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Catalytic spectrophotometric determination of trace selenium in microemulsion after separation and enrichment by SDG

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Rare Metals 2006年第3期25卷 281-286页

作者： li huizhi ZHAI Diantang FAN Yingju School of Chemistry and Chemical Engineering Jinan University Jinan 250022 China

A new catalytic spectrophotometric method was developed for the determination of trace amount of Se（Ⅳ） in microemulsion medium. The method is based on the catalytic effect of traces of Se（Ⅳ） on the oxidation of 2＇,4＇-dichlorophenylfluomne （p-CPF） by potassium bromate with HNO3 as an activator in the presence of nonionic microemulsion medium. Under optimum conditions, the calibration graph is linear in the range of 0.4-15 μg·L^-1 of Se（Ⅳ） at 480 nm. The detection limit achieved is 9.86 × 10^-10μg·L^-1. Samples were dissolved and the obtained trace Se（Ⅳ） was separated and enriched by sulphydryl dextrane gel （SDG）. The method has been applied for determination of trace selenium with satisfactory results.

关键词： analytical chemistry Se(Ⅳ) catalytic spectrophotometric microemulsion medium separation enrichment

An acetylcholinesterase inhibitor, 3-benzidino-5-methyl-6-phenylpyridazine, blocking outward potassium currents in acutely isolated rat hippocampal pyramidal neurons

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Chinese Science Bulletin 2009年第2期54卷 212-219页

作者： DU huizhi li MiaoYu YANG Pin Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education Institute of Molecular Science Shanxi University Taiyuan 030006 China

3-benzidino-5-methyl-6-phenylpyridazine (BMP) inhibited electric eel acetylcholinesterase (AChE), with IC50 being 0.58 μmol·L-1. As an AChE inhibitor, the effects of BMP on delayed rectifier potassium current (IK(DR)) and transient outward potassium current (IK(A)) in acutely isolated rat hippocampal pyramidal neurons were studied using the whole cell patch-clamp technique. BMP (0.1―50 μmol·L-1) inhibited IK(DR) and IK(A) in a concentration-dependent and voltage-independent manner. The IC50 value for the blocking action of BMP on IK(DR) and IK(A) was calculated to be 2.92 and 2.11 μmol·L-1, respectively. At the concentration of 10 μmol·L-1, BMP shifted the activation curve of IK(DR) to negative potential by 8.85 mV. Meanwhile, at the concentration of 10 μmol·L-1, BMP also shifted the activation and the steady-state inactivation curve of IK(A) to negative potential by 5.82 mV and 10.02 mV, respectively. In conclusion, BMP potently inhibits IK(DR) and IK(A) in rat hippocampal pyramidal neurons, which may contribute to restore the damaged central nervous system.

关键词：乙酰胆碱脂酶 BMP ACHE 活化激活

The patterns and participants of parental histone recycling during DNA replication in Saccharomyces cerevisiae

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Science China(life Sciences) 2023年第7期66卷 1600-1614页

作者： Zhongqing Shan Yan Zhang Jiachen Bu huizhi li Zhuqiang Zhang Jun Xiong Bing Zhu National Laboratory of Biomacromolecules CAS Center for Excellence in BiomacromoleculesInstitute of BiophysicsChinese Academy of SciencesBeijing100101China College of life Sciences University of Chinese Academy of SciencesBeijing100049China

Epigenetic information carried by histone modifications not only reflects the state of gene expression,but also participates in the maintenance of chromatin states and the regulation of gene *** of parental histones to daughter chromatin after DNA replication is vital to mitotic inheritance of epigenetic information and the maintenance of cell identity,because the locus-specific modifications of the parental histones need to be *** assess the precision of parental histone recycling,we developed a synthetic local label-chasing system in budding yeast Saccharomyces *** this system,we observed that parental histone H3 can be recycled to their original position,thereby recovering their position information after DNA replication at all tested loci,including heterochromatin boundary,non-transcribed region,and actively transcribed ***,the recycling rate appears to be affected by local chromatin *** surveyed a number of potential regulatory factors and observed that histone H3-H4 chaperon Asf1 contributed to parental histone recycling,while the eukaryotic replisome-associated components Mcm2 and Dpb3 displayed compounding effects in this *** addition,the FACT complex also plays a role in the recycling of parental histones and helps to stabilize the nucleosomes.

