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Oxidative Stress and Apoptotic Changes of Rat Cerebral Cortical Neurons Exposed to Cadmium in Vitro

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Biomedical and Environmental Sciences 2012年第2期25卷 172-181页

作者： YUAN Yan BIAN jian Chun LIU Xue Zhong ZHANG Ying SUN Ya LIU Zong ping College of Veterinary Medicine Yangzhou UniversityYangzhou 225009JiangsuChina

Objective To investigate the cytotoxic mechanism of cadmium（Cd） on cerebral cortical *** The primary cultures of rat cerebral cortical neurons were treated with different concentrations of cadmium acetate（0,5,10,and 20 μmol/L）,and then the cell viability,apoptosis,ultrastructure,intracellular [Ca2＋]i and reactive oxygen species（ROS） levels,mitochondrial membrane potential（ΔΨ）,activities of catalase（CAT） and superoxide dismutase（SOD） were *** A progressive loss in cell viability and an increased number of apoptotic cells were *** addition,Cd-induced apoptotic morphological changes in cerebral cortical neurons were also demonstrated by Hoechst 33258 ***,ultrastructural changes were distortion of mitochondrial cristae and an unusual ***,elevation of intracellular [Ca2＋]i and ROS levels,depletion of ΔΨ were revealed in a dose-dependent manner during the ***,CAT and SOD activities in the living cells increased *** Exposure of cortical neurons to different doses of Cd led to cellular death,mediated by an apoptotic mechanism,and the apoptotic death induced by oxidative stress may be a potential *** the disorder of intracellular homeostasis caused by oxidative stress and mitochondrial dysfunction may be a trigger for apoptosis in cortical neurons.

关键词： Cadmium Apoptosis Oxidative stress Cerebral cortical neurons

不匹配不确定性系统的近似变结构输出跟踪控制

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控制与决策 2001年第1期16卷 25-28页

作者：胡剑波褚健苏宏业浙江大学工业控制技术国家重点实验室先进控制研究所浙江杭州310027

针对一类具有不匹配不确定性的非线性系统 ,提出一种结合变结构控制方法及自适应控制方法输出跟踪控制器。首先提出一种保证不确定性系统跟踪误差指数稳定的近似变结构控制器 ;进而得到一种具有不确定性范数上界估计能力的自适应近似变... 详细信息

针对一类具有不匹配不确定性的非线性系统 ,提出一种结合变结构控制方法及自适应控制方法输出跟踪控制器。首先提出一种保证不确定性系统跟踪误差指数稳定的近似变结构控制器 ;进而得到一种具有不确定性范数上界估计能力的自适应近似变结构控制器。

关键词：近似变结构控制自适应控制不确定性输出跟踪非线性系统

Does antecolic reconstruction for duodenojejunostomy improve delayed gastric emptying after pylorus-preserving pancreaticoduodenectomy? A systematic review and meta-analysis

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World Journal of Gastroenterology 2012年第43期18卷 6315-6323页

作者： An-ping Su Shuang-Shuang Cao Yi Zhang Zhao-Da Zhang Wei-Ming Hu bo-Le Tian Department of Hepatobiliopancreatic Surgery West China Hospital Sichuan University Chengdu 610041 Sichuan Province China

AIM:To evaluate whether antecolic reconstruction for duodenojejunostomy (DJ) can decrease delayed gastric emptying (DGE) rate after pylorus-preserving pancreaticoduodenectomy (PPPD) through literature review and meta-analysis. METHODS:Articles published between January 1991 and April 2012 comparing antecolic and retrocolic reconstruction for DJ after PPPD were retrieved from the databases of MEDLINE (PubMed), EMBASE, OVID and Cochrane Library Central. The primary outcome of interest was DGE. Either fixed effects model or random effects model was used to assess the pooled effect based on the heterogeneity. RESULTS:Five articles were identified for inclusion:two randomized controlled trials and three non-randomized controlled trials. The meta-analysis revealed that antecolic reconstruction for DJ after PPPD was associated with a statistically significant decrease in the incidence of DGE [odds ratio (OR), 0.06; 95% CI, 0.02-0.17; P < 0.00 001] and intra-operative blood loss [mean difference (MD), -317.68; 95% CI, -416.67 to -218.70; P < 0.00 001]. There was no significant difference between the groups of antecolic and retrocolic reconstruction in operative time (MD, 25.23; 95% CI, -14.37 to 64.83; P = 0.21), postoperative mortality, overall morbidity (OR, 0.54; 95% CI, 0.20-1.46; P = 0.22) and length of postoperative hospital stay (MD, -9.08; 95% CI, -21.28 to 3.11; P = 0.14). CONCLUSION:Antecolic reconstruction for DJ can decrease the DGE rate after PPPD.

