal protein,AFP)及尿转铁蛋白( transferrin,TRF)水平的影响及意义。方法选取温州医科大学附属第三医院2013年1月~2014年10月产科收治的75例妊娠期高血压患者,随机分为2组,对照组37例行临床常规治疗;实验组38例,在对照组基础上加用硫酸镁和钙离子通道拮抗剂治疗。检测2组患者血清胱抑素C、尿酸、甲胎蛋白及尿转铁蛋白水平变化,比较2组临床疗效。结果与对照组比较,实验组Cys C、尿酸水平较低(P<0.05),血清AFP水平、尿TRF水平较低(P<0.05),血清血细胞比容、血液粘度及红细胞聚集指数较低(P<0.05),总有效率明显高于对照组(P<0.05)。结论硫酸镁联合钙离子通道拮抗剂对妊娠期高血压疾病患者治疗有较好的临床疗效,能有效改善血液粘度,降低血清Cys C、尿酸、AFP和尿TRF水平。%Objective To explore the effect of magnesium sulfate combined with calcium channel blockers on cystatin C, uric acid, alpha fetal protein and urinary transferrin in patients with hypertension pregnancy.Methods 75 cases with hypertension of pregnancy were selected and divided into two groups, control group(n=37) were treated with conventional therapy, experiment group(n=38) were treated with magnesium sulfate combined with calcium channel blockers on the basis of control group.Cystatin C, uric acid, alpha fetal protein and urinary transferrin were compared after treatment between two groups.Results Compared with control group, Cys C, uric acid, serum AFP l, urinary TRF levels were all lower in experiment group( P<0.05), serum hematocrit, whole blood viscosity and erythrocyte aggregation index were all lower in experiment group(P<0.05).The total efficiency of experiment group was significantly higher than

  10. Study on synthesis and application of magnesium oxalate%草酸镁的合成与应用研究

    Institute of Scientific and Technical Information of China (English)

    张静; 沈国良; 马晓雨; 刘红宇; 徐铁军; 陈远南

    2013-01-01

    The synthesis technology of magnesium oxalate were reviewed respectively to use metal magnesium, magnesium hydroxide, magnesium nitrate, magnesium sulfate, magnesium chloride, magnesium acetate as raw materials. Hie application status on the magnesium oxalate as catalyst and precursor of preparation of magnesium alu-minate spinel and nanometer magnesium oxide were introduced in detail. The magnesium oxalate will find broad of application and development in industry.%分别概述了以金属Mg、氢氧化镁、硝酸镁、硫酸镁、氯化镁、乙酸镁等为原料制取草酸镁的合成方法,详细介绍了草酸镁作为催化剂和作为制取镁铝尖晶石、纳米氧化镁的前驱物等方面的应用现状.草酸镁有着广阔的应用和发展前景.

  11. Acidosis, magnesium and acetylsalicylic acid: Effects on thrombin

    Science.gov (United States)

    Borisevich, Nikolaj; Loznikova, Svetlana; Sukhodola, Aleksandr; Halets, Inessa; Bryszewska, Maria; Shcharbin, Dzmitry

    2013-03-01

    Thrombin, an enzyme from the hydrolase family, is the main component of the blood coagulation system. In ischemic stroke it acts as a serine protease that converts soluble fibrinogen into insoluble strands of fibrin forming blood clots in the brain. It has been found to phosphoresce at room temperature in the millisecond and microsecond ranges. The phosphorescence of thrombin was studied under physiological conditions, in acidosis (decrease of pH from 8.0 to 5.0) and on the addition of salts (magnesium sulfate and sodium chloride) and of acetylsalicylic acid, and its connection with thrombin function is discussed. Acidosis significantly increased the internal dynamics of thrombin. We propose that lactate-acidosis plays a protective role in stroke, preventing the formation of clots. The addition of NaCl and MgSO4 in different concentrations increased the internal dynamics of thrombin. Also, the addition of MgSO4 decreased thrombin-induced platelet aggregation. However, magnesium sulfate and acetylsalicylic acid in the therapeutic concentrations used for treatment of ischemic stroke had no effect on thrombin internal dynamics. The data obtained will help to elucidate the conformational stability of thrombin under conditions modulating lactate-acidosis and in the presence of magnesium sulfate.

  12. Role of Magnesium Sulfate in Prolonging the Analgesic Effect of ...

    African Journals Online (AJOL)

    Journal of Basic and Clinical Reproductive Sciences · January - June 2015 · Vol 4 · Issue 1. 24 ... rescue analgesic requirement in Group BM 2.5 (0.4) compared to Group B 3.6 (0.4). Incidence of postpartum .... nursing personnel. Data were ...

  13. 硫酸镁湿热敷配合电动吸乳仪在治疗初产妇产后乳汁淤积中的应用%Application of magnesium sulfate hot-wet dressing cooperating with electric breast bump in the treatment of primiparas' postpartum galactostasis

    Institute of Scientific and Technical Information of China (English)

    杨康春; 任秀琼; 唐余; 高靖

    2012-01-01

    Objective To discuss effective nursing measures for postpartum galactostasis in maternalneonatal unit,in order to increase the breastfeeding rate.Methods 82 cases of primipara galactostasis were randomly divided into two groups:the experimental group (42 cases) and the control group (40 cases).The experimental group received 50% magnesium sulfate hot-wet dressing for 15 to 20 minutes and then electric breast bump treatment for 20 minutes,while the control group received conventional hot-wet dressing for 15 to 20 minutes and then manual milking for 20 minutes.Two groups' remission of galactostasis and whether the milk can meet the needs of the newborns 24 hours after the treatment was compared.Results Out of the 42 cases in the experimental group,29 cases were cured and 11 had improvements,with the total effective rate of 95.2%.Out of the 40 cases in the control group,13 cases were cured and 15 had improvements,with the total effective rate of 70.0%.The difference was statistically significant (x2 =9.217,P < 0.05).36 out of 42 cases in the experimental group had sufficient maternal breast milk,with the breastfeeding rate of 85.7%,while 21 out of 40 cases in the control group had sufficient maternal breast milk,with the breastfeeding rate of 52.5%.The difference was statistically significant (x2 =10.665,P < 0.05).Conclusions 50% magnesium sulfate hotwet dressing cooperating with electric breast bump had obvious effect on the primiparas' postpartum galactostasis,and can effectively improve the breasffeeding rate.%目的 探讨母婴同室区初产妇乳汁淤积的有效护理措施,以提高母乳喂养率.方法 将82例乳汁淤积的初产妇随机分为观察组42例和对照组40例,观察组采用50%硫酸镁湿热敷15~20 min后行电动吸乳仪治疗20 min,对照组采用普通湿热敷15 ~ 20 min后,行人工挤奶20 min,比较两组产妇治疗24 h后乳汁淤积缓解情况及乳汁排出量是否能满足新生儿需要.结果

  14. Magnesium Borohydride: From Hydrogen Storage to Magnesium Battery**

    OpenAIRE

    Mohtadi, Rana; Matsui, Masaki; Arthur, Timothy S; Hwang, Son-Jong

    2012-01-01

    Beyond hydrogen storage: The first example of reversible magnesium deposition/stripping onto/from an inorganic salt was seen for a magnesium borohydride electrolyte. High coulombic efficiency of up to 94 % was achieved in dimethoxyethane solvent. This Mg(BH_4)_2 electrolyte was utilized in a rechargeable magnesium battery.

  15. Magnesium borohydride: from hydrogen storage to magnesium battery.

    Science.gov (United States)

    Mohtadi, Rana; Matsui, Masaki; Arthur, Timothy S; Hwang, Son-Jong

    2012-09-24

    Beyond hydrogen storage: The first example of reversible magnesium deposition/stripping onto/from an inorganic salt was seen for a magnesium borohydride electrolyte. High coulombic efficiency of up to 94 % was achieved in dimethoxyethane solvent. This Mg(BH(4))(2) electrolyte was utilized in a rechargeable magnesium battery.

  16. Formation of porous gas hydrates

    CERN Document Server

    Salamatin, Andrey N

    2015-01-01

    Gas hydrates grown at gas-ice interfaces are examined by electron microscopy and found to have a submicron porous texture. Permeability of the intervening hydrate layers provides the connection between the two counterparts (gas and water molecules) of the clathration reaction and makes further hydrate formation possible. The study is focused on phenomenological description of principal stages and rate-limiting processes that control the kinetics of the porous gas hydrate crystal growth from ice powders. Although the detailed physical mechanisms involved in the porous hydrate formation still are not fully understood, the initial stage of hydrate film spreading over the ice surface should be distinguished from the subsequent stage which is presumably limited by the clathration reaction at the ice-hydrate interface and develops after the ice grain coating is finished. The model reveals a time dependence of the reaction degree essentially different from that when the rate-limiting step of the hydrate formation at...

  17. Hydrated mineral stratigraphy of Ius Chasma, Valles Marineris

    Science.gov (United States)

    Roach, L.H.; Mustard, J.F.; Swayze, G.; Milliken, R.E.; Bishop, J.L.; Murchie, S.L.; Lichtenberg, K.

    2010-01-01

    New high-resolution spectral and morphologic imaging of deposits on walls and floor of Ius Chasma extend previous geomorphic mapping, and permit a new interpretation of aqueous processes that occurred during the development of Valles Marineris. We identify hydrated mineralogy based on visible-near infrared (VNIR) absorptions. We map the extents of these units with CRISM spectral data as well as morphologies in CTX and HiRISE imagery. Three cross-sections across Ius Chasma illustrate the interpreted mineral stratigraphy. Multiple episodes formed and transported hydrated minerals within Ius Chasma. Polyhydrated sulfate and kieserite are found within a closed basin at the lowest elevations in the chasma. They may have been precipitates in a closed basin or diagenetically altered after deposition. Fluvial or aeolian processes then deposited layered Fe/Mg smectite and hydrated silicate on the chasma floor, postdating the sulfates. The smectite apparently was weathered out of Noachian-age wallrock and transported to the depositional sites. The overlying hydrated silicate is interpreted to be an acid-leached phyllosilicate transformed from the underlying smectite unit, or a smectite/jarosite mixture. The finely layered smectite and massive hydrated silicate units have an erosional unconformity between them, that marks a change in surface water chemistry. Landslides transported large blocks of wallrock, some altered to contain Fe/Mg smectite, to the chasma floor. After the last episode of normal faulting and subsequent landslides, opal was transported short distances into the chasma from a few m-thick light-toned layer near the top of the wallrock, by sapping channels in Louros Valles. Alternatively, the material was transported into the chasma and then altered to opal. The superposition of different types of hydrated minerals and the different fluvial morphologies of the units containing them indicate sequential, distinct aqueous environments, characterized by alkaline

  18. Ferrous Sulfate (Iron)

    Science.gov (United States)

    Ferrous sulfate provides the iron needed by the body to produce red blood cells. It is used ... Ferrous sulfate comes as regular, coated, and extended-release (long-acting) tablets; regular and extended-release capsules; ...

  19. INVESTIGATION OF MAGNESIUM ALLOYS MACHINABILITY

    Directory of Open Access Journals (Sweden)

    Berat Barıs BULDUM

    2013-01-01

    Full Text Available Magnesium is the lightest structural metal. Magnesium alloys have a hexagonal lattice structure, which affects the fundamental properties of these alloys. Plastic deformation of the hexagonal lattice is more complicated than in cubic latticed metals like aluminum, copper and steel. Magnesium alloy developments have traditionally been driven by industry requirements for lightweight materials to operate under increasingly demanding conditions. Magnesium alloys have always been attractive to designers due to their low density, only two thirds that of aluminium and its alloys [1]. The element and its alloys take a big part of modern industry needs. Especially nowadays magnesium alloys are used in automotive and mechanical (trains and wagons manufacture, because of its lightness and other features. Magnesium and magnesium alloys are the easiest of all metals to machine, allowing machining operations at extremely high speed. All standard machining operations such as turning, drilling, milling, are commonly performed on magnesium parts.

  20. COMPARISON OF INTRAVENOUS MAGNESIUM AND PLACEBO ADMINISTRATION ON POSTOPERATIVE PAIN AND ANALGESIC CONSUMPTION DURING SPINAL ANESTHESIA FOR INGUINAL HERNIA REPAIR

    Directory of Open Access Journals (Sweden)

    Olapour A

    2013-06-01

    Full Text Available Previous studies have suggested that magnesium may be a useful adjuvant to postoperative analgesia. We investigated efficacy of intravenous infusion of magnesium sulfate during spinal anesthesia to reduce post-operative pain and opioid consumption in patients undergoing inguinal hernia surgery.We randomly divided one hundred patients’ age 18-55 years old and ASA class I-II undergoing inguinal surgery into two groups. The magnesium group (Group M received magnesium sulfate 50 mg/kg in 100 ml normal saline intravenously within 10 minutes and 15 mg/kg/h by continuous infusion during the operation in one hour. The control group (Group S received the same amount of normal saline without magnesium sulfate. All patients received spinal anesthesia. Postoperative pain scores, meperidine consumption, and motor block were evaluated during 24 hours after surgery.Postoperative pain scores were significantly lower in Group M at 2, 3, 4 and 6 hours after surgery (P<0.05. Motor block was longer in Group M (P<0.05. Cumulative postoperative meperidine consumptions were also significantly lower in Group M at 24 h after surgery (P<0.05. 12% nausea and 26% flashing have been reported in Group M. A bolus and intravenous infusion of magnesium sulfate administration during spinal anesthesia improves postoperative analgesia. IRCT201201088645N1.

  1. COMPARISON OF INTRAVENOUS LIGNOCAINE AND MAGNESIUM SULPHATE FOR ATTENUATION OF PRESSOR RESPONSE DURING TRACHEAL INTUBATION

    Directory of Open Access Journals (Sweden)

    Megha

    2015-03-01

    Full Text Available BACKGROUND : Laryngoscopy and Endotracheal intubation are the heart of airway management. But it induces stress response which is very detrimental for the patient. Various drugs are been tried to reduce this stress response. Magnesium Sulphate and lignocaine is been tried to reduce the pressor response during laryngoscopy and endotracheal intubation. AIM: To compare the effectiveness of Magnesium sulphate and lignocaine to reduce the pressor response during tracheal intubation. STUDY DESIGN: Contro lled clinical trial was undertaken which included three groups having fifty patients in each group . METHOD: ASA I patients were included in the study. In Control group [group 1] normal saline 10 ml was given 1 min before induction. In magnesium sulfate [gr oup 2] 50% in dose of 50mg/kg diluted in 10 ml magnesium sulfate was given 1min before induction over a period of 1min. In lignocaine group [group3] lignocaine 2% [xylocard] was given in the dose of 1 . 5mg /kg diluted in 10 ml, 90 seconds before induction. Haemodynamic changes were noted in all the three groups. STATISTICAL ANALYSIS: The students paired[t] test was used in statistical analysis. RESULT: Both the drugs produced tachycardia and hypotention. Increase in pulse rate in [ group 2] was 20.44% which was comparatively more and statistically significant to 7 . 55% increase in pulse rate produced by lignocaine. Reduction in systolic blood pressure in lignocaine group was 13 . 23% which was more and statis tically significant to 5 . 25% decrease produced by magnesium sulphate. Reduction in rate pressure product was due to attenuation of hypertensive response alone in magnesium sulfate group. Whereas attenuation of both hypertensive and tachy cardiac response c ontributed to decrease in rate pressure product in lignocaine group. CONCLUSION: It can be concluded that magnesium sulfate is effective in protecting against the hypertensive response alone, while lignocaine is effective in attenuating

  2. [Hydration in clinical practice].

    Science.gov (United States)

    Maristany, Cleofé Pérez-Portabella; Segurola Gurruchaga, Hegoi

    2011-01-01

    Water is an essential foundation for life, having both a regulatory and structural function. The former results from active and passive participation in all metabolic reactions, and its role in conserving and maintaining body temperature. Structurally speaking it is the major contributer to tissue mass, accounting for 60% of the basis of blood plasma, intracellular and intersticial fluid. Water is also part of the primary structures of life such as genetic material or proteins. Therefore, it is necessary that the nurse makes an early assessment of patients water needs to detect if there are signs of electrolyte imbalance. Dehydration can be a very serious problem, especially in children and the elderly. Dehydrations treatment with oral rehydration solution decreases the risk of developing hydration disorders, but even so, it is recommended to follow preventive measures to reduce the incidence and severity of dehydration. The key to having a proper hydration is prevention. Artificial nutrition encompasses the need for precise calculation of water needs in enteral nutrition as parenteral, so the nurse should be part of this process and use the tools for calculating the patient's requirements. All this helps to ensure an optimal nutritional status in patients at risk. Ethical dilemmas are becoming increasingly common in clinical practice. On the subject of artificial nutrition and hydration, there isn't yet any unanimous agreement regarding hydration as a basic care. It is necessary to take decisions in consensus with the health team, always thinking of the best interests of the patient.

  3. The developing strategy of Chinese magnesium and magnesium alloy

    Institute of Scientific and Technical Information of China (English)

    ZUO; Tie-yong; DU; Wen-bo

    2005-01-01

    The status and developing strategy of Chinese magnesium industry are summarized in the present paper. The output and export of Chinese magnesium ingot have rapidly increased in the recent ten years, but the magnesium products with high value, such as the wrought magnesium alloys, and their applications are insufficient. Chinese magnesium industry should develop toward the direction of large scale, specialization and collectivization in the future. The enterprises should enhance the level of management and reinforce the international competing ability with the help of governmental policies.

  4. Chemical heat pumping - a rapid experimental procedure for investigating the suitability of salt hydrates under dynamic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Jan; Azoulay, Michel; Pablo, J. de

    A rapid experimental procedure of interest in determining the suitability of salt hydrates to be used in chemical heat pumping is described. Thermogravimetry under controlled water vapour pressure is utilized as the key diagnostic method. The test procedure relies largely on two critical tests: a cycling and an inhibition test. The former gives information on the stoichiometric reversibility and hysteresis between the dehydration and rehydration branches, while the inhibition test yields more quantitative information about the extent of inhibition. The latter represents a source of irreversibility inherent to the salt hydrate system. The test procedure is discussed and illustrated using four different salt hydrates: barium chloride, sodium sulphide, magnesium chloride and lithium hydroxide.

  5. Status of Research on Magnesium Oxide Backfill

    Energy Technology Data Exchange (ETDEWEB)

    PAPENGUTH,HANS W.; KRUMHANSL,JAMES L.; BYNUM,R. VANN; WANG,YIFENG; KELLY,JOHN W.; ANDERSON,HOWARD; NOWAK,E. JAMES

    2000-07-31

    For the WIPP, chemical and physical characteristics of MgO suggest it to be the most beneficial backfill choice, particularly because it has the ability to buffer the aqueous chemical conditions to control actinide volubility. In the current experimental program, the authors are developing a technical basis for taking credit for the complete set of attributes of MgO in geochemical, hydrogeological, and geomechanical technical areas, resulting in an improved conceptual model for the WIPP such as the following. Water uptake by MgO will delay the development of mobile actinides and gas generation by microbes and corrosion. Reduced gas generation will reduce or even eliminate spallings releases. As MgO hydrates, it swells, reducing porosity and permeability, which will inhibit gas flow in the repository, in turn reducing spallings releases. Hydration will also result in a self-sealing mechanism by which water uptake and swelling of MgO adjacent to a groundwater seep cuts off further seepage. Reaction with some groundwaters will produce cementitious materials, which will help to cement waste particles or produce a cohesive solid mass. Larger particles are less likely to be entrained in a spallings release. If sufficient water eventually accumulates in a repository to support microbial gas generation, magnesium carbonate cements will form; also producing good cohesion and strength.

  6. Clinical analysis of high frequency oscillatory ventilation and magnesium sulfate in treatment of neonatal respiratory distress syndrome with persistent pulmonary hypertension of the newborn%硫酸镁联合高频振荡通气治疗新生儿呼吸窘迫综合征并发新生儿持续肺动脉高压的临床分析

    Institute of Scientific and Technical Information of China (English)

    魏红娟; 邵惠敏; 刘坤; 仇玉桃; 王伟烈

    2016-01-01

    目的:探讨硫酸镁(MgSO4)联合高频振荡通气(HFOV)治疗新生儿呼吸窘迫综合征(RDS)并发新生儿持续肺动脉高压(PPHN)的临床效果及安全性。方法选取黑龙江省大庆油田总医院 NICU 2014年8月至2015年12月收治的重度 RDS 并发 PPHN 患儿30例,采用硫酸镁(MgSO4)联合高频振荡通气(HFOV)方法,用自身对照法,在治疗前与治疗后4 h、12 h、24 h、48 h 监测动脉血气,同时监测动脉血压。结果治疗后 pH 值明显改善,PO2、SpO2较前明显上升,PCO2明显下降,差异有统计学意义(P 0. 05).Conclusions Magnesium sulfate ( MgSO4 ) and high-frequency oscillatory ventilation ( HFOV ONLY) in the treatment of severe neonatal respiratory distress syndrome (RDS) with persistent pulmonary hypertension of the newborn(PPHN) can improve oxygenation, reduce the clinical symptoms, and has no significant effect on mean systemic arterial pressure.

  7. FOCUS ON MAGNESIUM BASED DRUGS

    Directory of Open Access Journals (Sweden)

    I. I. Esenova

    2011-01-01

    Full Text Available Magnesium deficiency in the organism is one of the most common human deficiency states. The prevalence of magnesium deficiency is about 15%, and suboptimal magnesium level is observed more than in 30% of people in the general population. Clinical signs of hypomagnesaemia are observed in 40% of patients in general care hospitals, in 70% of patients - in intensive care units, and magnesium deficiency occurs in 90% of patients with acute coronary syndrome. Magnesium metabolic disorders in the organism accelerate significantly development of complications of coronary heart disease, hypertension, type 2 diabetes, asthma and a number of neurological and psychiatric diseases. The value of this macro in the body is well studied, and its daily need is identified depending on age and sex. It is known that magnesium intake with the food does not cover an organism need. It is a rationale for preventive and therapeutic use of magnesium based drugs in various diseases. Organic salts of magnesium are recommended for these purposes. Magnesium metabolic disorders, approaches to pharmacotherapeutic correction of magnesium deficiency, advantages of magnesium salts of orotic acid are reviewed.

