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Sample records for calcium magnesium acetate

  1. 40 CFR 721.2076 - D-Glucuronic acid, polymer with 6-deoxy-L-mannose and D-glucose, acetate, calcium magnesium...

    Science.gov (United States)

    2010-07-01

    ...-deoxy-L-mannose and D-glucose, acetate, calcium magnesium potassium sodium salt. 721.2076 Section 721...-Glucuronic acid, polymer with 6-deoxy-L-mannose and D-glucose, acetate, calcium magnesium potassium sodium... identified as D-Glucuronic acid, polymer with 6-deoxy-L-mannose and D-glucose, acetate, calcium...

  2. Extraction and sorption of acetic acid at pH above pK{sub a} to form calcium magnesium acetate

    Energy Technology Data Exchange (ETDEWEB)

    Reisinger, H.; King, C.J. [Lawrence Berkeley Lab., CA (United States)

    1995-03-01

    The use of rock salt for deicing roads has many negative effects on automobiles, highway systems, and the environment. Calcium magnesium acetate, hence-forth denoted CMA, has been identified as a more desirable, environmentally benign solid deicer for high-ways, airport runaways, and similar applications. CMA is also of interest as an additive for scavenging sulfur in combustion processes so as to reduce emissions of sulfur oxides and as a catalyst for coal gasification. Different extractants (trioctylphosphine oxide and secondary, tertiary, and quaternary amines) and solid sorbents (tertiary and quaternary amines) were investigated as agents for recovery of acetic acid as part of a process for production of CMA from fermentation acetic acid. The pH and temperature dependencies for uptake of acetic acid by these extractants and sorbents were measured, along with the degrees of regeneration by aqueous suspensions of slaked dolomitic lime. These results enable identification of agents having optimal basicity. Among the extractants, the secondary amine Amberlite LA-2 gave the best combined performance for extraction and regeneration. Among the sorbents, a tertiary amine, Amberlite IRA-35, gave the best performance. Trioctylphosphine oxide does not maintain capacity in the pH range (about 6) most attractive for acetic acid fermentation. Slurred crushed dolomite is not sufficiently basic to accomplish regeneration.

  3. The effects of calcium magnesium acetate (CMA) deicing material on the water quality of Bear Creek, Clackamas County, Oregon, 1999

    Science.gov (United States)

    Tanner, Dwight Q.; Wood, Tamara M.

    2000-01-01

    This report presents the results of a study by the U.S. Geological Survey, done in cooperation with the Oregon Department of Transportation (ODOT), to evaluate the effects of the highway deicing material, calcium magnesium acetate (CMA), on the water quality of Bear Creek, in the Cascade Range of Oregon. ODOT began using CMA (an alternative deicer that has fewer adverse environmental effects than road salt) in the mid-1990s and began this study with the USGS to ensure that there were no unexpected effects on the water quality of Bear Creek. Streamflow, precipitation, dissolved oxygen, pH, specific conductance, and water temperature were measured continuously through the 1998?99 winter. There was no measurable effect of the application of CMA to Highway 26 on the biochemical oxygen demand (BOD), calcium concentration, or magnesium concentration of Bear Creek and its tributaries. BOD was small in all of the water samples, some of which were collected before CMA application, and some of which were collected after application. Five-day BOD values ranged from 0.1 milligrams per liter to 1.5 milligrams per liter, and 20-day BOD values ranged from 0.2 milligrams per liter to 2.0 milligrams per liter. Dissolved copper concentrations in a small tributary ditch on the north side of Highway 26 exceeded the U.S. Environmental Protection Agency aquatic life criteria on three occasions. These exceedances were probably not caused by the application of CMA because (1) one of the samples was a background sample (no recent CMA application), and (2) dissolved copper was not detected in Bear Creek water samples to which CMA was added during laboratory experiments.

  4. Effects of calcium magnesium acetate on the combustion of coal-water slurries. Final project report, 1 September 1989--28 February 1993

    Energy Technology Data Exchange (ETDEWEB)

    Levendis, Y.A.; Wise, D.; Metghalchi, H.; Cumper, J.; Atal, A.; Estrada, K.R.; Murphy, B.; Steciak, J.; Hottel, H.C.; Simons, G.

    1993-07-01

    To conduct studies on the combustion of coal water fuels (CWFs) an appropriate facility was designed and constructed. The main components were (1) a high-temperature isothermal laminar flow furnace that facilitates observation of combustion events in its interior. The design of this system and its characterization are described in Chapter 1. (2) Apparatus for slurry droplet/agglomerate particle generation and introduction in the furnace. These devices are described in Chapters 1 and 3 and other attached publications. (3) An electronic optical pyrometer whose design, construction theory of operation, calibration and performance are presented in Chapter 2. (4) A multitude of other accessories, such as particle fluidization devices, a suction thermometer, a velocimeter, high speed photographic equipment, calibration devices for the pyrometer, etc., are described throughout this report. Results on the combustion of CWF droplets and CWF agglomerates made from micronized coal are described in Chapter 3. In the same chapter the combustion of CWF containing dissolved calcium magnesium acetate (CMA) axe described. The combustion behavior of pre-dried CWF agglomerates of pulverized grain coal is contrasted to that of agglomerates of micronized coal in Chapter 4. In the same chapter the combustion of agglomerates of carbon black and diesel soot is discussed as well. The effect of CMA on the combustion of the above materials is also discussed. Finally, the sulfur capture capability of CMA impregnated micronized and pulverized bituminous coals is examined in Chapter 5.

  5. Zinc, magnesium, and calcium ion supplementation confers tolerance to acetic acid stress in industrial Saccharomyces cerevisiae utilizing xylose.

    Science.gov (United States)

    Ismail, Ku Syahidah Ku; Sakamoto, Takatoshi; Hasunuma, Tomohisa; Zhao, Xin-Qing; Kondo, Akihiko

    2014-12-01

    Lignocellulosic biomass is a potential substrate for ethanol production. However, pretreatment of lignocellulosic materials produces inhibitory compounds such as acetic acid, which negatively affect ethanol production by Saccharomyces cerevisiae. Supplementation of the medium with three metal ions (Zn(2+) , Mg(2+) , and Ca(2+) ) increased the tolerance of S. cerevisiae toward acetic acid compared to the absence of the ions. Ethanol production from xylose was most improved (by 34%) when the medium was supplemented with 2 mM Ca(2+) , followed by supplementation with 3.5 mM Mg(2+) (29% improvement), and 180 μM Zn(2+) (26% improvement). Higher ethanol production was linked to high cell viability in the presence of metal ions. Comparative transcriptomics between the supplemented cultures and the control suggested that improved cell viability resulted from the induction of genes controlling the cell wall and membrane. Only one gene, FIT2, was found to be up-regulated in common between the three metal ions. Also up-regulation of HXT1 and TKL1 might enhance xylose consumption in the presence of acetic acid. Thus, the addition of ionic nutrients is a simple and cost-effective method to improve the acetic acid tolerance of S. cerevisiae.

  6. The effect of calcium gluconate and other calcium supplements as a dietary calcium source on magnesium absorption in rats.

    Science.gov (United States)

    Chonan, O; Takahashi, R; Yasui, H; Watanuki, M

    1997-01-01

    The effects of commercially available calcium supplements (calcium carbonate, calcium gluconate, oyster shell preparation and bovine bone preparation) and gluconic acid on the absorption of calcium and magnesium were evaluated for 30 days in male Wistar rats. There were no differences in the apparent absorption ratio of calcium among rats fed each calcium supplement; however, the rats fed the calcium gluconate diet had a higher apparent absorption ratio of magnesium than the rats fed the other calcium supplements. Dietary gluconic acid also more markedly stimulated magnesium absorption than the calcium carbonate diet, and the bone (femur and tibia) magnesium contents of rats fed the gluconic acid diet were significantly higher than those of the rats fed the calcium carbonate diet. Furthermore, the weight of cecal tissue and the concentrations of acetic acid and butyric acid in cecal digesta of rats fed the calcium gluconate diet or the gluconic acid diet were significantly increased. We speculate that the stimulation of magnesium absorption in rats fed the calcium gluconate diet is a result of the gluconic acid component and the effect of gluconic acid on magnesium absorption probably results from cecal hypertrophy, magnesium solubility in the large intestine and the effects of volatile fatty acids on magnesium absorption.

  7. 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)

  8. 乳清两步发酵法制取环保型融雪剂醋酸钙镁盐%Production of environment friendly deicer calcium magnesium acetate by two-stage fermentation process from cheese whey

    Institute of Scientific and Technical Information of China (English)

    韩爱霞; 吕海棠; 王兆谦; 任彦蓉; 王海鹏; 郗怡佳; 黄靖; 李春花

    2012-01-01

    To reasonably utilize cheese whey which was a by-product from the manufacture of cheese and casein,the anaerobic fermentation process was developed to produce acetic acid from lactose in cheese whey .Then environment friendly deicers calcium magnesium acetate (CMA) can be produced with the acetic acid and CaO/MgO.A lactobacillus plantarum was used to convert lactose in cheese whey to lactic acid in the first stage,the conversion rate of lactic acid was 47.47%. Propionibac-terium was used to convert lactic acid to acetic acid and propionic acid which could be separated by gas chromatography method in the second stage,and the conversion rate of acetic acid was 5.643%.Structure of CMA was verified by IR.This method effectively utilized cheese whey and reduced production costs of calcium magnesium acetate, will have a bright future.%为合理利用乳酪和乳酪素的副产品乳清,研究了一种新的厌氧发酵方法将乳清中的乳糖发酵成醋酸,以此醋酸与CaO/MgO反应制备得到环保型融雪剂醋酸钙镁盐(CMA).第一步用植物乳杆菌将乳清中的乳糖发酵成乳酸,乳酸的转化率是47.47%;第二步用丙酸杆菌将乳酸发酵成醋酸与丙酸,用气相色谱法将二者分离,得到醋酸的转化率为5.643%;用红外光谱法验证了此醋酸与CaO/MgO反应制备得到的CMA的结构.该法既有效地利用了乳酪和乳酪素的副产品乳清,又降低了环保型融雪剂醋酸钙镁盐的生产成本,具有很好的应用前景.

  9. Calcium, magnesium, and potassium in food

    Science.gov (United States)

    The biochemical and physiological functions and consequences of deficient intakes, which show the nutritional importance of calcium, magnesium and potassium for humans, are reviewed. The dietary recommendations and food sources for these essential mineral elements for humans are presented. Factors t...

  10. The Association Between Calcium, Magnesium, and Ratio of Calcium/Magnesium in Seminal Plasma and Sperm Quality.

    Science.gov (United States)

    Liang, Hong; Miao, Maohua; Chen, Jianping; Chen, Kanglian; Wu, Bin; Dai, Qi; Wang, Jian; Sun, Fei; Shi, Huijuan; Yuan, Wei

    2016-11-01

    The study aimed to examine the relationships between calcium, magnesium, and calcium/magnesium ratio in semen plasma and sperm quality. It was a cross-sectional study based on a program aiming at promoting the reproductive health in less-developed areas. A total of 515 men aged between 18 and 55 years provided semen specimens at family planning clinics in Sandu County, Guizhou Province, China. Total calcium and magnesium concentrations in semen plasma were measured with flame atomic absorption spectrometry. Sperm quality, including sperm motility and concentration, was evaluated by using a computer-assisted sperm analysis method. The medians of seminal plasma calcium, magnesium, and zinc concentrations were 9.61, 4.41, and 2.23 mmol/l, respectively. Calcium concentration and calcium/magnesium ratio were negatively associated with sperm concentrations (β = -0.47, P = 0.0123 for calcium; β = -0.25, P = 0.0393 for calcium/magnesium ratio) after adjusting for zinc and other covariates. In stratified analyses, the association between calcium and sperm concentrations only persisted among subjects with a calcium/magnesium ratio of ≤2.5 (β = -0.71, P = 0.0268). In the same stratum, magnesium was associated with increased sperm concentration (β = 0.73, P = 0.0386). Among subjects with a calcium/magnesium ratio of >2.5, neither calcium nor magnesium was associated with sperm concentration. In conclusion, total calcium and magnesium concentrations were associated with sperm concentration among subjects with a lower calcium/magnesium ratio. The calcium and magnesium ratio had a modifying effect on the associations of calcium and magnesium with sperm concentration.

  11. Elemental calcium intake associated with calcium acetate/calcium carbonate in the treatment of hyperphosphatemia

    OpenAIRE

    Wilson, Rosamund J; Copley, J Brian

    2017-01-01

    Background Calcium-based and non-calcium-based phosphate binders have similar efficacy in the treatment of hyperphosphatemia; however, calcium-based binders may be associated with hypercalcemia, vascular calcification, and adynamic bone disease. Scope A post hoc analysis was carried out of data from a 16-week, Phase IV study of patients with end-stage renal disease (ESRD) who switched to lanthanum carbonate monotherapy from baseline calcium acetate/calcium carbonate monotherapy. Of the intent...

  12. Magnesium-Calcite Crystal Formation Mediated by the Thermophilic Bacterium Geobacillus thermoglucosidasius Requires Calcium and Endospores.

    Science.gov (United States)

    Murai, Rie; Yoshida, Naoto

    2016-11-01

    Fresh Geobacillus thermoglucosidasius cells grown on soybean-casein digest nutrient agar were inoculated as a parent colony 1 cm in diameter on the surface of an agar gel containing acetate and calcium ions (calcite-promoting hydrogel) and incubated at 60 °C for 4 days, after which magnesium-calcite single crystals of 50-130 µm in size formed within the parent colony. Addition of EDTA, polyacrylic acid or N,N-dicyclohexylcarbodiimide to the calcite-forming hydrogel inhibited the parent colony from forming magnesium-calcite crystals. Inoculation of G. thermoglucosidasius on calcite-forming hydrogel containing 5 µM cadmium and 20 µM zinc resulted in a decrease in the sporulation rate from 55 to 7-8 %. Magnesium-calcite synthesis decreased relative to the sporulation rate. G. thermoglucosidasius exhibited higher adsorption/absorbance of calcium than other Geobacillus sp. that do not mediate calcite formation and higher levels of magnesium accumulation. Calcium ions contained in the calcite-promoting hydrogel and magnesium ions concentrated in G. thermoglucosidasius cells serve as the elements for magnesium-calcite synthesis. The observed decreases in sporulation rate and magnesium-calcite formation support the hypothesis that endospores act as nuclei for the synthesis of magnesium-calcite single crystals.

  13. Role of magnesium on the biomimetic deposition of calcium phosphate

    Science.gov (United States)

    Sarma, Bimal K.; Sarma, Bikash

    2016-10-01

    Biomimetic depositions of calcium phosphate (CaP) are carried out using simulated body fluid (SBF), calcifying solution and newly developed magnesium containing calcifying solution. Calcium phosphate has a rich phase diagram and is well known for its excellent biocompatibility and bioactivity. The most common phase is hydroxyapatite (HAp), an integral component of human bone and tooth, widely used in orthopedic and dental applications. In addition, calcium phosphate nanoparticles show promise for the targeted drug delivery. The doping of calcium phosphate by magnesium, zinc, strontium etc. can change the protein uptake by CaP nanocrystals. This work describes the role of magnesium on the nucleation and growth of CaP on Ti and its oxide substrates. X-ray diffraction studies confirm formation of HAp nanocrystals which closely resemble the structure of bone apatite when grown using SBF and calcifying solution. It has been observed that magnesium plays crucial role in the nucleation and growth of calcium phosphate. A low magnesium level enhances the crystallinity of HAp while higher magnesium content leads to the formation of amorphous calcium phosphate (ACP) phase. Interestingly, the deposition of ACP phase is rapid when magnesium ion concentration in the solution is 40% of calcium plus magnesium ions concentration. Moreover, high magnesium content alters the morphology of CaP films.

  14. Calcium, magnesium, and phosphorus metabolism in dogs given intravenous triacetin.

    Science.gov (United States)

    Bailey, J W; Heath, H; Miles, J M

    1989-02-01

    Previous studies suggested that acetate in parenteral solutions may adversely affect mineral metabolism by causing sequestration of inorganic phosphate and calcium in the liver. In this study, triacetin, a short-chain triglyceride of acetate and a potential parenteral nutrient, was infused for 3 h at an isocaloric rate in mongrel dogs (n = 6) to test its effects on serum phosphorus, calcium, and magnesium metabolism. There was no change in serum P or Ca. The serum Mg concentration decreased from 0.7 +/- 0.03 to 0.57 +/- 0.03 mmol/L (p less than 0.001) by 90 min and remained at this level for the remainder of the study. The triacetin infusion did not influence fractional urinary Mg excretion; thus, the decrease in serum Mg was likely because of an increase in cellular transport of this cation. A short-chain triglyceride administered to dogs at a rate approximating resting energy expenditure has no demonstrable adverse effects on mineral metabolism.

  15. Oxygen Permeability of Polypropylene Containing Polyisobutene with Magnesium Acetate

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The oxygen permeabilities of polypropylene films are reduced by adding a minor percentage of a polyisobutene ionomer. The polyisobutene ionomers were prepared by in situ salt exchange of magnesium acetate with maleated polyisobutenes of commercially available low relative molecular mass. The more polar magnesium salts aided phase separation during crystallization from the molten polypropylene mixture. Scanning electron microscope photographs revealed that the polyisobutene ionomer is largely concentrated in the amorphous regions between the polypropylene spherulites, where the ionomer tends to concentrate during crystallization. The influence of the polyisobutene ionomer on the oxygen permeability of polypropylene was found to be slightly dependent upon the relative molecular mass of the polyisobutene precursor. Under optimum conditions, the oxygen permeability of polypropylene is reduced by 20% with only 1% additive.

  16. Effects of calcium gluconate on the utilization of magnesium and the nephrocalcinosis in rats fed excess dietary phosphorus and calcium.

    Science.gov (United States)

    Chonan, O; Takahashi, R; Kado, S; Nagata, Y; Kimura, H; Uchida, K; Watanuki, M

    1996-08-01

    The effects of calcium gluconate on the utilization of magnesium and nephrocalcinosis in male Wistar rats made magnesium-deficient by adding excess dietary phosphorus (1.195 g of phosphorus/100 g of diet) and calcium (1.04 g of calcium/100 g of diet) were compared with the effects of calcium carbonate. The effects of dietary magnesium concentration on the magnesium status and nephrocalcinosis were also examined. Adding excess dietary phosphorus and calcium decreased the apparent magnesium absorption ratios and the concentrations of magnesium in the serum and femur and increased the deposition of calcium in the kidney, and the low magnesium condition (0.024 g of magnesium/100 g of diet) aggravated the deposition of calcium and the low magnesium status. The apparent magnesium absorption ratios and femur magnesium concentration in the rats fed a calcium gluconate diet (an equimolar mixture of calcium gluconate and calcium carbonate was used as a source of calcium) were significantly higher than in the rats fed a calcium carbonate diet (only calcium carbonate was used as a source of calcium), irrespective of dietary magnesium concentration. Dietary calcium gluconate lessened the accumulation of calcium in the kidney and increased the serum magnesium concentration compared with dietary calcium carbonate, when the rats were fed the normal magnesium diet (0.049 g of magnesium/100 g of diet) but not the low magnesium diet. We speculate that the increased utilization of magnesium by feeding the calcium gluconate diet to a limited extent prevented the low magnesium status and the severity of nephrocalcinosis caused by adding excess dietary phosphorus and calcium.

  17. Injectable bioactive calcium-magnesium phosphate cement for bone regeneration.

    Science.gov (United States)

    Wu, Fan; Su, Jiacan; Wei, Jie; Guo, Han; Liu, Changsheng

    2008-12-01

    Novel injectable and degradable calcium-magnesium phosphate cement (CMPC) with rapid-setting characteristic was developed by the introduction of magnesium phosphate cement (MPC) into calcium phosphate cement (CPC). The calcium-magnesium phosphate cement prepared under the optimum P/L ratio exhibited good injectability and desired workability. It could set within 10 min at 37 degrees C in 100% relative humidity and the compressive strength could reach 47 MPa after setting for 48 h, indicating that the prepared cement has relatively high initial mechanical strength. The results of in vitro degradation experiments demonstrated the good degradability of the injectable CMPC, and its degradation rate occurred significantly faster than that of pure CPC in simulated body fluid (SBF) solution. It can be concluded that the novel injectable calcium-magnesium phosphate cement is highly promising for a wide variety of clinical applications, especially for the development of minimally invasive techniques.

  18. Elemental calcium intake associated with calcium acetate/calcium carbonate in the treatment of hyperphosphatemia

    Science.gov (United States)

    Wilson, Rosamund J; Copley, J Brian

    2017-01-01

    Background Calcium-based and non-calcium-based phosphate binders have similar efficacy in the treatment of hyperphosphatemia; however, calcium-based binders may be associated with hypercalcemia, vascular calcification, and adynamic bone disease. Scope A post hoc analysis was carried out of data from a 16-week, Phase IV study of patients with end-stage renal disease (ESRD) who switched to lanthanum carbonate monotherapy from baseline calcium acetate/calcium carbonate monotherapy. Of the intent-to-treat population (N=2520), 752 patients with recorded dose data for calcium acetate (n=551)/calcium carbonate (n=201) at baseline and lanthanum carbonate at week 16 were studied. Elemental calcium intake, serum phosphate, corrected serum calcium, and serum intact parathyroid hormone levels were analyzed. Findings Of the 551 patients with calcium acetate dose data, 271 (49.2%) had an elemental calcium intake of at least 1.5 g/day at baseline, and 142 (25.8%) had an intake of at least 2.0 g/day. Mean (95% confidence interval [CI]) serum phosphate levels were 6.1 (5.89, 6.21) mg/dL at baseline and 6.2 (6.04, 6.38) mg/dL at 16 weeks; mean (95% CI) corrected serum calcium levels were 9.3 (9.16, 9.44) mg/dL and 9.2 (9.06, 9.34) mg/dL, respectively. Of the 201 patients with calcium carbonate dose data, 117 (58.2%) had an elemental calcium intake of at least 1.5 g/day, and 76 (37.8%) had an intake of at least 2.0 g/day. Mean (95% CI) serum phosphate levels were 5.8 (5.52, 6.06) mg/dL at baseline and 5.8 (5.53, 6.05) mg/dL at week 16; mean (95% CI) corrected serum calcium levels were 9.7 (9.15, 10.25) mg/dL and 9.2 (9.06, 9.34) mg/dL, respectively. Conclusion Calcium acetate/calcium carbonate phosphate binders, taken to control serum phosphate levels, may result in high levels of elemental calcium intake. This may lead to complications related to calcium balance. PMID:28182142

  19. A sequential injection system for the spectrophotometric determination of calcium, magnesium and alkalinity in water samples.

    Science.gov (United States)

    Mesquita, Raquel B R; Rangel, António O S S

    2004-08-01

    A sequential injection methodology for the spectrophotometric determination of calcium, magnesium and alkalinity in water samples is proposed. A single manifold is used for the determination of the three analytes, and the same protocol sequence allows the sequential determination of calcium and magnesium (the sum corresponds to the water hardness). The determination of both metals is based on their reaction with cresolphtalein complexone; mutual interference is minimized by using 8-hydroxyquinoline for the determination of calcium and ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) for the determination of magnesium. Alkalinity determination is based on a reaction with acetic acid, and corresponding color change of Bromcresol Green. Working ranges of 0.5 - 5 mg dm(-3) for Ca, 0.5 - 10 mg dm(-3) for Mg, and 10 - 100 mg HCO3- dm(-3), for alkalinity have been achieved. The results for water samples were comparable to those of the reference methods and to a certified reference water sample. RSDs lower than 5% were obtained, a low reagent consumption and a reduced volume of effluent have been accomplished. The determination rate for calcium and magnesium is 80 h(-1), corresponding to 40 h(-1) per element, while 65 determinations of alkalinity per hour could be carried out.

  20. Renal control of calcium, phosphate, and magnesium homeostasis.

    Science.gov (United States)

    Blaine, Judith; Chonchol, Michel; Levi, Moshe

    2015-07-01

    Calcium, phosphate, and magnesium are multivalent cations that are important for many biologic and cellular functions. The kidneys play a central role in the homeostasis of these ions. Gastrointestinal absorption is balanced by renal excretion. When body stores of these ions decline significantly, gastrointestinal absorption, bone resorption, and renal tubular reabsorption increase to normalize their levels. Renal regulation of these ions occurs through glomerular filtration and tubular reabsorption and/or secretion and is therefore an important determinant of plasma ion concentration. Under physiologic conditions, the whole body balance of calcium, phosphate, and magnesium is maintained by fine adjustments of urinary excretion to equal the net intake. This review discusses how calcium, phosphate, and magnesium are handled by the kidneys.

  1. The determination of ultrafiltrable calcium and magnesium in serum.

    Science.gov (United States)

    Danielson, B G; Pallin, E; Sohtell, M

    1982-01-01

    Ultrafiltrate of human serum was investigated in order to evaluate the serum content of calcium and magnesium. The acid and base concentrations and pH of the serum was altered through titration with HCl- or NaOH-solutions. The Pco2 was varied in the titrated serum using different carbon dioxide tensions. This was performed when serum was filtered in a recycling system. It is shown that the analysis of calcium and magnesium have to be done under anaerobic conditions or at standardized pH and Pco2 situations, as the concentrations vary with both pH and Pco2. The concentration ratio between ultrafiltrate and serum for calcium and magnesium was found to be 0.56 and 0.74 respectively at pH=7.41 and Pco2=40 mmHg.

  2. Magnesium: Effect on ocular health as a calcium channel antagonist

    Directory of Open Access Journals (Sweden)

    Şafak Korkmaz

    2013-06-01

    Full Text Available Magnesium is the physiologic calcium channel blocker,involving in many different metabolic processes by maintainingcell membrane function, modulating smooth musclecontraction and influencing enzymatic activities. Magnesiumhas been shown to increase blood flow to tissuesby modifying endothelial function via endothelin-1 (ET-1and nitric Oxide (NO pathways. Magnesium also exhibitsneuroprotective role by blocking N-methyl-D-aspartate(NMDA receptor related calcium influx and by inhibitingthe release of glutamate, hence protects the cell againstoxidative stress and apoptosis. Both increase in bloodflow and its neuroprotective effect make magnesium agood candidate for glaucoma studies. Magnesium hasbeen shown to decrease oxidative stress and apoptosisin retinal tissue and to have retinal ganglion cell sparingeffect. A series of studies has been conducted aboutmagnesium could decrease insulin resistance in diabeticpatients, ease glycemia control and prevent diabetic retinopathy.Magnesium is found to be critically important inmaintaining normal ionic homeostasis of lens. Magnesiumdeficiency has been shown to cause increased lenticularoxidative stress and ionic imbalance in the lens so triggercataractogenesis. J Clin Exp Invest 2013; 4 (2: 244-251Key words: Magnesium, calcium channel blockage,glaucoma, neuroprotection, diabetic retinopathy, cataract

  3. Solubilities of magnesium-L-ascorbate, calcium-L-ascorbate, magnesium-L-glutamate, magnesium-D-gluconate, calcium-D-gluconate, calcium-D-heptagluconate, L-aspartic acid, and 3-nitrobenzoic acid in water

    Energy Technology Data Exchange (ETDEWEB)

    Mishelevich, Alexander [Department of Chemical Engineering, Ben Gurion University of the Negev, Beer Sheva 84105 (Israel); Apelblat, Alexander [Department of Chemical Engineering, Ben Gurion University of the Negev, Beer Sheva 84105 (Israel)], E-mail: apelblat@bgu.ac.il

    2008-05-15

    The solubility in water of magnesium-L-ascorbate, calcium-L-ascorbate, magnesium-L-glutamate, magnesium-D-gluconate, calcium-D-gluconate, calcium-D-heptagluconate, L-aspartic acid, and 3-nitrobenzoic acid was determined in the 278.15 K to 343.15 K temperature range. The solubility of these compounds served to permit the evaluation of the apparent molar enthalpies of solution.

  4. Abnormalities of serum calcium and magnesium

    Science.gov (United States)

    Neonatal hypocalcemia is defined as a total serum calcium concentration of <7 mg/dL or an ionized calcium concentration of <4 mg/dL (1mmol/L). In very low birth weight (VLBW) infants, ionized calcium values of 0.8 to 1 mmol/L are common and not usually associated with clinical symptoms. In larger in...

  5. Boron, calcium and magnesium in Kavaratti lagoon water, Lakshadweep Archipelago

    Digital Repository Service at National Institute of Oceanography (India)

    Nasnolkar, C.M.; Salkar, V.R.; Shirodkar, P.V.; Abidi, S.A.H.

    Analysis of major elements in the water of Kavaratti lagoon show variations in the concentrations of boron from 4.08 to 4.25 mg kg sup(-1) (av. 4.15 mg kg sup(-1)); calcium from 420.4 to 429.3 mg kg sup(-1) (av. 424.79 mg kg sup(-1)); magnesium from...

  6. Relation of urinary calcium and magnesium excretion to blood pressure

    DEFF Research Database (Denmark)

    Kesteloot, Hugo; Tzoulaki, Ioanna; Brown, Ian J

    2011-01-01

    of calcium and magnesium in 2 cross-sectional studies. The International Study of Macro- and Micro-Nutrients and Blood Pressure (INTERMAP) comprised 4,679 persons aged 40-59 years from 17 population samples in China, Japan, the United Kingdom, and the United States, and the International Cooperative Study...

  7. Calcium acetate versus calcium carbonate as phosphorus binders in patients on chronic haemodialysis: a controlled study.

    Science.gov (United States)

    Ring, T; Nielsen, C; Andersen, S P; Behrens, J K; Sodemann, B; Kornerup, H J

    1993-01-01

    The first reported double-blind cross-over comparison between the phosphorus binders calcium carbonate and calcium acetate was undertaken in 15 stable patients on chronic maintenance haemodialysis. Detailed registration of diet and analysis of the protein catabolic rate suggested an unchanged phosphorus intake during the study. It was found that predialytic serum phosphate concentration was significantly decreased by 0.11 mmol/l (0.34 mg/dl) (P = 0.021, 95% confidence limits 0.02-0.21 mmol/l; 0.06-0.65 mg/dl) during calcium acetate treatment. The calcium phosphate product was insignificantly decreased during treatment with calcium acetate whereas we could not exclude the possibility that calcium concentration had increased.

  8. Bioactivity studies of calcium magnesium silicate prepared from eggshell waste by sol–gel combustion synthesis

    Directory of Open Access Journals (Sweden)

    Rajan Choudhary

    2015-06-01

    Full Text Available The present study focused on the synthesis of calcium magnesium silicate (akermanite, Ca2MgSi2O7 using eggshell biowaste (as calcium source, magnesium nitrate and tetraethyl orthosilicate (TEOS as starting materials. Sol–gel combustion method was adopted to obtain calcium magnesium silicate. Citric acid was used as a fuel (reducing agent and nitrate ions present in the metal nitrates acts as an oxidizing agent during combustion process. The characterization of synthesized calcium magnesium silicate was carried out by powder X-ray diffraction (XRD, Fourier transform infrared (FTIR and scanning electron microscopy (SEM techniques. Calcium magnesium silicate crystallite size was observed in nano regime which can effectively mimic natural bone apatite composition. In-vitro bioactivity was investigated by immersing calcium magnesium silicate pellet in simulated body fluid (SBF for three weeks. Results show effective deposition of crystallized hydroxyapatite (HAP layer on its surface and predicting its possibilities for applications in hard tissue regeneration.

  9. Magnesium substitution in the structure of orthopedic nanoparticles: A comparison between amorphous magnesium phosphates, calcium magnesium phosphates, and hydroxyapatites.

    Science.gov (United States)

    Nabiyouni, Maryam; Ren, Yufu; Bhaduri, Sarit B

    2015-01-01

    As biocompatible materials, magnesium phosphates have received a lot of attention for orthopedic applications. During the last decade multiple studies have shown advantages for magnesium phosphate such as lack of cytotoxicity, biocompatibility, strong mechanical properties, and high biodegradability. The present study investigates the role of Mg(+2) and Ca(+2) ions in the structure of magnesium phosphate and calcium phosphate nanoparticles. To directly compare the effect of Mg(+2) and Ca(+2) ions on structure of nanoparticles and their biological behavior, three groups of nanoparticles including amorphous magnesium phosphates (AMPs) which release Mg(+2), calcium magnesium phosphates (CMPs) which release Mg(+2) and Ca(+2), and hydroxyapatites (HAs) which release Ca(+2) were studied. SEM, TEM, XRD, and FTIR were used to evaluate the morphology, crystallinity, and chemical properties of the particles. AMP particles were homogeneous nanospheres, whereas CMPs were combinations of heterogeneous nanorods and nanospheres, and HAs which contained heterogeneous nanosphere particles. Cell compatibility was monitored in all groups to determine the cytotoxicity effect of particles on studied MC3T3-E1 preosteoblasts. AMPs showed significantly higher attachment rate than the HAs after 1 day and both AMPs and CMPs showed significantly higher proliferation rate when compared to HAs after 7days. Gene expression level of osteoblastic markers ALP, COL I, OCN, OPN, RUNX2 were monitored and they were normalized to GAPDH housekeeping gene. Beta actin expression level was monitored as the second housekeeping gene to confirm the accuracy of results. In general, AMPs and CMPs showed higher expression level of osteoblastic genes after 7 days which can further confirm the stimulating role of Mg(+2) and Ca(+2) ions in increasing the proliferation rate, differentiation, and mineralization of MC3T3-E1 preosteoblasts.

  10. Stability and broad-sense heritability of mineral content in potato: calcium and magnesium

    Science.gov (United States)

    Calcium and magnesium are two minerals with prominent roles in animal and plant metabolism. Advanced potato breeding lines were found to contain between 266 and 944 µg per gram fresh weight of calcium and between 705 1089 µg per gram fresh weight of magnesium. All trials had significant genotype b...

  11. Magnesium supplementation through seaweed calcium extract rather than synthetic magnesium oxide improves femur bone mineral density and strength in ovariectomized rats.

    Science.gov (United States)

    Bae, Yun Jung; Bu, So Young; Kim, Jae Young; Yeon, Jee-Young; Sohn, Eun-Wha; Jang, Ki-Hyo; Lee, Jae-Cheol; Kim, Mi-Hyun

    2011-12-01

    Commercially available seaweed calcium extract can supply high amounts of calcium as well as significant amounts of magnesium and other microminerals. The purpose of this study was to investigate the degree to which the high levels of magnesium in seaweed calcium extract affects the calcium balance and the bone status in ovariectomized rats in comparison to rats supplemented with calcium carbonate and magnesium oxide. A total of 40 Sprague-Dawley female rats (7 weeks) were divided into four groups and bred for 12 weeks: sham-operated group (Sham), ovariectomized group (OVX), ovariectomized with inorganic calcium and magnesium supplementation group (OVX-Mg), and ovariectomized with seaweed calcium and magnesium supplementation group (OVX-SCa). All experimental diets contained 0.5% calcium. The magnesium content in the experimental diet was 0.05% of the diet in the Sham and OVX groups and 0.1% of the diet in the OVX-Mg and OVX-SCa groups. In the calcium balance study, the OVX-Mg and OVX-SCa groups were not significantly different in calcium absorption compared to the OVX group. However, the femoral bone mineral density and strength of the OVX-SCa group were higher than those of the OVX-Mg and OVX groups. Seaweed calcium with magnesium supplementation or magnesium supplementation alone did not affect the serum ALP and CTx levels in ovariectomized rats. In summary, consumption of seaweed calcium extract or inorganic calcium carbonate with magnesium oxide demonstrated the same degree of intestinal calcium absorption, but only the consumption of seaweed calcium extract resulted in increased femoral bone mineral density and strength in ovariectomized rats. Our results suggest that seaweed calcium extract is an effective calcium and magnesium source for improving bone health compared to synthetic calcium and magnesium supplementation.

  12. Effects of high doses of magnesium in drinking water and voluntary wheel running on magnesium and calcium concentrations in rats.

    Science.gov (United States)

    Meludu, S C; Nishimuta, M; Aboh, N A; Okonkwo, C; Dioka, C E

    2002-12-01

    The effect of high magnesium intake in addition to supplementation and voluntary wheel activity on magnesium and calcium homeostasis was investigated in rats. Thirty-six 5-week-old male Wistar rats were divided into four groups (n = 9). Groups 2 and 4 received five hundred ppm of elemental magnesium as MgCl2 provided in drinking water. After 1 week of acclimatization and 4 weeks of supplement and/or exercise, the animals were fasted and sacrificed. It appears that magnesium supplementation as well as exercise played some significant role in the homeostatic changes of magnesium and calcium. This could be of great significance in better understanding of mineral homeostasis particularly in sports medicine.

  13. Calcium orthophosphate coatings on magnesium and its biodegradable alloys.

    Science.gov (United States)

    Dorozhkin, Sergey V

    2014-07-01

    Biodegradable metals have been suggested as revolutionary biomaterials for bone-grafting therapies. Of these metals, magnesium (Mg) and its biodegradable alloys appear to be particularly attractive candidates due to their non-toxicity and as their mechanical properties match those of bones better than other metals do. Being light, biocompatible and biodegradable, Mg-based metallic implants have several advantages over other implantable metals currently in use, such as eliminating both the effects of stress shielding and the requirement of a second surgery for implant removal. Unfortunately, the fast degradation rates of Mg and its biodegradable alloys in the aggressive physiological environment impose limitations on their clinical applications. This necessitates development of implants with controlled degradation rates to match the kinetics of bone healing. Application of protective but biocompatible and biodegradable coatings able to delay the onset of Mg corrosion appears to be a reasonable solution. Since calcium orthophosphates are well tolerated by living organisms, they appear to be the excellent candidates for such coatings. Nevertheless, both the high chemical reactivity and the low melting point of Mg require specific parameters for successful deposition of calcium orthophosphate coatings. This review provides an overview of current coating techniques used for deposition of calcium orthophosphates on Mg and its biodegradable alloys. The literature analysis revealed that in all cases the calcium orthophosphate protective coatings both increased the corrosion resistance of Mg-based metallic biomaterials and improved their surface biocompatibility.

  14. Magnesium substitution in the structure of orthopedic nanoparticles: A comparison between amorphous magnesium phosphates, calcium magnesium phosphates, and hydroxyapatites

    Energy Technology Data Exchange (ETDEWEB)

    Nabiyouni, Maryam, E-mail: maryam.nabiyouni@rockets.utoledo.edu [Department of Bioengineering, University of Toledo, Toledo, OH (United States); Ren, Yufu [Department of Mechanical, Industrial and Manufacturing Engineering, University of Toledo, Toledo, OH (United States); Bhaduri, Sarit B. [Department of Mechanical, Industrial and Manufacturing Engineering, University of Toledo, Toledo, OH (United States); Department of Surgery (Dentistry), University of Toledo, Toledo, OH (United States)

    2015-07-01

    As biocompatible materials, magnesium phosphates have received a lot of attention for orthopedic applications. During the last decade multiple studies have shown advantages for magnesium phosphate such as lack of cytotoxicity, biocompatibility, strong mechanical properties, and high biodegradability. The present study investigates the role of Mg{sup +2} and Ca{sup +2} ions in the structure of magnesium phosphate and calcium phosphate nanoparticles. To directly compare the effect of Mg{sup +2} and Ca{sup +2} ions on structure of nanoparticles and their biological behavior, three groups of nanoparticles including amorphous magnesium phosphates (AMPs) which release Mg{sup +2}, calcium magnesium phosphates (CMPs) which release Mg{sup +2} and Ca{sup +2}, and hydroxyapatites (HAs) which release Ca{sup +2} were studied. SEM, TEM, XRD, and FTIR were used to evaluate the morphology, crystallinity, and chemical properties of the particles. AMP particles were homogeneous nanospheres, whereas CMPs were combinations of heterogeneous nanorods and nanospheres, and HAs which contained heterogeneous nanosphere particles. Cell compatibility was monitored in all groups to determine the cytotoxicity effect of particles on studied MC3T3-E1 preosteoblasts. AMPs showed significantly higher attachment rate than the HAs after 1 day and both AMPs and CMPs showed significantly higher proliferation rate when compared to HAs after 7 days. Gene expression level of osteoblastic markers ALP, COL I, OCN, OPN, RUNX2 were monitored and they were normalized to GAPDH housekeeping gene. Beta actin expression level was monitored as the second housekeeping gene to confirm the accuracy of results. In general, AMPs and CMPs showed higher expression level of osteoblastic genes after 7 days which can further confirm the stimulating role of Mg{sup +}2 and Ca{sup +2} ions in increasing the proliferation rate, differentiation, and mineralization of MC3T3-E1 preosteoblasts. - Highlights: • Role of Mg{sup 2

  15. Calcium and magnesium concentrations in mature human milk: influence of calcium intake, age and socioeconomic level.

    Science.gov (United States)

    Vítolo, M R; Valente Soares, L M; Carvalho, E B; Cardoso, C B

    2004-03-01

    Concentrations of calcium and magnesium were measured in mature milk, collected between 30 and 90 days after childbirth, from a group of 90 mothers between 14 and 39 years of age, exclusively breastfeeding. The group was divided into three sub-groups: low socioeconomic-level adolescents (LSAd), low socioeconomic-level adults (LSA), and high socioeconomic-level adults (HSA). Each mother's nutritional status was determined using the body-mass index (BMI) and her eating habits, obtained on the basis of a 24-h dietary recall. Adolescent and adult mothers in the low socioeconomic-level group had lower average calcium intake (LSAd = 618.4 +/- 555.2 mg and LSA = 679.4 +/- 411.4 mg) than adult mothers in the higher socioeconomic-level group (853.6 +/- 415.5 mg). The average concentration of calcium in the adolescent mothers' milk (LSAd) was significantly lower (5.30 +/- 1.42 mmol Ca/L, P = 0.01) than that of the two adult groups (LSA = 5.82 +/- 1.55 mmol Ca/L and HSA = 6.40 mmol Ca/L). The average magnesium concentrations for all groups did not show significant differences (LSAd = 1.06 +/- 0.18, LSA = 1.16 +/- 0.23 and HSA = 1.11 +/- 0.23 mmol Mg/L, for P= 0.16). These results indicate that magnesium concentrations in mature human milk do not seem to depend on maternal nutritional status. The condition of adolescence, however, associated with lower calcium intake by the mother, resulted in lower calcium concentrations in the milk secreted when compared to that of adult mothers.

  16. Crystallization Kinetics of Calcium-magnesium Aluminosilicate (CMAS) Glass

    Science.gov (United States)

    Wiesner, Valerie L.; Bansal, Narottam P.

    2015-01-01

    The crystallization kinetics of a calcium-magnesium aluminosilicate (CMAS) glass with composition relevant for aerospace applications, like air-breathing engines, were evaluated using differential thermal analysis (DTA) in powder and bulk forms. Activation energy and frequency factor values for crystallization of the glass were evaluated. X-ray diffraction (XRD) was used to investigate the onset of crystallization and the phases that developed after heat treating bulk glass at temperatures ranging from 690 to 960 deg for various times. Samples annealed at temperatures below 900 deg remained amorphous, while specimens heat treated at and above 900 deg exhibited crystallinity originating at the surface. The crystalline phases were identified as wollastonite (CaSiO3) and aluminum diopside (Ca(Mg,Al) (Si,Al)2O6). Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were employed to examine the microstructure and chemical compositions of crystalline phases formed after heat treatment.

  17. 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

  18. Magnesium, Calcium, Potassium, and Sodium Intakes and Risk of Stroke in Male Smokers

    NARCIS (Netherlands)

    Larsson, S.C.; Virtanen, M.J.; Mars, M.; Mannisto, S.; Pietinen, P.; Albanes, D.; Virtamo, J.

    2008-01-01

    Background A high intake of magnesium, calcium, and potassium and a low intake of sodium have been hypothesized to reduce the risk of stroke. However, prospective data relating intake of these minerals to risk of stroke are inconsistent. Methods We examined the relationship of dietary magnesium, cal

  19. Plasma calcium, magnesium, phosphorus, and alkaline phosphatase levels in normal British schoolchildren.

    Science.gov (United States)

    Round, J M

    1973-07-21

    In a cross-sectional survey 624 schoolchildren were screened for plasma calcium, inorganic phosphate, and alkaline phosphatase levels. Plasma magnesium and alkaline phosphatase isoenzymes were also estimated in some cases.No significant difference was found between adult and childhood values for calcium and magnesium. Levels of alkaline phosphatase and inorganic phosphorus varied with both age and sex. The magnitude of these variations in normal ranges is of clear importance in assessing data from individual paediatric or adolescent patients.

  20. Essential Nutrient Interactions: Does Low or Suboptimal Magnesium Status Interact with Vitamin D and/or Calcium Status?

    Science.gov (United States)

    Rosanoff, Andrea; Dai, Qi; Shapses, Sue A

    2016-01-01

    Although much is known about magnesium, its interactions with calcium and vitamin D are less well studied. Magnesium intake is low in populations who consume modern processed-food diets. Low magnesium intake is associated with chronic diseases of global concern [e.g., cardiovascular disease (CVD), type 2 diabetes, metabolic syndrome, and skeletal disorders], as is low vitamin D status. No simple, reliable biomarker for whole-body magnesium status is currently available, which makes clinical assessment and interpretation of human magnesium research difficult. Between 1977 and 2012, US calcium intakes increased at a rate 2-2.5 times that of magnesium intakes, resulting in a dietary calcium to magnesium intake ratio of >3.0. Calcium to magnesium ratios 2.8 can be detrimental, and optimal ratios may be ∼2.0. Background calcium to magnesium ratios can affect studies of either mineral alone. For example, US studies (background Ca:Mg >3.0) showed benefits of high dietary or supplemental magnesium for CVD, whereas similar Chinese studies (background Ca:Mg vitamin D is widely recommended in US age-sex groups with low dietary magnesium. Magnesium is a cofactor for vitamin D biosynthesis, transport, and activation; and vitamin D and magnesium studies both showed associations with several of the same chronic diseases. Research on possible magnesium and vitamin D interactions in these human diseases is currently rare. Increasing calcium to magnesium intake ratios, coupled with calcium and vitamin D supplementation coincident with suboptimal magnesium intakes, may have unknown health implications. Interactions of low magnesium status with calcium and vitamin D, especially during supplementation, require further study.

  1. Hemolysis effect and calcium-phosphate precipitation of heat-organic-film treated magnesium

    Institute of Scientific and Technical Information of China (English)

    GAO Jia-cheng; QIAO Li-ying; LI Long-chuan; WANG Yong

    2006-01-01

    A heat-organic-films process was employed to induce calcium-phosphate apatites formation on magnesium, consequently the corrosion resistance and hemolysis properties of magnesium were improved for biomedical applications. Firstly, magnesium samples were heat-treated at 773 K for 10 h; secondly, stearic acid films were coated on the surface of the heat-treated magnesium.Then the surface modified magnesium was soaked in simulated body fluid (SBF) to test its corrosion resistance. The results show that the heat treatment process allows magnesium to form a dense oxide layer with a thickness of around 20 μm, thereby the surface modified magnesium has higher corrosion resistance. After 24 h in SBF island apatite was deposited on magnesium. The unevenly precipitates were characterized by XRD and FTIR as the mixture of hydroxyapatite(HA) and octacalcium phosphate(OCP). The preliminary hemolysis experiment indicates that untreated magnesium has hemolytic effect (about 60%); whereas the heat-organic film treated samples has no hemolytic effect. The mechanism of fast nucleation and growth of calcium-phosphate apatites on surface modified magnesium in SBF was also discussed.

  2. Magnesium and occluded water in calcium carbonate monohydrate

    Science.gov (United States)

    Dejehet, F.; Idrissi, S.; Debuys, R.

    1999-04-01

    Calcium carbonate monohydrate spherulites (˜102 μm diameter) with different magnesium contents were synthesized from artificial seawater. Stable spherulites are only obtained if [Mg]/[Ca] ≥ 1-1.3 in the mother solution. Spherulites are surrounded by a skin of ˜15 μm thickness, about 5 times richer in Mg2+ than the bulk and which play a protective role from the stability viewpoint. Etching and crushing experiments were performed which confirm i.a. that the isotropic CO3- and CO2- radicals are located in the occluded water surrounding the constituent crystallites of the spherulites. Des sphérules de carbonate de calcium monohydraté de ˜102 μm de diamètre avec des teneurs en magnésium différentes ont été synthétisées à partir d'eau de mer artificielle. Des sphérules stables ne sont obtenues que si [Mg]/[Ca] ≥ 1-1.3 dans la solution mère. Les sphérules sont entourées d'une peau de ˜15 μm d'épaisseur, à peu près 5 fois plus riche en Mg2+ que la masse et qui assure sa stabilité. Des expériences de décapage et de broyage ont confirmé e.a. que les radicaux isotropes CO3- et CO2- sont localisés dans l'eau occluse entourant les cristallites à l'intérieur des sphérules.

  3. The influence of lithium on calcium and magnesium homeostasis in serum and tissues of rats.

    Science.gov (United States)

    Kiełczykowska, Małgorzata; Pasternak, Kazimierz; Musik, Irena

    2003-01-01

    Lithium is used in medicine. However, its administration can have negative side effects, disturb the water-electrolyte equilibrium and affect the level of essential elements. For these reasons the influence of oral lithium intoxication at the dose of 150 mg Li dm(-3) on magnesium and calcium levels in serum and tissues of rats was investigated. The concentration of Mg and Ca in serum increased throughout the experiment. The concentration of magnesium in tissues decreased after three weeks in liver, kidney, brain and femoral muscle. The trend of the changes of calcium tissue concentration was opposite to the one observed in the case of magnesium.

  4. Calcium and magnesium status is not impaired in pregnant women.

    Science.gov (United States)

    Rocha, Vivianne S; Lavanda, Ivana; Nakano, Eduardo Y; Ruano, Rodrigo; Zugaib, Marcelo; Colli, Célia

    2012-07-01

    Deficiencies in calcium (Ca) and magnesium (Mg) are associated with various complications during pregnancy. To test the hypothesis that the status of these minerals is inadequate in pregnancy, a cross-sectional study was conducted of the dietary intake and status of Ca and Mg in pregnant women (n = 50) attending a general public university hospital in Brazil. Dietary intake was assessed from 4-day food records; levels of plasma Mg, erythrocyte Mg, and urinary Ca and Mg excretion were determined by flame atomic absorption spectroscopy; and type I collagen C-telopeptides were evaluated by enzyme-linked immunosorbent assay. Probabilities of inadequate Ca and Mg intake were exhibited by 58 and 98% of the study population, respectively. The mean levels of urinary Ca and Mg excretion were 8.55 and 3.77 mmol/L, respectively. Plasma C-telopeptides, plasma Mg, and erythrocyte Mg were within normal levels. Multiple linear regression analysis revealed positive relationships among urinary Ca excretion, Ca intake (P = .002) and urinary Mg excretion (P < .001) and between erythrocyte Mg and Mg intake (P = .023). It is concluded that the Ca and Mg status of participants was adequate even though the intake of Ca and Mg was lower than the recommended level.

  5. New agent to treat elevated phosphate levels: magnesium carbonate/calcium carbonate tablets.

    Science.gov (United States)

    Meyer, Caitlin; Cameron, Karen; Battistella, Marisa

    2012-01-01

    In summary, Binaphos CM, a magnesium carbonate/calcium carbonate combination phosphate binder, is marketed for treating elevated phosphate levels in dialysis patients. Although studies using magnesium/calcium carbonate as a phosphate binder are short term with small numbers of patients, this phosphate binder has shown some promising results and may provide clinicians with an alternative for phosphate binding. Using a combination phosphate binder may reduce pill burden and encourage patient compliance. In addition to calcium and phosphate, it is imperative to diligently monitor magnesium levels in patients started on this medication, as magnesium levels may increase with longer duration of use. Additional randomized controlled trials are necessary to evaluate long-term efficacy and safety of this combination phosphate binder.

  6. Use of ultrafiltration probes in sheep to collect interstitial fluid for measurement of calcium and magnesium.

    Science.gov (United States)

    Janle, E M; Sojka, J E

    2000-11-01

    Studies of calcium and magnesium changes in living animals usually involve blood, urine, and fecal samples. These samples provide only information on whole-body averages and give no indication of differences between tissues. Ultrafiltration probes were developed to sample interstitial fluid from muscle, bone, and subcutaneous tissue of sheep to provide a tool for investigating tissue differences in calcium and magnesium concentrations. The potential of the probes for mineral distribution studies was demonstrated in sheep by using infusion of a calcium gluconate solution.

  7. Simultaneous determination of calcium and magnesium by derivative spectrophotometry in pharmaceutical products

    Science.gov (United States)

    Benamor, M.; Aguerssif, N.

    2008-02-01

    First- and second-derivative spectrophotometric methods for the simultaneous determination of calcium and magnesium in their mixtures are described. The methods are based on the colored complexes formed by calcium and magnesium with bromopyrogallol red in presence of Tween 80 as a surfactant. The zero-crossing method has been utilized to measure the first- and second-derivative value of the derivative spectrum. Calcium (0.8-4.8 μg ml -1) is determined in the presence of magnesium (0.5-3.5 μg ml -1) at the pH 10 and vice versa at zero-crossing wavelengths of 544.5 and 570 nm in the first-derivative procedure and 574 and 531 nm in the second-derivative procedure, respectively. The detection limits achieved were 0.0575 μg ml -1 of calcium and 0.03 μg ml -1 of magnesium. The relative standard deviations were in all instances less than 2%. The proposed method has been applied to the simultaneous determination of calcium and magnesium in different samples: commercial multivitamin, human serum and drinking water where excellent agreement between reported and obtained results was achieved.

  8. A brief review of calcium phosphate conversion coating on magnesium and its alloys

    Science.gov (United States)

    Zaludin, Mohd Amin Farhan; Jamal, Zul Azhar Zahid; Jamaludin, Shamsul Baharin; Derman, Mohd Nazree

    2016-07-01

    Recent developments have shown that magnesium is a promising candidate to be used as a biomaterial. Owing to its light weight, biocompatibility and compressive strength comparable with natural bones makes magnesium as an excellent choice for biomaterial. However, high reactivity and low corrosion resistance properties have restricted the application of magnesium as biomaterials. At the moment, several strategies have been developed to solve this problem. Surface modification of magnesium is one of the popular solutions to solve the problem. Among many techniques developed in the surface modification, conversion coating method is one of the simple and effective techniques. From various types of conversion coating, calcium phosphate-based conversion coating is the most suitable for biomedical fields. This paper reviews some studies on calcium phosphate coating on Mg and its alloys via chemical conversion method and discusses some factors determining the coating performance.

  9. Effect of cadmium or magnesium on calcium-dependent central function that reduces blood pressure

    Energy Technology Data Exchange (ETDEWEB)

    Sutoo, D.; Akiyama, K. [Univ. of Tsukuba (Japan). Inst. of Medical Sci.

    2000-03-01

    The effect of intracerebroventricular (i.c.v.) administration of cadmium or magnesium on central calcium-dependent blood pressure regulation was investigated. The systolic blood pressure of spontaneously hypertensive rats (SHR; male, 13 weeks of age) decreased following i.c.v. administration of cadmium chloride (20 nmol/rat), and increased following i.c.v. administration of magnesium chloride (20, 600, and 1200 nmol/rat). The hypotensive effect of cadmium was suppressed by i.c.v. administration of W-7 (a calmodulin antagonist, 30 {mu}g/rat). Taking into consideration these results with our previous reports, it is suggested that cadmium binds to the calcium-binding sites of calmodulin and activates calcium/calmodulin-dependent enzymes in a disorderly manner, whereas magnesium does not. Therefore, cadmium increases dopamine synthesis in the brain via a calmodulin-dependent system, and the resultant increase in dopamine levels inhibits sympathetic nerve activity and reduces blood pressure in SHR. (orig.)

  10. Determination of calcium, magnesium and zinc in unused lubricating oils by atomic absorption spectroscopy.

    Science.gov (United States)

    Udoh, A P

    1995-12-01

    Varying concentrations of lanthanum and strontium were added to solutions of ashed unused lubricating oils for the determination of calcium, magnesium and zinc content using flame atomic absorption spectrophotometry. At least 3000 mug g(-1) of lanthanum or strontium was required to completely overcome the interference of the phosphate ion, PO(3-)(4), and give peak values for calcium. The presence of lanthanum or strontium did not cause an appreciable increase in the amount of magnesium and zinc obtained from the analyses. The method is fast and reproducible, and the coefficients of variation calculated for the elements using one of the samples were 1.6% for calcium, 3.5% for magnesium and 0.2% for zinc. Results obtained by this method were better than those obtained by other methods for the same samples.

  11. [Impact of drinking water calcium and magnesium levels on morbidity in the Omsk Region].

    Science.gov (United States)

    Erofeev, Iu V; Neskin, T A; Turchaninov, D V

    2006-01-01

    Drinking water calcium and magnesium levels were examined for impact on morbidity in a model rural area of a West Siberian region. It was ascertained that there were negative correlations between the water levels of the above elements and the incidence of respiratory, gastrointestinal, and locomotor diseases and positive correlations between the concentrations of calcium and magnesium and the incidence of nervous, urogenital, and eye diseases. It is concluded that by adjusting the findings, the medical care availability factor should be taken into account in the investigations using the health indices calculated on the data from official medical accounts. This investigation has shown the estimation of the drinking water levels of calcium and magnesium as a significant hygienic problem for a model region.

  12. The study of serum calcium and serum magnesium in pregnancy induced hypertension and normal pregnancy

    Directory of Open Access Journals (Sweden)

    Jagannath Pairu

    2015-02-01

    Full Text Available Background: Preeclampsia along with its complications is one of the major causes of maternal and fetal mortality and morbidity. Association of calcium and magnesium with pregnancy induced hypertension is known since decades. Evidence of decreased serum calcium and decreased serum magnesium has been observed in patients with pregnancy induced hypertension and has been implicated in the etiopathogenesis of preeclampsia. Methods: The present study was undertaken in 100 pregnant women. Data for the study was collected from 50 normotensive pregnant women with more than 20 weeks of gestational age (control group and 50 pregnancy induced hypertension patients (study group attending for the antenatal care in department of obstetrics and gynaecology in Vanivilas hospital, Bowring and Lady Curzon hospital attached to Bangalore medical college and research institute. Cases and controls were matched. Serum calcium and serum magnesium levels were estimated by spectrophotometry method. Results: The mean serum calcium is significantly lower in pregnancy induced hypertension group (8.15 +/- 0.37 mg/dl compared to normal pregnancy (9.16 +/- 0.82 mg/dl. The mean serum magnesium is lower in pregnancy induced hypertension group (1.78 +/- 0.70 mEq/L than normal pregnancy (2.08 +/- 0.46 mEq/L which is moderately significant. Conclusions: The serum calcium and serum magnesium levels are decreased in pregnancy induced hypertension patients compared to normotensive normal pregnant women, suggesting the possible role of calcium and magnesium in etiopathophysiology of pregnancy induced hypertension. [Int J Reprod Contracept Obstet Gynecol 2015; 4(1.000: 30-34

  13. Calcium phosphate coating on magnesium alloy by biomimetic method :Investigation of morphology ,composition and formation process

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Magnesium alloy has similar mechanical properties with natural bone and can degrade via corrosion in the electrolytic environment of the human body.Calcium phosphate has been proven to possess bioactivity and bone inductivity.In order to integrate both advantages,calcium phosphate coating was fabricated on magnesium alloy by a biomimetic method.Supersaturated calcification solutions (SCSs) with different Ca/P ratio and C1- concentration were used as mimetic solutions.The morphology,composition and formation process of the coating were studied with scanning electron microscopy (SEM),energy dispersive spectrometer (EDS),Fourier transformed infrared spectroscopy (FTIR) and X-ray diffraction (XRD).The results show that a uniform calcium phosphate coating was observed on magnesium alloy,the properties of which could be adjusted by the SCSs with different Ca/P ratio.The formation process of the coating was explored by immersing magnesium alloy in SCSs with different Cl- concentration which could adjust the hydrogen production.According to SEM results,the hydrogen bubbles were associated with the formation of grass-like and flower-like coating morphologies.In conclusion,the biomimetic method was effective to form calcium phosphate coating on magnesium alloy and the morphology and composition of the coating could be accommodated by the Ca/P ratio and Cl- concentration in SCSs.

  14. THE STUDY ON THE CHANGES OF ZINC,COPPER,CALCIUM AND MAGNESIUM IN PLASMA AND ERYTHROCYTES DURING CARDIOPULMONARY BYPASS

    Institute of Scientific and Technical Information of China (English)

    耿希刚; 李兆志; 李明; 师桃

    2004-01-01

    Objective To study the changes and their influence factors involved of zinc, copper, calcium and magnesium in plasma and erythrocytes during cardiopulmonary bypass(CPB). Methods Zinc, copper, calcium and magnesium values in plasma and erythrocytes were measured by atomic absorption spectrophotometer during CPB. Results Zinc and copper levels in plasma were significantly elevated above preinduction level before perfusion, but calcium and magnesium levels did not change significantly; zinc, copper and calcium levels in plasma were significantly below preoperation level during CPB, but magnesium level in plasma was significantly increased above preoperation; zinc level in plasma was increased to preoperation level after CPB and began to decrease again at 8 hours after CPB, copper level in plasma was increased to preoperation level at 20 hours after CPB, calcium in plasma was increased significantly from beginning to 8 hours after CPB, magnesium level in plasma was decreased to preoperation level at 8 hours afterCPB. Concentration of zinc , copper, calcium and magnesium in erythrocytes did not change significantly. Conclusion During CPB, the changes of zinc, copper, calcium and magnesium had relation to hemodilution, operative wound, carrier protein, stress and component of priming solution and cardioplegic solution, but no relation to transfer from plasma erythrocytes. The results indicate that it is beneficial to patient's recovery to supplement zinc, copper, calcium and magnesium properly by different ways during cardiac perioperation.

  15. The initial phases of calcium and magnesium phosphates precipitated from solutions of high to medium concentrations

    Science.gov (United States)

    Abbona, F.; Madsen, H. E. Lundager; Boistelle, R.

    1986-04-01

    The precipitation of calcium and magnesium phosphates is performed at 25°C by mixing solutions of ammonium phosphate and solutions of calcium and magnesium chlorides under the condition [ P] = [ Ca] + [ Mg] in large pH intervals. Before any nucleation the phosphate concentration ranges from 0.50M to 0.01M. The phases first precipitated are CaHPO 4·2H 2O (brushite), CaHPO 4 (monetite), Ca 3(PO 4) 2· xH 2O (amorphous calcium phosphate), MgNH 4PO 4·6H 2O (struvite), and MgHPO 4·3H 2O (newberyite). The precipitation fields of each phase are determined and discussed as a function of pH, composition and supersaturation. The solutions are even supersaturated with respect to several other calcium phosphates but they never occur first even if their supersaturation is the highest.

  16. Impact of Testosterone, Zinc, Calcium and Magnesium Concentrations on Sperm Parameters in Subfertile Men

    Science.gov (United States)

    Aydemir, Birsen; Kiziler, Ali Riza; Onaran, Ilhan; Alici, Bülent; Özkara, Hamdi; Akyolcu, Mehmet Can

    2007-04-01

    To investigate the impact of testosterone, zinc, calcium and magnesium concentrations in serum and seminal plasma on sperm parameters. There were significant decrease in sperm parameters, serum and seminal plasma zinc levels in subfertile males. It indicates zinc has a essential role in male infertility; the determination the level of zinc during infertility investigation is recommended.

  17. Soil tillage, water erosion, and calcium, magnesium and organic carbon losses

    Directory of Open Access Journals (Sweden)

    Bertol Ildegardis

    2005-01-01

    Full Text Available Soil tillage influences water erosion, and consequently, losses of calcium, magnesium and organic carbon in surface runoff. Nutrients and organic carbon are transported by surface runoff in particulate form, adsorbed to soil colloids or soluble in water, depending on the soil tillage system. This study was carried out on an Inceptisol, representative of the Santa Catarina highlands, southern Brazil, between November 1999 and October 2001, under natural rainfall. The soil tillage treatments (no replications were: no-tillage (NT, minimum soil tillage with chiseling + disking (MT, and conventional soil tillage with plowing + two diskings (CT. The crop cycles sequence was soybean (Glycine max, oats (Avena sativa, beans (Phaseolus vulgaris and vetch (Vicia sativa. Conventional soil tillage treatment with plowing + two disking in the absence of crops (BS was also studied. Calcium and magnesium concentrations were determined in both water and sediments of the surface runoff, while organic carbon was measured only in sediments. Calcium and magnesium concentrations were greater in sediments than in surface runoff, while total losses of these elements were greater in surface runoff than in sediments. The greatest calcium and magnesium concentrations in surface runoff were obtained under CT, while in sediments the greatest concentration occurred under MT. Organic carbon concentration in sediments did not differ under the different soil tillage systems, and the greatest total loss was under CT system.

  18. Effects of dietary calcium, phosphorus and magnesium on intranephronic calculosis in rats.

    Science.gov (United States)

    Woodward, J C; Jee, W S

    1984-12-01

    The effects of varying dietary levels of calcium, phosphorus and magnesium on the incidence and severity of intranephronic calculosis were studied. Renal calculi were induced by feeding female rats the AIN-76TM semipurified diet for 4 weeks. During this time period, dietary levels of 350, 450 or 550 mg calcium per 100 g diet did not influence the occurrence of urolithiasis. Increasing dietary magnesium levels from 50 to 350 mg was beneficial in preventing the occurrence of calculi if the diet contained 400 mg or less phosphorus. The protective effects of dietary magnesium were counteracted when dietary phosphorus levels were increased from 400 mg to 550 or 700 mg. If the dietary content of phosphorus and magnesium permitted the formation of renal calculi, the severity of the condition was also influenced by the dietary level of calcium. Some animal groups fed semipurified diets did not have microscopic or radiographic evidence of renal calculi but were found to have significantly elevated renal calcium values. It was suggested that these animals might be in a precalculus-forming state.

  19. Calcium/magnesium intake ratio, but not magnesium intake, interacts with genetic polymorphism in relation to colorectal neoplasia in a two-phase study.

    Science.gov (United States)

    Zhu, Xiangzhu; Shrubsole, Martha J; Ness, Reid M; Hibler, Elizabeth A; Cai, Qiuyin; Long, Jirong; Chen, Zhi; Li, Guoliang; Jiang, Ming; Hou, Lifang; Kabagambe, Edmond K; Zhang, Bing; Smalley, Walter E; Edwards, Todd L; Giovannucci, Edward L; Zheng, Wei; Dai, Qi

    2016-10-01

    Some studies suggest that the calcium to magnesium ratio intakes modify the associations of calcium or magnesium with risk of colorectal adenoma, adenoma recurrence, and cancer. Parathyroid hormone (PTH) plays a key role in the regulation of homeostasis for both calcium and magnesium. We hypothesized that polymorphisms in PTH and 13 other genes may modify the association between the calcium/magnesium intake ratio and colorectal neoplasia risk. We conducted a two-phase study including 1336 cases and 2891 controls from the Tennessee Colorectal Polyp Study. In Phase I, we identified 19 SNPs that significantly interacted with the calcium/magnesium intake ratio in adenoma risk. In Phase II, rs11022858 in PTH was replicated. In combined analysis of phases I and II, we found high calcium/magnesium intake ratio tended to be associated with a reduced risk of colorectal adenoma (P for trend, 0.040) among those who carried the TT genotype in rs11022858. In stratified analyses, calcium intake (≥ 1000 mg/d) was significantly associated with 64% reduced adenoma risk (OR = 0.36 (95% CI : 0.18-0.74)) among those homozygous for the minor allele (TT genotype) (P for trend, 0.012), but not associated with risk in other genotypes (CC/TC). Conversely, we found that highest magnesium intake was significantly associated with 27% reduced risk (OR = 0.73 (95% CI : 0.54-0.97)) of colorectal adenoma (P for trend, 0.026) among those who possessed the CC/TC genotypes, particularly among those with the TC genotype, whereas magnesium intake was not linked to risk among those with the TT genotype. These findings, if confirmed, will help for the development of personalized prevention strategies for colorectal cancer. © 2015 Wiley Periodicals, Inc.

