The degradation behavior of ethyl xanthate(EX) salt was the most widely used collector in sulfide mineral flotation and emission of flotation tailings with residual EX was harmful to environment. In this work, hydroge...The degradation behavior of ethyl xanthate(EX) salt was the most widely used collector in sulfide mineral flotation and emission of flotation tailings with residual EX was harmful to environment. In this work, hydrogen peroxide(H2O2) was investigated by UV-visible spectroscopy(UV/Vis) at different p H values from 3 to 12. For p H value from 5 to 12, EX was oxidized into ethyl per xanthate(EPX) by H2O2. Then EPX was further oxidized into thiosulfate(TS) salt rather than ethyl thiocarbonate(ETC) and this step was the reaction-limited step. Then depending on p H values, TS was degraded into sulphate and carbonate salts(p H>7) or elemental sulfur(p H<7). The kinetics data show that the degradation rate of EX increases with increasing the H2O2 concentration and is independent on the p H values. Without H2O2, EX is hydrolyzed to carbon disulfide fast at p H value <3.0, but the reaction of hydrolysis is undetectable at p H value >3.0 during test time.展开更多
Changes in erythrocyte membrane ATPases and plasma lipid peroxides（LPO） were studiedperioperatively in 15 abdominal surgical patients under intravenous procaine-balanced anesthesia.The resultsrevealed that erythrocy...Changes in erythrocyte membrane ATPases and plasma lipid peroxides（LPO） were studiedperioperatively in 15 abdominal surgical patients under intravenous procaine-balanced anesthesia.The resultsrevealed that erythrocyte membrne Na<sup>+</sup>-K<sup>+</sup>ATPase,Mg<sup>2+</sup>ATPase and Ca<sup>2+</sup>-Mg<sup>2+</sup>ATPase activities werenot significantly changed at 60～90 min after incision as compared with 30 min before anesthesia,but weredecreased markedly at 10 rain and 24 hours after completion of operation（P【0.01）.Plasma LPO wereincreased significantly by 24 hours after surgery（P【0.01） following an initially marked but transientreduction.Plasma LPO changes were not correlated with erythrocyte membrane ATPase activities,r=-0.0396,-0.0097 and-0.4383 respeetively（P】0.05）.These correlations are suggested to be inducedby neuroendoerine responses after anesthesia and/or surgical trauma.展开更多
Several mixtures,based on urea derivatives and some inorganic oxidants,including also alumina,were studied by means of ballistic mortar techniques with TNT as the reference standard.The detonation pressure(P),detonati...Several mixtures,based on urea derivatives and some inorganic oxidants,including also alumina,were studied by means of ballistic mortar techniques with TNT as the reference standard.The detonation pressure(P),detonation velocity(D),detonation energy(Q),and volume of gaseous product at standard temperature and pressure(STP),V,were calculated using EXPLO5V6.3 thermochemical code.The performance of the mixtures studied was discussed in relation to their thermal reactivity,determined by means of differential thermal analysis(DTA).It is shown that the presence of hydrogen peroxide in the form of its complex with urea(i.e.as UHP)has a positive influence on the explosive strength of the corresponding mixtures which is linked to the hydroxy-radical formation in the mixtures during their initiation reaction.These radicals might initiate(at least partially)powdered aluminum into oxidation in the CJ plane of the detonation wave.Mixtures containing UHP and magnesium are dangerous because of potential auto-ignition.展开更多