关键词： Pylorus-preserving pancreaticoduodenectomy Delayed gastric emptying Antecolic reconstruction Retrocolic reconstruction Duodenojejunostomy

运输能力约束条件下的旅客出行选择Logit模型

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长安大学学报（自然科学版） 2024年第2期44卷 115-122页

作者：陈波赵春剑长安大学运输工程学院陕西西安710064

为了提升旅客运输通道交通需求预测的准确性,针对现有旅客出行选择模型未充分考虑交通方式运输能力约束的不足,在深入分析旅客出行选择机理和运输能力约束机制的基础上,通过经典多项Logit(MNL)模型效用函数的优化设计,引入惩罚因子表征... 详细信息

为了提升旅客运输通道交通需求预测的准确性,针对现有旅客出行选择模型未充分考虑交通方式运输能力约束的不足,在深入分析旅客出行选择机理和运输能力约束机制的基础上,通过经典多项Logit(MNL)模型效用函数的优化设计,引入惩罚因子表征运输能力对旅客出行选择的约束,建立运输能力约束条件下的旅客出行选择Logit模型(约束MNL模型),并设计模型求解算法预测各交通方式的分担率。以西宝(西安—宝鸡)客运通道为对象进行实例分析,通过2种MNL模型预测结果的对比分析,验证约束MNL模型预测性能的优越性。研究结果表明:在旅客出行选择过程中,交通方式运输能力的约束具有普遍性,是有效交通需求预测不可忽略的重要因素,约束MNL模型考虑了运输能力对旅客出行选择的影响,更符合旅客出行选择的决策过程,从机理上为提升交通需求预测的准确性提供了可靠保障;惩罚因子反映了运输能力约束对旅客出行选择的影响,代表了运输能力约束条件下运输服务质量的下降和旅客出行效用的损失;通过惩罚因子的合理赋值,建立旅客出行选择概率重新分配机制,能有效模拟旅客出行方式的转换、控制旅客出行选择的概率;与传统MNL模型相比,约束MNL模型表现出了更优异的预测性能,能始终将预测结果控制在由运输能力决定的分担率上限范围内,预测结果符合实际、科学有效,能够为旅客运输通道的网络布局优化、运输组织设计等提供可靠数据支持。

关键词：交通工程运输通道 Logit模型运输能力惩罚因子

Effect of graphitization degree of fuel cell gas diffusion layers on their heat management:Modeling and experiments

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Journal of Central South University 2022年第1期29卷 80-88页

作者： WU Xiao-bo YANG Piao-piao GAO ping-ping LIU Chun-xuan XIE Zhi-yong HUANG Qi-zhong College of Metallurgy and Materials Engineering Hunan University of TechnologyZhuzhou 412007China State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China Hunan Gold Sky Aluminum Industry High-Tech Co. Ltd.Changsha 410083China

Serving as gas diffusion layers(GDLs),the thermal conductivity of carbon paper(CP)plays a significant role in the heat transfer management in fuel *** the present study,the effect of graphitization degree of CP on its through plane thermal conductivity and in-plane thermal conductivity is *** relationship between heat treatment temperatures(1800,2000,2200,2400 and 2500℃)and graphitization degree is also investigated by SEM,XRD and Raman measurements.A model for CP under different graphitization degree is suggested considering the thermal conductivity difference of carbon fiber and matrix *** experimental and simulation results are *** results show that the graphitization degree has a significant impact on the through-plane thermal conductivity and in plane thermal conductivity.

关键词： through-plane thermal conductivity graphitization degree heat transfer carbon papers

Genetic Analysis and Mapping of TWH Gene in Rice Twisted Hull Mutant

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Rice science 2009年第1期16卷 79-82页

作者： LI Jin-bo XIA Ming-yuan WAN Bing-liang DU Xue-shu ZHA Zhong-ping Yu Da-zhao QI Hua-xiong Food Crops Research Institute Hubei Academy of Agricultural Sciences Wuhan 430064 China Plant Protection and Soil and Fertilizer Research Institute Hubei Academy of Agricultural Sciences Wuhan 430064 China

A mutant with twisted hulls was found in a breeding population of rice （Oryza sativa L.）. The mutant shows less grain weight and inferior grain quality in addition to twisted hulls. Genetic analysis indicated that the phenotype of mutant was controlled by a single recessive gene （temporarily designated as TW（H）. To map the TWH gene, an F2 population was generated by crossing the twh mutant to R725, an indica rice variety with normal hulls. For bulked segregant analysis, the bulk of mutant plants was prepared by mixing equal amount of plant tissue from 10 twisted-hull plants and the bulk of normal plants was obtained by pooling equal amount tissue of 10 normal-hull plants. Two hundred and seven pairs of simple sequence repeat （SSR） primers, which are distributed on 12 rice chromosomes, were used for polymorphism analysis of the parents and the two bulks. The TWH locus was initially mapped close to the SSR marker RM526 on chromosome 2. Therefore, further mapping was performed using 50 pairs of SSR primers around the marker RM526. The TWH was delimited between the SSR markers RM14128 and RM208 on the long arm of chromosome 2 at the genetic distances of 1.4 cM and 2.7 cM, respectively. These results provide the foundation for further fine mapping, cloning and functional analysis of the TWH gene.