  20. Comparison of serum calcium and magnesium levels between preeclamptic and normotensive healthy pregnant women

    Directory of Open Access Journals (Sweden)

    Shilpa Mittal

    2014-08-01

    Full Text Available Background: Preeclampsia is idiopathic multisystem disorder specific to human pregnancy. Its incidence is 8-10% of total pregnancies in India. It is one of the leading causes of maternal and fetal morbidity and mortality worldwide. Alterations in serum calcium and magnesium levels have been suggested as effective factors in causing preeclampsia. The aim of this study was to compare serum calcium and magnesium levels in preeclamptic and normal pregnant women in third trimester of pregnancy. Methods: The study was conducted in the department of biochemistry in collaboration with department of obstetrics and gynaecology, Sri Aurobindo medical college and P. G. institute, Indore during the period January 2012 to January 2013. Subjects were divided into two groups: group-I included 100 preeclamptic women group-II included 100 age matched, healthy pregnant women. Serum calcium and magnesium was estimated by Arsenazo III method and by Calmagite method in ERBA CHEM-5 respectively (Enzymatic kit method. Results: Serum levels of calcium (8.27 +/- 0.37 mg/dL vs. 9.06 +/- 0.27 mg/dL and magnesium (1.99 +/- 0.13 mEq/L vs. 2.03 +/- 0.13 mEq/L were significantly lower in preeclamptic women than the control group (i.e. healthy pregnant women. Conclusions: Hypocalcaemia and hypomagnesaemia are seen in the preeclamptic women may be responsible for the vascular pathology associated with onset of preeclampsia. Hence it can be concluded that adjuvant supplementation of calcium and magnesium may prevent further progression of preeclampsia. [Int J Reprod Contracept Obstet Gynecol 2014; 3(4.000: 959-962

  1. Magnesium supplement in pregnancy-induced hypertension: effects on maternal and neonatal magnesium and calcium homeostasis

    DEFF Research Database (Denmark)

    Rudnicki, M; Frølich, A; Fischer-Rasmussen, W

    1991-01-01

    The objective of this study was to evaluate the effect of low dose magnesium supplement upon maternal and fetal serum levels of mineral status in pregnancies complicated with hypertension (PIH). Twenty-five patients with PIH agreed to participate and were randomly allocated, in a double...

  2. Phase composition, mechanical performance and in vitro biocompatibility of hydraulic setting calcium magnesium phosphate cement.

    Science.gov (United States)

    Klammert, Uwe; Reuther, Tobias; Blank, Melanie; Reske, Isabelle; Barralet, Jake E; Grover, Liam M; Kübler, Alexander C; Gbureck, Uwe

    2010-04-01

    Brushite (CaHPO(4) x 2H(2)O)-forming calcium phosphate cements are of great interest as bone replacement materials because they are resorbable in physiological conditions. However, their short setting times and low mechanical strengths limit broad clinical application. In this study, we showed that a significant improvement of these properties of brushite cement could be achieved by the use of magnesium-substituted beta-tricalcium phosphate with the general formula Mg(x)Ca((3-x))((PO(4))(2) with 0 cement reactants. The incorporation of magnesium ions increased the setting times of cements from 2 min for a magnesium-free matrix to 8-11 min for Mg(2.25)Ca(0.75)(PO(4))(2) as reactant. At the same time, the compressive strength of set cements was doubled from 19 MPa to more than 40 MPa after 24h wet storage. Magnesium ions were not only retarding the setting reaction to brushite but were also forming newberyite (MgHPO(4) x 3H(2)O) as a second setting product. The biocompatibility of the material was investigated in vitro using the osteoblast-like cell line MC3T3-E1. A considerable increase of cell proliferation and expression of alkaline phosphatase, indicating an osteoblastic differentiation, could be noticed. Scanning electron microscopy analysis revealed an obvious cell growth on the surface of the scaffolds. Analysis of the culture medium showed minor alterations of pH value within the physiological range. The concentrations of free calcium, magnesium and phosphate ions were altered markedly due to the chemical solubility of the scaffolds. We conclude that the calcium magnesium phosphate (newberyite) cements have a promising potential for their use as bone replacement material since they provide a suitable biocompatibility, an extended workability and improved mechanical performance compared with brushite cements.

  3. Calcium and Magnesium Supplementation Improves Serum OPG/RANKL in Calcium-Deficient Ovariectomized Rats.

    Science.gov (United States)

    Bae, Yun Jung; Kim, Mi-Hyun

    2010-10-01

    Magnesium (Mg) deficiency has been reported to result in increases in bone resorption through changes in the cytokine system, such as decreases in serum osteoprotegerin (OPG) concentrations and increases in receptor activator of NF-κB ligand (RANKL) concentrations. However, there are few data about the effects of Mg supplementation on OPG and RANKL. This study was carried out to investigate the effects of Mg supplementation on bone mineral density (BMD), bone mineral content (BMC), serum OPG, and RANKL in ovariectomized (OVX) rats relative to calcium (Ca) intake levels. Fifty-five Sprague-Dawley female rats were divided into the following five groups and fed for 12 weeks as indicated: sham-operated control group (sham), OVX Ca-deficient group (OLCa, 0.1% Ca and 0.05% Mg), OVX Ca-deficient and Mg-supplemented group (OLCaMg, 0.1% Ca and 0.1% Mg), OVX Ca-adequate group (OACa, 0.5% Ca and 0.05% Mg), and OVX Ca-adequate and Mg-supplemented group (OACaMg, 0.5% Ca and 0.1% Mg). The BMD of the lumbar spine, femur, and tibia in the OVX groups was significantly lower than that in the sham group. The OVX group with an adequate-Ca diet showed significantly higher BMC of the lumbar spine compared to the low Ca-diet group regardless of Mg supplementation. The OACaMg group had significantly higher levels of OPG and OPG/RANKL ratio than did the OLCa group. From the above results, it is still unclear whether Mg supplementation can improve bone mineral status, while Mg supplementation with an adequate-Ca diet resulted in a change in cytokines that may promote bone formation.

  4. Serum calcium and magnesium level in dairy cows at calving

    Directory of Open Access Journals (Sweden)

    A.M. Pulimeno

    2011-03-01

    Full Text Available Milk fever and hypocalcaemia are post-partum metabolic diseases affecting about 6% of dairy cows and are due to a fail of the homeostatic metabolism regulating the calcium blood level around 9 and 10mg/100mL. The calcium drainage to the mammary gland along with the reduced capacity of the animal to mobilize calcium from bone reserve lead to a drop of the calcium blood level under 5-6mg/100mL with paresis like clinical symptoms known as milk fever. The incidence of the clinical milk fever is low, however the occurrence of mild hypocalcaemia (subclinical could be as high as 15- 20% within few days after calving, particularly in multiparous cows. The hypocalcaemia status as for the reduced bone calcium mobilization and intestinal absorption leads to reduced feed intake and make it a good start for ketosis, retained placenta, displaced abomasums and mastitis problems (Beede, 1991. The acid-base balance of the cow in the late pregnancy is determinant for hypocalcaemia............

  5. Characterization of calcium containing plasma electrolytic oxidation coatings on AM50 magnesium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Srinivasan, P. Bala, E-mail: bala.srinivasan@gkss.de [Institute of Materials Research, GKSS-Forschungszentrum Geesthacht GmbH, D-21502 Geesthacht (Germany); Liang, J.; Blawert, C.; Stoermer, M.; Dietzel, W. [Institute of Materials Research, GKSS-Forschungszentrum Geesthacht GmbH, D-21502 Geesthacht (Germany)

    2010-04-01

    An attempt was made to produce calcium containing plasma electrolytic oxidation (PEO) coatings on AM50 magnesium alloy using an alkaline electrolyte. This study was performed in three alkaline electrolytes containing calcium hydroxide and sodium phosphate with three different mass ratios viz., 1:2.5, 1:5 and 1:7.5. All the three coatings produced were found to contain Ca and P in appreciable amounts. The concentration of P was found to be higher in the coatings obtained in the electrolytes with higher concentration of phosphate ions. Even though all the three coatings were found to be constituted with magnesium oxide and magnesium phosphate phases, X-ray diffraction analyses revealed that the phase composition was influenced by the phosphate ion concentration/conductivity of the electrolyte. Further, the PEO coating obtained in the 1:7.5 ratio electrolyte was found to contain di-calcium phosphate (monetite) and calcium peroxide phases, which were absent in the other two coatings. Potentiodynamic polarization studies performed in 0.1 M NaCl solution showed that the coatings obtained from the 1:5 ratio electrolyte possessed a superior corrosion resistance, which is attributed to the combined effect of thickness, compactness and phase/chemical composition of this coating.

  6. Why and how to implement sodium, potassium, calcium, and magnesium changes in food items and diets?

    Science.gov (United States)

    Karppanen, H; Karppanen, P; Mervaala, E

    2005-12-01

    The present average sodium intakes, approximately 3000-4500 mg/day in various industrialised populations, are very high, that is, 2-3-fold in comparison with the current Dietary Reference Intake (DRI) of 1500 mg. The sodium intakes markedly exceed even the level of 2500 mg, which has been recently given as the maximum level of daily intake that is likely to pose no risk of adverse effects on blood pressure or otherwise. By contrast, the present average potassium, calcium, and magnesium intakes are remarkably lower than the recommended intake levels (DRI). In USA, for example, the average intake of these mineral nutrients is only 35-50% of the recommended intakes. There is convincing evidence, which indicates that this imbalance, that is, the high intake of sodium on one hand and the low intakes of potassium, calcium, and magnesium on the other hand, produce and maintain elevated blood pressure in a big proportion of the population. Decreased intakes of sodium alone, and increased intakes of potassium, calcium, and magnesium each alone decrease elevated blood pressure. A combination of all these factors, that is, decrease of sodium, and increase of potassium, calcium, and magnesium intakes, which are characteristic of the so-called Dietary Approaches to Stop Hypertension diets, has an excellent blood pressure lowering effect. For the prevention and basic treatment of elevated blood pressure, various methods to decrease the intake of sodium and to increase the intakes of potassium, calcium, and magnesium should be comprehensively applied in the communities. The so-called 'functional food/nutraceutical/food-ceutical' approach, which corrects the mineral nutrient composition of extensively used processed foods, is likely to be particularly effective in producing immediate beneficial effects. The European Union and various governments should promote the availability and use of such healthier food compositions by tax reductions and other policies, which make the

  7. Synthesis and Structural Studies of Calcium and Magnesium Phosphinate and Phosphonate Compounds

    Science.gov (United States)

    Bampoh, Victoria Naa Kwale

    The work presented herein describes synthetic methodologies leading to the design of a wide array of magnesium and calcium based phosphinate and phosphonates with possible applications as bone scaffolding materials or additives to bone cements. The challenge to the chemistry of the alkaline earth phosphonate target compounds includes poor solubility of compounds, and poorly understood details on the control of the metal's coordination environment. Hence, less is known on phosphonate based alkaline earth metal organic frameworks as compared to transition metal phosphonates. Factors governing the challenges in obtaining crystalline, well-defined magnesium and calcium solids lie in the large metal diameters, the absence of energetically available d-orbitals to direct metal geometry, as well as the overall weakness of the metal-ligand bonds. A significant part of this project was concerned with the development of suitable reaction conditions to obtain X-ray quality crystals of the reaction products to allow for structural elucidation of the novel compounds. Various methodologies to aid in crystal growth including hydrothermal methods and gel crystallization were employed. We have used phosphinate and phosphonate ligands with different number of phosphorus oxygen atoms as well as diphosphonates with different linker lengths to determine their effects on the overall structural features. An interesting correlation is observed between the dimensionality of products and the increasing number of donor oxygen atoms in the ligands as we progress from phosphinic acid to the phosphorous acids. As an example, monophosphinate ligand only yielded one-dimensional compounds, whereas the phosphonates crystallize as one and two-dimensional compounds, and the di- and triphosphonate based compounds display two or three-dimensional geometries. This thesis provides a selection of calcium and magnesium compounds with one-dimensional geometry, as represented in a calcium phosphinate to novel

  8. Synergistic flame retardant effects between sepiolite and magnesium hydroxide in ethylene-vinyl acetate (EVA matrix

    Directory of Open Access Journals (Sweden)

    2010-04-01

    Full Text Available Some customers are reluctant to change, because the halogen-free solutions may have higher cost. This is one of the reasons that the synergistic effect is always the subject for researchers to pursue. The synergy between sepiolite and magnesium hydroxide (MH in halogen-free flame retardant ethylene-vinyl acetate (EVA copolymer was investigated in the paper through some common facilities, such as limiting oxygen index (LOI, UL-94 test, thermogravimetric analysis (TGA, differential thermal analysis (DTA and cone calorimeter test (CCT. In the wake of the positive results from the LOI and UL-94 tests, the CCT data indicated not only the reduction of heat release rate (HRR and mass loss rates (MLR, but also prolonged ignition time (TTI and depressed smoke release (SR were observed during combustion. Simultaneously, the tensile strength and Young’s modulus of the system were also much better improved with the increase of sepiolite added due to the hydrogen bonds between silanol groups attached to the sepiolite molecules and the ester groups of EVA. The synergistic mechanism has been discussed in the paper in terms of the barrier mechanism in the condensed phase.

  9. Plasma Calcium, Inorganic Phosphate and Magnesium During Hypocalcaemia Induced by a Standardized EDTA Infusion in Cows

    Directory of Open Access Journals (Sweden)

    Enemark JMD

    2001-06-01

    Full Text Available The intravenous Na2EDTA infusion technique allows effective specific chelation of circulating Ca2+ leading to a progressive hypocalcaemia. Methods previously used were not described in detail and results obtained by monitoring total and free ionic calcium were not comparable due to differences in sampling and analysis. This paper describes a standardized EDTA infusion technique that allowed comparison of the response of calcium, phosphorus and magnesium between 2 groups of experimental cows. The concentration of the Na2EDTA solution was 0.134 mol/l and the flow rate was standardized at 1.2 ml/kg per hour. Involuntary recumbency occurred when ionised calcium dropped to 0.39 – 0.52 mmol/l due to chelation. An initial fast drop of ionized calcium was observed during the first 20 min of infusion followed by a fluctuation leading to a further drop until recumbency. Pre-infusion [Ca2+] between tests does not correlate with the amount of EDTA required to induce involuntary recumbence. Total calcium concentration measured by atomic absorption remained almost constant during the first 100 min of infusion but declined gradually when the infusion was prolonged. The concentration of inorganic phosphate declined gradually in a fluctuating manner until recumbency. Magnesium concentration remained constant during infusion. Such electrolyte responses during infusion were comparable to those in spontaneous milk fever. The standardized infusion technique might be useful in future experimental studies.

  10. A study of serum magnesium and serum calcium in major depressive disorder

    Directory of Open Access Journals (Sweden)

    Niladri Deb

    2016-01-01

    Full Text Available Background: Depression is arguably the epidemic of our time. In one of the reports of the World Health Organization, it was projected that depression and heart disease will be the most common diseases on Earth by 2020. The paper attempts to determine the relationship between the pathophysiology of major depressive disorder (MDD and serum magnesium and serum calcium levels. Methodology: The study is based on a sample of 60 subjects–30 healthy normal individuals and 30 indoor and outdoor patients of the Department of Psychiatry of Gauhati Medical College and Hospital, Guwahati, who were identified by psychiatrist as having MDD as per the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV criteria. Estimation of the parameters of the study was done by using spectrophotometre (Spectra scan UV 2600. The result values of both the groups were compared by using independent ‘t’ test. Further, the correlation between serum magnesium and serum calcium among individuals of control as well as case groups were carried out by using Pearson’s correlation test. Results: Analysis of data reveals the mean value of serum magnesium among subjects of control group was higher than that of the subjects of the case (before treatment group while in case of serum calcium, it was the vice versa. Moreover, in both the cases, the differences in mean values were found to be statistically significant. Conclusion: The present study shows that alterations in the concentrations of magnesium and calcium may play a role in depressive illnesses and thus, may have a possible role in causing various mood disorders like MDD.

  11. 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 ...

  12. Dosimetric properties of dysprosium doped calcium magnesium borate glass subjected to Co-60 gamma ray

    Energy Technology Data Exchange (ETDEWEB)

    Omar, R. S., E-mail: ratnasuffhiyanni@gmail.com; Wagiran, H., E-mail: husin@utm.my; Saeed, M. A. [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310 Johor Bahru (Malaysia)

    2016-01-22

    Thermoluminescence (TL) dosimetric properties of dysprosium doped calcium magnesium borate (CMB:Dy) glass are presented. This study is deemed to understand the application of calcium as the modifier in magnesium borate glass with the presence of dysprosium as the activator to be performed as TL dosimeter (TLD). The study provides fundamental knowledge of a glass system that may lead to perform new TL glass dosimetry application in future research. Calcium magnesium borate glass systems of (70-y) B{sub 2}O{sub 3} − 20 CaO – 10 MgO-(y) Dy{sub 2}O{sub 3} with 0.05  mol % ≤ y ≤ 0.7  mol % of dyprosium were prepared by melt-quenching technique. The amorphous structure and TL properties of the prepared samples were determined using powder X-ray diffraction (XRD) and TL reader; model Harshaw 4500 respectively. The samples were irradiated to Co-60 gamma source at a dose of 50 Gy. Dosimetric properties such as annealing procedure, time temperature profile (TTP) setting, optimization of Dy{sub 2}O{sub 3} concentration of 0.5 mol % were determined for thermoluminescence dosimeter (TLD) reader used.

  13. The simultaneous removal of calcium, magnesium and chloride ions from industrial wastewater using magnesium-aluminum oxide.

    Science.gov (United States)

    Hamidi, Roya; Kahforoushan, Davood; Fatehifar, Esmaeil

    2013-01-01

    In this article, a method for simultaneous removal of calcium, magnesium and chloride by using Mg0.80Al0.20O1.10 as a Magnesium-Aluminum oxide (Mg‒Al oxide) was investigated. Mg‒Al oxide obtained by thermal decomposition of the Mg-Al layered double hydroxide (Mg-Al LDH). The synthesized Mg‒Al oxide were characterized with respect to nitrogen physicosorption, X-ray diffraction (XRD) and field emission scan electron microscopy (FESEM) morphology. Due to high anion-exchange capacity of Mg‒Al oxide, it was employed in simultaneously removal of Cl(-), Mg(+2) and Ca(+2) from distiller waste of a sodium carbonate production factory. For this purpose, experiments were designed to evaluate the effects of quantity of Mg‒Al oxide, temperature and time on the removal process. The removal of Cl(-), Mg(+2) and Ca(+2) from wastewater was found 93.9%, 93.74% and 93.25% at 60°C after 0.5 h, respectively. Results showed that the removal of Cl(-), Mg(+2) and Ca(+2) by Mg‒Al oxide increased with increasing temperature, time and Mg‒Al oxide quantity.

  14. Microwave assisted synthesis and characterization of magnesium substituted calcium phosphate bioceramics

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Nida Iqbal [Interdisciplinary Research Centre in Biomedical Materials, COMSATS Institute of Information Technology, M. A. Jinnah Campus, Defence Road, Off Raiwind Road, Lahore (Pakistan); Medical Implant Technology Group (MEDITEG), Faculty of Bioscience and Medical Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor Darul Takzim (Malaysia); Ijaz, Kashif; Zahid, Muniza; Khan, Abdul S. [Interdisciplinary Research Centre in Biomedical Materials, COMSATS Institute of Information Technology, M. A. Jinnah Campus, Defence Road, Off Raiwind Road, Lahore (Pakistan); Abdul Kadir, Mohammed Rafiq [Medical Implant Technology Group (MEDITEG), Faculty of Bioscience and Medical Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor Darul Takzim (Malaysia); Hussain, Rafaqat [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, Skudai, Johore (Malaysia); Anis-ur-Rehman [Department of Physics, COMSATS Institute of Information Technology, Chakshahzad Campus, Islamabad (Pakistan); Darr, Jawwad A. [Clean Materials Technology Group, Department of Chemistry, University College London, Christopher Ingold Laboratories, 20 Gordon Street, London WC1H 0AJ (United Kingdom); Ihtesham-ur-Rehman [The Kroto Research Institute, North Campus, University of Sheffield, Broad Lane, Sheffield S3 7HQ (United Kingdom); Chaudhry, Aqif A., E-mail: aqifanwar@ciitlahore.edu.pk [Interdisciplinary Research Centre in Biomedical Materials, COMSATS Institute of Information Technology, M. A. Jinnah Campus, Defence Road, Off Raiwind Road, Lahore (Pakistan)

    2015-11-01

    Hydroxyapatite is used extensively in hard tissue repair due to its biocompatibility and similarity to biological apatite, the mineral component of bone. It differs subtly in composition from biological apatite which contains other ions such as magnesium, zinc, carbonate and silicon (believed to play biological roles). Traditional methods of hydroxyapatite synthesis are time consuming and require strict reaction parameter control. This paper outlines synthesis of magnesium substituted hydroxyapatite using simple microwave irradiation of precipitated suspensions. Microwave irradiation resulted in a drastic decrease in ageing times of amorphous apatitic phases. Time taken to synthesize hydroxyapatite (which remained stable upon heat treatment at 900 °C for 1 h) reduced twelve folds (to 2 h) as compared to traditionally required times. The effects of increasing magnesium concentration in the precursors on particle size, surface area, phase-purity, agglomeration and thermal stability, were observed using scanning electron microscopy, BET surface area analysis, X-ray diffraction and photo acoustic Fourier transform infra-red spectroscopy. Porous agglomerates were obtained after a brief heat-treatment (1 h) at 900 °C. - Highlights: • Microwave irradiation of suspensions of calcium phosphates accelerated maturation. • Reactions took 2 h to complete as compared to 18 h required traditionally. • Magnesium contents higher than 1 wt.% lead to the presence of non-apatitic phases. • Agglomerates with micron and sub-micron porosity were obtained after heat-treatment.

  15. Effect of microflora and lactose on the absorption of calcium, phosphorus and magnesium in the hindgut of the rat.

    Science.gov (United States)

    Andrieux, C; Sacquet, E

    1983-01-01

    For 4 weeks, 3-month old germfree (GF) and conventional (CV) rats were given a semi-synthetic diet sterilized by irradiation with or without 10% of lactose. During the 5th week, 0.2% of titanium oxide (TiO2) was added to the diet and the rats were killed at regular intervals throughout the light/dark cycle. The patterns of TiO2 and 45Ca excretion were similar, indicating that TiO2 was a good marker of unabsorbed calcium transit. The apparent absorption coefficient of calcium, magnesium and phosphorus was determined in the ileum, caecum, large intestine and faeces by the mineral/TiO2 ratio. The effects of microflora and lactose varied with the mineral and the digestive tract level studied. --In the small intestine, microflora had no effect on the apparent absorption of calcium and magnesium but did have an unfavorable influence on phosphorus absorption. Lactose increased calcium and magnesium absorption, and this increase was similar in GF and CV rats, but lactose had a favorable effect on phosphorus absorption only in CV rats. --In the caecum, microflora had an unfavorable effect on the apparent absorption of calcium and magnesium and a favorable effect on phosphorus absorption. The ingestion of lactose reduced calcium and magnesium absorption in the caecum of GF rats and phosphorus absorption in the caecum of CV animals. --In the colon, mineral absorption was not significant in either CV or GF rats receiving the lactose-free diets. Lactose ingestion caused the absorption of calcium, magnesium and phosphorus to rise significantly only in GF rats. This absorption contributed to the stronger effect of lactose on total calcium and phosphorus absorption in GF rats.

  16. Calcium phosphate coating on magnesium alloy for modification of degradation behavior

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Magnesium alloy has similar mechanical properties with natural bone,but its high susceptibility to corrosion has limited its application in orthopedics.In this study,a calcium phosphate coating is formed on magnesium alloy (AZ31) to control its degradation rate and enhance its bioactivity and bone inductivity.Samples of AZ31 plate were placed in the supersaturated calcification solution prepared with Ca(NO3)2,NaH2PO4 and NaHCO3,then the calcium phosphate coating formed.Through adjusting the immersion time,the thickness of uniform coatings can be changed from 10 to 20 μm.The composition,phase structure and morphology of the coatings were investigated.Bonding strength of the coatings and substrate was 2-4 MPa in this study.The coatings significantly decrease degradation rate of the original Mg alloy,indicating that the Mg alloy with calcium phosphate coating is a promising degradable bone material.

  17. Mechanical Properties and Durability of Advanced Environmental Barrier Coatings in Calcium-Magnesium-Alumino-Silicate Environments

    Science.gov (United States)

    Miladinovich, Daniel S.; Zhu, Dongming

    2011-01-01

    Environmental barrier coatings are being developed and tested for use with SiC/SiC ceramic matrix composite (CMC) gas turbine engine components. Several oxide and silicate based compositons are being studied for use as top-coat and intermediate layers in a three or more layer environmental barrier coating system. Specifically, the room temperature Vickers-indentation-fracture-toughness testing and high-temperature stability reaction studies with Calcium Magnesium Alumino-Silicate (CMAS or "sand") are being conducted using advanced testing techniques such as high pressure burner rig tests as well as high heat flux laser tests.

  18. Second hyperpolarizability of delta shaped disubstituted acetylene complexes of beryllium, magnesium, and calcium.

    Science.gov (United States)

    Hatua, Kaushik; Nandi, Prasanta K

    2015-10-01

    Present theoretical study involves the delta shape complexes of beryllium, magnesium, and calcium where the metal atom interacts perpendicularly with disubstituted acetylene. Most of the complexes are found to be fairly stable. The dependence of second-hyperpolarizability on the basis set with increasing polarization and diffuse functions has been examined which showed the importance of 'f-type' type polarization function for heavy metal (Mg, Ca) and 'd-type' polarization function for beryllium. Larger second hyperpolarizability has been predicted for complexes having significant ground state polarization and low lying excited states favoring strong electronic coupling. Transition energy plays the most significant role in modulating the second hyperpolarizability.

  19. The content determination of calcium, magnesium and ascorbic acid in sea buckthorn fruits at vulcan coal dump

    Directory of Open Access Journals (Sweden)

    Andreea BRASOVAN

    2009-11-01

    Full Text Available The study presents data on content determination of calcium, magnesium and ascorbic acid in sea buckthorn fruits collected from Vulcan coal dump. The dump was never covered with soil or fertilizers containing azoth, potassium and phosphorus. The sea buckthorn was planted directly on the sterile and it has an important function in stabilizing the acclivity and fixing the atmospheric azoth with the nodosities on the roots. So, the sea buckthorn becomes widespread plant in coal dumps because it helps to the soil formation. The results obtained after the determination of calcium, magnesium and ascorbic acid from the fruits of this plant were compared with the values already reported in various references, concluding that these differences are insignificant (3.7% for magnesium and 9.4% for calcium. Therefore, the sea buckthorn from the dump can be used in food industry, as well as in pharmaceutics and medicine.

  20. [Calcium, magnesium, iron and zinc in drinking water and status biomarkers of these minerals among elder people from Warsaw region].

    Science.gov (United States)

    Madej, Dawid; Kaluza, Joanna; Antonik, Anna; Brzozowska, Anna; Roszkowski, Wojciech

    2011-01-01

    The aim of this study was to estimate the influence of calcium, magnesium, iron and zinc contents in drinking water on chosen parameters of nutritional status of these minerals in 164 elder people, 75-80 age, living in Warsaw region. Blood, hair and saliva were collected to assess the calcium, magnesium, iron and zinc nutritional status, while the samples of drinking water were collected to determine these minerals in water Mineral concentrations in blood, hair saliva and water were assessment using the atomic spectrophotometer absorption method It was showed that contribution of drinking water to calcium, magnesium, iron and zinc intake was: 15%, 4%, 5%, 9%, respectively. The relationship between the contents of these minerals in drinking water and their levels in the blood, hair and saliva had low correlation coefficients. It probably showed that homeostasis was maintained in the human body and other factors such as demographic or lifestyle factors were important.

  1. 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 ...

  2. Intraoperative infusion of acetated Ringer solution containing glucose and ionized magnesium reduces ketogenesis and maintains serum magnesium.

    Science.gov (United States)

    Yokoyama, Takeshi; Suwa, Kunio; Yamasaki, Fumiyasu; Yokoyama, Reiko; Yamashita, Koichi; Sellden, Eva

    2008-01-01

    The effect of glucose infusion during surgery on glucose metabolism has not been investigated sufficiently. We, therefore, examined the effect after the infusion of 1% glucose acetated Ringer solution containing Mg2+ during surgery on ketogenesis and serum Mg2+ concentrations. Patients, classified as ASA I-II, age 51-80 years, were randomly assigned to receive infusion of acetated Ringer solution. The G/Mg group received infusion with 1% glucose, Na+ 140mEq/L, Mg2+ 2 mEq/L, and the C group received infusion with glucose free solution containing Na+ 130 mEq/L without Mg2+. Both solutions were infused at a rate of 25 mL/kg for the first hour, and main-tained at 4 mL/kg/hr thereafter. Blood samples were collected three times: before infusion and at 1 hour and 4 hours after the start of infusion. Electrolytes and glucose metabolism were evaluated at each sampling. After rapid infusion, blood glucose level significantly increased to 170+/-19mg/dL in the G/Mg group, but it returned to close to baseline after 4 hours and serum ketone bodies did not increase during infusion. In the C group, however, blood glucose never increased beyond 110 mg/dL, but both acetoacetic and hydroxybutyric acids increased significantly at the third measurement.

  3. Analysis of serum Calcium, Magnesium, and Parathyroid Hormone in neonates delivered following preeclampsia treatment.

    Science.gov (United States)

    Vahabi, S; Zaman, M; Farzan, B

    2016-12-30

    Due to the approximate clinical and biochemical manifestations of calcium and magnesium disturbances, with regard to the regulatory effects of parathyroid hormone (PTH), this present study is designed to analyze serum calcium (Ca), magnesium (Mg), and (PTH) at the time of birth, 24 hours afterwards in newborns after the mother has been treated with Mg-sulfate. We registered 86 term and preterm neonates (43 in each group) using simple census method delivered through vagina to preeclampsia pregnant women treated with Mg-sulfate immediately before birth in Khoramabad Asali Hospital, Iran. The first specimen was obtained from umbilical cord blood at birth, followed by the second sample of 2cc peripherally obtained from blood 24 hours after birth. The mean serum Mg level was higher than normal for both specimens in both term and preterm groups with no significant difference. The mean serum Ca level was higher in term group at both occasions, which turned out to be statistically significant (Pmagnesium level showed a significant decline at 24 hours (P = 0.005) while PTH increased significantly (p<0.000) and (p=0.005) for term and preterm groups respectively. In contrast, Ca changes were not significantly different between the two specimens. Treatment with Mg-sulfate immediately before vaginal delivery increases Mg in both term and preterm neonates with no effect on Ca and PTH levels.

  4. Biodegradable Orthopedic Magnesium-Calcium (MgCa Alloys, Processing, and Corrosion Performance

    Directory of Open Access Journals (Sweden)

    Yuebin Guo

    2012-01-01

    Full Text Available Magnesium-Calcium (Mg-Ca alloy has received considerable attention as an emerging biodegradable implant material in orthopedic fixation applications. The biodegradable Mg-Ca alloys avoid stress shielding and secondary surgery inherent with permanent metallic implant materials. They also provide sufficient mechanical strength in load carrying applications as opposed to biopolymers. However, the key issue facing a biodegradable Mg-Ca implant is the fast corrosion in the human body environment. The ability to adjust degradation rate of Mg-Ca alloys is critical for the successful development of biodegradable orthopedic implants. This paper focuses on the functions and requirements of bone implants and critical issues of current implant biomaterials. Microstructures and mechanical properties of Mg-Ca alloys, and the unique properties of novel magnesium-calcium implant materials have been reviewed. Various manufacturing techniques to process Mg-Ca based alloys have been analyzed regarding their impacts on implant performance. Corrosion performance of Mg-Ca alloys processed by different manufacturing techniques was compared. In addition, the societal and economical impacts of developing biodegradable orthopedic implants have been emphasized.

  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. 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. CALCIUM AND MAGNESIUM CONCENTRATION OF BREAST MILK IN RELATION WITH AGE AND PARITY OF NURSING WOMEN

    Directory of Open Access Journals (Sweden)

    Zofia Goc

    2012-08-01

    Full Text Available The aim of this study was determination of the concentration of calcium and magnesium in human milk (n=150 taken from nursing women who lived permanently in Malopolska district (South Poland. Milk samples were classified into groups taking into account women’ age and parity. According to the various age of the women milk samples were segregated into three groups: 20-25 years old, 26-31 years old and 32-37 years old. Included parity milk samples were spitted into two groups: the first group consisted of women who were primiparous (1 baby, the second group included women who were multiparous (≥2 babies. Milk samples were taken between the 7th and 14th day of the postpartum in each age group. The samples were taken by manual expression every morning. The analyses of metals were done by flame atomic absorption spectrophotometry (FAAS, after all samples had been collected. The mean concentration of cooper in milk taken from women of first age group (20-25 years old was 209.44±15.10 mg/L, in second group (26-31 years old was 238.65±13.34 mg/L and in the oldest group (32-37 years old was 261.44±17.16 mg/L. The mean concentration of magnesium in the same group of age was 42.12±3.793 mg/L, 47.51±2.728 mg/L and 45.43±3.840 mg/L, respectively. The mean concentration of calcium in milk taken from primiparous was 223.17±10.50mg/L, in multiparous was 266.37±16.20 mg/L. Whereas, the mean concentration of magnesium in transitional milk taken from the same group was 44.12±2.58 mg/L and 47.412±3.16 mg/L, respectively. Statistical analyses showed that there were statistically significant differences between calcium level in milk taken from the youngest group and the concentration of this metal in milk from the oldest group (p=0.032. Also, when comparing women’s parity, significant differences were found in the concentration of calcium (p=0.022. However, the differences in magnesium levels between tested groups were no statistically significant

  9. Effects of calcium and magnesium hardness on the fertilization and hatching success of channel X blue hybrid catfish eggs

    Science.gov (United States)

    The aquifer used for hybrid catfish hatcheries is less than 10 mg/L of calcium hardness and 1- 25 mg/L of magnesium hardness. Embryonic development is deemed to be the most sensitive stage in the life cycle of a teleost. As egg development takes outside the fish’s body, water hardness is one abioti...

  10. Influence of calcium, magnesium, or potassium ions on the formation and stability of emulsions prepared using highly hydrolyzed whey proteins.

    Science.gov (United States)

    Ramkumar, C; Singh, H; Munro, P A; Singh, A M

    2000-05-01

    Oil-in-water emulsions (4 wt % soy oil) containing 4 wt % whey protein hydrolysate (WPH) (27% degree of hydrolysis) and different levels of calcium, magnesium, or potassium chloride were prepared in a two-stage homogenizer. Other emulsions containing 4 wt % WPH but including 0.35 wt % hydroxylated lecithin and different levels of the above minerals were similarly prepared. The formation and stability of these emulsions were determined by measuring oil droplet size distributions using laser light scattering and by confocal scanning laser microscopy and a gravity creaming test. Both lecithin-free and lecithin-containing emulsions showed no change in droplet size distributions with increasing concentration of potassium in the range 0-37.5 mM. In contrast, the diameter of emulsion droplets increased with increasing calcium or magnesium concentration >12.5 mM. Emulsions containing hydroxylated lecithin were more sensitive to the addition of calcium or magnesium than the lecithin-free emulsions. Storage of emulsions at 20 degrees C for 24 h further increased the diameter of droplets and resulted in extensive creaming in emulsions containing >25 mM calcium or magnesium. It appears that both flocculation and coalescence processes were involved in the destabilization of emulsions induced by the addition of divalent cations.

  11. Effect of cold-setting calcium- and magnesium phosphate matrices on protein expression in osteoblastic cells.

    Science.gov (United States)

    Ewald, Andrea; Helmschrott, Kerstin; Knebl, Georg; Mehrban, Nazia; Grover, Liam M; Gbureck, Uwe

    2011-02-01

    Bone loss due to accidents or tissue diseases requires replacement of the structure by either autografts, allografts, or artificial materials. Reactive cements, which are based on calcium phosphate chemistry, are commonly used in nonload bearing areas such as the craniofacial region. Some of these materials are resorbed by the host under physiological conditions and replaced by bone. The aim of this study was to test different calcium and magnesium cement composites in vitro for their use as bone substitution material. Phase composition of calcium deficient hydroxyapatite (Ca(9) (PO(4) )(5) HPO(4) OH), brushite (CaHPO(4) ·2H(2) O), and struvite (MgNH(4) PO(4) ·6H(2) O) specimens has been determined by means of X-ray diffraction, and compressive strength was measured. Cell growth and activity of osteoblastic cells (MG 63) on the different surfaces was determined, and the expression of bone marker proteins was analyzed by western blotting. Cell activity normalized to cell number revealed higher activity of the osteoblasts on brushite and struvite when compared to hydroxyapatite and also the expression of osteoblastic marker proteins was highest on brushite scaffolds. While brushite sets under acidic conditions, formation of struvite occurs under physiological pH, similar to hydroxyapatite cements, providing the possibility of additional modifications with proteins or other active components.

  12. CALCIUM AND MAGNESIUM CONTENT IN CANCEROUS AND HEALTHY TISSUES OF GASTROINTESTINAL TRACT

    Directory of Open Access Journals (Sweden)

    Marta Głogowska

    2012-10-01

    Full Text Available Studies concerning concentration of biogenic metals in tissues of digestive system are sparse and diversified. The objectives of this study were to determine the mean concentration of biogenic metals: Mg and Ca, in cancerous and normal tissues of digestive system. Research was conducted on samples taken from different segments of human digestive tract. Tissues were taken during biopsy, surgery, and post-mortem from Military Hospital and PROSMED Health Center Patients’ located in Cracow. Samples were mineralized by wet digestion. First, they were dried and after dry mass were obtained the samples were put into digestion flasks and 1cm3 of nitric acid 65% was added to each of them. The samples were heated for about 2 hours, at 105°C. Mineralized material was moved to tubes with a capacity of 10 cm3 and filled with distilled water up to this volume. The resulting solutions were used to analyze the content of selected elements by FAAS method. The results are expressed in micrograms per gram of dry weight of tissue (µg•g-1d.m.. Average calcium content is higher in the tissues of the gastrointestinal tract of both healthy women (15890,28 µg•g-1d.m. and men (13040,24 µg•g-1d.m. in comparison with tumor tissues of the gastrointestinal tract of women (5365,19 µg•g-1 d.m. and men (2459,42 µg•g-1d.m.. Average magnesium content is higher in the tissues of the gastrointestinal tract of both healthy women (2887,19 µg•g-1 d.m. and men (1112,69 µg•g-1 d.m., in comparison with gastrointestinal cancerous tissues of women (1146,77 µg•g-1 d.m. and men (621,42 µg•g-1 d.m.. It was shown that differences between calcium and magnesium contents in the digestive tract tissues depend on the state of health - significantly higher contents of Ca and Mg were present in the tissues of healthy men and women in comparison to the tissues of men and women with digestive tract cancer. Magnesium and calcium have protective properties (they prevent the

  13. Effects of beta 1-->4 linked galactooligosaccharides on use of magnesium and calcification of the kidney and heart in rats fed excess dietary phosphorous and calcium.

    Science.gov (United States)

    Chonan, O; Takahashi, R; Yasui, H; Watanuki, M

    1996-10-01

    Magnesium deficiency was induced in male Wistar rats by adding an excess of phosphorous and calcium to the diet (1.195 g of phosphorous and 1.04 g of calcium/100 g of diet). Feeding of these animals with a diet containing beta 1-->4 linked galactooligosaccharides (4'-GOS) (5 g of 4'-GOS/100 g of diet) increased the apparent magnesium absorption ratios and the concentrations of magnesium in the serum and femur, and reduced accumulation of calcium in the kidney and heart. We speculate that the use of magnesium increased by feeding 4'-GOS to a limited extent prevented the lower magnesium status and the severity of calcification of the kidney and heart caused by excess dietary phosphorous and calcium.

  14. Effects of phosphates on microstructure and bioactivity of micro-arc oxidized calcium phosphate coatings on Mg-Zn-Zr magnesium alloy.

    Science.gov (United States)

    Pan, Y K; Chen, C Z; Wang, D G; Zhao, T G

    2013-09-01

    Calcium phosphate (CaP) coatings were prepared on Mg-Zn-Zr magnesium alloy by micro-arc oxidation (MAO) in electrolyte containing calcium acetate monohydrate (CH3COO)2Ca·H2O) and different phosphates (i.e. disodium hydrogen phosphate dodecahydrate (Na2HPO4·12H2O), sodium phosphate (Na3PO4·H2O) and sodium hexametaphosphate((NaPO3)6)). Scanning electron microscope (SEM), energy-dispersive X-ray spectrometry (EDS) and X-ray diffractometer (XRD) were employed to characterize the microstructure, elemental distribution and phase composition of the CaP coatings. Simulated body fluid (SBF) immersion test was used to evaluate the coating bioactivity and degradability. Systemic toxicity test was used to evaluate the coating biocompatibility. Fluoride ion selective electrode (ISE) was used to measure F(-) ions concentration during 30 days SBF immersion. The CaP coatings effectively reduced the corrosion rate and the surfaces of CaP coatings were covered by a new layer formed of numerous needle-like and scale-like apatites. The formation of these calcium phosphate apatites indicates that the coatings have excellent bioactivity. The coatings formed in (NaPO3)6-containging electrolyte exhibit thicker thickness, higher adhesive strength, slower degradation rate, better apatite-inducing ability and biocompatibility.

  15. Rapid coating of AZ31 magnesium alloy with calcium deficient hydroxyapatite using microwave energy

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Yufu, E-mail: Yufu.Ren@rockets.utoledo.edu [Department of Mechanical, Industrial and Manufacturing Engineering, The University of Toledo, Toledo, OH (United States); Zhou, Huan [Department of Mechanical, Industrial and Manufacturing Engineering, The University of Toledo, Toledo, OH (United States); Institute of Biomedical Engineering and Health Sciences, Changzhou University, Changzhou, Jiangsu (China); Nabiyouni, Maryam [Department of Bioengineering, The University of Toledo, Toledo, OH (United States); Bhaduri, Sarit B. [Department of Mechanical, Industrial and Manufacturing Engineering, The University of Toledo, Toledo, OH (United States); Division of Dentistry, The University of Toledo, Toledo, OH (United States)

    2015-04-01

    Due to their unique biodegradability, magnesium alloys have been recognized as suitable metallic implant materials for degradable bone implants and bioresorbable cardiovascular stents. However, the extremely high degradation rate of magnesium alloys in physiological environment has restricted its practical application. This paper reports the use of a novel microwave assisted coating technology to improve the in vitro corrosion resistance and biocompatibility of Mg alloy AZ31. Results indicate that a dense calcium deficient hydroxyapatite (CDHA) layer was uniformly coated on a AZ31 substrate in less than 10 min. Weight loss measurement and SEM were used to evaluate corrosion behaviors in vitro of coated samples and of non-coated samples. It was seen that CDHA coatings remarkably reduced the mass loss of AZ31 alloy after 7 days of immersion in SBF. In addition, the prompt precipitation of bone-like apatite layer on the sample surface during immersion demonstrated a good bioactivity of the CDHA coatings. Proliferation of osteoblast cells was promoted in 5 days of incubation, which indicated that the CDHA coatings could improve the cytocompatibility of the AZ31 alloy. All the results suggest that the CDHA coatings, serving as a protective layer, can enhance the corrosion resistance and biological response of magnesium alloys. Furthermore, this microwave assisted coating technology could be a promising method for rapid surface modification of biomedical materials. - Highlights: • A microwave assisted coating process for biodegradable Mg alloy. • CDHA coatings were successfully developed on AZ31 alloy in minutes. • The as-deposited CDHA coatings significantly reduced the degradation rate of AZ31 alloy. • The CDHA coated AZ31 alloy showed good bioactivity and biocompatibility in vitro. • The microwave assisted coating process can be used as rapid surface modification for bioimplants.

  16. Magnesium and Calcium Aluminate Liquids: In Situ High-Temperature 27Al NMR Spectroscopy.

    Science.gov (United States)

    Poe, B T; McMillan, P F; Coté, B; Massiot, D; Coutures, J P

    1993-02-05

    The use of high-temperature nuclear magnetic resonance (NMR) spectroscopy provides a means of investigating the structure of refractory aluminate liquids at temperatures up to 2500 K. Time-averaged structural information indicates that the average aluminum coordination for magnesium aluminate (MgAl(2)O(4)) liquid is slightly greater than for calcium aluminate (CaAl(2)O(4)) liquid and that in both liquids it is close to four. Ion dynamics simulations for these liquids suggest the presence of four-, five-, and six-coordinated aluminate species, in agreement with NMR experiments on fast-quenched glasses. These species undergo rapid chemical exchange in the high-temperature liquids, which is evidenced by a single Lorentzian NMR line.

  17. Calcium-magnesium Aluminosilicate (CMAS) Interactions with Advanced Environmental Barrier Coating Material

    Science.gov (United States)

    Wiesner, Valerie L.; Bansal, Narottam P.

    2015-01-01

    Particulates, like sand and volcanic ash, threaten the development of robust environmental barrier coatings (EBCs) that protect next-generation silicon-based ceramic matrix composite (CMC) turbine engine components from harsh combustion environments during service. The siliceous particulates transform into molten glassy deposits of calcium-magnesium aluminosilicate (CMAS) when ingested by an aircraft engine operating at temperatures above 1200C. In this study, a sample of desert sand was melted into CMAS glass to evaluate high-temperature interactions between the sand glass and an advanced EBC material. Desert sand glass was added to the surface of hot-pressed EBC substrates, which were then heated in air at temperatures ranging from 1200C to 1500C. Scanning electron microscopy and X-ray energy-dispersive spectroscopy were used to evaluate microstructure and phase compositions of specimens and the CMASEBC interface after heat treatments.

  18. The final phases of calcium and magnesium phosphates precipitated from solutions of high to medium concentration

    Science.gov (United States)

    Abbona, Francesco; Lundager Madsen, Hans Erik; Boistelle, Roland

    1988-07-01

    The phases of calcium and magnesium phosphates, which are obtained by evolution at 25°C of the first precipitates in their mother solutions, are described in terms of pH and composition of solutions. The initial conditions were: 0.050M ≤ [P] ≤ 0.500M; [P] = [Ca] + [Mg]; 0 ≤ [Mg]/[Ca] ≤ 1. The most abundant final phases are brushite, CaHPO 4·2H 2O; monetite, CaHPO 4; newberyite, MgHPO 4·3H 2O and struvite, MgNH 4PO 4·6H 2O. At low concentration whitlockite, Ca 9MgH(PO 4) 7, occurs with the amorphous phase previously precipitated, Ca 3(PO 4) 2·nH 2O. The conditions for stability are discussed and the changes observed are interpreted.

  19. Growth of calcium phosphates on magnesium substrates for corrosion control in biomedical applications via immersion techniques.

    Science.gov (United States)

    Shadanbaz, Shaylin; Walker, Jemimah; Staiger, Mark P; Dias, George J; Pietak, Alexis

    2013-01-01

    Magnesium (Mg) has been suggested as a revolutionary biodegradable replacement for current permanent metals used in orthopedic applications. Current investigations concentrate on the control of the corrosion rate to match bone healing. Calcium phosphate coatings have been a recent focus of these investigations through various coating protocols. Within this investigation, an in situ crystallization technique was utilized as an inexpensive and relatively simple method to produce a brushite and monetite coating on pure Mg. Coatings were characterized using energy dispersive spectroscopy, glancing angle X-ray diffraction and field emission scanning electron microscopy. Corrosion protection properties of the coatings were assessed in physiological buffers, Earles balanced salt solution, minimum essential media, and minimum essential media containing serum albumin, over a 4-week period. Using this novel coating protocol, our findings indicate brushite and monetite coated Mg to have significant corrosive protective effects when compared with its uncoated counterpart whilst maintaining high coating substrate adhesion, homogeneity, and reproducibility.

  20. [Concentrations of calcium, magnesium, sodium and potassium in human milk and infant formulas].

    Science.gov (United States)

    Rodríguez Rodríguez, E M; Sanz Alaejos, M; Díaz Romero, C

    2002-12-01

    Concentrations of calcium, magnesium, sodium and potassium were determined in 55 samples of mature human milk from Canary women and 5 samples of powdered infant formula. According to the literature our data fell within the normal intervals described for each kind of milk. The mean concentration of Ca, Mg, Na y K of powdered infant formula was higher than those concentrations found in the human milks. Significant differences among the concentrations of Ca, Mg and Na for the milks of the considered mothers were observed. Only the Ca intakes for infants fed with human milk were lower than those requirements recommended by the Food and Nutrition Board (1989). However, the infants fed with powdered infant formula had an adequate intake of all the studied metals. A progressive decrease of the Na, K and Ca concentrations with the lactation stage was observed. Maternal age, parity and sex of the newborns did not affect the metal concentrations significantly.

  1. Dialysability of magnesium and calcium from hospital duplicate meals: influence exerted by other elements.

    Science.gov (United States)

    Velasco-Reynold, Carlos; Navarro-Alarcon, Miguel; Lopez-Ga de la Serrana, Herminia; Perez-Valero, Vidal; Agil, Ahmad; Lopez-Martinez, Maria C

    2010-03-01

    Total and dialysable magnesium and calcium levels and corresponding dialysabilities were measured in duplicate meals (n = 108) during 36 consecutive days. The interaction exerted by other nutrients and energy on them was also performed. Total mean magnesium and calcium fractions of 113.9 +/- 98.3 and 337.2 +/- 278.9 mg/meal respectively, were found. The Mg and Ca levels supplied by meals are positively (p < 0.05) correlated with macronutrient contents (carbohydrates and proteins). The mean dialysable Mg and Ca fractions were 56.9 +/- 36.3 and 127.4 +/- 112.3 mg/meal (50.4 +/- 13.2 and 37.8 +/- 10.7% as dialysabilities, respectively). Total Mg and Ca levels are significantly correlated with corresponding element dialysabilities (p < 0.05). For both minerals, significant correlations between their total and dialysable fractions and between their dialysable level and dialysabilities were noted (p < 0.01). The mean Mg and Ca daily dietary intakes (DDI) were 341.7 +/- 68.0 and 1,011.6 +/- 424.4 mg/day, respectively. For Ca and Mg the existence of similarities in their behaviour in meals and absorptive processes has been found. Duplicate meals with raw vegetables are good sources of bioaccessible Mg. High Ca dialysability has been found in the analysed meals. The fish and products constitute a good source of bioaccessible Ca. Mg, Ca, zinc, and chromium levels enhanced significantly the Mg dialysability. The Ca dialysability rose significantly with dialysable Ca and chromium fractions (p < 0.05).

  2. Hierarchically microporous/macroporous scaffold of magnesium-calcium phosphate for bone tissue regeneration.

    Science.gov (United States)

    Wei, Jie; Jia, Junfeng; Wu, Fan; Wei, Shicheng; Zhou, Huanjun; Zhang, Hongbo; Shin, Jung-Woog; Liu, Changsheng

    2010-02-01

    Hierarchically 3D microporous/macroporous magnesium-calcium phosphate (micro/ma-MCP) scaffolds containing magnesium ammonium phosphate hexahydrate [NH(4)MgPO(4).6H(2)O] and hydroxyapatite [Ca(10)(PO(4))(6)(OH)(2)] were fabricated from cement utilizing leaching method in the presence of sodium chloride (NaCl) particles and NaCl saturated water solution. NaCl particles produced macroporosity, and NaCl solution acted as both cement liquid and porogens, inducing the formation of microporosity. The micro/ma-MCP scaffolds with porosities varied from 52 to 78% showed well interconnected and open macropores with the sizes of 400-500 microm, and degradation of the scaffolds was significantly enhanced in Tris-HCl solution compared with macroporous MCP (ma-MCP) and corresponding calcium phosphate cement (CPC) scaffolds. Cell attachment and proliferation of MG(63) on micro/ma-MCP were significantly better than ma-MCP and CPC scaffolds because of the presence of microporosity, which enhanced the surface area of the scaffolds. Moreover, the alkaline phosphatase (ALP) activity of the MG(63) cells on micro/ma-MCP was significantly higher than ma-MCP and CPC scaffolds at 7 days, and the MG(63) cells with normal phenotype spread well and formed confluent layers across the macroporous walls of the micro/ma-MCP scaffolds. Histological evaluation confirmed that the micro/ma-MCP scaffolds improved the efficiency of new bone regeneration, and exhibited excellent biocompatibility, biodegradability and faster and more effective osteogenesis in vivo.

  3. Analysis of changes in selected parameters of calcium and magnesium metabolism in response to diet composition and B-group vitamin supplementation in rat

    Directory of Open Access Journals (Sweden)

    Joanna Sadowska

    2010-09-01

    Full Text Available Background. The aim of the study was to investigate the effects of a diet modification and supplementation with B-group vitamins, on selected characteristics of calcium and magnesium management in rats. Material and methods. The experiment was carried out on 60 rats aged 5 months. Animals were fed two different diets. Groups I and II received clean tap water to drink, while group III had water solution of group-B vitamins. Results. Analysis of blood plasma calcium and magnesium concentrations in the studied animals did not reveal a significant effect of the analysed factors on blood plasma calcium concentration in examined rats. An increase of the plasma level of magnesium was observed with a change in the diet composition. The supplementation reduced magnesium level to those observed in animals fed a basic feed. Diet modification and supplementation exerted the influence on whole blood calcium and magnesium levels. A change in the composition of the diet and its supplementation results also in an increase in bone calcium content in males, and in an increase in bone magnesium content in females. Conclusions. Lack of changes in blood plasma calcium levels in the studied animals implies the preservation of the homeostatic mechanisms that regulate its concentration, whereas the observed significant changes in the concentration of magnesium, point to a significant effect of this factor on its metabolism. Changes in hematocrit indicator, whole blood concentrations of calcium and magnesium and the absence of changes in concentrations of these elements in blood plasma of supplemented animals may indicate that the elements move to erythrocytes, which may imply a distortion of cellular membrane and an increase in its permeability. Composition of the diet and its supplementation modified also bone calcium and magnesium concentrations in the studied rats.

  4. Beta-type calcium phosphates with and without magnesium: From hydrolysis of brushite powder to robocasting of periodic scaffolds.

    Science.gov (United States)

    Richard, Raquel C; Sader, Márcia S; Dai, Jisen; Thiré, Rossana M S M; Soares, Gloria D A

    2014-10-01

    Several approaches have attempted to replace extensive bone loss, but each of them has their limitation. Nowadays, additive manufacture techniques have shown great potential for bone engineering. The objective of this study was to synthesize beta tricalcium phosphate (β-TCP), beta tricalcium phosphate substituted by magnesium (β-TCMP), and biphasic calcium phosphate substituted by magnesium (BCMP) via hydrolysis and produce scaffolds for bone regeneration using robocasting technology. Calcium deficient apatites, with and without magnesium were obtained by hydrolysis, calcined and physico-chemically characterized. Colorimetric cell viability assay, calcium nodule formation, and the expression of alkaline phosphatase, osteocalcin, transforming growth factor beta-1 and collagen were assessed using a mouse osteoblastic cell line (MC3T3-E1). Direct-write assembly of cylindrical periodic scaffolds was done via robotic deposition using β-TCP, β-TCMP, and BCMP colloidal inks. The sintered scaffolds were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, Archimede's method, and uniaxial compression test. According to the cell viability assay, the powders induced cell proliferation. Calcium nodule formation and bone markers activity suggested that the materials present potential value in bone tissue engineering. The scaffolds built by robocasting presented interconnected porous and exhibited mean compressive strength between 7.63 and 18.67 MPa, compatible with trabecular bone.

  5. Effects of low calcium plus high aluminum diet on magnesium and calcium contents in spinal cord and trabecular bone of rats

    Energy Technology Data Exchange (ETDEWEB)

    Yasui, Masayuki; Ota, Kiichiro [Wakayama Medical Coll. (Japan); Sasajima, Kazuhisa

    1998-01-01

    Current epidemiological surveys in the Western Pacific area and Kii Peninsula have suggested that low calcium (Ca), magnesium (Mg), and high aluminum (Al) and manganese (Mn) in river, soil and drinking water may be implicated in the pathogenetic process of amyotrophic lateral sclerosis (ALS) and parkinsonism-dementia (PD). The condition of unbalanced minerals was experimentally duplicated in this study using rats. Male Wistar rats, weighing 200 g, were maintained for 60 days on the following diets: (A) standard diet, (B) low Ca diet, (C) low Ca diet with high Al. Magnesium concentration was determined in spinal cord and trabecular bone using inductively coupled plasma emission spectrometry (ICP) and the calcium concentration was determined using neutron activation method. In the group maintained on low Ca high Al diet, magnesium content of the spinal cord was lower than the group fed standard diet. Also, magnesium content of lumbar bone showed lower values in the unbalanced diet group fed low Ca high Al diet than those in the standard diet and low Ca diet groups. Calcium content of spinal cord was highest in rats maintained on low Ca high Al diet. Calcium content in lumbar bone of rats significantly decreased in rats maintained on the low Ca diet (group B and C) compared to rats given a standard diet (group A). Our data indicate that low Ca and high Al dietary intake influence Mg concentration in bone and central nervous system (CNS) tissues and that low Ca and high Al diet diminish Mg in bone and CNS tissues, thereby inducing loss of calcification in bone and degeneration of CNS tissues due to disturbance of the normal biological effects of Mg. (author)

  6. Preparation of amorphous calcium-magnesium phosphates at pH 7 and characterization by x-ray absorption and fourier transform infrared spectroscopy

    NARCIS (Netherlands)

    Holt, C.; Kemenade, M.J.J.M. van; Harries, J.E.; Nelson, L.S.; Bailey, R.T.; Hukins, D.W.L.; Hasnain, S.S.; Bruyn, P.L. de

    1988-01-01

    Amorphous calcium-magnesium phosphates were prepared by precipitation from moderately supersaturated aqueous solutions at pH 7. Chemical analysis of the samples by ion chromatography showed that up to about 50% of the phosphate ions were protonated, the proportion increasing with the magnesium to ca

  7. Effect of Spirulina maxima Supplementation on Calcium, Magnesium, Iron, and Zinc Status in Obese Patients with Treated Hypertension.

    Science.gov (United States)

    Suliburska, J; Szulińska, M; Tinkov, A A; Bogdański, P

    2016-09-01

    The effects of Spirulina maxima supplementation on calcium, magnesium, iron, and zinc status were studied in a double-blind placebo-controlled trial of 50 obese subjects with treated hypertension, each randomized to receive 2 g of spirulina or a placebo daily for 3 months. At baseline and after treatment, the calcium, magnesium, iron, and zinc concentration in plasma was assessed. It was found that 3 months of S. maxima supplementation resulted in a significant decrease in the iron level in the plasma of obese patients. In conclusion, this is the first clinical study on the influence of spirulina supplementation on mineral status in obese patients with hypertension. Spirulina supplementation affects the iron status of obese Caucasians with well-treated hypertension.

  8. Analysis of the effects of calcium or magnesium on voltage-clamp currents in perfused squid axons bathed in solutions of high potassium.

    Science.gov (United States)

    Rojas, E; Taylor, R E; Atwater, I; Bezanilla, F

    1969-10-01

    Isolated axons from the squid, Dosidicus gigas, were internally perfused with potassium fluoride solutions. Membrane currents were measured following step changes of membrane potential in a voltage-clamp arrangement with external isosmotic solution changes in the order: potassium-free artificial seawater; potassium chloride; potassium chloride containing 10, 25, 40 or 50, mM calcium or magnesium; and potassium-free artificial seawater. The following results suggest that the currents measured under voltage clamp with potassium outside and inside can be separated into two components and that one of them, the predominant one, is carried through the potassium system. (a) Outward currents in isosmotic potassium were strongly and reversibly reduced by tetraethylammonium chloride. (b) Without calcium or magnesium a progressive increase in the nontime-dependent component of the currents (leakage) occurred. (c) The restoration of calcium or magnesium within 15-30 min decreases this leakage. (d) With 50 mM divalent ions the steady-state current-voltage curve was nonlinear with negative resistance as observed in intact axons in isosmotic potassium. (e) The time-dependent components of the membrane currents were not clearly affected by calcium or magnesium. These results show a strong dependence of the leakage currents on external calcium or magnesium concentration but provide no support for the involvement of calcium or magnesium in the kinetics of the potassium system.

  9. Assessment of salivary calcium, phosphate, magnesium, pH, and flow rate in healthy subjects, periodontitis, and dental caries

    Directory of Open Access Journals (Sweden)

    K S Rajesh

    2015-01-01

    Full Text Available Aim: This study was conducted to estimate and compare inorganic salivary calcium, phosphate, magnesium, salivary flow rate, and pH of unstimulated saliva and oral hygiene status of healthy subjects, subjects with periodontitis and dental caries, and to correlate salivary calcium level with number of intact teeth. Materials and Methods: The study population consisted of 48 systemically healthy subjects in the age group of 18-55 years, which was further divided into three groups: healthy, periodontitis, and dental caries. Oral hygiene index-simplified, probing pocket depth, clinical attachment level, the number of intact teeth, and active carious lesions were recorded. Estimation of inorganic salivary calcium, phosphate, and magnesium was performed spectrophotometrically using Vitros 5.1 FS. Statistical analysis was performed using the one-way analysis of variance test at 5% significance level. Results: There was a statistically significant increase in inorganic salivary calcium, phosphate, pH, flow rate, and poor oral hygiene status in periodontitis group compared to dental caries and healthy group. Conclusion: Subjects with increased inorganic salivary calcium, phosphate, pH, flow rate, and poor oral hygiene are at a higher risk of developing periodontitis. Since there is increased remineralization potential, these subjects have more number of intact teeth compared to the dental caries group.

  10. Electrochemical characteristics of calcium-phosphatized AZ31 magnesium alloy in 0.9 % NaCl solution.

    Science.gov (United States)

    Hadzima, Branislav; Mhaede, Mansour; Pastorek, Filip

    2014-05-01

    Magnesium alloys suffer from their high reactivity in common environments. Protective layers are widely created on the surface of magnesium alloys to improve their corrosion resistance. This article evaluates the influence of a calcium-phosphate layer on the electrochemical characteristics of AZ31 magnesium alloy in 0.9 % NaCl solution. The calcium phosphate (CaP) layer was electrochemically deposited in a solution containing 0.1 M Ca(NO3)2, 0.06 M NH4H2PO4 and 10 ml l(-1) of H2O2. The formed surface layer was composed mainly of brushite [(dicalcium phosphate dihidrate (DCPD)] as proved by energy-dispersive X-ray analysis. The surface morphology was observed by scanning electron microscopy. Immersion test was performed in order to observe degradation of the calcium phosphatized surfaces. The influence of the phosphate layer on the electrochemical characteristics of AZ31, in 0.9 % NaCl solution, was evaluated by potentiodynamic measurements and electrochemical impedance spectroscopy. The obtained results were analysed by the Tafel-extrapolation method and equivalent circuits method. The results showed that the polarization resistance of the DCPD-coated surface is about 25 times higher than that of non-coated surface. The CaP electro-deposition process increased the activation energy of corrosion process.

  11. Effect Of Haemodialysis On Intra Dialytic Calcium, Phosphorus,Magnesium, Levels In Relation To AutonomicNervous System Activity

    Directory of Open Access Journals (Sweden)

    Mona Hosny, Sahar Shawky, Ahmed Ramadan , Hany Refaat

    2004-03-01

    Full Text Available Autonomic nervous system dysfunction is common in uremia and in patients under hemodialysis. Changes in serum calcium, serum phosphorus and serum magnesuim always occur during hemodialysis. The relation between these changes and autonomic nervous system activity during hemodialysis has not been fully studied. This study was carried out on 30 patients with chronic renal failure on regular hemo-dialysis with nearly similar age group. We measured serum calcium, serum phosphorus and serum magnesium throughout the session (at predialysis state, middialysis state: after 2 hours of the session and postdialysis: at the end of the hemodialysis Session. We have also assessed autonomic function (sympathetic by cold pressor test and parasympathetic by Valsalva maneuver test. Autonomic function tests were assessed at predialysis state, middialysis state and postdialysis state. Calcuim level uncreased throughout the session (P<0.05, phosphorus leuel and Magnesium levels decreased , (P<0.001 and (P<0.05, throghout session . As reguards parasympathetie dysfunetion, there was a significamt relation (P<0.05 with calcuim changes at predialytic and post dialytic states, a highly significant relation (P<0.001 with phosphorus and (P<0.05 with magnesiun, both at predialysis states. Concerging sympathetie dysfunction, there was a significant relation (P<0.05 with calcium levels at end of session. There was a signifcant relation (P<0.05 with predialytic and postdialytic phosphorus levels .There was also significant relation (P<0.05 with predialytic magnesium level.

  12. Association of dietary calcium, phosphorus, and magnesium intake with caries status among schoolchildren.

    Science.gov (United States)

    Lin, Han-Shan; Lin, Jia-Rong; Hu, Suh-Woan; Kuo, Hsiao-Ching; Yang, Yi-Hsin

    2014-04-01

    The aim of this study was to investigate the associations between caries experience and daily intake of calcium (Ca), phosphorus (P), magnesium (Mg), and Ca/P ratio. A total of 2248 schoolchildren were recruited based on a population-based survey. Each participant received a dental examination and questionnaire interviews about the 24-hour dietary recalls and food frequency. The daily intake of Ca, P, Mg, and Ca/P ratio were inversely associated with primary caries index, but only the Ca/P ratio remained significant after adjusting for potential confounders. According to the Taiwanese Dietary Reference Intakes, the Ca/P ratio was related to both caries in primary teeth (odds ratio = 0.52, p = 0.02) and in permanent teeth (odds ratio = 0.59, p = 0.02). The daily intakes of Ca/P ratio remained an important factor for caries after considering potential confounding factors.

  13. Calcium-Magnesium-Aluminosilicate (CMAS) Reactions and Degradation Mechanisms of Advanced Environmental Barrier Coatings

    Science.gov (United States)

    Ahlborg, Nadia L.; Zhu, Dongming

    2013-01-01

    The thermochemical reactions between calcium-magnesium-aluminosilicate- (CMAS-) based road sand and several advanced turbine engine environmental barrier coating (EBC) materials were studied. The phase stability, reaction kinetics and degradation mechanisms of rare earth (RE)-silicates Yb2SiO5, Y2Si2O7, and RE-oxide doped HfO2 and ZrO2 under the CMAS infiltration condition at 1500 C were investigated, and the microstructure and phase characteristics of CMAS-EBC specimens were examined using Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD). Experimental results showed that the CMAS dissolved RE-silicates to form crystalline, highly non-stoichiometric apatite phases, and in particular attacking the silicate grain boundaries. Cross-section images show that the CMAS reacted with specimens and deeply penetrated into the EBC grain boundaries and formed extensive low-melting eutectic phases, causing grain boundary recession with increasing testing time in the silicate materials. The preliminary results also showed that CMAS reactions also formed low melting grain boundary phases in the higher concentration RE-oxide doped HfO2 systems. The effect of the test temperature on CMAS reactions of the EBC materials will also be discussed. The faster diffusion exhibited by apatite and RE-doped oxide phases and the formation of extensive grain boundary low-melting phases may limit the CMAS resistance of some of the environmental barrier coatings at high temperatures.

  14. Chemical and mechanical consequences of environmental barrier coating exposure to calcium-magnesium-aluminosilicate.

    Energy Technology Data Exchange (ETDEWEB)

    Harder, B.; Ramirez-Rico, J.; Almer, J. D.; Kang, L.; Faber, K. (X-Ray Science Division); (NASA Glenn Research Center); (Univ. of Seville); (Rolls-Royce Corp.); (Northwestern Univ.)

    2011-06-01

    The success of Si-based ceramics as high-temperature structural materials for gas turbine applications relies on the use of environmental barrier coatings (EBCs) with low silica activity, such as Ba{sub 1-x}Sr{sub x}Al{sub 2}Si{sub 2}O{sub 8} (BSAS), which protect the underlying components from oxidation and corrosion in combustion environments containing water vapor. One of the current challenges concerning EBC lifetime is the effect of sandy deposits of calcium-magnesium-aluminosilicate (CMAS) glass that melt during engine operation and react with the EBC, changing both its composition and stress state. In this work, we study the effect of CMAS exposure at 1300 C on the residual stress state and composition in BSAS-mullite-Si-SiC multilayers. Residual stresses were measured in BSAS multilayers exposed to CMAS for different times using high-energy X-ray diffraction. Their microstructure was studied using a combination of scanning electron microscopy and transmission electron microscopy techniques. Our results show that CMAS dissolves the BSAS topcoat preferentially through the grain boundaries, dislodging the grains and changing the residual stress state in the topcoat to a nonuniform and increasingly compressive stress state with increasing exposure time. The presence of CMAS accelerates the hexacelsian-to-celsian phase transformation kinetics in BSAS, which reacts with the glass by a solution-reprecipitation mechanism. Precipitates have crystallographic structures consistent with Ca-doped celsian and Ba-doped anorthite.