  8. Controlling Sulfate Attack in Mississippi Department of Transportation Structures

    Science.gov (United States)

    2010-08-01

    one of the materials that normally forms during the early setting of portland cement from a reaction between calcium aluminate and gypsum in the...such as calcium aluminates and calcium hydroxide, can influence the degree of damage observed. In all cases, the deterioration observed appears to be...counterions, such as calcium, magnesium , or sodium. Additionally, there are well-documented cases of concrete deterioration due to acid sulfate attack

  9. MAGNESIUM CARBONATE AS A COAGULANT, RECOVERY AND REUSE

    Directory of Open Access Journals (Sweden)

    M.Shariat

    1982-03-01

    Full Text Available In order to prevent water losses through disposing hydrous sludge during treatment of water, also recovery and reuse of chemicals; treatment by magnesium carbonate as a coagulant was examined in batch and continuous systems. 600 mg/1 MgCO3 as optimum dosage reduced 80% turbidity of a highly turbid water containing 200 NTU. Sulfates decreased, but hardness and alkalinity showed some increases. Recarbonation by CO2 resulted in recovery of 45% of magnesium carbonate which was used again as part of coagulants in continuous system. A mixture of magnesium carbonate and calcium oxide (lime was examined. 600 mg/1 MgCO3+250 mg/1 CaO as optimum dosage showed 90% reduction in turbidity, 10% reduction in both hardness and alkalinity and almost 60% reduction in sulfates. Recarbonation of sludge resulted in 73.5% recovery for magnesium carbonate and 40% for the lime, which were used again in a continuous system. Six hours operation of a continuous system with a detention time of 1 hour confirmed results obtained from batch analysis. A third trial was experienced with a mixture of magnesium carbonate+sodium carbonate. Although the total hardness showed more decreases, but the turbidity reduction was not satisfactory. As the conclusion, treatment of water by a mixture of MgCO3+ CaO is our choice. There will be no water losses in this method, resulting additional incomes by selling the 15-20% saved water and savings in expenditure and cost of coagulants. Cost of new constructions and CO2 production seems insignificant, comparing to savings and new income.

  10. Solfataric Alteration in Hawaii as a Mechanism for Formation of the Sulfates Observed on Mars by OMEGA and the MER Instruments

    Science.gov (United States)

    Bishop, J. L.; Schiffman, P.; Lane, M. D.; Dyar, M. D.

    2005-03-01

    Solfataric alteration in the Kilauea caldera, HI, forms sulfates and hydrated phases from volcanic ash. Spectral analyses are presented for detection of these minerals/phases on Mars by OMEGA and for groundtruthing the OMEGA spectra with MER data.

  11. Modeling Hydrates and the Gas Hydrate Markup Language

    Directory of Open Access Journals (Sweden)

    Weihua Wang

    2007-06-01

    Full Text Available Natural gas hydrates, as an important potential fuels, flow assurance hazards, and possible factors initiating the submarine geo-hazard and global climate change, have attracted the interest of scientists all over the world. After two centuries of hydrate research, a great amount of scientific data on gas hydrates has been accumulated. Therefore the means to manage, share, and exchange these data have become an urgent task. At present, metadata (Markup Language is recognized as one of the most efficient ways to facilitate data management, storage, integration, exchange, discovery and retrieval. Therefore the CODATA Gas Hydrate Data Task Group proposed and specified Gas Hydrate Markup Language (GHML as an extensible conceptual metadata model to characterize the features of data on gas hydrate. This article introduces the details of modeling portion of GHML.

  12. Overview: Nucleation of clathrate hydrates

    Science.gov (United States)

    Warrier, Pramod; Khan, M. Naveed; Srivastava, Vishal; Maupin, C. Mark; Koh, Carolyn A.

    2016-12-01

    Molecular level knowledge of nucleation and growth of clathrate hydrates is of importance for advancing fundamental understanding on the nature of water and hydrophobic hydrate formers, and their interactions that result in the formation of ice-like solids at temperatures higher than the ice-point. The stochastic nature and the inability to probe the small length and time scales associated with the nucleation process make it very difficult to experimentally determine the molecular level changes that lead to the nucleation event. Conversely, for this reason, there have been increasing efforts to obtain this information using molecular simulations. Accurate knowledge of how and when hydrate structures nucleate will be tremendously beneficial for the development of sustainable hydrate management strategies in oil and gas flowlines, as well as for their application in energy storage and recovery, gas separation, carbon sequestration, seawater desalination, and refrigeration. This article reviews various aspects of hydrate nucleation. First, properties of supercooled water and ice nucleation are reviewed briefly due to their apparent similarity to hydrates. Hydrate nucleation is then reviewed starting from macroscopic observations as obtained from experiments in laboratories and operations in industries, followed by various hydrate nucleation hypotheses and hydrate nucleation driving force calculations based on the classical nucleation theory. Finally, molecular simulations on hydrate nucleation are discussed in detail followed by potential future research directions.

  13. A study on gas hydrate

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Byoung Jae; Jung, Tae Jin; Sunwoo, Don [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of)

    1996-12-01

    Sufficient documents were reviewed to understand solid components of water and gaseous hydrocarbon known as gas hydrates, which represent an important potential energy resource of the future. The review provides us with valuable information on crystal structures, kinetics, origin and distribution of gas hydrates. In addition, the review increased our knowledge of exploration and development methods of gas hydrates. Large amounts of methane, the principal component of natural gas, in the form of solid gas hydrate are found mainly offshore in outer continental margin sediment and, to a lesser extent, in polar regions commonly associated with permafrost. Natural gas hydrates are stable in some environments where the hydrostatic pressure exerted by overlying water column is sufficient for hydrate formation and stability. The required high pressures generally restrict gas hydrate to sediments beneath water of approximately 400 m. Higher sediment temperatures at greater subbottom depths destabilize gas hydrates. Based on the pressure- temperature condition, the outer continental margin of East Sea where water depth is deep enough to form gas hydrate is considered to have high potential of gas hydrate accumulations. (author). 56 refs., tabs., figs.

  14. Observed correlation between the depth to base and top of gas hydrate occurrence from review of global drilling data

    Science.gov (United States)

    Riedel, Michael; Collett, Timothy S.

    2017-01-01

    A global inventory of data from gas hydrate drilling expeditions is used to develop relationships between the base of structure I gas hydrate stability, top of gas hydrate occurrence, sulfate-methane transition depth, pressure (water depth), and geothermal gradients. The motivation of this study is to provide first-order estimates of the top of gas hydrate occurrence and associated thickness of the gas hydrate occurrence zone for climate-change scenarios, global carbon budget analyses, or gas hydrate resource assessments. Results from publically available drilling campaigns (21 expeditions and 52 drill sites) off Cascadia, Blake Ridge, India, Korea, South China Sea, Japan, Chile, Peru, Costa Rica, Gulf of Mexico, and Borneo reveal a first-order linear relationship between the depth to the top and base of gas hydrate occurrence. The reason for these nearly linear relationships is believed to be the strong pressure and temperature dependence of methane solubility in the absence of large difference in thermal gradients between the various sites assessed. In addition, a statistically robust relationship was defined between the thickness of the gas hydrate occurrence zone and the base of gas hydrate stability (in meters below seafloor). The relationship developed is able to predict the depth of the top of gas hydrate occurrence zone using observed depths of the base of gas hydrate stability within less than 50 m at most locations examined in this study. No clear correlation of the depth to the top and base of gas hydrate occurrences with geothermal gradient and sulfate-methane transition depth was identified.

  15. Magnesium tube hydroforming

    Energy Technology Data Exchange (ETDEWEB)

    Liewald, M.; Pop, R. [Institute for Metal Forming Technology (IFU), Stuttgart (Germany)

    2008-04-15

    Magnesium alloys reveal a good strength-to-weight ratio in the family of lightweight metals and gains potential to provide up to 30% mass savings compared to aluminium and up to 75 % compared to steel. The use of sheet magnesium alloys for auto body applications is however limited due to the relatively low formability at room temperature. Within the scope of this paper, extruded magnesium tubes, which are suitable for hydroforming applications, have been investigated. Results obtained at room temperature using magnesium AZ31 tubes show that circumferential strains are limited to a maximal value of 4%. In order to examine the influence of the forming temperature on tube formability, investigations have been carried out with a new die set for hot internal high pressure (IHP) forming at temperatures up to 400 C. Earlier investigations with magnesium AZ31 tubes have shown that fractures occur along the welding line at tubes extruded over a spider die, whereby a non-uniform expansion at bursting with an elongation value of 24% can be observed. A maximum circumferential strain of approx. 60% could be attained when seamless, mechanically pre-expanded and annealed tubes of the same alloy have been used. The effect of annealing time on materials forming properties shows a fine grained structure for sufficient annealing times as well as deterioration with a large increase at same time. Hence, seamless ZM21 tubes have been used in the current investigations. With these tubes, an increased tensile fracture strain of 116% at 350 C is observed as against 19% at 20 C, obtained by tensile testing of milled specimens from the extruded tubes. This behaviour is also seen under the condition of tool contact during the IHP forming process. To determine the maximum circumferential strain at different forming temperatures and strain rates, the tubes are initially bulged in a die with square cross-section under plane stress conditions. Thereafter, the tubes are calibrated by using an

  16. Tetrahydrofuran-promoted clathrate hydrate phase equilibria of CO{sub 2} in aqueous electrolyte solutions

    Energy Technology Data Exchange (ETDEWEB)

    Sabil, K.M.; Roman, V.R. [Delft Univ. of Technology, Delft (Netherlands). Physical Chemistry and Molecular Thermodynamics; Witkamp, G.J.; Peters, C.J. [Delft Univ. of Technology, Delft, (Netherlands). Laboratory of Process Equipment, Mechanical, Maritime and Materials Engineering

    2008-07-01

    The phase behavior of a system consisting of carbon dioxide (CO{sub 2}) hydrates is of significant importance for many industrial and natural processes. Carbon dioxide and water are part of natural gas streams and they are also found in oil reservoirs during enhanced oil recovery. Formation of hydrate in these cases may cause problems during production and processing. Alternatively, carbon dioxide hydrate formation may be desirable since it can facilitate separation processes, freezing and refrigeration processes and sequestration of CO{sub 2}. The need for phase equilibrium data of systems, particularly electrolyte solutions containing CO{sub 2} are therefore needed. This paper presented a study that attempted to measure the hydrate equilibrium condition for quaternary system consisting of CO{sub 2}, tetrahydrofuran (THF), an electrolyte and water. The purpose of the study was to examine the competing effect of tetrahydrofuran and an electrolyte on the phase behavior of CO{sub 2} hydrates when both were simultaneously present in a system at hydrate forming condition and to compare the effect of different salts inhibition on tetrahydrofuran-promoted CO{sub 2} hydrate. Six different electrolytes were utilized, including sodium chloride, calcium chloride, magnesium chloride, potassium bromide, sodium fluoride and sodium bromide. It was concluded that the inhibiting effect among the cations increased with increasing charge of the cation and its radius. It was also found that the inhibiting effect of the anions decreased with a decrease on their ion radius. 12 refs., 4 figs.

  17. Drilling Gas Hydrates on hydrate Ridge, Oregon continental margin

    Science.gov (United States)

    Trehu, A. M.; Bohrmann, G.; Leg 204 Science Party

    2002-12-01

    During Leg 204, we cored and logged 9 sites on the Oregon continental margin to determine the distribution and concentration of gas hydrates in an accretionary ridge and adjacent slope basin, investigate the mechanisms that transport methane and other gases into the gas hydrate stability zone (GHSZ), and obtain constraints on physical properties of hydrates in situ. A 3D seismic survey conducted in 2000 provided images of potential subsurface fluid conduits and indicated the position of the GHSZ throughout the survey region. After coring the first site, we acquired Logging-While-Drilling (LWD) data at all but one site to provide an overview of downhole physical properties. The LWD data confirmed the general position of key seismic stratigraphic horizons and yielded an initial estimate of hydrate concentration through the proxy of in situ electrical resistivity. These records proved to be of great value in planning subsequent coring. The second new hydrate proxy to be tested was infrared thermal imaging of cores on the catwalk as rapidly as possible after retrieval. The thermal images were used to identify hydrate samples and to estimate the distribution and texture of hydrate within the cores. Geochemical analyses of interstitial waters and of headspace and void gases provide additional information on the distribution and concentration of hydrate within the stability zone, the origin and pathway of fluids into and through the GHSZ, and the rates at which gas hydrate is forming. Bio- and lithostratigraphic description of cores, measurement of physical properties, and in situ pressure core sampling and thermal measurements complement the data set, providing ground-truth tests of inferred physical and sedimentological properties. Among the most interesting preliminary results are: 1) that gas hydrates are distributed through a broad depth range within the GHSZ and that different physical and chemical proxies for hydrate distribution and concentration give generally

  18. Tyrosine Sulfation of Statherin

    Directory of Open Access Journals (Sweden)

    C. Kasinathan, N. Gandhi, P. Ramaprasad, P. Sundaram, N. Ramasubbu

    2007-01-01

    Full Text Available Tyrosylprotein sulfotransferase (TPST, responsible for the sulfation of a variety of secretory and membrane proteins, has been identified and characterized in submandibular salivary glands (William et al. Arch Biochem Biophys 1997; 338: 90-96. In the present study we demonstrate the sulfation of a salivary secretory protein, statherin, by the tyrosylprotein sulfotransferase present in human saliva. Optimum statherin sulfation was observed at pH 6.5 and at 20 mm MnCl2. Increase in the level of total sulfation was observed with increasing statherin concentration. The Km value of tyrosylprotein sulfotransferase for statherin was 40 μM. Analysis of the sulfated statherin product on SDS-polyacrylamide gel electrophoresis followed by autoradiography revealed 35S-labelling of a 5 kDa statherin. Further analysis of the sulfated statherin revealed the sulfation on tyrosyl residue. This study is the first report demonstrating tyrosine sulfation of a salivary secretory protein. The implications of this sulfation of statherin in hydroxyapatite binding and Actinomyces viscosus interactions are discussed.

  19. Mass Transfer and Kinetics Study of Heterogeneous Semi-Batch Precipitation of Magnesium Carbonate

    DEFF Research Database (Denmark)

    Han, B.; Qu, H. Y.; Niemi, H.

    2014-01-01

    Precipitation kinetics and mass transfer of magnesium carbonate (MgCO3) hydrates from a reaction of magnesium hydroxide (Mg(OH)(2)) and CO2 were analyzed. The effect of CO2 flow rate and mixing intensity on precipitation was investigated under ambient temperature and atmospheric pressure. Raman...... on the dissolution of Mg(OH)(2). In the researched system, the main driver of the precipitation kinetics was the mass transfer of CO2. Nesquehonite (MgCO3 center dot 3H(2)O), as needle-like crystals, was precipitated as the main product. Raman spectroscopy can serve as a potential tool to monitor the carbonation...

  20. Rapid gas hydrate formation process

    Science.gov (United States)

    Brown, Thomas D.; Taylor, Charles E.; Unione, Alfred J.

    2013-01-15

    The disclosure provides a method and apparatus for forming gas hydrates from a two-phase mixture of water and a hydrate forming gas. The two-phase mixture is created in a mixing zone which may be wholly included within the body of a spray nozzle. The two-phase mixture is subsequently sprayed into a reaction zone, where the reaction zone is under pressure and temperature conditions suitable for formation of the gas hydrate. The reaction zone pressure is less than the mixing zone pressure so that expansion of the hydrate-forming gas in the mixture provides a degree of cooling by the Joule-Thompson effect and provides more intimate mixing between the water and the hydrate-forming gas. The result of the process is the formation of gas hydrates continuously and with a greatly reduced induction time. An apparatus for conduct of the method is further provided.

  1. Magnesium for Hydrogen Storage

    DEFF Research Database (Denmark)

    Pedersen, Allan Schrøder; Kjøller, John; Larsen, B.

    1983-01-01

    A study of the hydrogenation characteristics of fine magnesium powder during repeated cycling has been performed using a high-pressure microbalance facility. No effect was found from the cycling regarding kinetics and storage capacity. The reaction rate of the absorption process was fast at tempe......A study of the hydrogenation characteristics of fine magnesium powder during repeated cycling has been performed using a high-pressure microbalance facility. No effect was found from the cycling regarding kinetics and storage capacity. The reaction rate of the absorption process was fast...... at temperatures around 600 K and above, but the reversed reaction showed somewhat slower kinetics around 600 K. At higher temperatures the opposite was found. The enthalpy and entropy change by the hydrogenation, derived from pressure-concentration isotherms, agree fairly well with those reported earlier....

  2. Magnesium oxychloride cement concrete

    Indian Academy of Sciences (India)

    A K Misra; Renu Mathur

    2007-06-01

    The scope of magnesium oxychloride (MOC) cement in concrete works has been evaluated. MOC cement concrete compositions of varying strengths having good placing and finishing characteristics were prepared and investigated for their compressive and flexural strengths, -values, abrasion resistance etc. The durability of MOC concrete compositions against extreme environmental conditions viz. heating–cooling, freezing–thawing, wetting–drying and penetration and deposition of salts etc were investigated. The results reveal that MOC concrete has high compressive strength associated with high flexural strength and the ratio of compressive to flexural strength varies between 6 and 8. The elastic moduli of the compositions studied are found to be 23–85 GPa and the abrasion losses between 0.11 and 0.20%. While alternate heating–cooling cycles have no adverse effect on MOC concrete, it can be made durable against freezing–thawing and the excessive exposure to water and salt attack by replacing 10% magnesium chloride solution by magnesium sulphate solution of the same concentration.

  3. Fundamental Properties of Magnesium Phosphate Cement Mortar for Rapid Repair of Concrete

    OpenAIRE

    2016-01-01

    Fundamental properties of magnesium phosphate cement (MPC) were investigated in this paper. The setting time and compressive and bond (i.e., flexural and tensile bond) strengths were measured to assess the applicability, and hydration product was detected by the X-ray diffraction. The specimens were manufactured with magnesia and potassium dihydrogen phosphate (K2HPO4) was added to activate hydration process. The Borax (Na2B4O7·10H2O) was used as a retarder to mitigate overwhelming rapid hard...

  4. Magnesium as Biodegradable Implant Material

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Drawbacks associated with permanent metallic implants lead to the search for degradable metallic biomaterials. Magnesium alloys have been highly considered as Mg has a high biocorrosion potential and is essential to bodies. In this study, corrosion behaviour of pure magnesium and magnesium alloy AZ31 in both static and dynamic physiological conditions (Hank's solution) has been investigated. It is found that the materials degrade fast at beginning, then stabilize after 5 days of immersion. High purity in th...

  5. Roles of heparan sulfate sulfation in dentinogenesis.

    Science.gov (United States)

    Hayano, Satoru; Kurosaka, Hiroshi; Yanagita, Takeshi; Kalus, Ina; Milz, Fabian; Ishihara, Yoshihito; Islam, Md Nurul; Kawanabe, Noriaki; Saito, Masahiro; Kamioka, Hiroshi; Adachi, Taiji; Dierks, Thomas; Yamashiro, Takashi

    2012-04-06

    Cell surface heparan sulfate (HS) is an essential regulator of cell signaling and development. HS traps signaling molecules, like Wnt in the glycosaminoglycan side chains of HS proteoglycans (HSPGs), and regulates their functions. Endosulfatases Sulf1 and Sulf2 are secreted at the cell surface to selectively remove 6-O-sulfate groups from HSPGs, thereby modifying the affinity of cell surface HSPGs for its ligands. This study provides molecular evidence for the functional roles of HSPG sulfation and desulfation in dentinogenesis. We show that odontogenic cells are highly sulfated on the cell surface and become desulfated during their differentiation to odontoblasts, which produce tooth dentin. Sulf1/Sulf2 double null mutant mice exhibit a thin dentin matrix and short roots combined with reduced expression of dentin sialophosphoprotein (Dspp) mRNA, encoding a dentin-specific extracellular matrix precursor protein, whereas single Sulf mutants do not show such defective phenotypes. In odontoblast cell lines, Dspp mRNA expression is potentiated by the activation of the Wnt canonical signaling pathway. In addition, pharmacological interference with HS sulfation promotes Dspp mRNA expression through activation of Wnt signaling. On the contrary, the silencing of Sulf suppresses the Wnt signaling pathway and subsequently Dspp mRNA expression. We also show that Wnt10a protein binds to cell surface HSPGs in odontoblasts, and interference with HS sulfation decreases the binding affinity of Wnt10a for HSPGs, which facilitates the binding of Wnt10a to its receptor and potentiates the Wnt signaling pathway, thereby up-regulating Dspp mRNA expression. These results demonstrate that Sulf-mediated desulfation of cellular HSPGs is an important modification that is critical for the activation of the Wnt signaling in odontoblasts and for production of the dentin matrix.

  6. INVESTIGATION ON PROPERTIES OF CONCRETE CONTAINING NATURAL POZZOLAN VOLCANIC ORIGIN DUE TO SULFATE ATTACK

    OpenAIRE

    MERIDA AHCENE; KHARCHI FATTOUM

    2013-01-01

    Sulfate attack and its effects are important from both scientific and industrial viewpoints. It is perceived that concretes containing pozzolan have better performance in sulfate solutions, since the pozzolanic reactions reduce the quantity of calcium hydroxide and increase calcium silicate hydrate. This paper investigates thecontribution of natural pozzolan volcanic origin on the physico - mechanical and physico-chemical characteristics of the concretes. When it is coupled to a water reducin...

  7. The ceric sulfate dosimeter

    DEFF Research Database (Denmark)

    Bjergbakke, Erling

    1970-01-01

    The process employed for the determination of absorbed dose is the reduction of ceric ions to cerous ions in a solution of ceric sulfate and cerous sulfate in 0.8N sulfuric acid: Ce4+→Ce 3+ The absorbed dose is derived from the difference in ceric ion concentration before and after irradiation...

  8. Effect of fly ash on the optimum sulfate of Portland Cement

    Science.gov (United States)

    Niemuth, Mark D.

    Calcium sulfate is typically added to ordinary portland cement (OPC) clinker during grinding to prevent flash set and to improve early-age strength development without causing volume instabilities. Recent changes to ASTM C150, Standard Specification for Portland Cement, have enabled greater flexibility in determining optimum sulfate levels in portland cement by not requiring ASTM C563, Approximation of Optimum SO3 in Hydraulic Cement Using Compressive Strength, to be used in setting sulfate target levels. ASTM C563 requires strength testing using only the hydraulic cement, which is not always indicative of the optimum sulfate for field use, since supplementary materials (e.g., fly ash) may be used by the concrete producer. Adding additional sulfate to account for the sulfate demand of fly ashes can enable an improvement in the early age strength for cement-fly ash systems and decrease in problems that may be attributed to OPC-admixture-fly ash incompatibility such as abnormal setting and slow strength gain. This thesis provides experimental data on the strength development and heat release during early hydration for cement-fly ash systems with different sulfate levels. The thesis focused on high calcium fly ashes, but low calcium fly ash was also tested. It is demonstrated that some fly ashes have their own sulfate demand and when these ashes are used in cement-fly ash blends there is effectively an increase in the optimal sulfate level that could be used for the OPC. It is also shown that optimum sulfate determined by heat of hydration measured with isothermal calorimetry is similar to the optimum sulfate determined by compressive strength at 1 day. Using isothermal calorimetry can result in substantial time and cost savings at plants for determining the optimal sulfate content. Theories for the mechanisms that drive the differences in sulfate demand in OPC are reviewed. These theories are adapted for OPC-fly ash blends and are outlined, tested and discussed. The

  9. DEVELOPMENT AND APPLICATION OF MAGNESIUM HYDROXIDE- FLAME RETARDAR.%氢氧化镁阻燃剂的开发与应用

    Institute of Scientific and Technical Information of China (English)

    杨鸿

    2001-01-01

    The present status and apphcations of magnesium hydrate flame retardar production at home and abroad are introduced. The conclusion is that magnesium hydrate as a new type inorganic flame retardar will have a widely development prospect.%介绍了氢氧化镁阻燃剂的国内外生产现状和应用情况,提出氢氧化镁阻燃剂是最具发展前景的无机阻燃剂。

  10. Heparan sulfate biosynthesis

    DEFF Research Database (Denmark)

    Multhaupt, Hinke A B; Couchman, John R

    2012-01-01

    Heparan sulfate is perhaps the most complex polysaccharide known from animals. The basic repeating disaccharide is extensively modified by sulfation and uronic acid epimerization. Despite this, the fine structure of heparan sulfate is remarkably consistent with a particular cell type. This suggests...... that the synthesis of heparan sulfate is tightly controlled. Although genomics has identified the enzymes involved in glycosaminoglycan synthesis in a number of vertebrates and invertebrates, the regulation of the process is not understood. Moreover, the localization of the various enzymes in the Golgi apparatus has......-quality resolution of the distribution of enzymes. The EXT2 protein, which when combined as heterodimers with EXT1 comprises the major polymerase in heparan sulfate synthesis, has been studied in depth. All the data are consistent with a cis-Golgi distribution and provide a starting point to establish whether all...

