自身催化的

Ascorbate is concomitantly oxidized to monodehydroascorbate. Some monodehydroascorbate radicals are re-reduced in a reaction catalyzed by monodehy- droascorbate reductase, but the remainder undergoes spontaneous dismutation to ascorbate and dehydroascorbate.

在抵抗氧化胁迫的反应中，抗坏血酸自身被氧化为单脱氢抗坏血酸，一部分单脱氢抗坏血酸在单脱氢抗坏血酸还原酶的催化作用下还原为抗坏血酸，另一部分单脱氢抗坏血酸的在歧化作用下被不成比例地还原为抗坏血酸或氧化为脱氢抗坏血酸。

The favorable regions for DNA cleavage were observed to be pH 3.6-5.6 and pH 9.0-10, suggesting that the species responsible for DNA cleavage are different in different pH regionsOur results do not support a widely accepted conclusion that the copper-bound or free hydroxyl radicals provided by CuZnSOD with its end product hydrogen peroxide lead to release of copper from its host, the Fenton reaction between the free copper and the hydrogen peroxide being responsible for the aberrant copper-mediated oxidation chemistry in CuZnSOD.

目前广泛接受的一个推测机理是CuZnSOD与H_2O_2反应生成羟自由基损伤酶自身导致Cu释放，而释放出的游离Cu进一步与H_2O_2发生Fenton反应导致了异常催化氧化反应的发生。

objective: to achieve the soluble expression of mn-sod gene in e.coli and assay the enzyme activity of the expressed product. methods: the coding region of superoxide dismutase was amplified using pcr method from the e.coli genome. the pcr product was cloned into puc19-t vector and sequenced.in addition,the cloned coding region of mn-sod was inserted into the expression vector pet-28a to form the recombinant plasmid pet-28a-mn-sod and was then transformed into e.coli bl21 for expression.

超氧化物歧化酶(superoxide dismutase，sod)是细胞体内歧化超氧阴离子自由基(o-2)的一个抗氧化酶，按其结合的金属性离子根据其中金属辅基的不同可分为4类：cu/zn-sod、mn-sod、fe-sod和ni-sod，它们通过催化超氧阴离子自由基0-2发生歧化反应，达到清除o-2的效果，具有防御氧毒性、增强机体抗辐射损伤能力、防衰老以及治疗某些肿瘤、炎症、自身免疫疾病等功效，广受国内外科研工作者的关注和重视[1]。

Studies illustrated that though it could be decomposed under UV light by itself for about 5%, the decolouration of acid red 3B was due to the degradation of K4Nb6O17, but not to the adsorption on it. And the strong oxidic free radicals attracted the conjugated radical first.

研究表明，酸性红3B的去除主要是K_4Nb_6O_(17)对其的光催化降解，而并非吸附作用，但酸性红3B自身也存在少量的光降解，约为5％，且强氧化基团首先进攻的是共轭基团。

Comparing with chicken egg-white lysozyme which is widely used in clinic, hLYZ has many advantages: it is a natural protein in human body, so it is safe and harmless when used as a drug; its bioactivity to kill bacterium is three times higher than chicken egg-white lysozyme, and its thermal stability is much higher, too; it also has many other specific important functions which are not related with its catalysis, such as anti-virus and anti-tumor and improving immunization.

人溶菌酶与目前临床上应用最多的鸡蛋清溶菌酶相比具有以下优势：人溶菌酶是人体内的蛋白，具有天然的相容性，没有毒性和副作用；人溶菌酶比鸡蛋清溶菌酶的杀菌活性高3倍，而且热稳定性也要远高于鸡蛋清溶菌酶；人溶菌酶还有多种特有的与其自身的催化作用无关的理化作用，如抗病毒和抗肿瘤。

The analysis of decomposition mechanisms of the catalyst surface revealed that one of the mechanisms is that activated gas phase O2 captures the hydrogen of the organic pollutants to produce free radicals, which then initiate the catalytic reaction, and produce CO2 and H2O ultimately; and the other mechanism is that the activated organic compounds attack the crystal lattice oxygen, which reduces the valances of the transition metals, then the oxidant of the oxygen oxidizes the transition metals to high valances, which realize the self oxidation-reduction of the catalyst.

催化剂表面有机物降解的机理分析表明，一种反应机理为气相中的O2活化后直接夺取有机污染物的氢，产生自由基，并引发催化反应，最终生成CO2和H2O；另一种反应机理为活化后的有机物直接进攻催化剂的晶格氧，并且使得过渡金属由高价态变为低价态，反应气中的O2再将低价态的金属氧化为高价态，实现催化剂自身的氧化还原循环。

In the Phenoxy/SAN blends, it has been demonstrated that the crosslinking has taken place for Phenoxy components, which was proposed that the reaction is catalyzed by the SAN component which acts as a Lewis base.

在逐步原位聚合的Phenoxy/SAN共混体系中，研究结果表明，由于SAN组分的存在，导致了Phenoxy自身凝胶的形成，这可以归结为SAN组分对DGEBA均聚反应的催化作用。

In the United States, chronic alcoholism and hepatitis C are the most common ones.

在美国，慢性酒精中毒，肝炎是最常见的。

If you have any questions, you can contact me anytime.

如果有任何问题，你可以随时联系我。