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Sample records for calcium oxalate monohydrate

  1. Calcium oxalate monohydrate precipitation investigation by thermometric method

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    Söhnel, O.; Costa-Bauzá, A.; Velich, V.

    1993-01-01

    Calcium oxalate monohydrate (COM) precipitation from diluted solutions of 100 mol m -3 ionic strength at 25°C was studied by an isoperibolic reaction twin calorimeter. The molar reaction enthalpy was determined as - 17.5 kJ mol -1. Results achieved with a pure system were highly reproducible. Citrate, pyrophosphate and phytate retard COM precipitation that is manifested mainly by an induction period appearance and a decrease of the initial precipitation rate. Effect of the studied impurities on individual precipitation experiments carried out under identical conditions was to some extent "random", i.e. the reaction extent reached at arbitrary time considerably differed for individual experiments. Impurity effectiveness in retarding spontaneous precipitation increases in succession citrate phytate.

  2. Growth kinetics of calcium oxalate monohydrate. III. Variation of solution composition

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    Bijvoet, Olav L. M.; Blomen, Leo J. M. J.; Will, Eric J.; van der Linden, Hanneke

    1983-11-01

    The influence of the variations of initial supersaturation, ionic strength and calcium-to-oxalate ratio on the growth kinetics of calcium oxalate monohydrate from suspension at 37°C have been investigated in an isotopic system. All experiments can be described with a single growth formula, containing three constants: kA (growth rate constant), La (thermodynamic solubility product) and [ tm] (a parameter describing the agglomeration of any seed suspension). This formula is able to predict any growth curve when the initial concentrations of seed, oxalate and indifferent electrolyte are known. Comparisons with datak from the literature are discussed.

  3. The influence of crystal morphology on the kinetics of growth of calcium oxalate monohydrate

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    Millan, A.; Sohnel, O.; Grases, F.

    1997-08-01

    The growth of several calcium oxalate monohydrate seeds in the presence and absence of additives (phytate, EDTA and citrate) has been followed by potentiometry measurements. Growth rates have been calculated from precipitate curves by a cubic spline method and represented in logarithmic plots versus supersaturation. Crystal growth kinetics were found to be dependent on crystal morphology, crystal perfection and degree of aggregation. Some seeds were dissolving in supersaturated solutions. Other seeds showed an initial growth phase of high-order kinetics. The effect of the additives was also different on each seed. Three alternative mechanisms for calcium oxalate crystal growth are proposed.

  4. Proteomic Analysis after Sequential Extraction of Matrix Proteins in Urinary Stones Composed of Calcium Oxalate Monohydrate and Calcium Oxalate Dihydrate.

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    Kaneko, Kiyoko; Nishii, Shin-ichiro; Izumi, Yoko; Yasuda, Makoto; Yamanobe, Tomoyo; Fukuuchi, Tomoko; Yamaoka, Noriko; Horie, Shigeo

    2015-01-01

    In this study, we performed proteomic analysis following sequential protein extraction on calcium oxalate monohydrate (COM) and calcium oxalate dihydrate (COD) urinary stones to determine the specific matrix proteins according to the crystal components of the stones. After X-ray and IR analysis of 13 urinary stones, matrix proteins were sequentially extracted with KCl, formic acid, guanidine-HCl, and EDTA, before SDS-electrophoresis followed by liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS). The electrophoretic patterns of the extracted proteins differed from that of COM and COD stones. LC-MS/MS identified 65 proteins, of which many were cellular plasma proteins, and were frequently detected regardless of the crystal components. However, 6 proteins (protein Z, protein S, prothrombin, osteopontin, fatty acid binding protein 5, and ubiquitin) were detected in the final EDTA fractions of COM stones. These proteins are involved in the coagulation process or osteometabolism, and thus the roles they play are of particular interest.

  5. Papillary and Nonpapillary Calcium Oxalate Monohydrate Renal Calculi: Comparative Study of Etiologic Factors

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    Enrique Pieras

    2006-01-01

    Full Text Available Calcium oxalate monohydrate (COM renal calculi can be classified into two groups: papillary and nonpapillary. In this paper, a comparative study between etiologic factors of COM papillary and nonpapillary calculi is performed. The study included 40 patients with COM renal calculi. The urine of these individuals was analyzed. Case history, lifestyle, and dietetic habits were obtained.No significant differences between urinary biochemical data of both groups were observed; 50% of COM papillary stone formers and 40% of COM nonpapillary stone formers had urolithiasis family history. A low consumption of phytate-rich products was observed for both groups. A relationship between profession with occupational exposure to cytotoxic products and COM papillary renal lithiasis was detected.The results suggest that COM papillary calculi would be associated to papillary epithelium alterations together with a crystallization inhibitors deficit, whereas COM nonpapillary calculi would be associated to the presence of heterogeneous nucleants and a crystallization inhibitors deficit.

  6. Calcium oxalate monohydrate crystals internalized into renal tubular cells are degraded and dissolved by endolysosomes.

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    Chaiyarit, Sakdithep; Singhto, Nilubon; Thongboonkerd, Visith

    2016-02-25

    Interaction between calcium oxalate crystals and renal tubular cells has been recognized as one of the key mechanisms for kidney stone formation. While crystal adhesion and internalization have been extensively investigated, subsequent phenomena (i.e. crystal degradation and dissolution) remained poorly understood. To explore these mechanisms, we used fluorescein isothiocyanate (FITC)-labelled calcium oxalate monohydrate (COM) crystals (1000 μg/ml of crystals/culture medium) to confirm crystal internalization into MDCK (Type II) renal tubular cells after exposure to the crystals for 1 h and to trace the internalized crystals. Crystal size, intracellular and extracellular fluorescence levels were measured using a spectrofluorometer for up to 48 h after crystal internalization. Moreover, markers for early endosome (Rab5), late endosome (Rab7) and lysosome (LAMP-2) were examined by laser-scanning confocal microscopy. Fluorescence imaging and flow cytometry confirmed that FITC-labelled COM crystals were internalized into MDCK cells (14.83 ± 0.85%). The data also revealed a reduction of crystal size in a time-dependent manner. In concordance, intracellular and extracellular fluorescence levels were decreased and increased, respectively, indicating crystal degradation/dissolution inside the cells and the degraded products were eliminated extracellularly. Moreover, Rab5 and Rab7 were both up-regulated and were also associated with the up-regulated LAMP-2 to form large endolysosomes in the COM-treated cells at 16-h after crystal internalization. We demonstrate herein, for the first time, that COM crystals could be degraded/dissolved by endolysosomes inside renal tubular cells. These findings will be helpful to better understand the crystal fate and protective mechanism against kidney stone formation.

  7. Reinjury risk of nano-calcium oxalate monohydrate and calcium oxalate dihydrate crystals on injured renal epithelial cells: aggravation of crystal adhesion and aggregation

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    Gan, Qiong-Zhi; Sun, Xin-Yuan; Bhadja, Poonam; Yao, Xiu-Qiong; Ouyang, Jian-Ming

    2016-01-01

    Background Renal epithelial cell injury facilitates crystal adhesion to cell surface and serves as a key step in renal stone formation. However, the effects of cell injury on the adhesion of nano-calcium oxalate crystals and the nano-crystal-induced reinjury risk of injured cells remain unclear. Methods African green monkey renal epithelial (Vero) cells were injured with H2O2 to establish a cell injury model. Cell viability, superoxide dismutase (SOD) activity, malonaldehyde (MDA) content, propidium iodide staining, hematoxylin–eosin staining, reactive oxygen species production, and mitochondrial membrane potential (Δψm) were determined to examine cell injury during adhesion. Changes in the surface structure of H2O2-injured cells were assessed through atomic force microscopy. The altered expression of hyaluronan during adhesion was examined through laser scanning confocal microscopy. The adhesion of nano-calcium oxalate monohydrate (COM) and calcium oxalate dihydrate (COD) crystals to Vero cells was observed through scanning electron microscopy. Nano-COM and COD binding was quantitatively determined through inductively coupled plasma emission spectrometry. Results The expression of hyaluronan on the cell surface was increased during wound healing because of Vero cell injury. The structure and function of the cell membrane were also altered by cell injury; thus, nano-crystal adhesion occurred. The ability of nano-COM to adhere to the injured Vero cells was higher than that of nano-COD crystals. The cell viability, SOD activity, and Δψm decreased when nano-crystals attached to the cell surface. By contrast, the MDA content, reactive oxygen species production, and cell death rate increased. Conclusion Cell injury contributes to crystal adhesion to Vero cell surface. The attached nano-COM and COD crystals can aggravate Vero cell injury. As a consequence, crystal adhesion and aggregation are enhanced. These findings provide further insights into kidney stone

  8. Inhibition of calcium oxalate monohydrate growth by citrate and the effect of the background electrolyte

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    Weaver, Matthew L.; Qiu, S. Roger; Hoyer, John R.; Casey, William H.; Nancollas, George H.; De Yoreo, James J.

    2007-08-01

    Pathological mineralization is a common phenomenon in broad range of plants and animals. In humans, kidney stone formation is a well-known example that afflicts approximately 10% of the population. Of the various calcium salt phases that comprise human kidney stones, the primary component is calcium oxalate monohydrate (COM). Citrate, a naturally occurring molecule in the urinary system and a common therapeutic agent for treating stone disease, is a known inhibitor of COM. Understanding the physical mechanisms of citrate inhibition requires quantification of the effects of both background electrolytes and citrate on COM step kinetics. Here we report the results of an in situ AFM study of these effects, in which we measure the effect of the electrolytes LiCl, NaCl, KCl, RbCl, and CsCl, and the dependence of step speed on citrate concentration for a range of COM supersaturations. We find that varying the background electrolyte results in significant differences in the measured step speeds and in step morphology, with KCl clearly producing the smallest impact and NaCl the largest. The kinetic coefficient for the former is nearly three times larger than for the latter, while the steps change from smooth to highly serrated when KCl is changed to NaCl. The results on the dependence of step speed on citrate concentration show that citrate produces a dead zone whose width increases with citrate concentration as well as a continual reduction in kinetic coefficient with increasing citrate level. We relate these results to a molecular-scale view of inhibition that invokes a combination of kink blocking and step pinning. Furthermore, we demonstrate that the classic step-pinning model of Cabrera and Vermilyea (C-V model) does an excellent job of predicting the effect of citrate on COM step kinetics provided the model is reformulated to more realistically account for impurity adsorption, include an expression for the Gibbs-Thomson effect that is correct for all supersaturations

  9. Reinjury risk of nano-calcium oxalate monohydrate and calcium oxalate dihydrate crystals on injured renal epithelial cells: aggravation of crystal adhesion and aggregation

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    Gan QZ

    2016-06-01

    Full Text Available Qiong-Zhi Gan,1,2 Xin-Yuan Sun,1,2 Poonam Bhadja,1,2 Xiu-Qiong Yao,1,2 Jian-Ming Ouyang1,2 1Department of Chemistry, Jinan University, Guangzhou, People’s Republic of China; 2Institute of Biomineralization and Lithiasis Research, Jinan University, Guangzhou, People’s Republic of China Background: Renal epithelial cell injury facilitates crystal adhesion to cell surface and serves as a key step in renal stone formation. However, the effects of cell injury on the adhesion of nano-calcium oxalate crystals and the nano-crystal-induced reinjury risk of injured cells remain unclear.Methods: African green monkey renal epithelial (Vero cells were injured with H2O2 to establish a cell injury model. Cell viability, superoxide dismutase (SOD activity, malonaldehyde (MDA content, propidium iodide staining, hematoxylin–eosin staining, reactive oxygen species production, and mitochondrial membrane potential (ΔΨm were determined to examine cell injury during adhesion. Changes in the surface structure of H2O2-injured cells were assessed through atomic force microscopy. The altered expression of hyaluronan during adhesion was examined through laser scanning confocal microscopy. The adhesion of nano-calcium oxalate monohydrate (COM and calcium oxalate dihydrate (COD crystals to Vero cells was observed through scanning electron microscopy. Nano-COM and COD binding was quantitatively determined through inductively coupled plasma emission spectrometry.Results: The expression of hyaluronan on the cell surface was increased during wound healing because of Vero cell injury. The structure and function of the cell membrane were also altered by cell injury; thus, nano-crystal adhesion occurred. The ability of nano-COM to adhere to the injured Vero cells was higher than that of nano-COD crystals. The cell viability, SOD activity, and ΔΨm decreased when nano-crystals attached to the cell surface. By contrast, the MDA content, reactive oxygen species production

  10. Herbal extracts of Tribulus terrestris and Bergenia ligulata inhibit growth of calcium oxalate monohydrate crystals in vitro

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    Joshi, V. S.; Parekh, B. B.; Joshi, M. J.; Vaidya, A. B.

    2005-02-01

    A large number of people in this world are suffering from urinary stone problem. Calcium oxalate monohydrate (COM) and calcium oxalate dihydrate (COD) containing stones (calculi) are commonly found. In the present study, COM crystals were grown by a double diffusion gel growth technique using U-tubes. The gel was prepared from hydrated sodium metasilicate solution. The gel framework acts like a three-dimensional crucible in which the crystal nuclei are delicately held in the position of their formation, and nutrients are supplied for the growth. This technique can be utilized as a simplified screening static model to study the growth, inhibition and dissolution of urinary stones in vitro. The action of putative litholytic medicinal plants, Tribulus terrestris Linn. ( T.t) and Bergenia ligulata Linn. ( B.l.), has been studied in the growth of COM crystals. Tribulus terrestris and Bergenia ligulata are commonly used as herbal medicines for urinary calculi in India. To verify the inhibitive effect, aqueous extracts of Tribulus terrestris and Bergenia ligulata were added along with the supernatant solutions. The growth was measured and compared, with and without the aqueous extracts. Inhibition of COM crystal growth was observed in the herbal extracts. Maximum inhibition was observed in Bergenia ligulata followed by Tribulus terrestris. The results are discussed.

  11. L-Carnitine Protects Renal Tubular Cells Against Calcium Oxalate Monohydrate Crystals Adhesion Through Preventing Cells From Dedifferentiation

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    Shujue Li

    2016-08-01

    Full Text Available Background/Aims: The interactions between calcium oxalate monohydrate (COM crystals and renal tubular epithelial cells are important for renal stone formation but still unclear. This study aimed to investigate changes of epithelial cell phenotype after COM attachment and whether L-carnitine could protect cells against subsequent COM crystals adhesion. Methods: Cultured MDCK cells were employed and E-cadherin and Vimentin were used as markers to estimate the differentiate state. AlexaFluor-488-tagged COM crystals were used in crystals adhesion experiment to distinguish from the previous COM attachment, and adhesive crystals were counted under fluorescence microscope, which were also dissolved and the calcium concentration was assessed by flame atomic absorption spectrophotometry. Results: Dedifferentiated MDCK cells induced by transforming growth factor β1 (TGF-β1 shown higher affinity to COM crystals. After exposure to COM for 48 hours, cell dedifferentiation were observed and more subsequent COM crystals could bind onto, mediated by Akt/GSK-3β/Snail signaling. L-carnitine attenuated this signaling, resulted in inhibition of cell dedifferentiation and reduction of subsequent COM crystals adhesion. Conclusions: COM attachment promotes subsequent COM crystals adhesion, by inducing cell dedifferentiation via Akt/GSK-3β/Snail signaling. L-carnitine partially abolishes cell dedifferentiation and resists COM crystals adhesion. L-carnitine, may be used as a potential therapeutic strategy against recurrence of urolithiasis.

  12. High-throughput platform for design and screening of peptides as inhibitors of calcium oxalate monohydrate crystallization

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    Farmanesh, Sahar; Chung, Jihae; Chandra, Divya; Sosa, Ricardo D.; Karande, Pankaj; Rimer, Jeffrey D.

    2013-06-01

    Crystal growth modifiers present a versatile tool for controlling crystal shape and size. Our work described here focuses on the design and screening of short peptides as inhibitors of calcium oxalate monohydrate (COM) crystals using high-throughput approaches. We designed a small library of 13 peptides containing Ala and Asp amino acids arranged in varying sequences that mimic ubiquitous motifs in natural calcium-binding proteins. Peptides were screened using a quick assay to measure their efficacy for inhibiting COM crystallization. Our results show that subtle variations in the placement of Ala and Asp residues in the peptide sequence can have a profound effect on their inhibition potential. We were able to discover peptide sequences that inhibit COM crystallization more effectively than some of the well-known COM inhibitors, such as citrate. Our results also demonstrate that peptides can be engineered to bind to specific faces of COM crystals. Peptide sequences identified in this work are promising candidates for further development as therapies for biomineral-related diseases, such as kidney stone disease. Collectively, our work establishes new paradigms for the design, synthesis, and screening of peptides for controlling crystal habit with the potential to impact a variety of fields, including drug discovery, advanced materials, catalysis and separations.

  13. Effect of biomolecules from human renal matrix of calcium oxalate monohydrate (CaOx stones on in vitro calcium phosphate crystallization

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    Priyadarshini Pathak

    2010-10-01

    Full Text Available PURPOSE: Investigate the activity of high and low molecular weight biomolecules present in the matrix of human calcium oxalate (CaOx stones not only on the initial mineral phase formation of calcium and phosphate (CaP but also on its growth and demineralization of the preformed mineral phase. MATERIALS AND METHODS: Surgically removed renal stones were analyzed by Fourier Transform Infra Red (FTIR spectroscopy and only CaOx stones were extracted with 0.05M EGTA, 1 mM PMSF and 1% ß-mercaptoethanol. Renal CaOx stone extract was separated into > 10 kDa and 10 kDa and 10 kDa fraction lane. CONCLUSION: Both high and low molecular weight biomolecules extracted from human renal matrix of calcium oxalate (CaOx stones have a significant influence on calcium and phosphate (CaP crystallization.

  14. Surface aggregation of urinary proteins and aspartic acid-rich peptides on the faces of calcium oxalate monohydrate investigated by in situ force microscopy

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    Weaver, M L; Qiu, S R; Hoyer, J R; Casey, W H; Nancollas, G H; De Yoreo, J J

    2008-05-28

    The growth of calcium oxalate monohydrate in the presence of Tamm-Horsfall protein (THP), osteopontin (OPN), and the 27-residue synthetic peptides (DDDS){sub 6}DDD and (DDDG){sub 6}DDD [where D = aspartic acid and X = S (serine) or G (glycine)] was investigated via in situ atomic force microscopy (AFM). The results show that these three growth modulators create extensive deposits on the crystal faces. Depending on the modulator and crystal face, these deposits can occur as discrete aggregates, filamentary structures, or uniform coatings. These proteinaceous films can lead to either the inhibition or increase of the step speeds (with respect to the impurity-free system) depending on a range of factors that include peptide or protein concentration, supersaturation and ionic strength. While THP and the linear peptides act, respectively, to exclusively increase and inhibit growth on the (-101) face, both exhibit dual functionality on the (010) face, inhibiting growth at low supersaturation or high modulator concentration and accelerating growth at high supersaturation or low modulator concentration. Based on analyses of growth morphologies and dependencies of step speeds on supersaturation and protein or peptide concentration, we argue for a picture of growth modulation that accounts for the observations in terms of the strength of binding to the surfaces and steps and the interplay of electrostatic and solvent-induced forces at crystal surface.

  15. Internalization of Calcium Oxalate Calculi Developed in Narrow Cavities

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    Fèlix Grases

    2014-03-01

    Full Text Available We describe the case of a patient with calcium oxalate monohydrate and calcium oxalate dihydrate calculi occluded in cavities. All those calculi were located inside narrow cavities covered with a thin epithelium that permits their visualization. Urinary biochemical analysis showed high calciuria, not hypercalciuria, hypocitraturia, and a ratio [calcium]/[citrate] >0.33. The existence of cavities of very low urodynamic efficacy was decisive in the formation of such calculi. It is important to emphasize that we observed a thin epithelium covering such cavities, demonstrating that this epithelium may be formed after the development of the calculi through a re-epithelialization process.

  16. Aggregation of Calcium Phosphate and Oxalate Phases in the Formation of Renal Stones

    OpenAIRE

    2014-01-01

    The majority of human kidney stones are comprised of multiple calcium oxalate monohydrate (COM) crystals encasing a calcium phosphate nucleus. The physiochemical mechanism of nephrolithiasis has not been well determined on the molecular level; this is crucial to the control and prevention of renal stone formation. This work investigates the role of phosphate ions on the formation of calcium oxalate stones; recent work has identified amorphous calcium phosphate (ACP) as a rapidly forming initi...

  17. Simulation of calcium oxalate stone in vitro

    Institute of Scientific and Technical Information of China (English)

    欧阳健明; 姚秀琼; 苏泽轩; 崔福斋

    2003-01-01

    Crystallization of calcium oxalate is studied mainly in the diluted healthy urine using scanning electron microscopy (SEM), and is compared with the crystallization in the diluted pathological urine. It suggests that the average sizes of calcium oxalate crystals are not in direct proportion to the concentrations of Ca2+ and Ox2- ions. Only in the concentration range of 0.60-0.90 mmol/L can larger size of CaOx crystals appear. When the concentrations of Ca2+ and Ox2- ions are 1.20, 0.80, 0.60, 0.30 and 0.15 mmol/L in the healthy urine, the average sizes of calcium oxalate crystallites are 9.5 × 6.5, 20.0 × 13.5 and 15.0 μm × 10.0 μm, respectively, for the former three samples after 6 d crystallization. No crystal appears even after 30 d crystallization for the samples of concentrations of 0.30 and 0.15 mmol/L due to their low supersaturations. The results theoretically explain why the probability of stone forming is clinically not in direct proportion to the concentrations of Ca 2+ and Ox2- ions. Laser scattering technology also confirms this point. The reason why healthy human has no risk of urinary stone but stone-formers have is that there are more urinary macromolecules in healthy human urines than that in stone-forming urines. These macromolecules may control the transformation in CaOx crystal structure from monohydrate calcium oxalate (COM) to dihydrate calcium oxalate (COD). COD has a weaker affinity for renal tubule cell membranes than COM. No remarkable effect of the crystallization time is observed on the crystal morphology of CaOx. All the crystals are obtuse hexagon. However, the sizes and the number of CaOx crystals can be affected by the crystallization time. In the early stage of crystallization (1-6 d), the sizes of CaOx crystals increase and the number of crystal particles changes little as increasing the crystallization time due to growth control. In the middle and late stages (6-30 d), the number of crystals increases markedly while the

  18. Inhibition of the Crystal Growth and Aggregation of Calcium Oxalate by Algae Sulfated Polysaccharide In-vitro

    Institute of Scientific and Technical Information of China (English)

    Xiu Mei WU; Jian Ming OUYANG; Sui Ping DENG; Ying Zhou CEN

    2006-01-01

    The influence of sulfated polysaccharide (SPS) isolated from marine algae Sargassum fusiforme on the morphology and phase compositions of urinary crystal calcium oxalate was investigated in vitro by means of scanning electron microscopy and X-ray diffraction. SPS maybe is a potential inhibitor to CaOxa urinary stones by inhibiting the growth of calcium oxalate monohydrate (COM), preventing the aggregation of COM, and inducing the formation of calcium oxalate dihydrate (COD) crystals.

  19. 肾上皮细胞损伤使草酸钙晶体黏附增强的分子机制%Molecular Mechanism of Adhesion of Monohydrate and Dihydrate Calcium Oxalate Crystals on Injured Kidney Epithelial Cells

    Institute of Scientific and Technical Information of China (English)

    甘琼枝; 孙新园; 姚秀琼; 欧阳健明

    2016-01-01

    研究了非洲绿猴肾上皮细胞( Vero)在损伤前后与一水合草酸钙( COM)和二水合草酸钙( COD)晶体的黏附作用及其引起的细胞反应,探讨了肾结石形成机理。 COM和COD晶体与损伤细胞的黏附加重了细胞的过氧化损伤程度,导致损伤细胞的活力进一步降低,乳酸脱氢酶( LDH)释放量和活性氧( ROS)进一步增加,坏死细胞数量进一步增多,细胞体积缩小,并出现凋亡小体。 COM晶体对细胞的损伤能力显著大于COD晶体。扫描电子显微镜( SEM)观测结果表明,损伤组Vero与COM微晶的黏附作用显著强于对照组,且能促进COM微晶的聚集。共聚焦显微镜观测结果表明, Vero损伤后,其表面表达的晶体黏附分子透明质酸( HA)显著增加, HA分子是促进微晶黏附的重要原因。细胞表面草酸钙的黏附量和晶体聚集程度与细胞的损伤程度成正相关。本文结果从分子和细胞水平上提示,细胞损伤是导致草酸钙肾结石形成的重要因素。%Effects of cell injury on calcium oxalate monohydrate( COM) and calcium oxalate dihydrate( COD) microcrystalline adhesion and cellular response of calcium oxalate microcrystalline on African green monkey renal epithelial( Vero) cells after adhesion were evaluated. COM amd COD crystal adhesion to injured Vero cells increased oxidative damage degree, the LDH release amount, reactive oxygen species( ROS) and dead cells and decreased cell viability. The cells shrinked and apoptotic bodies appeared. COM crystals caused more serious damage to injured Vero cells than COD crystals. The results of scanning electron microscopy ( SEM) showed that the adhesive capacity of injured Vero cells to COM was significantly stronger than the con-trol group, which enhanced crystals adhesion and aggregation. Laser scanning confocal microscope showed that Vero cell injury increased the expression of crystal binding hyaluronic acid ( HA ) molecules which were

  20. Interactions in Calcium Oxalate Hydrate/Surfactant Systems.

    Science.gov (United States)

    Sikiric; Filipovic-Vincekovic; Babic-Ivancić Vdović Füredi-Milhofer

    1999-04-15

    Phase transformation of calcium oxalate dihydrate (COD) into the thermodynamically stable monohydrate (COM) in anionic (sodium dodecyl sulfate (SDS)) and cationic (dodecylammonium chloride) surfactant solutions has been studied. Both surfactants inhibit, but do not stop transformation from COD to COM due to their preferential adsorption at different crystal faces. SDS acts as a stronger transformation inhibitor. The general shape of adsorption isotherms of both surfactants at the solid/liquid interface is of two-plateau-type, but differences in the adsorption behavior exist. They originate from different ionic and molecular structures of crystal surfaces and interactions between surfactant headgroups and solid surface. Copyright 1999 Academic Press.

  1. A study about some phosphate derivatives as inhibitors of calcium oxalate crystal growth

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    Grases, F.; March, P.

    1989-08-01

    The kinetic of crystal growth of calcium oxalate monohydrate seed crystals were investigated potentiometrically in the presence of several phosphate derivatives, D-fructose-1,6-diphosphate, pyrophosphate, methylene diphosphonate and phytate, and it was found that in some cases they strongly inhibited crystal growth. The inhibitory action of the different substances assayed was comparatively evaluated.

  2. Characterization of calcium oxalate biominerals in some (non-Cactaceae) succulent plant species.

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    Monje, Paula V; Baran, Enrique J

    2010-01-01

    The water-accumulating leaves of crassulacean acid metabolism plants belonging to five different families were investigated for the presence of biominerals by infrared spectroscopic and microscopic analyses. Spectroscopic results revealed that the mineral present in succulent species of Agavaceae, Aizoaceae, and Asphodelaceae was calcium oxalate monohydrate (whewellite, CaC2O4 x H2O). Crystals were predominantly found as raphides or solitary crystals of various morphologies. However, representative Crassulaceae members and a succulent species of Asteraceae did not show the presence of biominerals. Overall, these results suggest no correlation between calcium oxalate generation and crassulacean acid metabolism in succulent plants.

  3. Nanoscale observations of the effect of citrate on calcium oxalate precipitation on calcite surfaces.

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    Burgos-Cara, Alejandro; Ruiz-Agudo, Encarnacion; Putnis, Christine V.

    2016-04-01

    Calcium oxalate (CaC2O4ṡxH2O) minerals are naturally occurring minerals found in fossils, plants, kidney stones and is a by-product in some processes such as paper, food and beverage production [1,2]. In particular, calcium oxalate monohydrate phase (COM) also known as whewellite (CaC2O4ṡH2O), is the most frequently reported mineral phase found in urinary and kidney stones together with phosphates. Organic additives are well known to play a key role in the formation of minerals in both biotic and abiotic systems, either facilitating their precipitation or hindering it. In this regard, recent studies have provided direct evidence demonstrating that citrate species could enhance dissolution of COM and inhibit their precipitation. [3,4] The present work aims at evauate the influence of pH, citrate and oxalic acid concentrations in calcium oxalate precipitation on calcite surfaces (Island Spar, Chihuahua, Mexico) through in-situ nanoscale observation using in situ atomic force microscopy (AFM, Multimode, Bruker) in flow-through experiments. Changes in calcium oxalate morphologies and precipitated phases were observed, as well as the inhibitory effect of citrate on calcium oxalate precipitation, which also lead to stabilization an the amorphous calcium oxalate phase. [1] K.D. Demadis, M. Öner, Inhibitory effects of "green"additives on the crystal growth of sparingly soluble salts, in: J.T. Pearlman (Ed.), Green Chemistry Research Trends, Nova Science Publishers Inc., New York, 2009, pp. 265-287. [2] M. Masár, M. Zuborová, D. Kaniansky, B. Stanislawski, Determination of oxalate in beer by zone electrophoresis on a chip with conductivity detection, J. Sep. Sci. 26 (2003) 647-652. [3] Chutipongtanate S, Chaiyarit S, Thongboonkerd V. Citrate, not phosphate, can dissolve calcium oxalate monohydrate crystals and detach these crystals from renal tubular cells. Eur J Pharmacol 2012;689:219-25. [4] Weaver ML, Qiu SR, Hoyer JR, Casey WH, Nancollas GH, De Yoreo JJ

  4. Influence of essential and non-essential amino acids on calcium oxalate crystallization

    Energy Technology Data Exchange (ETDEWEB)

    Sargut, S.T.; Sayan, P.; Kiran, B. [Marmara University, Faculty of Engineering, Department of Chemical Engineering, 34722 Istanbul (Turkey)

    2010-01-15

    The investigation on the mechanism of nucleation and growth of crystals at organic-inorganic interfaces is crucial for understanding biological and physiological calcification processes such as the formation of urinary stones. The effects of five different amino acids on the crystallization of calcium oxalate have been investigated at pH 4.5 and 37 C in aqueous solutions in the batch type crystallizer. The products were characterized by Scanning Electron Microscopy (SEM), Fourier Transfer Infrared Spectroscopy (FT/IR) and X-Ray diffraction (XRD) analysis. Crystal size distribution (CSD) and filtration rate measurements were done. In order to determine the adsorption characteristics of amino acids on the calcium oxalate crystal surfaces, zeta potential measurements were also done and discussed. The results indicate that in the presence of all investigated amino acids, calcium oxalate monohydrate (COM) crystals were preferentially produced, but the crystal morphology varied with amino acid types and concentrations. Various crystal morphologies such as elongated hexagonal, coffin or platy habits were observed. In the presence of all investigated amino acids, the calcium oxalate crystallized in a monohydrate form. Electrostatic/ionic interaction, different adsorption properties and special functional effects of amino acids led to find different crystal morphology. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  5. Raman spectroscopy study of calcium oxalate extracted from cacti stems.

    Science.gov (United States)

    Frausto-Reyes, Claudio; Loza-Cornejo, Sofia; Terrazas, Teresa; Terrazas, Tania; Miranda-Beltrán, María de la Luz; Aparicio-Fernández, Xóchitl; López-Macías, Brenda M; Morales-Martínez, Sandra E; Ortiz-Morales, Martín

    2014-01-01

    To find markers that distinguish the different Cactaceae species, by using near infrared Raman spectroscopy and scanning electron microscopy, we studied the occurrence, in the stem, of solid deposits in five Cactaceae species (Coryphantha clavata, Ferocactus latispinus, Opuntia ficus-indica, O. robusta, and O. strepthacantha) collected from their natural habitats from a region of México. The deposits in the tissues usually occurred as spheroidal aggregates, druses, or prismatic crystals. From the Raman spectra, the crystals were identified either as calcium oxalate monohydrate (CaC2O4·H2O) or calcium oxalate dihydrate (CaC2O4·2H2O). Opuntia species (subfamily Opuntioideae) showed the presence of CaC2O4·H2O, and the deposition of CaC2O4·2H2O was present in C. clavata and F. latispinus (subfamily Cactoideae, Cacteae tribe). As a punctual technique, Raman spectroscopy seems to be a useful tool to identify crystal composition. In addition to allowing the analysis of crystal morphology, this spectroscopic technique can be used to identify Cactaceae species and their chemotaxonomy.

  6. Mediation of calcium oxalate crystal growth on human kidney epithelial cells with different degrees of injury

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Shen [Graduate School of Southern Medical University, Guangzhou 510515 (China); Institute of Biomineralization and Lithiasis Research, Jinan University, Guangzhou 510632 (China); Su Zexuan, E-mail: suz2008@126.com [The First Affiliated Hospital, Jinan University, Guangzhou 510632 (China); Yao Xiuqiong; Peng Hua; Deng Suiping [Institute of Biomineralization and Lithiasis Research, Jinan University, Guangzhou 510632 (China); Ouyang Jianming, E-mail: toyjm@jnu.edu.cn [Institute of Biomineralization and Lithiasis Research, Jinan University, Guangzhou 510632 (China)

    2012-05-01

    The current study examined the role of injured human kidney tubular epithelial cell (HKC) in the mediation of formation of calcium oxalate (CaOxa) crystals by means of scanning electronic microscopy and X-ray diffraction. HKC was injured using different concentrations of H{sub 2}O{sub 2}. Cell injury resulted in a significant decrease in cell viability and superoxide dismutase (SOD) concentration and an increase in the level of malondialdehyde (MDA) and expression of osteopontin (OPN). Injured cells not only promote nucleation and aggregation of CaOxa crystals, but also induce the formation of calcium oxalate monohydrate (COM) crystals that strongly adhere to cells. These results imply that injured HKCs promote stone formation by providing more nucleating sites for crystals, promoting the aggregation of crystals, and inducing the formation of COM crystals. - Graphical abstract: Injured cells promote nucleation and aggregation of CaOxa crystals, induce the formation of calcium oxalate monohydrate (COM) crystals. Highlights: Black-Right-Pointing-Pointer A direct nucleation and growth of CaOxa crystals on both normal and injured cells. Black-Right-Pointing-Pointer Stronger green fluorescence, i.e. OPN expression, was seen on the injury cell surface Black-Right-Pointing-Pointer Injured cells promote nucleation and aggregation of CaOxa crystals. Black-Right-Pointing-Pointer Injured cells induce the formation of calcium oxalate monohydrate crystals. Black-Right-Pointing-Pointer H{sub 2}O{sub 2} decrease cell viability in a dose-dependent manner at 0.1-1 mmol/L.

  7. Effects of temperature and sodium carboxylate additives on mineralization of calcium oxalate in silica gel systems

    Institute of Scientific and Technical Information of China (English)

    OUYANG; Jianming; DENG; Suiping; LI; Xiangping; TAN; Yanh

    2004-01-01

    [1]Ouyang, J. M., Yao, X. Q., Su, Z. X. et al., Simulation of calcium oxalate stone in Vitro, Science in China, Ser. B, 2003, 46(3):234-242.[2]Xu, S. H., Chen, J. Q., Zhou, H., Nepidemiological study of renal calculus in Shenshen region, Chin. J. Urol. (in Chinese), 1999,20(11): 655-657.[3]Bretherton, T., Rodgers, A., Crystallization of calcium oxalate in minimally diluted urine, J. Crystal Growth, 1998, 192: 448-455.[4]Grover, P. K., Ryall, R. L., Effect of seed crystals of uric acid and monosodium urate on the crystallization of CaOxa in undiluted human urine in vitro, Clin. Sci., 1997, 92: 205-213.[5]Laube, N., Mohr, B., Hesse, A., Laser-probe-based investigation of the evolution of particle size distributions of calcium oxalate particles formed in artificial urines, J. Crystal Growth, 2001, 233:367-374.[6]Tunik, L., Fueredi-Milhofer, H., Garti, N., Adsorption of sodium diisooctyl sulfosuccinate onto calcium oxalate crystals, Langmuir,1998, 14: 3351-3355.[7]Cody, A. M., Cody, R. D., Calcium oxalate trihydrate phase control by structurally-specific carboxylic acids, J. Cryst. Growth,1994, 135: 234-245.[8]Ouyang, J. M., Duan, L., Tieke, B., Effects of carboxylic acids on the crystal growth of calcium oxalate nanoparticles in lecithin-water liposome systems, Langmuir, 2003, 19: 8980-8985.[9]Guo, S., Ward, M. D., Wesson, J. A., Direct visualization of calcium oxalate monohydrate crystallization and dissolution with atomic force microscopy and the role of polymeric additives,Langmuir, 2002, 18:4284-4291.[10]Yasui, T., Sato, M., Fujita, K., Effects of citrate on renal stone formation and osteopontin expression in a rat urolithiasis model,Urol. Res., 2001,29: 50-56.[11]Ouyang, J. M., Deng, S. P., Controlled and uncontrolled crystallization of calcium oxalate monohydrate in the presence of citric acid, Dalton Transactions, 2003, (14): 2846-2851.[12]Khan, S. R., Whalen, P. O., Glenton, P. A., Heterogeneous nucleation of

  8. Electron imaging of calcium oxalate crystals in beagle dogs’ urine

    Directory of Open Access Journals (Sweden)

    Walaa I. Mohamaden

    2014-06-01

    Full Text Available Calcium oxalate crystalluria appears to be a common problem in most of small animal clinics. This current study aimed at inducing a condition of oxalate crystalluria in beagles and record the primary changes in canine blood and urine on response to oxalates injection. 15 dogs were divided into two groups; those in the treatment group were injected intravenously with 0.5 M potassium oxalate and the dogs of control group were injected with physiological saline for five successive days. Urine test revealed a significant decrease in urinary creatinine and urinary urea nitrogen levels. The ultrastructural examination of urine sediment showed typical and atypical phases of calcium oxalate crystals and the X-ray defractionation of these crystals showed high content of calcium in addition to other minerals. Therefore potassium oxalate injection may provide an example of calcium oxalate crystalluria which may answer some question around the pathogenesis of this problem in dogs.

  9. Calcium Oxalate Accumulation in Malpighian Tubules of Silkworm (Bombyx mori)

    Science.gov (United States)

    Wyman, Aaron J.; Webb, Mary Alice

    2007-04-01

    Silkworm provides an ideal model system for study of calcium oxalate crystallization in kidney-like organs, called Malpighian tubules. During their growth and development, silkworm larvae accumulate massive amounts of calcium oxalate crystals in their Malpighian tubules with no apparent harm to the organism. This manuscript reports studies of crystal structure in the tubules along with analyses identifying molecular constituents of tubule exudate.

  10. Spectroscopic study of the inhibition of calcium oxalate calculi by Larrea tridentata

    Science.gov (United States)

    Pinales, Luis Alonso

    The causes of urolithiasis include such influences as diet, metabolic disorders, and genetic factors which have been documented as sources that aggravate urinary calculi depositions and aggregations, and, implicitly, as causes of urolithiasis. This study endeavors to detail the scientific mechanisms involved in calcium oxalate calculi formation, and, more importantly, their inhibition under growth conditions imposed by the traditional medicinal approach using the herbal extract, Larrea tridentata. The calculi were synthesized without and with Larrea tridentata infusion by employing the single diffusion gel technique. A visible decrease in calcium oxalate crystal growth with increasing amounts of Larrea tridentata herbal infusion was observed in photomicrographs, as well as a color change from white-transparent for pure crystals to light orange-brown for crystals with inhibitor. Analysis of the samples, which includes Raman, infrared absorption, scanning electron microscopy (SEM), and X-ray powder diffraction (XRD) techniques, demonstrate an overall transition in morphology of the crystals from monohydrate without herbal extract to dihydrate with inhibitor. Furthermore, the resulting data from Raman and infrared absorption support the possibilities of the influences, in this complex process, of NDGA and its derivative compounds from Larrea tridentata, and of the bonding of the magnesium of the inhibitor with the oxalate ion on the surface of the calculi crystals. This assumption corroborates well with the micrographs obtained under higher magnification, which show that the separated small crystallites consist of darker brownish cores, which we attribute to the dominance of growth inhibition by NDGA, surrounded by light transparent thin shells, which possibly correspond to passivation of the crystals by magnesium oxalate. The SEM results reveal the transformation from the dominant monoclinic structure of the calcium oxalate crystals grown alone to the tetragonal

  11. Studying inhibition of calcium oxalate stone formation: an in vitro approach for screening hydrogen sulfide and its metabolites

    Directory of Open Access Journals (Sweden)

    S. Vaitheeswari

    2015-06-01

    Full Text Available ABSTRACTPurpose:Calcium oxalate urolithiasis is one of the most common urinary tract diseases and is of high prevalence. The present study proposes to evaluate the antilithiatic property of hydrogen sulfide and its metabolites like thiosulfate & sulfate in an in vitro model.Materials and Methods:The antilithiatic activity of sodium hydrogen sulfide (NaSH, sodium thiosulfate (Na2S2O3 and sodium sulfate (Na2SO4 on the kinetics of calcium oxalate crystal formation was investigated both in physiological buffer and in urine from normal and recurrent stone forming volunteers. The stones were characterized by optical and spectroscopic techniques.Results:The stones were characterized to be monoclinic, prismatic and bipyramidal habit which is of calcium monohydrate and dihydrate nature. The FTIR displayed fingerprint corresponding to calcium oxalate in the control while in NaSH treated, S=O vibrations were visible in the spectrum. The order of percentage inhibition was NaSH>Na2S2O3>Na2SO4.Conclusion:Our study indicates that sodium hydrogen sulfide and its metabolite thiosulfate are inhibitors of calcium oxalate stone agglomeration which makes them unstable both in physiological buffer and in urine. This effect is attributed to pH changes and complexing of calcium by S2O32-and SO42- moiety produced by the test compounds.

  12. Urinary supersaturation with respect to brushite in patients suffering calcium oxalate lithiasis.

    Science.gov (United States)

    Berland, Y; Boistelle, R; Olmer, M

    1990-01-01

    The urines of 23 stone-formers presenting repeated calcium oxalate lithiasis and 12 control subjects were collected at six different time periods daily. Supersaturations for calcium oxalate and brushite (DCPD) were calculated using ionic and solubility products. Urines of both groups were supersaturated for calcium oxalate but only urines of the stone-formers were supersaturated for brushite, the most simple calcium phosphate which nucleates very easily at the urinary pH. This fact suggests that the core of the calcium oxalate stone could be made of either a calcium oxalate crystallite or a brushite seed onto which hetergeneous nucleation of calcium oxalate can take place.

  13. Induction of Ring-Shaped Calcium Oxalate Patterns by Boundaries between Liquid Expanded Phase and Liquid Condensed Phase in Langmuir-Blodgett Film

    Institute of Scientific and Technical Information of China (English)

    WAN Mu-Hua; ZHANG Sheng; ZHENG Hui; OUYANG Jian-Ming

    2008-01-01

    The formation of calcium oxalate kidney stones was related to injuries of renal epithelial membranes.The liquid condensed(LC)domains in Langmuir-Blodgett(LB)film of dipalmitoylphosphatidylcholine(DPPC)were used as a model system to induce crystal growth of urinary mineral calcium oxalate monohydrate(COM).The circular defective boundaries between the LC and liquid expanded(LE)phases of the DPPC monolayer could provide much more nucleating sites for crystallization of COM crystals.It induced ring-shaped or solid circular patterns of COM crystals on hydrophobic quartz substrates depending on the crystallization time.

  14. Dual roles of brushite crystals in calcium oxalate crystallization provide physicochemical mechanisms underlying renal stone formation.

    Science.gov (United States)

    Tang, R; Nancollas, G H; Giocondi, J L; Hoyer, J R; Orme, C A

    2006-07-01

    Calcium oxalate monohydrate (COM) crystals are the major mineral component of most kidney stones, and thus have an important role in chronic human disease. However, the physicochemical mechanisms leading to calcium oxalate (CaOx) stone disease are only partially defined. As spontaneous precipitation of CaOx is rare under renal conditions, an alternative pathway for CaOx crystallization seems necessary to resolve this central issue. We performed kinetic studies using the dual constant composition method to simultaneously analyze the crystallization of COM and brushite, the form of calcium phosphate that is most readily formed in the typical slightly acidic urinary milieu. These studies were supported by parallel analysis by scanning electron and atomic force microscopy. In these studies, mineralization of a thermodynamically stable phase (COM) was induced by the presence of brushite, a more readily precipitated inorganic phase. Furthermore, once formed, the COM crystals grew at the expense of brushite crystals causing the dissolution of the brushite crystals. These studies show that brushite may play crucial roles in the formation of COM crystals. The definition of these two roles for brushite thereby provides physicochemical explanations for the initiation of COM crystallization and also for the relative paucity of calcium phosphate detected in the majority of CaOx renal stones.

  15. Drug dosage protocol for calcium oxalate stone.

    Science.gov (United States)

    Marickar, Y M Fazil; Salim, Abiya

    2009-12-01

    In earlier studies, we have confirmed that in most patients with calcium oxalate stone formation, a combination of allopurinol and pyridoxine is best suited for treatment and prevention of the stone forming process. The objective of this study is to identify the most effective directed medical treatment of urinary stones. The drug dose adjustment was based on clinical, radiological, biochemical, and microscopic parameters. 444 patients with proved calcium oxalate stone disease who were getting a combination of allopurinol and pyridoxine for a minimum period of 36 months were enrolled in this prospective study. The dosage schedule of these patients was recorded. Dosage adjustment was made depending upon the various clinical, biochemical, microscopic, and radiological changes during the study period. The dosage schedules were in six categories, namely very high dose chemotherapy (VHDC), i.e. allopurinol 600 mg/day and pyridoxine 240 mg/day, high-dose chemotherapy (HDC), i.e. allopurinol 300 mg/day and pyridoxine 120 mg/day, moderate dose prophylaxis (MDP), i.e. allopurinol 200 mg/day and pyridoxine 80 mg/day, low-dose prophylaxis (LDP), i.e. allopurinol 100 mg/day and pyridoxine 40 mg/day, and very low-dose prophylaxis (VLDP), i.e. allopurinol 50 mg/day and pyridoxine 20 mg/day and intermittent VLDP, wherein the VLDP was given on alternate months and still later at longer intervals. The temporary risk was assessed at each visit and dosage adjustment was made. The effect of the intervention was assessed during the next visit. All the patients involved in the study needed dose adjustment. The following schedules were initiated: VHDC (12) 3.5%, HDC (103) 23.2%, MDP (78) 17.57%, or LDP (251) 56.53%. Patients who defaulted for more than a month were excluded from the study. During each visit for follow up, all patients were advised change over of dose depending upon the clinical situation at the time of review. Patients on VHDC were advised reduction to lower doses

  16. Crystal growth and morphology of calcium oxalates and carbonates

    NARCIS (Netherlands)

    Heijnen, W.M.M.

    1986-01-01

    The main purpose of the research described in this thesis is to establish a relationship between the crystal structure and morphology of calcium oxalate and calcium carbonate crystals grown from aqueous solutions. Starting point is the PBC (Periodic Bond Chain) theory formulated by Hartman and Perdo

  17. Factors affecting calcium oxalate dihydrate fragmented calculi regrowth

    Directory of Open Access Journals (Sweden)

    Sanchis P

    2006-07-01

    Full Text Available Abstract Background The use of extracorporeal shock wave lithotripsy (ESWL to treat calcium oxalate dihydrate (COD renal calculi gives excellent fragmentation results. However, the retention of post-ESWL fragments within the kidney remains an important health problem. This study examined the effect of various urinary conditions and crystallization inhibitors on the regrowth of spontaneously-passed post-ESWL COD calculi fragments. Methods Post-ESWL COD calculi fragments were incubated in chambers containing synthetic urine varying in pH and calcium concentration: pH = 5.5 normocalciuria (3.75 mM, pH = 5.5 hypercalciuria (6.25 mM, pH = 6.5 normocalciuria (3.75 mM or pH = 6.5 hypercalciuria (6.25 mM. Fragment growth was evaluated by measuring increases in weight. Fragment growth was standardized by calculating the relative mass increase. Results Calcium oxalate monohydrate (COM crystals formed on COD renal calculi fragments under all conditions. Under pH = 5.5 normocalciuria conditions, only COM crystals formed (growth rate = 0.22 ± 0.04 μg/mg·h. Under pH = 5.5 hypercalciuria and under pH = 6.5 normocalciuria conditions, COM crystals and a small number of new COD crystals formed (growth rate = 0.32 ± 0.03 μg/mg·h and 0.35 ± 0.05 μg/mg·h, respectively. Under pH = 6.5 hypercalciuria conditions, large amounts of COD, COM, hydroxyapatite and brushite crystals formed (growth rate = 3.87 ± 0. 34 μg/mg·h. A study of three crystallization inhibitors demonstrated that phytate completely inhibited fragment growth (2.27 μM at pH = 5.5 and 4.55 μM at pH = 6.5, both under hypercalciuria conditions, while 69.0 μM pyrophosphate caused an 87% reduction in mass under pH = 6.5 hypercalciuria conditions. In contrast, 5.29 mM citrate did not inhibit fragment mass increase under pH = 6.5 hypercalciuria conditions. Conclusion The growth rate of COD calculi fragments under pH = 6.5 hypercalciuria conditions was approximately ten times that observed under

  18. The influence of scale inhibitors on calcium oxalate

    Energy Technology Data Exchange (ETDEWEB)

    Gill, J.S. [Calgon Corp., Pittsburgh, PA (United States)

    1999-11-01

    Precipitation of calcium oxalate is a common occurrence in mammalian urinary tract deposits and in various industrial processes such as paper making, brewery fermentation, sugar evaporation, and tannin concentration. Between pH 3.5 to 4.5 the driving force for calcium oxalate precipitation increases almost by three fold. It is a complicated process to predict both the nature of a deposit and at which stage of a multi-effect evaporator a particular mineral will deposit, as this depends on temperature, pH, total solids, and kinetics of mineralization. It is quite a challenge to inhibit calcium oxalate precipitation in the pH range of 4--6. Al{sup 3+} ions provide excellent threshold inhibition in this pH range and can be used to augment traditional inhibitors such as polyphosphates and polycarboxylates.

  19. Circular patterns of calcium oxalate crystals induced by defective Langmuir-Blodgett film

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The injury of the renal epithelial cell membrane can promote the nucleation of nascent crystals, as well as adhesion of crystals on it. It thus accelerates the formation of renal calculi. In this paper, the defective Langmuir-Blodgett(LB)films were used as a model system to simulate the injured renal epithelial cell membrane. The microcosmic structure of the defective LB film and the molecular mechanism of the effect of this film on nucleation, growth, deposited patterns and adhesion of calcium oxalate monohydrate(COM)were investigated. The circular defective domains were formed in dipalmitoylphosphatidylcholine(DPPC)LB film after the film was treated by potassium oxalate. These domains could induce ring-shaped patterns of COM crystals. In comparison, the LB film without pretreatment by potassium oxalate only induced random growth of hexagonal COM crystals. As the crystallization time increased, the size of COM crystals in the patterns increased, the crystal patterns changed from empty circles to solid circles, and the number of the circular patterns with small size(5-20μm)increased. The results would shed light on the molecular mechanism of urolithiasis induced by injury of the renal epithelial membrane at the molecular and supramolecular level.

  20. Circular patterns of calcium oxalate crystals induced by defective Langmuir-Blodgett film

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The injury of the renal epithelial cell membrane can promote the nucleation of nascent crystals, as well as adhesion of crystals on it. It thus accelerates the formation of renal calculi. In this paper, the defective Langmuir-Blodgett (LB) films were used as a model system to simulate the injured renal epithelial cell membrane. The microcosmic structure of the defective LB film and the molecular mechanism of the effect of this film on nucleation, growth, deposited patterns and adhesion of calcium oxalate monohydrate (COM) were investigated. The circular defective domains were formed in dipalmitoylphosphatidylcholine (DPPC) LB film after the film was treated by potassium oxalate. These domains could induce ring-shaped patterns of COM crystals. In comparison, the LB film without pretreatment by potassium oxalate only induced random growth of hexagonal COM crystals. As the crystallization time increased, the size of COM crystals in the patterns increased, the crystal patterns changed from empty circles to solid circles, and the number of the circular patterns with small size (5-20 μm) increased. The results would shed light on the molecular mechanism of urolithiasis induced by injury of the renal epithelial membrane at the molecular and supramolecular level.

  1. Characterization of calcium oxalate biominerals in Pereskia species (Cactaceae).

    Science.gov (United States)

    Monje, Paula V; Baran, Enrique J

    2009-01-01

    Calcium oxalate druses were isolated from the stems and leaves of six Pereskioideae family members and investigated by infrared spectroscopy, showing that in all samples the biomineral was present in the form of whewellite, CaC2O4 x H2O. As Pereskia is thought to represent the "ancestral" condition of the leafless stem-succulent cacti, these results suggest that the biomineralization of calcium oxalate in Cactaceae represents a primitive characteristic of the group and also support a close genetic relationship between Pereskia and Opuntia.

  2. 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

  3. In vitro effect of hydro alcoholic extract of Adiantum capillus-veneris Linn. on calcium oxalate crystallization

    Directory of Open Access Journals (Sweden)

    Ajij Ahmed

    2013-01-01

    Full Text Available Background: Adiantum capillus-veneris Linn. is widely used in the management of urolithiasis in Unani system of medicine. Aim: To evaluate the effect of the hydro alcoholic extract of A. capillus-veneris Linn. on calcium oxalate crystallisation by in vitro study. Materials and Methods: The study includes crystallization, nucleation and aggregation assay. Crystallization was induced by addition of 50 μl of 0.1 M sodium oxalate in whole urine in the absence and the presence of extract at different concentrations (0.50 mg, 0.75 mg and 1 mg. The nucleation and aggregation rates were followed at 620 nm after mixing calcium chloride and sodium oxalate solution and in a buffered solution containing calcium oxalate monohydrate crystals, respectively. The rate was evaluated by comparing the slope of turbidity in the presence of extract with that of control using the spectrophotometer. Crystals in the urine were also analysed by light microscopy. Results and Conclusion: Extract of the test drug inhibited the crystallization in solution; less and smaller particles were observed in the presence of extract. These results were further confirmed in the nucleation assay, though the rate of nucleation was not inhibited but number of crystals was found to be decreased. The test drug also inhibited crystal aggregation. It can be concluded therefore, that the test drug possesses significant antilithiasic activity.

  4. Effects of temperature and sodium carboxylate additives on mineralization of calcium oxalate in silica gel systems

    Institute of Scientific and Technical Information of China (English)

    OUYANG Jianming; DENG Suiping; LI Xiangping; TAN Yanhua; Bernd Tieke

    2004-01-01

    The effects of temperature and multifunctional sodium carboxylate additives on the phase composition and morphology of calcium oxalate (CaOxa) crystals grown in silica gel system were systematically investigated using scanning electron microscopy (SEM), powder X-ray diffraction (XRD), and Fourier-transform infrared spectra (FT-IR). The sodium carboxylates investigated include: monocarboxylate sodium acetate (NaAc), disodium tartrate (Na2tart), trisodium citrate (Na3cit), and the disodium salt of ethylenediaminetetraacetic acid (Na2edta). The temperature range was from 7℃ to 67℃. The crystallization temperature affects the phase compositions, the growth rate, and the morphology of CaOxa. First, the logarithm of the percentage of calcium oxalate dihydrate (COD) formed at a certain temperature (T) is proportional to the reciprocal of temperature (1/T). Second, the weight of CaOxa crystals decreases as decreasing the temperature. At a given temperature, the ability of the sodium carboxylates to induce COD follows the order: Na2edta > Na3cit > Na2tart >> NaAc. Third, the multicarboxylates can decrease the surface area of calcium oxalate monohydrate (COM).It makes the edges and tips of COM crystals blunt and oval. All the three changes, an increase of the content of COD, a decrease of the weight of CaOxa crystals, and a decrease of the surfacearea of COM crystals,can inhibit the formation of CaOxa stones. These results support the clinical use of citrates and may be helpful in elucidating the mechanisms of the formation of CaOxa calculus.

  5. 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.

  6. Effect of Concentration of Structurally-Different Carboxylic Acids on Growth and Aggregation of Calcium Oxalate in Gel Systems

    Institute of Scientific and Technical Information of China (English)

    DENG,Sui-Ping; OUYANG,Jian-Ming

    2007-01-01

    The effect of concentration of structurally-different carboxylic acids such as ethylene diamine tetraacetic acid (H4edta), citric acid (H3cit), tartaric acid (H2tart), and acetic acid (HOAc) on growth and aggregation of calcium oxalate (CaOxa) in gel systems was comparatively investigated. H2tart and H3cit could change the morphology of calcium oxalate monohydrate (COM) and induce the formation of calcium oxalate dihydrate (COD). H4edta could induce the formation of COD at a lower concentration of 0.33 mmol/L and have the strongest ability to inhibit aggregation of COM. HOAc inhibited COM aggregation only at a higher concentration than 500 mmol/L. With increasing the number of carboxylic groups in an acid or increasing the concentration of carboxylic acid, the capacity of this acid to induce COD formation and to inhibit growth and aggregation of COM crystals increased. That is, this capacity followed the order: H4edta>H3cit>H2tart>>HOAc. The result in this work suggested that the presence of H3cit and H2tart in urine played a role in the natural defense against stone formation.

  7. Characterization of calcium oxalates generated as biominerals in cacti.

    Science.gov (United States)

    Monje, Paula V; Baran, Enrique J

    2002-02-01

    The chemical composition and morphology of solid material isolated from various Cactaceae species have been analyzed. All of the tested specimens deposited high-purity calcium oxalate crystals in their succulent modified stems. These deposits occurred most frequently as round-shaped druses that sometimes coexist with abundant crystal sand in the tissue. The biominerals were identified either as CaC(2)O(4).2H(2)O (weddellite) or as CaC(2)O(4).H(2)O (whewellite). Seven different species from the Opuntioideae subfamily showed the presence of whewellite, and an equal number of species from the Cereoideae subfamily showed the deposition of weddellite. The chemical nature of these deposits was assessed by infrared spectroscopy. The crystal morphology of the crystals was visualized by both conventional light and scanning electron microscopy. Weddellite druses were made up of tetragonal crystallites, whereas those from whewellite were most often recognized by their acute points and general star-like shape. These studies clearly demonstrated that members from the main traditional subfamilies of the Cactaceae family could synthesize different chemical forms of calcium oxalate, suggesting a definite but different genetic control. The direct relationship established between a given Cactaceae species and a definite calcium oxalate biomineral seems to be a useful tool for plant identification and chemotaxonomy.

  8. Characterization of Calcium Oxalates Generated as Biominerals in Cacti1

    Science.gov (United States)

    Monje, Paula V.; Baran, Enrique J.

    2002-01-01

    The chemical composition and morphology of solid material isolated from various Cactaceae species have been analyzed. All of the tested specimens deposited high-purity calcium oxalate crystals in their succulent modified stems. These deposits occurred most frequently as round-shaped druses that sometimes coexist with abundant crystal sand in the tissue. The biominerals were identified either as CaC2O4.2H2O (weddellite) or as CaC2O4.H2O (whewellite). Seven different species from the Opuntioideae subfamily showed the presence of whewellite, and an equal number of species from the Cereoideae subfamily showed the deposition of weddellite. The chemical nature of these deposits was assessed by infrared spectroscopy. The crystal morphology of the crystals was visualized by both conventional light and scanning electron microscopy. Weddellite druses were made up of tetragonal crystallites, whereas those from whewellite were most often recognized by their acute points and general star-like shape. These studies clearly demonstrated that members from the main traditional subfamilies of the Cactaceae family could synthesize different chemical forms of calcium oxalate, suggesting a definite but different genetic control. The direct relationship established between a given Cactaceae species and a definite calcium oxalate biomineral seems to be a useful tool for plant identification and chemotaxonomy. PMID:11842173

  9. Calcium oxalate crystals in eucalypt ectomycorrhizae: morphochemical characterization.

    Directory of Open Access Journals (Sweden)

    Victor Satler Pylro

    Full Text Available Ectomycorrhizal fungi are ubiquitous in forest ecosystems, benefitting plants principally by increasing the uptake of water and nutrients such as calcium from the soil. Previous work has demonstrated accumulation of crystallites in eucalypt ectomycorrhizas, but detailed morphological and chemical characterization of these crystals has not been performed. In this work, cross sections of acetic acid-treated and cleared ectomycorrhizal fragments were visualized by polarized light microscopy to evaluate the location of crystals within cortical root cells. Ectomycorrhizal sections were also observed by scanning electron microscopy (SEM coupled with energy dispersive x-ray (EDS microprobe analysis. The predominant forms of crystals were crystal sand (granules and concretions. Calcium, carbon and oxygen were detected by EDS as constituent elements and similar elemental profiles were observed between both crystal morphologies. All analyzed crystalline structures were characterized as calcium oxalate crystals. This is the first report of the stoichiometry and morphology of crystals occurring in eucalypt ectomycorrhizas in tropical soils. The data corroborates the role of ectomycorrhizae in the uptake and accumulation of calcium in the form of calcium oxalate crystals in hybrid eucalypt plants.

  10. In vivo Drosophilia genetic model for calcium oxalate nephrolithiasis.

    Science.gov (United States)

    Hirata, Taku; Cabrero, Pablo; Berkholz, Donald S; Bondeson, Daniel P; Ritman, Erik L; Thompson, James R; Dow, Julian A T; Romero, Michael F

    2012-12-01

    Nephrolithiasis is a major public health problem with a complex and varied etiology. Most stones are composed of calcium oxalate (CaOx), with dietary excess a risk factor. Because of complexity of mammalian system, the details of stone formation remain to be understood. Here we have developed a nephrolithiasis model using the genetic model Drosophila melanogaster, which has a simple, transparent kidney tubule. Drosophilia reliably develops CaOx stones upon dietary oxalate supplementation, and the nucleation and growth of microliths can be viewed in real time. The Slc26 anion transporter dPrestin (Slc26a5/6) is strongly expressed in Drosophilia kidney, and biophysical analysis shows that it is a potent oxalate transporter. When dPrestin is knocked down by RNAi in fly kidney, formation of microliths is reduced, identifying dPrestin as a key player in oxalate excretion. CaOx stone formation is an ancient conserved process across >400 My of divergent evolution (fly and human), and from this study we can conclude that the fly is a good genetic model of nephrolithiasis.

  11. Effect of calcium intake on urinary oxalate excretion in calcium stone-forming patients

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    Nishiura J.L.

    2002-01-01

    Full Text Available Dietary calcium lowers the risk of nephrolithiasis due to a decreased absorption of dietary oxalate that is bound by intestinal calcium. The aim of the present study was to evaluate oxaluria in normocalciuric and hypercalciuric lithiasic patients under different calcium intake. Fifty patients (26 females and 24 males, 41 ± 10 years old, whose 4-day dietary records revealed a regular low calcium intake (<=500 mg/day, received an oral calcium load (1 g/day for 7 days. A 24-h urine was obtained before and after load and according to the calciuria under both diets, patients were considered as normocalciuric (NC, N = 15, diet-dependent hypercalciuric (DDHC, N = 9 or diet-independent hypercalciuric (DIHC, N = 26. On regular diet, mean oxaluria was 30 ± 14 mg/24 h for all patients. The 7-day calcium load induced a significant decrease in mean oxaluria compared to the regular diet in NC and DIHC (20 ± 12 vs 26 ± 7 and 27 ± 18 vs 32 ± 15 mg/24 h, respectively, P<0.05 but not in DDHC patients (22 ± 10 vs 23 ± 5 mg/24 h. The lack of an oxalate decrease among DDHC patients after the calcium load might have been due to higher calcium absorption under higher calcium supply, with a consequent lower amount of calcium left in the intestine to bind with oxalate. These data suggest that a long-lasting regular calcium consumption <500 mg was not associated with high oxaluria and that a subpopulation of hypercalciuric patients who presented a higher intestinal calcium absorption (DDHC tended to hyperabsorb oxalate as well, so that oxaluria did not change under different calcium intake.

  12. Evaluation of sulfated polysaccharides from the brown seaweed Dictyopteris justii as antioxidant agents and as inhibitors of the formation of calcium oxalate crystals.

    Science.gov (United States)

    Melo, Karoline Rachel Teodosio; Camara, Rafael Barros Gomes; Queiroz, Moacir Fernandes; Vidal, Arthur Anthunes Jacome; Lima, Camila Renata Machado; Melo-Silveira, Raniere Fagundes; Almeida-Lima, Jailma; Rocha, Hugo Alexandre Oliveira

    2013-11-25

    Oxalate crystals and other types of crystals are the cause of urolithiasis, and these are related to oxidative stress. The search for new compounds with antioxidant qualities and inhibitors of these crystal formations is therefore necessary. In this study, we extracted four sulfated polysaccharides, a fucoglucoxyloglucuronan (DJ-0.3v), a heterofucan (DJ-0.4v), and two glucans (DJ-0.5v and DJ-1.2v), from the marine alga Dictyopteris justii. The presence of sulfated polysaccharides was confirmed by chemical analysis and FT-IR. All the sulfated polysaccharides presented antioxidant activity under different conditions in some of the in vitro tests and inhibited the formation of calcium oxalate crystals. Fucan DJ-0.4v was the polysaccharide that showed the best antioxidant activity and was one of the best inhibitors of the crystallization of calcium oxalate. Glucan DJ-0.5v was the second most potent inhibitor of the formation of oxalate crystals, as it stabilized dehydrated oxalate crystals (less aggressive form), preventing them from transforming into monohydrate crystals (more aggressive form). The obtained data lead us to propose that these sulfated polysaccharides are promising agents for use in the treatment of urolithiasis.

  13. Evaluation of Sulfated Polysaccharides from the Brown Seaweed Dictyopteris Justii as Antioxidant Agents and as Inhibitors of the Formation of Calcium Oxalate Crystals

    Directory of Open Access Journals (Sweden)

    Karoline Rachel Teodosio Melo

    2013-11-01

    Full Text Available Oxalate crystals and other types of crystals are the cause of urolithiasis, and these are related to oxidative stress. The search for new compounds with antioxidant qualities and inhibitors of these crystal formations is therefore necessary. In this study, we extracted four sulfated polysaccharides, a fucoglucoxyloglucuronan (DJ-0.3v, a heterofucan (DJ-0.4v, and two glucans (DJ-0.5v and DJ-1.2v, from the marine alga Dictyopteris justii. The presence of sulfated polysaccharides was confirmed by chemical analysis and FT-IR. All the sulfated polysaccharides presented antioxidant activity under different conditions in some of the in vitro tests and inhibited the formation of calcium oxalate crystals. Fucan DJ-0.4v was the polysaccharide that showed the best antioxidant activity and was one of the best inhibitors of the crystallization of calcium oxalate. Glucan DJ-0.5v was the second most potent inhibitor of the formation of oxalate crystals, as it stabilized dehydrated oxalate crystals (less aggressive form, preventing them from transforming into monohydrate crystals (more aggressive form. The obtained data lead us to propose that these sulfated polysaccharides are promising agents for use in the treatment of urolithiasis.

  14. A Comparative Study on Several Models of Experimental Renal Calcium Oxalate Stones Formation in Rats

    Institute of Scientific and Technical Information of China (English)

    LIU Jihong; CAO Zhenggno; ZHANG Zhaohui; ZHOU Siwei; YE Zhangqun

    2007-01-01

    In order to compare the effects of several experimental renal calcium oxalate stones formation models in rats and to find a simple and convenient model with significant effect of calcium oxalate crystals deposition in the kidney, several rat models of renal calcium oxalate stones formation were induced by some crystal-inducing drugs (CID) including ethylene glycol (EG), ammonium chloride (AC), vitamin D3 [1α(OH)VitD3, alfacalcidol], calcium gluconate, ammonium oxalate, gentamicin sulfate, L-hydroxyproline. The rats were fed with drugs given singly or unitedly. At the end of experiment, 24-h urines were collected and the serum creatinine (Cr), blood urea nitrogen (BUN), the extents of calcium oxalate crystal deposition in the renal tissue, urinary calcium and oxalate excretion were measured. The serum Cr levels in the stone-forming groups were significantly higher than those in the control group except for the group EG+L-hydroxyproline, group calcium gluconate and group oxalate. Blood BUN concentration was significantly higher in rats fed with CID than that in control group except for group EG+L-hydroxyproline and group ammonium oxalate plus calcium gluconate. In the group of rats administered with EG plus Vitamin D3, the deposition of calcium oxalate crystal in the renal tissue and urinary calcium excretion were significantly greater than other model groups. The effect of the model induced by EG plus AC was similar to that in the group induced by EG plus Vitamin D3. EG plus Vitamin D3 or EG plus AC could stably and significantly induced the rat model of renal calcium oxalate stones formation.

  15. Renal histopathology and crystal deposits in patients with small bowel resection and calcium oxalate stone disease.

    Science.gov (United States)

    Evan, Andrew P; Lingeman, James E; Worcester, Elaine M; Bledsoe, Sharon B; Sommer, Andre J; Williams, James C; Krambeck, Amy E; Philips, Carrie L; Coe, Fredric L

    2010-08-01

    We present here the anatomy and histopathology of kidneys from 11 patients with renal stones following small bowel resection, including 10 with Crohn's disease and 1 resection in infancy for unknown cause. They presented predominantly with calcium oxalate stones. Risks of formation included hyperoxaluria (urine oxalate excretion greater than 45 mg per day) in half of the cases, and acidic urine of reduced volume. As was found with ileostomy and obesity bypass, inner medullary collecting ducts (IMCDs) contained crystal deposits associated with cell injury, interstitial inflammation, and papillary deformity. Cortical changes included modest glomerular sclerosis, tubular atrophy, and interstitial fibrosis. Randall's plaque (interstitial papillary apatite) was abundant, with calcium oxalate stone overgrowth similar to that seen in ileostomy, idiopathic calcium oxalate stone formers, and primary hyperparathyroidism. Abundant plaque was compatible with the low urine volume and pH. The IMCD deposits all contained apatite, with calcium oxalate present in three cases, similar to findings in patients with obesity bypass but not an ileostomy. The mechanisms for calcium oxalate stone formation in IMCDs include elevated urine and presumably tubule fluid calcium oxalate supersaturation, but a low calcium to oxalate ratio. However, the mechanisms for the presence of IMCD apatite remain unknown.

  16. Promotion on Nucleation and Aggregation of Calcium Oxalate Crystals by Injured African Green Monkey Renal Epithelial Cells

    Institute of Scientific and Technical Information of China (English)

    张燊; 彭花; 姚秀琼; 苏泽轩; 欧阳健明

    2012-01-01

    The purpose of this work was to detect the properties of African green monkey renal epithelial cells (Vero) after oxidative injury and to study the mediation of the injured Vero on aggregation and formation of calcium oxalate crystals. This injury model was induced by 0.15 mmol/L H2O2 according to the pretest evaluation. The results suggested that H2O2 could injure Vero significantly and decrease cell viability in a time-dependent manner for exposure time of 0.5--2 h. After cell injury, the indexes connected with oxidative injury changed. The malondialdehyde (MDA) content and osteopontin (OPN) expression increased, while superoxide dismutase (SOD) level decreased. It resulted in the increase of both the amount of CaOxa crystals and the degree of crystal aggregation on the injured cells. This work indicated that injured cells promoted the formation of calcium oxalate monohydrate (COM) crystals, thus increased the risk of formation of urinary stone.

  17. [Study on inhibitory effect of EGCG on Calcium oxalate nephrolithiasis in rats and its related mechanism].

    Science.gov (United States)

    Zhou, Yong; Wang, Shuo; Tang, Chun-bo

    2015-04-01

    In the study, the inhibitory effect of epigallocatechin gallate (EGCG) on Calcium oxalate nephrolithiasis and its possible mechanism were investigated. The rat Calcium oxalate nephrolithiasis model was induced through the combined oral administration of ethylene glycol and ammonium chloride, which was intervened with EGCG. Rat blood samples were collected to detect blood creatinine (Cr), blood urea nitrogen (BUN) and blood calcium. Rat urine samples were collected to observe and compare 24-hour urine volume, oxalic acid (Ox) and calcium in urine. Renal samples were collected to prepare tissue slices and observe the pathological changes in Calcium oxalate nephrolithiasis. The expression of osteopontin (OPN) in renal tissues was evaluated by Real-time PCR and Western blot. According to the results, compared with normal rats, rats in the nephrolithiasis model showed significant increases in Cr, BUN, urine Calcium, urine Ox and renal OPN expression (P nephrolithiasis, those processed with EGCG revealed remarkable declines in Cr, BUN, urine Calcium and urine Ox (P nephrolithiasis rats showed significant pathological changes in Calcium oxalate calculus. After ECCG treatment, the renal pathological changes and OPN expression attenuated significantly in a concentration-dependent manner. The results showed that EGCG inhibits the formation of calcium oxalate nephrolithiasis in rats and shows a notable protective effect on renal functions.

