近生理浓度的脲对核黄素与牛血清蛋白结合作用的影响     

瞿鹏 《商丘师范学院学报》2012,28(9):53-58

用CD光谱和荧光光谱研究了近生理浓度的脲存在和不存在两种情况下核黄素和牛血清蛋白之间的相互作用.一定浓度的核黄素结合在牛血清蛋白上可以引起BSA分子结构伸展,二级结构和三级结构减少.近生理浓度的脲可以诱导核黄素变性的牛血清蛋白二级结构和三级结构部分恢复.脲存在时,核黄素对牛血清蛋白的熄灭常数（Kq）以及供体和受体之间的距离（r）增大.相反地,结合常数（Ka）和结合位点数（n）减小.脲存在下,核黄素和牛血清蛋白的结合作用是一个熄灭作用增强,结合作用减弱的过程.人体内血脲的正常范围为0.0025–0.0075M,脲浓度达到0.01 M时,由于核黄素和HAS分子的弱结合作用导致血浆中核黄素缺乏,一些病人可能会因为核黄素缺乏,结合着药物的生物大分子不能被有效地转移进细胞内,不能被某些药物有效地治疗.  相似文献   

Fast evaluation of degradation degree of organic coatings by analyzing electrochemical impedance spectroscopy data   总被引：3，自引：0，他引：3  

夏大海  宋诗哲  王吉会  毕慧超  韩哲文 《天津大学学报(英文版)》2012,18(1):15-20

The degradation coefficient is proposed to evaluate the degradation degree of organic coatings by directly analyzing the Bode plots of the electrochemical impedance spectroscopy (EIS) data.This paper investigated the degradation of phenolic epoxy coating/tinplate system by EIS and the degradation coefficient value,which correlates well with the results of breakpoint frequency and variation of phase angle at 10 Hz.Furthermore,the degradation process was confirmed by scanning electron microscope (SEM) and scanning probe microscopy (SPM).It is concluded that degradation coefficient can be used for the fast evaluation of degradation degree of organic coatings in practical applications.  相似文献   

CVD金刚石膜的光电性能及其在辐射探测器中的应用     

张明龙 《上海大学学报(英文版)》2006,10(6):561-562

The outstanding properties of CVD diamond film such as electronic, optical, thermal and mechanical and the high radiation hardness have made it an ideal candidate material for radiation detectors in severe environments. Fabrication of ＇detector grade＇ CVD diamond films and development of CVD diamond detectors have been leading edge subjects. Micro-strip gas chamber （MSGC） fabricated on CVD diamond substrate would overcome the charge-up effect and the substrate instability, which has been a hotspot in the research of gas detectors.  相似文献   

三溴偶氮胂镧(III)与蛋白质相互作用的反射散射光度研究     

衷明华  温红丽 《韩山师范学院学报》2004,(3)

研究了微晶石蜡吸萃蛋白质 三溴偶氮胂镧(III)复合物的条件,并设计了固相反射散射分光光度直接测定石蜡相中蛋白质的方法,所拟定的方法有较好的灵敏度和选择性,可以用于实际生物样品中蛋白质含量的测定.  相似文献   

金属材料表面Mo(W)-S彩色簇合物膜的红外光谱和光电子能谱研究     

李道华 《内江师范学院学报》2006,21(4):34-37

利用化学浸渍法,使M o(W)S42-与金属材料M(M=F e、Cu、Zn、N i、Sn)表面发生配位化学反应,得到了不溶性且具有装饰效果的M o(W)-S彩色簇合物膜。用红外光谱(FT-IR)、远红外光谱(F-IR)、拉曼光谱(FT-R am an)和光电子能谱(XPS与AES)研究了M o(W)S42-在金属材料表面的成键特征和波谱变化,分析了彩色簇合物膜的组成、结构、化学状态和形成机理。  相似文献   

太赫兹时域光谱技术     

孟田华  赵国忠 《雁北师范学院学报》2007,(6)

