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采用紫外-可见光谱法、荧光光谱法、圆二色谱法等研究了荧光素酶(Luc)与金丝桃素-镁离子配合物(Hyp-Mg~(2+))的相互作用,包括结合位点、结合常数、结合力强弱、生物大分子构象变化等因素的影响.紫外-可见光谱表明,Hyp-Mg~(2+)与荧光素酶发生反应且改变了荧光素酶的分子结构.荧光数据表明Hyp-Mg~(2+)与荧光素酶通过生成非荧光复合物的静态猝灭而有效地猝灭了荧光素酶的荧光.对荧光光谱数据处理得到298 K下Hyp-Mg~(2+)与荧光素酶的结合常数为3.13×10~5L/mol.CD光谱表明,Hyp-Mg~(2+)可改变荧光素酶的分子构象. 相似文献
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Determination of Polysaccharide in Radix pseudostellariae Extract by Size-Exclusion High-Performance Liquid Chromatography 总被引:1,自引:0,他引:1
A simple size-exclusion high-performance liquid chromatographic method was developed for rapid molecular mass screening to determine the average molecular mass, polydispersity, and quantity of Taizishen polysaccharides extract. The screening used a TOSOH TSK-GEL G3000SW high-performance liquid chromatographic column with 0.1 mol/L NaNO3 buffer as the mobile phase and refractive index detec- tor. The molecular mass calibration curve was linear for polysaccharide standards from 10 to 100 kDa with a correlation coefficient of 0.9991. The method can be used to analyze the quantity, average molecular mass, and polydispersity of polysaccharides. In addition, the screening method is suitable for quality control of polysaccharide preparations in Chinese medicines and pharmaceutical products. 相似文献
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The cephalosporin acylases are a group of enzymes that hydrolyze cephalosporin C and/or glutaryl 7-aminocephalosporanic acid to produce ?-aminocephalosporanic acid. The cephalosporin acylase from Pseudomonas sp. strain 130 was crystallized in two different forms suitable for structural studies. A tetragonal crystal form diffracted to 0.24 nm belonged to the space group P41212. There was one αβ heterodimer per asymmetric unit. A second crystal form diffracted to 0.21nm belonged to the space group P21. There was four αβ heterodimers per asymmetric unit. The tetragonal crystal structure of CA-130 was determined using the multiwavelength anomalous diffraction method and the P21 crystal structure was then determined using the molecular replacement method. 相似文献
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本文是我在长期从事学生思想品德教育教学实践的基础上总结形成的一些观点,关于德育工作缺乏实效性和出现功利化倾向等问题进行了初步探索。 相似文献
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从心理学角度讲:心理素质包括情感,信心,意志力,和韧性等等。一个人的心理素质是在先天素质的基础上,经过后天的环境与教育的影响而逐步形成的。德育工作是塑造学生心灵的工作,心灵的塑造必须以心理健康为基础,必须把健康的心理,健全的人格作为重要目标和内容。 相似文献
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Different Kinetics of Puerarin in Plasma of Normal and Depressed Rats After Oral Administration of Chinese Medicine TZ18 总被引:2,自引:0,他引:2
The objective of this study is to quantify the puerarin in rat plasma following oral administration of TZ18 and compare the pharmacokinetics characteristics of puerarin in normal rats with that in depression model rats. A high performance liquid chromatography method was used to quantify the puerarin due to its good selectivity and linearity (coefficient correlation, r2 = 0.9991) within the tested range (0.028-0.889 μg·mL-1). Intra- and inter-day precision coefficients of variation and accuracy bias were acceptable (Maximum coeffi- cient of variation was 5.74% for intra-day and 3.09% for inter-day) over the entire range. The recoveries were found to be 98.3%, 101.4%, and 103.4% for concentrations of 0.028, 0.222, and 0.444 μg·mL-1, re- spectively. The concentration-time curves for both normal rats and depression model rats were fit to a two- compartment model with the first order absorption. The results show significant differences in the main phar- macokinetic parameters of peak time, peak concentration, and the area under the concentration-time curve between the two kinds of rats. 相似文献
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会计目标的定位问题一直是会计界的热点问题,其中,尤其是从规范性会计目标中衍生出的两种观点受托责任观与决策有用观,到底哪一种更适合中国市场经济的发展,更是众多会计学者争论的焦点.根据我国目前的不完善市场经济转轨中的资本市场这一国情,现阶段应采用受托责任观.与此同时,我国经济发展趋势使决策有用观成为今后必然的发展目标. 相似文献