Background : This study examined the ameliorative effect of D-3-O-methylchiroinositol, isolated from the stem bark of Piliostigma thonningii, on cadmium chloride-induced osteoporosis in male Wistar rats. Methods : Thi...Background : This study examined the ameliorative effect of D-3-O-methylchiroinositol, isolated from the stem bark of Piliostigma thonningii, on cadmium chloride-induced osteoporosis in male Wistar rats. Methods : Thirty-six rats were assigned to three treatment groups(n = 12). Group A(2 mL distilled water), group B:(2.5 mg/kg b.w. CdCl_2) and group C:(2.5 mg/kg b.w. CdCl_2 and D-3-O-methyl-chiroinositol 2 mg/kg b.w.). Bone ash, calcium, phosphate, magnesium, and zinc content, as well as bone histological changes were determined at the end of months 1, 2, and 3. Results : There were significant differences( P ≤ 0.05) in the weight of the cervical, tibia, and femoral bones in all groups. The serum concentration of CdCl_2 was significantly different across the three groups with time. There was significant variation( P < 0.005) in the mean bone ash across groups. The concentration of OH-proline was significantly different( P < 0.0001) across groups. There were significant differences( P < 0.0001) in bone calcium, magnesium, zinc, and phosphorus concentrations. Histology revealed high levels of bone mineralisation in the CdCl_2-treated group, indicative of osteoporosis with hypertrophied osteocytes, while the femur of Wistar rats treated with D-3-O-methyl-chiroinositol showed bone trabeculae and viable osteocytes. Conclusion : The study concluded that D-3-O-methyl-chiroinositol extract from Piliostigma thionningii stem bark ameliorated cadmium chloride-induced osteoporosis in male Wistar rats.展开更多
LiNi0.8Co0.1Mn0.1O2 was prepared by a chloride co-precipitation method and characterized by thermogravimetric analysis, X-ray diffractometry with Rietveld refinement,electron scanning microscopy and electrochemical me...LiNi0.8Co0.1Mn0.1O2 was prepared by a chloride co-precipitation method and characterized by thermogravimetric analysis, X-ray diffractometry with Rietveld refinement,electron scanning microscopy and electrochemical measurements.Effects of lithium ion content and sintering temperature on physical and electrochemical performance of LiNi0.8Co0.1Mn0.1O2 were also investigated. The results show that the sample synthesized at 750℃with 105%lithium content has fine particle sizes around 200 nm and homogenous sizes distribution.The initial discharge capacity for the powder is 184 mA·h/g between 2.7 and 4.3 V at 0.1C and room temperature.展开更多
N-Trimethylsilylvaline trimethylsilyl ester IIa, N-triethylsilylvaline triethylsilyl ester IIb and N-tert-butyldimethylsilylvaline tert-butyldimethylester IIc showed evidently different reactivities with O,O'-phen...N-Trimethylsilylvaline trimethylsilyl ester IIa, N-triethylsilylvaline triethylsilyl ester IIb and N-tert-butyldimethylsilylvaline tert-butyldimethylester IIc showed evidently different reactivities with O,O'-phenylenephosphorylchloride The formation speed of the fmal spiro-bicyclic pentacoordinated phosphorus compounds IV depends on the intramolecular transfer ability of the silyl moiety crucially展开更多
The electrochemical characteristics of Ta2O5-IrO2 electrodes prepared from different chemical compositions and coating methods were observed by using cyclic voltammetry, potentiostatic polarization, galvanostatic pola...The electrochemical characteristics of Ta2O5-IrO2 electrodes prepared from different chemical compositions and coating methods were observed by using cyclic voltammetry, potentiostatic polarization, galvanostatic polarization and scanning electron microscopy. The efficiency for chloride oxidation and oxygen evolution processes was not only influenced by the chemical composition but also by the surface morphology of the oxide electrode which was susceptible to the ratio of the two components and the coating method. Ta2O5(50)-IrO2(50) electrodes revealed the highest catalytic activity for the chloride ion oxidation and oxygen evolution reaction because they had the largest effective surface area. The durability of the oxide electrodes in the accelerated life tests was improved as the thickness of the oxide layer increased and the ratio of [IrO2] to [Ta2O5] approached 80/20.展开更多