  18. Oxalate co-precipitation synthesis of calcium zirconate and calcium titanate powders.

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Sanchez, Bernadette A.; Tuttle, Bruce Andrew

    2009-06-01

    Fine powders of calcium zirconate (CaZrO{sub 3}, CZ) and calcium titanate (CaTiO{sub 3}, CT) were synthesized using a nonaqueous oxalate co-precipitation route from Ca(NO{sub 3}){sub 2}{center_dot}4 H{sub 2}O and group(IV) n-butoxides (Ti(OBu{sup n}){sub 4} or Zr(OBu{sup n}){sub 4}). Several reaction conditions and batch sizes (2-35 g) were explored to determine their influence on final particle size, morphology, and phase. Characterization of the as-prepared oxalate precursors, oven dried oxalate precursors (60-90 C), and calcined powders (635-900 C) were analyzed with TGA/DTA, XRD, TEM, and SEM. Densification and sintering studies on pressed CZ pellets at 1375 and 1400 C were also performed. Through the developed oxalate co-precipitation route, densification temperatures for CZ were lowered by 125 C from the 1500 C firing temperature required for conventional mixed oxide powders. Low field electrical tests of the CZ pellets indicated excellent dielectric properties with dielectric constants of {approx}30 and a dissipation factor of 0.0004 were measured at 1 kHz.

  19. Is there a role for pentosan polysulfate in the prevention of calcium oxalate stones?

    Science.gov (United States)

    Jones, Marklyn; Monga, Manoj

    2003-12-01

    The clinical role for pentosan polysulfate (PPS) in the prevention of calcium oxalate urolithiasis is not known. Crystallization and aggregation are important steps in calcium oxalate stone formation, and PPS has been shown to inhibit these steps, both in vitro and in vivo. In addition, PPS has a role in repairing injured urothelium and inhibiting adhesion to epithelial defects. A randomized double-blind placebo-controlled study appears warranted to assess the utility of PPS in the prevention of recurrent calcium oxalate stones.

  20. Modulation of Tartrates with Various Counterions on the Phases of Calcium Oxalate in Gelatinous Systems

    Institute of Scientific and Technical Information of China (English)

    Jian Ming OUYANG; Xiang Ping LI

    2005-01-01

    Effect of various counterions of tartrate on the crystallization of calcium oxalate in gel system was investigated using scanning electron microscopy and X-ray diffraction. Various tartrates with hydrogen (H2tart), sodium (Na2tart), potassium (K2tart), ammonium ((NH4)2tart), and a mixture of sodium and potassium cations (NaKtart) were considered. For H2tart, Na2tart, and (NH4)2tart, calcium oxalate dihydrate (COD) was induced. However, for K2tart and NaKtart,calcium oxalate trihydrate (COT) was obtained.

  1. [Urinary calcium oxalate supersaturation beyond nephrolithiasis. Relationship with tubulointerstitial damage].

    Science.gov (United States)

    Toblli, Jorge E; Angerosa, Margarita; Stella, Inés; Ferder, León; Inserra, Felipe

    2003-01-01

    A number of studies have demonstrated that the urinary ion activity product (IAP) of calcium oxalate (CaOx), as an index of urinary CaOx supersaturation (SS), is higher in renal stone formers than in normal subjects. Besides, the relation between CaOx SS and lithogenesis, crystal CaOx exposition can produce tubular cell as well as renal interstitial lesions. The aim of our study was to evaluate the possible relationship between CaOx SS and tubulointerstitial (TI) damage in an animal model of hyperoxaluria. During four weeks, male Sprague-Dawley rats received: G1 (n = 8) control regular water, and G2 (n = 8) 1% ethylene glycol (ETG) (precursor for oxalates) in drinking water. In order to evaluate urinary CaOx SS, IAP assessed by Tisselius formula was performed. At the end of the study, renal lesions were evaluated by light microscopy and immunohistochemistry. Animals from G2 (ETG) presented higher (p intersticial fibrosis; e) interstitial alpha-smooth muscle actin; f) collagen type III; g) TI TGF beta 1 compared with G1 (control). Rats from G2 (ETG) presented a high correlation between urinary CaOx SS and most of the TI damage parameters evaluated, in especial with interstitial fibrosis. Both, inflammatory infiltrates and urinary CaOx SS were the most significant variables related to interstitial fibrosis. Finally, since hyperoxaluric animals showed higher urinary CaOx SS associated with higher renal TI damage, the results from this study suggest the presence of a tight link between urinary CaOx SS and renal TI damage. Considering these findings we think that urinary CaOx SS control rises in importance beyond nephrolithiasis.

  2. Inhibition of crystallization of calcium oxalate by the extraction of Tamarix gallica L.

    Science.gov (United States)

    Bensatal, Ahmed; Ouahrani, M R

    2008-12-01

    The main objective is to study the inhibitor effect of acid fraction of the extract of Tamarix gallica L on the crystallization of calcium oxalate. The extract of Tamarix gallica L is very rich by acid compounds that are used as an inhibitor of nephrolithiasis (calcium oxalate). Our study of the calcium oxalate crystallization is based on the model of turbidimetry by means of a spectrophotometer. The calcium oxalate formation is induced by the addition of oxalate solutions of sodium and of calcium chloride. The addition of inhibitor with various concentrations enabled us to give information on the percentage of inhibition. The comparison between the turbidimetric slopes with and without inhibitor gives the effectiveness of inhibitor for the acid fraction. By comparing the photographs of with and without inhibitor, we concluded that the extract of Tamarix gallica L acts at the stage of growth. The acid fraction of the extract of Tamarix gallica L gives an activity remarkable in the formation of urinary lithiasis (calcium oxalate); this effectiveness is due to the presence of functions of acid.

  3. Association of Vitamin D Receptor Gene Polymorphisms with Calcium Oxalate Calcul us Disease

    Institute of Scientific and Technical Information of China (English)

    王少刚; 刘继红; 胡少群; 叶章群

    2003-01-01

    To study the relationship between polymorphism of vitamin D receptor (VDR) allele with formation of calcium oxalate calculus and find the predisposing genes of calcium oxalate calculus, we screened out 150 patients who suffered from calcium oxalate calculus. 36 of them had idiopathic hypercalciuria according to analysis of calculus component and assay of urine calcium. The polymorphisms of VDR gene Taq1, Apa1 and Fok1 were detected using PCR-RFLP technique and the correlation were analyzed between the polymorphism and urinary calculus or between the polymorphism and hypercalciuria. The difference in each genotypic frequency of the allele of promoter Fok1 between calculus group and healthy group or between idiopathic hypercalciuria calculus group and health group was significant. The content of 24-h urine calcium of those who had genotype ff was obviously higher than that of those who have other genotypes in the same group. There was no significant difference in the polymorphism of gene Apa1 and Taq1 between each two groups. It is concluded that hypercalciuria and calcium oxalate calculus were related to the polymorphism of VDR gene's promoter Fok1 allele, but it had nothing to do with the polymorphism of gene Apa1 and Taq1. The genotype ff was a candidate heredity marker of calcium calculus disease.

  4. Decreased renal vitamin K-dependent γ-glutamyl carboxylase activity in calcium oxalate calculi patients

    Institute of Scientific and Technical Information of China (English)

    陈俊汇; 刘继红; 章咏裳; 叶章群; 王少刚

    2003-01-01

    Objective To study the activity of vitamin K-dependent γ-glutamyl carboxylase in patients with calcium oxalate (CaOx) urolithiasis compared with healthy individuals and to assess its relationship to the renal calcium oxalate urolithiasis. Methods Renal parenchymas were harvested from urolithic patients and renal tumor patients undergoing nephrectomy. The renal carboxylase activity was evaluated as the radioactivity of [14C] labeled sodium bicarbonate in carboxylic reactions in vitro using β-liquid scintillation counting. Results Significantly reduced activity of renal vitamin K-dependent γ-glutamyl carboxylase was observed in the urolithic group as compared with normal controls (P<0.01). Conclusion It suggests that the reduced carboxylase activity observed in the urolithic patients may play an important role in the course of renal calcium oxalate urolithiasis.

  5. Smad signaling pathway in pathogenesis of kidney injury induced by calcium oxalate stone in rats

    Institute of Scientific and Technical Information of China (English)

    Fan Zhang

    2016-01-01

    Objective:To investigate the involvement of Smad signaling pathway in the pathogenesis of kidney injury induced by calcium oxalate stone in rats to provide a reference for clinical treatment.Methods: Clean SD rats were randomly divided into 3 group, namely the control group, model group and pirfenidone group. Ethylene glycol + αhydroxy vitamin D3 was used as a stone-inducing agent to replicate the renal calcium oxalate stone model. Rats in the pirfenidone group were treated with pirfenidone intragastric administration. The serum Cr, BUN and 24-hour oxalate and calcium in renal tissues were assayed. The expressions of Bax/Bcl2 protein, Caspase3 protein, TGFβ, Smad1, Smad2 and Smad3 proteins were detected by the fluorescent quantitation PCR method.Results:Compared with the rats of the control group, the results showed that the levels of serum BUN, Cr and 24-hour oxalate in rats of the model group were increased greatly,BaxandCaspase3 mRNA also increased while the level ofBcl2 decreased significantly, and the expressions of TGFβ, Smad1, Smad2 and Smad3 proteins increased distinctly as well (P<0.01). These abnormal parameters could be normalized effectively by pirfenidone.Conclusions:Activated TGFβ/Smad signaling pathway is involved in the pathogenesis of kidney injury induced by calcium oxalate stone in rats.

  6. Alpha-enolase on apical surface of renal tubular epithelial cells serves as a calcium oxalate crystal receptor

    Science.gov (United States)

    Fong-Ngern, Kedsarin; Thongboonkerd, Visith

    2016-10-01

    To search for a strategy to prevent kidney stone formation/recurrence, this study addressed the role of α-enolase on apical membrane of renal tubular cells in mediating calcium oxalate monohydrate (COM) crystal adhesion. Its presence on apical membrane and in COM crystal-bound fraction was confirmed by Western blotting and immunofluorescence staining. Pretreating MDCK cells with anti-α-enolase antibody, not isotype-controlled IgG, dramatically reduced cell-crystal adhesion. Immunofluorescence staining also confirmed the direct binding of purified α-enolase to COM crystals at {121} > {100} > {010} crystal faces. Coating COM crystals with urinary proteins diminished the crystal binding capacity to cells and purified α-enolase. Moreover, α-enolase selectively bound to COM, not other crystals. Chemico-protein interactions analysis revealed that α-enolase interacted directly with Ca2+ and Mg2+. Incubating the cells with Mg2+ prior to cell-crystal adhesion assay significantly reduced crystal binding on the cell surface, whereas preincubation with EDTA, a divalent cation chelator, completely abolished Mg2+ effect, indicating that COM and Mg2+ competitively bind to α-enolase. Taken together, we successfully confirmed the role of α-enolase as a COM crystal receptor to mediate COM crystal adhesion at apical membrane of renal tubular cells. It may also serve as a target for stone prevention by blocking cell-crystal adhesion and stone nidus formation.

  7. Leaf calcium oxalate crystal structure and its role in defense against a chewing insect in Medicago truncatula

    Science.gov (United States)

    Crystals of calcium oxalate are common in plants and widely distributed among many plant families. These hard and largely insoluble crystals take on many shapes and sizes depending on the tissue and species. In Medicago truncatula, calcium oxalate crystals are abundant in leaves and accumulate in sh...

  8. Potassium citrate decreases urine calcium excretion in patients with hypocitraturic calcium oxalate nephrolithiasis.

    Science.gov (United States)

    Song, Yan; Hernandez, Natalia; Shoag, Jonathan; Goldfarb, David S; Eisner, Brian H

    2016-04-01

    Two previous studies (nephrolithiasis. The hypothesized mechanisms are (1) a decrease in bone turnover due to systemic alkalinization by the medications; (2) binding of calcium by citrate in the gastrointestinal tract; (3) direct effects on TRPV5 activity in the distal tubule. We performed a retrospective review of patients on potassium citrate therapy to evaluate the effects of this medication on urinary calcium excretion. A retrospective review was performed of a metabolic stone database at a tertiary care academic hospital. Patients were identified with a history of calcium oxalate nephrolithiasis and hypocitraturia who were on potassium citrate therapy for a minimum of 3 months. 24-h urine composition was assessed prior to the initiation of potassium citrate therapy and after 3 months of therapy. Patients received 30-60 mEq potassium citrate by mouth daily. Inclusion criterion was a change in urine potassium of 20 mEq/day or greater, which suggests compliance with potassium citrate therapy. Paired t test was used to compare therapeutic effect. Twenty-two patients were evaluated. Mean age was 58.8 years (SD 14.0), mean BMI was 29.6 kg/m(2) (SD 5.9), and gender prevalence was 36.4% female:63.6% male. Mean pre-treatment 24-h urine values were as follows: citrate 280.0 mg/day, potassium 58.7 mEq/day, calcium 216.0 mg/day, pH 5.87. Potassium citrate therapy was associated with statistically significant changes in each of these parameters-citrate increased to 548.4 mg/day (p < 0.0001), potassium increased to 94.1 mEq/day (p < 0.0001), calcium decreased to 156.5 mg/day (p = 0.04), pH increased to 6.47 (p = 0.001). Urine sodium excretion was not different pre- and post-therapy (175 mEq/day pre-therapy versus 201 mEq/day post-therapy, p = NS). Urinary calcium excretion decreased by a mean of 60 mg/day on potassium citrate therapy-a nearly 30 % decrease in urine calcium excretion. These data lend support to the hypothesis that alkali therapy reduces urine calcium

  9. Simplified estimates of ion-activity products of calcium oxalate and calcium phosphate in mouse urine.

    Science.gov (United States)

    Tiselius, Hans-Göran; Ferraz, Renato Ribeiro Nogueira; Heilberg, Ita Pfeferman

    2012-08-01

    This study aimed at formulating simplified estimates of ion-activity products of calcium oxalate (AP(CaOx)) and calcium phosphate (AP(CaP)) in mouse urineto find the most important determinants in order to limit the analytical work-up. Literature data on mouse urine composition was used to determine the relative effect of each urine variable on the two ion-activity products. AP(CaOx) and AP(CaP) were calculated by iterative approximation with the EQUIL2 computerized program. The most important determinants for AP(CaOx) were calcium, oxalate and citrate and for AP(CaP) calcium, phosphate, citrate, magnesium and pH. Urine concentrations of the variables were used. A simplified estimate of AP(CaOx) (AP(CaOx)-index(MOUSE)) that numerically approximately corresponded to 10(8) × AP(CaOx) was given the following expression:[Formula: see text]For a series of urine samples with various composition the coefficient of correlation between AP(CaOx)-index(MOUSE) and 10(8) × AP(CaOx) was 0.99 (p = 0.00000). A similar estimate of AP(CaP) (AP(CaP)-index(MOUSE)) was formulated so that it approximately would correspond numerically to 10(14) × AP(CaP) taking the following form:[Formula: see text]For a series of variations in urine composition the coefficient of correlation was 0.95 (p = 0.00000). The two approximate estimates shown in this article are simplified expressions of AP(CaOx) and AP(CaP). The intention of these theoretical calculations was not to get methods for accurate information on the saturation levels in urine, but to have mathematical tools useful for rough conclusions on the outcome of different experimental situations in mice. It needs to be emphasized that the accuracy will be negatively influenced if urine variables not included in the formulas differ very much from basic concentrations.

  10. Formation of ring calcium oxalate patterns induced by domains in DPPC Langmuir-Blodgett films

    Institute of Scientific and Technical Information of China (English)

    Yi Ming Liu; Sui Ping Deng; Hui Zheng; Jian Ming Ouyang

    2007-01-01

    The ring patterns of calcium oxalate crystals were induced by domains in Langmuir-Blodgett (LB) films of dipalmitoylpho-sphatidylcholine (DPPC). The result was explained by the defects at the ring boundaries of liquid condensed (LC) and liquid expanded (LE) phases of LB film. These boundaries could provide less free energy and much more nucleating sites for COM crystals.

  11. A Case of Randall's Plugs Associated to Calcium Oxalate Dihydrate Calculi

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    Felix Grases

    2016-07-01

    Full Text Available A case of a patient who developed multiple calcium oxalate dihydrate calculi, some of them connected to intratubular calcifications (Randall's plugs, is presented. Randall's plugs were isolated and studied. The mechanism of Randall's plug development is also suggested.

  12. Comparison of the x-ray attenuation properties of breast calcifications, aluminium, hydroxyapatite and calcium oxalate.

    Science.gov (United States)

    Warren, L M; Mackenzie, A; Dance, D R; Young, K C

    2013-04-07

    Aluminium is often used as a substitute material for calcifications in phantom measurements in mammography. Additionally, calcium oxalate, hydroxyapatite and aluminium are used in simulation studies. This assumes that these materials have similar attenuation properties to calcification, and this assumption is examined in this work. Sliced mastectomy samples containing calcification were imaged at ×5 magnification using a digital specimen cabinet. Images of the individual calcifications were extracted, and the diameter and contrast of each calculated. The thicknesses of aluminium required to achieve the same contrast as each calcification when imaged under the same conditions were calculated using measurements of the contrast of aluminium foils. As hydroxyapatite and calcium oxalate are also used to simulate calcifications, the equivalent aluminium thicknesses of these materials were also calculated using tabulated attenuation coefficients. On average the equivalent aluminium thickness was 0.85 times the calcification diameter. For calcium oxalate and hydroxyapatite, the equivalent aluminium thicknesses were 1.01 and 2.19 times the thickness of these materials respectively. Aluminium and calcium oxalate are suitable substitute materials for calcifications. Hydroxyapatite is much more attenuating than the calcifications and aluminium. Using solid hydroxyapatite as a substitute for calcification of the same size would lead to excessive contrast in the mammographic image.

  13. Elemental Content of Calcium Oxalate Stones from a Canine Model of Urinary Stone Disease.

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    David W Killilea

    Full Text Available One of the most common types of urinary stones formed in humans and some other mammals is composed of calcium oxalate in ordered hydrated crystals. Many studies have reported a range of metals other than calcium in human stones, but few have looked at stones from animal models such as the dog. Therefore, we determined the elemental profile of canine calcium oxalate urinary stones and compared it to reported values from human stones. The content of 19 elements spanning 7-orders of magnitude was quantified in calcium oxalate stones from 53 dogs. The elemental profile of the canine stones was highly overlapping with human stones, indicating similar inorganic composition. Correlation and cluster analysis was then performed on the elemental profile from canine stones to evaluate associations between the elements and test for potential subgrouping based on elemental content. No correlations were observed with the most abundant metal calcium. However, magnesium and sulfur content correlated with the mineral hydration form, while phosphorous and zinc content correlated with the neuter status of the dog. Inter-elemental correlation analysis indicated strong associations between barium, phosphorous, and zinc content. Additionally, cluster analysis revealed subgroups within the stones that were also based primarily on barium, phosphorous, and zinc. These data support the use of the dog as a model to study the effects of trace metal homeostasis in urinary stone disease.

  14. Calcium oxalate crystallization index (COCI): an alternative method for distinguishing nephrolithiasis patients from healthy individuals.

    Science.gov (United States)

    Yang, Bowei; Dissayabutra, Thasinas; Ungjaroenwathana, Wattanachai; Tosukhowong, Piyaratana; Srisa-Art, Monpichar; Supaprom, Thavorn; Insin, Numpon; Boonla, Chanchai

    2014-01-01

    Urinary supersaturation triggers lithogenic crystal formation. We developed an alternative test, designated calcium oxalate crystallization index (COCI), to distinguish nephrolithiasis patients from healthy individuals based on their urinary crystallization capability. The effect of urine volume, oxalate, phosphate, citrate, potassium, and sodium on COCI values was investigated. COCI values were determined in 24-hr urine obtained from nephrolithiasis patients (n=72) and matched healthy controls (n=71). Increases in urine oxalate and phosphate and decreases in urine volume and citrate resulted in significantly increased COCI values. The urinary COCI in nephrolithiasis patients was significantly higher than that in healthy individuals. Two healthy subjects who had elevated COCI values were found to have asymptomatic kidney calculi. The receiver operating characteristic analysis showed an area under the curve of the urinary COCI test of 0.9499 (95%CI: 0.9131-0.9868) for distinguishing between nephrolithiasis and healthy subjects. At the cutoff of 165 mg oxalate equivalence/day, the urinary COCI test provided sensitivity, specificity, and accuracy amounts of 83.33%, 97.18%, and 90.21%, respectively. Urinary COCI values were primarily dependent on urine volume, oxalate, and phosphate. The test provided high sensitivity and specificity for clinically discriminating nephrolithiasis patients from healthy controls. It might be used to detect individuals with asymptomatic kidney calculi.

  15. Alarm Photosynthesis: Calcium Oxalate Crystals as an Internal CO2 Source in Plants.

    Science.gov (United States)

    Tooulakou, Georgia; Giannopoulos, Andreas; Nikolopoulos, Dimosthenis; Bresta, Panagiota; Dotsika, Elissavet; Orkoula, Malvina G; Kontoyannis, Christos G; Fasseas, Costas; Liakopoulos, Georgios; Klapa, Maria I; Karabourniotis, George

    2016-08-01

    Calcium oxalate crystals are widespread among animals and plants. In land plants, crystals often reach high amounts, up to 80% of dry biomass. They are formed within specific cells, and their accumulation constitutes a normal activity rather than a pathological symptom, as occurs in animals. Despite their ubiquity, our knowledge on the formation and the possible role(s) of these crystals remains limited. We show that the mesophyll crystals of pigweed (Amaranthus hybridus) exhibit diurnal volume changes with a gradual decrease during daytime and a total recovery during the night. Moreover, stable carbon isotope composition indicated that crystals are of nonatmospheric origin. Stomatal closure (under drought conditions or exogenous application of abscisic acid) was accompanied by crystal decomposition and by increased activity of oxalate oxidase that converts oxalate into CO2 Similar results were also observed under drought stress in Dianthus chinensis, Pelargonium peltatum, and Portulacaria afra Moreover, in A. hybridus, despite closed stomata, the leaf metabolic profiles combined with chlorophyll fluorescence measurements indicated active photosynthetic metabolism. In combination, calcium oxalate crystals in leaves can act as a biochemical reservoir that collects nonatmospheric carbon, mainly during the night. During the day, crystal degradation provides subsidiary carbon for photosynthetic assimilation, especially under drought conditions. This new photosynthetic path, with the suggested name "alarm photosynthesis," seems to provide a number of adaptive advantages, such as water economy, limitation of carbon losses to the atmosphere, and a lower risk of photoinhibition, roles that justify its vast presence in plants.

  16. Rare calcium oxalate monohydrate calculus attached to the wall of the renal pelvis.

    Science.gov (United States)

    Grases, Felix; Costa-Bauza, Antonia; Prieto, Rafael M; Saus, Carlos; Servera, Antonio; García-Miralles, Reyes; Benejam, Joan

    2011-04-01

    Most renal calculi can be classified using well-established criteria in a manner that reflects both composition and fine structure under specific pathophysiological conditions. However, when a large patient population is considered, rare renal calculi invariably appear, some of which have never been classified; careful study is required to establish stone etiology in such cases. The patient in the present case report formed two types of calculi. One was attached on the wall of the renal pelvis near the ureter and part of the calculus was embedded inside pelvic renal tissue. The calculus developed on an ossified calcification located in the pelvis tissue. Current knowledge on the development of calcification in soft tissues suggests a pre-existing injury as an inducer of its development. A mechanism of calculus formation is proposed. The second stone was a typical jack-stone calculus.

  17. Electron paramagnetic resonance dosimetry and dating potential of whewellite (calcium oxalate monohydrate)

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, J. [Medical Physics and Applied Radiation Sciences Unit, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4K1 (Canada)], E-mail: thompjw@mcmaster.ca; Schwarcz, H.P. [School of Geography and Earth Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4K1 (Canada)

    2008-08-15

    We use electron paramagnetic resonance (EPR) to demonstrate the presence of radiation-induced paramagnetic species in synthetic whewellite (CaC{sub 2}O{sub 4}.H{sub 2}O), with the primary EPR signal at g=2.0042. The radiosensitive EPR signal has a lifetime of at least 1 year. Freshly synthesized whewellite also displays a paramagnetic signal that increases in intensity upon exposure to fluorescent light. Although the widespread occurrence of natural whewellite suggests applications in geological or archaeological dating, no corresponding radiosensitive EPR signal has been identified in samples of natural whewellite.

  18. Synthesis of calcium oxalate crystals in culture medium irradiated with non-equilibrium atmospheric-pressure plasma

    Science.gov (United States)

    Kurake, Naoyuki; Tanaka, Hiromasa; Ishikawa, Kenji; Nakamura, Kae; Kajiyama, Hiroaki; Kikkawa, Fumitaka; Mizuno, Masaaki; Yamanishi, Yoko; Hori, Masaru

    2016-09-01

    Octahedral particulates several tens of microns in size were synthesized in a culture medium irradiated through contact with a plume of non-equilibrium atmospheric-pressure plasma (NEAPP). The particulates were identified in the crystalline phase as calcium oxalate dihydrate (COD). The original medium contained constituents such as NaCl, d-glucose, CaCl2, and NaHCO3 but not oxalate or oxalic acid. The oxalate was clearly synthesized and crystallized in the medium as thermodynamically unstable COD crystals after the NEAPP irradiation.

  19. Reevaluation of the plant "gemstones": Calcium oxalate crystals sustain photosynthesis under drought conditions.

    Science.gov (United States)

    Tooulakou, Georgia; Giannopoulos, Andreas; Nikolopoulos, Dimosthenis; Bresta, Panagiota; Dotsika, Elissavet; Orkoula, Malvina G; Kontoyannis, Christos G; Fasseas, Costas; Liakopoulos, Georgios; Klapa, Maria I; Karabourniotis, George

    2016-09-01

    Land plants face the perpetual dilemma of using atmospheric carbon dioxide for photosynthesis and losing water vapors, or saving water and reducing photosynthesis and thus growth. The reason behind this dilemma is that this simultaneous exchange of gases is accomplished through the same minute pores on leaf surfaces, called stomata. In a recent study we provided evidence that pigweed, an aggressive weed, attenuates this problem exploiting large crystals of calcium oxalate as dynamic carbon pools. This plant is able to photosynthesize even under drought conditions, when stomata are closed and water losses are limited, using carbon dioxide from crystal decomposition instead from the atmosphere. Abscisic acid, an alarm signal that causes stomatal closure seems to be implicated in this function and for this reason we named this path "alarm photosynthesis." The so-far "enigmatic," but highly conserved and widespread among plant species calcium oxalate crystals seem to play a crucial role in the survival of plants.

  20. Renal intratubular crystals and hyaluronan staining occur in stone formers with bypass surgery but not with idiopathic calcium oxalate stones.

    Science.gov (United States)

    Evan, Andrew P; Coe, Fredric L; Gillen, Daniel; Lingeman, James E; Bledsoe, Sharon; Worcester, Elaine M

    2008-03-01

    Whether idiopathic calcium oxalate (CaOx) stone formers form inner medullary collecting duct (IMCD) crystal deposits bears on pathogenetic mechanisms of stone formation. In prior work, using light and transmission electron microscopy, we have found no IMCD crystal deposits. Here, we searched serial sections of papillary biopsies from a prior study of 15 idiopathic calcium oxalate stone formers, 4 intestinal bypass patients with CaOx stones, and 4 non-stone-forming subjects, and biopsies from an additional hitherto unreported 15 idiopathic calcium oxalate stone formers and 1 bypass patient using polarized light oil immersion optics, for deposits overlooked in our original study. We found no IMCD deposits in any of 1,500 serial sections from the 30 idiopathic calcium oxalate stone formers, nor in 87 additional sections from a frozen idiopathic calcium oxalate stone former biopsy sample processed without exposure to aqueous solutions. Among 4 of the 5 bypass patients but in none of the 30 idiopathic calcium oxalate stone formers or 4 normal stone formers, we found tiny birefringent thin crystalline overlays on scattered IMCD cell membranes. We also found IMCD lumen deposits in two bypass patients that contained mixed birefringent and nonbirefringent crystals, presumably CaOx and apatite. In the bypass patients, we observed focal apical IMCD cell hyaluronan staining, which was absent in idiopathic calcium oxalate stone formers. The absence of any IMCD deposits in 1,500 serial sections of biopsies from 30 idiopathic calcium oxalate stone formers allows us to place the upper limit on the probability of their occurrence at approximately 0.002 and place the lower limit of their size at the resolution of the optics (crystal lesion.

  1. Does aridity influence the morphology, distribution and accumulation of calcium oxalate crystals in Acacia (Leguminosae: Mimosoideae)?

    Science.gov (United States)

    Brown, Sharon L; Warwick, Nigel W M; Prychid, Christina J

    2013-12-01

    Calcium oxalate (CaOx) crystals are a common natural feature of many plant families, including the Leguminosae. The functional role of crystals and the mechanisms that underlie their deposition remain largely unresolved. In several species, the seasonal deposition of crystals has been observed. To gain insight into the effects of rainfall on crystal formation, the morphology, distribution and accumulation of calcium oxalate crystals in phyllodes of the leguminous Acacia sect. Juliflorae (Benth.) C. Moore & Betche from four climate zones along an aridity gradient, was investigated. The shapes of crystals, which include rare Rosanoffian morphologies, were constant between species from different climate zones, implying that morphology was not affected by rainfall. The distribution and accumulation of CaOx crystals, however, did appear to be climate-related. Distribution was primarily governed by vein density, an architectural trait which has evolved in higher plants in response to increasing aridity. Furthermore, crystals were more abundant in acacias from low rainfall areas, and in phyllodes containing high concentrations of calcium, suggesting that both aridity and soil calcium levels play important roles in the precipitation of CaOx. As crystal formation appears to be calcium-induced, we propose that CaOx crystals in Acacia most likely function in bulk calcium regulation.

  2. Bulk crystal growth, optical, mechanical and ferroelectric properties of new semiorganic nonlinear optical and piezoelectric Lithium nitrate monohydrate oxalate single crystal

    Science.gov (United States)

    Dalal, Jyoti; Kumar, Binay

    2016-01-01

    New semiorganic nonlinear optical single crystals of Lithium nitrate oxalate monohydrate (LNO) were grown by slow evaporation solution technique. Single crystal X-ray diffraction study indicated that LNO crystal belongs to the triclinic system with space group P1. Various functional groups present in the material were identified by FTIR and Raman analysis. UV-vis study showed the high transparency of crystals with a wide band gap 5.01 eV. Various Optical constants i.e. Urbach energy (Eu), extinction coefficient (K), refractive index, optical conductivity, electric susceptibility with real and imaginary parts of dielectric constant were calculated using the transmittance data which have applications in optoelectronic devices. A sharp emission peak was found at 438 nm in photoluminescence measurement, which revealed suitability of crystal for fabricating violet lasers. In dielectric studies, a peak has been observed at 33 °C which is due to ferroelectric to paraelectric phase transition. Piezoelectric charge coefficients (d33 = 9.2 pC/N and g33) have been calculated, which make it a suitable for piezoelectric devices applications. In ferroelectric studies, a saturated loop was found in which the values of coercive field and remnant polarization were found to be 2.18 kV/cm and 0.39 μC/cm2, respectively. Thermal behavior was studied by TGA and DSC studies. The relative SHG efficiency of LNO was found to be 1.2 times that of KDP crystal. In microhardness study, Meyer's index value was found to be 1.78 which revealed its soft nature. These optical, dielectric, piezoelectric, ferroelectric, mechanical and non-linear optical properties of grown crystal establish the usefulness of this material for optoelectronics, non-volatile memory and piezoelectric devices applications.

  3. Risk factors associated with calcium oxalate urolithiasis in dogs evaluated at general care veterinary hospitals in the United States.

    Science.gov (United States)

    Okafor, Chika C; Lefebvre, Sandra L; Pearl, David L; Yang, Mingyin; Wang, Mansen; Blois, Shauna L; Lund, Elizabeth M; Dewey, Cate E

    2014-08-01

    Calcium oxalate urolithiasis results from the formation of aggregates of calcium salts in the urinary tract. Difficulties associated with effectively treating calcium oxalate urolithiasis and the proportional increase in the prevalence of calcium oxalate uroliths relative to other urolith types over the last 2 decades has increased the concern of clinicians about this disease. To determine factors associated with the development of calcium oxalate urolithiasis in dogs evaluated at general care veterinary hospitals in the United States, a retrospective case-control study was performed. A national electronic database of medical records of all dogs evaluated between October 1, 2007 and December 31, 2010 at 787 general care veterinary hospitals in the United States was reviewed. Dogs were selected as cases at the first-time diagnosis of a laboratory-confirmed urolith comprised of at least 70% calcium oxalate (n=452). Two sets of control dogs with no history of urolithiasis diagnosis were randomly selected after the medical records of all remaining dogs were reviewed: urinalysis examination was a requirement in the selection of one set (n=1808) but was not required in the other set (n=1808). Historical information extracted included urolith composition, dog's diet, age, sex, neuter status, breed size category, hospital location, date of diagnosis, and urinalysis results. Multivariable analysis showed that the odds of first-time diagnosis of calcium oxalate urolithiasis were significantly (P30 mg/dL (OR: 1.55, 1.04-2.30). Patient demographics and urinalysis results are important factors that can support risk assessment and early identification of canine oxalate urolithiasis. Therefore, periodic urolith screening and monitoring of urine parameters should be encouraged for dogs at risk of developing these uroliths.

  4. Study of Growth, Structural, Thermal and Nonlinear Optical Properties of Silica Gel Grown Calcium Iodate Monohydrate Crystals

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    Sharda J. Shitole

    2015-12-01

    Full Text Available Single crystals of calcium iodate, monohydrate [Ca (IO32, H2O] were grown by simple gel technique by single and double diffusion method. Morphologies and habit faces like prismatic, prismatic pyramidal, needle shaped, hopper crystals were obtained. Few crystals were opaque, some were translucent and some good quality transparent crystals were obtained. EDAX spectrum verified that crystals are of calcium iodate, monohydrate indeed and was used to find Atomic % and Weight %. Unit cell parameters were obtained from the X-ray diffractogram. The calculated unit cell parameters, β, and‘d’ values are in good agreement with reported ones. Structural analysis was done by using FTIR spectroscopy which confirmed the presence of fundamental infrared frequencies, generally observed in all iodate compounds. Thermal analysis exhibits three steps explicitly on heating the samples. The first step involves dehydration at 5500C, second step shows decomposition at 5800C, and the third step involves again decomposition at 6400C. Powder second harmonic generation experiments exhibit the nonlinear nature of the substance.

  5. Role of Tamm-Horsfall protein and uromodulin in calcium oxalate crystallization

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    Carvalho M.

    2002-01-01

    Full Text Available One of the defenses against nephrolithiasis is provided by macromolecules that modulate the nucleation, growth, aggregation and retention of crystals in the kidneys. The aim of the present study was to determine the behavior of two of these proteins, Tamm-Horsfall and uromodulin, in calcium oxalate crystallization in vitro. We studied a group of 10 male stone formers who had formed at least one kidney stone composed of calcium oxalate. They were classified as having idiopathic nephrolithiasis and had no well-known metabolic risk factors involved in kidney stone pathogenesis. Ten normal men were used as controls, as was a group consisting of five normal women and another consisting of five pregnant women. Crystallization was induced by a fixed supersaturation of calcium oxalate and measured with a Coulter Counter. All findings were confirmed by light and scanning electron microscopy. The number of particulate material deposited from patients with Tamm-Horsfall protein was higher than that of the controls (P<0.001. However, Tamm-Horsfall protein decreased the particle diameter of the stone formers when analyzed by the mode of the volume distribution curve (P<0.002 (5.64 ± 0.55 µm compared to 11.41 ± 0.48 µm of uromodulin; 15.94 ± 3.93 µm and 12.45 ± 0.97 µm of normal men Tamm-Horsfall protein and uromodulin, respectively; 8.17 ± 1.57 µm and 9.82 ± 0.95 µm of normal women Tamm-Horsfall protein and uromodulin, respectively; 12.17 ± 1.41 µm and 12.99 ± 0.51 µm of pregnant Tamm-Horsfall protein and uromodulin, respectively. Uromodulin produced fewer particles than Tamm-Horsfall protein in all groups. Nonetheless, the total volume of the crystals produced by uromodulin was higher than that produced by Tamm-Horsfall protein. Our results indicate a different effect of Tamm-Horsfall protein and uromodulin. This dual behavior suggests different functions. Tamm-Horsfall protein may act on nucleation and inhibit crystal aggregation, while

  6. INHIBITION OF CALCIUM OXALATE CRYSTALLIZATION IN-VITRO BY VARIOUS EXTRACTS OF HYPTIS SUAVEOLENS (L. POIT.

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    Agarwal Kumkum

    2012-03-01

    Full Text Available Hyptis suaveolens (L Poit. commonly known as Vilayati tulsi, belongs to the Mint family Lamiaceae. The inhibition of in-vitro calcium-oxalate crystal (a major component of most urinary stones formation by various extracts of Hyptis was investigated by titrimetric method. The inhibitor potency of alcohol extracts of Hyptis suaveolens (L. Poit was found to be comparable to that of cystone (a proprietary drug for dissolving kidney stones. Thus alcohol extract could be further analyzed in vivo and further characterization of its active compound could lead to the discovery of a new candidate drug for the patients with urolithiasis.

  7. Calcium oxalate crystals: an integral component of the Sclerotinia sclerotiorum/Brassica carinata pathosystem.

    Science.gov (United States)

    Uloth, Margaret B; Clode, Peta L; You, Ming Pei; Barbetti, Martin J

    2015-01-01

    Oxalic acid is an important virulence factor for disease caused by the fungal necrotrophic pathogen Sclerotinia sclerotiorum, yet calcium oxalate (CaOx) crystals have not been widely reported. B. carinata stems were infected with S. sclerotiorum and observed using light microscopy. Six hours post inoculation (hpi), CaOx crystals were evident on 46% of stem sections and by 72 hpi on 100%, demonstrating that the secretion of oxalic acid by S. sclerotiorum commences before hyphal penetration. This is the first time CaOx crystals have been reported on B. carinata infected with S. sclerotiorum. The shape of crystals varied as infection progressed. Long tetragonal rods were dominant 12 hpi (68% of crystal-containing samples), but by 72 hpi, 50% of stems displayed bipyramidal crystals, and only 23% had long rods. Scanning electron microscopy from 24 hpi revealed CaOx crystals in all samples, ranging from tiny irregular crystals (Crystal morphology encompassed various forms, including tetragonal prisms, oval plates, crystal sand, and druses. Large conglomerates of CaOx crystals were observed in the hyphal mass 72 hpi and these are proposed as a strategy of the fungus to hold and detoxify Ca2+ions. The range of crystal morphologies suggests that S. sclerotiorum growth and infection controls the form taken by CaOx crystals.

  8. An Assessment of Engineered Calcium Oxalate Crystal Formation on Plant Growth and Development as a Step toward Evaluating Its Use to Enhance Plant Defense.

    Science.gov (United States)

    Nakata, Paul A

    2015-01-01

    The establishment of new approaches to control chewing insects has been sought not only for direct use in reducing crop loss but also in managing resistance to the pesticides already in use. Engineered formation of calcium oxalate crystals is a potential strategy that could be developed to fulfill both these needs. As a step toward this development, this study investigates the effects of transforming a non-calcium oxalate crystal accumulating plant, Arabidopsis thaliana, into a crystal accumulating plant. Calcium oxalate crystal accumulating A. thaliana lines were generated by ectopic expression of a single bacterial gene encoding an oxalic acid biosynthetic enzyme. Biochemical and cellular studies suggested that the engineered A. thaliana lines formed crystals of calcium oxalate in a manner similar to naturally occurring crystal accumulating plants. The amount of calcium oxalate accumulated in leaves also reached levels similar to those measured in the leaves of Medicago truncatula in which the crystals are known to play a defensive role. Visual inspection of the different engineered lines, however, suggested a phenotypic consequence on plant growth and development with higher calcium oxalate concentrations. The restoration of a near wild-type plant phenotype through an enzymatic reduction of tissue oxalate supported this observation. Overall, this study is a first to provide initial insight into the potential consequences of engineering calcium oxalate crystal formation in non-crystal accumulating plants.

  9. Calcium Oxalate Stone Agglomeration Inhibition [tm] Reflects Renal Stone-Forming Activity.

    Science.gov (United States)

    Lindberg, J S; Cole, F E; Romani, W; Husserl, F E; Fuselier, H A; Kok, D J; Erwin, D T

    2000-04-01

    Louisiana and other Gulf South states comprise a "Stone Belt" where calcium oxalate stone formers (CaOx SFs) are found at a high rate of approximately 5%. In these patients, the agglomeration of small stone crystals, which are visible in nearly all morning urine collections, forms stones that can become trapped in the renal parenchyma and the renal pelvis. Without therapy, about half of CaOx SFs repeatedly form kidney stones, which can cause excruciating pain that can be relieved by passage, fragmentation (lithotripsy), or surgical removal. The absence of stones in "normal" patients suggests that there are stone inhibitors in "normal" urines.At the Ochsner Renal Stone Clinic, 24-hour urine samples are collected by the patient and sent to the Ochsner Renal Stone Research Program where calcium oxalate stone agglomeration inhibition [tm] measurements are performed. Urine from healthy subjects and inactive stone formers has demonstrated strongly inhibited stone growth [tm] in contrast to urine from recurrent CaOx SFs. [tm] data from 1500 visits of 700 kidney stone patients have been used to evaluate the risk of recurrence in Ochsner's CaOx SF patients. These data have also been used to demonstrate the interactive roles of certain identified urinary stone-growth inhibitors, citrate and Tamm-Horsfall protein (THP), which can be manipulated with medication to diminish recurrent stone formation. Our goal is to offer patients both financial and pain relief by reducing their stones with optimized medication, using medical management to avoid costly treatments.

  10. Modulation of Calcium Oxalate Crystallization by Proteins and Small Molecules Investigated by In Situ Atomic Force Microscopy

    Science.gov (United States)

    Qiu, R.; Orme, C.; Cody, A. M.; Wierzbicki, A.; Hoyer, J.; Nancollas, G.; de Yoreo, J.

    2002-12-01

    Understanding the physical mechanisms by which biological inhibitors control nucleation and growth of inorganic crystals is a major focus of biomineral research. Calcium oxalate monohydrate (COM), which plays a functional role in plant physiology, is also a source of pathogenesis in humans where it causes kidney stone disease. Although a great deal of research has been carried out on the modulation COM by proteins and small molecules, the basic mechanism has not yet been understood. However, because the proteins that play a role in COM growth have been identified and sequenced, COM provides an excellent model system for research into biomineral growth. In this study, in situ atomic force microscopy (AFM) was used to monitor the COM surface under controlled growth conditions both from pure solutions and those doped with citrate and osteopontin (OPN) in order to determine their effects on surface morphology and growth dynamics at the molecular level. As with other solution-grown crystals such as calcite, COM grows on complex dislocation hillocks. In pure solution, while growth on the (010) face is isotropic, hillocks on the (-101) face exhibit anisotropic step kinetics. Steps of [-10-1] and orientation are clearly delineated with the [-10-1] being the fast growing direction. When citrate is added to the solution, both growth rate and morphology are drastically changed on (-101) face, especially along the [-10-1] direction. This results in isotropic disc-shaped hillocks a shape that is then reflected in the macroscopic growth habit. In contrast, no large growth changes were observed on the (010) facet. At the same time, molecular modeling predicts an excellent fit of the citrate ion into the (-101) plane and a poor fit to the (010) face. Here we propose a model that reconciles the step-specific interactions implied by the AFM results with the face-specific predictions of the calculations. Finally, we present the results of doping with aspartic acid as well as OPN, an

  11. Crystal morphology and carbon/carbon composition of solid oxalate in cacti.

    Science.gov (United States)

    Rivera, E R; Smith, B N

    1979-12-01

    Morphology, crystal structure, and carbon isotopic composition of calcium oxalate from representative species from the family Cactaceae were determined using scanning electron microscopy, x-ray diffraction, and isotope ratio mass spectrometry. Crystals from one species in the Opuntieae tribe of the Cactaceae were druses with acute points composed of the monohydrate form of calcium oxalate (whewellite). Crystals from three species in the Cereeae tribe were the dihydrate form of calcium oxalate (weddellite) forming druses made up of tetragonal and isodiametric crystallites. The oxalate was relatively enriched in (13)C isotope (-7.3 to - 8.7 per thousand) compared with woody fibers (-13.3 to 14.1 per thousand) from the same plants.

  12. Crystal Morphology and 13Carbon/12Carbon Composition of Solid Oxalate in Cacti 1

    Science.gov (United States)

    Rivera, E. R.; Smith, B. N.

    1979-01-01

    Morphology, crystal structure, and carbon isotopic composition of calcium oxalate from representative species from the family Cactaceae were determined using scanning electron microscopy, x-ray diffraction, and isotope ratio mass spectrometry. Crystals from one species in the Opuntieae tribe of the Cactaceae were druses with acute points composed of the monohydrate form of calcium oxalate (whewellite). Crystals from three species in the Cereeae tribe were the dihydrate form of calcium oxalate (weddellite) forming druses made up of tetragonal and isodiametric crystallites. The oxalate was relatively enriched in 13C isotope (-7.3 to - 8.7 ‰) compared with woody fibers (-13.3 to 14.1 ‰) from the same plants. Images PMID:16661115

  13. Physical characteristics of calcium oxalate crystals as determinants in structural defense against chewing insects in Medicago truncatula

    Science.gov (United States)

    In addition to the numerous chemical defenses that plants employ to fend off insect herbivores, simple structural components can also play important roles in effective protection. Our investigations have shown that plant crystals of calcium oxalate can function in insect defense. The isolation of ca...

  14. Medicago truncatula-derived calcium oxalate crystals have a negative impact on chewing insect performance via their physical properties

    Science.gov (United States)

    Plant structural traits often act as defenses against herbivorous insects, causing them to avoid feeding on a given plant or tissue. Mineral crystals of calcium oxalate in Medicago truncatula Gaertn. (Fabaceae) leaves have previously been shown to be effective deterrents of lepidopteran insect feedi...

  15. Calcium-induced patterns of calcium-oxalate crystals in isolated leaflets of Gleditsia triacanthos L. and Albizia julibrissin Durazz.

    Science.gov (United States)

    Borchert, R

    1985-08-01

    For experimental induction of crystal cells (=crystal idioblasts) containing calcium-oxalate crystals, the lower epidermis was peeled from seedling leaflets of Gleditsia triacanthos L., exposing the crystal-free mesophyll and minor veins to the experimental solutions on which leaflets were floated for up to 10 d under continous light. On 0.3-2.0 mM Ca-acetate, increasing numbers of crystals, appearing 96 h after peeling, were induced. The pattern of crystal distribution changed with Ca(2+)-concentration ([Ca(2+)]): at low [Ca(2+)], crystals formed only in the non-green bundlesheath cells surrounding the veins, believed to have a relatively low Ca(2+)-extrusion capacity; at higher [Ca(2+)], crystals developed in up to 90% of the mesophyll cells, and at supraoptimal [Ca(2+)], large extracellular crystals formed on the tissue surface. By sequential treatments with solutions of different [Ca(2+)], the following three phases were identified in the induction of crystal cells: (1) during the initial 24-h period (adaptive aging), Ca(2+) is not required and crystal induction is not possible; (2) during the following 48 h (induction period), exposure to 1-2 mM Ca-acetate induces the differentiation of mesophyll cells into crystal cells; (3) crystal growth begins 72 h after the start of induction. In intact leaflets of Albizia julibrissin Durazz., calcium-oxalate crystals are found exclusively in the bundle-sheath cells of the veins, but crystals were induced in the mesophyll of peeled leaflets floating on 1 mM Ca-acetate. Exposure to inductive [Ca(2+)] will thus trigger the differentiation of mature leaf cells into crystal cells; the spatial distribution of crystals is determined by the external [Ca(2+)] and by the structural and functional properties of the cells in the tissue.

  16. Wu-Ling-San formula prophylaxis against recurrent calcium oxalate nephrolithiasis - a prospective randomized controlled trial.

    Science.gov (United States)

    Lin, Eugene; Ho, Lin; Lin, Mao-Sheng; Huang, Min-Ho; Chen, Wen-Chi

    2013-01-01

    Wu-Ling-San (WLS) formula has been proved to prevent calcium oxalate nephrolithiasis both in vitro and in vivo. This is the first prospective, randomized and placebo-controlled clinical trial of WLS in calcium oxalate nephrolithiasis prevention. All patients who enrolled were asked to drink enough fluid to urinate at least 2 L daily during the study period. A 24-hour urine collection was performed to establish the baseline levels of multiple urinary parameters before taking the medicine. The patients were randomized and divided into two groups. The medication group took 2 gm WLS formula three times daily for 1 month. The control group took 2 gm placebo three times daily for 1 month. A 24-hour urine collection was performed to evaluate multiple urinary and serum parameters from all patients during the study period. A total of 39 patients were enrolled and 28 patients completed the study. Fourteen patients were allocated to WLS group and 14 patients to placebo group. After treatment, the mean urine output level increased to 2796.4 ± 525.7 ml/day (percentage of change, 13.9 %) in the WLS formula group. With placebo therapy, the mean decreased slightly to 2521.4 ± 762.7ml/day (percentage of change, -5.7 %). The percentage of change was significantly different between the two groups (independent t-test, P=0.02). No patient complained of side effects, such as fatigue, dizziness, musculoskeletal symptoms, or gastrointestinal disturbance. WLS formula is a promising adjunct to surgical and medical management of kidney stones. Active therapy with WLS formula has a positive effect on diuresis without leading to electrolyte imbalance.

  17. Reduction of oxalate-induced renal tubular epithelial (NRK-52E cell injury and inhibition of calcium oxalate crystallisation in vitro by aqueous extract of Achyranthes aspera

    Directory of Open Access Journals (Sweden)

    Aggarwal Anshu

    2010-01-01

    Full Text Available Despite considerable progress in medical therapy, there is no satisfactory drug to treat kidney stones. Therefore, this study is aimed to look for an alternative treatment by using Achyranthes aspera. Here, the inhibitory potency of A. aspera was investigated on nucleation and the growth of the calcium oxalate (CaOx crystals as well as on oxalate-induced cell injury of NRK 52E renal epithelial cells in vitro. Data are expressed as mean values of three independent experiments (each in triplicate and analysed by the analysis of variance (P < 0.05 to estimate the differences between values of extracts tested. A. aspera extract exhibited a concentration-dependent inhibition of the growth of CaOx crystals but a similar pattern of inhibition was not observed with increase in the plant extract concentration for the nucleation assay. When NRK 52E cells were injured by exposure to oxalate for 72 hours, A. aspera extract prevented the injury in a dose-dependent manner. On treatment with the different concentrations of the plant, the cell viability increased and the lactate dehydrogenase (LDH release decreased in a concentration-dependent manner. These studies indicate that A. aspera extract besides having a cytoprotective role also has a potential to inhibit both nucleation and the growth of the CaOx crystals and can prove to be a potent candidate for phytotherapy against urolithiasis.

  18. Diminution of oxalate induced renal tubular epithelial cell injury and inhibition of calcium oxalate crystallization in vitro by aqueous extract of Tribulus terrestris

    Directory of Open Access Journals (Sweden)

    A. Aggarwal

    2010-08-01

    Full Text Available PURPOSE: Recurrence and persistent side effects of present day treatment for urolithiasis restrict their use, so an alternate solution, using phytotherapy is being sought. The present study attempted to evaluate the antilithiatic properties of Tribulus terrestris commonly called as “gokhru” which is often used in ayurveda to treat various urinary diseases including urolithiasis. MATERIALS AND METHODS: The activity of Tribulus terrestris was investigated on nucleation and the growth of the calcium oxalate (CaOx crystals as well as on oxalate induced cell injury of NRK 52E renal epithelial cells. RESULTS: Tribulus terrestris extract exhibited a concentration dependent inhibition of nucleation and the growth of CaOx crystals. When NRK-52E cells were injured by exposure to oxalate for 72 h, Tribulus terrestris extract prevented the injury in a dose-dependent manner. On treatment with the different concentrations of the plant, the cell viability increased and lactate dehydrogenase release decreased in a concentration dependent manner. CONCLUSION: The current data suggests that Tribulus terrestris extract not only has a potential to inhibit nucleation and the growth of the CaOx crystals but also has a cytoprotective role. Our results indicate that it could be a potential candidate for phytotherapy against urolithiasis.

  19. Quantitative analysis of colonization with real-time PCR to identify the role of Oxalobacter formigenes in calcium oxalate urolithiasis.

    Science.gov (United States)

    Batislam, Ertan; Yilmaz, Erdal; Yuvanc, Ercan; Kisa, Ozgul; Kisa, Ucler

    2012-10-01

    The objective of the study was to quantitatively measure the number of Oxalobacter formigenes (O. formigenes) colonizations in the gastrointestinal tract in calcium oxalate-forming patients with real-time polymerase chain reaction (PCR). Calcium oxalate-forming patients (n: 27) were included in the study. Serum calcium, sodium, potassium, urea and creatinine levels, as well as 24 h urine levels of calcium and oxalate were measured. The numbers of O. formigenes colonies in stool samples were detected by real-time PCR. One or two metabolic abnormalities were detected in 15 of 27 patients. The O. formigenes levels in patients with metabolic disturbance were significantly decreased when compared to the patients with no metabolic abnormalities (p: 0.038). The undetectable levels of O. formigenes were encountered in one of five patients with hypercalciuria, in three of four patients with hyperoxaluria and in four of six patients with both hypercalciuria and hyperoxaluria. In nine patients with a history of stone recurrence, O. formigenes colonization was significantly lower than the patients with the first stone attack (p: 0.001). O. formigenes formation ceased or significantly diminished in patients with calcium oxalate stones with a coexistence of both hyperoxaluria and hypercalciuria. The measurement of O. formigenes colonies by real-time PCR seemed to be an inconvenient and expensive method. For this reason, the real-time PCR measurements can be spared for the patients with stone recurrences and with metabolic abnormalities like hypercalciuria and hyperoxaluria. The exact measurement of O. formigenes may also help more accurate programming of O. formigenes-based treatments.

  20. Genetic Mutation of Vitamin K-dependent Gamma-glutamyl Car-boxylase Domain in Patients with Calcium Oxalate Urolithiasis

    Institute of Scientific and Technical Information of China (English)

    Jiankun QIAO; Tao WANG; Jun YANG; Jihong LIU; Xiaoxin GONG; Xiaolin GUO; Shaogang WANG; Zhangqun YE

    2009-01-01

    To investigate the exon mutation of vitamin K-dependent gamma-glutamyl carboxylase (GGCX or VKDC) in patients with calcium oxalate urolithasis, renal cortex and peripheral blood sam-ples were obtained from severe hydronephrosis patients (with or without calculi), and renal tumor pa-tients undergoing nephrectomy. GGCX mutations in all 15 exons were examined in 44 patients with calcium oxalate urolithiasis (COU) by polymerase chain reaction (PCR) and denatured high pressure liquid chromatography (DHPLC), and confirmed by sequencing. Mutation was not found in all COU samples compared to the controls. These data demonstrated that functional GGCX mutations in all 15 exons do not occur in most COU patients. It was suggested that there may be no significant association between the low activity and mutation of GGCX in COU.

  1. Calcium oxalate crystals induces tight junction disruption in distal renal tubular epithelial cells by activating ROS/Akt/p38 MAPK signaling pathway.

    Science.gov (United States)

    Yu, Lei; Gan, Xiuguo; Liu, Xukun; An, Ruihua

    2017-11-01

    Tight junction plays important roles in regulating paracellular transports and maintaining cell polarity. Calcium oxalate monohydrate (COM) crystals, the major crystalline composition of kidney stones, have been demonstrated to be able to cause tight junction disruption to accelerate renal cell injury. However, the cellular signaling involved in COM crystal-induced tight junction disruption remains largely to be investigated. In the present study, we proved that COM crystals induced tight junction disruption by activating ROS/Akt/p38 MAPK pathway. Treating Madin-Darby canine kidney (MDCK) cells with COM crystals induced a substantial increasing of ROS generation and activation of Akt that triggered subsequential activation of ASK1 and p38 mitogen-activated protein kinase (MAPK). Western blot revealed a significantly decreased expression of ZO-1 and occludin, two important structural proteins of tight junction. Besides, redistribution and dissociation of ZO-1 were observed by COM crystals treatment. Inhibition of ROS by N-acetyl-l-cysteine (NAC) attenuated the activation of Akt, ASK1, p38 MAPK, and down-regulation of ZO-1 and occludin. The redistribution and dissociation of ZO-1 were also alleviated by NAC treatment. These results indicated that ROS were involved in the regulation of tight junction disruption induced by COM crystals. In addition, the down-regulation of ZO-1 and occludin, the phosphorylation of ASK1 and p38 MAPK were also attenuated by MK-2206, an inhibitor of Akt kinase, implying Akt was involved in the disruption of tight junction upstream of p38 MAPK. Thus, these results suggested that ROS-Akt-p38 MAPK signaling pathway was activated in COM crystal-induced disruption of tight junction in MDCK cells.

  2. Antilithiatic Activity of phlorotannin rich extract of Sarghassum Wightii on Calcium Oxalate Urolithiais – In Vitro and In VivoEvaluation

    Directory of Open Access Journals (Sweden)

    D. Sujatha

    2015-06-01

    Full Text Available ABSTRACTPurpose:Urolithiasis is a common urological disorder responsible for serious human affliction and cost to the society with a high recurrence rate. The aim of the present study was to systematically evaluate the phlorotannin rich extract of Sargassum wightii using suitable in vitro and in vivo models to provide scientific evidence for its antilithiatic activity.Materials and Methods:To explore the effect of Sargassum wightii on calcium oxalate crystallization, in vitro assays like crystal nucleation, aggregation and crystal growth were performed. Calcium oxalate urolithiasis was induced in male Sprague dawley rats using a combination of gentamicin and calculi producing diet (5% ammonium oxalate and rat pellet feed. The biochemical parameters like calcium, oxalate, magnesium, phosphate, sodium and potassium were evaluated in urine, serum and kidney homogenates. Histopathological studies were also done to confirm the biochemical findings.Results:The yield of Sargassum wightii extract was found to be 74.5 gm/kg and confirmed by quantitative analysis. In vitro experiments with Sargassum wightii showed concentration dependent inhibition of calcium oxalate nucleation, aggregation and growth supported by SEM analysis. In the in vivo model, Sargassum wightiireduced both calcium and oxalate supersaturation in urine, serum and deposition in the kidney. The biochemical results were supported by histopathological studies.Conclusion:The findings of the present study suggest that Sargassum wightii has the ability to prevent nucleation, aggregation and growth of calcium oxalate crystals. Sargassum wightii has better preventive effect on calcium oxalate stone formation indicating its strong potential to develop as a therapeutic option to prevent recurrence of urolithiasis.

  3. Chronic stress and calcium oxalate stone disease: is it a potential recurrence risk factor?

    Science.gov (United States)

    Arzoz-Fabregas, Montserrat; Ibarz-Servio, Luis; Edo-Izquierdo, Sílvia; Doladé-Botías, María; Fernandez-Castro, Jordi; Roca-Antonio, Josep

    2013-04-01

    Chronic emotional stress is associated with increased cortisol release and metabolism disorders. However, few studies have evaluated the influence of chronic stress on calcium oxalate (CaOx) stone disease and its recurrence. A total of 128 patients were enrolled in this case-control study over a period of 20 months. All patients were CaOx stone formers with a recent stone episode (chronic stress were evaluated with self-reported validated questionnaires measuring stressful life events, perceived stress, anxiety, depression, burnout and satisfaction with life. An ad hoc self-reporting questionnaire was designed to evaluate stress-related specifically to stone episodes. Blood and urine samples were collected to determine cortisol levels and urinary composition. In addition, epidemiological data, socioeconomic information, diet and incidences of metabolic syndrome (MS) were reported. Overall, no significant differences were observed in the scores of cases and controls on any of the questionnaires dealing with stress. The number (p chronic stress, the number and intensity of stressful life events were higher in RS than in FS. These differences correlate with variations in blood and urinary levels and with metabolic disorders, indicating an association between chronic stress and risk of recurrent CaOx stone formation.

  4. [Biochemical effects of potassium citrate in the treatment of calcium oxalate lithiasis].

    Science.gov (United States)

    Conte Visús, A; Ibarz Servio, L; Arrabal Martín, M; Ibarz Navarro, J M; Ruiz Marcellán, F J

    1994-03-01

    The serum and urinary biochemical changes observed one month and six months after oral potassium citrate therapy (600 mEq/day) in 119 patients with calcium oxalate calculi were compared with those of 16 untreated cases with lithiasis. The patients that received treatment were previously divided into two groups: group A comprised 61 hypocitraturic patients and group B comprised 58 patients with other urinary disorders who were normo or hypocitraturic. The urinary pH increased by approximately half a point in both treated groups. In group A calciuria increased slightly from 180 +/- 8 to 216 +/- 10 mg/24 h but remained within the normal ranges. Creatinuria, oxaluria, uricosuria and diuresis showed no changes. Citraturia increased very significantly in both groups and more markedly in the hypocitraturic group of patients (from 198 +/- 13 to 476 +/- 35 mg/24 h). The LRC (lithogenic risk coefficient = Ca/Cit x Diu) dropped by 50%. The patients tolerated the treatment regimen well; of the 119 treated patients, only 11 abandoned treatment due to GI intolerance.

  5. Calcium oxalate crystal deposition in kidneys of hypercalciuric mice with disrupted type IIa sodium-phosphate cotransporter

    OpenAIRE

    Khan, Saeed R.; Glenton, Patricia A.

    2008-01-01

    The most common theories about the pathogenesis of idiopathic kidney stones consider precipitation of calcium phosphate (CaP) within the kidneys critical for the development of the disease. We decided to test the hypothesis that a CaP substrate can promote the deposition of calcium oxalate (CaOx) in the kidneys. Experimental hyperoxaluria was induced by feeding glyoxylate to male mice with knockout (KO) of NaPi IIa (Npt2a), a sodium-phosphate cotransporter. Npt2a KO mice are hypercalciuric an...

  6. Mechanisms involved in calcium oxalate endocytosis by Madin-Darby canine kidney cells

    Directory of Open Access Journals (Sweden)

    A.H. Campos

    2000-01-01

    Full Text Available Calcium oxalate (CaOx crystals adhere to and are internalized by tubular renal cells and it seems that this interaction is related (positively or negatively to the appearance of urinary calculi. The present study analyzes a series of mechanisms possibly involved in CaOx uptake by Madin-Darby canine kidney (MDCK cells. CaOx crystals were added to MDCK cell cultures and endocytosis was evaluated by polarized light microscopy. This process was inhibited by an increase in intracellular calcium by means of ionomycin (100 nM; N = 6; 43.9% inhibition; P<0.001 or thapsigargin (1 µM; N = 6; 33.3% inhibition; P<0.005 administration, and via blockade of cytoskeleton assembly by the addition of colchicine (10 µM; N = 8; 46.1% inhibition; P<0.001 or cytochalasin B (10 µM; N = 8; 34.2% inhibition; P<0.001. Furthermore, CaOx uptake was reduced when the activity of protein kinase C was inhibited by staurosporine (10 nM; N = 6; 44% inhibition; P<0.01, or that of cyclo-oxygenase by indomethacin (3 µM; N = 12; 17.2% inhibition; P<0.05; however, the uptake was unaffected by modulation of potassium channel activity with glibenclamide (3 µM; N = 6, tetraethylammonium (1 mM; N = 6 or cromakalim (1 µM; N = 6. Taken together, these data indicate that the process of CaOx internalization by renal tubular cells is similar to the endocytosis reported for other systems. These findings may be relevant to cellular phenomena involved in early stages of the formation of renal stones.

  7. Extraction and estimation of the quantity of calcium oxalate crystals in the foliage of conifer and hardwood trees.

    Science.gov (United States)

    Minocha, Rakesh; Chamberlain, Bradley; Long, Stephanie; Turlapati, Swathi A; Quigley, Gloria

    2015-05-01

    The main goal of this study was to develop a method for the extraction and indirect estimation of the quantity of calcium oxalate (CaOx) in the foliage of trees. Foliar tissue was collected from a single tree of each species (five conifers and five hardwoods) for comparison of extractions in different solvents using 10 replicates per species from the same pool of tissue. For each species, calcium (Ca) and oxalate were extracted sequentially in double deionized water and 2N acetic acid, and finally, five replicate samples were extracted in 5% (0.83N) perchloric acid (PCA) and the other five in 2N hydrochloric acid (HCl); three cycles of freezing and thawing were used for each solvent. Total ions were extracted by microwave digestion. Calcium was quantified with an inductively coupled plasma emission spectrophotometer method and oxalate was eluted and quantified using a high performance liquid chromatography method. This experiment was repeated again with two conifer and two hardwood species using four trees per species, and two analytical replicates for each tree. We report here that, regardless of age of individual trees within a species, time of collection or species type, the third extraction in PCA or HCl resulted in near equimolar quantities of Ca and oxalate (r(2) ≥ 0.99). This method provides an easy estimate of the quantity of CaOx crystals using a small sample of foliar tissue. An additional benefit of PCA is that it precipitates the nucleic acids and proteins, allowing the quantification of several free/soluble metabolites such as amino acids, polyamines, organic acids and inorganic elements all from a single sample extract.

  8. Renal tubular injury induced by ischemia promotes the formation of calcium oxalate crystals in rats with hyperoxaluria.

    Science.gov (United States)

    Cao, Yanwei; Liu, Wanpeng; Hui, Limei; Zhao, Jianjun; Yang, Xuecheng; Wang, Yonghua; Niu, Haitao

    2016-10-01

    Hyperoxaluria and cell injury are key factors in urolithiasis. Oxalate metabolism may be altered by renal dysfunction and therefore, impact the deposition of calcium oxalate (CaOx) crystals. We investigated the relationship of renal function, oxalate metabolism and CaOx crystal deposition in renal ischemia. One hundred male Sprague-Dawley rats were randomly divided into four groups. Hyperoxaluria model (Group A and B) was established by feeding rats with 0.75 % ethylene glycol (EG). The left renal pedicle was clamped for 30 min to establish renal ischemia Groups (B and C), while Groups A and D underwent sham operation. Then, serum and urine oxalate (Ox), creatinine (Cr) and urea nitrogen (UN) levels were evaluated by liquid chromatography mass spectrometry (LCMS) and ion mass spectrum (IMS) at days 0, 2, 4, 7, and 14. CaOx crystallization was assessed by transmission electron microscope (TEM). A temporal and significant increase of serum Cr and UN levels was observed in Groups B and C compared to values obtained for Groups A and D (P renal tissue. Our results indicated that renal tubular injury induced by renal ischemia might not affect Ox levels but could promote CaOx crystal retention under hyperoxaluria.

  9. Kinetic versus thermodynamic factors in calcium renal lithiasis.

    Science.gov (United States)

    Grases, F; Costa-Bauzá, A; Königsberger, E; Königsberger, L C

    2000-01-01

    Calcium renal lithiasis formation depends on the balance between thermodynamic (supersaturation) and kinetic (inhibitors, nucleants) factors. In this paper, the importance of both groups was evaluated using (a) the complete urine analysis data obtained from 32 healthy volunteers and 141 active stone-formers, and (b) a comprehensive computer model to calculate the supersaturation values of calcium oxalate monohydrate, hydroxyapatite and brushite in each urine sample. The results of this evaluation were used to assess the possible effectiveness of a given pharmacological treatment.

  10. Correlation between air pollution and crystal pattern of calcium oxalate in plant leaves of street trees in Itami City. [Ginkgo biloba; Salix babylonica; Aphananthe aspera; Robinia pseudoacacia

    Energy Technology Data Exchange (ETDEWEB)

    Umemoto, K.; Tatsumi, S.

    1975-01-01

    A characteristic difference in calcium oxalate crystal patterns in leaves of roadside trees planted in relatively unpolluted northern parts of Itami City and in parts of the city polluted by automobile exhaust was discovered. The species of trees examined were Ginkgo biloba, Salix babylonica, Aphananthe aspera, Robinia pseudoacacia, and Poplar. The leaves of trees grown in relatively less air polluted areas displayed crystal aggregates of calcium oxalate (50-80 micron) that were arranged in rows on both sides of the central vein; some scattered crystal aggregates between veins were observed. Trees grown in air polluted areas showed irregular crystal patterns and more scattering of the crystals between veins. The cause of the observed differences in the pattern of crystal aggregates was attributed to the difference in metabolism of trees under different environmental conditions. Air pollutants disturb the normal metabolism of the tree and cause hyperproduction of calcium oxalate.

  11. Peeping into human renal calcium oxalate stone matrix: characterization of novel proteins involved in the intricate mechanism of urolithiasis.

    Directory of Open Access Journals (Sweden)

    Kanu Priya Aggarwal

    Full Text Available BACKGROUND: The increasing number of patients suffering from urolithiasis represents one of the major challenges which nephrologists face worldwide today. For enhancing therapeutic outcomes of this disease, the pathogenic basis for the formation of renal stones is the need of hour. Proteins are found as major component in human renal stone matrix and are considered to have a potential role in crystal-membrane interaction, crystal growth and stone formation but their role in urolithiasis still remains obscure. METHODS: Proteins were isolated from the matrix of human CaOx containing kidney stones. Proteins having MW>3 kDa were subjected to anion exchange chromatography followed by molecular-sieve chromatography. The effect of these purified proteins was tested against CaOx nucleation and growth and on oxalate injured Madin-Darby Canine Kidney (MDCK renal epithelial cells for their activity. Proteins were identified by Matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF MS followed by database search with MASCOT server. In silico molecular interaction studies with CaOx crystals were also investigated. RESULTS: Five proteins were identified from the matrix of calcium oxalate kidney stones by MALDI-TOF MS followed by database search with MASCOT server with the competence to control the stone formation process. Out of which two proteins were promoters, two were inhibitors and one protein had a dual activity of both inhibition and promotion towards CaOx nucleation and growth. Further molecular modelling calculations revealed the mode of interaction of these proteins with CaOx at the molecular level. CONCLUSIONS: We identified and characterized Ethanolamine-phosphate cytidylyltransferase, Ras GTPase-activating-like protein, UDP-glucose:glycoprotein glucosyltransferase 2, RIMS-binding protein 3A, Macrophage-capping protein as novel proteins from the matrix of human calcium oxalate stone which play a critical role in kidney stone

  12. Synthesis of CaTiO3 from calcium titanyl oxalate hexahydrate (CTO) as precursor employing microwave heating technique

    Indian Academy of Sciences (India)

    B M Patil; R S Srinivasa; S R Dharwadkar

    2007-06-01

    Calcium titanate, CaTiO3, an important microwave dielectric material and one of major phases in synroc (synthetic rock), a titanate ceramic with potential application for fixation of high level nuclear waste was synthesized from calcium titanyl oxalate [CaTiO (C2O4)2.6H2O] (CTO) by employing microwave heating technique. CTO heated in microwave heating system in air at 500°C for 1 h gave a perovskite, CaTiO3. The product obtained by heating of CTO in the same system at 700°C for the same duration was however, much more crystalline. CaTiO3 obtained by the present method was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and BET surface area measurement.

  13. Do teas rich in antioxidants reduce the physicochemical and peroxidative risk factors for calcium oxalate nephrolithiasis in humans? Pilot studies with Rooibos herbal tea and Japanese green tea.

    Science.gov (United States)

    Rodgers, A; Mokoena, M; Durbach, I; Lazarus, J; de Jager, S; Ackermann, H; Breytenbach, I; Okada, A; Usami, M; Hirose, Y; Ando, R; Yasui, T; Kohri, K

    2016-08-01

    Several experimental and animal studies have demonstrated that substances rich in antioxidants can reduce the physicochemical and peroxidative risk factors for calcium oxalate (CaOx) renal stone formation in urine and blood. However, there are very few such investigations in humans. In the present pilot study, two varieties of tea, a green one from Japan (JGT) and a herbal one from South Africa (Rooibos) (RT), both rich in antioxidants, were administered to a group of CaOx stone formers (SF) (n = 8) for 30 days. Both teas were analysed for polyphenols by high-performance liquid chromatography and for minerals by plasma atomic and optical emission spectroscopy. 24 h urines (baseline and day 30) were analysed for lithogenic factors. CaOx metastable limits and crystal nucleation and growth kinetics were also determined in each urine sample. Deposited crystals were inspected by scanning electron microscopy. Blood samples were collected (baseline and day 30). Biomarkers of oxidative stress including plasma and urinary thiobarbituric acid reactive substances (TBARS) and urinary N-acetyl-β-D-glucosaminidase (NAG) were also determined. Urinary physicochemical risk factors were also investigated after ingestion of RT for 30 days in two control groups (CG1 and CG2), the latter one of which consisted of habitual JGT drinkers. Statistical analyses were performed using Wilcoxon signed rank tests and Mann-Whitney tests for paired and independent measurements, respectively. Several flavonoids and catechins were quantified in RT and JGT, respectively, confirming that both teas are rich sources of antioxidants. Mineral content was found to be far below dietary reference intakes. There were no significant changes in any of the urinary physicochemical or peroxidative risk factors in the control groups or in SF, except for the supersaturation (SS) of brushite (Bru) which decreased in the latter group after ingestion of JGT. Crystal morphology showed a tendency to change from

  14. An oxalyl-CoA dependent pathway of oxalate catabolism plays a role in regulating calcium oxalate crystal accumulation and defending against oxalate-secreting phytopathogens in Medicago truncatula

    Science.gov (United States)

    Considering the widespread occurrence of oxalate in nature and its broad impact on a host of organisms, it is surprising that so little is known about the turnover of this important acid. In plants, oxalate oxidase is the most well studied enzyme capable of degrading oxalate, but not all plants pos...