  15. Calcium, copper, iron, magnesium, silicon and zinc content of hair in Parkinson's disease.

    Science.gov (United States)

    Forte, Giovanni; Alimonti, Alessandro; Violante, Nicola; Di Gregorio, Marco; Senofonte, Oreste; Petrucci, Francesco; Sancesario, Giuseppe; Bocca, Beatrice

    2005-01-01

    The aetiology of Parkinson's disease (PD) is still unknown, but some hypotheses have focused on the imbalances in body levels of metals as co-factors of risk. To assess whether hair could be a reliable marker of possible changes, calcium (Ca), copper (Cu), iron (Fe), magnesium (Mg), silicon (Si) and zinc (Zn) were determined in hair from 81 patients affected by PD and 17 age-matched controls. Care was taken to eliminate external contamination of the hair by thorough washing. Digestion of the matrix was achieved by an acid-assisted microwave procedure. Quantification of the elements was performed by inductively coupled plasma atomic emission spectrometry. Results indicated significantly lower levels of Fe in the hair of patients (p=0.018) compared with controls. Ca and Mg levels were slightly lower while Zn levels were higher in patients, although these differences were not significant; neither were variations in Cu and Si. Ca and Mg were at least 1.5 times higher in females than in males in both controls and patients. In addition, Ca correlated positively with Mg in both groups and in both sexes (p-value always less than 0.03), and negatively with age in patients (p<0.01). Finally, element levels did not correlate with either the duration or the severity of the disease or with anti-Parkinson treatment.

  16. 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 %.

  17. Synthesis, crystal structure and properties of magnesium and calcium salts of p-anisic acid

    Indian Academy of Sciences (India)

    Kiran T Dhavskar; Pooja H Bhargao; Bikshandarkoil R Srinivasan

    2016-03-01

    The synthesis, crystal structure and properties of the magnesium and calcium salts of p-anisic acid viz. [Mg(H2O)6](C8H7O3)2·2H2O (C8H7O3=p-anisate or 4-methoxybenzoate) (1) and [Ca(H2O)(C8H7O3)2] (2) are reported. The p-anisate ion is not coordinated to Mg(II) and functions as a charge balancing counter anion for the centrosymmetric octahedral [Mg(H2O)6]2+ unit in 1. The unique lattice water molecule links pairs of [Mg(H2O)6] 2+ cations and p-anisate anions with the aid of O-H···O interactions. The μ2-bridging bidentate and the μ3-bridging tetradentate binding modes of the crystallographically unique p-anisate ligands in (2) result in a two-dimensional (2-D) coordination polymer.

  18. Simultaneously detection of calcium and magnesium in various samples by calmagite and chemometrics data processing

    Science.gov (United States)

    Rasouli, Zolaikha; Ghavami, Raouf

    2016-12-01

    The current study describes results of the application of radial basis function-partial least squares (RBF-PLS), partial robust M-regression (PRM), singular value decomposition (SVD), evolving factor analysis (EFA), multivariate curve resolution with alternating least squares (MCR-ALS) and rank annihilation factor analysis (RAFA) methods for the purposes of simultaneous determination of trace amounts calcium (Ca2 +) and magnesium (Mg2 +) and exploratory analysis based on their colored complexes formation with 1-(1-hydroxy-4-methyl-2-phenylazo)-2-naphthol-4-sulfonic acid (calmagite) as chromomeric reagent. The complex formation Ca2 + and Mg2 + with calmagite was investigated under pH 10.20. The performance of RBF-PLS model in detection of minerals was compared with PRM as a linear model. The pure concentration and spectral profiles were obtained using MCR-ALS. EFA and SVD were used to distinguish the number species. The stability constants of the complexes were derived using RAFA. Finally, RBF-PLS was utilized for simultaneous determination of minerals in pharmaceutical formulation and various vegetable samples.

  19. Deep SDSS optical spectroscopy of distant halo stars II. Iron, calcium, and magnesium abundances

    CERN Document Server

    Fernández-Alvar, E; Schlesinger, K J; Beers, T C; Robin, A C; Schneider, D P; Lee, Y S; Bizyaev, D; Ebelke, G; Malanushenko, E; Malanushenko, V; Oravetz, D; Pan, K; Simmons, A

    2015-01-01

    We analyze a sample of 3,944 low-resolution (R ~ 2000) optical spectra from the Sloan Digital Sky Survey (SDSS), focusing on stars with effective temperatures 5800 < Teff < 6300 K, and distances from the Milky Way plane in excess of 5 kpc, and determine their abundances of Fe, Ca, and Mg. We followed the same methodology as in the previous paper in this series, deriving atmospheric parameters by chi2 minimization, but this time we obtained the abundances of individual elements by fitting their associated spectral lines. Distances were calculated from absolute magnitudes obtained by a statistical comparison of our stellar parameters with stellar-evolution models. The observations reveal a decrease in the abundances of iron, calcium, and magnesium at large distances from the Galactic center. The median abundances for the halo stars analyzed are fairly constant up to a Galactocentric distance r ~ 20 kpc, rapidly decrease between r ~ 20 and r ~ 40 kpc, and flatten out to significantly lower values at larger...

  20. In vivo degradation of low temperature calcium and magnesium phosphate ceramics in a heterotopic model.

    Science.gov (United States)

    Klammert, Uwe; Ignatius, Anita; Wolfram, Uwe; Reuther, Tobias; Gbureck, Uwe

    2011-09-01

    Bone replacement using synthetic and degradable materials is desirable in various clinical conditions. Most applied commercial materials are based on hydroxyapatite, which is not chemically degradable under physiological conditions. Here we report the effect of a long-term intramuscular implantation regime on the dissolution of various low temperature calcium and magnesium phosphate ceramics in vivo. The specimens were analysed by consecutive radiographs, micro-computed tomography scans, compressive strength testing, scanning electron microscopy and X-ray diffractometry. After 15months in vivo, the investigated materials brushite (CaHPO(4)·2H(2)O), newberyite (MgHPO(4)·3H(2)O), struvite (MgNH(4)PO(4)·6H(2)O) and hydroxyapatite (Ca(9)(PO(4))(5)HPO(4)OH) showed significant differences regarding changes of their characteristics. Struvite presented the highest loss of mechanical performance (95%), followed by newberyite (67%) and brushite (41%). This was accompanied by both a distinct extent of cement dissolution as well as changes of the phase composition of the retrieved cement implants. While the secondary phosphate phases (brushite, newberyite, struvite) completely dissolved, re-precipitates of whitlockite and octacalcium phosphate were formed in either particulate or whisker-like morphology. Furthermore, for the first time the possibility of a macropore-free volume degradation mechanism of bioceramics was demonstrated.

  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. Pedogenic and Anthropogenic Influence on Calcium and Magnesium Behaviors in Stagnic Anthrosols

    Institute of Scientific and Technical Information of China (English)

    JIANG Yong; ZHANG Yu-Ge; LIANG Wen-Ju; LI Qi

    2005-01-01

    The formation of Stagnic Anthrosols is closely related to rice planting and parent materials. Six representative pedons,two from each of three Stagnic Anthrosol subgroups, Vertic Haplic-, Vertic Gleyic-, and Sulfic Gleyic-Stagnic Anthrosols,from different parent materials and soil formation processes, from Liaoning Province, China, were selected and used along with additional supporting data to assess the potential impact in each soil subgroup combination of both pedogenic and anthropogenic factors on the migration and geochemical characteristics of calcium (Ca) and magnesium (Mg) and their relations to soil particle-size composition. Results revealed that exchangeable Mg was correlated positively with clay and silt content, but negatively with sand content, suggesting that clay and silt could retain more exchangeable Mg than sand. Also, in the six pedons exchangeable Ca/Mg ratios generally decreased with depth, which was most likely due to the preferential retention of Mg below the Ap1 horizon and the effects of bio-cycling in rice-soil systems. The pedons with high pH had smaller exchangeable Ca/Mg ratios than those with low pH. Thus, it was concluded that exchangeable Ca/Mg ratios could be helpful in classification of Stagnic Anthrosols.

  3. Properties of Calcium Acetate Manufactured with Etching Waste Solution and Limestone Sludge as a Cementitious High-Early-Strength Admixture

    Directory of Open Access Journals (Sweden)

    Deuck-Mo Kim

    2016-01-01

    Full Text Available Concrete is one of the most widely used construction materials. There are several methods available to improve its performance, with one of them being the use of high-early-strength admixtures (HESAs. Typical HESAs include calcium nitrate, calcium chloride, and calcium formate (CF. Industrial by-products, such as acetic acid and lime stone sludge (LSS, can be used together to produce calcium acetate (CA, which can subsequently be used as a cementitious HESA. In this study, calcium carbonate and LSS were mixed with cement in weight ratios of 1 : 1, 1 : 1.5, and 1 : 2, and the properties of the as-produced CA were evaluated. CA and CF were mixed with cement in different weight ratios (0, 1, 2, and 3 wt% to obtain CA- and CF-mortars, respectively. The flow behavior, setting time, pH, and compressive strength of these mortars were evaluated, and their X-ray diffraction patterns were also analyzed. It was found that as the CF content in the CF-mortar increased, the initial strength of the mortar also increased. However, it impaired its long-term strength. On the other hand, when 1% CA was mixed with cement, satisfactory early and long-term strengths were achieved. Thus, CA, which is obtained from industrial by-products, can be an effective HESA.

  4. Synthesis, characterization, and in-vitro cytocompatibility of amorphous β-tri-calcium magnesium phosphate ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Satish S., E-mail: sss42@pitt.edu [Department of Chemical & Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Roy, Abhijit, E-mail: abr20@pitt.edu [Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Lee, Boeun, E-mail: bol11@pitt.edu [Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Banerjee, Ipsita [Department of Chemical & Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Kumta, Prashant N., E-mail: pkumta@pitt.edu [Department of Chemical & Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Center for Craniofacial Regeneration, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Department of Mechanical Engineering and Materials Science, University of Pittsburgh, PA 15261 (United States)

    2016-10-01

    Biphasic mixtures of crystalline β-tricalcium magnesium phosphate (β-TCMP) and an amorphous calcium magnesium phosphate have been synthesized and reported to support enhanced hMSC differentiation in comparison to β-tricalcium phosphate (β-TCP) due to the release of increased amounts of bioactive ions. In the current study, completely amorphous β-TCMP has been synthesized which is capable of releasing increased amounts of Mg{sup 2+} and PO{sub 4}{sup 3−} ions, rather than a biphasic mixture as earlier reported. The amorphous phase formed was observed to crystallize between temperatures of 400–600 °C. The scaffolds prepared with amorphous β-TCMP were capable of supporting enhanced hMSC proliferation and differentiation in comparison to commercially available β-TCP. However, a similar gene expression of mature osteoblast markers, OCN and COL-1, in comparison to biphasic β-TCMP was observed. To further study the role of Mg{sup 2+} and PO{sub 4}{sup 3−} ions in regulating hMSC osteogenic differentiation, the capability of hMSCs to mineralize in growth media supplemented with Mg{sup 2+} and PO{sub 4}{sup 3−} ions was studied. Interestingly, 5 mM PO{sub 4}{sup 3−} supported mineralization while the addition of 5 mM Mg{sup 2+} to 5 mM PO{sub 4}{sup 3−} inhibited mineralization. It was therefore concluded that the release of Ca{sup 2+} ions from β-TCMP scaffolds also plays a role in regulating osteogenic differentiation on these scaffolds and it is noted that further work is required to more accurately determine the exact role of Mg{sup 2+} in regulating hMSC osteogenic differentiation. - Highlights: • Synthesis of amorphous Mg containing beta tricalcium phosphate ceramics • Amorphous beta TCMP supports enhanced hMSC proliferation and differentiation. • Amorphous beta TCMP shows comparable OCN and COL-1 expression to biphasic TCMP. • Presence of 5 mM Mg{sup 2+} and PO{sub 4}{sup 3−} ions in growth media inhibits hMSC mineralization.

  5. 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.

  6. Are cyclopentadienylberyllium, magnesium and calcium hydrides carbon or metal acids in the gas phase?

    Science.gov (United States)

    Hurtado, Marcela; Lamsabhi, Al-Mokhtar; Mó, Otilia; Yáñez, Manuel; Guillemin, Jean-Claude

    2010-05-21

    The structure and bonding of cyclopentadienylberyllium (CpBeH), magnesium (CpMgH), and calcium (CpCaH) hydrides as well as those of their deprotonated species have been investigated by means of B3LYP/6-311+G(3df,2p)//B3LYP/6-311+G(d,p) and B3LYP/6-311+G(3df,2p)//QCISD/6-311+G(d,p) density functional theory (DFT) calculations. The three compounds exhibit C(5v) equilibrium conformations in their ground states. For CpBeH the agreement between the calculated geometry and that determined by MW spectroscopy is excellent. CpMgH and CpCaH can be viewed almost as the result of the interaction between a C₅H₅⁻ anion and a XH(+) (X = Mg, Ca) cation. Conversely, for CpBeH the interaction between the C₅H₅ and the BeH subunits is significantly covalent. These compounds exhibit a significant aromaticity, usually named three-dimension aromaticity, in contrast with the unsubstituted cyclopentadiene compound. The CpBeH derivative behaves as a C acid in the gas phase and is less acidic than cyclopentadiene. More importantly, CpMgH and CpCaH, in spite of the X(+δ)H(-δ) polarity exhibited by the X-H bond in the neutral systems, are predicted to be metal acids in the gas phase. Also surprisingly, both the Mg and the Ca derivatives are stronger acids than the Be analogue, and only slightly weaker acids than cyclopentadiene. This somewhat unexpected result is the consequence of two concomitant facts: the lower dissociation energy of the X-H (X = Mg, Ca) bonds with respect to the C-H bonds, and the significantly high electron affinity of the C₅H₅X* (X = Mg, Ca) radicals.

  7. Determination of calcium, magnesium and zinc in lubricating oils by flame atomic absorption spectrometry using a three-component solution.

    Science.gov (United States)

    Zmozinski, Ariane V; de Jesus, Alexandre; Vale, Maria G R; Silva, Márcia M

    2010-12-15

    Lubricating oils are used to decrease wear and friction of movable parts of engines and turbines, being in that way essential for the performance and the increase of that equipment lifespan. The presence of some metals shows the addition of specific additives such as detergents, dispersals and antioxidants that improve the performance of these lubricants. In this work, a method for determination of calcium, magnesium and zinc in lubricating oil by flame atomic absorption spectrometry (F AAS) was developed. The samples were diluted with a small quantity of aviation kerosene (AVK), n-propanol and water to form a three-component solution before its introduction in the F AAS. Aqueous inorganic standards diluted in the same way have been used for calibration. To assess the accuracy of the new method, it was compared with ABNT NBR 14066 standard method, which consists in diluting the sample with AVK and in quantification by F AAS. Two other validating methods have also been used: the acid digestion and the certified reference material NIST (SRM 1084a). The proposed method provides the following advantages in relation to the standard method: significant reduction of the use of AVK, higher stability of the analytes in the medium and application of aqueous inorganic standards for calibration. The limits of detection for calcium, magnesium and zinc were 1.3 μg g(-1), 0.052 μg g(-1) and 0.41 μg g(-1), respectively. Concentrations of calcium, magnesium and zinc in six different samples obtained by the developed method did not differ significantly from the results obtained by the reference methods at the 95% confidence level (Student's t-test and ANOVA). Therefore, the proposed method becomes an efficient alternative for determination of metals in lubricating oil.

  8. Simultaneous measurements of magnesium, calcium and sodium influxes in perfused squid giant axons under membrane potential control.

    Science.gov (United States)

    Rojas, E; Taylor, R E

    1975-10-01

    1. Giant axons from the squids Dosidicus gigas, Loligo forbesi and Loligo vulgaris were internally perfused with 550 or 275 mM KF plus sucrose and bathed in artificial sea water containing 45Ca, 28Mg or mixtures of 45Ca-28Mg or 45Ca-22Na. Resting influxes and extra influxes during voltage-clamp pulses were measured by collecting and counting the internal perfusate. 2. For Dosidicus axons in 10 mM-CaCl2 the resting influx of calcium was 0-016 +/- 0-007 p-mole/cm2 sec and a linear function of external concentration. For two experiments in 10 and 84-7 mM-CaCl2, 100 nM tetrodotoxin had no effect. Resting calcium influx in 10 mM-CaCl2 was 0-017 +/- 0-013 p-mole/cm2 sec for Loligo axons. 3. With 55 mM-MgCl2 outside the average resting magnesium influx was 0-124 +/- 0-080 p-mole/cm2 sec for Loligo axons. Discarding one aberrant point the value is 0-105 +/- 0-046 which is not significantly different from the resting calcium influx for Dosidicus fibres in 55 mM-CaCl2, given as 0-094 p-mole/cm2 sec by the regression line shown in Fig. 1. In two experiments 150 nM tetrodotoxin had no effect. 4. With 430 mM-NaCl outside 100 nM tetrodotoxin reduced the average resting influx of sodium in Dosidicus axon from 27-7 +/- 4-5 to 25-1 +/- 6-2 p-mole/cm2 sec and for Loligo fibres in 460 mM-NaCl from 50-5 +/- 4 to 20 +/- 8 p-mole/cm2 sec. 5. Using depolarizing pulses of various durations, the extra calcium influx occurred in two phases. The early phase was eliminated by external application of tetrodotoxin. The results of analysis are consistent with, but do not rigorously demonstrate, the conclusion that the tetrodotoxin sensitive calcium entry is flowing through the normal sodium channels (cf. Baker, Hodgkin & Ridgway, 1971). 6. Measurements of extra influxes using 22Na and 45Ca simultaneously indicate that the time courses of tetrodotoxin sensitive calcium and sodium entry are similar but not necessarily identical. It is very doubtful that any significant calcium entry occurs before

  9. Associations of intakes of magnesium and calcium and survival among women with breast cancer: results from Western New York Exposures and Breast Cancer (WEB) Study.

    Science.gov (United States)

    Tao, Meng-Hua; Dai, Qi; Millen, Amy E; Nie, Jing; Edge, Stephen B; Trevisan, Maurizio; Shields, Peter G; Freudenheim, Jo L

    2016-01-01

    Magnesium (Mg) and calcium (Ca) antagonizes each other in (re) absorption, cell cycle regulation, inflammation, and many other physiologic activities. However, few studies have investigated the association between magnesium and calcium intakes and breast cancer survival, and the interaction between calcium and magnesium intake. In a cohort of 1,170 women with primary, incident, and histologically confirmed breast cancer from Western New York State, we examined the relationship between intakes of these two minerals and survival. Cox regression models were used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI). Mean follow-up time was 87.4 months after breast cancer diagnosis; there were 170 deaths identified. After adjustment for known prognostic factors, and intakes of energy, total vitamin D and total calcium, higher dietary intake of magnesium was inversely associated with risk of all-cause mortality (HR = 0.50, 95% CI, 0.28-0.90 for highest vs. lowest tertile; p trend = 0.02). Likewise, a marginal association was found for total Magnesium intake from foods and supplements combined (HR = 0.58, 95% CI, 0.31-1.08; p trend = 0.09). The inverse association of higher total magnesium intake with all-cause mortality was primarily presented among postmenopausal women and was stronger among women who had a high Ca:Mg intake ratio (>2.59). There were no clear associations for prognosis with intake of calcium. We found that magnesium intake alone may improve overall survival following breast cancer, and the association may be stronger among those with high Ca:Mg intake ratio.

  10. EFFECT OF LIMING AND USE OF WASTE ORGANIC MATERIALS ON THE CONTENTS OF CALCIUM AND MAGNESIUM IN COCK’S-FOOT CULTIVATED ON NICKEL-CONTAMINATED SOIL

    Directory of Open Access Journals (Sweden)

    Beata Kuziemska

    2016-05-01

    Full Text Available The effect of liming and the addition to soil of waste organic materials on the contents of calcium and magnesium in cock’s-foot (Dactylis glomerata L. cultivated on soil contaminated to various degrees with nickel was studied in a pot culture experiment. Plants from four cuts of grass were analysed in the third year of the study. The following factors were taken into account: 1 – contamination of soils with nickel (0, 75, 150 and 225 mg N·kg-1 of soil; 2 – liming (0 Ca and Ca according to Hh of soil; 3 – waste organic materials (no waste organic materials added, brown coal and rye straw. With increasing nickel content in soil, the magnesium content in biomass of the test plant decreased. The applied liming resulted in an increase in the average calcium content and a decrease in the magnesium content in cock’s-foot. No significant effect of introducing straw to soil on the contents of calcium and magnesium in biomass of the grass was found, while the effect of brown coal was visible both for calcium and for magnesium (in the plants harvested from the objects to which brown coal was applied, the contents of both macroelements were, on average, lower than in the plants harvested from the control objects.

  11. Effect of low ambient mineral concentrations on the accumulation of calcium, magnesium and phosphorus by early life stages of the air-breathing armoured catfish Megalechis personata (Siluriformes; Callichthyidae)

    NARCIS (Netherlands)

    Mol, J.H.; Atsma, W.; Flik, G.; Bouwmeester, H.; Osse, J.W.M.

    1999-01-01

    he accumulation of calcium, magnesium and phosphorus was measured during an 8-week period in the early life stages of the air-breathing armoured catfish Megalechis personata acclimated to low-mineral fresh water (0.073 mmol l-1 calcium, 0.015 mmol l-1 magnesium, <0.001 mmol l-1 phosphate) and high-m

  12. Surface properties of calcium and magnesium oxide nanopowders grafted with unsaturated carboxylic acids studied with inverse gas chromatography.

    Science.gov (United States)

    Maciejewska, Magdalena; Krzywania-Kaliszewska, Alicja; Zaborski, Marian

    2012-09-28

    Inverse gas chromatography (IGC) was applied at infinite dilution to evaluate the surface properties of calcium and magnesium oxide nanoparticles and the effect of surface grafted unsaturated carboxylic acid on the nanopowder donor-acceptor characteristics. The dispersive components (γ(s)(D)) of the free energy of the nanopowders were determined by Gray's method, whereas their tendency to undergo specific interactions was estimated based on the electron donor-acceptor approach presented by Papirer. The calcium and magnesium oxide nanoparticles exhibited high surface energies (79 mJ/m² and 74 mJ/m², respectively). Modification of nanopowders with unsaturated carboxylic acids decreased their specific adsorption energy. The lowest value of γ(s)(D) was determined for nanopowders grafted with undecylenic acid, approximately 55 mJ/m². The specific interactions were characterised by the molar free energy (ΔG(A)(SP)) and molar enthalpy (ΔH(A)(SP)) of adsorption as well as the donor and acceptor interaction parameters (K(A), K(D)).

  13. Self-setting bioactive calcium-magnesium phosphate cement with high strength and degradability for bone regeneration.

    Science.gov (United States)

    Wu, Fan; Wei, Jie; Guo, Han; Chen, Fangping; Hong, Hua; Liu, Changsheng

    2008-11-01

    Calcium phosphate cement (CPC) has been successfully used in clinics as bone repair biomaterial for many years. However, poor mechanical properties and a low biodegradation rate limit any further applications. Magnesium phosphate cement (MPC) is characterized by fast setting, high initial strength and relatively rapid degradation in vivo. In this study, MPC was combined with CPC to develop novel calcium-magnesium phosphate cement (CMPC). The setting time, compressive strength, phase composition of hardened cement, degradation in vitro, cells responses in vitro by MG-63 cell culture and tissue responses in vivo by implantation of CMPC in bone defect of rabbits were investigated. The results show that CMPC has a shorter setting time and markedly better mechanical properties than either CPC or MPC. Moreover, CMPC showed significantly improved degradability compared to CPC in simulated body fluid. Cell culture results indicate that CMPC is biocompatible and could support cell attachment and proliferation. To investigate the in vivo biocompatibility and osteogenesis, the CMPC samples were implanted into bone defects in rabbits. Histological evaluation showed that the introduction of MPC into CPC enhanced the efficiency of new bone formation. CMPC also exhibited good biocompatibility, biodegradability and osteoconductivity with host bone in vivo. The results obtained suggest that CMPC, having met the basic requirements of bone tissue engineering, might have a significant clinical advantage over CPC, and may have the potential to be applied in orthopedic, reconstructive and maxillofacial surgery.

  14. Magnesium modification of a calcium phosphate cement alters bone marrow stromal cell behavior via an integrin-mediated mechanism.

    Science.gov (United States)

    Zhang, Jing; Ma, Xiaoyu; Lin, Dan; Shi, Hengsong; Yuan, Yuan; Tang, Wei; Zhou, Huanjun; Guo, Han; Qian, Jiangchao; Liu, Changsheng

    2015-06-01

    The chemical composition, structure and surface characteristics of biomaterials/scaffold can affect the adsorption of proteins, and this in turn influences the subsequent cellular response and tissue regeneration. With magnesium/calcium phosphate cements (MCPC) as model, the effects of magnesium (Mg) on the initial adhesion and osteogenic differentiation of bone marrow stromal cells (BMSCs) as well as the underlying mechanism were investigated. A series of MCPCs with different magnesium phosphate cement (MPC) content (0∼20%) in calcium phosphate cement (CPC) were synthesized. MCPCs with moderate proportion of MPC (5% and 10%, referred to as 5MCPC and 10MCPC) were found to effectively modulate the orientation of the adsorbed fibronectin (Fn) to exhibit enhanced receptor binding affinity, and to up-regulate integrin α5β1 expression of BMSCs, especially for 5MCPC. As a result, the attachment, morphology, focal adhesion formation, actin filaments assembly and osteogenic differentiation of BMSCs on 5MCPC were strongly enhanced. Further in vivo experiments confirmed that 5MCPC induced promoted osteogenesis in comparison to ot her CPC/MCPCs. Our results also suggested that the Mg on the underlying substrates but not the dissolved Mg ions was the main contributor to the above positive effects. Based on these results, it can be inferred that the specific interaction of Fn and integrin α5β1 had predominant effect on the MCPC-induced enhanced cellular response of BMSCs. These results provide a new strategy to regulate BMSCs adhesion and osteogenic differentiation by adjusting the Mg/Ca content and distribution in CPC, guiding the development of osteoinductive scaffolds for bone tissue regeneration.

  15. Study on Producing Magnesium Hydroxide by Concentrated Seawater- calcium Method%浓海水-钙法制取氢氧化镁工艺研究

    Institute of Scientific and Technical Information of China (English)

    高春娟; 张雨山; 黄西平; 蔡荣华

    2011-01-01

    Calcium method ( light burned dolomite and lime) producing magnesium hydroxide from concentrated seawater of desalination plant has advantages of low producing cost and rich resources. However, magnesium hydroxide produced by traditional calcium method has high -content impurities and low purity. Based on patent technology developing independently, the technology of concentrated seawater - calcium method producing magnesium hydroxide was improved in raw material pretreatment, magnesium hydroxide synthesis, calcium sulfate precipitation and precipitate washing. The results showed that the quantities of magnesium hydroxide produced by new technology accord with industry standard, while the content of calcium oxide is reduced significantly. Meanwhile, high quantity byproduct calcium sulfate was obtained.%浓海水一钙法(轻烧白云石、石灰)制取氢氧化镁具有生产成本低、资源丰富的优势,但传统钙法生产的氢氧化镁存在杂质含量高、产品纯度低等缺陷.文章以自主研发的专利技术为基础,从原料预处理、氢氧化镁合成、硫酸钙沉降、沉淀洗涤等方面对浓海水-钙法制取氢氧化镁的工艺进行改进.结果表明,采用改进后的工艺制备的氢氧化镁质量符合行业标准要求,氧化钙含量明显降低,同时得到高质量的副产硫酸钙.

  16. Relationship between tap water hardness, magnesium, and calcium concentration and mortality due to ischemic heart disease or stroke in the Netherlands

    NARCIS (Netherlands)

    Leurs, L.J.; Schouten, L.J.; Mons, M.N.; Goldbohm, R.A.; Brandt, P.A. van den

    2010-01-01

    BACKGROUND: Conflicting results on the relationship between the hardness of drinking water and mortality related to ischemic heart disease (IHD) or stroke have been reported. OBJECTIVES: We investigated the possible association between tap water calcium or magnesium concentration and total hardness

  17. Time bound changes (in 24 h in human sperm motility and level of calcium and magnesium in seminal plasma

    Directory of Open Access Journals (Sweden)

    J. Valsa

    2016-09-01

    Level of calcium (27.2 mg/dl and magnesium (13.54 mg/dl in seminal plasma did not show any significant changes during study period from that of at ½ h. The study concluded that electrolytes under study were not responsible for the decrease in motility during study period.

  18. Microstructure characterization and micro- and nanoscale mechanical behaviour of magnesium-aluminum and magnesium-aluminum-calcium alloys

    Science.gov (United States)

    Han, Lihong

    The application in the automotive industry of the as-cast AM50 alloy (Mg-5.0 wt.%%Al-0.3 wt.%Mn) has been limited by its low creep resistance at elevated temperatures. Permanent mold cast (PM) Mg-Al-Ca alloys with calcium additions (0 ˜ 2.0 wt.%) were investigated in this study due to their potential for improving the high temperature creep strength. The microstructures of the die cast (DC) or PM AM50 alloys consisted of an intergranular beta-Mg17Al12 phase surrounded by a region of Al-rich eutectic alpha-Mg phase, sometimes with attached Al8Mn5 particles. In this study, significant grain refinement was observed in the PM Mg-Al-Ca alloys with Ca addition to the AM50 alloy. The grain refining effect was confirmed by quantitative image analysis through measurement of the secondary dendrite arm spacing (SDAS). The intergranular phases in Mg-Al-Ca alloys with 0.5 or 1.0 wt.% Ca were beta-Mg17Al 12 and (Al, Mg)2Ca phases. As the Ca addition was increased to 1.5 wt.% Ca, the (beta-Mg17Al12 phase was completely replaced by a (Al, Mg)2Ca phase. Differential scanning calorimetry (DSC) results showed that the (Al, Mg)2Ca phase was thermally more stable than the beta-Mg 17Al12 phase, which contributed to the better creep strength of the Mg-Al-Ca alloys. The change in heating/cooling rates played an important role in the redistribution of alloying elements and the dissolution or precipitation of the eutectic phases in the as-cast Mg alloys during DSC runs. The micro- and nano-scale hardness and composite modulus of the PM Mg-Al-Ca alloys increased with increasing Ca content, and the indentation size effect (ISE) was also observed in the as-cast Mg-Al and Mg-Al-Ca alloys. PM AC52 alloy (Mg-5.0wt.%Al-2.0wt.%Ca) was a much more creep resistant alloy than other Mg-Al-Ca alloys with lower Ca contents because of the higher solute content in the primary alpha-Mg in the as-cast state and also because of the presence of nano precipitates within the primary alpha-Mg. The size and

  19. A grid of NLTE corrections for magnesium and calcium in late-type giant and supergiant stars: application to Gaia

    CERN Document Server

    Merle, Thibault; Pichon, Bernard; Bigot, Lionel

    2011-01-01

    We investigate NLTE effects for magnesium and calcium in the atmospheres of late-type giant and supergiant stars. The aim of this paper is to provide a grid of NLTE/LTE equivalent width ratios W/W* of Mg and Ca lines for the following range of stellar parameters: Teff in [3500, 5250] K, log g in [0.5, 2.0] dex and [Fe/H] in [-4.0, 0.5] dex. We use realistic model atoms with the best physics available and taking into account the fine structure. The Mg and Ca lines of interest are in optical and near IR ranges. A special interest concerns the lines in the Gaia spectrograph (RVS) wavelength domain [8470, 8740] A. The NLTE corrections are provided as function of stellar parameters in an electronic table as well as in a polynomial form for the Gaia/RVS lines.

  20. Neutron and X-ray diffraction and empirical potential structure refinement modelling of magnesium stabilised amorphous calcium carbonate

    DEFF Research Database (Denmark)

    Cobourne, G.; Mountjoy, G.; Rodriguez Blanco, Juan Diego

    2014-01-01

    from CO3 molecules and 0.6 oxygen atoms from H2O molecules. The average CaO bond length is 2.40 Å. The distribution of Ca in the model is homogeneous with a uniformly distributed Ca-rich network and no evidence of the Ca-poor channels as previously reported for a reverse Monte Carlo model of ACC......Amorphous calcium carbonate (ACC) plays a key role in biomineralisation processes in sea organisms. Neutron and X-ray diffraction have been performed for a sample of magnesium-stabilised ACC, which was prepared with a Mg:Ca ratio of 0.05:1 and 0.25 H2O molecules per molecule of CO3. The empirical...... potential structure refinement method has been used to make a model of magnesium-stabilised ACC and the results revealed a fair agreement with the experimental diffraction data. The model has well-defined CO3 and H2O molecules. The average coordination number of Ca is 7.4 and is composed of 6.8 oxygen atoms...

  1. Preparation and characterization of bioactive and degradable composites containing ordered mesoporous calcium-magnesium silicate and poly(L-lactide)

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Jiajin [Key Shanghai Key Laboratory of Advanced Polymeric Materials, East China University of Science and Technology, Shanghai 200237 (China); Dong, Xieping, E-mail: jxzhyxh@163.com [Department of Orthopaedic Surgery, Jiangxi People' s Hospital, Nanchang 330006 (China); Ma, Xuhui [Polymer Science (Shenzhen) New Materials Co., Ltd., Shenzhen 518101 (China); Tang, Songchao, E-mail: schtang@ecust.edu.cn [Key Shanghai Key Laboratory of Advanced Polymeric Materials, East China University of Science and Technology, Shanghai 200237 (China); Wu, Zhaoying; Xia, Ji; Wang, Quanxiang; Wang, Yutao; Wei, Jie [Key Shanghai Key Laboratory of Advanced Polymeric Materials, East China University of Science and Technology, Shanghai 200237 (China)

    2014-10-30

    Highlights: • Mesoporous calcium-magnesium silicate and poly(L-lactide) composite was fabricated. • The composite has good hydrophilicity, in vitro degradation and bioactivity. • The composite could support cell attachment, proliferation and differentiation. - Abstract: Polylactide (PLA) and its copolymers have been widely used for bone tissue regeneration. In this study, a bioactive composite of ordered mesoporous calcium–magnesium silicate (m-CMS) and poly(L-lactide) (PLLA) was fabricated by melt blending method. The results indicated that the m-CMS particles were entrapped by polymer phase, and crystallinity of PLLA significantly decreased while the thermal stability of the m-CMS/PLLA composites was not obviously affected by addition of the m-CMS into PLLA. In addition, compared to PLLA, incorporation of the m-CMS into PLLA significantly improved the hydrophilicity, in vitro degradability and bioactivity (apatite-formation ability) of the m-CMS/PLLA composite, which were m-CMS content dependent. Moreover, it was found that incorporation of the m-CMS into PLLA could neutralize the acidic degradation by-products and thus compensated for the decrease of pH value. In cell culture experiments, the results showed that the composite enhanced attachment, proliferation and alkaline phosphatase activity (ALP) of MC3T3-E1 cells, which were m-CMS content dependent. The results indicated that the addition of bioactive materials to PLLA could result in a composite with improved properties of hydrophilicity, degradability, bioactivity and cytocompatibility.

  2. Changes in Sodium, Calcium, and Magnesium Ion Concentrations That Inhibit Geobacillus Biofilms Have No Effect on Anoxybacillus flavithermus Biofilms.

    Science.gov (United States)

    Somerton, B; Lindsay, D; Palmer, J; Brooks, J; Flint, S

    2015-08-01

    This study investigated the effects of varied sodium, calcium, and magnesium concentrations in specialty milk formulations on biofilm formation by Geobacillus spp. and Anoxybacillus flavithermus. The numbers of attached viable cells (log CFU per square centimeter) after 6 to 18 h of biofilm formation by three dairy-derived strains of Geobacillus and three dairy-derived strains of A. flavithermus were compared in two commercial milk formulations. Milk formulation B had relatively high sodium and low calcium and magnesium concentrations compared with those of milk formulation A, but the two formulations had comparable fat, protein, and lactose concentrations. Biofilm formation by the three Geobacillus isolates was up to 4 log CFU cm(-2) lower in milk formulation B than in milk formulation A after 6 to 18 h, and the difference was often significant (P ≤ 0.05). However, no significant differences (P ≤ 0.05) were found when biofilm formations by the three A. flavithermus isolates were compared in milk formulations A and B. Supplementation of milk formulation A with 100 mM NaCl significantly decreased (P ≤ 0.05) Geobacillus biofilm formation after 6 to 10 h. Furthermore, supplementation of milk formulation B with 2 mM CaCl2 or 2 mM MgCl2 significantly increased (P ≤ 0.05) Geobacillus biofilm formation after 10 to 18 h. It was concluded that relatively high free Na(+) and low free Ca(2+) and Mg(2+) concentrations in milk formulations are collectively required to inhibit biofilm formation by Geobacillus spp., whereas biofilm formation by A. flavithermus is not impacted by typical cation concentration differences of milk formulations.

  3. Concentration changeability of phosphorus, calcium and magnesium in selected partial drainage basins of the River Drwęca

    Directory of Open Access Journals (Sweden)

    Pius Bożena

    2015-12-01

    Full Text Available The paper presents the results of the research conducted between November 2008 and October 2009. The research included seasonal dynamics of the flow and runoff of phosphorus compounds (TP and P-PO43-, as well as Ca2+ and Mg2+ from 13 partial drainage basins of the River Drwęca. Water levels were registered automatically every day by recorders, and measurements of the flow were conducted once a month. Major differences were found in the water abundance as indicated by specific discharges in individual, partial drainage basins: from 1.87 dm3 s-1 km-2 (Lubianka - a lower part of the River Drwęca drainage basin to 8.22 dm3 s-1 km-2 (Gizela - an upper part of the River Drwęca drainage basin. The studied rivers were characterised by very diverse average content of total phosphorus compounds: from 0.047 mg dm-3 (Iłga to 0.816 mg dm-3 (Sandela; calcium: from 47.18 mg dm-3 (Iłga to 131.65 mg dm-3 (Trynka; and magnesium: from 9.71 mg dm-3 (Wel to 36.76 mg dm-3 (Struga Rychnowska. Analysis of variance carried out on hydrochemical properties of the studied rivers divides the rivers into two separate groups: rivers with much higher content of phosphorus, calcium and magnesium compounds (Struga Rychnowska, Trynka, Ruziec, Lubianka, Kujawka, Sandela and Gizela, and a group of rivers with low content of these compounds (Brynica, Brodniczanka, Skarlanka, Wel, Iłga.

  4. Crystal structure of the magnesium salt of the herbicide 2,4-D: pentaaqua[(2,4-dichlorophenoxy)acetato-κO]magnesium (2,4-dichlorophenoxy)acetate hemihydrate

    OpenAIRE

    2014-01-01

    In the crystal structure of the title magnesium salt of the phenoxy herbicide (2,4-dichlorophenoxy)acetic acid (2,4-D), [Mg(C8H5Cl2O3)(H2O)5](C8H5Cl2O3)·0.5H2O, the discrete cationic MgO6 complex unit comprises a carboxylate O-donor from a monodentate 2,4-D anionic ligand and five water molecules, resulting in a slightly distorted octahedral coordination sphere. The free 2,4-D anions are linked to the complex units through duplex water–carboxylate O—H...O hydrogen bonds through the coordinati...

  5. Microwave assisted synthesis and characterization of magnesium substituted calcium phosphate bioceramics.

    Science.gov (United States)

    Khan, Nida Iqbal; Ijaz, Kashif; Zahid, Muniza; Khan, Abdul S; Abdul Kadir, Mohammed Rafiq; Hussain, Rafaqat; Anis-Ur-Rehman; Darr, Jawwad A; Ihtesham-Ur-Rehman; Chaudhry, Aqif A

    2015-11-01

    Hydroxyapatite is used extensively in hard tissue repair due to its biocompatibility and similarity to biological apatite, the mineral component of bone. It differs subtly in composition from biological apatite which contains other ions such as magnesium, zinc, carbonate and silicon (believed to play biological roles). Traditional methods of hydroxyapatite synthesis are time consuming and require strict reaction parameter control. This paper outlines synthesis of magnesium substituted hydroxyapatite using simple microwave irradiation of precipitated suspensions. Microwave irradiation resulted in a drastic decrease in ageing times of amorphous apatitic phases. Time taken to synthesize hydroxyapatite (which remained stable upon heat treatment at 900°C for 1h) reduced twelve folds (to 2h) as compared to traditionally required times. The effects of increasing magnesium concentration in the precursors on particle size, surface area, phase-purity, agglomeration and thermal stability, were observed using scanning electron microscopy, BET surface area analysis, X-ray diffraction and photo acoustic Fourier transform infra-red spectroscopy. Porous agglomerates were obtained after a brief heat-treatment (1h) at 900°C.

  6. 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.

  7. Dietary magnesium, not calcium, prevents vascular calcification in a mouse model for pseudoxanthoma elasticum

    OpenAIRE

    Gorgels, Theo; Waarsing, Jan; Wolf, Anneke; Brink, Jacoline; Loves, Willem; Bergen, Arthur

    2010-01-01

    textabstractPseudoxanthoma elasticum (PXE) is a heritable disorder characterized by ectopic calcification of connective tissue in skin, Bruch's membrane of the eye, and walls of blood vessels. PXE is caused by mutations in the ABCC6 gene, but the exact etiology is still unknown. While observations on patients suggest that high calcium intake worsens the clinical symptoms, the patient organization PXE International has published the dietary advice to increase calcium intake in combination with...

  8. Rapid Inhibition of the Glutamate-induced Increase of Intracellular Free Calcium by Magnesium in Rat Hippocampal Neurons

    Institute of Scientific and Technical Information of China (English)

    张蕲; 胡波; 孙圣刚; 邓学军; 梅元武; 童萼塘

    2004-01-01

    By using Fura-2/AM, the effects of magnesium (Mg2+) on the glutamate-induced increase of intracellular free calcium ([Ca2+]i) in the cultured hippocampal neurons and the features were investigated by integrated photoelectric detecting system. The experiments were designed to three groups (The drug was spit to the cells for 20 s): Group A receiving 1×10-5 mol/L glutamate; Group B receiving 1 × 10-5 mol/L glutamate and1× 10-5 mol/L Mg2+ simultaneously; Group C receiving 1 × 10-5 mol/L glutamate again after [Ca2+]i in group B back to the baseline. The results showed that in group A, [Ca2+]i was obviously increased. In group B, the changes in [Ca2+]i and the peak value were significantly decreased. Moreover, the elevation of Phase 1 was slowed down and Phase 2 was shortened to some extent, and the plateau phase between them was relatively prolonged. In group C, calcium oscillation similar to that in group A occurred, but both the Phase 1 and Phase 2 were shortened and the △[Ca2+]i was slightly decreased. It was suggested that Mg2+ could quickly inhibit the rise of [Ca2+]i induced by glutamate in the cultured hippocampal neurons in rats.

  9. The role of calcium in growth induced by indole-3-acetic acid and gravity in the leaf-sheath pulvinus of oat (Avena sativa)

    Science.gov (United States)

    Brock, T. G.; Burg, J.; Ghosheh, N. S.; Kaufman, P. B.

    1992-01-01

    Leaf-sheath pulvini of excised segments from oat (Avena sativa L.) were induced to grow by treatment with 10 micromoles indole-3-acetic acid (IAA), gravistimulation, or both, and the effects of calcium, EGTA, and calcium channel blockers on growth were evaluated. Unilaterally applied calcium (10 mM CaCl2) significantly inhibited IAA-induced growth in upright pulvini but had no effect on growth induced by either gravity or gravity plus IAA. Calcium alone had no effect on upright pulvini. The calcium chelator EGTA alone (10 mM) stimulated growth in upright pulvini. However, EGTA had no effect on either IAA- or gravity-induced growth but slightly diminished growth in IAA-treated gravistimulated pulvini. The calcium channel blockers lanthanum chloride (25 mM), verapamil (2.5 mM), and nifedipine (2.5 mM) greatly inhibited growth as induced by IAA (> or = 50% inhibition) or IAA plus gravity (20% inhibition) but had no effect on gravistimulated pulvini. Combinations of channel blockers were similar in effect on IAA action as individual blockers. Since neither calcium ions nor EGTA significantly affected the graviresponse of pulvini, we conclude that apoplastic calcium is unimportant in leaf-sheath pulvinus gravitropism. The observation that calcium ions and calcium channel blockers inhibit IAA-induced growth, but have no effect on gravistimulated pulvini, further supports previous observations that gravistimulation alters the responsiveness of pulvini to IAA.

  10. Electrolytic deposition of calcium phosphate/chitosan coating on titanium alloy: Growth kinetics and influence of current density, acetic acid, and chitosan

    NARCIS (Netherlands)

    Wang, Jiawei; Apeldoorn, van Aart; Groot, de Klaas

    2006-01-01

    Electrolytically deposited calcium phosphate/chitosan coating demonstrated good bone marrow stromal cell attachment. The aim of this study was to understand the coating's growth kinetics as well as the effects of current density, acetic acid, and chitosan on the coating's formation. The scanning ele

  11. Relationship between magnesium extracted by 0.01 M calcium chloride extraction procedure and conventional procedures

    NARCIS (Netherlands)

    Erp, van P.J.; Houba, V.J.G.; Reijneveld, J.A.; Beusichem, van M.L.

    2001-01-01

    A multinutrient soil extraction procedure in routine soil testing is attractive. Therefore, it has been suggested to convert conventional soil testing programs into a 0.01 M calcium chloride (CaCl2) multinutrient soil testing program using the relationship between test values of the 0.01 M CaCl2 ext

  12. Zirconium, calcium, and strontium contents in magnesium based biodegradable alloys modulate the efficiency of implant-induced osseointegration

    Directory of Open Access Journals (Sweden)

    Mushahary D

    2013-08-01

    Full Text Available Dolly Mushahary,1,2 Ragamouni Sravanthi,2 Yuncang Li,2 Mahesh J Kumar,1 Nemani Harishankar,4 Peter D Hodgson,1 Cuie Wen,3 Gopal Pande2 1Institute for Frontier Materials, Deakin University, Geelong, Australia; 2CSIR- Centre for Cellular and Molecular Biology, Hyderabad, India; 3Faculty of Engineering and Industrial Sciences, Swinburne University of Technology, Hawthorn, Australia; 4National Institute of Nutrition (ICMR, Tarnaka, Hyderabad, India Abstract: Development of new biodegradable implants and devices is necessary to meet the increasing needs of regenerative orthopedic procedures. An important consideration while formulating new implant materials is that they should physicochemically and biologically mimic bone-like properties. In earlier studies, we have developed and characterized magnesium based biodegradable alloys, in particular magnesium-zirconium (Mg-Zr alloys. Here we have reported the biological properties of four Mg-Zr alloys containing different quantities of strontium or calcium. The alloys were implanted in small cavities made in femur bones of New Zealand White rabbits, and the quantitative and qualitative assessments of newly induced bone tissue were carried out. A total of 30 experimental animals, three for each implant type, were studied, and bone induction was assessed by histological, immunohistochemical and radiological methods; cavities in the femurs with no implants and observed for the same period of time were kept as controls. Our results showed that Mg-Zr alloys containing appropriate quantities of strontium were more efficient in inducing good quality mineralized bone than other alloys. Our results have been discussed in the context of physicochemical and biological properties of the alloys, and they could be very useful in determining the nature of future generations of biodegradable orthopedic implants. Keywords: osteoblasts, bone mineralization, corrosion, osseointegration, surface energy, peri-implant

  13. DEGRADATION OF SM2ZR2O7 THERMAL BARRIER COATING CAUSED BY CALCIUM-MAGNESIUM-ALUMINUM-SILICON OXIDE (CMAS) DEPOSITION

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Honglong; Sheng, Zhizhi; Tarwater, Emily; Zhang, Xingxing; Dasgupta, Sudip; Fergus, Jeffrey

    2015-03-16

    Rare earth zirconates are promising materials for use as thermal barrier coatings in gas turbine engines. Among the lanthanide zirconate materials, Sm2Zr2O7 with the pyrochlore structure has lower thermal conductivity and better corrosion resistance against calcium-magnesium-aluminum-silicon oxide (CMAS). In this work, after reaction with CMAS, the pyrochlore structure transforms to the cubic fluorite structure and Ca2Sm8(SiO4)6O2 forms in elongated grain.

  14. 合成磷酸钙磷酸镁复合物工艺研究%A Study on the Synthesis Process of Calcium Phosphate and Magnesium Phosphate

    Institute of Scientific and Technical Information of China (English)

    王秀文; 李悦

    2014-01-01

    This paper is intended to study the theoretical basis of the use of dolomite and industrial phosphoric acid to synthesize calcium phosphate and magnesium phosphate,analyze the factors influencing the synthesis process,and discuss the influence of the molar ratio of calcium+ mag-nesium and phosphorus(Ca+Mg)/P,phosphoric acid addition rate,synthesis temperature and holding time on the synthesis.The experiment results show the optimum parameters of the syn-thetic process of calcium phosphate and magnesium phosphate:the molar ratio of calcium+ mag-nesium and phosphorus(Ca+Mg)/P is 1.60,the phosphoric acid addition rate is 2 mL/min,the synthesis temperature is 1050 1 050 ℃,and the holding time is 40 min.%探讨了利用白云石和工业磷酸合成磷酸钙磷酸镁复合物的理论依据,分析了影响合成的工艺因素,讨论了钙镁合量与磷的摩尔比(Ca+Mg)/P、磷酸加入速率、合成温度和保温时间对合成的影响。实验结果表明,合成磷酸钙磷酸镁复合物的最佳工艺参数为:钙镁合量与磷的摩尔比(Ca+Mg)/P1.60,磷酸加入速率2 mL/min,合成温度1050℃,保温时间40 min。

  15. Final report of the safety assessment of L-Ascorbic Acid, Calcium Ascorbate, Magnesium Ascorbate, Magnesium Ascorbyl Phosphate, Sodium Ascorbate, and Sodium Ascorbyl Phosphate as used in cosmetics.

    Science.gov (United States)

    Elmore, Amy R

    2005-01-01

    L-Ascorbic Acid, Calcium Ascorbate, Magnesium Ascorbate, Magnesium Ascorbyl Phosphate, Sodium Ascorbate, and Sodium Ascorbyl Phosphate function in cosmetic formulations primarily as antioxidants. Ascorbic Acid is commonly called Vitamin C. Ascorbic Acid is used as an antioxidant and pH adjuster in a large variety of cosmetic formulations, over 3/4 of which were hair dyes and colors at concentrations between 0.3% and 0.6%. For other uses, the reported concentrations were either very low (Sodium Ascorbyl Phosphate functions as an antioxidant in cosmetic products and is used at concentrations ranging from 0.01% to 3%. Magnesium Ascorbyl Phosphate functions as an antioxidant in cosmetics and was reported being used at concentrations from 0.001% to 3%. Sodium Ascorbate also functions as an antioxidant in cosmetics at concentrations from 0.0003% to 0.3%. Related ingredients (Ascorbyl Palmitate, Ascorbyl Dipalmitate, Ascorbyl Stearate, Erythorbic Acid, and Sodium Erythorbate) have been previously reviewed by the Cosmetic Ingredient Review (CIR) Expert Panel and found "to be safe for use as cosmetic ingredients in the present practices of good use." Ascorbic Acid is a generally recognized as safe (GRAS) substance for use as a chemical preservative in foods and as a nutrient and/or dietary supplement. Calcium Ascorbate and Sodium Ascorbate are listed as GRAS substances for use as chemical preservatives. L-Ascorbic Acid is readily and reversibly oxidized to L-dehydroascorbic acid and both forms exist in equilibrium in the body. Permeation rates of Ascorbic Acid through whole and stripped mouse skin were 3.43 +/- 0.74 microg/cm(2)/h and 33.2 +/- 5.2 microg/cm(2)/h. Acute oral and parenteral studies in mice, rats, rabbits, guinea pigs, dogs, and cats demonstrated little toxicity. Ascorbic Acid and Sodium Ascorbate acted as a nitrosation inhibitor in several food and cosmetic product studies. No compound-related clinical signs or gross or microscopic pathological effects were

  16. ELDOR study of methyl radical production at 77 K in irradiated acetate powders as a function of metal cation

    Energy Technology Data Exchange (ETDEWEB)

    Mottley, C.; Kispert, L.D.; Wang, P.S.

    1976-08-12

    Paramagnetic relaxation characteristics of the methyl radical at 77/sup 0/K in irradiated powders of magnesium acetate tetrahydrate, potassium acetate, sodium acetate trihydrate, calcium acetate monohydrate, zinc acetate dihydrate, and lithium acetate dihydrate were measured by power saturation techniques and ELDOR spectroscopy. For magnesium acetate tetrahydrate the characteristic relaxation time (T/sub 1e/T/sub 2e/)/sup /sup 1///sub 2// for the methyl radical is relatively constant with radiation dose at low doses and decreases at higher doses. For sodium acetate trihydrate the relaxation time decreases even at low dose. ELDOR measurements of the ratio of the intermolecular relaxation time (T/sub po/) between methyl radicals to the spin--lattice relaxation time (T/sub 1e/) shows an increase from 0.05 for magnesium acetate trihydrate to greater than 1 for sodium acetate trihydrate. In addition, the field-swept ELDOR reduction factors for the m/sub I/ = -/sup 3///sub 2/ ESR line of the methyl radical utilizing 100-kHz field modulation decreases from 73 percent in irradiated magnesium acetate tetrahydrate to 2 percent in irradiated calcium acetate monohydrate. These features suggest that the radiation produced methyl radicals are trapped in clusters in acetates at low dose forming a nonuniform spatial distribution that is dependent on the cation and decreases in the approximate order Mg/sup 2 +/ greater than K/sup +/ greater than Na/sup +/ greater than Ca/sup 2 +/. No estimate of the amount of clustering in the irradiated Zn/sup 2 +/ and Li/sup +/ salts could be made due to the long T/sub 1e/'s exhibited by the methyl radical.

  17. Micromorphological effect of calcium phosphate coating on compatibility of magnesium alloy with osteoblast

    Science.gov (United States)

    Hiromoto, Sachiko; Yamazaki, Tomohiko

    2017-01-01

    Abstract Octacalcium phosphate (OCP) and hydroxyapatite (HAp) coatings were developed to control the degradation speed and to improve the biocompatibility of biodegradable magnesium alloys. Osteoblast MG-63 was cultured directly on OCP- and HAp-coated Mg-3Al-1Zn (wt%, AZ31) alloy (OCP- and HAp-AZ31) to evaluate cell compatibility. Cell proliferation was remarkably improved with OCP and HAp coatings which reduced the corrosion and prevented the H2O2 generation on Mg alloy substrate. OCP-AZ31 showed sparse distribution of living cell colonies and dead cells. HAp-AZ31 showed dense and homogeneous distribution of living cells, with dead cells localized over and around corrosion pits, some of which were formed underneath the coating. These results demonstrated that cells were dead due to changes in the local environment, and it is necessary to evaluate the local biocompatibility of magnesium alloys. Cell density on HAp-AZ31 was higher than that on OCP-AZ31 although there was not a significant difference in the amount of Mg ions released in medium between OCP- and HAp-AZ31. The outer layer of OCP and HAp coatings consisted of plate-like crystal with a thickness of around 0.1 μm and rod-like crystals with a diameter of around 0.1 μm, respectively, which grew from a continuous inner layer. Osteoblasts formed focal contacts on the tips of plate-like OCP and rod-like HAp crystals, with heights of 2–5 μm. The spacing between OCP tips of 0.8–1.1 μm was wider than that between HAp tips of 0.2–0.3 μm. These results demonstrated that cell proliferation depended on the micromorphology of the coatings which governed spacing of focal contacts. Consequently, HAp coating is suitable for improving cell compatibility and bone-forming ability of the Mg alloy. PMID:28179963

  18. Complexometric titration with potenciometric indicator to determination of calcium and magnesium in soil extracts¹

    Directory of Open Access Journals (Sweden)

    Claudia Mara Pereira

    2011-08-01

    Full Text Available This study proposes a method of direct and simultaneous determination of the amount of Ca2+ and Mg2+ present in soil extracts using a Calcium Ion-Selective Electrode and by Complexometric Titration (ISE-CT. The results were compared to those obtained by conventional analytical techniques of Complexometric Titration (CT and Flame Atomic Absorption Spectrometry (FAAS. There were no significant differences in the determination of Ca2+ and Mg2+ in comparison with CT and FAAS, at a 95 % confidence level. Additionally, results of this method were more precise and accurate than of the Interlaboratorial Control (IC.

  19. Stabilization/solidification of mercury-contaminated waste ash using calcium sodium phosphate (CNP) and magnesium potassium phosphate (MKP) processes.

    Science.gov (United States)

    Cho, Jae Han; Eom, Yujin; Lee, Tai Gyu

    2014-08-15

    This study examined the stabilization and solidification (S/S) of mercury (Hg)-contaminated waste ash generated from an industrial waste incinerator using chemically bonded phosphate ceramic (CBPC) technology. A magnesium potassium phosphate (MKP; MgKPO4 · 6H2O) ceramic, fabricated from MgO and KH2PO4, and a calcium sodium phosphate (CNP; CaNaPO4) ceramic, fabricated from CaO and Na2HPO4, were used as solidification binders in the CBPC process, and Na2S or FeS was added to each solidification binder to stabilize the Hg-contaminated waste ash. The S/S processes were conducted under various operating conditions (based on the solidification binder and stabilization reagent, stabilization reagent dosage, and waste loading ratio), and the performance characteristics of the S/S sample under each operating condition were compared, including the Hg leaching value and compressive strength. The Hg leaching value of untreated Hg-contaminated waste ash was 231.3 μg/L, whereas the S/S samples treated using the MKP and CNP processes exhibited Hg leaching values below the universal treatment standard (UTS) limit (25 μg/L). Although the compressive strengths of the S/S samples decreased as the sulfide dosage and waste loading ratio were increased, most of the S/S samples fabricated by the MKP and CNP processes exhibited good mechanical properties.

  20. Precursor preparation for Ca-Al layered double hydroxide to remove hexavalent chromium coexisting with calcium and magnesium chlorides

    Science.gov (United States)

    Zhong, Lihua; He, Xiaoman; Qu, Jun; Li, Xuewei; Lei, Zhiwu; Zhang, Qiwu; Liu, Xinzhong

    2017-01-01

    Al(OH)3 and Ca(OH)2 powders are co-ground to prepare a precursor which hydrates into a layered double hydroxide (LDH) phase by agitation in aqueous solution with target hexavalent chromium (Cr(VI)) at room temperature, to achieve an obvious improvement in removal efficiency of Cr(VI) through an easy incorporation into the structure. Although the prepared precursor transforms into LDH phases also when agitated in the solutions of calcium and magnesium chlorides, it incorporates Cr(VI) preferentially to the chloride salts when they coexist. The adsorption isotherm and kinetic studies show that the phenomena occurring on the Al-Ca precursor fit a pseudo-second-order kinetics with a Langmuir adsorption capacity of 59.45 mg/g. Besides, characterizations of the prepared precursor and the samples after adsorption are also performed by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), Transmission electron microscope (TEM) to understand the reason of the preferential incorporation of Cr(VI) to the coexisting chloride salts during the LDH phase formation.

  1. Individual effects of sodium, potassium, calcium, and magnesium chloride salts on Lactobacillus pentosus and Saccharomyces cerevisiae growth.

    Science.gov (United States)

    Bautista-Gallego, J; Arroyo-López, F N; Durán-Quintana, M C; Garrido-Fernandez, A

    2008-07-01

    A quantitative investigation on the individual effects of sodium (NaCl), potassium (KCl), calcium (CaCl2), and magnesium (MgCl2) chloride salts against Lactobacillus pentosus and Saccharomyces cerevisiae, two representative microorganisms of table olives and other fermented vegetables, was carried out. In order to assess their potential activities, both the kinetic growth parameters and dose-response profiles in synthetic media (deMan Rogosa Sharpe broth medium and yeast-malt-peptone-glucose broth medium, respectively) were obtained and analyzed. Microbial growth was monitored via optical density measurements as a function of contact time in the presence of progressive chloride salt concentrations. Relative maximum specific growth rate and lag-phase period were modeled as a function of the chloride salt concentrations. Moreover, for each salt and microorganism tested, the noninhibitory concentrations and the MICs were estimated and compared. All chloride salts exerted a significant antimicrobial effect on the growth cycle; particularly, CaCl2 showed a similar effect to NaCl, while KCl and MgCl2 were progressively less inhibitory. Microbial susceptibility and resistance were found to be nonlinearly dose related.

  2. Calcium-Magnesium-Aluminosilicate (CMAS) Infiltration and Cyclic Degradations of Thermal and Environmental Barrier Coatings in Thermal Gradients

    Science.gov (United States)

    Zhu, Dongming; Harder, Bryan; Smialek, Jim; Miller, Robert A.

    2014-01-01

    In a continuing effort to develop higher temperature capable turbine thermal barrier and environmental barrier coating systems, Calcium-Magnesium-Aluminosilicate (CMAS) resistance of the advanced coating systems needs to be evaluated and improved. This paper highlights some of NASA past high heat flux testing approaches for turbine thermal and environmental barrier coatings assessments in CMAS environments. One of our current emphases has been focused on the thermal barrier - environmental barrier coating composition and testing developments. The effort has included the CMAS infiltrations in high temperature and high heat flux turbine engine like conditions using advanced laser high heat flux rigs, and subsequently degradation studies in laser heat flux thermal gradient cyclic and isothermal furnace cyclic testing conditions. These heat flux CMAS infiltration and related coating durability testing are essential where appropriate CMAS melting, infiltration and coating-substrate temperature exposure temperature controls can be achieved, thus helping quantify the CMAS-coating interaction and degradation mechanisms. The CMAS work is also playing a critical role in advanced coating developments, by developing laboratory coating durability assessment methodologies in simulated turbine engine conditions and helping establish CMAS test standards in laboratory environments.

  3. Quantitative Proteomic Analysis of the Response to Zinc, Magnesium, and Calcium Deficiency in Specific Cell Types of Arabidopsis Roots

    Directory of Open Access Journals (Sweden)

    Yoichiro Fukao

    2016-01-01

    Full Text Available The proteome profiles of specific cell types have recently been investigated using techniques such as fluorescence activated cell sorting and laser capture microdissection. However, quantitative proteomic analysis of specific cell types has not yet been performed. In this study, to investigate the response of the proteome to zinc, magnesium, and calcium deficiency in specific cell types of Arabidopsis thaliana roots, we performed isobaric tags for relative and absolute quantification (iTRAQ-based quantitative proteomics using GFP-expressing protoplasts collected by fluorescence-activated cell sorting. Protoplasts were collected from the pGL2-GFPer and pMGP-GFPer marker lines for epidermis or inner cell lines (pericycle, endodermis, and cortex, respectively. To increase the number of proteins identified, iTRAQ-labeled peptides were separated into 24 fractions by OFFGFEL electrophoresis prior to high-performance liquid chromatography coupled with mass spectrometry analysis. Overall, 1039 and 737 proteins were identified and quantified in the epidermal and inner cell lines, respectively. Interestingly, the expression of many proteins was decreased in the epidermis by mineral deficiency, although a weaker effect was observed in inner cell lines such as the pericycle, endodermis, and cortex. Here, we report for the first time the quantitative proteomics of specific cell types in Arabidopsis roots.

  4. Estimation of calcium, magnesium, cadmium, and lead in biological samples from paralyzed quality control and production steel mill workers.

    Science.gov (United States)

    Afridi, Hassan Imran; Talpur, Farah Naz; Kazi, Tasneem Gul; Kazi, Naveed; Arain, Sadaf Sadia; Shah, Faheem

    2015-06-01

    The determination of trace and toxic metals in the biological samples of human beings is an important clinical screening procedure. The aim of the present study was to compare the level of essential trace and toxic elements cadmium (Cd), calcium (Ca), lead (Pb), and magnesium (Mg) in biological samples (whole blood, urine, and scalp hair) of male paralyzed production (PPW) and quality control workers (PQW) of a steel mill, age ranged (35-55 years). For comparison purposes, healthy age-matched exposed referent subjects (EC), working in steel mill and control subjects (NEC), who were not working in industries and lived far away from the industrial areas, were selected as control subjects. The concentrations of electrolytes and toxic elements in biological samples were measured by atomic absorption spectrometry after microwave-assisted acid digestion. The validity and accuracy of the methodology were checked using certified reference materials. The results of this study showed that the mean values of Cd and Pb were significantly higher in scalp hair, blood, and urine samples of PPW and PQW as compared to NEC and EC (p urine samples of PPW and PQW. The results show the need for immediate improvements in workplace, ventilation, and industrial hygiene practices.

  5. Experimental and theoretical study of molecular structure of beryllium, magnesium, calcium, strontium and barium 4-nitrobenzoates.

    Science.gov (United States)

    Samsonowicz, M; Regulska, E; Świsłocka, R; Lewandowski, W

    2013-02-15

    The influence of alkaline earth metal ions on the electronic system of 4-nitrobenzoic acid was studied in this paper. The vibrational (FT-IR) and NMR ((1)H and (13)C) spectra were recorded for 4-nitrobenzoic acid (4-nba) and its salts (4-nb). The assignment of vibrational spectra was done. Some shifts of band wavenumbers in alkaline earth metal 4-nitrobenzoates spectra were observed in the series from magnesium to barium salts. Good correlations between wavenumbers of the vibrational bands in the IR spectra of studied salts and ionic potential, electronegativity, inverse of atomic mass, ionic radius and ionization energy of studied metals were found. The regular changes in the chemical shifts of protons ((1)H NMR) and carbons ((13)C NMR) in the series of studied salts were also observed. Optimized geometrical structures of studied compounds were calculated by B3LYP method using 6-311++G(**) as well as LANL2DZ basis sets. Theoretical wavenumbers and intensities in IR and chemical shifts in NMR spectra were also obtained. The calculated parameters were compared with experimental data of studied compounds.

  6. Biocorrosion resistance of coated magnesium alloy by microarc oxidation in electrolyte containing zirconium and calcium salts

    Science.gov (United States)

    Wang, Ya-Ming; Guo, Jun-Wei; Wu, Yun-Feng; Liu, Yan; Cao, Jian-Yun; Zhou, Yu; Jia, De-Chang

    2014-09-01

    The key to use magnesium alloys as suitable biodegradable implants is how to adjust their degradation rates. We report a strategy to prepare biocompatible ceramic coating with improved biocorrosion resistance property on AZ91D alloy by microarc oxidation (MAO) in a silicate-K2ZrF6 solution with and without Ca(H2PO4)2 additives. The microstructure and biocorrosion of coatings were characterized by XRD and SEM, as well as electrochemical and immersion tests in simulated body fluid (SBF). The results show that the coatings are mainly composed of MgO, Mg2SiO4, m-ZrO2 phases, further Ca containing compounds involve the coating by Ca(H2PO4)2 addition in the silicate-K2ZrF6 solution. The corrosion resistance of coated AZ91D alloy is significantly improved compared with the bare one. After immersing in SBF for 28 d, the Si-Zr5-Ca0 coating indicates a best corrosion resistance performance.

  7. Study of the protein-bound fraction of calcium, iron, magnesium and zinc in bovine milk

    Science.gov (United States)

    Silva, Fernando V.; Lopes, Gisele S.; Nóbrega, Joaquim A.; Souza, Gilberto B.; Nogueira, Ana Rita A.

    2001-10-01

    Two approaches were used to study the interaction of Ca, Fe, Mg and Zn with bovine milk proteins by inductively coupled plasma optical emission spectrometry (ICPOES). Selective separations in bovine milk samples were accomplished employing an acid protein precipitation using 100 g l -1 trichloroacetic acid (TCA), and an enzymatic protein hydrolysis using 50 g l -1 pepsin (PEP) solution, respectively. The results were compared with total mineral contents determined after microwave-assisted acid digestion. The results obtained by enzymatic and acid precipitation evidenced the different interaction forms of Ca, Fe, Mg and Zn in the system formed by milk components. Iron was not solubilized by the TCA treatment, but was recovered completely after the enzymatic treatment. Quantitative recoveries of Ca, Mg and Zn were obtained using both approaches, showing that these analytes were bound to milk compounds affected by either treatment. Calcium, Mg and Zn are mainly associated with colloidal calcium phosphate and Fe is bound to the backbone of the casein polypeptide chain, cleaved by pepsin enzyme. The proposed approaches could be used to assess the complexity of these chemical interactions.