A ternary complex [Sm(o-NBA)3phen]2 (o-NBA: o-Nitrobenzoate; phen: 1,10-phenanthroline) was synthesized and characterized by elemental analysis, IR, molar conductance, and thermogravimetric analysis. The dissolution e...A ternary complex [Sm(o-NBA)3phen]2 (o-NBA: o-Nitrobenzoate; phen: 1,10-phenanthroline) was synthesized and characterized by elemental analysis, IR, molar conductance, and thermogravimetric analysis. The dissolution enthalpies of SmCl3·6H2O(s), o-HNBA(s) and phen·H2O(s) in mixed solvent (VHCl :VDMF :VDMSO=2:2:1) were determined by calorimetry at 298.15 K. The enthalpy change of the reaction was determined to be rHmΔ θ=252.49±1.60 kJ/mol. Using the relevant data in the literature and a thermochemical recycle...展开更多
A ternary solid complex Yb（Et2dtc）3（phen） was obtained from the reaction of hydrous ytterbium chloride with sodium diethyldithiocarbamate （NaEt2dtc）, and 1, 10-phenanthroline （o-phen·H2O） in absolute etha...A ternary solid complex Yb（Et2dtc）3（phen） was obtained from the reaction of hydrous ytterbium chloride with sodium diethyldithiocarbamate （NaEt2dtc）, and 1, 10-phenanthroline （o-phen·H2O） in absolute ethanol. The bonding characteristics of the complex were characterized by IR. The result shows Yb3^＋ bands with two sulfur atoms in the Na（Et2dtc）3 and two nitrogen atoms in the o-phen. The enthalpy change of liquid-phase reaction of formation of the complex △rHm^θ（Ⅰ）, was determined as being （-24.838±0.114） kJ·mol^-1 at 298.15 K, by an RD-496 Ⅲ type heat conduction microcalormeter. The enthalpy change of the solid-phase reaction of formation of the complex △rHm^θ（s）, was calculated as being （108.015±0.479） kJ·mol^-1 on the basis of an appropriate thermochemistry cycle. The thermodynamics of liquid-phase reaction of formation of the complex was investigated by changing the temperature during the liquid-phase reaction. Fundamental parameters, the activation enthalpy, △H≠^θ, the activation entropy, △S≠^θ, the activation free energy,△G≠^θ, the apparent reaction rate constant k, the apparent activation energy E, the pre-exponential constant A, and the reaction order n, were obtained by a combination of the reaction thermodynamic and kinetic equations with the data from the thermokinetic expenments. At the same time, the molar heat capacity of the complex cm. p, Was determined to be （86.34± 1.74） J·mol^-1·K^-1 by the same microcalormeter. The constant-volume combus- tion energy of the complex, △cU, was determined to be （ - 17954.08 ± 8.11） kJ·mol^-1 by an RBC-Ⅱ type rotating-bomb calo- rimeter at 298.15 K. Its standard enthalpy of combustion, △cHm^θ, and standard enthalpy of formation, △fHm^θ, were calculated to be （- 17973.29±8.11） kJ·mol^-1 and （-770.36±9.02） kJ·mol^-1, respectively.展开更多
A novel ternary solid complex, Yb （C5H8NS2）3 （C12H8N2）, was obtained from treating hydrous ytterbium chloride, ammonium pyrrolidin- edithiocarbamate （ APDC ） and 1, 10-phenanthroline （o-phen· H2O） in abso...A novel ternary solid complex, Yb （C5H8NS2）3 （C12H8N2）, was obtained from treating hydrous ytterbium chloride, ammonium pyrrolidin- edithiocarbamate （ APDC ） and 1, 10-phenanthroline （o-phen· H2O） in absolute ethanol, and characterized by elemental analysis. The enthalpies of solution of hydrous ytterbium chloride, APDC, o-phen·H2O, the mixture of APDC with o-phen· H2O in absolute ethanol at 298. 15 K, and the enthalpy changes of liquid- phase reaction of formation for Yb （ C5H8NS2 ）3 （ C12H8N2） at different temperatures were measured by using a RD496-Ⅲ microcalorimeter. Fundamental paconduction microcalorimeter, determining the specific heat a calculation model for capacity of solid subrameters, the activation enthalpy （ΔH≠^θ）, the activation entropy （ΔS≠^θ）, the activation free energy （ΔG≠^θ）, the apparent reaction rate constant （k）, the apparent activation energy （ E ）, the pre-exponential constant （A） and the reaction order （n）, were obtained by the combination of the thermochemical data of the reaction and kinetic equations with the data of thermokinetic experiments. The enthalpy change of complex formation from the reaction of the regents in solid phase, ΔrH≠^θ（s）, was calculated on the basis of an appropriate thermochemical cycle and other auxiliary thermodynamic data. Based on a RD496-Ⅲ heat stance was developed, and the title complex, c m, were accordingly determined.展开更多