  11. Hydration and physical performance.

    Science.gov (United States)

    Murray, Bob

    2007-10-01

    There is a rich scientific literature regarding hydration status and physical function that began in the late 1800s, although the relationship was likely apparent centuries before that. A decrease in body water from normal levels (often referred to as dehydration or hypohydration) provokes changes in cardiovascular, thermoregulatory, metabolic, and central nervous function that become increasingly greater as dehydration worsens. Similarly, performance impairment often reported with modest dehydration (e.g., -2% body mass) is also exacerbated by greater fluid loss. Dehydration during physical activity in the heat provokes greater performance decrements than similar activity in cooler conditions, a difference thought to be due, at least in part, to greater cardiovascular and thermoregulatory strain associated with heat exposure. There is little doubt that performance during prolonged, continuous exercise in the heat is impaired by levels of dehydration >or= -2% body mass, and there is some evidence that lower levels of dehydration can also impair performance even during relatively short-duration, intermittent exercise. Although additional research is needed to more fully understand low-level dehydration's effects on physical performance, one can generalize that when performance is at stake, it is better to be well-hydrated than dehydrated. This generalization holds true in the occupational, military, and sports settings.

  12. Ductile flow of methane hydrate

    Science.gov (United States)

    Durham, W.B.; Stern, L.A.; Kirby, S.H.

    2003-01-01

    Compressional creep tests (i.e., constant applied stress) conducted on pure, polycrystalline methane hydrate over the temperature range 260-287 K and confining pressures of 50-100 MPa show this material to be extraordinarily strong compared to other icy compounds. The contrast with hexagonal water ice, sometimes used as a proxy for gas hydrate properties, is impressive: over the thermal range where both are solid, methane hydrate is as much as 40 times stronger than ice at a given strain rate. The specific mechanical response of naturally occurring methane hydrate in sediments to environmental changes is expected to be dependent on the distribution of the hydrate phase within the formation - whether arranged structurally between and (or) cementing sediments grains versus passively in pore space within a sediment framework. If hydrate is in the former mode, the very high strength of methane hydrate implies a significantly greater strain-energy release upon decomposition and subsequent failure of hydrate-cemented formations than previously expected.

  13. Some thermodynamical aspects of protein hydration water

    Energy Technology Data Exchange (ETDEWEB)

    Mallamace, Francesco, E-mail: francesco.mallamace@unime.it [Dipartimento di Fisica e Scienze della Terra, Università di Messina and CNISM, I-98168 Messina (Italy); Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Center for Polymer Studies and Department of Physics, Boston University, Boston, Massachusetts 02215 (United States); Corsaro, Carmelo [Dipartimento di Fisica e Scienze della Terra, Università di Messina and CNISM, I-98168 Messina (Italy); CNR-IPCF, Viale F. Stagno D’Alcontres 37, I-98158 Messina (Italy); Mallamace, Domenico [Dipartimento SASTAS, Università di Messina, I-98166 Messina (Italy); Vasi, Sebastiano [Dipartimento di Fisica e Scienze della Terra, Università di Messina and CNISM, I-98168 Messina (Italy); Vasi, Cirino [CNR-IPCF, Viale F. Stagno D’Alcontres 37, I-98158 Messina (Italy); Stanley, H. Eugene [Center for Polymer Studies and Department of Physics, Boston University, Boston, Massachusetts 02215 (United States); Chen, Sow-Hsin [Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2015-06-07

    We study by means of nuclear magnetic resonance the self-diffusion of protein hydration water at different hydration levels across a large temperature range that includes the deeply supercooled regime. Starting with a single hydration shell (h = 0.3), we consider different hydrations up to h = 0.65. Our experimental evidence indicates that two phenomena play a significant role in the dynamics of protein hydration water: (i) the measured fragile-to-strong dynamic crossover temperature is unaffected by the hydration level and (ii) the first hydration shell remains liquid at all hydrations, even at the lowest temperature.

  14. Magnesium Hall Thruster

    Science.gov (United States)

    Szabo, James J.

    2015-01-01

    This Phase II project is developing a magnesium (Mg) Hall effect thruster system that would open the door for in situ resource utilization (ISRU)-based solar system exploration. Magnesium is light and easy to ionize. For a Mars- Earth transfer, the propellant mass savings with respect to a xenon Hall effect thruster (HET) system are enormous. Magnesium also can be combusted in a rocket with carbon dioxide (CO2) or water (H2O), enabling a multimode propulsion system with propellant sharing and ISRU. In the near term, CO2 and H2O would be collected in situ on Mars or the moon. In the far term, Mg itself would be collected from Martian and lunar regolith. In Phase I, an integrated, medium-power (1- to 3-kW) Mg HET system was developed and tested. Controlled, steady operation at constant voltage and power was demonstrated. Preliminary measurements indicate a specific impulse (Isp) greater than 4,000 s was achieved at a discharge potential of 400 V. The feasibility of delivering fluidized Mg powder to a medium- or high-power thruster also was demonstrated. Phase II of the project evaluated the performance of an integrated, highpower Mg Hall thruster system in a relevant space environment. Researchers improved the medium power thruster system and characterized it in detail. Researchers also designed and built a high-power (8- to 20-kW) Mg HET. A fluidized powder feed system supporting the high-power thruster was built and delivered to Busek Company, Inc.

  15. Hydrostatic extrusion of magnesium alloys

    NARCIS (Netherlands)

    Sillekens, W.H.; Bohlen, J.

    2012-01-01

    This chapter deals with the capabilities and limitations of the hydrostatic extrusion process for the manufacturing of magnesium alloy sections. Firstly, the process basics for the hydrostatic extrusion of materials in general and of magnesium in particular are introduced. Next, some recent research

  16. Electrolytes for magnesium electrochemical cells

    Energy Technology Data Exchange (ETDEWEB)

    Burrell, Anthony K.; Sa, Niya; Proffit, Danielle Lee; Lipson, Albert; Liao, Chen; Vaughey, John T.; Ingram, Brian J.

    2017-07-04

    An electrochemical cell includes a high voltage cathode configured to operate at 1.5 volts or greater; an anode including Mg.sup.0; and an electrolyte including an ether solvent and a magnesium salt; wherein: a concentration of the magnesium salt in the ether is 1 M or greater.

  17. Flow assurance intervention, hydrates remediation

    Energy Technology Data Exchange (ETDEWEB)

    Mancini, Christopher S. [Oceaneering International Inc., Houston, TX (United States)

    2012-07-01

    This paper addresses the issues of removing hydrates in sub sea flow lines and associated equipment with an Remotely Operated Vehicle (ROV) of opportunity and a multi-service-vessel (MSV). The paper is split into three topics: the equipment used with the ROV, assessing the interface points and handling fluids produced from drawing down the pressure. Each section is explained thoroughly and backed up with real world experience. The equipment section details information from actual jobs performed and why the particular components were utilized. The system is generally contained in an ROV mounted skid. Pumps are utilized to draw down the pressure inside the hydrated section of equipment, removing one of the three necessary components for hydrates formation. Once the section is pumped down, several options exist for handling the fluids pumped out of the system: pumping to surface, re-injection into the well, or injection into an operating flow line. This method of hydrates remediation is both economical and timely. Hydrate blockages form in low temperatures and high pressures. Reducing the pressure or increasing the temperature so the conditions lie to the right of the hydrate dissociation curve will slowly decompose the blockage. Depressurization and the use of MEG or methanol will give favorable conditions to remove the hydrate plug. Oceaneering has the capabilities to remove hydrates using the FRS in conjunction with an installation vessel to dispose of the gas and fluid removed from the flow line. Hydrate remediation techniques should be implemented into the initial design to reduce costs later. The cost of stopped production combined with the day rate for equipment needed for hydrate removal outweighs the costs if no technique is utilized. (author)

  18. Innovative Vacuum Distillation for Magnesium Recycling

    Science.gov (United States)

    Zhu, Tianbai; Li, Naiyi; Mei, Xiaoming; Yu, Alfred; Shang, Shixiang

    Magnesium recycling now becomes a very important subject as magnesium consumption increases fast around the world. All commonly used magnesium die-casting alloys can be recycled and recovered to the primary metal quality. The recycled materials may be comprised of biscuits, sprues, runners, flash, overflows, dross, sludge, scrap parts, and old parts that are returned from service, An innovative magnesium recycle method, vacuum distillation, is developed and proved out to be able to recycle magnesium scraps, especially machining chips, oily magnesium, smelting sludge, dross or the mixture. With this process at a specific temperature and environment condition, magnesium in scraps can be gasified and then solidified to become crystal magnesium crown. This `recycled' magnesium crown is collected and used as the raw material of magnesium alloys. The experimental results show the vacuum distillation is a feasible and plausible method to recycle magnesium. Further, the cost analysis will be addressed in this paper.

  19. Magnesium substitution in brushite cements.

    Science.gov (United States)

    Alkhraisat, Mohammad Hamdan; Cabrejos-Azama, Jatsue; Rodríguez, Carmen Rueda; Jerez, Luis Blanco; Cabarcos, Enrique López

    2013-01-01

    The use of magnesium-doped ceramics has been described to modify brushite cements and improve their biological behavior. However, few studies have analyzed the efficiency of this approach to induce magnesium substitution in brushite crystals. Mg-doped ceramics composed of Mg-substituted β-TCP, stanfieldite and/or farringtonite were reacted with primary monocalcium phosphate (MCP) in the presence of water. The cement setting reaction has resulted in the formation of brushite and newberyite within the cement matrix. Interestingly, the combination of SAED and EDX analyses of single crystal has indicated the occurrence of magnesium substitution within brushite crystals. Moreover, the effect of magnesium ions on the structure, and mechanical and setting properties of the new cements was characterized as well as the release of Ca(2+) and Mg(2+) ions. Further research would enhance the efficiency of the system to incorporate larger amounts of magnesium ions within brushite crystals.

  20. Magnesium in Prevention and Therapy

    Directory of Open Access Journals (Sweden)

    Uwe Gröber

    2015-09-01

    Full Text Available Magnesium is the fourth most abundant mineral in the body. It has been recognized as a cofactor for more than 300 enzymatic reactions, where it is crucial for adenosine triphosphate (ATP metabolism. Magnesium is required for DNA and RNA synthesis, reproduction, and protein synthesis. Moreover, magnesium is essential for the regulation of muscular contraction, blood pressure, insulin metabolism, cardiac excitability, vasomotor tone, nerve transmission and neuromuscular conduction. Imbalances in magnesium status—primarily hypomagnesemia as it is seen more common than hypermagnesemia—might result in unwanted neuromuscular, cardiac or nervous disorders. Based on magnesium’s many functions within the human body, it plays an important role in prevention and treatment of many diseases. Low levels of magnesium have been associated with a number of chronic diseases, such as Alzheimer’s disease, insulin resistance and type-2 diabetes mellitus, hypertension, cardiovascular disease (e.g., stroke, migraine headaches, and attention deficit hyperactivity disorder (ADHD.

  1. Polyethylene Glycol Drilling Fluid for Drilling in Marine Gas Hydrates-Bearing Sediments: An Experimental Study

    Directory of Open Access Journals (Sweden)

    Lixin Kuang

    2011-01-01

    Full Text Available Shale inhibition, low-temperature performance, the ability to prevent calcium and magnesium-ion pollution, and hydrate inhibition of polyethylene glycol drilling fluid were each tested with conventional drilling-fluid test equipment and an experimental gas-hydrate integrated simulation system developed by our laboratory. The results of these tests show that drilling fluid with a formulation of artificial seawater, 3% bentonite, 0.3% Na2CO3, 10% polyethylene glycol, 20% NaCl, 4% SMP-2, 1% LV-PAC, 0.5% NaOH and 1% PVP K-90 performs well in shale swelling and gas hydrate inhibition. It also shows satisfactory rheological properties and lubrication at temperature ranges from −8 °C to 15 °C. The PVP K-90, a kinetic hydrate inhibitor, can effectively inhibit gas hydrate aggregations at a dose of 1 wt%. This finding demonstrates that a drilling fluid with a high addition of NaCl and a low addition of PVP K-90 is suitable for drilling in natural marine gas-hydrate-bearing sediments.

  2. Gas hydrate decomposition recorded by authigenic barite at pockmark sites of the northern Congo Fan

    Science.gov (United States)

    Kasten, Sabine; Nöthen, Kerstin; Hensen, Christian; Spieß, Volkhard; Blumenberg, Martin; Schneider, Ralph R.

    2012-12-01

    The geochemical cycling of barium was investigated in sediments of pockmarks of the northern Congo Fan, characterized by surface and subsurface gas hydrates, chemosynthetic fauna, and authigenic carbonates. Two gravity cores retrieved from the so-called Hydrate Hole and Worm Hole pockmarks were examined using high-resolution pore-water and solid-phase analyses. The results indicate that, although gas hydrates in the study area are stable with respect to pressure and temperature, they are and have been subject to dissolution due to methane-undersaturated pore waters. The process significantly driving dissolution is the anaerobic oxidation of methane (AOM) above the shallowest hydrate-bearing sediment layer. It is suggested that episodic seep events temporarily increase the upward flux of methane, and induce hydrate formation close to the sediment surface. AOM establishes at a sediment depth where the upward flux of methane from the uppermost hydrate layer counterbalances the downward flux of seawater sulfate. After seepage ceases, AOM continues to consume methane at the sulfate/methane transition (SMT) above the hydrates, thereby driving the progressive dissolution of the hydrates "from above". As a result the SMT migrates downward, leaving behind enrichments of authigenic barite and carbonates that typically precipitate at this biogeochemical reaction front. Calculation of the time needed to produce the observed solid-phase barium enrichments above the present-day depths of the SMT served to track the net downward migration of the SMT and to estimate the total time of hydrate dissolution in the recovered sediments. Methane fluxes were higher, and the SMT was located closer to the sediment surface in the past at both sites. Active seepage and hydrate formation are inferred to have occurred only a few thousands of years ago at the Hydrate Hole site. By contrast, AOM-driven hydrate dissolution as a consequence of an overall net decrease in upward methane flux seems to

  3. Hydration mechanisms of two polymorphs of synthetic ye'elimite

    Energy Technology Data Exchange (ETDEWEB)

    Cuesta, A.; Álvarez-Pinazo, G. [Departamento de Química Inorgánica, Universidad de Málaga, Campus Teatinos S/N. 29071-Málaga (Spain); Sanfélix, S.G. [Unidad Técnica de Investigación de Materiales, AIDICO, Avda. Benjamín Franklin, 17 Paterna, Valencia (Spain); Peral, I. [ALBA-CELLS Synchrotron, Carretera BP 1413, Km. 3.3, E-08290 Cerdanyola, Barcelona (Spain); Aranda, M.A.G. [Departamento de Química Inorgánica, Universidad de Málaga, Campus Teatinos S/N. 29071-Málaga (Spain); ALBA-CELLS Synchrotron, Carretera BP 1413, Km. 3.3, E-08290 Cerdanyola, Barcelona (Spain); De la Torre, A.G., E-mail: mgd@uma.es [Departamento de Química Inorgánica, Universidad de Málaga, Campus Teatinos S/N. 29071-Málaga (Spain)

    2014-09-15

    Ye'elimite is the main phase in calcium sulfoaluminate cements and also a key phase in sulfobelite cements. However, its hydration mechanism is not well understood. Here we reported new data on the hydration behavior of ye'elimite using synchrotron and laboratory powder diffraction coupled to the Rietveld methodology. Both internal and external standard methodologies have been used to determine the overall amorphous contents. We have addressed the standard variables: water-to-ye'elimite ratio and additional sulfate sources of different solubilities. Moreover, we report a deep study of the role of the polymorphism of pure ye'elimites. The hydration behavior of orthorhombic stoichiometric and pseudo-cubic solid-solution ye'elimites is discussed. In the absence of additional sulfate sources, stoichiometric-ye'elimite reacts slower than solid-solution-ye'elimite, and AFm-type phases are the main hydrated crystalline phases, as expected. Moreover, solid-solution-ye'elimite produces higher amounts of ettringite than stoichiometric-ye'elimite. However, in the presence of additional sulfates, stoichiometric-ye'elimite reacts faster than solid-solution-ye'elimite.

  4. 21 CFR 184.1431 - Magnesium oxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium oxide. 184.1431 Section 184.1431 Food and... Substances Affirmed as GRAS § 184.1431 Magnesium oxide. (a) Magnesium oxide (MgO, CAS Reg. No. 1309-48-4... powder (light) or a relatively dense white powder (heavy) by heating magnesium hydroxide or...

  5. Magnesium deficiency: What is our status

    Science.gov (United States)

    Low magnesium intake has been implicated in a broad range of cardiometabolic conditions, including diabetes, hypertension, and cardiovascular disease. Dietary magnesium and total body magnesium status have a widely-used but imperfect biomarker in serum magnesium. Despite serum magnesium’s limitation...

  6. Mineral resource of the month: magnesium

    Science.gov (United States)

    Kramer, Deborah A.

    2012-01-01

    Magnesium is the eighthmost abundant element in Earth’s crust, and the second-most abundant metal ion in seawater. Although magnesium is found in more than 60 minerals, only brucite, dolomite, magnesite and carnallite are commercially important for their magnesium content. Magnesium and its compounds also are recovered from seawater, brines found in lakes and wells, and bitterns (salts).

  7. 21 CFR 184.1426 - Magnesium chloride.

    Science.gov (United States)

    2010-04-01

    ... mineral bischofite. It is prepared by dissolving magnesium oxide, hydroxide, or carbonate in aqueous... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium chloride. 184.1426 Section 184.1426 Food... Specific Substances Affirmed as GRAS § 184.1426 Magnesium chloride. (a) Magnesium chloride (MgC12·6H2O,...

  8. Magnesium Oxide Induced Metabolic Alkalosis in Cattle

    OpenAIRE

    Ogilvie, T H; Butler, D G; Gartley, C J; Dohoo, I. R.

    1983-01-01

    A study was designed to compare the metabolic alkalosis produced in cattle from the use of an antacid (magnesium oxide) and a saline cathartic (magnesium sulphate). Six, mature, normal cattle were treated orally with a magnesium oxide (MgO) product and one week later given a comparable cathartic dose of magnesium sulphate (MgSO4).

  9. 21 CFR 184.1434 - Magnesium phosphate.

    Science.gov (United States)

    2010-04-01

    ... solution of magnesite with phosphoric acid. (b) Magnesium phosphate, dibasic, meets the specifications of... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium phosphate. 184.1434 Section 184.1434 Food... Specific Substances Affirmed as GRAS § 184.1434 Magnesium phosphate. (a) Magnesium phosphate includes...

  10. Direct Sulfation of Limestone

    DEFF Research Database (Denmark)

    Hu, Guilin; Dam-Johansen, Kim; Wedel, Stig

    2007-01-01

    The direct sulfation of limestone was studied in a laboratory fixed-bed reactor. It is found that the direct sulfation of limestone involves nucleation and crystal grain growth of the solid product (anhydrite). At 823 K and at low-conversions (less than about 0.5 %), the influences of SO2, O-2...... and CO2 on the direct sulfation of limestone corresponds to apparent reaction orders of about 0.2, 0.2 and -0.5, respectively. Water is observed to promote the sulfation reaction and increase the apparent reaction orders of SO2 and O-2. The influence of O-2 at high O-2 concentrations (> about 15...... %) becomes negligible. In the temperature interval from 723 K to 973 K, an apparent activation energy of about 104 kJ/mol is observed for the direct sulfation of limestone. At low temperatures and low conversions, the sulfation process is most likely under mixed control by chemical reaction and solid...

  11. Anxiolytic and antidepressive effects of magnesium in rats and their effect on general behavioural parameters

    Directory of Open Access Journals (Sweden)

    Samardžić Janko

    2011-01-01

    Full Text Available Magnesium (Mg is an essential element that catalyses more than 300 enzyme systems. Its effects on the central nervous system are exhibited through the blocking of activity of N-methyl D-aspartat (NMDA receptors and potentiating of GABA-ergic neurotransmission. Due to the vast importance of these two neurotransmission systems in the fine regulation of the central integrative function activity, the aim of this research was to test the anxiolytic and antidepressive effects of magnesium, after acute and repeated application, and its influence on general behavioural parameters. In this research Wistar albino rats were treated with increasing doses of Mg chloride 6-hydrate (MgCl 10, 20, 30 mg/kg. In order to determine anxiolytic and antidepressive properties of magnesium two models were used: elevated plus maze (EPM and forced swim test (FST. Behavioural parameters (stillness and mobility were recorded during acute and repeated administration of the active substance. Results of EPM testing showed no significant difference between groups, p>0.05. After acute application of increasing doses of magnesium chloride hydrate in FST, we showed the statistically significant difference in immobility time between the group of animals treated with Mg and the control group treated with the solvent, p<0.01. The statistically significant difference between groups treated with the lowest and the middle dose of magnesium and the controls was observed already on the first day of examining behavioural parameters (p=0.020, p=0.010. Our research has showed that magnesium, following acute administration, increases locomotor activity, and has an antidepressive but not an anxiolytic effect.

  12. Hydrates fighting tools; Des outils de lutte contre les hydrates

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2003-04-01

    Shell Exploration and Production company (SEPCo) is the operator of the 'Popeye' deep offshore field in the Gulf of Mexico. Thanks to the introduction of a low dosing hydrates inhibitor (LDHI) elaborated by Shell Global Solutions, the company has added a 7.5 Gpc extra volume of gas to its recoverable reserves. This new technology avoids the plugging of pipes by hydrates formation. (J.S.)