关键词： epigenetic inheritance parental histone recycling Asf1 Mcm2 Dpb3 FACT

Fluorescence determination of platinum with dibromohydroxyphenyl-fluorone in microemulsion after separation and enrichment by sulfhydryl dextrose gel

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Rare Metals 2008年第1期27卷 101-105页

作者： li huizhi ZHAI Yubo ZHAI Diantang School of Chemistry and Chemical Engineering Jinan University Jinan 250022 China School of life Science Nanjing University Nanjing 210093 China

A new fluorescence quenching method has been developed for the determination of platinum in nonionic microemulsion *** method is based on the fact that platinum can form a stable chelate with dibromohydroxyphenyl-fluorine（DBHPF） when they are in the molar ratio of 1：2 in the nonionic microemulsion *** optimum conditions,the system,having the maximum excitation and emission wavelengths at 468 nm and 532 nm,respectively,shows constant fluorescence intensity in the pH range of 3.5-4.0 and high selectivity and sensitivity as well as low interference from foreign ***,this fluorescence intensity is a linear function of Pt（IV） concentration in the range of 0.002-1.00 μg·mL^-1 and the limit of detection is 2.90 ng·mL^-1.

关键词： analytical chemistry separation and enrichment fluorescence determination microemulsion platinum(IV)

巯基活性炭分离富集发射光谱法同时测定金、铂、钯和铊

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稀有金属材料与工程 2005年第6期34卷 1005-1008页

作者：张瑾李慧芝济南大学山东济南250022

研究了巯基活性炭在盐酸介质中对金、铂、钯和铊的吸附能力。该法具有吸附速度快、吸附容量大、在一定条件下,普通金属不被吸附的特点,可用于分离富集各类矿物中微量贵金属。吸附后巯基活性炭低温灰化,与缓冲剂混合发射光谱法同时测定... 详细信息

研究了巯基活性炭在盐酸介质中对金、铂、钯和铊的吸附能力。该法具有吸附速度快、吸附容量大、在一定条件下,普通金属不被吸附的特点,可用于分离富集各类矿物中微量贵金属。吸附后巯基活性炭低温灰化,与缓冲剂混合发射光谱法同时测定金、铂、钯和铊,选择锆作内标线,直接压样于杯形的石墨电极中,该方法简便、快速、准确。对测定条件、干扰因素进行了研究,从而建立测定金、铂、钯和铊的新方法。金、铂、钯和铊的分析线分别为312.3nm,306.5nm,311.4nm和313.1nm,内标线选择为310.7nm的锆,金、铂、钯和铊的线性范围(原子百分数)分别为0-0.20%,0-0.40%,0-0.20%和0-0.40%。金、铂、钯和铊的检测限分别0.01%,0.003%,0.003%和0.001%。用于样品的测定获得满意结果。

关键词：巯基活性炭发射光谱法金铂钯和铊

Effects of Rubus parvifolius L. on neuronal apoptosis and expression of apoptosis-related proteins in a rat model of focal cerebral ischemic-reperfusion injury

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Neural Regeneration Research 2008年第7期3卷 742-746页

作者： lirong Xu Jisheng Wang huizhi li Zongyin Qiu Yongpeng Xia lingyan Ren Department of Pharmaceutical Analysis College of Pharmacy Chongqing Medical University Chongqing 400016 China

BACKGROUND： Studies have shown that the Rubus parvifolius L. （RP） plant extract exhibits protective effects on cerebral ischemia. This effect is reflected in altered ischemic neuronal apoptosis and associated protein expression. OBJECTIVE： To explore the neuroprotective mechanism of RP after cerebral ischemia injury. DESIGN, TIME AND SETTING： Randomized control experiment of cellular, molecular, and protein levels. The experiment was completed at Chongqing Medical University at the School of Pharmacy Laboratories and Basic Medical Institute from October 2005 to January 2006. MATERIALS： Twenty-four adult, male, Wistar rats, weighing （28 ± 20） g. RP extract, which was a product of ethanol extraction, was provided by the Laboratory of Pharmaceutical Analysis, Chongqing Medical University. RP was dissolved in distilled water to a concentration of 10 mg/mL. All rats were randomly assigned into four groups： 5 g/kg RP, 10 g/kg RP, model, and sham-surgery, with 6 rats in each group. METHODS： In the 5 and 10 g/kg RP groups, as well as the model group, the middle cerebral artery was occluded （MCAO） for 60 minutes, resulting in focal cerebral ischemia, followed by reperfusion for 24 hours. Rats in the 5 and 10 g/kg RP groups received 5 and 10 g/kg RP, respectively. The RP treatment group received RP intragastrically （once a day） for 3 days. One hour after the last dose, rats were subjected to MCAO. The same surgical procedure was performed in the sham-surgery group, except the suture was introduced into the external carotid artery, but not advanced. Rats in the model group were subjected to MCAO. The sham-surgery and model groups received intragastrically administered normal saline once per day for 3 days. One hour after the last dose, the rats were subjected to surgery. MAIN OUTCOME MEASURES： TUNEL labeling and immunohistochemical methods were used to investigate changes in neuronal apoptosis and expression of the apoptosis-related proteins, Bax and Bcl-2, on the is

