大同市空气中NOx的污染分析及治理

通过对大同市近3年的氮氧化物数据监测，分析了氮氧化物的组成，来源及对人体的危害，并根据大同市的实际情况提出了氮氧化物污染的治理技术。     

The superoxide-generating NADPH oxidase: structural aspects and activation mechanism

Flavocytochrome b ₅₅₈ is the catalytic core of the respiratory-burst oxidase, an enzyme complex that catalyzes the NADPH-dependent reduction of O₂ into the superoxide anion O₂ ^- in phagocytic cells. Flavocytochrome b ₅₅₈ is anchored in the plasma membrane. It is a heterodimer that consists of a large glycoprotein gp91phox (phox for phagocyte oxidase) (β subunit) and a small protein p22phox (α subunit). The other components of the respiratory-burst oxidase are water-soluble proteins of cytosolic origin, namely p67phox, p47phox, p40phox and Rac. Upon cell stimulation, they assemble with the membrane-bound flavocytochrome b ₅₅₈ which becomes activated and generates O₂ ^-. A defect in any of the genes encoding gp91phox, p22phox, p67phox or p47phox results in chronic granulomatous disease, a genetic disorder characterized by severe and recurrent infections, illustrating the role of O₂ ^- and the derived metabolites H₂O₂ and HOCl in host defense against invading microorganisms. The electron carriers, FAD and hemes b, and the binding site for NADPH are confined to the gp91phox subunit of flavocytochrome b ₅₅₈ . The p22phox subunit serves as a docking site for the cytosolic phox proteins. This review provides an overview of current knowledge on the structural organization of the O₂ ^--generating flavocytochrome b ₅₅₈ , its kinetics, its mechanism of activation and the regulation of its biosynthesis. Homologues of gp91phox, called Nox and Duox, are present in a large variety of non-phagocytic cells. They exhibit modest O₂ ^--generating oxidase activity, and some act as proton channels. Their role in various aspects of signal transduction is currently under investigation and is briefly discussed. Received 28 May 2002; received after revision 20 June 2002; accepted 24 June 2002     

国内外目前具有研究价值的烟气脱硝技术

随着氮氧化物污染越来越严重,研究并发展更有效、更实用的的烟气脱氮技术越来越迫切。本文主要介绍几种当前多种脱氮技术中比较具有研究价值烟气脱氮技术。这些技术大都是目前已经投入生产使用的技术,但在不同的方面存在很多的不足,若通过进一步的研究与实践,拟补这些不足,将会使目前的烟气脱硝技术进入一个崭新的阶段。     

慢病毒介导的HTRA1突变基因感染对人脑血管平滑肌细胞内氧化应激反应的影响

检测HTRA1及HTRA1-Mut基因慢病毒载体转染HBVSMC后,HBVSMC内氧化应激水平的变化。以HTRA1及HTRA1-Mut基因慢病毒载体转染HBVSMC后,在特定的时间点收集NC、OE-WT HTRA1及OE-MU HTRA1三组细胞的总RNA及总蛋白,分别用RT-PCR和Western Blot的方法检测三组细胞的NOX4 mRNA及蛋白水平的表达情况;用DCFH-DA法检测三组细胞内的活性氧水平。从定量PCR结果可以看出,人脑血管平滑肌细胞中,OE-MU组NOX4基因表达丰度是NC组的2.015倍。从Western blot结果可以看出,在正常的人脑血管平滑肌细胞中NOX4蛋白水平表达较低,而在慢病毒LV-HRTA1及LV-HRTA1-MUT感染后NOX4蛋白表达水平增高。在正常的人脑血管平滑肌细胞中ROS水平表达较低,而在慢病毒LVHRTA1及LV-HRTA1-MUT感染后ROS蛋白表达水平增高,在突变型病毒感染细胞组表现更为明显。说明:1HTRA1突变型基因感染人脑血管平滑肌细胞后,细胞内活性氧产量增加,NOX4 mRNA水平的表达正常细胞升高,但较HTRA1野生型基因无明显差别;NOX4在蛋白水平表达较其他两组均升高;2HTRA1突变型基因感染的人脑血管平滑肌细胞出现增殖减少、迁移活力降低以及凋亡增加可能与细胞内的氧化应激有关,为进一步研究CARASIL发病机制奠定基础。     

可同化有机碳测定方法探讨

研究了以３种不同接种方法测定水中可同化有机碳（ＡＯＣ）,结果显示,混合接种法所测结果较接近实际值,分别接种法结果明显高于实际值,依次接种法可能存在Ｐ１７（荧光假单胞菌,Ｐｓｅｕｄｏｍｏｎａｓ ｆｌｔｏｒｅｓｃｅｎｓ）溶解、释放细胞中有机物所至的ＡＯＣ偏高问题。依次接种法有时存在巴氏消毒不能完全杀灭Ｐ１７,从而干扰ＡＯＣ－ＮＯＸ的测定;混合接种法缩短了实验时间,简化了操作步骤,当１个平皿中Ｐ１７和Ｎ