一氧化氮代谢与细胞色素P450

本文阐述了一氧化氮的生理功能及其作用机理,一氧化氮的生成及调节,并探讨了细胞色素P450mor的发现以及细胞色素P450与一氧化氮的关系。     

Optimization of fermentation conditions for P450 BM-3 monooxygenase production by hybrid design methodology

INTRODUCTION P450 enzymes are found throughout nature and can catalyze the oxidation of various chemicals (Ortiz de Montellano, 1995). Because of their important roles in these processes, numerous systems have been developed for the expression of P450s in vitro (Helvig and Capdevila, 2000; Nakamura et al., 2001; Deeni, 2001). But P450 enzymes fermentation levels in the microbial system are too low to catalyze the reactions for industrial preparations. Therefore, it is necessary to impr…     

单加氧酶细胞色素P-450的模拟

本文评述了用金属卟啉模拟单加氧酶细胞色素P－450的研究现状及其在有机合成和生物医学等方面的应用．     

Effects of chromium nanoparticle dosage on growth,body composition,serum hormones and tissue chromium in Sprague-Dawley rats

This 6-week study was conducted to evaluate the effects of seven different levels of dietary chromium (Cr) (0, 75, 150,300, 450, 600, and 1200 ppb Cr) in the form of Cr nanoparticle (CrNano) on growth, body composition, serum hormones and tissue Cr in Sprague-Dawley (SD) rats. Seventy male SD rats (average initial body weight of (83.2±4.4) g) were randomly assigned to seven dietary treatments (n=10). At the end of the trial, body composition was assessed via dual energy X-ray absorptiometry (DEXA). All rats were then sacrificed to collect samples of blood, organs and tissues for determination of serum hormones and tissue Cr contents. The results indicated that lean body mass was significantly increased (P＜0.05) due to the addition of 300 and 450 ppb Cr from CrNano. Supplementation of 150, 300, 450, and 600 ppb Cr decreased (P＜0.05) percent body fat significantly. Average daily gain was increased (P＜0.05) by addition of 75, 150, and 300 ppb Cr and feed efficiency was increased (P＜0.05) by supplementation of 75, 300, and 450 ppb Cr. Addition of 300 and 450 ppb Cr decreased (P＜0.05) the insulin level in serum greatly. Cr contents in liver and kidney were greatly increased (P＜0.05) by the addition of Cr as CrNano in the dosage of from 150 ppb to 1200 ppb. In addition, Supplementation of 300, 450, and 600 ppb Cr significantly increased (P＜0.05) Cr content in the hind leg muscle. These results suggest that supplemental CrNano has beneficial effects on growth performance and body composition, and increases tissue Cr concentration in selected muscles.     

细胞色素P450介导的维甲酸耐药机制及其逆转

全反式维甲酸(ATRA)作为诱导分化剂可使大多数急性早幼粒细胞白血病(APL)患者取得完全缓解,但是几乎普遍发生的维甲酸耐药,使APL患者完全缓解后短期内复发,并失去对维甲酸的反应性,严重影响其疗效.对于ATRA耐药机制的解释,认为系统的细胞色素P450介导的ATRA代谢增强,使得ATRA水平难以维持.现就细胞色素P450介导的维甲酸耐药机制及其逆转的研究进展综述如下.     

联宝T5系列笔记本电脑亮相京城

联宝T5系列笔记本电脑,12月16日由北京联宝讯通科技有限公司在京城推出。T5系列笔记本电脑具有更轻、更薄、更优雅,造型更加别致等特点。它采用先进的PⅢ450MHZ处     

中考数学2·关于汶川地震

例1汶川地震后,救援队派一架直升飞机去A、B两个村庄抢险,飞机在距地面450米上空的P点,测得A村的俯角为30°,B村的俯角为60°.如图1,求A、     

灰化温度对测定鱼肉中重金属含量的影响

报道了用瓷坩埚高温灰化鲫鱼、鳊鱼样品,灰化温度对测定样品中重金属Cu、Mn、Fe、Zn含量的影响．结果表明：测定鱼肉样重金属Cu、Mn、Fe、Zn含量时,可以用瓷坩埚进行高温灰化,适宜灰化温度分别为450-550、450-550、450-600、450-500℃;同时测定该四种元素含量时,适宜灰化温度为450-500℃．且500℃灰化时,元素的平均回收率为97％-106％．     

化学实验习题中一个实验的改进

初中化学课本(九年义务教育人教版)P319实验习题中的第5题,证明黑色粉末里有炭粉的解答,虽在人教版教师教学用书P450中介绍了参考方法,我们在使用教材三年来,对该实验反复研究和实践后作了改进,取得很好的教学效果。本人认为教学用书所用的操作方法存在以下缺点:     

电子阅览室管理实践探讨

一、从长计议,合理布局 我校电子阅览室是1999年建立的。在建设前期,我们进行了长期的研究,还进行了调研,组织人力到其它图书馆进行参观学习。最后,我们决定从高标准、高起点着手。购进的电脑都是国际知名品牌DELL公司GX1原装机,CPU是PⅢ450,内存128SDRAM,硬