Fenton法在废水处理过程中的研究现状与进展

Fenton法对废水有较好的处理效果,本文阐述了Fenton法的处理原理及影响因素,并阐述了目前Fenton法的主要发展方向.     

声旁规则性对留学生形声字输出能力的影响

针对各个水平的非汉字背景留学生,文章设计了一种听写任务的纸笔测试,实验材料为规则形声字与不规则形声字各10个,通过对听写正确率和偏误情况的分析,考察了形声字的规则性对留学生字形输出能力的影响。结果发现：与本族儿童不同,形声字的规则性对留学生字形输出的正确率没有表现出显著的影响,但是却影响了同声旁偏误的比例;声旁输出情况比较好,形旁则不太好。与声旁相比,形旁属于比较细微的差别,因此在字形输出的心理加工过程中,很容易处在被忽视的地位。     

Antioxidant and lipid lowering activities of Indian black tea

Indian black tea; CTC leaf and dust, produced by Tata Tea Limited, Kolkata, (India) was studiedin vitro as potential scavenger of oxygen free radicals. Super oxide anions were generated in a system containing xanthine—xanthine oxidase (enzymic system) and by NADH- phenozine methosulphate (non enzymic system). Anions were assayed in terms of uric acid formation and reduction of nitroblue tetrazolium salt, which were shown to be suppressed by tea extracts. Extracts from both leaf and dust also inhibted the formation of hydroxyl radicalsin vitro in the enzymic system comprising hypoxanthine—Cu⁺²—sodium ascorbate and xanthine oxidase and in non enzymic system of deoxyribose—Cu⁺²—sodium ascorbate and H₂O₂ as well as the Cu⁺² induced lipid peroxidation in human low density lipoprotein. Feeding with black tea in normal rats for sixty days increased their antioxidant activity and their liver microsomes were shown to be protected against peroxidation of lipids as stimulated by metal ions with enzymic or non enzymic reactants. Furthermore feeding with tea extracts in normal as well as triton WR—1339 induced hyperlipidemic rats caused decrease in their plasma levels of total cholesterol, phospholipids and triglycerides. The antioxidant and lipid lowering activities of both extracts from CTC leaf and dust tea was comparable and may be due to the presence of natural products like catechin and others.     

Oxidant and antioxidant status in vegetarians and fish eaters

An adequate antioxidant reserve which is usually present in a vegetarian diet is associated with higher life expectancy. On the other hand habitual consumption of fish is associated with lower risk of cardiovascular diseases which is attributed to the polyunsaturated fatty acids (PUFA) present in it. However the PUFA are readily susceptible to oxidation leading to the formation of free radicals which is known to be involved in the causation of several diseases. The oxidant-antioxidant status of 23 vegetarians and 22 fish eaters was studied by determining the plasma lipid peroxides measured as malondialdehyde (MDA) and the antioxidants, viz. glutathione (GSH), ascorbic acid, ceruloplasmin and uric acid. Results show that the ascorbic acid values were significantly higher in vegetarians. In addition, MDA correlated negatively with ascorbic acid only in vegetarians. However, correlation of MDA with glutathione showed a significant negative correlation only in fish eaters. There was no statistically significant difference in the MDA, GSH, ceruloplasmin and uric acid levels. The mechanism behind these findings are not clear and needs to be explored.     

自由基稳定性的新观点

许多《有机化学》教科书一致认为烷基的相对稳定性次序是：叔基＞仲基＞伯基＞甲基，事实上这种次序犯有严重的逻辑错误，通过举例说明了错误所在，并介绍了一种新的自由基相对稳定性次序定量化标准－－稳定化能（SE）的计算方法，叔基、仲基、伯基、甲基的SE值分别为16.73、4.35、7.28、0kJ/mol。利用求得的SE值估算了20种烃类的健离解能（BDE）。结果表明，计算值与文献报道值吻合良好，有75％的BDE值计算结果与文献报道值的相对误差小于3.00%，有90％的BDE值计算结果与文献报道值的相对误差小于8.3%。     

Evaluation of antioxidant properties of berries

The present paper focuses on assessing the levels of various enzymatic and non-enzymatic antioxidants in selected berries of Indian sub-continent viz., gooseberry, grapes, orange and tomato. This study has revealed that orange, tomato and grapes possess predominant quantities of enzymatic antioxidants namely SOD, catalase and glutathione peroxidase respectively. The levels of antioxidants analyzed namely reduced glutathione, vitamin C and vitamin A were maximal in grapes, orange and tomato respectively. All the extracts of berries included in the present study inhibited iron inducedin vitro lipid peroxidation in erythrocytes, the extend of inhibition being highest for gooseberry and orange compared to tomato and grapes which could be attributed to their in-built antioxidant system.     

第一部音序检字法字书——论《龙龛手镜》的编排体例

历来对《龙龛手镜》的编排体例褒贬不一。它是第一部音序检字法字书 ,偏旁归部按敦煌写本而定 ,正俗说体依当时的实际用法为标准。     

Free radical generation and lipid peroxidation among the dry cell industry workers exposed to carbon

A total of 75 healthy male dry cell industry workers exposed to carbon for 5, 8 and 10 years were compared with 48 controls matched for age and economic status with respect to free radical generation, lipid peroxidation and antioxidant levels. Lymphocytes were seperated from the whole blood and used for estimation of free radicals and antioxidants. Plasma lipid peroxidation products were estimated in the form of thiobarbituric acid reactive substances. Significant increase in free radical generation and lipid peroxidation products were observed in carbon exposed population than controls, and the increase was found to be significant with increase in the period of exposure. The levels of antioxidants i.e., superoxide dismutase (SOD) and catalase were found to decrease with the increase in exposure to carbon in industrial workers. These results suggest that exposure to carbon augments free radical generation, lipid peroxidation and promotes decline in antioxidant enzymes.     

不同强度力竭运动大鼠运动后12h肝细胞凋亡的研究

研究对象、方法:利用细胞免疫组化的方法研究力竭运动后12 h成年雄性SD大鼠肝细胞凋亡同肝细胞内的自由基水平和钙代谢之间的关系。结果:1)运动组与C组相比,凋亡细胞的数量差异显著(p<0.05);运动组组间差异也具有显著意义(p<0.05)。2)ME、HE组肝细胞内SOD活性与C组相比差异显著(p<0.05),但运动组组间差异不显著。3)ME组肝细胞中MDA含量增加、GSH含量降低,且相对于对照组差异显著(p<0.05);HE组虽有类似变化,但与其它各组相比无显著性差异。4)运动组肝细胞中Ca2+含量较对照组增加,差异显著(ME:p<0.01,HE:p<0.05),运动组组间差异显著(p<0.05)。结论:1)力竭运动可导致肝细胞凋亡,氧化应激及钙离子超载是引起细胞凋亡的重要因素,且前者可能发挥更重要作用。2)中等强度力竭运动更易于导致肝细胞凋亡,其原因可能同长时间力竭运动引起中暑或严重缺水,进而导致恢复期内中性粒细胞发生呼吸爆发有关。