关键词： cerebral ischemia/reperfusion apoptosis Bcl-2/Bax

基于同轴图像传感的激光焊接过程质量监测技术

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焊接学报 2019年第1期40卷 37-42,162,163页

作者：宫建锋李慧知李俐群王刚哈尔滨工业大学先进焊接与连接国家重点试验室哈尔滨150001 西安航天动力试验技术研究所西安710000

针对激光焊接过程中由于参数不匹配、装配误差等原因造成的焊接过程不稳定等焊接缺陷,基于同轴图像传感技术,建立起一套激光焊接过程中的质量在线监测系统,对焊接过程中的熔池图像进行了采集分析及其熔池特征信息的提取.结果表明,在激... 详细信息

针对激光焊接过程中由于参数不匹配、装配误差等原因造成的焊接过程不稳定等焊接缺陷,基于同轴图像传感技术,建立起一套激光焊接过程中的质量在线监测系统,对焊接过程中的熔池图像进行了采集分析及其熔池特征信息的提取.结果表明,在激光功率为1 500 W的不等厚不锈钢薄板激光焊接试验条件下,焊接过程中的不稳定、下塌缺陷以及焊偏现象与熔池形状各特征信息变化具有一定的相关性.结合BP神经网络算法对所提特征信息进行分类、识别,基于LabVIEW软件平台,可实现相应缺陷的自动化识别及报警功能.

关键词：激光焊接同轴图像传感质量在线监测缺陷识别

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超静定梁弹塑性加载过程分析的教学内容构建

力学与实践 2015年第4期37卷 527-532页

作者：李会知沈超郑州大学土木工程学院郑州450001

"超静定梁的塑性极限分析"作为塑性力学教材中的一节内容,阐述了如何用"机动法"和"静力法"求最终的塑性极限破坏载荷,却没有分析超静定梁的弹塑性加载变形过程.通过把结构力学中计算弹性位移的单位载荷法扩展应用到超静定梁的弹塑性加... 详细信息

"超静定梁的塑性极限分析"作为塑性力学教材中的一节内容,阐述了如何用"机动法"和"静力法"求最终的塑性极限破坏载荷,却没有分析超静定梁的弹塑性加载变形过程.通过把结构力学中计算弹性位移的单位载荷法扩展应用到超静定梁的弹塑性加载过程,以均布载荷作用下两端固支超静定梁的弹塑性加载和变形全过程分析为例,构建了超静定梁弹塑性加载过程分析的教学内容,给出了两端固支超静定梁在均布载荷加载过程中弯矩内力和挠度随外载荷而变化的解析公式.主要目的是引导学生掌握超静定梁复杂的非线性弹塑性加载变形全过程的分析方法,可供塑性力学教材改编时参考引用.

关键词：塑性力学超静定梁均布载荷塑性铰挠度

2型糖尿病患者高血压与糖尿病性神经病变的关系

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临床内科杂志 2001年第3期18卷 178-180页

作者：冯波李栩李惠芝上海市东方医院内分泌科 200120

目的　探讨 2型糖尿病患者高血压与糖尿病性神经病变的关系。方法　利用心自主神经功能检测系统和神经电生理检测仪对 10 7例 (高血压组 5 2例 ,非高血压组 5 5例 ) 2型糖尿病患者的心自主神经功能和肢体的末梢神经传导速度、皮肤痛温... 详细信息

目的　探讨 2型糖尿病患者高血压与糖尿病性神经病变的关系。方法　利用心自主神经功能检测系统和神经电生理检测仪对 10 7例 (高血压组 5 2例 ,非高血压组 5 5例 ) 2型糖尿病患者的心自主神经功能和肢体的末梢神经传导速度、皮肤痛温觉、振动觉进行测定 ,以判断心自主神经病变和末梢神经病变。结果　两组间末梢神经功能和心自主神经功能各指标除心搏间距频谱分析的高频值外差异均无显著性 (P <0 .0 5 )。Logistic回归分析显示高血压与心自主神经病变显著相关 (P <0 .0 1) ,而与末梢神经病变无显著相关。结论　 2型糖尿病患者高血压是心自主神经病变发病的危险因素 ,而与末梢神经病变无明显关系。

关键词： Ⅱ型糖尿病心自主神经病变末梢神经病变高血压