  8. The transport of indole-3-acetic Acid in boron- and calcium-deficient sunflower hypocotyl segments.

    Science.gov (United States)

    Tang, P M; Dela Fuente, R K

    1986-06-01

    Transfer of sunflower (Helianthus annuus L. cv Russian Mammoth) seedlings from complete nutrient solution to solutions deficient in either boron or calcium resulted in a steady decline in the rate of auxin transport, compared to seedlings that remained in the complete solution. In seedlings transferred to solutions deficient in both B and Ca, the decline in auxin transport was greater than seedlings deficient in only one element. The transfer of B- or Ca-deficient seedlings back to the complete solution prevented further decline in auxin transport, but auxin transport did not increase to the same level as seedlings maintained in complete solution. The significant reduction in auxin transport during the early stages of B or Ca deficiency was not related to (a) reduced growth rate of the hypocotyl, (b) increased acropetal movement of auxin, or (c) lack of respiratory substrates in the hypocotyl. In addition, no difference was found in the water-extractable total and ionic Ca in B-deficient and control nondeficient hypocotyls, indicating a direct effect of B on auxin transport, rather than indirectly by affecting Ca absorption. The rate of auxin transport in hypocotyls deficient in either B or Ca, was inversely correlated with K(+) leakage and rate of respiration. The data presented strongly support the view that there are separate sites for B and Ca in the basipetal transport of the plant hormone indoleacetic acid.

  9. The effects of prolonged consumption of wholemeal bread upon metabolism of calcium, magnesium, zinc and phosphorus of two young American adults.

    Science.gov (United States)

    Campbell, B J; Reinhold, J G; Cannell, J J; Nourmand, I

    1976-01-01

    The ability to adapt to a large daily intake of unleavened bread made from wheaten wholemeals of high extraction rate was examined in two young Americans who had not previously consumed fiber, phytate-, and phosphate-rich bread of this type. Adaptation was evaluated by comparing balances of zinc, calcium, magnesium, and phosphorus for a 12 day period after ten days of bread consumption with those during a similar period after 50 days and also by observing changes in blood composition during this period of bread consumption. Significantly negative balances of zinc, magnesium and phosphorus were observed in the initial period. However, all had become positive or nearly so after 50 days. By contrast, calcium balances which were also negative during the initial period remained negative at the end of the study. Plasma calcium and zinc concentrations had declined to low normal or subnormal values at this time. The failure to overcome the disturbing effects of consumption of wholemeal bread upon calcium metabolism occurred despite daily exposure to sunshine for many hours under conditions favorable for Vitamin D biosynthesis.

  10. Establishing homology between mitochondrial calcium uniporters, prokaryotic magnesium channels and chlamydial IncA proteins.

    Science.gov (United States)

    Lee, Andre; Vastermark, Ake; Saier, Milton H

    2014-08-01

    Mitochondrial calcium uniporters (MCUs) (TC no. 1.A.77) are oligomeric channel proteins found in the mitochondrial inner membrane. MCUs have two well-conserved transmembrane segments (TMSs), connected by a linker, similar to bacterial MCU homologues. These proteins and chlamydial IncA proteins (of unknown function; TC no. 9.B.159) are homologous to prokaryotic Mg(2+) transporters, AtpI and AtpZ, based on comparison scores of up to 14.5 sds. A phylogenetic tree containing all of these proteins showed that the AtpZ proteins cluster coherently as a subset within the large and diverse AtpI cluster, which branches separately from the MCUs and IncAs, both of which cluster coherently. The MCUs and AtpZs share the same two TMS topology, but the AtpIs have four TMSs, and IncAs can have either two (most frequent) or four (less frequent) TMSs. Binary alignments, comparison scores and motif analyses showed that TMSs 1 and 2 align with TMSs 3 and 4 of the AtpIs, suggesting that the four TMS AtpI proteins arose via an intragenic duplication event. These findings establish an evolutionary link interconnecting eukaryotic and prokaryotic Ca(2+) and Mg(2+) transporters with chlamydial IncAs, and lead us to suggest that all members of the MCU superfamily, including IncAs, function as divalent cation channels.

  11. Mechanochemically Activated, Calcium Oxide-Based, Magnesium Oxide-Stabilized Carbon Dioxide Sorbents.

    Science.gov (United States)

    Kurlov, Alexey; Broda, Marcin; Hosseini, Davood; Mitchell, Sharon J; Pérez-Ramírez, Javier; Müller, Christoph R

    2016-09-01

    Carbon dioxide capture and storage (CCS) is a promising approach to reduce anthropogenic CO2 emissions and mitigate climate change. However, the costs associated with the capture of CO2 using the currently available technology, that is, amine scrubbing, are considered prohibitive. In this context, the so-called calcium looping process, which relies on the reversible carbonation of CaO, is an attractive alternative. The main disadvantage of naturally occurring CaO-based CO2 sorbents, such as limestone, is their rapid deactivation caused by thermal sintering. Here, we report a scalable route based on wet mechanochemical activation to prepare MgO-stabilized, CaO-based CO2 sorbents. We optimized the synthesis conditions through a fundamental understanding of the underlying stabilization mechanism, and the quantity of MgO required to stabilize CaO could be reduced to as little as 15 wt %. This allowed the preparation of CO2 sorbents that exceed the CO2 uptake of the reference limestone by 200 %.

  12. Passive and active in vitro resorption of calcium and magnesium phosphate cements by osteoclastic cells.

    Science.gov (United States)

    Grossardt, Christian; Ewald, Andrea; Grover, Liam M; Barralet, Jake E; Gbureck, Uwe

    2010-12-01

    Biocements are clinically applied materials for bone replacement in non-load-bearing defects. Depending on their final composition, cements can be either resorbed or remain stable at the implantation site. Degradation can occur by two different mechanisms, by simple dissolution (passive) or after osteoclastic bone remodeling (active). This study investigated both the passive and active in vitro resorption behavior of brushite (CaHPO₄ · 2H₂O), monetite (CaHPO₄), calcium-deficient hydroxyapatite (CDHA; Ca₉(PO₄)₅HPO₄OH), and struvite (MgNH₄PO₄ · 6H₂O) cements. Passive resorption was measured by incubating the cement samples in a cell culture medium, whereas active resorption was determined during the surface culture of multinuclear osteoclastic cells derived from RAW 264.7 macrophages. Osteoclast formation was confirmed by showing tartrate resistant acid phosphatase (TRAP) activity on CDHA, brushite, and monetite surfaces, as well as by measuring calcitonin receptor (CT-R) expression as an osteoclast-specific protein by Western blot analysis for struvite ceramics. An absence of passive degradation and only marginally active degradation of struvite cement was the most degradable with a passive (active) release of 9.26 (2.92) Mg²+ ions and a total weight loss of 4.7% over 13 days of the study.

  13. Copper, zinc, calcium and magnesium content of alcoholic beverages and by-products from Spain: nutritional supply.

    Science.gov (United States)

    Navarro-Alarcon, M; Velasco, C; Jodral, A; Terrés, C; Olalla, M; Lopez, H; Lopez, M C

    2007-07-01

    Levels of copper, zinc, calcium and magnesium were measured in alcoholic beverages (whiskies, gins, rums, liquors, brandies, wines and beers) and by-products (non-alcoholic liquors and vinegars) using flame atomic absorption spectrometry (FAAS). Mineral concentrations were found to be significantly different between the nine alcoholic and non-alcoholic by-products studied (p < 0.001). In distilled alcoholic beverages, concentrations measured in rums and brandies were statistically lower than those determined in gins and alcoholic liquors (p = 0.001). For Cu, measured concentrations were statistically different for each of the five groups of distilled alcoholic beverages studied (p < 0.001). In fermented beverages, Zn, Ca and Mg levels were significantly higher than those concentrations determined in distilled drinks (p < 0.005). Contrarily, Cu concentrations were statistically lower (p < 0.001). Wines designated as sherry had significantly higher Ca and Mg levels (p < 0.005). White wines had significantly higher Ca and Zn levels (p < 0.05) compared with red wines and, contrarily, Cu concentrations were significantly lower (p < 0.005). In wine samples and corresponding by-products (brandy and vinegar), statistical differences were established for all minerals analysed (p < 0.01). Remarkably, for Cu, the concentrations determined in brandies were statistically higher. On the basis of element levels and the official data on consumption of alcoholic beverages and by-products in Spain, their contribution to the daily dietary intake (DDI) was calculated to be 124.6 microg Cu day(-1) and 193.3 microg Zn day(-1), 40.3 mg Ca day(-1) and 19.9 mg Mg day(-1). From all studied elements, Cu was the one for which alcoholic beverages constitute a significant source (more than 10% of recommended daily intake). These findings are of potential use to food composition tables.

  14. Europium doped di-calcium magnesium di-silicate orange–red emitting phosphor by solid state reaction method

    Directory of Open Access Journals (Sweden)

    Ishwar Prasad Sahu

    2015-07-01

    Full Text Available A new orange–red europium doped di-calcium magnesium di-silicate (Ca2MgSi2O7:Eu3+ phosphor was prepared by the traditional high temperature solid state reaction method. The prepared Ca2MgSi2O7:Eu3+ phosphor was characterized by X-ray diffractometer (XRD, transmission electron microscopy (TEM, field emission scanning electron microscopy (FESEM with energy dispersive x-ray spectroscopy (EDX, fourier transform infrared spectra (FTIR, photoluminescence (PL and decay characteristics. The phase structure of sintered phosphor was akermanite type structure which belongs to the tetragonal crystallography with space group P4¯21m, this structure is a member of the melilite group and forms a layered compound. The chemical composition of the sintered Ca2MgSi2O7:Eu3+ phosphor was confirmed by EDX spectra. The PL spectra indicate that Ca2MgSi2O7:Eu3+ can be excited effectively by near ultraviolet (NUV light and exhibit bright orange–red emission with excellent color stability. The fluorescence lifetime of Ca2MgSi2O7:Eu3+ phosphor was found to be 28.47 ms. CIE color coordinates of Ca2MgSi2O7:Eu3+ phosphor is suitable as orange-red light emitting phosphor with a CIE value of (X = 0.5554, Y = 0.4397. Therefore, it is considered to be a new promising orange–red emitting phosphor for white light emitting diode (LED application.

  15. Differential effects of zinc and magnesium ions on mineralization activity of phosphatidylserine calcium phosphate complexes.

    Science.gov (United States)

    Wu, Licia N Y; Genge, Brian R; Wuthier, Roy E

    2009-07-01

    Mg(2+) and Zn(2+) are present in the mineral of matrix vesicles (MVs) and biological apatites, and are known to influence the onset and progression of mineral formation by amorphous calcium phosphate (ACP) and hydroxyapatite (HAP). However, neither has been studied systematically for its effect on mineral formation by phosphatidylserine-Ca(2+)-Pi complexes (PS-CPLX), an important constituent of the MV nucleation core. Presented here are studies on the effects of increasing levels of Mg(2+) and Zn(2+) on the process of mineral formation, either when present in synthetic cartilage lymph (SCL), or when incorporated during the formation of PS-CPLX. Pure HAP and PS-CPLX proved to be powerful nucleators, but ACP took much longer to induce mineral formation. In SCL, Mg(2+) and Zn(2+) had significantly different inhibitory effects on the onset and amount of mineral formation; HAP and PS-CPLX were less affected than ACP. Mg(2+) and Zn(2+) caused similar reductions in the rate and length of rapid mineral formation, but Zn(2+) was a more potent inhibitor on a molar basis. When incorporated into PS-CPLX, Mg(2+) and Zn(2+) caused significantly different effects than when present in SCL. Even low, subphysiological levels of Mg(2+) altered the inherent structure of PS-CPLX and markedly reduced its ability to induce and propagate mineral formation. Incorporated Zn(2+) caused significantly less effect, low (<20 microM) levels causing almost no inhibition. Levels of Zn(2+) present in MVs do not appear to inhibit their nucleational activity.

  16. Laser Sintered Magnesium-Calcium Silicate/Poly-ε-Caprolactone Scaffold for Bone Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Kuo-Yang Tsai

    2017-01-01

    Full Text Available In this study, we manufacture and analyze bioactive magnesium–calcium silicate/poly-ε-caprolactone (Mg–CS/PCL 3D scaffolds for bone tissue engineering. Mg–CS powder was incorporated into PCL, and we fabricated the 3D scaffolds using laser sintering technology. These scaffolds had high porosity and interconnected-design macropores and structures. As compared to pure PCL scaffolds without an Mg–CS powder, the hydrophilic properties and degradation rate are also improved. For scaffolds with more than 20% Mg–CS content, the specimens become completely covered by a dense bone-like apatite layer after soaking in simulated body fluid for 1 day. In vitro analyses were directed using human mesenchymal stem cells (hMSCs on all scaffolds that were shown to be biocompatible and supported cell adhesion and proliferation. Increased focal adhesion kinase and promoted cell adhesion behavior were observed after an increase in Mg–CS content. In addition, the results indicate that the Mg–CS quantity in the composite is higher than 10%, and the quantity of cells and osteogenesis-related protein of hMSCs is stimulated by the Si ions released from the Mg–CS/PCL scaffolds when compared to PCL scaffolds. Our results proved that 3D Mg–CS/PCL scaffolds with such a specific ionic release and good degradability possessed the ability to promote osteogenetic differentiation of hMSCs, indicating that they might be promising biomaterials with potential for next-generation bone tissue engineering scaffolds.

  17. Calcium, potassium and magnesium treatment of Chrysanthemum morifolium cv. "Bi Time" and callogenesis in vitro Tratamento de plantas matrizes de Chrysanthemum morifolium cv. "Bi Time" com Ca2+, K+ E Mg2+ e calogênese in vitro

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    Fábio Borgatto

    2002-12-01

    Full Text Available The chemical composition and vegetative vigor of the donor plant are essential for the satisfactory performance of explants in vitro. In order to test the effect of potassium, calcium and magnesium nutritional status of Chrysanthemum morifolium plants on callogenesis in vitro, pot plants growing in sand were irrigated with nutrient solution containing different levels of potassium (0; 58.5; 117 and 234 mg L-1, calcium (0; 50; 100 e 200 mg L-1 and magnesium (0;12; 48 e 96 mg L-1. After 30 and 45 days, explants (shoot segments and leaf discs were collected, desinfected and inoculated on MS solid medium supplemented with 0.1 mg L-1 of kinetin and 5.0 mg L-1 of nafthalene acetic acid for callogenesis induction. Callogenesis evaluated as callus fresh weight was affected by nutrients treatment. Callus growth on leaf explants was inversely proporcional to potassium concentration and directly proportional to magnesium concentration in shoot explants. The calcium effect on callogensis of leaf explants was dependent on treatment duration. For 30 days treatment callogenseis was inversely related to calcium concentration and after 45 days was directly related to calcium concentration.A composição química e o vigor vegetativo de plantas matrizes são essenciais no desenvolvimento de explantes in vitro. Com o objetivo de testar o efeito do estado nutricional de plantas matrizes de Chrysanthemum morifolium no processo de calogênese in vitro, plantas crescendo em vasos contendo areia lavada foram irrigadas com soluções nutritivas contendo diferentes concentrações de cálcio (0, 50, 100 e 200 mg L-1, potássio (0, 58,5, 117 e 234 mg L-1, e magnésio (0,12, 48 e 96 mg L-1. Aos 30 e 45 dias de duração do tratamento com solução nutritiva, explantes (segmento caulinar e foliar das matrizes foram coletados, desinfestados e inoculados em meio de cultura MS sólido suplementado com 0,1 mg L-1 de Kin e 5,0 mg L-1 NAA. A calogênese foi afetada pelos

  18. EDTA络合滴定法测定铁矿石中钙和镁%Determination of calcium and magnesium in iron ore by EDTA complexometric titration

    Institute of Scientific and Technical Information of China (English)

    赵树宝

    2009-01-01

    在微氨性溶液中,采用硫化钠及铜试剂使铜、铅、锌、铁、钴、镍、锰、铬、镉、铋等生成硫化物沉淀和铜试剂内络盐沉淀与钙镁分离,然后以盐酸羟胺将微量的锰还原成低价消除其干扰,用三乙醇胺和L-半胱氨酸掩蔽残留的其他金属离子.在pH10氨水-氯化铵缓冲溶液中,以酸性铬蓝K-萘酚绿B为指示剂,用EDTA络合滴定法测定钙、镁合量;另在氢氧化钾溶液中,用钙试剂为指示剂,以EDTA络合滴定法测定钙量,用差减法计算镁的含量.该方法对铁矿石标准样品中的钙和镁进行多次测定,结果与认定值相符,相对标准偏差在0.99%~3.4%(n=6)之间,加标回收率在98%~101%之间.%In weak ammonia solution, sodium sulfide and cupral reacted with copper, lead, zinc, iron, cobalt, nickel, manganese, chromium, cadmium and bismuth to form a sulfide precipitatie and a cupral complex inner salt precipitate, realizing the separation of calcium and magnesium. Then, trace manganese was reduced to low valency by hydroxylamine hydrochloride to eliminate its interference, while other residual metal ions were masked by triethanolamine and L-cysteine. In ammonia water-ammonium chloride buffer solution at pHIO, total content of calcium and magnesium was determined by EDTA complexometric titration with acid chrome blue K-naphthol green B as the indicator. In addition, the content of calcium was determined by EDTA complexometric titration with calcon as the indicator in potassium hydroxide solution. As a consequence, the content of magnesium could be calculated with difference subtraction method. Calcium and magnesium in iron ore standard sample were determined for many times by this method. The results were in agreement with the certified values, with the relative deviation of 0. 99 % - 3. 4 % (n = 6) and recovery of standard addition between 98 % -101 %.

  19. Role of activity of gastrointestinal microflora in absorption of calcium and magnesium in rats fed beta1-4 linked galactooligosaccharides.

    Science.gov (United States)

    Chonan, O; Takahashi, R; Watanuki, M

    2001-08-01

    Rats fed a diet containing beta1-4 linked galactooligosaccharides (GOS) (5 g/100 g of diet) absorbed calcium and magnesium more efficiently than those fed the control diet. However, the increment obtained through GOS-feeding was reduced by neomycin sulfate (0.67 g/100 g of diet). Since the decrease in cecal pH in rats fed GOS was suppressed by neomycin-feeding, bacterial action in the digestive tract was considered to be reduced by neomycin-feeding. Our findings suggest that the action of intestinal bacteria is necessary for the effects of GOS.

  20. The Journal of Nutrition, Volume 106, 1976: Decreased absorption of calcium, magnesium, zinc and phosphorus by humans due to increased fiber and phosphorus consumption as wheat bread.

    Science.gov (United States)

    Reinhold, J G; Faradji, B; Abadi, P; Ismail-Beigi, F

    1991-07-01

    During a 20 day period of high fiber consumption in the form of bread made partly from wheaten wholemeal, two men developed negative balances of calcium, magnesium, zinc and phosphorus due to increased fecal excretion of each element. The fecal losses correlated closely with fecal dry matter and phosphorus. Fecal dry matter, in turn, was directly proportional to fecal fiber excretion. Balances of nitrogen remained positive. Mineral elements were well-utilized by the same subjects during a 20 day period of white bread consumption.

  1. To evaluate the levels of glycated hemoglobin, serum calcium, magnesium, phosphate, uric acid and microalbuminuria in patients with newly diagnosed type 2 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Qazi Najeeb

    2014-08-01

    Conclusion: There is decrease in serum calcium, magnesium and phosphate levels, all these plays an important role in the regulation of glucose level in the blood. Hence oral supplementation of all these ions other than diet is recommended. Increased serum uric acid and microalbuminuria was seen with reduced glucose tolerance hence early estimation of both the parameters should be done while monitoring case of Type-2 diabetes and thus will help to decrease the incidence of renal complications. [Int J Res Med Sci 2014; 2(4.000: 1462-1465

  2. Reference intervals of plasma calcium, phosphorus, and magnesium for African grey parrots (Psittacus erithacus) and Hispaniolan parrots (Amazona ventralis).

    Science.gov (United States)

    de Carvalho, Fernanda M; Gaunt, Stephen D; Kearney, Michael T; Rich, Gregory A; Tully, Thomas N

    2009-12-01

    Calcium (Ca), phosphorus (P), and magnesium (Mg) are important elements for body homeostasis in several diseases associated with imbalances in the plasma concentration of these ions. This is the first published report of reference intervals for Mg in association with Ca and P levels for psittacine species. One milliliter of blood was collected from 26 Hispaniolan parrots (Amazona ventralis) and 24 African grey parrots (Psittacus erithacus). The plasma concentrations of Ca, P, and Mg were determined for each sample. Statistical analyses were performed including all data (analysis 1) and after exclusion of the subjects with Ca > or = 14.00 mg/dl (3.5 mmol) (analysis 2). The data from analysis 1 have a narrower interval than that observed in analysis 2. Following the normality test (Shapiro-Wilk, alpha = 0.05), the univariate and mean procedures were run. For the reference intervals, the lower and upper values were used, after elimination of the outliers calculated by Blom scores from the ranked variables. The analysis 1 references for the Hispaniolans were Ca = 8.80-10.40 mg/dl (2.20-2.60 mmol/L), P = 1.80-4.40 mg/dl (0.58-1.42 mmol/L), Mg = 1.80-3.10 mg/dl (0.74-1.27 mmol/L), and Ca:P ratio = 2.62-5.39; for the African greys analysis 1 references were Ca = 8.20-20.20 mg/dl (2.05-5.05 mmol/L), P = 2.50-5.90 mg/dl (0.81-1.91 mmol/L), Mg = 2.10-3.40 mg/dl (0.82-1.4 mmol/L), and Ca:P ratio = 1.81-3.77. The analysis 2 references for the Hispaniolans were Ca = 8.80-10.30 mg/dl (2.20-2.58 mmol/L), P = 1.80-3.80 mg/dl (0.58-1.23 mmol/L), Mg = 1.90-3.00 mg/dl (0.82-1.07 mmol/L), Ca:P ratio = 2.62-5.39; for the African greys analysis 2 references were Ca = 1.07 mmol/L), Ca:P ratio = 1.67-3.50. The results of this study are important for evaluating Mg concentrations in relation to the Ca and P parameters in psittacines. This information will be particularly helpful for veterinarians evaluating the hypocalcemic syndrome in African grey parrots and other disease processes

  3. Effects of surface application of calcium-magnesium silicate and gypsum on soil fertility and sugarcane yield

    Directory of Open Access Journals (Sweden)

    Carlos Alexandre Costa Crusciol

    2014-12-01

    Full Text Available Lime application recommendations for amendment of soil acidity in sugarcane were developed with a burnt cane harvesting system in mind. Sugarcane is now harvested in most areas without burning, and lime application for amendment of soil acidity in this system in which the sugarcane crop residue remains on the ground has been carried out without a scientific basis. The aim of this study was to evaluate the changes in soil acidity and stalk and sugar yield with different rates of surface application of calcium, magnesium silicate, and gypsum in ratoon cane. The experiment was performed after the 3rd harvest of the variety SP 81-3250 in a commercial green sugarcane plantation of the São Luiz Sugar Mill (47º 25' 33" W; 21º 59' 46" S, located in Pirassununga, São Paulo, in southeast Brazil. A factorial arrangement of four Ca-Mg silicate rates (0, 850, 1700, and 3400 kg ha-1 and two gypsum rates (0 and 1700 kg ha-1 was used in the experiment. After 12 months, the experiment was harvested and technological measurements of stalk and sugar yield were made. After harvest, soil samples were taken at the depths of 0.00-0.05, 0.05-0.10, 0.10-0.20, 0.20-0.40, and 0.40-0.60 m in all plots, and the following determinations were made: soil pH in CaCl2, organic matter, P, S, K, Ca, Mg, H+Al, Al, Si, and base saturation. The results show that the application of gypsum reduced the exchangeable Al3+ content and Al saturation below 0.05 m, and increased the Ca2+ concentration in the whole profile, the Mg2+ content below 0.10 m, K+ below 0.4 m, and base saturation below 0.20 m. This contributed to the effect of surface application of silicate on amendment of soil acidity reaching deeper layers. From the results of this study, it may be concluded that the silicate rate recommended may be too low, since the greater rates used in this experiment showed greater reduction in soil acidity, higher levels of nutrients at greater depths and an increase in stalk and sugar

  4. Calcium-aluminum-rich inclusions with fractionation and unidentified nuclear effects (FUN CAIs): II. Heterogeneities of magnesium isotopes and 26Al in the early Solar System inferred from in situ high-precision magnesium-isotope measurements

    Science.gov (United States)

    Park, Changkun; Nagashima, Kazuhide; Krot, Alexander N.; Huss, Gary R.; Davis, Andrew M.; Bizzarro, Martin

    2017-03-01

    Calcium-aluminum-rich inclusions with isotopic mass fractionation effects and unidentified nuclear isotopic anomalies (FUN CAIs) have been studied for more than 40 years, but their origins remain enigmatic. Here we report in situ high precision measurements of aluminum-magnesium isotope systematics of FUN CAIs by secondary ion mass spectrometry (SIMS). Individual minerals were analyzed in six FUN CAIs from the oxidized CV3 carbonaceous chondrites Axtell (compact Type A CAI Axtell 2271) and Allende (Type B CAIs C1 and EK1-4-1, and forsterite-bearing Type B CAIs BG82DH8, CG-14, and TE). Most of these CAIs show evidence for excess 26Mg due to the decay of 26Al. The inferred initial 26Al/27Al ratios [(26Al/27Al)0] and the initial magnesium isotopic compositions (δ26Mg0) calculated using an exponential law with an exponent β of 0.5128 are (3.1 ± 1.6) × 10-6 and 0.60 ± 0.10‰ (Axtell 2271), (3.7 ± 1.5) × 10-6 and -0.20 ± 0.05‰ (BG82DH8), (2.2 ± 1.1) × 10-6 and -0.18 ± 0.05‰ (C1), (2.3 ± 2.4) × 10-5 and -2.23 ± 0.37‰ (EK1-4-1), (1.5 ± 1.1) × 10-5 and -0.42 ± 0.08‰ (CG-14), and (5.3 ± 0.9) × 10-5 and -0.05 ± 0.08‰ (TE) with 2σ uncertainties. We infer that FUN CAIs recorded heterogeneities of magnesium isotopes and 26Al in the CAI-forming region(s). Comparison of 26Al-26Mg systematics, stable isotope (oxygen, magnesium, calcium, and titanium) and trace element studies of FUN and non-FUN igneous CAIs indicates that there is a continuum among these CAI types. Based on these observations and evaporation experiments on CAI-like melts, we propose a generic scenario for the origin of igneous (FUN and non-FUN) CAIs: (i) condensation of isotopically normal solids in an 16O-rich gas of approximately solar composition; (ii) formation of CAI precursors by aggregation of these solids together with variable abundances of isotopically anomalous grains-possible carriers of unidentified nuclear (UN) effects; and (iii) melt evaporation of these precursors

  5. 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.

  6. Bioavailability of iodine and hardness (magnesium and calcium salt) in drinking water in the etiology of endemic goitre in Sundarban delta of West Bengal (India).

    Science.gov (United States)

    Chandra, Amar K; Tripathy, Smritiratan; Debnath, Arijit; Ghosh, Dishari

    2007-04-01

    Endemic goitre has been reported from the ecologically diverse Sundarban delta of West Bengal (India). To study the etiological factors for the persistence of endemic goitre, bioavailability of iodine and hardness of water used for drinking in the region were evaluated because these common environmental factors are inversely and directly related with goitre prevalence in several geographical regions. For the present study from 19 Community Development Blocks of Sundarban delta, 19 areas were selected at random. From each area at least 8 drinking water samples were collected and analyzed for iodine and the hardness (calcium and magnesium salt content). Iodine content in the drinking water samples was found in the range from 21 to 119 mg/L and total hardness of drinking water was found to range from 50 to 480 ppm. Presence of magnesium salt was found higher than the calcium salts in most of the samples. These findings suggest that the entire delta region is environmentally iodine sufficient but water is relatively hard and thus possibility of hardness of water for the persistence of endemic goitre may not be ruled out.

  7. The Effect of Ethyl Acetate on Crystallization of Calcium Sulfate Whisker%乙酸乙酯对硫酸钙晶须结晶的影响

    Institute of Scientific and Technical Information of China (English)

    李胜利

    2012-01-01

    The half water calcium sulphate whisker was prepared by hydrothermal synthesis process with calcium sulfate as raw material. When ethyl acetate was used as addition agent, the effects of the temperature, the reaction time, ethyl acetate and the mass ratio of dihydrate calcium sulphate to water on crystallization of half calcium sulfate whisker were studied by using the method of orthogonal design. The results sho.red that the increase of the reaction temperature induced the decrease of the ratio of length to width of whisker, the ratio of length to width of whisker increased at first and then decreased with the reaction time, the ratio of length to width of whisker increased with increasing the mass ratio of dihydrate calcium sulphate to water, namely the decrease of concentration of solution, ethyl acetate led to crystal form of half water calcium sulphate whisker from slender corrugated to massive prismatic%以硫酸钙为原料,采用水热法合成了半水硫酸钙晶须;并采用正交设计的方法来分析乙酸乙酯作为添加剂时,各因素对半水硫酸钙晶须结晶的影响:温度、时间、乙酸乙酯及二水硫酸钙与水的质量比。结果表明:反应温度的升高使得晶须的长宽比降低,反应时间的延长使得晶须的长宽比先升高后降低,二水硫酸钙与水的质量比增大即料浆浓度的降低使得晶须的长宽比增大,乙酸乙酯使半水硫酸钙晶须的的晶形由细长的瓦楞状变为粗大的棱柱状。

  8. 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

  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. 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.

  11. Crystal growth of calcium carbonate on the cellulose acetate/pyrrolidon blend films in the presence of L-aspartic acid

    Science.gov (United States)

    Zhang, Xiuzhen; Xie, Anjian; Huang, Fangzhi; Shen, Yuhua

    2014-03-01

    The morphogenesis and growth process of calcium carbonate on the cellulose acetate/polyvinyl pyrrolidone (CA/PVP) blend films in the presence of L-aspartic acid was carefully investigated. The results showed that the concentration of L-aspartic acid, the initial pH value of reaction solution and temperature turned out to be important factors for the control of morphologies and polymorphs of calcium carbonate. Complex morphologies of CaCO3 particles, such as cubes, rose-like spheres, twinborn-spheres, cone-like, bouquet-like, etc. could be obtained under the different experimental conditions. The dynamic process of formation of rose-like sphere crystals was analyzed by monitoring the continuous morphological and structural evolution and components of crystals in different crystal stages. This research may provide a promising method to prepare other inorganic materials with complex morphologies.

  12. Short term spatio-temporal variability of soil water-extractable calcium and magnesium after a low severity grassland fire in Lithuania.

    Science.gov (United States)

    Pereira, Paulo; Martin, David

    2014-05-01

    Fire has important impacts on soil nutrient spatio-temporal distribution (Outeiro et al., 2008). This impact depends on fire severity, topography of the burned area, type of soil and vegetation affected, and the meteorological conditions post-fire. Fire produces a complex mosaic of impacts in soil that can be extremely variable at small plot scale in the space and time. In order to assess and map such a heterogeneous distribution, the test of interpolation methods is fundamental to identify the best estimator and to have a better understanding of soil nutrients spatial distribution. The objective of this work is to identify the short-term spatial variability of water-extractable calcium and magnesium after a low severity grassland fire. The studied area is located near Vilnius (Lithuania) at 54° 42' N, 25° 08 E, 158 masl. Four days after the fire, it was designed in a burned area a plot with 400 m2 (20 x 20 m with 5 m space between sampling points). Twenty five samples from top soil (0-5 cm) were collected immediately after the fire (IAF), 2, 5, 7 and 9 months after the fire (a total of 125 in all sampling dates). The original data of water-extractable calcium and magnesium did not respected the Gaussian distribution, thus a neperian logarithm (ln) was applied in order to normalize data. Significant differences of water-extractable calcium and magnesium among sampling dates were carried out with the Anova One-way test using the ln data. In order to assess the spatial variability of water-extractable calcium and magnesium, we tested several interpolation methods as Ordinary Kriging (OK), Inverse Distance to a Weight (IDW) with the power of 1, 2, 3 and 4, Radial Basis Functions (RBF) - Inverse Multiquadratic (IMT), Multilog (MTG), Multiquadratic (MTQ) Natural Cubic Spline (NCS) and Thin Plate Spline (TPS) - and Local Polynomial (LP) with the power of 1 and 2. Interpolation tests were carried out with Ln data. The best interpolation method was assessed using the

  13. Maxillary sinus floor elevation using a tissue-engineered bone with calcium-magnesium phosphate cement and bone marrow stromal cells in rabbits.

    Science.gov (United States)

    Zeng, Deliang; Xia, Lunguo; Zhang, Wenjie; Huang, Hui; Wei, Bin; Huang, Qingfeng; Wei, Jie; Liu, Changsheng; Jiang, Xinquan

    2012-04-01

    The objective of this study was to assess the effects of maxillary sinus floor elevation with a tissue-engineered bone constructed with bone marrow stromal cells (bMSCs) and calcium-magnesium phosphate cement (CMPC) material. The calcium (Ca), magnesium (Mg), and phosphorus (P) ions released from calcium phosphate cement (CPC), magnesium phosphate cement (MPC), and CMPC were detected by inductively coupled plasma atomic emission spectroscopy (ICP-AES), and the proliferation and osteogenic differentiation of bMSCs seeded on CPC, MPC, and CMPC or cultured in CPC, MPC, and CMPC extracts were measured by MTT analysis, alkaline phosphatase (ALP) activity assay, alizarin red mineralization assay, and real-time PCR analysis of the osteogenic genes ALP and osteocalcin (OCN). Finally, bMSCs were combined with CPC, MPC, and CMPC and used for maxillary sinus floor elevation in rabbits, while CPC, MPC, or CMPC without cells served as control groups. The new bone formation in each group was detected by histological finding and fluorochrome labeling at weeks 2 and 8 after surgical operation. It was observed that the Ca ion concentrations of the CMPC and CPC scaffolds was significantly higher than that of the MPC scaffold, while the Mg ions concentration of CMPC and MPC was significantly higher than that of CPC. The bMSCs seeded on CMPC and MPC or cultured in their extracts proliferated more quickly than the cells seeded on CPC or cultured in its extract, respectively. The osteogenic differentiation of bMSCs seeded on CMPC and CPC or cultured in the corresponding extracts was significantly enhanced compared to that of bMSCs seeded on MPC or cultured in its extract; however, there was no significant difference between CMPC and CPC. As for maxillary sinus floor elevation in vivo, CMPC could promote more new bone formation and mineralization compared to CPC and MPC, while the addition of bMSCs could further enhance its new bone formation ability significantly. Our data suggest that

  14. Short-chain fructo-oligosaccharides improve magnesium absorption in adolescent girls with a low calcium intake

    NARCIS (Netherlands)

    Heuvel, E.G.H.M. van den; Muijs, T.; Brouns, F.; Hendriks, H.F.J.

    2009-01-01

    Consumption of fructo-oligosaccharides (FOS) has been shown to improve mineral absorption in the short term, but no long-term effects were studied in girls with a low calcium intake. Therefore, we hypothesized that short- and long-term consumption of short-chain FOS (sc-FOS) improves calcium and mag

  15. Reported Dietary Intake, Disparity between the Reported Consumption and the Level Needed for Adequacy and Food Sources of Calcium, Phosphorus, Magnesium and Vitamin D in the Spanish Population: Findings from the ANIBES Study †

    Science.gov (United States)

    Olza, Josune; Aranceta-Bartrina, Javier; González-Gross, Marcela; Ortega, Rosa M.; Serra-Majem, Lluis; Varela-Moreiras, Gregorio; Gil, Ángel

    2017-01-01

    Calcium, phosphorus, magnesium and vitamin D have important biological roles in the body, especially in bone metabolism. We aimed to study the reported intake, the disparity between the reported consumption and the level needed for adequacy and food sources of these four nutrients in the Spanish population. We assessed the reported intake for both, general population and plausible reporters. Results were extracted from the ANIBES survey, n = 2009. Three-day dietary reported intake data were obtained and misreporting was assessed according to the European Food Safety Authority (EFSA). Mean ± SEM (range) total reported consumption of calcium, phosphorus, magnesium, and vitamin D for the whole population were 698 ± 7 mg/day (71–2551 mg/day), 1176 ± 8 mg/day, (331–4429 mg/day), 222 ± 2 mg/day (73–782 mg/day), and 4.4 ± 0.1 µg/day (0.0–74.2 µg/day), respectively. In the whole group, 76% and 66%; 79% and 72%; and 94% and 93% of the population had reported intakes below 80% of the national and European recommended daily intakes for calcium, magnesium and vitamin D, respectively; these percentages were over 40% when the plausible reporters were analysed separately. The main food sources were milk and dairy products for calcium and phosphorus, cereals and grains for magnesium and fish for vitamin D. In conclusion, there is an important percentage of the Spanish ANIBES population not meeting the recommended intakes for calcium, magnesium and vitamin D. PMID:28230782

  16. Comparison of renal calcium concentration in obese, lean, diabetic, and non-diabetic Zucker rats fed a magnesium-deficient fructose diet.

    Science.gov (United States)

    Koh, E T; Min, K W; Scholfield, D J; Sarkarcadeh, A

    1991-01-01

    In order to determine the effects of hypoinsulinaemia or hyperinsulinaemia on nephrocalcinosis induced by the interaction between fructose and magnesium (Mg) deficiency, we compared kidney calcification in obese versus lean, and non-diabetic versus diabetic female Zucker rats fed a magnesium-deficient fructose diet. One half of the obese and lean animals, respectively, was injected with streptozotocin to produce diabetes, and the other half was injected with citrate buffer alone. Diabetic, non-diabetic, obese, and lean animals were divided into two dietary groups, consisting of high starch or high fructose without added Mg. After a four week period, 24 hour urine was collected for urinary output, protein, oxalate, citrate, MG, and calcium (Ca) measurements. The animals were then decapitated, and blood was collected for glucose, Mg, and Ca determinations, and kidneys were removed to determine their Mg and Ca contents. All fructose-fed animals exhibited significantly more kidney Ca then the starch-fed animals. Lean non-diabetic rats fed fructose showed the greatest kidney Ca along with the greatest urinary protein excretion among all experimental groups. The significant finding in the present study is that diabetes or obesity reduced nephrocalcinosis regardless of the insulin status of the rats. Diuresis and hypercitraturia in diabetic and/or obese animals may cause a reduction in nephrocalcinosis induced by the interaction between fructose and magnesium deficiency. Hyperproteinuria (uromucoid) in combination with hypercalciuria and hypomagnesuria may be responsible for greater nephrocalcinosis in the fructose than the starch group. The possible mechanisms for this interaction on nephrocalcinosis have been discussed.

  17. Preparation and In Vitro and In Vivo Performance of Magnesium Ion Substituted Biphasic Calcium Phosphate Spherical Microscaffolds as Human Adipose Tissue-Derived Mesenchymal Stem Cell Microcarriers

    Directory of Open Access Journals (Sweden)

    Dong-Hyun Kim

    2013-01-01

    Full Text Available Magnesium ion substituted biphasic calcium phosphate (Mg-BCP bioceramic microscaffolds with spherical and porous morphology were successfully prepared using in situ coprecipitation and rotary spray drying atomization process for application of tissue engineering combined with human adipose tissue-derived mesenchymal stem cells (hAT-MSCs. After 4 weeks of immersion in Hanks’ balanced salt solution (HBSS, Mg-BCP micro-scaffolds showed the enhanced biodegradation and bioactivity due to the substituted Mg2+ ion present in the BCP structure. In this study, it was observed that hAT-MSCs have clearly attached on the surface of Mg-BCP micro-scaffolds. In addition, Mg-BCP micro-scaffolds exhibited the improved biocompatibility and osteoconductivity via in vitro and in vivo biological tests with hAT-MSCs. Therefore, these bioceramic micro-scaffolds had potential to be used as hAT-MSCs microcarriers for biomedical applications.

  18. Study of calcium phosphate (DCPD electrodeposition process on a Mg-3Al-1Zn magnesium alloy surface

    Directory of Open Access Journals (Sweden)

    Filip Pastorek

    2013-02-01

    Full Text Available Evaluation of calcium phosphating process realized on Mg-3Al-1Zn alloy surface after grinding was investigated by electrochemical tests supported by photodocumentation. The electrodeposition treatment was performed by electrochemical method in water solution of Ca(NO32.4H2O, (NH42HPO4 and H2O2. The formation of calcium phosphate was divided into several stages and described using light microscopy. The progress in corrosion protection of created calcium phosphate layer in 0.9% NaCl after particular electrodeposition steps was evaluated by electrochemical impedance spectroscopy. The results in the form of Nyquist plots were analyzed using equivalent circuits.

  19. 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 ...

  20. CO2碳酸化石灰岩酸解产物回收乙酸及副产沉淀碳酸钙%CO2 carbonation of calcium acetate derived from acidolysis of natural CaCO3 for recycling of acetic acid and production of precipitated calcium carbonate

    Institute of Scientific and Technical Information of China (English)

    杨政; 岳海荣; 周向葛; 梁斌; 谢和平

    2014-01-01

    Acetic acid dissolution of limestone for formation of cavity is a kind of environmental approach to fabricating underground storage and preparing precipitated calcium carbonate. This process is an integrated technology consisting of acetic acid dissolution of limestone and CO2 carbonation of calcium acetate. The kinetics of limestone acidolysis with acetic acid was investigated. Orthogonal experiments were conducted with emphasis on operation conditions (i.e., concentration of calcium acetate, pressure of CO2, reaction temperature, and reaction time) of the carbonation reaction. The highest conversion of calcium acetate (23.13%) was achieved at the calcium acetate concentration of 0.631 mol·L-1, CO2 pressure of 5 MPa, reaction temperature of 80℃ and reaction for 50 min. The product of calcium carbonate was analyzed and could meet the requirements of Chinese national standard.%乙酸酸解石灰石造腔是一种建造地下储库同时环保地开采石灰岩制备沉淀碳酸钙的新方法。通过耦合乙酸酸解石灰石及酸解产物乙酸钙 CO2碳酸化的工艺过程,研究了乙酸酸解石灰岩的表面反应动力学和乙酸钙 CO2碳酸化的工艺技术条件。采用正交实验分析法,研究了CO2碳酸化反应中乙酸钙浓度、反应温度、CO2压力、反应时间对乙酸钙碳酸化反应制沉淀碳酸钙的影响,并通过正交实验确定了最优化操作条件。实验结果表明,乙酸酸解反应速率主要受乙酸浓度控制。CO2碳酸化反应在当乙酸钙溶液浓度为0.631 mol·L-1,CO2压力为5.0 MPa,温度为80℃,反应时间为50 min时CO2碳酸化效率达到最高(23.13%),生成的沉淀碳酸钙产品各项指标均符合中国国标优级要求。

  1. Calcium, magnesium, and phosphorus metabolism, and parathyroid-calcitonin function during prolonged exposure to elevated CO2 concentrations on submarines.

    Science.gov (United States)

    Messier, A A; Heyder, E; Braithwaite, W R; McCluggage, C; Peck, A; Schaefer, K E

    1979-01-01

    Studies of calcium and phosphorus metabolism and acid-base balance were carried out on three Fleet Ballistic Missile (FBM) submarines during prolonged exposure to elevated concentrations of CO2. The average CO2 concentration in the submarine atmosphere during patrols ranged from 0.85% to 1% CO2. In the three studies, in which 9--15 subjects participated, the urinary excretion of calcium and phosphate fell during the first three weeks to a level commensurate with a decrease in plasma calcium and increase in phosphorus. In the fourth week of one patrol, a marked increase was found in urinary calcium excretion, associated with a rise in blood PCO2 and bicarbonate. Urinary calcium excretion decreased again during the 5th to 8th week, with a secondary decrease in blood pH and plasma calcium. During the third patrol, the time course of acid-base changes corresponded well with that found during the second patrol. There was a trend toward an increase in plasma calcium between the fourth and fifth week commensurate with the transient rise in pH and bicarbonate. Plasma parathyroid and calcitonin hormone activities were measured in two patrols and no significant changes were found. Hydroxyproline excretion decreased in the three-week study and remained unchanged in the second patrol, which lasted 57 days. It is suggested that during prolonged exposure to low levels of CO2 (up to 1% CO2), calcium metabolism is controlled by the uptake and release of CO2 in the bones. The resulting phases in bone buffering, rather than renal regulation, determine acid-base balance.

  2. Effect Of Haemodialysis On Intra Dialytic Calcium, Phosphorus,Magnesium, Levels In Relation To AutonomicNervous System Activity

    OpenAIRE

    Mona Hosny, Sahar Shawky, Ahmed Ramadan , Hany Refaat

    2004-01-01

    Autonomic nervous system dysfunction is common in uremia and in patients under hemodialysis. Changes in serum calcium, serum phosphorus and serum magnesuim always occur during hemodialysis. The relation between these changes and autonomic nervous system activity during hemodialysis has not been fully studied. This study was carried out on 30 patients with chronic renal failure on regular hemo-dialysis with nearly similar age group. We measured serum calcium, serum phosphorus and serum magnesi...

  3. Determinação de cálcio e de magnésio em plantas, por fotometria de chama de absorção Determination of calcium and magnesium in plant material, by absorption flame photometry

    Directory of Open Access Journals (Sweden)

    Ondino Cleante Bataglia

    1972-01-01

    Full Text Available As concentrações de cálcio e magnésio em extratos de plantas podem ser determinadas por fotometria de chama de absorção com a precisão e exatidão requeridas, mediante a adição de lantânio na concentração de 0,1 %,como agente protetor. Para obtenção dos dados utilizou-se um espectrofotômetro Perkin-Elmer, modelo 303, equipado com sistema digital de leitura.A method for determination of calcium and magnesium by absorption flame photometry was studied using a Perkin-Elmer model 303 spectrophotometer equiped with digital concentration readout model DCR1. The study of interferents was carried out with concentration usually present in plant material or even in higher concentrations to get information about the possibility of applying this method to other materials. Within the limits of concentration studied, it was observed that calcium determination was affected by the ions Fe 3+, Al3+ , Mn 2+, Si 4+, PO3-4 and SO2-4 . The ions Mg2+ , K+ , Na+ , Cu2+ , Zn2+ , CI- , NO-3 and ClO-4 had no interference. Magnesium determination was affected only by the presence of the ions Al3+ and Si4+. The use of 0.1% lanthanum solution suppressed the interference of 10 ppm of Al3+, Fe3+ or Mn2+, 50 ppm of Si4+ and 100 ppm of PO3-4 or SO2-4 on a 5 ppm calcium solution. It suppressed also the effect of 10 ppm of Al or 50 ppm of Si in the absorbance of 1 ppm magnesium solution. In the application of the method for calcium and magnesium in plant analysis, 0.200 g of dried plant material was digested with 1 ml of nitric acid and 0.5 ml percloric acid. The volume was completed to 50 ml with distilled water. A portion (2 to 10 ml was transfered to a 50 ml volumetric flask, lanthanum was added to a final concentration of 0.1% and the volume was taken to 50 ml. Calcium and magnesium in plant material were determined using calibration curves, obtained with calcium solutions varying from 0 to 10 ppm and magnesium solutions varying from 0 to 2 ppm (both had 0

  4. Magnesium modification up-regulates the bioactivity of bone morphogenetic protein-2 upon calcium phosphate cement via enhanced BMP receptor recognition and Smad signaling pathway.

    Science.gov (United States)

    Ding, Sai; Zhang, Jing; Tian, Yu; Huang, Baolin; Yuan, Yuan; Liu, Changsheng

    2016-09-01

    Efficient presentation of growth factors is one of the great challenges in tissue engineering. In living systems, bioactive factors exist in soluble as well as in matrix-bound forms, both of which play an integral role in regulating cell behaviors. Herein, effect of magnesium on osteogenic bioactivity of recombinant human bone morphogenetic protein-2 (rhBMP-2) was investigated systematically with a series of Mg modified calcium phosphate cements (xMCPCs, x means the content of magnesium phosphate cement wt%) as matrix model. The results indicated that the MCPC, especially 5MCPC, could promote the rhBMP-2-induced in vitro osteogenic differentiation via Smad signaling of C2C12 cells. Further studies demonstrated that all MCPC substrates exhibited similar rhBMP-2 release rate and preserved comparable conformation and biological activity of the released rhBMP-2. Also, the ionic extracts of MCPC made little difference to the bioactivity of rhBMP-2, either in soluble or in matrix-bound forms. However, with the quartz crystal microbalance (QCM), we observed a noticeable enhancement of rhBMP-2 mass-uptake on 5MCPC as well as a better recognition of the bound rhBMP-2 to BMPR IA and BMPR II. In vivo results demonstrated a better bone regeneration capacity of 5MCPC/rhBMP-2. From the above, our results demonstrated that it was the Mg anchored on the underlying substrates that tailored the way of rhBMP-2 bound on MCPC, and thus facilitated the recognition of BMPRs to stimulate osteogenic differentiation. The study will guide the development of Mg-doped bioactive bone implants for tissue regeneration.

  5. Novel injectable, self-gelling hydrogel-microparticle composites for bone regeneration consisting of gellan gum and calcium and magnesium carbonate microparticles.

    Science.gov (United States)

    Douglas, Timothy E L; Łapa, Agata; Reczyńska, Katarzyna; Krok-Borkowicz, Małgorzata; Pietryga, Krzysztof; Samal, Sangram Keshari; Declercq, Heidi A; Schaubroeck, David; Boone, Marijn; Van der Voort, Pascal; De Schamphelaere, Karel; Stevens, Christian V; Bliznuk, Vitaliy; Balcaen, Lieve; Parakhonskiy, Bogdan V; Vanhaecke, Frank; Cnudde, Veerle; Pamuła, Elżbieta; Skirtach, Andre G

    2016-11-21

    The suitability of hydrogel biomaterials for bone regeneration can be improved by incorporation of an inorganic phase in particle form, thus maintaining hydrogel injectability. In this study, carbonate microparticles containing different amounts of calcium (Ca) and magnesium (Mg) were added to solutions of the anionic polysaccharide gellan gum (GG) to crosslink GG by release of Ca(2+) and Mg(2+) from microparticles and thereby induce formation of hydrogel-microparticle composites. It was hypothesized that increasing Mg content of microparticles would promote GG hydrogel formation. The effect of Mg incorporation on cytocompatibility and cell growth was also studied. Microparticles were formed by mixing Ca(2+) and Mg(2+) and [Formula: see text] ions in varying concentrations. Microparticles were characterized physiochemically and subsequently mixed with GG solution to form hydrogel-microparticle composites. The elemental Ca:Mg ratio in the mineral formed was similar to the Ca:Mg ratio of the ions added. In the absence of Mg, vaterite was formed. At low Mg content, magnesian calcite was formed. Increasing the Mg content further caused formation of amorphous mineral. Microparticles of vaterite and magnesium calcite did not induce GG hydrogel formation, but addition of Mg-richer amorphous microparticles induced gelation within 20 min. Microparticles were dispersed homogeneously in hydrogels. MG-63 osteoblast-like cells were cultured in eluate from hydrogel-microparticle composites and on the composites themselves. All composites were cytocompatible. Cell growth was highest on composites containing particles with an equimolar Ca:Mg ratio. In summary, carbonate microparticles containing a sufficient amount of Mg induced GG hydrogel formation, resulting in injectable, cytocompatible hydrogel-microparticle composites.

  6. Oxygen- and magnesium-isotope compositions of calcium-aluminum-rich inclusions from CR2 carbonaceous chondrites

    Science.gov (United States)

    Makide, Kentaro; Nagashima, Kazuhide; Krot, Alexander N.; Huss, Gary R.; Hutcheon, Ian D.; Bischoff, Addi

    2009-09-01

    We report both oxygen- and magnesium-isotope compositions measured in situ using a Cameca ims-1280 ion microprobe in 20 of 166 CAIs identified in 47 polished sections of 15 CR2 (Renazzo-type) carbonaceous chondrites. Two additional CAIs were measured for oxygen isotopes only. Most CR2 CAIs are mineralogically pristine; only few contain secondary phyllosilicates, sodalite, and carbonates - most likely products of aqueous alteration on the CR2 chondrite parent asteroid. Spinel, hibonite, grossite, anorthite, and melilite in 18 CAIs have 16O-rich (Δ 17O = -23.3 ± 1.9‰, 2 σ error) compositions and show no evidence for postcrystallization isotopic exchange commonly observed in CAIs from metamorphosed CV carbonaceous chondrites. The inferred initial 26Al/ 27Al ratios, ( 26Al/ 27Al) 0, in 15 of 16 16O-rich CAIs measured are consistent with the canonical value of (4.5-5) × 10 -5 and a short duration (oxygen- and magnesium-isotope compositions (˜11 and 23‰/amu, respectively), a deficit of 26Mg, and a relatively low ( 26Al/ 27Al) 0 = (2.0 ± 1.7) × 10 -5. This could be the first FUN ( Fractionation and Unidentified Nuclear effects) CAI found in CR2 chondrites. Because this inclusion is slightly 16O-depleted compared to most CR2 CAIs and has lower than the canonical ( 26Al/ 27Al) 0, it may have experienced multistage formation from precursors with nonsolar magnesium-isotope composition and recorded evolution of oxygen-isotope composition in the early solar nebula over 0.9+2.2-0.7 My. Eight of the 166 CR2 CAIs identified are associated with chondrule materials, indicating that they experienced late-stage, incomplete melting during chondrule formation. Three of these CAIs show large variations in oxygen-isotope compositions (Δ 17O ranges from -23.5‰ to -1.7‰), suggesting dilution by 16O-depleted chondrule material and possibly exchange with an 16O-poor (Δ 17O > -5‰) nebular gas. The low inferred ( 26Al/ 27Al) 0 ratios of these CAIs (2 My after crystallization

  7. The influence of calcium magnesium, and sodium on the spectrographic analysis of natural waters; Estudio de la influencia del calcio, magnesio y sodio en un metodo de analisis espectrografico de aguas naturales

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Guerra, J. P.; Capdevilla, C.

    1969-07-01

    The influences of 1000 {mu}g/ml of calcium and sodium and 300 {mu}g/ml of magnesium, on the spectrographic determination of Al, Ba, Cr, Fe, Li , Mn, Ni, Pb, Sr and Ti, minor constituents in natural waters, have been studied, In order to eliminate them, the elements Ga, In, La, Ti and Zn, as well as a mixture containing 30 % Tl-70 % In, have been tested as spectrochemical buffers. (Author) 7 refs.

  8. 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 ...

  9. Determination of residual organic solvent acetic acid in Omeprazole Magnesium by HPLC%HPLC 法测定奥美拉唑镁原料药中醋酸的残留量

    Institute of Scientific and Technical Information of China (English)

    李菊平; 刘效平; 金永亮

    2015-01-01

    目的:建立高效液相色谱法测定奥美拉唑镁原料药中有机溶剂醋酸含量。方法以色谱柱:以 X -Bridge TM C18(4.6 mm ×250 mm,5μm)为分离柱,采用等度洗脱,检测波长:210 nm。结果线性关系良好,方法精密度,重复性均符合要求。冰醋酸检测浓度线性范围为0.01~0.06 mg·mL -1(r =0.999994),低、中、高浓度平均回收率(n =9)分别为100.60%、100.38%、100.23%,RSD 分别为2.20%、2.21%、1.60%,最低检测限为0.0050 mg·mL -1。结论该方法可用于奥美拉唑镁原料药中残留溶剂醋酸含量的测定,限度为不得过0.05%(500 ppm)。%Objective To establish a method for the determination of residual acetic acid in Omeprazole Magnesium by HPLC Methods The X - Bridge TM C18(4. 6 mm × 250 mm,5 μm)column was adopted,temperature programming and FID detector was used. Results The solvent had good linear relationship and the precision and reproducibility of the meth-od were in accord with the requests. The linear range of acetic acid was 0. 01 ~ 0. 06 mg·mL - 1(r = 0. 999 994);The aver-age recovery rates of low,middle,high concentration(n = 9)were 100. 60% ,100. 38% ,100. 23% ,respectively and the RSDs were 2. 20% ,2. 21% ,1. 60% ,respectively;LOD was 0. 005 0 mg·mL - 1 . Conclusion This method could be used to determine residual acetic acid in Omeprazole Magnesium. The limit was not more than 0. 05%(500 ppm).

  10. 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.

  11. Effects of Calcium and Magnesium Ions on Acute Copper Toxicity to Glochidia and Early Juveniles of the Chinese Pond Mussel Anodonta woodiana.

    Science.gov (United States)

    Liu, Hongbo; Chen, Xiubao; Su, Yanping; Kang, Ik Joon; Qiu, Xuchun; Shimasaki, Yohei; Oshima, Yuji; Yang, Jian

    2016-10-01

    We evaluated the effects of calcium (Ca(2+)) and magnesium (Mg(2+)) ions on copper (Cu) toxicity to glochidia and newly-transformed juvenile mussels (age 1-2 days) of the Chinese pond mussel (Anodonta woodiana). Acute Cu toxicity tests were performed with glochidia for 24 h and juveniles for 96 h with measured Ca(2+) concentrations of 1.1, 14, 26, 51, and 99 mg L(-1), or measured Mg(2+) concentrations of 2.6, 11, 21, and 39 mg L(-1). The Ca(2+) and Mg(2+) cations provided no statistically significant protection against Cu toxicity to glochidia or juveniles. The 24-h EC50 value for glochidia was 82 μg L(-1) Cu, and contrastly, 96-h EC50 value for newly-transformed juvenile mussels was as low as 12 μg L(-1) Cu, implying that the juveniles of A. woodiana are more vulnerable to Cu contamination at concentrations close to currently-accepted levels.

  12. Method development for the determination of calcium, copper, magnesium, manganese, iron, potassium, phosphorus and zinc in different types of breads by microwave induced plasma-atomic emission spectrometry.

    Science.gov (United States)

    Ozbek, Nil; Akman, Suleyman

    2016-06-01

    A novel method was developed for the determination of calcium, magnesium, potassium, iron, copper, zinc, and manganese and phosphorous in various kinds of breads samples sold in Turkey by microwave plasma-atomic emission spectrometry (MIP-AES). Breads were dried at 100 °C for one day, ground thoroughly and then digested using nitric acid/hydrogen per oxide (3:1). The analytes in certified reference wheat flour and maize flour samples were determined in the uncertainty limits of the certified values as well as the analytes added to the mixture of ground bread and acid mixture prior to digestion were recovered quantitatively (>90%). Therefore, all determinations were made by linear calibration technique using aqueous standards. The LOD values for Ca, Cu, Fe, K, Mg, Mn, P and Zn were 13.1, 0.28, 4.47, 118, 1.10, 0.41, 7550 and 3.00 ng mL(-1), respectively. No spectral interference was detected at the working wavelengths of the analytes.

  13. Effect of Metal Chelators on γ-Secretase Indicates That Calcium and Magnesium Ions Facilitate Cleavage of Alzheimer Amyloid Precursor Substrate

    Directory of Open Access Journals (Sweden)

    Michael Ho

    2011-01-01

    Full Text Available Gamma-secretase is involved in the production of Aβ amyloid peptides. It cleaves the transmembrane domain of the amyloid precursor protein (APP at alternative sites to produce Aβ and the APP intracellular domain (AICD. Metal ions play an important role in Aβ aggregation and metabolism, thus metal chelators and ligands represent potential therapeutic agents for AD treatment. A direct effect of metal chelators on γ-secretase has not yet been investigated. The authors used an in vitro  γ-secretase assay consisting of cleavage of APP C100-3XFLAG by endogenous γ-secretase from rodent brains and human neuroblastoma SH-SY5Y, and detected AICD production by western blotting. Adding metalloprotease inhibitors to the reaction showed that clioquinol, phosphoramidon, and zinc metalloprotease inhibitors had no significant effect on γ-secretase activity. In contrast, phenanthroline, EDTA, and EGTA markedly decreased γ-secretase activity that could be restored by adding back calcium and magnesium ions. Mg2+ stabilized a 1,000 kDa presenilin 1 complex through blue native gel electrophoresis and size-exclusion chromatography. Data suggest that Ca2+ and Mg2+ stabilize γ-secretase and enhance its activity.

  14. Biofortification of crops with seven mineral elements often lacking in human diets--iron, zinc, copper, calcium, magnesium, selenium and iodine.

    Science.gov (United States)

    White, Philip J; Broadley, Martin R

    2009-01-01

    The diets of over two-thirds of the world's population lack one or more essential mineral elements. This can be remedied through dietary diversification, mineral supplementation, food fortification, or increasing the concentrations and/or bioavailability of mineral elements in produce (biofortification). This article reviews aspects of soil science, plant physiology and genetics underpinning crop biofortification strategies, as well as agronomic and genetic approaches currently taken to biofortify food crops with the mineral elements most commonly lacking in human diets: iron (Fe), zinc (Zn), copper (Cu), calcium (Ca), magnesium (Mg), iodine (I) and selenium (Se). Two complementary approaches have been successfully adopted to increase the concentrations of bioavailable mineral elements in food crops. First, agronomic approaches optimizing the application of mineral fertilizers and/or improving the solubilization and mobilization of mineral elements in the soil have been implemented. Secondly, crops have been developed with: increased abilities to acquire mineral elements and accumulate them in edible tissues; increased concentrations of 'promoter' substances, such as ascorbate, beta-carotene and cysteine-rich polypeptides which stimulate the absorption of essential mineral elements by the gut; and reduced concentrations of 'antinutrients', such as oxalate, polyphenolics or phytate, which interfere with their absorption. These approaches are addressing mineral malnutrition in humans globally.

  15. A CALPHAD study on the thermodynamic stability of calcium-, zinc-, and yttrium-doped magnesium in aqueous environments

    Energy Technology Data Exchange (ETDEWEB)

    Wu Kaisheng, E-mail: kaisheng.wu@netl.doe.gov [National Energy Technology Lab, 1450 Queen Ave SW, Albany, OR 97321 (United States); URS Corporation, PO Box 1959, Albany, OR 97321-0521 (United States); Dogan, Oemer N., E-mail: omer.dogan@netl.doe.gov [National Energy Technology Lab, 1450 Queen Ave SW, Albany, OR 97321 (United States); Velikokhatnyi, Oleg I., E-mail: olv3@pitt.edu [Center for Complex Engineered Multifunctional Materials, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Kumta, Prashant N., E-mail: pkumta@pitt.edu [Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Swanson School of Engineering and School of Dental Medicine, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Center for Complex Engineered Multifunctional Materials, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer Execution of CALPHAD thermodynamic study and hydrolysis reactions of Mg-alloys. Black-Right-Pointing-Pointer CALPHAD and ab-initio studies demonstrate very similar results in pure water. Black-Right-Pointing-Pointer Alloying of Mg with Ca and Y promote hydrolysis, while Zn resists the hydrolysis. Black-Right-Pointing-Pointer Mg-(Ca, Y, Zn) alloys yield similar stability effects in water and in bio-solution. Black-Right-Pointing-Pointer Kinetic aspects are vital for aqueous stability studies of biodegradable Mg-alloys. - Abstract: Magnesium has attracted the attention of the biomaterials community as a potential biodegradable metallic candidate for use in stents and orthopedic applications. Alloying of Mg with metals such as Ca, Y and Zn, etc., to form alloy precursors is important to optimize its corrosion rate in electrolytic and aqueous environments to understand the alloy response in body fluid environments. In the current study, the chemical reactions of Mg-Me alloys (Me = Ca, Y, and Zn) with pure water have been investigated using the CALPHAD technique. A qualitative agreement between CALPHAD and first-principles results has been obtained. The CALPHAD method has also been employed to study the reactions of Mg alloys in the human blood fluid environment. The effects of alloying elements and compositions on the reaction enthalpies, reaction products, amount of gas release and gas compositions as well as the pH of the fluids have been systematically discussed and reported.

  16. "Slow" Voltage-Dependent Inactivation of CaV2.2 Calcium Channels Is Modulated by the PKC Activator Phorbol 12-Myristate 13-Acetate (PMA.

    Directory of Open Access Journals (Sweden)

    Lei Zhu

    Full Text Available CaV2.2 (N-type voltage-gated calcium channels (Ca2+ channels play key roles in neurons and neuroendocrine cells including the control of cellular excitability, neurotransmitter / hormone secretion, and gene expression. Calcium entry is precisely controlled by channel gating properties including multiple forms of inactivation. "Fast" voltage-dependent inactivation is relatively well-characterized and occurs over the tens-to- hundreds of milliseconds timeframe. Superimposed on this is the molecularly distinct, but poorly understood process of "slow" voltage-dependent inactivation, which develops / recovers over seconds-to-minutes. Protein kinases can modulate "slow" inactivation of sodium channels, but little is known about if/how second messengers control "slow" inactivation of Ca2+ channels. We investigated this using recombinant CaV2.2 channels expressed in HEK293 cells and native CaV2 channels endogenously expressed in adrenal chromaffin cells. The PKC activator phorbol 12-myristate 13-acetate (PMA dramatically prolonged recovery from "slow" inactivation, but an inactive control (4α-PMA had no effect. This effect of PMA was prevented by calphostin C, which targets the C1-domain on PKC, but only partially reduced by inhibitors that target the catalytic domain of PKC. The subtype of the channel β-subunit altered the kinetics of inactivation but not the magnitude of slowing produced by PMA. Intracellular GDP-β-S reduced the effect of PMA suggesting a role for G proteins in modulating "slow" inactivation. We postulate that the kinetics of recovery from "slow" inactivation could provide a molecular memory of recent cellular activity and help control CaV2 channel availability, electrical excitability, and neurotransmission in the seconds-to-minutes timeframe.

  17. Glatiramer acetate (copaxone modulates platelet activation and inhibits thrombin-induced calcium influx: possible role of copaxone in targeting platelets during autoimmune neuroinflammation.

    Directory of Open Access Journals (Sweden)

    Sarah C Starossom

    Full Text Available BACKGROUND: Glatiramer acetate (GA, Copaxone, Copolymer-1 is an FDA approved drug for the treatment of MS and it is very effective in suppressing neuroinflammation in experimental autoimmune encephalitis (EAE, an animal model of MS. Although this drug was designed to inhibit pathogenic T cells, the exact mechanism of EAE/MS suppression by GA is still not well understood. Previously we presented evidence that platelets become activated and promote neuroinflammation in EAE, suggesting a possible pathogenic role of platelets in MS and EAE. We hypothesized that GA could inhibit neuroinflammation by affecting not only immune cells but also platelets. METHODOLOGY/PRINCIPAL FINDINGS: We investigated the effect of GA on the activation of human platelets in vitro: calcium influx, platelet aggregation and expression of activation markers. Our results in human platelets were confirmed by in-vitro and in-vivo studies of modulation of functions of platelets in mouse model. We found that GA inhibited thrombin-induced calcium influx in human and mouse platelets. GA also decreased thrombin-induced CD31, CD62P, CD63, and active form of αIIbβ3 integrin surface expression and formation of platelet aggregates for both mouse and human platelets, and prolonged the bleeding time in mice by 2.7-fold. In addition, we found that GA decreased the extent of macrophage activation induced by co-culture of macrophages with platelets. CONCLUSIONS: GA inhibited the activation of platelets, which suggests a new mechanism of GA action in suppression of EAE/MS by targeting platelets and possibly preventing their interaction with immune cells such as macrophages. Furthermore, the reduction in platelet activation by GA may have additional cardiovascular benefits to prevent thrombosis.

  18. Crystal structure of the magnesium salt of the herbicide 2,4-D: penta­aqua­[(2,4-di­chloro­phenoxy)acetato-κO]magnesium (2,4-di­chloro­phen­oxy)acetate hemihydrate

    OpenAIRE

    2014-01-01

    In the crystal structure of the title magnesium salt of the phen­oxy herbicide (2,4-di­chloro­phen­oxy)acetic acid (2,4-D), [Mg(C8H5Cl2O3)(H2O)5](C8H5Cl2O3)·0.5H2O, the discrete cationic MgO6 complex unit comprises a carboxyl­ate O-donor from a monodentate 2,4-D anionic ligand and five water mol­ecules, resulting in a slightly distorted octa­hedral coordination sphere. The free 2,4-D anions are linked to the complex units through duplex water–carboxyl­ate O—H⋯O hydrogen bonds through the coor...