The work is a study of the influence of Ca2+ (0.01 - 1 mM) on neuronal CI-, HCO3-, -ATPase complex: an enzyme that is a CI--pump which is functionally and structurally coupled to GABAA-receptors. It is found that infl...The work is a study of the influence of Ca2+ (0.01 - 1 mM) on neuronal CI-, HCO3-, -ATPase complex: an enzyme that is a CI--pump which is functionally and structurally coupled to GABAA-receptors. It is found that influence of Ca2+ on the multifunctional complex starts at concentration of 50·M and at concentration of 0.1 mM, it reduces the “basal” one and increases the CI-, HCO3-, -stimulated Mg2+-ATPase activities. GABA (0.1 - 100μM) activates the “basal” Mg2+-ATPase activity in the ab-sence of calcium. The effect of GABA on the enzyme in the presence of 0.01 ·M Ca2+ does not change. At the same time, 1 mM Ca2+eliminates the GABA effect on the “basal” Mg2+-ATPase activity. Competitive blocker of GABAA-receptors bicuculline (5 - 20 μM) in the absence of Ca2+ ions elimi-nates the stimulation of the “basal” Mg2+-ATPase by anions. When 0.25 mM Ca2+ is added to the in-cubation medium the inhibitory bicuculline effect on the enzyme does not appear. We found that 0.1 mM o-vanadate (protein tyrosine phosphatase blocker) reduces the GABA-activated ATPase activity. At the same time, 0.1 mM genistein (a protein tyrosine kinase blocker) has no effect on enzyme activity. In the presence of Ca2+ (0.25 mM), the effect of o-vanadate on the “basal” and CI-, HCO3-, -ATPase activities does not appear. It is shown for the first time that high concentrations of Ca2+prevent the action of GABAA-ergic ligands on the study ATPase. It is assumed that there is the involvement of protein kinases and protein phosphatases in the modulation of the enzyme activity by calcium. The observed effect of calcium on the ATPase may play an important role in the study of the mechanisms of epileptogenesis and seizure activity.展开更多
文摘Background : This study examined the ameliorative effect of D-3-O-methylchiroinositol, isolated from the stem bark of Piliostigma thonningii, on cadmium chloride-induced osteoporosis in male Wistar rats. Methods : Thirty-six rats were assigned to three treatment groups(n = 12). Group A(2 mL distilled water), group B:(2.5 mg/kg b.w. CdCl_2) and group C:(2.5 mg/kg b.w. CdCl_2 and D-3-O-methyl-chiroinositol 2 mg/kg b.w.). Bone ash, calcium, phosphate, magnesium, and zinc content, as well as bone histological changes were determined at the end of months 1, 2, and 3. Results : There were significant differences( P ≤ 0.05) in the weight of the cervical, tibia, and femoral bones in all groups. The serum concentration of CdCl_2 was significantly different across the three groups with time. There was significant variation( P < 0.005) in the mean bone ash across groups. The concentration of OH-proline was significantly different( P < 0.0001) across groups. There were significant differences( P < 0.0001) in bone calcium, magnesium, zinc, and phosphorus concentrations. Histology revealed high levels of bone mineralisation in the CdCl_2-treated group, indicative of osteoporosis with hypertrophied osteocytes, while the femur of Wistar rats treated with D-3-O-methyl-chiroinositol showed bone trabeculae and viable osteocytes. Conclusion : The study concluded that D-3-O-methyl-chiroinositol extract from Piliostigma thionningii stem bark ameliorated cadmium chloride-induced osteoporosis in male Wistar rats.