介绍了太赫兹时域光谱技术的优势,太赫兹时域光谱系统及太赫兹时域光谱技术的原理和应用.  相似文献   

几种新颖的分析方法(Ⅰ)     

韩志萍 《湖州师范学院学报》1993,(5)

本文主要介绍光声光谱分析法的测定原理和有关应用.  相似文献   

利用荧光法研究不同条件下肌红蛋白去氧过程     

马君燕  唐乾  郑学仿 《大连大学学报》2013,(3):75-78,106

利用荧光法研究不同条件下肌红蛋白去氧过程,发现肌红蛋白随着温度的升高结合氧的能力逐渐增加;在改变溶液酸碱性的条件下,肌红蛋白在酸性条件下比在碱性条件下更容易去氧;减小压力有助于肌红蛋白去氧;相反,增加压力有助于结合氧;肌红蛋白溶液通入CO2,通气量一定,随反应时间延长,可以得出,在短时间内,CO2利于肌红蛋白结合氧,随着反应时间再增加,肌红蛋白又逐渐去氧;在通入CO时,CO与肌红蛋白中的Fe(II)结合,可使肌红蛋白去氧。  相似文献   

No effect of glutamine supplementation and hyperoxia on oxidative metabolism and performance during high-intensity exercise     

Simon Marwood  Jo Bowtell 《Journal of sports sciences》2013,31(10):1081-1090

Abstract

Glutamine enhances the exercise-induced expansion of the tricarboxylic acid intermediate pool. The aim of the present study was to determine whether oral glutamine, alone or in combination with hyperoxia, influenced oxidative metabolism and cycle time-trial performance. Eight participants consumed either placebo or 0.125 g · kg body mass^?1 of glutamine in 5 ml · kg body mass^?1 placebo 1 h before exercise in normoxic (control and glutamine respectively) or hyperoxic (FiO₂ = 50%; hyperoxia and hyperoxia + glutamine respectively) conditions. Participants then cycled for 6 min at 70% maximal oxygen uptake ([Vdot]O_2max) immediately before completing a brief high-intensity time-trial (～4 min) during which a pre-determined volume of work was completed as fast as possible. The increment in pulmonary oxygen uptake during the performance test (Δ[Vdot]O_2max, P = 0.02) and exercise performance (control: 243 s, s _x  = 7; glutamine: 242 s, s _x  = 3; hyperoxia: 231 s, s _x  = 3; hyperoxia + glutamine: 228 s, s _x  = 5; P < 0.01) were significantly improved in hyperoxic conditions. There was some evidence that glutamine ingestion increased Δ[Vdot]O_2max in normoxia, but not hyperoxia (interaction drink/FiO₂, P = 0.04), but there was no main effect or impact on performance. Overall, the data show no effect of glutamine ingestion either alone or in combination with hyperoxia, and thus no limiting effect of the tricarboxylic acid intermediate pool size, on oxidative metabolism and performance during maximal exercise.  相似文献   

Morphology of polyethylene ski base materials     

Jörg Fischer  Gernot M. Wallner  Alois Pieber 《Journal of sports sciences》2013,31(5):555-562

Abstract

We used high-resolution Raman spectroscopy and differential scanning calorimetry for a comprehensive analysis of carbon black-filled polyethylene ski base grades at processing stages from the raw material to the structured ski base. Based on Raman mapping, we assessed the applicability of an advanced evaluation procedure for amorphous, disordered, and crystalline phase fractions of polyethylene for polyethylene extrusion and sinter grades. For sinter grades, a sufficient segregation between carbon black and polyethylene was confirmed, allowing for a comprehensive Raman spectroscopic morphological analysis. Significant morphological changes in polyethylene due to processing from the raw material to the semi-finished film and to the structured ski base were identified. Throughout the processing chain, we observed a decrease in crystallinity and an increase in the amorphous phase fraction. Although the raw material and the sintered semi-finished film exhibited a different but uniform polyethylene morphology, the morphological changes due to structuring of the ski base are limited to the top surface layer. The highest amorphous phase fractions were detected in the surface of the structured ski bases.  相似文献