  19. Shear flocculation of celestite with sodium oleate and tallow amine acetate: effects of cations.

    Science.gov (United States)

    Ozkan, A; Yekeler, M

    2004-05-01

    Sodium oleate and tallow amine acetate (TAA) were used as surfactants for the shear flocculation of celestite. The shear-flocculation power values obtained with sodium oleate were higher than those obtained with TAA in terms of the concentrations used in the shear-flocculation experiments. In addition, sodium oleate and TAA were more effective on the celestite suspension in the pH ranges of 7-11 and 6-10, respectively. For the shear-flocculation experiments with sodium oleate at pH 11, with preaddition of calcium or magnesium ions at 5 x 10(-5) M and lower concentrations into the suspension, the shear flocculation of the celestite suspension was promoted by the coagulation process due to the calcium and magnesium cations added. However, the shear-flocculation power values decreased due to the interaction between surfactant and cations at concentration values higher than 5 x 10(-5) M for magnesium ions and 10(-3) M for calcium ion. Particularly, magnesium ions significantly reduced the shear-flocculation power values by slime coating of Mg(OH)2 precipitates.

  20. On the role of calcium in indole-3-acetic acid movement and graviresponse in etiolated pea epicotyls

    Science.gov (United States)

    Migliaccio, F.; Galston, A. W.

    1989-01-01

    To determine whether Ca2+ plays a special role in the early graviresponse of shoots, as has been reported for roots, we treated etiolated pea epicotyls with substances known to antagonize Ca2+ (La3+), to remove Ca2+ from the wall (spermidine, EGTA), to inhibit calmodulin mediated reactions (chlorpromazine), or to inhibit IAA transport (TIBA). We studied the effect of these substances on IAA and Ca2+ uptake into 7 mm long subapical 3rd internode etiolated pea epicotyl sections and pea leaf protoplasts, on pea epicotyl growth, and graviresponse and on lateral IAA redistribution during gravistimulation. Our results support the view that adequate Ca2+ in the apoplast is required for normal IAA uptake, transport and graviresponse. Experiments with protoplasts indicate that Ca2+ may be controlling a labile membrane porter, possibly located on the external surface of cell membrane, while inhibitor experiments suggest that calmodulin is also implicated in both the movement of IAA and graviresponse. Since a major transfer of Ca2+ through free space during graviresponse has not yet been demonstrated, and since inhibition of calcium channels does not affect IAA redistribution (Migliaccio and Galston, 1987, Plant Physiology 85:542), we conclude that no clear evidence links prior Ca2+ movement with IAA redistribution during graviresponse in stems.

  1. Development and characterization of a novel bioresorbable and bioactive biomaterial based on polyvinyl acetate, calcium carbonate and coralline hydroxyapatite

    Directory of Open Access Journals (Sweden)

    Javier Aragón

    2011-03-01

    Full Text Available Coralina® HAP-200 (coralline hydroxyapatite obtained by hydrothermal treatment of marine corals and POVIAC® (polymeric matrix based on PVAc, commercial trade marks were mixed with a natural product from the Cuban sea costs, i.e. calcium carbonate from Porites Porites coral, to obtain a novel bioactive composite with potential use as bone restoration material. The samples were characterized by physical-chemical (FTIR, XRD, SEM, EDS and mechanical studies. It was shown that there is no chemical interaction between the inorganic filler and the polymer matrix, each conserving the original properties of the raw materials. The studied formulation had a compressive strength similar to that reported for trabecular bone. Scanning electron microscopy examination revealed that the addition of CaCO3 induces a change on the morphologic structure of the composite obtained after 30 days of SBF immersion. These composites generate novel biomaterials capable of promoting the deposition of a new phase, a Ca-P layer due to the bioactivity of a Ca2+ precursors.

  2. Study on the Injectable Magnesium-calcium Phosphate Cements%可注射镁基磷酸钙骨水泥的研究

    Institute of Scientific and Technical Information of China (English)

    戴红莲; 胡付俭; 方彩萍; 李世普

    2014-01-01

    Injectable magnesium-calcium phosphate cements (IMPC) was prepared using magnesium oxide (MgO), monopotassium phosphate (KH2PO4),β-tricalcium phosphate (β-TCP), glucose and phosphoric acid solution. The ef-fects of liquid to powder ratio(LPR), contents of MgO and glucose on IMPC’s gelling and mechanical properties were investigated. The results showed that increase of LPR and glucose content resulted in increased IMPC setting time and injectability, and decreased compressive strength. With the MgO content decreasing, the setting time and the in-jectability were decreased, whereas the compressive strength was increased. To obtain optimal formula for the new IMPC, the MgO and glucose contents and LPR were selected based on orthogonal experiments, and the result was 26wt% MgO, 6wt% glucose and 0.30 mL/g LPR. The new IMPC has moderate hydration with low exothermic reac-tion and ideal hardening performance, indicating that it may be used as a novel bone adhesive material.%采用MgO、KH2PO4、β-TCP、葡萄糖作为骨水泥的固相,磷酸溶液作为液相,制备可注射镁基磷酸钙骨水泥(IMPC)。考察液固比(LPR)、MgO含量、葡萄糖含量变化对IMPC胶凝性能和力学性能的影响。实验结果显示:液固比和缓凝剂葡萄糖含量增大均会导致凝结时间变长和抗压强度下降,但有益于可注射性;随 MgO 含量增大,凝结时间缩短,可注射率降低,但抗压强度提高。采用正交实验法确定MgO含量26wt%,液固比0.30 mL/g,葡萄糖含量6wt%时得到的IMPC综合性能良好,水化过程缓和,放热量低。该IMPC有望成为一种新型骨粘结材料。

  3. Effect of applied voltage on surface properties of anodised titanium in mixture of β-glycerophosphate (β-GP) and calcium acetate (CA)

    Energy Technology Data Exchange (ETDEWEB)

    Chuan, Lee Te, E-mail: gd130079@siswa.uthm.edu.my; Rathi, Muhammad Fareez Mohamad, E-mail: cd110238@siswa.uthm.edu.my; Abidin, Muhamad Yusuf Zainal, E-mail: cd110221@siswa.uthm.edu.my; Abdullah, Hasan Zuhudi, E-mail: hasan@uthm.edu.my; Idris, Maizlinda Izwana, E-mail: izwana@uthm.edu.my [Faculty of Mechanical and Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia, 86400 Parit Raja, Batu Pahat, Johor (Malaysia)

    2015-07-22

    Anodic oxidation is a surface modification method which combines electric field driven metal and oxygen ion diffusion for formation of oxide layer on the anode surface. This method has been widely used to modify the surface morphology of biomaterial especially titanium. This study aimed to investigate the effect of applied voltage on titanium. Specifically, the titanium foil was anodised in mixture of β-glycerophosphate disodium salt pentahydrate (β-GP) and calcium acetate monohydrate (CA) with different applied voltage (50-350 V), electrolyte concentration (0.04 M β-GP + 0.4 M CA), anodising time (10minutes) and current density (50 and 70 mA.cm{sup −2}) at room temperature. Surface oxide properties of anodised titanium were characterised by digital single-lens reflex camera (DSLR camera), field emission scanning electron microscope (FESEM) and atomic force microscopy (AFM). At lower applied voltage (≤150 V), surface of titanium foils were relatively smooth. With increasing applied voltage (≥250 V), the oxide layer became more porous and donut-shaped pores were formed on the surface of titanium foils. The AFM results indicated that the surface roughness of anodised titanium increases with increasing of applied voltage. The porous and rough surface is able to promote the osseointegration and reduce the suffering time of patient.

  4. Immunodeficiency after allogeneic bone marrow transplantation in man. Effect of phorbol ester (phorbol myristate acetate) and calcium ionophore (A23187) in vitro

    DEFF Research Database (Denmark)

    Møller, J; Hofmann, B; Langhoff, E

    1989-01-01

    This study was undertaken to clarify the mechanism behind the severely decreased lymphocyte proliferative response upon stimulation with mitogens and antigens seen after allogeneic bone marrow transplantation (BMT) in man. We investigated eight BMT patients and eight controls and found that the p......This study was undertaken to clarify the mechanism behind the severely decreased lymphocyte proliferative response upon stimulation with mitogens and antigens seen after allogeneic bone marrow transplantation (BMT) in man. We investigated eight BMT patients and eight controls and found...... that the proliferative response of patient cells was reduced both when the cells were stimulated with phytohaemagglutinin (PHA) and when they were stimulated with a combination of phorbol myristate acetate (PMA), which is an activator of protein kinase C (PKC), and the calcium ionophore A23187, which irreversibly opens......) receptors (CD25) was only slightly decreased. However, the production of IL-2 was severely decreased in patient cells after stimulation with A23187/PMA (median 3541 units), although it was higher than in PHA-stimulated control cells (median 354 units). These results show that a direct activation of PKC...

  5. Surface properties, crystallinity and optical properties of anodised titanium in mixture of β-glycerophosphate (β-GP) and calcium acetate (CA)

    Science.gov (United States)

    Chuan, Lee Te; Abdullah, Hasan Zuhudi; Idris, Maizlinda Izwana

    2015-07-01

    Anodic oxidation is an electrochemical method for the production of ceramic films on a metallic substrate. It had been widely used to deposit the ceramic coatings on the metals surface. This method has been widely used in surface modification of biomaterials especially for dental implants. In this study, the surface morphology, crystallinity and optical properties of titanium foil was modified by anodising in mixture of β-glycerophosphate disodium salt pentahydrate (β-GP) and calcium acetate monohydrate (CA). The experiments were carried out at high voltage (350 V), different anodising time (5 and 10 minutes) and current density (10-70 mA.cm-2) at room temperature. Anodised titanium was characterised by using field emission scanning electron microscopy (FESEM), X-ray diffractometer (XRD), and UV-Vis spectrometry. The result of the experiment showed that surface morphology, crystallinity and optical properties depended strongly on the current density and anodising time. More porous surface and large amount of anatase and rutile was produced at higher current density and longer anodising time. Apart from that, it is also revealed that the energy band gap of anodised titanium increases as the increase in current density due to the presence of anatase and rutile TiO2.

  6. Surface properties, crystallinity and optical properties of anodised titanium in mixture of β-glycerophosphate (β-GP) and calcium acetate (CA)

    Energy Technology Data Exchange (ETDEWEB)

    Chuan, Lee Te, E-mail: gd130079@siswa.uthm.edu.my; Abdullah, Hasan Zuhudi, E-mail: hasan@uthm.edu.my; Idris, Maizlinda Izwana, E-mail: izwana@uthm.edu.my [Faculty of Mechanical and Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia, 86400 Parit Raja, Batu Pahat, Johor (Malaysia)

    2015-07-22

    Anodic oxidation is an electrochemical method for the production of ceramic films on a metallic substrate. It had been widely used to deposit the ceramic coatings on the metals surface. This method has been widely used in surface modification of biomaterials especially for dental implants. In this study, the surface morphology, crystallinity and optical properties of titanium foil was modified by anodising in mixture of β-glycerophosphate disodium salt pentahydrate (β-GP) and calcium acetate monohydrate (CA). The experiments were carried out at high voltage (350 V), different anodising time (5 and 10 minutes) and current density (10-70 mA.cm{sup −2}) at room temperature. Anodised titanium was characterised by using field emission scanning electron microscopy (FESEM), X-ray diffractometer (XRD), and UV-Vis spectrometry. The result of the experiment showed that surface morphology, crystallinity and optical properties depended strongly on the current density and anodising time. More porous surface and large amount of anatase and rutile was produced at higher current density and longer anodising time. Apart from that, it is also revealed that the energy band gap of anodised titanium increases as the increase in current density due to the presence of anatase and rutile TiO{sub 2}.

  7. Use of propranolol-magnesium aluminium silicate intercalated complexes as drug reservoirs in polymeric matrix tablets

    Directory of Open Access Journals (Sweden)

    T Pongjanyakul

    2012-01-01

    Full Text Available The objective of the present study was to investigate the use of propranolol-magnesium aluminium silicate intercalated complexes as drug reservoirs in hydroxypropylmethylcellulose tablets. The matrix tablets containing the complexes were prepared and characterised with respect to propranolol release and were subsequently compared with those loading propranolol or a propranolol-magnesium aluminium silicate physical mixture. Additionally, the effects of varying viscosity grades of hydroxypropyl methylcellulose, compression pressures and calcium acetate incorporation on the drug release characteristics of the complex-loaded tablets were also examined. The results showed that the complex-loaded tablets have higher tablet hardness than those containing propranolol or a physical mixture. The drug release from the complex-loaded tablets followed a zero-order release kinetic, whereas an anomalous transport was found in the propranolol or physical mixture tablets. The drug release rate of the complex tablet significantly decreased with increasing hydroxypropylmethylcellulose viscosity grade. Increase in the compression pressure caused a decrease in the drug release rate of the tablets. Furthermore, the incorporation of calcium ions could accelerate propranolol release, particularly in acidic medium, because calcium ions could be exchanged with propranolol molecules intercalated in the silicate layers of magnesium aluminium silicate. These findings suggest that propranolol-magnesium aluminium silicate intercalated complexes show strong potential for use as drug reservoirs in matrix tablets intended for modifying drug release.

  8. A preorganized metalloreceptor for alkaline earth ions showing calcium versus magnesium selectivity in water: biological activity of selected metal complexes.

    Science.gov (United States)

    Amatori, Stefano; Ambrosi, Gianluca; Fanelli, Mirco; Formica, Mauro; Fusi, Vieri; Giorgi, Luca; Macedi, Eleonora; Micheloni, Mauro; Paoli, Paola; Rossi, Patrizia

    2014-08-25

    The N,N'-bis[(3-hydroxy-4-pyron-2-yl)methyl]-N,N'-dimethylethylendiamine (Malten = L) forms the highly stable [CuH(-2)L] species in water, in which the converging maltol oxygen atoms form an electron-rich area able to host hard metal ions. When considering the alkaline earth series (AE), the [Cu(H(-2)L)] species binds all metal ions, with the exception of Mg(2+), exhibiting the relevant property to discriminate Ca(2+) versus Mg(2+) at physiological pH 7.4; the binding of the AE metal is visible to the naked eye. The stability constant values of the trinuclear [AE{Cu(H(-2)L)}2](2+) species formed reach the maximum for Ca(2+) (log K=7.7). Ca(2+) also forms a tetranuclear [Ca{Cu(H(-2)L)}]2(4+) species at a high Ca(2+) concentration. Tri- and tetranuclear calcium complexes show blue- and pink-colored crystals, respectively. [Cu(H(-2)L)] is the most active species in inducing DNA alterations. The DNA damages are compatible with its hydrolytic cleavages.

  9. Crystallization of calcium sulfate dihydrate under simulated conditions of phosphoric acid production in the presence of aluminum and magnesium ions

    Science.gov (United States)

    Rashad, M. M.; Mahmoud, M. H. H.; Ibrahim, I. A.; Abdel-Aal, E. A.

    2004-06-01

    The effect of Al 3+ and Mg 2+ ions, as additives, on the crystallization of gypsum was studied under simulated conditions of the phosphoric acid production. Calcium hydrogen phosphate and sulfuric acid were mixed with dilute phosphoric acid at 80°C, and the turbidity of the reaction mixture was measured at different time periods to calculate the induction time of gypsum crystals formation. Addition of Al 3+ ions up to 2% decreased the induction time and increased the growth efficiency while addition of Mg 2+ increased the induction time and decreased the growth efficiency compared with in absence of additives. Interestingly, the crystals mean and median diameters were found to increase in the presence of Al 3+ and decrease in the presence of Mg 2+. The surface energy increased with Al 3+ and decreased with Mg 2+ compared to the baseline (without additives). Gypsum morphology changed from needle-like type in absence of additives to thick-rhombic in the presence of Al 3+ ions.

  10. NASA's Advanced Environmental Barrier Coatings Development for SiC/SiC Ceramic Matrix Composites: Understanding Calcium Magnesium Alumino-Silicate (CMAS) Degradations and Resistance

    Science.gov (United States)

    Zhu, Dongming

    2014-01-01

    Environmental barrier coatings (EBCs) and SiCSiC ceramic matrix composites (CMCs) systems will play a crucial role in next generation turbine engines for hot-section component applications because of their ability to significantly increase engine operating temperatures with improved efficiency, reduce engine weight and cooling requirements. The development of prime-reliant environmental barrier coatings is essential to the viability and reliability of the envisioned CMC engine component applications, ensuring integrated EBC-CMC system durability and designs are achievable for successful applications of the game-changing component technologies and lifing methodologies.This paper will emphasize recent NASA environmental barrier coating developments for SiCSiC turbine airfoil components, utilizing advanced coating compositions, state-of-the-art processing methods, and combined mechanical and environment testing and durability evaluations. The coating-CMC degradations in the engine fatigue-creep and operating environments are particularly complex; one of the important coating development aspects is to better understand engine environmental interactions and coating life debits, and we have particularly addressed the effect of Calcium-Magnesium-Alumino-Silicate (CMAS) from road sand or volcano-ash deposits on the durability of the environmental barrier coating systems, and how the temperature capability, stability and cyclic life of the candidate rare earth oxide and silicate coating systems will be impacted in the presence of the CMAS at high temperatures and under simulated heat flux conditions. Advanced environmental barrier coating systems, including HfO2-Si with rare earth dopant based bond coat systems, will be discussed for the performance improvements to achieve better temperature capability and CMAS resistance for future engine operating conditions.

  11. The effects of secular calcium and magnesium concentration changes on the thermodynamics of seawater acid/base chemistry: Implications for Eocene and Cretaceous ocean carbon chemistry and buffering

    Science.gov (United States)

    Hain, Mathis P.; Sigman, Daniel M.; Higgins, John A.; Haug, Gerald H.

    2015-05-01

    Reconstructed changes in seawater calcium and magnesium concentration ([Ca2+], [Mg2+]) predictably affect the ocean's acid/base and carbon chemistry. Yet inaccurate formulations of chemical equilibrium "constants" are currently in use to account for these changes. Here we develop an efficient implementation of the MIAMI Ionic Interaction Model to predict all chemical equilibrium constants required for carbon chemistry calculations under variable [Ca2+] and [Mg2+]. We investigate the impact of [Ca2+] and [Mg2+] on the relationships among the ocean's pH, CO2, dissolved inorganic carbon (DIC), saturation state of CaCO3 (Ω), and buffer capacity. Increasing [Ca2+] and/or [Mg2+] enhances "ion pairing," which increases seawater buffering by increasing the concentration ratio of total to "free" (uncomplexed) carbonate ion. An increase in [Ca2+], however, also causes a decline in carbonate ion to maintain a given Ω, thereby overwhelming the ion pairing effect and decreasing seawater buffering. Given the reconstructions of Eocene [Ca2+] and [Mg2+] ([Ca2+]~20 mM; [Mg2+]~30 mM), Eocene seawater would have required essentially the same DIC as today to simultaneously explain a similar-to-modern Ω and the estimated Eocene atmospheric CO2 of ~1000 ppm. During the Cretaceous, at ~4 times modern [Ca2+], ocean buffering would have been at a minimum. Overall, during times of high seawater [Ca2+], CaCO3 saturation, pH, and atmospheric CO2 were more susceptible to perturbations of the global carbon cycle. For example, given both Eocene and Cretaceous seawater [Ca2+] and [Mg2+], a doubling of atmospheric CO2 would require less carbon addition to the ocean/atmosphere system than under modern seawater composition. Moreover, increasing seawater buffering since the Cretaceous may have been a driver of evolution by raising energetic demands of biologically controlled calcification and CO2 concentration mechanisms that aid photosynthesis.

  12. Non-free ionic transport of sodium, magnesium, and calcium in streams of two adjacent headwater catchments with different vegetation types in Japan

    Science.gov (United States)

    Terajima, Tomomi; Moriizumi, Mihoko; Nakamura, Tomohiro

    2017-01-01

    Sodium (Na), magnesium (Mg), calcium (Ca) are usually believed to occur mostly as free ions in the fresh water and consequently little is known about their chemical species. To understand the importance of non-free ionic fractions (NIF) of major metals in freshwater streams, Na, Mg, Ca, silicon (Si), and fulvic acid-like materials (FAM) were measured in streams of mountainous adjacent headwater catchments dominated by different vegetation types (planted evergreen coniferous forest and natural deciduous broadleaf forest). During both no rainfall periods and rainstorms, the proportion of NIF relative to total elements was lower in the coniferous catchment than in the deciduous catchment, although it sometimes accounted for half or more of the total concentrations of Na, Mg, and Ca in both catchments. The solubility of metal compounds was higher than the measured maximum concentrations of Na+, Mg2+, and Ca2+ to the extent that inorganic bonding was hardly possible. During no rainfall periods when FAM was slightly produced into the streams, the fluxes of NIF and Si were highly correlated (r > 0.92, p NIF correlated weakly with that of Si but did not correlate with that of FAM in both catchments. In contrast, during a heavy rainstorm, the flux of NIF correlated strongly (r ⩾ 0.83, p NIF originated in the quick-flow component (i.e., surface or near-surface water) in stream water (ΔNIF) correlated strongly (r ⩾ 0.81, p < 0.0001, n = 22) with that of FAM. These findings imply that heavy rainstorms may enhance the bonding of the major metals with humic substances mainly in the deciduous catchment; and also exhibit that, in the headwater catchments, both water flow pathways resulted from the different vegetation types play a very important role to promote the bonding of major metals with humic substances in stream water.

  13. Determination of Calcium, Magnesium, Zinc in Mongolian milk by flame atomic absorption spectrometry%火焰原子吸收法测定蒙古奶茶中的钙、镁、锌

    Institute of Scientific and Technical Information of China (English)

    张金生; 林静; 李丽华; 杨宏娟; 赵文涛

    2012-01-01

    The determination of trace elements in the Mongolian milk tea, such as Calcium, Magnesium and Zinc, was performed by flame atomic absorption spectrometry. The operation conditions were optimized. The Mongolian milk tea was treated by ashing method before determination. The results show that,there is a good linear relationship between the absorbance and concentration of trace elements. The regression equations of Calcium, Magnesium and Zinc are A = 0. 1334C+ 0.0025 (R2 =0.9993),4 = 0. 4838C + 0. 0311 (R2 =0.9998), A = 0. 2149C + 0. 0224 ( R2 =0.9997), respectively. The determination of Calcium, Magnesium and Zinc in three different Mongolian milk teas is carried out. Their RSD values are all lower than 1. 25% and the recovery is around 95. 0% - 105. 0% .%用火焰原子吸收光谱法(FAAS)测定蒙古奶茶中的微量元素钙、镁、锌.对测定条件、干扰因素、准确度和精密度进行了考察.用灰化法处理蒙古奶茶.对3种元素进行测定,结果表明,吸光度与浓度之间呈良好线性关系,钙、镁、锌回归方程分别为:A =0.1334C +0.0025(R2=0.9993),A=0.4838C +0.0311(R2=0.9998),A=0.2149C +0.0224(R2=0.9997).3种不同的蒙古奶茶中的钙、镁、锌测定结果的RSD值均小于1.25%,回收率在95.0%~105.0%.

  14. Removal of Calcium and Magnesium Ions From High Lithium Solution%从吸附法盐湖卤水提锂溶液中去除钙、镁试验研究

    Institute of Scientific and Technical Information of China (English)

    李存增; 常华; 柳杰; 罗清平

    2014-01-01

    利用碳酸钙、碳酸镁、碳酸锂在溶液中的溶度积的差异,研究了用碳酸钠从吸附法盐湖卤水提锂所得高锂溶液中去除钙、镁离子,考察了反应时间、碳酸钠用量、体系pH及晶种循环方式对钙、镁去除率的影响。试验结果表明:用质量浓度为50 g/L的碳酸钠溶液,在反应时间30 min、碳酸钠用量为沉淀钙、镁所需理论量、溶液p H为11.5,采用晶种循环方式改善过滤性能条件下,钙、镁去除率分别为98.8%和99.98%,所得溶液中,Ca2+质量浓度为9 mg/L ,M g2+质量浓度为0.7 mg/L ,整个除杂过程锂损失仅为3%左右。%By the solubility differences of calcium carbonate ,magnesium carbonate and lithium carbonate ,removing calcium and magnesium ions from high lithium solution was studied .The effects of reaction time ,sodium carbonate dosage ,solution ,pH and seed circulation style on the removal of impurities w ere investigated . T he results show that at the conditions of sodium carbonate concentrations of 50 g/L ,reaction time of 30 min ,sodium carbonate dosage as much as the theoretical amount for precipitation of calcium and magnesium ,adjusting the pH to 11 .5 ,the crystal cycle ways , removal rates of calcium and magnesium are 98 .8% and 99 .98% ,respectively .The high lithium solution with Ca2+ concentration of 10 mg/L and Mg2+ concentration of 0 .7 mg/L can be obtained . T he lithium loss in the process is only about 3% .

  15. Degradation of Calcium/Phosphorus Coating Plasma Sprayed on Magnesium Alloy in SBF Solution%镁合金表面等离子喷涂钙/磷涂层在SBF中的降解行为研究

    Institute of Scientific and Technical Information of China (English)

    郭远军; 宁成云; 谭帼馨; 黄闪闪; 熊文名; 朱红

    2012-01-01

    采用大气等离子喷涂在镁合金AZ31B表面制备了可降解钙/磷涂层.利用XRD、SEM、EDS分析了涂层的相组成、结晶度及在人体模拟液(SBF)中浸泡前后的显微形貌和元素组成,根据pH值和降解速率研究了涂层的体外降解性能.研究表明:钙/磷涂层与镁合金基体紧密结合,致密度高,涂层由较难降解的HA相和较易降解的Ca3(PO4)2、Ca4P2O9和CaO组成,涂层中HA结晶度为49.3%.生物降解性能研究显示,钙/磷涂层材料在SBF溶液中的pH值和降解速率均小于镁合金基体,且较小的变化幅度使涂层材料的降解行为控制在稳定范围内.%The biodegradable calcium/phosphate coating on the surface of the magnesium alloy AZ31B was prepared by atmospheric plasma spraying. The phase compositions and crystallinity of the coating were quantitative investigated by XRD, and the microscopic morphology and elemental composition of the coating before and after immersion in the simulated body fluid (SBF) were investigated by SEM and EDS. The degradability of magnesium alloy with calcium/phosphorus coating in SBF solution were studied according to the pH value and the degradation rate of the coating. The results show that the high density calcium/phosphate coating is closely integrated with the magnesium alloy substrate. The coating is composed of HA with difficult degradation and Ca3(PO4)2, Ca4P2O9 and CaO with easy degradation, and the crystallinity of HA in the coating is 49.3%. In addition, the study of biodegradation shows that the pH value and the degradation rate of the calcium/phosphorus coating in SBF are less than that of magnesium alloy, and the smaller change magnitude makes the coating material's degradation be controlled in a stable range.

  16. 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 ...

  17. 土壤施钙对芒果果实钾、钙、镁含量及品质的影响%Effects of different lime nitrate application rates on potassium, calcium and magnesium content and quality in mango

    Institute of Scientific and Technical Information of China (English)

    李华东; 白亭玉; 郑妍; 张贺; 林电

    2014-01-01

    以“台农1号”芒果为试材,田间试验研究了花前土施不同用量硝酸钙对芒果果实钾、钙、镁含量及产量、品质的影响。结果表明:(1)与不施钙相比,土施钙肥可明显提高果实糖酸比,其原因主要是降低了可滴定酸含量,提高了可溶性糖含量,同时可显著提高果实Vc含量,降低贮藏期果实发病率,在土施钙150 g/株时产量最高,增产率为14.25%。(2)在一定钙用量范围内,土施钙肥可显著提高果肉钙含量,使果皮、果肉与果核的钾、镁含量下降。(3)果皮、果肉及果核钙含量与钙肥用量呈正相关,钾、镁含量与钙肥用量呈负相关。(4)果实可溶性糖含量、 Vc含量及糖酸比与钙肥用量呈正相关,果实可溶性固形物含量、可滴定酸含量、失重率、发病率与钙肥用量呈负相关。土壤增施钙肥有利于提高芒果果实品质,提高果实耐贮性。%A field trial was undertaken to evaluate the effects of applying Ca( NO3 ) 2 in soil before flower period on the contents of potassium, calcium, magnesium and quality of “tainung No. 1” mango. The results showed that: (1) Compare with the results of the control, applying calcium fertilizer could obviously increase the fruit sugar acid ratio because of the increase of content of soluble sugars and acidity reduced, and improve the vitamin C in the fruit, reduce the rotten fruit rate during stor-age. The highest yield occurred when 150 g/plant calcium was applicated, and the yield increased by 14. 25% compared to the control. (2) By applying calcium fertilizer, the calcium content of pulp in fruit was significantly increased, the magnesi-um and potassium contents of peel, pulp and seed in fruit reduced. (3) The calcium contents of peel, pulp and seed in fruit had positive correlation with the calcium application amounts, and the potassium and magnesium contents of peel, pulp and seed in fruit had negative correlation with

  18. Intake of dairy products, calcium, magnesium, and phosphorus in childhood and age at menarche in the Tehran Lipid and Glucose Study.

    Directory of Open Access Journals (Sweden)

    Fahimeh Ramezani Tehrani

    Full Text Available PURPOSE: Studies indicate that milk intake is associated with insulin-like growth factor 1 (IGF-1 concentrations and height in childhood, whether milk and other dairy products promote puberty remains unclear. This study aimed to investigate influences of pre-pubertal intakes of milk, yogurt and cheese on menarcheal age in Tehranian girls. The associations of total dietary calcium (Ca, magnesium (Mg, and phosphorus (P with menarcheal age were also examined. METHODS: This prospective study was conducted on 134 pre-pubertal girls, aged 4-12 years at baseline, who participated in the Tehran Lipid and Glucose Study (TLGS, and were followed for a median of 6.5 years. Dietary intakes were determined at initiation of the study using two non-consecutive 24-h dietary recalls and the age of menarche was documented during the follow-up. Logistic regression was used to calculate the risk of reaching menarche ≤ 12 years according to pre-pubertal levels of dairy or mineral intakes. RESULTS: The risk of earlier menarche was higher in girls with higher intakes of milk [OR: 2.28 (95% CI: 1.03-5.05], Ca [OR: 3.20 (95%CI: 1.39-7.42], Mg [OR: 2.43 (95% CI: 1.12-5.27] and P [OR: 3.37 (95 % CI: 1.44-7.87 after controlling for energy and protein intake, interval between the age at study initiation and the age of menarche, and maternal age at menarche (Model 1. Girls in the middle tertile of cheese intakes had a lower risk of reaching menarche ≤ 12 years than those in the lowest tertile after controlling for covariates in model 1. These associations remained significant after further adjustment of BMI Z-score at baseline. The relationship of Ca, Mg, and P with menarche remained after further adjustment for height Z-score at baseline, whereas the association between milk and cheese intakes became non-significant. CONCLUSIONS: Pre-pubertal intake of milk, but not cheese and yogurt, may hasten age at menarche.

  19. Photosynthetic and growth response of sugar maple (Acer saccharum Marsh.) mature trees and seedlings to calcium, magnesium, and nitrogen additions in the Catskill Mountains, NY, USA

    Science.gov (United States)

    Momen, Bahram; Behling, Shawna J; Lawrence, Gregory B.; Sullivan, Joseph H

    2015-01-01

    Decline of sugar maple in North American forests has been attributed to changes in soil calcium (Ca) and nitrogen (N) by acidic precipitation. Although N is an essential and usually a limiting factor in forests, atmospheric N deposition may cause N-saturation leading to loss of soil Ca. Such changes can affect carbon gain and growth of sugar maple trees and seedlings. We applied a 22 factorial arrangement of N and dolomitic limestone containing Ca and Magnesium (Mg) to 12 forest plots in the Catskill Mountain region of NY, USA. To quantify the short-term effects, we measured photosynthetic-light responses of sugar maple mature trees and seedlings two or three times during two summers. We estimated maximum net photosynthesis (An-max) and its related light intensity (PAR at An-max), apparent quantum efficiency (Aqe), and light compensation point (LCP). To quantify the long-term effects, we measured basal area of living mature trees before and 4 and 8 years after treatment applications. Soil and foliar chemistry variables were also measured. Dolomitic limestone increased Ca, Mg, and pH in the soil Oe horizon. Mg was increased in the B horizon when comparing the plots receiving N with those receiving CaMg. In mature trees, foliar Ca and Mg concentrations were higher in the CaMg and N+CaMg plots than in the reference or N plots; foliar Ca concentration was higher in the N+CaMg plots compared with the CaMg plots, foliar Mg was higher in the CaMg plots than the N+CaMg plots; An-max was maximized due to N+CaMg treatment; Aqe decreased by N addition; and PAR at An-max increased by N or CaMg treatments alone, but the increase was maximized by their combination. No treatment effect was detected on basal areas of living mature trees four or eight years after treatment applications. In seedlings, An-max was increased by N+CaMg addition. The reference plots had an open herbaceous layer, but the plots receiving N had a dense monoculture of common woodfern in the

  20. Effect of dietary Garcinia cambogia extract on serum essential minerals (calcium, phosphorus, magnesium) and trace elements (iron, copper, zinc) in rats fed with high-lipid diet.

    Science.gov (United States)

    Gürsel, Feraye Esen; Ateş, Atila; Bilal, Tanay; Altiner, Ayşen

    2012-09-01

    The aim of the study was to investigate the effect of Garcinia cambogia extract on serum calcium (Ca), phosphorus (P), magnesium (Mg), iron (Fe), zinc (Zn) and copper (Cu) concentrations in rats fed with the normal or the high-lipid and -cholesterol diet. Thirty 1-year-old female Sprague-Dawley rats (pathogen-free), weighing an average of 229 g, were randomly assigned to three experimental groups of ten animals each. Diets and tap water were given ad libitum for 75 days. Group 1 (control group) was fed with basal diet (2 % liquid vegetable oil, 0 % cholesterol), while the diets of groups 2 and 3 contained vegetable oil (2 % liquid vegetable oil and 5 % hydrogenated vegetable oil) and cholesterol (3 %) in high levels. 4,5 % G. cambogia extract containing 65 % HCA was added to the diet of group 3 as from day 45. Blood samples were withdrawn on days 0, 45 and 75. Serum mineral levels were analyzed using standard enzymatic colorimetric methods with a spectrophotometer. All significant differences were pcambogia extract than in the control group on day 45. Serum Mg level was significantly higher in group 2 than in the control group on day 45. Serum Fe levels were significantly lower in the control group than in the other groups on days 45 and 75. Serum Zn level of the group fed with high-lipid diet and G. cambogia extract was significantly higher than in the control group on day 75. Serum Cu levels were significantly higher in group 2 than in the control group, and in group 3 than in group 2 on day 75. In conclusion, a diet containing the high fat amounts may lead to the increase in circular levels of some minerals due to the short-chain fatty acid production lowering the luminal pH which increases mineral solubility, or serving as a fuel for mucosal cells and stimulating cell proliferation in the large intestine. G. cambogia extract may be used in the P and Cu deficiencies due to increases resulting in the present P and Cu amounts in G. cambogia extract, or the use of

  1. 原子吸收光度法分析临沧饮用水中钙、镁元素%Analysis of Calcium and Magnesium of Drinking Water in Lincang by Atomic Absorption Photometry Method

    Institute of Scientific and Technical Information of China (English)

    阳小勇; 徐运贵

    2016-01-01

    分析云南省临沧农村地区饮用水的钙、镁离子浓度.在选定的最佳实验条件下采取火焰原子吸收法.所得钙镁离子的线性回归方程分别为Y=0.0659x+0.0403(R2=0.9965), Y=0.1242x+0.0014(R2=0.9981);钙、镁离子的加标回收率分别在97.1%~103.6%,95.3%~101.4%之间。结果表明:该地区饮用水的钙、镁元素最高浓度为160 mg/kg,属于软水。%The concentration of calcium and magnesium ion of drinking in rural areas of Lincang was analyzed. Flame atomic absorption spectroscopy method was used under best experimental condition. The equation of linear regression was as follows: Ca: Y=0. 0659x+0. 0403 (R2=0. 9965), Mg: Y=0. 1242x+0. 0014 (R2=0. 9981). The recoveries of standard addition were as follows:Ca:97. 1% ~103. 6%, Mg:95. 3% ~101. 4%. The results showed that the highest concentration of calcium and magnesium of drinking water in rural areas of Lincang were 160 mg/kg. The water belonged to soft water.

  2. Calcium carbonate with magnesium overdose

    Science.gov (United States)

    ... K. General approach to the poisoned patient. In: Marx JA, Hockberger RS, Walls RM, eds. Rosen's Emergency ... 147. Pfennig CL, Slovis CM. Electrolyte disorders. In: Marx JA, Hockberger RS, Walls RM, eds. Rosen's Emergency ...

  3. Calcium, Magnesium and Total Antioxidant Capacity (TAC in Seminal Plasma of Water Buffalo (Bubalus Bubalis Bulls and their Relationships with Semen Characteristics

    Directory of Open Access Journals (Sweden)

    Mohammad-Hassan Khadem Ansari

    2010-06-01

    Full Text Available In order to determine calcium (Ca, magnesium (Mg content and total antioxidant capacity (TAC of seminal plasma in buffalo and to study their associations with the semen characteristics, 54 semen samples were collected from 10 buffalo bulls; semen quality was evaluated, seminal plasma was then harvested by centrifugation and its Ca and Mg content were estimated and its TAC determined. The Ca and Mg content of the seminal plasma (Mean ± SEM were recorded as 22.36 ± 0.52 mg dl-1 and 11.94 ± 0.36 mg dl-1 respectively, while, its mean TAC value was 1.50 ± 0.02 mmol L-1. The mean Ca value was highly associated with sperm progressive motility, gross motility, viability (P = 0.000 for all, negatively with semen volume (P = 0.01, and with Mg and TAC values (P = 0.000 for both. The mean Mg values was highly associated with sperm progressive motility, gross motility and viability and seminal plasma Ca and TAC (P = 0.000 for all and negatively associated with semen volume (P = 0.014. The mean TAC values was highly associated with sperm progressive motility, gross motility and viability and seminal plasma Ca and Mg (P = 0.000 for all. For further clarification of these associations, the data was categorized in three groups of excellent (Ex, >90% motile, n = 33, good (Go, 80-89% motile, n = 15 and moderate (Mo, <79% motile, n = 6 according to their percentage of sperm motility. The mean progressive motility in Ex group was 92.24 ± 0.51%, in Go group it was 81.66 ± 0.62 %, and in Mo group it was 71.66 ± 1.05 %. The mean Ca, Mg and TAC values were respectively recorded as 25.12 ± 0.29 mg dl-1, 13.78 ± 0.20 mg dl-1, and 1.57 ± 0.009 mmol L-1 in Ex, 18.74 ± 0.63 mg dl-1, 9.14 ± 0.33mg dl-1, and 1.42 ± 0.044 mmol L-1 in Go, and 17.34 ± 0.18 mg dl-1, 8.06 ± 0.25 mg dl-1, and 1.23± 0.05 mmol L-1 in Mo groups. The associations in groups are discussed. These results show that seminal plasma Ca and Mg content and TAC are associated with semen

  4. Stimulation of large-conductance calcium-activated potassium channels inhibits neurogenic contraction of human bladder from patients with urinary symptoms and reverses acetic acid-induced bladder hyperactivity in rats.

    Science.gov (United States)

    La Fuente, José M; Fernández, Argentina; Cuevas, Pedro; González-Corrochano, Rocío; Chen, Mao Xiang; Angulo, Javier

    2014-07-15

    We have analysed the effects of large-conductance calcium-activated potassium channel (BK) stimulation on neurogenic and myogenic contraction of human bladder from healthy subjects and patients with urinary symptoms and evaluated the efficacy of activating BK to relief bladder hyperactivity in rats. Bladder specimens were obtained from organ donors and from men with benign prostatic hyperplasia (BPH). Contractions elicited by electrical field stimulation (EFS) and carbachol (CCh) were evaluated in isolated bladder strips. in vivo cystometric recordings were obtained in anesthetized rats under control and acetic acid-induced hyperactive conditions. Neurogenic contractions of human bladder were potentiated by blockade of BK and small-conductance calcium-activated potassium channels (SK) but were unaffected by the blockade of intermediate calcium-activated potassium channels (IK). EFS-induced contractions were inhibited by BK stimulation with NS-8 or NS1619 or by SK/IK stimulation with NS309 (3µM). CCh-induced contractions were not modified by blockade or stimulation of BK, IK or SK. The anti-cholinergic agent, oxybutynin (0.3µM) inhibited either neurogenic or CCh-induced contractions. Neurogenic contractions of bladders from BPH patients were less sensitive to BK inhibition and more sensitive to BK activation than healthy bladders. The BK activator, NS-8 (5mg/kg; i.v.), reversed bladder hyperactivity induced by acetic acid in rats, while oxybutynin was ineffective. NS-8 did not significantly impact blood pressure or heart rate. BK stimulation specifically inhibits neurogenic contractions in patients with urinary symptoms and relieves bladder hyperactivity in vivo without compromising bladder contractile capacity or cardiovascular safety, supporting its potential therapeutic use for relieving bladder overactivity.

  5. Leguminous Plants Rhizobia Degradation of Calcium Carbonate and Magnesium Carbonate%石漠化地区豆科植物根瘤菌降解碳酸钙、镁能力研究

    Institute of Scientific and Technical Information of China (English)

    王明月; 刘绍雄; 熊智; 丁雅迪; 王艳玲; 李克艳; 阳廷丹; 陶茜; 王金华

    2014-01-01

    , the thesis studied on the 9 strains from leguminous plants rhizobia by the test of doing the strains in liquid medium with difficult soluble calcium carbonate or magnesium carbonate, then, handled with 28.5℃, 160 r·min-1 and 15 d table culture, sampled 2 ml of three at 0, 1, 3, 6, 10, 15 d. Samples added into the 10 mL digestive juices for a night, nitric acid and perchloric acid volume ratio was 5 to 1 of the digestive juices, heating Slowly, get clear solutions, the capacity to 10 mL by adding 2% hydrochloric acid solution which contain La3+,the same do with blank,used the flame atomic absorption method to determin contents of Ca2+ and Mg2+ in the samples parallel. We eagered to obtain the certain strains had strong degradation of calcium carbonate or magnesium carbonate. The results showed that the best calcium carbonate degradation strains wereRhizobium tropici (SWFU09) andRhizobium sp. (SWFU02), the best strains of magnesium carbonate degradation wereRhizobiumsp. (SWFU03), Rhizobium tropici(SWFU05) andBradyrhizobium sp. (SWFU01). The solution pH had an important influence on degradation of magnesium carbonate, but not obvious on calcium carbonate degradation. We could have a conclusion: acid producted by microbial metabolism had a certain influence on degradations of calcium carbonate and magnesium carbonate, but it was not the only factor. Organic ligand (base) also producted by microbial metabolism might adsorpt on calcium carbonate or magnesium carbonate surface, it could form compounds with ingredients in the water, change the balance of dissolution, Ca2+ and Mg2+were replaced.

  6. 75 FR 51002 - Pure Magnesium In Granular Form from the People's Republic of China: Initiation of Changed...

    Science.gov (United States)

    2010-08-18

    ... make magnesium-based reagent mixtures. The non-magnesium granular materials of which the Department is aware used to make such excluded reagents are: lime, calcium metal, calcium silicon, calcium carbide... (Al2O3), calcium aluminate, soda ash, hydrocarbons, graphite, coke, silicon, rare earth...

  7. 77 FR 63787 - Pure Magnesium in Granular Form from the People's Republic of China: Continuation of Antidumping...

    Science.gov (United States)

    2012-10-17

    ... materials to make magnesium-based reagent mixtures. The non-magnesium granular materials of which the Department is aware used to make such excluded reagents are: Lime, calcium metal, calcium silicon, calcium..., alumina (Al2O3), calcium aluminate, soda ash, hydrocarbons, graphite, coke, silicon, rare earth...

  8. 77 FR 46030 - Pure Magnesium in Granular Form From the People's Republic of China: Preliminary Results of...

    Science.gov (United States)

    2012-08-02

    ... materials to make magnesium-based reagent mixtures. The non-magnesium granular materials of which the Department is aware used to make such excluded reagents are: Lime, calcium metal, calcium silicon, calcium..., alumina (Al 2 O 3 ), calcium aluminate, soda ash, hydrocarbons, graphite, coke, silicon, rare earth...

  9. 76 FR 47147 - Pure Magnesium in Granular Form From the People's Republic of China: Rescission of Antidumping...

    Science.gov (United States)

    2011-08-04

    ... materials to make magnesium-based reagent mixtures. The non-magnesium granular materials of which the Department is aware used to make such excluded reagents are: lime, calcium metal, calcium silicon, calcium..., alumina (Al2O3), calcium aluminate, soda ash, hydrocarbons, graphite, coke, silicon, rare earth...

  10. 77 FR 33165 - Pure Magnesium in Granular Form From the People's Republic of China: Final Results of Expedited...

    Science.gov (United States)

    2012-06-05

    ... materials to make magnesium-based reagent mixtures. The non-magnesium granular materials of which the Department is aware used to make such excluded reagents are: lime, calcium metal, calcium silicon, calcium..., alumina (Al2O3), calcium aluminate, soda ash, hydrocarbons, graphite, coke, silicon, rare earth...

  11. 醋酸钙/飞灰复合脱硫脱硝剂热解性能实验研究%Experimental Study on the Pyrolysis of Calcium Acetate/Fly Ash Compound Adsorbent Used as Desulfurizer and Denitrificater

    Institute of Scientific and Technical Information of China (English)

    李范范; 冯立斌; 谢为涛

    2016-01-01

    为了提高脱硫脱硝效率同时合理利用火电厂产生的飞灰,研究了醋酸钙中加入飞灰制备的复合脱硫脱硝剂的热解性能.对不同条件下制得的醋酸钙/飞灰复合脱硫脱硝剂的热重特性、X射线衍射图谱、比表面积、扫描电镜结果等进行了分析,结果表明:利用醋酸钙和飞灰水合制备的脱硫脱硝剂具有比单纯的醋酸钙和飞灰更大的比表面积;经过900℃煅烧后脱硫脱硝剂孔隙结构最好;脱硫脱硝剂经过900℃煅烧后的热解产物(SiO2、Al2O3、Fe2O3和CaO)有助于脱除烟气中的硫氧化物和氮氧化物.%In order to improve the efficiency of absorbent for desulfurization and denitrification simultaneously to utilize the coal fly ash produced by thermal power plants more effectively,this paper analyzed the pyrolysis of the compound absorbent used as desulfurizer and denitrificater which was prepared from calcium acetate and coal fly ash. TG,XRD,BET and SEM analyses about the compound absorbent produced under different conditions showed that:the compound absorbent which was obtained through hydration of calcium acetate and coal fly ash had the greater spe-cific surface area than calcium acetate and coal fly ash,and it had the best pore structure after 900 ℃ calcination;The pyrolysis products (SiO2 ,Al2O3 ,Fe2O3 and CaO)of the compound absorbent after 900 ℃ calcination are helpful for removing sulfur oxides and nitrogen oxides from flue gas.

  12. 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.

  13. Influence of sodium, calcium, magnesium, and ammonium in the sorption of cadmium in a zeolite rock; Influencia del sodio, calcio, magnesio y amonio en la sorcion de cadmio en una roca zeolitica

    Energy Technology Data Exchange (ETDEWEB)

    Teutli S, E.A

    2007-07-01

    The cadmium is one of the more toxic heavy metals and the water pollution by this metal, is originated by industries whose turn is the production of batteries, electroplating processes, the production of pigments and in the refinement process of others metals. The objective of this work was to evaluate the ion exchange of cadmium using natural zeolite, obtained from the Arroyo zone, La Haciendita Municipality, in the State of Chihuahua. The parameters considered in this investigation were: the sorption time, the pH, the initial concentration of cadmium and the influence of sodium, calcium, magnesium and ammonium on the sorption of cadmium in the natural zeolite. Also, the theoretical pattern for kinetics and isotherm that better it is adjusted to those experimental results it was determined. The experimentation results allowed to establish the following conclusions: the sorption of the cadmium doesn't depend on the pH in an interval between 4 and 6; the pattern that better it describes the kinetics it is that of Pseudo-second order of Ho and Mc Kay; the Langmuir-Freundlich pattern is the one that better it describes the sorption isotherm and the calcium is the component that interferes in an important manner in the sorption of cadmium. The carried out investigation contributes to the definition of some of the parameters that should be considered in the development of ion exchangers for the cadmium removal. (Author)

  14. Effect of lanthanum carbonate combined calcium acetate on calcium and phosphorus metabolism in patients with mai-ntenance hemodialysis%碳酸镧联合醋酸钙对维持性血液透析患者钙磷代谢的影响

    Institute of Scientific and Technical Information of China (English)

    汪嘉莉; 杨晗; 张林; 廖丹; 张逢莲

    2016-01-01

    Objective To investigate the effect of lanthanum carbonate combined calcium acetate in maintaining he-modialysis patients.Methods Seventy-eighy cases of maintenance hemodialysis patients in Mianyang Central Hospital from December 2014 to January 2009 were randomly divided into 3 groups:lanthanum carbonate group (16 cases), calcium acetate group (37 cases) and lanthanum carbonate group ( combined group 25 cases) .Treatment of 12 weeks, compared the 3 groups of patients'calcium and phosphorus metabolism.Results ( 1 ) Calcium and phosphorus metabolism: Compared with before treatment, serum calcium levels after 12 weeks in the three groups showed no significant changes, the difference was not statis-tically significant ( P >0.05), serum phosphorus, serum calcium and phosphorus product parathyroid hormone (iPTH) were significantly lower, the difference was statistically significant (lanthanum carbonate group:t =5.88,2.22,6.20,calcium ace-tate group:t =5.11,3.28,6.02, combined group:t =10.08,6.90,9.33, P 0.05);among the three groups, before and after treatment, the indicators showed no significant differences ( P >0.05).(3)Ultrasound:3 groups of patients before and after treatment of carotid intimal thickening and plaque formation ratio's difference did not show statistically significant ( P >0.05).Conclusion Lanthanum carbonate combined with calcium acetate can be used in the treatment of chronic kidney dis-ease hemodialysis patients with high phosphorus, it can effectively reduce the level of serum phosphorus and PTH.%目的 观察碳酸镧联合醋酸钙对维持性血液透析患者钙磷代谢的影响.方法 选取2009年1月—2014年12月绵阳市中心医院维持性血液透析高磷血症患者78例,采用简单随机化分组法分为碳酸镧组(16例)、醋酸钙组(37例)和碳酸镧联合醋酸钙组(联合组,25例).治疗12周,比较3组患者的钙磷代谢情况.结果 (1)钙磷代谢指标:与治疗前比较,治疗12周后3组患者血钙水平均

  15. 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%.

  16. Simultaneous determination of free calcium, magnesium, sodium and potassium ion concentrations in simulated milk ultrafiltrate and reconstituted skim milk using the Donnan Membrane Technique

    NARCIS (Netherlands)

    Gao, R.; Temminghoff, E.J.M.; Leeuwen, van H.P.; Valenberg, van H.J.F.; Eisner, M.D.; Boekel, van M.A.J.S.

    2009-01-01

    This study focused on determination of free Ca2+, Mg2+, Na+ and K+ concentrations in a series of CaCl2 solutions, simulated milk ultrafiltrate and reconstituted skim milk using a recently developed Donnan Membrane Technique (DMT). A calcium ion selective electrode was used to compare the DMT results

  17. 氯化镁对铝酸钙水泥结合浇注料性能的影响%Influence of magnesium chloride on properties of calcium aluminate cement bonded castables

    Institute of Scientific and Technical Information of China (English)

    王青峰; 王亚娟; 李坤鹏; 宋秀娟; 张传银; 叶国田

    2014-01-01

    为了改善铝酸钙水泥结合浇注料的高温体积稳定性,以 w (Al2 O3)≥99.5%的板状刚玉为骨料, w(Al2O3)≥99.7%的活性Al2O3微粉和板状刚玉细粉(≤0.044 mm)为基质,以铝酸钙水泥Secar 71为结合剂,添加适量氯化镁制备铝酸钙水泥结合浇注料,分别在1100℃3 h和1450℃3 h进行热处理,测定浇注料试样的常温物理性能,并分析基质试样的物相组成和显微结构。结果表明:氯化镁的加入会导致浇注料经高温处理后的体积密度下降,显气孔率升高,并降低浇注料高温处理后的力学性能;但是,含氯化镁的浇注料经高温处理后的线膨胀较小。通过显微结构分析发现,在含氯化镁的浇注料基质中有发育良好的板片状CA6,氯化镁分解所产生的孔隙可以为高温下CA6的形成提供部分可膨胀的空间,从而降低CA6形成所带来的体积膨胀,有利于改善浇注料经高温处理后的体积稳定性。%To improve the volume stability at high tempeartures,calcium aluminate cement bonded castables were prepared using tabular alumina (Al2O3≥99.5 mass%)as aggregate,reactive alumina micropowder (Al2O3≥99.7 mass%),and tabular alumina fines (≤0.044 mm)as matrix,calcium aluminate cement (Se-car 71)as binder,and magnesium chloride as additive.The castables were fired at 1 100 ℃ and 1 450 ℃for 3 h,respectively.Then physical properties of the castables were tested,and phase composition and mi-crostructure of castable matrix specimens were analyzed.The results show that the castable with magnesi-um chloride has the decreased bulk density,the increased apparent porosity and the decreased mechani-cal properties and linear expansion after firing at high temperatures.It is found in the microstructure that the well developed tabular CA6 crystals disperse in the matrix of the castable with magnesium chloride.There-fore,these voids generated from the decomposition of

  18. 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

  19. Determinação de cálcio e magnésio pelo EDTA em extratos ácidos de solos Calcium and magnesium determination in soils with EDTA

    Directory of Open Access Journals (Sweden)

    Bernardo van Raij

    1966-01-01

    Full Text Available Foi estudada marcha analítica para determinação de cálcio e magnésio, pelo EDTA, em soluções que continham também ferro, alumínio, manganês e cobre. Para extratos ácidos de solos, é proposta uma marcha analítica com as seguintes etapas: separação de ferro, alumínio e manganês, por precipitação em meio amoniacal, em presença de água oxigenada; titulação do cálcio com solução de EDTA a um pH maior que 12, empregando como indicador a murexida; destruição da murexida por acidificação e aquecimento; complexação do cobre com o dietilditiocarbamato de sódio e determinação do magnésio pela solução de EDTA, a pH 10, com o indicador preto de eriocromo T.A procedure for the determination of calcium and magnesium with EDTA in solutions containing iron, aluminum, manganese and copper was studied. The following procedure is proposed for 0.05 Nnitric acid extracts of soils: aprecipitation of iron, aluminum and manganese with ammonium hydroxide and hydrogen peroxide; bcalcium titration with EDTA solution at pH higher than 12, using murexide as dye; c destruction of the murexide by acidification and heating; dcopper complexing by sodium diethyldithyocarbamate and magnesium determination with EDTA, at pH 10, using Eriochrome Black T as dye.

  20. 生态葛根奶中铜、锌、铁、钙、镁含量测定%DETERMINATION OF COPPER, ZINC, IRON, CALCIUM AND MAGNESIUM IN ECOLOGICAL PUERARIA LOBA TA OHWI MILK

    Institute of Scientific and Technical Information of China (English)

    张文静; 刘洁; 韩萍; 黄润平; 王旗

    2011-01-01

    测定生态葛根奶中矿物质的含量,探讨其营养价值.硝酸-高氯酸消解样品,用火焰原子吸收光谱法测定生态葛根奶(饲喂葛根4周)及未饲喂葛根的对照组奶样中铜、锌、铁、钙、镁的含量,应用F检验、SNK法和LSD-t检验对结果进行统计分析.测定方法的精密度介于0.04%~0.7%,平均回收率介于93.70%~106.20%.试验组和对照组比较:铜的含量差异没有统计学意义(F=2.702,P>0.05);锌的含量差异没有统计学意义(F=1.684,P>0.05);钙的含量差异没有统计学意义(F=2.253,P>0.05);铁的含量试验组(饲喂葛根1周、2周、3周)高于对照组且差异有统计学意义(F=9.369,P<0.05);镁的含量试验组(饲喂葛根1周、2周、4周)高于对照组且差异有统计学意义(F=4.142,P<0.05).生态葛根奶中铜、锌、钙含量与普通奶中含量无显著差异,铁、镁的含量较普通奶含量丰富.%In order to determine the content of minerals and discuss the nutritive value of ecological Pueraria lobata Ohwi milk, the paper determined the content of copper, zinc, iron, calcium and magnesium in a milk sample of a test group (fed with Pueraria lobata Ohwi for four weeks) and in a control milk sample of a control group (produced by cows not fed with Pueraria lobata Ohwi) by flame atomic absorption spectrophotometry (FAAS) using HNO3 and HC1O4 to digest the samples, and also analyzed the determination results by F test, SNK method and LSD-t test. The determination results of the test group and the control group showed that the differences in copper content, zinc content and calcium content had no statistical significance (F=2.702, /M).O5), (F=1.684, P>0.05)and (F=2.253, P>0.05); the iron content of the test group (fed with Pueraria lobata Ohwi for one week, two weeks and three weeks) was higher than that of the control group, and the difference in the iron content had statistical significance (F=9.369, P<0.05); and the magnesium

  1. 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.

  2. Andrographolide suppresses thymic stromal lymphopoietin in phorbol myristate acetate/calcium ionophore A23187-activated mast cells and 2,4-dinitrofluorobenzene-induced atopic dermatitis-like mice model

    Directory of Open Access Journals (Sweden)

    Li CX

    2016-02-01

    Full Text Available Chun-xiao Li,* Hua-guo Li,* Hui Zhang,* Ru-hong Cheng, Ming Li, Jian-ying Liang, Yan Gu, Bo Ling, Zhi-rong Yao, Hong Yu Department of Dermatology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China *These authors contributed equally to this work Background: Atopic dermatitis (AD is one of the most common inflammatory cutaneous diseases. Thymic stromal lymphopoietin (TSLP has been demonstrated to be an important immunologic factor in the pathogenesis of AD. The production of TSLP can be induced by a high level of intracellular calcium concentration and activation of the receptor-interacting protein 2/caspase-1/NF-κB pathway. Andrographolide (ANDRO, a natural bicyclic diterpenoid lactone, has been found to exert anti-inflammatory effects in gastrointestinal inflammatory disorders through suppressing the NF-κB pathway. Objective: To explore the effect of ANDRO on the production of TSLP in human mast cells and AD mice model. Methods: We utilized enzyme-linked immunosorbent assay, real-time reverse transcription polymerase chain reaction analysis, Western blot analysis, and immunofluorescence staining assay to investigate the effects of ANDRO on AD. Results: ANDRO ameliorated the increase in the intracellular calcium, protein, and messenger RNA levels of TSLP induced by phorbol myristate acetate/calcium ionophore A23187, through the blocking of the receptor-interacting protein 2/caspase-1/NF-κB pathway in human mast cell line 1 cells. ANDRO, via oral or local administration, also attenuated clinical symptoms in 2,4-dinitrofluorobenzene-induced AD mice model and suppressed the levels of TSLP in lesional skin. Conclusion: Taken together, ANDRO may be a potential therapeutic agent for AD through suppressing the expression of TSLP. Keywords: atopic dermatitis, thymic stromal lymphopoietin, andrographolide, human mast cell

  3. Relationship between macrofauna, mineralogy and exchangeable calcium and magnesium in Cerrado Oxisols under pasture Relações entre macrofauna, mineralogia, cálcio e magnésio trocáveis em Latossolos do Cerrado sob pastagem

    Directory of Open Access Journals (Sweden)

    Pedro Rodolfo Siqueira Vendrame

    2009-08-01

    Full Text Available The objective of this work was to assess the relationship between macrofauna, mineralogy and exchangeable calcium and magnesium in Cerrado Oxisols under pasture. Twelve collection points were chosen in the Distrito Federal and in Formosa municipality, Goiás state, Brazil, representing four soil groups with varied levels of calcium + magnesium and kaolinite/(kaolinite + gibbsite ratios. Soil macrofauna was collected in triplicate at each collection point, and identified at the level of taxonomic groups. Macrofauna density showed correlation with contents of kaolinite, gibbsite and exchangeable Ca + Mg in the soils. Mineralogy and exchangeable Ca + Mg had significant effects on taxonomic groups and relative density of soil macrofauna. The termites (Isoptera were more abundant in soils with low exchangeable Ca + Mg; earthworms (Oligochaeta, in soils with high levels of kaolinite; and Hemiptera and Coleoptera larvae were more abundant in gibbsitic soils with higher contents of total carbon.O objetivo deste trabalho foi avaliar as relações entre a macrofauna, a mineralogia e os teores de cálcio e magnésio, em latossolos do Cerrado sob pastagem. Doze pontos de coleta foram escolhidos no Distrito Federal e no Município de Formosa, GO, e representaram quatro grupos de solo com variados teores de cálcio + magnésio e razões caulinita/(caulinita + gibsita. A macrofauna do solo foi coletada em triplicata, em cada ponto, e identificada quanto ao grupo taxonômico. A densidade da macrofauna foi relacionada aos teores de caulinita, gibsita e Ca + Mg trocáveis. Houve efeito significativo da mineralogia e dos teores de Ca + Mg trocáveis sobre os grupos taxonômicos e sobre a densidade relativa da macrofauna edáfica. Verificou-se maior densidade de Isoptera nos solos com baixos teores de Ca + Mg, de Oligochaeta nos solos cauliníticos, e maior densidade de Hemiptera e larvas de Coleoptera nos solos gibsiticos e com maiores teores de carbono total.

  4. Study of the effect of magnesium concentration on the deposit of allotropic forms of calcium carbonate and related carbon steel interface behavior

    Energy Technology Data Exchange (ETDEWEB)

    Ben Amor, Y., E-mail: yasser_ben@yahoo.f [Institut Superieur des Sciences et Technologies de l' Environnement de Borj-Cedria, B.P 1003, Hammam-Lif 2050 (Tunisia); Bousselmi, L. [Laboratoire Traitement et Recyclage des Eaux, B.P 273, Hammam-Lif, Technopole de Borj-Cedria, 8020 Soliman (Tunisia); Tribollet, B. [UPR 15 CNRS - Physique des liquides et Electrochimie, Universite Pierre et Marie Curie - Tour 22, 4 place Jussieu, 75252 Paris Cedex 05 (France); Triki, E. [Unite de recherche Corrosion et Protection des metalliques, Ecole Nationale d' Ingenieurs de Tunis, P.B. 37, 1002 Tunis, Belvedere (Tunisia)

    2010-06-30

    Different allotropic forms of calcium carbonate scales were electrochemically deposited on a carbon steel surface in artificial underground Tunisian water at -0.95 V{sub SCE} and various Mg{sup 2+} concentrations. Because of the importance of the diffusion process, the rotating disk electrode was used. The deposition kinetics were analyzed by chronoamperometry measurements and the calcareous layers were characterized by electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). The physical model proposed by Gabrielli was used to analyze the EIS measurements. Independent of the deposited allotropic form of calcium carbonate, the measurements showed that the oxygen reduction occurs in the pores formed between the CaCO{sub 3} crystals and the metallic surface.

  5. Computational Material Modeling of Hydrated Cement Paste Calcium Silicate Hydrate (C-S-H) Chemistry Structure - Influence of Magnesium Exchange on Mechanical Stiffness: C-S-H Jennite

    Science.gov (United States)

    2015-04-27

    material chemistry structure are studied following a molecular dynamics (MD) computational modeling methodology. Calcium ions are replaced with... chemistry structure. Conference Name: 1st Pan-American Conference on Computational Mechanics Conference Date: April 27, 2015 1st Pan-American Congress on...MODELING OF C-S-H Material chemistry level modeling following the principles and techniques commonly grouped under Computational Material Science is

  6. Simultaneous Determination of Diatomite in Silicon, Aluminum, Iron, Calcium and Magnesium by ICP-OES Method%ICP-OES法同时测定硅藻土中硅、铝、铁、钙、镁

    Institute of Scientific and Technical Information of China (English)

    张立新; 孙有娥

    2015-01-01

    A method for the simultaneous determination of diatomite in silicon, aluminum, iron, calcium and magnesium was studied by plasma atomic emission spectroscopy method. The samples were pre-treated with microwave digestion with ICP determination and resulted in terms of oxide. The results showed that 5 elements had a good linear correlation coefficient ( r) of 0. 999 or more, precision ( RSD) was less than 2%, recoveries were between 96% and 106%. The method is stable and reliable, simple operation, small reagent consumption.%研究利用等离子体原子发射光谱同时测定硅藻土中硅、铝、铁、钙、镁五种元素的方法。样品经微波消解前处理后,用ICP测定,结果再换算成氧化物。结果显示:5种元素的线性好,相关系数均( r)为0.999以上;精密度( RSD)小于2%;回收率在96%~106%之间。该方法稳定可靠、操作简单、试剂消耗量小。

  7. Loading rutin into nanoliposomes by forming calcium acetate gradient and its quality evaluation%醋酸钙梯度主动载药法制备芦丁纳米脂质体

    Institute of Scientific and Technical Information of China (English)

    李海霞; 杨耀; 路春波; 罗政; 张振中

    2015-01-01

    Aim:To prepare nanoliposomes with high entrapment efficiencies ( EE) by active loading drug method for improving absorption of rutin in the body .Methods:The gradient of calcium acetate was used to produce the driving force of loading drug .HPLC, centrifugal ultrafiltration and laser particle size analyzer were employed to determined rutin con -tent, EE, size distribution and zeta potential , respectively .The influence of various factors on the EE and size was investi-gated.Furthermore, the release behavior in vitro and stability under 4℃were studied.Results:The conditions of genera-ting calcium acetate gradient were determined as 10 volumes of 30 g/L sucrose to dialyze three times .The EE and stability of liposomes were enhanced by 20 g/L PVP solubilizing rutin .Under the optimized preparation conditions ( phospholipid con-centration 40 g/L, phospholipid:cholesterol 5:1, drug-lipid ratio 1:30, 50 ℃ incubation foe 15 min), the EE a-chieved 80.3%.Rutin was nanosized with an average size of 185 nm, a zeta potential of -1.2 mV.Also, the preparation was stable within 28 days and more drug was released compared with native rutin .Conclusion:Active loading druy method of calcium acetate gradient can prepare rutin nanoliposomes with high EE and better release .%目的:采用主动载药法制备芦丁纳米脂质体,提高包封率,增加药物在体外的释放。方法:利用醋酸钙梯度造成主动载药的驱动力,HPLC测定芦丁含量,离心超滤法测定脂质体包封率,激光粒度仪测定粒径分布和电位,考察单因素对包封率及粒径的影响,并进一步研究芦丁纳米脂质体在4℃的稳定性和体外释放。结果:空白脂质体10倍体积的30 g/L蔗糖、透析3次可高效建立醋酸钙梯度,20 g/L PVP作为溶解介质可有效增加芦丁的包封率和稳定性,在最佳制备工艺条件(磷脂浓度40 g/L、磷脂:胆固醇质量比为5:1、药脂质量比1:30、50℃孵育15 min

  8. High Levels of Copper, Zinc, Iron and Magnesium, but not Calcium, in the Cerebrospinal Fluid of Patients with Fahr’s Disease

    Directory of Open Access Journals (Sweden)

    Isao Hozumi

    2010-05-01

    Full Text Available Patients with marked calcification of the basal ganglia and cerebellum have traditionally been referred to as having Fahr’s disease, but the nomenclature has been criticized for including heterogeneous etiology. We describe 3 patients with idiopathic bilateral striatopallidodentate calcinosis (IBSPDC. The patients were a 24-year-old man with mental deterioration, a 57-year-old man with parkinsonism and dementia, and a 76-year-old woman with dementia and mild parkinsonism. The former 2 patients showed severe calcification of the basal ganglia and cerebellum, and the latter patient showed severe calcification of the cerebellum. We found significantly increased levels of copper (Cu, zinc (Zn, iron (Fe and magnesium (Mg, using inductively coupled plasma mass spectrometry in the CSF of all these 3 patients. The increased levels of Cu, Zn, Fe and Mg reflect the involvement of metabolism of several metals and/or metal-binding proteins during the progression of IBSPDC. More numerous patients with IBSPDC should be examined in other races to clarify the common mechanism of the disease and to investigate the specific treatment.