  15. An understanding of renal stone development in a mixed oxalate-phosphate system.

    Science.gov (United States)

    Guan, Xiangying; Wang, Lijun; Dosen, Anja; Tang, Ruikang; Giese, Rossman F; Giocondi, Jennifer L; Orme, Christine A; Hoyer, John R; Nancollas, George H

    2008-07-15

    The in vivo formation of calcium oxalate concretions having calcium phosphate nidi is simulated in an in vitro (37 degrees C, pH 6.0) dual constant composition (DCC) system undersaturated (sigma DCPD = -0.330) with respect to brushite (DCPD, CaHPO 4 . 2H 2O) and slightly supersaturated (sigma COM = 0.328) with respect to calcium oxalate monohydrate (COM, CaC2O4 . H2O). The brushite dissolution provides calcium ions that raise the COM supersaturation, which is heterogeneously nucleated either on or near the surface of the dissolving calcium phosphate crystals. The COM crystallites may then aggregate, simulating kidney stone formation. Interestingly, two intermediate phases, anhydrous dicalcium phosphate (monetite, CaHPO4) and calcium oxalate trihydrate (COT), are also detected by X-ray diffraction during this brushite-COM transformation. In support of clinical observations, the results of these studies demonstrate the participation of calcium phosphate phases in COM crystallization providing a possible physical chemical mechanism for kidney stone formation.

  16. Low temperature synthesis of high quality carbon nanospheres through the chemical reactions between calcium carbide and oxalic acid

    Energy Technology Data Exchange (ETDEWEB)

    Xie Yonggui, E-mail: xieyg2004@163.com [State Key Laboratory for Powder Metallurgy, Central South University, Changsha, Hunan 410083 (China); Huang Qizhong, E-mail: qzhuang@mail.csu.edu.cn [State Key Laboratory for Powder Metallurgy, Central South University, Changsha, Hunan 410083 (China); Huang Baiyun [State Key Laboratory for Powder Metallurgy, Central South University, Changsha, Hunan 410083 (China); Xie Xiangmin [Applied Chemistry Department, College of Science, Hunan Agricultural University, Changsha, Hunan 410128 (China)

    2010-11-01

    Carbon nanospheres (CNSs) were synthesized through the chemical reactions of calcium carbide and oxalic acid without using catalysts. The chemical reactions were carried out in a sealed stainless steel pressure vessel with various molar ratios at temperatures of 65-250 deg. C. The synthesized CNSs have been characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) attached to the SEM, transmission electron microscopy (TEM), X-ray diffraction (XRD) and Raman spectroscopy. The total yield of carbonaceous materials relative to the starting material is about 4% (w/w). SEM and TEM results reveal that the percentage of CNSs is high (>95%). The CNSs that have been synthesized are roe-like spheres of relatively uniform size with diameters of 60-120 nm. The attached EDS result shows that the carbon content of CNSs reaches up to 98%.

  17. Contrasting histopathology and crystal deposits in kidneys of idiopathic stone formers who produce hydroxy apatite, brushite, or calcium oxalate stones.

    Science.gov (United States)

    Evan, Andrew P; Lingeman, James E; Worcester, Elaine M; Sommer, Andre J; Phillips, Carrie L; Williams, James C; Coe, Fredric L

    2014-04-01

    Our previous work has shown that stone formers who form calcium phosphate (CaP) stones that contain any brushite (BRSF) have a distinctive renal histopathology and surgical anatomy when compared with idiopathic calcium oxalate stone formers (ICSF). Here we report on another group of idiopathic CaP stone formers, those forming stone containing primarily hydroxyapatite, in order to clarify in what ways their pathology differs from BRSF and ICSF. Eleven hydroxyapatite stone formers (HASF) (2 males, 9 females) were studied using intra-operative digital photography and biopsy of papillary and cortical regions to measure tissue changes associated with stone formation. Our main finding is that HASF and BRSF differ significantly from each other and that both differ greatly from ICSF. Both BRSF and ICSF patients have significant levels of Randall's plaque compared with HASF. Intra-tubular deposit number is greater in HASF than BRSF and nonexistent in ICSF while deposit size is smaller in HASF than BRSF. Cortical pathology is distinctly greater in BRSF than HASF. Four attached stones were observed in HASF, three in 25 BRSF and 5-10 per ICSF patient. HASF and BRSF differ clinically in that both have higher average urine pH, supersaturation of CaP, and calcium excretion than ICSF. Our work suggests that HASF and BRSF are two distinct and separate diseases and both differ greatly from ICSF.

  18. Relevance of dietary protein concentration and quality as risk factors for the formation of calcium oxalate stones in cats.

    Science.gov (United States)

    Paßlack, Nadine; Burmeier, Hannes; Brenten, Thomas; Neumann, Konrad; Zentek, Jürgen

    2014-01-01

    The role of dietary protein for the development of feline calcium oxalate (CaOx) uroliths has not been conclusively clarified. The present study evaluated the effects of a varying dietary protein concentration and quality on critical indices for the formation of CaOx uroliths. Three diets with a high protein quality (10-11 % greaves meal/diet) and a varying crude protein (CP) concentration (35, 44 and 57 % in DM) were compared. Additionally, the 57 % CP diet was compared with a fourth diet that had a similar CP concentration (55 % in DM), but a lower protein quality (34 % greaves meal/diet). The Ca and oxalate (Ox) concentrations were similar in all diets. A group of eight cats received the same diet at the same time. Each feeding period was divided into a 21 d adaptation period and a 7 d sampling period to collect urine. There were increases in urinary volume, urinary Ca concentrations, renal Ca and Ox excretion and urinary relative supersaturation (RSS) with CaOx with increasing dietary protein concentrations. Urinary pH ranged between 6·34 and 6·66 among all groups, with no unidirectional effect of dietary protein. Lower renal Ca excretion was observed when feeding the diet with the lower protein quality, however, the underlying mechanism needs further evaluation. In conclusion, although the observed higher urinary volume is beneficial, the increase in urinary Ca concentrations, renal Ca and Ox excretion and urinary RSS CaOx associated with a high-protein diet may be critical for the development of CaOx uroliths in cats.

  19. Infusum Daun Alpukat Sebagai Inhibitor Kristalisasi Kalsium Oksalat pada Ginjal (THE AVOCADO LEAVES INFUSUM AS INHIBITOR ON RENAL CALCIUM OXALATE CRYSTALIZATION

    Directory of Open Access Journals (Sweden)

    Rini Madyastuti

    2016-01-01

    Full Text Available Urine crystal is a crystal nucleus which tend to form urine stone. The case of urine stone seems to beincreased every year. Crystallization could induce acute tubular necrosis which impact on renal dysfunction.The signs of this condition are high level of urea, creatinine and decrease glomerulus filtration rate. Theobjective of this research was to evaluate the effects of infusum Persea americana Mill as an inhibitorcrystallization which induced by ethylene glycol on white male rats. 20 male rats were divided into 4groups; K1 as negative group received only distilled water ad libitum, K2 as positive group receiveddistilled water containing ethylene glycol, K3 (dose 5% and K4 (dose 10% as treatment groups receivedwater containing ethylene glycol and avocado leaves infusion. Phytochemsitry screening of infusion avocadoleaves consisted of flavonoid, saponin, tanine and quinone. Result of analysis showed that the level ofureum and creatinine on K2 was higher than K3 and K4 group. The increased level could be inhibited byinfusion avocado leaves. The measurement of glomerular filtration rate in treatment groups wassignificantly different (p<0.05. Descriptive histopathology observation showed that renal lesio in grouptreatment (K3 and K4 were declined. Large crystal calcium oxalate on K2 group was observed by usingpolarized microscope, whereas small crystal calcium oxalate were seen in the infusion of avocado leavesgroups. These result showed the ability of infusion of avocado leaves as an inhibitor on the growth ofcrystallization calcium oxalate

  20. Occurrence and characterisation of calcium oxalate crystals in stems and fruits of Hylocereus costaricensis and Selenicereus megalanthus (Cactaceae: Hylocereeae).

    Science.gov (United States)

    Viñas, María; Jiménez, Víctor M

    2016-10-01

    Detailed description about occurrence of calcium oxalate (CaOx) crystals in the edible vine cactus species Hylocereus costaricensis and Selenicereus megalanthus is scarce. Therefore, we evaluated and characterized the presence, morphology and composition of CaOx crystals in both species. Crystals were isolated from greenhouse and in vitro vegetative stems, and from ripe fruit peels and pulp by enzymatic digestion and density centrifugation and quantified with a haemocytometer. Morphologies were studied using scanning electron microscopy, elemental composition with energy-dispersive X-ray spectroscopy and salt composition with X-ray powder diffraction. Analyses conducted confirmed that isolated crystals were exclusively composed by CaOx, both mono- and dihydrated. Highest crystal contents were measured in greenhouse stems, followed by the fruit peels. While very few crystals were quantified in in vitro plants, they were not detected in the fruit pulp at all, which is of advantage for its human consumption and could be linked to mechanisms of seed dispersal through animals. Different crystal morphologies were observed, sometimes varying between genotypes and tissues analysed. This is the first work known to the authors with a detailed characterization of CaOx crystals in vine cacti.

  1. A study on calcium oxalate crystals in Tinantia anomala (Commelinaceae) with special reference to ultrastructural changes during anther development.

    Science.gov (United States)

    Gębura, Joanna; Winiarczyk, Krystyna

    2016-07-01

    Calcium oxalate (CaOx) crystals in higher plants occur in five forms: raphides, styloids, prisms, druses, and crystal sand. CaOx crystals are formed in almost all tissues in intravacuolar crystal chambers. However, the mechanism of crystallization and the role of CaOx crystals have not been clearly explained. The aim of this study was to explore the occurrence and location of CaOx crystals in organs of Tinantia anomala (Torr.) C.B. Clarke (Commelinaceae) with special attention to ultrastructural changes in the quantity of tapetal raphides during microsporogenesis. We observed various parts of the plant, that is, stems, leaves, sepals, petals, anthers, staminal trichomes and stigmatic papillae and identified CaOx crystals in all parts except staminal trichomes and stigmatic papillae in Tinantia anomala. Three morphological forms: styloids, raphides and prisms were found in different amounts in different parts of the plant. Furthermore, in this species, we identified tapetal raphides in anthers. The number of tapetal raphides changed during microsporogenesis. At the beginning of meiosis, the biosynthesis of raphides proceeded intensively in the provacuoles. These organelles were formed from the endoplasmic reticulum system. In the tetrad stage, we observed vacuoles with needle-shaped raphides (type I) always localised in the centre of the organelle. When the amoeboid tapetum was degenerating, vacuoles also began to fade. We observed a small number of raphides in the stage of mature pollen grains.

  2. Urinary Calcium and Oxalate Excretion in Healthy Adult Cats Are Not Affected by Increasing Dietary Levels of Bone Meal in a Canned Diet

    OpenAIRE

    2013-01-01

    This study aimed to investigate the impact of dietary calcium (Ca) and phosphorus (P), derived from bone meal, on the feline urine composition and the urinary pH, allowing a risk assessment for the formation of calcium oxalate (CaOx) uroliths in cats. Eight healthy adult cats received 3 canned diets, containing 12.2 (A), 18.5 (B) and 27.0 g Ca/kg dry matter (C) and 16.1 (A), 17.6 (B) and 21.1 g P/kg dry matter (C). Each diet was fed over 17 days. After a 7 dayś adaptation period, urine and fa...

  3. Isovaline monohydrate

    Directory of Open Access Journals (Sweden)

    Jason P. Dworkin

    2013-12-01

    Full Text Available The title compound, C5H11NO2·H2O, is an isomer of the α-amino acid valine that crystallizes from water in its zwitterion form as a monohydrate. It is not one of the 20 proteinogenic amino acids that are used in living systems and differs from the natural amino acids in that it has no α-H atom. The compound exhibits hydrogen bonding between the water molecule and the carboxylate O atoms and an amine H atom. In addition, there are intermolecular hydrogen-bonding interactions between the carboxylate O atoms and amine H atoms. In the crystal, these extensive N—H...O and O—H...O hydrogen bonds lead to the formation of a three-dimensional network.

  4. Micro-CT observations of the 3D distribution of calcium oxalate crystals in cotyledons during maturation and germination in Lotus miyakojimae seeds.

    Science.gov (United States)

    Yamauchi, Daisuke; Tamaoki, Daisuke; Hayami, Masato; Takeuchi, Miyuki; Karahara, Ichirou; Sato, Mayuko; Toyooka, Kiminori; Nishioka, Hiroshi; Terada, Yasuko; Uesugi, Kentaro; Takano, Hidekazu; Kagoshima, Yasushi; Mineyuki, Yoshinobu

    2013-06-01

    The cotyledon of legume seeds is a storage organ that provides nutrients for seed germination and seedling growth. The spatial and temporal control of the degradation processes within cotyledons has not been elucidated. Calcium oxalate (CaOx) crystals, a common calcium deposit in plants, have often been reported to be present in legume seeds. In this study, micro-computed tomography (micro-CT) was employed at the SPring-8 facility to examine the three-dimensional distribution of crystals inside cotyledons during seed maturation and germination of Lotus miyakojimae (previously Lotus japonicus accession Miyakojima MG-20). Using this technique, we could detect the outline of the embryo, void spaces in seeds and the cotyledon venation pattern. We found several sites that strongly inhibited X-ray transmission within the cotyledons. Light and polarizing microscopy confirmed that these areas corresponded to CaOx crystals. Three-dimensional observations of dry seeds indicated that the CaOx crystals in the L. miyakojimae cotyledons were distributed along lateral veins; however, their distribution was limited to the abaxial side of the procambium. The CaOx crystals appeared at stage II (seed-filling stage) of seed development, and their number increased in dry seeds. The number of crystals in cotyledons was high during germination, suggesting that CaOx crystals are not degraded for their calcium supply. Evidence for the conservation of CaOx crystals in cotyledons during the L. miyakojimae germination process was also supported by the biochemical measurement of oxalic acid levels.

  5. Crystal structure and spectroscopic analysis of a new oxalate-bridged MnII compound: catena-poly[guanidinium [[aquachloridomanganese(II]-μ2-oxalato-κ4O1,O2:O1′,O2′] monohydrate

    Directory of Open Access Journals (Sweden)

    Hiba Sehimi

    2016-05-01

    Full Text Available As part of our studies on the synthesis and the characterization of oxalate-bridged compounds M–ox–M (ox = oxalate dianion and M = transition metal ion, we report the crystal structure of a new oxalate-bridged MnII phase, {(CH6N3[Mn(C2O4Cl(H2O]·H2O}n. In the compound, a succession of MnII ions (situated on inversion centers adopting a distorted octahedral coordination and bridged by oxalate ligands forms parallel zigzag chains running along the c axis. These chains are interconnected through O—H...O hydrogen-bonding interactions to form anionic layers parallel to (010. Individual layers are held together via strong hydrogen bonds involving the guanidinium cations (N—H...O and N—H...Cl and the disordered non-coordinating water molecule (O—H...O and O—H...Cl, as well as by guanidinium π–π stacking. The structural data were confirmed by IR and UV–Visible spectroscopic analysis.

  6. Irritant contact dermatitis caused by needle-like calcium oxalate crystals, raphides, in Agave tequilana among workers in tequila distilleries and agave plantations.

    Science.gov (United States)

    Salinas, M L; Ogura, T; Soffchi, L

    2001-02-01

    It was found that needle-like calcium oxalate crystals, raphides, are found abundantly in all tissues of Agave tequilana plants; thus, 1 droplet (0.03 ml) of juice pressed from leaves contains 100-150 crystals, 30-500 microm in length, sharpened at both ends. In tequila distilleries, 5/6 of the workers who handle the agave stems have experienced the characteristic irritation. In contrast, only 1/3 of workers in agave plantations who harvest agave plants, complain of the irritation. It is confirmed that all the irritation suffered in both distilleries and plantations takes place at bodily locations where the plants come into contact with the worker's skin in the course of their work.

  7. Urinary calcium and oxalate excretion in healthy adult cats are not affected by increasing dietary levels of bone meal in a canned diet.

    Science.gov (United States)

    Passlack, Nadine; Zentek, Jürgen

    2013-01-01

    This study aimed to investigate the impact of dietary calcium (Ca) and phosphorus (P), derived from bone meal, on the feline urine composition and the urinary pH, allowing a risk assessment for the formation of calcium oxalate (CaOx) uroliths in cats. Eight healthy adult cats received 3 canned diets, containing 12.2 (A), 18.5 (B) and 27.0 g Ca/kg dry matter (C) and 16.1 (A), 17.6 (B) and 21.1 g P/kg dry matter (C). Each diet was fed over 17 days. After a 7 dayś adaptation period, urine and faeces were collected over 2×4 days (with a two-day rest between), and blood samples were taken. Urinary and faecal minerals, urinary oxalate (Ox), the urinary pH and the concentrations of serum Ca, phosphate and parathyroid hormone (PTH) were analyzed. Moreover, the urine was microscopically examined for CaOx uroliths. The results demonstrated that increasing levels of dietary Ca led to decreased serum PTH and Ca and increased faecal Ca and P concentrations, but did not affect the urinary Ca or Ox concentrations or the urinary fasting pH. The urinary postprandial pH slightly increased when the diet C was compared to the diet B. No CaOx crystals were detected in the urine of the cats. In conclusion, urinary Ca excretion in cats seems to be widely independent of the dietary Ca levels when Ca is added as bone meal to a typical canned diet, implicating that raw materials with higher contents of bones are of subordinate importance as risk factors for the formation of urinary CaOx crystals.

  8. Urinary calcium and oxalate excretion in healthy adult cats are not affected by increasing dietary levels of bone meal in a canned diet.

    Directory of Open Access Journals (Sweden)

    Nadine Passlack

    Full Text Available This study aimed to investigate the impact of dietary calcium (Ca and phosphorus (P, derived from bone meal, on the feline urine composition and the urinary pH, allowing a risk assessment for the formation of calcium oxalate (CaOx uroliths in cats. Eight healthy adult cats received 3 canned diets, containing 12.2 (A, 18.5 (B and 27.0 g Ca/kg dry matter (C and 16.1 (A, 17.6 (B and 21.1 g P/kg dry matter (C. Each diet was fed over 17 days. After a 7 dayś adaptation period, urine and faeces were collected over 2×4 days (with a two-day rest between, and blood samples were taken. Urinary and faecal minerals, urinary oxalate (Ox, the urinary pH and the concentrations of serum Ca, phosphate and parathyroid hormone (PTH were analyzed. Moreover, the urine was microscopically examined for CaOx uroliths. The results demonstrated that increasing levels of dietary Ca led to decreased serum PTH and Ca and increased faecal Ca and P concentrations, but did not affect the urinary Ca or Ox concentrations or the urinary fasting pH. The urinary postprandial pH slightly increased when the diet C was compared to the diet B. No CaOx crystals were detected in the urine of the cats. In conclusion, urinary Ca excretion in cats seems to be widely independent of the dietary Ca levels when Ca is added as bone meal to a typical canned diet, implicating that raw materials with higher contents of bones are of subordinate importance as risk factors for the formation of urinary CaOx crystals.

  9. STUDIES ON THE THERMAL DECOMPOSITION OF POTASSIUM HYDROGEN OXALATE MONOHYDRATE BY COMBINED THERMAL ANALYSIS AND GAS CHROMATOGRAPHY%热分析与气相色谱联用研究一水合草酸氢钾

    Institute of Scientific and Technical Information of China (English)

    杜廷发; 张世进

    1999-01-01

    The thermal decomposition of KHC2O4.H2O was investigated by means of discontinuous simultaneous techniques of thermal analysis and gas chromatography (TA-GC). In air and helium the decomposition of KHC2O4.H2O was initially a slow dehydration process of the monohydrate, followed by a rapid decomposition of KHC2O4 to K2C2O4 with the production of some gaseous products, O2 (initial stage of decomposition), CO, CO2 and H2O. The decomposition mechanism of KHC2O4 was discussed.%用热分析与气相色谱联用技术(TA-GC)研究KHC2O4·H2O的热分解表明,在空气和氦气当中,开始时缓慢分解,放出结晶水.接着KHC2O4快速分解成K2C2O4,并释放出一些气体产物:O2(分解初期)、CO、CO2和H2O.讨论了KHC2O4的分解机理.

  10. Clinical investigation on gastric oxalate absorption

    Institute of Scientific and Technical Information of China (English)

    陈志强; 叶章群; 曾令启; 杨为民

    2003-01-01

    Objective To study the stomach role in exogenous oxalate absorption.Methods The kinetic variation of urinary oxalate excretion (mg/min) in 10 healthy adults and 8 patients who underwent total gastrectomy was investigated before and after an oral spinach oxalate load. The bioavailability of the oxalate load in the healthy adults was calculated and compared with that in the patients.Results The oxalate content in the oral spinach load was 2567-2670 mg. The urinary oxalate excretion (mg/min) in the 10 healthy adults increased significantly 20 minutes after loading (this increase was compared against their basic oxalate excretion level of 0.0331±0.0203). Further observations after loading include: a first peak of oxalate excretion 40 minutes after loading; an oxalate excretion level double that of the basic level after 60 minutes (0.0732±0.0294) and a second peak appearing at 3 hours (P<0.01). A "first peak" (0.063%±0.062%) was not in any of the patients who underwent a total gastrectomy. Furthermore, a bioavailability of oxalate, which was 50% lower than that in the healthy subjects, appeared 60 minutes after loading (0.098%±0.071%, P<0.01). Conclusions The stomach is a powerful oxalate absorption organ under normal physiological conditions. Further investigation on the relationship between stomach dysfunction and urinary calcium oxalate formation is needed.

  11. Ozone-induced responses in Croton floribundus Spreng. (Euphorbiaceae): metabolic cross-talk between volatile organic compounds and calcium oxalate crystal formation.

    Science.gov (United States)

    Cardoso-Gustavson, Poliana; Bolsoni, Vanessa Palermo; de Oliveira, Debora Pinheiro; Guaratini, Maria Tereza Gromboni; Aidar, Marcos Pereira Marinho; Marabesi, Mauro Alexandre; Alves, Edenise Segala; de Souza, Silvia Ribeiro

    2014-01-01

    Here, we proposed that volatile organic compounds (VOC), specifically methyl salicylate (MeSA), mediate the formation of calcium oxalate crystals (COC) in the defence against ozone (O3) oxidative damage. We performed experiments using Croton floribundus, a pioneer tree species that is tolerant to O3 and widely distributed in the Brazilian forest. This species constitutively produces COC. We exposed plants to a controlled fumigation experiment and assessed biochemical, physiological, and morphological parameters. O3 induced a significant increase in the concentrations of constitutive oxygenated compounds, MeSA and terpenoids as well as in COC number. Our analysis supported the hypothesis that ozone-induced VOC (mainly MeSA) regulate ROS formation in a way that promotes the opening of calcium channels and the subsequent formation of COC in a fast and stable manner to stop the consequences of the reactive oxygen species in the tissue, indeed immobilising the excess calcium (caused by acute exposition to O3) that can be dangerous to the plant. To test this hypothesis, we performed an independent experiment spraying MeSA over C. floribundus plants and observed an increase in the number of COC, indicating that this compound has a potential to directly induce their formation. Thus, the tolerance of C. floribundus to O3 oxidative stress could be a consequence of a higher capacity for the production of VOC and COC rather than the modulation of antioxidant balance. We also present some insights into constitutive morphological features that may be related to the tolerance that this species exhibits to O3.

  12. Ozone-Induced Responses in Croton floribundus Spreng. (Euphorbiaceae): Metabolic Cross-Talk between Volatile Organic Compounds and Calcium Oxalate Crystal Formation

    Science.gov (United States)

    Cardoso-Gustavson, Poliana; Bolsoni, Vanessa Palermo; de Oliveira, Debora Pinheiro; Guaratini, Maria Tereza Gromboni; Aidar, Marcos Pereira Marinho; Marabesi, Mauro Alexandre; Alves, Edenise Segala; de Souza, Silvia Ribeiro

    2014-01-01

    Here, we proposed that volatile organic compounds (VOC), specifically methyl salicylate (MeSA), mediate the formation of calcium oxalate crystals (COC) in the defence against ozone (O3) oxidative damage. We performed experiments using Croton floribundus, a pioneer tree species that is tolerant to O3 and widely distributed in the Brazilian forest. This species constitutively produces COC. We exposed plants to a controlled fumigation experiment and assessed biochemical, physiological, and morphological parameters. O3 induced a significant increase in the concentrations of constitutive oxygenated compounds, MeSA and terpenoids as well as in COC number. Our analysis supported the hypothesis that ozone-induced VOC (mainly MeSA) regulate ROS formation in a way that promotes the opening of calcium channels and the subsequent formation of COC in a fast and stable manner to stop the consequences of the reactive oxygen species in the tissue, indeed immobilising the excess calcium (caused by acute exposition to O3) that can be dangerous to the plant. To test this hypothesis, we performed an independent experiment spraying MeSA over C. floribundus plants and observed an increase in the number of COC, indicating that this compound has a potential to directly induce their formation. Thus, the tolerance of C. floribundus to O3 oxidative stress could be a consequence of a higher capacity for the production of VOC and COC rather than the modulation of antioxidant balance. We also present some insights into constitutive morphological features that may be related to the tolerance that this species exhibits to O3. PMID:25165889

  13. Vibrational spectra of the two hydrates of strontium oxalate.

    Science.gov (United States)

    D'Antonio, Maria C; Torres, María M; Palacios, Daniel; González-Baró, Ana C; Baran, Enrique J

    2015-02-25

    The infrared and Raman spectra of the two hydrates of strontium oxalate, SrC2O4⋅H2O and SrC2O4⋅2H2O, were recorded and discussed on the basis of their structural peculiarities and in comparison with the spectra of the related calcium oxalates and other previously investigated metallic oxalates.

  14. The paradoxical role of urinary macromolecules in the aggregation of calcium oxalate: a further plea to increase diuresis in stone metaphylaxis.

    Science.gov (United States)

    Baumann, J M; Affolter, B

    2016-08-01

    This study was designed to get information on aggregation (AGN) of urinary calcium oxalate crystals (CaOx) which seems to occur in stone formation despite a protecting coat of urinary macromolecules (UMs). CaOx crystallization was directly produced in urine, control and albumin solution by Ox titration and was spectrophotometrically followed. A rapid decrease of optical density indicating AGN was absent in 14 of 15 freshly voided urines of 5 healthy controls. However, in the presence of UM-coated hydroxyapatite all urines with relative high sodium concentration, being an indicator of concentrated urine, showed a pronounced AGN which was abolished when these urines were diluted. Albumin relatively found to be an inhibitor of AGN showed after temporary adsorption on Ca Phosphate (CaP) massive self-AGN and changed to a promoter of CaOx AGN. Self-AGN after adsorption on surfaces especially of CaP, being an important compound of Randall's plaques, can thus explain this paradoxical behavior of UMs. Aggregated UMs probably bridge zones of electrostatic repulsion between UM-coated crystals with identical electrical surface charge. These zones extend by urine dilution which decreases ionic strength. Diminution of urinary concentration by increasing diuresis seems, therefore, to be important in stone metaphylaxis.

  15. Modulation of calcium oxalate dihydrate growth by selective crystal-face binding of phosphorylated osteopontin and polyaspartate peptide showing occlusion by sectoral (compositional) zoning.

    Science.gov (United States)

    Chien, Yung-Ching; Masica, David L; Gray, Jeffrey J; Nguyen, Sarah; Vali, Hojatollah; McKee, Marc D

    2009-08-28

    Calcium oxalate dihydrate (COD) mineral and the urinary protein osteopontin/uropontin (OPN) are commonly found in kidney stones. To investigate the effects of OPN on COD growth, COD crystals were grown with phosphorylated OPN or a polyaspartic acid-rich peptide of OPN (DDLDDDDD, poly-Asp(86-93)). Crystals grown with OPN showed increased dimensions of the {110} prismatic faces attributable to selective inhibition at this crystallographic face. At high concentrations of OPN, elongated crystals with dominant {110} faces were produced, often with intergrown, interpenetrating twin crystals. Poly-Asp(86-93) dose-dependently elongated crystal morphology along the {110} faces in a manner similar to OPN. In crystal growth studies using fluorescently tagged poly-Asp(86-93) followed by imaging of crystal interiors using confocal microscopy, sectoral (compositional) zoning in COD was observed resulting from selective binding and incorporation (occlusion) of peptide exclusively into {110} crystal sectors. Computational modeling of poly-Asp(86-93) adsorption to COD {110} and {101} surfaces also suggests increased stabilization of the COD {110} surface and negligible change to the natively stable {101} surface. Ultrastructural, colloidal-gold immunolocalization of OPN by transmission electron microscopy in human stones confirmed an intracrystalline distribution of OPN. In summary, OPN and its poly-Asp(86-93) sequence similarly affect COD mineral growth; the {110} crystallographic faces become enhanced and dominant attributable to {110} face inhibition by the protein/peptide, and peptides can incorporate into the mineral phase. We, thus, conclude that the poly-Asp(86-93) domain is central to the OPN ability to interact with the {110} faces of COD, where it binds to inhibit crystal growth with subsequent intracrystalline incorporation (occlusion).

  16. Effect of dietary moisture and sodium content on urine composition and calcium oxalate relative supersaturation in healthy miniature schnauzers and labrador retrievers.

    Science.gov (United States)

    Stevenson, A E; Hynds, W K; Markwell, P J

    2003-04-01

    The aim of this series of studies was to evaluate two possible feeding strategies as methods for reducing the risk of calcium oxalate (CaOx) formation in two breeds of healthy dog. The studies compared the effect of dietary moisture (Study 1) and dietary sodium (Na), (Study 2) on urine composition of labrador retrievers (LR) and miniature schnauzers (MS). A nutritionally complete dry dog food was fed to 16 dogs (eight LR, eight MS; Study 1) and 15 dogs (seven LR, eight MS; Study 2) for 24 days (Study 1), or 36 days (Study 2). The dogs were fed the diet alone (7% moisture, 0.06 g Na/100 kcal), or supplemented with deionised water to 73% moisture (Study 1), or dietary Na, to deliver 0.20 or 0.30 g Na per 100 kcal (Study 2). Urine pH, volume, specific gravity, and concentrations of 12 analytes were measured for each dog. Urinary relative supersaturations (RSS) with CaOx were calculated from these values. The effects of supplemental Na or water were established using t tests (Study 1) or analysis of variance, and multiple range tests (least significant difference) (Study 2); Phigh moisture diet may reduce the risk of CaOx formation in high-risk breeds. Increasing dietary Na led to production of urine with a significantly lower CaOx RSS in both breeds, indicating that sodium supplementation to dry diet formats may reduce the risk of CaOx formation. These feeding strategies should be considered when evaluating methods for preventing CaOx formation within high-risk groups.

  17. The changes of CaSR activity on the formation of calcium oxalate stones%钙敏感受体活性改变对大鼠泌尿系草酸钙结石形成的影响

    Institute of Scientific and Technical Information of China (English)

    李笑然; 岳中瑾; 马俊海; 裴薇; 辛文虎; 明星; 杨雄

    2013-01-01

    Objective To study the changes of CaSR activity on the formation of calcium oxalate stones. Methods A-dult male Sprague Dawley rats were given ethylene glycol and ammonium chloride to induce urolithiasis. Meanwhile, different doses of CaSR inhibitors (NPS-2390) were administered. The values of serum urea, creatinine,P,Ca2+ and Mg2+ ,PTH,24 h urine volume,urine pH,Ca2+ , Mg2+and oxalate were evaluated at the end of the experiment. Kidney sections were examined under a light microscope to study the calcium oxalate crystal deposition, pathological changes and the expression of CaSR. Results The urolithiasis induced by ethylene glycol and ammonium chloride caused not only significant increase of serum ure-a,creatinine, urine oxalate and Ca2+ ,but also great amount of calcium oxalate crystal deposition in kidney. PTH secretion of CaSR inhibitor group increased and blood Ca2+ urine Ca2+ raised. Renal histopathologic examination showed significant increase of calcium oxalate crystals in the kidney tissue of the CaSR inhibitor group,and kidney tissue damage was obvious.Conclusions In the kidney and parathyroid gland the low expression of CaSR can increase the formation of calcium oxalate crystal.%目的 探讨钙敏感受体(CaSR)活性改变对草酸钙结石形成的影响.方法 在实验期间给予乙二醇和氯化铵诱导雄性SD大鼠产生泌尿系草酸钙结石.在造模期间给予不同剂量的CaSR抑制剂(NPS-2390).实验结束时检测各组大鼠血尿素氮(BUN)、肌酐(Cr)、血磷、血钙、血镁、PTH的含量、24 h尿量、尿pH值、尿钙、镁、尿草酸的分泌量,显微镜下观察肾组织切片中草酸钙结晶沉积及病理变化情况及肾脏中CaSR表达情况.从而评价CaSR活性的改变对泌尿系结石形成的影响.结果 成石对照组大鼠血BUN、Cr、尿草酸、尿钙较空白组明显升高并且有大量结晶形成,表明建模成功.CaSR抑制剂组较成石对照组甲状旁腺激素(PTH

  18. Experimental study of the inhibitory effect of γ-linolenic acid on calcium oxalate crystalization in rats%月见草油抑制草酸钙结晶形成的实验研究

    Institute of Scientific and Technical Information of China (English)

    张海滨; 石玮; 岳中瑾

    2012-01-01

    目的 了解月见草油在草酸钙结石形成中的作用,为临床治疗提供新的方法与思路.方法 雄性SD大鼠60只,随机分为4组,各组15只.C组和D组以月见草油(含γ-亚麻酸9.2%)或葵花籽油(含亚油酸70%)10 g/kg灌胃4周后,用诱石剂1%乙二醇(EG)加2%氯化氨喂饮,同时继续以月见草油或葵花籽油灌胃4周,8周后检测各组大鼠肾功能、24 h血尿生化指标和肾草酸钙结晶情况;仅饲普通饲料(A组,空白组)和普通饲料加1%乙二醇(EG)加2%氯化氨喂饮(B组,成石组)大鼠作为对照.结果 月见草油组肾组织水肿较轻,肾内草酸钙结晶数及肾成石率低于成石组(P<0.05),尿枸橼酸较成石组高(P<0.01),24 h尿钙、尿草酸排泄均低于成石组(P<0.01),血尿素氮(P<0.01)、血肌酐(P<0.05)低于成石组.结论 γ-亚麻酸能有效改善肾功能,减少尿钙及草酸的排泄,抑制实验鼠肾草酸钙结晶形成,在尿石症防治方面可能有一定应用价值.%Objective To compare the role of y-linolenic acid (y-LNA) in the prevention of stone-forming with that of linoleic acid (LNA). Methods 60 male adult SD rats were divided into 4 groups, group A (normal control), group B (stone forming), group C (evening primrose oil, 9. 2% y-LNA), and group D (sunflower seed oil, 70% LN). Rats in group C were fed with evening primrose oil and rats in group D with sunflower seed oil for 4 weeks. Renal stone formation was induced by 1% ethylene glycol (EG) plus 2% muriate. Meanwhile, gavage was continued with evening primrose oil and sunflower seeds oil. After 8 weeks, all rats were sacrificed and the renal function, 24 h blood and urine biochemical indexes, renal calcium oxalate crystallization and urinary oxalate were detected. Results The parenchymal edema in group C were milder compared with that in group B. Calcium oxalate crystallization, urinary calcium excretion (P<0. 01), urinary oxalate(P<0. 01), blood urea nitrogen (P<0. 01) and creatinine (P<0. 05

  19. Oxalate-Degrading Capacities of Gastrointestinal Lactic Acid Bacteria and Urinary Tract Stone Formation

    OpenAIRE

    Mohammad Kargar; Rouhi Afkari; Sadegh Ghorbani-Dalini

    2013-01-01

    Background: Calcium oxalate is one the most significant causes of human kidney stones. Increasing oxalate uptake results in increased urinary oxalate. Elevated urinary oxalate is one the most important causes of kidney stone formation. This study aims to evaluate oxalate-degrading capacity of lactic acid bacteria and its impact on incidence of kidney stone.Materials and Methods: This case-control study was conducted on serum, urinary, and fecal samples. The research population included a tota...

  20. 姜黄素干预对乙二醇诱导的大鼠肾草酸钙结石形成的影响%Effects of curcumin intervention on ethylene glycol-induced calcium oxalate nephrolithiasis in rats

    Institute of Scientific and Technical Information of China (English)

    卢锋; 张士青

    2012-01-01

    Objective To investigate the effects of curcumin intervention on ethylene glycol-induced calcium oxalate nephrolithiasis in rats. Methods Thirty-two Wistar rats were randomly divided into single nephrolithiasis induction group (calcium oxalate nephrolithiasis induced by 1% ethylene glycol drinking), nephrolithiasis induction + curcumin intervention group (1% ethylene glycol drinking + intragastric administration of 20 mg o kg-1 o d-1 curcumin), single curcumin group (deionized water drinking + intragastric administration of 20 mg o kg-1 o d-1 curcumin) and blank control group (deionized water drinking), with 8 rats in each group. Before and after the experiment (4 weeks after treatment), serum and urine concentrations of ionized calcium and magnesium, urine oxalic acid, urine citric acid and serum concentration of creatinine were measured in rats. Rats were sacrificed, renal tissues were obtained, the content of malondialdehyde (MDA) and activity of total superoxide dismutase (T-SOD) in renal tissues were determined, the formation of calcium oxalate crystals in renal tissues was observed with HE staining, and the apoptosis of renal tubular epithelial cells was detected by TUNEL method. Results Compared with blank control group, the urine oxalic acid, apoptosis index of renal tubular epithelial cells, content of MDA in renal tissues and serum concentration of creatinine were moderately higher, and the urine concentration of ionized magnesium, urine content of citric acid and activity of T-SOD in renal tissues were moderately lower in single curcumin group. Compared with single nephrolithiasis induction group, the urine oxalic acid, apoptosis index of renal tubular epithelial cells and content of MDA in renal tissues were significantly decreased, and the Urine concentration of ionized magnesium, urine content of citric acid and activity of T-SOD in renal tissues were significantly increased in nephrolithiasis induction + curcumin intervention group ( P < 0. 05

  1. 2-Methylaspartic acid monohydrate

    Directory of Open Access Journals (Sweden)

    Ray J. Butcher

    2013-12-01

    Full Text Available The title compound, C5H9NO4·H2O, is an isomer of the α-amino acid glutamic acid that crystallizes from water in its zwitterionic form as a monohydrate. It is not one of the 20 proteinogenic α-amino acids that are used in living systems and differs from the natural amino acids in that it has an α-methyl group rather than an α-H atom. In the crystal, an O—H...O hydrogen bond is present between the acid and water molecules while extensive N—H...O and O—H...O hydrogen bonds link the components into a three-dimensional array.

  2. Oxalate catabolism in Arabidopsis

    Science.gov (United States)

    Oxalic acid is found in most plant species and can serve beneficial roles that protect the plant from a variety of environmental stresses. Excessive amounts of oxalate, however, can be detrimental to plant health. Thus, careful coordination of oxalate metabolism is needed. Despite the important impa...

  3. In vitro studies of calcium mixed minerals growth in different growth faces and semiconductor laser induced suppression of nuclei strategy

    Indian Academy of Sciences (India)

    G Kanchana; P Sundaramoorthi

    2008-12-01

    Kidney stone consists of various organic, inorganic and semi organic compounds. Mineral oxalate monohydrate and di-hydrate are the main organic constituents of kidney stones. However, mechanisms leading to the formation of mineral oxalate kidney stones are not clearly understood. The effect of some urinary stone constituents such as ammonium oxalate, calcium citrate, proteins and trace elements were reported by us. The calcium magnesium hydrogen phosphate (CaMHP) crystals were grown in SMS gel medium which provides the necessary kidney stimuli growth medium. The growth processes were done by single diffusion method for different physical and chemical parameters. The pH range in which HPO$^{2-}_{4}$ ions dominates were considered which in turn is necessary for the growth of CaMHP crystals. In the present study, calcium magnesium hydrogen phosphate (CaMHP) crystals are grown in three different growth faces to attain the total nucleation reduction. As an extension of this research, many characterization studies have been carried out like XRD, FTIR, TGA, SEM and etching and the results are reported.

  4. Nutrition and oxalate metabolism in cats

    NARCIS (Netherlands)

    Dijcker, J.C.

    2013-01-01

    Over the past 30 years, a progressive increase in calcium oxalate (CaOx) urolith prevalence is reported in cats and dogs diagnosed with urolithiasis. This increase in prevalence appears to have occurred since dietary modifications were introduced to address magnesium ammonium phosphate urolithiasis.

  5. Contrasting calcium localization and speciation in leaves of Medicago trunculata mutant COD5 analyzed via synchrotron X-ray techniques

    Science.gov (United States)

    Oxalate-producing plants accumulate calcium oxalate crystals (CaOx(C)) in the range of 3-80%(w/w) of their dry weight, reducing calcium (Ca) bioavailability. The calcium oxalate deficient 5 (cod5) mutant of Medicago truncatula has been previously shown to contain similar Ca, but lower oxalate and Ca...

  6. Oxalate-Degrading Capacities of Gastrointestinal Lactic Acid Bacteria and Urinary Tract Stone Formation

    Directory of Open Access Journals (Sweden)

    Mohammad Kargar

    2013-10-01

    Full Text Available Background: Calcium oxalate is one the most significant causes of human kidney stones. Increasing oxalate uptake results in increased urinary oxalate. Elevated urinary oxalate is one the most important causes of kidney stone formation. This study aims to evaluate oxalate-degrading capacity of lactic acid bacteria and its impact on incidence of kidney stone.Materials and Methods: This case-control study was conducted on serum, urinary, and fecal samples. The research population included a total of 200 subjects divided in two equal groups. They were selected from the patients with urinary tract stones, visiting urologist, and also normal people. The level of calcium, oxalate, and citrate in the urinary samples, parathyroid and calcium in the serum samples, and degrading activity of fecal lactobacillus strains of all the subjects were evaluated. Then, data analysis was carried out using SPSS-11.5, χ2 test, Fisher’s exact test, and analysis of variance. Results: The results revealed that the patients had higher urinary level of oxalate and calcium, as well as higher serum level of parathyroid hormone than normal people. In contrast, urinary level of citrate was higher in normal people. In addition, there was a significant difference between the oxalate-degrading capacities of lactobacillus isolated from the patients and their normal peers.Conclusion: Reduction of digestive lactobacillus-related oxalate-degrading capacity and increased serum level of parathyroid hormone can cause elevated urinary level of oxalate and calcium in people with kidney stone.

  7. 草酸钙结石不同层面的扫描电镜能谱和X线衍射分析%Analysis of the calcium oxalate stone composition in different layers by SEM-EDS and X-ray diffraction

    Institute of Scientific and Technical Information of China (English)

    冯彬; 姜宁; 王国增; 章璟; 刁海彦

    2012-01-01

    目的:分析草酸钙结石不同层面的化学成分,探讨其形成机制.方法:结合扫描电镜能谱分析(SEM-EDS)和X线衍射(XRD)定性、定量分析24例完整草酸钙结石样本不同层面的化学成分.结果:所有结石均为草酸钙混合结石,均含有磷酸钙成分.SEM-EDS显示结石核心、中间、外周的元素含量C(27.97%、30.83%、33.73%)、Ca(12.05%、9.36%、8.95%)、P(3.28%、2.34%、1.67%)差异存在显著性(P<0.05).XRD显示核心区域含有草酸钙和磷酸钙晶体,外层区域仅含有草酸钙晶体.结论:联合运用SEM-EDS和XRD对结石的不同层面进行成分分析,能够较为准确地检测结石的组分和物相.草酸钙混合结石可能起始于磷酸钙晶体的聚集,草酸钙晶体在此基础上沉积生长可能是结石逐渐增大的原因.%Objective To analysis the chemical composition of calcium oxalate stones in different layers and study the mechanisms of their formation. Methods 24 calcium oxalate calculus were collected and analyzed in different layers by scanning electron microscope-energy dispersive spectrometer (SEM-EDS) and X-ray diffraction (XRD). Results The 24 mix stones which major constituent was calcium oxalate all contained calcium phosphate. SEM-EDS showed the percentages of carbon in core , middle and outside of the stone were 27.97%, 30.83%, 33.73%, respectively. Those of calcium werel2.05%, 9.36%,8.95% and phosphorus were 3.28%, 2.34%, 1.67%, which have significant differences (P < 0.05). The XRD indicated that calcium oxalate and calcium phosphate crystals were founded in the core of the stone, while calcium oxalate crystals were founded in the outer layers. Conclusions The results of stone component analysis were more accurate by combining SEM-EDS with XRD. The mixed calcium oxalate stones may originate from the deposit of calcium phosphate crystals and followed by calcium oxalate crystals, which may be the cause of the stone formation.

  8. Extraction and concentration of biogenic calcium oxalate from plant leaves Extração e concentração de oxalato de cálcio biogênico de folhas de plantas

    Directory of Open Access Journals (Sweden)

    Liovando Marciano da Costa

    2009-06-01

    Full Text Available The objective of this study was to extract and concentrate calcium oxalate (CaOx crystals from plant leaves that form the above mentioned crystals. The chemical and physical studies of CaOx from plant to be performed depend on an adequate amount of the crystals. The plant used in this study was croton (Codiaeum variegatum. The leaves were ground in a heavy duty blender and sieved through a 0.20 mm sieve. The suspension obtained was suspended in distilled water. The crystals were concentrated at the bottom of a test tube. The supernatant must be washed until it is free of plant pigments and other organic substances. Biogenic CaOx crystals have well-defined and sharp peaks, indicating very high crystallinity. Moreover, the CaOx crystals were not damaged during the extraction procedure, as can be seen on the scanning electron microscope images. The porposed method can be considered efficient to extract and concentrate biogenic calcium oxalate.O objetivo deste estudo foi extrair e concentrar cristais de oxalato de cálcio (CaOx a partir de folhas de plantas que formam os cristais mencionados. Os estudos químicos e físicos de CaOx de plantas a serem realizados demandam uma massa adequada dos cristais. A planta usada neste estudo foi o cróton (Codiaeum variegatum. As folhas foram trituradas por um liquidificador industrial e peneiradas em peneira de 0,20 mm. Ao suco obtido foi adicionada água destilada. Os cristais foram concentrados no fundo da proveta. É necessário manter a lavagem dos cristais até que o sobrenadante fique livre de pigmentos de plantas e outras substâncias orgânicas. Os cristais de CaOx apresentaram picos bem formados e estreitos, indicando que sua cristalinidade é muito alta; além disso, esses cristais não foram danificados durante o procedimento de extração, o que pode ser visto observando-se as fotos obtidas pelo microscópio eletrônico de varredura. O método apresentado pode ser considerado eficiente para extrair

  9. Oxalate metal complexes in aerosol particles: implications for the hygroscopicity of oxalate-containing particles

    Directory of Open Access Journals (Sweden)

    T. Furukawa

    2011-05-01

    Full Text Available Atmospheric aerosols have both a direct and an indirect cooling effect that influences the radiative balance at the Earth's surface. It has been estimated that the degree of cooling is large enough to weaken the warming effect of carbon dioxide. Among the cooling factors, secondary organic aerosols (SOA play an important role in the solar radiation balance in the troposphere as SOA can act as cloud condensation nuclei (CCN and extend the lifespan of clouds because of their high hygroscopic and water soluble nature. Oxalic acid is an important component of SOA, and is produced via several formation pathways in the atmosphere. However, it is not certain whether oxalic acid exists as free oxalic acid or as metal oxalate complexes in aerosols, although there is a marked difference in their solubility in water and their hygroscopicity. We employed X-ray absorption fine structure spectroscopy to characterize the calcium (Ca and zinc (Zn in aerosols collected at Tsukuba in Japan. Size-fractionated aerosol samples were collected for this purpose using an impactor aerosol sampler. It was shown that 10–60% and 20–100% of the total Ca and Zn in the finer particles (<2.1 μm were present as Ca and Zn oxalate complexes, respectively. Oxalic acid is hygroscopic and can thus increase the CCN activity of aerosol particles, while complexes with various polyvalent metal ions such as Ca and Zn are not hygroscopic, which cannot contribute to the increase of the CCN activity of aerosols. Based on the concentrations of noncomplexed and metal-complexed oxalate species, we found that most of the oxalic acid is present as metal oxalate complexes in the aerosols, suggesting that oxalic acid does not always increase the hygroscopicity of aerosols in the atmosphere. Similar results are expected for other dicarboxylic acids, such as malonic and succinic acids. Thus, it is advisable that the cooling effect of organic aerosols should be estimated by including the

  10. Effects of Modified Jianpi Yishen Decoction on Urinary Osteopontin of Calcium Oxalate Nephrolithiasis Patients After Operation%加味健脾益肾方对草酸钙肾结石患者术后尿骨桥蛋白的影响

    Institute of Scientific and Technical Information of China (English)

    王炎; 林峰; 翁雪云; 许旭敏; 余绍龙; 陈智锋; 温志鹏

    2015-01-01

    目的:观察加味健脾益肾方对草酸钙肾结石患者经皮肾镜碎石取石或输尿管镜碎石取石术后尿骨桥蛋白(OPN)的影响,探讨加味健脾益肾方预防草酸钙肾结石的作用机制。方法将116例草酸钙肾结石术后患者随机分为试验组62例和对照组54例。试验组服用加味健脾益肾方,隔日1次;对照组口服枸橼酸氢钾钠颗粒,每日3次。观察2组患者服药前及服药2、4周时尿OPN、尿钙、尿草酸含量。结果治疗组治疗2、4周时患者尿OPN含量与治疗前比较显著上升(P<0.05),且与对照组比较差异有统计学意义(P<0.05),对照组治疗前后OPN含量比较差异无统计学意义(P>0.05)。2组治疗后尿草酸、尿钙含量与治疗前比较,差异均无统计学意义(P>0.05)。结论加味健脾益肾方可以升高尿中OPN水平,抑制草酸钙结石形成,从而预防草酸钙肾结石经皮肾镜碎石取石或输尿管镜碎石取石术后患者结石复发。%Objective To observe the effects of modified Jianpi Yishen Decoction on urinary osteopontin (OPN) in calcium oxalate nephrolithiasis patients after percutaneous nephrolithotomy (PCNL) or ureteroscope lithotomy (URL);To clarify the mechanism of modified Jianpi Yishen Decoction on the prevention of calcium oxalate kidney stones. Methods Totally 116 calcium oxalate nephrolithiasis patients were randomly divided into trial group (62 cases) and control group (54 cases). The trial group took modified Jianpi Yishen Decoction every other day, while the control group took potassium sodium hydrogen citrate granules three times a day. The concentrations of OPN, urinary calcium and urinary oxalic acid of the patients in the two groups were observed before treatment and 2 weeks and 4 weeks of treatment. Results The concentration of urinary OPN of 2 weeks and 4 weeks of the treatment in the trial group was significantly increased compared with before treatment (P0.05). The

  11. Sobresaturacion urinaria del Oxalato de Calcio más alla de la Nefrolitiasis: La relación con el daño tubulointersticial Urinary calcium oxalate supersaturation beyond nephrolithiasis: Relationship with tubulointerstitial damage

    Directory of Open Access Journals (Sweden)

    J. E. Toblli

    2003-04-01

    Full Text Available Numerosos estudios han demostrado que el producto de la actividad iónica (PAI de oxalato de calcio (OxCa en la orina, como indicador de sobresaturación (SS urinaria, es mayor en pacientes formadores de cálculos que en sujetos normales. Más allá de la relación entre SS urinaria del OxCa y litogénesis, la exposición de OxCa al epitelio tubular puede ocasionar lesiones en la célula tubular y en el intersticio renal. Nuestro objetivo fue evaluar la posible relación entre SS urinaria de OxCa y el daño tubulointersticial (TI en un modelo animal de hiperoxaluria. Durante cuatro semanas, ratas Sprague-Dawley machos, divididas en dos grupos recibieron: grupo 1 Control [G1], (n= 8 agua, grupo 2 [G2], (n = 8 etilenglicol (ETG al 1% en el agua de beber. La SS urinaria de OxCa se valoró mediante el PAI del OxCa. Las lesiones TI se analizaron al finalizar el estudio por microscopía óptica e inmunohistoquímica. El G2 (ETG presentó valores mayores (pA number of studies have demonstrated that the urinary ion activity product (IAP of calcium oxalate (CaOx, as an index of urinary CaOx supersaturation (SS, is higher in renal stone formers than in normal subjects. Besides, the relation between CaOx SS and lithogenesis, crystal CaOx exposition can produce tubular cell as well as renal interstitial lesions. The aim of our study was to evaluate the possible relationship between CaOx SS and tubulointerstitial (TI damage in an animal model of hyperoxaluria. During four weeks, male Sprague-Dawley rats received: G1 (n=8 control regular water, and G2 (n= 8 1% ethylene glycol (ETG (precursor for oxalates in drinking water. In order to evaluate urinary CaOx SS, IAP assessed by Tisselius formula was performed. At the end of the study, renal lesions were evaluated by light microscopy and immunohistochemistry. Animals from G2 (ETG presented higher (p< 0.01 values of: a urinary oxalate excretion; b urinary CaOx SS; c crystalluria score; d proteinuria; and lower (p

  12. Uranyl Oxalate Solubility

    Energy Technology Data Exchange (ETDEWEB)

    Leturcq, G.; Costenoble, S.; Grandjean, S. [CEA Marcoule DEN/DRCP/SCPS/LCA - BP17171 - 30207 Bagnols sur Ceze cedex (France)

    2008-07-01

    The solubility of uranyl oxalate was determined at ambient temperature by precipitation in oxalic-nitric solutions, using an initial uranyl concentration of 0.1 mol/L. Oxalic concentration varied from 0.075 to 0.3 mol/L while nitric concentration ranged between 0.75 and 3 mol/L. Dissolution tests, using complementary oxalic-nitric media, were carried out for 550 hours in order to study the kinetic to reach thermodynamic equilibrium. Similar solubility values were reached by dissolution and precipitation. Using the results, it was possible to draw the solubility surface versus oxalic and nitric concentrations and to determine both the apparent solubility constant of UO{sub 2}C{sub 2}O{sub 4}, 3H{sub 2}O (Ks) and the apparent formation constant of the first uranyl-oxalate complex UO{sub 2}C{sub 2}O{sub 4} (log {beta}1), for ionic strengths varying between 1 and 3 mol/L. Ks and log {beta}1 values were found to vary from 1.9 10{sup -8} to 9.2 10{sup -9} and from 5.95 to 6.06, respectively, when ionic strength varied from 1 to 3 mol/L. A second model may fit our data obtained at an ionic strength of 3 mol/L suggesting as reported by Moskvin et al. (1959) that no complexes are formed for [H{sup +}] at 3 M. The Ks value would then be 1.3 10{sup -8}. (authors)

  13. Sodium 2-mercaptoethanesulfonate monohydrate (coenzyme M sodium salt monohydrate

    Directory of Open Access Journals (Sweden)

    Stefan Mayr

    2008-11-01

    Full Text Available The 2-thioethanesulfonate anion is the smallest known coenzyme in nature (HS–CoM and plays a key role in methanogenesis by anaerobic archaea, as well as in the oxidation of alkenes by Gram-negative and Gram-positive eubacteria. The title compound, Na+·C2H5O3S2−·H2O, is the Na+ salt of HS–CoM crystallized as the monohydrate. Six O atoms form a distorted octahedral coordination geometry around the Na atom, at distances in the range 2.312 (4–2.517 (3 Å. Two O atoms of the sulfonate group, one O atom of each of three other symmetry-related sulfonate groups plus the water O atom form the coordination environment of the Na+ ion. This arrangement forms Na–O–Na layers in the crystal structure, parallel to (100.

  14. Literature review for oxalate oxidation processes and plutonium oxalate solubility

    Energy Technology Data Exchange (ETDEWEB)

    Nash, C. A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-10-01

    A literature review of oxalate oxidation processes finds that manganese(II)-catalyzed nitric acid oxidation of oxalate in precipitate filtrate is a viable and well-documented process. The process has been operated on the large scale at Savannah River in the past, including oxidation of 20 tons of oxalic acid in F-Canyon. Research data under a variety of conditions show the process to be robust. This process is recommended for oxalate destruction in H-Canyon in the upcoming program to produce feed for the MOX facility. Prevention of plutonium oxalate precipitation in filtrate can be achieved by concentrated nitric acid/ferric nitrate sequestration of oxalate. Organic complexants do not appear practical to sequester plutonium. Testing is proposed to confirm the literature and calculation findings of this review at projected operating conditions for the upcoming campaign.

  15. Acúmulo de ácido oxálico e cristais de cálcio em ectomicorrizas de eucalipto.: II- formação de cristais de oxalato de cálcio induzida por fungos ectomicorrízicos em raízes laterais finas Accumulation of oxalic acid and calcium crystals in ectomycorrhizas of eucalypt.: II- calcium oxalate crystal formation induced by ectomicorrhizal fungi in fine lateral roots

    Directory of Open Access Journals (Sweden)

    Jhon Alexander Zambrano Gonzalez

    2009-06-01

    Full Text Available O eucalipto é eficiente na aquisição de Ca do solo, mas pouco se sabe sobre a participação das ectomicorrizas e dos ácidos orgânicos nesse processo em campo. O acúmulo de cristais de Ca (CaOx foi avaliado em, aproximadamente, 2.100 raízes laterais finas e ectomicorrizas do híbrido de Eucalyptus grandis x Eucalyptus urophylla, cultivado por 2,5 anos em área com topografia típica em meia laranja, com vertente côncavo-convexa, na região de Viçosa, MG. Técnicas de microscopia óptica e microscopia eletrônica de varredura foram usadas para a visualização dos CaOx. Em 73,7 % das raízes, ocorreu abundante acúmulo de drusas e grânulos de CaOx nas células do córtex. A presença conspícua de CaOx foi observada em 56,2 % das ectomicorrizas e em 17,5 % das raízes laterais finas não colonizadas, evidenciando o papel das micorrizas no acúmulo de Ca em eucalipto. A forma predominante dos CaOx foram as drusas nas ectomicorrizas e os grânulos cristalinos nas raízes. Os dez morfotipos de ectomicorrizas observados na área diferiram quanto à presença e à morfologia dos CaOx, o que pode representar distintas capacidades dos fungos ectomicorrízicos em fornecer Ca para a planta hospedeira. A análise da superfície do manto das ectomicorrizas por microscopia eletrônica de varredura não evidenciou a presença de CaOx nessa estrutura, confirmando que, nas condições avaliadas, o acúmulo de cristais limita-se ao córtex radicular. Este é o primeiro relato da ocorrência de CaOx em ectomicorrizas de eucalipto no Brasil, com dados que comprovam que há mecanismos de armazenamento de Ca nas ectomicorrizas em áreas com baixa disponibilidade do elemento.Eucalypt is efficient at taking up Ca from the soil, however little is known about the contribution of ectomycorrhizas and organic acids to this process under field conditions. The accumulation of calcium oxalate crystals (CaOx was evaluated in, approximately, 2,100 fine lateral roots

  16. LITERATURE REVIEW FOR OXALATE OXIDATION PROCESSES AND PLUTONIUM OXALATE SOLUBILITY

    Energy Technology Data Exchange (ETDEWEB)

    Nash, C.

    2012-02-03

    A literature review of oxalate oxidation processes finds that manganese(II)-catalyzed nitric acid oxidation of oxalate in precipitate filtrate is a viable and well-documented process. The process has been operated on the large scale at Savannah River in the past, including oxidation of 20 tons of oxalic acid in F-Canyon. Research data under a variety of conditions show the process to be robust. This process is recommended for oxalate destruction in H-Canyon in the upcoming program to produce feed for the MOX facility. Prevention of plutonium oxalate precipitation in filtrate can be achieved by concentrated nitric acid/ferric nitrate sequestration of oxalate. Organic complexants do not appear practical to sequester plutonium. Testing is proposed to confirm the literature and calculation findings of this review at projected operating conditions for the upcoming campaign. H Canyon plans to commence conversion of plutonium metal to low-fired plutonium oxide in 2012 for eventual use in the Mixed Oxide Fuel (MOX) Facility. The flowsheet includes sequential operations of metal dissolution, ion exchange, elution, oxalate precipitation, filtration, and calcination. All processes beyond dissolution will occur in HB-Line. The filtration step produces an aqueous filtrate that may have as much as 4 M nitric acid and 0.15 M oxalate. The oxalate needs to be removed from the stream to prevent possible downstream precipitation of residual plutonium when the solution is processed in H Canyon. In addition, sending the oxalate to the waste tank farm is undesirable. This report addresses the processing options for destroying the oxalate in existing H Canyon equipment.

  17. In vivo evaluation of injectable calcium phosphate cement composed of Zn- and Si-incorporated β-tricalcium phosphate and monocalcium phosphate monohydrate for a critical sized defect of the rabbit femoral condyle.

    Science.gov (United States)

    Paul, Kallyanashis; Lee, Byung Yeol; Abueva, Celine; Kim, Boram; Choi, Hwan Jun; Bae, Sang Ho; Lee, Byong Taek

    2017-02-01

    Zinc (Zn) enhances bone formation with mineralization and is an essential element of osteoblastic proliferation. Silicon (Si) is important in apatite formation coupled with the promotion of osteogenesis. The primary focus of this work was the assessment of the bone healing capacity of calcium phosphate cements (CPC) composed of Zn- and Si-incorporated β-tri calcium phosphate (TCP) and mono calcium phosphate mono hydrate (MCPM). Zn- and Si-incorporated β-TCP was synthesized through a sol gel process with varying amounts of Zn: (3, 6, or 9% w/w) and 15% w/w Si. Fabricated CPC samples were characterized by scanning electron microscopy, setting time, injectability, compressive strength and initial pH change with time. Compositional analysis and the effects of Zn and Si on cellular interaction were evaluated by energy dispersive X-ray spectroscopy mapping, viability determination and F-actin assay. The data were used to optimize the CPC formulation. The efficacy of bone healing was investigated via implantation into critical sized rabbit femoral condyle defects for 4 and 8 weeks. CPC cement with 6% (w/w) Zn content was the best candidate for faster bone healing (bone to tibial volume ratio in 8 weeks: 22.78% ± 0.02). Significantly faster degradation was also revealed. Bone healing was significantly delayed when CPC cement with 9% (w/w) Zn was used. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 260-271, 2017.

  18. Tetraphenylphosphonium hydrogen oxalate

    Directory of Open Access Journals (Sweden)

    Philip A. W. Dean

    2008-01-01

    Full Text Available In the title compound, C24H20P+·C2HO4−, two symmetry-independent ion pairs are present. The cations aggregate into puckered sheets via zigzag infinite chains of sixfold phenyl embraces and parallel fourfold phenyl embraces, while the anions form hydrogen-bonded chains between the sheets of cations. In the two independent oxalate anions, the angles between the normals to the two least-squares carboxylate COO planes are unusually large, viz. 72.5 (1 and 82.1 (1°.

  19. Renal lithiasis and nutrition

    Directory of Open Access Journals (Sweden)

    Prieto Rafel M

    2006-09-01

    Full Text Available Abstract Renal lithiasis is a multifactorial disease. An important number of etiologic factors can be adequately modified trough diet, since it must be considered that the urine composition is directly related to diet. In fact, the change of inappropriate habitual diet patterns should be the main measure to prevent kidney stones. In this paper, the relation between different dietary factors (liquid intake, pH, calcium, phosphate, oxalate, citrate, phytate, urate and vitamins and each type of renal stone (calcium oxalate monohydrate papillary, calcium oxalate monohydrate unattached, calcium oxalate dihydrate, calcium oxalate dihydrate/hydroxyapatite, hydroxyapatite, struvite infectious, brushite, uric acid, calcium oxalate/uric acid and cystine is discussed.

  20. Renal lithiasis and nutrition.

    Science.gov (United States)

    Grases, Felix; Costa-Bauza, Antonia; Prieto, Rafel M

    2006-09-06

    Renal lithiasis is a multifactorial disease. An important number of etiologic factors can be adequately modified through diet, since it must be considered that the urine composition is directly related to diet. In fact, the change of inappropriate habitual diet patterns should be the main measure to prevent kidney stones. In this paper, the relation between different dietary factors (liquid intake, pH, calcium, phosphate, oxalate, citrate, phytate, urate and vitamins) and each type of renal stone (calcium oxalate monohydrate papillary, calcium oxalate monohydrate unattached, calcium oxalate dihydrate, calcium oxalate dihydrate/hydroxyapatite, hydroxyapatite, struvite infectious, brushite, uric acid, calcium oxalate/uric acid and cystine) is discussed.

  1. Functional characterization of the oxaloacetase encoding gene and elimination of oxalate formation in the β-lactam producer Penicillium chrysogenum

    NARCIS (Netherlands)

    Daran, J.M.; Pronk, J.T.; Driessen, A.J.M.; Nijland, J.G.; Lamboo, F.; Puig-Martinez, M.; Veiga, T.; Gombert, A.K.

    2011-01-01

    Penicillium chrysogenum is widely used as an industrial antibiotic producer, in particular in the synthesis of ß-lactam antibiotics such as penicillins and cephalosporins. In industrial processes, oxalic acid formation leads to reduced product yields. Moreover, precipitation of calcium oxalate compl

  2. Effect of different brewing times on soluble oxalate content of loose-packed black teas and tea bags.

    Science.gov (United States)

    Mahdavi, Reza; Lotfi Yagin, Neda; Liebman, Michael; Nikniaz, Zeinab

    2013-02-01

    Because of the postulated role of increased dietary oxalate intake in calcium oxalate stone formation, the effect of different brewing times on soluble oxalate contents of loose-packed black tea and tea bags was studied. The oxalate content of 25 different samples of loose-packed black teas after brewing at 5, 10, 15, 30, and 60 min and of ten brands of tea bags after infusion for 1, 2, 3, 4, and 5 min was measured by enzymatic assay. The oxalate concentration resulting from different brewing times ranged from 4.3 to 6.2 mg/240 ml for loose-packed black teas and from 2.7 to 4.8 mg/240 ml for tea bags. There was a stepwise increase in oxalate concentration associated with increased brewing times.

  3. Metal complexation inhibits the effect of oxalic acid in aerosols as cloud condensation nuclei (CCN

    Directory of Open Access Journals (Sweden)

    T. Furukawa

    2010-11-01

    Full Text Available Atmospheric aerosols have both a direct and an indirect cooling effect that influences the radiative balance at the Earth's surface. It has been estimated that the degree of cooling is large enough to cancel the warming effect of carbon dioxide. Among the cooling factors, secondary organic aerosols (SOA play a key role in the solar radiation balance in the troposphere as SOA can act as cloud condensation nuclei (CCN and extend the lifespan of clouds because of their high hygroscopic and water soluble nature. Oxalic acid is one of the major components of SOA, and is produced via several formation pathways in the atmosphere. However, it is not certain whether oxalic acid exists as free oxalic acid or as metal oxalate complexes in aerosols, although there is a marked difference in their solubility in water and their hygroscopicity. We employed X-ray absorption fine structure spectroscopy to characterize the calcium (Ca and zinc (Zn in aerosols collected at Tsukuba in Japan with fractionation based on particle size using an impactor aerosol sampler. It was shown that 10–60% and 20–100% of the total Ca and Zn in the finer particles (<2.1 μm were present as Ca and Zn oxalate complexes, respectively. Oxalic acid can act as CCN because of its hygroscopic properties, while metal complexes are not hygroscopic, and so cannot be CCN. Based on the concentration of noncomplexed and metal-complexed oxalate species, we found that most of the oxalic acid is present as metal oxalate complexes in the aerosols, suggesting that oxalic acid does not act as CCN in the atmosphere. Similar results are expected for other dicarboxylic acids, such as malonic and succinic acids. Thus, it is possible that the cooling effect of organic aerosols assumed in various climate modeling studies is overestimated because of the lack of information on metal oxalate complexes in aerosols.

  4. Effect calcusol to reduce the calcium crystal retention in kidney epithelial cells model of nephrolothiasis

    Directory of Open Access Journals (Sweden)

    Ahmad Soni

    2014-12-01

    Full Text Available Kidney stones is a disease that characterized by a disturbance in the bladder. The main constituent of kidney stones namely Calcium Oxalate Monohydrate (COM crystals. The presence of a COM crystal adhesion to renal tubular cells, will initiate the internalization which will further lead to the formation of crystals retention in the kidney. In Indonesia, there are many herbal products are considered able to cope the complaints due to the kidney stone disease. One of the herbal product is Calcusol „¢, which is the main constituent of those herbal product was the leaf extract of tempuyung. This study observed the effectiveness of Calcusol „¢ in reducing crystals retention that was formed in kidney epithelial cells model of nephrolithiasis. The result showed that Calcusol „¢ is able to reduce the average number of calcium crystals retention in the renal epithelial cells. It indicate that Calcusol „¢ has the ability to reduce crystals retention that already formed in renal epithelial cells. Furthermore, the results of this study are expected to be one of the considerations for further research on the potential of overcoming Calcusol „¢ in kidney stone disease

  5. Functional characterization of the oxaloacetase encoding gene and elimination of oxalate formation in the β-lactam producer Penicillium chrysogenum.

    Science.gov (United States)

    Gombert, A K; Veiga, T; Puig-Martinez, M; Lamboo, F; Nijland, J G; Driessen, A J M; Pronk, J T; Daran, J M

    2011-08-01

    Penicillium chrysogenum is widely used as an industrial antibiotic producer, in particular in the synthesis of ß-lactam antibiotics such as penicillins and cephalosporins. In industrial processes, oxalic acid formation leads to reduced product yields. Moreover, precipitation of calcium oxalate complicates product recovery. We observed oxalate production in glucose-limited chemostat cultures of P. chrysogenum grown with or without addition of adipic acid, side-chain of the cephalosporin precursor adipoyl-6-aminopenicillinic acid (ad-6-APA). Oxalate accounted for up to 5% of the consumed carbon source. In filamentous fungi, oxaloacetate hydrolase (OAH; EC3.7.1.1) is generally responsible for oxalate production. The P. chrysogenum genome harbours four orthologs of the A. niger oahA gene. Chemostat-based transcriptome analyses revealed a significant correlation between extracellular oxalate titers and expression level of the genes Pc18g05100 and Pc22g24830. To assess their possible involvement in oxalate production, both genes were cloned in Saccharomyces cerevisiae, yeast that does not produce oxalate. Only the expression of Pc22g24830 led to production of oxalic acid in S. cerevisiae. Subsequent deletion of Pc22g28430 in P. chrysogenum led to complete elimination of oxalate production, whilst improving yields of the cephalosporin precursor ad-6-APA.

  6. Analytical Study of Oxalates Coprecipitation

    Directory of Open Access Journals (Sweden)

    Liana MARTA

    2003-03-01

    Full Text Available The paper deals with the establishing of the oxalates coprecipitation conditions in view of the synthesis of superconducting systems. A systematic analytical study of the oxalates precipitation conditions has been performed, for obtaining superconducting materials, in the Bi Sr-Ca-Cu-O system. For this purpose, the formulae of the precipitates solubility as a function of pH and oxalate excess were established. The possible formation of hydroxo-complexes and soluble oxalato-complexes was taken into account. A BASIC program was used for tracing the precipitation curves. The curves of the solubility versus pH for different oxalate excess have plotted for the four oxalates, using a logaritmic scale. The optimal conditions for the quantitative oxalate coprecipitation have been deduced from the diagrams. The theoretical curves were confirmed by experimental results. From the precursors obtained by this method, the BSCCO superconducting phases were obtained by an appropriate thermal treatment. The formation of the superconducting phases was identified by X-ray diffraction analysis.

  7. Aluminum-activated Oxalate Secretion does not Associate with Internal Content among Some Oxalate Accumulators

    Institute of Scientific and Technical Information of China (English)

    Jian Li Yang; Lei Zhang; Shao Jian Zheng

    2008-01-01

    Although aluminum (AI)-activated secretion of oxalate has been considered to be an Important AI-exclusion mechanism,whether it is a general response in oxalate accumulators and related to oxalate content in roots are still not clear.Here,we examined the oxalate secretion and oxalate content in some oxalate accumulators,and investigated the role of oxalate secretion in AI resistance.When oxalate content in amaranth roots was decreased by about 50% with the increased ratio of NH4+-N to NO3——N in nutrient solution,the amount of AI-activated oxalate secretion still remained constant.There was no relationship between the content of the water soluble oxalate in four species of oxalate accumulators and the amount of the AI-activated oxalate secretion in roots.Furthermore,oxalate secretion is poorly associated with AI resistance among these species.Based on the above results,we concluded that although all of the oxalate accumulators tested could secrete oxalate rapidly,the density of anion channels in plasma membrane may play a more important role in AI-activated oxalate secretion.Key words: aluminum toxicity; Amaranthus; anion channel; oxalate accumulator; oxalate secretion.