基金Project(2007CB613607)supported by National Basic Research Program of China
文摘LiNi0.8Co0.1Mn0.1O2 was prepared by a chloride co-precipitation method and characterized by thermogravimetric analysis, X-ray diffractometry with Rietveld refinement,electron scanning microscopy and electrochemical measurements.Effects of lithium ion content and sintering temperature on physical and electrochemical performance of LiNi0.8Co0.1Mn0.1O2 were also investigated. The results show that the sample synthesized at 750℃with 105%lithium content has fine particle sizes around 200 nm and homogenous sizes distribution.The initial discharge capacity for the powder is 184 mA·h/g between 2.7 and 4.3 V at 0.1C and room temperature.
文摘N-Trimethylsilylvaline trimethylsilyl ester IIa, N-triethylsilylvaline triethylsilyl ester IIb and N-tert-butyldimethylsilylvaline tert-butyldimethylester IIc showed evidently different reactivities with O,O'-phenylenephosphorylchloride The formation speed of the fmal spiro-bicyclic pentacoordinated phosphorus compounds IV depends on the intramolecular transfer ability of the silyl moiety crucially
文摘The electrochemical characteristics of Ta2O5-IrO2 electrodes prepared from different chemical compositions and coating methods were observed by using cyclic voltammetry, potentiostatic polarization, galvanostatic polarization and scanning electron microscopy. The efficiency for chloride oxidation and oxygen evolution processes was not only influenced by the chemical composition but also by the surface morphology of the oxide electrode which was susceptible to the ratio of the two components and the coating method. Ta2O5(50)-IrO2(50) electrodes revealed the highest catalytic activity for the chloride ion oxidation and oxygen evolution reaction because they had the largest effective surface area. The durability of the oxide electrodes in the accelerated life tests was improved as the thickness of the oxide layer increased and the ratio of [IrO2] to [Ta2O5] approached 80/20.
基金supported by the National Natural Sciences Foundation of China (20773034)the Natural Science Foundation of Hebei Province (B2007000237)
文摘A ternary complex [Sm(o-NBA)3phen]2 (o-NBA: o-Nitrobenzoate; phen: 1,10-phenanthroline) was synthesized and characterized by elemental analysis, IR, molar conductance, and thermogravimetric analysis. The dissolution enthalpies of SmCl3·6H2O(s), o-HNBA(s) and phen·H2O(s) in mixed solvent (VHCl :VDMF :VDMSO=2:2:1) were determined by calorimetry at 298.15 K. The enthalpy change of the reaction was determined to be rHmΔ θ=252.49±1.60 kJ/mol. Using the relevant data in the literature and a thermochemical recycle...
文摘A ternary solid complex Yb（Et2dtc）3（phen） was obtained from the reaction of hydrous ytterbium chloride with sodium diethyldithiocarbamate （NaEt2dtc）, and 1, 10-phenanthroline （o-phen·H2O） in absolute ethanol. The bonding characteristics of the complex were characterized by IR. The result shows Yb3^＋ bands with two sulfur atoms in the Na（Et2dtc）3 and two nitrogen atoms in the o-phen. The enthalpy change of liquid-phase reaction of formation of the complex △rHm^θ（Ⅰ）, was determined as being （-24.838±0.114） kJ·mol^-1 at 298.15 K, by an RD-496 Ⅲ type heat conduction microcalormeter. The enthalpy change of the solid-phase reaction of formation of the complex △rHm^θ（s）, was calculated as being （108.015±0.479） kJ·mol^-1 on the basis of an appropriate thermochemistry cycle. The thermodynamics of liquid-phase reaction of formation of the complex was investigated by changing the temperature during the liquid-phase reaction. Fundamental parameters, the activation enthalpy, △H≠^θ, the activation entropy, △S≠^θ, the activation free energy,△G≠^θ, the apparent reaction rate constant k, the apparent activation energy E, the pre-exponential constant A, and the reaction order n, were obtained by a combination of the reaction thermodynamic and kinetic equations with the data from the thermokinetic expenments. At the same time, the molar heat capacity of the complex cm. p, Was determined to be （86.34± 1.74） J·mol^-1·K^-1 by the same microcalormeter. The constant-volume combus- tion energy of the complex, △cU, was determined to be （ - 17954.08 ± 8.11） kJ·mol^-1 by an RBC-Ⅱ type rotating-bomb calo- rimeter at 298.15 K. Its standard enthalpy of combustion, △cHm^θ, and standard enthalpy of formation, △fHm^θ, were calculated to be （- 17973.29±8.11） kJ·mol^-1 and （-770.36±9.02） kJ·mol^-1, respectively.
