The Se-Se bond in diaryl diselenides was reduced by Zn/ZrCl4 system to produce selenide anions, which react with acyl chlorides or acid anhydrides to afford selenoesters in THF under mild and neutral conditions.
采用综合热分析仪研究了碱式碳酸锆在空气气氛中热分解非等温动力学,热分解升温速率分别为10℃/min、20℃/min、30℃/min,根据固相反应动力学理论及TG-DTG数据,计算其动力学参数.采用Kissinger-Akah-Sunose方程与Flynn-Wall-Ozawa方程...采用综合热分析仪研究了碱式碳酸锆在空气气氛中热分解非等温动力学,热分解升温速率分别为10℃/min、20℃/min、30℃/min,根据固相反应动力学理论及TG-DTG数据,计算其动力学参数.采用Kissinger-Akah-Sunose方程与Flynn-Wall-Ozawa方程及应用最小二乘法进行线性回归推导了其最可几机理函数.结果表明,碱式碳酸锆非等温热分解分为四阶段,第Ⅰ阶段表观活化能为94.963 k J/mol,指前因子为27.407 6~27.864 1,最可机理函数为NO.27,随机成核和随后生长机制;第Ⅱ阶段表观活化能为309.781 k J/mol,指前因子为57.730 4~58.873 6,最可几机理函数为NO.28,随机成核和随后生长机制;第Ⅲ阶段表观活化能为362.591 k J/mol,指前因子为53.268 8~55.034 6,最可理机函数为NO.21,化学反应机制.为以碱式碳酸锆作为原料热分解制备纳米氧化锆粉体及碳酸锆铵、碳酸锆钾等衍生化合物提供了理论依据.展开更多
Association of Alzheimer's disease(AD) with cerebral glucose hypometabolism, likely due to impairments of insulin signaling,has been reported recently, with encouraging results when additional insulin is provided ...Association of Alzheimer's disease(AD) with cerebral glucose hypometabolism, likely due to impairments of insulin signaling,has been reported recently, with encouraging results when additional insulin is provided to AD patients. Here, we tested the potential effects of the anti-diabetic vanadium, vanadyl(IV) acetylacetonate(VAC), on AD in vitro and in vivo models. The experimental results showed that VAC at sub-micromolar concentrations improved the viability of neural cells with or without increased β-amyloid(Aβ) burden; and in APP/PS1 transgenic mice, VAC treatment(0.1 mmol kg-1 d-1) preserved cognitive function and attenuated neuron loss, but did not reduce brain Aβ plaques. Further studies revealed that VAC attenuated Aβpathogenesis by(i) activation of the PPARγ-AMPK signal transduction pathway, leading to improved glucose and energy metabolism;(ii) up-regulation of the expression of glucose-regulated protein 75(Grp75), thus suppressing p53-mediated neuronal apoptosis under Aβ-related stresses; and(iii) decreasing toxic soluble Aβ peptides. Overall, our work suggested that vanadyl complexes may have great potential for effective therapeutic treatment of AD.展开更多
文摘The Se-Se bond in diaryl diselenides was reduced by Zn/ZrCl4 system to produce selenide anions, which react with acyl chlorides or acid anhydrides to afford selenoesters in THF under mild and neutral conditions.
文摘采用综合热分析仪研究了碱式碳酸锆在空气气氛中热分解非等温动力学,热分解升温速率分别为10℃/min、20℃/min、30℃/min,根据固相反应动力学理论及TG-DTG数据,计算其动力学参数.采用Kissinger-Akah-Sunose方程与Flynn-Wall-Ozawa方程及应用最小二乘法进行线性回归推导了其最可几机理函数.结果表明,碱式碳酸锆非等温热分解分为四阶段,第Ⅰ阶段表观活化能为94.963 k J/mol,指前因子为27.407 6~27.864 1,最可机理函数为NO.27,随机成核和随后生长机制;第Ⅱ阶段表观活化能为309.781 k J/mol,指前因子为57.730 4~58.873 6,最可几机理函数为NO.28,随机成核和随后生长机制;第Ⅲ阶段表观活化能为362.591 k J/mol,指前因子为53.268 8~55.034 6,最可理机函数为NO.21,化学反应机制.为以碱式碳酸锆作为原料热分解制备纳米氧化锆粉体及碳酸锆铵、碳酸锆钾等衍生化合物提供了理论依据.
基金supported by National Natural Science Foundation of China (21571006, 21771010)Beijing Municipal Science & Technology Commission (A61120-01)the "Strategic Priority Research Program" of the Chinese Academy of Sciences (XDA 12040101)
文摘Association of Alzheimer's disease(AD) with cerebral glucose hypometabolism, likely due to impairments of insulin signaling,has been reported recently, with encouraging results when additional insulin is provided to AD patients. Here, we tested the potential effects of the anti-diabetic vanadium, vanadyl(IV) acetylacetonate(VAC), on AD in vitro and in vivo models. The experimental results showed that VAC at sub-micromolar concentrations improved the viability of neural cells with or without increased β-amyloid(Aβ) burden; and in APP/PS1 transgenic mice, VAC treatment(0.1 mmol kg-1 d-1) preserved cognitive function and attenuated neuron loss, but did not reduce brain Aβ plaques. Further studies revealed that VAC attenuated Aβpathogenesis by(i) activation of the PPARγ-AMPK signal transduction pathway, leading to improved glucose and energy metabolism;(ii) up-regulation of the expression of glucose-regulated protein 75(Grp75), thus suppressing p53-mediated neuronal apoptosis under Aβ-related stresses; and(iii) decreasing toxic soluble Aβ peptides. Overall, our work suggested that vanadyl complexes may have great potential for effective therapeutic treatment of AD.