  13. 0℃以下含SDS的甲烷水合物生成方式及过程对其分解速率的影响%The Dependence of the Dissociation Rate of Methane-SDS Hydrate below Ice Point on Its Manners of Forming and Processing

    Institute of Scientific and Technical Information of China (English)

    王秀林; 陈卫东; 陈光进; 孙长宇; 杨兰英; 马庆兰; 陈俊; 刘鹏; 唐绪龙; 赵焕伟

    2009-01-01

    The dissociation rates of methane hydrates formed with and without the presence of sodium dodecyl sulfate (methane-SDS hydrates), were measured under atmospheric pressure and temperatures below ice point to investigate the influence of the hydrate production conditions and manners upon its dissociation kinetic behavior. The experimental results demonstrated that the dissociation rate of methane hydrate below ice point is strongly dependent on the manners of hydrate formation and processing. The dissociation rate of hydrate formed quiescently was lower than that of hydrate formed with stirring; the dissociation rate of hydrate formed at lower pressure was higher than that of hydrate formed at higher pressure; the compaction of hydrate after its formation lowered its sta-bility, i.e., increased its dissociation rate. The stability of hydrate could be increased by prolonging the time period for which hydrate was held at formation temperature and pressure before it was cooled down, or by prolonging the time period for which hydrate was held at dissociation temperature and formation pressure before it was depressurized to atmospheric pressure. It was found that the dissociation rate of methane hydrate varied with the temperature (ranging from 245.2 to 272.2 K) anomalously as reported on the dissociation of methane hydrate without the presence of surfactant as kinetic promoter. The dissociation rate at 268 K was found to be the lowest when the manners and conditions at which hydrates were formed and processed were fixed.

  14. Confession of a Magnesium Battery.

    Science.gov (United States)

    Bucur, Claudiu B; Gregory, Thomas; Oliver, Allen G; Muldoon, John

    2015-09-17

    Magnesium is an ideal metal anode that has nearly double the volumetric capacity of lithium metal with a very negative reduction potential of -2.37 vs SHE. A significant advantage of magnesium is the apparent lack of dendrite formation during charging, which overcomes major safety and performance challenges encountered with using lithium metal anodes. Here, we highlight major recent advances in nonaqueous Mg electrochemistry, notably the development of electrolytes and cathodes, and discuss some of the challenges that must be overcome to realize a practical magnesium battery.

  15. Obsidian Hydration: A New Paleothermometer

    Energy Technology Data Exchange (ETDEWEB)

    Anovitz, Lawrence {Larry} M [ORNL; Riciputi, Lee R [ORNL; Cole, David R [ORNL; Fayek, Mostafa [ORNL; Elam, J. Michael [University of Tennessee, Knoxville (UTK)

    2006-01-01

    The natural hydration of obsidian was first proposed as a dating technique for young geological and archaeological specimens by Friedman and Smith (1960), who noted that the thickness of the hydrated layer on obsidian artifacts increases with time. This approach is, however, sensitive to temperature and humidity under earth-surface conditions. This has made obsidian hydration dating more difficult, but potentially provides a unique tool for paleoclimatic reconstructions. In this paper we present the first successful application of this approach, based on combining laboratory-based experimental calibrations with archaeological samples from the Chalco site in the Basin of Mexico, dated using stratigraphically correlated 14C results and measuring hydration depths by secondary ion mass spectrometry. The resultant data suggest, first, that this approach is viable, even given the existing uncertainties, and that a cooling trend occurred in the Basin of Mexico over the past 1450 yr, a result corroborated by other paleoclimatic data.

  16. Obsidian hydration: A new paleothermometer

    Science.gov (United States)

    Anovitz, Lawrence M.; Riciputi, Lee R.; Cole, David R.; Fayek, Mostafa; Elam, J. Michael

    2006-07-01

    The natural hydration of obsidian was first proposed as a dating technique for young geological and archaeological specimens by Friedman and Smith (1960), who noted that the thickness of the hydrated layer on obsidian artifacts increases with time. This approach is, however, sensitive to temperature and humidity under earth-surface conditions. This has made obsidian hydration dating more difficult, but potentially provides a unique tool for paleoclimatic reconstructions. In this paper we present the first successful application of this approach, based on combining laboratory-based experimental calibrations with archaeological samples from the Chalco site in the Basin of Mexico, dated using stratigraphically correlated 14C results and measuring hydration depths by secondary ion mass spectrometry. The resultant data suggest, first, that this approach is viable, even given the existing uncertainties, and that a cooling trend occurred in the Basin of Mexico over the past 1450 yr, a result corroborated by other paleoclimatic data.

  17. Obsidian hydration dates glacial loading?

    Science.gov (United States)

    Friedman, I; Pierce, K L; Obradovich, J D; Long, W D

    1973-05-18

    Three different groups of hydration rinds have been measured on thin sections of obsidian from Obsidian Cliff, Yellowstone National Park, Wyoming. The average thickness of the thickest (oldest) group of hydration rinds is 16.3 micrometers and can be related to the original emplacement of the flow 176,000 years ago (potassium-argon age). In addition to these original surfaces, most thin sections show cracks and surfaces which have average hydration rind thicknesses of 14.5 and 7.9 micrometers. These later two hydration rinds compare closely in thickness with those on obsidian pebbles in the Bull Lake and Pinedale terminal moraines in the West Yellowstone Basin, which are 14 to 15 and 7 to 8 micrometers thick, respectively. The later cracks are thought to have been formed by glacial loading during the Bull Lake and Pinedale glaciations, when an estimated 800 meters of ice covered the Obsidian Cliff flow.

  18. Buffer-regulated biocorrosion of pure magnesium.

    Science.gov (United States)

    Kirkland, Nicholas T; Waterman, Jay; Birbilis, Nick; Dias, George; Woodfield, Tim B F; Hartshorn, Richard M; Staiger, Mark P

    2012-02-01

    Magnesium (Mg) alloys are being actively investigated as potential load-bearing orthopaedic implant materials due to their biodegradability in vivo. With Mg biomaterials at an early stage in their development, the screening of alloy compositions for their biodegradation rate, and hence biocompatibility, is reliant on cost-effective in vitro methods. The use of a buffer to control pH during in vitro biodegradation is recognised as critically important as this seeks to mimic pH control as it occurs naturally in vivo. The two different types of in vitro buffer system available are based on either (i) zwitterionic organic compounds or (ii) carbonate buffers within a partial-CO(2) atmosphere. This study investigated the influence of the buffering system itself on the in vitro corrosion of Mg. It was found that the less realistic zwitterion-based buffer did not form the same corrosion layers as the carbonate buffer, and was potentially affecting the behaviour of the hydrated oxide layer that forms on Mg in all aqueous environments. Consequently it was recommended that Mg in vitro experiments use the more biorealistic carbonate buffering system when possible.

  19. Storing natural gas as frozen hydrate

    Energy Technology Data Exchange (ETDEWEB)

    Gudmundsson, J.S.; Khokhar, A.A. (Univ. of Trondheim (Norway)); Parlaktuna, M. (Middle East Technical Univ., Ankara (Turkey))

    1994-02-01

    The formation of natural gas hydrates is a well-known problem in the petroleum and natural gas industries. Hydrates are solid materials that form when liquid water and natural gas are brought in contact under pressure. Hydrate formation need not be a problem. On the contrary, it can be an advantage. The volume of hydrates is much less than that of natural gas. At standard conditions, hydrates occupy 150 to 170 times less volume than the corresponding gas. Typically, natural gas hydrates contain 15% gas and 85% water by mass. It follows that hydrates can be used for large-scale storage of natural gas. Benesh proposed using hydrates to improve the load factor of natural gas supply systems. The author suggested that hydrates could be produced by bringing liquid water into contact with natural gas at the appropriate temperature and high pressure. The hydrate then would be stored at a temperature and pressure where it was stable. When gas was needed for the supply system, the hydrate would be melted at low pressure. The stability of a natural gas hydrate during storage at atmospheric pressure and below-freezing temperatures was studied in the laboratory. The gas hydrate was produced in a stirred vessel at 2- to 6-MPa pressure and temperatures from 0 to 20 C. The hydrate was refrigerated and stored in deep freezers at [minus]5, [minus]10, and [minus]18 C for up to 10 days. The natural gas hydrate remained stable when kept frozen at atmospheric pressure.

  20. The structure and regulation of magnesium selective ion channels.

    Science.gov (United States)

    Payandeh, Jian; Pfoh, Roland; Pai, Emil F

    2013-11-01

    The magnesium ion (Mg(2+)) is the most abundant divalent cation within cells. In man, Mg(2+)-deficiency is associated with diseases affecting the heart, muscle, bone, immune, and nervous systems. Despite its impact on human health, little is known about the molecular mechanisms that regulate magnesium transport and storage. Complete structural information on eukaryotic Mg(2+)-transport proteins is currently lacking due to associated technical challenges. The prokaryotic MgtE and CorA magnesium transport systems have recently succumbed to structure determination by X-ray crystallography, providing first views of these ubiquitous and essential Mg(2+)-channels. MgtE and CorA are unique among known membrane protein structures, each revealing a novel protein fold containing distinct arrangements of ten transmembrane-spanning α-helices. Structural and functional analyses have established that Mg(2+)-selectivity in MgtE and CorA occurs through distinct mechanisms. Conserved acidic side-chains appear to form the selectivity filter in MgtE, whereas conserved asparagines coordinate hydrated Mg(2+)-ions within the selectivity filter of CorA. Common structural themes have also emerged whereby MgtE and CorA sense and respond to physiologically relevant, intracellular Mg(2+)-levels through dedicated regulatory domains. Within these domains, multiple primary and secondary Mg(2+)-binding sites serve to staple these ion channels into their respective closed conformations, implying that Mg(2+)-transport is well guarded and very tightly regulated. The MgtE and CorA proteins represent valuable structural templates to better understand the related eukaryotic SLC41 and Mrs2-Alr1 magnesium channels. Herein, we review the structure, function and regulation of MgtE and CorA and consider these unique proteins within the expanding universe of ion channel and transporter structural biology.

  1. Airway Hydration and COPD

    Science.gov (United States)

    Ghosh, Arunava; Boucher, R.C.; Tarran, Robert

    2015-01-01

    Chronic obstructive pulmonary disease (COPD) is one of the prevalent causes of worldwide mortality and encompasses two major clinical phenotypes, i.e., chronic bronchitis (CB) and emphysema. The most common cause of COPD is chronic tobacco inhalation. Research focused on the chronic bronchitic phenotype of COPD has identified several pathological processes that drive disease initiation and progression. For example, the lung’s mucociliary clearance (MCC) system performs the critical task of clearing inhaled pathogens and toxic materials from the lung. MCC efficiency is dependent on: (i) the ability of apical plasma membrane ion channels such as the cystic fibrosis transmembrane conductance regulator (CFTR) and the epithelial Na+ channel (ENaC) to maintain airway hydration; (ii) ciliary beating; and, (iii) appropriate rates of mucin secretion. Each of these components is impaired in CB and likely contributes to the mucus stasis/accumulation seen in CB patients. This review highlights the cellular components responsible for maintaining MCC and how this process is disrupted following tobacco exposure and with CB. We shall also discuss existing therapeutic strategies for the treatment of chronic bronchitis and how components of the MCC can be used as biomarkers for the evaluation of tobacco or tobacco-like-product exposure. PMID:26068443

  2. Mechanism of gypsum hydration

    Directory of Open Access Journals (Sweden)

    Pacheco, G.

    1991-06-01

    Full Text Available There is an hypothesis that the mechanism o f gypsum hydration and dehydration is performed through two simultaneous phenomena. In this study we try to clear up this phenomenon using chlorides as accelerators or a mixture of ethanol-methanol as retarders to carry out the gypsum setting. Natural Mexican gypsum samples and a hemihydrate prepared in the laboratory are used. The following analytical techniques are used: MO, DRX, DTA, TG and DTG. In agreement with the obtained results, it can be concluded: that colloid formation depends on the action of accelerators or retarders and the crystals are a consequence of the quantity of hemihydrate formed.

    En el mecanismo de hidratación y deshidratación del yeso existe la hipótesis de que éste se efectúa por dos fenómenos simultáneos. Este estudio intenta esclarecer estos fenómenos, empleando: cloruros como aceleradores o mezcla etanol-metanol como retardadores para efectuar el fraguado del yeso. Se emplean muestras de yeso de origen natural mexicano y hemihydrate preparado en laboratorio; se utilizan técnicas analíticas: MO, DRX, DTA, TG y DTG. De acuerdo a los resultados obtenidos se puede deducir: que la formación del coloide depende de la acción de los agentes aceleradores o retardadores y que los cristales son consecuencia de la cantidad de hemihidrato formado.

  3. Study of Synergistic Flame Retarded Ethylene-Vinyl Acetate/Magnesium Hydroxide Sulfate Hydrate Whisker Composite%阻燃协效聚乙烯-醋酸乙烯酯/碱式硫酸镁晶须复合材料的研究

    Institute of Scientific and Technical Information of China (English)

    鲁红典; 于晓灵

    2008-01-01

    通过极限氧指数(LOI)和UL-94垂直燃烧试验研究了微胶囊化红磷(MRP)和有机改性蒙脱土(OMT)对聚乙烯-醋酸乙烯酯/碱式硫酸镁晶须(EVA/MHSH)复合材料阻燃性能的影响.结果表明:MRP或OMT与MHSH联合使用具有阻燃协同效应.

  4. Chemical and isotopic characteristics of gas hydrate- and pore-water samples obtained from gas hydrate-bearing sediment cores retrieved from a mud volcano in the Kukuy Canyon, Lake Baikal

    Energy Technology Data Exchange (ETDEWEB)

    Minami, H.; Hachikubo, A.; Krylov, A.; Sakagami, H.; Ohashi, M.; Bai, J.; Kataoka, S.; Yamashita, S.; Takahashi, N.; Shoji, H. [Kitami Inst. of Technology, Kitami (Japan); Khlystov, O.; Zemskaya, T.; Grachev, M. [Russian Academy of Sciences, Irkutsk (Russian Federation). Limnological Inst.

    2008-07-01

    This paper provided details of a method developed to obtain gas hydrate water samples from a mud volcano in Lake Baikal, Russia. Chemical and isotopic analyses were conducted to examine the hydrate and pore water samples as well as to evaluate the original water involved in shallow gas hydrate accumulations in the region. Lake sediment core samples were retrieved from the bottom of the lake with gravity corers. A squeezer was used to take pore water samples from the sediments. Hydrate samples were taken from a gas hydrate placed on a polyethylene funnel. Dissolved hydrate water was filtered through a membrane into bottles. Both samples were kept under chilled or liquid nitrogen temperatures. Ion chromatography was used to determine concentrations of anions and hydrogen carbonate ions. Sodium and magnesium concentrations were determined using an inductively coupled plasma atomic emission spectrometer. An absorption spectrometer was used to determine potassium and calcium concentrations, and a mass spectrometer was used to analyze stable isotopes of oxygen and hydrogen. Results of the study suggested that the gas dissolved in pore water and adsorbed on the surfaces of sediment particles was not the original gas from the hydrates retrieved at the mud volcano. Original gas hydrate-forming fluids were chemically different from the pore- and lake-water samples. The oxygen isotopic composition of the gas hydrate water samples correlated well with hydrogen values. It was concluded that ascending fluid and water delivered the gas into the gas stability zone, and is the main gas hydrate-forming fluid in the area of study. 12 refs., 1 fig.

  5. Syndecan heparan sulfate proteoglycans

    DEFF Research Database (Denmark)

    Gomes, Angélica Maciel; Sinkeviciute, Dovile; Multhaupt, Hinke A.B.

    2016-01-01

    Virtually all animal cells express heparan sulfate proteoglycans on the cell surface and in the extracellular matrix. Syndecans are a major group of transmembrane proteoglycans functioning as receptors that mediate signal transmission from the extracellular microenvironment to the cell. Their hep......Virtually all animal cells express heparan sulfate proteoglycans on the cell surface and in the extracellular matrix. Syndecans are a major group of transmembrane proteoglycans functioning as receptors that mediate signal transmission from the extracellular microenvironment to the cell....... Their heparan sulfate chains, due to their vast structural diversity, interact with a wide array of ligands including potent regulators of adhesion, migration, growth and survival. Frequently, ligands interact with cell surface heparan sulfate in conjunction with high affinity receptors. The consequent...... signaling can therefore be complex, but it is now known that syndecans are capable of independent signaling. This review is divided in two sections, and will first discuss how the assembly of heparan sulfate, the anabolic process, encodes information related to ligand binding and signaling. Second, we...

  6. Hydrated Minerals at Yellowknife Bay, Gale Crater, Mars: Observations from Mastcam's Science Filters

    Science.gov (United States)

    Rice, M. S.; Bell, J. F.; Wellington, D. F.; Godber, A.; Hardgrove, C. J.; Ehlmann, B. L.; Grotzinger, J. P.; Kinch, K. M.; Clegg, S. M.; Fraeman, A. A.; Johnson, J. R.; Malin, M.; Stack, K.; Siebach, K. L.; Kah, L. C.; Team, M.

    2013-12-01

    The Mastcam imaging investigation on the Mars Science Laboratory Curiosity rover can help constrain the mineralogy of sulfates and phyllosilicates present in the outcrop at Yellowknife Bay within Gale crater. The two Mastcams provide high-resolution morphological information, RGB color, and visible to near-infrared (Vis-NIR) multispectral data using narrowband 'science filters' covering 12 unique wavelengths between 432 and 1013 nm. The longest wavelength filters have some sensitivity to hydrated and/or hydroxylated minerals, as they can detect an absorption due to the 2ν1 + ν3 H2O combination band and/or the 3ν OH overtone when this band minimum occurs between 980 and 1000 nm (in water ice and some carbonates and hydrated sulfates). This narrow hydration band leads to a Mastcam spectral profile that is distinguishable from spectra of iron-bearing minerals with broad absorptions near 1000 nm. Here we use this spectral profile to help interpret the mineralogy hydrated surface materials in Mastcam multispectral images. The light-toned, Ca-sulfate fracture-fills of the Sheepbed Unit at Yellowknife Bay show some evidence for hydration in calibrated Mastcam spectra from sols 133-269. From comparisons to laboratory reflectance spectra of Ca-sulfate minerals convolved to Mastcam bandpasses, the hydration signature near 1013 nm is consistent with the presence of gypsum, but not bassanite or anhydrite. Several narrow fracture-fills observed in the Sheepbed Unit show no evidence for hydration, such as the thin veins at the John Klein and Cumberland drill sites. These observations are in accord with CheMin XRD observations (where bassanite and anhydrite were detected, but not gypsum). Mastcam hydration detections in nearby veins, however, suggest that Ca-sulfate hydration states may vary within the fracture-fill networks on local scales. The phyllosilicate-bearing outcrop of the Sheepbed Unit, when broken by Curiosity's wheels or brushed by the rover's Dust Removal Tool

  7. Formation of ettringite, Ca 6Al 2(SO 4) 3(OH) 12·26H 2O, AFt, and monosulfate, Ca 4Al 2O 6(SO 4)·14H 2O, AFm-14, in hydrothermal hydration of Portland cement and of calcium aluminum oxide—calcium sulfate dihydrate mixtures studied by in situ synchrotron X-ray powder diffraction

    Science.gov (United States)

    Christensen, Axel Nørlund; Jensen, Torben R.; Hanson, Jonathan C.

    2004-06-01

    In the hydration of calcium aluminum oxide-gypsum mixtures, i.e., Ca 3Al 2O 6, Ca 12Al 14O 33 and CaSO 4·2H 2O, the reaction products can be ettringite, Ca 6Al 2(SO 4) 3(OH) 12·26H 2O, monosulfate, Ca 4Al 2O 6(SO 4)·14H 2O, or the calcium aluminum oxide hydrate, Ca 4Al 2O 7·19H 2O. Ettringite is formed if sufficient CaSO 4·2H 2O is present in the mixture. Ettringite is converted to monosulfate when all CaSO 4·2H 2O is consumed in the synthesis of ettringite. The reactions were investigated in the temperature range 25-170°C using in situ synchrotron X-ray powder diffraction. This technique allows the study of very fast chemical reactions that are observed here under hydrothermal conditions. A new experimental approach was developed to perform in situ mixing of the reactants during X-ray data collection.

  8. Drug: D08711 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available D08711 Mixture, Drug Coptis rhizome - senna leaf - rhubarb - magnesium oxide - magn...esium sulfate hydrate mixt; Cetilo (TN) Coptis rhizome [DR:D00092], Senna leaf [DR:D06751], Rhubarb [DR:D067...3 Digestive organ agents 235 Purgatives, clysters 2359 Others D08711 Coptis rhizome - senna leaf - rhubarb - magnesium oxide - magnesium sulfate hydrate mixt PubChem: 96025394 ...

  9. Cement from magnesium substituted hydroxyapatite.

    Science.gov (United States)

    Lilley, K J; Gbureck, U; Knowles, J C; Farrar, D F; Barralet, J E

    2005-05-01

    Brushite cement may be used as a bone graft material and is more soluble than apatite in physiological conditions. Consequently it is considerably more resorbable in vivo than apatite forming cements. Brushite cement formation has previously been reported by our group following the mixture of nanocrystalline hydroxyapatite and phosphoric acid. In this study, brushite cement was formed from the reaction of nanocrystalline magnesium-substituted hydroxyapatite with phosphoric acid in an attempt to produce a magnesium substituted brushite cement. The presence of magnesium was shown to have a strong effect on cement composition and strength. Additionally the presence of magnesium in brushite cement was found to reduce the extent of brushite hydrolysis resulting in the formation of HA. By incorporating magnesium ions in the apatite reactant structure the concentration of magnesium ions in the liquid phase of the cement was controlled by the dissolution rate of the apatite. This approach may be used to supply other ions to cement systems during setting as a means to manipulate the clinical performance and characteristics of brushite cements.

  10. Sulfuric acid deposition from stratospheric geoengineering with sulfate aerosols

    KAUST Repository

    Kravitz, Ben

    2009-07-28

    We used a general circulation model of Earth\\'s climate to conduct geoengineering experiments involving stratospheric injection of sulfur dioxide and analyzed the resulting deposition of sulfate. When sulfur dioxide is injected into the tropical or Arctic stratosphere, the main additional surface deposition of sulfate occurs in midlatitude bands, because of strong cross-tropopause flux in the jet stream regions. We used critical load studies to determine the effects of this increase in sulfate deposition on terrestrial ecosystems by assuming the upper limit of hydration of all sulfate aerosols into sulfuric acid. For annual injection of 5 Tg of SO2 into the tropical stratosphere or 3 Tg of SO2 into the Arctic stratosphere, neither the maximum point value of sulfate deposition of approximately 1.5 mEq m−2 a−1 nor the largest additional deposition that would result from geoengineering of approximately 0.05 mEq m−2 a−1 is enough to negatively impact most ecosystems.

