过氧化氢对人视网膜色素上皮细胞ARPE-19中20S蛋白酶体表达的上调作用

目的:探讨过氧化氢诱导的氧化应激对人视网膜色素上皮细胞ARPE-19中20S蛋白酶体表达的影响。方法:分别选择0,100,300μmol/L过氧化氢作用ARPE-19细胞4h后收集样本,Western blot方法检测细胞中20S蛋白酶体表达水平,细胞免疫荧光方法检测20S蛋白酶体在细胞中的分布。结果:100和300μmol/L过氧化氢溶液处理的细胞中20S蛋白酶体的表达和对照组相比明显增加(100μmol/L过氧化氢处理组vs0和300μmol/L过氧化氢处理组,P<0.05),并呈现剂量依赖性。正常培养情况下,细胞内20S蛋白酶体在核周微量表达,100和300μmol/L过氧化氢溶液处理的细胞内20S蛋白酶体和对照组相比明显增加,其分布集中在核内及核膜周围。结论:过氧化氢对ARPE-19的20S蛋白酶体表达有上调作用。

双氧水在治理污染方面的应用

近年来,国外有关双氧水在废物治理方面的报道很多。本文综述了这方面的情况,说明开发双氧水应用前景广阔。

Growing Development and Physiological Characteristics of Seeds Harvested Different Days after Pollination and Their 7-day Seedlings of Two Yellow-Seeded Cultivars of Brassica napus L.

This study aimed to understand the growing development and physiological characteristics of seeds harvested different days after pollination and the seedlings emerged from the seeds of yellow-seeded Brassica napus L..Two yellow-seeded cultivars‘Hongyuan 558’and‘Qinyou 806’were selected in this study,and 50 seeds were collected 30,35,and 40 d after pollination,respectively.The seeds were weighed and placed on filter paper for hydroponic experiments.The seed germination rate was determined 3-5 d later.The physiological indicators including superoxide dismutase(SOD),peroxidase(POD),and catalase(CAT)activities and malondialdehyde(MDA)content were measured for the seeds harvested different days after pollination and the 7-day-seedlings emerged from the seeds.The results showed that the seed dry weights and germination rates of both‘Qinyou 806’and‘Hongyuan 558’increased as the days after pollination increased,especially 30-35 d after pollination.The germination rate and dry and fresh weights of the seeds showed no significant differences between the two cultivars,and almost all the seeds germinated 40 d after pollination.As the days after pollination increased,the SOD activities in the seeds of both cultivars first increased and then decreased,reaching their peaks 35 d after pollination,which may be related to encountering adverse stress.The POD activity in the seeds of‘Qinyou 806’kept declining,and that of‘Hongyuan 558’first increased and then decreased,which may be related to the antioxidant mechanism and adaptive regulation.The CAT activities in the seeds of both cultivars first decreased and then increased.The MDA content in the seeds of‘Qinyou 806’first decreased and then increased,while that of‘Hongyuan 558’kept reducing and was the highest in the seeds 30 d after pollination,which indicated‘Hongyuan 558’was mildly affected by the environment and had strong resistance.The activities of SOD and POD in the seedlings of two cultivars that were emerged from the seeds 35-40 d after pollination became weakened,which may be related to their exposure to stress.The CAT activity in the seedlings of‘Hongyuan 558’was generally higher than that of‘Qinyou 806’,indicating that‘Hongyuan 558’had stronger stress resistance.The MDA content in the seedlings emerged from the seeds 35-40 d after pollination showed a decreasing trend,indicating that the seedlings emerged from the seeds harvested at this stage had mild cell membrane damage and enhanced stress resistance.In conclusion,‘Hongyuan 558’had strong environmental adaptability and stress resistance.

