The high temperature phase a-Ba3Y(BO3)3 was synthesized by Czochralski method, and its crystal structure has been determined by single-crystal X-ray diffraction. It crystallizes in the trigonal system, space group 3R ...The high temperature phase a-Ba3Y(BO3)3 was synthesized by Czochralski method, and its crystal structure has been determined by single-crystal X-ray diffraction. It crystallizes in the trigonal system, space group 3R with a = 13.028(2), c = 9.4992(2) ? V = 1396.1(5) ?, Ba3YB3O9, Mr = 677.36, Z = 6, Dc = 4.834 g/cm3, l(MoKa) = 0.71073 ? m = 18.721 mm-1, F(000) = 1764, the final R = 0.0718 and wR = 0.1640 for 1199 observed reflections with I > 2s(I). In this structure two alternate nonequivalent Y atoms form one-dimensional chains bridged by the Ba atoms with BO3 triangles which link Y(1) and Y(2), respectively. The Ba atom is surrounded by nine O atoms belonging to six BO3 triangles.展开更多
Hyperglycemia has been identified as one of the important factors involved in the microvascular complications of diabetes, and has been related to increased cardiovascular mortality. Endothelial damage and dysfunction...Hyperglycemia has been identified as one of the important factors involved in the microvascular complications of diabetes, and has been related to increased cardiovascular mortality. Endothelial damage and dysfunction result from diabetes; therefore, the aim of this study was to determine the response of endothelial cells to stressful stimuli, modelled in normal and high glucose concentrations in vitro. EAhy 926 endothelial ceils were cultured in 5 mmol/L or 30 mmol/L glucose conditions for a 24 hour period and oxidative stress was induced by exposure to hydrogen peroxide （HzO2） or tumour necrosis factor- α （TNF- α ）, following which the protective effect of the glucocorticoid dexamethasone was assessed. Apoptosis, necrosis and cell viability were determined using an ELISA for DNA fragmentation, an enzymatic lactate dehydrogenase assay and an MTT assay, respectively. High glucose significantly increased the susceptibility of EAhy 926 cells to apoptosis in the presence of 500 gmol/L H2O2 , above that induced in normal glucose （P〈0.02）. A reduction of H2O2- and TNF- a -induced apoptosis occurred in both high and low glucose after treatment with dexamethasone （P〈0.05）. Conclusion high glucose is effective in significantly augmenting stress caused by H2O2, but not in causing stress alone. These findings suggest a mechanism by which short term hyperglycemia may facilitate and augment endothelial damage.展开更多
基金the Key Project of Science and Technology of Fujian province (2001H107) and National Natural Science Foundation of China (N0. 59972037)
文摘The high temperature phase a-Ba3Y(BO3)3 was synthesized by Czochralski method, and its crystal structure has been determined by single-crystal X-ray diffraction. It crystallizes in the trigonal system, space group 3R with a = 13.028(2), c = 9.4992(2) ? V = 1396.1(5) ?, Ba3YB3O9, Mr = 677.36, Z = 6, Dc = 4.834 g/cm3, l(MoKa) = 0.71073 ? m = 18.721 mm-1, F(000) = 1764, the final R = 0.0718 and wR = 0.1640 for 1199 observed reflections with I > 2s(I). In this structure two alternate nonequivalent Y atoms form one-dimensional chains bridged by the Ba atoms with BO3 triangles which link Y(1) and Y(2), respectively. The Ba atom is surrounded by nine O atoms belonging to six BO3 triangles.
文摘Hyperglycemia has been identified as one of the important factors involved in the microvascular complications of diabetes, and has been related to increased cardiovascular mortality. Endothelial damage and dysfunction result from diabetes; therefore, the aim of this study was to determine the response of endothelial cells to stressful stimuli, modelled in normal and high glucose concentrations in vitro. EAhy 926 endothelial ceils were cultured in 5 mmol/L or 30 mmol/L glucose conditions for a 24 hour period and oxidative stress was induced by exposure to hydrogen peroxide （HzO2） or tumour necrosis factor- α （TNF- α ）, following which the protective effect of the glucocorticoid dexamethasone was assessed. Apoptosis, necrosis and cell viability were determined using an ELISA for DNA fragmentation, an enzymatic lactate dehydrogenase assay and an MTT assay, respectively. High glucose significantly increased the susceptibility of EAhy 926 cells to apoptosis in the presence of 500 gmol/L H2O2 , above that induced in normal glucose （P〈0.02）. A reduction of H2O2- and TNF- a -induced apoptosis occurred in both high and low glucose after treatment with dexamethasone （P〈0.05）. Conclusion high glucose is effective in significantly augmenting stress caused by H2O2, but not in causing stress alone. These findings suggest a mechanism by which short term hyperglycemia may facilitate and augment endothelial damage.