  11. SULFATE RESISTANCE MECHANISM OF HIGH-PERFORMANCE CONCRETE CONTAINING NCI

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    It is found that the incorporation of Nitrite Corrosion Inhibitor (NCI) greatly weakens the resistance of mixtures to sulfate attack.To study the mechanism of this phenomenon,in this paper,the influence of NCI additionon on the cement paste and microstructure change of high performance concrete specimens is studied by means of quantitative XRD,SEM tests.The results demonstrate that the incorporation of NCI accelerates the formation of calcium hydroxide and ettringite crystals,and weakens the pore refinement effect caused by the secondary hydration reaction of fly ash and microsilica.At the age up to one year,the relative crystal quantity in mixture containing NCI is always higher than that in control mixture.The reasons for the degradation in sulfate resisitance of mixtures may be attributed to the increase and stability of the calcium hydroxide and ettringite crystals formed and the weakening of secondary hydration reaction.Based on the results,conclusion can be drawn that NCI should be used cautiously in practical engineering where high resistance to sulfate attack is required.

  12. Acid Sulfate Alteration in Gusev Crater, Mars

    Science.gov (United States)

    Morris, R. V.; Ming, D. W.; Catalano, J. G.

    2016-01-01

    dust. The Moessbauer parameters are not definitive for mineralogical speciation (other than octahedrally-coordinated Fe(3+) but are consistent with a schwertmannite-like phase (i.e., a nanophase ferric oxide). The high oxidation state and values of Moessbauer parameters (center shift and quadrupole splitting) for the high-SO3 samples imply ferric sulfate (i.e., oxidized sulfur), although the hydration state cannot be constrained. In no case is there an excess of SO3 over available cations (i.e., no evidence for elemental sulfur), and Fe sulfide (pyrite) has been detected in only one Gusev sample. The presence of both high-SiO2 (and low total iron and SO3) and high SO3 (and high total iron as ferric sulfate) can be accommodated by a two-step geochemical model developed with the Geochemist's Workbench. (1) Step 1 is anoxic acid sulfate leaching of Martian basalt at high water-to rock ratios (greater than 70). The result is a high-SiO2 residue0, and anoxic conditions are required to solubilize Fe as Fe(2+). (2) Step 2 is the oxic precipitation of sulfate salts from the leachate. Oxic conditions are required to produce the high concentrations of ferric sulfate with minor Mg-sulfates and no detectable Fe(2+)-sulfates.

  13. Tetrahydrofuran hydrate decomposition characteristics in porous media

    Science.gov (United States)

    Song, Yongchen; Wang, Pengfei; Wang, Shenglong; Zhao, Jiafei; Yang, Mingjun

    2016-12-01

    Many tetrahydrofuran (THF) hydrate properties are similar to those of gas hydrates. In the present work THF hydrate dissociation in four types of porous media is studied. THF solution was cooled to 275.15 K with formation of the hydrate under ambient pressure, and then it dissociated under ambient conditions. THF hydrate dissociation experiments in each porous medium were conducted three times. Magnetic resonance imaging (MRI) was used to obtain images. Decomposition time, THF hydrate saturation and MRI mean intensity (MI) were measured and analyzed. The experimental results showed that the hydrate decomposition time in BZ-4 and BZ-3 was similar and longer than that in BZ-02. In each dissociation process, the hydrate decomposition time of the second and third cycles was shorter than that of the first cycle in BZ-4, BZ-3, and BZ-02. The relationship between THF hydrate saturation and time is almost linear.

  14. Microstructural Origins of Cement Paste Degradation by External Sulfate Attack

    Science.gov (United States)

    Feng, Pan; Garboczi, Edward J.; Miao, Changwen; Bullard, Jeffrey W.

    2015-01-01

    A microstructure model has been applied to simulate near-surface degradation of portland cement paste in contact with a sodium sulfate solution. This new model uses thermodynamic equilibrium calculations to guide both compositional and microstructure changes. It predicts localized deformation and the onset of damage by coupling the confined growth of new solids with linear thermoelastic finite element calculations of stress and strain fields. Constrained ettringite growth happens primarily at the expense of calcium monosulfoaluminate, carboaluminate and aluminum-rich hydrotalcite, if any, respectively. Expansion and damage can be mitigated chemically by increasing carbonate and magnesium concentrations or microstructurally by inducing a finer dispersion of monosulfate. PMID:26722191

  15. Electroplating zinc transition layer for electroless nickel plating on AM60 magnesium alloys

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-min; ZHOU Wan-qiu; HAN En-Hou

    2006-01-01

    Electroplating zinc coating as transition layer of electroless nickel plating on AM60 magnesium alloys was investigated. The zinc film can be deposited in a pyrophosphate bath at 50-60 ℃ under current density of 0.5-1.5 A/dm2. A new fore treatment technology was applied by acid cleaning with a solution containing molybdate and phosphorous acid, by alkaline cleaning in a bath containing molybdate and sodium hydroxide. The subsequent electroless plating was carried out in nickel sulfate bath. The SEM observation shows that the deposition is uniform and compact. The polarization curve measurements show that the corrosion potential of the zinc plating in 3.5% NaCl is about -1.3 V(vs SCE) which is noble than that of magnesium substrate. The zinc electroplating can be applied as the pretreatment process for electroless nickel plating on magnesium alloys.

  16. [Effect of magnesium, acetylsalicilic acid and emoxypine on aggregation of platelets].

    Science.gov (United States)

    Loznikova, S Zh; Sukhodola, A A; Shcharbina, N Iu; Shcharbin, D G

    2014-01-01

    The thrombin-induced platelet aggregation was studied in the absence and presence of magnesium sulfate, acetylsalicylic acid and emoxypine. It was found that all the preparations studied were able separately to decrease platelet aggregation. In contrast, their joint action was not able to affect the aggregation of platelets. The data obtained can be used to choose the treatment strategy for patients with ischemic stroke.

  17. Clinker mineral hydration at reduced relative humidities

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede; Hansen, Per Freiesleben; Lachowski, Eric E.;

    1999-01-01

    Vapour phase hydration of purl cement clinker minerals at reduced relative humidities is described. This is relevant to modern high performance concrete that may self-desiccate during hydration and is also relevant to the quality of the cement during storage. Both the oretical considerations...... and experimental data are presented showing that C(3)A can hydrate at lower humidities than either C3S or C2S. It is suggested that the initiation of hydration during exposure to water vapour is nucleation controlled. When C(3)A hydrates at low humidity, the characteristic hydration product is C(3)AH(6...

  18. Progress of Gas Hydrate Studies in China

    Institute of Scientific and Technical Information of China (English)

    樊栓狮; 汪集旸

    2006-01-01

    A brief overview is given on the gas hydrate-related research activities carried out by Chinese researchers in the past 15 years. The content involves: (1) Historical review. Introducing the gas hydrate research history in China; (2) Gas hydrate research groups in China. There are nearly 20 groups engaged in gas hydrate research now; (3) Present studies.Including fundamental studies, status of the exploration of natural gas hydrate resources in the South China Sea region, and development of hydrate-based new techniques; (4) Future development.

  19. Magnesium and fetal growth

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, K.

    1988-01-01

    Fetal growth retardation and premature labor are major problems in perinatal medicine today and account for a great deal of the observed fetal morbidity. While the neonatal death rate has steadily declined over the past decade, there has been a lack of concommitant decrease in these two leading problems. Magnesium (Mg/sup ++/) plays a major role in both of these areas of concern. The fact that it is used as a treatment for premature labor has led investigators to look at low Mg/sup ++/ as a possible cause of this poorly understood phenomenon. The second major cause of small for gestational age infants is intrauterine growth retardation, a condition which may be of either fetal or maternal origin. In either case, Mg/sup ++/ may be implicated since it exerts a strong influence on the underlying pathophysiology of placental failure and maternal hypertension. Both of these conditions are mediated by vascular and platelet hyperactivity as well as by and increase in the ration of thromboxane to prostacyclin. Studies in both the human and animal species are beginning to show how Mg/sup ++/ interacts in these conditions to produce such a damaging fetal outcome. The recent use of Doppler velocimetry of the developing fetus has shown reduced fetal vascular and maternal uterine vascular compliance as early as 14 weeks of gestation in those who would be so affected.

  20. Magnesium and healthy aging.

    Science.gov (United States)

    Veronese, Nicola; Zanforlini, Bruno Micael; Manzato, Enzo; Sergi, Giuseppe

    2015-01-01

    Magnesium (Mg) is relatively stable in the intracellular compartment, although decreases linearly with advancing age. This begs the question as to whether Mg could be used as biomarker of aging. A biomarker of aging is a biological parameter of an organism that, in the absence of disease, better predicts functional capability at a later age than the chronological age. Bone and muscle Mg content might be useful biomarkers, but the need for biopsies and the heterogeneous distribution of Mg in bones and muscles strongly limit the application of these methods in clinical practice. Similar considerations can be made for urinary Mg assessment, particularly after a loading test. Markers of Mg in blood seem fairly unreliable as biomarkers of aging since they are strongly dependent upon renal function, do not reflect the intracellular Mg status, and, in some investigations, are within normal ranges although other Mg parameters are not. Other investigations (e.g. nuclear magnetic resonance with fluorescent probes) seem to be promising, but their availability remains limited.

  1. Hydration of fly ash cement

    Energy Technology Data Exchange (ETDEWEB)

    Etsuo Sakai; Shigeyoshi Miyahara; Shigenari Ohsawa; Seung-Heun Lee; Masaki Daimon [Tokyo Institute of Technology, Tokyo (Japan). Department of Metallurgy and Ceramics Science, Graduate School of Science and Engineering

    2005-06-01

    It is necessary to establish the material design system for the utilization of large amounts of fly ash as blended cement instead of disposing of it as a waste. Cement blended with fly ash is also required as a countermeasure to reduce the amount of CO{sub 2} generation. In this study, the influences of the glass content and the basicity of glass phase on the hydration of fly ash cement were clarified and hydration over a long curing time was characterized. Two kinds of fly ash with different glass content, one with 38.2% and another with 76.6%, were used. The hydration ratio of fly ash was increased by increasing the glass content in fly ash in the specimens cured for 270 days. When the glass content of fly ash is low, the basicity of glass phase tends to decrease. Reactivity of fly ash is controlled by the basicity of the glass phase in fly ash during a period from 28 to 270 days. However, at an age of 360 days, the reaction ratios of fly ash show almost identical values with different glass contents. Fly ash also affected the hydration of cement clinker minerals in fly ash cement. While the hydration of alite was accelerated, that of belite was retarded at a late stage.

  2. Chemistry, isotopic composition, and origin of a methane-hydrogen sulfide hydrate at the Cascadia subduction zone

    Science.gov (United States)

    Kastner, M.; Kvenvolden, K.A.; Lorenson, T.D.

    1998-01-01

    Although the presence of extensive gas hydrate on the Cascadia margin, offshore from the western U.S. and Canada, has been inferred from marine seismic records and pore water chemistry, solid gas hydrate has only been found at one location. At Ocean Drilling Program (ODP) Site 892, offshore from central Oregon, gas hydrate was recovered close to the sediment - water interface at 2-19 m below the seafloor, (mbsf) at 670 m water depth. The gas hydrate occurs as elongated platy crystals or crystal aggregates, mostly disseminated irregularly, with higher concentrations occurring in discrete zones, thin layers, and/or veinlets parallel or oblique to the bedding. A 2-to 3-cm thick massive gas hydrate layer, parallel to bedding, was recovered at ???17 mbsf. Gas from a sample of this layer was composed of both CH4 and H2S. This sample is the first mixed-gas hydrate of CH4-H2S documented in ODP; it also contains ethane and minor amounts of CO2. Measured temperature of the recovered core ranged from 2 to - 18??C and are 6 to 8 degrees lower than in-situ temperatures. These temperature anomalies were caused by the partial dissociation of the CH4-H2S hydrate during recovery without a pressure core sampler. During this dissociation, toxic levels of H2S (??34S, +27.4???) were released. The ??13C values of the CH4 in the gas hydrate, -64.5 to -67.5???(PDB), together with ??D values of - 197 to - 199???(SMOW) indicate a primarily microbial source for the CH4. The ??18O value of the hydrate H2O is +2.9???(SMOW), comparable with the experimental fractionation factor for sea-ice. The unusual composition (CH4-H2S) and depth distribution (2-19 mbsf) of this gas hydrate indicate mixing between a methane-rich fluid with a pore fluid enriched in sulfide; at this site the former is advecting along an inclined fault into the active sulfate reduction zone. The facts that the CH4-H2S hydrate is primarily confined to the present day active sulfate reduction zone (2-19 mbsf), and that from here

  3. Magnesium Versus Bupivacaine Infiltration in Controlling Postoperative Pain in Inguinal Hernia Repair

    Science.gov (United States)

    Razavi, Seyed Sajad; Peyvandi, Hasan; Badrkhani Jam, Ali Reza; Safari, Farhad; Teymourian, Houman; Mohajerani, Seyed Amir

    2015-01-01

    Background: Postoperative pain is one of the most common problems after hernia repair. Decrease in postoperative pain accelerates functional recovery, decreases duration of hospital stay and postoperative morbidity. Objectives: To compare postoperative analgesic effect of infiltration of magnesium versus bupivacaine into incision of inguinal hernia repair. Patients and Methods: In a double blind clinical trial, 80 patients’ candidates for elective inguinal hernia repair were enrolled. Right before closure of incision, in Bupivacaine group 5 mL Bupivacaine 0.5% added to 5 mL normal saline and in Magnesium group, 10 mL Magnesium sulfate 20% was infused subcutaneously. Pain score was measured using numeric rating score (NRS) at 1, 3, 6, 12 and 24 hours postoperatively. If NRS was above 3, 1 mg morphine was administered as rescue analgesic until patient felt comfortable or NRS < 3. Results: Postoperative pain scores at 1 and 3 hours were not significantly different between bupivacaine and magnesium groups (P = 0.21, 0.224; respectively). However, at 6 (P = 0.003), 12 (P = 0.028) and 24 (P = 0.022) hours postoperative, pain score (NRS) was significantly lower in bupivacaine group. Number of patients needed at least 1 dose of rescue morphine (P = 0.001), mean number of episodes asked for morphine during next 24 hours (P = 0.001) and total dose of morphine requirement (P = 0.01) were significantly lower in bupivacaine group. Conclusions: Magnesium infiltration did not decrease total dose and number of episodes needed for morphine rescue analgesic. Bupivacaine infiltration into surgical site was more effective than magnesium sulfate infiltration in postoperative pain control. PMID:26705525

  4. Interactions between bicarbonate, potassium, and magnesium, and sulfur-dependent induction of luminescence in Vibrio fischeri.

    Science.gov (United States)

    Tabei, Yosuke; Era, Mariko; Ogawa, Akane; Morita, Hiroshi

    2012-06-01

    In spite of its central importance in research efforts, the relationship between seawater compounds and bacterial luminescence has not previously been investigated in detail. Thus, in this study, we investigated the effect of cations (Na(+) , K(+) , NH(4) (+) , Mg(2+) , and Ca(2+) ) and anions (Cl(-) , HCO(3) (-) , CO(3) (2-) , and NO(3) (-) ) on the induction of both inorganic (sulfate, sulfite, and thiosulfate) and organic (L-cysteine and L-cystine) sulfur-dependent luminescence in Vibrio fischeri. We found that HCO(3) (-) (bicarbonate) and CO(3) (2-) (carbonate), in the form of various compounds, had a stimulatory effect on sulfur-dependent luminescence. The luminescence induced by bicarbonate was further promoted by the addition of magnesium. Potassium also increased sulfur-dependent luminescence when sulfate or thiosulfate was supplied as the sole sulfur source, but not when sulfite, L-cysteine, or L-cystine was supplied. The positive effect of potassium was accelerated by the addition of magnesium and/or calcium. Furthermore, the additional supply of magnesium improved the induction of sulfite- or L-cysteine-dependent luminescence, but not the l-cystine-dependent type. These results suggest that sulfur-dependent luminescence of V. fischeri under nutrient-starved conditions is mainly controlled by bicarbonate, carbonate, and potassium. In addition, our results indicate that an additional supply of magnesium is effective for increasing V. fischeri luminescence.

  5. Comparison of stromal hydration techniques for clear corneal cataract incisions: conventional hydration versus anterior stromal pocket hydration.

    Science.gov (United States)

    Mifflin, Mark D; Kinard, Krista; Neuffer, Marcus C

    2012-06-01

    Anterior stromal pocket hydration was compared with conventional hydration for preventing wound leak after 2.8 mm uniplanar clear corneal incisions (CCIs) in patients having routine cataract surgery. Conventional hydration involves hydration of the lateral walls of the main incision with visible whitening of the stroma. The anterior stromal pocket hydration technique involves creation of an additional supraincisional stromal pocket overlying the main incision, which is then hydrated instead of the main incision. Sixty-six eyes of 48 patients were included in the data analysis with 33 assigned to each study group. The anterior stromal pocket hydration technique was significantly better than conventional hydration in preventing wound leak due to direct pressure on the posterior lip of the incision. Copyright © 2012 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  6. Calcium dependent magnesium uptake in myocardium.

    Science.gov (United States)

    Bianchi, C P; Liu, D

    1993-01-01

    The frog myocardium maintains magnesium content at a steady state level when stimulated at 0.4Hz while being perfused with Ringer's solution containing 1 x 10(-3) M Ca2+ and 5 x 10(-7) M magnesium. When calcium is removed 43% of tissue magnesium is lost within 30 seconds or 12 beats. Restoration of calcium to the perfusion solution causes reaccumulation of magnesium from a solution containing 5 x 10(-7) M magnesium. The reaccumulation of magnesium indicates a highly selective transport system for magnesium which is dependent upon the presence of calcium. Calcium appears to reduce the leak of magnesium from the myocardium and enhances the transport of magnesium into the myocardial cell. Intracellular magnesium is a necessary cofactor for hundreds of enzymes, and is essential for protein synthesis and as an extracellular divalent cation helps to stabilize excitable membranes in conjunction with calcium. The concentration of ionized magnesium in the sarcoplasm of myocardial muscle has an average value of 1.45 mM +/- 1.37 (standard deviation), N = 19) with a range of 0.5 to 3.6 mM (1). The heart with its numerous mitochondria and high enzymatic activity is vulnerable to myocardial damage due to magnesium loss. The isolated frog ventricle conserves intracellular magnesium when perfused with Ringer's solution containing no added magnesium and maintains function for hours. The ability to conserve magnesium suggests a low permeability of the sarcolemma to magnesium and an extremely efficient inward transport system. Removal of calcium as well as magnesium from the perfusion solution causes a rapid loss of tension in the electrically driven frog ventricle (0.4) Hz.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. Gas hydrates forming and decomposition conditions analysis

    Directory of Open Access Journals (Sweden)

    А. М. Павленко

    2017-07-01

    Full Text Available The concept of gas hydrates has been defined; their brief description has been given; factors that affect the formation and decomposition of the hydrates have been reported; their distribution, structure and thermodynamic conditions determining the gas hydrates formation disposition in gas pipelines have been considered. Advantages and disadvantages of the known methods for removing gas hydrate plugs in the pipeline have been analyzed, the necessity of their further studies has been proved. In addition to the negative impact on the process of gas extraction, the hydrates properties make it possible to outline the following possible fields of their industrial use: obtaining ultrahigh pressures in confined spaces at the hydrate decomposition; separating hydrocarbon mixtures by successive transfer of individual components through the hydrate given the mode; obtaining cold due to heat absorption at the hydrate decomposition; elimination of the open gas fountain by means of hydrate plugs in the bore hole of the gushing gasser; seawater desalination, based on the hydrate ability to only bind water molecules into the solid state; wastewater purification; gas storage in the hydrate state; dispersion of high temperature fog and clouds by means of hydrates; water-hydrates emulsion injection into the productive strata to raise the oil recovery factor; obtaining cold in the gas processing to cool the gas, etc.

  8. Predicting effects on oxaliplatin clearance: in vitro, kinetic and clinical studies of calcium- and magnesium-mediated oxaliplatin degradation.

    Science.gov (United States)

    Han, Catherine H; Khwaounjoo, Prashannata; Hill, Andrew G; Miskelly, Gordon M; McKeage, Mark J

    2017-06-22

    This study evaluated the impact of calcium and magnesium on the in vitro degradation and in vivo clearance of oxaliplatin. Intact oxaliplatin and Pt(DACH)Cl2 were measured in incubation solutions by HPLC-UV. A clinical study determined changes in plasma concentrations of calcium and magnesium in cancer patients and their impact on oxaliplatin clearance. Kinetic analyses modelled oxaliplatin degradation reactions in vitro and contributions to oxaliplatin clearance in vivo. Calcium and magnesium accelerated oxaliplatin degradation to Pt(DACH)Cl2 in chloride-containing solutions in vitro. Kinetic models based on calcium and magnesium binding to a monochloro-monooxalato ring-opened anionic oxaliplatin intermediate fitted the in vitro degradation time-course data. In cancer patients, calcium and magnesium plasma concentrations varied and were increased by giving calcium gluconate and magnesium sulfate infusions, but did not alter or correlate with oxaliplatin clearance. The intrinsic in vitro clearance of oxaliplatin attributed to chloride-, calcium- and magnesium-mediated degradation predicted contributions of vitro degradation of oxaliplatin by binding to a monochloro-monooxalato ring-opened anionic intermediate. Kinetic analysis of in vitro oxaliplatin stability data can be used for in vitro prediction of potential effects on oxaliplatin clearance in vivo.

  9. System and process for production of magnesium metal and magnesium hydride from magnesium-containing salts and brines

    Science.gov (United States)

    McGrail, Peter B.; Nune, Satish K.; Motkuri, Radha K.; Glezakou, Vassiliki-Alexandra; Koech, Phillip K.; Adint, Tyler T.; Fifield, Leonard S.; Fernandez, Carlos A.; Liu, Jian

    2016-11-22

    A system and process are disclosed for production of consolidated magnesium metal products and alloys with selected densities from magnesium-containing salts and feedstocks. The system and process employ a dialkyl magnesium compound that decomposes to produce the Mg metal product. Energy requirements and production costs are lower than for conventional processing.

  10. Comparison of magnesium status using X-ray dispersion analysis following magnesium oxide and magnesium citrate treatment of healthy subjects.

    Science.gov (United States)

    Shechter, Michael; Saad, Tomer; Shechter, Alon; Koren-Morag, Nira; Silver, Burton B; Matetzky, Shlomi

    2012-03-01

    The magnesium content in food consumed in the Western world is steadily decreasing. Hypomagnesemia is associated with increased incidence of diabetes mellitus, metabolic syndrome, all-cause and coronary artery disease mortality. We investigated the impact of supplemental oral magnesium citrate versus magnesium oxide on intracellular magnesium levels ([Mg2+]i) and platelet function in healthy subjects with no apparent heart disease. In a randomized, prospective, double-blind, crossover study, 41 (20 women) healthy volunteers [mean age 53±8 (range 31-75) years] received either magnesium oxide monohydrate tablets (520 mg/day of elemental magnesium) or magnesium citrate tablets (295.8 mg/day of elemental magnesium) for one month (phase 1), followed by a four-week wash-out period, and then crossover treatment for one month (phase 2). [Mg2+]i was assessed from sublingual cells through x-ray dispersion (normal values 37.9±4.0 mEq/L), serum magnesium levels, platelet aggregation, and quality-of-life questionnaires were assessed before and after each phase. Oral magnesium oxide, rather than magnesium citrate, significantly increased [Mg2+]i (34.4±3 versus 36.3±2 mEq/L, pmagnesium oxide treatment significantly improved [Mg2+]i, total and LDL cholesterol compared with magnesium citrate, while both treatments similarly inhibited platelet aggregation in healthy subjects with no apparent heart disease.