甘草次酸的电化学研究

用单扫示波极谱法研究了甘草次酸在 Na Ac- HAc缓冲液中 ( p H4.0～ 5 .5 )的电化学行为和反应机理。甘草次酸于 - 1 .5 3V( vs.SCE) ( P1)左右有一个二阶示波导数峰 ( p H=4.0～ 4.9) ,峰高与甘草次酸浓度在 0 .4～ 6.3μg/m L范围内呈正比 ,检出限为 0 .2 μg/m L;p H在 5 .0 0～ 5 .5 3之间 ,甘草次酸有两个还原峰 ,其电位分别为 - 1 .5 1 V( P2 )和 - 1 .5 7V( P3)。实验证明甘草次酸的电极过程为不可逆的逐级电子转移过程 ,H2 O2

Occurrences of Yttrium in Soil and Its Potential Impacts on Paddy Rice Triticum aestivum

[Objective] The effects of yttrium nitrate （YNO3） on biomass and antioxi- dant systems of paddy rice （Yttrium （Y）; Oxidative stress; Dismutases （SOD）; Per- oxidases （POD）, Catalases （CAT）, Paddy rice （Triticum aestivum）） together with the occurrences of Y in soils were investigated to assess its ecotoxicological effects on plant. [Method]Y solutions with various concentrations were sprinkled on soil sam- ples, which were well mixed and then put into culture dishes to culture paddy rice seeds for further evaluation. [Result] The results indicated that 25-100 mg/kg Y treatments significantly increased the biomass （total weight, root weight, shoot weight and leaf weight）, chlorophyll （CHL） content and protein content of paddy rice, whereas 200-800 mg/kg Y treatments had a converse effect. Similarly, biomarker for the antioxidant systems including superoxide dismutases （SOD）, peroxidases （POD） and catalases （CAT） all exhibited similar trends in both shoots and roots of paddy rice. At the same time, the malonaldehyde （MDA） content increased at from 25 to 100 mg/kg and decreased with concentrations of Y from 100 to 800 mg/kg in both shoots and roots of paddy rice. This indicated that Y could stimulate the growth of plant at low concentration, but inhibit the growth at relatively high concen- tration. [Conclusion] The levels of Y were 641＋49, 328_＋16 and 473_＋40 mg/kg in soils collected from mining area, farmland and navel orange orchard respectively. The levels of Y in the investigated area were higher than the benefit level （100 mg/kg）, which could cause low biomass as well as low activity of SOD, POD and CAT in paddy rice. Therefore, a more careful use of Y is necessary in crop management.

Effects of Catalase and Ascorbate Peroxidase on the Root Growth of Rice under Cadmium Stress

[Objective] The research aimed to study the correlations between catalase（CAT） and ascorbate peroxidase（ASP） and the growth and development of rice roots under cadmium stress.[Method] Taking rice variety Zhonghua No.11 as materials,the changes of rice seedlings under the treatment conditions of Cd,Cd＋CAT inhibitor,Cd＋APX inhibitor were studied.[Result] Under Cd stress,inhibition of CAT activity caused the significant inhibition on the growth of aerial parts,decreased the number of adventitious roots and lateral roots,but it can significant promote the elongation growth of adventitious roots and lateral roots.Moreover,the length of the first lateral root from root tip on the primary roots and adventitious roots was also increased than control.When APX activity was inhibited,the growth changes of rice were similar with that treated by CAT inhibitor.[Conclusion] CAT and APX may play important roles in the regulation of rice root system growth in both non-stress and Cd-stressed rice

Effects of Drought Stress on Activity of POD and CAT in Wheat during Generation Period

[Objective] This study aimed to investigate the changes in activity of POD and CAT in wheat during generation period under drought stress. [Method] Four wheat cultivars, including Yunong 51, Zhoumai 22, Jimai 19 and Huaimai 22, were selected as experimental materials and cultured under drought stress simulated by different concentrations of PEG6000, to determine the activity of POD and CAT. [Result] POD and CAT activity in wheat during generation period increased gradual y under stress of 5% and 15% PEG6000 from 0 to 120 h; POD and CAT activity in wheat under stress of 15% PEG6000 increased more compared with that under stress of 5% PEG6000; POD and CAT activity in wheat under stress of 25% and 35% PEG6000 increased first and then decreased. Stress duration significantly af-fected the activity of POD and CAT in wheat during generation period. [Conclusion] This study provided theoretical references for breeding drought-tolerant wheat.

Effects of Breviscapine on the Changes in Antioxidant Enzyme Activity Induced by Cerebral Ischemia-reperfusion in Rats

\ Effects of breviscapine, the active ingredient isolated from Erigeron breviscapus (Vant) Handmazz, on the changes in antioxidant enzyme activity induced by cerebral ischemiareperfusion in rats were explored. It was found that breviscapine improved the activities of superoxide dismutase (SOD), GSHperoxidase and catalase, while decreasing the malondialdehyde (MDA) content in the brain, which was benificial in reducing the damage from cerebral ischemiareperfusion.