  9. Calcium Supplements Might Raise Older Women's Dementia Risk

    Science.gov (United States)

    ... nutrient," she said. "For example, calcium, phosphorus and magnesium all are typically looked at for their effects ... which was not originally designed to assess calcium intake," MacKay noted. "Further, the new analysis included only ...

  10. Preparation of Light-weight Magnesium Oxide and Calcium Carbonate from Dolomite by Acidification:An Experimental Study%白云岩酸解法制备轻质氧化镁和碳酸钙实验研究

    Institute of Scientific and Technical Information of China (English)

    姚文贵; 马鸿文; 姜晓谦; 刘玉芹

    2011-01-01

    The dolomite powder, sampled from Huangyue valley, Lushi County of Henan Province, was dissolved using hydrochloric acid to obtain the solution of MgCl2 and CaCl2. The iron and aluminium cations in the solution were removed by adjusting its pH to 6 -7. The light-weight magnesium oxide and calcium carbonate were prepared using the purified solution by ammonification, aging and carbonization. This study mainly investigates the effect of ammonification temperature(time) and the aging temperature(time) on the ratio of Mg2+ precipitation, and the effect of carbonization time on the crystal form of calcium carbonate. Scanning electron microscope (SEM) and chemical analysis methods were used to characterize the products. The light-weight magnesium oxide obtained is platelet in form with the average particle size of 150 nm, and matches the chemical industry standard HG/T2573-2006. The light-weight calcium carbonate obtained is sphere in form with the average particle size of 100 nm, and matches the chemical industry standard HG/T2567-1994. The presented technique which is characterized by low energy consumption and high utilization ratio, is a potential environmental friendly way for the clean processing of dolomite ores.%以河南卢氏县黄跃沟纯质白云岩为原料,利用盐酸进行分解,制得MgCl_2-CaCl_2溶液.经过通氨气调节pH值除铁、氨化反应、陈化反应以及碳化反应等过程,制备轻质氧化镁和轻质碳酸钙,研究氨化过程中温度和时间对Mg2+沉淀率的影响,以及碳化时间对碳酸钙制品晶vi的影响.采用化学分析方法和扫描电镜分析对制品进行表征,结果表明:轻质氧化镁制品颗粒形貌呈片状,粒径为150 nm左右,其性能达到HG/T2573-2006优等品标准;轻质碳酸钙制品颗粒形貌呈球状,粒径为100 nm左右,其性能达到HG/T2567-1994优等品的标准.实验采用的工艺路线具有能耗低、白云石资源利用率高、加工过程符合清洁生产要求等优

  11. The role of calbindin-D28k on renal calcium and magnesium handling during treatment with loop and thiazide diuretics.

    Science.gov (United States)

    Lee, Chien-Te; Ng, Hwee-Yeong; Lee, Yueh-Ting; Lai, Li-Wen; Lien, Yeong-Hau H

    2016-02-01

    Calbindin-D28k (CBD-28k) is a calcium binding protein located in the distal convoluted tubule (DCT) and plays an important role in active calcium transport in the kidney. Loop and thiazide diuretics affect renal Ca and Mg handling: both cause Mg wasting, but have opposite effects on Ca excretion as loop diuretics increase, but thiazides decrease, Ca excretion. To understand the role of CBD-28k in renal Ca and Mg handling in response to diuretics treatment, we investigated renal Ca and Mg excretion and gene expression of DCT Ca and Mg transport molecules in wild-type (WT) and CBD-28k knockout (KO) mice. Mice were treated with chlorothiazide (CTZ; 50 mg · kg(-1) · day(-1)) or furosemide (FSM; 30 mg · kg(-1) · day(-1)) for 3 days. To avoid volume depletion, salt was supplemented in the drinking water. Urine Ca excretion was reduced in WT, but not in KO mice, by CTZ. FSM induced similar hypercalciuria in both groups. DCT Ca transport molecules, including transient receptor potential vanilloid 5 (TRPV5), TRPV6, and CBD-9k, were upregulated by CTZ and FSM in WT, but not in KO mice. Urine Mg excretion was increased and transient receptor potential subfamily M, member 6 (TRPM6) was upregulated by both CTZ and FSM in WT and KO mice. In conclusion, CBD-28k plays an important role in gene expression of DCT Ca, but not Mg, transport molecules, which may be related to its being a Ca, but not a Mg, intracellular sensor. The lack of upregulation of DCT Ca transport molecules by thiazides in the KO mice indicates that the DCT Ca transport system is critical for Ca conservation by thiazides.

  12. Dolomite supplementation improves bone metabolism through modulation of calcium-regulating hormone secretion in ovariectomized rats.

    Science.gov (United States)

    Mizoguchi, Toshihide; Nagasawa, Sakae; Takahashi, Naoyuki; Yagasaki, Hiroshi; Ito, Michio

    2005-01-01

    Dolomite, a mineral composed of calcium magnesium carbonate (CaMg (CO3)2), is used as a food supplement that supplies calcium and magnesium. However, the effect of magnesium supplementation on bone metabolism in patients with osteoporosis is a matter of controversy. We examined the effects of daily supplementation with dolomite on calcium metabolism in ovariectomized (OVX) rats. Dolomite was administered daily to OVX rats for 9 weeks. The same amount of magnesium chloride as that supplied by the dolomite was given to OVX rats as a positive control. Histological examination revealed that ovariectomy decreased trabecular bone and increased adipose tissues in the femoral metaphysis. Dolomite or magnesium supplementation failed to improve these bone histological features. Calcium content in the femora was decreased in OVX rats. Neither calcium nor magnesium content in the femora in OVX rats was significantly increased by dolomite or magnesium administration. Urinary deoxypyridinoline excretion was significantly increased in OVX rats, and was not affected by the magnesium supplementation. Serum concentrations of magnesium were increased, and those of calcium were decreased, in OVX rats supplemented with dolomite or magnesium. However, there was a tendency toward decreased parathyroid hormone secretion and increased calcitonin secretion in OVX rats supplemented with dolomite or magnesium. Serum 1,25-dihydroxyvitamin D(3) and osteocalcin levels were significantly increased in the supplemented OVX rats. These results suggest that increased magnesium intake improves calcium metabolism in favor of increasing bone formation, through the modulation of calcium-regulating hormone secretion.

  13. 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 . ...

  14. Cokrigagem na estimativa dos teores de Ca e Mg em um Latossolo Vermelho distroférrico Cokriging to estimate levels of calcium and magnesium in a Rhodic Hapludox

    Directory of Open Access Journals (Sweden)

    Eduardo Leonel Bottega

    2011-12-01

    Full Text Available Buscou-se, com este estudo, estimar, através do uso da cokrigagem, valores de cálcio e magnésio, utilizando como co-variável valores de pH. Em um Latossolo Vermelho Distroférrico, amostrou-se a camada de 0-0,2 m, utilizando grade de 25 x 25 m, totalizando 60 pontos em 5,02 ha. Realizou-se, inicialmente, análise descritiva e de correlação e, posteriormente, análise geoestatística, para identificar a dependência espacial das variáveis estudadas. Utilizando a técnica da cokrigagem, os valores de pH mostraram-se eficientes na estimativa de teores de Ca e Mg, devido a elevada correlação entre esta co-variável e as variáveis a serem estimadas.Sought, with this study, estimating, through the use of cokriging, values of calcium and magnesium, using as covariate pH. In a Rhodic Hapludox, sampled the layer of 0-0.2 m, using the grid of 25 x 25 m, totaling 60 points from 5.02 ha. Was held, initially, descriptive analysis and correlation, and subsequently, geostatistical analysis to identify the spatial dependence of variables. Using the technique of cokriging pH values were efficient in the estimation of Ca and Mg, due to the high correlation between this covariate and the variables to be estimated.

  15. ICP-OES法同时测定燕麦片中的钾、钠、钙、镁、铁、锌%Simultaneous determination of potassium, sodium, calcium, magnesium, iron, zinc in oatmeal with ICP-OES

    Institute of Scientific and Technical Information of China (English)

    孙丽萍; 张素娟; 梁宝爱

    2015-01-01

    The determination method of potassium, sodium, calcium, magnesium, iron, zinc in oatmeal was established by the optimization of ICP-AES instruments conditions, with three different digestion methods. The results show that the linear relationship of each element elements is good, the correlation coefficient is above 0.999 9, the relative standard deviation is 1.5%~3.3% and the recovery rate is 82.3%~ 109.4%. The method is operated conveniently, with high accuracy and good precision. The test results of both the method (ICP-OES) and the national standard method are consistent, with no significant difference, and suitable for determination of mineral element in oatmeal.%通过对ICP-OES仪器条件的优化,采用3种不同消解方法,建立了燕麦片中钾、钠、钙、镁、铁、锌各元素的测定方法。试验结果表明,该方法中各元素的线性关系良好,相关系数均在0.9999以上,其相对标准偏差为1.5%~3.3%,回收率为82.3%~109.4%。该方法操作便捷、准确度高、精密度好,与国标方法比较检测结果一致,无显著性差异,适用于燕麦片中矿物质元素的测定。

  16. Magnesium based degradable biomaterials: A review

    Science.gov (United States)

    Gu, Xue-Nan; Li, Shuang-Shuang; Li, Xiao-Ming; Fan, Yu-Bo

    2014-09-01

    Magnesium has been suggested as a revolutionary biodegradable metal for biomedical applications. The corrosion of magnesium, however, is too rapid to match the rates of tissue healing and, additionally, exhibits the localized corrosion mechanism. Thus it is necessary to control the corrosion behaviors of magnesium for their practical use. This paper comprehensively reviews the research progress on the development of representative magnesium based alloys, including Mg-Ca, Mg-Sr, Mg-Zn and Mg-REE alloy systems as well as the bulk metallic glass. The influence of alloying element on their microstructures, mechanical properties and corrosion behaviors is summarized. The mechanical and corrosion properties of wrought magnesium alloys are also discussed in comparison with those of cast alloys. Furthermore, this review also covers research carried out in the field of the degradable coatings on magnesium alloys for biomedical applications. Calcium phosphate and biodegradable polymer coatings are discussed based on different preparation techniques used. We also compare the effect of different coatings on the corrosion behaviors of magnesium alloys substrate.

  17. 硅钙镁磷钾肥不同用量对超级稻产量及磷钾吸收利用的影响%The Effects of Silicon, Calcium, Magnesium, Phosphorus and Potassium Fertilization Level on Yield and Phosphorus and Potassium Absorption of Super Rice

    Institute of Scientific and Technical Information of China (English)

    李敏; 叶舒娅; 刘枫; 郭熙盛; 黄义德

    2014-01-01

    In order to explore the application effect of silicon, calcium, magnesium, phosphorus and potassium fertilizer on super rice, a field plots experiment was conducted to investigate the effects of silicon, calcium, magnesium, phosphorus and potassium fertilizer on the yield and phosphorus and potassium absorption of rice and soil nutrient contents. The results showed that in comparison with farmer custom fertilizer (CF 1) and custom fertilizer with phosphorus and potassium halving (CF2), silicon, calcium, magnesium, phosphorus and potassium fertilizer could increase yield of super-rice, and the yield increased 1.87%-10.65% and 3.69%-12.63%, respectively. The yield was consistent between T100 and T125. Silicon, calcium, magnesium, phosphorus and potassium fertilizer could increase filled grain. With the increasing of the application, contents and uptake amounts of phosphorus and potassium in grain and straw increased. Silicon, calcium, magnesium, phosphorus and potassium fertilizer could increase soil available phosphorus, available potassium and pH value, but had no significant effects on soil total nitrogen, total phosphorus, organic matter and available nitrogen content. The feasible silicon, calcium, magnesium, phosphorus and potassium fertilization was 1500 kg/hm2 (T100) and the yield, phosphorus and potassium absorption and soil nutrient contents would be increased.%为了探讨硅钙镁磷钾肥在超级稻上施用效果,通过采用田间小区试验,研究了硅钙镁磷钾肥不同用量和习惯施肥磷钾减半(CF2)配合施用对水稻产量磷钾吸收利用及土壤养分含量的影响。结果表明,施用硅钙镁磷钾肥较习惯施肥能够有效提高超级稻产量,随着施用量的增加而增大,比习惯施肥(CF1)增产1.87%~10.65%,比习惯施肥磷钾减半(CF2)增产3.69%~12.63%,施用量1500 kg/hm2(T100)和1875 kg/hm2(T125)产量结果一致。施用硅钙镁磷钾肥通过提高每穗实粒数来提高水稻产量。

  18. 60Co辐射交联乙烯-醋酸乙烯酯共聚物/氢氧化镁复合材料的热、力学及阻燃性能研究%Thermal, mechanical and flame-retardant properties of crosslinked ethylene vinyl-acetate copolymer/magnesium hydroxide blends by 60Co irradiation

    Institute of Scientific and Technical Information of China (English)

    李振中; 何伟; 张文熊; 瞿保钧

    2007-01-01

    Three types of ethylene vinyl-acetate copolymer (EVA)/magnesium hydroxide (MH) blends were crosslinked by 60Co γ-irradiation in the presence of trimethylolpropane triacrylate. The influences of irradiation dose on the crosslinking degree and thermal, mechanical and flame retardant properties of EVA/MH blends were studied through the measurements of gel content, Vicat point, limiting oxygen index (LOI), UL-94, tensile testing and the thermogravimetric analysis (TGA). The test results show that the EVA/MH blend with higher vinyl-acetate content in EVA is easier to be crosslinked. The thermal distortion resistance, mechanical and flame-retardant properties of EVA/MH blends are obviously improved by 60Co irradiation. The TGA shows that the thermal stabilities of EVA/MH blends are apparently affected by 60Co γ-irradiation.%以三羟甲基丙烷三丙烯酸酯为交联助剂,以60Co为辐射源,对三种不同醋酸乙烯酯(Vinyl-acetate,VA)含量的乙烯-醋酸乙烯酯共聚物(Ethylene vinyl-acetate copolymer,EVA)/氢氧化镁混合材料进行了辐照交联.通过对凝胶含量、维卡软化点、氧指数、UL-94垂直燃烧和拉伸性能的测试及热重分析,研究了辐照剂量对EVA/氢氧化镁交联体的交联度、热性能、力学性能和阻燃性能的影响.研究结果表明:VA含量高的EVA/氢氧化镁交联体更容易产生辐射交联;辐照交联后的EVA/氢氧化镁复合材料的抗热变形能力、力学性能及阻燃性能都获得明显改善.热重分析结果表明,60Co辐射明显影响EVA/氢氧化镁的热氧稳定性.

  19. 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 ...

  20. Effect of Feeding Propylene Glycol and the Mixtures of Calcium, Phosphate and Magnesium on Four Biochemical Indexes of Postpartum Dairy Cows%产后灌服丙二醇与钙磷镁合剂及复方口服补液盐对奶牛血液生化指标的影响

    Institute of Scientific and Technical Information of China (English)

    严宝英; 侯引绪; 曾光祥; 魏朝利; 王海丽; 段素云; 刘德占

    2014-01-01

    产后灌服丙二醇防控奶牛产后能量负平衡在一些规模化奶牛场已得到了应用。为了进一步研究奶牛产后灌服保健技术,本试验研究了产后灌服丙二醇与钙磷镁合剂+复方口服补液盐对奶牛四项血液生化指标的影响。分娩后第18天的测定结果表明,试验Ⅰ组(灌服丙二醇)和试验Ⅱ组(灌服钙磷镁合剂+复方口服补液盐)的血酮(β-羟丁酸)含量差异显著(P<0.05)。与灌服丙二醇相比,灌服钙磷镁合剂+复方口服补液盐不仅在预防奶牛隐性酮病方面效果显著,在预防产后低血钙症方面也有一定的实际意义。%Feeding propylene glycol to postpartum dairy cows is the effective measure to control negative energy balance, and has been taken by some large-scale dairy farms. The purposes of the paper are to study and compare the inlfuence of feeding propylene glycol and the mixtures of calcium, phosphate and magnesium with oral rehydration salts on four biochemical indexes of postpartum dairy cows. The results indicated that the difference in the content of blood ketone (β-hydroxybutyrate)between group 1 (feeding propylene glycol) and group 2(feeding calcium, phosphate and magnesium with oral rehydration salts) was striking(P<0.05), and illustrated that the preventative effect of feeding calcium, phosphate and magnesium with oral rehydration salts was very superior to feeding propylene glycol. What’s more, feeding calcium, phosphate and magnesium with oral rehydration salts can also play a role in the prevention of postpartum hypocalcemia.

  1. 断根、环割对烟草体内钾、钙、镁循环和积累的影响%Effects of the Root-cutting and Girding on the Circulation and Accumulation of the Potassium, Calcium and Magnesium in Tobacco

    Institute of Scientific and Technical Information of China (English)

    沈方科; 韦忠; 黄芩芬; 唐新莲; 尹永强; 廖曼玲; 张坚超; 顾明华

    2011-01-01

    在网室内采用水培方式栽培烟草,于烟草打顶期及打顶后一周进行断根、环割处理,探讨断根、环割及断根+环割对烟草吸收钾、钙、镁和烟株体内钾、钙、镁循环、积累的影响.结果表明:断根降低了木质部汁液单位时间的钙、镁吸收循环量及钙、镁在韧皮部的积累量,而环割处理的结论刚好相反.断根+环割显著提高了木质部汁液单位时间的钾吸收循环量和烟叶的钾积累量,提高上部叶的钾含量,降低了中、下部烟叶钙、镁的含量,因此该处理提高烟叶品质的效果最好.%The tobacco plants were cultivated under solution culture conditions in the net room, and the root cutting and girdling were implemented in topping period and the eighth days after topping. The aim was to study the effects of the root cutting treatment, girdling treatment and the root cutting combined with girdling treatment on the circulation and accumulation of the potassium, calcium and magnesium in tobacco plants. The results showed that the root cutting treatment reduced the calcium, magnesium circulation amount of the xylem sap in unit time; however, the calcium, magnesium accumulation amount of the phloem; the girdling treatment had the opposite conclusion. The root cutting combined with girdling treatment increased the potassium circulation amount of the xylem sap in the unit time and the potassium circulation amount of the tobacco leaves, improved the potassium content in upper leaves and reduced the calcium and magnesium content in the middle, lower leaves. Therefore, this treatment reflected the best effect on improving the quality of the tobacco leaves.

  2. Magnesium sulphate increases lymphocyte adenosine 3':5'-cyclic monophosphate in humans.

    Science.gov (United States)

    Von Mandach, U; Bürgi, M; Huch, R; Huch, A

    1993-01-01

    We determined the effect of i.v. magnesium sulphate, which is often combined with beta 2-adrenoceptor agonists for tocolytic therapy, on lymphocyte cyclic AMP production, extracellular magnesium and blood calcium concentrations. Sixteen healthy volunteers received i.v. magnesium sulphate 1 g h-1 over 8 h; seven volunteers also had infusion of NaCl 18 mg h-1 as control. Venous blood was taken pre- and post-infusion to determine basal lymphocyte cyclic AMP and the increase evoked by 0.1 mM isoprenaline, as well as serum and plasma concentrations of total and non-protein-bound magnesium and calcium. Following magnesium sulphate there was a significant rise in the isoprenaline-evoked increase in cyclic AMP (P < 0.05) and in the magnesium concentrations (P < 0.01) and a decrease in the free calcium concentration (P < 0.01). PMID:8385975

  3. Magnesium sulphate increases lymphocyte adenosine 3':5'-cyclic monophosphate in humans.

    Science.gov (United States)

    Von Mandach, U; Bürgi, M; Huch, R; Huch, A

    1993-03-01

    We determined the effect of i.v. magnesium sulphate, which is often combined with beta 2-adrenoceptor agonists for tocolytic therapy, on lymphocyte cyclic AMP production, extracellular magnesium and blood calcium concentrations. Sixteen healthy volunteers received i.v. magnesium sulphate 1 g h-1 over 8 h; seven volunteers also had infusion of NaCl 18 mg h-1 as control. Venous blood was taken pre- and post-infusion to determine basal lymphocyte cyclic AMP and the increase evoked by 0.1 mM isoprenaline, as well as serum and plasma concentrations of total and non-protein-bound magnesium and calcium. Following magnesium sulphate there was a significant rise in the isoprenaline-evoked increase in cyclic AMP (P < 0.05) and in the magnesium concentrations (P < 0.01) and a decrease in the free calcium concentration (P < 0.01).

  4. 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。

  5. Water requirements of the rayon- and acetate-fiber industry

    Science.gov (United States)

    Mussey, Orville Durey

    1957-01-01

    untreated waters were generally cool, low in content of calcium and magnesium, and very low in iron and manganese. At many plants, water was obtained from more than one source, and thus had different quality characteristics. Dissolved solids in all the untreated waters analyzed ranged between 14 and 747 ppm (parts per million) but in those waters used in processing the dissolved solids content was less than 200 ppm. The cooling water used by the industry is also generally of very high quality, principally because the requirements for a high-quality process water necessitate location of the plants in areas where such water is available.

  6. Effect of Magnesium Supplementation on Physical Activity of Overweight or

    Directory of Open Access Journals (Sweden)

    Behnood Abbasi

    2013-03-01

    Full Text Available Background: Strategies for weight reduction often promote lifestyle changes like encouraging participation in physical activity. Also there is some evidence suggesting an association between insomnia and physical activity level and probable beneficial effect of magnesium supplementation on insomnia. The objective of this study was to determine the effect of magnesium supplementation on physical activity level in insomniac elderly subjects.Materials and Methods: A double blind randomized clinical trial was conducted in 46 overweight or obese subjects, randomly allocated into the magnesium or the placebo group and received 500 mg magnesium or placebo daily for 8 weeks. Questionnaires of insomnia severity index (ISI, physical activity and sleep-log were completed and serum magnesium measured at baseline and after the intervention period. Anthropometric confounding factors, daily intake of magnesium, calcium, potassium, caffeine, calorie form carbohydrates, fat, protein and total calorie intake, were obtained using 24-hrs recall for 3-days. Statistical analyses were performed using SPSS-19 software.Results: No significant differences were observed in assessed variables between the two groups at the baseline. According to our research magnesium supplementation significantly increased sleep indices and physical activity level, also resulted in significantly decrease of total calorie intake in magnesium group. Although serum magnesium concentration and weight did not show any differences.Conclusion: In the present study magnesium supplementation resulted in improvement of sleep indices and physical activity level in elderly subjects. Although according to our short term intervention no significant beneficial effect was observed on subject`s weight.

  7. 驼初乳中钾、钙、钠、镁、铜、铁、锌质量浓度的检测%Detection of potassium,calcium,sodium, magnesium,copper,iron,zinc concentration in Xinjiang Bactrian milk Camel colostrum

    Institute of Scientific and Technical Information of China (English)

    苏薇; 杨洁

    2011-01-01

    为研究新疆双峰驼驼初乳中钾、钙、钠、镁、铜、铁、锌的质量浓度及其在泌乳期内的变化,采用火焰原子吸收分光光度法进行测定,回收率为92.45%~110.85%之间,相对标准偏差小于5%,说明该法具有良好的准确性和精密度.结果表明,新疆双峰驼驼初乳中钾的质量浓度最为丰富高,其次为钠、钙和镁;检测发现驼初乳中铜、铁、锌质量浓度未达到仪器最佳工作条件下的最低检出限.在泌乳期1~6d内,钙元素和镁元素质量浓度的变化有相关性,差异显著;钠元素和钙元素质量浓度的变化与泌乳天数有相关性,差异显著;钙元素质量浓度的变化与泌乳天数有相关性,差异极显著.与牛乳相比,新疆双峰驼驼初乳中含有相对较高质量浓度的钾、钙、钠、镁的质量浓度较高,饮用驼初乳可作为补充人体所需钾、钙、钠、镁元素的一种有效途径.%The content of potassium,calcium,sodium, magnesium,copper,iron,zinc in Xinjiang Bactrian camel colostrum changes in the lactation period. By flame atomic absorption spectrometry were determined,recovery was between 92.45%~110.85%, the relative standard deviation less than 5%, it showed that the method has good accuracy and precision. The concentrantion of potassium was highest in Xinjiang Bactrian camel colostrum, followed by sodium,calcium and magnesium. The concentrantion of Ccopper, iron, zinc content in camel milk does did not meet the minimum detection limit of the instrument. In lactation 1 ~6 days,calcium and magnesium concentration changes was relevant,significant difference. The concentration changes of sodium,calcium and days of lactation was relevant,significant difference. Compared with bovine milk, the concentration of potassium,calcium,sodium, magnesium are higher in Xinjiang Bactrian camel colostrum. Drinking camel milk is an effective way as a supplement of potassium,calcium,sodium,magnesium elements needed by

  8. 叶面喷施钙镁肥对结球甘蓝养分积累及产量的影响%Effects of Foliar Application of Calcium and Magnesium Fertilizers on Nutrient Accumulation and Yield of Cabbage

    Institute of Scientific and Technical Information of China (English)

    周晓琳; 李洪杰; 赵同凯; 韩海红; 刘树堂

    2015-01-01

    通过大田小区试验研究叶面喷施钙、镁肥对结球甘蓝产量与品质的影响。结果表明:不同浓度的Ca(NO3)2和 MgSO4单施或配施,均可显著提高甘蓝球的横径、纵径和产量,其中0.7 g/L Ca(NO3)2+0.6 g/L MgSO4处理(T5)效果最好,与对照相比,分别增加29.10%、70.41%、32.09%;T5处理的甘蓝球全氮、全磷含量最高,与对照相比,分别增加40.1%、321.0%;全钾含量以0.3 g/L MgSO4(T3)处理最高,比对照增加15.98%。%The plot experiments were conducted in field to study the effects of foliar application of calci-um and magnesium fertilizers on the yield and quality of cabbage.The results indicated that the transverse di-ameter,vertical diameter and yield of cabbage could be significantly increased by both single and combined application of Ca(NO3 )2 and MgSO4 among which T5 treatment with 0.7 g/L Ca(NO3 )2 and 0.6 g/L MgSO4 had the best effect and increased them by 29.10%,70.41% and 32.09% compared with the control.The total nitrogen content and total phosphorus content increased by 40.1% and 321.0% respectively under T5 treat-ment compared with the control.The total potassium content was the highest under T3 treatment with 0.3 g/L MgSO4 ,which increased by 15.98% compared with the control.

  9. 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.

  10. Mechanisms of magnesium-induced vasodilation in cerebral penetrating arterioles.

    Science.gov (United States)

    Murata, Takahiro; Dietrich, Hans H; Horiuchi, Tetsuyoshi; Hongo, Kazuhiro; Dacey, Ralph G

    2016-06-01

    We investigated in cerebral penetrating arterioles the signaling mechanisms and dose-dependency of extracellular magnesium-induced vasodilation and also its vasodilatory effects in vessels preconstricted with agonists associated with delayed cerebral vasospasm following SAH. Male rat penetrating arterioles were cannulated. Their internal diameters were monitored. To investigate mechanisms of magnesium-induced vasodilation, inhibitors of endothelial function, potassium channels and endothelial impairment were tested. To simulate cerebral vasospasm we applied several spasmogenic agonists. Increased extracellular magnesium concentration produced concentration-dependent vasodilation, which was partially attenuated by non-specific calcium-sensitive potassium channel inhibitor tetraethylammonium, but not by other potassium channel inhibitors. Neither the nitric oxide synthase inhibitor L-NNA nor endothelial impairment induced by air embolism reduced the dilation. Although the magnesium-induced vasodilation was slightly attenuated by the spasmogen ET-1, neither application of PF2α nor TXA2 analog effect the vasodilation. Magnesium induced a concentration- and smooth muscle cell-dependent dilation in cerebral penetrating arterioles. Calcium-sensitive potassium channels of smooth muscle cells may play a key role in magnesium-induced vasodilation. Magnesium also dilated endothelium-impaired vessels as well as vessels preconstricted with spasmogenic agonists. These results provide a fundamental background for the clinical use of magnesium, especially in treatment against delayed cerebral ischemia or vasospasm following SAH.

  11. Dual effect of magnesium on compound 48/80-induced histamine secretion from rat peritoneal mast cells

    DEFF Research Database (Denmark)

    Bertelsen, Niels Haldor; Johansen, Torben

    1991-01-01

    The effect of magnesium on the secretory response to compound 48/80 from rat peritoneal mast cells was studied. The decrease in secretion caused by calcium deprivation was enlarged by magnesium. Glucose partially counteracted the decrease caused by calcium deprivation but not the one caused by ma...

  12. DISTILLATION OF CALCIUM

    Science.gov (United States)

    Barton, J.

    1954-07-27

    This invention relates to an improvement in the process for the purification of caicium or magnesium containing an alkali metal as impurity, which comprises distiiling a batch of the mixture in two stages, the first stage distillation being carried out in the presence of an inert gas at an absolute pressure substantially greater than the vapor pressure of calcium or maguesium at the temperature of distillation, but less than the vaper pressure at that temperature of the alkali metal impurity so that only the alkali metal is vaporized and condensed on a condensing surface. A second stage distilso that substantially only the calcium or magnesium distills under its own vapor pressure only and condenses in solid form on a lower condensing surface.

  13. Simultaneous determination of arsenic, cadmium, calcium, chromium, cobalt, copper, iron, lead, magnesium, manganese, molybdenum, nickel, selenium, and zinc in fertilizers by microwave acid digestion and inductively coupled plasma-optical emission spectrometry detection: single-laboratory validation of a modification and extension of AOAC 2006.03.

    Science.gov (United States)

    Webb, Sharon; Bartos, James; Boles, Rhonda; Hasty, Elaine; Thuotte, Ethel; Thiex, Nancy J

    2014-01-01

    A single-laboratory validation study was conducted for the simultaneous determination of arsenic, cadmium, calcium, cobalt, copper, chromium, iron, lead, magnesium, manganese, molybdenum, nickel, selenium, and zinc in all major types of commercial fertilizer products by microwave digestion and inductively coupled plasma-optical emission spectroscopy analysis. This validation study proposes an extension and modification of AOAC 2006.03. The extension is the inclusion of calcium, copper, iron, magnesium, manganese, and zinc, and the modification is incorporation of hydrochloric acid in the digestion system. This dual acid digestion utilizes both hydrochloric and nitric acids in a 3 to 9 mL volume ratio/100 mL. In addition to 15 of the 30 original validation materials used in the 2006.03 collaborative study, National Institute of Standards and Technology Standard Reference Material 695 and Magruder 2009-06 were incorporated as accuracy materials. The main benefits of this proposed method are a significant increase in laboratory efficiency when compared to the use of both AOAC Methods 965.09 and 2006.03 to achieve the same objective and an enhanced recovery of several metals.

  14. Effects of Tin Oxide on Preparation and Properties of Calcium Aluminate/Magnesium-Aluminum Spinel Composites%氧化锡对铝酸钙/镁铝尖晶石复相材料制备和性能的影响

    Institute of Scientific and Technical Information of China (English)

    商恒; 员文杰; 朱青友; 邓承继; 祝洪喜

    2016-01-01

    With the advantages of their components such as high melting point, low thermal conductivity and good corrosion resistance, calcium aluminate/magnesium-aluminum spinel composites have a very wide application prospect in high temperature industries. Calcium aluminate/magnesium-aluminum spinel composites were prepared at 1300-1600 °C by using light-burned dolomite, alumina and tin oxide as raw materials. Effects of tin oxide on the phase composition, microstructure and properties of calcium aluminate/magnesium-aluminum spinel composites were investigated by X-ray diffraction and scanning electron microscopy. The results showed that the mass loss and shrinkage of sintered samples varied due to the sublimation of tin oxide and the decomposition of light-burned dolomite. Tin oxide not only enhanced the formation of calcium hexaluminate and magnesium-aluminum spinel but also made monocalcium aluminate and CaSnO3 involved in composites as a result of the effect of SnO2 on the reaction process. Moreover, the morphology of the phases was changed because of the solution of SnO2 in calcium hexaluminate and magnesium-aluminum spinel. With the increase of SnO2 addition, the apparent porosity of composites ifrstly increased and then decreased. When the SnO2 content was 35%, the composites sintered at 1600℃achieved the highest compressive strength of 240 MPa.%结合组分高熔点、低热导率和抗侵蚀等优点,铝酸钙/镁铝尖晶石复相材料在高温工业中具有十分广泛的应用前景。以轻烧白云石、氧化铝和氧化锡为原料,在1300-1600℃烧结合成铝酸钙/镁铝尖晶石复相材料。利用X射线衍射和扫描电子显微镜等测试方法,研究添加氧化锡对铝酸钙/镁铝尖晶石复相材料的物相组成、显微结构和性能的影响。结果表明:因氧化锡的分解,反应烧结过程中试样的失重和收缩率均有明显相应变化。氧化锡不仅促进六铝酸钙和镁铝尖晶石的形成,同时

  15. 钠钾镁钙葡萄糖注射液(乐加)在急诊低血容量性休克液体复苏中的应用研究%The Application of the Emergency Hypovolemic Shock Fluid Resuscitation by Sodium, Potassium, Magnesium Calcium Glucose Injection (Lejia)

    Institute of Scientific and Technical Information of China (English)

    覃双全; 刘笋; 曾宪华; 曾景亭; 张春阳; 贺永明

    2014-01-01

    Objective To study the emergency hypovolemic shock lfuid resuscitation, sodium, potassium, magnesium, calcium process to give glucose injection methods and results. Methods July 2011 - February 2014 in our hospital emergency department patients with hypovolemic shock were 52 cases of clinical study, patients were randomly divided into two groups. Control group of 26 patients using conventional lfuid resuscitation Ringer's lactate;26 cases of patients in the experimental group, given the sodium, potassium, magnesium, calcium and glucose injection recovery, patients were compared before and after potassium treatment, sodium, calcium, magnesium equivalent; determination 1 h after resuscitation of patients in mean arterial pressure (MAP) and heart rate.Result Patients Experimental group after resuscitation 1 h, the patient's serum sodium, potassium, calcium, magnesium blood-related indicators are better than the control group of patients, the statistical analysis, P<0.05, signiifcant difference;patients in the experimental group after recovery 1h, MAP higher heart rate is relatively low, compared with the control group, P<0.05, the difference was statistically signiifcant. Conclusions Patients with hypovolemic shock emergency resuscitation sodium, potassium, magnesium, calcium given glucose injection treatment and better clinical results, helps to maintain a stable internal environment, worthy of promotion.%目的:研究急诊低血容量性休克液体复苏过程中给予钠钾镁钙葡萄糖注射液的方法和效果。方法选择2011年7月至2014年2月我院急诊低血容量性休克患者共52例为临床研究对象,将患者随机分为两组。对照组共26例,使用乳酸林格液常规液体复苏;实验组患者26例,给予钠钾镁钙葡萄糖注射液复苏,观察比较患者治疗前后的血钾、钠、钙、镁等值;测定复苏1h后患者平均动脉压(MAP)和心率。结果实验组患者在复苏1h后,患者的血钠、

  16. 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- ...

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. Role of magnesium in alleviation of aluminium toxicity in plants.

    Science.gov (United States)

    Bose, Jayakumar; Babourina, Olga; Rengel, Zed

    2011-04-01

    Magnesium is pivotal for activating a large number of enzymes; hence, magnesium plays an important role in numerous physiological and biochemical processes affecting plant growth and development. Magnesium can also ameliorate aluminium phytotoxicity, but literature reports on the dynamics of magnesium homeostasis upon exposure to aluminium are rare. Herein existing knowledge on the magnesium transport mechanisms and homeostasis maintenance in plant cells is critically reviewed. Even though overexpression of magnesium transporters can alleviate aluminium toxicity in plants, the mechanisms governing such alleviation remain obscure. Possible magnesium-dependent mechanisms include (i) better carbon partitioning from shoots to roots; (ii) increased synthesis and exudation of organic acid anions; (iii) enhanced acid phosphatase activity; (iv) maintenance of proton-ATPase activity and cytoplasmic pH regulation; (v) protection against an aluminium-induced cytosolic calcium increase; and (vi) protection against reactive oxygen species. Future research should concentrate on assessing aluminium toxicity and tolerance in plants with overexpressed or antisense magnesium transporters to increase understanding of the aluminium-magnesium interaction.

  2. 儿童全血钙、铁、锌等矿物质测定参考值的研究现状%Review of reference intervals for calcium, iron, zinc, magnesium and copper in children’ s blood

    Institute of Scientific and Technical Information of China (English)

    贾妮; 戴耀华

    2014-01-01

    Calcium ( Ca) , iron ( Fe) , zinc ( Zn) , magnesium ( Mg) and copper ( Cu) are the most common trace elements in blood test for child health assessment in China.Whole blood test of these trace elements has been applied in clinical examination and scientific research for its simple operation and little blood sample needed, and it can be used to evaluate level in the body.It is valuable to build reference intervals for Ca, Fe, Zn, Mg and Cu for Chinese children.This article reviewed the studies of reference intervals for these trace elements in children’ s whole blood in the past decade, and the following suggestions were provided.Reference intervals for Chinese children should be set and more standard management should be taken since the standards for quality control in laboratories of the studies are not unified.Reference intervals are used for clinical diagnosis and prevalence survey, thus defining reference intervals of laboratories provides evidence only and more work is needed to confirm.More population and feasible sampling methods are needed to apply the reference intervals.Furthermore, more studies should be conducted in young children and in rural areas.%钙、铁、锌、镁、铜是我国儿童保健领域检测较多的矿物质,全血检测操作简单、采血量少,且可以用于检验人体水平,因此,被临床检验和科学研究领域接受。建立儿童全血钙、铁、锌、镁、铜参考值是有意义的。该文综述中国10年来的多地区和单个地区的儿童全血中钙、铁、锌、镁、铜参考值的研究,提出:①各研究中制定参考值的实验室都有质量控制相关操作,但标准不统一,建议建立中国儿童群体自己参考区间,并进行更加规范化的管理;②确定参考区间供临床和科研调查使用,因此,确定了实验室参考区间,只是提供了依据,需要进一步论证;③确定参考区间如果要推广到其他区域,就需要更多的人

  3. 猪场废水灌溉对地下水中钾、钙、钠、镁含量的影响%Influence of Livestock Wastewater Irrigation on Potassium,Calcium,Sodium and Magnesium Contents in Groundwater

    Institute of Scientific and Technical Information of China (English)

    赵君怡; 张克强; 王风; 刘鸣达

    2011-01-01

    Three volumes of anaerobic water and the output of three stages of livestock wastewater treatment mixed with groundwater were used as irrigation water three years in the area where maize-wheat rotated.As the monitoring of potassium,calcium,sodium,magnesium concentration in groundwater,the results showed that:(1)The change trends of potassium concentration in groundwater with different volume of anaerobic wastewater was HaMaLa,with the three tragedy of livestock wastewater treatment mixed with groundwater,the tendency of potassium concentration in groundwater was TagTogTeg;(2)The change trends of other three ions concentration in groundwater was LaMaHa with different volume of anaerobic wastewater and TegTogTag with the three stages of livestock wastewater treatment mixed with groundwater.%应用猪场废水处理工程中产出的厌氧水不同灌溉量和3个处理阶段出水与地下水按体积比1∶5混合对冬小麦-夏玉米轮作系统进行3年的小区灌溉试验,监测地下水的总矿化度及钾、钙、钠、镁等含量的变化。结果表明:(1)地下水中钾含量在厌氧水不同灌溉量条件下呈现高量厌氧水(Ha)〉中量厌氧水(Ma)〉低量厌氧水(La)的变化趋势,在混水灌溉处理地下水中钾含量均呈厌氧水与地下水1∶5混合(Tag)〉原水与地下水1∶5混合(Tog)〉仿生态塘水与地下水1∶5混合(Teg)的变化趋势;(2)地下水中钠、钙、镁含量大致呈现低量厌氧水(La)〉中量厌氧水(Ma)〉高量厌氧水(Ha),仿生态塘水与地下水1∶5混合(Teg)〉原水与地下水1∶5混合(Tog)〉厌氧水与地下水1∶5混合(Tag)的变化趋势。

  4. Properties of Ethylene-vinyl Acetate/Magnesium Hydroxide Blends Modified by Melamine Cyanurate%三聚氰胺氰尿酸盐协效氢氧化镁阻燃乙烯-醋酸乙烯酯共聚物的性能研究

    Institute of Scientific and Technical Information of China (English)

    徐亚新; 虞鑫海; 李四新

    2011-01-01

    Using ethylene-vinyl acetate copolymer (EVA) as matrix resin, magnesium hydroxide(MH) modified by KH-550 as main flame retardant, melamine cyanurate(MCA) as synergistic flame retardant, a kind of EVA composite was prepared by adding compatibilizer(MC328). The effects of MCA and MC328 content on the mechanical properties, melt flow rate, vertical combustion and limiting oxygen index(LOI) of the composite were studied. The results show that the addition of MCA improves the mechanical properties, processability and vertical combustion property of the composite, but the LOI decreases. The addition of MC328 improves the mechanical properties and LOI of the composite, but the flame retardant grade decreases.%以EVA为基体树脂,硅烷偶联剂KH-550改性氢氧化镁(MH)为主阻燃剂,三聚氰胺氰尿酸盐(MCA)为协效阻燃剂,添加相容剂MC328,制备了EVA复合材料,研究和对比了MCA、MC328含量对复合材料的力学性能、加工性能、燃烧、极限氧指数等性能的影响.结果表明:MCA的加入改善了体系力学性能及加工性能,提高了燃烧性能,但对氧指数有负面影响;而相容剂MC328的加入可以极大提高复合材料的力学性能及氧指数,但是降低了阻燃等级.

  5. 放电等离子烧结制备刚玉-铝酸钙-镁铝尖晶石复相材料%Preparation of corundum-calcium aluminate-magnesium aluminate spinel composites by spark plasma sin-tering

    Institute of Scientific and Technical Information of China (English)

    唐海; 员文杰; 商恒; 樊希安; 邓承继; 祝洪喜

    2016-01-01

    In order to reduce the synthesis temperature of the composite material and maintain its physical properties,corundum-calcium aluminate-magnesium aluminate spinel composites were prepared using 35.16 mass% underburnt dolomite and 64.84 mass% flake alumina as raw materials by spark plasma sin-tering at different temperatures (1 050,1 100,and 1 150 ℃).The effects of the firing temperature on phase composition and strength of corundum-calcium aluminate-magnesium aluminate spinel composites were investigated.The results show that with the temperature increasing the corundum content decreases gradu-ally,while the contents of calcium aluminate and magnesium aluminate spinel gradually increase,the ap-parent porosity of composites slightly increases while the splitting tensile strength improves;flake corun-dum,formed calcium aluminate and magnesium aluminate spinel bond together at high temperatures by spark plasma sintering.The composites with the apparent porosity of 23.2% fired at 1 150 ℃ achieve the splitting tensile strength of 20 MPa.%为了降低复相材料的合成温度并保证其相应的物理性能,以质量分数分别为35.16%的欠烧白云石和64.84%的片状氧化铝为原料,在1050、1100和1150℃下利用放电等离子烧结法(SPS)制备了刚玉-铝酸钙-镁铝尖晶石复相材料,并研究了烧成温度对复相材料的物相组成及强度的影响。结果表明:随着温度的升高,复相材料中刚玉相的含量逐渐降低,而铝酸钙和镁铝尖晶石的含量逐渐上升,材料的显气孔率略有增大,但是其劈裂抗拉强度逐渐增大。放电等离子烧结使复相材料中片状刚玉、生成的铝酸钙和镁铝尖晶石在高温下相互结合。当烧成温度为1150℃时,所制备的复相材料显气孔率为23.2%,劈裂抗拉强度达到20 MPa。

  6. Effect of different premature infant formula feedings on the levels of calcium, magnesium and blood lipid in newborn%不同早产儿配方奶喂养对新生儿钙镁及血脂水平的影响

    Institute of Scientific and Technical Information of China (English)

    张静; 黄宏云; 杨坤

    2015-01-01

    目的 探讨不同早产儿配方奶喂养对新生儿钙镁及血脂水平的影响,为早产儿保健提供理论依据.方法 120例早产儿按照随机数字法分为A,B,C组,每组40例. A组在医师指导下喂养101千卡(100 mL)雅培早产儿配方奶,B组在医师指导下喂养81千卡(100 mL)雅培早产儿配方奶,C组在医师指导下喂养S-26 早产儿配方奶. 观察3组早产儿的钙镁水平与血脂水平. 结果 A,B组早产儿的钙镁水平差异无统计学意义( P >0.05 ) ,但均显著高于 C 组( P0.05 ). 结论 雅培早产儿配方奶能够显著提高早产儿的钙镁水平,有利于骨骼的生长发育,但不会升高血脂水平,说明合理的喂养配方奶不会引起婴儿超重和肥胖的发生,是适合早产儿的喂养方式.%Objective To explore the effect of different premature infant formula feedings on the levels of calcium, magnesium and blood lipid in newborn, in order to provide a theoretical basis for the preterm child care.Methods A total of 120 cases of premature children were random-ly divided into A,B,C group, each group 40 cases.Group A was given 101 kcal(100 mL) Abbott formula preterm, group B was fed 81 kcal (100 mL) preterm children Abbott formula, group C was fed S-26 for-mula.The calcium and magnesium levels as well as lipid levels of the three groups were observed.Results The calcium and magnesium levels had no significant difference in group A and B ( P>0.05 ) , but were sig-nificantly higher than those in group C ( P 0.05 ) . Conclusion Abbott formula preterm can significantly improve the level of calcium and magnesium in preterm children, beneficial to the growth of bone.This formula did not elevate the lipid levels, indicating that jus-tify feeding infant formula milk does not cause overweight and obesity, suitable for the feeding of premature infants.

  7. Obtaining of inulin acetate

    OpenAIRE

    Khusenov, Arslonnazar; Rakhmanberdiev, Gappar; Rakhimov, Dilshod; Khalikov, Muzaffar

    2014-01-01

    In the article first obtained inulin ester inulin acetate, by etherification of inulin with acetic anhydride has been exposed. Obtained product has been studied using elementary analysis and IR spectroscopy.

  8. Scientific Opinion on the safety of the change in the production method of L-glutamic acid (E620, monosodium L-glutamate (E621, monopotassium L-glutamate (E622, calcium di-L-glutamate (E623, monoammonium L-glutamate (E624 and magnesium di-L-glutamate (E625

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Food Additives and Nutrient Sources added to food (ANS

    2015-01-01

    Full Text Available The Panel on Food Additives and Nutrient Sources added to Food (ANS was asked to deliver a scientific opinion evaluating   the safety of the change in the production method for the production of L-glutamic acid (E620, monosodium - L-glutamate (E621, monopotassium L-glutamate (E622, calcium di-L-glutamate (E623, monoammonium L-glutamate (E624 and magnesium di-L-glutamate (E625. The L-glutamic acid is produced by the genetically modified Corynebacterium glutamicum EA-12 strain. The recipient strain Corynebacterium glutamicum  strain2256  has been recommended for Qualified Presumption of Safety (QPS status. No antibiotic resistance genes were left in the genome and neither the production strain nor its recombinant DNA were detected in the final product. The Panel considered there were no safety concerns for consumers from the genetic modification. The proposed uses or use levels of L-glutamic acid and its salt derivatives produced with the current strain and the new genetically modified microorganism (GMM strain will be identical and thus the Panel considered that the exposure to the food additive will remain unaffected. Provided that the L-glutamic acid and its salts both produced with the current strain and with the GMM strain are equal in the specifications and physicochemical characteristics, the biological and toxicological data for the L-glutamic acid and its salts produced with the current strain are considered by the Panel to support the safety of the food additives produced with the GMM strain. The Panel concluded that there are no safety concerns from the  change in the production method of the food additives L-glutamic acid (E620, monosodium L-glutamate (E621, monopotassium L-glutamate (E622, calcium di-L-glutamate (E623, monoammonium L-glutamate (E624 and magnesium di-L-glutamate (E625 meeting their existing specifications.

  9. Lactogenic study of the ethyl-acetate fraction of Hibiscus sabdariffa linn seed on pituitary prolactin level of lactating albino rats

    Directory of Open Access Journals (Sweden)

    I G Bako

    2013-03-01

    Full Text Available Summary. The effect of ethyl-acetate fraction of Hibiscus sabdariffa l. seed on pituitary prolactin and milk production was evaluated in albino rats. Twenty four lactating rats were randomly grouped at parturition into control, metoclopramide-treated and Ethyl-acetate-treated group consist of six rats in each group (n=6. The lactating rats were administered control (normal saline, metoclopramide (5mg/kg and ethyl-acetate fraction (100 and 200mg/kg respectively from day 3-17 of lactation. Milk yield for rats were estimated by pup weight and weight gain. The animals were then euthanized on the day 18 and pituitary prolactin was analyzed using prolactin kit. The prolactin level of ethyl-acetate fraction of Hibiscus sabdariffa showed a significant increase (P<0.01 when compared to control group. Pup weight gain was also significantly higher (P<0.05 than the control group. This can be inferred that ethyl-acetate fraction of Hibiscus sabdariffa l. seed has lactogenic activity because it increases pituitary prolactin level and milk production in lactating female albino rats. The LD50 of Ethyl-acetate fraction Hibiscus sabdariffa l. was found to be above 5000mg/kg. Industrial relevance. The outstanding advantage of this galactagogue option is that, it is safer, affordable and tolerable, and it is taken as an alternative in preference to anti-psychotic drugs that have side effect of drowsiness and depression. The plant calyces, leaves and seeds are eaten as foods because it contain substantial amount of essential fatty, Tocopherol (Vitamin E, ascorbic acid (Vitamin C, mineral salts calcium, magnesium, sodium, potassium and phosphorus. Keywords. Hibiscus sabdariffa; prolactin; lactation; milk; pituitary

  10. 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...

  11. Magnesium substitution in brushite cements for enhanced bone tissue regeneration.

    Science.gov (United States)

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

    2014-10-01

    We have synthesized calcium phosphate cements doped with different amounts of magnesium (Mg-CPC) with a twofold purpose: i) to evaluate in vitro the osteoblast cell response to this material, and ii) to compare the bone regeneration capacity of the doped material with a calcium cement prepared without magnesium (CPC). Cell proliferation and in vivo response increased in the Mg-CPCs in comparison with CPC. The Mg-CPCs have promoted higher new bone formation than the CPC (p<0.05). The cytocompatibility and histomorfometric analysis performed in the rabbit calvaria showed that the incorporation of magnesium ions in CPC improves osteoblasts proliferation and provides higher new bone formation. The development of a bone substitute with controllable biodegradable properties and improved bone regeneration can be considered a step toward personalized therapy that can adapt to patient needs and clinical situations.

  12. A novel acidic matrix protein, PfN44, stabilizes magnesium calcite to inhibit the crystallization of aragonite.

    Science.gov (United States)

    Pan, Cong; Fang, Dong; Xu, Guangrui; Liang, Jian; Zhang, Guiyou; Wang, Hongzhong; Xie, Liping; Zhang, Rongqing

    2014-01-31

    Magnesium is widely used to control calcium carbonate deposition in the shell of pearl oysters. Matrix proteins in the shell are responsible for nucleation and growth of calcium carbonate crystals. However, there is no direct evidence supporting a connection between matrix proteins and magnesium. Here, we identified a novel acidic matrix protein named PfN44 that affected aragonite formation in the shell of the pearl oyster Pinctada fucata. Using immunogold labeling assays, we found PfN44 in both the nacreous and prismatic layers. In shell repair, PfN44 was repressed, whereas other matrix proteins were up-regulated. Disturbing the function of PfN44 by RNAi led to the deposition of porous nacreous tablets with overgrowth of crystals in the nacreous layer. By in vitro circular dichroism spectra and fluorescence quenching, we found that PfN44 bound to both calcium and magnesium with a stronger affinity for magnesium. During in vitro calcium carbonate crystallization and calcification of amorphous calcium carbonate, PfN44 regulated the magnesium content of crystalline carbonate polymorphs and stabilized magnesium calcite to inhibit aragonite deposition. Taken together, our results suggested that by stabilizing magnesium calcite to inhibit aragonite deposition, PfN44 participated in P. fucata shell formation. These observations extend our understanding of the connections between matrix proteins and magnesium.

  13. Physicochemical action of potassium-magnesium citrate in nephrolithiasis

    Science.gov (United States)

    Pak, C. Y.; Koenig, K.; Khan, R.; Haynes, S.; Padalino, P.

    1992-01-01

    Effect of potassium-magnesium citrate on urinary biochemistry and crystallization of stone-forming salts was compared with that of potassium citrate at same dose of potassium in five normal subjects and five patients with calcium nephrolithiasis. Compared to the placebo phase, urinary pH rose significantly from 6.06 +/- 0.27 to 6.48 +/- 0.36 (mean +/- SD, p less than 0.0167) during treatment with potassium citrate (50 mEq/day for 7 days) and to 6.68 +/- 0.31 during therapy with potassium-magnesium citrate (containing 49 mEq K, 24.5 mEq Mg, and 73.5 mEq citrate per day). Urinary pH was significantly higher during potassium-magnesium citrate than during potassium citrate therapy. Thus, the amount of undissociated uric acid declined from 118 +/- 61 mg/day during the placebo phase to 68 +/- 54 mg/day during potassium citrate treatment and, more prominently, to 41 +/- 46 mg/day during potassium-magnesium citrate therapy. Urinary magnesium rose significantly from 102 +/- 25 to 146 +/- 37 mg/day during potassium-magnesium citrate therapy but not during potassium citrate therapy. Urinary citrate rose more prominently during potassium-magnesium citrate therapy (to 1027 +/- 478 mg/day from 638 +/- 252 mg/day) than during potassium citrate treatment (to 932 +/- 297 mg/day). Consequently, urinary saturation (activity product) of calcium oxalate declined significantly (from 1.49 x 10(-8) to 1.03 x 10(-8) M2) during potassium-magnesium citrate therapy and marginally (to 1.14 x 10(-8) M2) during potassium citrate therapy.(ABSTRACT TRUNCATED AT 250 WORDS).

  14. Impurities Removal in Seawater to Optimize the Magnesium Extraction

    Science.gov (United States)

    Natasha, N. C.; Firdiyono, F.; Sulistiyono, E.

    2017-02-01

    Magnesium extraction from seawater is promising way because magnesium is the second abundant element in seawater and Indonesia has the second longest coastline in the world. To optimize the magnesium extraction, the impurities in seawater need to be eliminated. Evaporation and dissolving process were used in this research to remove the impurities especially calcium in seawater. Seawater which has been evaporated from 100 ml to 50 ml was dissolved with variations solution such as oxalic acid and ammonium bicarbonate. The solution concentration is 100 g/l and it variations are 2 ml, 4 ml, 6 ml, 8 ml, 10 ml, 20 ml, 30 ml, 40 ml and 50 ml. This step will produce precipitate and filtrate then it will be analysed to find out the result of this process. The precipitate was analysed by X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM) but the filtrate was analysed by Inductively Coupled Plasma (ICP). XRD analysis shows that calcium oxalate and calcium carbonate were formed and ICP analysis shows that the remaining calcium in seawater using oxalic acid is about 0.01% and sodium 0.14% but when using ammonium bicarbonate the remaining calcium is 2.5% and sodium still more than 90%. The results show that both oxalic acid and ammonium bicarbonate can remove the impurities but when using oxalic acid, not only the impurities but also magnesium was precipitated. The conclusion of this research is the best solution to remove the impurities in seawater without precipitate the magnesium is using ammonium bicarbonate.

  15. Thermodynamic criteria for the removal of impurities from end-of-life magnesium alloys by evaporation and flux treatment

    Directory of Open Access Journals (Sweden)

    Takehito Hiraki, Osamu Takeda, Kenichi Nakajima, Kazuyo Matsubae, Shinichiro Nakamura and Tetsuya Nagasaka

    2011-01-01

    Full Text Available In this paper, the possibility of removing impurities during magnesium recycling with pyrometallurgical techniques has been evaluated by using a thermodynamic analysis. For 25 different elements that are likely to be contained in industrial magnesium alloys, the equilibrium distribution ratios between the metal, slag and gas phases in the magnesium remelting process were calculated assuming binary systems of magnesium and an impurity element. It was found that calcium, gadolinium, lithium, ytterbium and yttrium can be removed from the remelted end-of-life (EoL magnesium products by oxidization. Calcium, cerium, gadolinium, lanthanum, lithium, plutonium, sodium, strontium and yttrium can be removed by chlorination with a salt flux. However, the other elements contained in magnesium alloy scrap are scarcely removed and this may contribute toward future contamination problems. The third technological option for the recycling of EoL magnesium products is magnesium recovery by a distillation process. Based on thermodynamic considerations, it is predicted that high-purity magnesium can be recovered through distillation because of its high vapor pressure, yet there is a limit on recoverability that depends on the equilibrium vapor pressure of the alloying elements and the large energy consumption. Therefore, the sustainable recycling of EoL magnesium products should be an important consideration in the design of advanced magnesium alloys or the development of new refining processes.

  16. 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.

  17. Effects of a low-radiotoxicity uranium salt (uranyl acetate) on biochemical and hematological parameters of the catfish, Clarias gariepinus

    Science.gov (United States)

    Al-Ghanim, Khalid A.; Ahmad, Zubair; Al-Kahem Al-Balawi, Hmoud F.; Al-Misned, Fahad; Maboob, Shahid; Suliman, El-Amin M.

    2016-01-01

    Specimens of Clarias gariepinus were treated with lethal (70, 75, 80, 85, 90, and 95 mg/L) and sub-lethal concentrations (8, 12 and 16 mg/L) of uranyl acetate, a low-radiotoxicity uranium salt. The LC 50 value was registered as 81.45 mg/L. The protein and glycogen concentrations in liver and muscles were decreased in the fish exposed to sub-lethal concentrations. The red blood cell (RBC) and white blood cell (WBC) counts, haemoglobin (Hb) concentration and haematocrit (Hct) values were decreased. Different blood indices like mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) were negatively affected. Level of plasma glucose was elevated whereas protein was decreased. The level of calcium concentration (Ca) was declined in the blood of exposed fish whereas magnesium (Mg) remains unchanged. The activity level of glutamic-oxaloacetic transaminase (GOT) and glutamic-pyruvic transaminase (GPT) was elevated in exposed fish. These effects were more pronounced in the last period of exposure and in higher concentrations. Results of the present study indicate that uranyl acetate has adverse effects on Clarias gariepinus and causes changes in the biochemical and hematological parameters of the fish.

  18. The Association Between Serum Magnesium Concentrations and Coronary Artery Calcification Scores in Astronauts

    Science.gov (United States)

    Betcher, Jenna; Zwart, Sara; Smith, Scott M.

    2016-01-01

    Magnesium is a natural calcium antagonist, and is inversely associated with coronary heart disease, cardiovascular mortality rates, and vascular calcification. Coronary artery calcification score is a tool used to evaluate the prognosis of coronary artery disease in individuals. Higher magnesium intake is associated with lower coronary artery calcification scores (CACS), and recent studies have found a significant inverse relationship between serum magnesium concentrations and CACS in Korean and Mexican-mestizo populations. The correlation between serum magnesium concentrations and CACS is not well researched, so our aim was to examine this relationship in astronauts. We found that a higher serum magnesium concentration is significantly related to a higher coronary artery calcification score (p=.0217), and that there is a significant difference in magnesium concentrations of subjects who have a CACS greater than 100 and a CACS less than 100.

  19. Direct-reading spectrochemical analysis of magnesium alloys; Analisis espectroquimico de lectura directa de aleaciones de magnesio

    Energy Technology Data Exchange (ETDEWEB)

    Roca Adell, M.

    1964-07-01

    A Quantometer has been applied to the determination of aluminum, berylium, calcium, iron, silicon and zinc in magnesium alloys Magnox, after the conversion of the samples to the oxide. For the aluminum, whose concentration is relatively high, the conducting briquets technique with an interrupted discharge is employed, using the magnesium as the internal standard. For the other elements a total burning method with direct current arc is employed, using also the magnesium as the internal standard. (Author) 7 refs.

  20. 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.

  1. 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 ...

  2. Sol - Gel synthesis and characterization of magnesium peroxide nanoparticles

    Science.gov (United States)

    Jaison, J.; Ashok raja, C.; Balakumar, S.; Chan, Y. S.

    2015-04-01

    Magnesium peroxide is an excellent source of oxygen in agriculture applications, for instance it is used in waste management as a material for soil bioremediation to remove contaminants from polluted underground water, biological wastes treatment to break down hydrocarbon, etc. In the present study, sol-gel synthesis of magnesium peroxide (MgO2) nanoparticles is reported. Magnesium peroxide is odourless; fine peroxide which releases oxygen when reacts with water. During the sol-gel synthesis, the magnesium malonate intermediate is formed which was then calcinated to obtain MgO2 nanoparticles. The synthesized nanoparticles were characterized using Thermo gravimetric -Differential Thermal Analysis (TG- DTA), X-Ray Diffraction studies (XRD) and High Resolution Transmission Electron Microscope (HRTEM). Our study provides a clear insight that the formation of magnesium malonate during the synthesis was due to the reaction between magnesium acetate, oxalic acid and ethanol. In our study, we can conclude that the calcination temperature has a strong influence on particle size, morphology, monodispersity and the chemistry of the particles.

  3. 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

  4. Hydrogen generation from magnesium hydride by using organic acid

    Science.gov (United States)

    Ho, Yen-Hsi

    In this paper, the hydrolysis of solid magnesium hydride has been studied with the high concentration of catalyst at the varying temperature. An organic acid (acetic acid, CH3COOH) has been chosen as the catalyst. The study has three objectives: first, using three different weights of MgH 2 react with aqueous solution of acid for the hydrogen generation experiments. Secondly, utilizing acetic acid as the catalyst accelerates hydrogen generation. Third, emphasizing the combination of the three operating conditions (the weight of MgH2, the concentration of acetic acid, and the varying temperature) influence the amount of hydrogen generation. The experiments results show acetic acid truly can increase the rate of hydrogen generation and the weight of MgH2 can affect the amount of hydrogen generation more than the varying temperature.

  5. Estimation of presynaptic calcium currents and endogenous calcium buffers at the frog neuromuscular junction with two different calcium fluorescent dyes

    Directory of Open Access Journals (Sweden)

    Dmitry eSamigullin

    2015-01-01

    Full Text Available At the frog neuromuscular junction, under physiological conditions, the direct measurement of calcium currents and of the concentration of intracellular calcium buffers—which determine the kinetics of calcium concentration and neurotransmitter release from the nerve terminal—has hitherto been technically impossible. With the aim of quantifying both Ca2+ currents and the intracellular calcium buffers, we measured fluorescence signals from nerve terminals loaded with the low-affinity calcium dye Magnesium Green or the high-affinity dye Oregon Green BAPTA-1, simultaneously with microelectrode recordings of nerve-action potentials and end-plate currents. The action-potential-induced fluorescence signals in the nerve terminals developed much more slowly than the postsynaptic response. To clarify the reasons for this observation and to define a spatiotemporal profile of intracellular calcium and of the concentration of mobile and fixed calcium buffers, mathematical modeling was employed. The best approximations of the experimental calcium transients for both calcium dyes were obtained when the calcium current had an amplitude of 1.6 ± 0.08 рА and a half-decay time of 1.2 ± 0.06 ms, and when the concentrations of mobile and fixed calcium buffers were 250 ± 13 µM and 8 ± 0.4 mM, respectively. High concentrations of endogenous buffers define the time course of calcium transients after an action potential in the axoplasm, and may modify synaptic plasticity.

  6. Effect of calcium and magnesium silicate on the growth of the castor oil plant subjected to salinity levels Efeito de silicato de cálcio e magnésio sobre o crescimento de plantas de mamoneira submetidas a níveis de salinidade

    Directory of Open Access Journals (Sweden)

    José Félix Brito Neto

    2012-12-01

    Full Text Available Salt stress decreases the osmotic potential of soil solution causing water stress, causing toxic effects in the plants resulting in injuries on the metabolism and nutritional disorders, thus compromising the plant growth, resulting in lower production. The calcium silicate and magnesium can perform the same function as limestone, besides providing silicon to plants, may also contribute to the resistance of plants to salt stress. Thus, the objective of this study was to evaluate the effect of calcium and magnesium silicate on the growth of the castor oil plant BRS Energia cultivated under saline conditions. This study evaluated plant height, stem diameter, number of leaves, leaf area, dry weight of shoot and root, and soil chemical characteristics. There was no interaction between factors of salinity level and of silicate level regarding the evaluated variables. There was a direct relationship between salinity levels and plant growth in height and stem diameter. The K concentration in soil were affected by salinity levels. O estresse salino diminui o potencial osmótico da solução do solo causando estresse hídrico, provocando efeitos tóxicos nas plantas que resultam em injúrias no metabolismo e desordens nutricionais, comprometendo assim o crescimento das plantas, resultando em menor produção. O silicato de cálcio e magnésio pode desempenhar a mesma função do calcário, além de fornecer silício para as plantas, podendo ainda, contribuir para a resistência de plantas ao estresse salino. Nesse sentido, objetivou-se com esse trabalho avaliar o efeito do silicato de cálcio e magnésio no crescimento da mamoneira BRS Energia cultivada sob condições salinas. Avaliou-se a altura da planta, diâmetro do caule, número de folhas, área foliar, massa seca da parte aérea e da raiz e as características químicas do solo. Não houve interação entre os fatores níveis de salinidade e silicato sobre as variáveis analisadas. Houve rela

  7. 醋酸钙片对血液透析高磷血症患者血Ca、P水平的影响分析%Analysis of the influence of Ca、P levels of calcium acetate tablets on hemodialysis patients with hyperphosphatemia

    Institute of Scientific and Technical Information of China (English)

    朱再志; 白佳柠; 袁锦; 邹茜婷; 晁群; 许志忠

    2015-01-01

    目的 探讨醋酸钙片对血液透析(HD)高磷血症患者血钙(Ca)、磷(P)水平的影响.方法 选择2012年2月至2014年2月本院收治的HD高磷血症患者64例,随机分为研究组(32例)和对照组(32例).在原有HD方案的基础上,对照组患者采用碳酸钙片治疗,研究组患者采用醋酸钙片治疗.结果 研究组治疗4周、治疗8周时P及CaP乘积显著降低,与治疗前相比差异具有统计学意义(P<0.05);且治疗8周时P及CaP乘积显著低于对照组(P<0.05).两组Ca、iPTH水平对比差异无统计学意义(P>0.05).研究组药物不良反应发生率为18.75%,对照组为21.86%,两组患者不良反应症状均较轻微,减药或停药后症状完全消失.结论 醋酸钙片可以有效控制HD高磷血症患者体内的P水平,且对Ca无明显影响,大大降低了高钙血症的发生机率,疗效确切,安全性佳,适于临床推广与应用.%Objectives To investigate influence of Ca,P levels of Calcium Acetate Tablets on hemodialysis patients with hyperphosphatemia.Methods Selected 64 HD patients with hyperphosphatemia in 2012 February ~2014 February in our hospital,which were randomly divided into the study group(32 cases) and control group (32 cases).On the basis of the original HD scheme,the control group was treated with Calcium Carbonate Tablets treatment,the study group was trcated with Calcium Acetate Tablets treatment.Results For 4 weeks,8 weeks of treatment,P and CaP product in the study group were significantly reduced than before treatment,the difference was statistically significant (P <0.05);and the 8 weeks of treatment P and CaP product was significantly lower than the control group(P < 0.05).The two groups had no statistically significant difference between Ca,iPTH levels (P >0.05).The incidence of adverse reaction of study group was 18.75%,the incidence of adverse reaction of control group 28.13%,two groups of patients with adverse reactions were mild

  8. Magnesium-containing mixed coatings on zirconia for dental implants: mechanical characterization and in vitro behavior.

    Science.gov (United States)

    Pardun, Karoline; Treccani, Laura; Volkmann, Eike; Streckbein, Philipp; Heiss, Christian; Gerlach, Juergen W; Maendl, Stephan; Rezwan, Kurosch

    2015-07-01

    An important challenge in the field of dental and orthopedic implantology is the preparation of implant coatings with bioactive functions that feature a high mechanical stability and at the same time mimic structural and compositional properties of native bone for a better bone ingrowth. This study investigates the influence of magnesium addition to zirconia-calcium phosphate coatings. The mixed coatings were prepared with varying additions of either magnesium oxide or magnesium fluoride to yttria-stabilized zirconia and hydroxyapatite. The coatings were deposited on zirconia discs and screw implants by wet powder spraying. Microstructure studies confirm a porous coating with similar roughness and firm adhesion not hampered by the coating composition. The coating morphology, mechanical flexural strength and calcium dissolution showed a magnesium content-dependent effect. Moreover, the in vitro results obtained with human osteoblasts reveal an improved biological performance caused by the presence of Mg(2+) ions. The magnesium-containing coatings exhibited better cell proliferation and differentiation in comparison to pure zirconia-calcium phosphate coatings. In conclusion, these results demonstrate that magnesium addition increases the bioactivity potential of zirconia-calcium phosphate coatings and is thus a highly suitable candidate for bone implant coatings.

