PS4.0微机极谱法测定食品中微量钙

采用PS4.0微机极谱仪标准加入法测定了食品中的微量钙 ,采用DTD -40型恒温消解仪消化食品 ,检测下限 1 0 0 μg/L ,线性范围 0 .1 0～ 4.0 0mg/L ,相对标准偏差为 6.62 % ,回收率为97 2 % .锌、锰、铅、铜、镉不干扰测量 .分析结果令人满意     

全站仪的使用与维护

阐述了全站仪的基本组成,介绍了在日常工作中全站仪的使用、保管、转运和全站仪电池充放电的注意事项。     

9920直流比较仪电桥在计量回路电阻测试仪和直阻测试仪中的运用

介绍了直流大功率模拟电阻的原理,分析了直流大功率模拟电阻在计量中的运用,提出了使用9920匝比测量仪器时的接线方法。     

临床医学工程技术在现代医疗机构的应用

文章通过查阅相关文献和实践,探讨临床医学工程技术在医疗仪器调试与临床应用中的价值及医疗仪器设备的技术管理与评价。     

生物滴滤塔净化中低浓度H2S气体的挂膜实验研究

本文通过对两种填料处理硫化氢气体的挂膜实验研究,表明挂膜方法、填料性能、温度、PH值、入口浓度等均影响挂膜效果与硫化氢去除率,并且得出陶粒挂膜启动时间比阶梯环快。     

分析化学几个领域的发展现状

综合分析生物电化学、功能高分子修饰电极及现代分析仪器几个领域的发展现状及应用前景。     

打点记录式校表仪的精度校验

打点记录式校表仪是我国手表厂广泛使用的一种校验仪器．本文介绍了一种能够对这种校表仪的精度进行校验的仪器，性能可靠，价格低廉，效果很好．     

雅乐--特定时代和文化的象征

雅乐是中国传统音乐的重要组成部分,它曾书写了中国古代历史的难忘的一页。深入分析和探究它的历史和文化特征是具有现实意义的。     

膜结构裁剪及展开的修正二次测地线法

对膜结构裁剪分析中目前应用较广的裁剪线的生成方法进行了比较研究，提出修正二次测地线法。确定了采用测地线作为裁剪线及展开图形的基准线。之后对已有图形展开方法——二次测地线法做了适当改进，提出修正二次测地线法。     

Changes in erythrocyte membrane lipid composition affect the transient decrease in membrane order which accompanies insulin receptor down-regulation

We have recently demonstrated, using electron paramagnetic resonance (EPR) spectroscopy, that insulin receptor internalization in response to insulin incubation (down-regulation) in human erythrocytes is accompanied by a transient decrease in membrane order, as measured by the 2T order parameter. Since membrane lipids play such an important role in receptor internalization, we investigated the possible effects that an alteration of the normally-occurring lipid profile might have on down-regulation and the concomitant transient decrease in membrane order. Consequently, human erythrocytes enriched with cholesterol and erythrocytes from cirrhotic patients were examined, because both of these groups of cells have a higher cholesterol/phospholipid molar ratio (CH/PL) than controls. The 5-nitroxystearate spin label, which inserts into the lipid bilayer of cell membranes, was used to monitor changes in 2T for a 3-h period at 37°C. We report here that both cholesterol-enriched and cirrhotic erythrocytes do not down-regulate, as demonstrated by binding assays, and that they do not show the typical transient decrease in membrane order observed in controls. The results seem to indicate that a more ordered membrane inhibits internalization of the insulin receptor in erythrocytes, and that an increase in membrane disorder is necessary for insulin receptor down-regulation.