文摘A novel ternary solid complex, Yb （C5H8NS2）3 （C12H8N2）, was obtained from treating hydrous ytterbium chloride, ammonium pyrrolidin- edithiocarbamate （ APDC ） and 1, 10-phenanthroline （o-phen· H2O） in absolute ethanol, and characterized by elemental analysis. The enthalpies of solution of hydrous ytterbium chloride, APDC, o-phen·H2O, the mixture of APDC with o-phen· H2O in absolute ethanol at 298. 15 K, and the enthalpy changes of liquid- phase reaction of formation for Yb （ C5H8NS2 ）3 （ C12H8N2） at different temperatures were measured by using a RD496-Ⅲ microcalorimeter. Fundamental paconduction microcalorimeter, determining the specific heat a calculation model for capacity of solid subrameters, the activation enthalpy （ΔH≠^θ）, the activation entropy （ΔS≠^θ）, the activation free energy （ΔG≠^θ）, the apparent reaction rate constant （k）, the apparent activation energy （ E ）, the pre-exponential constant （A） and the reaction order （n）, were obtained by the combination of the thermochemical data of the reaction and kinetic equations with the data of thermokinetic experiments. The enthalpy change of complex formation from the reaction of the regents in solid phase, ΔrH≠^θ（s）, was calculated on the basis of an appropriate thermochemical cycle and other auxiliary thermodynamic data. Based on a RD496-Ⅲ heat stance was developed, and the title complex, c m, were accordingly determined.
文摘The work is a study of the influence of Ca2+ (0.01 - 1 mM) on neuronal CI-, HCO3-, -ATPase complex: an enzyme that is a CI--pump which is functionally and structurally coupled to GABAA-receptors. It is found that influence of Ca2+ on the multifunctional complex starts at concentration of 50·M and at concentration of 0.1 mM, it reduces the “basal” one and increases the CI-, HCO3-, -stimulated Mg2+-ATPase activities. GABA (0.1 - 100μM) activates the “basal” Mg2+-ATPase activity in the ab-sence of calcium. The effect of GABA on the enzyme in the presence of 0.01 ·M Ca2+ does not change. At the same time, 1 mM Ca2+eliminates the GABA effect on the “basal” Mg2+-ATPase activity. Competitive blocker of GABAA-receptors bicuculline (5 - 20 μM) in the absence of Ca2+ ions elimi-nates the stimulation of the “basal” Mg2+-ATPase by anions. When 0.25 mM Ca2+ is added to the in-cubation medium the inhibitory bicuculline effect on the enzyme does not appear. We found that 0.1 mM o-vanadate (protein tyrosine phosphatase blocker) reduces the GABA-activated ATPase activity. At the same time, 0.1 mM genistein (a protein tyrosine kinase blocker) has no effect on enzyme activity. In the presence of Ca2+ (0.25 mM), the effect of o-vanadate on the “basal” and CI-, HCO3-, -ATPase activities does not appear. It is shown for the first time that high concentrations of Ca2+prevent the action of GABAA-ergic ligands on the study ATPase. It is assumed that there is the involvement of protein kinases and protein phosphatases in the modulation of the enzyme activity by calcium. The observed effect of calcium on the ATPase may play an important role in the study of the mechanisms of epileptogenesis and seizure activity.