  9. Kinetics of Leaching Calcium from Dolomite

    Directory of Open Access Journals (Sweden)

    Azizi, A.

    2011-06-01

    Full Text Available Magnesia is obtained from magnesite ore and the production process applied should remove accompanying minerals that reduce its refractoriness. Given that magnesite reservoirs are more exploited and largely exhausted, there is a growing need for production of magnesia on the basis of other magnesium minerals. Dolomite is a promising source of magnesia because it forms large deposits, is easy to exploit, and generally contains a small quantity of impurities.The kinetics of calcium leaching from dolomite by magnesium-nitrate solution has been studied. The research program included the influence of temperature, mass fraction of magnesium nitrate in solution, dolomite particle size and leaching time. Time dependence of calcium leaching is described by relevant kinetic equations. Rate coefficients, their temperature dependence and Arrhenius activation energy have been determined.

  10. Extracellular magnesium decreases the secretory response of rat peritoneal mast cells to compound 48/80 in vitro

    DEFF Research Database (Denmark)

    Bertelsen, Niels Haldor; Johansen, Torben

    1991-01-01

    Exposure of rat peritoneal mast cells to magnesium in the absence of extracellular calcium resulted in a time- and dose-dependent decrease in the secretory response induced by compound 48/80. The decrease was prevented by a low extracellular concentration of calcium. Furthermore, the decreased...... and the secretory stimulus. A dose-dependent decrease in antigen induced histamine secretion that was reversed by calcium was also observed. Exposure of the mast cells to magnesium for 15 min resulted in a parallel decrease in histamine secretion and in the cellular content of 45Ca2+. These observations suggest...... secretory responsiveness was dose-dependently restored by the addition of calcium to the cells simultaneously with compound 48/80. Preincubation with magnesium also inhibited antigen-induced histamine secretion in a dose-dependent manner. This was reversed by the simultaneous addition of calcium...

  11. 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.

  12. 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.

  13. 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.

  14. 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 ...

  15. Chemical speciation of uranium(VI) in marine environments: complexation of calcium and magnesium ions with [(UO2 )(CO3 )3 ](4-) and the effect on the extraction of uranium from seawater.

    Science.gov (United States)

    Endrizzi, Francesco; Rao, Linfeng

    2014-10-27

    The interactions of Ca(2+) and Mg(2+) with [UO2 (CO3 )3 ](4-) were studied by calcium ion selective electrode potentiometry and spectrophotometry. The stability constants of ternary Ca-UO2 -CO3 and Mg-UO2 -CO3 complexes were determined with calcium ion selective electrode potentiometry and optical absorption spectrophotometry, respectively. The enthalpies of complexation for two successive complexes, [CaUO2 (CO3 )3 ](2-) and [Ca2 UO2 (CO3 )3 ](aq), were determined for the first time by microcalorimetry. The data help to revise the speciation of uranium(VI) species under seawater conditions. In contrast to the previously accepted assumption that the highly negatively charged [UO2 (CO3 )3 ](4-) is the dominant species, the revised speciation indicates that the dominant aqueous uranium(VI) species under seawater conditions is the neutral [Ca2 UO2 (CO3 )3 ](aq). The results have a significant impact on the strategies for developing efficient sorption processes to extract uranium from seawater.

  16. Magnesium diboride: one year on

    Energy Technology Data Exchange (ETDEWEB)

    Canfield, Paul [Iowa State University (United States); Ames Laboratory (United States); Bud' ko, Sergey L. [Ames Laboratory (United States)

    2002-01-01

    Last January physicists discovered that an innocuous compound that had been sitting on the shelf for decades was, in fact, a record-breaking intermetallic superconductor. At the end of 2000 superconductivity in metal alloys and compounds appeared to remain trapped by a glass ceiling. Over the previous 10 years the temperature at which certain oxide-based compounds - such as bismuth strontium calcium copper oxide and mercury barium calcium copper oxide - lost their resistance to electric current had soared to well over 100 K. Meanwhile, the transition temperature, T{sub c}, for carbon-based materials, including alkali-doped carbon-60 compounds, had risen close to the boiling point of liquid nitrogen (77 K). During the same period, however, the superconducting transition temperature of intermetallic compounds (materials made solely of metals and metal-like elements) remained close to 20 K - as it had been since the mid-1960s. By February 2001 everything had totally changed. It was as if a firecracker had gone off in the tidy little ant hill of superconductivity research. For the first few months of 2001, groups all over the world raced to understand the properties of a new intermetallic superconductor. The substance that everyone was scrambling to buy or make, the substance that was causing this grand commotion, was magnesium diboride (MgB{sub 2}). This seemingly innocuous binary compound, which had been present in many labs for over half a century, had been discovered to superconduct just below 40 K. Even though we already know an amazing amount about MgB{sub 2}, our knowledge of superconductivity in this compound is only one year old. There is therefore the very real potential to improve its critical properties. In a similar vein, it is almost certain that our understanding of this extreme example of intermetallic superconductivity will greatly improve over the next few years and may even reveal other extreme superconductors. (U.K.)

  17. Calcium supplements

    Science.gov (United States)

    ... do not help. Always tell your provider and pharmacist if you are taking extra calcium. Calcium supplements ... 2012:chap 251. The National Osteoporosis Foundation (NOF). Clinician's Guide to prevention and treatment of osteoporosis . National ...

  18. 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.

  19. Acetate Kinase Isozymes Confer Robustness in Acetate Metabolism

    DEFF Research Database (Denmark)

    Chan, Siu Hung Joshua; Nørregaard, Lasse; Solem, Christian;

    2014-01-01

    strains reveal that AckA1 has a higher capacity for acetate production which allows faster growth in an environment with high acetate concentration. Meanwhile, AckA2 is important for fast acetate-dependent growth at low concentration of acetate. The results demonstrate that the two ACKs have complementary...... physiological roles in L. lactis to maintain a robust acetate metabolism for fast growth at different extracellular acetate concentrations. The existence of ACK isozymes may reflect a common evolutionary strategy in bacteria in an environment with varying concentrations of acetate....

  20. Microbiological preservation of cucumbers for bulk storage by the use of acetic acid and food preservatives

    Science.gov (United States)

    Microbial growth did not occur when cucumbers were preserved without a thermal process by storage in solutions containing acetic acid, sodium benzoate, and calcium chloride to maintain tissue firmness. The concentrations of acetic acid and sodium benzoate required to assure preservation were low en...

  1. Altered magnesium transport in slices of kidney cortex from chemically-induced diabetic rats

    Energy Technology Data Exchange (ETDEWEB)

    Hoskins, B.

    1981-10-01

    The uptake of magnesium-28 was measured in slices of kidney cortex from rats with alloxan-diabetes and from rats with streptozotocin-diabetes of increasing durations. In both forms of chemically-induced diabetes, magnesium-28 uptake by kidney cortex slices was significantly increased over uptake measured in kidney cortex slices from control rats. Immediate institution of daily insulin therapy to the diabetic rats prevented the diabetes-induced elevated uptake of magnesium without controlling blood glucose levels. Late institution of daily insulin therapy was ineffective in restoring the magnesium uptake to control values. These alterations in magnesium uptake occurred prior to any evidence of nephropathy (via the classic indices of proteinuria and increased BUN levels). The implications of these findings, together with our earlier demonstrations of altered calcium transport by kidney cortex slices from chemically-induced diabetic rats, are discussed in terms of disordered divalent cation transport being at least part of the basic pathogenesis underlying diabetic nephropathy.

  2. The Effects of High Level Magnesium Dialysis/Substitution Fluid on Magnesium Homeostasis under Regional Citrate Anticoagulation in Critically Ill.

    Directory of Open Access Journals (Sweden)

    Mychajlo Zakharchenko

    Full Text Available The requirements for magnesium (Mg supplementation increase under regional citrate anticoagulation (RCA because citrate acts by chelation of bivalent cations within the blood circuit. The level of magnesium in commercially available fluids for continuous renal replacement therapy (CRRT may not be sufficient to prevent hypomagnesemia.Patients (n = 45 on CRRT (2,000 ml/h, blood flow (Qb 100 ml/min with RCA modality (4% trisodium citrate using calcium free fluid with 0.75 mmol/l of Mg with additional magnesium substitution were observed after switch to the calcium-free fluid with magnesium concentration of 1.50 mmol/l (n = 42 and no extra magnesium replenishment. All patients had renal indications for CRRT, were treated with the same devices, filters and the same postfilter ionized calcium endpoint (<0.4 mmol/l of prefilter citrate dosage. Under the high level Mg fluid the Qb, dosages of citrate and CRRT were consequently escalated in 9h steps to test various settings.Median balance of Mg was -0.91 (-1.18 to -0.53 mmol/h with Mg 0.75 mmol/l and 0.2 (0.06-0.35 mmol/h when fluid with Mg 1.50 mmol/l was used. It was close to zero (0.02 (-0.12-0.18 mmol/h with higher blood flow and dosage of citrate, increased again to 0.15 (-0.11-0.25 mmol/h with 3,000 ml/h of high magnesium containing fluid (p<0.001. The arterial levels of Mg were mildly increased after the change for high level magnesium containing fluid (p<0.01.Compared to ordinary dialysis fluid the mildly hypermagnesemic fluid provided even balances and adequate levels within ordinary configurations of CRRT with RCA and without a need for extra magnesium replenishment.ClinicalTrials.gov Identifier: NCT01361581.

  3. 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.

  4. Magnesium substitution in brushite cements for enhanced bone tissue regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Cabrejos-Azama, Jatsue, E-mail: jacaza@farm.ucm.es [Departamento de Química-Física II, Facultad de Farmacia, UCM, Madrid (Spain); Departamento de Estomatología III, Facultad de Odontología UCM, Madrid (Spain); Alkhraisat, Mohammad Hamdan; Rueda, Carmen [Departamento de Química-Física II, Facultad de Farmacia, UCM, Madrid (Spain); Torres, Jesús [Facultad de Ciencias de la salud URJC, Alcorcón, Madrid (Spain); Blanco, Luis [Departamento de Estomatología III, Facultad de Odontología UCM, Madrid (Spain); López-Cabarcos, Enrique [Departamento de Química-Física II, Facultad de Farmacia, UCM, Madrid (Spain)

    2014-10-01

    We have synthesized calcium phosphate cements doped with different amounts of magnesium (Mg-CPC) with a twofold purpose: i) to evaluate in vitro the osteoblast cell response to this material, and ii) to compare the bone regeneration capacity of the doped material with a calcium cement prepared without magnesium (CPC). Cell proliferation and in vivo response increased in the Mg-CPCs in comparison with CPC. The Mg-CPCs have promoted higher new bone formation than the CPC (p < 0.05). The cytocompatibility and histomorfometric analysis performed in the rabbit calvaria showed that the incorporation of magnesium ions in CPC improves osteoblasts proliferation and provides higher new bone formation. The development of a bone substitute with controllable biodegradable properties and improved bone regeneration can be considered a step toward personalized therapy that can adapt to patient needs and clinical situations. - Highlights: • The Mg-CPCs promote higher new bone formation than the CPC. • The incorporation of magnesium ions in CPC improves osteoblasts proliferation. • Mg-CPC is a bone substitute with controllable biodegradable properties. • We suggest that the use of Mg ions could improve the clinical efficiency of CPCs.

  5. Study of interactions of L-aspartic acid and L-glutamic acid with some metal acetates through volumetric behaviour over the temperature range (288.15 to 318.15) K

    Energy Technology Data Exchange (ETDEWEB)

    Banipal, Tarlok S. [Department of Applied Chemistry, Guru Nanak Dev University, Amritsar 143 005 (India)], E-mail: tsbanipal@yahoo.com; Singh, Kultar [Department of Applied Chemistry, Guru Nanak Dev University, Amritsar 143 005 (India); Banipal, Parampaul K. [Department of Chemistry, Guru Nanak Dev University, Amritsar 143 005 (India); Kaur, Jasbir [Department of Applied Chemistry, Guru Nanak Dev University, Amritsar 143 005 (India)

    2008-07-15

    Apparent molar volumes, V{sub 2,{phi}}, of L-aspartic acid and L-glutamic acid have been determined in aqueous solutions of (0.1, 0.25, 0.5, and 1.0) mol . kg{sup -1} of lithium acetate dihydrate, magnesium acetate tetrahydrate, and calcium acetate at T = (288.15, 298.15, 308.15, and 318.15) K by density measurements. The data have been used to calculate partial molar volume, V{sub 2}{sup 0}, and transfer function, {delta}{sub t}V{sup 0}, at infinite dilution from water to aqueous solutions of co-solutes by applying the correction due to ionisation of amino acids. Partial molar expansibilities, V{sub E}{sup 0}, hydration numbers, n{sub H}, and interaction coefficients of amino acids have also been determined. The dependence of above thermodynamic functions on concentration, temperature and nature of co-solute has been discussed in terms of various interactions taking place between hydrophobic and hydrophilic parts of amino acids and ions of co-solutes. Further, a comparison between present work and data reported in the literature for neutral amino acids DL-alanine, DL-{alpha}-amino-n-butyric acid and their corresponding hydroxy derivatives, L-serine and L-threonine in aqueous solutions of these co-solutes has been made.

  6. Physicochemical study of alkaline earth metal and magnesium maleates

    Energy Technology Data Exchange (ETDEWEB)

    Koblova, O.E.; Vdovina, L.M.; Frolova, L.A. (Saratovskij Gosudarstvennyj Univ. (USSR); Saratovskij Gosudarstvennyj Pedagogicheskij Inst. (USSR))

    1982-01-01

    Magnesium, calcium, strontium and barium maleates are synthesized. Their thermal stability in the atmosphere of air and argon is studied. It is shown that the dehydration of initial salts proceeds in the temperature range of 100-300 deg C. The decomposition of anhydrous salts takes place in the temperature range of 380-600 deg C. The values of the effective activation energy are determined.

  7. 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.

  8. Study on the bonding strength between calcium phosphate/chitosan composite coatings and a Mg alloy substrate

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Jie [School of Chemistry Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China); Pharmacy College, Jiamusi University, Jiamusi 154007 (China); Dai Changsong, E-mail: changsd@hit.edu.cn [School of Chemistry Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China); Wei Jie [School of Chemistry Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China); School of Chemistry and Bioengineering, Suzhou Science Technology University, Suzhou 215009 (China); Wen Zhaohui, E-mail: wenzhaohui1968@163.com [Department of Neuro intern, First Affiliated Hospital of Harbin Medical University, Harbin 150001 (China)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer Calcium phosphate/chitosan composite coatings on the MAO-AZ91D alloy were prepared. Black-Right-Pointing-Pointer The bonding force between the coating and the magnesium alloy was optimized. Black-Right-Pointing-Pointer The composite coating slowed down the corrosion rate of magnesium alloy in m-SBF. - Abstract: In order to improve the bonding strength between calcium phosphate/chitosan composite coatings and a micro-arc oxidized (MAO)-AZ91D Mg alloy, different influencing parameters were investigated in the process of electrophoretic deposition (EPD) followed by conversion in a phosphate buffer solution (PBS). Surface morphology and phase constituents of the as-prepared materials were investigated by using X-ray diffractometer (XRD), Fourier-transformed infrared spectrophotometer (FTIR), Raman spectrometer, scanning electron microscope (SEM) with an energy dispersive spectrometer (EDS), and a thermo gravimetric and differential thermal analyzer (TG-DTA). Scratch tests were carried out to study the bonding properties between the coatings and the substrates. In vitro immersion tests were conducted to determine the corrosion behaviors of samples with and without deposit layers through electrochemical experiments. In the EPD process, the acetic acid content in the electrophoresis suspension and the electrophoretic voltage played important roles in improving the bonding properties, while the contents of chitosan (CS) and nano-hydroxyapatite (nHA, Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}) in the suspension had less significant influences on the mechanical bonding strength. It was observed that the coatings showed the excellent bonding property when an electrophoretic voltage was in a range of 40-110 V with other reagent amounts as follows: acetic acid: 4.5 vol.%, CS {<=} 0.25 g, nHA {<=} 2.0 g in 200 ml of a CS-acetic acid aqueous solution and nHA {<=} 2.5 g in 300 ml of absolute ethanol. The morphology of the composite coating

  9. 新型钙镁磷酸复合材料理化机械性能的初步评价%Mechanical and chemical properties of novel calcium-magnesium phosphate cements

    Institute of Scientific and Technical Information of China (English)

    沈晴昳; 李恺; 李国强

    2016-01-01

    Objective To study the mechanical and chemical properties of novel calcium⁃magnesium phosphate cements( CMPCs) . Methods Components of the CMPCs were analyzed by XRD and SEM. The physicochemical properties of the CMPCs were investiga⁃ted, and the effects of different components on setting time, compressive strength, rate of degradation were studied. Results Accord⁃ing to the analysis of XRD and SEM, CMPCs were composed of Ca3( PO4 ) 2 , Mg3( PO4 ) 2 and HA, and a small amount of unreacted MgO was also observed. It showed that with the increasing amount the CMPCs exhibited shorter setting time and higher compressive strength than the CPC. In addition, CMPCs showed significantly improved degradability compared with the CPC in SBF. Conclusion CMPCs possess a significant clinical advantage over CPC, and it might have the value of in⁃depth study as dental restorative material.%目的:研究新型磷酸钙-磷酸镁水门汀( CMPCs)的理化机械性能。方法采用 X 射线衍射( XRD)、扫描电镜( SEM)分析主要物相组成,研究比较材料不同组成对固化时间、抗压强度、降解率的影响。结果 XRD、SEM 分析显示, CMPCs主要包含Ca3( PO4)2、Mg3( PO4)2、HA以及少量MgO。随着磷酸镁水门汀含量的增加,CMPCs的固化时间缩短,抗压强度提高,降解率升高。结论 CMPCs理化机械性能优良,作为齿科修复材料具有深入研究的价值。

  10. Chemical synthesis and stabilization of magnesium substituted brushite

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Donghyun [Department of Biomedical Engineering, Chung-Ang University, 221 Heukseok-Dong, Dongjak-Gu, Seoul 156-756 (Korea, Republic of); Kumta, Prashant N., E-mail: pkumta@pitt.edu [Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Department of Mechanical Engineering and Materials Sceince, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA 15260 (United States)

    2010-08-30

    Hydroxyapatite (Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}) is the most ubiquitous calcium phosphate phase used in implant coatings and more recently in gene/drug delivery applications due to its chemical stability under normal physiological conditions (37 deg. C, pH {approx} 7.5, 1 atm.). However, different calcium phosphate phases, such as brushite (CaH(PO{sub 4}){center_dot}2(H{sub 2}O)) and tricalcium phosphate (Ca{sub 3}(PO{sub 4}){sub 2}) which are thermodynamically unstable under physiological conditions are also being explored for biomedical applications. One way of stabilizing these phases under physiological conditions is to introduce magnesium to substitute for calcium in the brushite lattice. The role of magnesium as a stabilizing agent for synthesizing brushite under physiological conditions at room temperature has been studied. Chemical analysis, Fourier transform infrared spectroscopy and X-ray diffraction have also been conducted to validate the formation of magnesium substituted brushite under physiological conditions.

  11. 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.

  12. 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

  13. Efeito do triglicerídeo de cadeia média, fibra e cálcio na disponibilidade de ferro, magnésio e zinco em uma formulação de alimentação enteral com otimização conjunta para os três minerais Effect of medium-chain triglycerides, fiber, and calcium on enteral feeding formulation optimized for the availability of iron, magnesium and zinc

    Directory of Open Access Journals (Sweden)

    Luciana Bueno

    2008-12-01

    Full Text Available A terapia nutricional com dietas enterais vem se especializando muito nos últimos anos. Este trabalho teve por objetivo estudar o efeito dos componentes das formulações de dietas enterais: fibra, cálcio e triacilglicerídeos de cadeia média, visando otimizar uma formulação para a dialisabilidade de ferro, magnésio e zinco, utilizando a Metodologia de Superfície de Resposta para Misturas. De acordo com os resultados, a melhor formulação de alimentação enteral otimizada em função da dialisabilidade do ferro, magnésio e zinco foi a proporção de 32,5% de TCM e fibra e 35% de cálcio, o que caracterizou uma formulação otimizada simultaneamente para os três minerais.The nutritional therapy with enteral diets has had a major development in the past few years. The aim of this work is to study the effect of the enteral diet formulations components such as fiber, calcium, and medium-chain triglycerides, seeking in order to optimize a formulation for iron, magnesium, and zinc dialysability using the Response Surface Methodology. According to the result, the best enteral diet formulation optimized based on mineral dialysability was the one containing 32,5% of TCM, 32,5% of fiber, and 35% of calcium. It proved the best enteral diet formulation for the availability of iron, magnesium, and zinc.

  14. Increased responsiveness of rat mast cells to compound 48/80 due to removal of extracellular magnesium. Effects of ouabain and EGTA

    DEFF Research Database (Denmark)

    Bertelsen, Niels Haldor; Johansen, Torben

    1991-01-01

    A decreased secretory response of mast cells to compound 48/80 (12% of control value) after preincubation of the cells with magnesium but without calcium was partially restored by removal of magnesium. EGTA (10 microM) blocked the restoration and decreased the restored secretory activity again...

  15. Efficacy comparison of calcium-magnesium infusion and mecobalamin to prevent the neurotoxicity induced by oxaliplatin%钙镁合剂和甲钴胺预防奥沙利铂所致神经毒性疗效比较

    Institute of Scientific and Technical Information of China (English)

    杨武; 喻永龙; 王新帅; 朱西平; 张振华

    2013-01-01

    目的:评估钙镁合剂和甲钴胺对奥沙利铂引起神经毒性的预防作用.方法:采用随机、安慰剂对照的方法,将接受奥沙利铂+氟尿嘧啶+亚叶酸钙方案化疗的90例大肠癌患者随机分为3组,分别给予钙镁合剂、甲钴胺和生理盐水.利用奥沙利铂专用神经毒性分级和神经症状评分(NSS)观察患者神经毒性发生率及严重程度.结果:单纯化疗组、钙镁合剂组、甲钴胺组急性神经毒性发生率分别为93.1%、66.7%、65.5%,差异有统计学意义(P0.05).化疗6周期时3组差异有统计学意义(P0.05).根据NSS评分,单纯化疗组3周期、6周期时评分均高于其他2组(P0.05).结论:钙镁合剂和甲钴胺均能降低奥沙利铂神经毒性的发生率和程度.%Objective: To evaluate the effects of calcium-magnesium ( Ca/Mg) infusion and mecobalamin on preventing the neurotoxicity induced by oxaliplatin. Methods: Taking the method of random and placebo control, 90 patients with colon cancer treated with oxaliplatin + fluorouracil + calcium folinate chemotherapy were randomly divided into three groups which were treated with Ca/Mg infusion, mecobalamin and normal saline, respectively. According to Sanofisyn thelabo and neuropathy symptom score ( NSS ) , the neurotoxicity incidence and severity of all patients were observed. Results: The actue neurotoxicity incidence of normal saline, Ca/Mg infusion and mecobalamin group were 27 cases(93. 1% ) ,20 cases(66. 7% ) and 19 cases(65. 5% ) , respectively, which differences were statistical significance ( P 0. 05) ,but which were lower than that of chemotherapy group ( P 0. 05 ). The NSS score of chemotherapy group was higher than that of other two groups after 3 and 6 cycles of chemotherapy ( P 0. 05 ) . Conclusions; Ca/Mg infusion and mecobalamin can decrease the incidence and intensity of neurotoxicity induced by oxaliplatin.

  16. 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.

  17. Association between magnesium-deficient status and anthropometric and clinical-nutritional parameters in posmenopausal women

    Directory of Open Access Journals (Sweden)

    Beatriz López-González

    2014-03-01

    Full Text Available Background: During menopause occurs weight gain and bone loss occurs due to the hormone decline during this period and other factors such as nutrition. Magnesium deficiency suggests a risk factor for obesity and osteoporosis. Objective: To evaluate the clinical and nutritional magnesium status in a population of postmenopausal women, assessing intake and serum levels of magnesium in the study population and correlation with anthropometric parameters such as body mass index (BMI and body fat, and biochemical parameters associated. Subjects and Method: The study involved 78 healthy women aged 44-76, with postmenopausal status, from the province of Grenade, Spain. The sample was divided into two age groups: group 1, aged 58. Anthropometric parameters were recorded and nutritional intake was assessed by 72-hour recall, getting the RDAs through Nutriber® program. To assess the biochemical parameters was performed a blood sample was taken. Magnesium was analyzed by flame atomic absorption spectrophotometry (FAAS in erythrocyte and plasma wet-mineralized samples. Results: Our results show that 37.85% of the total subjects have an overweight status. Magnesium intake found in our population is insufficient in 36% of women, while plasma magnesium deficiency corresponds to 23% of the population and 72% of women have deficient levels of magnesium in erythrocyte. Positive correlations were found between magnesium intake and dietary intake of calcium, of phosphorus, and with prealbumin plasma levels, as well as with a lower waist / hip ratio. Magnesium levels in erythrocyte were correlated with lower triglycerides and urea values. Conclusion: It is important to control and monitor the nutritional status of magnesium in postmenopausal -women to prevent nutritional alterations and possible clinical and chronic degenerative diseases associated with magnesium deficiency and with menopause.

  18. 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...

  19. REGIOSELECTIVE REACTIONS OF 3-ALKYL-1-PHENYL-2-PYRAZOLIN-5-ONES WITH ACYL HALIDES IN THE PRECENCE OF NONOSIZED MAGNESIUM HYDROXIDE AS A HIGHLY EFFECTIVE HETEROGENOUS BASE CATALYST Regioselektive Reaktionen von 3-Alkyl-1-PHENYL-2-pyrazolin-5-ONES Mit Acylhalogeniden IN DER PRECENCE DER NONOSIZED MAGNESIUM HYDROXIDE als hochwirksame heterogene BASE CATALYST

    Directory of Open Access Journals (Sweden)

    Hassan Sheibani and Bahman Massomi Nejad

    2012-07-01

    Full Text Available 4-Acyl-3-alkyl-1-phenyl-2-pyrazolin-5-one derivatives were prepared by the regioselective acylation of 3-alkyl-1-phenyl-2-pyrazolin-5-ones in the presence of base catalysts such as calcium hydroxide [Ca(OH2], magnesium hydroxide [Mg(OH2] and nanosized magnesium hydroxide. In the presence of nanosized magnesium hydroxide, excellent yields of products were obtained and reaction times were significantly reduced.

  20. Preparing Process of Cerium Acetate and Rare Earth Acetate

    Institute of Scientific and Technical Information of China (English)

    Qiao Jun; Ma Ying; Xu Yanhui; Zhang Jun; Chang Shu; Hao Xianku

    2004-01-01

    Preparing process was presented and the influences of concentration of acetic acid, reaction temperature, the ratio of cerium carbonate and acetic acid, heat preservation time to the yield of cerium acetate were discussed.The crystalline cerium acetate and rare earth acetate such as ( La, Ce, Pr, Nd) (Ac) 3, ( Ce, Pr, Nd) (Ac) 3, ( Pr, Nd, Er,Y) (Ac) 3 and yttrium acetate were prepared under this condition.The shape, structure and composition of the crystals were determined by the methods of SEM, TG-DTA, X-ray diffraction and chemical analysis.The optimum prepared conditions of cerium acetate were described.This prepared process has characteristics such as simple process route, low cost, high yield, good quality, no pollution to environment, etc.

  1. Magnesium inhibits Wnt/β-catenin activity and reverses the osteogenic transformation of vascular smooth muscle cells.

    Science.gov (United States)

    Montes de Oca, Addy; Guerrero, Fatima; Martinez-Moreno, Julio M; Madueño, Juan A; Herencia, Carmen; Peralta, Alan; Almaden, Yolanda; Lopez, Ignacio; Aguilera-Tejero, Escolastico; Gundlach, Kristina; Büchel, Janine; Peter, Mirjam E; Passlick-Deetjen, Jutta; Rodriguez, Mariano; Muñoz-Castañeda, Juan R

    2014-01-01

    Magnesium reduces vascular smooth muscle cell (VSMC) calcification in vitro but the mechanism has not been revealed so far. This work used only slightly increased magnesium levels and aimed at determining: a) whether inhibition of magnesium transport into the cell influences VSMC calcification, b) whether Wnt/β-catenin signaling, a key mediator of osteogenic differentiation, is modified by magnesium and c) whether magnesium can influence already established vascular calcification. Human VSMC incubated with high phosphate (3.3 mM) and moderately elevated magnesium (1.4 mM) significantly reduced VSMC calcification and expression of the osteogenic transcription factors Cbfa-1 and osterix, and up-regulated expression of the natural calcification inhibitors matrix Gla protein (MGP) and osteoprotegerin (OPG). The protective effects of magnesium on calcification and expression of osteogenic markers were no longer observed in VSMC cultured with an inhibitor of cellular magnesium transport (2-aminoethoxy-diphenylborate [2-APB]). High phosphate induced activation of Wnt/β-catenin pathway as demonstrated by the translocation of β-catenin into the nucleus, increased expression of the frizzled-3 gene, and downregulation of Dkk-1 gene, a specific antagonist of the Wnt/β-catenin signaling pathway. The addition of magnesium however inhibited phosphate-induced activation of Wnt/β-catenin signaling pathway. Furthermore, TRPM7 silencing using siRNA resulted in activation of Wnt/β-catenin signaling pathway. Additional experiments were performed to test the ability of magnesium to halt the progression of already established VSMC calcification in vitro. The delayed addition of magnesium decreased calcium content, down-regulated Cbfa-1 and osterix and up-regulated MGP and OPG, when compared with a control group. This effect was not observed when 2-APB was added. In conclusion, magnesium transport through the cell membrane is important to inhibit VSMC calcification in vitro

  2. Absence of rebound effect with calcium carbonate.

    Science.gov (United States)

    Simoneau, G

    1996-01-01

    This was an open, randomised balance cross-over study in 12 healthy male volunteers. The antacid activity of calcium carbonate plus magnesium carbonate (Rennie and hydrotalcite (Talcid), given in the recommended dose of 2 tablets 4 times daily, were compared using 24 h intragastric measurement of pH. The volunteers received 2 tablets of calcium carbonate plus magnesium carbonate or hydrotalcite according to a randomised order 1 h after each meal and at bedtime. Results showed that both treatments have similar antacid efficacy and a similar duration of action of about one hour. There was no evidence of acid 'rebound' following either treatment during the second and third hours following the administration of antacid.

  3. Coal-based 50 kt/a Vinyl Acetate Project Is To Be Constructed in Bashan, Yunnan Province

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ The largest in western Yunnan Chemical projects -the 200 kt/a calcium carbide project and the 50 kt/a vinyl acetate project- will be officially constructed in Baoshan city by the Yunwei Company under Yunnan Coal Chemical Group.

  4. Removal of organic magnesium in coccolithophore calcite

    Science.gov (United States)

    Blanco-Ameijeiras, S.; Lebrato, M.; Stoll, H. M.; Iglesias-Rodriguez, M. D.; Méndez-Vicente, A.; Sett, S.; Müller, M. N.; Oschlies, A.; Schulz, K. G.

    2012-07-01

    Coccolithophore calcite refers to the plates of calcium carbonate (CaCO3) produced by the calcifying phytoplankton, coccolithophores. The empirical study of the elemental composition has a great potential in the development of paleoproxies. However, the difficulties to separate coccolithophore carbonates from organic phases hamper the investigation of coccoliths magnesium to calcium ratios (Mg/Ca) in biogeochemical studies. Magnesium (Mg) is found in organic molecules in the cells at concentrations up to 400 times higher than in inorganically precipitated calcite in present-day seawater. The aim of this study was to optimize a reliable procedure for organic Mg removal from coccolithophore samples to ensure reproducibility in measurements of inorganic Mg in calcite. Two baseline methods comprising organic matter oxidations with (1) bleach and (2) hydrogen peroxide (H2O2) were tested on synthetic pellets, prepared by mixing reagent grade CaCO3 with organic matter from the non-calcifying marine algae Chlorella autotrophica and measured with an ICP-AES (inductively coupled plasma-atomic emission spectrometer). Our results show that treatments with a reductive solution [using hydroxylamine-hydrochloride (NH2OH·HCl + NH4OH)] followed by three consecutive oxidations (using H2O2) yielded the best cleaning efficiencies, removing >99% of organic Mg in 24 h. P/Ca and Fe/Ca were used as indicators for organic contamination in the treated material. The optimized protocol was tested in dried coccolithophore pellets from batch cultures of Emiliania huxleyi, Calcidiscus leptoporus and Gephyrocapsa oceanica. Mg/Ca of treated coccolithophores were 0.151 ± 0.018, 0.220 ± 0.040, and 0.064 ± 0.023 mmol/mol, respectively. Comparison with Mg/Ca literature coccolith values, suggests a tight dependence on modern seawater Mg/Ca, which changes as a consequence of different seawater origins (protocol applicable to field and laboratory studies of trace elemental composition in

  5. 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.

  6. 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

  7. Calcium in diet

    Science.gov (United States)

    ... D is needed to help your body use calcium. Milk is fortified with vitamin D for this reason. ... of calcium dietary supplements include calcium citrate and calcium carbonate. Calcium citrate is the more expensive form of ...

  8. Magnesium for Hydrogen Storage

    DEFF Research Database (Denmark)

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

    1983-01-01

    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.......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...

  9. 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.

  10. 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.

  11. Effect of acute acid loading on acid-base and calcium metabolism

    DEFF Research Database (Denmark)

    Osther, Palle J

    2006-01-01

    male recurrent idiopathic calcium stone-formers and 12 matched healthy men using a randomized, placebo-controlled, cross-over design. Arterialized capillary blood, serum and urine were collected hourly for measurement of electrolytes, ionized calcium, magnesium, phosphate, parathyroid hormone and acid...

  12. Electrophoretic deposition of magnesium silicates on titanium implants: Ion migration and silicide interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Afshar-Mohajer, M. [Center for Advanced Manufacturing and Material Processing, Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur 50603 (Malaysia); Yaghoubi, A., E-mail: yaghoubi@siswa.um.edu.my [Center for High Impact Research, University of Malaya, Kuala Lumpur 50603 (Malaysia); Ramesh, S., E-mail: ramesh79@um.edu.my [Center for Advanced Manufacturing and Material Processing, Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur 50603 (Malaysia); Bushroa, A.R.; Chin, K.M.C.; Tin, C.C. [Center for Advanced Manufacturing and Material Processing, Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur 50603 (Malaysia); Chiu, W.S. [Low Dimensional Materials Research Center, Department of Physics, University of Malaya, Kuala Lumpur 50603 (Malaysia)

    2014-07-01

    Magnesium silicates (Mg{sub x}SiO{sub y}) and in particular forsterite (Mg{sub 2}SiO{sub 4}) owing to their low thermal expansion mismatch with metals are promising materials for bioactive coating of implants. Here, we report the electrophoretic deposition (EPD) of forsterite onto titanium substrates using different precursors. Unlike bulk samples which achieve full stoichiometry only beyond 1400 °C, non-stoichiometric magnesium silicate rapidly decomposes into magnesium oxide nanowires during sintering. Elemental mapping and X-ray diffraction suggest that oxygen diffusion followed by ion exchange near the substrate leads to formation of an interfacial Ti{sub 5}Si{sub 3} layer. Pre-annealed forsterite powder on the other hand shows a comparatively lower diffusion rate. Overall, magnesium silicate coatings do not exhibit thermally induced microcracks upon sintering as opposed to calcium phosphate bioceramics which are currently in use.

  13. 4-Carbamoylpiperidinium acetate monohydrate

    Directory of Open Access Journals (Sweden)

    Urs D. Wermuth

    2010-12-01

    Full Text Available In the structure of the title compound, C6H13N2O+·C2H3O2−·H2O, the amide H atoms of the cations form centrosymmetric cyclic hydrogen-bonding associations incorporating two water molecules [graph set R42(8], which are conjoint with cyclic water-bridged amide–amide associations [R44(12] and larger R44(20 associations involving the water molecule and the acetate anions, which bridge through the piperidinium H-bond donors, giving an overall three-dimensional framework structure.

  14. Calcium Electroporation

    DEFF Research Database (Denmark)

    Frandsen, Stine Krog; Gibot, Laure; Madi, Moinecha;

    2015-01-01

    BACKGROUND: Calcium electroporation describes the use of high voltage electric pulses to introduce supraphysiological calcium concentrations into cells. This promising method is currently in clinical trial as an anti-cancer treatment. One very important issue is the relation between tumor cell kill...... efficacy-and normal cell sensitivity. METHODS: Using a 3D spheroid cell culture model we have tested the effect of calcium electroporation and electrochemotherapy using bleomycin on three different human cancer cell lines: a colorectal adenocarcinoma (HT29), a bladder transitional cell carcinoma (SW780......), and a breast adenocarcinoma (MDA-MB231), as well as on primary normal human dermal fibroblasts (HDF-n). RESULTS: The results showed a clear reduction in spheroid size in all three cancer cell spheroids three days after treatment with respectively calcium electroporation (p

  15. Extractive process for preparing high purity magnesium chloride hexahydrate

    Directory of Open Access Journals (Sweden)

    Fezei Radouanne

    2012-01-01

    Full Text Available This paper refers a method for the preparation of magnesium chloride hexahydrate (bischofite from Sebkha el Melah of Zarzis Tunisian natural brine. It is a five-stage process essentially based on crystallization by isothermal evaporation and chemical precipitation. The two first steps were dedicated to the crystallization of sodium chloride and potassiummagnesium double salts, respectively. Then, the resulting liquor was desulfated using calcium chloride solution. After that another isothermal evaporation stage was implemented in order to eliminate potassium ions in the form of carnallite, KCl.MgCl2.6H2O. At the end of this step, the recovered solution primarily composed of magnesium and chloride ions was treated by dioxan in order to precipitate magnesium chloride as MgCl2.6H2O.C4H8O2. This compound dried at constant temperature of 100°C gave good quality magnesium chloride hexahydrate. Besides this salt, the various by-products obtained from the different treatment stages are also useful.

  16. THE ROLE OF MAGNESIUM METABOLISM IN ESSENTIALHYPERTENSION WITH INSULIN RESISTANCE

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective To investigate the effects of magnesium metabolism and other positive ions in pathogenesis of essential hypertension(EH) patients with insulin resistance(IR). Methods The levels of Na+, K+, Ca2+, Mg2+ in erythrocyte and 24-hour urine samples were observed in 47 EH patients and in 30 subjects with normal blood pres sure. Insulin sensitivity index was used to evaluate the insulin sensitivity. Results In EH patients, the levels of K+ and Mg2+ in erythrocyte declined, but the levels of Na+ and Ca2+ in erythrocyte increased, and the 24-hour urinary excretion of Mg2+ reduced as compared to the subjects with normal blood pressure (P <0. 05). The levels of K+ and Mg2+ in erythrocyte of EH patients positively correlated with insulin sensitivity index, and the Mg2+ level in erythro cyte positively correlated with 24-hour urinary excretion of Ca2+ and Mg2+ , and the K+ level in erythrocyte. Conclu sion Abnormality of magnesium metabolism in EH patients may be the linking factor for hypertension and insulin re sistance, and may relate to inadequate intake of magnesium. Calcium and potassium may be involved in the occur rence of insulin resistance through affecting magnesium metabolism.

  17. Magnesium improves hydrogen production by a novel fermentative hydrogen-producing bacterial strain B49

    Institute of Scientific and Technical Information of China (English)

    WANG Xiang-jing; REN Nan-qi; XIANG Wen-sheng

    2005-01-01

    Batch experiments were conducted to investigate the effects of magnesium on glucose metabolism, including growth and hydrogen-producing capacity of fermentative hydrogen-producing bacterial strain B49. These abilities were enhanced with an increase in magnesium concentration. At the end of fermentation from 10 g/L ratio of ethanol amount (mg/L) to acetate amount (mg/L) was 1.1, and the accumulated hydrogen volume hydrogen volume was increased to 2 360. 5 mL H2/L culture, the ratio of ethanol amount (mg/L) to acetate amount (mg/L) was increased to 1.3 and polysaccharide was decreased to 2. 5 mg/L. Moreover, the magnesium solution addition to the medium at different fermentation times affected hydrogen-producing ability. However,the later the addition time was postponed, the less the effect was on hydrogen evolution. Further experiments confirmed the enhancement was dependent on magnesium ions and not on the other inorganic ions such as SO42- or Cl-, which constituted the magnesium salts.

  18. [Magnesium deficiency and stress: Issues of their relationship, diagnostic tests, and approaches to therapy].

    Science.gov (United States)

    Tarasov, E A; Blinov, D V; Zimovina, U V; Sandakova, E A

    2015-01-01

    Magnesium plays an important role in the functions of the central nervous system. It takes part in the regulation of the cell membrane, the transmembrane transport of calcium and sodium ions, and metabolic reactions that produce, accumulate, transfer, and utilize energy, free radicals, and their oxidation products. The magnesium-containing substances include many sequestered antigens, such as glial fibrillary acidic protein, S100, and neuron-specific enolase; magnesium may act as a neuroprotector that is able to modulate the regulation of blood-brain barrier permeability. Investigations have demonstrated a relationship between the manifestations of stress reactions (anxiety, autonomic dysfunction, and maladjustment) and magnesium deficiency (MD). Thus, mental and physical stresses cause an increase in magnesium elimination from the body. MD in turn enhances a response to stress, by paradoxically aggravating its sequels. Compensation for MD increases the ability of the nervous system to resist stress. The valid diagnosis of MD present difficulties; namely, a blood magnesium concentration decrease below 0.8 mmol/l is evidence of MD; but the constant blood level of magnesium may be long maintained due to its release from the bone tissue depot. So it is necessary to keep in mind the clinical manifestations of MD. The authors have developed and tested a simple rapid MD assessment test and a stress resistance self-rating test. The proposed tests will help to screen stress resistance and MD in outpatient settings.

  19. Threshold Acetate Concentrations for Acetate Catabolism by Aceticlastic Methanogenic Bacteria

    OpenAIRE

    Westermann, Peter; Ahring, Birgitte K.; Mah, Robert A.

    1989-01-01

    Marked differences were found for minimum threshold concentrations of acetate catabolism by Methanosarcina barkeri 227 (1.180 mM), Methanosarcina mazei S-6 (0.396 mM), and a Methanothrix sp. (0.069 mM). This indicates that the aceticlastic methanogens responsible for the conversion of acetate to methane in various ecosystems might be different, depending on the prevailing in situ acetate concentrations.

  20. Kallolide A acetate pyrazoline.

    Science.gov (United States)

    Rodríguez-Escudero, Idaliz; Marrero, Jeffrey; Rodríguez, Abimael D

    2012-01-01

    IN THE CRYSTAL STRUCTURE OF KALLOLIDE A ACETATE PYRAZOLINE [SYSTEMATIC NAME: 7-methyl-16-oxo-4,10-bis-(prop-1-en-2-yl)-17,18-dioxa-14,15-diaza-tetra-cyclo-[9.4.2.1(6,9).0(1,12)]octa-deca-6,8,14-trien-5-yl acetate], C(23)H(28)N(2)O(5), there is a 12-member-ed carbon macrocyclic structure. In addition, there is a tris-ubstituted furan ring, an approximately planar γ-lactone ring [maximum deviation of 0.057 (3) Å] and a pyraz-oline ring, the latter in an envelope conformation. The pyrazoline and the γ-lactone rings are fused in a cis configuration. In the crystal, mol-ecules are linked by weak C-H⋯O inter-actions, forming a two-dimensional network parallel to (001). An intra-molecular C-H⋯O hydrogen bond is also present.

  1. 碱熔—电感耦合等离子体原子发射光谱法测定红土镍矿中硅钙镁铝锰钛铬镍钴%Determination of silicon, calcium, magnesium, aluminium, manganese,titanium, chromium, nickel and cobalt in laterite nickel ore by alkali fusion-inductively coupled plasma atomic emission spectrometry

    Institute of Scientific and Technical Information of China (English)

    高亮

    2013-01-01

    The determination method of nine elements (silicon, calcium, magnesium, aluminium, manganese, titanium, chromium, nickel and cobalt) in laterite nickel ore by inductively coupled plasma atomic emission spectrometry (ICP-AES) was established. The laterite nickel ore sample was fused by anhydrous Na2CO3-H3BO3 mixed flux, then acidified and leached by hydrochloric acid. The high salt atomizer and cyclone chamber were used. Under the selected measurement conditions, the content of nine elements in sample solution was determined by ICP-AES. The influence of salts introduced by matrix iron and sample treatment could be eliminated by matrix matching method. The precision test results showed that, the relative standard deviations (RSD) of elements were smaller than 5 %. The proposed method was applied to the determination of reference material, and the determination results of nine elements were basically consistent with the certified values.%建立了红土镍矿中Si、Ca、Mg、Al、Mn、Ti、Cr、Ni、Co 9种元素的电感耦合等离子体原子发射光谱测定方法.红土镍矿样品用无水Na2CO3-H3BO3混合熔剂熔融,盐酸浸取、酸化,选用高盐雾化器和旋流雾室,在选定的测量条件下,用电感耦合等离子体原子发射光谱法测定试液中9种元素含量.基体铁和处理样品时引入试液中的盐分对测定的影响可以通过基体匹配的方法消除.精密度试验结果表明,样品中各元素测定结果的相对标准偏差小于5%.用本法测定标准样品,9种元素的测定值与认定值基本一致.

  2. 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...

  3. 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...

  4. 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...

  5. 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).

  6. 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,...

  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. Serum electrolyte and blood gas changes after intrathecal and intravenous bolus injections of magnesium sulphate. An experimental study in a rat model.

    Science.gov (United States)

    Bahar, M; Cohen, M L; Grinshpun, Y; Datski, R; Kaufman, J; Zaidman, J L; Nissenbaum, H; Chanimov, M

    1997-11-01

    The effect of intrathecally administered magnesium sulphate on serum levels of magnesium, sodium, potassium, calcium and blood gas variables was studied in a rat model. Magnesium sulphate given intrathecally has previously been shown to produce segmental spinal blockade with no permanent neurological damage. The previous studies, however, had not investigated the possible systemic effects of the magnesium sulphate. The serum magnesium level increased significantly at 1 and 2 h after the intrathecal injection of both 6.3% and 12.6% magnesium sulphate (6.3%: 28% at 1 h, 24% at 2 h; 12.6%: 22% at 1 h, 16% at 2 h). These changes were not as great as occurred when the same dose of magnesium sulphate was administered intravenously. In all cases, the serum magnesium had returned to normal by 24 h. There were no significant changes in calcium, sodium or potassium levels, nor in arterial blood gas variables. These results show that intrathecally administered magnesium sulphate has little effect on electrolyte homeostasis.

  11. Stimulation of hepatic glycogenolysis by phorbol-12-myristate-13-acetate

    Energy Technology Data Exchange (ETDEWEB)

    Patel, T.B.

    1986-05-01

    In isolated perfused rat livers, infusion of phorbol-12-myristate-13-acetate (150 nM) resulted in a three-fold stimulation of the rate of glucose production. This response was maximal at perfusate phorbol ester concentration of 150 nM, and was significantly diminished at higher concentrations of the phorbol ester (e.g. 300 nM). Stimulation of glycogenolysis by phorbol ester was greatly decreased in livers perfused infusion into livers perfused with calcium-free medium. Phorbol-12-myristate-13-acetate infusion into livers perfused in the absence of calcium did not result in calcium efflux from the livers. Additionally, in hepatocytes isolated from livers of fed rats neither the phorbol ester nor 1-oleoyl-2-acetyl-rac-glycerol, stimulated the rate of glucose production. This last result along with the observations that in isolated perfused rat livers, phorbol-12-myristate-13-acetate increases portal pressure, and decreases oxygen consumption suggests that stimulation of hepatic glycogenolysis by phorbol ester is the result of increased vasoconstriction, and is not a consequence of a direct effect of the phorbol ester on liver parenchymal cells.

  12. 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

  13. Preliminary study of biodegradation of AZ31B magnesium alloy

    Institute of Scientific and Technical Information of China (English)

    REN Yibin; HUANG Jingjing; ZHANG Bingchun; YANG Ke

    2007-01-01

    Magnesium alloys are potential to be developed as a new type of biodegradable implant material by use of their active corrosion behavior.Both in vitro and in vivo biodegradation properties of an AZ31B magnesium alloy were investigated in this work.The results showed that AZ31B alloy has a proper degradation rate and much lower hydrogen release in Hank's solution,with a degradation rate of about 0.3 mm/year and hydrogen release below 0.15mL/cm2.The animal implantation test showed that the AZ31B alloy could slowly biodegrade in femur of the rabbit and form calcium phosphate around the alloy sample,with the Ca/P ratio close to the natural bone.

  14. Effects of dietary sodium and magnesium on cyclosporin A-induced hypertension and nephrotoxicity in spontaneously hypertensive rats.

    Science.gov (United States)

    Mervaala, E M; Pere, A K; Lindgren, L; Laakso, J; Teräväinen, T L; Karjala, K; Vapaatalo, H; Ahonen, J; Karppanen, H

    1997-03-01

    Arterial hypertension, nephrotoxicity, and magnesium loss are common side effects of the immunosuppressive agent cyclosporin A (CsA). In the present study, the effects of dietary sodium and magnesium on CsA toxicity were examined in spontaneously hypertensive rats. A 6-week treatment with CsA during a moderately low-sodium diet (Na 0.3%, Mg 0.2% of the dry weight of the chow) raised blood pressure only slightly, without evidence of nephrotoxicity. By contrast, CsA during a high-sodium diet (Na 2.6%) produced a pronounced rise in blood pressure as well as marked nephrotoxicity, comprising decreased creatinine clearance, increased levels of serum creatinine and urea, and increased urinary protein excretion. During the high-sodium diet, CsA decreased myocardial and bone magnesium concentration and increased myocardial and renal calcium concentration. Magnesium supplementation (Mg 0.6%) protected against the CsA-induced hypertension and nephrotoxicity during the high-sodium diet. Magnesium supplementation also completely prevented the CsA-induced myocardial magnesium depletion and calcium accumulation in the heart and kidney during the high-sodium diet. Our findings indicate a detrimental interaction between increased sodium intake and CsA treatment and a marked protection by concomitant oral magnesium supplementation.

  15. Characteristics of plant calcium fractions for 25 species in Tengger Desert

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Little attention has been paid to plant calcium fractions in the desert.To address the characteristic of the calcium fractions of desert plants,we collected 25 plant species in Tengger Desert,observed the calcium crystals using an optical microscope and determined water soluble calcium,acetic acid soluble calcium,and hydrochloric acid soluble calcium.To do so,we used sequential fractionation procedures to probe the relationships among different functional groups,different growth forms,or different successional stages.The results showed that the psammophyte,the late successional plants,and the drought-resistant shrub and semi-shrub all held considerable calcium oxalate crystal compared to the grassland plants,the early successional plants,and the perennial herb.With the proceeding succession,the acetic acid soluble calcium decreased gradually,and the hydrochloric acid soluble calcium increased gradually.The perennial herb had more water soluble calcium,while shrub held greater hydrochloric acid soluble calcium.The grassland plants held more water soluble calcium,while psammophyte had greater hydrochloric acid soluble calcium.This implies that the plants that are relatively sensitive to drought hold more calcium ion,while the drought-resistance plants hold more calcium oxalate.Thus,the plant calcium components are in close relation to plant drought-resistance,and of important significance in plant physiology of the desert.

  16. 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.

  17. Antibiofilm Properties of Acetic Acid

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Alhede, Morten; Jensen, Peter Østrup;

    2014-01-01

    of the infected implant, tissue, or organ and thereby the biofilm. Acetic acid is known for its antimicrobial effect on bacteria in general, but has never been thoroughly tested for its efficacy against bacterial biofilms. In this article, we describe complete eradication of both Gram-positive and Gram......-negative biofilms using acetic acid both as a liquid and as a dry salt. In addition, we present our clinical experience of acetic acid treatment of chronic wounds. In conclusion, we here present the first comprehensive in vitro and in vivo testing of acetic acid against bacterial biofilms....

  18. ACETIC ACID AND A BUFFER

    DEFF Research Database (Denmark)

    2009-01-01

    The present invention relates to a composition comprising : a) 0.01-20% wt/wt acetic acid and b) a physiologically tolerable buffer capable of maintaining acetic acid at a pH in the range of 2-7; and use of such a composition as an antimicrobial agent.......The present invention relates to a composition comprising : a) 0.01-20% wt/wt acetic acid and b) a physiologically tolerable buffer capable of maintaining acetic acid at a pH in the range of 2-7; and use of such a composition as an antimicrobial agent....

  19. Strong and tough magnesium wire reinforced phosphate cement composites for load-bearing bone replacement.

    Science.gov (United States)

    Krüger, Reinhard; Seitz, Jan-Marten; Ewald, Andrea; Bach, Friedrich-Wilhelm; Groll, Jürgen

    2013-04-01

    Calcium phosphate cements are brittle biomaterials of low bending strength. One promising approach to improve their mechanical properties is reinforcement with fibers. State of the art degradable reinforced composites contain fibers made of polymers, resorbable glass or whiskers of calcium minerals. We introduce a new class of composite that is reinforced with degradable magnesium alloy wires. Bending strength and ductility of the composites increased with aspect ratio and volume content of the reinforcements up to a maximal bending strength of 139±41MPa. Hybrid reinforcement with metal and polymer fibers (PLA) further improved the qualitative fracture behavior and gave indication of enhanced strength and ductility. Immersion tests of composites in SBF for seven weeks showed high corrosion stability of ZEK100 wires and slow degradation of the magnesium calcium phosphate cement by struvite dissolution. Finally, in vitro tests with the osteoblast-like cell line MG63 demonstrate cytocompatibility of the composite materials.

  20. Inhibitory action of oestrogen on calcium-induced mitosis in rat bone marrow and thymus.

    Science.gov (United States)

    Smith, G R; Gurson, M L; Riddell, A J; Perris, A D

    1975-04-01

    In the male rat injections of CaCl-2 and MgCl-2 stimulated mitosis in bone marrow and thymus tissue. The magnesium salt was also mitogenic in the normal female, but calcium only exerted its mitogenic effect after ovariectomy. Oestradiol, but not progesterone replacement therpy abolished calcium-induced mitosis in the ovariectomized rat. The inability of calcium to stimulate cell division was also apparent in the thyroparathyroidectomized female rat, suggesting the oestradiol blockage did not operate via some indirect action on the calcium homeostatic hormones calcitonin or parathyroid hormone. When thymic lymphocytes derived from male or female rats were isolated and maintained in suspension, increased calcium or magnesium concentrations in the culture medium stimulated the entry of cells into mitosis. Addition of oestradiol to the culture medium abolished the mitogenic effect of increased calcium levels, but had no effect on magnesium-induced proliferation. These experiments suggested that oestradiol might act at the cell surface to prevent the influx of calcium but not magnesium ions into the interior of the cell and thus to block the sequence of biochemical events which led to the initiation of DNA synthesis and culminate in mitosis.

  1. Behavior of CaO and Calcium in pure Magnesium

    Institute of Scientific and Technical Information of China (English)

    HA Seong-Ho; LEE Jin-Kyu; JO Hyung-Ho; JUNG Seung-Boo; KIM Shae K.

    2006-01-01

    Mg alloys exhibit a number of good properties such as low density, good castability and high specific strength.However, molten Mg and Mg alloys are ignited without the melt protective gases during melting and casting process due to their high reactivity.The purpose of this study is to investigate effects of Ca and CaO on pure Mg through microstructure observation, ignition test and phase analysis.With increasing Ca and CaO contents, the ignition resistance of Ca or CaO added pure Mg is increased and the grains are refined.As results of XRD and EDS, CaO is reduced to Ca in CaO added pure Mg.Mg2Ca phase is formed even in 0.1 wt.%CaO added pure Mg by reduction mechanism, while Mg2Ca phase is formed over 1.35 wt.% Ca added pure Mg.

  2. Effects of magnesium infusion on renal calcium excretion

    Energy Technology Data Exchange (ETDEWEB)

    Shafik, I.M.

    1986-01-01

    The effect of acute I.V. infusion of Mg on Ca excretion was investigated. Mg infusion resulted in a significantly increased urinary Ca excretion compared to the control group. The hypercalciuric effect of Mg was not accompanied by diuresis or natriuresis but was associated with significantly increased urinary Ca concentration suggesting a specific effect of Mg on urinary Ca excretion. The effect of 4mM MgCl/sub 2/ infusion on plasma Ca concentrations was also investigated. A comparable calciuric effect was again observed in the Mg infused group and was found to be associated with a significantly reduced whole kidney filtered load and absolute and fractional reabsorption of Ca. Intratubular microinjection experiments were performed to investigate the direct effects of raising Mg concentration on the unidirectional reabsorptive flux of (/sup 45/Ca). The unidirectional reabsorption of Ca injected into PCT was measured during four experimental conditions; with an d without Mg in the injectate solution during either saline or Mg infusion. Raising the intraluminal Mg significantly decreased unidirectional reabsorption of (/sup 45/Ca).

  3. 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.

  4. EFFECT OF MAGNESIUM AS SUBSTITUTE MATERIAL IN ENZYME MEDIATED CALCITE PRECIPITATION (EMCP FOR SOIL IMPROVEMENT TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Heriansyah ePutra

    2016-05-01

    Full Text Available The optimization of enzyme-mediated calcite precipitation (EMCP was evaluated as a soil improvement technique. In our previous works, purified urease was utilized to bio-catalyze the hydrolysis of urea, which causes the supplied Ca2+ to precipitate with CO32- as calcium carbonate. In the present work, magnesium chloride was newly added to the injecting solutions to delay the reaction rate and to enhance the amount of carbonate precipitation. Soil specimens were prepared in PVC cylinders and treated with concentration-controlled solutions composed of urea, urease, calcium, and magnesium chloride. The mechanical properties of the treated soil specimens were examined through unconfined compressive strength (UCS tests. A precipitation ratio of the carbonate up to 90% of the maximum theoretical precipitation was achieved by adding a small amount of magnesium chloride. Adding magnesium chloride as a delaying agent was indeed found to reduce the reaction rate of the precipitation, which may increase the volume of the treated soil if used in real fields because of the slower precipitation rate and the resulting higher injectivity. A mineralogical analysis revealed that magnesium chloride decreases the crystal size of the precipitated materials and that another carbonate of aragonite is newly formed. Mechanical test results indicated that carbonate precipitates within the soils and brings about a significant improvement in strength. A maximum UCS of 0.6 MPa was obtained from the treated samples.

  5. Serum Magnesium and Vitamin D Levels as Indicators of Asthma Severity

    Directory of Open Access Journals (Sweden)

    Mohammed Nadeem Shaikh

    2016-01-01

    Full Text Available Background. Serum magnesium levels affect the concentration of circulating vitamin D in blood and subsequently it affects the immunity; thus it plays significant role in the pathogenesis of asthma. Asthma, in adults, is less studied and hypomagnesemia along with vitamin D deficiency and insufficiency is common in asthmatic individuals, which causes frequent asthma attacks, respiratory infections, severe exacerbations, and poor response to bronchodilators. Objective. To detect the magnitude of vitamin D insufficiency and deficiency and serum magnesium levels among asthmatic patients and to correlate them with the severity of asthma. Materials and Methods. This is a cross-sectional case-control study which includes 60 patients of chronic stable asthma and 60 healthy controls. After taking clinical history and systemic examination, pulmonary function test was done. Serum levels of magnesium, 25-hydroxycholecalciferol [25(OHD], and calcium were measured in all the subjects. Results. Significant correlation was found between vitamin D deficiency, hypomagnesemia, and asthma severity. Serum calcium levels were unaffected by that. Conclusion. Vitamin D and serum magnesium deficiency are highly prevalent in patients with asthma. Increased asthma severity, frequency of attacks, and exacerbation are associated with lower levels of one or both. Serum 25(OHD and magnesium levels may serve as important markers of asthma severity.

  6. 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.

  7. Acetate metabolism in Methanothrix soehngenii.

    NARCIS (Netherlands)

    Jetten, M.S.M.

    1991-01-01

    Acetate is quantitatively the most important intermediate in the anaerobic degradation of soluble organic matter. The conversion rate of acetate by methanogenic bacteria is proposed to be the rate limiting step in this degradation The study of acetoclastic methanogens, therefore is of relevance to o

  8. Calcium and bones

    Science.gov (United States)

    Bone strength and calcium ... calcium (as well as phosphorus) to make healthy bones. Bones are the main storage site of calcium in ... your body does not absorb enough calcium, your bones can get weak or will not grow properly. ...

  9. OSTEOPOROSIS IN CALCIUM PYROPHOSPHATE CRYSTAL DEPOSITION DISEASE

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    S A Vladimirov

    2013-01-01

    Full Text Available Objective: to study the incidence of osteoporosis (OP in patients with calcium pyrophosphate crystal deposition disease (CPCDD. Subjects and methods. Eighty patients with CPCDD were examined. Bone mineral density (BMD of the forearm, lumbar spine, and femoral neck was determined by dual-energy X-ray absorptiometry. Laboratory diagnosis involved determination of the blood levels of C-reactive protein, parathyroid hormone, calcium, magnesium, and phosphorus and the daily urinary excretion of calcium and phosphates. Results. The patients with OP were significantly older than those with normal BMD and osteopenia. Forearm bones were the most common isolated location of OP and osteopenia. Injuries in the history, traumatic fractures, and the intake of diuretics were somewhat more common in the patients diagnosed with OP. The incidence of hyperparathyroidism did not differ significantly in the groups.

  10. Calcium Test

    Science.gov (United States)

    ... if a person has symptoms of a parathyroid disorder , malabsorption , or an overactive thyroid. A total calcium level is often measured as part of a routine health screening. It is included in the comprehensive metabolic panel (CMP) and the basic metabolic panel (BMP) , ...

  11. Calcium Carbonate

    Science.gov (United States)

    ... doctor if you have or have ever had kidney disease or stomach conditions.tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking calcium carbonate, call your doctor.

  12. Correcting magnesium deficiencies may prolong life

    Directory of Open Access Journals (Sweden)

    Rowe WJ

    2012-02-01

    Full Text Available William J RoweFormer Assistant Clinical Professor of Medicine, Medical University of Ohio at Toledo, Ohio, USAAbstract: The International Space Station provides an extraordinary facility to study the accelerated aging process in microgravity, which could be triggered by significant reductions in magnesium (Mg ion levels with, in turn, elevations of catecholamines and vicious cycles between the two. With space flight there are significant reductions of serum Mg (P < 0.0001 that have been shown in large studies of astronauts and cosmonauts. The loss of the functional capacity of the cardiovascular system with space flight is over ten times faster than the course of aging on Earth. Mg is an antioxidant and calcium blocker and in space there is oxidative stress, insulin resistance, and inflammatory conditions with evidence in experimental animals of significant endothelial injuries and damage to mitochondria. The aging process is associated with progressive shortening of telomeres, repetitive DNA sequences, and proteins that cap and protect the ends of chromosomes. Telomerase can elongate pre-existing telomeres to maintain length and chromosome stability. Low telomerase triggers increased catecholamines while the sensitivity of telomere synthesis to Mg ions is primarily seen for the longer elongation products. Mg stabilizes DNA and promotes DNA replication and transcription, whereas low Mg might accelerate cellular senescence by reducing DNA stability, protein synthesis, and function of mitochondria. Telomerase, in binding to short DNAs, is Mg dependent. On Earth, in humans, a year might be required to detect changes in telomeres, but in space there is a predictably much shorter duration required for detection, which is therefore more reasonable in time and cost. Before and after a space mission, telomere lengths and telomerase enzyme activity can be determined and compared with age-matched control rats on Earth. The effect of Mg supplementation

  13. Mercury's Exosphere During MESSENGER's Second Flyby: Detection of Magnesium and Distinct Distributions of Neutral Species

    Science.gov (United States)

    McClintock, William E.; Vervack, Ronald J., Jr.; Bradley, E. Todd; Killen, Rosemary M.; Mouawad, Nelly; Sprague, Ann L.; Burger, Matthew H.; Solomon, Sean C.; Izenberg, Noam R.

    2009-01-01

    During MESSENGER's second Mercury flyby, the Mercury Atmospheric and Surface Composition Spectrometer observed emission from Mercury's neutral exosphere. These observations include the first detection of emission from magnesium. Differing spatial distributions for sodium, calcium, and magnesium were revealed by observations beginning in Mercury's tail region, approximately 8 Mercury radii anti-sunward of the planet, continuing past the nightside, and ending near the dawn terminator. Analysis of these observations, supplemented by observations during the first Mercury flyby as well as those by other MESSENGER instruments, suggests that the distinct spatial distributions arise from a combination of differences in source, transfer, and loss processes.

  14. Magnesium sulphate and the development of the common bean cultivated in an ultisol of Northeast Australia.

    OpenAIRE

    OLIVEIRA, I. P. de; ASHER, C. J.; Edwards, D.G.; SANTOS, R. S. M. dos

    2000-01-01

    Magnesium applications (MgS0(4).7H(2)0) to achieve 8 and 16 mmol c/cm3 of Mg (324 and 1284 kg of MgS0(4) ha-1) were made on one Ultisol from Australia Northeast to correct Mg deficiency in plants and to verify the optimum level of Mg to grow common bean (Phaseolus vulgaris L). Magnesium was applied together with lime, N, K, Cu, Zn, B, and Mo as calcium carbonate, ammonium nitrate, potassium phosphate, cupric and zinc sulphate, boric acid and sodium molybdate respectively a month before planti...

  15. 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.

  16. In vitro Degradation and Biocompatibility of Ca-P Coated Magnesium Alloy

    Institute of Scientific and Technical Information of China (English)

    XIAO Xing; ZHU Qing-san; SU Ying-chao; LI Guang-yu

    2013-01-01

    Calcium-phosphate compounds(Ca-P) coating was prepared on an Mg-Al alloy(AZ60).Biodegradation of Ca-P coated magnesium alloy was evaluated in simulated body fluid(SBF) by examining the changes in magnesium ion concentration and pH value,which indicated that the Ca-P coating on magnesium alloy strongly affected the corrosion of magnesium alloy.Osteoblast MC3T3-El cells were utilized to investigate the cellular cytocompatibility.The cytocompatibility was measured by carrying out a series of tests,such as cholecystokinin-octapeptide(CCK-8) test,alkaline phosphatase activity(ALP) test,cellular morphology of hematoxylin-eosin(HE) staining and the induction of apoptosis.It was found that the cell function showed better in the Ca-P coated Mg-alloy extract than in the uncoated magnesium alloy extract.In summary,the results indicate that the Ca-P coating can improve the corrosion resistance of magnesium alloy and elevate cellular proliferation and differentiation of osteoblast MC3T3-E1 cells.