  8. A Search for Interstellar Monohydric Thiols

    Science.gov (United States)

    Gorai, Prasanta; Das, Ankan; Das, Amaresh; Sivaraman, Bhalamurugan; Etim, Emmanuel E.; Chakrabarti, Sandip K.

    2017-02-01

    It has been pointed out by various astronomers that a very interesting relationship exists between interstellar alcohols and the corresponding thiols (sulfur analog of alcohols) as far as the spectroscopic properties and chemical abundances are concerned. Monohydric alcohols such as methanol and ethanol are widely observed and 1-propanol was recently claimed to have been seen in Orion KL. Among the monohydric thiols, methanethiol (chemical analog of methanol) has been firmly detected in Orion KL and Sgr B2(N2) and ethanethiol (chemical analog of ethanol) has been observed in Sgr B2(N2), though the confirmation of this detection is yet to come. It is very likely that higher order thiols could be observed in these regions. In this paper, we study the formation of monohydric alcohols and their thiol analogs. Based on our quantum chemical calculation and chemical modeling, we find that the Tg conformer of 1-propanethiol is a good candidate of astronomical interest. We present various spectroscopically relevant parameters of this molecule to assist in its future detection in the interstellar medium.

  9. The role of intestinal oxalate transport in hyperoxaluria and the formation of kidney stones in animals and man.

    Science.gov (United States)

    Whittamore, Jonathan M; Hatch, Marguerite

    2017-02-01

    The intestine exerts a considerable influence over urinary oxalate in two ways, through the absorption of dietary oxalate and by serving as an adaptive extra-renal pathway for elimination of this waste metabolite. Knowledge of the mechanisms responsible for oxalate absorption and secretion by the intestine therefore have significant implications for understanding the etiology of hyperoxaluria, as well as offering potential targets for future treatment strategies for calcium oxalate kidney stone disease. In this review, we present the recent developments and advances in this area over the past 10 years, and put to the test some of the new ideas that have emerged during this time, using human and mouse models. A key focus for our discussion are the membrane-bound anion exchangers, belonging to the SLC26 gene family, some of which have been shown to participate in transcellular oxalate absorption and secretion. This has offered the opportunity to not only examine the roles of these specific transporters, revealing their importance to oxalate homeostasis, but to also probe the relative contributions made by the active transcellular and passive paracellular components of oxalate transport across the intestine. We also discuss some of the various physiological stimuli and signaling pathways which have been suggested to participate in the adaptation and regulation of intestinal oxalate transport. Finally, we offer an update on research into Oxalobacter formigenes, alongside recent investigations of other oxalate-degrading gut bacteria, in both laboratory animals and humans.

  10. Inhibition of oxalate nephrolithiasis with Ammi visnaga (AI-Khillah).

    Science.gov (United States)

    Khan, Z A; Assiri, A M; Al-Afghani, H M; Maghrabi, T M

    2001-01-01

    We investigated the effect of Ammi visnaga seeds on experimentally - induced kidney stones - in male Wistar albino rats. Oxalate nephrolithiasis was experimentally induced by 3% glycolic acid (added in their diet) given for the period of four weeks. A highly significant amount of deposits were found in the kidneys, which were analyzed quantitatively. These deposits were mainly of calcium oxalate in composition. Daily oral (gavage) treatment with Ammi visnaga (500 mg/kg) highly reduced the incidence of nephrolithiasis (calcium oxalate deposition in the kidneys). Ammi visnaga seeds extract showed highly potent diuretic activity. The reduction in body weight, increase in kidneys weight, increase in water intake, decrease in urine output found in glycolic acid control group were prevented to various extent on Ammi visnaga treatment; and the values became to insignificant difference with control group. The changes in weights of liver, heart and lungs of the three groups were insignificant. Uraemia and hyperbilirubinaemia observed in glycolic acid control group were found to be ameliorated by Ammi visnaga seed extract treatment.

  11. Effect of Kimchi Fermentation on Oxalate Levels in Silver Beet (Beta vulgaris var. cicla).

    Science.gov (United States)

    Wadamori, Yukiko; Vanhanen, Leo; Savage, Geoffrey P

    2014-04-23

    Total, soluble and insoluble oxalates were extracted and analyzed by high performance liquid chromatography (HPLC) following the preparation of kimchi using silver beet (Beta vulgaris var. cicla) stems and leaves. As silver beet contains high oxalate concentrations and consumption of high levels can cause the development of kidney stones in some people, the reduction of oxalate during preparation and fermentation of kimchi was investigated. The silver beet stems and leaves were soaked in a 10% brine solution for 11 h and then washed in cold tap water. The total, soluble and insoluble oxalate contents of the silver beet leaves were reduced by soaking in brine, from 4275.81 ± 165.48 mg/100 g to 3709.49 ± 216.51 mg/100 g fresh weight (FW). Fermenting the kimchi for 5 days at 19.3 ± 0.8 °C in 5 L ceramic jars with a water airtight seal resulted in a mean 38.50% reduction in total oxalate content and a mean 22.86% reduction in soluble oxalates. The total calcium content was essentially the same before and after the fermentation of the kimchi (mean 296.1 mg/100 g FW). The study showed that fermentation of kimchi significantly (p < 0.05) reduced the total oxalate concentration in the initial mix from 609.32 ± 15.69 to 374.71 ± 7.94 mg/100 g FW in the final mix which led to a 72.3% reduction in the amount of calcium bound to insoluble oxalate.

  12. Urolithiasis in a herd of beef cattle associated with oxalate ingestion.

    Science.gov (United States)

    Waltner-Toews, D; Meadows, D H

    1980-02-01

    An unusually high incidence of urinary calculi in a group of feeder cattle is described. Necropsy findings in one affected animal suggested that oxalates in the feed, specifically in fescue (Festuca spp.) seed screenings, may have been the cause. Low dietary calcium and decreased water intake by the cattle appear to have been predisposing factors. Control measures are discussed.

  13. Urolithiasis in a Herd of Beef Cattle Associated with Oxalate Ingestion

    OpenAIRE

    Waltner-Toews, D; Meadows, D H

    1980-01-01

    An unusually high incidence of urinary calculi in a group of feeder cattle is described. Necropsy findings in one affected animal suggested that oxalates in the feed, specifically in fescue (Festuca spp.) seed screenings, may have been the cause. Low dietary calcium and decreased water intake by the cattle appear to have been predisposing factors. Control measures are discussed.

  14. A model of relationship between climate and soil factors related to oxalate content in porang (Amorphophallus muelleri Blume corm

    Directory of Open Access Journals (Sweden)

    SERAFINAH INDRIYANI

    2011-01-01

    Full Text Available Indriyani S, Arisoesilaningsih E, Wardiyati T, Purnobasuki H (2011 A model of relationship between climate and soil factors related to oxalate content in porang (Amorphophallus muelleri Blume corm. Biodiversitas 12: 45-51. The abiotic environment as well as the biotic environment, involved climate and soil affect directly or indirectly to plant growth as well as plant substance. The objective of the research was to obtain a model of relationship between climate and soil factors related to oxalate content in porang corm. Porang corms were collected from five locations of porang agroforestry in East Java. The locations were (i Klangon Village, Saradan Subdistrict, Madiun District; (ii Klino Villlage, Sekar Subdistrict, Bojonegoro District; (iii Bendoasri Village, Rejoso Subdistrict, Nganjuk District; (iv Sugihwaras Village, Nggluyu Subdistrict, Nganjuk District and (v Kalirejo Village, Kalipare Subdistrict, Malang District. Geography variable consist of altitude. Climate variables consist of percentage of radiation, temperature and rainfall. Soil variables consist of electrical conductivity, pH, soil specific gravity, soil organic matter, available of calcium, and cation exchange capacity (CEC. Vegetation variables consist of species of plant tree and percentage of coverage. Porang vegetative growth variables consist of plant height, number of bulbil, canopy diameter, and petiole diameter. Corm variables consist of corm diameter, corm weight, and corm specific gravity. Oxalate variables consist of total oxalate, soluble oxalate, insoluble oxalate, and density of calcium oxalate crystal. Oxalate contents were measured based on AOAC method. All of variables were collected from first to fourth growth period of porang. Data were analyzed by smartPLS (Partial Least Square software. The results showed that there were significantly direct effect between altitude and temperature, altitude and CEC of soil, temperature and CEC of soil, altitude and

  15. Enzymatic Method for Rapid Determination of Oxalic Acid in Bleaching Filtrates from the Pulp and Paper Industry

    Institute of Scientific and Technical Information of China (English)

    HONG Feng; SJ(O)DE Anders; NILVEBRANT Nils-Olof; J(O)NSSON Leif J.

    2005-01-01

    Bleaching with oxygen-containing agents and recirculation of process streams in the pulp and paper industry has increased the accumulation of oxalic acid and danger for precipitation of calcium oxalate encrusts, scaling. Analysis and control of oxalic acid in bleaching filtrates is therefore becoming increasingly important in the pulp and paper industry.Chromatographic methods, such as IC and HPLC, are generally more time-consuming but are valuable as standard methods for determination of oxalic acid. However, the instrumentation needed is expensive and stationary. In this study, an enzymatic method based on oxalate oxidase and peroxidase was developed to determine oxalic acid in authentic bleaching filtrates using a spectrophotometer. The results showed that bleaching filtrates contain some compounds interfering with the enzymatic method.Pretreatment of the samples with activated charcoal was a successful approach for decreasing problems with interference. By using dilution followed by charcoal treatment, the results obtained from five bleaching filtrates with the colorimetric method correlated very well with those obtained using IC. This study offers a selective, fast and mobile analysis method to determine oxalic acid in bleaching filtrates from the pulp and paper industry. The convenient enzyme-based method improves the possibilities for control of critical oxalic acid concentrations in closed-loop bleaching streams.

  16. Variation in oxalate and oxalate decarboxylase production by six species of brown and white rot fungi

    DEFF Research Database (Denmark)

    Hastrup, Anne Christine Steenkjær; Oliver, Jason; Howell, Caitlin;

    cell lumen where it quickly dissociates into hydrogen ions and oxalate, resulting in a pH decrease of the environment, and oxalate-cation complexes. Generally, brown rot fungi accumulate larger quantities of oxalic acid in the wood than white rot fungi. The amount of oxalic acid has been shown to vary...... of formic acid and CO2 (Makela et al., 2002). So far only a few species of brown rot fungi have been shown to accumulate this enzyme (Micales, 1995, Howell and Jellison, 2006).   The purpose of this study was to investigate the variation in the levels of soluble oxalate and total oxalate, in correlation...

  17. An aqueous extract of Ammi visnaga fruits and its constituents khellin and visnagin prevent cell damage caused by oxalate in renal epithelial cells.

    Science.gov (United States)

    Vanachayangkul, P; Byer, K; Khan, S; Butterweck, V

    2010-07-01

    Teas prepared from the fruits of Ammi visnaga L. (syn. "Khella") have been traditionally used in Egypt as a remedy to treat kidney stones. It was the aim of our study to evaluate the effect of a Khella extract (KE) as well as the two major constituents khellin and visnagin on renal epithelial injury using LLC-PK1 and Madin-Darby-canine kidney (MDCK) cells. Both cell lines provide suitable model systems to study cellular processes that are possibly involved in the development of a renal stone. LLC-PK1 and MDCK cell lines were exposed to 300 microM oxalate (Ox) or 133 microg/cm(2) calcium oxalate monohydrate (COM) in presence or absence of 10, 50, 100 or 200 microg/mL KE. To evaluate cell damage, cell viability was assessed by determining the release of lactate dehydrogenase (LDH). KE (e.g. 100 microg/ml) significantly decreased LDH release from LLC-PK1 (Ox: 8.46+0.76%; Ox + 100 microg/ml KE: 5.41+0.94%, p<0.001) as well as MDCK cells (Ox: 30.9+6.58%; Ox+100 microg/ml KE: 17.5+2.50%, p<0.001), which indicated a prevention of cell damage. Similar effects for KE were observed in both cell lines when COM crystals were added. In LLC-PK1 cells khellin and visnagin both decreased the % LDH release significantly in cells that were pretreated with Ox or COM crystals. However, khellin and visnagin exhibited different responses in MDCK cells. Whereas khellin slightly reduced the % LDH release after exposure of the cells to Ox and COM crystals, visnagin significantly decreased % LDH release only after COM crystal exposure. Overall both compounds were more active in LLC-PK1 than in MDCK cells. In summary, exposure of renal epithelial cells to Ox or COM crystals was associated with a significant release of LDH indicating cell injury. Our data demonstrate that KE as well as khellin and visnagin could prevent renal epithelial cell damage caused by Ox and COM and could therefore play a potential role in the prevention of stone formation associated with hyperoxaluria.

  18. Hyperoxaluria in idiopathic calcium nephrolithiasis--what are the limits?

    DEFF Research Database (Denmark)

    Osther, P J

    1999-01-01

    OBJECTIVE: The object of this study was to investigate the role for measurement of 24-h renal oxalate excretion in the evaluation of idiopathic calcium stone formers. MATERIALS AND METHODS: Renal excretion rates of oxalate and creatinine were measured in 24-h urines in 46 consecutive male recurrent...

  19. Synthesis and magnetic properties of one-dimensional metal oxalate networks as molecular-based magnets

    Indian Academy of Sciences (India)

    B P Singh; B Singh

    2000-02-01

    The homo- and heteropolymetallic assemblies of MM′(OX)2(H2O)4, where MM′ represents MnMn, CoMn, NiMn, CuMn, CoCo, NiCo, CuCo, NiNi, CuNi, and CuCu; and the respective complexes, numbered 1–10, have been prepared by reacting metal(II) salts—i.e. of Mn, Co, Ni, and Cu—and potassium oxalate monohydrate in hot water (90–100°C). The magnetic susceptibility data of the complexes 8 and 9 in the 300 K–20 K temperature range obeys the Curie–Weiss law and exhibits Weiss constants – 50 K and – 100 K, respectively. On lowering the temperature, the effective magnetic moment decreases gradually and is indicative of antiferromagnetic phase transition. The complexes have also been characterized by ES mass spectrometry, infrared (IR), electronic, and electron spin resonance (ESR) spectra.

  20. In vivo oxalate degradation by liposome encapsulated oxalate oxidase in rat model of hyperoxaluria

    Directory of Open Access Journals (Sweden)

    Tulika Dahiya

    2013-01-01

    Interpretation & conclusions: EMA-oxalate oxidase encapsulated liposome caused oxalate degradation in experimental hyperoxaluria indicating that the enzyme could be used as a therapeutic agent in hyperoxaluria leading to urinary stones.

  1. Trapping crystal nucleation of cholesterol monohydrate

    DEFF Research Database (Denmark)

    Solomonov, I.; Weygand, M.J.; Kjær, K.

    2005-01-01

    Crystalline nucleation of cholesterol at the air-water interface has been studied via grazing incidence x-ray diffraction using synchrotron radiation. The various stages of cholesterol molecular assembly from monolayer to three bilayers incorporating interleaving hydrogen-bonded water layers...... in a monoclinic cholesterol . H2O phase, has been monitored and their structures characterized to near atomic resolution. Crystallographic evidence is presented that this multilayer phase is similar to that of a reported metastable cholesterol phase of undetermined structure obtained from bile before...... transformation to the triclinic phase of cholesterol . H2O, the thermodynamically stable macroscopic form. According to grazing incidence x-ray diffraction measurements and crystallographic data, a transformation from the monoclinic film structure to a multilayer of the stable monohydrate phase involves...

  2. 2-Methyl­aspartic acid monohydrate

    OpenAIRE

    Brewer, Greg; Burton, Aaron S.; Dworkin, Jason P.; Butcher, Ray J.

    2013-01-01

    The title compound, C5H9NO4·H2O, is an isomer of the α-amino acid glutamic acid that crystallizes from water in its zwitterionic form as a monohydrate. It is not one of the 20 proteinogenic α-amino acids that are used in living systems and differs from the natural amino acids in that it has an α-methyl group rather than an α-H atom. In the crystal, an O—H⋯O hydrogen bond is present between the acid and water mol­ecules while extensive N—H⋯O and O—H⋯O hydrogen bonds link the components into a ...

  3. Genome wide analysis of differentially expressed genes in HK-2 cells, a line of human kidney epithelial cells in response to oxalate.

    Directory of Open Access Journals (Sweden)

    Sweaty Koul

    Full Text Available Nephrolithiasis is a multi-factorial disease which, in the majority of cases, involves the renal deposition of calcium oxalate. Oxalate is a metabolic end product excreted primarily by the kidney. Previous studies have shown that elevated levels of oxalate are detrimental to the renal epithelial cells; however, oxalate renal epithelial cell interactions are not completely understood. In this study, we utilized an unbiased approach of gene expression profiling using Affymetrix HG_U133_plus2 gene chips to understand the global gene expression changes in human renal epithelial cells [HK-2] after exposure to oxalate. We analyzed the expression of 47,000 transcripts and variants, including 38,500 well characterized human genes, in the HK2 cells after 4 hours and 24 hours of oxalate exposure. Gene expression was compared among replicates as per the Affymetrix statistical program. Gene expression among various groups was compared using various analytical tools, and differentially expressed genes were classified according to the Gene Ontology Functional Category. The results from this study show that oxalate exposure induces significant expression changes in many genes. We show for the first time that oxalate exposure induces as well as shuts off genes differentially. We found 750 up-regulated and 2276 down-regulated genes which have not been reported before. Our results also show that renal cells exposed to oxalate results in the regulation of genes that are associated with specific molecular function, biological processes, and other cellular components. In addition we have identified a set of 20 genes that is differentially regulated by oxalate irrespective of duration of exposure and may be useful in monitoring oxalate nephrotoxicity. Taken together our studies profile global gene expression changes and provide a unique insight into oxalate renal cell interactions and oxalate nephrotoxicity.

  4. Fungi, bacteria and soil pH: the oxalate-carbonate pathway as a model for metabolic interaction.

    Science.gov (United States)

    Martin, Gaëtan; Guggiari, Matteo; Bravo, Daniel; Zopfi, Jakob; Cailleau, Guillaume; Aragno, Michel; Job, Daniel; Verrecchia, Eric; Junier, Pilar

    2012-11-01

    The oxalate-carbonate pathway involves the oxidation of calcium oxalate to low-magnesium calcite and represents a potential long-term terrestrial sink for atmospheric CO(2). In this pathway, bacterial oxalate degradation is associated with a strong local alkalinization and subsequent carbonate precipitation. In order to test whether this process occurs in soil, the role of bacteria, fungi and calcium oxalate amendments was studied using microcosms. In a model system with sterile soil amended with laboratory cultures of oxalotrophic bacteria and fungi, the addition of calcium oxalate induced a distinct pH shift and led to the final precipitation of calcite. However, the simultaneous presence of bacteria and fungi was essential to drive this pH shift. Growth of both oxalotrophic bacteria and fungi was confirmed by qPCR on the frc (oxalotrophic bacteria) and 16S rRNA genes, and the quantification of ergosterol (active fungal biomass) respectively. The experiment was replicated in microcosms with non-sterilized soil. In this case, the bacterial and fungal contribution to oxalate degradation was evaluated by treatments with specific biocides (cycloheximide and bronopol). Results showed that the autochthonous microflora oxidized calcium oxalate and induced a significant soil alkalinization. Moreover, data confirmed the results from the model soil showing that bacteria are essentially responsible for the pH shift, but require the presence of fungi for their oxalotrophic activity. The combined results highlight that the interaction between bacteria and fungi is essential to drive metabolic processes in complex environments such as soil.

  5. Molecular mechanisms of crystallization impacting calcium phosphate cements

    OpenAIRE

    2010-01-01

    The biomineral calcium hydrogen phosphate dihydrate (CaHPO4·2H2O), known as brushite, is a malleable material that both grows and dissolves faster than most other calcium minerals, including other calcium phosphate phases, calcium carbonates and calcium oxalates. Within the body, this ready formation and dissolution can play a role in certain diseases, such as kidney stone and plaque formation. However, these same properties, along with brushite’s excellent biocompatibility, can be used to gr...

  6. Potential etiologic role of brushite in the formation of calcium (renal) stones

    Science.gov (United States)

    Pak, Charles Y. C.

    1981-05-01

    Brushite may play an important regulatory role in the formation of calcium -containing renal stones. The urinary environment from patients with hypercalciuric nephrolithiasis is typically supersaturated and shows an increased propensity for the spontaneous nucleation of brushite. Brushite has been identified in "stone-forming" urine and in stones. This crystalline phase may undergo phase transformation to hydroxyapatite or cause heterogeneous nucleation or epitaxial growth of calcium oxalate. Thus, brushite may also participate in the formation of stones of hydroxypatite or calcium oxalate.

  7. Crystal structure of dimethylammonium hydrogen oxalate hemi(oxalic acid

    Directory of Open Access Journals (Sweden)

    Waly Diallo

    2015-05-01

    Full Text Available Single crystals of the title salt, Me2NH2+·HC2O4−·0.5H2C2O4, were isolated as a side product from the reaction involving Me2NH, H2C2O4 and Sn(n-Bu3Cl in a 1:2 ratio in methanol or by the reaction of the (Me2NH22C2O4 salt and Sn(CH33Cl in a 2:1 ratio in ethanol. The asymmetric unit comprises a dimethylammonium cation (Me2NH2+, an hydrogenoxalate anion (HC2O4−, and half a molecule of oxalic acid (H2C2O4 situated about an inversion center. From a supramolecular point of view, the three components interact together via hydrogen bonding. The Me2NH2+ cations and the HC2O4− anions are in close proximity through bifurcated N—H...(O,O hydrogen bonds, while the HC2O4− anions are organized into infinite chains via O—H...O hydrogen bonds, propagating along the a-axis direction. In addition, the oxalic acid (H2C2O4 molecules play the role of connectors between these chains. Both the carbonyl and hydroxyl groups of each diacid are involved in four intermolecular interactions with two Me2NH2+ and two HC2O4− ions of four distinct polymeric chains, via two N—H...O and two O—H...O hydrogen bonds, respectively. The resulting molecular assembly can be viewed as a two-dimensional bilayer-like arrangement lying parallel to (010, and reinforced by a C—H...O hydrogen bond.

  8. Molecular Structure of Aminoguanidine Sulfate Monohydrate

    Institute of Scientific and Technical Information of China (English)

    CHEN Hong-yan; ZHANG Tong-lai; QIAO Xiao-jing; YANG Li; SHAO Feng-lei

    2006-01-01

    The single crystal of aminoguanidine sulfate monohydrate [(AG)2SO4·H2O] is obtained and its structure is determined by X-ray diffraction analysis. The compound crystallizes in orthorhombic system with space group Pnma and the empirical formula C2H16N8O5S. The unit cell parameters are as follows: a=0.6759(2)nm, b=1.4131(5)nm, c=1.1650(4)nm, V=1.1128(6)n m3, Z=4, Dc=1.578g/cm3, F(000)=560, s=1.069, μ(MoKα)=0.318mm-1. The final R and Wr are 0.0312 and 0.0833, respectively. The title compound is an ionic compound and its structure unit consists of two aminoguanidium cations, one sulfate anion and one crystal water molecule, which are interconnected by electrostatic forces and hydrogen bond s into net structure, making the title compound very stable. Under a linear heat ingrate, the thermal decomposition processes of (AG)2SO4·H2O have one en dothermal dehydration stage, one melting process and one exothermic decomposition stage at 50-400℃, and can evolve abundant gas products.

  9. Calcium Forms,Subcelluar Distribution and Ultrastructure of Pulp Cells as Influenced by Calcium Deficiency in Apple (Malus pumila) Fruits

    Institute of Scientific and Technical Information of China (English)

    CHEN Jian-hui; ZHOU Wei

    2004-01-01

    Calcium in Red Fuji and Starkrimson apples during storage were fractionated by sequent extracting. Localization and distribution of calcium and influence of calcium nutrition on cell ultrastructure were observed by transmission electron microscopy combined with in situ precipitation of calcium with an improved method of potassium pyroantimonate technique. Results indicated that spraying calcium solution on surface of young fruits increased contents of calcium in all forms. During storage, contents of soluble calcium and pectic calcium declined and thosein calcium phosphate, calcium oxalate and calcium silicate increased. Calcium contents of Red Fuji in all forms were higher than those of Starkrimson, indicating that calcium accumulating capability of Red Fuji fruits preceded that of Starkrimson. Under transmission electron microscopy, calcium antimonite precipitates (CaAP) was mainly distributed in cell wall, tonoplast, nuclear membrane and nucleoplasm,much more CaAP deposited in vacuole. Calcium deficiency during storage leads to decrease of CaAP in locations mentioned above, disappearance of compartmentation, and entrance of CaAP to cytoplasm. Transformation from soluble calcium and pectic calcium to calcium phosphate,oxalate and damages of biomembranes structuraly and functionally resulted from calcium deficiency during storage were the crucial causation of physiological disorder.

  10. Crystallo-chemical analyses of calcium phosphates

    Energy Technology Data Exchange (ETDEWEB)

    Sakae, Toshiro; Hayakawa, Tohru; Maruyama, Fumiaki; Nemoto, Kimiya; Kozawa, Yukishige [Nihon Univ., Matsudo, Chiba (Japan). School of Dentistry

    1997-12-01

    Several analytical techniques, methodology and their practical data processing were briefly described to investigate the crystallographic properties of calcium phosphates which are encountered in the field of dental sciences. The applied analytical techniques were X-ray fluorescence spectrometry (XFS), energy dispersive spectrometry (EDS), Fourier transform infrared spectrometry (FT-IR) and X-ray diffraction (XRD). The used materials were tetracalcium phosphate, hydroxyapatite, fluorapatite, {alpha}-tricalcium phosphate, {beta}-tricalcium phosphate, octacalcium phosphate, monetite, brushite and monocalcium phosphate monohydrate. (author)

  11. The tetrapeptide Z-Leu-Aib-Pro-Val-OBg monohydrate.

    Science.gov (United States)

    Gessmann, Renate; Schiemann, Norbert; Brückner, Hans; Petratos, Kyriacos

    2003-08-01

    The intramolecular hydrogen-bonding pattern of Z-Leu-Aib-Pro-Val-OBg monohydrate [(N-benzhydrylamino)carbonylmethyl N-benzyloxycarbonyl-alpha-aminoisobutyrylprolylvalinate monohydrate], C(43)H(55)N(5)O(8).H(2)O, is unusual for a tetrapeptide because, in addition to a 1-->4 hydrogen bond, a second hydrogen bond of the type 1-->5 is formed. This folding reflects the intramolecular hydrogen-bonding pattern that this amino acid sequence adopts in the naturally occurring peptaibol alamethicin.

  12. Artificial photosynthesis of oxalate and oxalate-based polymer by a photovoltaic reactor

    Science.gov (United States)

    Nong, Guangzai; Chen, Shan; Xu, Yuanjin; Huang, Lijie; Zou, Qingsong; Li, Shiqiang; Mo, Haitao; Zhu, Pingchuan; Cen, Weijian; Wang, Shuangfei

    2014-01-01

    A photovoltaic reactor was designed for artificial photosynthesis, based on the reactions involved in high energy hydrogen atoms, which were produced from water electrolysis. Water and CO2, under the conditions studied, were converted to oxalate (H2C2O4) and a polymer. This was the first time that the oxalates and oxalate-based polymer were produced from the artificial photosynthesis process.

  13. Structural information from OH stretching frequencies monohydric saturated alcohols

    NARCIS (Netherlands)

    Maas, J.H. van der; Lutz, E.T.G.

    1974-01-01

    Infrared data have been recorded of the hydroxyl stretching band for about 70 monohydric saturated alcohols in dilute carbon tetrachloride solution. The wavenumber maximum, the half-bandwidth and the band pattern could be related to the structure of the molecules. Not only primary, secondary and ter

  14. Chronic metabolic acidosis reduces urinary oxalate excretion and promotes intestinal oxalate secretion in the rat.

    Science.gov (United States)

    Whittamore, Jonathan M; Hatch, Marguerite

    2015-11-01

    Urinary oxalate excretion is reduced in rats during a chronic metabolic acidosis, but how this is achieved is not clear. In this report, we re-examine our prior work on the effects of a metabolic acidosis on urinary oxalate handling [Green et al., Am J Physiol Ren Physiol 289(3):F536-F543, 2005], offering a more detailed analysis and interpretation of the data, together with new, previously unpublished observations revealing a marked impact on intestinal oxalate transport. Sprague-Dawley rats were provided with 0.28 M ammonium chloride in their drinking water for either 4 or 14 days followed by 24 h urine collections, blood-gas and serum ion analysis, and measurements of (14)C-oxalate fluxes across isolated segments of the distal colon. Urinary oxalate excretion was significantly reduced by 75% after just 4 days compared to control rats, and this was similarly sustained at 14 days. Oxalate:creatinine clearance ratios indicated enhanced net re-absorption of oxalate by the kidney during a metabolic acidosis, but this was not associated with any substantive changes to serum oxalate levels. In the distal colon, oxalate transport was dramatically altered from net absorption in controls (6.20 ± 0.63 pmol cm(-2) h(-1)), to net secretion in rats with a metabolic acidosis (-5.19 ± 1.18 and -2.07 ± 1.05 pmol cm(-2) h(-1) at 4 and 14 days, respectively). Although we cannot rule out modifications to bi-directional oxalate movements along the proximal tubule, these findings support a gut-kidney axis in the management of oxalate homeostasis, where this shift in renal handling during a metabolic acidosis is associated with compensatory adaptations by the intestine.

  15. Evidence of formation of glushinskite as a biomineral in a Cactaceae species.

    Science.gov (United States)

    Monje, Paula V; Baran, Enrique J

    2005-03-01

    The X-ray diffractometric and infrared spectroscopic investigation of crystalline material isolated from the Cactaceae species Opuntia ellisiana shows the presence of a very complex mineral composition, including whewellite (monohydrated calcium oxalate), opal (SiO2), calcite (CaCO3) and glushinskite (dihydrated magnesium oxalate). This is the first report of the presence of magnesium oxalate in plants.

  16. Treatment of calcium nephrolithiasis in the patient with hyperuricosuria.

    Science.gov (United States)

    Arowojolu, Omotayo; Goldfarb, David S

    2014-12-01

    Nearly one-third of patients with calcium stones have hyperuricosuria. In vitro studies and clinical trials have investigated the relationship between uric acid and calcium stones, but the association between hyperuricosuria and calcium stone formation in patients is still being debated. Uric acid appears to cause salting out of calcium oxalate in human urine. However, the importance of this in vitro phenomenon to the proposed association is not supported in cross-sectional observational studies. A small placebo-controlled randomized clinical trial showed that allopurinol decreased the rate of recurrent calcium oxalate calculi in patients with hyperuricosuria and normocalciuria. An assessment of the effect of combination therapy of allopurinol with indapamide showed no additive effect. Allopurinol may have antioxidant effects that are responsible for its reducing calcium stone formation, which are independent of xanthine oxidase inhibition. In addition, a newer xanthine oxidoreductase inhibitor, febuxostat, may also be effective in the prevention of calcium stones, as it reduces urinary uric acid excretion.

  17. Kaleidoscopic Views in the Bone Marrow: Oxalate Crystals in a Patient Presenting with Bicytopenia

    Directory of Open Access Journals (Sweden)

    Yelda Dere

    2016-03-01

    Full Text Available Pancytopenia associated with BM infiltration of different deposits is a rare condition mostly associated with amyloidosis or the accumulation of iron. One of the rarest deposits in the BM is oxalate crystals due to hyperoxaluria [1,2,3]. Primary hyperoxaluria, a genetic disorder due to mutation in the alanine glyoxylate aminotransferase gene, located on chromosome 2q37.3 and resulting in the conversion of glyoxylate to oxalate, is characterized by increased production of oxalic acid because of the specific liver enzyme deficiency and generally presents with renal stones, renal or liver failure, and oxalosis [4]. Calcium oxalate may even be deposited into various tissues such as those of the retina, peripheral nerves, arterial media, and heart [4,5]. The medical history of nephrolithiasis at early ages, characteristic appearance of birefringent crystals forming rosettes in the BM, and the envelope-like forms in the BM aspirates seen in our case supported the diagnosis of primary hyperoxaluria, which is best confirmed by genetic studies and treated with liver transplantation because of the location of the abnormal enzymes in the hepatocytes.

  18. High variability of the heterogeneous ice nucleation potential of oxalic acid dihydrate and sodium oxalate

    Directory of Open Access Journals (Sweden)

    R. Wagner

    2010-08-01

    Full Text Available The heterogeneous ice nucleation potential of airborne oxalic acid dihydrate and sodium oxalate particles in the deposition and condensation mode has been investigated by controlled expansion cooling cycles in the AIDA aerosol and cloud chamber of the Karlsruhe Institute of Technology at temperatures between 244 and 228 K. Previous laboratory studies have highlighted the particular role of oxalic acid dihydrate as the only species amongst a variety of other investigated dicarboxylic acids to be capable of acting as a heterogeneous ice nucleus in both the deposition and immersion mode. We could confirm a high deposition mode ice activity for 0.03 to 0.8 μm sized oxalic acid dihydrate particles that were either formed by nucleation from a gaseous oxalic acid/air mixture or by rapid crystallisation of highly supersaturated aqueous oxalic acid solution droplets. The critical saturation ratio with respect to ice required for deposition nucleation was found to be less than 1.1 and the size-dependent ice-active fraction of the aerosol population was in the range from 0.1 to 22%. In contrast, oxalic acid dihydrate particles that had crystallised from less supersaturated solution droplets and had been allowed to slowly grow in a supersaturated environment from still unfrozen oxalic acid solution droplets over a time period of several hours were found to be much poorer heterogeneous ice nuclei. We speculate that under these conditions a crystal surface structure with less-active sites for the initiation of ice nucleation was generated. Such particles partially proved to be almost ice-inactive in both the deposition and condensation mode. At times, the heterogeneous ice nucleation ability of oxalic acid dihydrate significantly changed when the particles had been processed in preceding cloud droplet activation steps. Such behaviour was also observed for the second investigated species, namely sodium oxalate. Our experiments address the atmospheric scenario

  19. ADVANCED OXIDATION: OXALATE DECOMPOSITION TESTING WITH OZONE

    Energy Technology Data Exchange (ETDEWEB)

    Ketusky, E.; Subramanian, K.

    2012-02-29

    At the Savannah River Site (SRS), oxalic acid is currently considered the preferred agent for chemically cleaning the large underground Liquid Radioactive Waste Tanks. It is applied only in the final stages of emptying a tank when generally less than 5,000 kg of waste solids remain, and slurrying based removal methods are no-longer effective. The use of oxalic acid is preferred because of its combined dissolution and chelating properties, as well as the fact that corrosion to the carbon steel tank walls can be controlled. Although oxalic acid is the preferred agent, there are significant potential downstream impacts. Impacts include: (1) Degraded evaporator operation; (2) Resultant oxalate precipitates taking away critically needed operating volume; and (3) Eventual creation of significant volumes of additional feed to salt processing. As an alternative to dealing with the downstream impacts, oxalate decomposition using variations of ozone based Advanced Oxidation Process (AOP) were investigated. In general AOPs use ozone or peroxide and a catalyst to create hydroxyl radicals. Hydroxyl radicals have among the highest oxidation potentials, and are commonly used to decompose organics. Although oxalate is considered among the most difficult organic to decompose, the ability of hydroxyl radicals to decompose oxalate is considered to be well demonstrated. In addition, as AOPs are considered to be 'green' their use enables any net chemical additions to the waste to be minimized. In order to test the ability to decompose the oxalate and determine the decomposition rates, a test rig was designed, where 10 vol% ozone would be educted into a spent oxalic acid decomposition loop, with the loop maintained at 70 C and recirculated at 40L/min. Each of the spent oxalic acid streams would be created from three oxalic acid strikes of an F-area simulant (i.e., Purex = high Fe/Al concentration) and H-area simulant (i.e., H area modified Purex = high Al/Fe concentration

  20. Milk of calcium renal stone: a case report

    OpenAIRE

    守屋, 賢治; 西尾, 正一; 前川, 正信; 小早川, 等; 安本, 亮二

    1989-01-01

    A case of milk of calcium renal stone is reported. The patient was a 24-year-old woman who complained of dull flank pain on the right side. A plain film of the abdomen revealed a right renal stone, which showed peculiar radiopacity of a half-moon shape in the upright position. The operation was performed on July 6, 1984. Postoperative chemical analysis of sand granules showed calcium oxalate and calcium phosphate.

  1. Effect of Lagenaria siceraria fruit powder on sodium oxalate induced urolithiasis in Wistar rats

    Directory of Open Access Journals (Sweden)

    Rahul V Takawale

    2012-01-01

    Full Text Available Background: In spite of advances in the present practice of medicine, the formation and growth of calculi continues to trouble mankind, as there is no satisfactory drug to treat kidney stones. In India, many indigenous drugs are in use for the treatment of urinary calculus disease. Objective: The present study was intended to determine anti-urolithiatic effect of Lagenaria siceraria fruit powder (LSFP against sodium oxalate (NaOx induced urolithiasis in rats. Materials and Methods: Animals were grouped as Vehicle Group (received vehicle gum acacia 2% w/v 1 mL/kg/p.o., NaOx Group(Sodium oxalate 70 mg/kg,i.p., LSFP Group (500 mg/kg, p.o. LSFP suspended in gum acacia 2% + Sodium oxalate 70 mg/kg, Cystone Group (500 mg/kg, p.o. Cystone suspended in gum acacia 2% + Sodium oxalate 70 mg/kg. Result: The increased severity of microscopic calcium oxalate (CaOx crystals deposition along with increased concentration in the kidney was seen after 7 days of NaOx (70 mg/kg, i.p. pre-treatment. LSFP (500 mg/kg, p.o. and standard marketed formulation Cystone (500 mg/kg, p.o. caused a significant reversal of NaOx-induced changes in ion excretion and urinary CaOx concentration in 7 days treatment. Conclusion: From the results, it was concluded that LSFP showed beneficial effect against urolithiasis by decreasing CaOx excretion and preventing crystal deposition in the kidney tubules.

  2. 21 CFR 524.1610 - Orbifloxacin, mometasone furoate monohydrate, and posaconazole suspension.

    Science.gov (United States)

    2010-04-01

    ... posaconazole suspension. 524.1610 Section 524.1610 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... DOSAGE FORM NEW ANIMAL DRUGS § 524.1610 Orbifloxacin, mometasone furoate monohydrate, and posaconazole... furoate monohydrate equivalent to 1 mg mometasone furoate, and 1 mg posaconazole. (b) Sponsor. See...

  3. Thermal decomposition of potassium bis-oxalatodiaquaindate(III) monohydrate

    Indian Academy of Sciences (India)

    Tesfahun Kebede; Karri V Ramana; M S Prasada Rao

    2001-08-01

    Indium (III) is precipitated with oxalic acid in the presence of potassium nitrate maintaining an overall concentration of 0 125 M in HNO3. Chemical analysis of the complex salt obtained indicates the formula, K[In(C2O4)2] 3H2O. Thermal decomposition studies show that the compound decomposes first to the anhydrous potassium indium oxalate and then to the final mixture of the oxides through formation of potassium carbonate and indium (III) oxide as intermediates. Isothermal study, X-ray diffraction pattern and IR spectral data support the proposed thermal decomposition mechanism.

  4. Preparation and characterization of calcium phosphate biomaterials.

    Science.gov (United States)

    Calafiori, A R; Di Marco, G; Martino, G; Marotta, M

    2007-12-01

    Calcium phosphate cement (CPC) samples have been prepared with a mixture of monocalciumphosphate monohydrate (MCPM) and calcium carbonate (CC) powders, in stechiometric moles ratio 1:2.5 to obtain a Ca/P ratio of about 1.67 typical of hydroxyapatite (HAp), with or without addition of HAp. All specimens are incubated at 30 degrees C in a steam saturated air environment for 3, 6 and 15 days respectively, afterwards dried and stored under nitrogen. The calcium phosphate samples have been characterized by X-ray diffraction (XRD), Vickers hardness test (HV), diametral compression (d.c.), strength compression, and porosity evaluation. MCPM/CC mixture has a 30% HAp final concentration and is characterized by higher porosity (amount 78%) and mechanical properties useful as filler in bone segments without high mechanical stress.

  5. Efficiency and resistance of the artificial oxalate protection treatment on marble against chemical weathering

    Energy Technology Data Exchange (ETDEWEB)

    Doherty, B. [Dipartimento di Chimica, Universita degli Studi di Perugia, via Elce di Sotto, 8, I-60123 Perugia (Italy); Pamplona, M. [Centro de Petrologia e Geoquimica do Instituto Superior Tecnico Universidade Tecnica de Lisboa, Avenida Rovisco Pais, 1049-001 Lisbon (Portugal); Selvaggi, R. [Dipartimento di Chimica, Universita degli Studi di Perugia, via Elce di Sotto, 8, I-60123 Perugia (Italy); Miliani, C. [Istituto CNR di Scienze e Tecnologie Molecolari (ISTM), Dipartimento di Chimica, Universita degli Studi di Perugia, via Elce di Sotto, 8, I-60123 Perugia (Italy)]. E-mail: miliani@thch.unipg.it; Matteini, M. [CNR Istituto, Conservazione e Valorizzazione dei Beni Culturali (ICVBC), Via Madonna del Piano, 10, Edifico C-50019, Florence (Italy); Sgamellotti, A. [Dipartimento di Chimica, Universita degli Studi di Perugia, via Elce di Sotto, 8, I-60123 Perugia (Italy); Istituto CNR di Scienze e Tecnologie Molecolari (ISTM), Dipartimento di Chimica, Universita degli Studi di Perugia, via Elce di Sotto, 8, I-60123 Perugia (Italy); Brunetti, B. [Dipartimento di Chimica, Universita degli Studi di Perugia, via Elce di Sotto, 8, I-60123 Perugia (Italy)

    2007-03-15

    The artificial oxalate protection method was analyzed in laboratory experiments in order to achieve an optimum treatment application and concentration giving rise to its most effective protective nature. Spectroscopic (Fourier transform infrared, Micro-Raman and UV-vis colorimetry), microscopic (scanning electron microscope) and contact-angle analyses were carried out to characterize Carrara marble samples before and after application of the treatment to validate its efficiency. The resistance effects against chemical weathering were subsequently observed in a lab-controlled weak acid rain experiment. An acid spray at pH 5.5, representative of normal rain was used to provoke degrade of natural marble, marble treated with the artificial oxalate protective at concentrations of 0.4 and 5% and marble treated with a commercial organic silicon product. Run-off solutions sampled at timely intervals were tested for any change in pH followed by ion chromatography measurements for the presence of calcium ions in solution. The chromatography results of the oxalate treatment applied at a 5% concentration are analogous to an organic commercial product indicating its validity as a method for the conservation of carbonate substrates conferring protection to stone materials against acid environments.

  6. Crystal and molecular structures of alkali oxalates: first proof of a staggered oxalate anion in the solid state.

    Science.gov (United States)

    Dinnebier, Robert E; Vensky, Sascha; Panthöfer, Martin; Jansen, Martin

    2003-03-10

    The molecular and crystal structures of solvent-free potassium, rubidium, and cesium oxalates have been determined ab initio from high-resolution synchrotron and X-ray laboratory powder patterns. In the case of potassium oxalate K(2)C(2)O(4) (a = 10.91176(7) A, b = 6.11592(4) A, c = 3.44003(2) A, orthorhombic, Pbam, Z = 2), the oxalate anion is planar, whereas in cesium oxalate Cs(2)C(2)O(4) (a = 6.62146(5) A, b = 11.00379(9) A, c = 8.61253(7) A, beta = 97.1388(4) degrees, monoclinic, P2(1)/c, Z = 4) it exhibits a staggered conformation. For rubidium oxalate at room temperature, two polymorphs exist, one (beta-Rb(2)C(2)O(4)) isotypic to potassium oxalate (a = 11.28797(7) A, b = 6.29475(4) A, c = 3.62210(2) A, orthorhombic, Pbam, Z = 2) and the other (alpha-Rb(2)C(2)O(4)) isotypic to cesium oxalate (a = 6.3276(1) A, b = 10.4548(2) A, c = 8.2174(2) A, beta = 98.016(1) degrees, monoclinic, P2(1)/c, Z = 4). The potassium oxalate structure can be deduced from the AlB(2) type, and the cesium oxalate structure from the Hg(99)As type, respectively. The relation between the two types of crystal structures and the reason for the different conformations of the oxalate anion are discussed.

  7. Kinetic study of oxalic acid inhibition on enzymatic browning.

    Science.gov (United States)

    Son, S M; Moon, K D; Lee, C Y

    2000-06-01

    Oxalic acid has a strong antibrowning activity. The inhibitory pattern on catechol-PPO model system appeared to be competitive, with a K(i) value of 2.0 mM. When the PPO was incubated with oxalic acid, the activity was not recovered via dialysis, but the inactivated enzyme partially recovered its activity when cupric ion was added. Comparing the relative antibrowning effectiveness of oxalic acid with other common antibrowning agents, oxalic acid with I(50) value of 1.1 mM is as effective as kojic acid and more potent than cysteine and glutathione.

  8. 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.

  9. Crystal structure of (ferrocenylmethyldimethylammonium hydrogen oxalate

    Directory of Open Access Journals (Sweden)

    Mamadou Ndiaye

    2015-08-01

    Full Text Available The crystal structure of the title salt, [Fe(C5H5(C8H13N](HC2O4, consists of discrete (ferrocenylmethyldimethylammonium cations and hydrogen oxalate anions. The anions are connected through a strong O—H...O hydrogen bond, forming linear chains running parallel to [100]. The cations are linked to the anions through bifurcated N—H...(O,O′ hydrogen bonds. Weak C—H...π interactions between neighbouring ferrocenyl moieties are also observed.

  10. Total and soluble oxalate content of some Indian spices.

    Science.gov (United States)

    Ghosh Das, Sumana; Savage, G P

    2012-06-01

    Spices, such as cinnamon, cloves, cardamom, garlic, ginger, cumin, coriander and turmeric are used all over the world as flavouring and colouring ingredients in Indian foods. Previous studies have shown that spices contain variable amounts of total oxalates but there are few reports of soluble oxalate contents. In this study, the total, soluble and insoluble oxalate contents of ten different spices commonly used in Indian cuisine were measured. Total oxalate content ranged from 194 (nutmeg) to 4,014 (green cardamom) mg/100 g DM, while the soluble oxalate contents ranged from 41 (nutmeg) to 3,977 (green cardamom) mg/100 g DM. Overall, the percentage of soluble oxalate content of the spices ranged from 4.7 to 99.1% of the total oxalate content which suggests that some spices present no risk to people liable to kidney stone formation, while other spices can supply significant amounts of soluble oxalates and therefore should be used in moderation.

  11. Production of oxalic acid by some fungi infected tubers.

    Science.gov (United States)

    Faboya, O; Ikotun, T; Fatoki, O S

    1983-01-01

    Oxalic acid (as oxalate) was detected in four tubers commonly used for food in Nigeria-Dioscorea rotundata (White yam), Solanum tuberosum (Irish potato), Ipomoea batatas (Sweet potato), and Manihot esculenta (cassava). Whereas healthy I. batata had the highest oxalic acid content, healthy M. esculenta contained the lowest. When all tubers were artifically inoculated with four fungi-Penicillium oxalicum CURIE and THOM, Aspergillus niger VAN TIEGH, A. flavus and A. tamarii KITA, there was an increase in oxalate content/g of tuber tissue. The greatest amount of oxalate was produced by P. oxalicum in D. rotundata tuber. Consistently higher amounts of oxalate were produced by the four fungi in infected sweet potato tuber than in any other tuber and consistently lower amounts of oxalate were produced by the four fungi in Irish potato tuber. Differences in the carbohydrate type present in the tubers and in the biosynthesis pathway are thought to be responsible for variation in the production of oxalate in the different tubers by the four fungi used.

  12. [Formation of oxalate in oxaliplatin injection diluted with infusion solutions].

    Science.gov (United States)

    Eto, Seiji; Yamamoto, Kie; Shimazu, Kounosuke; Sugiura, Toshimune; Baba, Kaori; Sato, Ayaka; Goromaru, Takeshi; Hagiwara, Yoshiaki; Hara, Keiko; Shinohara, Yoshitake; Takahashi, Kojiro

    2014-01-01

    Oxaliplatin use can cause acute peripheral neuropathy characterized by sensory paresthesias, which are markedly exacerbated by exposure to cold temperatures, and is a dose-limiting factor in the treatment of colorectal cancer.Oxalate is eliminated in a series of nonenzymatic conversions of oxaliplatin in infusion solutions or biological fluids.Elimination of oxalate from oxaliplatin has been suggested as one of the reasons for the development of acute neuropathy.In this study, we developed a high-performance liquid chromatography(HPLC)-based method to detect oxalate formation, and investigated the time dependent formation of oxalate in oxaliplatin diluted with infusion solutions.The results obtained showed that the amount of oxalate in the solution corresponded to 1.6% of oxaliplatin 8 h after oxaliplatin dilution with a 5% glucose solution. On the other hand, oxalate formation from oxaliplatin diluted with a saline solution was ten-fold higher than that from oxaliplatin diluted with the 5% glucose solution.Most patients who were intravenously injected with oxaliplatin experienced venous pain.As a preventive measure against venous pain, dexamethasone was added to the oxaliplatin injection.We measured the amount of oxalate formed in the dexamethasone-containing oxaliplatin injection diluted with a 5% glucose solution.The amount of oxalate formed when dexamethasone was added did not differ significantly from that formed when dexamethasone was not added.Thus, there are no clinical problems associated with the stability of oxaliplatin solutions.

  13. Oxalate Synthesis and Pyrolysis: A Colorful Introduction to Stoichiometry

    Science.gov (United States)

    Vannatta, Michael W.; Richards-Babb, Michelle; Sweeney, Robert J.

    2010-01-01

    Metal oxalate synthesis and pyrolysis provides an opportunity for students to (i) learn stoichiometry, (ii) experience the consequences of proper stoichiometric calculations and experimental techniques, and (iii) be introduced to the relevance of chemistry by highlighting oxalates in context, for example, usages and health effects. At our…

  14. (S-2-Azaniumyl-2-methyl-3-phenylpropanoate monohydrate

    Directory of Open Access Journals (Sweden)

    Isao Fujii

    2016-10-01

    Full Text Available The title compound, C10H13NO2·H2O, crystallizes in a zwitterionic form as a monohydrate, involving the propylbenzene group with a trans conformation. It is a non-natural amino acid, and has attracted attention as an inhibitor of phenylalanine hydroxylase. In the crystal, molecules are linked by N—H...O hydrogen bonds, forming C(5 chains along the c-axis direction. Two chains are linked by another N—H...O hydrogen bond, forming an R33(11 ring motif. Further O—H...O hydrogen bonds link these motifs via the water molecules, to form a three-dimensional framework.

  15. Perfluorobutyric Acid and its Monohydrate: a Chirped Pulse and Cavity Based Fourier Transform Microwave Spectroscopic Study

    Science.gov (United States)

    Thomas, Javix; Serrato, Agapito, III; Lin, Wei; Jaeger, Wolfgang; Xu, Yunjie

    2014-06-01

    Perfluorobutyric acid (PFBA) is highly soluble in water and is a molecule of environmental importance. Rotational spectra of PFBA and its monohydrate were studied using a broadband chirped pulse and a narrow band cavity based Fourier transform microwave spectrometers and high level ab initio calculations. Extensive conformational search was performed for both the acid and its monohydrate at the MP2/6-311++G(2d,p) level of theory. Two and three conformers were predicted for PFBA and its monohydrate, respectively. One set of rotational transitions of PFBA and its mono-hydrate in each case was observed and assigned. Based on the broadband spectra obtained, one can confidently conclude that only one dominate conformer exists in each case. The orientation of the hydroxyl group in PFBA was determined using isotopic analysis. Comparison of the observed transition intensities and the calculated electric dipole moment components allowed one to identify the most stable monohydrate conformation which takes on the insertion hydrogen-bonding topology. Comparison to the shorter chain analogues, i.e. trifluoroacetic acid, perfluoropropionic acid, and their monohydrates, was made to elucidate the general trend in their conformational preference and binding topologies.

  16. Perfluorobutyric acid and its monohydrate: a chirped pulse and cavity based fourier transform microwave spectroscopic study.

    Science.gov (United States)

    Thomas, Javix; Serrato, Agapito; Lin, Wei; Jäger, Wolfgang; Xu, Yunjie

    2014-05-12

    Rotational spectra of perfluorobutyric acid (PFBA) and its monohydrate were studied with a broadband chirped pulse and a narrow-band cavity based Fourier transform microwave spectrometer, and high-level ab initio calculations. Extensive conformational searches were performed for both the acid and its monohydrate at the MP2/6-311++G(2d,p) level of theory. Two and three conformers were predicted to exist for PFBA and its monohydrate, respectively. One set of rotational transitions was observed and assigned for each, PFBA and its monohydrate. Based on the measured broadband spectra, we confidently conclude that only one dominant conformer exists in each case. The orientation of the hydroxyl group in PFBA was determined by using isotopic analysis. Comparison of the observed transition intensities and the calculated electric dipole moment components allowed us to identify the most stable monohydrate conformation, which takes on an insertion hydrogen-bonding topology. Comparisons to the shorter chain analogues, that is, trifluoroacetic acid, perfluoropropionic acid, and their monohydrates, are made to elucidate the general trend in their conformational preference and binding topologies.

  17. Urinary pH and renal lithiasis.

    Science.gov (United States)

    Grases, F; Costa-Bauzá, A; Gomila, I; Ramis, M; García-Raja, A; Prieto, R M

    2012-02-01

    Formation of calcium oxalate crystals, either as monohydrate or dihydrate, is apparently unrelated to urinary pH because the solubilities of these salts are practically unaltered at physiologic urinary pH values. However, a urinary pH 6.0 may induce uric acid or calcium phosphate crystals formation, respectively, which under appropriate conditions may induce the development of the calcium oxalate calculi. We assessed the relationship between the urinary pH and the formation of different types of calculi. A retrospective study in 1,478 patients was done. We determined the composition, macrostructure, and microstructure of the calculi and the urinary pH, 50.9% of calcium oxalate monohydrate unattached calculi were present in patients with urinary pH 6.0, respectively. Infectious calculi were found primarily in patients with urinary pH >6.0 (50.7%). Only calcium oxalate monohydrate papillary calculi were associated with urinary pH between 5.5 and 6.0 (43.1%). Urine of pH 6.0 has an increased capacity to develop calcium phosphate crystals, which can act as a heterogeneous nuclei of calcium oxalate crystals. Oxalate monohydrate papillary calculi were associated to pH between 5.5 and 6.0 because the injured papilla acts as a heterogeneous nucleant. Consequently, measurement of urinary pH may be used to evaluate the lithogen risk of given urine.

  18. OXALATE MASS BALANCE DURING CHEMICAL CLEANING IN TANK 6F

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, M.; Fink, S.

    2011-07-22

    The Savannah River Remediation (SRR) is preparing Tank 6F for closure. The first step in preparing the tank for closure is mechanical sludge removal. Following mechanical sludge removal, SRS performed chemical cleaning with oxalic acid to remove the sludge heel. Personnel are currently assessing the effectiveness of the chemical cleaning to determine whether the tank is ready for closure. SRR personnel collected liquid samples during chemical cleaning and submitted them to Savannah River National Laboratory (SRNL) for analysis. Following chemical cleaning, they collected a solid sample (also known as 'process sample') and submitted it to SRNL for analysis. The authors analyzed these samples to assess the effectiveness of the chemical cleaning process. Analysis of the anions showed the measured oxalate removed from Tank 6F to be approximately 50% of the amount added in the oxalic acid. To close the oxalate mass balance, the author collected solid samples, leached them with nitric acid, and measured the concentration of cations and anions in the leachate. Some conclusions from this work are: (1) Approximately 65% of the oxalate added as oxalic acid was removed with the decanted liquid. (2) Approximately 1% of the oxalate (added to the tank as oxalic acid) formed precipitates with compounds such as nickel, manganese, sodium, and iron (II), and was dissolved with nitric acid. (3) As much as 30% of the oxalate may have decomposed forming carbon dioxide. The balance does not fully account for all the oxalate added. The offset represents the combined uncertainty in the analyses and sampling.

  19. Efficient electron-induced removal of oxalate ions and formation of copper nanoparticles from copper(II oxalate precursor layers

    Directory of Open Access Journals (Sweden)

    Kai Rückriem

    2016-06-01

    Full Text Available Copper(II oxalate grown on carboxy-terminated self-assembled monolayers (SAM using a step-by-step approach was used as precursor for the electron-induced synthesis of surface-supported copper nanoparticles. The precursor material was deposited by dipping the surfaces alternately in ethanolic solutions of copper(II acetate and oxalic acid with intermediate thorough rinsing steps. The deposition of copper(II oxalate and the efficient electron-induced removal of the oxalate ions was monitored by reflection absorption infrared spectroscopy (RAIRS. Helium ion microscopy (HIM reveals the formation of spherical nanoparticles with well-defined size and X-ray photoelectron spectroscopy (XPS confirms their metallic nature. Continued irradiation after depletion of oxalate does not lead to further particle growth giving evidence that nanoparticle formation is primarily controlled by the available amount of precursor.

  20. Mode of Action: Oxalate Crystal-Induced Renal Tubule Degeneration and Glycolic Acid-Induced Dysmorphogenesis—Renal and Developmental Effects of Ethylene Glycol

    Energy Technology Data Exchange (ETDEWEB)

    Corley, Rick A.; Meek, M E.; Carney, E W.

    2005-10-01

    Ethylene glycol can cause both renal and developmental toxicity, with metabolism playing a key role in the mode of action (MOA) for each form of toxicity. Renal toxicity is ascribed to the terminal metabolite oxalic acid, which precipitates in the kidney in the form of calcium oxalate crystals and is believed to cause physical damage to the renal tubules. The human relevance of the renal toxicity of ethylene glycol is indicated by the similarity between animals and humans of metabolic pathways, the observation of renal oxalate crystals in toxicity studies in experimental animals and human poisonings, and cases of human kidney and bladder stones related to dietary oxalates and oxalate precursors. High-dose gavage exposures to ethylene glycol also cause axial skeletal defects in rodents (but not rabbits), with the intermediary metabolite, glycolic acid, identified as the causative agent. However, the mechanism by which glycolic acid perturbs development has not been investigated sufficiently to develop a plausible hypothesis of mode of action, nor have any cases of ethylene glycol-induced developmental effects been reported in humans. Given this, and the variations in sensitivity between animal species in response, the relevance to humans of ethylene glycol-induced developmental toxicity in animals is unknown at this time.

  1. Calcium ferrite formation from the thermolysis of calcium tris (maleato) ferrate(III)

    Indian Academy of Sciences (India)

    B S Randhawa; Kamaljeet Sweety

    2000-08-01

    For preparing calcium ferrite, calcium tris (maleato) ferrate(III) precursor was prepared by mixing aqueous solutions of iron(III) maleate, calcium maleate and maleic acid. Various physico-chemical techniques i.e. TG, DTG, DTA, Mössbauer, XRD, IR etc have been used to study the decomposition behaviour from ambient to 900°C and ferrite formation. Three consecutive decomposition steps leading to the formation of -Fe2O3 and calcium carbonate have been observed at various stages of thermolysis. In the final stage the ferrite, Ca2Fe2O5, is obtained as a result of solid state reaction between -Fe2O3 and calcium carbonate at 788°C, a temperature much lower than for ceramic method. The results have been compared with those of the oxalate precursor.

  2. Diagnostic value of color Doppler twinkling artifact and in urinary calcium stones: an in vitro experiment%彩色多普勒闪烁伪像对泌尿系含钙结石诊断价值的实验研究

    Institute of Scientific and Technical Information of China (English)

    刘青; 李杰; 孙霄; 商蒙蒙; 时丹丹; 宁松; 程琳

    2015-01-01

    目的 探讨彩色多普勒闪烁伪像对泌尿系含钙结石的诊断及鉴别诊断价值.方法 制备一水草酸钙、羟基磷灰石及磷酸三钙三种结石模型,分别包埋于猪肾内进行超声扫查,测量闪烁伪像长度及宽度,计算闪烁伪像强度及声影对比噪声比(C/N ratio),并进行统计学分析.结果 所有结石模型均产生闪烁伪像及声影,各成分结石闪烁伪像强度、长度、宽度及声影C/N差异均有统计学意义(P均<0.01);各成分结石闪烁伪像强度95%置信区间无重叠,任意两种成分闪烁伪像强度差异有统计学意义(P<0.05);一水草酸钙声影C/N和磷酸三钙声影C/N均大于羟基磷灰石声影C/N,差异有统计学意义(P<0.05).ROC曲线分析显示,以1 127为截断值,闪烁伪像强度诊断为羟基磷灰石的曲线下面积为0.743,诊断敏感性74%,特异性68 %,阳性预测值69.8%,阴性预测值72.3%.结论 彩色多普勒闪烁伪像可区分泌尿系含钙结石的化学成分,提高了超声定性诊断泌尿系结石的应用价值.%Objective To investigate the diagnostic value of twinkling artifact in urinary calcium stones.Methods Calcium oxalate monohydrate,hydroxyapatite and whitlockite stone phantoms were prepared and embedded in porcine kidneys for ultrasound scanning.The length and width of twinkling artifact were measured.The intensity of twinkling artifact and the contrast-to-noise ratio (C/N ratio) of acoustic shadowing were recorded and all the data was analyzed statistically.Results All the stone phantoms generated twinkling artifact and acoustic shadowing.The difference of the intensity,length and width of twinkling artifact and the C/N ratio of acoustic shadowing had statistically significant each composition (P <0.01).There was no overlap between 95% confidence interval of the intensity of twinkling artifact for any two compositions,and any two compositions of stones could be differentiated by the intensity of

  3. Citrate, oxalate, sodium, and magnesium levels in fresh juices of three different types of tomatoes: evaluation in the light of the results of studies on orange and lemon juices.

    Science.gov (United States)

    Yilmaz, Erdal; Batislam, Ertan; Kacmaz, Murat; Erguder, Imge

    2010-06-01

    Fruit and vegetable juices containing citrate may be recommended as an alternative in mild to moderate level hypocitraturic calcium stone formers who cannot tolerate pharmacological treatment. Tomato has been proved a citrate-rich vegetable. Tomato juice usage as citrate sources in hypocitraturic recurrent stone formers were evaluated in the light of the results of studies on orange and lemon juices. Ten 100 ml samples were prepared from three different tomato types processed through a blender. These samples were examined in terms of citrate, oxalate, calcium, magnesium, and sodium contents. No difference was detected between the parameters tested in three different tomato juices. Fresh tomato juice may be useful in hypocitraturic recurrent stone formers due to its high content of citrate and magnesium, and low content of sodium and oxalate. As the three different types of tomatoes did not differ in terms of citrate, magnesium, sodium, and oxalate content, they may be useful for clinical use if also supported by clinical studies.

  4. A new polymorph of magnesium oxalate dihydrate

    Directory of Open Access Journals (Sweden)

    Xue-An Chen

    2008-07-01

    Full Text Available In the asymmetric unit of the title compound, catena-poly[[diaquamagnesium(II]-μ-oxalato], [Mg(C2O4(H2O2]n, there is one Mg atom in an octahedral coordination with site symmetry 222, a unique C atom of the oxalate anion lying on a twofold axis, an O atom of the anion in a general position and a water O atom at a site with imposed twofold rotation symmetry. The Mg2+ ions are ligated by water molecules and bridged by the anions to form chains that are held together by O—H...O hydrogen bonds. The structure of the title compound has already been reported in a different space group [Lagier, Pezerat & Dubernat (1969. Rev. Chim. Miner. 6, 1081–1093; Levy, Perrotey & Visser (1971. Bull. Soc. Chim. Fr. pp. 757–761].

  5. A previously unknown oxalyl-CoA synthetase is important for oxalate catabolism in Arabidopsis

    Science.gov (United States)

    Oxalate is produced by several catabolic pathways in plants. The best characterized pathway for subsequent oxalate degradation is via oxalate oxidase, but some species, such as Arabidopsis thaliana, have no oxalate oxidase activity. Previously, an alternative pathway was proposed in which oxalyl-CoA...

  6. Thermochemical Properties and Decomposition Kinetics of Ammonium Magnesium Phosphate Monohydrate

    Institute of Scientific and Technical Information of China (English)

    WU,Jian; YUAN,Ai-Qun; HUANG,Zai-Yin; TONG,Zhang-Fa; CHEN,Jie; LIANG,Rong-Lan

    2007-01-01

    Ammonium magnesium phosphate monohydrate NH4MgPO4·H2O was prepared via solid state reaction at room temperature and characterized by XRD, FT-IR and SEM. Thermochemical study was performed by an isoperibol solution calorimeter, non-isothermal measurement was used in a multivariate non-linear regression analysis to determine the kinetic reaction parameters. The results show that the molar enthalpy of reaction above is (28.795±0.182) kJ/mol (298.15 K), and the standard molar enthalpy of formation of the title complex is (-2185.43±13.80)kJ/mol (298.15 K). Kinetics analysis shows that the second decomposition of NH4MgPO4·H2O acts as a double-step reaction: an nth-order reaction (Fn) with n=4.28, E1=147.35 kJ/mol, A1=3.63×1013 s-1 is followed by a second-order reaction (F2) with E2=212.71 kJ/mol, A2= 1.82×1018 s-1.

  7. Synthesis, properties and supramolecular structure of piperazinediium thiosulfate monohydrate

    Indian Academy of Sciences (India)

    Bikshandarkoil R Srinivasan; Ashish R Naik; Sunder N Dhuri; Christian Näther; Wolfgang Bensch

    2011-01-01

    Aqueous reaction of ammonium thiosulfate with piperazine (pip) results in the formation of the title compound (pipH2)[S2O3]$\\cdot$H2O 1 (pipH2 = piperazinediium) in good yield. 1 was characterized by elemental analysis, IR, Raman andNMRspectra, X-ray powder pattern and its structure was determined. On heating at 100°C, 1 transforms to anhydrous piperazinediium thiosulfate 2, which can be rehydrated to the monohydrate on exposure tomoisture. The structure of 1 consists of two crystallographically independent piperazinediium (pipH2)2+ cations located on inversion centers, a thiosulfate anion and a lattice water. The organic cations, thiosulfate anion and lattice water are linked by six varieties of hydrogen bond namely O-H$\\cdots$O, O-H$\\cdots$S, N-H$\\cdots$O, N-H$\\cdots$S, C-H$\\cdots$O and C-H$\\cdots$S, leading to the formation of alternating layers of (pipH2)2+ cations and water linked thiosulfate chains. A comparative study of several compounds charge balanced by the piperazinediium cation is described.

  8. Terahertz spectra of l-phenylalanine and its monohydrate.

    Science.gov (United States)

    Pan, Tingting; Li, Shaoping; Zou, Tao; Yu, Zheng; Zhang, Bo; Wang, Chenyang; Zhang, Jianbing; He, Mingxia; Zhao, Hongwei

    2017-05-05

    The low-frequency vibrational property of l-phenylalanine (l-Phe) and l-phenylalanine monohydrate (l-Phe·H2O) has been investigated by terahertz time-domain spectroscopy (THz-TDS) at room and low temperature ranging from 0.5 to 4.5THz. Distinctive THz absorption spectra of the two compounds were observed. Density functional theory (DFT) calculations based on the crystal structures have been performed to simulate the vibrational modes of l-Phe and l-Phe·H2O and the results agree well with the experimental observations. The study indicates that the characterized features of l-Phe mainly originate from the collective vibration of molecules. And the characterized features of l-Phe·H2O mainly come from hydrogen bond interactions between l-Phe and water molecules. l-Phe and l-Phe·H2O were also verified by differential scanning calorimetry and thermogravimetry (DSC-TG) and powder X-ray diffraction (PXRD) examinations.

  9. 3.2.1. Synthesis, crystal and molecular structure of catena-(bis(µ1-oxalic acid-µ3-hydrogen oxalate-di-aqua-sodium(I.

    Directory of Open Access Journals (Sweden)

    Olga Kovalchukova*, Sergey Aldoshin, Andrey Utenyshev, Konstantin Bogenko, Valeriy Tkachev

    2015-07-01

    Full Text Available The crystal and molecular structure of catena-(bis(µ- oxalic acid-µ-hydrogen oxalate-di-aqua-sodium(I was detected by X-Ray analysis. The compound crystallizes in the triclinic space group P-1, with a(Å 6.2378(12; b(Å 7,1115(14; c(Å 10.489(2; α(° 94.65(3; β(° 100.12(3; γ(° 97.78(3. The sodium cation in the title compound is eight coordinated and forms a square antiprism. It is surrounded by two molecules of oxalic acid, one hydrogen oxalate anion and one water molecule. Both oxalic acid and hydrogen oxalate anion act as polydentate bridging ligands. Centrosymmetric sodium cations are bounded by hydrogen oxalate anions through a system of H bonds involving the molecules of oxalic acid. In the lattice, the 3D structure stabilized by H bonds is formed.

  10. Orlistat-induced oxalate nephropathy may be dose-independent and present as a late manifestation.

    Science.gov (United States)

    Dossabhoy, Neville R; McRight, Scott; Sangha, Bhupinder; Khan, Sarah; Adgeh, Cherinet

    2013-01-01

    We present the case of a 61-year-old Caucasian male veteran who had been on orlistat (120mg dosing) for four years, and had changed to the over-the-counter (OTC) form, Alli (orlistat 60mg), about three months before presentation. He had been experiencing nausea and vomiting for three weeks prior to evaluation. Laboratory studies revealed a serum creatinine of 6.2 mg/dL--his previous renal function having been normal. An ultrasound-guided renal biopsy was performed, which revealed deposition of calcium oxalate crystals in the renal tubules. Orlistat is a popular weight-loss medication. Orlistat-induced oxalate crystal nephropathy has recently been reported in the literature, resulting from the original, patented version. We report a case with the first such complication from the OTC version, Alli - which is a reduced-dose formulation. Our case report highlights that this complication can occur after several years of use of the medication and is not necessarily dose dependant.

  11. Oxalic acid biosynthesis and oxalacetate acetylhydrolase activity in Streptomyces cattleya.

    Science.gov (United States)

    Houck, D R; Inamine, E

    1987-11-15

    In addition to producing the antibiotic thienamycin, Streptomyces cattleya accumulates large amounts of oxalic acid during the course of a fermentation. Washed cell suspensions were utilized to determine the specific incorporation of carbon-14 into oxalate from a number of labeled organic and amino acids. L-[U-14C]aspartate proved to be the best precursor, whereas only a small percentage of label from [1,5-14C]citrate was found in oxalate. Cell-free extracts catalyzed the formation of [14C]oxalate and [14C]acetate from L-[U-14C]aspartate. When L-[4-14C]aspartate was the substrate only [14C]acetate was formed. The cell-free extracts were found to contain oxalacetate acetylhydrolase (EC 3.7.1.1), the enzyme that catalyzes the hydrolysis of oxalacetate to oxalate and acetate. The enzyme is constitutive and is analogous to enzymes in fungi that produce oxalate from oxalacetate. Properties of the crude enzyme were examined.

  12. Oxalic acid biosynthesis and oxalacetate acetylhydrolase activity in Streptomyces cattleya

    Energy Technology Data Exchange (ETDEWEB)

    Houck, D.R.; Inamine, E.

    1987-11-15

    In addition to producing the antibiotic thienamycin, Streptomyces cattleya accumulates large amounts of oxalic acid during the course of a fermentation. Washed cell suspensions were utilized to determine the specific incorporation of carbon-14 into oxalate from a number of labeled organic and amino acids. L-(U-/sup 14/C)aspartate proved to be the best precursor, whereas only a small percentage of label from (1,5-/sup 14/C)citrate was found in oxalate. Cell-free extracts catalyzed the formation of (/sup 14/C)oxalate and (/sup 14/C)acetate from L-(U-/sup 14/C)aspartate. When L-(4-/sup 14/C)aspartate was the substrate only (/sup 14/C)acetate was formed. The cell-free extracts were found to contain oxalacetate acetylhydrolase, the enzyme that catalyzes the hydrolysis of oxalacetate to oxalate and acetate. The enzyme is constitutive and is analogous to enzymes in fungi that produce oxalate from oxalacetate. Properties of the crude enzyme were examined.

  13. The effects of the recommended dose of creatine monohydrate on kidney function.

    Science.gov (United States)

    Taner, Basturk; Aysim, Ozagari; Abdulkadir, Unsal

    2011-02-01

    We report a case of a heretofore healthy 18-year-old man who presented with a 2-day history of nausea, vomiting and stomach ache while taking creatine monohydrate for bodybuilding purposes. The patient had acute renal failure, and a renal biopsy was performed to determine the cause of increased creatinine and proteinuria. The biopsy showed acute tubular necrosis. In the literature, creatine monohydrate supplementation and acute tubular necrosis coexistence had not been reported previously. Twenty-five days after stopping the creatine supplements, the patient recovered fully. Even recommended doses of creatine monohydrate supplementation may cause kidney damage; therefore, anybody using this supplement should be warned about this possible side effect, and their renal functions should be monitored regularly.

  14. 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 ...