  11. System and process for production of magnesium metal and magnesium hydride from magnesium-containing salts and brines

    Energy Technology Data Exchange (ETDEWEB)

    McGrail, Peter B.; Nune, Satish K.; Motkuri, Radha K.; Glezakou, Vassiliki-Alexandra; Koech, Phillip K.; Adint, Tyler T.; Fifield, Leonard S.; Fernandez, Carlos A.; Liu, Jian

    2016-11-22

    A system and process are disclosed for production of consolidated magnesium metal products and alloys with selected densities from magnesium-containing salts and feedstocks. The system and process employ a dialkyl magnesium compound that decomposes to produce the Mg metal product. Energy requirements and production costs are lower than for conventional processing.

  12. Hydration of highly charged ions.

    Science.gov (United States)

    Hofer, Thomas S; Weiss, Alexander K H; Randolf, Bernhard R; Rode, Bernd M

    2011-08-01

    Based on a series of ab initio quantum mechanical charge field molecular dynamics (QMCF MD) simulations, the broad spectrum of structural and dynamical properties of hydrates of trivalent and tetravalent ions is presented, ranging from extreme inertness to immediate hydrolysis. Main group and transition metal ions representative for different parts of the periodic system are treated, as are 2 threefold negatively charged anions. The results show that simple predictions of the properties of the hydrates appear impossible and that an accurate quantum mechanical simulation in cooperation with sophisticated experimental investigations seems the only way to obtain conclusive results.

  13. [Development of biodegradable magnesium-based biomaterials].

    Science.gov (United States)

    Zhu, Shengfa; Xu, Li; Huang, Nan

    2009-04-01

    Magnesium is a macroelement which is indispensable to human bodies. As a lightweight metal with high specific strength and favorable biocompatibility, magnesium and its alloys have been introduced in the field of biomedical materials research and have a broad application prospect. It is possible to develop new type of biodegradable medical magnesium alloys by use of the poor corrosion resistance of magnesium. Bioabsorbable magnesium stents implanted in vivo could mechanically support the vessel in a short term, effectly prevent the acute coronary occlusion and in-stent restenosis, and then be gradully biodegraded and completely absorbed in a long term. Osteoconductive bioactivity in magnesium-based alloys could promote the apposition growth of bone tissue. This paper reviews the progress of magnesium and its alloys applied in bone tissue and cardiovascular stents, and the prospect of the future research of magnesium-based biomaterials is discussed.

  14. Great Market Potential of Hydrazine Hydrate

    Institute of Scientific and Technical Information of China (English)

    Shi Yuying

    2007-01-01

    @@ Stable consumption growth worldwide Hydrazine hydrate is an organic chemical raw material with extensive applications. The world's capacity to produce hydrazine hydrate has reached more than 200 thousand t/atoday (based on 100% hydrazine content).

  15. Novel understanding of calcium silicate hydrate from dilute hydration

    KAUST Repository

    Zhang, Lina

    2017-05-13

    The perspective of calcium silicate hydrate (C-S-H) is still confronting various debates due to its intrinsic complicated structure and properties after decades of studies. In this study, hydration at dilute suspension of w/s equaling to 10 was conducted for tricalcium silicate (C3S) to interpret long-term hydration process and investigate the formation, structure and properties of C-S-H. Based on results from XRD, IR, SEM, NMR and so forth, loose and dense clusters of C-S-H with analogous C/S ratio were obtained along with the corresponding chemical formulae proposed as Ca5Si4O13∙6.2H2O. Crystalline structure inside C-S-H was observed by TEM, which was allocated at the foil-like proportion as well as the edge of wrinkles of the product. The long-term hydration process of C3S in dilute suspension could be sketchily described as migration of calcium hydroxide and in-situ growth of C-S-H with equilibrium silicon in aqueous solution relatively constant and calcium varied.

  16. Characteristics of Phosphorus in Some Eastern Australian Acid Sulfate Soils

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Forty-five acid sulfate topsoil samples (depth < 0.5 m) from 15 soil cores were collected from 11 locations along the New South Wales coast, Australia. There was an overall trend for the concentration of the HC1extractable P to increase along with increasing amounts of organic C and the HCl-extractable trivalent metals in the topsoils of some less-disturbed acid sulfate soils (pH <4.5). This suggests that inorganic P in these soils probably accumulated via biological cycling and was retained by complexation with trivalent metals or their oxides and hydroxides. While there was no clear correlation between pH and the water-extractable P, the concentration of the water-extractable P tended to increase with increasing amounts of the HCl-extractable P. This disagrees with some established models which suggest that the concentration of solution P in acid soils is independent of total P and decreases with increasing acidity. The high concentration of sulfate present in acid sulfate soils appeared to affect the chemical behavior of P in these soil systems. Comparison was made between a less disturbed wetland acid sulfate soil and a more intensively disturbed sugarcane acid sulfate soil.The results show that reclamation of wetland acid sulfate soils for sugarcane production caused a significant decrease in the HCl-extractable P in the topsoil layer as a result of the reduced bio-cycling of phosphorus following sugarcane farming. Simulation experiment shows that addition of hydrated lime had no effects on the immobilization of retained P in an acid sulfate soil sample within a pH range 3.5~4.6. When the pH was raised to above 4.6, soluble P in the soil extracts had a tendency to increase with increasing pH until the 15th extraction (pH 5.13). This, in combination with the poor pH-soluble P relationship observed from the less-disturbed acid sulfate soils, suggests that soluble P was not clearly pH-dependent in acid sulfate soils with pH < 4.5.

  17. The inhibition of methane hydrate formation by water alignment underneath surface adsorption of surfactants

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Ngoc N.; Nguyen, Anh V.; Dang, Liem X.

    2017-06-01

    Sodium dodecyl sulfate (SDS) has been widely shown to strongly promote the formation of methane hydrate. Here we show that SDS displays an extraordinary inhibition effect on methane hydrate formation when the surfactant is used in sub-millimolar concentration (around 0.3 mM). We have also employed Sum Frequency Generation vibrational spectroscopy (SFG) and molecular dynamics simulation (MDS) to elucidate the molecular mechanism of this inhibition. The SFG and MDS results revealed a strong alignment of water molecules underneath surface adsorption of SDS in its sub-millimolar solution. Interestingly, both the alignment of water and the inhibition effect (in 0.3 mM SDS solution) went vanishing when an oppositely-charged surfactant (tetra-n-butylammonium bromide, TBAB) was suitably added to produce a mixed solution of 0.3 mM SDS and 3.6 mM TBAB. Combining structural and kinetic results, we pointed out that the alignment of water underneath surface adsorption of dodecyl sulfate (DS-) anions gave rise to the unexpected inhibition of methane hydration formation in sub-millimolar solution of SDS. The adoption of TBAB mitigated the SDS-induced electrostatic field at the solution’s surface and, therefore, weakened the alignment of interfacial water which, in turn, erased the inhibition effect. We discussed this finding using the concept of activation energy of the interfacial formation of gas hydrate. The main finding of this work is to reveal the interplay of interfacial water in governing gas hydrate formation which sheds light on a universal molecular-scale understanding of the influence of surfactants on gas hydrate formation. This work was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences. The calculations were carried out using computer resources provided by the Office of Basic Energy Sciences.

  18. Molecular Dynamics Modeling of Hydrated Calcium-Silicate-Hydrate (CSH) Cement Molecular Structure

    Science.gov (United States)

    2014-08-30

    properties of key hydrated cement constituent calcium-silicate-hydrate (CSH) at the molecular, nanometer scale level. Due to complexity, still unknown...public release; distribution is unlimited. Molecular Dynamics Modeling of Hydrated Calcium-Silicate- Hydrate (CSH) Cement Molecular Structure The views... Cement Molecular Structure Report Title Multi-scale modeling of complex material systems requires starting from fundamental building blocks to

  19. Solid-state rechargeable magnesium battery

    Science.gov (United States)

    Shao, Yuyan; Liu, Jun; Liu, Tianbiao; Li, Guosheng

    2016-09-06

    Embodiments of a solid-state electrolyte comprising magnesium borohydride, polyethylene oxide, and optionally a Group IIA or transition metal oxide are disclosed. The solid-state electrolyte may be a thin film comprising a dispersion of magnesium borohydride and magnesium oxide nanoparticles in polyethylene oxide. Rechargeable magnesium batteries including the disclosed solid-state electrolyte may have a coulombic efficiency .gtoreq.95% and exhibit cycling stability for at least 50 cycles.

  20. Hydration and Thermal Expansion in Anatase Nanoparticles.

    Science.gov (United States)

    Zhu, He; Li, Qiang; Ren, Yang; Fan, Longlong; Chen, Jun; Deng, Jinxia; Xing, Xianran

    2016-08-01

    A tunable thermal expansion is reported in nanosized anatase by taking advantage of surface hydration. The coefficient of thermal expansion of 4 nm TiO2 along a-axis is negative with a hydrated surface and is positive without a hydrated surface. High-energy synchrotron X-ray pair distribution function analysis combined with ab initio calculations on the specific hydrated surface are carried out to reveal the local structure distortion that is responsible for the unusual negative thermal expansion.

  1. Hydration and Thermal Expansion in Anatase Nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, He [Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083 China; Li, Qiang [Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083 China; Ren, Yang [Argonne National Laboratory, X-Ray Science Division, Argonne IL 60439 USA; Fan, Longlong [Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083 China; Chen, Jun [Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083 China; Deng, Jinxia [Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083 China; Xing, Xianran [Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083 China

    2016-06-06

    A tunable thermal expansion is reported in nanosized anatase by taking advantage of surface hydration. The coefficient of thermal expansion of 4 nm TiO2 along a-axis is negative with a hydrated surface and is positive without a hydrated surface. High-energy synchrotron X-ray pair distribution function analysis combined with ab initio calculations on the specific hydrated surface are carried out to reveal the local structure distortion that is responsible for the unusual negative thermal expansion.

  2. Magnesium sulphate for fetal neuroprotection

    DEFF Research Database (Denmark)

    Bickford, Celeste D; Magee, Laura A; Mitton, Craig;

    2013-01-01

    BACKGROUND: The aim of this study was to assess the cost-effectiveness of administering magnesium sulphate to patients in whom preterm birth at ... sensitivity analyses were used to compare the administration of magnesium sulphate with the alternative of no treatment. Two separate cost perspectives were utilized in this series of analyses: a health system and a societal perspective. In addition, two separate measures of effectiveness were utilized: cases...... of cerebral palsy (CP) averted and quality-adjusted life years (QALYs). RESULTS: From a health system and a societal perspective, respectively, a savings of $2,242 and $112,602 is obtained for each QALY gained and a savings of $30,942 and $1,554,198 is obtained for each case of CP averted when magnesium...

  3. [Magnesium as a food supplement].

    Science.gov (United States)

    Haber, Paul

    2004-05-01

    Magnesium is a Cofactor in all enzymes transfering phosphate. It is therefore necessary for the energymetabolism and for many synthesis, i.e. DNA and RNA. Mg is one of the most widespread elements of the earthcrust and is found in many nutritients. Nevertheless the daily intake in the western countries is often under the recommended level, due to the western life stile. Regular alcohol intake lessens the resorption and regular sport enhances the excretion via the sweat. Especially in elderly people this can lead to a lack of Magnesium. This may promote muscular cramps and weakness, cardiac arrhythmias, hypertension or bronchial hyperreactivity. It seems to be reasonable to recommend liberally a oral supplementation with magnesium.

  4. Magnesium Lowers the Incidence of Postoperative Junctional Ectopic Tachycardia in Congenital Heart Surgical Patients: Is There a Relationship to Surgical Procedure Complexity?

    Science.gov (United States)

    He, Dingchao; Sznycer-Taub, Nathaniel; Cheng, Yao; McCarter, Robert; Jonas, Richard A; Hanumanthaiah, Sridhar; Moak, Jeffrey P

    2015-08-01

    Magnesium sulfate was given to pediatric cardiac surgical patients during cardiopulmonary bypass period in an attempt to reduce the occurrence of postoperative junctional ectopic tachycardia (PO JET). We reviewed our data to evaluate the effect of magnesium on the occurrence of JET and assess a possible relationship between PO JET and procedure complexity. A total of 1088 congenital heart surgeries (CHS), performed from 2005 to 2010, were reviewed. A total of 750 cases did not receive magnesium, and 338 cases received magnesium (25 mg/kg). All procedures were classified according to Aristotle score from 1 to 4. Overall, there was a statistically significant decrease in PO JET occurrence between the two groups regardless of the Aristotle score, 15.3 % (115/750) in non-magnesium group versus 7.1 % (24/338) in magnesium group, P < 0.001. In the absence of magnesium, the risk of JET increased with increasing Aristotle score, P = 0.01. Following magnesium administration and controlling for body weight, surgical and aortic cross-clamp times in the analyses, reduction in adjusted risk of JET was significantly greater with increasing Aristotle level of complexity (JET in non-magnesium vs. magnesium group, Aristotle level 1: 9.8 vs. 14.3 %, level 4: 11.5 vs. 3.2 %; odds ratio 0.54, 95 % CI 0.31-0.94, P = 0.028). Our data confirmed that intra-operative usage of magnesium reduced the occurrence of PO JET in a larger number and more diverse group of CHS patients than has previously been reported. Further, our data suggest that magnesium's effect on PO JET occurrence seemed more effective in CHS with higher levels of Aristotle complexity.

  5. 21 CFR 582.5434 - Magnesium phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Magnesium phosphate. 582.5434 Section 582.5434 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5434 Magnesium phosphate. (a) Product. Magnesium phosphate (di- and tribasic)....

  6. 21 CFR 201.71 - Magnesium labeling.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Magnesium labeling. 201.71 Section 201.71 Food and... LABELING Labeling Requirements for Over-the-Counter Drugs § 201.71 Magnesium labeling. (a) The labeling of over-the-counter (OTC) drug products intended for oral ingestion shall contain the magnesium...

  7. 21 CFR 582.5431 - Magnesium oxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Magnesium oxide. 582.5431 Section 582.5431 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5431 Magnesium oxide. (a) Product. Magnesium oxide. (b) Conditions of use. This...

  8. Zonder magnesium zouden planten niet groen zijn

    NARCIS (Netherlands)

    Heuvelink, E.; Kierkels, T.

    2007-01-01

    Magnesium is het centrale element in het molecuul van het bladgroen. Bij een gebrek kleuren daarom de bladeren geel tussen de nerven. Zware metalen kunnen de plaats van magnesium in het bladgroen innemen. De plant kan dan niet meer assimileren. Magnesium is verder belangrijk bij heel veel processen

  9. 21 CFR 582.1431 - Magnesium oxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Magnesium oxide. 582.1431 Section 582.1431 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1431 Magnesium oxide. (a) Product. Magnesium oxide. (b) Conditions of use. This substance...

  10. 76 FR 69284 - Pure Magnesium From China

    Science.gov (United States)

    2011-11-08

    ... COMMISSION Pure Magnesium From China Determination On the basis of the record \\1\\ developed in the subject... order on pure magnesium from China would be likely to lead to continuation or recurrence of material... USITC Publication 4274 (October 2011), entitled Pure Magnesium from China: Investigation No....

  11. Hydrophobic Gating of Ion Permeation in Magnesium Channel CorA.

    Directory of Open Access Journals (Sweden)

    Chris Neale

    2015-07-01

    Full Text Available Ion channels catalyze ionic permeation across membranes via water-filled pores. To understand how changes in intracellular magnesium concentration regulate the influx of Mg2+ into cells, we examine early events in the relaxation of Mg2+ channel CorA toward its open state using massively-repeated molecular dynamics simulations conducted either with or without regulatory ions. The pore of CorA contains a 2-nm-long hydrophobic bottleneck which remained dehydrated in most simulations. However, rapid hydration or "wetting" events concurrent with small-amplitude fluctuations in pore diameter occurred spontaneously and reversibly. In the absence of regulatory ions, wetting transitions are more likely and include a wet state that is significantly more stable and more hydrated. The free energy profile for Mg2+ permeation presents a barrier whose magnitude is anticorrelated to pore diameter and the extent of hydrophobic hydration. These findings support an allosteric mechanism whereby wetting of a hydrophobic gate couples changes in intracellular magnesium concentration to the onset of ionic conduction.

  12. Hydrophobic Gating of Ion Permeation in Magnesium Channel CorA.

    Science.gov (United States)

    Neale, Chris; Chakrabarti, Nilmadhab; Pomorski, Pawel; Pai, Emil F; Pomès, Régis

    2015-07-01

    Ion channels catalyze ionic permeation across membranes via water-filled pores. To understand how changes in intracellular magnesium concentration regulate the influx of Mg2+ into cells, we examine early events in the relaxation of Mg2+ channel CorA toward its open state using massively-repeated molecular dynamics simulations conducted either with or without regulatory ions. The pore of CorA contains a 2-nm-long hydrophobic bottleneck which remained dehydrated in most simulations. However, rapid hydration or "wetting" events concurrent with small-amplitude fluctuations in pore diameter occurred spontaneously and reversibly. In the absence of regulatory ions, wetting transitions are more likely and include a wet state that is significantly more stable and more hydrated. The free energy profile for Mg2+ permeation presents a barrier whose magnitude is anticorrelated to pore diameter and the extent of hydrophobic hydration. These findings support an allosteric mechanism whereby wetting of a hydrophobic gate couples changes in intracellular magnesium concentration to the onset of ionic conduction.

  13. Influence of Temperature on Sulfate Attack of Limestone Filler Cement Mortar

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Mortar prisms were made with three different cementitious materials (with or without mineral admixture) plus 30% mass of limestone filler. After 28 days of curing in water at room temperature, the mortars were submerged in 2% magnesium sulfate solution at different temperatures (5 ℃, 20 ℃ and alternate temperature between 5 ℃ and 20 ℃) for a year. The appearance and strength development were measured on these immersed prisms at intervals, and samples selected from the surface of prisms were examined by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The results show that the influence of temperature on the resistance to sulfate attack of mortar is related to the binder compositions. A higher temperature leads to a quicker strength loss and appearance deterioration of the mortar without mineral admixture. For blended cements, a higher temperature is favorable for the pozzolanic reaction of mineral admixture and the overall deterioration of mortar is reduced with the increasing temperature. When the mineral admixture has a lower reactivity, such influence of temperature on the resistance to sulfate attack of mortar containing admixtures becomes greater. At the three different solution temperatures, two blended cements show significantly improved resistances to sulfate attack. After 1 year of exposure to magnesium sulfate solutions, the formation of thaumasite was checked in the OPC mortars at both 5 ℃ and 20 ℃. It is concluded that the thaumasite formation is not limited to structures at low temperature (less than 15 ℃).

  14. Intravenous magnesium for acute asthma?

    Science.gov (United States)

    2003-10-01

    Each year in the UK, around 1,500 people die from asthma. Standard treatment has been based on bronchodilators (e.g. beta 2-stimulants) and anti-inflammatory drugs (corticosteroids). The recently revised British Guideline on the Management of Asthma suggests also using a single dose of i.v. magnesium sulphate in patients with acute severe asthma, an unlicensed indication. Here we discuss the rationale for giving i.v. magnesium and whether it offers any advantage for patients with acute severe asthma.

  15. Controlling barium sulfate

    Energy Technology Data Exchange (ETDEWEB)

    Greenley, R.

    Even though for several years success has been realized in controlling barium sulfate scale deposition in relatively shallow, low pressure oil wells--by squeezing an organic phosphonate scale inhibitor into the producing zone--barium sulfate scale depositon in deep, high pressure/high temperature wells usually meant an expensive workover operation. A case history of a deep (16,000 ft) well in St. Mary Parish, Louisiana, and the scale inhibitor squeeze operation are described. Based on the successful results obtained in treating this well, a generalized treating procedure for combating downhole scale deposition in high pressure/high temperature gas wells is presented. Formation squeezing with such an inhibitor represents a significant breakthrough for the oil and gas industry.

  16. The use of intravenous magnesium in non-preeclamptic pregnant women: fetal/neonatal neuroprotection.

    Science.gov (United States)

    Jacquemyn, Y; Zecic, A; Van Laere, D; Roelens, K

    2015-05-01

    To review the effect of intravenous magnesium in obstetrics on fetal/neonatal neuroprotection. A systematic review of published studies. Five randomized trials and 4 meta-analyses have shown a significant 32% reduction of cerebral palsy when administering magnesium sulfate in case of preterm delivery. The pathophysiologic mechanism is not fully unraveled: modulation of the inflammatory process, both in the mother and the fetus, and downregulation of neuronal stimulation seem to be involved. After long-term high-dose intravenous administration of magnesium, maternal and neonatal adverse effects such as maternal and neonatal hypotonia and osteoporosis and specific fetal/neonatal cerebral lesions have been described. In case of administration for less than 48 h at 1 g/h and a loading dose of 4 g, these toxic amounts are not achieved. American, Canadian and Australian guidelines recommend the use of intravenous magnesium in any threatening delivery at less than 32 weeks. The "number needed to treat" to avoid 1 cerebral palsy is between 15 and 35. Intravenous magnesium significantly reduces the risk for cerebral palsy in preterm birth. Open questions remain the optimal dosing schedule, whether or not repeating when delivery has been successfully postponed and a new episode of preterm labor occurs. Some concern has been raised on a too optimistic value for random error which might have led to over-optimistic conclusions in classic meta-analysis. Randomized trials comparing different doses and individual patient data meta-analysis might resolve these issues.

  17. Terahertz sensing of corneal hydration.

    Science.gov (United States)

    Singh, Rahul S; Tewari, Priyamvada; Bourges, Jean Louis; Hubschman, Jean Pierre; Bennett, David B; Taylor, Zachary D; Lee, H; Brown, Elliott R; Grundfest, Warren S; Culjat, Martin O

    2010-01-01

    An indicator of ocular health is the hydrodyanmics of the cornea. Many corneal disorders deteriorate sight as they upset the normal hydrodynamics of the cornea. The mechanisms include the loss of endothelial pump function of corneal dystophies, swelling and immune response of corneal graft rejection, and inflammation and edema, which accompany trauma, burn, and irritation events. Due to high sensitivity to changes of water content in materials, a reflective terahertz (300 GHz and 3 THz) imaging system could be an ideal tool to measure the hydration level of the cornea. This paper presents the application of THz technology to visualize the hydration content across ex vivo porcine corneas. The corneas, with a thickness variation from 470 - 940 µm, were successfully imaged using a reflective pulsed THz imaging system, with a maximum SNR of 50 dB. To our knowledge, no prior studies have reported on the use of THz in measuring hydration in corneal tissues or other ocular tissues. These preliminary findings indicate that THz can be used to accurately sense hydration levels in the cornea using a pulsed, reflective THz imaging system.