The thermal decomposition temperature is one of the most important parameters to evaluate fire hazard of organic peroxide. A quantitative structure-property relationship model was proposed for estimating the thermal d...The thermal decomposition temperature is one of the most important parameters to evaluate fire hazard of organic peroxide. A quantitative structure-property relationship model was proposed for estimating the thermal decomposition temperatures of organic peroxides. The entire set of 38 organic peroxides was at random divided into a training set for model development and a prediction set for external model validation. The novel local molecular descriptors of AT1, AT2, AT3, AT4, AT5, AT6 and global molecular descriptor of ATC have been proposed in order to character organic peroxides’ molecular structures. An accurate quantitative structure-property relationship （QSPR） equation is developed for the thermal decomposition temperatures of organic peroxides. The statistical results showed that the QSPR model was obtained using the multiple linear regression （MLR） method with correlation coefficient （R）, standard deviation （S）, leave-one-out validation correlation coefficient （RCV） values of 0.9795, 6.5676 ℃ and 0.9328, respectively. The average absolute relative deviation （AARD） is only 3.86% for the experimental values. Model test by internal leave-one-out cross validation and external validation and molecular descriptor interpretation were discussed. Comparison with literature results demonstrated that novel local and global descriptors were useful molecular descriptors for predicting the thermal decomposition temperatures of organic peroxides.展开更多
目的 在动物水平探讨铁死亡脂质过氧化损伤调控通路与帕金森病(Parkinson's disease, PD)的发病机制。方法 建立PD斑马鱼动物模型,取受精后48 h斑马鱼胚胎为对照组(n=100),200μmol/L的1-甲基-4-苯基-1,2,3,6-四氢吡啶(1-methyl-4-p...目的 在动物水平探讨铁死亡脂质过氧化损伤调控通路与帕金森病(Parkinson's disease, PD)的发病机制。方法 建立PD斑马鱼动物模型,取受精后48 h斑马鱼胚胎为对照组(n=100),200μmol/L的1-甲基-4-苯基-1,2,3,6-四氢吡啶(1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, MPTP)为MPTP组(n=100),200μmol/L的MPTP+1.5μg/ml诺米芬辛为诺米芬辛组(n=100)。对受精后5 d斑马鱼进行行为学分析(检测运动能力、运动速率及运动距离);免疫荧光检测斑马鱼脑内α突触核蛋白和酪氨酸羟化酶表达,评估多巴胺能神经元(dopaminergic neurons, DA)活性;检测铁、谷胱甘肽(glutathione, GSH)及脂质过氧化水平,包括过氧化氢酶(catalase, CAT)、谷胱甘肽过氧化物酶4(glutathione peroxidase 4,GPX4)、脂质过氧化物(lipid peroxide, LPO)、丙二醛、活性氧,验证铁沉积可能通过铁死亡的脂质过氧化代谢调控机制引起DA损伤。结果 与对照组比较,MPTP组运动速率和运动距离明显降低,差异有统计学意义(P<0.01);与MPTP组比较,诺米芬辛组运动速率和运动距离明显升高,差异有统计学意义(P<0.01)。免疫荧光检测显示,与对照组比较,MPTP组DA损伤明显增加,诺米芬辛组DA损伤明显轻于MPTP组。各组CAT水平比较,差异无统计学意义(P>0.05)。与对照组比较,MPTP组铁、LPO和丙二醛水平明显升高,GSH、GPX4水平明显降低,差异有统计学意义(838.18±143.42 vs 478.53±112.58,P<0.05;1.71±0.11 vs 1.48±0.14,P<0.05;4.50±0.64 vs 4.23±0.13,P<0.05;38.93±1.72 vs 45.97±2.32,P<0.05;0.17±0.03 vs 0.39±0.04,P<0.05);与MPTP组比较,诺米芬辛组GSH、GPX4水平明显升高,铁、LPO水平明显降低,差异有统计学意义(40.79±1.02 vs 38.93±1.72,P<0.05;0.26±0.05 vs 0.17±0.03,P<0.05;326.75±110.95 vs 838.18±143.42,P<0.05;1.01±0.27 vs 1.71±0.11,P<0.05)。活性氧流式细胞检测结果显示,对照组、MPTP组及诺米芬辛组活性氧阳性细胞占比分别为直方图:31.6%、46.2%、31.3%,散点图:62.4%、73.0%、65.7%。结论 在MPTP诱导的斑马鱼基础上,PD斑马鱼存在铁死亡。从动物水平阐明铁沉积引起DA损伤与铁死亡脂质过氧化代谢机制有关。展开更多