  15. Sildenafil citrate monohydrate-cyclodextrin nanosuspension complexes for use in metered-dose inhalers.

    Science.gov (United States)

    Sawatdee, Somchai; Phetmung, Hirihattaya; Srichana, Teerapol

    2013-10-15

    Sildenafil is a selective phosphodiesterase-5 inhibitor used for the treatment of erectile dysfunction and pulmonary hypertension. Sildenafil citrate monohydrate was complexed with α-, hydroxypropyl-β- and γ-cyclodextrin (α-CD, HP-β-CD and γ-CD, respectively) to enhance its water solubility. The complexes of sildenafil citrate monohydrate with all types of CDs were characterized by phase solubility diagrams, (1)H and (13)C NMR, and dielectric constants. Sildenafil citrate monohydrate complexed with CDs was developed as nanosuspensions for use in a pressurized metered-dose inhaler (pMDI). Sildenafil citrate monohydrate pMDI formulations were prepared by a bottom-up process using dried ethanol as a solvent and HFA-134a as an antisolvent and propellant in order to form nanosuspensions. A 3×3 factorial design was applied for the contents of the dried ethanol and HFA-134a propellant. The phase solubility profiles of the sildenafil and cyclodextrins were described as AL type with a mole ratio 1:1. The piperazine moiety of sildenafil formed an inclusion in the cavity of the CDs. The particle diameters of the sildenafil citrate monohydrate suspensions in pMDIs were all within a nanosuspension size range. An assay of the sildenafil content showed that the formation of complexes with CDs was close to 100%. In the case of the formulations with CDs, the emitted doses varied within 97.4±10.8%, the fine particle fractions (FPFs) were in a range of 45-81%, the fine particle dose (FPD) was 12.6±2.0 μg and the mass median aerodynamic diameters (MMADs) were 1.86±0.41 μm. In contrast, the formulations without CDs produced a low emitted dose of sildenafil (<60%). Therefore, only sildenafil citrate monohydrate pMDI formulations containing CDs were suitable for use as aerosols.

  16. Preclinical Evaluation of Antiurolithiatic Activity of Viburnum opulus L. on Sodium Oxalate-Induced Urolithiasis Rat Model

    Directory of Open Access Journals (Sweden)

    Mert İlhan

    2014-01-01

    Full Text Available The aim of the present research is to evaluate the antiurolithiatic effect of the various extracts prepared from the fruits of Viburnum opulus L., in regard to its ethnobotanical record. To induce urolithiasis, 70 mg/kg sodium oxalate was injected to the rats which were housed individually in metabolic cages. The test materials were applied during 7 days. Biochemical (urine and serum parameters, histopathological and antioxidant (TBARs, TSH and GSH assays were conducted. The urine samples were examined by light microscope for the determination of the calcium oxalate crystals. Lyophilized juice of V. opulus (LJVO and lyophilized commercial juice of V. opulus (LCJVO exerted potential antiurolithiatic activity which was attributed to its diuretic effect along with the inhibitory action on the oxalate levels and free radical production. We also determined the chlorogenic acid content of the LJVO by high-performance liquid chromatography (HPLC. Chlorogenic acid was determined by using Supelcosil LC-18 (250×4.6 mm, 5 µm column and acetonitrile: water: 0.2% o-phosphoric acid as a mobile phase. The chlorogenic acid content of V. opulus was found to be 0.3227 mg/mL in fruit juice. The results obtained in this study have provided a scientific evidence for the traditional usage of V. opulus on passing kidney stones in Turkish folk medicine.

  17. Surface analysis of transition metal oxalates: Damage aspects

    Energy Technology Data Exchange (ETDEWEB)

    Chenakin, S.P., E-mail: chenakin@imp.kiev.ua [Université Libre de Bruxelles (ULB), Chimie-Physique des Matériaux, B-1050 Bruxelles (Belgium); Institute of Metal Physics, Nat. Acad. Sci. of Ukraine, Akad. Vernadsky Blvd. 36, 03680 Kiev (Ukraine); Szukiewicz, R. [Université Libre de Bruxelles (ULB), Chimie-Physique des Matériaux, B-1050 Bruxelles (Belgium); Barbosa, R.; Kruse, N. [Université Libre de Bruxelles (ULB), Chimie-Physique des Matériaux, B-1050 Bruxelles (Belgium); Voiland School of Chemical Engineering and Bioengineering, Washington State University, 155 Wegner Hall, Pullman, WA 99164-6515 (United States)

    2016-05-15

    Highlights: • Gas evolution from the Mn, Co, Ni and Cu oxalate hydrates in vacuum, during exposure to X-rays and after termination of X-ray irradiation is studied. • A comparative study of the damage caused by X-rays in NiC{sub 2}O{sub 4} and CuC{sub 2}O{sub 4} is carried out. • Effect of Ar{sup +} bombardment on the structure and composition of CoC{sub 2}O{sub 4} is studied. - Abstract: The behavior of transition metal oxalates in vacuum, under X-ray irradiation and low-energy Ar{sup +} ion bombardment was studied. A comparative mass-spectrometric analysis was carried out of gas evolution from the surface of Mn, Co, Ni and Cu oxalate hydrates in vacuum, during exposure to X-rays and after termination of X-ray irradiation. The rates of H{sub 2}O and CO{sub 2} liberation from the oxalates were found to be in an inverse correlation with the temperatures of dehydration and decomposition, respectively. X-ray photoelectron spectroscopy (XPS) was employed to study the X-ray induced damage in NiC{sub 2}O{sub 4} and CuC{sub 2}O{sub 4} by measuring the various XP spectral characteristics and surface composition of the oxalates as a function of time of exposure to X-rays. It was shown that Cu oxalate underwent a significantly faster degradation than Ni oxalate and demonstrated a high degree of X-ray induced reduction from the Cu{sup 2+} to the Cu{sup 1+} chemical state. 500 eV Ar{sup +} sputter cleaning of CoC{sub 2}O{sub 4} for 10 min was found to cause a strong transformation of the oxalate structure which manifested itself in an appreciable alteration of the XP core-level and valence band spectra. The analysis of changes in stoichiometry and comparison of XP spectra of bombarded oxalate with respective spectra of a reference carbonate CoCO{sub 3} implied that the bombardment-induced decomposition of CoC{sub 2}O{sub 4} gave rise to the formation of CoO-like and disordered CoCO{sub 3}-like phases.

  18. Computational and experimental studies on oxalic acid imprinted polymer

    Indian Academy of Sciences (India)

    Kiran Kumar Tadi; R V Motghare

    2013-03-01

    Computational approach plays an important role to pre-evaluate the interactions between template and functional monomer, so that to choose functional monomer having stronger interactions with template during synthesis of molecularly imprinted polymers (MIPs). Hence template-monomer interactions in pre-polymerization were mainly focused. In this paper, computational chemistry was applied to screen the number of mol of functional monomer that interacts with one mol of template. Intermolecular interactions between oxalic acid and acrylamide have been investigated. The binding energies Ebind were calculated by DFT (B3LYP) level of theory with the 6−31+G(d,p) basis set. It was found that four mol of acrylamide were sufficient to interact with one mol of oxalic acid in the pre-polymerization mixture. Four possible conformations and frequency calculations were performed to locate minima. Oxalic acid specific bulk polymer was obtained by the thermal initiated free radical co-polymerization of acrylamide and ethylene glycol dimethacrylate with oxalic acid as template and acetonitrile as porogen. The synthesized MIP efficiently adsorbed oxalic acid from aqueous solutions. The binding parameters ofMIP and non-imprinted polymer (NIP) were compared by Freundlich and Langmuir adsorption isotherms.

  19. Influence of solvents on the habit modification of alpha lactose monohydrate single crystals

    Science.gov (United States)

    Parimaladevi, P.; Srinivasan, K.

    2013-02-01

    Restricted evaporation of solvent method was adopted for the growth of alpha lactose monohydrate single crystals from different solvents. The crystal habits of grown crystals were analysed. The form of crystallization was confirmed by powder x-ray diffraction analysis. Thermal behaviour of the grown crystals was studied by using differential scanning calorimetry.

  20. Characterization of wheat germin (oxalate oxidase) expressed by Pichia pastoris

    Science.gov (United States)

    Pan, Heng-Yen; Whittaker, Mei M.; Bouveret, Romaric; Berna, Anne; Bernier, François; Whittaker, James W.

    2007-01-01

    High-level secretory expression of wheat (Triticum aestivum) germin/oxalate oxidase was achieved in Pichia pastoris fermentation cultures as an α-mating factor signal peptide fusion, based on the native wheat cDNA coding sequence. The oxalate oxidase activity of the recombinant enzyme is substantially increased (7-fold) by treatment with sodium periodate, followed by ascorbate reduction. Using these methods, approximately 1 g (4×104 U) of purified, activated enzyme was obtained following eight days of induction of a high density Pichia fermentation culture, demonstrating suitability for large-scale production of oxalate oxidase for biotechnological applications. Characterization of the recombinant protein shows that it is glycosylated, with N-linked glycan attached at Asn47. For potential biomedical applications, a nonglycosylated (S49A) variant was also prepared which retains essentially full enzyme activity, but exhibits altered protein-protein interactions. PMID:17399681

  1. Oxalic acid adsorption states on the clean Cu(110) surface

    Science.gov (United States)

    Fortuna, Sara

    2016-11-01

    Carboxylic acids are known to assume a variety of configurations on metallic surfaces. In particular oxalic acid on the Cu(110) surface has been proposed to assume a number of upright configurations. Here we explore with DFT calculations the possible structures that oxalic acid can form on copper 110 at different protonation states, with particular attention at the possibility of forming structures composed of vertically standing molecules. In its fully protonated form it is capable of anchoring itself on the surface thanks to one of its hydrogen-free oxygens. We show the monodeprotonated upright molecule with two oxygens anchoring it on the surface to be the lowest energy conformation of a single oxalic molecules on the Cu(110) surface. We further show that it is possible for this configuration to form dense hexagonally arranged patterns in the unlikely scenario in which adatoms are not involved.

  2. Crystal structure of di­methyl­ammonium hydrogen oxalate hemi(oxalic acid)

    Science.gov (United States)

    Diallo, Waly; Gueye, Ndongo; Crochet, Aurélien; Plasseraud, Laurent; Cattey, Hélène

    2015-01-01

    Single crystals of the title salt, Me2NH2 +·HC2O4 −·0.5H2C2O4, were isolated as a side product from the reaction involving Me2NH, H2C2O4 and Sn(n-Bu)3Cl in a 1:2 ratio in methanol or by the reaction of the (Me2NH2)2C2O4 salt and Sn(CH3)3Cl in a 2:1 ratio in ethanol. The asymmetric unit comprises a di­methyl­ammonium cation (Me2NH2 +), an hydrogenoxalate anion (HC2O4 −), and half a mol­ecule of oxalic acid (H2C2O4) situated about an inversion center. From a supra­molecular point of view, the three components inter­act together via hydrogen bonding. The Me2NH2 + cations and the HC2O4 − anions are in close proximity through bifurcated N—H⋯(O,O) hydrogen bonds, while the HC2O4 − anions are organized into infinite chains via O—H⋯O hydrogen bonds, propagating along the a-axis direction. In addition, the oxalic acid (H2C2O4) mol­ecules play the role of connectors between these chains. Both the carbonyl and hydroxyl groups of each diacid are involved in four inter­molecular inter­actions with two Me2NH2 + and two HC2O4 − ions of four distinct polymeric chains, via two N—H⋯O and two O—H⋯O hydrogen bonds, respectively. The resulting mol­ecular assembly can be viewed as a two-dimensional bilayer-like arrangement lying parallel to (010), and reinforced by a C—H⋯O hydrogen bond. PMID:25995858

  3. Crystal structure of di-methyl-ammonium hydrogen oxalate hemi(oxalic acid).

    Science.gov (United States)

    Diallo, Waly; Gueye, Ndongo; Crochet, Aurélien; Plasseraud, Laurent; Cattey, Hélène

    2015-05-01

    Single crystals of the title salt, Me2NH2 (+)·HC2O4 (-)·0.5H2C2O4, were isolated as a side product from the reaction involving Me2NH, H2C2O4 and Sn(n-Bu)3Cl in a 1:2 ratio in methanol or by the reaction of the (Me2NH2)2C2O4 salt and Sn(CH3)3Cl in a 2:1 ratio in ethanol. The asymmetric unit comprises a di-methyl-ammonium cation (Me2NH2 (+)), an hydrogenoxalate anion (HC2O4 (-)), and half a mol-ecule of oxalic acid (H2C2O4) situated about an inversion center. From a supra-molecular point of view, the three components inter-act together via hydrogen bonding. The Me2NH2 (+) cations and the HC2O4 (-) anions are in close proximity through bifurcated N-H⋯(O,O) hydrogen bonds, while the HC2O4 (-) anions are organized into infinite chains via O-H⋯O hydrogen bonds, propagating along the a-axis direction. In addition, the oxalic acid (H2C2O4) mol-ecules play the role of connectors between these chains. Both the carbonyl and hydroxyl groups of each diacid are involved in four inter-molecular inter-actions with two Me2NH2 (+) and two HC2O4 (-) ions of four distinct polymeric chains, via two N-H⋯O and two O-H⋯O hydrogen bonds, respectively. The resulting mol-ecular assembly can be viewed as a two-dimensional bilayer-like arrangement lying parallel to (010), and reinforced by a C-H⋯O hydrogen bond.

  4. THORIUM OXALATE-URANYL ACETATE COUPLED PROCEDURE FOR THE SEPARATION OF RADIOACTIVE MATERIALS

    Science.gov (United States)

    Gofman, J.W.

    1959-08-11

    The recovery of fission products from neutronirradiated uranium is described. The neutron-irradiated uranium is dissolved in acid and thorium oxalate is precipitated in ihe solution formed, whereby the fission products are carried on the thorium oxalate. The separated thorium oxalate precipitate is then dissolved in an aqueous oxalate solution and the solution formed is acidified, limiting ihe excess acidity to a maximum of 2 N, whereby thorium oxalate precipitates and carries lanthanum-rareearth- and alkaline-earth-metal fission products while the zirconium-fission-product remains in solution. This precipitate, too, is dissolved in an aqaeous oxalate solution at elevated temperature, and lanthanum-rare-earth ions are added to the solution whereby lanthanum-rare-earth oxalate forms and the lanthanum-rare-earth-type and alkalineearth-metal-type fission products are carried on the oxalate. The precipitate is separated from the solution.

  5. Inositol trisphosphate and thapsigargin discriminate endoplasmic reticulum stores of calcium in rat brain

    DEFF Research Database (Denmark)

    Verma, A; Hirsch, D J; Hanley, M R

    1990-01-01

    ATP dependent Ca2+ accumulation into oxalate-loaded rat brain microsomes is potently inhibited by thapsigargin with an IC50 of 2 nM and maximal inhibition at 10 nM. Approximately 15% of the total A23187-releasable microsomal calcium store is insensitive to thapsigargin concentrations up to 100 mi...

  6. Microwave studies on double rare earth oxalate crystals

    Energy Technology Data Exchange (ETDEWEB)

    Elizabeth, Anit [School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam 686560 (India); Joseph, Cyriac [School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam 686560 (India); Paul, Issac [School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam 686560 (India); Ittyachen, M.A. [School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam 686560 (India); Mathew, K.T. [Microwave Imaging and Material Research Laboratory, Department of Electronics, Cochin University of Science and Technology, Kochi 682022 (India)]. E-mail: ktm@cusat.ac.in; Lonappan, Anil [Microwave Imaging and Material Research Laboratory, Department of Electronics, Cochin University of Science and Technology, Kochi 682022 (India); Jacob, Joe [Microwave Imaging and Material Research Laboratory, Department of Electronics, Cochin University of Science and Technology, Kochi 682022 (India)

    2005-01-25

    Rare earth compounds are recognized for outstanding physical, magnetic and optical properties. The oxalates and molybdates have gained importance for their various properties, which find applications in electro and accusto optical devices. This paper reports the microwave dielectric studies on double rare earth oxalate crystals. Using the cavity perturbation technique dielectric parameters such as complex permittivity and conductivity at microwave frequencies is determined. Using X-ray diffraction study the crystalline nature of the samples was established. The molecular and crystal structures were identified by IR analysis.

  7. Concentration and size distribution of particulate oxalate in marine and coastal atmospheres - Implication for the increased importance of oxalate in nanometer atmospheric particles

    Science.gov (United States)

    Guo, Tianfeng; Li, Kai; Zhu, Yujiao; Gao, Huiwang; Yao, Xiaohong

    2016-10-01

    In literature, particulate oxalate has been widely studied in the total suspended particles (TSP), particles 100 nm. In this article, we measured oxalate's concentrations in size-segregated atmospheric particles down to 10 nm or 56 nm during eight campaigns performed at a semi-urban coastal site, over the marginal seas of China and from the marginal seas to the northwest Pacific Ocean (NWPO) in 2012-2015. When the sum of the oxalate's concentration in particles pollution event. Mode analysis results of particulate oxalate and the correlation between oxalate and sulfate suggested that the elevated concentrations of oxalate in PM10 were mainly related to enhanced in-cloud formation of oxalate via anthropogenic precursors. Size distribution data in the total of 136 sets of samples also showed approximately 80% of particulate oxalate's mass existing in atmospheric particles >100 nm. Consistent with previous studies, particulate oxalate in particles >100 nm was a negligible ionic component when comparing to particulate SO42- in the same size range. However, the mole ratios of oxalate/sulfate in particles 100 nm atmospheric particles such as PM2.5, PM10, TSP, etc.

  8. Oxaloacetate hydrolase, the C-C bond lyase of oxalate secreting fungi

    NARCIS (Netherlands)

    Han, Y.; Joosten, H.J.; Niu, W.; Zhao, Z.; Mariano, P.S.; McCalman, M.; Kan, van J.; Schaap, P.J.; Dunaway-Mariano, D.

    2007-01-01

    Oxalate secretion by fungi is known to be associated with fungal pathogenesis. In addition, oxalate toxicity is a concern for the commercial application of fungi in the food and drug industries. Although oxalate is generated through several different biochemical pathways, oxaloacetate acetylhydrolas

  9. Effect of aqueous extract of Tribulus terrestris on oxalate-induced oxidative stress in rats.

    Science.gov (United States)

    Kamboj, P; Aggarwal, M; Puri, S; Singla, S K

    2011-07-01

    The present study was aimed at studying the effect of Tribulus terrestris on different parameters of oxidative stress and gene expression profiles of antioxidant enzymes in renal tissues of male wistar rats after induction of hyperoxaluria. The animals were divided into three groups. The animals in group I (control) were administered vehicle only. In group II, the animals were treated with ethylene glycol (hyperoxaluric agent) and those in group III were administered T. terrestris plant extract in addition to ethylene glycol. All treatments were continued for a period of seven weeks. Ethylene glycol feeding resulted in hyperoxaluria as well as increased excretion of calcium and phosphate. Serum creatinine, uric acid and blood urea nitrogen levels were also altered in hyperoxaluric animals. Various oxidative stress parameters viz. lipid peroxidation and activity of antioxidant enzymes were used to confirm the peroxidant state. Reverse transcription-polymerase chain reaction (RT-PCR) analysis was used to confirm whether steady-state transcription level of different antioxidant enzymes was altered. T. terrestris significantly reduced the excretion of oxalate, calcium, and phosphate along with decreased levels of blood urea nitrogen, uric acid and creatinine in serum. T. terrestris also reduced hyperoxaluria- caused oxidative stress, and restored antioxidant enzyme activity and their expression profile in kidney tissue. Histological analysis depicted that T. terrestris treatment decreased renal epithelial damage, inflammation, and restored normal glomerular morphology.

  10. Ca{sub 0.15}Zr{sub 0.85}O{sub 1.85} powder from oxalate precursor: Microwave aided synthesis and thermal characterization

    Energy Technology Data Exchange (ETDEWEB)

    Malghe, Y.S. [Department of Chemistry, The Institute of Science, 15 Madam Cama Road, Mumbai 400032 (India)], E-mail: ymalghe@yahoo.com; Dharwadkar, S.R. [Department of Chemistry, The Institute of Science, 15 Madam Cama Road, Mumbai 400032 (India)

    2008-09-30

    Calcia stabilized zirconia (Ca{sub 0.15}Zr{sub 0.85}O{sub 1.85}) (CSZ) an oxygen ion conducting electrolyte was synthesized from mixed oxalate precursor, namely calcium zirconyl oxalate (CZO). CZO heated in microwave heating system for 1 h yielded the stabilized zirconia in the cubic form at 400 deg. C. Same precursor (CZO) heated in resistance heated furnace for 1 h yielded pure CSZ at 800 deg. C. Thermogravimetry, differential thermal analysis and X-ray diffraction techniques were used to characterize the precursor and optimize the conditions for microwave processing. BET surface areas of CSZ powders prepared by conventional and microwave heating method at 800 and 400 deg. C are 3.28 and 4.46 m{sup 2} g{sup -1}, respectively.

  11. Oxalate Mass Balance During Chemical Cleaning in Tank 5F

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, M.; Fink, S.

    2011-07-08

    The Savannah River Site (SRS) is preparing Tank 5F for closure. The first step in preparing the tank for closure is mechanical sludge removal. Following mechanical sludge removal, SRS performed chemical cleaning with oxalic acid to remove the sludge heel. Personnel are currently assessing the effectiveness of the chemical cleaning to determine whether the tank is ready for closure. SRS personnel collected liquid samples during chemical cleaning and submitted them to Savannah River National Laboratory (SRNL) for analysis. Following chemical cleaning, they collected a solid sample (also known as 'process sample') and submitted it to SRNL for analysis. The authors analyzed these samples to assess the effectiveness of the chemical cleaning process. Analysis of the anions showed the measured oxalate removed from Tank 5F to be approximately 50% of the amount added in the oxalic acid. To close the oxalate mass balance, the author collected solid samples, leached them with nitric acid, and measured the concentration of cations and anions in the leachate.

  12. Phase transition in L-alaninium oxalate by photoacoustics

    Indian Academy of Sciences (India)

    M Sivabarathy; S Natarajan; S K Ramakrishnan; K Ramachandran

    2004-10-01

    Phase transition in L-alaninium oxalate is studied by using TG, DTA and photoacoustic spectroscopy. A sharp transition at 378 K by photoacoustics is observed whereas at the same temperature the endothermic energy change observed by TG and DTA is not very sharp. This is discussed in detail with reference to the other known data for the organic crystals.

  13. Production of battery grade materials via an oxalate method

    Energy Technology Data Exchange (ETDEWEB)

    Belharouak, Ilias; Amine, Khalil

    2016-05-17

    An active electrode material for electrochemical devices such as lithium ion batteries includes a lithium transition metal oxide which is free of sodium and sulfur contaminants. The lithium transition metal oxide is prepared by calcining a mixture of a lithium precursor and a transition metal oxalate. Electrochemical devices use such active electrodes.

  14. Transcellular oxalate and Cl- absorption in mouse intestine is mediated by the DRA anion exchanger Slc26a3, and DRA deletion decreases urinary oxalate.

    Science.gov (United States)

    Freel, Robert W; Whittamore, Jonathan M; Hatch, Marguerite

    2013-10-01

    Active transcellular oxalate transport in the mammalian intestine contributes to the homeostasis of this important lithogenic anion. Several members of the Slc26a gene family of anion exchangers have a measurable oxalate affinity and are expressed along the gut, apically and basolaterally. Mouse Slc26a6 (PAT1) targets to the apical membrane of enterocytes in the small intestine, and its deletion results in net oxalate absorption and hyperoxaluria. Apical exchangers of the Slc26a family that mediate oxalate absorption have not been established, yet the Slc26a3 [downregulated in adenoma (DRA)] protein is a candidate mediator of oxalate uptake. We evaluated the role of DRA in intestinal oxalate and Cl(-) transport by comparing unidirectional and net ion fluxes across short-circuited segments of small (ileum) and large (cecum and distal colon) intestine from wild-type (WT) and DRA knockout (KO) mice. In WT mice, all segments demonstrated net oxalate and Cl(-) absorption to varying degrees. In KO mice, however, all segments exhibited net anion secretion, which was consistently, and solely, due to a significant reduction in the absorptive unidirectional fluxes. In KO mice, daily urinary oxalate excretion was reduced 66% compared with that in WT mice, while urinary creatinine excretion was unchanged. We conclude that DRA mediates a predominance of the apical uptake of oxalate and Cl(-) absorbed in the small and large intestine of mice under short-circuit conditions. The large reductions in urinary oxalate excretion underscore the importance of transcellular intestinal oxalate absorption, in general, and, more specifically, the importance of the DRA exchanger in oxalate homeostasis.

  15. 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 ...

  16. Real-Time kinetic studies of Bacillus subtilis oxalate decarboxylase and Ceriporiopsis subvermispora oxalate oxidase using a luminescent oxygen sensor

    Directory of Open Access Journals (Sweden)

    Laura Molina

    2014-12-01

    Full Text Available Oxalate decarboxylase (OxDC, an enzyme of the bicupinsuperfamily, catalyzes the decomposition of oxalate into carbondioxide and formate at an optimal pH of 4.3 in the presence ofoxygen. However, about 0.2% of all reactions occur through anoxidase mechanism that consumes oxygen while producing twoequivalents of carbon dioxide and one equivalent of hydrogenperoxide. The kinetics of oxidase activity were studied bymeasuring the consumption of dissolved oxygen over time using a luminescent oxygen sensor. We describe the implementation of and improvements to the oxygen consumption assay. The oxidase activity of wild type OxDC was compared to that of the T165V OxDC mutant, which contains an impaired flexible loop covering the active site. The effects of various carboxylic acid-based buffers on the rate of oxidase activity were also studied. These results were compared to the oxidase activity of oxalate oxidase (OxOx, a similar bicupin enzyme that only carries out oxalate oxidation. Thetemperature dependence of oxidase activity was analyzed, andpreliminary results offer an estimate for the overall activationenergy of the oxidase reaction within OxDC. The data reported here thus provide insights into the mechanism of the oxidase activity of OxDC.

  17. 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

  18. Dependence of bisphenol A photodegradation on the initial concentration of oxalate in the lepidocrocite-oxalate complex system

    Institute of Scientific and Technical Information of China (English)

    DONG Jun; LI Fang-bai; LAN Chong-yu; LIU Cheng-shuai; LI Xiao-min; LUAN Tian-gang

    2006-01-01

    To understand the degradation of endocrine disrupting chemicals (EDCs) in natural environment with existence of iron oxides and carboxylic acids, the dependence ofbisphenol A (BPA) photodegradation on the initial concentration ofoxalate (Cox) in lepidocrocite (γ-FeOOH) aqueous suspension was investigated under both UV and visible lights in this study. Lepidocrocite powder was home-prepared by a hydrothermal process. It was found that BPA degradation was promoted greatly in the presence of oxalate owing to the formation of lepidocrocite-oxalate complex. And there was an optimal Cox, which was 2.0 and 2.4 mmol/L, under UV and visible lights, respectively. The first-order kinetic constant, k value increased 38 times from 0.17 × 10-2 min-1 in the absence of oxalate to 6.39 × 10-2 min-1 in the presence ofoxalate with an optimal Cox (2.0 mmol/L) under UV irradiation, and almost 306 times from 0.02 × 10-2 min-1 in the absence ofoxalate to 6.11 × 10-2 min-1 in the presence of oxalate with an optimal Cox (2.4 mmol/L) under visible irradiation. The BPA degradation rate increased and the first-order kinetic constants decreased with the increase in BPA initial concentration. The dependence of the variation of pH value, total-Fe and Fe2+ during the photoreaction on Cox was also investigated.The pH value increased obviously with the reaction time. Total-Fe increased dramatically at the first 5 min and then decreased quickly under UV irradiation and slowly under visible irradiation. The initial concentration of oxalate is a main factor to affect BPA photodegradation in aqueous suspension under both UV and visible lights.

  19. Structure and vibrational spectra of L-alanine L-alaninium picrate monohydrate

    Science.gov (United States)

    Ghazaryan, V. V.; Fleck, M.; Petrosyan, A. M.

    2012-05-01

    Preparation, crystal and molecular structure as well as vibrational spectra of the crystal L-alanine L-alaninium picrate monohydrate are described. The title crystal is monoclinic, space group P21. The asymmetric unit contains one dimeric (L-Ala⋯L-Ala+) cation, one picrate anion and a water molecule. The O⋯O distance in the dimeric cation is equal to 2.553(2) Å. The IR and Raman spectra are interpreted based on the structure.

  20. Simultaneous Determination of Sitagliptin Phosphate Monohydrate and Metformin Hydrochloride in Tablets by a Validated UPLC Method.

    Science.gov (United States)

    Malleswararao, Chellu S N; Suryanarayana, Mulukutla V; Mukkanti, Khagga

    2012-01-01

    A novel approach was used to develop and validate a rapid, specific, accurate and precise reverse phase ultra performance liquid chromatographic (UPLC) method for the simultaneous determination of Sitagliptin phosphate monohydrate and Metformin hydrochloride in pharmaceutical dosage forms. The chromatographic separation was achieved on Aquity UPLC BEH C8 100 × 2.1 mm, 1.7 μm, column using a buffer consisting of 10 mM potassium dihydrogen phosphate and 2 mM hexane-1-sulfonic acid sodium salt (pH adjusted to 5.50 with diluted phosphoric acid) and acetonitrile as organic solvent in a gradient program. The flow rate was 0.2 mL min(-1) and the detection wavelength was 210 nm. The limit of detection (LOD) for Sitagliptin phosphate monohydrate and Metformin hydrochloride was 0.2 and 0.06 μg mL(-1), respectively. The limit of quantification (LOQ) for Sitagliptin phosphate monohydrate and Metformin hydrochloride was 0.7 and 0.2 μg mL(-1), respectively. This method was validated with respect to linearity, accuracy, precision, specificity and robustness. The method was also found to be stability-indicating.

  1. Bis(l-serinium oxalate dihydrate: polymorph II

    Directory of Open Access Journals (Sweden)

    Marta Kulik

    2013-11-01

    Full Text Available A corrected and improved structure of the polymorph II of 2C3H8NO3+·C2O42−·2H2O, based on single-crystal data, is presented. The structure is refined with anisotropic displacement parameters for all non-H atoms and all H atoms are located. Due to the charged moieties, the structure is classified as a molecular salt. Intermolecular O—H...O−, O—H...O and N+—H...O−hydrogen bonds link the components of the structure. The l-serinium cations and oxalate anions form a network of channels in [100] direction, filled with the water molecules of crystallization. The dihedral angle between the CO2 units of the oxalate dianion is 10.2 (3°

  2. Growth of strontium oxalate crystals in agar–agar gel

    Indian Academy of Sciences (India)

    P V Dalal; K B Saraf

    2011-04-01

    Single crystals of strontium oxalate have been grown by using strontium chloride and oxalic acid in agar–agar gel media at ambient temperature. Different methods for growing crystals were adopted. The optimum conditions were employed in each method by varying concentration of gel and reactants, and gel setting time etc. Transparent prismatic bi-pyramidal platy-shaped and spherulite crystals were obtained in various methods. The grown crystals were characterized with the help of FT–IR studies and monoclinic system of crystals were supported with lattice parameters = 9.67628 Å, = 6.7175 Å, = 8.6812 Å, = 113.566°, and = 521.84 Å3 calculated from X-ray diffractogram.

  3. Preparation, spectral and thermal studies of neodymium zirconyl oxalate hexahydrate

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, V.B.; Mehrotra, P.N. (Roorkee Univ. (India). Dept. of Chemistry)

    Neodymium zirconyl oxalate (NdZrOX) is prepared and characterized by chemical analysis and IR spectral studies. Its thermal decomposition was investigated using DTA, TG, DTG, x-ray diffraction and IR spectroscopy. Based on thermogravimetry and isothermal studies a probable mechanism for the decomposition is proposed. The decomposition proceeds mainly through three stages: dehydration between RT-413 K; decomposition of oxalate between 413-943 K; and decomposition of the carbonate between 1028-1235 K to give a mixed oxide. The IR spectra and x-ray diffraction studies are made for identification of the intermediates. X-ray diffraction studies of the end product indicates that it belongs to cubic crystal system.

  4. Effect of oxalic acid on garden plants%草酸对园林植物的影响分析

    Institute of Scientific and Technical Information of China (English)

    谢佳亮

    2014-01-01

    The effect and damage oxalic acid on the human body is known to everyone. Oxalic acid is not easy to be oxidized and decomposed in the human body. The products after metabolism can cause the body pH unbalance, and affect the absorption of calcium and zinc. It is widely used in industry. Also from time to time it is used in districts to clean the exterior wall tiles or marble pavement and so on. So more or less it will have some impact on the garden plants. Therefore, we need to do some measures to minimize their influence and damage.%草酸对人体的影响和伤害为大家所熟知,草酸在人体内不容易被氧化分解掉,经代谢作用后形成的产物,可导致人体内酸碱度失去平衡,并影响对钙和锌的吸收。而在工业中被广泛应用的草酸,在小区中也不时会被用到,比如清洗外墙瓷砖或者地面大理石铺装等,对园林植物或多或少会造成一些影响,因此,需采取一些措施,使影响和伤害减到最低。

  5. Conductivity of Oxalic Acid in Aqueous Solution at Low Concentration

    Institute of Scientific and Technical Information of China (English)

    倪良; 韩世钧

    2005-01-01

    Oxalic acid is a weak and unsymmetrical bi-basic acid. There exist dissociation and association equilibria among the species in aqueous solution. The molar conductivity of the solution is the sum of the ionic contributions.Based on this idea, a new prediction equation of ionic conductivity was proposed at low concentration. The molar conductivities of the solution and its relevant ions were calculated respectively. The results obtained were in good agreement with those from experiments and the Quint-Viallard equation.

  6. Neutral tripodal receptors towards efficient trapping of oxalate

    Indian Academy of Sciences (India)

    Ranjan Dutta; Bijit Chowdhury; Purnandhu Bose; Pradyut Ghosh

    2014-09-01

    Tris(2-aminoethyl)amine (TREN) based pentafluorophenyl urea and 4-cyanophenyl thiourea receptors have shown encapsulation of oxalate (C2O$^{2−}_{4}$) in semi-aqueous environment. A single crystal X-ray study shows trapping of planar conformer of C2O$^{2−}_{4}$ in both the cases. Further solution state binding of C2O$^{2−}_{4}$ is probed by 1H-NMR titration study in semi-aqueous solvent.

  7. Equilibrium studies of oxalate and aluminum containing solutions

    Energy Technology Data Exchange (ETDEWEB)

    Hay, M. S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); King, W. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Peters, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Jones, D. H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-11-01

    The Savannah River National Laboratory (SRNL) was tasked to develop data on the solubility and conditions leading to precipitation of sodium oxalate, sodium nitrate, Bayerite (a polymorph of gibbsite, Al(OH)3), and sodium aluminosilicate solids recently found in the Modular Caustic Side Solvent Extraction Unit (MCU). The data generated will be used to improve the OLI Systems thermodynamic database for these compounds allowing better prediction of solids formation by the modeling software in the future.

  8. Carcinogenicity and chronic toxicity of hydrazine monohydrate in rats and mice by two-year drinking water treatment.

    Science.gov (United States)

    Matsumoto, Michiharu; Kano, Hirokazu; Suzuki, Masaaki; Katagiri, Taku; Umeda, Yumi; Fukushima, Shoji

    2016-04-01

    The carcinogenicity and chronic toxicity of hydrazine monohydrate was examined by administrating hydrazine monohydrate in drinking water to groups of 50 F344/DuCrj rats and 50 Crj:BDF1 mice of both sexes for two years. The drinking water concentration of hydrazine monohydrate was 0, 20, 40 or 80 ppm (wt/wt) for male and female rats and male mice; and 0, 40, 80 or 160 ppm for female mice. Survival rates of each group of males and females rats and mice were similar to the respective controls, except female rats administered 80 ppm. Two-year administration of hydrazine monohydrate produced an increase in the incidences of hepatocellular adenomas and carcinomas in rats of both sexes along with hepatic foci. In mice, the incidences of hepatocellular adenomas and carcinomas were increased in females, and significantly increased incidences of hepatocellular adenomas in females administered 160 ppm were observed. Thus, hydrazine monohydrate is carcinogenic in two species, rats and mice. Additionally, non-neoplastic renal lesions in rats and mice and non-neoplastic nasal lesions in mice were observed.

  9. Antioxidant Pre-Treatment Reduces the Toxic Effects of Oxalate on Renal Epithelial Cells in a Cell Culture Model of Urolithiasis

    Directory of Open Access Journals (Sweden)

    Tomislav Kizivat

    2017-01-01

    Full Text Available Urolithiasis is characterized by the formation and retention of solid crystals within the urinary tract. Kidney stones are mostly composed of calcium oxalate, which predominantly generates free radicals that are toxic to renal tubular cells. The aim of the study is to explore possible effects of antioxidant pre-treatment on inhibition of oxidative stress. Three cell lines were used as in vitro model of urolithiasis: MDCK I, MDCK II and LLC-PK1. Oxidative stress was induced by exposure of cells to sodium oxalate in concentration of 8 mM. In order to prevent oxidative stress, cells were pre-treated with three different concentrations of l-arginine and vitamin E. Oxidative stress was evaluated by determining the expression of superoxide dismutase (SOD, osteopontin (OPN, and by the concentration of glutathione (GSH. In all three cell lines, pre-treatment of antioxidants increased cell survival. Positive correlation of SOD and OPN expression as well as GSH concentration was observed in all groups of cells. Our results indicate that an antioxidant pre-treatment with l-arginine and vitamin E is able to hamper oxalate-induced oxidative stress in kidney epithelial cells and as such could play a role in prevention of urolithiasis.

  10. Novel Peptide with Specific Calcium-Binding Capacity from Schizochytrium sp. Protein Hydrolysates and Calcium Bioavailability in Caco-2 Cells

    Science.gov (United States)

    Cai, Xixi; Lin, Jiaping; Wang, Shaoyun

    2016-01-01

    Peptide-calcium can probably be a suitable supplement to improve calcium absorption in the human body. In this study, a specific peptide Phe-Tyr (FY) with calcium-binding capacity was purified from Schizochytrium sp. protein hydrolysates through gel filtration chromatography and reversed phase HPLC. The calcium-binding capacity of FY reached 128.77 ± 2.57 μg/mg. Results of ultraviolet spectroscopy, fluorescence spectroscopy, and infrared spectroscopy showed that carboxyl groups, amino groups, and amido groups were the major chelating sites. FY-Ca exhibited excellent thermal stability and solubility, which were beneficial to be absorbed and transported in the basic intestinal tract of the human body. Moreover, the calcium bioavailability in Caco-2 cells showed that FY-Ca could enhance calcium uptake efficiency by more than three times when compared with CaCl2, and protect calcium ions against dietary inhibitors, such as tannic acid, oxalate, phytate, and Zn2+. Our findings further the progress of algae-based peptide-calcium, suggesting that FY-Ca has the potential to be developed as functionally nutraceutical additives. PMID:28036002

  11. Novel Peptide with Specific Calcium-Binding Capacity from Schizochytrium sp. Protein Hydrolysates and Calcium Bioavailability in Caco-2 Cells

    Directory of Open Access Journals (Sweden)

    Xixi Cai

    2016-12-01

    Full Text Available Peptide-calcium can probably be a suitable supplement to improve calcium absorption in the human body. In this study, a specific peptide Phe-Tyr (FY with calcium-binding capacity was purified from Schizochytrium sp. protein hydrolysates through gel filtration chromatography and reversed phase HPLC. The calcium-binding capacity of FY reached 128.77 ± 2.57 μg/mg. Results of ultraviolet spectroscopy, fluorescence spectroscopy, and infrared spectroscopy showed that carboxyl groups, amino groups, and amido groups were the major chelating sites. FY-Ca exhibited excellent thermal stability and solubility, which were beneficial to be absorbed and transported in the basic intestinal tract of the human body. Moreover, the calcium bioavailability in Caco-2 cells showed that FY-Ca could enhance calcium uptake efficiency by more than three times when compared with CaCl2, and protect calcium ions against dietary inhibitors, such as tannic acid, oxalate, phytate, and Zn2+. Our findings further the progress of algae-based peptide-calcium, suggesting that FY-Ca has the potential to be developed as functionally nutraceutical additives.

  12. 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. ...

  13. Acute Oxalate Nephropathy Associated with Orlistat: A Case Report with a Review of the Literature

    OpenAIRE

    2013-01-01

    Orlistat is a gastrointestinal lipase inhibitor used for weight reduction in obese individuals. Enteric hyperoxaluria caused by orlistat leads to oxalate absorption. Acute oxalate nephropathy is a rare complication of treatment with orlistat. Herein we report a patient presenting with acute renal failure which improved minimal with intravenous hydration. She was found to have oxalate crystals on renal biopsy. Patient admitted orlistat use over the counter for weight reduction on further quest...

  14. Determination of residues in honey after treatments with formic and oxalic acid under field conditions

    OpenAIRE

    Bogdanov, Stefan; Charrière, Jean-Daniel; IMDORF, Anton; KILCHENMANN, Verena; Fluri, Peter

    2002-01-01

    International audience; Formic acid and oxalic acid field trials for control of Varroa destructor were carried out in autumn according to the Swiss prescriptions during three successive years in different apiaries in Switzerland. The following parameters were determined in honey that was harvested the year after treatment: formic acid, oxalic acid and free acidity. The following range of values were found in honeys of untreated colonies: formic acid, from 17 to 284 mg/kg, n = 34; oxalic acid,...

  15. Determination of common anions in oxalate by ion chromatography coupled with UV photolysis pretreatment

    Institute of Scientific and Technical Information of China (English)

    Sheng Lin Cao; Ming Li Ye; Wei De Lv; Guang Wen Pan; Ting Ting Zhang; Zhong Yang Hu; Li Na Liang; Yan Zhu

    2012-01-01

    A new and simple method was developed to determine anions in oxalate of analytical reagent grade.After UV photolysis with optimal 1% H2O2 in 10,000 mg/L oxalate in the fabricated photoreactor,sample was directly injected into IC system.Satisfactory linearity,detections limits,good repeatability and spiked recovery were obtained.The method was successfully applied to determine anions in two commercial oxalate samples.

  16. Determining the Biochemical Properties of the Oxalate Biosynthetic Component (Obc)1 from Burkholderia mallei

    OpenAIRE

    Lambert, Peter M.; Nakata, Paul A.

    2016-01-01

    Oxalic acid is produced by a variety of organisms ranging from simple microbes to complex animals. This acid has been proposed to fulfill various physiological and pathological functions which vary between organisms. In bacteria from the Burkholderia genus, oxalate secretion has been shown to be quorum sensing dependent and to support pathogenicity and cell viability. In light of the critical roles of oxalate in Burkholderia as well as other organisms, it is surprising that our understanding ...

  17. 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) , ...

  18. 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.

  19. Obtaining Ca(H2PO4)(2)·H2O, monocalcium phosphate monohydrate, via monetite from brushite by using sonication.

    Science.gov (United States)

    Sánchez-Enríquez, J; Reyes-Gasga, J

    2013-05-01

    Brushite was synthesized by precipitation of calcium chloride (CaCl(2)) and sodium phosphate monobasic (Na(2)HPO(4)) dried in vacuum and monetite was obtained from this brushite by sonication with a frequency of 90kHz at 500W for 90min. Monetite itself was also transformed in Ca(H(2)PO(4))(2)·H(2)O, monocalcium phosphate monohydrate (MCPM), by sonication with a frequency of 90kHz at 500W for 60min followed by lyophilization. The MCPM was sonicated and lyophilized by three times more until reach over 240min, but any other phase transformation was observed. All these phase transformations were analyzed by X-ray diffraction (XRD) and infrared spectroscopy (FTIR). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicated a grain size of about 200nm in all the samples. The morphology observed was a corn-flake-like grain for brushite, a pseudo-needle-like grains for monetite, and lamellar-like grains for MCPM.

  20. The effects of oxalate treatment on the smear layer of ground surfaces of human dentine.

    Science.gov (United States)

    Pashley, D H; Galloway, S E

    1985-01-01

    The layer was evaluated by scanning electron microscopy and by measurement of hydraulic conductance before and after 2-min topical treatment with potassium chloride, neutral potassium oxalate, half-neutralized oxalic acid or both neutral and acidic oxalates. The treated smear layers were then re-evaluated microscopically and functionally both before and after acid challenge. The layers treated with KCl were not altered either microscopically or functionally and were susceptible to acid etching. Dentine surfaces treated with either oxalate solutions became less permeable and were acid-resistant.

  1. [Silica, aluminum, iron, sulfur, and barium in a urinary calculus].

    Science.gov (United States)

    Rodríguez-Miñón Cifuentes, J L; Salvador, E; Bellanato, J; Medina, J A

    1994-05-01

    Presentation of the analytical results by Sweep Microscopy of a small papillary calculus spontaneously eliminated after a nephritic colic. The main component is monohydrate calcium oxalate. When the stone core was analyzed with EDAX, silica, aluminium, iron, sulphur and barium were detected. The origin of these elements is discussed and the presence of barium emphasized as exceptional.

  2. A human strain of Oxalobacter (HC-1) promotes enteric oxalate secretion in the small intestine of mice and reduces urinary oxalate excretion.

    Science.gov (United States)

    Hatch, Marguerite; Freel, Robert W

    2013-10-01

    Enteric oxalate secretion that correlated with reductions in urinary oxalate excretion was previously reported in a mouse model of primary hyperoxaluria, and in wild type (WT) mice colonized with a wild rat strain (OXWR) of Oxalobacter (Am J Physiol 300:G461–G469, 2010). Since a human strain of the bacterium is more likely to be clinically used as a probiotic therapeutic, we tested the effects of HC-1 in WT. Following artificial colonization of WT mice with HC-1, the bacteria were confirmed to be present in the large intestine and, unexpectedly, detected in the small intestine for varying periods of time. The main objective of the present study was to determine whether the presence of HC-1 promoted intestinal secretion in the more proximal segments of the gastrointestinal tract. In addition, we determined whether HC-1 colonization led to reductions in urinary oxalate excretion in these mice. The results show that the human Oxalobacter strain promotes a robust net secretion of oxalate in the distal ileum as well as in the caecum and distal colon and these changes in transport correlate with the beneficial effect of reducing renal excretion of oxalate. We conclude that OXWR effects on intestinal oxalate transport and oxalate homeostasis are not unique to the wild rat strain and that, mechanistically, HC-1 has significant potential for use as a probiotic treatment for hyperoxaluria especially if it is also targeted to the upper and lower gastrointestinal tract.

  3. Radiolysis of Sulfuric Acid, Sulfuric Acid Monohydrate, and Sulfuric Acid Tetrahydrate and Its Relevance to Europa

    Science.gov (United States)

    Loeffler, M. J.; Hudson, R. L.; Moore, M. H.; Carlson, R. W.

    2011-01-01

    We report laboratory studies on the 0.8 MeV proton irradiation of ices composed of sulfuric acid (H2SO4), sulfuric acid monohydrate (H2SO4 H2O), and sulfuric acid tetrahydrate (H2SO4 4H2O) between 10 and 180 K. Using infrared spectroscopy, we identify the main radiation products as H2O, SO2, (S2O3)x, H3O+, HSO4(exp -), and SO4(exp 2-). At high radiation doses, we find that H2SO4 molecules are destroyed completely and that H2SO4 H2O is formed on subsequent warming. This hydrate is significantly more stable to radiolytic destruction than pure H2SO4, falling to an equilibrium relative abundance of 50% of its original value on prolonged irradiation. Unlike either pure H2SO4 or H2SO4 H2O, the loss of H2SO4 4H2O exhibits a strong temperature dependence, as the tetrahydrate is essentially unchanged at the highest irradiation temperatures and completely destroyed at the lowest ones, which we speculate is due to a combination of radiolytic destruction and amorphization. Furthermore, at the lower temperatures it is clear that irradiation causes the tetrahydrate spectrum to transition to one that closely resembles the monohydrate spectrum. Extrapolating our results to Europa s surface, we speculate that the variations in SO2 concentrations observed in the chaotic terrains are a result of radiation processing of lower hydration states of sulfuric acid and that the monohydrate will remain stable on the surface over geological times, while the tetrahydrate will remain stable in the warmer regions but be destroyed in the colder regions, unless it can be reformed by other processes, such as thermal reactions induced by diurnal cycling.

  4. The effects of creatine monohydrate supplementation with and without D-pinitol on resistance training adaptations.

    Science.gov (United States)

    Kerksick, Chad M; Wilborn, Colin D; Campbell, William I; Harvey, Travis M; Marcello, Brandon M; Roberts, Mike D; Parker, Adam G; Byars, Allyn G; Greenwood, Lori D; Almada, Anthony L; Kreider, Richard B; Greenwood, Mike

    2009-12-01

    Coingestion of D-pinitol with creatine (CR) has been reported to enhance creatine uptake. The purpose of this study was to evaluate whether adding D-pinitol to CR affects training adaptations, body composition, whole-body creatine retention, and/or blood safety markers when compared to CR ingestion alone after 4 weeks of resistance training. Twenty-four resistance trained males were randomly assigned in a double-blind manner to creatine + pinitol (CRP) or creatine monohydrate (CR) prior to beginning a supervised 4-week resistance training program. Subjects ingested a typical loading phase (i.e., 20 g/d-1 for 5 days) before ingesting 5 g/d-1 the remaining 23 days. Performance measures were assessed at baseline (T0), week 1 (T1), and week 4 (T2) and included 1 repetition maximum (1RM) bench press (BP), 1RM leg press (LP), isokinetic knee extension, and a 30-second Wingate anaerobic capacity test. Fasting blood and body composition using dual-energy x-ray absorptiometry (DEXA) were determined at T1 and T3. Data were analyzed by repeated measures analysis of variance (ANOVA). Creatine retention increased (p 0.05). Significant improvements in upper- and lower-body strength and body composition occurred in both groups. However, significantly greater increases in lean mass and fat-free mass occurred in the CR group when compared to CRP (p pinitol to creatine monohydrate does not appear to facilitate further physiological adaptations while resistance training. Creatine monohydrate supplementation helps to improve strength and body composition while resistance training. Data from this study assist in determining the potential role the addition of D-pinitol to creatine may aid in facilitating training adaptations to exercise.

  5. An Understanding of Renal Stone Development in a Mixed Oxalate–Phosphate System

    OpenAIRE

    2008-01-01

    The in vivo formation of calcium oxalate concretions having calcium phosphate nidi is simulated in an in vitro (37 °C, pH 6.0) dual constant composition (DCC) system undersaturated (σDCPD = −0.330) with respect to brushite (DCPD, CaHPO4 · 2H2O) and slightly supersaturated (σCOM = 0.328) with respect to calcium oxalate monohydrate (COM, CaC2O4 · H2O). The brushite dissolution provides calcium ions that raise the COM supersaturation, which is heterogeneously nucleated either on or near the surf...

  6. Inhibition of Monosodium Urate Monohydrate-mediated Hemolysis by Vitamin E

    Institute of Scientific and Technical Information of China (English)

    Qiong XIE; Shude LI; Weiyang FENG; Yongzhi LI; Yuanliang WU; Wei HU; Youguang HUANG

    2007-01-01

    Microcrystals of monosodium urate monohydrate (MSUM) induce cytolysis and hemolysis in erythrocytes. In this report, we studied the effect of vitamin E on MSUM-mediated hemolysis in human erythrocytes. Vitamin E significantly inhibited hemolysis induced by MSUM. The hydroxyl group in the chromanol ring of vitamin E is dispensable for protecting erythrocytes against hemolysis induced by MSUM,indicating that the inhibitory effect of vitamin E is not due to its antioxidant properties. However, both the chromanol ring and the isoprenoid side chain are important for vitamin E to suppress MSUM-induced hemolysis.Our current study suggests that vitamin E inhibits hemolysis induced by MSUM as a membrane stabilizer.

  7. In vivo comet assay of acrylonitrile, 9-aminoacridine hydrochloride monohydrate and ethanol in rats.

    Science.gov (United States)

    Nakagawa, Yuzuki; Toyoizumi, Tomoyasu; Sui, Hajime; Ohta, Ryo; Kumagai, Fumiaki; Usumi, Kenji; Saito, Yoshiaki; Yamakage, Kohji

    2015-07-01

    As part of the Japanese Center for the Validation of Alternative Methods (JaCVAM)-initiative international validation study of the in vivo rat alkaline comet assay, we examined the ability of acrylonitrile, 9-aminoacridine hydrochloride monohydrate (9-AA), and ethanol to induce DNA damage in the liver and glandular stomach of male rats. Acrylonitrile is a genotoxic carcinogen, 9-AA is a genotoxic non-carcinogen, and ethanol is a non-genotoxic carcinogen. Positive results were obtained in the liver cells of male rats treated with known genotoxic compounds, acrylonitrile and 9-AA.

  8. Thermal Decomposition Kinetics of Lead 2,4,6-Trinitroresorcinate Monohydrate

    Institute of Scientific and Technical Information of China (English)

    HU Rong-zu; YAO Pu; LI Jing; CHEN San-ping; GAO Sheng-li; ZHAO Feng-qi; SONG Ji-rong; SHI Qi-zhen; CHEN Pei; LUO Yang; ZHAO Hong-an

    2004-01-01

    The non-isothermal decomposition of lead 2,4,6-trinitroresorcinate monohydrate, Pb (TNR) · H2O. was investigated by means of TG-DTA, DSC and IR. The thermal decomposition mechanism and the dissociated kinetics were also investigated. The kinetic parameters were obtained from the analysis of the DSC curves by integral and differential methods. The most probable kinetic model function of the dehydration reaction of Pb(TNR) · H2O was suggested by the comparison of the kinetic parameters.

  9. Characterization of crystalline structures in Opuntia ficus-indica

    OpenAIRE

    Contreras-Padilla, Margarita; Rivera-Muñoz, Eric M.; Gutiérrez-Cortez, Elsa; del López, Alicia Real; Rodríguez-García, Mario Enrique

    2014-01-01

    This research studies the crystalline compounds present in nopal (Opuntia ficus-indica) cladodes. The identification of the crystalline structures was performed using X-ray diffraction, scanning electron microscopy, mass spectrometry, and Fourier transform infrared spectroscopy. The crystalline structures identified were calcium carbonate (calcite) [CaCO3], calcium-magnesium bicarbonate [CaMg(CO3)2], magnesium oxide [MgO], calcium oxalate monohydrate [Ca(C2O4)•(H2O)], potassium peroxydiphosph...

  10. Gadolinium oxalate derivatives with enhanced magnetocaloric effect via ionothermal synthesis.

    Science.gov (United States)

    Meng, Yan; Chen, Yan-Cong; Zhang, Ze-Min; Lin, Zhuo-Jia; Tong, Ming-Liang

    2014-09-02

    Two new oxalate-bridged Gd(III) coordination polymers, namely, (choline)[Gd(C2O4)(H2O)3Cl]Cl·H2O (1) and [Gd(C2O4)(H2O)3Cl] (2), were first obtained ionothermally by using a deep eutectic solvent (DES). The magnetic studies and heat capacity measurements reveal that the two-dimensional Gd(III)-based coordination polymer of 2 has the higher magnetic density and exhibits a larger cryogenic magnetocaloric effect (MCE) (ΔS(m) = 48 J kg(-1) K(-1) for ΔH = 7 T at 2.2 K).

  11. Development of Endoplasmic Reticulum Stress during Experimental Oxalate Nephrolithiasis.

    Science.gov (United States)

    Motin, Yu G; Lepilov, A V; Bgatova, N P; Zharikov, A Yu; Motina, N V; Lapii, G A; Lushnikova, E L; Nepomnyashchikh, L M

    2016-01-01

    Morphological and ultrastructural study of the kidney was performed in rats with oxalate nephrolithiasis. Specific features of endoplasmic reticulum stress were evaluated during nephrolithiasis and treatment with α-tocopherol. We observed the signs of endoplasmic reticulum stress with activation of proapoptotic pathways and injury to the cell lining in nephron tubules and collecting ducts. Ultrastructural changes were found in the organelles, nuclei, and cell membranes of epitheliocytes. A relationship was revealed between endoplasmic reticulum stress and oxidative damage, which developed at the early state of lithogenesis.

  12. Sequestration of Sr(II) by calcium oxalate—A batch uptake study and EXAFS analysis of model compounds and reaction products

    Science.gov (United States)

    Singer, David M.; Johnson, Stephen B.; Catalano, Jeffrey G.; Farges, François; Brown, Gordon E., Jr.

    2008-10-01

    Calcium oxalate monohydrate (CaC 2O 4·H 2O—abbreviated as CaOx) is produced by two-thirds of all plant families, comprising up to 80 wt.% of the plant tissue and found in many surface environments. It is unclear, however, how CaOx in plants and soils interacts with metal ions and possibly sequesters them. This study examines the speciation of Sr(II) aq following its reaction with CaOx. Batch uptake experiments were conducted over the pH range 4-10, with initial Sr solution concentrations, [Sr] aq, ranging from 1 × 10 -4 to 1 × 10 -3 M and ionic strengths ranging of 0.001-0.1 M, using NaCl as the background electrolyte. Experimental results indicate that Sr uptake is independent of pH and ionic strength over these ranges. After exposure of CaOx to Sr aq for two days, the solution Ca concentration, [Ca] aq, increased for all samples relative to the control CaOx suspension (with no Sr added). The amount of Sr aq removed from solution was nearly equal to the total [Ca] aq after exposure of CaOx to Sr. These results suggest that nearly 90% of the Sr is removed from solution to a solid phase as Ca is released into solution. We suggest that the other 10% is sequestered through surface adsorption on a solid phase, although we have no direct evidence for this. Extended X-ray absorption fine structure (EXAFS) spectroscopy was used to determine the molecular-level speciation of Sr in the reaction products. Deconvolutions of the Sr K-edge EXAFS spectra were performed to identify multi-electron excitation (MEE) features. MEE effects were found to give rise to low-frequency peaks in the Fourier transform before the first shell of oxygen atoms and do not affect EXAFS fitting results. Because of potential problems caused by asymmetric distributions of Sr-O distances when fitting Sr K-edge EXAFS data using the standard harmonic model, we also employed a cumulant expansion model and an asymmetric analytical model to account for anharmonic effects in the EXAFS data. For Sr

  13. Total, Soluble and Insoluble Oxalate Contents of Ripe Green and Golden Kiwifruit

    Directory of Open Access Journals (Sweden)

    Hà Vũ Hồng Nguyễn

    2013-03-01

    Full Text Available Three bulk samples of two different cultivars of kiwifruit, green (Actinidia deliciosa L. and golden (Actinidia chinensis L. were bought ripe, ready to eat from a local market. The aim of the study was to determine the oxalate composition of each of the three fractions of kiwifruit, namely skin, pulp and seeds. The pulp consisted of 90.4% of the edible portion of the two cultivars while the skin and seeds made up a mean of 8.0% and 1.6% respectively. Total oxalate was extracted with 2.0 M HCL at 21 °C for 15 min and soluble oxalates extracted at 21 °C in water for 15 min from each fraction. The total and soluble oxalate compositions of each fraction were determined using ion exchange HPLC chromatography. The pulp of golden kiwifruit contained lower amounts of total oxalates (15.7 vs. 19.3 mg/100 g FW and higher amounts of soluble oxalates (8.5 vs. 7.6 mg/100 g FW when compared to the green cultivar. The skin of the green cultivar contained lower levels of insoluble oxalates (36.9 vs. 43.6 mg/100 g FW, while the seeds of the green cultivar contained higher levels of insoluble oxalates 106.7 vs. 84.7 mg/100 g FW.

  14. An oxalyl-CoA synthetase is important for oxalate metabolism in Saccharomyces cerevisiae

    Science.gov (United States)

    Although oxalic acid is common in nature, our understanding of the mechanism(s) regulating its turnover remains incomplete. In this study we identify Saccharomyces cerevisiae acyl-activating enzyme 3 (ScAAE3) as an enzyme capable of catalyzing the conversion of oxalate to oxalyl-CoA. Based on our fi...

  15. Oxalic acid biosynthesis is encoded by an operon in Burkholderia glumae

    Science.gov (United States)

    Although the biosynthesis of oxalic acid is known to occur in a number of bacteria, the mechanism(s) regulating its production remains largely unknown. To date, there is no report on the identification of an oxalic acid biosynthetic pathway gene from bacteria. In an attempt to identify such a gene...

  16. Kinetic Spectrophotometric Method for Determination of Oxalic Acid and Its application in Lathyrus sativus

    Institute of Scientific and Technical Information of China (English)

    YAN Ze-Yi; XING Geng-Mei; LI Zhi-Xiao

    2003-01-01

    @@ Oxalic acid is one of the most common nutrient chelators in the human diet found in many vegetables, such as mushroom, spinach, fresh kidney beans, rhubarb leaves and beet leaves. Some recent reports demonstrate that oxalate plays an important role in resistance stress metabolism and steady state regulation in plant. [1

  17. Reflectance spectroscopy of oxalate minerals and relevance to Solar System carbon inventories

    Science.gov (United States)

    Applin, Daniel M.; Izawa, Matthew R. M.; Cloutis, Edward A.

    2016-11-01

    The diversity of oxalate formation mechanisms suggests that significant concentrations of oxalic acid and oxalate minerals could be widely distributed in the Solar System. We have carried out a systematic study of the reflectance spectra of oxalate minerals and oxalic acid, covering the 0.2-16 μm wavelength region. Our analyses show that oxalates exhibit unique spectral features that enable discrimination between oxalate phases and from other commonly occurring compounds, including carbonates, in all regions of the spectrum except for the visible. Using these spectral data, we consider the possible contribution of oxalate minerals to previously observed reflectance spectra of many objects throughout the Solar System, including satellites, comets, and asteroids. We find that polycarboxylic acid dimers and their salts may explain the reflectance spectra of many carbonaceous asteroids in the 3 μm spectral region. We suggest surface concentration of these compounds may be a type of space weathering from the photochemical and oxidative decomposition of the organic macromolecular material found in carbonaceous chondrites. The stability and ubiquity of these minerals on Earth, in extraterrestrial materials, and in association with biological processes make them useful for many applications in Earth and planetary sciences.

  18. Desalted duck egg white peptides promote calcium uptake by counteracting the adverse effects of phytic acid.

    Science.gov (United States)

    Hou, Tao; Liu, Weiwei; Shi, Wen; Ma, Zhili; He, Hui

    2017-03-15

    The structure of the desalted duck egg white peptides-calcium chelate was characterized by fluorescence spectroscopy, fourier transform infrared spectroscopy, and dynamic light scattering. Characterization results showed structural folding and aggregation of amino acids or oligopeptides during the chelation process. Desalted duck egg white peptides enhanced the calcium uptake in the presence of oxalate, phosphate and zinc ions in Caco-2 monolayers. Animal model indicated that desalted duck egg white peptides effectively enhanced the mineral absorption and counteracted the deleterious effects of phytic acid. These findings suggested that desalted duck egg white peptides might promote calcium uptake in three pathways: 1) desalted duck egg white peptides bind with calcium to form soluble chelate and avoid precipitate; 2) the chelate is absorbed as small peptides by enterocyte; and 3) desalted duck egg white peptides regulate the proliferation and differentiation of enterocytes through the interaction with transient receptor potential vanilloid 6 calcium channel.

  19. Facile fabrication of cobalt oxalate nanostructures with superior specific capacitance and super-long cycling stability

    Science.gov (United States)

    Cheng, Guanhua; Si, Conghui; Zhang, Jie; Wang, Ying; Yang, Wanfeng; Dong, Chaoqun; Zhang, Zhonghua

    2016-04-01

    Transition metal oxalate materials have shown huge competitive advantages for applications in supercapacitors. Herein, nanostructured cobalt oxalate supported on cobalt foils has been facilely fabricated by anodization, and could directly serve as additive/binder-free electrodes for supercapacitors. The as-prepared cobalt oxalate electrodes present superior specific capacitance of 1269 F g-1 at the current density of 6 A g-1 in the galvanostatic charge/discharge test. Moreover, the retained capacitance is as high as 87.2% as the current density increases from 6 A g-1 to 30 A g-1. More importantly, the specific capacitance of cobalt oxalate retains 91.9% even after super-long cycling of 100,000 cycles. In addition, an asymmetric supercapacitor assembled with cobalt oxalate (positive electrode) and activated carbon (negative electrode) demonstrates excellent capacitive performance with high energy density and power density.

  20. Hydrogen bonding in oxalic acid and its complexes: A database study of neutron structures

    Indian Academy of Sciences (India)

    R Chitra; Amit Das; R R Choudhury; M Ramanadham; R Chidambaram

    2004-08-01

    The basic result of carboxylic group that the oxygen atom of the –OH never seems to be a hydrogen bond acceptor is violated in the cases, namely urea oxalic acid and bis urea oxalic acid complexes, where the hydroxyl oxygen atom is an acceptor of a weak N–H... O hydrogen bond. The parameters of this hydrogen bond, respectively in these structures are: hydrogen acceptor distance 2.110 Å and 2.127 Å and the bending angle at hydrogen, 165.6° and 165.8°. The bond strength around the hydroxyl oxygen is close to 1.91 valence units, indicating that it has hardly any strength left to form hydrogen bonds. These two structures being highly planar, force the formation of this hydrogen bond. As oxalic acid is the common moiety, the structures of the two polymorphs, -oxalic acid and -oxalic acid, also were looked into in terms of hydrogen bonding and packing.

  1. Protection of metal artefacts with the formation of metal-oxalates complexes by Beauveria bassiana.

    Directory of Open Access Journals (Sweden)

    Edith eJoseph

    2012-01-01

    Full Text Available Several fungi present high tolerance to toxic metals and some are able to transform metals into metal-oxalate complexes. In this study, the ability of Beauveria bassiana to produce copper oxalates was evaluated in vitro. Growth performance was tested on various copper-containing media. B. bassiana proved highly resistant to copper, tolerating concentrations of up to 20 g.L-1, and precipitating copper oxalates on all media tested. Chromatographic analyses showed that this species produced oxalic acid as sole metal chelator. The production of metal-oxalates can be used in the restoration and conservation of archaeological and modern metal artefacts. The production of copper-oxalates was confirmed directly using metallic pieces (both archaeological and modern. The conversion of corrosion products into copper oxalates was demonstrated as well. In order to assess whether the capability of B. bassiana to produce metal-oxalates could be applied to other metals, iron and silver were tested as well. Iron appears to be directly sequestered in the wall of the fungal hyphae forming oxalates and probably goethite. However, the formation of a homogeneous layer on the object is not yet optimal. Silver nitrate was extracellularly reduced into nanoparticles of elemental silver by an unknown mechanism. The production of copper oxalates is immediately applicable for the conservation of copper-based artefacts. For iron and silver this is not yet the case. However, the vast ability of B. bassiana to transform toxic metals using different immobilization mechanisms seems to offer considerable possibilities for industrial applications, such as the bioremediation of contaminated soils or the green synthesis of chemicals.

  2. The effects of the calcium-restricted diet of urolithiasis patients with absorptive hypercalciuria type II on risk factors for kidney stones and osteopenia

    NARCIS (Netherlands)

    Faassen, A. van; Ploeg, E.M.C. van der; Habets, H.M.L.; Meer, R. van der; Hermus, R.J.J.; Janknegt, R.A.

    1998-01-01

    The calcium (Ca)-restricted diet of urolithiasis patients with absorptive hypercalciuria type II may decrease Ca excretion but increase biochemical markers of risk for osteopenia. We randomly allocated 25 patients from six hospitals into an experimental group (Ca restriction to 500 mg/day, oxalate-r

  3. Molecular mechanisms of crystallization impacting calcium phosphate cements

    Science.gov (United States)

    Giocondi, Jennifer L.; El-Dasher, Bassem S.; Nancollas, George H.; Orme, Christine A.

    2010-01-01

    The biomineral calcium hydrogen phosphate dihydrate (CaHPO4·2H2O), known as brushite, is a malleable material that both grows and dissolves faster than most other calcium minerals, including other calcium phosphate phases, calcium carbonates and calcium oxalates. Within the body, this ready formation and dissolution can play a role in certain diseases, such as kidney stone and plaque formation. However, these same properties, along with brushite’s excellent biocompatibility, can be used to great benefit in making resorbable biomedical cements. To optimize cements, additives are commonly used to control crystallization kinetics and phase transformation. This paper describes the use of in situ scanning probe microscopy to investigate the role of several solution parameters and additives in brushite atomic step motion. Surprisingly, this work demonstrates that the activation barrier for phosphate (rather than calcium) incorporation limits growth kinetics and that additives such as magnesium, citrate and bisphosphonates each influence step motion in distinctly different ways. Our findings provide details of how, and where, molecules inhibit or accelerate kinetics. These insights have the potential to aid in designing molecules to target specific steps and to guide synergistic combinations of additives. PMID:20308110

  4. Molecular mechanisms of crystallization impacting calcium phosphate cements.

    Science.gov (United States)

    Giocondi, Jennifer L; El-Dasher, Bassem S; Nancollas, George H; Orme, Christine A

    2010-04-28

    The biomineral calcium hydrogen phosphate dihydrate (CaHPO(4).2H(2)O), known as brushite, is a malleable material that both grows and dissolves faster than most other calcium minerals, including other calcium phosphate phases, calcium carbonates and calcium oxalates. Within the body, this ready formation and dissolution can play a role in certain diseases, such as kidney stone and plaque formation. However, these same properties, along with brushite's excellent biocompatibility, can be used to great benefit in making resorbable biomedical cements. To optimize cements, additives are commonly used to control crystallization kinetics and phase transformation. This paper describes the use of in situ scanning probe microscopy to investigate the role of several solution parameters and additives in brushite atomic step motion. Surprisingly, this work demonstrates that the activation barrier for phosphate (rather than calcium) incorporation limits growth kinetics and that additives such as magnesium, citrate and bisphosphonates each influence step motion in distinctly different ways. Our findings provide details of how, and where, molecules inhibit or accelerate kinetics. These insights have the potential to aid in designing molecules to target specific steps and to guide synergistic combinations of additives.

  5. Effect of Indole Butyric Acid on the Transportation of Stored Calcium in Malus hupehensis Rhed. Seedling

    Institute of Scientific and Technical Information of China (English)

    LI Jia; YANG Hong-qiang; YAN Tian-li; SHU Huai-rui

    2006-01-01

    Calcium (Ca) plays an important role in the metabolism of higher plants. Recently, research on Ca2+ in plants has been focused especially at the cellular and molecular levels. Uptake, transport, and distribution are also very important for Ca to accomplish its function at the whole-plant level. In this experiment, one-year-old apple seedlings (M. hupehensis Rehd.) were investigated to determine the distribution of stored Ca, the different forms of Ca, and Ca2+-ATPase activity after treatment with indole butyric acid (IBA). The results showed that the total Ca measured in mature leaves and Ca2+-ATPase activity in tender leaves were higher compared with those in the control (CK). Calcium nitrate and calcium chloride (ALe-Ca) and calcium phosphate and calcium carbonate (HAC-Ca) decreased in both mature leaves and shoots,whereas water-soluble calcium (H2O-Ca), calcium pectate (NaCl-Ca), and calcium oxalate (HCl-Ca) increased. The percentage of active calcium, calcium pectate, and water-soluble calcium increased, whereas the percentage of calcium phosphate and calcium carbonate decreased. When treated with IBA, calcium fractions and percentage of the different forms of Ca was enhanced in 40 part per million (ppm) IBA compared with 20 ppm IBA and water. The results indicated that IBA increased the percentage of both active calcium (NaCl-Ca and H2O-Ca) in tender shoots and boosted the transportation of stored Ca in plants. IBA promoted Ca2+-ATPase activity and Ca2+ uptake in tender shoots of M. hupehensis. It can improve the total Ca contents and the relative percentage of Ca.

  6. Porosity prediction of calcium phosphate cements based on chemical composition.

    Science.gov (United States)

    Öhman, Caroline; Unosson, Johanna; Carlsson, Elin; Ginebra, Maria Pau; Persson, Cecilia; Engqvist, Håkan

    2015-07-01

    The porosity of calcium phosphate cements has an impact on several important parameters, such as strength, resorbability and bioactivity. A model to predict the porosity for biomedical cements would hence be a useful tool. At the moment such a model only exists for Portland cements. The aim of this study was to develop and validate a first porosity prediction model for calcium phosphate cements. On the basis of chemical reaction, molar weight and density of components, a volume-based model was developed and validated using calcium phosphate cement as model material. 60 mol% β-tricalcium phosphate and 40 mol% monocalcium phosphate monohydrate were mixed with deionized water, at different liquid-to-powder ratios. Samples were set for 24 h at 37°C and 100% relative humidity. Thereafter, samples were dried either under vacuum at room temperature for 24 h or in air at 37 °C for 7 days. Porosity and phase composition were determined. It was found that the two drying protocols led to the formation of brushite and monetite, respectively. The model was found to predict well the experimental values and also data reported in the literature for apatite cements, as deduced from the small absolute average residual errors (brushite, monetite and apatite cements. The model gives a good estimate of the final porosity and has the potential to be used as a porosity prediction tool in the biomedical cement field.