  18. Physical properties of gas hydrates

    Energy Technology Data Exchange (ETDEWEB)

    Kliner, J.T.R.; Grozic, J.L.H. [Calgary Univ., AB (Canada)

    2003-07-01

    Gas hydrates are naturally occurring, solid crystalline compounds (clathrates) that encapsulate gas molecules inside the lattices of hydrogen bonded water molecules within a specific temperature-pressure stability zone. Estimates of the total quantity of available methane gas in natural occurring hydrates are based on twice the energy content of known conventional fossil fuels reservoirs. Accurate and reliable in-situ quantification techniques are essential in determining the economic viability of this potential energy yield, which is dependent upon several factors such as sensitivity of the temperature-pressure stability zone, sediment type, porosity, permeability, concentration/abundance of free gas, spatial distribution in pore spaces, specific cage occupancy, and the influence of inhibitors. Various techniques like acoustic P and S waves, time domain reflectometry, and electrical resistance have been used to analyze the quantity and spatial distribution of the gas hydrate samples. These techniques were reviewed and the results obtained in the course of gas hydrate research were presented. 34 refs., 8 figs.

  19. Hydration kinetics of transgenic soybeans

    Directory of Open Access Journals (Sweden)

    Aline Francielle Fracasso

    2015-01-01

    Full Text Available The kinetic and experimental analyses of the hydration process of transgenic soybeans (BRS 225 RR are provided. The importance of the hydration process consists of the grain texture modifications which favor grinding and extraction of soybeans. The soaking isotherms were obtained for four different temperatures. Results showed that temperature affected transgenic soybeans´ hydration rate and time. Moisture content d.b. of the soybeans increased from 0.12 ± 0.01 kg kg-1 to 1.45 ± 0.19 kg kg-1 during 270 min. of process. Two models were used to fit the kinetic curves: an empirical model developed by Peleg (1988 and a phenomenological one, proposed by Omoto et al. (2009. The two models adequately represented the hydration kinetics. Peleg model was applied to the experimental data and the corresponding parameters were obtained and correlated to temperature. The model by Omoto et al. (2009 showed a better statistical fitting. Although Ks was affected by temperature (Ks = 0.38079 exp (-2289.3 T-1, the equilibrium concentration remained practically unchanged.

  20. Sulfation of chondroitin. Specificity, degree of sulfation, and detergent effects with 4-sulfating and 6-sulfating microsomal systems

    Energy Technology Data Exchange (ETDEWEB)

    Sugumaran, G.; Silbert, J.E.

    1988-04-05

    Microsomal preparations from chondroitin 6-sulfate-producing chick embryo epiphyseal cartilage, and from chondroitin 4-sulfate-producing mouse mastocytoma cells, were incubated with UDP-(14C)glucuronic acid and UDP-N-acetylgalactosamine to form non-sulfated proteo(14C)chondroitin. Aliquots of the incubations were then incubated with 3'-phosphoadenylylphosphosulfate (PAPS) in the presence or absence of various detergents. In the absence of detergents, there was good sulfation of this endogenous proteo(14C)chondroitin by the original microsomes from both sources. Detergents, with the exception of Triton X-100, markedly inhibited sulfation in the mast cell system but not in the chick cartilage system. These results indicate that sulfation and polymerization are closely linked on cell membranes and that in some cases this organization can be disrupted by detergents. When aliquots of the original incubation were heat inactivated, and then reincubated with new microsomes from chick cartilage and/or mouse mastocytoma cells plus PAPS, there was no significant sulfation of this exogenous proteo(14C) chondroitin with either system unless Triton X-100 was added. Sulfation of exogenous chondroitin and chondroitin hexasaccharide was compared with sulfation of endogenous and exogenous proteo(14C)chondroitin. Sulfate incorporation into hexasaccharide and chondroitin decreased as their concentrations (based on uronic acid) approached that of the proteo(14C)chondroitin. At the same time, the degree of sulfation in percent of substituted hexosamine increased. However, the degree of sulfation did not reach that of the endogenous proteo(14C)chondroitin. Hexasaccharide and chondroitin sulfation were stimulated by the presence of Triton X-100. However, in contrast to the exogenous proteo(14C)chondroitin, there was some sulfation of hexasaccharide and chondroitin in the absence of this detergent.

  1. Magnesium Diboride Current Leads

    Science.gov (United States)

    Panek, John

    2010-01-01

    A recently discovered superconductor, magnesium diboride (MgB2), can be used to fabricate conducting leads used in cryogenic applications. Dis covered to be superconducting in 2001, MgB2 has the advantage of remaining superconducting at higher temperatures than the previously used material, NbTi. The purpose of these leads is to provide 2 A of electricity to motors located in a 1.3 K environment. The providing environment is a relatively warm 17 K. Requirements for these leads are to survive temperature fluctuations in the 5 K and 11 K heat sinks, and not conduct excessive heat into the 1.3 K environment. Test data showed that each lead in the assembly could conduct 5 A at 4 K, which, when scaled to 17 K, still provided more than the required 2 A. The lead assembly consists of 12 steelclad MgB2 wires, a tensioned Kevlar support, a thermal heat sink interface at 4 K, and base plates. The wires are soldered to heavy copper leads at the 17 K end, and to thin copper-clad NbTi leads at the 1.3 K end. The leads were designed, fabricated, and tested at the Forschungszentrum Karlsruhe - Institut foer Technische Physik before inclusion in Goddard's XRS (X-Ray Spectrometer) instrument onboard the Astro-E2 spacecraft. A key factor is that MgB2 remains superconducting up to 30 K, which means that it does not introduce joule heating as a resistive wire would. Because the required temperature ranges are 1.3-17 K, this provides a large margin of safety. Previous designs lost superconductivity at around 8 K. The disadvantage to MgB2 is that it is a brittle ceramic, and making thin wires from it is challenging. The solution was to encase the leads in thin steel tubes for strength. Previous designs were so brittle as to risk instrument survival. MgB2 leads can be used in any cryogenic application where small currents need to be conducted at below 30 K. Because previous designs would superconduct only at up to 8 K, this new design would be ideal for the 8-30 K range.

  2. Off limits: sulfate below the sulfate-methane transition

    Science.gov (United States)

    Brunner, Benjamin; Arnold, Gail; Røy, Hans; Müller, Inigo; Jørgensen, Bo

    2016-07-01

    One of the most intriguing recent discoveries in biogeochemistry is the ubiquity of cryptic sulfur cycling. From subglacial lakes to marine oxygen minimum zones, and in marine sediments, cryptic sulfur cycling - the simultaneous sulfate consumption and production - has been observed. Though this process does not leave an imprint in the sulfur budget of the ambient environment - thus the term cryptic - it may have a massive impact on other element cycles and fundamentally change our understanding of biogeochemical processes in the subsurface. Classically, the sulfate-methane transition (SMT) in marine sediments is considered to be the boundary that delimits sulfate reduction from methanogenesis as the predominant terminal pathway of organic matter mineralization. Two sediment cores from Aarhus Bay, Denmark reveal the constant presence of sulfate (generally 0.1 to 0.2 mM) below the SMT. The sulfur and oxygen isotope signature of this deep sulfate (34S = 18.9‰, 18O = 7.7‰) was close to the isotope signature of bottom-seawater collected from the sampling site (34S = 19.8‰, 18O = 7.3‰). In one of the cores, oxygen isotope values of sulfate at the transition from the base of the SMT to the deep sulfate pool (18O = 4.5‰ to 6.8‰) were distinctly lighter than the deep sulfate pool. Our findings are consistent with a scenario where sulfate enriched in 34S and 18O is removed at the base of the SMT and replaced with isotopically light sulfate below. Here, we explore scenarios that explain this observation, ranging from sampling artifacts, such as contamination with seawater or auto-oxidation of sulfide - to the potential of sulfate generation in a section of the sediment column where sulfate is expected to be absent which enables reductive sulfur cycling, creating the conditions under which sulfate respiration can persist in the methanic zone.

  3. Nematodes join the family of chondroitin sulfate-synthesizing organisms: Identification of an active chondroitin sulfotransferase in Caenorhabditis elegans

    Science.gov (United States)

    Dierker, Tabea; Shao, Chun; Haitina, Tatjana; Zaia, Joseph; Hinas, Andrea; Kjellén, Lena

    2016-01-01

    Proteoglycans are proteins that carry sulfated glycosaminoglycans (GAGs). They help form and maintain morphogen gradients, guiding cell migration and differentiation during animal development. While no sulfated GAGs have been found in marine sponges, chondroitin sulfate (CS) and heparan sulfate (HS) have been identified in Cnidarians, Lophotrocozoans and Ecdysozoans. The general view that nematodes such as Caenorhabditis elegans, which belong to Ecdysozoa, produce HS but only chondroitin without sulfation has therefore been puzzling. We have analyzed GAGs in C. elegans using reversed-phase ion-pairing HPLC, mass spectrometry and immunohistochemistry. Our analyses included wild type C. elegans but also a mutant lacking two HS sulfotransferases (hst-6 hst-2), as we suspected that the altered HS structure could boost CS sulfation. We could indeed detect sulfated CS in both wild type and mutant nematodes. While 4-O-sulfation of galactosamine dominated, we also detected 6-O-sulfated galactosamine residues. Finally, we identified the product of the gene C41C4.1 as a C. elegans CS-sulfotransferase and renamed it chst-1 (CarboHydrate SulfoTransferase) based on loss of CS-4-O-sulfation in a C41C4.1 mutant and in vitro sulfotransferase activity of recombinant C41C4.1 protein. We conclude that C. elegans indeed manufactures CS, making this widely used nematode an interesting model for developmental studies involving CS. PMID:27703236

  4. Physical activity, hydration and health

    Directory of Open Access Journals (Sweden)

    Ascensión Marcos

    2014-06-01

    Full Text Available Since the beginning of mankind, man has sought ways to promote and preserve health as well as to prevent disease. Hydration, physical activity and exercise are key factors for enhancing human health. However, either a little dose of them or an excess can be harmful for health maintenance at any age. Water is an essential nutrient for human body and a major key to survival has been to prevent dehydration. However, there is still a general controversy regarding the necessary amount to drink water or other beverages to properly get an adequate level of hydration. In addition, up to now the tools used to measure hydration are controversial. To this end, there are several important groups of variables to take into account such as water balance, hydration biomarkers and total body water. A combination of methods will be the most preferred tool to find out any risk or situation of dehydration at any age range. On the other hand, physical activity and exercise are being demonstrated to promote health, avoiding or reducing health problems, vascular and inflammatory diseases and helping weight management. Therefore, physical activity is also being used as a pill within a therapy to promote health and reduce risk diseases, but as in the case of drugs, dose, intensity, frequency, duration and precautions have to be evaluated and taken into account in order to get the maximum effectiveness and success of a treatment. On the other hand, sedentariness is the opposite concept to physical activity that has been recently recognized as an important factor of lifestyle involved in the obesogenic environment and consequently in the risk of the non-communicable diseases. In view of the literature consulted and taking into account the expertise of the authors, in this review a Decalogue of global recommendations is included to achieve an adequate hydration and physical activity status to avoid overweight/obesity consequences.

  5. Synthesis of Environmentally Friendly Magnesium Linoleate Detergent

    Institute of Scientific and Technical Information of China (English)

    Wang Yonglei; Li Haiyun; Fang Hongxia; Ni Zhifei; Zhao Lele

    2014-01-01

    This paper mainly covers a method for preparing a highly alkaline magnesium linoleate solution with a total base number (TBN) value of 328 mg KOH/g using linoleic acid as the biodegradable raw material, which can substitute for traditional lubricant detergents as an environmentally friendly detergent. Reaction conditions, including the molar ratio of magnesium oxide to linoleic acid, the molar ratio of methanol to magnesium oxide, the carbonation temperature, the molar ratio of water to magnesium oxide, the lfow rate of CO2 gas and the duration for injection of CO2 to magnesium oxide sys-tem, were optimized.

  6. Selenium and magnesium status in fibromyalgia.

    Science.gov (United States)

    Eisinger, J; Plantamura, A; Marie, P A; Ayavou, T

    1994-12-01

    Muscle pain has been associated with magnesium (Mg) and selenium (Se) deficiency: magnesium and selenium status were investigated in fibromyalgia (FM). Erythrocyte (E), leucocyte (L) and serum (S) magnesium, serum selenium and zinc, and vitamin B1, B2, A or E status were assessed in 22 patients with fibromyalgia and in 23 age-matched healthy controls. LMg is significantly increased (P fibromyalgia. These magnesium abnormalities are associated with previously-reported impairment of thiamin metabolism. Antioxidant status (as well as plasma malondialdehyde) is unchanged in fibromyalgia and serum selenium levels, slightly but not significantly correlated with serum magnesium, is normal.

  7. Computational study of the effect of glyoxal-sulfate clustering on the Henry's law coefficient of glyoxal.

    Science.gov (United States)

    Kurtén, Theo; Elm, Jonas; Prisle, Nønne L; Mikkelsen, Kurt V; Kampf, Christopher J; Waxman, Eleanor M; Volkamer, Rainer

    2015-05-14

    We have used quantum chemical methods to investigate the molecular mechanism behind the recently reported ( Kampf , C. J. ; Environ. Sci. Technol . 2013 , 47 , 4236 - 4244 ) strong dependence of the Henry's law coefficient of glyoxal (C2O2H2) on the sulfate concentration of the aqueous phase. Although the glyoxal molecule interacts only weakly with sulfate, its hydrated forms (C2O3H4 and C2O4H6) form strong complexes with sulfate, displacing water molecules from the solvation shell and increasing the uptake of glyoxal into sulfate-containing aqueous solutions, including sulfate-containing aerosol particles. This promotes the participation of glyoxal in reactions leading to secondary organic aerosol formation, especially in regions with high sulfate concentrations. We used our computed equilibrium constants for the complexation reactions to assess the magnitude of the Henry's law coefficient enhancement and found it to be in reasonable agreement with experimental results. This indicates that the complexation of glyoxal hydrates with sulfate can explain the observed uptake enhancement.

  8. Biomedical applications of magnesium alloys

    NARCIS (Netherlands)

    Sillekens, W.H.; Bormann, D.

    2012-01-01

    This chapter deals with the emerging field of biomedical applications for magnesium-based materials, envisioning degradable implants that dissolve in the human body after having cured a particular medical condition. After outlining the background of this interest, some major aspects concerning degra

  9. Seismic reflections associated with submarine gas hydrates

    Energy Technology Data Exchange (ETDEWEB)

    Andreassen, K.

    1995-12-31

    Gas hydrates are often suggested as a future energy resource. This doctoral thesis improves the understanding of the concentration and distribution of natural submarine gas hydrates. The presence of these hydrates are commonly inferred from strong bottom simulating reflection (BSR). To investigate the nature of BSR, this work uses seismic studies of hydrate-related BSRs at two different locations, one where gas hydrates are accepted to exist and interpreted to be very extensive (in the Beaufort Sea), the other with good velocity data and downhole logs available (offshore Oregon). To ascertain the presence of free gas under the BSR, prestack offset data must supplement near-vertical incidence seismic data. A tentative model for physical properties of sediments partially saturated with gas hydrate and free gas is presented. This model, together with drilling information and seismic data containing the BSR beneath the Oregon margin and the Beaufort Sea, made it possible to better understand when to apply the amplitude-versus-offset (AVO) method to constrain BSR gas hydrate and gas models. Distribution of natural gas hydrates offshore Norway and Svalbard is discussed and interpreted as reflections from the base of gas hydrate-bearing sediments, overlying sediments containing free gas. Gas hydrates inferred to exist at the Norwegian-Svalbard continental margin correlate well with Cenozoic depocenters, and the associated gas is assumed to be mainly biogenic. Parts of that margin have a high potential for natural gas hydrates of both biogenic and thermogenic origin. 235 refs., 86 figs., 4 tabs.

  10. Experimental (FT-IR, FT-Raman, 1H NMR) and theoretical study of magnesium, calcium, strontium, and barium picolinates.

    Science.gov (United States)

    Swiderski, G; Kalinowska, M; Wojtulewski, S; Lewandowski, W

    2006-05-01

    The experimental IR, Raman, and 1H NMR spectra of picolinic acid, as well as magnesium, calcium, strontium, and barium picolinates were registered, assigned and studied. Characteristic changes in the spectra of metal picolinates in comparison with the spectrum of ligand were observed, which lead to the conclusion that perturbation of the aromatic system of picolinates increases along with the series Mg-->Ca-->Sr-->Ba. Theoretical structures of beryllium and magnesium picolinates, as well as theoretical IR spectrum of magnesium picolinate were calculated in B3PW91/6-311++G(d, p) level. On the basis of calculated bond lengths in pyridine ring geometric, aromaticity indexes HOMA were calculated. The idea of these indexes is based on the fact that the essential factor in aromatic stabilization is the pi delocalization manifested in: planar geometry, equalization of the bond lengths and angles, and symmetry. The decidedly lower value of HOMA for magnesium picolinate (i.e. 0.545; 0.539) than that for beryllium picolinate (i.e. 0.998; 0.998) indicate higher aromatic properties of Be picolinate than of Mg picolinate. The comparison of theoretical and literature experimental structures of magnesium picolinate was done. The experimental structure contains two water molecules, so the calculations for hydrated magnesium picolinate were carried on, and the influence of coordinated water molecule on the structure of picolinates was discussed. The HOMAs for hydrated experimental and calculated Mg picolinate amount to 0.870; 0.743, and 0.900; 0.890, respectively, whereas for anhydrous structure, it is as described above, i.e. 0.545; 0.539. Thus, the calculations clearly showed that water molecules coordinated to the central atom weakens the effect of metal on the electronic system of ligand.

  11. LOW DOSE MAGNESIUM SULPHATE REGIME FOR ECLAMPSIA

    Directory of Open Access Journals (Sweden)

    Bangal V

    2009-09-01

    Full Text Available Pre- eclampsia is one of the commonest medical complications seen during pregnancy. It contributes significantly to maternal and perinatal morbidity and mortality. Dr.J.A.Pritchard in 1955, introduced magnesium sulphate for control of convulsions in eclampsia and is used worldwide. Considering the low body mass index of indian women, a low dose magnesium sulphate regime has been introduced by some authors. Present study was carried out at tertiary care centre in rural area. Fifty cases of eclampsia were randomly selected to find out the efficacy of low dose magnesium sulphate regime to control eclamptic convulsions. Maternal and perinatal outcome and magnesium toxicity were analyzed. It was observed that 86% cases responded to initial intravenous dose of 4 grams of 20% magnesium sulphate . Eight percent cases, who got recurrence of convulsion, were controlled by additional 2 grams of 20% magnesium sulphate. Six percent cases required shifting to standard Pritchard regime, as they did not respond to low dose magnesium sulphate regime. The average total dose of magnesium sulphate required for control of convulsions was 20 grams ie. 54.4% less than that of standard Pritchard regime. The maternal and perinatal morbidity and mortality in the present study werecomparable to those of standard Pritchard regime. The study did not find a single case of magnesium related toxicity with low dose magnesium sulphate regime. Low dose magnesium sulphate regime was found to be safe and effective in eclampsia.

  12. Methane seeps, methane hydrate destabilization, and the late Neoproterozoic postglacial cap carbonates

    Institute of Scientific and Technical Information of China (English)

    JIANG Ganqing; SHI Xiaoying; ZHANG Shihong

    2006-01-01

    Methane hydrates constitute the largest pool of readily exchangeable carbon at the Earth's sedimentary carapace and may destabilize, in some cases catastrophically, during times of global-scale warming and/or sea level changes. Given the extreme cold during Neoproterozoic ice ages, the aftermath of such events is perhaps amongst the most likely intervals in Earth history to witness a methane hydrate destabilization event. The coincidence of localized but widespread methane seep-like structures and textures, methane-derived isotopic signal,low sulfate concentration, marine barites, and a prominent, short-lived carbon isotope excursion (δ13C≤-5‰) from the post-Marinoan cap carbonates (~635 Ma) provides strong evidence for a methane hydrate destabilization event during the late Neoproterozoic postglacial warming and transgression. Methane release from hydrates could cause a positive feedback to global warming and oxidation of methane could result in ocean anoxia and fluctuation of atmospheric oxygen, providing an environmental force for the early animal evolution in the latest Neoproterozoic. The issues that remain to be clarified for this event include the trigger of methane hydrate destabilization, the time of initial methane release, the predicted ocean anoxia event and its relationship with the biological innovation, additional geochemical signals in response to methane release, and the regional and global synchrony of cap carbonate precipitation. The Doushantuo cap carbonate in South China provides one of the best examples of its age for a better understanding of these issues.

  13. Handbook of gas hydrate properties and occurrence

    Energy Technology Data Exchange (ETDEWEB)

    Kuustraa, V.A.; Hammershaimb, E.C.

    1983-12-01

    This handbook provides data on the resource potential of naturally occurring hydrates, the properties that are needed to evaluate their recovery, and their production potential. The first two chapters give data on the naturally occurring hydrate potential by reviewing published resource estimates and the known and inferred occurrences. The third and fourth chapters review the physical and thermodynamic properties of hydrates, respectively. The thermodynamic properties of hydrates that are discussed include dissociation energies and a simplified method to calculate them; phase diagrams for simple and multi-component gases; the thermal conductivity; and the kinetics of hydrate dissociation. The final chapter evaluates the net energy balance of recovering hydrates and shows that a substantial positive energy balance can theoretically be achieved. The Appendices of the Handbook summarize physical and thermodynamic properties of gases, liquids and solids that can be used in designing and evaluating recovery processes of hydrates. 158 references, 67 figures, 47 tables.

  14. Separation of water through gas hydrate formation

    DEFF Research Database (Denmark)

    Boch Andersen, Torben; Thomsen, Kaj

    2009-01-01

    Gas hydrate is normally recognized as a troublemaker in the oil and gas industry. However, gas hydrate has some interesting possibilities when used in connection with separation of water. Nordic Sugar has investigated the possibility of using gas hydrates for concentration of sugar juice. The goa...... volumes and the needs for high pressure. The process could be interesting for concentration of heat sensitive, high value products......Gas hydrate is normally recognized as a troublemaker in the oil and gas industry. However, gas hydrate has some interesting possibilities when used in connection with separation of water. Nordic Sugar has investigated the possibility of using gas hydrates for concentration of sugar juice. The goal...... of the project was to formulate an alternative separation concept, which can replace the traditional water evaporation process in the sugar production. Work with the separation concept showed that gas hydrates can be used for water separation. The process is not suitable for sugar production because of large...