关键词： rice twisted-hull mutant genetic analysis gene mapping

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主星带伴随分布式小卫星SAR系统效能分析

电子与信息学报 2005年第9期27卷 1345-1348页

作者：刘建平梁甸农国防科技大学电子科学与工程学院长沙410073

针对主星带伴随分布式小卫星系统效能分析中几个关键问题进行了研究。首先,根据分布式小卫星SAR 系统的任务需求,给出了系统效能评估指标体系;结合分布式小卫星轨道运行特点,建立了系统能力模型;根据系统的工作状态,建立了系统可靠性Mar... 详细信息

针对主星带伴随分布式小卫星系统效能分析中几个关键问题进行了研究。首先,根据分布式小卫星SAR 系统的任务需求,给出了系统效能评估指标体系;结合分布式小卫星轨道运行特点,建立了系统能力模型;根据系统的工作状态,建立了系统可靠性Markov模型;基于能力模型与可靠性模型,建立了主星带伴随分布式小卫星SAR 系统效能评估模型。仿真结果证明,以上模型的建立为主星带伴随分布式小卫星SAR系统效能分析以及系统参数设计提供理论依据。

关键词：分布式小卫星合成孔径需达效能分析可靠度

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基于孔隙分布模型的垫层料冻胀变形规律探讨

岩土力学 2014年第8期35卷 2179-2183,2190页

作者：袁俊平李康波何建新刘亮詹斌河海大学岩土工程科学研究所南京210098 河海大学岩土力学与堤坝工程教育部重点实验室南京210098 新疆农业大学水利与土木工程学院乌鲁木齐830052

垫层料冻胀变形过大会影响面板坝的正常使用,研究表明,垫层料冻胀变形量大小与其级配及孔隙分布有关。为了研究寒冷环境下垫层料冻胀变形机制和规律,基于土颗粒为理想球体且完全均匀分布的假定,提出了垫层料孔隙分布模型,确定了等效孔... 详细信息

垫层料冻胀变形过大会影响面板坝的正常使用,研究表明,垫层料冻胀变形量大小与其级配及孔隙分布有关。为了研究寒冷环境下垫层料冻胀变形机制和规律,基于土颗粒为理想球体且完全均匀分布的假定,提出了垫层料孔隙分布模型,确定了等效孔隙直径及等效孔隙数量的计算办法。利用单向固结仪,进行了不同孔隙尺寸和不同孔隙数量垫层料的冻融循环试验,冻胀试验结果表明:垫层料冻胀量大小随孔隙尺寸和孔隙数量变化而变化。存在一个临界孔隙尺寸,小于该尺寸的孔隙越小、小孔隙越多,冻胀量越大;反之,冻胀量越小。基于孔隙分布模型,构造定义了孔隙分布指数,发现垫层料冻胀变形量与孔隙分布指数呈线性正相关关系。研究结果可为工程设计确定合理的垫层料级配提供参考。

关键词：垫层料孔隙分布冻胀变形孔隙分布指数

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锂离子电池用Si-Mn复合电极的研究

高校化学工程学报 2006年第4期20卷 634-637页

作者：左朋建尹鸽平哈尔滨工业大学应用化学系黑龙江哈尔滨150001

利用机械球磨方法制得原子比为Si:Mn=3:5的硅-锰复合材料。利用XRD对材料进行物相分析,以锂片作为参比电极和对电极,通过充放电测试、循环伏安曲线研究了材料的电化学性能。XRD分析和电化学测试结果表明:在氩气气氛下球磨96h后所得材料... 详细信息

利用机械球磨方法制得原子比为Si:Mn=3:5的硅-锰复合材料。利用XRD对材料进行物相分析,以锂片作为参比电极和对电极,通过充放电测试、循环伏安曲线研究了材料的电化学性能。XRD分析和电化学测试结果表明:在氩气气氛下球磨96h后所得材料为Si和Mn的混合物;电极片在压制压力为10MPa条件下首次嵌锂容量为400mA·h·g-1,充放电效率为72%。对电极的热处理改善了材料的循环性能。材料的首次嵌锂容量随着热处理温度的提高而降低。电极在350℃处理后其可逆容量在第40次循环可保持在192mA·h·g-1。

关键词：锂离子电池负极材料 Si-Mn合金电化学性能