  7. Effects of monohydric alcohols and polyols on the thermal stability of a protein

    Science.gov (United States)

    Murakami, Shota; Kinoshita, Masahiro

    2016-03-01

    The thermal stability of a protein is lowered by the addition of a monohydric alcohol, and this effect becomes larger as the size of hydrophobic group in an alcohol molecule increases. By contrast, it is enhanced by the addition of a polyol possessing two or more hydroxyl groups per molecule, and this effect becomes larger as the number of hydroxyl groups increases. Here, we show that all of these experimental observations can be reproduced even in a quantitative sense by rigid-body models focused on the entropic effect originating from the translational displacement of solvent molecules. The solvent is either pure water or water-cosolvent solution. Three monohydric alcohols and five polyols are considered as cosolvents. In the rigid-body models, a protein is a fused hard spheres accounting for the polyatomic structure in the atomic detail, and the solvent is formed by hard spheres or a binary mixture of hard spheres with different diameters. The effective diameter of cosolvent molecules and the packing fractions of water and cosolvent, which are crucially important parameters, are carefully estimated using the experimental data of properties such as the density of solid crystal of cosolvent, parameters in the pertinent cosolvent-cosolvent interaction potential, and density of water-cosolvent solution. We employ the morphometric approach combined with the integral equation theory, which is best suited to the physical interpretation of the calculation result. It is argued that the degree of solvent crowding in the bulk is the key factor. When it is made more serious by the cosolvent addition, the solvent-entropy gain upon protein folding is magnified, leading to the enhanced thermal stability. When it is made less serious, the opposite is true. The mechanism of the effects of monohydric alcohols and polyols is physically the same as that of sugars. However, when the rigid-body models are employed for the effect of urea, its addition is predicted to enhance the

  8. Urinary oxalate excretion by very low birth weight infants receiving parenteral nutrition.

    Science.gov (United States)

    Campfield, T; Braden, G

    1989-11-01

    Renal calcifications have been described in very low birth weight (VLBW) infants, and diuretic drug-associated hypercalciuria is believed to play a role in the pathogenesis of this lesion. Hyperoxaluria is an important cause of renal stone formation in children and adults. Because parenteral nutrition solutions contain the oxalate precursors ascorbate and glycine, the relationship between total parenteral nutrition administration and oxalate excretion in VLBW infants was examined. Administration of approximately 0.5 g of total parenteral nutrition protein per kilogram per day to VLBW infants was associated with an increased urinary oxalate concentration and an increased urinary oxalate to creatinine ratio, when compared with VLBW infants receiving a glucose and electrolyte solution. A further increase in urinary oxalate concentration and oxalate to creatinine ratio was noted when total parenteral nutrition protein was increased to approximately 1.5 g of protein per kilogram per day. In VLBW infants who receive total parenteral nutrition, elevated urinary oxalate concentrations may develop and may be a factor in the pathogenesis of nephrocalcinosis in these infants.

  9. Synergistic effects of the combination of oxalate and ascorbate on arsenic extraction from contaminated soils.

    Science.gov (United States)

    Lee, Jae-Cheol; Kim, Eun Jung; Baek, Kitae

    2017-02-01

    Arsenic is often associated with iron oxides in soils due to its high affinity with iron oxides and the abundance of iron oxides in the environment. Dissolution of iron oxides can subsequently release arsenic associated with them into the environment, which results in the increase of arsenic mobility in the soil environment. In this study, arsenic extraction from soils via the dissolution of iron oxides was investigated using oxalate, ascorbate, and their combination in order to effectively remediate arsenic-contaminated soils. Oxalate mainly extracted iron from soils via a ligand-promoted reaction, while ascorbate extracted iron mainly via a reductive reaction. Arsenic extractions from soils by oxalate and ascorbate were shown to behave similarly to iron extractions, indicating the concurrent release of arsenic adsorbed on iron oxides upon the dissolution of iron oxides. The combination of oxalate and ascorbate greatly increased arsenic extraction, indicating the synergistic effects of the combination of oxalate and ascorbate on iron and arsenic extraction from soils. Oxalate and ascorbate are naturally-occurring organic reagents that have chelating and reducing capacity. Therefore, the use of oxalate and ascorbate is environmentally friendly and effective for the remediation of arsenic-contaminated soils.

  10. Remediation of arsenic contaminated soil by coupling oxalate washing with subsequent ZVI/Air treatment.

    Science.gov (United States)

    Cao, Menghua; Ye, Yuanyao; Chen, Jing; Lu, Xiaohua

    2016-02-01

    The application of a novel coupled process with oxalate washing and subsequent zero-valent iron (ZVI)/Air treatment for remediation of arsenic contaminated soil was investigated in the present study. Oxalate is biodegradable and widely present in the environment. With addition of 0.1 mol L(-1) oxalate under circumneutral condition, 83.7% and 52.6% of arsenic could be removed from a spiked kaolin and an actual contaminated soil respectively. Much more oxalate adsorption on the actual soil was attributed to the higher soil organic matter and clay content. Interestingly, oxalate retained in the washing effluent could act as an organic ligand to promote the oxidation efficiency of ZVI/Air at near neutral pH. Compared with the absence of oxalate, much more As(III) was oxidized. Arsenic was effectively adsorbed on iron (hydr)oxides as the consumption of oxalate and the increase of pH value. For the actual soil washing effluent, about 94.9% of total arsenic was removed after 120 min's treatment without pH adjustment. It has been demonstrated that As(V) was the dominant arsenic speciation adsorbed on iron (hydr)oxides. This study provides a promising alternative for remediation of arsenic contaminated soil in view of its low cost and environmental benign.

  11. [Catalytic ozonation by ceramic honeycomb for the degradation of oxalic acid in aqueous solution].

    Science.gov (United States)

    Zhao, Lei; Sun, Zhi-Zhong; Ma, Jun

    2007-11-01

    Comparative experiments for the degradation of oxalic acid in aqueous solution were carried out in the three processes of ozonation alone, ceramic honeycomb-catalyzed ozonation and ceramic honeycomb adsorption. The results show that the degradation rates of oxalic acid in the ceramic honeycomb-catalyzed ozonation, ozonation alone and ceramic honeycomb adsorption systems are 37.6%, 2.2% and 0.4%, and the presence of ceramic honeycomb catalyst significantly improves the degradation rate of oxalic acid compared to the results from non-catalytic ozonation and adsorption. With the addition of tert-butanol, the degradation rates of oxalic acid in catalytic ozonation system decrease by 24.1%, 29.0% and 30.1%, respectively, at the concentration of 5, 10 and 15 mg x L(-1). This phenomenon indicates that ceramic honeycomb-catalyzed ozonation for the degradation of oxalic acid in aqueous solution follows the mechanism of *OH oxidation, namely the heterogeneous surface of catalyst enhances the initiation of *OH. The results of TOC analysis demonstrate that the process of ceramic honeycomb-catalyzed ozonation can achieve the complete mineralization level without the formation of intermediary degradation products. The experimental results suggest that the reaction temperature has positive relationship with the degradation rate of oxalic acid. The degradation rates of oxalic acid in the ceramic honeycomb-catalyzed ozonation system are 16.4%, 37.6%, 61.3% and 68.2%, at the respective reaction temperature of 10, 20, 30 and 40 degrees C.

  12. Thorium adsorption behaviour on mixed ammonium lanthanum oxalate, LAOX

    Energy Technology Data Exchange (ETDEWEB)

    Valentini Ganzerli, M.T.; Maggi, L.; Crespi Caramella, V

    1999-07-01

    The cation-exchange properties of mixed ammonium lanthanum oxalate, LAOX, were studied by batch equilibration as a function of the concentration of some cations, such as alkaline earths or ammonium and of some anions and acids. The distribution coefficients for thorium are high, while U(VI) is not adsorbed over a large acidity range. Thus, the separation of thorium from uranium may be successfully carried out. The experimental conditions of adsorption, elution and recovery of thorium were investigated as well, by using chromatographic columns filled with LAOX, in order to set best the separation conditions from uranyl ions. Instrumental neutron activation analysis, ICP emission spectrometry and the UV spectrometry were used to evaluate the thorium, uranium and lanthanum concentrations00.

  13. The structural dynamics in the proton-conducting imidazolium oxalate

    Energy Technology Data Exchange (ETDEWEB)

    Rachocki, Adam; Pogorzelec-Glaser, Katarzyna; Tritt-Goc, Jadwiga [Institute of Molecular Physics, Polish Academy of Sciences, M. Smoluchowskiego 17, 60-179 Poznan (Poland); Pietraszko, Adam [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okolna 2, 50-422 Wroclaw (Poland)], E-mail: radam@ifmpan.poznan.pl

    2008-12-17

    The {sup 1}H spin-lattice relaxation times and high-resolution solid-state nuclear magnetic resonance (NMR) under fast magic spinning were used to study the structural dynamics in the proton-conducting material imidazolium oxalate. The measurements provide evidence for the ordered and disordered domains within the studied material. The two components drastically differ in their {sup 1}H spin-lattice relaxation times and {sup 1}H-{sup 13}C cross-polarization magic-angle-spinning (CP/MAS) spectra. The coalescence phenomenon of the resonances of the basal carbons of the imidazole ring undergoing a reorientation is observed only for mobile molecules in the disordered domains. Therefore, only these molecules can be responsible for proton conductivity allowing for the Grotthus mechanism.

  14. Charge dynamics in conducting polyaniline–metal oxalate composites

    Indian Academy of Sciences (India)

    R Murugesan; E Subramanian

    2003-08-01

    Polyaniline (Pani) and its metal oxalate composites (∼ 10 wt.%) of trivalent metal ions of Cr, Fe, Mn, Co and Al were synthesized by chemical oxidative polymerization technique with potassium perdisulphate oxidant in aqueous sulphuric acid medium. These materials were characterized by UV–VIS and EPR spectral techniques. Their d.c. electrical conductivities at room temperature and also as a function of temperature (307–453 K) were measured by four-probe technique. Presence of radical cation/polaron transition was indicated by UV–VIS absorption peak and EPR signals. Further, a close correlation existed between the conductivities and EPR parameters such as line width and peak ratio, which demonstrated that both mobile and fixed spins are involved in these composites. The dependence of conductivity on temperature, when analysed graphically by VRH, GB and TC mechanisms, pointed out that VRH is the predominant charge transport mechanism in these materials.

  15. The control of Varroa destructor using oxalic acid.

    Science.gov (United States)

    Gregorc, Ales; Planinc, I

    2002-05-01

    Twenty-four honeybee (Apis mellifera) colonies were used to monitor the efficacy of a solution of 2.9% oxalic acid (OA) and 31.9% sugar against the mite Varroa destructor. Mite mortality was established prior to and after OA treatments, which were conducted in August and September. The treatments resulted in 37% mite mortality as opposed to 1.11% in the controls. OA treatment conducted in September on previously untreated colonies resulted in 25% mite mortality. OA treatments in October and November resulted in approximately 97% mite mortality. These results suggest that OA is effective during the broodless period and less effective when applied to colonies with capped broods. The possible use of OA against the Varroa mite in honeybee colonies as an alternative to routine chemical treatments is discussed.

  16. Biocompatible laponite ionogels based non-enzymatic oxalic acid sensor

    Directory of Open Access Journals (Sweden)

    Nidhi Joshi

    2015-09-01

    Full Text Available An enzyme-free oxalic acid (OA electrochemical sensor was assembled on indium tin oxide (ITO plate on which a film of laponite ionogel was coated that resulted in an L/IL/ITO electrode. This ionogel electrode was characterized by scanning electron microscopy (SEM, Fourier transform infrared spectroscopy (FTIR, and UV–Vis spectroscopy techniques. Electrochemical oxidation of OA on the electrode surface was investigated by cyclic voltammetry. Further this electrode exhibited high electrochemical activity that yielded well-defined peaks of OA oxidation, and a notably suppressed over-potential compared to the laponite–ITO (L/ITO electrode. Under optimized conditions, a good linear response (anodic current was observed for the OA concentration in the 1–20 mM range with a detection limit of 3 μM. Furthermore, this electrochemical strip sensor presented good characteristics in terms of stability, and reproducibility offering promise of applicability of this green sensor platform.

  17. Growth and characterisation of gadolinium samarium oxalate single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Korah, I. [Dept. of Physics, St. George College, Aruvithura - 686122, Kerala (India); Joseph, C. [School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam - 686562 (India); Ittyachan, M.A. [Dept. of Physics, Cochin University of Science and Technology, Cochin (India)

    2007-10-15

    Single crystals of Gadolinium Samarium Oxalate (GSO) are grown by gel method. The crystals are pale yellowish in colour. Morphology and size of the crystals are found to depend on pH of the medium, gel density, concentration of the reactants and acidity of the feed solution. The crystallinity of the grown sample was confirmed by X-ray diffraction studies and the lattice parameters were determined. X-ray diffractogram shows well defined peaks. IR spectrum confirms the presence of water molecules and carboxylic group. EDAX analysis confirms the presence of Gd and Sm in the sample. The thermal decomposition behaviour of the crystal was analysed using TGA and DTA studies. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  18. Manganese oxalate nanorods as ballistic modifier for composite solid propellants

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Supriya [Department of Chemistry, DDU Gorakhpur University, Gorakhpur 273009, U.P. (India); Chawla, Mohit [School of Basic Sciences, Indian Institute of Technology Mandi, Mandi 175005, H.P. (India); Siril, Prem Felix, E-mail: prem@iitmandi.ac.in [School of Basic Sciences, Indian Institute of Technology Mandi, Mandi 175005, H.P. (India); Singh, Gurdip [Department of Chemistry, DDU Gorakhpur University, Gorakhpur 273009, U.P. (India)

    2014-12-10

    Highlights: • Manganese oxalate nanorods were prepared using mild thermal precipitation and aging. • The nanorods were found to be efficient ballistic modifier for solid propellants. • The nanorods sensitized the thermolysis of ammonium perchlorate. • Controlled thermal decomposition of nanorods yielded manganese oxide nanoparticles. • MnO nanoparticles formed insitu in the condensed phase enhance the burning rates. - Abstract: Rod-shaped nanostructures of manganese oxalate (MnC{sub 2}O{sub 4}) were synthesized via mild thermal precipitation and aging process. Chemical composition of the MnC{sub 2}O{sub 4} nanorods was confirmed using Fourier transform infra-red (FTIR) spectroscopy and energy dispersive X-ray spectroscopy (EDS). X-ray diffraction (XRD) and selected area electron diffraction (SAED) studies revealed the crystal structure. Field emission scanning electron microscopy (FE-SEM) imaging and high resolution transmission electron microscopy (HR-TEM) were employed to study the structural features of the nanorods. The MnC{sub 2}O{sub 4} nanorods were found to be efficient ballistic modifier for the burning rate enhancement of composite solid propellants (CSPs). Thermal analysis using TGA-DSC showed that MnC{sub 2}O{sub 4} nanorods sensitized the thermal decomposition of ammonium perchlorate (AP) and the CSPs. Controlled thermal decomposition of the MnC{sub 2}O{sub 4} nanorods resulted in the formation of managanese oxide nanoparticles with mesoporosity. A plausible mechanism for the burning rate enhancement using MnC{sub 2}O{sub 4} nanorods was proposed.

  19. EFFECTIVENESS OF USING DILUTE OXALIC ACID TO DISSOLVEHIGH LEVEL WASTE IRON BASED SLUDGE SIMULANT

    Energy Technology Data Exchange (ETDEWEB)

    Ketusky, E

    2008-07-11

    At the Savannah River Site (SRS), near Aiken South Carolina, there is a crucial need to remove residual quantities of highly radioactive iron-based sludge from large select underground storage tanks (e.g., 19,000 liters of sludge per tank), in order to support tank closure. The use of oxalic acid is planned to dissolve the residual sludge, hence, helping in the removal. Based on rigorous testing, primarily using 4 and 8 wt% oxalic acid solutions, it was concluded that the more concentrated the acid, the greater the amount of residual sludge that would be dissolved; hence, a baseline technology on using 8 wt% oxalic acid was developed. In stark contrast to the baseline technology, reports from other industries suggest that the dissolution will most effectively occur at 1 wt% oxalic acid (i.e., maintaining the pH near 2). The driver for using less oxalic acid is that less (i.e., moles) would decrease the severity of the downstream impacts (i.e., required oxalate solids removal efforts). To determine the initial feasibility of using 1 wt% acid to dissolve > 90% of the sludge solids, about 19,000 liters of representative sludge was modeled using about 530,000 liters of 0 to 8 wt% oxalic acid solutions. With the chemical thermodynamic equilibrium based software results showing that 1 wt% oxalic acid could theoretically work, simulant dissolution testing was initiated. For the dissolution testing, existing simulant was obtained, and an approximate 20 liter test rig was built. Multiple batch dissolutions of both wet and air-dried simulant were performed. Overall, the testing showed that dilute oxalic acid dissolved a greater fraction of the stimulant and resulted in a significantly larger acid effectiveness (i.e., grams of sludge dissolved/mole of acid) than the baseline technology. With the potential effectiveness confirmed via simulant testing, additional testing, including radioactive sludge testing, is planned.

  20. REINVESTIGATING THE PROCESS IMPACTS FROM OXALIC ACIDHIGH LEVEL WASTE TANK CLEANING

    Energy Technology Data Exchange (ETDEWEB)

    Ketusky, E

    2008-01-22

    The impacts and acceptability of using oxalic acid to clean the Savannah River Site, High Level Waste Tanks 1-8, were re-investigated using a two-phased approach. For the first phase, using a representative Tank 1-8 sludge, the chemical equilibrium based software, OLI ESP{copyright} and Savannah River Site laboratory test results were used to develop a chemically speciated material balance and a general oxalate mass balance. Using 8 wt% oxalic acid with a 100% molar excess, for every 1 kg of sludge solid that was dissolved, about 3.4 kg of resultant solids would form for eventual vitrification, while about 0.6 kg of soluble oxalate would precipitate in the evaporator system, and form a salt heel. Using available analyses, a list of potential safety and process impacts were developed, screened, and evaluated for acceptability. The results showed that the use of oxalic acid had two distinct types of impacts, those which were safety based and required potential upgrades or additional studies. Assuming such were performed and adequate, no further actions were required. The second type of impacts were also acceptable, but were long-term, and as such, would need to be managed. These impacts were directly caused by the solubility characteristics of oxalate in a concentrated sodium solution and, occurred after pH restoration. Since oxalate destruction methods are commonly available, their use should be considered. Using an oxalate destruction method could enable the benefits of oxalic to applied, while eliminating the long-term impacts that must be managed, and hence should be considered.

  1. Oxalic acid production by citric acid-producing Aspergillus niger overexpressing the oxaloacetate hydrolase gene oahA.

    Science.gov (United States)

    Kobayashi, Keiichi; Hattori, Takasumi; Honda, Yuki; Kirimura, Kohtaro

    2014-05-01

    The filamentous fungus Aspergillus niger is used worldwide in the industrial production of citric acid. However, under specific cultivation conditions, citric acid-producing strains of A. niger accumulate oxalic acid as a by-product. Oxalic acid is used as a chelator, detergent, or tanning agent. Here, we sought to develop oxalic acid hyperproducers using A. niger as a host. To generate oxalic acid hyperproducers by metabolic engineering, transformants overexpressing the oahA gene, encoding oxaloacetate hydrolase (OAH; EC 3.7.1.1), were constructed in citric acid-producing A. niger WU-2223L as a host. The oxalic acid production capacity of this strain was examined by cultivation of EOAH-1 under conditions appropriate for oxalic acid production with 30 g/l glucose as a carbon source. Under all the cultivation conditions tested, the amount of oxalic acid produced by EOAH-1, a representative oahA-overexpressing transformant, exceeded that produced by A. niger WU-2223L. A. niger WU-2223L and EOAH-1 produced 15.6 and 28.9 g/l oxalic acid, respectively, during the 12-day cultivation period. The yield of oxalic acid for EOAH-1 was 64.2 % of the maximum theoretical yield. Our method for oxalic acid production gave the highest yield of any study reported to date. Therefore, we succeeded in generating oxalic acid hyperproducers by overexpressing a single gene, i.e., oahA, in citric acid-producing A. niger as a host.

  2. Diminution of oxalate induced renal tubular epithelial cell injury and inhibition of calcium oxalate crystallization in vitro by aqueous extract of Tribulus terrestris

    OpenAIRE

    2010-01-01

    PURPOSE: Recurrence and persistent side effects of present day treatment for urolithiasis restrict their use, so an alternate solution, using phytotherapy is being sought. The present study attempted to evaluate the antilithiatic properties of Tribulus terrestris commonly called as “gokhru” which is often used in ayurveda to treat various urinary diseases including urolithiasis. MATERIALS AND METHODS: The activity of Tribulus terrestris was investigated on nucleation and the growth of the cal...

  3. Kinetics of wet air oxidation of glyoxalic acid and oxalic acid

    Energy Technology Data Exchange (ETDEWEB)

    Shende, R.V.; Mahajani, V.V. (Univ. of Bombay (India). Dept. of Chemical Technology)

    1994-12-01

    Oxidation of lower molecular weight monobasic and dibasic acids such as formic acid, acetic acid, glyoxalic acid, and oxalic acid is often the rate-controlling step during wet air oxidation (WAO) of an aqueous waste stream exhibiting very high chemical oxygen demand (COD). The kinetics of WAO of glyoxalic acid and oxalic acid was studied in absence and presence of a cupric sulfate catalyst in the temperature range of 120--245 C and oxygen partial pressure of 0.345--1.380 MPa. The wet oxidation of oxalic acid was found to require more severe conditions as compared to glyoxalic acid. The reaction mechanism and kinetic model have been discussed.

  4. Blue luminescence in porous anodic alumina films: the role of the oxalic impurities

    CERN Document Server

    Gao Tao; Zhang Li

    2003-01-01

    Porous anodic alumina (PAA) films with ordered nanopore arrays have been prepared by electrochemically anodizing aluminium in oxalic acid solutions, and the role of the oxalic impurities in the optical properties of PAA films has been discussed. Photoluminescence (PL) measurements show that the PAA films obtained have a blue PL band with a peak position at around 470 nm; the oxalic impurities, incorporated in the PAA films during the anodization processes and already existing in them, could be being transformed into PL centres and hence responsible for this PL emission.

  5. Crystallization and Structure Determination of Fac-Triammin-Aquo-Oxalato-Cobalt (III-Nitrate Monohydrate

    Directory of Open Access Journals (Sweden)

    Cristian G. Hrib

    2014-11-01

    Full Text Available The title compound, fac-triammin-aquo-oxalato-cobalt(III-nitrate monohydrate, fac-[Co(NH33(C2O4(H2O]NO3·H2O (2, was prepared according to an original synthetic protocol published exactly 100 years ago by Alfred Werner by dissolving the indigo-blue non-electrolyte complex mer-triammin-chloro-oxalato-cobalt(III, mer-[Co(NH33(C2O4Cl] (1, in boiling half-concentrated nitric acid. Contrary to the literature, it did not crystallize directly from the reaction mixture, but crystallization could be induced by saturating the solution with NaClO4. The structure of 2 has monoclinic (P21/n symmetry. The crystal structure displays an extensive array of N–H···O and O–H···O hydrogen bonding.

  6. Crystal structure of potassium (1S-d-lyxit-1-ylsulfonate monohydrate

    Directory of Open Access Journals (Sweden)

    Alan H. Haines

    2015-08-01

    Full Text Available The title compound, K+·C5H11O8S−·H2O [systematic name: potassium (1S,2S,3S,4R-1,2,3,4,5-pentahydroxypentane-1-sulfonate monohydrate], formed by reaction of d-lyxose with potassium hydrogen sulfite in water, crystallizes as colourless square prisms. The anion has an open-chain structure in which the S atom, the C atoms of the sugar chain and the oxygen atom of the hydroxymethyl group form an essentially all-trans chain with the corresponding torsion angles lying between 178.61 (12 and 157.75 (10°. A three-dimensional bonding network exists in the crystal structure involving coordination of two crystallographically independent potassium ions by O atoms (one cation being hexa- and the other octa-coordinate, with each lying on a twofold rotation axis, and extensive intermolecular O—H...O hydrogen bonding.

  7. A second monoclinic polymorph of ethylenediammonium bis(hydrogen squarate monohydrate

    Directory of Open Access Journals (Sweden)

    Louiza Zenkhri

    2011-05-01

    Full Text Available The title compound, C2H10N22+·2HC4O4−·H2O, a new polymorph of ethylenediammonium bis(hydrogen squarate monohydrate, was synthesized by slow evaporation of an acid solution. The asymetric unit contains two hydrogen squarate anions, two half-molecules of protonated ethylenediamine arranged around a twofold axis and one water molecule. In the crystal, N—H...O and O—H...O hydrogen bonds between the hydrogen squarate anions, protonated N atoms from the amine group and water molecules lead to a three-dimensional framework. In particular, the cohesion between the squarate groups is ensured by very short intermolecular hydrogen bonds bonds. The title compound crystallized together with the previously reported polymorph [Mathew et al. (2002. J. Mol. Struct. 641, 263–279].

  8. 1,3-Dicyclohexyl-3-[(pyridin-2-ylcarbonyl]urea monohydrate from synchrotron radiation

    Directory of Open Access Journals (Sweden)

    Solange M. S. V. Wardell

    2011-10-01

    Full Text Available The title urea derivative crystallizes as a monohydrate, C19H27N3O2·H2O. The central C3N grouping is almost planar (r.m.s. deviation = 0.0092 Å, and the amide and pyridine groups are substantially twisted out this plane [dihedral angles = 62.80 (12 and 34.98 (10°, respectively]. Supramolecular double chains propagating along the b-axis direction feature in the crystal packing whereby linear chains sustained by N—H...O hydrogen bonds formed between the amide groups are linked by helical chains of water molecules (linked by O—H...O hydrogen bonds. The H atom that participates in these water chains is disordered over two positions of equal occupancy. The double chains are connected into a two-dimensional array by C—H...O contacts and the layers stack along the a axis.

  9. 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 ...

  10. Calcium biofortification and bioaccessibility in soilless "baby leaf" vegetable production.

    Science.gov (United States)

    D'Imperio, Massimiliano; Renna, Massimiliano; Cardinali, Angela; Buttaro, Donato; Serio, Francesco; Santamaria, Pietro

    2016-12-15

    Calcium is an essential nutrient for human health, because it is a structural component and takes part in a variety of biological processes. The aim of this study was to increase Ca content of baby leaf vegetables (BLV: basil, mizuna, tatsoi and endive), as fresh-cut products. For the production of biofortified BLV, a floating system with two level of Ca (100 and 200mgL(-1)) in the nutrient solution was used. In addition, the assessment of bioaccessibility of Ca, by in vitro digestion process, was performed. In all vegetables, the Ca biofortification (200mgL(-1)) caused a significant Ca enrichment (9.5% on average) without affecting vegetables growth, oxalate contents and marketable quality. Calcium bioaccessibility ranged from 25% (basil) to 40% (endive) but the biofortified vegetables showed more bioaccessible Ca. These results underline the possibility to obtain Ca biofortified BLV by using agronomic approaches.

  11. 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.

  12. Oxalate nephropathy induced by octreotide treatment for acromegaly: a case report

    Directory of Open Access Journals (Sweden)

    Gariani Karim

    2012-07-01

    Full Text Available Abstract Introduction Oxalate nephropathy has various etiologies and remains a rare cause of renal failure. To the best of our knowledge, we report the first case of oxalate nephropathy following octreotide therapy. Case presentation We report the case of a 78-year-old Caucasian man taking chronic octreotide treatment for acromegaly who presented with acute oxalate nephropathy after antibiotic therapy. The diagnosis was confirmed by urinary analysis and a kidney biopsy. The recovery of renal function was favorable after hydration and withdrawal of octreotide therapy. Conclusions Oxalate nephropathy should be suspected in patients at risk who present with acute kidney injury after prolonged antibiotic treatment. This diagnosis should be distinguished from immuno-allergic interstitial nephritis and requires specific care. The evolution of this condition may be favorable if the pathology is identified correctly. Octreotide therapy should be considered a risk factor for enteric oxaluria.

  13. Alleviation of chilling injury in tomato fruit by exogenous application of oxalic acid.

    Science.gov (United States)

    Li, Peiyan; Yin, Fei; Song, Lijun; Zheng, Xiaolin

    2016-07-01

    The effects of oxalic acid on the development of chilling injury (CI), energy metabolism and lycopene metabolism in tomato fruit (Solanum lycopersicum L.) were investigated. Mature green tomatoes were dipped in 10mmoll(-1) oxalic acid (OA) solution for 10min at 25°C. Tomatoes were subsequently stored at 4±0.5°C for 20days before being transferred to 25°C for 12days. Oxalic acid treatment apparently alleviated CI development and membrane damage; maintained higher levels of ATP and ADP; increased activities of succinic dehydrogenase (SDH), Ca(2+)-adenosine triphosphatase (Ca(2+)-ATPase) and H(+)-adenosine triphosphatase (H(+)-ATPase); and elevated lycopene accumulation associated with the upregulation of PSY1 and ZDS expression in tomatoes during a period at room temperature following exposure to chilling stress. Thus, oxalic acid treatment benefited the control of CI and the maintenance of fruit quality in tomatoes stored for long periods (approximately 32days).

  14. Oxalate complexation with aluminum(III) and iron(III) at moderately elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Tait, C.D.; Janecky, D.R.; Clark, D.L. [Los Alamos National Lab., NM (United States); Bennett, P.C. [Texas Univ., Austin, TX (United States). Dept. of Geological Sciences

    1992-05-01

    To add to our understanding of the weathering of rocks in organic rich environments such as sedimentary brines and oil field waters, we have examined the temperature dependent complexation of aluminum with oxalate. Raman vibrational studies show that even the association constant for the highly charged Al(ox){sub 3}{sup 3{minus}} unexpectedly increases with moderate temperature increases to 80{degrees}C. To evaluate the potential importance of these Al-oxalate species in complex natural systems, temperature dependent competition experiments Fe(III) and Al(III) for oxalate have been initiated. Similar to aluminum, ferric oxalates show increases in association constants at higher temperatures. In competition experiments, the first association constant for Fe(ox){sup +} increases faster than that for Al(ox){sup +} to 90{degrees}C.

  15. An unusual cause of acute kidney injury due to oxalate nephropathy in systemic scleroderma.

    Science.gov (United States)

    Mascio, Heather M; Joya, Christie A; Plasse, Richard A; Baker, Thomas P; Flessner, Michael F; Nee, Robert

    2015-08-01

    Oxalate nephropathy is an uncommon cause of acute kidney injury. Far rarer is its association with scleroderma, with only one other published case report in the literature. We report a case of a 75-year-old African-American female with a history of systemic scleroderma manifested by chronic pseudo-obstruction and small intestinal bacterial overgrowth (SIBO) treated with rifaximin, who presented with acute kidney injury with normal blood pressure. A renal biopsy demonstrated extensive acute tubular injury with numerous intratubular birefringent crystals, consistent with oxalate nephropathy. We hypothesize that her recent treatment with rifaximin for SIBO and decreased intestinal transit time in pseudo-obstruction may have significantly increased intestinal oxalate absorption, leading to acute kidney injury. Oxalate nephropathy should be considered in the differential diagnosis of acute kidney injury in scleroderma with normotension, and subsequent evaluation should be focused on bowel function to include alterations in gut flora due to antibiotic administration.

  16. Stability Constants of Technetium (IV) Oxalate Complexes as a Function of Ionic Strength

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Yuanxian; Hess, Nancy J.; Felmy, Andrew R.

    2006-03-01

    Solvent extraction methods were used to determine the stability constants of Tc(IV) with oxalate anions in NaCl solutions ranging in concentration from 0.5 M to 2.0 M. All experiments were conducted in an atmosphere-controlled chamber under Ar atmosphere (< 1.0ppm O2). A reducing agent (hydrazine) was used during extractions to maintain technetium in the tetravalent oxidation state. Independent tests confirmed that the oxidation state of technetium did not change during extractions. The distribution ratio of Tc(IV) between the organic and aqueous phases was found to decrease as the concentration of oxalic acid increased. At the oxalic acid concentrations used in these experiments, the complexes TcO(Ox) and TcO(Ox)22- were found to be the dominant aqueous species. Based on these data, the thermodynamic stability constants of Tc(IV) with oxalate complexes were calculated by the Specific Ion Interaction Theory (SIT).

  17. Hypercalciuria, hyperoxaluria, and hypocitraturia screening from random urine samples in patients with calcium lithiasis.

    Science.gov (United States)

    Arrabal-Polo, Miguel Angel; Arias-Santiago, Salvador; Girón-Prieto, María Sierra; Abad-Menor, Felix; López-Carmona Pintado, Fernando; Zuluaga-Gomez, Armando; Arrabal-Martin, Miguel

    2012-10-01

    Calcium lithiasis is the most frequently diagnosed renal lithiasis and is associated with a high percentage of patients with metabolic disorders, such as hypercalciuria, hypocitraturia, and hyperoxaluria. The present study included 50 patients with recurrent calcium lithiasis. We conducted a random urine test during nocturnal fasting and a 24-h urine test, and examined calcium, oxalate, and citrate. A study of the linear correlation between the metabolites was performed, and the receiver operator characteristic (ROC) curves were analyzed in the random urine samples to determine the cutoff values for hypercalciuria (excretion greater than 200 mg), hyperoxaluria (excretion greater than 40 mg), and hypocitraturia (excretion less than 320 mg) in the 24-h urine. Linear relationships were observed between the calcium levels in the random and 24-h urine samples (R = 0.717, p = 0.0001), the oxalate levels in the random and 24-h urine samples (R = 0.838, p = 0.0001), and the citrate levels in the random and 24-h urine samples (R = 0.799, p = 0.0001). After obtaining the ROC curves, we observed that more than 10.15 mg/dl of random calcium and more than 16.45 mg/l of random oxalate were indicative of hypercalciuria and hyperoxaluria, respectively, in the 24-h urine. In addition, we found that the presence of less than 183 mg/l of random citrate was indicative of the presence of hypocitraturia in the 24-h urine. Using the proposed values, screening for hypercalciuria, hyperoxaluria, and hypocitraturia can be performed with a random urine sample during fasting with an overall sensitivity greater than 86%.

  18. Retinal and choroidal findings in oxalate retinopathy using EDI-OCT.

    Science.gov (United States)

    Roth, Bryan M; Yuan, Alex; Ehlers, Justis P

    2012-01-01

    A 55-year-old woman with extensive retinal crystalline deposition secondary to primary hyperoxaluria presented with bilateral loss of vision secondary to oxalate retinopathy. Enhanced depth imaging optical coherence tomography revealed intraretinal, subretinal, and intraretinal and subretinal pigment epithelium, and choroidal focal hyperreflective structures consistent with both neurosensory and uveal deposition of oxalate crystals. Serial optical coherence tomography revealed continued crystalline deposition with progressive retinal atrophy.

  19. Influence of nitrate on oxalate- and glyoxylate-dependent growth and acetogenesis by Moorella thermoacetica.

    Science.gov (United States)

    Seifritz, Corinna; Fröstl, Jürgen M; Drake, Harold L; Daniel, Steven L

    2002-12-01

    Oxalate and glyoxylate supported growth and acetate synthesis by Moorella thermoacetica in the presence of nitrate under basal (without yeast extract) culture conditions. In oxalate cultures, acetate formation occurred concomitant with growth and nitrate was reduced in the stationary phase. Growth in the presence of [(14)C]bicarbonate or [(14)C]oxalate showed that CO(2) reduction to acetate and biomass or oxalate oxidation to CO(2) was not affected by nitrate. However, cells engaged in oxalate-dependent acetogenesis in the presence of nitrate lacked a membranous b-type cytochrome, which was present in cells grown in the absence of nitrate. In glyoxylate cultures, growth was coupled to nitrate reduction and acetate was formed in the stationary phase after nitrate was totally consumed. In the absence of nitrate, glyoxylate-grown cells incorporated less CO(2) into biomass than oxalate-grown cells. CO(2) conversion to biomass by glyoxylate-grown cells decreased when cells were grown in the presence of nitrate. These results suggest that: (1) oxalate-grown cells prefer CO(2) as an electron sink and bypass the nitrate block on the acetyl-CoA pathway at the level of reductant flow and (2) glyoxylate-grown cells prefer nitrate as an electron sink and bypass the nitrate block of the acetyl-CoA pathway by assimilating carbon via an unknown process that supplements or replaces the acetyl-CoA pathway. In this regard, enzymes of known pathways for the assimilation of two-carbon compounds were not detected in glyoxylate- or oxalate-grown cells.

  20. Ability of sat-1 to transport sulfate, bicarbonate, or oxalate under physiological conditions.

    Science.gov (United States)

    Krick, Wolfgang; Schnedler, Nina; Burckhardt, Gerhard; Burckhardt, Birgitta C

    2009-07-01

    Tubular reabsorption of sulfate is achieved by the sodium-dependent sulfate transporter, NaSi-1, located at the apical membrane, and the sulfate-anion exchanger, sat-1, located at the basolateral membrane. To delineate the physiological role of rat sat-1, [(35)S]sulfate and [(14)C]oxalate uptake into sat-1-expressing oocytes was determined under various experimental conditions. Influx of [(35)S]sulfate was inhibited by bicarbonate, thiosulfate, sulfite, and oxalate, but not by sulfamate and sulfide, in a competitive manner with K(i) values of 2.7 +/- 1.3 mM, 101.7 +/- 9.7 microM, 53.8 +/- 10.9 microM, and 63.5 +/- 38.7 microM, respectively. Vice versa, [(14)C]oxalate uptake was inhibited by sulfate with a K(i) of 85.9 +/- 9.5 microM. The competitive type of inhibition indicates that these compounds are most likely substrates of sat-1. Physiological plasma bicarbonate concentrations (25 mM) reduced sulfate and oxalate uptake by more than 75%. Simultaneous application of sulfate, bicarbonate, and oxalate abolished sulfate as well as oxalate uptake. These data and electrophysiological studies using a two-electrode voltage-clamp device provide evidence that sat-1 preferentially works as an electroneutral sulfate-bicarbonate or oxalate-bicarbonate exchanger. In kidney proximal tubule cells, sat-1 likely completes sulfate reabsorption from the ultrafiltrate across the basolateral membrane in exchange for bicarbonate. In hepatocytes, oxalate extrusion is most probably mediated either by an exchange for sulfate or bicarbonate.

  1. In-cloud oxalate formation in the global troposphere: a 3-D modeling study

    Directory of Open Access Journals (Sweden)

    S. Myriokefalitakis

    2011-01-01

    Full Text Available Organic acids attract increasing attention as contributors to atmospheric acidity, secondary organic aerosol mass and aerosol hygroscopicity. Oxalic acid is globally the most abundant dicarboxylic acid, formed via chemical oxidation of gas-phase precursors in the aqueous phase of aerosols and droplets. Its lifecycle and atmospheric global distribution remain highly uncertain and are the focus of this study. The first global spatial and temporal distribution of oxalate, simulated using a state-of-the-art aqueous phase chemical scheme embedded within the global 3-dimensional chemistry/transport model TM4-ECPL, is here presented. The model accounts for comprehensive gas-phase chemistry and its coupling with major aerosol constituents (including secondary organic aerosol. Model results are consistent with ambient observations of oxalate at rural and remote locations (slope = 0.83 ± 0.06, r2 = 0.67, N = 106 and suggest that aqueous phase chemistry contributes significantly to the global atmospheric burden of secondary organic aerosol. In TM4-ECPL most oxalate is formed in-clouds and less than 10% is produced in aerosol water. About 61% of the oxalate is removed via wet deposition, 35% by in-cloud reaction with hydroxyl radical and 4% by dry deposition. The global oxalate net chemical production is calculated to be about 17–27 Tg yr−1 with almost 91% originating from biogenic hydrocarbons, mainly isoprene. This condensed phase net source of oxalate in conjunction with a global mean turnover time against deposition of about 5 days, maintain oxalate's global tropospheric burden of 0.24–0.39 Tg that is about 13–19% of calculated total organic aerosol burden.

  2. In-cloud oxalate formation in the global troposphere: a 3-D modeling study

    Directory of Open Access Journals (Sweden)

    S. Myriokefalitakis

    2011-06-01

    Full Text Available Organic acids attract increasing attention as contributors to atmospheric acidity, secondary organic aerosol mass and aerosol hygroscopicity. Oxalic acid is globally the most abundant dicarboxylic acid, formed via chemical oxidation of gas-phase precursors in the aqueous phase of aerosols and droplets. Its lifecycle and atmospheric global distribution remain highly uncertain and are the focus of this study. The first global spatial and temporal distribution of oxalate, simulated using a state-of-the-art aqueous-phase chemical scheme embedded within the global 3-dimensional chemistry/transport model TM4-ECPL, is here presented. The model accounts for comprehensive gas-phase chemistry and its coupling with major aerosol constituents (including secondary organic aerosol. Model results are consistent with ambient observations of oxalate at rural and remote locations (slope = 1.16 ± 0.14, r2 = 0.36, N = 114 and suggest that aqueous-phase chemistry contributes significantly to the global atmospheric burden of secondary organic aerosol. In TM4-ECPL most oxalate is formed in-cloud and less than 5 % is produced in aerosol water. About 62 % of the oxalate is removed via wet deposition, 30 % by in-cloud reaction with hydroxyl radical, 4 % by in-cloud reaction with nitrate radical and 4 % by dry deposition. The in-cloud global oxalate net chemical production is calculated to be about 21–37 Tg yr−1 with almost 79 % originating from biogenic hydrocarbons, mainly isoprene. This condensed phase net source of oxalate in conjunction with a global mean turnover time against deposition of about 5 days, maintain oxalate's global tropospheric burden of 0.2–0.3 Tg, i.e. 0.05–0.1 Tg-C that is about 5–9 % of model-calculated water soluble organic carbon burden.

  3. Oxalic acid for the control of varroosis in honey bee colonies - a review

    OpenAIRE

    RADEMACHER, Eva; Harz, Marika

    2006-01-01

    International audience; The review summarizes research results on the use of oxalic acid as an acaricide in honey bee colonies. Three different treatment techniques (i.e. trickling, evaporation and spraying) have been developed for the application of oxalic acid. Detailed information is given on the efficacy against Varroa destructor, tolerability by Apis mellifera, protective procedures for the user, residue situation and consumer safety, as well as recommendations for use.

  4. Effect of Oxalic Acid on Potassium Release from Typical Chinese Soils and Minerals

    Institute of Scientific and Technical Information of China (English)

    TU Shu-Xin; GUO Zhi-Fen; SUN Jin-He

    2007-01-01

    Oxalic acid plays an important role in improving the bioavailability of soil nutrients. Batch experiments were employed to examine the influences of oxalic acid on extraction and release kinetics of potassium (K) from soils and minerals along with the adsorption and desorption of soil K+. The soils and minerals used were three typical Chinese soils, black soil (Mollisol), red soil (Ultisol), and calcareous alluvial soil (Entisol), and four K-bearing minerals, biotite, phlogopite, muscovite, and microcline. The results showed that soil K extracted using 0.2 mol L-1 oxalic acid was similar to that using 1 mol L-1 boiling HNO3. The relation between K release (y) and concentrations of oxalic acid (c) could be best described logarithmically as y=a+blogc, while the best-fit kinetic equation of K release was y=a +b√t, where a and b are the constants and t is the elapsed time. The K release for minerals was ranked as biotite> phlogopite>> muscovite> microcline and for soils it was in the order: black soil> calcareous alluvial soil> red soil. An oxalic acid solution with low pH was able to release more K from weathered minerals and alkaline soils. Oxalic acid decreased the soil K+ adsorption and increased the soil K+ desorption, the effect of which tended to be greater at lower solution pH, especially in the red soil.

  5. Microstructure and properties of oxalate conversion coating on AZ91D magnesium alloy

    Institute of Scientific and Technical Information of China (English)

    JIANG Yong-feng; ZHOU Hai-tao; ZENG Su-min

    2009-01-01

    The oxalate coating formed on AZ91D magnesium alloy by chemical conversion treatment methods in oxalate salt solutions was investigated.The surface morphologies and chemical composition of coating were examined using scanning electron microscopy (SEM) equipped with energy dispersive analysis of X-ray (EDX).Electrochemical impedance spectroscopy (EIS),potentiodynamic polarization curves and salt spray tests were employed to evaluate corrosion protection of the coating to substrate in 5% NaCl solution.The mechanism of coating formations was also considered in details.The results indicate that a compact and dense surface morphology with fine particle clusters of the oxalate coating on magnesium alloy is presented,which mainly consists of oxide or/and organic of Mg,Al and Zn.And the anti-corrosion of the magnesium after oxalate conversion treatment is better than that of the magnesium substrate.The results of salt spray test for oxalate coating is evaluated as Grade 9 according to ASTM B117.The electric resistance of oxalate chemical conversion coating to substrate is below 0.1Ω.

  6. Determination of water-soluble forms of oxalic and formic acids in soils by ion chromatography

    Science.gov (United States)

    Karicheva, E.; Guseva, N.; Kambalina, M.

    2016-03-01

    Carboxylic acids (CA) play an important role in the chemical composition origin of soils and migration of elements. The content of these acids and their salts is one of the important characteristics for agrochemical, ecological, ameliorative and hygienic assessment of soils. The aim of the article is to determine water-soluble forms of same carboxylic acids — (oxalic and formic acids) in soils by ion chromatography with gradient elution. For the separation and determination of water-soluble carboxylic acids we used reagent-free gradient elution ion-exchange chromatography ICS-2000 (Dionex, USA), the model solutions of oxalate and formate ions, and leachates from soils of the Kola Peninsula. The optimal gradient program was established for separation and detection of oxalate and formate ions in water solutions by ion chromatography. A stability indicating method was developed for the simultaneous determination of water-soluble organic acids in soils. The method has shown high detection limits such as 0.03 mg/L for oxalate ion and 0.02 mg/L for formate ion. High signal reproducibility was achieved in wide range of intensities which correspond to the following ion concentrations: from 0.04 mg/g to 10 mg/L (formate), from 0.1 mg/g to 25 mg/L (oxalate). The concentration of formate and oxalate ions in soil samples is from 0.04 to 0.9 mg/L and 0.45 to 17 mg/L respectively.

  7. Characteristic of synergistic extraction of oxalic acid with system from rare earth metallurgical wastewater

    Institute of Scientific and Technical Information of China (English)

    QIU

    2010-01-01

    Large amount of high concentration acidic wastewater would be produced in the conversion process of chloride rare earth into oxide rare earth.It was a mixed solution of oxalic acid and hydrochloric acid,so the recycling use was very difficult.The method of liquid-liquid extraction was proposed in this paper to achieve wastewater treatment and reclamation.The mechanism of extraction of oxalic acid from the wastewater with the systems of 50% TOB+45% kerosene and 5% 2-ethyl hexanol was investigated.The composition and structure of the extracted species and the establishment of the mathematical model of the oxalic acid extraction were determined by the use of saturation method,equimolar series method.The results showed that extraction of oxalic acid by TOB was a neutral association extraction,oxalic acid existed mainly in a molecular form in the organic phase,and the extraction combination ratio was 2:1.The duality extraction system composed of extractant TOB and TOC had synergistic extraction effect on oxalic acid and chlorhydric acid,and the extraction dislribution ratio was improved greatly.The optimum volume fiaction of TOB was 0.6-0.8.

  8. Putative Aspergillus niger-induced oxalate nephrosis in sheep : clinical communication

    Directory of Open Access Journals (Sweden)

    C.J. Botha

    2009-05-01

    Full Text Available A sheep farmer provided a maize-based brewer's grain (mieliemaroek and bales of Eragrostis curvula hay to ewes and their lambs, kept on zero-grazing in pens. The 'mieliemaroek' was visibly mouldy. After 14 days in the feedlot, clinical signs, including generalised weakness, ataxia of the hind limbs, tremors and recumbency, were noticed. Six ewes died within a period of 7 days. A post mortem examination was performed on 1 ewe. The carcass appeared to be cachectic with mild effusions into the body cavities; mild lung congestion and pallor of the kidneys were observed. Microscopical evaluation revealed nephrosis and birefringent oxalate crystals in the renal tubules when viewed under polarised light. A provisional diagnosis of oxalate nephrosis with subsequent kidney failure was made. Amongst other fungi, Aspergillus niger was isolated from 'mieliemaroek' samples submitted for fungal culture and identification. As A. niger is known to synthesise oxalates, a qualitative screen to detect oxalic acid in the mieliemaroek and purified A. niger isolates was performed using high-performance liquid chromatography (HPLC. Oxalic acid was detected, which supported a diagnosis of soluble oxalate-induced nephropathy.

  9. Oxalic acid: a signal molecule for fungus-feeding bacteria of the genus Collimonas?

    Science.gov (United States)

    Rudnick, M B; van Veen, J A; de Boer, W

    2015-10-01

    Mycophagous (=fungus feeding) soil bacteria of the genus Collimonas have been shown to colonize and grow on hyphae of different fungal hosts as the only source of energy and carbon. The ability to exploit fungal nutrient resources might require a strategy for collimonads to sense fungi in the soil matrix. Oxalic acid is ubiquitously secreted by soil fungi, serving different purposes. In this study, we investigated the possibility that collimonads might use oxalic acid secretion to localize a fungal host and move towards it. We first confirmed earlier indications that collimonads have a very limited ability to use oxalic acid as growth substrate. In a second step, with using different assays, we show that oxalic acid triggers bacterial movement in such a way that accumulation of cells can be expected at micro-sites with high free oxalic acid concentrations. Based on these observations we propose that oxalic acid functions as a signal molecule to guide collimonads to hyphal tips, the mycelial zones that are most sensitive for mycophagous bacterial attack.

  10. Urinary excretion of orally administered oxalic acid in saccharin and o-phenylphenol-fed NMRI mice.

    Science.gov (United States)

    Salminen, E; Salminen, S

    1986-01-01

    Both saccharin and o-phenylphenol have been suggested to be carcinogenic to the urinary bladder in experimental animals, but the mechanism has remained unclear. The aim of this study was to investigate the effects of dietary saccharin and o-phenylphenol on the urinary excretion of dietary oxalic acid. Male NMRI mice were gradually adapted to either 3% o-phenylphenol or 5% saccharin in their diet. Having being adapted to these diets for 1 week or after consuming them for 3 months, the animals were fasted for 6 h and given a 2.5-microCi oral dose of U-14C-oxalic acid. Dosed animals were kept in metabolism cages for 48 h to monitor urinary and fecal excretion of the label. Adaptation to dietary o-phenylphenol appeared to increase the urinary excretion of orally administered U-14C-oxalic acid when food and water were available during urinary and fecal collections. Adaptation to dietary saccharin had little effect on urinary oxalate levels when compared to control animals. These results indicate that changes in urinary oxalate levels should be more carefully studied in connection with potential urinary bladder carcinogens to avoid the possibility of bladder irritation by increased urinary oxalate excretion.

  11. Oxalate supported pyrolysis of CoTMPP as electrocatalysts for the oxygen reduction reaction

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, I. [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Institute for Solar Fuel and Energy Storage Materials, Division for Solar Energy Research, Glienicker Strasse 100, D-14109 Berlin (Germany)], E-mail: iris.herrmann@helmholtz-berlin.de; Kramm, U.I.; Fiechter, S.; Bogdanoff, P. [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Institute for Solar Fuel and Energy Storage Materials, Division for Solar Energy Research, Glienicker Strasse 100, D-14109 Berlin (Germany)

    2009-07-15

    The utilisation of different metal oxalates in the pyrolysis of cobalt-tetramethoxyphenylporphyrin (CoTMPP) has been investigated as a structure forming agent to obtain highly active electrocatalysts for the oxygen reduction reaction (ORR). Decomposition products of the metal oxalates provide a nano-scaled template for the carbonisation of CoTMPP. After the pyrolysis this template is removed by an etching step so that highly porous carbon-based particles with different morphologies are attained. Thermogravimetric measurements, gas sorption isotherms (BET and pore size distribution), neutron activation analysis (NAA), SEM and XRD analysis examine the pyrolysis process of CoTMPP in the presence of the metal oxalates and the subsequent conditioning step. Thereby, the degree of graphitisation and the morphology of the formed carbon matrix are influenced by the decomposition products of the metal oxalates. Furthermore, the solubility of the decomposition products in the etching step is a crucial factor for the porosity of the final obtained product. Electrochemical analysis (CV and RDE) shows that the catalysts exhibit high kinetic current densities towards the ORR in acidic electrolyte, which is correlated with the contribution of mesopores within the catalyst. Among the investigated metal oxalates, the utilisation of tin oxalate reveals the most beneficial characteristics for the preparation.

  12. Brushite-based calcium phosphate cement with multichannel hydroxyapatite granule loading for improved bone regeneration.

    Science.gov (United States)

    Sarkar, Swapan Kumar; Lee, Byung Yeol; Padalhin, Andrew Reyas; Sarker, Avik; Carpena, Nathaniel; Kim, Boram; Paul, Kallyanshish; Choi, Hwan Jun; Bae, Sang-Ho; Lee, Byong Taek

    2016-01-01

    In this work, we report brushite-based calcium phosphate cement (CPC) system to enhance the in vivo biodegradation and tissue in-growth by incorporation of micro-channeled hydroxyapatite (HAp) granule and silicon and sodium addition in calcium phosphate precursor powder. Sodium- and silicon-rich calcium phosphate powder with predominantly tri calcium phosphate (TCP) phase was synthesized by an inexpensive wet chemical route to react with mono calcium phosphate monohydrate (MCPM) for making the CPC. TCP nanopowder also served as a packing filler and moderator of the reaction kinetics of the setting mechanism. Strong sintered cylindrical HAp granules were prepared by fibrous monolithic (FM) process, which is 800 µm in diameter and have seven micro-channels. Acid sodium pyrophosphate and sodium citrate solution was used as the liquid component which acted as a homogenizer and setting time retarder. The granules accelerated the degradation of the brushite cement matrix as well as improved the bone tissue in-growth by permitting an easy access to the interior of the CPC through the micro-channels. The addition of micro-channeled granule in the CPC introduced porosity without sacrificing much of its compressive strength. In vivo investigation by creating a critical size defect in the femur head of a rabbit model for 1 and 2 months showed excellent bone in-growth through the micro-channels. The granules enhanced the implant degradation behavior and bone regeneration in the implanted area was significantly improved after two months of implantation.

  13. REMOVING SLUDGE HEELS FROM SAVANNAH RIVER SITE WASTE TANKS BY OXALIC ACID DISSOLUTION

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, M; David Herman, D; Fernando Fondeur, F; John Pareizs, J; Michael Hay, M; Bruce Wiersma, B; Kim Crapse, K; Thomas Peters, T; Samuel Fink, S; Donald Thaxton, D

    2009-03-01

    The Savannah River Site (SRS) will remove sludge as part of waste tank closure operations. Typically the bulk sludge is removed by mixing it with supernate to produce a slurry, and transporting the slurry to a downstream tank for processing. Experience shows that a residual heel may remain in the tank that cannot be removed by this conventional technique. In the past, SRS used oxalic acid solutions to disperse or dissolve the sludge heel to complete the waste removal. To better understand the actual conditions of oxalic acid cleaning of waste from carbon steel tanks, the authors developed and conducted an experimental program to determine its effectiveness in dissolving sludge, the hydrogen generation rate, the generation rate of other gases, the carbon steel corrosion rate, the impact of mixing on chemical cleaning, the impact of temperature, and the types of precipitates formed during the neutralization process. The test samples included actual SRS sludge and simulated SRS sludge. The authors performed the simulated waste tests at 25, 50, and 75 C by adding 8 wt % oxalic acid to the sludge over seven days. They conducted the actual waste tests at 50 and 75 C by adding 8 wt % oxalic acid to the sludge as a single batch. Following the testing, SRS conducted chemical cleaning with oxalic acid in two waste tanks. In Tank 5F, the oxalic acid (8 wt %) addition occurred over seven days, followed by inhibited water to ensure the tank contained enough liquid to operate the mixer pumps. The tank temperature during oxalic acid addition and dissolution was approximately 45 C. The authors analyzed samples from the chemical cleaning process and compared it with test data. The conclusions from the work are: (1) Oxalic acid addition proved effective in dissolving sludge heels in the simulant demonstration, the actual waste demonstration, and in SRS Tank 5F. (2) The oxalic acid dissolved {approx} 100% of the uranium, {approx} 100% of the iron, and {approx} 40% of the manganese

  14. Downscaled anodic oxidation process for aluminium in oxalic acid

    Science.gov (United States)

    Sieber, M.; Morgenstern, R.; Kuhn, D.; Hackert-Oschätzchen, M.; Schubert, A.; Lampke, T.

    2017-03-01

    The increasing multi-functionality of parts and assemblies in several fields of engineering demands, amongst others, highly functionalised surfaces. For the different applications, on the one hand, there is a need to scale up surface modification processes originating in the nano- and micro-scale. On the other hand, conventional macro-scale surface refinement methods offer a huge potential for application in the said nano- and micro-scale. The anodic oxidation process, which is established especially for aluminium and its alloys, allows the formation of oxide ceramic layers on the surface. The build-up of an oxide ceramic coating comes along with altered chemical, tribological and electrical surface properties. As a basis for further investigations regarding the use of the anodic oxidation process for micro-scale-manufacturing, the scale effects of oxalic acid anodising on commercially pure aluminium as well as on the AlZn5.5MgCu alloy are addressed in the present work. The focus is on the amount of oxide formed during a potentiostatic process in relation to the exchanged amount of charge. Further, the hardness of the coating as an integral measure to assess the porous oxide structure is approached by nano-indentation technique.

  15. Isolation of americium (5) oxalate compounds from solutions

    Energy Technology Data Exchange (ETDEWEB)

    Zubarev, V.G.; Krot, N.N.

    1982-01-01

    Certain conditions of americium (5) isolation with solutions of ammonia and KOH are studied as well as the attitude of hydroxide obtained to heating. Like neptunium (5) hydroxide americium (5) hydroxide probably has the formula AmO/sub 2/OHxxH/sub 2/O, where x is approximately equal to 2.3. It is established that during heating in the air up to 120 deg C hydroxide transforms into AmO/sub 2/. It is shown that in solutions with a high concentration of oxalate-ion americium stability in oxidation state +5 depends greatly on the pH of solution. Complex salts KAmO/sub 2/C/sub 2/O/sub 4/xxH/sub 2/O and CsAmO/sub 2/C/sub 2/O/sub 4/xxH/sub 2/O are synthesized. The identification is made according to the method of preparation and results of analysis of C/sub 2/O/sub 4//sup 2 -/: AmO/sub 2//sup +/ ratio. It is found that the salts are non-isomorphous to similar salts of pentavalent neptunium. CsAmO/sub 2/C/sub 2/O/sub 4/xxH/sub 2/O is identified in cubic crystal system with the lattice constant a=1.25 nm.

  16. Calcium isolation from large-volume human urine samples for 41Ca analysis by accelerator mass spectrometry.

    Science.gov (United States)

    Miller, James J; Hui, Susanta K; Jackson, George S; Clark, Sara P; Einstein, Jane; Weaver, Connie M; Bhattacharyya, Maryka H

    2013-08-01

    Calcium oxalate precipitation is the first step in preparation of biological samples for (41)Ca analysis by accelerator mass spectrometry. A simplified protocol for large-volume human urine samples was characterized, with statistically significant increases in ion current and decreases in interference. This large-volume assay minimizes cost and effort and maximizes time after (41)Ca administration during which human samples, collected over a lifetime, provide (41)Ca:Ca ratios that are significantly above background.

  17. Calcium Isolation from Large-Volume Human Urine Samples for 41Ca Analysis by Accelerator Mass Spectrometry

    Science.gov (United States)

    Miller, James J; Hui, Susanta K; Jackson, George S; Clark, Sara P; Einstein, Jane; Weaver, Connie M; Bhattacharyya, Maryka H

    2013-01-01

    Calcium oxalate precipitation is the first step in preparation of biological samples for 41Ca analysis by accelerator mass spectrometry. A simplified protocol for large-volume human urine samples was characterized, with statistically significant increases in ion current and decreases in interference. This large-volume assay minimizes cost and effort and maximizes time after 41Ca administration during which human samples, collected over a lifetime, provide 41Ca:Ca ratios that are significantly above background. PMID:23672965

  18. A study of calcium intake and sources of calcium in adolescent boys and girls from two socioeconomic strata, in Pune, India.

    Science.gov (United States)

    Sanwalka, Neha J; Khadilkar, Anuradha V; Mughal, M Zulf; Sayyad, Mehmood G; Khadilkar, Vaman V; Shirole, Shilpa C; Divate, Uma P; Bhandari, Dhanshari R

    2010-01-01

    Adequate intake of calcium is important for skeletal growth. Low calcium intake during childhood and adolescence may lead to decreased bone mass accrual thereby increasing the risk of osteoporotic fractures. Our aim was to study dietary calcium intake and sources of calcium in adolescents from lower and upper economic strata in Pune, India. We hypothesized that children from lower economic strata would have lower intakes of calcium, which would predominantly be derived from non-dairy sources. Two hundred male and female adolescents, from lower and upper economic stratum were studied. Semiquantitative food frequency questionnaire was used to evaluate intakes of calcium, phosphorus, oxalic acid, phytin, energy and protein. The median calcium intake was significantly different in all four groups, with maximum intake in the upper economic strata boys (893 mg, 689-1295) and lowest intake in lower economic strata girls (506 mg, 380-674). The median calcium intake in lower economic strata boys was 767 mg (585-1043) and that in upper economic strata girls was 764 mg (541-959). The main source of calcium was dairy products in upper economic strata adolescents while it was dark green leafy vegetables in lower economic strata adolescents. The median calcium intake was much lower in lower economic strata than in the upper economic strata both in boys and girls. Girls from both groups had less access to dairy products as compared to boys. Measures need to be taken to rectify low calcium intake in lower economic strata adolescents and to address gender inequality in distribution of dairy products in India.

  19. Oral Reference Dose for ethylene glycol based on oxalate crystal-induced renal tubule degeneration as the critical effect

    Energy Technology Data Exchange (ETDEWEB)

    Snellings, William M.; Corley, Richard A.; McMartin, K. E.; Kirman, Christopher R.; Bobst, Sol M.

    2013-03-31

    Several risk assessments have been conducted for ethylene glycol (EG). These assessments identified the kidney as the primary target organ for chronic effects. None of these assessments have incorporated the robust database of species-specific toxicokinetic and toxicodynamic studies with EG and its metabolites in defining uncertainty factors used in reference value derivation. Pertinent in vitro and in vivo studies related to one of these metabolites, calcium oxalate, and its role in crystal-induced nephropathy are summarized, and the weight of evidence to establish the mode of action for renal toxicity is reviewed. Previous risk assessments were based on chronic rat studies using a strain of rat that was later determined to be less sensitive to the toxic effects of EG. A recently published 12-month rat study using the more sensitive strain (Wistar) was selected to determine the point of departure for a new risk assessment. This approach incorporated toxicokinetic and toxicodynamic data and used Benchmark Dose methods to calculate a Human Equivalent Dose. Uncertainty factors were chosen, depending on the quality of the studies available, the extent of the database, and scientific judgment. The Reference Dose for long-term repeat oral exposure to EG was determined to be 15 mg/kg bw/d.

  20. Biological Control of Meloidogyne incognita by Aspergillus niger F22 Producing Oxalic Acid

    Science.gov (United States)

    Jang, Ja Yeong; Choi, Yong Ho; Shin, Teak Soo; Kim, Tae Hoon; Shin, Kee-Sun; Park, Hae Woong; Kim, Young Ho; Kim, Hun; Choi, Gyung Ja; Jang, Kyoung Soo; Cha, Byeongjin; Kim, In Seon; Myung, Eul Jae

    2016-01-01

    Restricted usage of chemical nematicides has led to development of environmentally safe alternatives. A culture filtrate of Aspergillus niger F22 was highly active against Meloidogyne incognita with marked mortality of second-stage juveniles (J2s) and inhibition of egg hatching. The nematicidal component was identified as oxalic acid by organic acid analysis and gas chromatography-mass spectroscopy (GC-MS). Exposure to 2 mmol/L oxalic acid resulted in 100% juvenile mortality at 1 day after treatment and suppressed egg hatching by 95.6% at 7 days after treatment. Oxalic acid showed similar nematicidal activity against M. hapla, but was not highly toxic to Bursaphelenchus xylophilus. The fungus was incubated on solid medium and dried culture was used for preparation of a wettable powder-type (WP) formulation as an active ingredient. Two WP formulations, F22-WP10 (ai 10%) and oxalic acid-WP8 (ai 8%), were prepared using F22 solid culture and oxalic acid. In a field naturally infested with M. incognita, application of a mixture of F22-WP10 + oxalic acid-WP8 at 1,000- and 500-fold dilutions significantly reduced gall formation on the roots of watermelon plants by 58.8 and 70.7%, respectively, compared to the non-treated control. The disease control efficacy of the mixture of F22-WP10 + oxalic acid-WP8 was significantly higher than that of a chemical nematicide, Sunchungtan (ai 30% fosthiazate). These results suggest that A. niger F22 can be used as a microbial nematicide for the control of root-knot nematode disease. PMID:27258452

  1. Biological Control of Meloidogyne incognita by Aspergillus niger F22 Producing Oxalic Acid.

    Directory of Open Access Journals (Sweden)

    Ja Yeong Jang

    Full Text Available Restricted usage of chemical nematicides has led to development of environmentally safe alternatives. A culture filtrate of Aspergillus niger F22 was highly active against Meloidogyne incognita with marked mortality of second-stage juveniles (J2s and inhibition of egg hatching. The nematicidal component was identified as oxalic acid by organic acid analysis and gas chromatography-mass spectroscopy (GC-MS. Exposure to 2 mmol/L oxalic acid resulted in 100% juvenile mortality at 1 day after treatment and suppressed egg hatching by 95.6% at 7 days after treatment. Oxalic acid showed similar nematicidal activity against M. hapla, but was not highly toxic to Bursaphelenchus xylophilus. The fungus was incubated on solid medium and dried culture was used for preparation of a wettable powder-type (WP formulation as an active ingredient. Two WP formulations, F22-WP10 (ai 10% and oxalic acid-WP8 (ai 8%, were prepared using F22 solid culture and oxalic acid. In a field naturally infested with M. incognita, application of a mixture of F22-WP10 + oxalic acid-WP8 at 1,000- and 500-fold dilutions significantly reduced gall formation on the roots of watermelon plants by 58.8 and 70.7%, respectively, compared to the non-treated control. The disease control efficacy of the mixture of F22-WP10 + oxalic acid-WP8 was significantly higher than that of a chemical nematicide, Sunchungtan (ai 30% fosthiazate. These results suggest that A. niger F22 can be used as a microbial nematicide for the control of root-knot nematode disease.

  2. Stone composition among first-time symptomatic kidney stone formers in the community

    Science.gov (United States)

    Singh, Prince; Enders, Felicity T.; Vaughan, Lisa E.; Bergstralh, Eric J; Knoedler, John J.; Krambeck, Amy E; Lieske, John C; Rule, Andrew D

    2015-01-01

    Objective To determine the variation in kidney stone composition and its relationship to risk factors and recurrence among first-time stone formers in the general population. Patients and Methods Medical records were manually reviewed and validated for symptomatic kidney stone episodes among Olmsted County, Minnesota residents from January 1, 1984 to December 31, 2012. Clinical and laboratory characteristics and the risk of symptomatic recurrence were compared between stone compositions. Results There were 2961 validated first-time symptomatic kidney stone formers. Stone composition analysis was obtained in 1508 (51%) at the first episode. Stone formers were divided into the following mutually exclusive groups: any brushite (0.9%), any struvite (0.9%), any uric acid (4.8%), majority calcium oxalate (76%) or majority hydroxyapatite (18%). Stone composition varied with clinical characteristics. A multivariable model had a 69% probability of correctly estimating stone composition, but assuming calcium oxalate monohydrate stone was correct 65% of the time. Symptomatic recurrence at 10 years was approximately 50% for brushite, struvite, and uric acid, but approximately 30% for calcium oxalate and hydroxyapatite stones (P<.001). Recurrence was similar across different proportions of calcium oxalate and hydroxyapatite (P-trend=.10). However, among calcium oxalate stones, 10-year recurrence rate ranged from 38% for 100% calcium oxalate dihydrate to 26% for 100% calcium oxalate monohydrate (P-trend=.007). Conclusion Calcium stones are more common (94% of stone formers) than has been previously reported. While clinical and laboratory factors associate with the stone composition, they are of limited utility for estimating stone composition. Rarer stone compositions are more likely to recur. PMID:26349951

  3. One-year observations of size distribution characteristics of major aerosol constituents at a coastal receptor site in Hong Kong – Part 1: Inorganic ions and oxalate

    Directory of Open Access Journals (Sweden)

    Q. Bian

    2014-01-01

    Full Text Available Size distribution data of major aerosol constituents are essential in source apportioning of visibility degradation, testing and verification of air quality models incorporating aerosols. We report here one-year observations of mass size distributions of major inorganic ions (sulfate, nitrate, chloride, ammonium, sodium, potassium, magnesium and calcium and oxalate at a coastal suburban receptor site in Hong Kong, China. A total of 43 sets of size segregated samples in the size range of 0.056–18 μm were collected from March 2011 to February 2012. The size distributions of sulfate, ammonium, potassium and oxalate were characterized by a dominant droplet mode with a mass mean aerodynamic diameter (MMAD in the range of ~0.7–0.9 μm. Oxalate had a slightly larger MMAD than sulfate on days with temperatures above 22 °C as a result of the process of volatilization and repartitioning. Nitrate was mostly dominated by the coarse mode but enhanced presence in fine mode was detected on winter days with lower temperature and lower concentrations of sea salt and soil particles. This data set reveals an inversely proportional relationship between the fraction of nitrate in the fine mode and product of the sum of sodium and calcium in equivalent concentrations and the dissociation constant of ammonium nitrate (i.e., (1/[Na+] + 2[Ca2+] × (1/Ke'. The seasonal variation observed for sea salt aerosol abundance, with lower values in summer and winter, is possibly linked with the lower marine salinities in these two seasons. Positive matrix factorization was applied to estimate the relative contributions of local formation and transport to the observed ambient sulfate level through the use of the combined datasets of size-segregated sulfate and select gaseous air pollutants. On average, the regional/super-regional transport of air pollutants was the dominant source at this receptor site, especially on high sulfate days, while local formation processes

  4. Calcium and Mitosis

    Science.gov (United States)

    Hepler, P.

    1983-01-01

    Although the mechanism of calcium regulation is not understood, there is evidence that calcium plays a role in mitosis. Experiments conducted show that: (1) the spindle apparatus contains a highly developed membrane system that has many characteristics of sarcoplasmic reticulum of muscle; (2) this membrane system contains calcium; and (3) there are ionic fluxes occurring during mitosis which can be seen by a variety of fluorescence probes. Whether the process of mitosis can be modulated by experimentally modulating calcium is discussed.

  5. Calcium - Function and effects

    NARCIS (Netherlands)

    Liang, Jianfen; He, Yifan; Gao, Qian; Wang, Xuan; Nout, M.J.R.

    2016-01-01

    Rice is the primary food source for more than half of the world population. Levels of calcium contents and inhibitor - phytic acid are summarized in this chapter. Phytic acid has a very strong chelating ability and it is the main inhibit factor for calcium in rice products. Calcium contents in br

  6. Spectroscopic Manifestation of Vibrationally-Mediated Structure Change in the Isolated Formate Monohydrate

    Science.gov (United States)

    Denton, Joanna K.; Wolke, Conrad T.; Gorlova, Olga; Gerardi, Helen; McCoy, Anne B.; Johnson, Mark

    2016-06-01

    The breadth of the OH stretching manifold observed in the IR for bulk water is commonly attributed to the thermal population of excited states and the presence of many configurations within the water network. Here, I use carboxylate species as a rigid framework to isolate a single water molecule in the gas phase and cold ion vibrational pre-dissociation spectroscopy to explore excited state contributions to bandwidth. The spectrum of the carboxylate monohydrate exhibits a signature series of peaks in the OH stretching region of this system, providing an archetypal model to study vibrationally adiabatic mode separation. Previous analysis of this behavior accounts for the extensive progression in a Franck-Condon formalism involving displaced vibrationally adiabatic potentials. In this talk I will challenge this prediction by using isotopic substation to systematically change the level structure within these potentials. This picture quantitatively accounts for the diffuse spectrum of this complex at elevated temperature providing a convenient spectroscopic reporter for the temperature of ions in a trap. E. M. Myshakin, K. D. Jordan, E. L. Sibert III, M. A. Johnson J. Chem. Phys. 119, 10138 (2003) W.H. Robertson, et al. J. Phys Chem. 107, 6527 (2003)

  7. Growth and characterization of a third order nonlinear optical single crystal: Ethylenediamine-4-nitrophenolate monohydrate

    Energy Technology Data Exchange (ETDEWEB)

    Dhanalakshmi, B. [Department of Physics, Asan Memorial College of Engineering and Technology, Chengalpattu 603 203, Tamil Nadu (India); Ponnusamy, S., E-mail: suruponnus@gmail.com [Center for Materials Science and Nano Devices, Department of Physics, SRM University, Kattankulathur 603 203, Tamil Nadu (India); Muthamizhchelvan, C.; Subhashini, V. [Center for Materials Science and Nano Devices, Department of Physics, SRM University, Kattankulathur 603 203, Tamil Nadu (India)

    2015-10-15

    Highlights: • EDA4NPH crystal possesses negative nonlinear refractive index. • The crystal exhibits high third-order NLO susceptibility. • Wide transparency of the crystal makes it suitable for NLO applications. • Dielectric studies substantiate the suitability for electro-optic applications. • The crystal possesses suitable mechanical strength for device fabrication. - Abstract: Bulk crystals of the charge-transfer complex, ethylenediamine-4-nitrophenolate monohydrate, were grown by slow solvent evaporation method from aqueous solution at room temperature. The X-ray diffraction measurements showed that the crystal belongs to centrosymmetric space group C2/c of monoclinic system. The functional groups in the complex were identified using FTIR, FTRaman and FTNMR analyses. The Z-scan measurements revealed the negative nonlinear refractive index of the crystal. The nonlinear absorption coefficient and third order nonlinear optical susceptibility calculated from the measurements were −3.5823 × 10{sup −3} cm/W and 2.3762 × 10{sup −6} esu respectively. The crystal was shown to be highly transparent above 366 nm by UV–vis spectroscopy and a yellow fluorescence was observed from PL spectrum. The TG–DTA and DSC analyses showed that the crystal is thermally stable up to 117.4 °C. The crystals were characterized by dielectric, etching and microhardness studies.