  17. Rel ati onshi p betw een Reti nopathy and Serum L ev el s of Calcium and Magnesium in PIHS%妊娠高血压性视网膜病变与血清钙、镁离子的关系

    Institute of Scientific and Technical Information of China (English)

    胡鹭萍; 徐国兴

    2015-01-01

    Objective To investigate the relations between the retinopathy and serum calcium and magnesium levels in patients with pregnancy induced hypertension syndrome (PIHS) . Methods In this retrospective study ,medical charts for 129 patients with PIHS and 130 healthy pregnant women as the control group were analyzed . We examined the retina with direct ophthalmoscope ,measured the concen‐tration of Ca2+ and Mg2+ in the serum ,and then performed statistical analysis . Results More than half of PIHS patients were diagnosed with retinopathy (52 .7% ) ,the severity of PIHS and the prevalence of retinopathy were positively correlated . Serum Ca2+ and Mg2+ levels were decreased in PIHS patients than those in the control group (P<0 .05) . With the aggravation of retinopathy ,serum Ca2+ and Mg2+ levels decreased . Conclusion Serum Ca2+ and Mg2+ levels can be a new indicator for PIHS . Fundus examina‐tion regularly and detection of serum Ca2+ and Mg2+ levels during pregnancy can contribute to the diagno‐sis and severity evaluation of retinopathy in PIHS patients .%目的:探讨妊娠高血压综合征(妊高症)患者视网膜病变与血清钙、镁离子的关系。方法回顾性分析129例妊高症患者的资料,并随机抽取同期住院的130例正常妊娠的孕妇作为对照组,分析其视网膜病变与妊高症病情程度的关系;将妊高症患者按视网膜病变分组,分析各组血清钙、镁离子水平与视网膜病变程度的关系,并与对照组进行比较。结果妊高症患者视网膜病变发生率52.7%,且随着病程加重患病率越高;妊高症各组血清钙、镁离子水平均低于对照组(P<0.05),随着视网膜病变加重,钙、镁离子水平降低越明显,各组间差别有统计学意义(P<0.05)。结论血清钙、镁离子水平可反应妊高症患者病程及视网膜病变的严重程度。孕期定期检查眼底和检测血清钙、镁离子有助于妊高症眼底

  18. Calcium:magnesium ratio in amendments of soil acidity: nutrition and initial development of corn plants in a Humic Alic Cambisol / Relação cálcio:magnésio do corretivo da acidez do solo na nutrição e no desenvolvimento inicial de plantas de milho em um Cambissolo Húmico Álico

    Directory of Open Access Journals (Sweden)

    Luciano Colpo Gatiboni

    2008-07-01

    Full Text Available The variation in the Ca:Mg ratio in amendments used to neutralize soil acidity is one way of altering the availability of those nutrients to the plants in acid soils. The objective of the work was to evaluate the effect of different proportions of calcium and magnesium in the form of CaCO3 and MgCO3 on the nutrient uptake, and initial production of dry matter by corn plants. The study was carried out in greenhouse conditions, in Lages, SC, with a completely randomized experimental design, with three replications. The treatments were the application of equivalent to 21.0 t ha-1 of lime, using mixtures of CaCO3 and MgCO3 in several proportions to obtain different Ca:Mg ratios (1:1, 2:1, 4:1, 8:1, 16:1 and 32:1, on a Humic Alic Cambisol, with 310 g kg-1 of clay. The application of treatments caused the following Ca:Mg ratios in the CEC: 1.1:1, 2.1:1, 4.0:1, 8.1:1, 16.4:1 and 31.8:1. The high concentrations of exchangeable Ca in soil caused by addition of lime with high Ca content inhibited the uptake of Mg and K by the corn plants. The increase in the soil Ca:Mg ratio reduced the dry matter production and height of plants in the initial stage of developmentA variação na relação Ca:Mg em corretivos da acidez do solo é uma das principais formas de alterar a disponibilidade desses nutrientes às plantas em solos ácidos. O objetivo do trabalho foi avaliar o efeito de diferentes proporções entre cálcio e magnésio na forma de CaCO3 e MgCO3 sobre a absorção de nutrientes e produção inicial de matéria seca de plantas de milho. O estudo o foi desenvolvido em casa de vegetação, em Lages-SC, com delineamento experimental inteiramente casualizado e três repetições. Os tratamentos consistiram na aplicação de dose equivalente a 21,0 t ha-1 de calcário, usando misturas de CaCO3 e MgCO3 em diversas proporções até atingir relações Ca:Mg de 1:1, 2:1, 4:1, 8:1, 16:1 e 32:1, aplicadas num Cambissolo Húmico Álico, com 310 g kg-1 de argila

  19. Reference intervals for blood copper,zinc,calcium,magnesium and iron in infants and children of Fujian west area%福建闽西地区儿童全血铜、锌、钙、镁、铁微量元素参考范围调查

    Institute of Scientific and Technical Information of China (English)

    吴定昌; 肖婷; 王跃华; 郑艳斌; 郭笑如; 兰小鹏

    2013-01-01

    目的 调查福建闽西地区儿童年龄特异性全血铜(Cu)、锌(Zn)、钙(Ca)、镁(Mg)、铁(Fe)微量元素正常参考范围.方法 利用BH5300S原子吸收光谱仪分析福建闽西地区1 702例1个月至11岁健康儿童的全血Cu、Zn、Ca、Mg、Fe微量元素浓度.结果 经统计得到福建闽西地区儿童年龄特异性全血Cu、Zn、Ca、Mg、Fe微量元素参考范围.分析全血微量元素与年龄的相关性,发现Cu和Fe元素与年龄呈负相关(P0.05).经统计优化后,各元素参考范围年龄段划分减少.结论 全血Cu、Zn、Ca、Mg、Fe微量元素参考范围的建立可为儿童微量元素合理补充提供指导,特别为福建闽西地区儿童微量元素缺乏的实验室诊断和流行病学调查提供重要依据.%Objective To study and establish the age-specific reference intervals for blood copper(Cu) , zinc(Zn) , calcium(Ca) , magnesium(Mg) and iron(Fe) in infants and children of Fujian west area.Methods Blood concentrations of Cu,Zn,Ca,Mg and Fe were measured by BH5300s atomic absorption spectrometry from 1 702 healthy infants and children(aged 1 month to 11 years) of Fuzhou area.Results Age-specific reference intervals suitable for Fujian west area were established for Cu, Zn, Ca, Mg and Fe.Studying on the effects of age on blood element concentrations revealed that there were inverse correlations between age and blood concentrations of Cu and Fe,positive correlation between age and blood concentrations of Zn and Fe,and no correlation between age and blood concentration of Mg.The numbers of age divisions for each trace element reference interval were reduced effectively by statistical optimization.Conclusion Kstablished reference intervals for Cu,Zn,Ca,Mg and Fe can provide important guidance for the reasonable supplementation of trace elements,and form the basis for the accurate clinical diagnosis and epidemiological survey of infants and children trace element deficiency in Fujian west area clinical

  20. 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.

  1. 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.

  2. [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.

  3. Magnesium Modifies the Impact of Calcitriol Treatment on Vascular Calcification in Experimental Chronic Kidney Disease.

    Science.gov (United States)

    Zelt, Jason G E; McCabe, Kristin M; Svajger, Bruno; Barron, Henry; Laverty, Kim; Holden, Rachel M; Adams, Michael A

    2015-12-01

    Chronic kidney disease (CKD) patients are commonly treated with vitamin D analogs, such as calcitriol. Recent epidemiologic evidence revealed a significant interaction between vitamin D and magnesium, since an inverse relationship between vitamin D levels and mortality mainly occurs in patients with a high magnesium intake. The aim of the study was to assess the mechanisms involved by determining whether magnesium alone or combined with calcitriol treatments differentially impacts vascular calcification (VC) in male Sprague-Dawley rats with adenine-induced CKD. Treatment with moderate doses of calcitriol (80 μg/kg) suppressed parathyroid hormone to near or slightly below control levels. Given alone, this dose of calcitriol increased the prevalence of VC; however, when magnesium was given in combination, the severity of calcification was attenuated in the abdominal aorta (51% reduction), iliac (44%), and carotid arteries (46%) compared with CKD controls. The decreases in vascular calcium content were associated with a 20-50% increase in vascular magnesium. Calcitriol treatment alone significantly decreased TRPM7 protein (↓ to ∼11%), whereas the combination treatment increased both mRNA (1.7×) and protein (6.8×) expression compared with calcitriol alone. In summary, calcitriol increased VC in certain conditions, but magnesium prevented the reduction in TRPM7 and reduced the severity of VC, thereby increasing the bioavailable magnesium in the vascular microenvironment. These findings suggest that modifying the adverse effect profile of calcitriol with magnesium may be a plausible approach to benefiting the increasing number of CKD patients being prescribed calcitriol.

  4. The effect of foliar nutrition of spinach (Spinacia oleracea L. with magnesium salts and urea on gas exchange, leaf yield and quality

    Directory of Open Access Journals (Sweden)

    Edward Borowski

    2012-12-01

    Full Text Available In a pot experiment conducted in a phytotron, the effectiveness of foliar nutrition of spinach (Spinacia oleracea L. with different magnesium salts with and without the addition of 0.5% CO(NH22 was studied. Magnesium was applied 3 times in the form of solutions of MgSO4 x 7H2O, Mg(NO32 x 6H2O, MgCl2 x 6H2O, C4H6O4Mg x 4H2O, compared to water as the control treatment. The obtained results showed that foliar feeding of spinach with inorganic magnesium salts was an efficient method for supplementing the Mg level in plants during the growing period. But the application of a metalo-organic complex in the form of magnesium acetate (C4H6O4Mg x 4H2O at a concentration of 1.7%, in spite of a similar effect on leaf Mg content, induced phytotoxic symptoms in the form of chlorotic and necrotic spots on the leaves. The application of the solutions of inorganic magnesium salts had a significant effect, resulting in more intensive leaf gas exchange (stomatal conductance, transpiration and photosynthesis and an increase in leaf yield. Magnesium sulphate affected the abovementioned processes in the most effective way, while magnesium acetate had a negative impact. Foliar feeding of spinach with the magnesium salts resulted in an increased leaf content of protein, chlorophyll, carotenoids, nitrates and proline, but a decrease in vitamin C content. The addition of urea to the applied magnesium salt solutions increased the plant gas exchange rates and the leaf content of protein, chlorophyll, carotenoids, nitrates and proline, but it decreased the content of vitamin C, potassium and magnesium.

  5. 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.

  6. 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...

  7. [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.

  8. Magnesium alloys and graphite wastes encapsulated in cementitious materials: Reduction of galvanic corrosion using alkali hydroxide activated blast furnace slag.

    Science.gov (United States)

    Chartier, D; Muzeau, B; Stefan, L; Sanchez-Canet, J; Monguillon, C

    2017-03-15

    Magnesium alloys and graphite from spent nuclear fuel have been stored together in La Hague plant. The packaging of these wastes is under consideration. These wastes could be mixed in a grout composed of industrially available cement (Portland, calcium aluminate…). Within the alkaline pore solution of these matrixes, magnesium alloys are imperfectly protected by a layer of Brucite resulting in a slow corrosion releasing hydrogen. As the production of this gas must be considered for the storage safety, and the quality of wasteform, it is important to select a cement matrix capable of lowering the corrosion kinetics. Many types of calcium based cements have been tested and most of them have caused strong hydrogen production when magnesium alloys and graphite are conditioned together because of galvanic corrosion. Exceptions are binders based on alkali hydroxide activated ground granulated blast furnace slag (BFS) which are presented in this article.

  9. Fabrication and cytocompatibility of spherical magnesium ammonium phosphate granules.

    Science.gov (United States)

    Christel, Theresa; Geffers, Martha; Klammert, Uwe; Nies, Berthold; Höß, Andreas; Groll, Jürgen; Kübler, Alexander C; Gbureck, Uwe

    2014-09-01

    Magnesium phosphate compounds, as for example struvite (MgNH4PO4·6H2O), have comparable characteristics to calcium phosphate bone substitutes, but degrade faster under physiological conditions. In the present work, we used a struvite forming calcium doped magnesium phosphate cement with the formulation Ca0.75Mg2.25(PO4)2 and an ammonium phosphate containing aqueous solution to produce round-shaped granules. For the fabrication of spherical granules, the cement paste was dispersed in a lipophilic liquid and stabilized by surfactants. The granules were characterized with respect to morphology, size distribution, phase composition, compressive strength, biocompatibility and solubility. In general, it was seen that small granules can hardly be produced by means of emulsification, when the raw material is a hydraulic paste, because long setting times promote coalescence of initially small unhardened cement droplets. Here, this problem was solved by using an aqueous solution containing both the secondary (NH4)2HPO4 and primary ammonium phosphates NH4H2PO4 to accelerate the setting reaction. This resulted in granules with 97 wt.% having a size in the range between 200 and 1,000 μm. The novel solution composition doubled the compressive strength of the cement to 37 ± 5 MPa without affecting either the conversion to struvite or the cytocompatibility using human fetal osteoblasts.

  10. 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)....

  11. 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...

  12. 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...

  13. 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....

  14. 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

  15. 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...

  16. 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....

  17. Increased water hardness and magnesium levels may increase occurrence of urolithiasis in cows from the Burdur region (Turkey).

    Science.gov (United States)

    Sahinduran, S; Buyukoglu, T; Gulay, M S; Tasci, F

    2007-08-01

    Objectives of the study were to measure water hardness in Burdur, and to establish its possible association with urolithiasis in cattle. Water samples were obtained from different stables (n = 15). Water hardness and the concentrations of potassium, calcium, magnesium, sodium, iron, zinc, manganese and copper ions were calculated from these water samples. Total hardness of the samples (mean 285 ppm) exceeded the standards and the water was characterized by high content of magnesium ions. Kidneys (n = 500) were collected randomly from slaughterhouses and examined for urolithiasis. Urolithiasis was observed in 102 kidneys (20.4%). The weights of the stones were between 0.02 and 237.44 g and the colour varied from white to brown. The calculi collected had various shapes and composed of calcium apatite (42.45%), struvite (20.15%), magnesium carbonate (15.15%), calcium carbonate (12.12%), and calcium phosphate cystine (10.13%). It was concluded that high water hardness with high magnesium ion concentrations in water may contribute to urolithiasis and needs to be investigated further in future studies.

  18. 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.

  19. Magnesium Contamination in Soil at a Magnesite Mining Region of Liaoning Province, China.

    Science.gov (United States)

    Wang, Lei; Tai, Peidong; Jia, Chunyun; Li, Xiaojun; Li, Peijun; Xiong, Xianzhe

    2015-07-01

    Magnesite is the world's most important source material for magnesia refractory production, and Haicheng City in Liaoning Province, China has been called "the magnesium capital of the world." However, magnesite mining in these areas has caused serious environmental problems. Field investigations have shown that the soil profile of many sites in the mining region are contaminated by magnesium, and the magnesium-enriched crusts that have formed on the soil surface have affected ecologically important soil functions, particularly reduced water penetration rate. Laboratory experiment revealed that anionic polyacrylamide and calcium dihydrogen phosphate can be used to improve soil condition, and have positive effects on soil function. The findings of this study are of significance in the magnetite mining areas, providing clear options for the remediation of soils that should be carried out immediately.

  20. Studies on magnesium's mechanism of action in digitalis-induced arrhythmias.

    Science.gov (United States)

    Specter, M J; Schweizer, E; Goldman, R H

    1975-12-01

    The mechanism by which magnesium affects digitalis-induced arrhythmias was studied in dogs with and without beta-receptor blockade. Digoxin was infused at a rate of 2.5mug/kg/min until ventricular tachycardia developed, then half the animals were given MgSO4, the other half saline. In animals given MgSO4, sinus rhythm was immediately re-established; in animals given saline, ventricular tachycardia persisted. In animals with beta-receptor blockade, MgSO4 was as effective in abolishing ventricular tachycardia as in those without beta-receptor blockade. We found no evidence that magnesium re-activated digoxin-inhibited (Na+, K+)-ATPase, altered myocardial or microsomal digoxin binding, or acted via the autonomic nervous system. Magnesium's direct effect on calcium and potassium fluxes across the myocardial cell membrane may be the mechanism of its antiarrhythmic action in digitalis-toxic arrhythmias.

  1. Self-dissolution assisted coating on magnesium metal for biodegradable bone fixation devices

    Science.gov (United States)

    Khakbaz, Hadis; Walter, Rhys; Gordon, Timothy; Bobby Kannan, M.

    2014-12-01

    An attempt was made to develop a self-dissolution assisted coating on a pure magnesium metal for potential bone fixation implants. Magnesium phosphate cement (MPC) was coated successfully on the magnesium metal in ammonium dihydrogen phosphate solution. The in vitro degradation behaviour of the MPC coated metal was evaluated using electrochemical techniques. The MPC coating increased the polarisation resistance (RP) of the metal by ˜150% after 2 h immersion in simulated body fluid (SBF) and reduced the corrosion current density (icorr) by ˜80%. The RP of the MPC coated metal remained relatively high even after 8 h immersion period. However, post-degradation analysis of the MPC coated metal revealed localized attack. Hence, the study suggests that MPC coating alone may not be beneficial, but this novel coating could provide additional protection if used as a precursor for other potential coatings such as biodegradable polymers or calcium phosphates.

  2. 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.

  3. Lanthanum acetate inhibits vascular calcification induced by vitamin D3 plus nicotine in rats.

    Science.gov (United States)

    Zhou, Ye-Bo; Jin, Shao-Ju; Cai, Yan; Teng, Xu; Chen, Li; Tang, Chao-Shu; Qi, Yong-Fen

    2009-08-01

    Lanthanum, a rare earth element, has been used to decrease serum phosphorus level in patients with chronic renal disease and hyperphosphatemia. We aimed to observe the effect and mechanism of two doses of lanthanum acetate (375 and 750 mg/kg/day) on vascular calcification induced by vitamin D3 plus nicotine treatment in rats for 4 weeks. As compared with control rats, rats with calcification showed widespread calcified nodules and irregular elastic fibers in calcified aorta on von Kossa calcium staining and increased aortic calcium and phosphorus contents, alkaline phosphatase (ALP) activity and bone-related protein expressions for osteopontin (OPN) and type III sodium dependent phosphate cotransporter Pit-1 (Pit-1). After treatment with either dose of lanthanum acetate, the calcified nodules and degree of irregular elastic fibers decreased in aortas. Lanthanum acetate at 750 mg/kg/day was more effective than 375 mg/kg/day in lessening vascular calcification by significantly reducing plasma phosphorus level, calcium x phosphorus product and ALP activity, by 30.3%, 28.6%, and 68.6%, respectively; reducing aortic phosphorus and calcium contents and ALP activity, by 48%, 53.1%, and 63.5% (all P nicotine alone. Lanthanum acetate could effectively inhibit the pathogenesis of vascular calcification.

  4. Zinc Acetate Immobilized on Mesoporous Materials by Acetate Ionic Liquids as Catalysts for Vinyl Acetate Synthesis

    Directory of Open Access Journals (Sweden)

    Hang Xu

    2015-01-01

    Full Text Available Ionic liquid containing active ingredient Zn(CH3COO2 was loaded in mesoporous silica gel to form supported ionic liquids catalyst (SILC which was used to synthesize vinyl acetate monomer (VAM. SILC was characterized by 1HNMR, FT-IR, TGA, BET, and N2 adsorption/desorption and the acetylene method was used to evaluate SILC catalytic activity and stability in fixed reactor. The result shows that 1-allyl-3-acetic ether imidazole acetate ionic liquid is successfully fixed within mesoporous channel of silica gel. The average thickness of ionic liquid catalyst layer is about 1.05 nm. When the catalytic temperature is 195°C, the acetic acid (HAc conversion is 10.9% with 1.1 g vinyl acetate yield and 98% vinyl acetate (VAc selectivity. The HAc conversion is increased by rise of catalytic temperature and molar ratio of C2H2 : HAc and decreased by mass space velocity (WHSV. The catalyst activity is not significantly reduced within 7 days and VAc selectivity has a slight decrease.

  5. Preparation and application of magnesium hydroxide%氢氧化镁的制备与应用

    Institute of Scientific and Technical Information of China (English)

    常喜斌; 王冀锋

    2013-01-01

    Methods for preparation of magnesium hydroxide mainly include dolomite method , magne-site method, brucite method, magnesium chloride method (calcium hydroxide precipitation method, am-monia precipitation method , sodium hydroxide , magnesium chloride precipitation method ) , and hexam-moniated magnesium chloride -magnesium chloride method .Magnesium hydroxide can be used in water treatment, flue gas desulfurization , etc., and can also be used as inorganic flame retardants and a pre-cursor of magnesium oxide series products .%氢氧化镁制备方法主要包括:白云石法,菱镁矿法,水镁石法,氯化镁法(氢氧化钙沉淀法、氨沉淀法、氢氧化钠沉淀法),六氨氯化镁-氯化镁法。其可应用于水处理、烟气脱硫等领域,还可用作无机阻燃剂及制备氧化镁系列产品的前驱体。

  6. 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

  7. 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.

  8. 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.

  9. Bioavailability of calcium supplements and the effect of Vitamin D: comparisons between milk, calcium carbonate, and calcium carbonate plus vitamin D.

    Science.gov (United States)

    Mortensen, L; Charles, P

    1996-03-01

    Our aim was to examine a regimen for calcium supplementation because various factors seem to be important for its bioavailability, and to examine the effect of adding vitamin D to the supplement. The participants were 20 healthy women aged 28-59 y (chi: 38 y). During the 3-d periods and 1 d before, the participants were consuming a calcium and energy-balanced diet as similar to their usual daily diet as possible. The study was designed as a randomized, placebo-controlled, partly blinded crossover study divided into four periods of 3 d each: 1) three tablets containing 1000 mg CaCO3/d, 2) three tablets containing 1000 mg CaCO3 plus 5 micrograms (200 IU) vitamin D/d, 3)1 L more milk than in the usual daily diet, and 4) three placebo tablets daily. Bioavailability of the different calcium-supplement regimens were evaluated by changes in 24-h urinary excretion of calcium, phosphate, and magnesium. A significant increase in urinary calcium excretion was found during all periods of supplementation compared with the placebo period (Pcalcium in the calcium carbonate period was not significantly higher that that in the milk period, but calcium carbonate plus vitamin D resulted in significantly higher calcium excretion compared with that in the milk period. We conclude that the examined calcium carbonate regimen is at least as good a calcium supplement as milk, and that addition of 600 IU vitamin D/d promptly resulted in an increase in urinary calcium excretion after an increase in calcium absorption, even in healthy women.

  10. 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

  11. Magnesium intake is not related to depression risk in Spanish university graduates.

    Science.gov (United States)

    Derom, Marie-Laure; Martínez-González, Miguel A; Sayón-Orea, Maria del Carmen; Bes-Rastrollo, Maira; Beunza, Juan J; Sánchez-Villegas, Almudena

    2012-06-01

    Magnesium is the second most predominant intracellular cation and it is an important cofactor in over 300 enzymatic reactions. It is a calcium antagonist and a voltage-dependent blocker of the N-methyl-D-aspartate channel, which plays a role in the entrance of calcium into the neuron. Other mechanisms also add biological plausibility to neuro-protective properties for magnesium, including an inverse association with major depression. A higher magnesium intake has been related to lower depressive symptoms. However, epidemiological evidence on this issue is scarce. Our aim was to prospectively evaluate the association between dietary magnesium intake and depression incidence in a cohort of 12,939 Spanish university graduates initially free of depression (Seguimiento Universidad de Navarra Cohort Study). Total magnesium intake was assessed with a validated, semiquantitative FFQ and incident depression was ascertained through self-reports of a new clinical diagnosis of depression done by a medical doctor and/or the habitual use of antidepressive drugs. The self-report was validated against the Diagnostic and Statistical Manual of Mental Disorders (4th edition) criteria in a subsample of the cohort. Cox regression models were used to obtain HR of incident depression during follow-up according to baseline quintiles of magnesium intake using the lowest quintile as the reference category. After a median follow-up of 6.3 y, 737 new cases of depression were identified. No association between magnesium intake and depression was found, with multivariate-adjusted HR = 1 (reference), 1.00 (95% CI: 0.78-1.27), 1.00 (0.76-1.31), 0.95 (0.70-1.30), and 1.11 (0.77-1.59) for increasing categories (quintiles 1-5) of total magnesium intake. No dose-response relationship was found (P-trend = 0.59). Results were robust through different sensitivity analyses, including nutrient density or residual models. In conclusion, our findings do not suggest an inverse association between magnesium

  12. 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.

  13. Physicochemical properties of the novel biphasic hydroxyapatite-magnesium phosphate biomaterial.

    Science.gov (United States)

    Pijocha, Dawid; Zima, Aneta; Paszkiewicz, Zofia; Ślósarczyk, Anna

    2013-01-01

    Besides high-temperature calcium phosphates (CaPs), low-temperature calcium phosphate bone cements (CPCs), due to excellent biological properties: bioactivity, biocompability and osteoconductivity, are successfully used as bone substitutes. However, some disadvantages, related mainly to their low resorption rate and poor mechanical properties result in limited range of applications of these implant materials to non-loaded places in the skeletal system. To overcome this problem, magnesium phosphate cements (MPCs) with high strength have been considered as biomaterials. The main disadvantage of MPCs is that the acid-base setting reaction is an exothermic process that must be strictly controlled to avoid tissue necrosis. In this work, a new composite bone substitute (Hydroxyapatite Magnesium Phosphate Material - HMPM) based on hydroxyapatite (HA) and magnesium phosphate cement (MPC) with sodium pyrophosphate applied as a retardant of setting reaction was obtained. Its setting time was adequate for clinical applications. Combining properties of HA and MPC has made it possible to obtain microporous (showing bimodal pore size distribution in the range of 0.005-1.700 micrometers) potential implant material showing good surgical handiness and sufficient mechanical strength. Effectiveness of sodium pyrophosphate as a retardant of exothermic setting reaction of the new cement formulation was confirmed. After setting and hardening, the material consisted of hydroxyapatite and struvite as crystalline phases. Unreacted magnesium oxide was not detected.

  14. 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.

  15. Enterococcus faecium LKE12 Cell-Free Extract Accelerates Host Plant Growth via Gibberellin and Indole-3-Acetic Acid Secretion.

    Science.gov (United States)

    Lee, Ko-Eun; Radhakrishnan, Ramalingam; Kang, Sang-Mo; You, Young-Hyun; Joo, Gil-Jae; Lee, In-Jung; Ko, Jae-Hwan; Kim, Jin-Ho

    2015-09-01

    The use of microbial extracts containing plant hormones is a promising technique to improve crop growth. Little is known about the effect of bacterial cell-free extracts on plant growth promotion. This study, based on phytohormonal analyses, aimed at exploring the potential mechanisms by which Enterococcus faecium LKE12 enhances plant growth in oriental melon. A bacterial strain, LKE12, was isolated from soil, and further identified as E. faecium by 16S rDNA sequencing and phylogenetic analysis. The plant growth-promoting ability of an LKE12 bacterial culture was tested in a gibberellin (GA)-deficient rice dwarf mutant (waito-C) and a normal GA biosynthesis rice cultivar (Hwayongbyeo). E. faecium LKE12 significantly improved the length and biomass of rice shoots in both normal and dwarf cultivars through the secretion of an array of gibberellins (GA1, GA3, GA7, GA8, GA9, GA12, GA19, GA20, GA24, and GA53), as well as indole-3-acetic acid (IAA). To the best of our knowledge, this is the first study indicating that E. faecium can produce GAs. Increases in shoot and root lengths, plant fresh weight, and chlorophyll content promoted by E. faecium LKE12 and its cell-free extract inoculated in oriental melon plants revealed a favorable interaction of E. faecium LKE12 with plants. Higher plant growth rates and nutrient contents of magnesium, calcium, sodium, iron, manganese, silicon, zinc, and nitrogen were found in cell-free extract-treated plants than in control plants. The results of the current study suggest that E. faecium LKE12 promotes plant growth by producing GAs and IAA; interestingly, the exogenous application of its cell-free culture extract can be a potential strategy to accelerate plant growth.

  16. 熔融制样-波长色散X射线荧光光谱法测定红土镍矿中铁、镍、硅、铝、镁、钙、钛、锰、铜和磷%Determination of iron, nickel, silicon, aluminum, magnesium, calcium, titanium, manganese,copper and phosphorus in laterite nickel ores by wavelength dispersive X-ray fluorescence spectrometry with fusion sample preparation

    Institute of Scientific and Technical Information of China (English)

    林忠; 李卫刚; 褚宁; 蒋晓光; 孙涛; 林志伟; 王艳君

    2012-01-01

    A wavelength dispersive X - ray fluorescence spectrometry with fusion sample preparation has been developed for determination of iron, nickel, silicon, aluminum, magnesium, calcium, titanium, manganese, copper and phosphorus in laterite nickel ores. Calibration samples were prepared by adding high pure oxides and standard solutions of pending elements into iron ore standards, which were applied as matrix and ignited in 1000 ℃. The experimental conditions including of fluxing agent, fusion time, dilution ratios, doffing membrane reagent and matrix effects were determined. The analytical results were proposed by loss on ignition calibration, which were agreement with those obtained by wet method analysis, and the relative standard deviation was between 0. 219 % and 2. 817 %. The method was satisfied the request of laterite nickel ores test.%建立了熔融制样-波长色散X射线荧光光谱法测定红土镍矿中铁、镍、硅、铝、镁、钙、钛、锰、铜和磷含量的方法.采用经1000℃灼烧后的铁矿标准样品为基体,添加相关待测元素的高纯氧化物和标准溶液制作校准曲线用的校准样品,确定了助熔剂、熔融时间、稀释比、脱模剂和基体效应校正方式等试验条件.样品分析结果进行烧失量校正,与湿法分析结果的相对标准偏差介于0.219%~2.817%之间,满足红土镍矿检测需要.

  17. Lead removal in rats using calcium alginate.

    Science.gov (United States)

    Savchenko, Olga V; Sgrebneva, Marina N; Kiselev, Vladimir I; Khotimchenko, Yuri S

    2015-01-01

    Lead (Pb) exposure, even at low levels, causes a variety of health problems. The aims of this study were to investigate the tissue distribution of lead in the bodies of rats, to evaluate lead removal from the internal organs and bones using calcium alginate in doses of 500, 200 and 100 mg/kg per day for 28 days and to assess the impact of calcium alginate on the level of essential elements. Lead (Pb), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu) and zinc (Zn) levels in the blood, hearts, kidneys, livers and femurs of the experimental animals were measured using mass spectrometry with inductively coupled plasma. The results revealed that lead acetate exposure increased the levels of Pb in the blood and organs of the animals and significantly reduced contents of Ca, Mn, Fe, Cu and Zn. Treatment with calcium alginate in dose 500 mg/kg contributed to significant decreases in the amount of lead in the kidney, heart and bones of animals and a slight increase in the content of essential elements in the liver, kidneys and heart, although these changes were not significant. Decreasing of lead was not significant in the internal organs, bones and blood of animals treated with calcium alginate 200 and 100 mg/kg. Consequently, calcium alginate dose of 500 mg/kg more efficiently removes lead accumulated in the body. Calcium alginate does not have negative effect on level of essential elements quite the contrary; reducing the levels of lead, calcium alginate helps normalize imbalances of Ca, Mn, Fe, Cu and Zn. The results of this study suggest that calcium alginate may potentially be useful for the treatment and prevention of heavy metal intoxications.

  18. 钠钾镁钙葡萄糖注射液应用于烧伤休克液体复苏的临床疗效评估——前瞻性、随机、单盲、阳性药物对照、多中心临床试验%Clinical evaluation of sodium potassium magnesium calcium and glucose injection during fluid resuscitation of burn shock: a prospective, randomized, single-blinded, positive drug controlled, multicentre clinical trial

    Institute of Scientific and Technical Information of China (English)

    柴家科; 李利根; 罗高兴; 沈光裕; 张庆富; 王玉莲; 霍然; 牛希华; 孙海宁

    2013-01-01

    Objective To evaluate the efficacy and safety of sodium potassium magnesium calcium and glucose injection(Le Jia (R)) comparing with sodium lactated ringer's solution for burn resuscitation.Methods 198 burned patients who met the criterion were performed fluid resuscitation during the first 6 h after injury.All patients who were enrolled in this study had been assigned assigned either the sodium potassium magnesium calcium and glucose injection group (test group) or the sodium lactated ringer's group (control group) according to random number table.Before the fluid resuscitation according to 1970 National Conference of Burn Injuries formula,the clinical index such as routine blood count,liver and kidney functions,blood biochemistry and coagulation function were detected.The hemodynamic index,arterial blood gas and serum glucose levels were monitored during fluid infusion,and all blood lab indexes were detected at the end of the first and second 24 h after resuscitation beginning.The efficacy index is the changes of serum electrolyte,arterial blood lactate,blood gas and serum glucose levels after resuscitation of two different electrolyte solution.And the safety index is the incidence and specific situation of adverse drug reaction.Results Comprehensive analysis was performed from the aspects of maintaining of serum electrolyte,acid-base equilibrium,changes of blood lactate and glucose levels.No statistically significant difference was found between the two groups.In safety evaluation,safe cases in test group were 99(100%) as well as in control group.No statistically significant difference was found in safety evaluation.Conclusions Sodium potassium magnesium calcium and glucose injection (Le Jia (R)) has the comparative efficacy and safety to sodium lactated ringer's solution,the most commonly used in clinic for burn resuscitation.%目的 以乳酸钠林格注射液为对照,验证钠钾镁钙葡萄糖注射液(乐加(R))用于烧伤休克液体复苏方面

  19. Simultaneous incorporation of magnesium and carbonate in apatite: effect on physico-chemical properties

    Directory of Open Access Journals (Sweden)

    Marcia S. Sader

    2013-01-01

    Full Text Available Synthetic apatites are widely used both in the dental and the orthopaedic fields due to their similarity in composition with the inorganic phase of hard tissues. Biologic apatites are not pure hydroxyapatite (HA, but are calcium-deficient apatites with magnesium and carbonate as minor but important substituents. The aim of the present study was to produce a more soluble biomaterial through the simultaneous substitution of magnesium and carbonate in the apatite structure to accelerate the degradation time in the body. The physico-chemical and dissolution properties of unsintered magnesium and carbonate-substituted apatite (MCAp with similar Mg/Ca molar ratio (0.03 and varying C/P molar ratio were evaluated. The resultant powders were characterised using several techniques, such as FTIR, TGA, XRD, ICP and SEM, while the release of calcium ions in a pH 6 solution was monitored using a Ca-ion selective electrode. The results showed a decrease of crystallite size and an increase in the release of calcium to the medium as the carbonate content in the samples increased.

  20. Analysis of proteins responsive to acetic acid in Acetobacter: molecular mechanisms conferring acetic acid resistance in acetic acid bacteria.

    Science.gov (United States)

    Nakano, Shigeru; Fukaya, Masahiro

    2008-06-30

    Acetic acid bacteria are used for industrial vinegar production because of their remarkable ability to oxidize ethanol and high resistance to acetic acid. Although several molecular machineries responsible for acetic acid resistance in acetic acid bacteria have been reported, the entire mechanism that confers acetic acid resistance has not been completely understood. One of the promising methods to elucidate the entire mechanism is global analysis of proteins responsive to acetic acid by two-dimensional gel electrophoresis. Recently, two proteins whose production was greatly enhanced by acetic acid in Acetobacter aceti were identified to be aconitase and a putative ABC-transporter, respectively; furthermore, overexpression or disruption of the genes encoding these proteins affected acetic acid resistance in A. aceti, indicating that these proteins are involved in acetic acid resistance. Overexpression of each gene increased acetic acid resistance in Acetobacter, which resulted in an improvement in the productivity of acetic acid fermentation. Taken together, the results of the proteomic analysis and those of previous studies indicate that acetic acid resistance in acetic acid bacteria is conferred by several mechanisms. These findings also provide a clue to breed a strain having high resistance to acetic acid for vinegar fermentation.

  1. 5-(Chloromethylquinolin-8-yl acetate

    Directory of Open Access Journals (Sweden)

    Ling-Qian Kong

    2008-08-01

    Full Text Available The title compound, C12H10ClNO2, crystallizes with two independent molecules in the asymmetric unit; these are approximate mirror images of each other. In each molecule, the chloromethyl and acetate groups lie on the same side of the quinoline ring system, with dihedral angles between the ring plane and the plane of the acetate group of 82.0 (1 and −79.2 (1°. The C—C—C—Cl torsion angles for the chloromethyl groups of the two molecules are 80.9 (2 and −83.1 (2°.

  2. In Vivo Corrosion Resistance of Ca-P Coating on AZ60 Magnesium Alloy

    Institute of Scientific and Technical Information of China (English)

    Xing Xiao; Haiying Yu; Qingsan Zhu; Guangyu Li; Yang Qu; Rui Gu

    2013-01-01

    Magnesium-based alloys are frequently reported as potential biodegradable orthopedic implant materials.Controlling the degradation rate and mechanical integrity of magnesium alloys in the physiological environment is the key to their applications.In this study,calcium phosphate (Ca-P) coating was prepared on AZ60 magnesium alloy using phosphating technology.AZ60 samples were immersed in a phosphating solution at 37 ± 2 ℃ for 30 min,and the solution pH was adjusted to 2.6 to 2.8 by adding NaOH solution.Then,the samples were dried in an attemperator at 60 ℃.The degradation behavior was studied in vivo using Ca-P coated and uncoated magnesium alloys.Samples of these two different materials were implanted into rabbit femora,and the corrosion resistances were evaluated after 1,2,and 3 months.The Ca-P coated samples corroded slower than the uncoated samples with prolonged time.Significant differences (p < 0.05) in mass losses and corrosion rates between uncoated samples and Ca-P coated samples were observed by micro-computed tomography.The results indicate that the Ca-P coating could slow down the degradation of magnesium alloy in vivo.

  3. Copper, aluminum, iron and calcium inhibit human acetylcholinesterase in vitro.

    Science.gov (United States)

    Pohanka, Miroslav

    2014-01-01

    Acetylcholinesterase (AChE) is an important part of cholinergic nerves where it participates in termination of neurotransmission. AChE can be inhibited by e.g. some Alzheimer disease drugs, nerve agents, and secondary metabolites. In this work, metal salts aluminum chloride, calcium chloride, cupric chloride, ferric chloride, potassium chloride, magnesium chloride and sodium chloride were tested for their ability to inhibit AChE. Standard Ellman assay based on human recombinant AChE was done and inhibition was measured using Dixon plot. No inhibition was proved for sodium, potassium and magnesium ions. However, aluminum, cupric, ferric and calcium ions were able to inhibit AChE via noncompetitive mechanism of inhibition. Though the inhibition is much weaker when compared to e.g. drugs with noncompetitive mechanism of action, biological relevance of the findings can be anticipated.

  4. [Allergy of calcium phosphate cement material following skull reconstruction: a case report].

    Science.gov (United States)

    Mizowaki, Takashi; Miyake, Shigeru; Yoshimoto, Yuji; Matsuura, Yoshitaka; Akiyama, Sou

    2013-04-01

    The paste form of calcium phosphate cement is often used in skull reconstruction because of the biocompatibility and early handling of these cements. Although it had rarely been shown to produce a foreign body reaction, we encountered a patient who experienced an allergic reaction to calcium phosphate cements(Biopex®. A patch test was performed and a positive reaction to magnesium phosphate was obtained. Biopex® contains magnesium phosphate, so we diagnosed this case as allergic reaction. Pathological analysis revealed infiltration of plasmacytes in the bone flap around the calcium phosphate cement. The postoperative course was uneventful 3 years after surgery. Allergy to calcium phosphate cements is rare, but must be considered in differential diagnosis of its side effects.

  5. Physicochemical properties of calcium polycarbophil, a water-absorbing polymer.

    Science.gov (United States)

    Yamada, T; Kitayama, M; Yamazaki, M; Nagata, O; Tamaj, I; Tsuji, A

    1996-07-01

    The physicochemical properties of calcium polycarbophil were examined. Calcium polycarbophil was decalcified rapidly under acidic conditions, affording polycarbophil. Polycarbophil absorbed about 10 times its own weight of water under acidic conditions, but the swelling ratio markedly increased at above pH 4.0 and reached 70 times the initial weight under neutral conditions. The swelling of polycarbophil was not affected by non-ionic osmolarity, but was affected by ionic strength, showing a decrease with increase of ionic strength. Monovalent metal ions such as sodium and potassium ions in gastrointestinal fluid did not reduce the equilibrium swelling of polycarbophil, but divalent ions such as calcium and magnesium ions did. However, calcium ion only slightly reduced the equilibrium swelling under sodium-rich conditions. The viscosity (as an indicator of fluidity) of polycarbophil was larger than that of CMC-Na at every shear rate and polymer content examined.

  6. 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...

  7. Magnesium Inhibits Wnt/β-Catenin Activity and Reverses the Osteogenic Transformation of Vascular Smooth Muscle Cells

    Science.gov (United States)

    Montes de Oca, Addy; Guerrero, Fatima; Martinez-Moreno, Julio M.; Madueño, Juan A.; Herencia, Carmen; Peralta, Alan; Almaden, Yolanda; Lopez, Ignacio; Aguilera-Tejero, Escolastico; Gundlach, Kristina; Büchel, Janine; Peter, Mirjam E.; Passlick-Deetjen, Jutta; Rodriguez, Mariano; Muñoz-Castañeda, Juan R.

    2014-01-01

    Magnesium reduces vascular smooth muscle cell (VSMC) calcification in vitro but the mechanism has not been revealed so far. This work used only slightly increased magnesium levels and aimed at determining: a) whether inhibition of magnesium transport into the cell influences VSMC calcification, b) whether Wnt/β-catenin signaling, a key mediator of osteogenic differentiation, is modified by magnesium and c) whether magnesium can influence already established vascular calcification. Human VSMC incubated with high phosphate (3.3 mM) and moderately elevated magnesium (1.4 mM) significantly reduced VSMC calcification and expression of the osteogenic transcription factors Cbfa-1 and osterix, and up-regulated expression of the natural calcification inhibitors matrix Gla protein (MGP) and osteoprotegerin (OPG). The protective effects of magnesium on calcification and expression of osteogenic markers were no longer observed in VSMC cultured with an inhibitor of cellular magnesium transport (2-aminoethoxy-diphenylborate [2-APB]). High phosphate induced activation of Wnt/β-catenin pathway as demonstrated by the translocation of β-catenin into the nucleus, increased expression of the frizzled-3 gene, and downregulation of Dkk-1 gene, a specific antagonist of the Wnt/β-catenin signaling pathway. The addition of magnesium however inhibited phosphate-induced activation of Wnt/β-catenin signaling pathway. Furthermore, TRPM7 silencing using siRNA resulted in activation of Wnt/β-catenin signaling pathway. Additional experiments were performed to test the ability of magnesium to halt the progression of already established VSMC calcification in vitro. The delayed addition of magnesium decreased calcium content, down-regulated Cbfa-1 and osterix and up-regulated MGP and OPG, when compared with a control group. This effect was not observed when 2-APB was added. In conclusion, magnesium transport through the cell membrane is important to inhibit VSMC calcification in vitro

  8. Desmopressin Acetate in Intracranial Haemorrhage

    Directory of Open Access Journals (Sweden)

    Thomas Kapapa

    2014-01-01

    Full Text Available Introduction. The secondary increase in the size of intracranial haematomas as a result of spontaneous haemorrhage or trauma is of particular relevance in the event of prior intake of platelet aggregation inhibitors. We describe the effect of desmopressin acetate as a means of temporarily stabilising the platelet function. Patients and Methods. The platelet function was analysed in 10 patients who had received single (N=4 or multiple (N=6 doses of acetylsalicylic acid and 3 patients (control group who had not taken acetylsalicylic acid. All subjects had suffered intracranial haemorrhage. Analysis was performed before, half an hour and three hours after administration of desmopressin acetate. Statistical analysis was performed by applying a level of significance of P≤0.05. Results. (1 Platelet function returned to normal 30 minutes after administration of desmopressin acetate. (2 The platelet function worsened again after three hours. (3 There were no complications related to electrolytes or fluid balance. Conclusion. Desmopressin acetate can stabilise the platelet function in neurosurgical patients who have received acetylsalicylic acid prior to surgery without causing transfusion-related side effects or a loss of time. The effect is, however, limited and influenced by the frequency of drug intake. Further controls are needed in neurosurgical patients.

  9. Substrate and method for the formation of continuous magnesium diboride and doped magnesium diboride wire

    Science.gov (United States)

    Suplinskas, Raymond J.; Finnemore, Douglas; Bud'ko, Serquei; Canfield, Paul

    2007-11-13

    A chemically doped boron coating is applied by chemical vapor deposition to a silicon carbide fiber and the coated fiber then is exposed to magnesium vapor to convert the doped boron to doped magnesium diboride and a resultant superconductor.

  10. [Magnesium deficiency and therapy in cardiac arrhythmias: recommendations of the German Society for Magnesium Research].

    Science.gov (United States)

    Vierling, W; Liebscher, D-H; Micke, O; von Ehrlich, B; Kisters, K

    2013-05-01

    Aim of the recommendations of the German Society for Magnesium Research: Recognition and compensation of magnesium deficiency in patients with risk factors for cardiac arrhythmias or manifest rhythm disturbances. Prevention of arrhythmias by administration of magnesium. Therapeutic administration of magnesium in patients with arrhythmias with and without magnesium deficiency. The current state of knowledge claims for considering the status of magnesium and the possibility of a therapeutic intervention with magnesium within the concept of the treatment of cardiovascular diseases. The use of magnesium as single agent or as an adjunct to other therapeutic actions in the prevention and therapy of cardiac arrhythmias can be effective and, in case of oral administration, very safe. In case of parenteral administration, it is important to use adequate doses, monitor cardiovascular and neuromuscular parameters and to consider contraindications.

  11. Lightweight Heat Pipes Made from Magnesium

    Science.gov (United States)

    Rosenfeld, John N.; Zarembo, Sergei N.; Eastman, G. Yale

    2010-01-01

    Magnesium has shown promise as a lighter-weight alternative to the aluminum alloys now used to make the main structural components of axially grooved heat pipes that contain ammonia as the working fluid. Magnesium heat-pipe structures can be fabricated by conventional processes that include extrusion, machining, welding, and bending. The thermal performances of magnesium heat pipes are the same as those of equal-sized aluminum heat pipes. However, by virtue of the lower mass density of magnesium, the magnesium heat pipes weigh 35 percent less. Conceived for use aboard spacecraft, magnesium heat pipes could also be attractive as heat-transfer devices in terrestrial applications in which minimization of weight is sought: examples include radio-communication equipment and laptop computers.

  12. Preparation and characterization of porous magnesium materials

    Institute of Scientific and Technical Information of China (English)

    LIU Xi-qin; LIU Zi-li; ZHANG Xiao-hong; FENG Jun-dong; YU Ta-xi

    2006-01-01

    The proper spacer material and the preparation technology for biological compatible porous magnesium materials were explored by the powder metallurgy method, and microstructures, porosity and mechanical properties of sintered porous magnesium were investigated. The results show that compared with spacer materials of NH4CO3, NH3Cl and carbamide, NH4CO3 is the best one for preparation of sintered porous magnesium, and the worst one is NH3Cl. The isolated blind pores are formed mainly by the particle interval of the magnesium powders. Adding spacer material favors the formation of open pores, while has little contribution to the formation of blind pores. The overall porosity and porosity of open pore of the sintered porous magnesium increase with the increase of added spacer material, while decrease with the increase of the molding stress. The mechanical properties of sintered porous magnesium increase with decreasing addition of spacer material and increasing molding stress.

  13. Calcium and Vitamin D

    Science.gov (United States)

    ... Cart Home › Patients › Treatment › Calcium/Vitamin D Calcium/Vitamin D Getting enough calcium and vitamin D is ... the-counter medications and calcium supplements. What is Vitamin D and What Does it Do? Vitamin D ...

  14. Isolation, characterization and optimization of indigenous acetic acid bacteria and evaluation of their preservation methods

    Directory of Open Access Journals (Sweden)

    K Beheshti-Maal

    2010-06-01

    Full Text Available Background and Objectives: Acetic acid bacteria (AAB are useful in industrial production of vinegar. The present study aims at isolation and identification of acetic acid bacteria with characterization, optimization, and evaluation of their acetic acid productivity."nMaterials and Methods: Samples from various fruits were screened for presence of acetic acid bacteria on glucose, yeast extract, calcium carbonate (GYC medium. Carr medium supplemented with bromocresol green was used for distinguishing Acetobacter from Gluconobacter. The isolates were cultured in basal medium to find the highest acetic acid producer. Biochemical tests followed by 16S rRNA and restriction analyses were employed for identification of the isolate and phylogenic tree was constructed. Bacterial growth and acid production conditions were optimized based on optimal inoculum size, pH, temperature, agitation, aeration and medium composition."nResults: Thirty-seven acetic acid bacteria from acetobacter and gluconobacter members were isolated. Acetic acid productivity yielded 4 isolates that produced higher amounts of acid. The highest producer of acid (10.03% was selected for identification. The sequencing and restriction analyses of 16S rRNA revealed a divergent strain of Acetobacter pasteurianus (Gene bank accession number # GU059865. The optimum condition for acid production was a medium composed of 2% glucose, 2% yeast extract, 3% ethanol and 3% acid acetic at inoculum size of 4% at 3L/Min aeration level in the production medium. The isolate was best preserved in GYC medium at 12oC for more than a month. Longer preservation was possible at -70oC."nConclusion: The results are suggestive of isolation of an indigenous acetic acid bacteria. Pilot plan is suggested to study applicability of the isolated strain in acetic acid production.

  15. Imaging calcium in neurons.

    Science.gov (United States)

    Grienberger, Christine; Konnerth, Arthur

    2012-03-08

    Calcium ions generate versatile intracellular signals that control key functions in all types of neurons. Imaging calcium in neurons is particularly important because calcium signals exert their highly specific functions in well-defined cellular subcompartments. In this Primer, we briefly review the general mechanisms of neuronal calcium signaling. We then introduce the calcium imaging devices, including confocal and two-photon microscopy as well as miniaturized devices that are used in freely moving animals. We provide an overview of the classical chemical fluorescent calcium indicators and of the protein-based genetically encoded calcium indicators. Using application examples, we introduce new developments in the field, such as calcium imaging in awake, behaving animals and the use of calcium imaging for mapping single spine sensory inputs in cortical neurons in vivo. We conclude by providing an outlook on the prospects of calcium imaging for the analysis of neuronal signaling and plasticity in various animal models.

  16. Studi Kandungan Mineral Kalium, Natrium, Magnesium Pada Selada (Lactuca sativa L.) Hidroponik Dan Non-Hidroponik Secara Spektrofotometri Serapan Atom

    OpenAIRE

    Novin, Sondang

    2013-01-01

    Lettuce is one of the many cultivated plants in hydroponics. The method of hydroponics is cultivate method plants without the use of soil as a growing medium, but using water. The lettuce has a high mineral content to the needs of human beings is like minerals potassium, sodium, magnesium, calcium, phosphorus, iron, vitamin A, vitamin B, and vitamin C. In the extracellular fluid potassium and sodium is an essential cations play a role in pH balance and osmolarity. While magnesium plays an imp...

  17. A novel and simple fluorescence probe for detecting main group magnesium ion in HeLa cells and Arabidopsis.

    Science.gov (United States)

    Yu, Tingting; Sun, Ping; Hu, Yijie; Ji, Yinggang; Zhou, Hongping; Zhang, Baowei; Tian, Yupeng; Wu, Jieying

    2016-12-15

    A simple-molecule fluorescence probe L has been designed, synthesized and characterized, which shows high selectivity and sensitivity for the main group magnesium ion through fluorescence "turn-on" response in ethanol solution, and no interference from calcium ion in particular. Detection limit of probe L is 1.47×10(-6) M and the rapid response could reach about 15-20s. The recognition mechanism has been established by fluorescence spectra, (1)H NMR study. Moreover, probe L presents a great photostability, low toxicity and cellular permeability, then we have carried out fluorescent bio-imaging of the probe L for magnesium ions in HeLa cells, which showed that probe L could be utilized to detect the intracellular magnesium ion. Furthermore, it is successfully used as a magnesium ion developer in plant tissues, which shows that it not only can be well tracking the transport of magnesium ion but also make a corresponding fluorescence response to different concentrations magnesium ion. These results would make this probe a great potential application for detecting Mg(2+) in biological system.

  18. Carbon-isotopic analysis of dissolved acetate.

    Science.gov (United States)

    Gelwicks, J T; Hayes, J M

    1990-01-01

    Heating of dried, acetate-containing solids together with oxalic acid dihydrate conveniently releases acetic acid for purification by gas chromatography. For determination of the carbon-isotopic composition of total acetate, the acetate-containing zone of the chromatographic effluent can be routed directly to a combustion furnace coupled to a vacuum system allowing recovery, purification, and packaging of CO2 for mass-spectrometric analysis. For analysis of methyl carbon, acetic acid can be cryogenically trapped from the chromatographic effluent, then transferred to a tube containing excess NaOH. The tube is evacuated, sealed, and heated to 500 degrees C to produce methane by pyrolysis of sodium acetate. Subsequent combustion of the methane allows determination of the 13C content at the methyl position in the parent acetate. With typical blanks, the standard deviation of single analyses is less than 0.4% for acetate samples larger than 5 micromoles. A full treatment of uncertainties is outlined.

  19. Safety assessment of Salicylic Acid, Butyloctyl Salicylate, Calcium Salicylate, C12-15 Alkyl Salicylate, Capryloyl Salicylic Acid, Hexyldodecyl Salicylate, Isocetyl Salicylate, Isodecyl Salicylate, Magnesium Salicylate, MEA-Salicylate, Ethylhexyl Salicylate, Potassium Salicylate, Methyl Salicylate, Myristyl Salicylate, Sodium Salicylate, TEA-Salicylate, and Tridecyl Salicylate.

    Science.gov (United States)

    2003-01-01

    Salicylic Acid is an aromatic acid used in cosmetic formulations as a denaturant, hair-conditioning agent, and skin-conditioning agent--miscellaneous in a wide range of cosmetic products at concentrations ranging from 0.0008% to 3%. The Calcium, Magnesium, and MEA salts are preservatives, and Potassium Salicylate is a cosmetic biocide and preservative, not currently in use. Sodium Salicylate is used as a denaturant and preservative (0.09% to 2%). The TEA salt of Salicylic Acid is used as an ultraviolet (UV) light absorber (0.0001% to 0.75%). Several Salicylic Acid esters are used as skin conditioning agents--miscellaneous (Capryloyl, 0.1% to 1%; C12-15 Alkyl, no current use; Isocetyl, 3% to 5%; Isodecyl, no current use; and Tridecyl, no current use). Butyloctyl Salicylate (0.5% to 5%) and Hexyldodecyl Salicylate (no current use) are hair-conditioning agents and skin-conditioning agents--miscellaneous. Ethylhexyl Salicylate (formerly known as Octyl Salicylate) is used as a fragrance ingredient, sunscreen agent, and UV light absorber (0.001% to 8%), and Methyl Salicylate is used as a denaturant and flavoring agent (0.0001% to 0.6%). Myristyl Salicylate has no reported function. Isodecyl Salicylate is used in three formulations, but no concentration of use information was reported. Salicylates are absorbed percutaneously. Around 10% of applied salicylates can remain in the skin. Salicylic Acid is reported to enhance percutaneous penetration of some agents (e.g., vitamin A), but not others (e.g., hydrocortisone). Little acute toxicity (LD(50) in rats; >2 g/kg) via a dermal exposure route is seen for Salicylic Acid, Methyl Salicylate, Tridecyl Salicylate, and Butyloctyl Salicylate. Short-term oral, inhalation, and parenteral exposures to salicylates sufficient to produce high blood concentrations are associated primarily with liver and kidney damage. Subchronic dermal exposures to undiluted Methyl Salicylate were associated with kidney damage. Chronic oral exposure to

  20. Influence of nutrition on feline calcium oxalate urolithiasis with emphasis on endogenous oxalate synthesis

    NARCIS (Netherlands)

    Dijcker, J.C.; Plantinga, E.A.; Baal, van J.; Hendriks, W.H.

    2011-01-01

    The prevalence of calcium oxalate (CaOx) uroliths detected in cats with lower urinary tract disease has shown a sharp increase over the last decades with a concomitant reciprocal decrease in the occurrence of struvite (magnesium ammonium phosphate) uroliths. CaOx stone-preventative diets are availab

  1. Long-term excessive magnesium supplementation is deleterious whereas suboptimal supply is beneficial for bones in rats.

    Science.gov (United States)

    Riond, J L; Hartmann, P; Steiner, P; Ursprung, R; Wanner, M; Forrer, R; Spichiger, U E; Thomsen, J S; Mosekilde, L

    2000-12-01

    The long-term effects of a suboptimal magnesium supply inducing a marginal or moderate deficiency or of an excessive magnesium supplementation corresponding to a basal diet with a high pharmacological intake were investigated in 36 growing Sprague-Dawley female rats. The rats were randomly divided in three groups and received a purified diet with 7 g calcium, 5 g phosphorus and either 0.2, 0.5 or 2 g magnesium per kg diet for 7 months. At the end of the trial, plasma and erythrocyte total magnesium concentrations were significantly lower in the magnesium-deficient group than in the respective control group. Serum concentrations of 1,25-dihydroxyvitamin D, PTH and IGF-I and the length of the right humeri were not affected by the dietary treatment. The volumes corrected for body weight, the medio-lateral diameters and the ratios dry weight/length of the right humeri, and the dry weight corrected for body weight of the left tibiae and of the right humeri were significantly smaller in the magnesium-supplemented group than in the two other groups. The magnesium contents of the left tibiae and of the first lumbar vertebrae were significantly lower in the magnesium-deficient group than in the two other groups. In the right femora, dual energy X-ray absorptiometry revealed significantly smaller areas in the proximal part and significantly smaller mineral contents in the second proximal quarter in the magnesium-supplemented group compared with the two other groups. Peripheral quantitative computer tomography of the right humeri revealed in the cortex significantly larger values for the relative area, mineral content, mineral density and thickness in the magnesium-deficient group compared with the control group. The maximum point of the load-deformation curve was significantly reduced in the fifth lumbar vertebrae and in the proximal femoral metaphyses of the magnesium-supplemented group. These results indicate that the long-term suboptimal magnesium supply improved some of

  2. Effective estimation of correct platelet counts in pseudothrombocytopenia using an alternative anticoagulant based on magnesium salt.

    Science.gov (United States)

    Schuff-Werner, Peter; Steiner, Michael; Fenger, Sebastian; Gross, Hans-Jürgen; Bierlich, Alexa; Dreissiger, Katrin; Mannuß, Steffen; Siegert, Gabriele; Bachem, Maximilian; Kohlschein, Peter

    2013-09-01

    Pseudothrombocytopenia remains a challenge in the haematological laboratory. The pre-analytical problem that platelets tend to easily aggregate in vitro, giving rise to lower platelet counts, has been known since ethylenediamine-tetra acetic acid EDTA and automated platelet counting procedures were introduced in the haematological laboratory. Different approaches to avoid the time and temperature dependent in vitro aggregation of platelets in the presence of EDTA were tested, but none of them proved optimal for routine purposes. Patients with unexpectedly low platelet counts or flagged for suspected aggregates, were selected and smears were examined for platelet aggregates. In these cases patients were asked to consent to the drawing of an additional sample of blood anti-coagulated with a magnesium additive. Magnesium was used in the beginning of the last century as anticoagulant for microscopic platelet counts. Using this approach, we documented 44 patients with pseudothrombocytopenia. In all cases, platelet counts were markedly higher in samples anti-coagulated with the magnesium containing anticoagulant when compared to EDTA-anticoagulated blood samples. We conclude that in patients with known or suspected pseudothrombocytopenia the magnesium-anticoagulant blood samples may be recommended for platelet counting.

  3. Pallidol hexaacetate ethyl acetate monosolvate

    Directory of Open Access Journals (Sweden)

    Qinyong Mao

    2013-07-01

    Full Text Available The entire molecule of pallidol hexaacetate {systematic name: (±-(4bR,5R,9bR,10R-5,10-bis[4-(acetyloxyphenyl]-4b,5,9b,10-tetrahydroindeno[2,1-a]indene-1,3,6,8-tetrayl tetraacetate} is completed by the application of twofold rotational symmetry in the title ethyl acetate solvate, C40H34O12·C4H8O2. The ethyl acetate molecule was highly disordered and was treated with the SQUEEZE routine [Spek (2009. Acta Cryst. D65, 148–155]; the crystallographic data take into account the presence of the solvent. In pallidol hexaacetate, the dihedral angle between the fused five-membered rings (r.m.s. deviation = 0.100 Å is 54.73 (6°, indicating a significant fold in the molecule. Significant twists between residues are also evident as seen in the dihedral angle of 80.70 (5° between the five-membered ring and the pendent benzene ring to which it is attached. Similarly, the acetate residues are twisted with respect to the benzene ring to which they are attached [C—O(carboxy—C—C torsion angles = −70.24 (14, −114.43 (10 and −72.54 (13°]. In the crystal, a three-dimensional architecture is sustained by C—H...O interactions which encompass channels in which the disordered ethyl acetate molecules reside.

  4. Role of calcium in growth inhibition induced by a novel cell surface sialoglycopeptide

    Science.gov (United States)

    Betz, N. A.; Westhoff, B. A.; Johnson, T. C.; Spooner, B. S. (Principal Investigator)

    1995-01-01

    Our laboratory has purified an 18 kDa cell surface sialoglycopeptide growth inhibitor (CeReS-18) from intact bovine cerebral cortex cells. Evidence presented here demonstrates that sensitivity to CeReS-18-induced growth inhibition in BALB-c 3T3 cells is influenced by calcium, such that a decrease in the calcium concentration in the growth medium results in an increase in sensitivity to CeReS-18. Calcium did not alter CeReS-18 binding to its cell surface receptor and CeReS-18 does not bind calcium directly. Addition of calcium, but not magnesium, to CeReS-18-inhibited 3T3 cells results in reentry into the cell cycle. A greater than 3-hour exposure to increased calcium is required for escape from CeReS-18-induced growth inhibition. The calcium ionophore ionomycin could partially mimic the effect of increasing extracellular calcium, but thapsigargin was ineffective in inducing escape from growth inhibition. Increasing extracellular calcium 10-fold resulted in an approximately 7-fold increase in total cell-associated 45Ca+2, while free intracellular calcium only increased approximately 30%. However, addition of CeReS-18 did not affect total cell-associated calcium or the increase in total cell-associated calcium observed with an increase in extracellular calcium. Serum addition induced mobilization of intracellular calcium and influx across the plasma membrane in 3T3 cells, and pretreatment of 3T3 cells with CeReS-18 appeared to inhibit these calcium mobilization events. These results suggest that a calcium-sensitive step exists in the recovery from CeReS-18-induced growth inhibition. CeReS-18 may inhibit cell proliferation through a novel mechanism involving altering the intracellular calcium mobilization/regulation necessary for cell cycle progression.

  5. 21 CFR 582.1005 - Acetic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Acetic acid. 582.1005 Section 582.1005 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1005 Acetic acid. (a) Product. Acetic acid. (b) Conditions of use. This substance is...

  6. 21 CFR 522.2476 - Trenbolone acetate.

    Science.gov (United States)

    2010-04-01

    ... days. (A) 140 milligrams (mg) trenbolone acetate (one implant consisting of 7 pellets, each pellet containing 20 mg trenbolone acetate) per implant dose. (B) 140 mg trenbolone acetate (one implant consisting... 29 mg tylosin tartrate) per implant dose. (ii) Indications for use. For improved feed...

  7. Magnesium: Potential Roles in Neurovascular Disease

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    Jason J Chang

    2014-04-01

    Full Text Available Objective: Magnesium therapy has been studied extensively in pre-clinical and clinical trials in multiple organ systems. Cerebrovascular diseases are particularly likely to benefit from its neuroprotective properties. This review summarizes current studies of magnesium in a wide range of neurovascular diseases.Methods: We searched relevant terms in the National Library of Medicine PubMed database and selected research including basic science, translational reports, meta-analyses, and clinical studies.Results: Studies examining magnesium administration in ischemic stroke have failed to show any benefit in clinical outcome. Data on magnesium for intracerebral hemorrhage is limited. Preliminary investigations in subarachnoid hemorrhage were promising, but definitive studies did not reveal differences in clinical outcome between magnesium and placebo-treated groups. Studies examining magnesium administration in global ischemia following cardiac arrest suggest a trend toward improved clinical outcome. The strongest evidence for clinically relevant neuroprotection following magnesium administration derives from studies of pre-term infants and patients undergoing cardiac bypass and carotid endarterectomy procedures. Magnesium was found to have an excellent safety profile across all investigations.Conclusions: Magnesium is easy to administer and possesses a favorable safety profile. Its utility as a neuroprotectant in cardiac surgery, carotid enderaterectomy, and pre-term infant hypoxia remain promising. Value as a therapeutic agent in ischemic stroke, intracerebral hemorrhage and subarachnoid hemorrhage is unclear and appears to be limited by late administration. Ongoing clinical trials assessing magnesium administration in the first hours following symptom onset may help clarify the role of magnesium therapy in these disease processes.

  8. Mg-doped biphasic calcium phosphate by a solid state reaction route: Characterization and evaluation of cytotoxicity

    Energy Technology Data Exchange (ETDEWEB)

    Webler, Geovana D. [Instituto de Física, Universidade Federal de Alagoas, Maceió-AL 57072970 (Brazil); Correia, Ana C.C.; Barreto, Emiliano [Laboratório de Biologia Celular, Universidade Federal de Alagoas, Maceió-AL 57072970 (Brazil); Fonseca, Eduardo J.S., E-mail: eduardo@fis.ufal.br [Instituto de Física, Universidade Federal de Alagoas, Maceió-AL 57072970 (Brazil)

    2015-07-15

    Hydroxyapatite (HAP) and β-tricalcium phosphate (β-TCP) are widely used in tissue engineering because of their chemical similarity to the inorganic bone phase. In this work, we prepare biphasic calcium phosphate (BCP, a mixture of HAP and β-TCP) doped with different concentrations of magnesium to investigate the influence of magnesium on the BCP crystal structure. Magnesium is known to be an important element in the composition of bones and teeth. Recent research has shown that the doping of magnesium into BCP improves its bone metabolism and mechanical properties without affecting its biocompatibility. The samples were prepared by solid-state reaction from calcium carbonate, monobasic ammonium phosphate, and magnesium nitrate hexahydrate. Varying concentrations of magnesium were used and its modifications were examined by different characterization techniques. The phase composition and morphology of the ceramic powders were characterized by X-ray diffraction and scanning electron microscopy, respectively. The functional groups were analyzed using Fourier transform infrared spectroscopy and Raman spectroscopy. Cell viability experiments, using macrophage-like cell lines J774, showed that the synthesized Mg-doped BCP did not exhibit cytotoxicity regardless of the doses assayed or the different concentrations of magnesium used, suggesting it as a good material for potential biological applications. - Highlights: • Simple and fast method for the preparation of the Mg-BCP. • Study of the influence of the incorporation of Mg in the BCP. • Cell viability showed that the synthesized Mg-BCP did not exhibit cytotoxicity.

  9. Preparation and characterization of a degradable magnesium phosphate bone cement.

    Science.gov (United States)

    Yu, Ying; Xu, Chao; Dai, Honglian

    2016-12-01

    A kind of degradable magnesium phosphate bone cement (MPBC) was fabricated by using the mixed powders of magnesium oxide (MgO), potassium dihydrogen phosphate (KH2PO4) and calcium dihydrogen phosphate (Ca(H2PO4)2.H2O). As MgKPO4, the main product of MgO and KH2PO4 was alkaline, the Ca(H2PO4)2.H2O was added to neutralize the alkali of the system. And the effects of Ca(H2PO4)2.H2O on the performance of MPBC were discussed. The results showed that the adding of Ca(H2PO4)2.H2O extended the setting time, which was about 6 min to 18 min. The compressive strength increased first and then decreased, and maximum value reached 31.2 MPa after setting for 24 h without any additional pressure. The MPBC was degradable in Tris-HCl solution, and the extracts of the cytotoxicity assay showed that the MPBC had good biocompatibility, indicating that the MPBC had good biodegradable and biocompatible properties.

  10. The skeletal organic matrix from Mediterranean coral Balanophyllia europaea influences calcium carbonate precipitation.

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    Stefano Goffredo

    Full Text Available Scleractinian coral skeletons are made mainly of calcium carbonate in the form of aragonite. The mineral deposition occurs in a biological confined environment, but it is still a theme of discussion to what extent the calcification occurs under biological or environmental control. Hence, the shape, size and organization of skeletal crystals from the cellular level through the colony architecture, were attributed to factors as diverse as mineral supersaturation levels and organic mediation of crystal growth. The skeleton contains an intra-skeletal organic matrix (OM of which only the water soluble component was chemically and physically characterized. In this work that OM from the skeleton of the Balanophyllia europaea, a solitary scleractinian coral endemic to the Mediterranean Sea, is studied in vitro with the aim of understanding its role in the mineralization of calcium carbonate. Mineralization of calcium carbonate was conducted by overgrowth experiments on coral skeleton and in calcium chloride solutions containing different ratios of water soluble and/or insoluble OM and of magnesium ions. The precipitates were characterized by diffractometric, spectroscopic and microscopic techniques. The results showed that both soluble and insoluble OM components influence calcium carbonate precipitation and that the effect is enhanced by their co-presence. The role of magnesium ions is also affected by the presence of the OM components. Thus, in vitro, OM influences calcium carbonate crystal morphology, aggregation and polymorphism as a function of