基金Project(2013AA064102)supported by the National High Technology Research and Development Program of ChinaProject(B14034)supported by the Program of Introducing Talents of Discipline to Universities,ChinaProject supported by the 2011 Collaborative Innovation Center for Clean and Efficient utilization of Strategic Metal Mineral Resources,China
文摘The degradation behavior of ethyl xanthate(EX) salt was the most widely used collector in sulfide mineral flotation and emission of flotation tailings with residual EX was harmful to environment. In this work, hydrogen peroxide(H2O2) was investigated by UV-visible spectroscopy(UV/Vis) at different p H values from 3 to 12. For p H value from 5 to 12, EX was oxidized into ethyl per xanthate(EPX) by H2O2. Then EPX was further oxidized into thiosulfate(TS) salt rather than ethyl thiocarbonate(ETC) and this step was the reaction-limited step. Then depending on p H values, TS was degraded into sulphate and carbonate salts(p H>7) or elemental sulfur(p H<7). The kinetics data show that the degradation rate of EX increases with increasing the H2O2 concentration and is independent on the p H values. Without H2O2, EX is hydrolyzed to carbon disulfide fast at p H value <3.0, but the reaction of hydrolysis is undetectable at p H value >3.0 during test time.
文摘Changes in erythrocyte membrane ATPases and plasma lipid peroxides（LPO） were studiedperioperatively in 15 abdominal surgical patients under intravenous procaine-balanced anesthesia.The resultsrevealed that erythrocyte membrne Na<sup>+</sup>-K<sup>+</sup>ATPase,Mg<sup>2+</sup>ATPase and Ca<sup>2+</sup>-Mg<sup>2+</sup>ATPase activities werenot significantly changed at 60～90 min after incision as compared with 30 min before anesthesia,but weredecreased markedly at 10 rain and 24 hours after completion of operation（P【0.01）.Plasma LPO wereincreased significantly by 24 hours after surgery（P【0.01） following an initially marked but transientreduction.Plasma LPO changes were not correlated with erythrocyte membrane ATPase activities,r=-0.0396,-0.0097 and-0.4383 respeetively（P】0.05）.These correlations are suggested to be inducedby neuroendoerine responses after anesthesia and/or surgical trauma.
基金supported by means of the financial resources of Students Grant Projects No.SGSFCHT_2016002 of the Faculty of Chemical Technology at the University of Pardubice
文摘Several mixtures,based on urea derivatives and some inorganic oxidants,including also alumina,were studied by means of ballistic mortar techniques with TNT as the reference standard.The detonation pressure(P),detonation velocity(D),detonation energy(Q),and volume of gaseous product at standard temperature and pressure(STP),V,were calculated using EXPLO5V6.3 thermochemical code.The performance of the mixtures studied was discussed in relation to their thermal reactivity,determined by means of differential thermal analysis(DTA).It is shown that the presence of hydrogen peroxide in the form of its complex with urea(i.e.as UHP)has a positive influence on the explosive strength of the corresponding mixtures which is linked to the hydroxy-radical formation in the mixtures during their initiation reaction.These radicals might initiate(at least partially)powdered aluminum into oxidation in the CJ plane of the detonation wave.Mixtures containing UHP and magnesium are dangerous because of potential auto-ignition.