  15. A Search for Magnesium in Europa's Atmosphere

    CERN Document Server

    Horst, Sarah M

    2013-01-01

    Europa's tenuous atmosphere results from sputtering of the surface. The trace element composition of its atmosphere is therefore related to the composition of Europa's surface. Magnesium salts are often invoked to explain Galileo Near Infrared Mapping Spectrometer spectra of Europa's surface, thus magnesium may be present in Europa's atmosphere. We have searched for magnesium emission in Hubble Space Telescope Faint Object Spectrograph archival spectra of Europa's atmosphere. Magnesium was not detected and we calculate an upper limit on the magnesium column abundance. This upper limit indicates that either Europa's surface is depleted in magnesium relative to sodium and potassium, or magnesium is not sputtered as efficiently resulting in a relative depletion in its atmosphere.

  16. Well log characterization of natural gas hydrates

    Science.gov (United States)

    Collett, Timothy S.; Lee, Myung W.

    2011-01-01

    In the last 25 years we have seen significant advancements in the use of downhole well logging tools to acquire detailed information on the occurrence of gas hydrate in nature: From an early start of using wireline electrical resistivity and acoustic logs to identify gas hydrate occurrences in wells drilled in Arctic permafrost environments to today where wireline and advanced logging-while-drilling tools are routinely used to examine the petrophysical nature of gas hydrate reservoirs and the distribution and concentration of gas hydrates within various complex reservoir systems. The most established and well known use of downhole log data in gas hydrate research is the use of electrical resistivity and acoustic velocity data (both compressional- and shear-wave data) to make estimates of gas hydrate content (i.e., reservoir saturations) in various sediment types and geologic settings. New downhole logging tools designed to make directionally oriented acoustic and propagation resistivity log measurements have provided the data needed to analyze the acoustic and electrical anisotropic properties of both highly inter-bedded and fracture dominated gas hydrate reservoirs. Advancements in nuclear-magnetic-resonance (NMR) logging and wireline formation testing have also allowed for the characterization of gas hydrate at the pore scale. Integrated NMR and formation testing studies from northern Canada and Alaska have yielded valuable insight into how gas hydrates are physically distributed in sediments and the occurrence and nature of pore fluids (i.e., free-water along with clay and capillary bound water) in gas-hydrate-bearing reservoirs. Information on the distribution of gas hydrate at the pore scale has provided invaluable insight on the mechanisms controlling the formation and occurrence of gas hydrate in nature along with data on gas hydrate reservoir properties (i.e., permeabilities) needed to accurately predict gas production rates for various gas hydrate

  17. Thermal conductivity of hydrate-bearing sediments

    Science.gov (United States)

    Cortes, Douglas D.; Martin, Ana I.; Yun, Tae Sup; Francisca, Franco M.; Santamarina, J. Carlos; Ruppel, Carolyn

    2009-11-01

    A thorough understanding of the thermal conductivity of hydrate-bearing sediments is necessary for evaluating phase transformation processes that would accompany energy production from gas hydrate deposits and for estimating regional heat flow based on the observed depth to the base of the gas hydrate stability zone. The coexistence of multiple phases (gas hydrate, liquid and gas pore fill, and solid sediment grains) and their complex spatial arrangement hinder the a priori prediction of the thermal conductivity of hydrate-bearing sediments. Previous studies have been unable to capture the full parameter space covered by variations in grain size, specific surface, degree of saturation, nature of pore filling material, and effective stress for hydrate-bearing samples. Here we report on systematic measurements of the thermal conductivity of air dry, water- and tetrohydrofuran (THF)-saturated, and THF hydrate-saturated sand and clay samples at vertical effective stress of 0.05 to 1 MPa (corresponding to depths as great as 100 m below seafloor). Results reveal that the bulk thermal conductivity of the samples in every case reflects a complex interplay among particle size, effective stress, porosity, and fluid-versus-hydrate filled pore spaces. The thermal conductivity of THF hydrate-bearing soils increases upon hydrate formation although the thermal conductivities of THF solution and THF hydrate are almost the same. Several mechanisms can contribute to this effect including cryogenic suction during hydrate crystal growth and the ensuing porosity reduction in the surrounding sediment, increased mean effective stress due to hydrate formation under zero lateral strain conditions, and decreased interface thermal impedance as grain-liquid interfaces are transformed into grain-hydrate interfaces.

  18. Thermal conductivity of hydrate-bearing sediments

    Science.gov (United States)

    Cortes, D.D.; Martin, A.I.; Yun, T.S.; Francisca, F.M.; Santamarina, J.C.; Ruppel, C.

    2009-01-01

    A thorough understanding of the thermal conductivity of hydrate-bearing sediments is necessary for evaluating phase transformation processes that would accompany energy production from gas hydrate deposits and for estimating regional heat flow based on the observed depth to the base of the gas hydrate stability zone. The coexistence of multiple phases (gas hydrate, liquid and gas pore fill, and solid sediment grains) and their complex spatial arrangement hinder the a priori prediction of the thermal conductivity of hydrate-bearing sediments. Previous studies have been unable to capture the full parameter space covered by variations in grain size, specific surface, degree of saturation, nature of pore filling material, and effective stress for hydrate-bearing samples. Here we report on systematic measurements of the thermal conductivity of air dry, water- and tetrohydrofuran (THF)-saturated, and THF hydrate-saturated sand and clay samples at vertical effective stress of 0.05 to 1 MPa (corresponding to depths as great as 100 m below seafloor). Results reveal that the bulk thermal conductivity of the samples in every case reflects a complex interplay among particle size, effective stress, porosity, and fluid-versus-hydrate filled pore spaces. The thermal conductivity of THF hydrate-bearing soils increases upon hydrate formation although the thermal conductivities of THF solution and THF hydrate are almost the same. Several mechanisms can contribute to this effect including cryogenic suction during hydrate crystal growth and the ensuing porosity reduction in the surrounding sediment, increased mean effective stress due to hydrate formation under zero lateral strain conditions, and decreased interface thermal impedance as grain-liquid interfaces are transformed into grain-hydrate interfaces. Copyright 2009 by the American Geophysical Union.

  19. Effects of Short-term Feeding Magnesium before Slaughter on Blood Metabolites and Postmortem Muscle Traits of Halothane-carrier Pigs

    Directory of Open Access Journals (Sweden)

    Jing Chen

    2013-06-01

    Full Text Available Fifty-four, mixed-sex, halothane-carrier crossbred (Yorkshire×Landrace pigs with an average initial BW of 108.2±0.8 kg were randomly allotted to one of three dietary treatments for 5 d before slaughter: i a control corn-soybean meal finisher diet devoid of supplemental magnesium; ii a diet supplemented with 1.5 g/kg of elemental Mg from magnesium acetate; and iii a diet supplemented with 1.5 g/kg of elemental Mg from magnesium sulfate heptahydrate. Serum creatine kinase (CK, lactate and glucose were analyzed at slaughter. Muscles from longissimus (LM were packaged and stored to simulate display storage for muscle lactate and glycogen determinations at 0, 1, 2, 3, and 4 d. Mg supplementation reduced (p0.05 on serum glucose. Daily change of muscle lactate concentration linearly increased (p<0.01, while glucose concentration linearly decreased (p<0.05 as storage time increased in all treatments. However, dietary Mg acetate and Mg sulfate supplementation in pigs elevated (p<0.05 muscle glycogen and reduced (p<0.05 muscle lactate concentrations, especially during the first 2 d of display, compared with pigs fed the control diet. This study suggests that short-term feeding of magnesium acetate and magnesium sulfate to heterozygous carriers of the halothane gene has beneficial effects on stress response and pork quality by improving blood and muscle biochemical indexes.

  20. The effect of hydrate saturation on water retention curves in hydrate-bearing sediments

    Science.gov (United States)

    Mahabadi, Nariman; Zheng, Xianglei; Jang, Jaewon

    2016-05-01

    The experimental measurement of water retention curve in hydrate-bearing sediments is critically important to understand the behavior of hydrate dissociation and gas production. In this study, tetrahydrofuran (THF) is selected as hydrate former. The pore habit of THF hydrates is investigated by visual observation in a transparent micromodel. It is confirmed that THF hydrates are not wetting phase on the quartz surface of the micromodel and occupy either an entire pore or part of pore space resulting in change in pore size distribution. And the measurement of water retention curves in THF hydrate-bearing sediments with hydrate saturation ranging from Sh = 0 to Sh = 0.7 is conducted for excess water condition. The experimental results show that the gas entry pressure and the capillary pressure increase with increasing hydrate saturation. Based on the experimental results, fitting parameters for van Genuchten equation are suggested for different hydrate saturation conditions.

  1. Elucidating water dynamics in MgCl2 hydrates from molecular dynamics simulation

    Science.gov (United States)

    Huinink, Hendrik Pieter; Zahn, Dirk

    2017-07-01

    The water mobility in single crystals of MgCl2 hydrates has been investigated with molecular dynamics. Standard force fields have been benchmarked for molecular dynamics simulations of MgCl2 hydrates. To provide a reliable molecular mechanics model, force fields are selected on their ability to reproduce the structure of MgCl2·6H2O at 300 K. The selected force fields are then tested on their ability to also reproduce the structures of the different hydrates (n = 12, 8, 6, 4, 2, 1) and available thermodynamic data. For the currently best force-field available, constant-temperature, constant-pressure molecular dynamics simulations are preformed to elucidate the mechanisms of hydrate water mobility in perfect single crystals of the tetra- and hexahydrate. Long range water diffusion was not observed; each water molecule remained in the coordination sphere of its original Mg2+ host. However, collective ring-like motions of four water molecules at once within the coordination shell of a Magnesium ion were observed.

  2. Effect of raw material ratios on the compressive strength of magnesium potassium phosphate chemically bonded ceramics.

    Science.gov (United States)

    Wang, Ai-juan; Yuan, Zhi-long; Zhang, Jiao; Liu, Lin-tao; Li, Jun-ming; Liu, Zheng

    2013-12-01

    The compressive strength of magnesium potassium phosphate chemically bonded ceramics is important in biomedical field. In this work, the compressive strength of magnesium potassium phosphate chemically bonded ceramics was investigated with different liquid-to-solid and MgO-to-KH2PO4 ratios. X-ray diffractometer was applied to characterize its phase composition. The microstructure was imaged using a scanning electron microscope. The results showed that the compressive strength of the chemically bonded ceramics increased with the decrease of liquid-to-solid ratio due to the change of the packing density and the crystallinity of hydrated product. However, with the increase of MgO-to-KH2PO4 weight ratio, its compressive strength increased firstly and then decreased. The low compressive strength in lower MgO-to-KH2PO4 ratio might be explained by the existence of the weak phase KH2PO4. However, the low value of compressive strength with the higher MgO-to-KH2PO4 ratio might be caused by lack of the joined phase in the hydrated product. Besides, it has been found that the microstructures were different in these two cases by the scanning electron microscope. Colloidal structure appeared for the samples with lower liquid-to-solid and higher MgO-to-KH2PO4 ratios possibly because of the existence of amorphous hydrated products. The optimization of both liquid-to-solid and MgO-to-KH2PO4 ratios was important to improve the compressive strength of magnesium potassium phosphate chemically bonded ceramics.

  3. Evaluation of sulfate resistance of cement mortars containing black rice husk ash.

    Science.gov (United States)

    Chatveera, B; Lertwattanaruk, P

    2009-03-01

    In this paper, black rice husk ashes (BRHAs), which are agrowastes from an electricity generating power plant and a rice mill, were ground and used as a partial cement replacement. The durability of mortars under sulfate attack including expansion and compressive strength loss were investigated. For parametric study, BRHA were used as a Portland cement Type 1 replacement at the levels of 0%, 10%, 30%, and 50% by weight of binder. The water-to-binder ratios were 0.55 and 0.65. For the durability of mortar exposed to sulfate attack, 5% sodium sulfate (Na2SO4) and magnesium sulfate (MgSO4) solutions were used. As a result, when increasing the percentage replacement of BRHA, the expansion and compressive strength loss of mortar decreased. At the replacement levels of 30% and 50% of BRHA, the expansion of the mortars was less than those mixed with sulfate-resistant cement. However, the expansion of the mortars exposed to Na2SO4 was more than those exposed to MgSO4. Increasing the replacement level of BRHA tends to reduce the compressive strength loss of mortars exposed to Na2SO4 attack. In contrary, under MgSO4 attack, when increasing the replacement level of BRHA, the compressive strength loss increases from 0% to 50% in comparison to Portland cement mortar. Results show that ground BRHA can be applied as a pozzolanic material to concrete and also improve resistance to sodium sulfate attack, but it can impair resistance to magnesium sulfate attack.

  4. 2-Amino-4-hydroxyethylaminoanisole sulfate

    DEFF Research Database (Denmark)

    Madsen, Jakob T; Andersen, Klaus E

    2016-01-01

    positive patch test reactions to the coupler 2-amino-4-hydroxyethylaminoanisole sulfate 2% pet. from 2005 to 2014. METHODS: Patch test results from the Allergen Bank database for eczema patients patch tested with 2-amino-4-hydroxyethylaminoanisole sulfate 2% pet. from 2005 to 2014 were reviewed. RESULTS......: A total of 902 dermatitis patients (154 from the dermatology department and 748 from 65 practices) were patch tested with amino-4-hydroxyethylaminoanisole sulfate 2% pet. from 2005 to 2014. Thirteen (1.4%) patients had a positive patch test reaction. Our results do not indicate irritant reactions....... CONCLUSIONS: 2-Amino-4-hydroxyethylaminoanisole sulfate is a new but rare contact allergen....

  5. Synthesis of hydrated lutetium carbonate

    Energy Technology Data Exchange (ETDEWEB)

    Song Liu [South China Univ. of Technology, Dept. of Applied Chemistry, Guangdong (China); Rong-jun Ma [Changsha Research Institute of Minig and Metallurgy, Hunan (China)

    1997-09-01

    Crystalline lutetium carbonate was synthesized for the corresponding chloride using ammonium bicarbonate as precipitant. The chemical analyses suggest that the synthesized lutetium carbonate is a hydrated basic carbonate or oxycarbonate. The X-ray powder diffraction data are presented. The IR data for the compound show the presence of two different carbonate groups. There is no stable intermediate carbonate in the process of thermal decomposition of the lutetium carbonate. (au) 15 refs.

  6. Crystallite size distributions of marine gas hydrates

    Energy Technology Data Exchange (ETDEWEB)

    Klapp, S.A.; Bohrmann, G.; Abegg, F. [Bremen Univ., Bremen (Germany). Research Center of Ocean Margins; Hemes, S.; Klein, H.; Kuhs, W.F. [Gottingen Univ., Gottingen (Germany). Dept. of Crystallography

    2008-07-01

    Experimental studies were conducted to determine the crystallite size distributions of natural gas hydrate samples retrieved from the Gulf of Mexico, the Black Sea, and a hydrate ridge located near offshore Oregon. Synchrotron radiation technology was used to provide the high photon fluxes and high penetration depths needed to accurately analyze the bulk sediment samples. A new beam collimation diffraction technique was used to measure gas hydrate crystallite sizes. The analyses showed that gas hydrate crystals were globular in shape. Mean crystallite sizes ranged from 200 to 400 {mu}m for hydrate samples taken from the sea floor. Larger grain sizes in the hydrate ridge samples suggested differences in hydrate formation ages or processes. A comparison with laboratory-produced methane hydrate samples showed half a lognormal curve with a mean value of 40{mu}m. Results of the study showed that a cautious approach must be adopted when transposing crystallite-size sensitive physical data from laboratory-made gas hydrates to natural settings. It was concluded that crystallite size information may also be used to resolve the formation ages of gas hydrates when formation processes and conditions are constrained. 48 refs., 1 tab., 9 figs.

  7. IMPORTANCE OF HYDRATION IN SPORTS

    Directory of Open Access Journals (Sweden)

    Goran Vasić

    2008-08-01

    Full Text Available Importance of hydration is detrmined by importance of functions of water in the human organism: i.e. regulation of body temperature, transport, excretion of waste materials through urine, digestion of food which is facilititated by saliva and gastric juices, maintenance of flexibility of organs and tissues About 60 % body mass of an adult person (males: 61 %, females: 54 % is made up of water. Water content of a newly born baby reaches 77 %, and it is up to 50 % in adults. It is very important for sportsmen to provide adequate hydration during and after the time of bodily activities. A symptom of water shortage is thirst. However, thirst is a late response of an organism and it occurs when dehydration has already taken place. Minimum in take of fluids in humans should range between one-and-half to two liters. It has been known for a long time that there is no success in sport without proper hydration in a sportsman.

  8. Formation mechanism of authigenic gypsum in marine methane hydrate settings: Evidence from the northern South China Sea

    Science.gov (United States)

    Lin, Qi; Wang, Jiasheng; Algeo, Thomas J.; Su, Pibo; Hu, Gaowei

    2016-09-01

    During the last decade, gypsum has been discovered widely in marine methane hydrate-bearing sediments. However, whether this gypsum is an in-situ authigenic precipitate remains controversial. The GMGS2 expedition carried out in 2013 by the Guangzhou Marine Geological Survey (GMGS) in the northern South China Sea provided an excellent opportunity for investigating the formation of authigenic minerals and, in particular, the relationship between gypsum and methane hydrate. In this contribution, we analyzed the morphology and sulfur isotope composition of gypsum and authigenic pyrite as well as the carbon and oxygen isotopic compositions of authigenic carbonate in a drillcore from Site GMGS2-08. These methane-derived carbonates have characteristic carbon and oxygen isotopic compositions (δ13C: -57.9‰ to -27.3‰ VPDB; δ18O: +1.0‰ to +3.8‰ VPDB) related to upward seepage of methane following dissociation of underlying methane hydrates since the Late Pleistocene. Our data suggest that gypsum in the sulfate-methane transition zone (SMTZ) of this core precipitated as in-situ authigenic mineral. Based on its sulfur isotopic composition, the gypsum sulfur is a mixture of sulfate derived from seawater and from partial oxidation of authigenic pyrite. Porewater Ca2+ ions for authigenic gypsum were likely generated from carbonate dissolution through acidification produced by oxidation of authigenic pyrite and ion exclusion during methane hydrate formation. This study thus links the formation mechanism of authigenic gypsum with the oxidation of authigenic pyrite and evolution of underlying methane hydrates. These findings suggest that authigenic gypsum may be a useful proxy for recognition of SMTZs and methane hydrate zones in modern and ancient marine methane hydrate geo-systems.

  9. Magnesium: its role in nutrition and carcinogenesis.

    Science.gov (United States)

    Blaszczyk, Urszula; Duda-Chodak, Aleksandra

    2013-01-01

    Magnesium (Mg2+) plays a key role in many essential cellular processes such as intermediary metabolism, DNA replication and repair, transporting potassium and calcium ions, cell proliferation together with signalling transduction. Dietary sources rich in magnesium are whole and unrefined grains, seeds, cocoa, nuts, almonds and green leafy vegetables. Hard water is also considered to be an important source of magnesium beneficial to human health. The daily dietary intake of magnesium is however frequently found to be below that recommended in Western countries. Indeed, it is recognised that magnesium deficiency may lead to many disorders of the human body, where for instance magnesium depletion is believed to play an important role in the aetiology of the following; cardiovascular disease (including thrombosis, atherosclerosis, ishaemic heart disease, myocardial infarction, hypertension, arrhythmias and congestive heart failure in human), as well as diabetes mellitus, gastrointestinal (GI) tract disease, liver cirrhosis and diseases of the thyroid and parathyroid glands. Insufficient dietary intake of magnesium may also significantly affect the development and exacerbation ofADHD (Attention Deficit- Hyperactivity Disorder) symptoms in children. The known links between magnesium and carcinogenesis still remain unclear and complex, with conflicting results being reported from many experimental, epidemiological and clinical studies; further knowledge is thus required. Mg2+ ions are enzyme cofactors involved in DNA repair mechanisms that maintain genomic stability and fidelity. Any magnesium deficiencies could thereby cause a dysfunction of these systems to occur leading to DNA mutations. Magnesium deficiency may also be associated with inflammation and increased levels of free radicals where both inflammatory mediators and free radicals so arising could cause oxidative DNA damage and therefore tumour formation. The presented review article now provides a summary

  10. Effect of oxygen on the hydrogenation properties of magnesium films

    DEFF Research Database (Denmark)

    Ostenfeld, Christopher Worsøe; Chorkendorff, Ib

    2006-01-01

    The effect of magnesium oxide on the magnesium and hydrogen desorption properties of magnesium films have been investigated. We find that by capping metallic magnesium films with oxide overlayers the apparent desorption energy of magnesium is increased from 146 kJ/mol to 314 kJ/mol. The results...

  11. 21 CFR 184.1315 - Ferrous sulfate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ferrous sulfate. 184.1315 Section 184.1315 Food and... Substances Affirmed as GRAS § 184.1315 Ferrous sulfate. (a) Ferrous sulfate heptahydrate (iron (II) sulfate... as pale, bluish-green crystals or granules. Progressive heating of ferrous sulfate heptahydrate...

  12. Pore-water chemistry of sediment cores off Mahanadi Basin, Bay of Bengal: Possible link to deep seated methane hydrate deposit

    Digital Repository Service at National Institute of Oceanography (India)

    Mazumdar, A.; Peketi, A.; Joao, H; Dewangan, P.; Ramprasad, T.

    ) induced sulfate consumption. The gas rich layers just below the base of hydrate stability zone (BGHSZ) is the possible source of the enhanced diffusive flux of biogenic methane (dalta13CCH4 ranging from -99.7 to - 106.3 percentage...

  13. Hydration of calcium aluminate cement determined by thermal analysis

    Science.gov (United States)

    Scheinherrová, Lenka; Trník, Anton

    2017-07-01

    Calcium aluminate cements (CACs) are a very important type of non-Portland or special cements. Since they are considerably more expensive, they are not used as a simple substitute for Portland cement. Their structure allows them to achieve high compressive strength. They resist very well to high temperatures and temperature changes, or also to chemical attacks. The original motivation, why the CACs were developed, was the idea of finding new cement chemistries that would be more resistant to sulfate attack then Portland cements. Nowadays, the main usage of the CACs is in high temperatures applications. In this paper, we study the hydration of a CAC up to one year of age to control what happens in CACs structure during aging. The variety in the main products of hydration is studied using differential scanning calorimetry and thermogravimetry in the temperature range from 25 °C to 1000 °C with a heating rate of 5 °C/min in an argon atmosphere. The basic physical and mechanical properties are also determined.

  14. Study of Formation Mechanisms of Gas Hydrate

    Science.gov (United States)

    Yang, Jia-Sheng; Wu, Cheng-Yueh; Hsieh, Bieng-Zih

    2015-04-01

    Gas hydrates, which had been found in subsurface geological environments of deep-sea sediments and permafrost regions, are solid crystalline compounds of gas molecules and water. The estimated energy resources of hydrates are at least twice of that of the conventional fossil fuel in the world. Gas hydrates have a great opportunity to become a dominating future energy. In the past years, many laboratory experiments had been conducted to study chemical and thermodynamic characteristics of gas hydrates in order to investigate the formation and dissociation mechanisms of hydrates. However, it is difficult to observe the formation and dissociation of hydrates