  8. EPR and optical absorption studies of Cu 2+ doped bis (glycinato) Mg (II) monohydrate single crystals

    Science.gov (United States)

    Dwivedi, Prashant; kripal, Ram

    2010-02-01

    Electron paramagnetic resonance (EPR) study of Cu 2+ doped bis (glycinato) Mg (II) monohydrate single crystals is carried out at room temperature. Copper enters the lattice substitutionally and is trapped at two magnetically inequivalent sites. The observed spectra are fitted to a spin-Hamiltonian of rhombic symmetry with the following values of the parameters: Cu 2+ (I), gx = 2.1577 ± 0.0002, gy = 2.2018 ± 0.0002, gz = 2.3259 ± 0.0002, Ax = (87 ± 2) × 10 -4 cm -1, Ay = (107 ± 2) × 10 -4 cm -1, Az = (141 ± 2) × 10 -4 cm -1; Cu 2+ (II), gx = 2.1108 ± 0.0002, gy = 2.1622 ± 0.0002, gz = 2.2971 ± 0.0002, Ax = (69 ± 2) × 10 -4 cm -1, Ay = (117 ± 2) × 10 -4 cm -1and Az = (134 ± 2) × 10 -4 cm -1. The ground state wave function of the Cu 2+ ion in this lattice is evaluated to be predominantly | x2 - y2lbond2 . The g-factor anisotropy is also calculated and compared with the experimental value. With the help of the optical absorption study, the nature of bonding in the complex is discussed.

  9. The electronic structure of alloxan monohydrate. Spectroscopic and density functional synergic approach

    Science.gov (United States)

    Elroby, Shaaban A.; Aziz, Saadullah G.; Hilal, Rifaat H.

    2017-02-01

    In the present communication, quantitative interpretation and assignments of the electronic absorption spectra, vibrational and one- and two-dimensional NMR spectra of alloxan, are detailed. A synergic analysis based on DFT and TD-DFT calculations and the experimental findings are performed. Attempt is made to relate these spectral findings to the electronic structure of alloxan. The computed electronic spectrum predicted three well defined bands. Natural transition orbital analysis indicate an intramolecular charge transfer from npπ orbital of the water oxygen atom resulting in the short wavelength nπ* at ∼200 nm. Furthermore, UV-photoabsorption cross section for alloxan and its monohydrate are simulated. The spectrum, composed of 10 excited states, was simulated with the nuclear ensemble approximation, sampling a Wigner distribution with 300 points. The FT-IR spectrum of alloxan, measured in the solid state as KBr pellets is reported and is computed at the DFT/B3LYP/6-311++G** level of theory. All observed vibrations are assigned. The 600 MHz one- and two-dimensional COSY, 1H NMR spectra of alloxan, measured in DMSO, are reported and analyzed and computed theoretically using the GIAO method. Hydrogen-bond interactions are responsible for remarkable downfield shift of 1H NMR peaks for alloxan.

  10. Structural, Hirshfeld surface and spectroscopic studies of the noncentrosymmetric 1-ethylpiperazinediium pentachloroantimonate (III) monohydrate

    Science.gov (United States)

    Soudani, S.; Zeller, M.; Jelsch, C.; Lefebvre, F.; Ben Nasr, Cherif

    2016-08-01

    1-Ethylpiperazinediium pentachloroantimonate (III) monohydrate, C6H16N2SbCl5·H2O, has been synthesized by the reaction of antimony trioxide (Sb2O3) and 1-ethylpiperazine in an aqueous solution of hydrochloric acid. The structure crystallizes in orthorhombic system, in the non-centrosymmetric space group Pca21 and consists of isolated [C6H16N2]2+ cations, square pyramidal [SbCl5]2- anions and lattice water molecules. Osbnd H⋯Cl hydrogen bonds link the [SbCl5]2- anions and water molecules to form double chains stretching along the [101] direction. The chains in turn are linked to the organic cations via Nsbnd H⋯Cl, Csbnd H⋯Cl, Csbnd H⋯O and Nsbnd H⋯O hydrogen bonds to form a three-dimensional network. This structure presents an example of a general square pyramidal complex ion containing a stereo-chemically active lone pair of electrons. Solid state 13C and 15N CP-MAS NMR spectra are in agreement with the X-ray structure, and vibrational absorption bands were identified by infrared spectroscopy. DFT calculations allowed the attribution of the NMR peaks and IR absorption bands. The interactions variability of the two independent cations and ten chloride atoms is analyzed via Hirshfeld surface analysis.

  11. FORMULATION AND EVALUATION OF TASTE MASKED ORALLY DISINTEGRATING TABLETS OF SITAGLIPTIN PHOSPHATE MONOHYDRATE

    Directory of Open Access Journals (Sweden)

    Abbaraju Prasanna Lakshmi

    2012-09-01

    Full Text Available The purpose of the work is to mask the unpleasant taste of sitagliptin phosphate monohydrate with mannitol by co-grinding method and to formulate it as an oral disintegrating tablet by direct compression method. Drug-mannitol complexes were taken in 1:1, 1:1.5 and 1:2 ratios and tested for in vitro and in vivo bitter masking capacity of mannitol, drug content and molecular property. Different super-disintegrants like croscaramellose, sodium starch glycolate and crospovidone was used as disintegrating agents. The prepared tablets were characterized for tensile strength, wetting time, water absorption ratio, and In vitro and in vivo disintegration time. In addition, aspartame is used as sweetening agent which gives more pleasant taste in the mouth. Among all the formulations F1 to F6, Formulation F6 has good taste masking capacity and fast disintegration within 40sec. Furthermore, 96.7% of the drug has been released in 15min.The results disclosed that the productivity of taste masking of the drug has been done effectively with mannitol and 40mg of crosscarmellose sodium is efficient for rapid disintegrating of tablet.

  12. Mebendazole mesylate monohydrate: a new route to improve the solubility of mebendazole polymorphs.

    Science.gov (United States)

    de Paula, Karina; Camí, Gerardo E; Brusau, Elena V; Narda, Griselda E; Ellena, Javier

    2013-10-01

    Mebendazole mesylate monohydrate, a new stable salt of mebendazole (MBZ), has been synthesized and fully characterized. It was obtained from recrystallization of MBZ forms A, B, or C in diverse solvents with the addition of methyl sulfonic acid solution. The crystal packing is first organized as a two-dimensional array consisting of rows of alternating MBZ molecules linked to columns of mesylate ions by hydrogen bonds. The three-dimensional structure is further developed by classical intermolecular interactions involving water molecules. In addition, nonclassical contacts are also found. The vibrational behavior is consistent with the crystal structure, the most important functional groups showing shifts to lower or higher frequencies in relation to the MBZ polymorphs. Thermal analysis indicates that the compound is stable up to 50°C. Decomposition occurs in five steps. Solubility studies show that the title compound presents a significant higher performance than polymorph C. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 102:3528-3538, 2013.

  13. Growth and characterization of new semi-organic L-proline strontium chloride monohydrate single crystals

    Science.gov (United States)

    Gupta, Manoj K.; Sinha, Nidhi; Kumar, Binay

    2011-01-01

    The present communication deals with the synthesis, single crystal growth and characterization of a new nonlinear optical material L-proline strontium chloride monohydrate ( L-PSCM). Single crystals have been grown using the slow solvent evaporation technique. Single crystal XRD analysis confirmed that the crystal belongs to the orthorhombic structure with lattice parameter a=6.6966(3) Å, b=12.4530(5) Å, c=15.2432(5) Å and space group P2 12 12 1. Presence of various functional groups in L-PSCM and protonation of the ions were confirmed by Fourier transform infrared spectroscopy (FT-IR) analysis. The melting point of the single crystal was found to be 126 °C using DSC. Ultraviolet-visible spectral analyses showed that the crystal has low UV cut-off at 226 nm combined with very good transparency of 90% in a wide range. The optical band gap was estimated to be 5.82 eV. Capacitance and dielectric-loss measurements were carried out at different temperatures in the frequency range 1 kHz-2 MHz. The dielectric constant and loss factor were found to be 21 and 0.03 at 1 kHz at room temperature, respectively. Microhardness mechanical studies show that hardness number ( Hv) increases with load for L-PSCM single crystals the by Vickers microhardness method. Second harmonic generation (SHG) efficiency was found to be 0.078 times the value of KDP.

  14. 2-(4-Hydroxyphenyl-1H-benzimidazol-3-ium chloride monohydrate

    Directory of Open Access Journals (Sweden)

    Jazmin E. González-Padilla

    2013-09-01

    Full Text Available The title molecular salt, C13H11N2O+·Cl−·H2O, crystallizes as a monohydrate. In the cation, the phenol and benzimidazole rings are almost coplanar, making a dihedral angle of 3.18 (4°. The chloride anion and benzimidazole cation are linked by two N+—H...Cl− hydrogen bonds, forming chains propagating along [010]. These chains are linked through O—H...Cl hydrogen bonds involving the water molecule and the chloride anion, which form a diamond core, giving rise to the formation of two-dimensional networks lying parallel to (10-2. Two π–π interactions involving the imidazolium ring with the benzene and phenol rings [centroid–centroid distances = 3.859 (3 and 3.602 (3 Å, respectively], contribute to this second dimension. A strong O—H...O hydrogen bond involving the water molecule and the phenol substituent on the benzimidazole unit links the networks, forming a three-dimensional structure.

  15. ENHANCED CHEMICAL CLEANING: EFFECTIVENESS OF THE UV LAMP TO DECOMPOSE OXALATES

    Energy Technology Data Exchange (ETDEWEB)

    Ketusky, E.; Huff, T.; Sudduth, C.

    2010-01-19

    Enhanced Chemical Cleaning is a new process scheduled to begin cleaning Savannah River Site High Level Waste Tanks in 2012. It is an improvement over the current chemical cleaning method, in that it minimizes downstream impacts on the High Level Waste System. It is based on a state of the art scale removal process used on the secondary side of nuclear power plants, with modifications to accommodate the unique constraints created by the tanks. Both Enhanced Chemical Cleaning and the scale removal process are founded on dissolving metal oxides/hydroxides using oxalic acid, with subsequent oxalate decomposition via hydroxylation using ozone or peroxide, and UV light as a catalyst. A divergence Enhanced Chemical Cleaning has from nuclear power scale removal is the significantly increased solids concentration during oxalate decomposition. These solids can limit the ability of the UV light to create hydroxyl radicals, either by limiting the ability of the light to penetrate through the solution, or by increasing the fouling rate on the UV light. Both will decrease the overall catalytic effectiveness, thereby decreasing the concentration of formed hydroxyl radicals. The hydroxyl radicals are the driving force behind the oxalate decomposition. To understand the impact of increased solids, testing was performed using a medium pressure UV light inside an ozone supplied Oxalate Decomposition Reactor. Using a dissolved metal sludge simulant with an initial oxalate concentration greater than 12,000 ppm, and an initial pH of about 2.0, the spent acid solution was recirculated through the reactor, while the UV light was allowed to foul. For the first few hours, the oxalate decomposition rate was about 1,300 ppm/hour. After about 3 hours, enough time for the UV lamp to foul, the oxalate decomposition rate decreased to about 500 ppm/hour. The decomposition rate then remained roughly constant for the next 16 hours. Overall, testing showed that the oxalate destruction rate decreased

  16. Reactive calcium-phosphate-containing poly(ester-co-ether) methacrylate bone adhesives: chemical, mechanical and biological considerations.

    Science.gov (United States)

    Zhao, Xin; Olsen, Irwin; Li, Haoying; Gellynck, Kris; Buxton, Paul G; Knowles, Jonathan C; Salih, Vehid; Young, Anne M

    2010-03-01

    A poly(propylene glycol-co-lactide) dimethacrylate adhesive with monocalcium phosphate monohydrate (MCPM)/beta-tricalcium phosphate (beta-TCP) fillers in various levels has been investigated. Water sorption by the photo-polymerized materials catalyzed varying filler conversion to dicalcium phosphate (DCP). Polymer modulus was found to be enhanced upon raising total calcium phosphate content. With greater DCP levels, faster release of phosphate and calcium ions and improved buffering of polymer degradation products were observed. This could reduce the likelihood of pH-catalyzed bulk degradation and localized acid production and thereby may prevent adverse biological responses. Bone-like MG-63 cells were found to attach, spread and have normal morphology on both the polymer and composite surfaces. Moreover, composites implanted into chick embryo femurs became closely apposed to the host tissue and did not appear to induce adverse immunological reaction. The above results suggest that the new composite materials hold promise as clinical effective bone adhesives.

  17. Growth and characterization of Sm3+ doped cerium oxalate single crystals

    Directory of Open Access Journals (Sweden)

    Minu Mary C

    2016-07-01

    Full Text Available Single crystals of Sm3+ doped cerium oxalate decahydrate were synthesized using single diffusion gel technique and the conditions influencing the size, morphology, nucleation density and quality of the crystals were optimized. Highly transparent single crystals of average size 3 mm × 2 mm × 1 mm with well-defined hexagonal morphology were grown during a time period of two weeks. X-ray powder diffraction analysis revealed that the grown crystals crystallize in the monoclinic system with space group P21/c as identical with the pure cerium oxalate. The various functional groups of the oxalate ligand and the water of crystallization were identified by Fourier transform infrared spectroscopy. The photoluminescence spectrum of the Sm3+ doped cerium oxalate indicated that the Sm3+ ions are optically active in the cerium oxalate matrix. The crystal has a strong and efficient orange red emission with a wavelength peak at 595 nm and hence can be effectively used for optical amplification. Microhardness measurements of the crystal revealed that they belong to the soft material category.

  18. Immobilization of lead in anthropogenic contaminated soils using phosphates with/without oxalic acid.

    Science.gov (United States)

    Su, Xiaojuan; Zhu, Jun; Fu, Qingling; Zuo, Jichao; Liu, Yonghong; Hu, Hongqing

    2015-02-01

    Understanding the effects of oxalic acid (OA) on the immobilization of Pb(II) in contaminated soils by phosphate materials, has considerable benefits for risk assessment and remediation strategies for the soil. A series of phosphate amendments with/without oxalic acid were applied to two anthropogenic contaminated soils. We investigated the immobilization of Pb(II) by KH2PO4, phosphate rock (PR), activated phosphate rock (APR) and synthetic hydroxyapatite (HAP) at different phosphate:Pb (P:Pb) molar ratios (0, 0.6, 2.0 and 4.0) in the presence/absence of 50 mmol oxalic acid/kg soil, respectively. The effects of treatments were evaluated using single extraction with deionized water or CaCl2, Community Bureau of Reference (BCR) sequential extraction and toxicity characteristic leaching procedure (TCLP) methods. Our results showed that the concentration of water extractable, exchangeable and TCLP-Pb all decreased with incubation time. The concentration of water-extractable Pb after 120 days was reduced by 100% when soils were amended with APR, HAP and HAP+OA, and the TCLP-Pb was phosphate was detected at the P:Pb molar ratio 4.0 at the beginning of incubation. Oxalic acid activated phosphates, and so mixing insoluble phosphates with oxalic acid may be a useful strategy to improve their effectiveness in reducing Pb bioavailability.

  19. Effects of surface coordination on the temperature-programmed desorption of oxalate from goethite

    Energy Technology Data Exchange (ETDEWEB)

    Boily, Jean F.; Szanyi, Janos; Felmy, Andrew R.

    2007-11-15

    The temperature-programmed desorption (TPD) of weakly-bound, hydrogen-bonded and metal-bonded oxalate complexes at the goethite surface was investigated in the 300-900 K range with concerted Fourier Transform Infrared (FTIR) measurements (TPD-FTIR). These reactions took place with the concomitant dehydroxylation reaction of goethite to hematite and decarbonation of bulk-occluded carbonate. The measurements revealed three important stages of desorption. Stage I (300-440 K) corresponds to the desorption of weakly-and/or un-bound oxalate molecules in the goethite powder with a thermal decomposition reaction pathway characteristic of oxalic acid. Stage II (440-520 K) corresponds to a thermally-driven dehydration of hydrogen-bonded surface complexes, leading to a partial desorption via oxalic acid thermal decomposition pathways and to a partial conversion to metal-bonded surface complexes. This latter mechanism led to the increase in FTIR bands characteristic of these complexes. Finally, Stage III (520-660 K) corresponds to the thermal decomposition of the metal-bonded oxalate complex, proceeding through a 2 electron reduction pathway.

  20. Corrosion Behavior of Alloy 22 in Oxalic Acid and Sodium Chloride Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Day, S D; Whalen, M T; King, K J; Hust, G A; Wong, L L; Estill, J C; Rebak, R B

    2003-06-24

    Nickel based Alloy 22 (NO6022) is extensively used in aggressive industrial applications, especially due to its resistance to localized corrosion and stress corrosion cracking in high chloride environments. The purpose of this work was to characterize the anodic behavior of Alloy 22 in oxalic acid solution and to compare its behavior to sodium chloride (NaCl) solutions. Standard electrochemical tests such as polarization resistance and cyclic polarization were used. Results show that the corrosion rate of Alloy 22 in oxalic acid solutions increased rapidly as the temperature and the acid concentration increased. Extrapolation studies show that even at a concentration of 10{sup -4}M oxalic acid, the corrosion rate of Alloy 22 would be higher in oxalic acid than in 1 M NaCl solution. Alloy 22 was not susceptible to localized corrosion in oxalic acid solutions. Cyclic polarization tests in 1 M NaCl showed that Alloy 22 was susceptible to crevice corrosion at 90 C but was not susceptible at 60 C.

  1. Catalytic Kinetic Determination of Micro Amounts of Oxalic Acid by Second-Order Derivative Oscillopolarography

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    It was found that micro amounts of oxalate showed a very strong catalytic effect on the slow reaction between K2Cr2O7 and Orange Ⅳ in a diluted sulfuric acid medium in a water bath at 70 ℃. Orange Ⅳ exhibited a sensitive second-order derivative polarographic wave at -0.50 V(vs. SCE). This provides the basis for a sensitive and selective catalytic kinetic method for oxalate determination with second-order derivative oscillopolarography. The effects of sulphuric acid, K2Cr2O7, and orange Ⅳ concentrations, reaction temperature and reaction time were investigated. A calibration curve of oxalate in the range of 0.1—2.0 μg/mL was obtained by the fixed-time procedure. The detection limit was 0.03 μg/ mL. The possible interference from co-existing substances or ions was examined. The new method has a high sensitivity and a good selectivity compared to other existing methods for oxalic acid determination. It has been applied to the determination of micro amounts of oxalate in real urine samples with satisfactory results.

  2. Calcium signaling and epilepsy.

    Science.gov (United States)

    Steinlein, Ortrud K

    2014-08-01

    Calcium signaling is involved in a multitude of physiological and pathophysiological mechanisms. Over the last decade, it has been increasingly recognized as an important factor in epileptogenesis, and it is becoming obvious that the excess synchronization of neurons that is characteristic for seizures can be linked to various calcium signaling pathways. These include immediate effects on membrane excitability by calcium influx through ion channels as well as delayed mechanisms that act through G-protein coupled pathways. Calcium signaling is able to cause hyperexcitability either by direct modulation of neuronal activity or indirectly through calcium-dependent gliotransmission. Furthermore, feedback mechanisms between mitochondrial calcium signaling and reactive oxygen species are able to cause neuronal cell death and seizures. Unravelling the complexity of calcium signaling in epileptogenesis is a daunting task, but it includes the promise to uncover formerly unknown targets for the development of new antiepileptic drugs.

  3. Calcium bioavailability of vegetarian diets in rats: potential application in a bioregenerative life-support system

    Science.gov (United States)

    Nickel, K. P.; Nielsen, S. S.; Smart, D. J.; Mitchell, C. A.; Belury, M. A.

    1997-01-01

    Calcium bioavailability of vegetarian diets containing various proportions of candidate crops for a controlled ecological life-support system (CELSS) was determined by femur 45Ca uptake. Three vegetarian diets and a control diet were labeled extrinsically with 45Ca and fed to 5-wk old male rats. A fifth group of rats fed an unlabeled control diet received an intraperitoneal (IP) injection of 45Ca. There was no significant difference in mean calcium absorption of vegetarian diets (90.80 +/- 5.23%) and control diet (87.85 +/- 5.25%) when calculated as the percent of an IP dose. The amounts of phytate, oxalate, and dietary fiber in the diets did not affect calcium absorption.

  4. Hydrothermal decomposition of actinide(IV oxalates: a new aqueous route towards reactive actinide oxide nanocrystals

    Directory of Open Access Journals (Sweden)

    Walter Olaf

    2016-01-01

    Full Text Available The hydrothermal decomposition of actinide(IV oxalates (An= Th, U, Pu at temperatures between 95 and 250 °C is shown to lead to the production of highly crystalline, reactive actinide oxide nanocrystals (NCs. This aqueous process proved to be quantitative, reproducible and fast (depending on temperature. The NCs obtained were characterised by X-ray diffraction and TEM showing their size to be smaller than 15 nm. Attempts to extend this general approach towards transition metal or lanthanide oxalates failed in the 95–250 °C temperature range. The hydrothermal decomposition of actinide oxalates is therefore a clean, flexible and powerful approach towards NCs of AnO2 with possible scale-up potential.

  5. Acute oxalate nephropathy associated with orlistat: a case report with a review of the literature.

    Science.gov (United States)

    Chaudhari, Dhara; Crisostomo, Conchitina; Ganote, Charles; Youngberg, George

    2013-01-01

    Orlistat is a gastrointestinal lipase inhibitor used for weight reduction in obese individuals. Enteric hyperoxaluria caused by orlistat leads to oxalate absorption. Acute oxalate nephropathy is a rare complication of treatment with orlistat. Herein we report a patient presenting with acute renal failure which improved minimal with intravenous hydration. She was found to have oxalate crystals on renal biopsy. Patient admitted orlistat use over the counter for weight reduction on further questioning. The purpose of this case review is to increase awareness among patients since they are more focused on losing weight. This case also calls for the provider attention to educate patients regarding side effects of orlistat because of easy availability of orlistat over the counter.

  6. Acute Oxalate Nephropathy Associated with Orlistat: A Case Report with a Review of the Literature

    Directory of Open Access Journals (Sweden)

    Dhara Chaudhari

    2013-01-01

    Full Text Available Orlistat is a gastrointestinal lipase inhibitor used for weight reduction in obese individuals. Enteric hyperoxaluria caused by orlistat leads to oxalate absorption. Acute oxalate nephropathy is a rare complication of treatment with orlistat. Herein we report a patient presenting with acute renal failure which improved minimal with intravenous hydration. She was found to have oxalate crystals on renal biopsy. Patient admitted orlistat use over the counter for weight reduction on further questioning. The purpose of this case review is to increase awareness among patients since they are more focused on losing weight. This case also calls for the provider attention to educate patients regarding side effects of orlistat because of easy availability of orlistat over the counter.

  7. [Contents of tannins and oxalic acid in the selected forest fruits depending on the harvest site].

    Science.gov (United States)

    Sembratowicz, Iwona; Ognik, Katarzyna; Rusinek, Elzbieta; Truchliński, Jerzy

    2008-01-01

    Contents of anti-nutritional components (tannins and oxalic acid) were determined in samples of forest fruits: blueberry, raspberry and wild strawberry harvested in Lublin region from areas considered as potentially not exposed to pollution (Skierbieszów Landscape Park) and potentially polluted areas (Cement Factory Rejowiec S.A.). Study revealed that blueberry and raspberry fruits collected on potentially polluted area were characterized by higher tannins contents than those harvested on potentially not polluted area. Oxalic acid level in studied material indicated its significantly higher concentration in wild strawberry fruits collected both from not exposed and polluted areas as compared to raspberry and blueberry. Tannins and oxalic acid contents in analyzed berries may be accepted as low and safe for human's health.

  8. Stannous oxalate: An efficient catalyst for poly(trimethylene terephthalate) synthesis

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A complete study on the catalytic activity of stannous oxalate for poly(trimethylene terephthalate) (PTT) synthesis via esterification method is carried out by comparison to the well known catalysts (tetrabutyl titanate (TBT), dibutyltin oxide (Bu2SnO), and stannous octoate (SOC)). Their catalytic activity in the esterification process is monitored by measuring the amount of water generated, while intrinsic viscosity (IV) and content of terminal carboxyl groups (CTCG) are used as the index in the polycondensation process. Stannous oxalate shows higher activity than the other catalysts. Decrease in reaction time and improvements in PTT property are observed. The higher catalytic activity of stannous oxalate is attributed to its chelate molecular structure.

  9. Electrochemical Oxidation and Determination of Oxalic Acid at an Exfoliated Graphite-Polystyrene Composite Electrode

    Directory of Open Access Journals (Sweden)

    Joop Schoonman

    2007-04-01

    Full Text Available An exfoliated graphite-polystyrene composite electrode was evaluated as analternative electrode in the oxidation and the determination of oxalic acid in 0.1 M Na2SO4supporting electrolyte. Using CV, LSV, CA procedures, linear dependences I vs. C wereobtained in the concentrations range of oxalic acid between 0.5 to 3 mM, with LOD =0.05mM, and recovery degree of 98%, without need of surface renewing between successiveruns. The accuracy of the methods was evaluated as excellent comparing the detection resultswith that obtained using conventional KMnO4 titration method. In addition, the apparentdiffusion coefficient of oxalic acid D was found to be around 2.89 · 10-8 cm2·s-1 by CA andCV.

  10. Thermal, FT–IR and dielectric studies of gel grown sodium oxalate single crystals

    Indian Academy of Sciences (India)

    B B Parekh; P M Vyas; Sonal R Vasant; M J Joshi

    2008-04-01

    Oxalic acid metabolism is important in humans, animals and plants. The effect of oxalic acid sodium salt is widely studied in living body. The growth of sodium oxalate single crystals by gel growth is reported, which can be used to mimic the growth of crystals in vivo. The grown single crystals are colourless, transparent and prismatic. The crystals have been characterized by thermogravimetric analysis, FT–IR spectroscopy and dielectric response at various frequencies of applied field. The crystals become anhydrous at 129.3°C. Coats and Redfern relation is applied to evaluate the kinetic and thermodynamic parameters of dehydration. The dielectric study suggests very less variation of dielectric constant with frequency of applied field in the range of 1 kHz–1 MHz. The nature of variation of imaginary part of complex permittivity, dielectric loss and a.c. resistivity with applied frequency has been reported.

  11. SAVANNAH RIVER SITE TANK CLEANING: CORROSION RATE FOR ONE VERSUS EIGHT PERCENT OXALIC ACID SOLUTION

    Energy Technology Data Exchange (ETDEWEB)

    Ketusky, E.; Subramanian, K.

    2011-01-20

    Until recently, the use of oxalic acid for chemically cleaning the Savannah River Site (SRS) radioactive waste tanks focused on using concentrated 4 and 8-wt% solutions. Recent testing and research on applicable dissolution mechanisms have concluded that under appropriate conditions, dilute solutions of oxalic acid (i.e., 1-wt%) may be more effective. Based on the need to maximize cleaning effectiveness, coupled with the need to minimize downstream impacts, SRS is now developing plans for using a 1-wt% oxalic acid solution. A technology gap associated with using a 1-wt% oxalic acid solution was a dearth of suitable corrosion data. Assuming oxalic acid's passivation of carbon steel was proportional to the free oxalate concentration, the general corrosion rate (CR) from a 1-wt% solution may not be bound by those from 8-wt%. Therefore, after developing the test strategy and plan, the corrosion testing was performed. Starting with the envisioned process specific baseline solvent, a 1-wt% oxalic acid solution, with sludge (limited to Purex type sludge-simulant for this initial effort) at 75 C and agitated, the corrosion rate (CR) was determined from the measured weight loss of the exposed coupon. Environmental variations tested were: (a) Inclusion of sludge in the test vessel or assuming a pure oxalic acid solution; (b) acid solution temperature maintained at 75 or 45 C; and (c) agitation of the acid solution or stagnant. Application of select electrochemical testing (EC) explored the impact of each variation on the passivation mechanisms and confirmed the CR. The 1-wt% results were then compared to those from the 8-wt%. The immersion coupons showed that the maximum time averaged CR for a 1-wt% solution with sludge was less than 25-mils/yr for all conditions. For an agitated 8-wt% solution with sludge, the maximum time averaged CR was about 30-mils/yr at 50 C, and 86-mils/yr at 75 C. Both the 1-wt% and the 8-wt% testing demonstrated that if the sludge was removed

  12. Oxalic acid as a heterogeneous ice nucleus in the upper troposphere and its indirect aerosol effect

    Directory of Open Access Journals (Sweden)

    B. Zobrist

    2006-05-01

    Full Text Available Heterogeneous ice freezing points of aqueous solutions containing various immersed solid dicarboxylic acids (oxalic, adipic, succinic, phthalic and fumaric have been measured with a differential scanning calorimeter. The results show that only the dihydrate of oxalic acid (OAD acts as a heterogeneous ice nucleus, with an increase in freezing temperature between 2-5 K depending on solution composition. In several field campaigns, oxalic acid enriched particles have been detected in the upper troposphere with single particle aerosol mass spectrometry. Simulations with a microphysical box model indicate that the presence of OAD may reduce the ice particle number density in cirrus clouds by up to ~50% when compared to exclusively homogeneous cirrus formation without OAD. Using the ECHAM4 climate model we estimate the global net radiative effect caused by this heterogeneous freezing to result in a cooling as high as -0.3 Wm-2.

  13. [Effect of lectins from Azospirillum brasilense to peroxidase and oxalate oxidase activity regulation in wheat roots].

    Science.gov (United States)

    Alen'kina, S A; Nikitina, V E

    2010-01-01

    Lectins were extracted from the surface of nitrogen-fixing soil bacteria Azospirillum brasilense Sp7 and from its mutant A. brasilense Sp7.2.3 defective in lectin activity. The ability oflectins to stimulate the rapid formation of hydrogen peroxide related to increase of oxalate oxidase and peroxidase activity in the roots of wheat seedlings has been demonstrated. The most rapid induced pathway of hydrogen peroxide formation in the roots of wheat seedlings was the oxalic acid oxidation by oxalate oxidase which is the effect oflectin in under 10 min in a concentration of 10 microg/ml. The obtained results show that lectins from Azospirillum are capable of inducing the adaptation processes in the roots of wheat seedlings.

  14. Two novel metal–organic coordination polymers based on diphosphonate and oxalate: Synthesis, structures and properties

    Energy Technology Data Exchange (ETDEWEB)

    Niu, Qing-Jun; Zheng, Yue-Qing, E-mail: yqzhengmc@163.com; Zhou, Lin-Xia; Zhu, Hong-Lin

    2015-07-15

    Two 2-(1-imidazole)-1-hydroxyl-1,1'-ethylidenediphosphonato and oxalic acid bridged coordination polymers (H{sub 2}en)[Co{sub 3}(H{sub 2}zdn){sub 2}(ox)(H{sub 2}O){sub 2}] (1) and Cd{sub 2}(H{sub 2}zdn)(ox){sub 0.5}(H{sub 2}O) (2) (2-(1-imidazole)-1-hydroxyl-1,1'-ethylidenediphosphonic acid=H{sub 5}zdn; oxalic acid=H{sub 2}ox) were synthesized under hydrothermal conditions and characterized by the infrared (IR), thermogravimetric analyses (TGA), elemental analyses (EA) and X-ray diffraction (XRD). Compound 1 is bridged by phosphonate anions to 1D chain, and further linked by oxalate anions to 2D layer. Compound 2 is bridged by O–P–O units of H{sub 5}zdn to the layer, and then pillared by oxalate anions to generate 3D frameworks. Compound 1 shows anti-ferromagnetic behaviors analyzed with the temperature-dependent zero-field ac magnetic susceptibilities, while compound 2 exhibits an influence on the luminescent property. - Graphical abstract: Linked by oxalate, two zoledronate-based metal–organic frameworks are synthesized, which exhibits the different frameworks. Magnetism and luminescent properties have been studied. The weak antiferromagnetic coupling is conducted in 1. - Highlights: • Compound 1 and 2 are first linked by oxalate anion based on zoledronic acid. • Compound 1 generates a classic “dia Diamond” (6{sup 6}) topology. • Compound 2 exhibits a (4{sup 4}·6{sup 2})(4{sup 4}·6{sup 6}) topology. • Magnetism and luminescent properties of 1 and 2 have been studied, respectively.

  15. Stability-indicating RP-HPLC method for the simultaneous determination of escitalopram oxalate and clonazepam.

    Science.gov (United States)

    Kakde, Rajendra B; Satone, Dinesh D; Gadapayale, Kamalesh K; Kakde, Megha G

    2013-07-01

    The objective of the current study was to develop a validated, specific stability-indicating reversed-phase liquid chromatographic (LC) method for the quantitative determination of escitalopram oxalate and clonazepam and their related substances in bulk drugs and pharmaceutical dosage forms in the presence of degradation products. Forced degradation studies were performed on the pure drugs of escitalopram oxalate and clonazepam, as per the stress conditions prescribed by the International Conference on Harmonization (ICH) using acid, base, oxidation, thermal stress and photolytic degradation to show the stability-indicating power of the method. Significant degradation was observed during acid and alkaline hydrolysis and no degradation was observed in other stress conditions. The chromatographic method was optimized using the samples generated from forced degradation studies. Good resolution between the peaks corresponded to the active pharmaceutical ingredients, escitalopram oxalate and clonazepam, and degradation products from the analyte were achieved on an ODS Hypersil C18 column (250 × 4.6 mm) using a mobile phase consisting of a mixture of acetonitrile-50 mM phosphate buffer + 10 mM triethylamine (70:30, v/v). The detection was conducted at 268 nm. The limit of detection and the limit of quantitation for escitalopram oxalate and clonazepam were established. The stress test solutions were assayed against the qualified working standards of escitalopram oxalate and clonazepam, which indicated that the developed LC method was stability-indicating. Validation of the developed LC method was conducted as per ICH requirements. The developed LC method was found to be suitable to check the quality of bulk samples of escitalopram oxalate and clonazepam.

  16. Citric and Oxalic Acids Effect on Pb and Zn Uptake by Maize and Winter Wheat

    Institute of Scientific and Technical Information of China (English)

    Wang Xinmin; Hou Yanlin; Jie Xiaolei

    2004-01-01

    A pot experiment was conducted to investigate the influence of citric and oxalic acids effect on Pb and Zn uptake by corn and winter wheat.The experiment was employed with citric acid (CA)applied at 3 rates (0, 1.5 and 3.0 mmol kg-1 soil),oxalic acid (OA) at 3 rates (0, 1.5 and 3.0mmol kg-1soil) and citric acid combined with oxalic acid (1.5mmol citric acid combined with 1.5 mmol oxalic acid kg-1). Two types of soil were chose in the experiment.One was collected from the agricultural soil near a battery-recycling factory in Anhui province, China (site A) and the other was collected from a Pb-Zn mine residues in Hunan province, China (site B). The results showed that soil pH varied with the different treatment of citric and oxalic acids. However, there were no differences in all the treatments. 3.0mmol CA kg-1 soil addition significantly increased the concentrations of the CaCl2-extractable Pb and Zn and other treatments have no significantly increased.The highest shoot concentrations of Pb and Zn in both species occurred in application of 3.0 mmol CA/kg-1 soil and shoot concentrations of Pb and Zn in both species were significantly higher than the controls in this treatment. Shoot yields declined with application of citric and oxalic acids, indicating that the plants were sensitive to the toxicity of the metals or the amendments. The highest Pb uptake values by maize and wheat were112.3 and 77.2 μg pot-1in soil of site A, and occurred with the control and 3.0 mmol CA/kg-1 soil respectively.

  17. MitoTEMPO Prevents Oxalate Induced Injury in NRK-52E Cells via Inhibiting Mitochondrial Dysfunction and Modulating Oxidative Stress

    Science.gov (United States)

    Yu, Xiao; Liu, Jihong

    2017-01-01

    As one of the major risks for urolithiasis, hyperoxaluria can be caused by genetic defect or dietary intake. And high oxalate induced renal epithelial cells injury is related to oxidative stress and mitochondrial dysfunction. Here, we investigated whether MitoTEMPO, a mitochondria-targeted antioxidant, could protect against oxalate mediated injury in NRK-52E cells via inhibiting mitochondrial dysfunction and modulating oxidative stress. MitoSOX Red was used to determine mitochondrial ROS (mtROS) production. Mitochondrial membrane potential (Δψm) and quantification of ATP synthesis were measured to evaluate mitochondrial function. The protein expression of Nox4, Nox2, and p22 was also detected to explore the effect of oxalate and MitoTEMPO on NADPH oxidase. Our results revealed that pretreatment with MitoTEMPO significantly inhibited oxalate induced lactate dehydrogenase (LDH) and malondialdehyde (MDA) release and decreased oxalate induced mtROS generation. Further, MitoTEMPO pretreatment restored disruption of Δψm and decreased ATP synthesis mediated by oxalate. In addition, MitoTEMPO altered the protein expression of Nox4 and p22 and decreased the protein expression of IL-6 and osteopontin (OPN) induced by oxalate. We concluded that MitoTEMPO may be a new candidate to protect against oxalate induced kidney injury as well as urolithiasis.

  18. Effect of Diluents on the Extraction of Oxalic Acid by Trialkylphosphine Oxide

    Institute of Scientific and Technical Information of China (English)

    李玉鑫; 王运东; 戴猷元

    2004-01-01

    Abstract In liquid-liquid solvent extraction processes, diluents have a strong influence on the extraction mechanism and efficiency. In this study, benzene, cyclohexane, trichloromethane, carbon tetrachloride, methyl isobutyl ketone (MIBK), butyl acetate, and 1-octanol were used as diluents in the extraction of oxalic acid by trialkylphosphine oxide (TRPO). The effects of extractant concentration, initial concentration of oxalic acid and diluent type on the extraction equilibrium partition coefficient are analyzed. The sequence of the extraction ability by different diluents is MIBK > butyl acetate > cyclohexane=benzene > carbon tetrachloride > 1-octanol > trichloromethane. Extraction mechanism was analyzed and extraction model parameters were evaluated.

  19. Solid phase precipitates in (Zr,Th)-OH-(oxalate, malonate) ternary aqueous system

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, T.; Sasaki, T.; Takagi, I.; Moriyama, H. [Kyoto Univ. (Japan). Dept. of Nuclear Engineering

    2009-07-01

    The solubility-limiting solid phases in the ternary aqueous systems of Zr(IV)/OH/oxalate, Zr(IV)/OH/malonate, Th(IV)/OH/oxalate and Th(IV)/OH/malonate were characterized by elemental analysis, X-ray diffraction, thermogravimetric analysis and differential thermal analysis. The ternary solid phase of M(IV)/OH/carboxylate was observed to form, even under acidic conditions, depending on the pH and the concentration of carboxylate ligand. In the presence of a large excess of carboxylic acid, however; the binary M(IV)-carboxylate solid phase formed. (orig.)

  20. Viscosities of oxalic acid and its salts in water and binary aqueous mixtures of tetrahydrofuran at different temperatures

    Indian Academy of Sciences (India)

    M L Parmar; M K Guleria

    2005-07-01

    Relative viscosities for the solutions of oxalic acid and its salts, viz. ammonium oxalate, sodium oxalate and potassium oxalate, at different concentrations have been determined in water and in binary aqueous mixtures of tetrahydrofuran (THF) [5, 10, 15 and 20% by weight of THF] at 298.15 K, and in water and in 5% (w/w) THF + water at five different temperatures. The data have been evaluated using the Jones-Dole equation and the obtained parameters have been interpreted in terms of solute-solute and solute-solvent interactions. The activation parameters of viscous flow have been obtained which depicts the mechanism of viscous flow. The oxalic acid and its salts behave as structure breakers in water and in binary aqueous mixtures of THF.

  1. Enrofloxacinium citrate monohydrate: Preparation, crystal structure, thermal stability and IR-characterization

    Science.gov (United States)

    Golovnev, Nicolay N.; Vasiliev, Alexander D.; Kirik, Sergei D.

    2012-08-01

    Enrofloxacinium citrate monohydrate (I), CHFNO3+·CHO7-·HO, [C19H22FN3O3 - enrofloxacin, EnrH] has been crystallized from the mutual solution of citric acid and enrofloxacin in ambient conditions. The colorless crystals have been investigated using X-ray single crystal and powder techniques, and characterized by differential scanning calorimetry, thermogravimetry and infrared spectroscopy. The obtained compound can be considered as a salt with enrofloxacinium in the role of a cation and citrate as an anion. The ions ratio equals to 1:1. The compound crystallizes in the triclinic lattice with a = 9.0489(8) Å, b = 9.6531(8) Å, c = 14.913(1) Å, α = 98.813(1)°, β = 92.029(1)°, γ = 91.013(1)°, Z = 2, V = 1286.1(2) Å3, S.G. P1¯. The crystal structure determination reveals the importance of inter- and intramolecular interactions in the crystal formation. The EnrH2+ and HCit molecular ions are packed in alternating layers with water molecules inserted into the citrate layers. A citrate ion in the layer is linked via H-bondings with two adjacent ones and three water molecules. Enrofloxacinium cations are packaged by means of a benched mode and every cation is linked by three intermolecular thymus type H-bondings with nitrogens of adjacent cations and by two links with the oxygen of the citrate ions. The infrared spectra gave the evidence of H-bonding formation in the obtained salt. The π-stacking interactions are observed between the aromatic cycles of the adjacent cations which are located in an antiparallel style in a layer.

  2. Comparison of creatine monohydrate and carbohydrate supplementation on repeated jump height performance.

    Science.gov (United States)

    Koenig, Chad A; Benardot, Dan; Cody, Mildred; Thompson, Walter R

    2008-07-01

    Creatine monohydrate (CrMH) supplementation aids the ability to maintain performance during repeated bouts of high-intensity exercise, including jump performance. However, carbohydrate supplementation may also provide similar benefits and is less expensive. This study compared the effects of an energy-free placebo, 2 different caloric concentrations of carbohydrate drinks, and a CrMH supplement on repeated jump heights. Sixty active males (mean age, 22 +/- 3.2 years) performed 2 sets of countermovement static jump height tests (10 jumps over 60 seconds) separated by 5 days to determine the differential effects of the placebo, carbohydrate, and CrMH on jump height sustainability over 10 jumps. Subjects were randomly assigned to groups (15 subjects per group) to receive daily doses (x5 days) of carbohydrate drinks containing 100 or 250 kilocalories (kcal), a 25-g CrMH supplement, or an energy-free placebo. After 5 days, the CrMH group experienced a significant weight gain (+1.52; +/-0.89 kg, p energy-free placebo over the final 3-4 jumps. The 250-kcal carbohydrate-supplemented group experienced a level of benefit (p < 0.01) that was at least equal to that of the CrMH group (p < 0.05), suggesting that the higher dose of carbohydrate was as effective as CrMH in maintaining repeated bouts of high-intensity activity as measured by repeated static jumps. Given the equivalent performance improvement and the absence of weight gain, the carbohydrate supplementation could be considered the preferred option for weight-conscious power athletes involved in activities that require repeated- motion high-intensity activities.

  3. Oxalate-metabolising genes of the white-rot fungus Dichomitus squalens are differentially induced on wood and at high proton concentration

    NARCIS (Netherlands)

    Mäkelä, Miia R; Sietiö, Outi-Maaria; de Vries, Ronald P; Timonen, Sari; Hildén, Kristiina; van den Brink, J.

    2014-01-01

    Oxalic acid is a prevalent fungal metabolite with versatile roles in growth and nutrition, including degradation of plant biomass. However, the toxicity of oxalic acid makes regulation of its intra- and extracellular concentration crucial. To increase the knowledge of fungal oxalate metabolism, a tr

  4. Calcium is important forus.

    Institute of Scientific and Technical Information of China (English)

    高利平

    2005-01-01

    Calcium is important for our health.We must have it in our diet to stay well.A good place to get it is from dairy products like milk, cheese and ice cream.One pound of cheese has fifty times the calcium we should have every day.Other foods have less.For example,a pound of beans also has calcium.But it has only three times the amount we ought to have daily.

  5. Synthesis and molecular structure of the novel monohydrated 3- p-nitrophenylpyrazole derived from 1,3-diketone malonate

    Science.gov (United States)

    Jiménez-Cruz, Federico; Hernández-Ortega, Simón; Ríos-Olivares, Héctor

    2003-05-01

    The synthesis of dimethyl {2-[3-(4-nitrophenyl)-1 H-pyrazol-5-yl]ethyl}malonate monohydrate 1, C 16H 17N 3O 6·H 2O was performed and the molecular structure has been studied by using NMR, single crystal X-ray diffraction and ab initio calculations. The title compound presents a pyrazole ring (N1 to C5), a phenyl ring (C1″ to C6″) attached to C3 and the ethylene dimethyl malonate frame (C1' to C7') attached to C5. The torsion angle defined by N2C3C1″C2″ (-12.26°) showed that pyrazole and phenyl rings are not in the same plane. Monohydration in ( 1) is present in the structure by a NH⋯OH 2 hydrogen bonding, with a bond length of 1.782 Å. Experimental and theoretical evidences indicated the preference of the 3-tautomer over the corresponding 5-tautomer in the titled pyrazole.

  6. Synthesis, crystal growth and spectroscopic investigation of novel metal organic crystal: β-Alanine cadmium bromide monohydrate (β-ACBM)

    Science.gov (United States)

    Renugadevi, R.; Kesavasamy, R.

    2014-07-01

    β-Alanine cadmium bromide monohydrate (β-ACBM), a new metal organic crystal has been grown from aqueous solution by slow evaporation technique. The grown crystals have been subjected to single crystal X-ray diffraction analysis to determine the crystal structure. The β-ACBM crystallized in monoclinic system with space group P21/c. The presence of protons and carbons in the β-alanine cadmium bromide monohydrate was confirmed by 1H and 13C nuclear magnetic resonance spectral analysis. The mode of vibration of different molecular groups present in β-ACBM was identified by FT-IR spectral analysis. Transparency of crystals in UV-Vis-NIR region has also been studied. The thermal characteristics of as-grown crystals were analyzed using thermo gravimetric and differential thermal analyses. The magnetic property of the grown crystal was investigated using Vibrating Sample Magnetometer (VSM) at ambient temperature. The mechanical stability of β-ACBM was evaluated by Vickers microhardness measurement.

  7. Synthesis and non linear optical properties of new inorganic-organic hybrid material: 4-Benzylpiperidinium sulfate monohydrate

    Science.gov (United States)

    Kessentini, Yassmin; Ahmed, Ali Ben; Al-Juaid, Salih S.; Mhiri, Tahar; Elaoud, Zakaria

    2016-03-01

    Single crystals of 4-benzyl-piperidine sulfate monohydrate were grown by slow evaporation method at room temperature. The synthesized compound was characterized by means of single-crystal X-ray diffraction, FT-IR and Raman spectroscopy, UV-visible and photoluminescence studies. The title compound crystallises at room temperature in the non centrosymmetric space group P212121.The recorded UV-visible spectrum show good transparency in the visible region and indicates a non-zero value of the first Hyperpolarizability. Photoluminescence spectrum shows a broad and intense band at 440 nm and indicates that the crystal emits blue fluorescence. We also report DFT calculations of the electric dipole moments (μ), Polarizability (α), the static first Hyperpolarizability (β) and HOMO-LUMO analysis of the title compound was theoretically investigated by GAUSSIAN 03 package. The calculated static first Hyperpolarizability is equal to 6.4022 × 10-31 esu. The results show that 4-benzyl-piperidine sulfate monohydrate crystal might have important non linear optical behavior and can be a potential non linear optical material of interest.

  8. Solution properties and taste behavior of lactose monohydrate in aqueous ascorbic acid solutions at different temperatures: Volumetric and rheological approach.

    Science.gov (United States)

    Sarkar, Abhijit; Sinha, Biswajit

    2016-11-15

    The densities and viscosities of lactose monohydrate in aqueous ascorbic acid solutions with several molal concentrations m=(0.00-0.08)molkg(-1) of ascorbic acid were determined at T=(298.15-318.15)K and pressure p=101kPa. Using experimental data apparent molar volume (ϕV), standard partial molar volume (ϕV(0)), the slope (SV(∗)), apparent specific volumes (ϕVsp), standard isobaric partial molar expansibility (ϕE(0)) and its temperature dependence [Formula: see text] the viscosity B-coefficient and solvation number (Sn) were determined. Viscosity B-coefficients were further employed to obtain the free energies of activation of viscous flow per mole of the solvents (Δμ1(0≠)) and of the solute (Δμ2(0≠)). Effects of molality, solute structure and temperature and taste behavior were analyzed in terms of solute-solute and solute-solvent interactions; results revealed that the solutions are characterized predominantly by solute-solvent interactions and lactose monohydrate behaves as a long-range structure maker.

  9. The crystal structure, vibrational spectra, thermal behaviour and second harmonic generation of aminoguanidinium(1+) hydrogen L-tartrate monohydrate

    Science.gov (United States)

    Macháčková, Zorka; Němec, Ivan; Teubner, Karel; Němec, Petr; Vaněk, Přemysl; Mička, Zdeněk

    2007-04-01

    Aminoguanidinium(1+) hydrogen L-tartrate monohydrate was prepared by crystallisation from aqueous solution and X-ray structural analysis was carried out. The substance crystallises in the orthorhombic system in space group P2 12 12 1, a = 7.1380(2) Å, b = 9.9700(4) Å, c = 14.0790(6) Å, V = 1001.94(7) Å 3, Z = 4, R = 0.0271 for 2272 observed reflections. The crystal structure consists of a 3D framework formed by hydrogen tartrate anions and water molecules with incorporated aminoguanidinium(1+) cations connected by a system of hydrogen bonds. The FTIR and FT Raman spectra of natural and N,O-deuterated compounds were measured and discussed at laboratory temperature. DSC measurements were carried out in the temperature range from 95 to 380 K. A weak anomaly was observed at a temperature of 268 K. Quantitative measurements of second harmonic generation of powdered aminoguanidinium(1+) hydrogen tartrate monohydrate at 800 nm were performed relative to KDP and a relative efficiency of 14% was observed.

  10. Metal oxalate complexes as novel inorganic dopants: Studies on their effect on conducting polyaniline

    Indian Academy of Sciences (India)

    R Murugesan; E Subramanian

    2002-12-01

    Doped polyaniline materials with metal oxalate complexes of Cr, Fe, Mn, Co and Al were synthesized by in situ chemical oxidative polymerization of aniline using potassium perdisulphate as oxidant in aqueous sulphuric acid medium. These polymer materials were characterized by chemical analyses, spectral studies (UV-visible and IR), X-ray diffraction and thermal techniques and also by conductivity measurements by four-probe technique. The presence of complex anion in polyaniline material was confirmed by chemical and spectral analyses. The yield and conductivity of metal oxalate doped polyanilines were found to be high when compared to the simple sulphate ion doped polyaniline prepared under similar condition. UV-visible and IR spectral features not only confirmed the polyaniline doping by complex anions but also substantiated their facilitating effect on conductivity. The X-ray diffraction patterns indicated some crystalline nature in metal oxalate doped polyaniline and amorphous in polyaniline sulphate salt. The conductivity of the polymer samples strongly depended on the degree of crystallinity induced by complex counter anions as dopant. All the polymer materials, as evident from TGA curves, were observed to undergo three-step degradation of water loss, de-doping and decomposition of polymer. Further, the thermal stability of polyaniline was found to improve on doping with metal oxalate complex.

  11. Reconstruct Environmental Change through Reading Oxalate Records from the Ice Core

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ CAS scientists have made progress in investigating the past atmospheric changes by retrieving oxalate records from an ice core of Tianshan glaciers. An analysis shows that the variation of the organic acid mirrors the history of the regional economic development as well as environment protection in the west China over the past 40 years.

  12. Evaluation Of Sludge Heel Dissolution Efficiency With Oxalic Acid Cleaning At Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Sudduth, Christie; Vitali, Jason; Keefer, Mark

    2014-01-08

    The chemical cleaning process baseline strategy at the Savannah River Site was revised to improve efficiency during future execution of the process based on lessons learned during previous bulk oxalic acid cleaning activities and to account for operational constraints imposed by safety basis requirements. These improvements were also intended to transcend the difficulties that arise from waste removal in higher rheological yield stress sludge tanks. Tank 12 implemented this improved strategy and the bulk oxalic acid cleaning efforts concluded in July 2013. The Tank 12 radiological removal results were similar to previous bulk oxalic acid cleaning campaigns despite the fact that Tank 12 contained higher rheological yield stress sludge that would make removal more difficult than the sludge treated in previous cleaning campaigns. No appreciable oxalate precipitation occurred during the cleaning process in Tank 12 compared to previous campaigns, which aided in the net volume reduction of 75-80%. Overall, the controls established for Tank 12 provide a template for an improved cleaning process.

  13. Molybdenum carbide as an efficient catalyst for low-temperature hydrogenation of dimethyl oxalate.

    Science.gov (United States)

    Liu, Yanting; Ding, Jian; Sun, Jiaqiang; Zhang, Juan; Bi, Jicheng; Liu, Kefeng; Kong, Fanhua; Xiao, Haicheng; Sun, Yanping; Chen, Jiangang

    2016-04-11

    Silica-supported molybdenum carbide (Mo2C/SiO2) is found to be a highly active, selective and stable catalyst for the hydrogenation of dimethyl oxalate to ethanol at low temperatures (473 K). Moreover, the formation of ethanol over the Mo2C catalyst performs via the novel intermediate methyl acetate instead of ethylene glycol forming over the Cu catalyst.

  14. Oxalic acid complexes: Promising draw solutes for forward osmosis (FO) in protein enrichment

    KAUST Repository

    Ge, Qingchun

    2015-01-01

    Highly soluble oxalic acid complexes (OACs) were synthesized through a one-pot reaction. The OACs exhibit excellent performance as draw solutes in FO processes with high water fluxes and negligible reverse solute fluxes. Efficient protein enrichment was achieved. The diluted OACs can be recycled via nanofiltration and are promising as draw solutes.

  15. Degradation of reactive dyes by ozonation and oxalic acid-assimilating bacteria isolated from soil.

    Science.gov (United States)

    Kurosumi, Akihiro; Kaneko, Erika; Nakamura, Yoshitoshi

    2008-07-01

    Ozonation and treatment of wastewaters with oxalic acid-assimilating bacterium was attempted for the complete degradation of reactive dyes. Oxalic acid-assimilating bacterium, Pandoraea sp. strain EBR-01, was newly isolated from soil under bamboo grove and was identified to be a member of the genus Pandoraea by physicochemical and biochemical tests including 16S rDNA sequence analysis. The bacterium was grown optimally at pH 7 and temperature of 30 degrees C under the laboratory conditions. Reactive Red 120 (RR120), Reactive Green 19 (RG19), Reactive Black 5 (RB5) and Remazol Brilliant Blue R (RBBR) were used in degradation experiments. At the initial reactive dye concentrations of 500 mg/l and the ozonation time of 80 min, it was confirmed that 75-90 mg/l oxalic acid was generated from reactive dyes by ozonation. Microbial treatment using EBR-01 greatly decreased the amount of oxalic acid in the mixture after 48 h, but it was not removed completely. TOC/TOC(0) of reactive dye solutions was also decreased to 80-90% and 20-40% by ozonation and microbial treatment using EBR-01, respectively. The study confirmed that consecutive treatments by ozone and microorganisms are efficient methods to mineralize reactive dyes.

  16. In-cloud oxalate formation in the global troposphere: A 3-D modeling study

    NARCIS (Netherlands)

    Myriokefalitakis, S.; Tsigaridis, K.; Mihalopoulos, N.; Sciare, J.; Nenes, A.; Kawamura, K.; Segers, A.; Kanakidou, M.

    2011-01-01

    Organic acids attract increasing attention as contributors to atmospheric acidity, secondary organic aerosol mass and aerosol hygroscopicity. Oxalic acid is globally the most abundant dicarboxylic acid, formed via chemical oxidation of gas-phase precursors in the aqueous phase of aerosols and drople

  17. Oxalic Acid Catalyzed Three Component One Pot Synthesis of 3,4-Dihydroquinazolin-4-ones

    Institute of Scientific and Technical Information of China (English)

    SANGSHETTI Jaiprakash-N.; KOKARE Nagnnath-D.; SHINDE Devanand-B.

    2008-01-01

    An efficient one-pot method for synthesis of an array of 3,4-dihydroquinazolin-4-ones from anthranilicacid, triethyl orthoformate, and anilines using oxalic acid as a catalyst was described. The present protocol offers im-provements for the synthesis of 3,4-dihydroquinazolin-4-ones with regard to short reaction time, high yields of products, and simplicity in operation.

  18. An ATP and oxalate generating variant tricarboxylic acid cycle counters aluminum toxicity in Pseudomonas fluorescens.

    Directory of Open Access Journals (Sweden)

    Ranji Singh

    Full Text Available Although the tricarboxylic acid (TCA cycle is essential in almost all aerobic organisms, its precise modulation and integration in global cellular metabolism is not fully understood. Here, we report on an alternative TCA cycle uniquely aimed at generating ATP and oxalate, two metabolites critical for the survival of Pseudomonas fluorescens. The upregulation of isocitrate lyase (ICL and acylating glyoxylate dehydrogenase (AGODH led to the enhanced synthesis of oxalate, a dicarboxylic acid involved in the immobilization of aluminum (Al. The increased activity of succinyl-CoA synthetase (SCS and oxalate CoA-transferase (OCT in the Al-stressed cells afforded an effective route to ATP synthesis from oxalyl-CoA via substrate level phosphorylation. This modified TCA cycle with diminished efficacy in NADH production and decreased CO(2-evolving capacity, orchestrates the synthesis of oxalate, NADPH, and ATP, ingredients pivotal to the survival of P. fluorescens in an Al environment. The channeling of succinyl-CoA towards ATP formation may be an important function of the TCA cycle during anaerobiosis, Fe starvation and O(2-limited conditions.

  19. Oxalic acid catalyzed solvent-free one pot synthesis of coumarins

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Oxalic acid was found to be an efficient catalyst for Pechmann condensation, which includes the reaction between phenols and β-keto esters leading to formation of coumarin derivatives. The advantages of present methods are the use of cheap and easy available catalyst, solvent-free reaction conditions, better yields and shorter reaction time.

  20. Human serum transferrin: is there a link among autism, high oxalate levels, and iron deficiency anemia?

    Science.gov (United States)

    Luck, Ashley N; Bobst, Cedric E; Kaltashov, Igor A; Mason, Anne B

    2013-11-19

    It has been previously suggested that large amounts of oxalate in plasma could play a role in autism by binding to the bilobal iron transport protein transferrin (hTF), thereby interfering with iron metabolism by inhibiting the delivery of iron to cells. By examining the effect of the substitution of oxalate for the physiologically utilized synergistic carbonate anion in each lobe of hTF, we sought to provide a molecular basis for or against such a role. Our work clearly shows both qualitatively (6 M urea gels) and quantitatively (kinetic analysis by stopped-flow spectrofluorimetry) that the presence of oxalate in place of carbonate in each binding site of hTF does indeed greatly interfere with the removal of iron from each lobe (in the absence and presence of the specific hTF receptor). However, we also clearly demonstrate that once the iron is bound within each lobe of hTF, neither anion can displace the other. Additionally, as verified by urea gels and electrospray mass spectrometry, formation of completely homogeneous hTF-anion complexes requires that all iron must first be removed and hTF then reloaded with iron in the presence of either carbonate or oxalate. Significantly, experiments described here show that carbonate is the preferred binding partner; i.e., even if an equal amount of each anion is available during the iron loading process, the hTF-carbonate complex is formed.

  1. Morphology and optical properties of aluminum oxide formed into oxalic electrolyte with addition surface active agents

    Science.gov (United States)

    Kazarkin, B.; Stsiapanau, A.; Zhilinski, V.; Chernik, A.; Bezborodov, V.; Kozak, G.; Danilovich, S.; Smirnov, A.

    2016-08-01

    The article discusses the results of investigations of porous films of alumina, formed into oxalic electrolyte with addition surface active agents, in particular, ordering structure, roughness of a surface, the optical transparency of the electrolyte concentration and surface active agents. Also discusses the features of the formation of porous films of temperature and IR radiation.

  2. Cell wall oxalate oxidase modifies the ferulate metabolism in cell walls of wheat shoots.

    Science.gov (United States)

    Wakabayashi, Kazuyuki; Soga, Kouichi; Hoson, Takayuki

    2011-11-01

    Oxalate oxidase (OXO) utilizes oxalate to generate hydrogen peroxide, and thereby acts as a source of hydrogen peroxide. The present study was carried out to investigate whether apoplastic OXO modifies the metabolism of cell wall-bound ferulates in wheat seedlings. Histochemical staining of OXO showed that cell walls were strongly stained, indicating the presence of OXO activity in shoot walls. When native cell walls prepared from shoots were incubated with oxalate or hydrogen peroxide, the levels of ester-linked diferulic acid (DFA) isomers were significantly increased. On the other hand, the level of ester-linked ferulic acid (FA) was substantially decreased. The decrease in FA level was accounted neither by the increases in DFA levels nor by the release of FA from cell walls during the incubation. After the extraction of ester-linked ferulates, considerable ultraviolet absorption remained in the hemicellulosic and cellulose fractions, which was increased by the treatment with oxalate or hydrogen peroxide. Therefore, a part of FA esters may form tight linkages within cell wall architecture. These results suggest that cell wall OXO is capable of modifying the metabolism of ester-linked ferulates in cell walls of wheat shoots by promoting the peroxidase action via supply of hydrogen peroxide.

  3. Synthesis of Diethyl Oxalate by a Coupling-Regeneration Reaction of Carbon Monoxide

    Institute of Scientific and Technical Information of China (English)

    Fandong Meng; Genhui Xu; Baowei Wang; Xinbin Ma

    2002-01-01

    This article describes a process for the synthesis of diethyl oxalate by a coupling reaction ofcarbon monoxide, catalyzed by palladium in the presence of ethyl nitrite. The kinetics and mechanism ofthe coupling and regeneration reaction are also discussed. This paper presents the results of a scale-uptest of the catalyst and the process based on an a priori computer simulation.

  4. The role of nanoparticulate agglomerates in TiO2 photocatalysis: degradation of oxalic acid

    Science.gov (United States)

    Ivanova, Irina; Mendive, Cecilia B.; Bahnemann, Detlef

    2016-07-01

    The simultaneous bimodal study of the photocatalytic oxalic acid degradation by aqueous TiO2 suspensions revealed that particular systems possess the capacity to protect a certain amount of oxalic acid from oxidation, thus hindering, to some extent, the photocatalytic reaction. While measurements of the oxalic acid concentration in the bulk liquid phase indicated full photocatalytic degradation; in situ pH-stat measurements allowed the quantification of the amount of oxalic acid remaining in the part of the nanoparticulate agglomerates where light could apparently not access. An explanation for this phenomenon takes into account the possibility of the formation of TiO2 agglomerates in which these molecules are hidden from the effect of the light, thus being protected from photocatalytic degradation. Studies of different TiO2 materials with different particle sizes allowed a deeper exploration of this phenomenon. In addition, because this property of encapsulating pollutant molecules by photocatalytic systems is found to be a reversible phenomenon, P25 appears to be more convenient and advantageous as compared to the use of large surface area photocatalysts.

  5. Growth and characterization of cerium lanthanum oxalate crystals grown in hydro-silica gel

    Energy Technology Data Exchange (ETDEWEB)

    John, M.V.; Ittyachen, M.A. [Mahatma Gandhi Univ., Kerala (India). School of Pure and Applied Physics

    2001-07-01

    Single crystals of mixed cerium lanthanum oxalate (CLO) are grown by gel method. Over the hydrosilica gel prepared by mixing oxalic acid and sodium meta silicate, a mixture of aqueous solutions of cerium nitrate and lanthanum nitrate are poured gently. Cerium and lanthanum ions diffuse into the gel and react with oxalic acid to give colorless, transparent cerium lanthanum oxalate crystals with in a few days. Different growth parameters give crystals of various dimensions. Infrared (IR) spectrum confirms the presence of water molecules and carboxylic acid. X-ray diffraction (XRD) pattern of these samples reveals the crystalline nature. Diffraction peaks are indexed. Unit cell parameters are determined. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) data support the presence of 9 H{sub 2}O molecules attached to the CLO crystal lattice which are lost around 200 C as revealed by the endotherm record. Exothermic peak around 350 C-425 C shows the release of CO and CO{sub 2}. Elemental analysis done by energy dispersive X-ray fluorescence analysis (EDXRF) for the mixed rare earth compound is almost in good agreement with experimental and theoretical values. (orig.)

  6. Synthesis of Y2O3 Nano-Powder from Yttrium Oxalate under Ambient Temperature

    Institute of Scientific and Technical Information of China (English)

    Li Ling

    2005-01-01

    High purity Y2O3 nano-powders was synthesized directly from solution of industrial YCl3 by method of oxalate precipitation through super-micro-reactors made by complex non-ionic surfactant. The purity and diameter of Y2O3 particles were controlled by such processing parameters as concentration of YCl3 and oxalic acid and complex non-ionic surfactant etc. TEM photomicrographs show that Y2O3 particles are spherical in shape, with an average diameter of less than 30 nm. Test results certify that the purity and particle diameter as well as the dispersion of Y2O3 nano-powder depend on the concentrations of YCl3, oxalic acid and complex non-ionic surfactant. The optimum ranges of the concentrations for YCl3 and complex non-ionic surfactant when the diameter of Y2O3 particles is smaller than 100 nm are 0.43~1.4 mol·L-1 and 0.031~0.112 mol·L-1 respectively, while the mass fraction range of oxalic acid is 10%~18%. The purity of Y2O3 nano-powder tested by ICP-AES analysis is 99.99%.

  7. Raman and FTIR spectroscopy of natural oxalates: Implications for the evidence of life on Mars

    Institute of Scientific and Technical Information of China (English)

    R. L. Frost; YANG Jing; Zhe Ding

    2003-01-01

    Evidence for the existence of primitive life forms such as lichens andfungi can be based upon the formation of oxalates. Oxalates are most readily detected using Raman spectroscopy. A comparative study of a suite of natural oxalates including weddellite, whewellite, moolooite, humboldtine, glushinskite, natroxalate and oxammite has been undertaken using Raman spectroscopy. The minerals are characterised by the Raman position of the CO stretching vibration which is cation sensitive. The band is observed at 1468 cm-1 for weddellite, 1489 cm-1 for moolooite, 1471 cm-1 for glushinskite and 1456 cm-1 for natroxalate. Except for oxammite, the infrared and Raman spectra are mutually exclusive indicating theminerals are bidentate. Differences are also observed in the water OH stretching bands of the minerals. The significance of this work rests with the ability of Raman spectroscopy to identify oxalates which often occur as a film on a host rock. As such Raman spectroscopy has the potential to identify the existence or pre-existence of life forms on planets such as Mars.

  8. Solubilities of 2-Naphthalenesulfonic Acid Monohydrate and Sodium 2-Naphthalenesulfonate in Sulfuric Acid Solution and Their Application for Preparing Sodium 2-Naphthalenesulfonate

    Institute of Scientific and Technical Information of China (English)

    张凤宝; 景晖; 朱文宇; 张林; 刘博; 张国亮; 夏清

    2016-01-01

    The solubilities of 2-naphthalenesulfonic acid monohydrate and sodium 2-naphthalenesulfonate in sul-furic acid solutions were measured at temperatures ranging from 278.15 to 338.15 K by using a dynamic method. The concentration of sulfuric acid solution ranged from 0 to 80wt%,. The solubilities of 2-naphthalenesulfonic acid monohydrate and sodium 2-naphthalenesulfonate increased with temperature, and both of them were the lowest at 70wt%, of sulfuric acid solution(03w=0.70)while the highest in pure water. The solubility data were correlated by the modified Apelblat equation. Based on the solubility difference between 2-naphthalenesulfonic acid monohy-drate and sodium 2-naphthalenesulfonate, a new technique in which sodium sulfate was used to replace sodium sulfite in the neutralization reaction was developed. The suitable mole ratio of H2O to Na2SO4 in the neutralization reaction was 80∶1, and that of 2-naphthalenesulfonic acid monohydrate to Na2SO4 was 3.2∶1. The material bal-ance under the suitable mole ratios was given and discussed.

  9. ROLE OF THE MICROFLORA IN DISTAL INTESTINAL TRACT BY MAINTAINING OXALATE HOMEOSTASIS

    Directory of Open Access Journals (Sweden)

    Osolodchenko T.P.

    2015-05-01

    Full Text Available Human intestinal microflora is part of the human body and performs numerous function. Considerable research interest is in the field of probiotics for the prevention of kidney stones, which is one of the most common urological diseases.Urolithiasis is one of the most common urological diseases. This is polyetiological disease congenital and acquired character with complex physical and chemical processes that occur not only in the urinary system, but also the whole body. None of the treatments does not guarantee full recovery of the patient and often leads to relapse. The open methods of removal stones yield news minimally invasive the technologys. Development of stone formation depends on the presence of many factors, metabolic disorders, chronic urinary tract infections, genetic disorders and more. Most have the following metabolic disorders as hypercalciuria, hiperurikuria, hipotsytraturia , hyperoxaluria and hipomahniuria. Among all types of urolithiasis kaltsiyoksalatnyy ranked first in the prevalence rate - about 75.0 - 85.0 % of cases. Dietary restriction by oxalates іs the unreliable method of preventing disease. Although there is evidence for the growth inhibition normobiocenosis representatives, which in turn enhances the absorption of salts of oxalic acid oxalate in the application of sodium , magnesium and cobalt in their intragastric administration. Recently published many papers on the impact on the level of oxalate intestinal microflora. The first publications appeared on the influence of gram-negative obligate anaerobes O. formigenes the concentration of oxalate in the urine. This anaerobic bacteria living in the colon, its prevalence - 46.0 % - 77.0 % of the adult population. O. formigenes reveals the symbiotic interaction with the human body by reducing absorption of oxalate in the intestinal cavity with subsequent decrease in their concentration in plasma and urine. O. formigenes has two key enzymes - oksalyl

  10. Hyperoxaluria leads to dysbiosis and drives selective enrichment of oxalate metabolizing bacterial species in recurrent kidney stone endures

    Science.gov (United States)

    Suryavanshi, Mangesh V.; Bhute, Shrikant S.; Jadhav, Swapnil D.; Bhatia, Manish S.; Gune, Rahul P.; Shouche, Yogesh S.

    2016-01-01

    Hyperoxaluria due to endogenously synthesized and exogenously ingested oxalates is a leading cause of recurrent oxalate stone formations. Even though, humans largely rely on gut microbiota for oxalate homeostasis, hyperoxaluria associated gut microbiota features remain largely unknown. Based on 16S rRNA gene amplicons, targeted metagenomic sequencing of formyl-CoA transferase (frc) gene and qPCR assay, we demonstrate a selective enrichment of Oxalate Metabolizing Bacterial Species (OMBS) in hyperoxaluria condition. Interestingly, higher than usual concentration of oxalate was found inhibitory to many gut microbes, including Oxalobacter formigenes, a well-characterized OMBS. In addition a concomitant enrichment of acid tolerant pathobionts in recurrent stone sufferers is observed. Further, specific enzymes participating in oxalate metabolism are found augmented in stone endures. Additionally, hyperoxaluria driven dysbiosis was found to be associated with oxalate content, stone episodes and colonization pattern of Oxalobacter formigenes. Thus, we rationalize the first in-depth surveillance of OMBS in the human gut and their association with hyperoxaluria. Our findings can be utilized in the treatment of hyperoxaluria associated recurrent stone episodes. PMID:27708409

  11. Acidosis and Urinary Calcium Excretion

    DEFF Research Database (Denmark)

    Alexander, R Todd; Cordat, Emmanuelle; Chambrey, Régine

    2016-01-01

    Metabolic acidosis is associated with increased urinary calcium excretion and related sequelae, including nephrocalcinosis and nephrolithiasis. The increased urinary calcium excretion induced by metabolic acidosis predominantly results from increased mobilization of calcium out of bone and inhibi...