基金Project(2015SK20823) supported by Science and Technology Project of Hunan Province,ChinaProject(15A001) supported by Scientific Research Fund of Hunan Provincial Education Department,China+2 种基金Project(2017CL06) supported by Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation,ChinaProject(k1403029-11) supported by Science and Technology Project of Changsha City,ChinaProject(CX2015B372) supported by the Hunan Provincial Innovation Foundation for Postgraduate,China
文摘The thermal decomposition temperature is one of the most important parameters to evaluate fire hazard of organic peroxide. A quantitative structure-property relationship model was proposed for estimating the thermal decomposition temperatures of organic peroxides. The entire set of 38 organic peroxides was at random divided into a training set for model development and a prediction set for external model validation. The novel local molecular descriptors of AT1, AT2, AT3, AT4, AT5, AT6 and global molecular descriptor of ATC have been proposed in order to character organic peroxides’ molecular structures. An accurate quantitative structure-property relationship （QSPR） equation is developed for the thermal decomposition temperatures of organic peroxides. The statistical results showed that the QSPR model was obtained using the multiple linear regression （MLR） method with correlation coefficient （R）, standard deviation （S）, leave-one-out validation correlation coefficient （RCV） values of 0.9795, 6.5676 ℃ and 0.9328, respectively. The average absolute relative deviation （AARD） is only 3.86% for the experimental values. Model test by internal leave-one-out cross validation and external validation and molecular descriptor interpretation were discussed. Comparison with literature results demonstrated that novel local and global descriptors were useful molecular descriptors for predicting the thermal decomposition temperatures of organic peroxides.
文摘目的 在动物水平探讨铁死亡脂质过氧化损伤调控通路与帕金森病(Parkinson's disease, PD)的发病机制。方法 建立PD斑马鱼动物模型,取受精后48 h斑马鱼胚胎为对照组(n=100),200μmol/L的1-甲基-4-苯基-1,2,3,6-四氢吡啶(1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, MPTP)为MPTP组(n=100),200μmol/L的MPTP+1.5μg/ml诺米芬辛为诺米芬辛组(n=100)。对受精后5 d斑马鱼进行行为学分析(检测运动能力、运动速率及运动距离);免疫荧光检测斑马鱼脑内α突触核蛋白和酪氨酸羟化酶表达,评估多巴胺能神经元(dopaminergic neurons, DA)活性;检测铁、谷胱甘肽(glutathione, GSH)及脂质过氧化水平,包括过氧化氢酶(catalase, CAT)、谷胱甘肽过氧化物酶4(glutathione peroxidase 4,GPX4)、脂质过氧化物(lipid peroxide, LPO)、丙二醛、活性氧,验证铁沉积可能通过铁死亡的脂质过氧化代谢调控机制引起DA损伤。结果 与对照组比较,MPTP组运动速率和运动距离明显降低,差异有统计学意义(P<0.01);与MPTP组比较,诺米芬辛组运动速率和运动距离明显升高,差异有统计学意义(P<0.01)。免疫荧光检测显示,与对照组比较,MPTP组DA损伤明显增加,诺米芬辛组DA损伤明显轻于MPTP组。各组CAT水平比较,差异无统计学意义(P>0.05)。与对照组比较,MPTP组铁、LPO和丙二醛水平明显升高,GSH、GPX4水平明显降低,差异有统计学意义(838.18±143.42 vs 478.53±112.58,P<0.05;1.71±0.11 vs 1.48±0.14,P<0.05;4.50±0.64 vs 4.23±0.13,P<0.05;38.93±1.72 vs 45.97±2.32,P<0.05;0.17±0.03 vs 0.39±0.04,P<0.05);与MPTP组比较,诺米芬辛组GSH、GPX4水平明显升高,铁、LPO水平明显降低,差异有统计学意义(40.79±1.02 vs 38.93±1.72,P<0.05;0.26±0.05 vs 0.17±0.03,P<0.05;326.75±110.95 vs 838.18±143.42,P<0.05;1.01±0.27 vs 1.71±0.11,P<0.05)。活性氧流式细胞检测结果显示,对照组、MPTP组及诺米芬辛组活性氧阳性细胞占比分别为直方图:31.6%、46.2%、31.3%,散点图:62.4%、73.0%、65.7%。结论 在MPTP诱导的斑马鱼基础上,PD斑马鱼存在铁死亡。从动物水平阐明铁沉积引起DA损伤与铁死亡脂质过氧化代谢机制有关。