  12. Calcium signaling in neurodegeneration

    Directory of Open Access Journals (Sweden)

    Dreses-Werringloer Ute

    2009-05-01

    Full Text Available Abstract Calcium is a key signaling ion involved in many different intracellular and extracellular processes ranging from synaptic activity to cell-cell communication and adhesion. The exact definition at the molecular level of the versatility of this ion has made overwhelming progress in the past several years and has been extensively reviewed. In the brain, calcium is fundamental in the control of synaptic activity and memory formation, a process that leads to the activation of specific calcium-dependent signal transduction pathways and implicates key protein effectors, such as CaMKs, MAPK/ERKs, and CREB. Properly controlled homeostasis of calcium signaling not only supports normal brain physiology but also maintains neuronal integrity and long-term cell survival. Emerging knowledge indicates that calcium homeostasis is not only critical for cell physiology and health, but also, when deregulated, can lead to neurodegeneration via complex and diverse mechanisms involved in selective neuronal impairments and death. The identification of several modulators of calcium homeostasis, such as presenilins and CALHM1, as potential factors involved in the pathogenesis of Alzheimer's disease, provides strong support for a role of calcium in neurodegeneration. These observations represent an important step towards understanding the molecular mechanisms of calcium signaling disturbances observed in different brain diseases such as Alzheimer's, Parkinson's, and Huntington's diseases.

  13. 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.

  14. A Potentiometric, Spectrophotometric and Pitzer Ion-Interaction Study of Reaction Equilibria in the Aqueous H+-Al3+, H+-Oxalate and H+-Al3+-Oxalate Systems up to 5 mol*dm-3 NaCl

    Energy Technology Data Exchange (ETDEWEB)

    Boily, Jean F.; Qafoku, Odeta; Felmy, Andrew R.

    2007-12-01

    Aluminium-oxalate complexation was determined in acidic media of aqueous NaCl solutions ranging from 0.1-5.0 mol•dm-3. Complexation in the H+-Al3+ and H+-Oxalate systems was also studied to provide a set of internally consistent thermodynamic data. The ionic strength dependent formation constants describing the stabilities of the Al3+, AlOH2+, Al3(OH)45+, Al13O4(OH)247+, H2L, HL-, L2-, AlL+, AlL2- and AlL33- species (where L is the oxalate ion) was also described using a Pitzer ion interaction model. The derived parameters can be used to predict chemical speciation in the H+-Al3+-Oxalate system in the 0.1-5.0 mol•dm-3 NaCl range.

  15. The influence of oxalate-promoted growth of saponite and talc crystals

    Science.gov (United States)

    Schumann, Dirk; Hartman, Hyman; Eberl, Dennis D.; Sears, S. Kelly; Hesse, Reinhard; Vali, Hojatollah

    2013-01-01

    The intercalating growth of new silicate layers or metal hydroxide layers in the interlayer space of other clay minerals is known from various mixed-layer clay minerals such as illite-smectite (I-S), chlorite-vermiculite, and mica-vermiculite. In a recent study, the present authors proposed that smectite-group minerals can be synthesized from solution as new 2:1 silicate layers within the low-charge interlayers of rectorite. That study showed how oxalate catalyzes the crystallization of saponite from a silicate gel at low temperatures (60ºC) and ambient pressure. As an extension of this work the aim of the present study was to test the claim that new 2:1 silicate layers can be synthesized as new intercalating layers in the low-charge interlayers of rectorite and whether oxalate could promote such an intercalation synthesis. Two experiments were conducted at 60ºC and atmospheric pressure. First, disodium oxalate solution was added to a suspension of rectorite in order to investigate the effects that oxalate anions have on the structure of rectorite. In a second experiment, silicate gel of saponitic composition (calculated interlayer charge −0.33 eq/O10(OH)2) was mixed with a suspension of rectorite and incubated in disodium oxalate solution. The synthesis products were extracted after 3 months and analyzed by X-ray diffraction and high-resolution transmission electron microscopy (HRTEM). The treatment of ultrathin sections with octadecylammonium (nC = 18) cations revealed the presence of 2:1 layer silicates with different interlayer charges that grew from the silicate gel. The oxalate-promoted nucleation of saponite and talc crystallites on the rectorite led to the alteration and ultimately to the destruction of the rectorite structure. The change was documented in HRTEM lattice-fringe images. The crystallization of new 2:1 layer silicates also occurred within the expandable interlayers of rectorite but not as new 2:1 silicate layers parallel to the previous 2

  16. Surfactant-free nickel-silver core@shell nanoparticles in mesoporous SBA-15 for chemoselective hydrogenation of dimethyl oxalate.

    Science.gov (United States)

    Li, Molly Meng-Jung; Ye, Linmin; Zheng, Jianwei; Fang, Huihuang; Kroner, Anna; Yuan, Youzhu; Tsang, Shik Chi Edman

    2016-02-11

    Surfactant-free bimetallic Ni@Ag nanoparticles in mesoporous silica, SBA-15 prepared by simple wet co-impregnation catalyse hydrogenation of dimethyl oxalate to methyl glycolate or ethylene glycol in high yield.

  17. Flow Injection Determination of Oxalate Based on Its Catalytic Effect on the Oxidation of p-Chloride Aniline by Dichromate

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In a sulfuric acid medium, oxalate exhibits a strong catalytic effect on the oxidation of p-chloride aniline (ClBN) by dichromate, and the red oxidation product of ClBN has a maximum absorbancy at 520 nm. Based on this founding, a new FI method for determining oxalate was developed. A calibration curve of oxalate in the range of 0. 40-17.0 tg/mL was obtained. The detection limit was 0. 10 μg/mL. Sampling rate was 103-samples/h. The possible interference by the co-existing substances or ions was examined. This new method was applied to the determination of micro amounts of oxalate in real samples with satisfactory results.

  18. Crystal growth, structural and thermal studies of amino acids admixtured L-arginine phosphate monohydrate single crystals

    Science.gov (United States)

    Anandan, P.; Saravanan, T.; Parthipan, G.; Kumar, R. Mohan; Bhagavannarayana, G.; Ravi, G.; Jayavel, R.

    2011-05-01

    To study the improved characteristics of L-arginine phosphate monohydrate (LAP) crystals, amino acids mixed LAP crystals have been grown by slow cooling method. Amino acids like glycine, L-alanine, and L-valine have been selected for doping. Optical quality bulk crystals have been harvested after a typical growth period of about twenty days. The effect of amino acids in the crystal lattice and molecular vibrational frequencies of various functional groups in the crystals have been studied using X-ray powder diffraction and Fourier Transform infrared (FTIR) analyses respectively. Thermal behavior of the amino acids mixed LAP crystals have been studied from the TG and DTG analyses. High-resolution X-ray diffraction studies have been carried out to find the crystalline nature. Optical transmission studies have been carried out by UV-vis spectrophotometer. The cut off wavelength is below 240 nm for the grown crystals.

  19. Spectral, optical and mechanical studies on L-histidine hydrochloride monohydrate (LHC) single crystals grown by unidirectional growth technique

    Energy Technology Data Exchange (ETDEWEB)

    Robert, R. [Department of Physics, Government Arts College (Men), Krishnagiri (India); Justin Raj, C. [Department of Physics, Loyola College, Chennai 600 034 (India); Krishnan, S. [Department of Physics, R.M.K. Engineering College, Kavaripettai 601 206 (India); Uthrakumar, R.; Dinakaran, S. [Department of Physics, Loyola College, Chennai 600 034 (India); Jerome Das, S., E-mail: sjeromedas2004@yahoo.co [Department of Physics, Loyola College, Chennai 600 034 (India)

    2010-08-15

    Single crystals of nonlinear optical L-histidine hydrochloride monohydrate (LHC) were grown in an aqueous solution by the unidirectional crystal growth method within a period of 45 days along (1 0 1) plane. The grown crystals were subjected to single crystal X-ray diffraction analysis to confirm their orthorhombic structure having space group P2{sub 1}2{sub 1}2{sub 1}. Values of several physical parameters were determined for the grown crystal. Optical transmission studies revealed very low absorption and band gap energy was calculated for the LHC crystals. Further, some optical constant were also determined for the grown crystals. Anisotropy in Vicker's microhardness led to the assessment of fracture toughness, brittleness index and yield strength for the synthesized crystals. Nonlinear optical studies were carried out for the grown crystal and second harmonic generation (SHG) efficiency was found to be three times that of KDP crystals.

  20. RETRACTED: Crystal growth and spectroscopic characterization of Aloevera amino acid added lithium sulfate monohydrate: A non-linear optical crystal

    Science.gov (United States)

    Manimekalai, R.; Antony Joseph, A.; Ramachandra Raja, C.

    2014-03-01

    This article has been retracted: please see Elsevier Policy on Article Withdrawal. This article has been retracted at the request of authors. According to the author we have reported Aloevera Amino Acid added Lithium sulphate monohydrate [AALSMH] crystal is a new nonlinear optical crystal. From the recorded high performance liquid chromatography spectrum, by matching the retention times with the known compounds, the amino acids present in our extract are identified as homocystine, isoleucine, serine, leucine and tyrosine. From the thin layer chromatography and colorimetric estimation techniques, presence of isoleucine was identified and it was also confirmed by NMR spectrum. From the above studies, we came to conclude that AALSMH is new nonlinear optical crystal. After further investigation, lattice parameter values of AALSMH are coinciding with lithium sulphate. Therefore we have decided to withdraw our paper. Sorry for the inconvenience and time spent.

  1. Oxalic acid as an assisting agent for the electrodialytic remediation of chromated copper arsenate treated timber waste

    DEFF Research Database (Denmark)

    Ribeiro, Alexandra B.; Mateus, Eduardo P.; Ottosen, Lisbeth M.

    1999-01-01

    The electrodialytic process is proposed as a technique for the remediation of chromated copper arsenate treated timber waste, using oxalic acid as assisting agent. The method prowed succesfull 93% Cu, 95% Cr and 99% As was removed from the timber.......The electrodialytic process is proposed as a technique for the remediation of chromated copper arsenate treated timber waste, using oxalic acid as assisting agent. The method prowed succesfull 93% Cu, 95% Cr and 99% As was removed from the timber....

  2. Coadsorption of Cd(II) and oxalate ions at the TiO2/electrolyte solution interface.

    Science.gov (United States)

    Janusz, W; Matysek, M

    2006-04-01

    The study of the adsorptions of cadmium and oxalate ions at the titania/electrolyte interface and the changes of the electrical double layer (edl) structure in this system are presented. The adsorption of cadmium or oxalate ions was calculated from an uptake of their concentration from the solution. The concentration of Cd(II) or oxalate ions in the solution was determined by radiotracer method. For labeling the solution 14C and 115Cd isotopes were used. Coadsorption of Cd(II) and oxalic ions was determined simultaneously. Besides, the main properties of the edl, i.e., surface charge density and zeta potential were determined by potentiometer titration and electrophoresis measurements, respectively. The adsorption of cadmium ions increases with pH increase and shifts with an increase of the initial concentration of Cd(II) ions towards higher pH values. The adsorption process causes an increase of negatively charged sites on anatase and a decrease of the zeta potential with an increase of initial concentration of these ions. The adsorption of oxalate anions at the titania/electrolyte interface proceeds through the exchange with hydroxyl groups. A decrease of pH produces an increase of adsorption of oxalate ions. The processes of anion adsorption lead to increase the number of the positively charged sites at the titania surface. However, specific adsorption of bidenate ligand as oxalate on one surface hydroxyl group may form inner sphere complexes on the metal oxide surface and may overcharge the compact part of the edl. The presence of oxalate ions in the system affects the adsorption of Cd(II) ions on TiO2, increasing the adsorption at low pH range and decreasing the adsorption at high pH range. Using adsorption as a function of pH data, some characteristic parameters of adsorption envelope were calculated.

  3. Indium tin oxide thin films elaborated by sol-gel routes: The effect of oxalic acid addition on optoelectronic properties

    Energy Technology Data Exchange (ETDEWEB)

    Kesim, Mehmet Tumerkan; Durucan, Caner, E-mail: cdurucan@metu.edu.tr

    2013-10-31

    Single layer indium tin oxide (ITO) thin films were deposited on glass using modified sol-gel formulations. The coating sols were prepared using indium (InCl{sub 3}∙ 4H{sub 2}O) and tin salts (SnCl{sub 4}∙ 5H{sub 2}O). The stable sols were obtained using ethanol (C{sub 2}H{sub 5}OH) and acetylacetone (C{sub 5}H{sub 8}O{sub 2}) as solvents and by the addition of oxalic acid dihydrate (C{sub 2}H{sub 2}O{sub 4}∙ 2H{sub 2}O) in different amounts. The effect of oxalic acid content in the sol formulation and post-coating calcination treatment (in air at 300–600 °C) on electrical/optical properties of ITO films have been reported. It was shown that film formation efficiency, surface coverage and homogeneity were all enhanced with oxalic acid addition. Oxalic acid modification also leads to a significant improvement in electrical conductivity without affecting the film thickness (45 ± 3 nm). ITO films exhibiting high transparency (≈ 93%, visible region) with a sheet resistance as low as 3.8 ± 0.4 kΩ/sqr have been formed by employing coating sols with optimized oxalic acid amount. The mechanisms and factors affecting the functional performance of oxalic acid-modified films have been thoroughly discussed and related to the microstructural and chemical characteristic of the films achieved by oxalic acid addition. - Highlights: • A solution-based method for processing indium tin oxide (ITO) thin film is reported. • Oxalic acid (OAD) modification leads to a highly compacted film microstructure. • Bulk resistivity of a single layer OAD-modified ITO film was determined as 0.02 Ωcm. • Thin films with transparency values higher than 90% were produced.

  4. Calcium and Your Child

    Science.gov (United States)

    ... for dinner. Create mini-pizzas by topping whole-wheat English muffins or bagels with pizza sauce, low- ... Minerals Do I Need to Drink Milk? Lactose Intolerance Becoming a Vegetarian Soy Foods and Health Calcium ...

  5. Stoichiometry of Calcium Medicines

    Science.gov (United States)

    Pinto, Gabriel

    2005-01-01

    The topic of calcium supplement and its effects on human lives is presented in the way of questions to the students. It enables the students to realize the relevance of chemistry outside the classroom surrounding.

  6. Structures of protonated thymine and uracil and their monohydrated gas-phase ions from ultraviolet action spectroscopy and theory.

    Science.gov (United States)

    Pedersen, Sara Øvad; Byskov, Camilla Skinnerup; Turecek, Frantisek; Brøndsted Nielsen, Steen

    2014-06-19

    The strong UV chromophores thymine (Thy) and uracil (Ura) have identical heteroaromatic rings that only differ by one methyl substituent. While their photophysics has been elucidated in detail, the effect on the excited states of base protonation and single water molecules is less explored. Here we report gas-phase absorption spectra of ThyH(+) and UraH(+) and monohydrated ions and demonstrate that the substituent is not only responsible for spectral shifts but also influences the tautomer distribution, being different for bare and monohydrated ions. Spectra interpretation is aided by calculations of geometrical structures and transition energies. The lowest free-energy tautomer (denoted 178, enol-enol form) accounts for 230-280 nm (ThyH(+)) and 225-270 nm (UraH(+)) bands. ThyH(+) hardly absorbs above 300 nm, whereas a discernible band is measured for UraH(+) (275-320 nm), ascribed to the second lowest free-energy tautomer (138, enol-keto form) comprising a few percent of the UraH(+) population at room temperature. Band widths are similar to those measured of cold ions in support of very short excited-state lifetimes. Attachment of a single water increases the abundance of 138 relative to 178, 138 now clearly present for ThyH(+). 138 resembles more the tautomer present in aqueous solution than 178 does, and 138 may indeed be a relevant transition structure. The band of ThyH(+)(178) is unchanged, that of UraH(+)(178) is nearly unchanged, and that of UraH(+)(138) blue-shifts by about 10 nm. In stark contrast to protonated adenine, more than one solvating water molecule is required to re-establish the absorption of ThyH(+) and UraH(+) in aqueous solution.

  7. Microstructure of Yttria-Doped Ceria as a Function of Oxalate Co-Precipitation Synthesis Conditions

    Science.gov (United States)

    Brissonneau, Laurent; Mathieu, Aurore; Tormos, Brigitte; Martin-Garin, Anna

    2016-12-01

    In sodium fast reactors (SFR), dissolved oxygen in sodium can be monitored via potentiometric sensors with an yttria-doped thoria electrolyte. Yttria-doped ceria (YDC) was chosen as a surrogate material to validate the process of such sensors. The material must exhibit high density and a fine grain microstructure to be resistant to the corrosion by liquid sodium and thermal shocks. Thus, the oxalic co-precipitation route was chosen to avoid milling steps that could bring impurity incorporation which is suspected to induce grain boundary corrosion in sodium. The powder and sintered pellets examination show that the synthesis conditions are of primary importance on the process yield, the oxalate powder microstructure and, eventually, on the ceramic density and microstructure. The impurity content was limited by controlling the synthesis, calcination, and sintering steps.

  8. Photoelectrocatalytic Degradation of Sodium Oxalate by TiO2/Ti Thin Film Electrode

    Directory of Open Access Journals (Sweden)

    Chen-Yu Chang

    2012-01-01

    Full Text Available The photocatalytically active TiO2 thin film was deposited on the titanium substrate plate by chemical vapor deposition (CVD method, and the photoelectrocatalytic degradation of sodium oxalate was investigated by TiO2 thin film reactor prepared in this study with additional electric potential at 365 nm irradiation. The batch system was chosen in this experiment, and the controlled parameters were pH, different supporting electrolytes, applied additional potential, and different electrolyte solutions that were examined and discussed. The experimental results revealed that the additional applied potential in photocatalytic reaction could prohibit recombination of electron/hole pairs, but the photoelectrocatalytic effect was decreased when the applied electric potential was over 0.25 V. Among the electrolyte solutions added, sodium sulfate improved the photoelectrocatalytic effect most significantly. At last, the better photoelectrocatalytic degradation of sodium oxalate occurred at pH 3 when comparing the pH influence.

  9. ELECTROCHEMICAL STUDIES ON THE CORROSION OF CARBON STEEL IN OXALIC ACID CLEANING SOLUTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Wiersma, B; John Mickalonis, J

    2007-10-08

    The Savannah River Site (SRS) will disperse or dissolve precipitated metal oxides as part of radioactive waste tank closure operations. Previously SRS has utilized oxalic acid to accomplish this task. Since the waste tanks are constructed of carbon steel, a significant amount of corrosion may occur. Although the total amount of corrosion may be insignificant for a short contact time, a significant amount of hydrogen may be generated due to the corrosion reaction. Linear polarization resistance and anodic/cathodic polarization tests were performed to investigate the corrosion behavior during the process. The effect of process variables such as temperature, agitation, aeration, sample orientation, light as well as surface finish on the corrosion behavior were evaluated. The results of the tests provided insight into the corrosion mechanism for the iron-oxalic acid system.

  10. Construction and Characterization of Coated Wire Oxalate Ion Selective Electrode Based on Chitosan

    Directory of Open Access Journals (Sweden)

    Zuri Rismiarti

    2013-10-01

    Full Text Available PVC (polyvinyl chloride membrane based coated wire oxalate ion selective electrode has been developed by using chitosan. The results showed the optimum composition of the membrane was chitosan: aliquat 336: PVC: DBP = 4:1:33:62 (% weight. The electrode showed Nernstian response, Nernst factor 29.90 mV/decade of concentration, linier concentration range of 1x10-5 - 1x10-1 M, detection limit of 2.56 x10-6 M, response time of 30 second, and life time of 42 days. ISE’s performance worked well in pH range of 5-7 and temperature of 25-50 oC. Validation test showed no significant difference (t test with the SSA method so that the potentiometric method could be used as an alternative method for determining urinary oxalate.

  11. Room temperature magnetism in zinc nano ferrite synthesized by a novel oxalate-ceramic method

    Energy Technology Data Exchange (ETDEWEB)

    Bhatt, Kapil K., E-mail: getdrkapil@yahoo.com [Department of Physics, Wilson College, Chowpatty, Mumbai 400 007 (India); Department of Physics and National Centre for Nanosciences and Nanotechnology, University of Mumbai, Santacruz (E), Mumbai 400 098 (India); Niwate, Yogesh S.; Garje, Shivram S. [Department of Chemistry, University of Mumbai, Santacruz (E), Mumbai 400 098 (India); Kothari, D.C. [Department of Physics and National Centre for Nanosciences and Nanotechnology, University of Mumbai, Santacruz (E), Mumbai 400 098 (India)

    2015-07-01

    Zinc nano-ferrite has been synthesized using a novel oxalate-ceramic method and its magnetic properties are reported in this paper. The hysteresis loop recorded at 300 K exhibits ferrimagnetic behavior. The Neel temperature was found to be 557 K. The AC susceptibility curve also indicates ferrimagnetic behavior. The temperature dependent magnetization curves, obtained in the temperature range of 4–300 K, show spin glass behavior. Using this method of synthesis large quantity of ferrite can be synthesized therefore this method can become useful technique for industrial scale production. - Highlights: • Oxalate-ceramic method is a novel technique to synthesize spinel ferrites. • Zinc ferrite synthesized by this technique are in nanocrystalline form with average crystallite size of 32 nm. • Neel temperature of zinc ferrite is found to be 557 K. • Different magnetic behavior in different temperature regime.

  12. Stannous oxalate as a novel catalyst for the synthesis of polytrimethylene terephthalate

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Stannous oxalate was prepared efficiently and characterized by XRD and FT-IR. It exhibited higher catalytic activity and had profitable effect than tetrabutyl titanate and stannous octoate for the synthesis of polytrimethylene terephthalate (PTT) via esterification-route. Over this catalyst, the degree of esterification of pure terephthalic acid was up to 94.4% at 260 ℃ after 1.5 h,while the intrinsic viscosity and content of terminal carboxyl groups of the corresponding PTT polyester, polymerized at 260 ℃,60 Pa for 2 h, was 0.8950 dL/g and 15 mol/t, respectively. Stannous oxalate was a promising catalyst for the synthesis of PTT polyester.(C) 2007 Yun Cheng Cui. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

  13. The effect of sulfuric acid on pore initiation in anodic alumina formed in oxalic acid

    Directory of Open Access Journals (Sweden)

    Behnam Hafezi

    2014-07-01

    Full Text Available In this work, a tracer study on pore initiation in anodic alumina in oxalic acid was performed. Effects of some experimental parameters such as applied electrical potential, electrolyte composition and heat pretreatment were evaluated. Electrochemical and morphological experiments were performed using potentiostatic anodizing and scanning electron microscopy (SEM techniques, respectively. Effect of electrolyte composition on current density was discussed. In various electrical potentials, electrolyte composition had different effects on current density. Addition of sulfuric acid into oxalic acid increased porosity. Also, distribution of pore size and pore diameter were influenced by presence of sulfuric acid. Effect of electrolyte composition on the morphology of aluminum surface layer depended on the electric potential. Current density and porosity of aluminum surface layer was decreased by heat pretreatment.

  14. IN-SITU MONITORING OF CORROSION DURING A LABORATORY SIMULATION OF OXALIC ACID CHEMICAL CLEANING

    Energy Technology Data Exchange (ETDEWEB)

    Wiersma, B; John Mickalonis, J; Michael Poirier, M; John Pareizs, J; David Herman, D; David Beam, D; Samuel Fink, S; Fernando Fondeur, F

    2007-10-08

    The Savannah River Site (SRS) will disperse or dissolve precipitated metal oxides as part of radioactive waste tank closure operations. Previously SRS used oxalic acid to accomplish this task. To better understand the conditions of oxalic acid cleaning of the carbon steel waste tanks, laboratory simulations of the process were conducted to determine the corrosion rate of carbon steel and the generation of gases such as hydrogen and carbon dioxide. Open circuit potential measurements, linear polarization measurements, and coupon immersion tests were performed in-situ to determine the corrosion behavior of carbon steel during the demonstration. Vapor samples were analyzed continuously to determine the constituents of the phase. The combined results from these measurements indicated that in aerated environments, such as the tank, that the corrosion rates are manageable for short contact times and will facilitate prediction and control of the hydrogen generation rate during operations.

  15. The effects of pre versus post workout supplementation of creatine monohydrate on body composition and strength

    Science.gov (United States)

    2013-01-01

    Background Chronic supplementation with creatine monohydrate has been shown to promote increases in total intramuscular creatine, phosphocreatine, skeletal muscle mass, lean body mass and muscle fiber size. Furthermore, there is robust evidence that muscular strength and power will also increase after supplementing with creatine. However, it is not known if the timing of creatine supplementation will affect the adaptive response to exercise. Thus, the purpose of this investigation was to determine the difference between pre versus post exercise supplementation of creatine on measures of body composition and strength. Methods Nineteen healthy recreational male bodybuilders (mean ± SD; age: 23.1 ± 2.9; height: 166.0 ± 23.2 cm; weight: 80.18 ± 10.43 kg) participated in this study. Subjects were randomly assigned to one of the following groups: PRE-SUPP or POST-SUPP workout supplementation of creatine (5 grams). The PRE-SUPP group consumed 5 grams of creatine immediately before exercise. On the other hand, the POST-SUPP group consumed 5 grams immediately after exercise. Subjects trained on average five days per week for four weeks. Subjects consumed the supplement on the two non-training days at their convenience. Subjects performed a periodized, split-routine, bodybuilding workout five days per week (Chest-shoulders-triceps; Back-biceps, Legs, etc.). Body composition (Bod Pod®) and 1-RM bench press (BP) were determined. Diet logs were collected and analyzed (one random day per week; four total days analyzed). Results 2x2 ANOVA results - There was a significant time effect for fat-free mass (FFM) (F = 19.9; p = 0.001) and BP (F = 18.9; p supplementation with creatine post workout is possibly more beneficial in comparison to pre workout supplementation with regards to FFM, FM and 1-RM BP. The mean change in the PRE-SUPP and POST-SUPP groups for body weight (BW kg), FFM (kg), FM (kg) and 1-RM bench press (kg) were as follows

  16. Calcium and Calcium-Base Alloys

    Science.gov (United States)

    1949-01-01

    should be satisfactory, because the electrolytic process for •(!>: A. H. Everts and G. D. Baglev’, " Physical «nrt m<„.+„4 i «_ of Calcium«, Electrochem...Rev. Metalurgie , 3j2, (1), 129 (1935). 10 ^sm^mssss^ma^^ extension between two known loads, is preferable to the value of 3,700,000 p.B.i. obtained

  17. Catalytic ozonation of oxalate with a cerium supported palladium oxide: An efficient degradation not relying on hydroxyl radical oxidation

    KAUST Repository

    Zhang, Tao

    2011-11-01

    The cerium supported palladium oxide (PdO/CeO 2) at a low palladium loading was found very effective in catalytic ozonation of oxalate, a probe compound that is difficult to be efficiently degraded in water with hydroxyl radical oxidation and one of the major byproducts in ozonation of organic matter. The oxalate was degraded into CO 2 during the catalytic ozonation. The molar ratio of oxalate degraded to ozone consumption increased with increasing catalyst dose and decreasing ozone dosage and pH under the conditions of this study. The maximum molar ratio reached around 1, meaning that the catalyst was highly active and selective for oxalate degradation in water. The catalytic ozonation, which showed relatively stable activity, does not promote hydroxyl radical generation from ozone. Analysis with ATR-FTIR and in situ Raman spectroscopy revealed that 1) oxalate was adsorbed on CeO 2 of the catalyst forming surface complexes, and 2) O 3 was adsorbed on PdO of the catalyst and further decomposed to surface atomic oxygen (*O), surface peroxide (*O 2), and O 2 gas in sequence. The results indicate that the high activity of the catalyst is related to the synergetic function of PdO and CeO 2 in that the surface atomic oxygen readily reacts with the surface cerium-oxalate complex. This kind of catalytic ozonation would be potentially effective for the degradation of polar refractory organic pollutants and hydrophilic natural organic matter. © 2011 American Chemical Society.

  18. Oxalate Accumulation as Regulated by Nitrogen Forms and Its Relationship to Photosynthesis in Rice (Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    Xiu-Mei JI; Xin-Xiang PENG

    2005-01-01

    Four-leaf rice seedlings (Oryza sativa L.), which had been cultivated in Kimura B complete nutrient solution, were treated with two nitrogen forms by replacing the nitrogen element in the complete solution with sole nitrate or ammonium (2.86 mmol/L). Nitrate-N nutrition tended to increase oxalate content in all parts of the plant, including the leaves, stems, roots, and root exudates, whereas ammonium had the opposite effect. Consequently, marked differences in oxalate content were observed between the two treatments throughout the time tested (0--12 d), with maximal differences of approximately 12-fold at 6 d after treatment. Photosynthetic/respiratory parameters were examined over time simultaneously with changes in oxalate content. Net photosynthetic rate, chlorophyll fluorescence parameters (i.e. maximal photochemical efficiency (Fv/Fm) and photochemical quantum yields of photosystem (PS)Ⅱ (φ PSⅡ)), and respiratory rate were not significantly different between plants treated with the two nitrogen forms, although ammonium-fed plants had apparently higher leaf chlorophyll content than nitrate-fed plants. Leaf glucose content was altered little, but the content of fructose, sucrose, and total soluble sugar was significantly higher in the leaves of ammonium-fed plants than nitrate-fed plants, The results indicate that nitrate/ammonium may serve as efficient regulators of oxalate accumulation owing to regulation of metabolism in rice leaves rather than oxalate downward transfer and root excretion, and that photosynthetic metabolism is not directly correlated with the regulation of oxalate accumulation in rice plants.

  19. Reversal of Gastric Bypass Resolves Hyperoxaluria and Improves Oxalate Nephropathy Secondary to Roux-en-Y Gastric Bypass

    Science.gov (United States)

    Agrawal, Varun; Wilfong, Jonathan B.; Rich, Christopher E.; Gibson, Pamela C.

    2016-01-01

    Hyperoxaluria after Roux-en-Y gastric bypass (RYGB) increases the risk for kidney injury. Medical therapies for hyperoxaluria have limited efficacy. A 65-year-old female was evaluated for acute kidney injury [AKI, serum creatinine (Cr) 2.1 mg/dl, baseline Cr 1.0 mg/dl]. She did not have any urinary or gastrointestinal symptoms or exposure to nephrotoxic agents. Sixteen months prior to this evaluation, she underwent RYGB for morbid obesity. Her examination was unremarkable for hypertension or edema and there was no protein or blood on urine dipstick. Kidney biopsy revealed acute tubulointerstitial nephritis with oxalate crystals in tubules. The concurrent finding of severe hyperoxaluria (urine oxalate 150 mg/day) confirmed the diagnosis of oxalate nephropathy. Despite medical management of hyperoxaluria, her AKI worsened. Laparoscopic reversal of RYGB was performed and within 1 month, her hyperoxaluria resolved (urine oxalate 20 mg/day) and AKI improved (Cr 1.7 mg/dl). Surgical reversal of RYGB may be considered in patients with oxalate nephropathy at high risk of progression who fail medical therapy. Physicians need to be aware of the possibility of oxalate nephropathy after RYGB and promptly treat the hyperoxaluria to halt further kidney damage. PMID:27781207

  20. Isothermal titration calorimetry uncovers substrate promiscuity of bicupin oxalate oxidase from Ceriporiopsis subvermispora

    Directory of Open Access Journals (Sweden)

    Hassan Rana

    2016-03-01

    Full Text Available Isothermal titration calorimetry (ITC may be used to determine the kinetic parameters of enzyme-catalyzed reactions when neither products nor reactants are spectrophotometrically visible and when the reaction products are unknown. We report here the use of the multiple injection method of ITC to characterize the catalytic properties of oxalate oxidase (OxOx from Ceriporiopsis subvermispora (CsOxOx, a manganese dependent enzyme that catalyzes the oxygen-dependent oxidation of oxalate to carbon dioxide in a reaction coupled with the formation of hydrogen peroxide. CsOxOx is the first bicupin enzyme identified that catalyzes this reaction. The multiple injection ITC method of measuring OxOx activity involves continuous, real-time detection of the amount of heat generated (dQ during catalysis, which is equal to the number of moles of product produced times the enthalpy of the reaction (ΔHapp. Steady-state kinetic constants using oxalate as the substrate determined by multiple injection ITC are comparable to those obtained by a continuous spectrophotometric assay in which H2O2 production is coupled to the horseradish peroxidase-catalyzed oxidation of 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid and by membrane inlet mass spectrometry. Additionally, we used multiple injection ITC to identify mesoxalate as a substrate for the CsOxOx-catalyzed reaction, with a kinetic parameters comparable to that of oxalate, and to identify a number of small molecule carboxylic acid compounds that also serve as substrates for the enzyme.

  1. Oxidation of ferrocene by thiocyanic acid in the presence of ammonium oxalate

    Energy Technology Data Exchange (ETDEWEB)

    Ruslin, Farah bt; Yamin, Bohari M. [School of Chemical Science and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia (Malaysia)

    2014-09-03

    A flake-like crystalline salt was obtained from the reaction of ferrocene, oxalic acid and ammonium thiocyanate in ethanol The elemental analysis and spectroscopic data were in agreement with the preliminary X-ray molecular structure. The compound consists of four ferrocenium moieties and a counter anion consisting of two (tetraisothiocyanato)iron(III) linked by an oxalato bridging group in such a way that both iron central atoms adopt octahedral geometries.

  2. Kinetics and mechanism of the oxidation of formic and oxalic acids by benzyltrimethylammonium dichloroiodate

    Indian Academy of Sciences (India)

    Poonam Gupta; Seema Kothari

    2001-04-01

    The oxidation of formic and oxalic acids by benzyltrimethylammonium dichloroiodate (BTMACI), in the presence of zinc chloride, leads to the formation of carbon dioxide. The reaction is first order with respect to BTMACI, zinc chloride and organic acid. Oxidation of deuteriated formic acid indicates the presence of a kinetic isotope effect. Addition of benzyltrimethylammonium chloride enhances the rate. It is proposed that the reactive oxidizing species is [(PhCH2Me3N)+ (IZn2Cl6)−]. Suitablemechanisms have been proposed.

  3. Growth and study of barium oxalate single crystals in agar gel

    Indian Academy of Sciences (India)

    P V Dalal; K B Saraf

    2006-10-01

    Barium oxalate was grown in agar gel at ambient temperature. The effect of various parameters like gel concentration, gel setting time and concentration of the reactants on the growth of these crystals was studied. Prismatic platy shaped spherulites and dendrites were obtained. The grown crystals were characterized by X-ray powder diffractometry, infrared spectroscopy, thermogravimetric and differential thermal analysis. An attempt is made to explain the spherulitic growth mechanism.

  4. Synthesis of Diethyl Oxalate by a Coupling—Regeneration Reaction of Carbon Monoxide

    Institute of Scientific and Technical Information of China (English)

    FandongMeng; GenhuiXu; 等

    2002-01-01

    This article describes a process for the synthesis of diethyl oxalate by a copling reaction of carbon monoxide,catalyzed by palladium in the presence of ethyl nitrite ,The kinetics and mechanism of the coupling and regeneration reaction are also discussed ,This paper presents the results of a scale-up test of the catalyst and the process based on an a priori computer simulation.

  5. Use of oxalic acid to control Varroa destructor in honeybee (Apis mellifera L.) colonies

    OpenAIRE

    Akyol, Ethem; YENİNAR, Halil

    2009-01-01

    This study was carried out to determine the effects of oxalic acid (OA) on reducing Varroa mite (Varroa destructor) populations in honeybee (Apis mellifera L.) colonies in the fall. Twenty honeybee colonies, in wooden Langstroth hives, were used in this experiment. Average Varroa infestation levels (%) of the OA and control groups were 25.87% and 24.57% on adult workers before the treatments. The OA treatments were applied twice, on 3 November and 13 November 2006. Average Varroa infestation ...

  6. Preparation of Porous Alumina Film on Aluminum Substrate by Anodization in Oxalic Acid

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Self-ordering of the cell arrangement of the anodic porous alumina was prepared in oxalic acid solution at a constant potential of 40V and at a temperature of 20°C. The honeycomb structure made by one step anodization method and two step anodization method is different.Pores in the alumina film prepared by two step anodization method were more ordered than those by one step anodization method.

  7. Oscillatory bromate-oxalic acid-Ce-acetone-sulfuric acid reaction, in CSTR

    OpenAIRE

    Pereira,Janaina A. M.; Roberto B Faria

    2004-01-01

    Periodic oscillations were observed for the first time, in a CSTR, in the system bromate-oxalic acid-Ce(IV)-acetone-sulfuric acid, in a CSTR. A reaction between Ce(IV) and acetone, until now not described in the literature and occurring before the addition of the reagents to the reactor, was identified as a decisive factor for the appearing of the regular oscillations.

  8. EFFECT OF NATURAL IRON OXIDE, HYDROGEN PEROXIDE, AND OXALIC ACID ON PHOTOCHEMICAL DEGRADATION OF 2-CHLOROPHENOL

    Directory of Open Access Journals (Sweden)

    W REMACHE

    2014-07-01

    Full Text Available The voluntary or accidental release of chemical compounds in the environment is a major cause of pollution of natural waters. Most of chlorophenols are toxic and hardly biodegradable and are difficult to remove from the environment. Therefore, it is important to find innovative and economical methods for the safe and complete destruction. The objective of this work is to test the activity photocatalytic of natural iron oxide (NIO in the photodegradation of 2-chlorophenol (2-CP. The analysis chromatographic with HPLC of solutions exposed under UV irradiation revealed that the degradation of 2-CP was negligible under the condition of using only natural iron oxide. The effect of wavelength on photoreactivity of NIO was also investigated in this process: at high wavelength thus at low energy the efficiency of degradation is important. We have also investigated the activation of NIO by hydrogen peroxide and oxalic acid, The results showed that the photodegradation of 2-CP under UVA irradiation could be enhanced greatly in the presence of oxalate. 2-CP was completly removed after 240 minutes of irradiation when the concentration of oxalic acid is equal to 2.10-3 M. The use of 2.0 % of isopropanol as a scavenger confirmed the intervention of hydroxyl radicals in the photodegradation of 2-CP.

  9. Impact Of Sodium Oxalate, Sodium Aluminosilicate, and Gibbsite/Boehmite on ARP Filter Performance

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Burket, P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-11-01

    The Savannah River Site (SRS) is currently treating radioactive liquid waste with the Actinide Removal Process (ARP) and the Modular Caustic Side Solvent Extraction Unit (MCU). Recently, the low filter flux through the ARP of approximately 5 gallons per minute has limited the rate at which radioactive liquid waste can be treated. Salt Batch 6 had a lower processing rate and required frequent filter cleaning. Savannah River Remediation (SRR) has a desire to understand the causes of the low filter flux and to increase ARP/MCU throughput. SRR requested SRNL to conduct bench-scale filter tests to evaluate whether sodium oxalate, sodium aluminosilicate, or aluminum solids (i.e., gibbsite and boehmite) could be the cause of excessive fouling of the crossflow or secondary filter at ARP. The authors conducted the tests by preparing slurries containing 6.6 M sodium Salt Batch 6 supernate, 2.5 g MST/L slurry, and varying concentrations of sodium oxalate, sodium aluminosilicate, and aluminum solids, processing the slurry through a bench-scale filter unit that contains a crossflow primary filter and a dead-end secondary filter, and measuring filter flux and transmembrane pressure as a function of time. Among the conclusions drwn from this work are the following: (1) All of the tests showed some evidence of fouling the secondary filter. This fouling could be from fine particles passing through the crossflow filter. (2) The sodium oxalate-containing feeds behaved differently from the sodium aluminosilicate- and gibbsite/boehmite-containing feeds.

  10. COMPARATIVE ANALYSIS OF OXALIC ACID PRODUCED FROM RICE HUSK AND PADDY

    Directory of Open Access Journals (Sweden)

    P.I. Oghome

    2012-09-01

    Full Text Available In this research work, comparative analysis of Oxalic acid produced from Rice husk and Paddy was carried out in order to ascertain which waste sample produced a better yield. Nitric acid oxidation of carbohydrates was the method adopted in the production. The variable ratios of HNO3:H2SO4 used were 80:20, 70:30, 60:40, and 50:50. The variable ratio of 60:40 gave the maximum yield and at a maximum temperature of 75oC. Rice husk sample gave a percentage yield of 53.2, 64.4, 81.0, and 53.3 at temperatures of 55 oC, 65 oC, 75 oC, and 85 oC respectively. In the case of paddy a percentage yield of 53.1, 64.0, 79.9, and 52.8 at temperatures of 55 oC, 65 oC, 75 oC, and 85 oC were obtained respectively. The plots between yield and temperature at different variable ratios illustrate the dependence of yield on temperature, which was similar to a parabolic relationship and the peak value (yield was at 75 oC above which it decreased. The properties of oxalic acid from both sources were very close and compared favourably with literature. In comparing the yield, oxalic acid produced from Rice husk gave higher yield than that from Paddy.

  11. An oxalate selective electrode based on modified PVC-membrane with tetra-butylammonium--Clinoptilolite nanoparticles.

    Science.gov (United States)

    Hoseini, Zohre; Nezamzadeh-Ejhieh, Alireza

    2016-03-01

    A modified PVC-membrane electrode with tetra-butylammonium bromide - Clinoptilolite nano-particles (TBA-NCP) showed good Nernstian slope (29.9±0.6 mV per decade of oxalate concentration) in concentration range of 3.1×10(-7)-8.3×10(-1) mol L(-1) with a detection limit of 1.5×10(-7) mol L(-1). The best performance was obtained with a membrane composition of 31.5% PVC, 62.5% DOP and 6% TBA-NCP in the temperature range of 20-35 °C and the pH range of 4-9. The fast response time and good reproducibility over a period of 3 months are other characteristics of the sensor. The proposed electrode was successfully used as an indicator electrode in titration of oxalate ions with CaCl2 solution. The proposed electrode was also used in direct potentiometric determination of oxalate in many real samples such as: mushroom, black and green tea, spinach and beet.

  12. [Calcium suppletion for patients who use gastric acid inhibitors: calcium citrate or calcium carbonate?].

    NARCIS (Netherlands)

    Jonge, H.J. de; Gans, R.O.; Huls, G.A.

    2012-01-01

    Various calcium supplements are available for patients who have an indication for calcium suppletion. American guidelines and UpToDate recommend prescribing calcium citrate to patients who use antacids The rationale for this advice is that water-insoluble calcium carbonate needs acid for adequate ab

  13. Calcium in plant cells

    Directory of Open Access Journals (Sweden)

    V. V. Schwartau

    2014-04-01

    Full Text Available The paper gives the review on the role of calcium in many physiological processes of plant organisms, including growth and development, protection from pathogenic influences, response to changing environmental factors, and many other aspects of plant physiology. Initial intake of calcium ions is carried out by Ca2+-channels of plasma membrane and they are further transported by the xylem owing to auxins’ attractive ability. The level of intake and selectivity of calcium transport to ove-ground parts of the plant is controlled by a symplast. Ca2+enters to the cytoplasm of endoderm cells through calcium channels on the cortical side of Kaspary bands, and is redistributed inside the stele by the symplast, with the use of Ca2+-АТPases and Ca2+/Н+-antiports. Owing to regulated expression and activity of these calcium transporters, calclum can be selectively delivered to the xylem. Important role in supporting calcium homeostasis is given to the vacuole which is the largest depo of calcium. Regulated quantity of calcium movement through the tonoplast is provided by a number of potential-, ligand-gated active transporters and channels, like Ca2+-ATPase and Ca2+/H+ exchanger. They are actively involved in the inactivation of the calcium signal by pumping Ca2+ to the depo of cells. Calcium ATPases are high affinity pumps that efficiently transfer calcium ions against the concentration gradient in their presence in the solution in nanomolar concentrations. Calcium exchangers are low affinity, high capacity Ca2+ transporters that are effectively transporting calcium after raising its concentration in the cell cytosol through the use of protons gradients. Maintaining constant concentration and participation in the response to stimuli of different types also involves EPR, plastids, mitochondria, and cell wall. Calcium binding proteins contain several conserved sequences that provide sensitivity to changes in the concentration of Ca2+ and when you

  14. 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...

  15. Crystal growth and first crystallographic characterization of mixed uranium(IV)-plutonium(III) oxalates.

    Science.gov (United States)

    Tamain, Christelle; Arab Chapelet, Bénédicte; Rivenet, Murielle; Abraham, Francis; Caraballo, Richard; Grandjean, Stéphane

    2013-05-06

    The mixed-actinide uranium(IV)-plutonium(III) oxalate single crystals (NH4)0.5[Pu(III)0.5U(IV)0.5(C2O4)2·H2O]·nH2O (1) and (NH4)2.7Pu(III)0.7U(IV)1.3(C2O4)5·nH2O (2) have been prepared by the diffusion of different ions through membranes separating compartments of a triple cell. UV-vis, Raman, and thermal ionization mass spectrometry analyses demonstrate the presence of both uranium and plutonium metal cations with conservation of the initial oxidation state, U(IV) and Pu(III), and the formation of mixed-valence, mixed-actinide oxalate compounds. The structure of 1 and an average structure of 2 were determined by single-crystal X-ray diffraction and were solved by direct methods and Fourier difference techniques. Compounds 1 and 2 are the first mixed uranium(IV)-plutonium(III) compounds to be structurally characterized by single-crystal X-ray diffraction. The structure of 1, space group P4/n, a = 8.8558(3) Å, b = 7.8963(2) Å, Z = 2, consists of layers formed by four-membered rings of the two actinide metals occupying the same crystallographic site connected through oxalate ions. The actinide atoms are nine-coordinated by oxygen atoms from four bidentate oxalate ligands and one water molecule, which alternates up and down the layer. The single-charged cations and nonbonded water molecules are disordered in the same crystallographic site. For compound 2, an average structure has been determined in space group P6/mmm with a = 11.158(2) Å and c = 6.400(1) Å. The honeycomb-like framework [Pu(III)0.7U(IV)1.3(C2O4)5](2.7-) results from a three-dimensional arrangement of mixed (U0.65Pu0.35)O10 polyhedra connected by five bis-bidentate μ(2)-oxalate ions in a trigonal-bipyramidal configuration.

  16. [Microbial geochemical calcium cycle].

    Science.gov (United States)

    Zavarzin, G A

    2002-01-01

    The participation of microorganisms in the geochemical calcium cycle is the most important factor maintaining neutral conditions on the Earth. This cycle has profound influence on the fate of inorganic carbon, and, thereby, on the removal of CO2 from the atmosphere. The major part of calcium deposits was formed in the Precambrian, when prokaryotic biosphere predominated. After that, calcium recycling based on biogenic deposition by skeletal organisms became the main process. Among prokaryotes, only a few representatives, e.g., cyanobacteria, exhibit a special calcium function. The geochemical calcium cycle is made possible by the universal features of bacteria involved in biologically mediated reactions and is determined by the activities of microbial communities. In the prokaryotic system, the calcium cycle begins with the leaching of igneous rock predominantly through the action of the community of organotrophic organisms. The release of carbon dioxide to the soil air by organotrophic aerobes leads to leaching with carbonic acid and soda salinization. Under anoxic conditions, of major importance is the organic acid production by primary anaerobes (fermentative microorganisms). Calcium carbonate is precipitated by secondary anaerobes (sulfate reducers) and to a smaller degree by methanogens. The role of the cyanobacterial community in carbonate deposition is exposed by stromatolites, which are the most common organo-sedimentary Precambrian structures. Deposition of carbonates in cyanobacterial mats as a consequence of photoassimilation of CO2 does not appear to be a significant process. It is argued that carbonates were deposited at the boundary between the "soda continent", which emerged as a result of subaerial leaching with carbonic acid, and the ocean containing Ca2+. Such ecotones provided favorable conditions for the development of the benthic cyanobacterial community, which was a precursor of stromatolites.

  17. A study of the piezoelectric resonance in metal organic NLO single crystals: Sodium D-isoascorbate monohydrate and Lithium L-ascorbate dihydrate

    Science.gov (United States)

    Saripalli, Ravi Kiran; Raghavendra Rao, K.; Sanath Kumar, R.; Bhat, H. L.; Elizabeth, Suja

    2016-05-01

    Large single crystals of Sodium D-isoacsorbate monohydrate and Lithium L-ascorbate dehydrate were grown using solution growth technique. Dielectric constant and dielectric loss were monitored as a function of frequency at different temperatures. These are typically characterized by strong resonance peaks. The piezoelectric coefficients d31, elastic coefficient (S11) and electromechanical coupling coefficient (k31) were estimated by resonance-antiresonance method. The temperature dependence of the resonance-peaks frequencies was studied.

  18. Study on Thermodynamic Properties for Binary Systems of Water + L-Cysteine Hydrochloride Monohydrate, Glycerol, and D-Sorbitol at Various Temperatures

    OpenAIRE

    F. Koohyar; Rostami, A. A.; Chaichi, M. J.; F. kiani

    2013-01-01

    Viscosities, refractive indices, and densities for aqueous solution of L-cysteine hydrochloride monohydrate ([LCHCMH]) and D-sorbitol, and also densities (ρ), refractive indices ( ), excess molar volumes ( ), and change of refractive indices on mixing ( ) for aqueous solution of glycerol have been measured at several mole fractions and temperatures (between  K and  K) at atmospheric pressure. The measurements were carried out using a vibrating-tube density meter for density, an Abbe refractom...

  19. Dissolution of Simulated and Radioactive Savannah River Site High-Level Waste Sludges with Oxalic Acid & Citric Acid Solutions

    Energy Technology Data Exchange (ETDEWEB)

    STALLINGS, MARY

    2004-07-08

    This report presents findings from tests investigating the dissolution of simulated and radioactive Savannah River Site sludges with 4 per cent oxalic acid and mixtures of oxalic and citric acid previously recommended by a Russian team from the Khlopin Radium Institute and the Mining and Chemical Combine (MCC). Testing also included characterization of the simulated and radioactive waste sludges. Testing results showed the following: Dissolution of simulated HM and PUREX sludges with oxalic and citric acid mixtures at SRTC confirmed general trends reported previously by Russian testing. Unlike the previous Russian testing six sequential contacts of a mixture of oxalic acid citric acids at a 2:1 ratio (v/w) of acid to sludge did not produce complete dissolution of simulated HM and PUREX sludges. We observed that increased sludge dissolution occurred at a higher acid to sludge ratio, 50:1 (v/w), compared to the recommended ratio of 2:1 (v/w). We observed much lower dissolution of aluminum in a simulated HM sludge by sodium hydroxide leaching. We attribute the low aluminum dissolution in caustic to the high fraction of boehmite present in the simulated sludge. Dissolution of HLW sludges with 4 per cent oxalic acid and oxalic/citric acid followed general trends observed with simulated sludges. The limited testing suggests that a mixture of oxalic and citric acids is more efficient for dissolving HM and PUREX sludges and provides a more homogeneous dissolution of HM sludge than oxalic acid alone. Dissolution of HLW sludges in oxalic and oxalic/citric acid mixtures produced residual sludge solids that measured at higher neutron poison to equivalent 235U weight ratios than that in the untreated sludge solids. This finding suggests that residual solids do not present an increased nuclear criticality safety risk. Generally the neutron poison to equivalent 235U weight ratios of the acid solutions containing dissolved sludge components are lower than those in the untreated

  20. The influence of excipients on the stability of the moisture sensitive drugs aspirin and niacinamide: comparison of tablets containing lactose monohydrate with tablets containing anhydrous lactose.

    Science.gov (United States)

    Du, J; Hoag, S W

    2001-01-01

    The purpose of this study is to test the hypothesis that in tablet formulations, moisture-sensitive drugs formulated with lactose monohydrate have the same stability as formulations containing anhydrous lactose, and to characterize the kinetics of niacinamide degradation in the solid state. Aspirin and niacinamide decomposition were used as indicators of stability. Aspirin and niacinamide tablets containing either lactose monohydrate or anhydrous lactose were separately investigated at different temperatures and relative humidities; the stability tests were done at 25 degrees C--60% RH, 40 degrees C--80% RH, 60 degrees C--60% RH, 60 degrees C--80% RH, and 80 degrees C--80% RH. Official U.S. Pharmacopeia methods were used for the aspirin and niacinamide assays. Statistical analysis showed that tablets containing lactose monohydrate have the same stability as tablets containing anhydrous lactose, which means that even though water is present in the crystal structure, the bound water does not influence the reaction rate. In addition, niacinamide degradation in the solid-state can be described by a third order rate equation.

  1. Urinary creatine and methylamine excretion following 4 x 5 g x day(-1) or 20 x 1 g x day(-1) of creatine monohydrate for 5 days.

    Science.gov (United States)

    Sale, Craig; Harris, Roger C; Florance, James; Kumps, Alain; Sanvura, Robertine; Poortmans, Jacques R

    2009-05-01

    In this study, we examined the effect of two creatine monohydrate supplementation regimes on 24-h urinary creatine and methylamine excretion. Nine male participants completed two trials, separated by 6 weeks. Participants ingested 4 x 5 g x day(-1) creatine monohydrate for 5 days in one trial and 20 x 1 g x day(-1) for 5 days in the other. We collected 24-h urine samples on 2 baseline days (days 1-2), during 5 days of supplementation (days 3-7), and for 2 days post-supplementation (days 8-9). Urine was assayed for creatine using high-performance liquid chromatography and methylamine using gas chromatography. Less creatine was excreted following the 20 x 1 g x day(-1) regime (49.25 +/- 10.53 g) than the 4 x 5 g x day(-1) regime (62.32 +/- 9.36 g) (mean +/- s; P x 1 g x day(-1) and 4 x 5 g x day(-1) regimes, respectively (P x 1 g x day(-1) doses suggests a greater retention in the body and most probably in the muscle. Lower and more frequent doses of creatine monohydrate appear to further attenuate formation of methylamine.

  2. Synthesis and characterization of tungsten or calcium doped PZT ceramics; Sintese e caracterizacao do PZT dopado com W ou Ca

    Energy Technology Data Exchange (ETDEWEB)

    Santos, D.M.; Caracas, L.B.; Noronha, R.G.; Santos, M.M.T. dos [Universidade Federal do Maranhao (UFMA), Sao Luis, MA (Brazil). Dept. de Desenho e Tecnologia. Curso de Desenho Industrial; Paiva-Santos, C.O., E-mail: denilson@ufma.b [Universidade Estadual Paulista (IQ/UNESP), Araraquara, SP (Brazil). Inst. de Quimica

    2009-07-01

    Pure and doped (tungsten or calcium) PZT ceramics were prepared by association of the polymeric precursor and partial oxalate method. The phase formation was investigated by thermal analysis (TG/DSC) and X-ray diffraction (XRD). The affect of W or Ca doping PZT and their electrical properties was evaluated. Substitution of W by Ti and Ca by Pb leads to an increase of Curie temperature and broadening of dielectric constant. A typical hysteresis loop was observed at room temperature and the remnant polarization was increased with the content of W and Ca. (author)

  3. 色谱法测定制浆造纸工业漂白废液中的草酸浓度%CHROMATOGRAPHIC METHOD FOR DETERMINATION OF OXALIC ACID IN BLEACHING FILTRATES FROM THE PULP AND PAPER INDUSTRY

    Institute of Scientific and Technical Information of China (English)

    洪枫; REIMANN Anders; J(O)NSSON Leif-j; NILVEBRANT Nils-olof

    2005-01-01

    Analysis and control of oxalic acid in bleaching filtrates has recently gained considerable attention in the pulp and paper industry due to problems with the formation of calcium oxalate scaling.Chromatographic methods,such as HPLC and ion chromatography(IC),are generally valuable as standard methods for determination of oxalic acid.In this study,a HPLC system equipped with an Aminex HPX-87H column was applied to determine oxalic acid in authentic bleaching filtrates.An established IC method based on separation with an anion-exchange column was used as reference method.The results showed that bleaching filtrates contain compounds interfering with the HPLC method.A strategy, dilution of the samples followed by treatment with activated carbon,was needed to obtain similar oxalic acid concentrations as provided by the reference method.The correlation(R=0.994) between the HPLC method and the IC method is described by the equation y=1.294 7x.The method improves the possibility for control of critical oxalic acid concentration in closed-loop bleaching streams.%近年来草酸钙(草酸垢)的形成在制浆造纸工业中造成诸多问题,因此如何分析及控制漂白废液中的草酸浓度就显得尤为重要.高效液相色谱和离子交换色谱等色谱法一般可以作为测定草酸的标准方法.本研究以一个基于阴离子交换柱的离子交换色谱法作为对照方法,利用一套配备了Aminex HPX-87H液相色谱柱的高效液相色谱系统测定漂白废液中的草酸浓度.结果显示,漂白废液中含有一些干扰高效液相色谱法测定的化合物.通过采用稀释样品后再经活性炭吸附的处理方法,可以得到较为满意的结果.分析发现高效液相色谱法与离子交换色谱(对照法)之间的相关性较好,相关系数为0.994.该方法的建立将有利于监控制浆造纸企业中闭路循环漂液中形成草酸钙时的临界草酸浓度.

  4. Inositol trisphosphate and calcium signalling

    Science.gov (United States)

    Berridge, Michael J.

    1993-01-01

    Inositol trisphosphate is a second messenger that controls many cellular processes by generating internal calcium signals. It operates through receptors whose molecular and physiological properties closely resemble the calcium-mobilizing ryanodine receptors of muscle. This family of intracellular calcium channels displays the regenerative process of calcium-induced calcium release responsible for the complex spatiotemporal patterns of calcium waves and oscillations. Such a dynamic signalling pathway controls many cellular processes, including fertilization, cell growth, transformation, secretion, smooth muscle contraction, sensory perception and neuronal signalling.

  5. Detection of fluorescent labelled oligonucleotides using oxalate chemiluminiscence. Estudio de la deteccion de oligonucleotidos marcados con compuestos fluorescentes utilizando la quimioluminiscencia de los esteres del acido oxalico

    Energy Technology Data Exchange (ETDEWEB)

    Eritia, R. (Barcelona Univ. (Spain). Dept. de Quimica Organica); Johnson, D.; Paige, J.; Walker, P.; Kaplan, B. (Beckman Research Institute of City of Hope, CA (USA))

    1989-01-01

    The preparation and characterization of oligonucleotides containing fluorescent compounds at the 5' terminus is described together with the utilization of oxalate chemiluminiscence for their detection. (Author)

  6. Gravimetric Determination of Calcium as Calcium Carbonate Hydrate.

    Science.gov (United States)

    Henrickson, Charles H.; Robinson, Paul R.

    1979-01-01

    The gravimetric determination of calcium as calcium carbonate is described. This experiment is suitable for undergraduate quantitative analysis laboratories. It is less expensive than determination of chloride as silver chloride. (BB)

  7. Calcium and Calcium Supplements: Achieving the Right Balance

    Science.gov (United States)

    ... bone mass, which is a risk factor for osteoporosis. Many Americans don't get enough calcium in their diets. Children and adolescent girls are at particular risk, but so are adults age 50 and older. How much calcium you ...

  8. Characterization of crystalline structures in Opuntia ficus-indica.

    Science.gov (United States)

    Contreras-Padilla, Margarita; Rivera-Muñoz, Eric M; Gutiérrez-Cortez, Elsa; del López, Alicia Real; Rodríguez-García, Mario Enrique

    2015-01-01

    This research studies the crystalline compounds present in nopal (Opuntia ficus-indica) cladodes. The identification of the crystalline structures was performed using X-ray diffraction, scanning electron microscopy, mass spectrometry, and Fourier transform infrared spectroscopy. The crystalline structures identified were calcium carbonate (calcite) [CaCO3], calcium-magnesium bicarbonate [CaMg(CO3)2], magnesium oxide [MgO], calcium oxalate monohydrate [Ca(C2O4)•(H2O)], potassium peroxydiphosphate [K4P2O8] and potassium chloride [KCl]. The SEM images indicate that calcite crystals grow to dipyramidal, octahedral-like, prismatic, and flower-like structures; meanwhile, calcium-magnesium bicarbonate structures show rhombohedral exfoliation and calcium oxalate monohydrate is present in a drusenoid morphology. These calcium carbonate compounds have a great importance for humans because their bioavailability. This is the first report about the identification and structural analysis of calcium carbonate and calcium-magnesium bicarbonate in nopal cladodes, as well as the presence of magnesium oxide, potassium peroxydiphosphate and potassium chloride in these plants. The significance of the study of the inorganic components of these cactus plants is related with the increasing interest in the potential use of Opuntia as a raw material of products for the food, pharmaceutical, and cosmetic industries.

  9. 新型复合锂钙基润滑脂的研制与性能分析%Preparation and Properties Analysis of New Lithium/Calcium Complex Grease

    Institute of Scientific and Technical Information of China (English)

    张连惠; 王晓

    2013-01-01

    对新型的复合锂钙基润滑脂的生产工艺过程和产品性能进行了分析,结果表明,采用氢氧化锂油相悬浮液作为锂源,相比传统的单水氢氧化锂在生产复合锂钙基润滑脂的过程中,皂化时间短、稠化剂用量少、生产效率高而且环保节能;新型的复合锂钙基润滑脂与传统复合锂钙基润滑脂相比,具有更高的氧化安定性、更细腻的外观和更优异的性能.%New lithium/calcium complex grease was prepared from oil suspension of lithium hydrate instead of lithium hydroxide monohydrate.The preparation process of the new lithium/calcium complex grease was optimized,and found that the process with oil suspension of lithium hydrate as lithium source shows advantages of short saponification time,less thickener consumption,energy conservative and environmental friendly.As compared with the grease from lithium hydroxide monohydrate,this product has better oxidation stability,more smooth appearance and excellent properties.

  10. Calcium, vitamin D and bone

    OpenAIRE

    Borg, Andrew A.

    2012-01-01

    Calcium, protein and vitamin D are the main nutrients relevant to bone health. This short article discusses the importance of vitamin D and its relation to calcium homeostasis. The various causes, clinical manifestations and treatment are outlined.

  11. Thermodynamics of the Complexation of Uranium(VI) by oxalate in aqueous solution at 10-70oC

    Energy Technology Data Exchange (ETDEWEB)

    Di Bernardo, Plinio; Zanonato, Pier Luigi; Tian, Guoxin; Tolazzi, Marilena; Rao, Linfeng

    2009-03-31

    The protonation reactions of oxalate (ox) and the complex formation of uranium(VI) with oxalate in 1.05 mol kg{sup -1} NaClO{sub 4} were studied at variable temperatures (10-70 C). Three U(VI)/ox complexes (UO{sub 2}ox{sub j}{sup (2-2j){sup +}} with j = 1, 2, 3) were identified in this temperature range. The formation constants and the molar enthalpies of complexation were determined by spectrophotometry and calorimetry. The complexation of uranium(VI) with oxalate ion is exothermic at lower temperatures (10-40 C) and becomes endothermic at higher temperatures (55-70 C). In spite of this, the free energy of complexation becomes more negative at higher temperatures due to increasingly more positive entropy of complexation that exceeds the increase of the enthalpy of complexation. The thermodynamic parameters at different temperatures, in conjunction with the literature data for other dicarboxylic acids, provide insight into the relative strength of U(VI) complexes with a series of dicarboxylic acids (oxalic, malonic and oxydiacetic) and rationalization for the highest stability of U(VI)/oxalate complexes in the series. The data reported in this study are of importance in predicting the migration of uranium(VI) in geological environments in the case of failure of the engineering barriers which protect waste repositories.

  12. Iron dissolution of dust source materials during simulated acidic processing: the effect of sulfuric, acetic, and oxalic acids.

    Science.gov (United States)

    Chen, Haihan; Grassian, Vicki H

    2013-09-17

    Atmospheric organic acids potentially display different capacities in iron (Fe) mobilization from atmospheric dust compared with inorganic acids, but few measurements have been made on this comparison. We report here a laboratory investigation of Fe mobilization of coal fly ash, a representative Fe-containing anthropogenic aerosol, and Arizona test dust, a reference source material for mineral dust, in pH 2 sulfuric acid, acetic acid, and oxalic acid, respectively. The effects of pH and solar radiation on Fe dissolution have also been explored. The relative capacities of these three acids in Fe dissolution are in the order of oxalic acid > sulfuric acid > acetic acid. Oxalate forms mononuclear bidentate ligand with surface Fe and promotes Fe dissolution to the greatest extent. Photolysis of Fe-oxalate complexes further enhances Fe dissolution with the concomitant degradation of oxalate. These results suggest that ligand-promoted dissolution of Fe may play a more significant role in mobilizing Fe from atmospheric dust compared with proton-assisted processing. The role of atmospheric organic acids should be taken into account in global-biogeochemical modeling to better access dissolved atmospheric Fe deposition flux at the ocean surface.

  13. Scientific Opinion on safety and efficacy of coated granulated cobaltous carbonate monohydrate as feed additive for all species

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Additives and Products or Substances used in Animal Feed

    2012-07-01

    Full Text Available

    Cobalt(III is a component of cobalamin. Its essentiality as trace element results from the capacity of certain animal species to synthesise cobalamin by the gastrointestinal microbiota. Feeding cobalt(II carbonate hydroxide (2:3 monohydrate up to the maximum authorised total cobalt in feed is safe for the target animals. Cobalt is predominantly excreted via the faecal route. Absorbed cobalt follows aqueous excretion routes. About 43 % of body cobalt is stored in muscle; however, kidney and liver are the edible tissues containing the highest cobalt concentrations and are most susceptible to reflect dietary cobalt concentrations. In animals with the capacity to synthesise cobalamin, cobalt is also deposited in tissues as vitamin B12. Cobalt(II cations are genotoxic under in vitro and in vivo conditions. Cobalt(II carbonate has carcinogen, mutagen and reproduction toxicant (CMR properties. No data are available on the potential carcinogenicity of cobalt(II following oral exposure. However, oral exposure may potentially entail adverse threshold-related effects in humans. The estimated population intake of cobalt most likely includes the contribution of foodstuffs from animals fed cobalt-supplemented feedingstuffs. An increase in cobalt exposure by the use of cobalt-containing feed additives is therefore not expected. Considering the population exposure to cobalt, about 4–10 times lower than the health-based guidance value, no safety concern for the consumer is expected for threshold effects of oral cobalt. Cobalt(II carbonate is a skin and eye irritant, and a dermal and respiratory sensitiser. Its dust is a hazard to persons handling the substance. Exposure by inhalation must be avoided. The use of cobalt from any source at the authorised maximum content in feed does not provide a risk to the environment. The coated granulated cobalt(II carbonate hydroxide (2:3 monohydrate is available for cobalamin synthesis in

  14. Calcium ion channel and epilepsy

    Institute of Scientific and Technical Information of China (English)

    Yudan Lü; Weihong Lin; Dihui Ma

    2006-01-01

    OBJECTIVE: To review the relationship between calcium ion channel and epilepsy for well investigating the pathogenesis of epilepsy and probing into the new therapeutic pathway of epilepsy.DATA SOURCES: A computer-based online research Calcium ion channel and epilepsy related articles published between January 1994 and December 2006 in the CKNI and Wanfang database with the key words of "calcium influxion, epilepsy, calcium-channel blocker". The language was limited to Chinese. At the same time,related articles published between January 1993 and December 2006 in Pubmed were searched for on online with the key words of "calcium influxion, epilepsy" in English.STUDY SELECTION: The materials were selected firstly. Inclusive criteria: ① Studies related to calcium ion channel and the pat1hogenesis of epilepsy. ② Studies on the application of calcium ion channel blocker in the treatment of epilepsy. Exclusive criteria: repetitive or irrelated studies.DATA EXTRACTION: According to the criteria, 123 articles were retrieved and 93 were excluded due to repetitive or irrelated studies. Altogether 30 articles met the inclusive criteria, 11 of them were about the structure and characters of calcium ion channel, 10 about calcium ion channel and the pathogenesis of epilepsy and 9 about calcium blocker and the treatment of epilepsy.DATA SYNTHESIS: Calcium ion channels mainly consist of voltage dependent calcium channel and receptor operated calcium channel. Depolarization caused by voltage gating channel-induced influxion is the pathological basis of epileptic attack, and it is found in many studies that many anti-epileptic drugs have potential and direct effect to rivalizing voltage-dependent calcium ion channel.CONCLUSION: Calcium influxion plays an important role in the seizure of epilepsy. Some calcium antagonists seen commonly are being tried in the clinical therapy of epilepsy that is being explored, not applied in clinical practice. If there are enough evidences to

  15. Defective urinary crystallization inhibition and urinary stone formation

    Directory of Open Access Journals (Sweden)

    Mauricio Carvalho

    2006-06-01

    Full Text Available INTRODUCTION: Nephrocalcin (NC is a glycoprotein produced in the kidney and inhibits calcium oxalate crystal formation. It has been separated into 4 isoforms (A, B, C, and D and found that (A + B are more abundant than (C + D in urine of healthy subjects, but the reverse is seen in human urine of kidney stone patients. To further examine the role of this protein in inhibition of urinary crystallization, nephrocalcin isoforms were purified from 2 genetically pure dog species. MATERIALS AND METHODS: We studied healthy Beagles, known to be non-stone forming dogs, and Mini-Schnauzers, known to be calcium oxalate stone formers. NC was isolated and purified from each group. Urinary biochemistry and calcium oxalate crystal growth inhibition were measured. RESULTS: Specific crystal growth inhibition activity was significantly higher in non-stone forming dogs (9.79 ± 2.25 in Beagles vs. 2.75 ± 1.34 of Mini-Schnauzers, p < 0.005. Dissociation constants toward calcium oxalate monohydrate were 10-fold different, with Beagles' isoforms being 10 times stronger inhibitors compare to those of Mini-Schnauzers'. Isoforms C + D of NC were the main isoforms isolated in stone-forming dogs. CONCLUSION: NC of these two species of dogs differently affects calcium oxalate crystallization and might have a role in determining ulterior urinary stone formation.

  16. Calcium carbonate overdose

    Science.gov (United States)

    Calcium carbonate is not very poisonous. Recovery is quite likely. But, long-term overuse is more serious than a single overdose, because it can cause kidney damage. Few people die from an antacid overdose. Keep all medicines in child-proof bottles and out ...

  17. High Blood Calcium (Hypercalcemia)

    Science.gov (United States)

    ... as well as kidney function and levels of calcium in your urine. Your provider may do other tests to further assess your condition, such as checking your blood levels of phosphorus (a mineral). Imaging studies also may be helpful, such as bone ...

  18. Solar Imagery - Chromosphere - Calcium

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset consists of full-disk images of the sun in Calcium (Ca) II K wavelength (393.4 nm). Ca II K imagery reveal magnetic structures of the sun from about 500...

  19. Potential Pharmacologic Treatments for Cystinuria and for Calcium Stones Associated with Hyperuricosuria

    Energy Technology Data Exchange (ETDEWEB)

    Goldfarb, David S. (NYUSM)

    2012-03-14

    Two new potential pharmacologic therapies for recurrent stone disease are described. The role of hyperuricosuria in promoting calcium stones is controversial with only some but not all epidemiologic studies demonstrating associations between increasing urinary uric acid excretion and calcium stone disease. The relationship is supported by the ability of uric acid to 'salt out' (or reduce the solubility of) calcium oxalate in vitro. A randomized, controlled trial of allopurinol in patients with hyperuricosuria and normocalciuria was also effective in preventing recurrent stones. Febuxostat, a nonpurine inhibitor of xanthine oxidase (also known as xanthine dehydrogenase or xanthine oxidoreductase) may have advantages over allopurinol and is being tested in a similar protocol, with the eventual goal of determining whether urate-lowering therapy prevents recurrent calcium stones. Treatments for cystinuria have advanced little in the past 30 years. Atomic force microscopy has been used recently to demonstrate that effective inhibition of cystine crystal growth is accomplished at low concentrations of L-cystine methyl ester and L-cystine dimethyl ester, structural analogs of cystine that provide steric inhibition of crystal growth. In vitro, L-cystine dimethyl ester had a significant inhibitory effect on crystal growth. The drug's safety and effectiveness will be tested in an Slc3a1 knockout mouse that serves as an animal model of cystinuria.

  20. Crystal structure of zwitterionic 3-(2-hy-droxy-2-phospho-nato-2-phosphono-eth-yl)imidazo[1,2-a]pyridin-1-ium monohydrate (minodronic acid monohydrate): a redetermination.

    Science.gov (United States)

    Airoldi, Annalisa; Bettoni, Piergiorgio; Donnola, Monica; Calestani, Gianluca; Rizzoli, Corrado

    2015-01-01

    In a previous study, the X-ray structure of the title compound, C9H12N2O7P2·H2O, was reported [Takeuchi et al., (1998 ▶). Chem. Pharm. Bull. 46, 1703-1709], but neither atomic coordinates nor details of the geometry were published. The structure has been redetermined with high precision as its detailed knowledge is essential to elucidate the presumed polymorphism of minodronic acid monohydrate at room temperature. The mol-ecule crystallizes in a zwitterionic form with cationic imidazolium[1,2a]pyridine and anionic phospho-nate groups. The dihedral angle formed by the planes of the pyridine and imidazole rings is 3.55 (9)°. A short intra-molecular C-H⋯O contact is present. In the crystal, mol-ecules are linked by O-H⋯O, N-H⋯O and C-H⋯O hydrogen bonds and π-π inter-actions [centroid-to-centroid distance = 3.5822 (11) Å], forming a three-dimensional structure.