Studies on the Anti-lipid Peroxidative Actions of the Methanolic Extract of the Root of Aegle marmelos and Its Constituents In Vivo and In Vitro

The inhibitory effect of the methanolic extract of the root of Aegle marmelos (MERA) and its constituents on the lipid peroxidation in vivo and in vitro were studied. The results suggested that MERA increased the activities of superoxide dismutase (SOD) and GSH-peroxidase in the liver cytosol of mice, but showed no significant effect on the activity of catalase, and one of its major constituents, 4-methoxy-1-methyl-2-quinolone (MMQ) increased the activity of SOD in liver tissue of mice intoxicated with FeCl2-ascorbic acid (AA)-ADP in vivo. Various constituents isolated from the root of title plant inhibited the lipid peroxidation in rat liver homogenate, which was in vitro induced by FeCl2-ascorbic acid, CCl4-NADPH, or ADP- NADPH. Of the test compounds, MMQ and its derivatives integriquinolone were similar to (-tocopherol in inhibiting MDA production in rat liver microsomes induced by Fe2+-ascorbate, CCl4-NADPH, or ADP-NADPH.

Soil Enzyme Activity Changes in Different-Aged Spruce Forests of the Eastern Qinghai-Tibetan Plateau

Activities of selected soil enzymes (invertase, acid phosphatase, proteinase,catalase, peroxidase and polyphenoloxi-dase) were determined under different spruce forests withrestoration histories of 5, 13, 18, 23, 27 years and an old growth forest over 400 years old in theeastern Qinghai-Tibetan Plateau, China, and their possible use as indicators of ecosystems healthwere analyzed. Plots 10 X 10 m with 4 replications were established to investigate three hypotheses:soil enzyme activities a) would increase with the restoration process; b) would be greater insurface soils than at lower depths; and c) would be correlated to selected physicochemicalproperties. Results showed that as the forests developed after restoration, invertase and peroxidaseactivities usually increased up to the 23 year point. Also soil enzyme activities were associatedwith surface soils and decreased with depths, suggesting that in earlier restoration stages surfaceaddition of organic fertilizer to soils might be more effective than additions at depth. In the 0-20cm soil, there were significant correlations (P < 0.01 or < 0.05) between some soil enzymeactivities and some selected chemical properties. Therefore, temporal changes in enzyme activitiesshould be included as an indicator when evaluating sustainable forest management practices.

Comparison of deep desulfurization methods in alumina production process

Several methods of deep desulfurization in alumina production process were studied, and the costs of these methods were compared. It is found that most of the S2- in sodium aluminate solution can be removed by adding sodium nitrate or hydrogen peroxide in digestion process, and in this way the effect of S2- on alumina product quality is eliminated. However, the removal efficiency of 2?32OS in sodium aluminate solution is very low by this method. Both S2- and 2?32OS in sodium aluminate solution can be removed completely by wet oxidation method in digestion process. The cost of desulfurization by wet oxidation is lower than by adding sodium nitrate or hydrogen peroxide. The results of this research reveal that wet oxidation is an economical and feasible method for the removal of sulfur in alumina production process to improve alumina quality, and provide valuable guidelines for alumina production by high-sulfur bauxite.

Physiological Response of Hydrilla verticillata （I.f.） Royle Exposed to Cadmium Stress

Hydrilla verticillata （I.f.） Royle twigs were exposed to CdCI2 （50, 100, 200 and 500 BM） under continuous light for 48 hrs and the physiological parameters like photosynthetic pigment （chlorophylls a, b and carotenoids） contents, activities of antioxidative enzymes like superoxide dismutase （SOD）, catalase （CAT） and peroxidase （POX） along with lipid peroxidation level were determined. With respect to increase in Cd concentration in the medium and exposure duration, decrease in pigment contents, and decrease in the activities of SOD, CAT and POX were found. The increased levels of lipid peroxidation indicated the prevalence of oxidative stress situation in the tissues which might be one of the reasons behind Cd induced toxicity in Hydrilla verticillata. Since there was significant decrease in the activities of key antioxidative ezymes, the study suggests that Hydrilla verticillata may not be effective for phytoremediation of cadmium in these concentration ranges.

Degradation of p-nitrotoluene by O_3/H_2O_2 process and oxidation mechanism

The degradation of p-nitrotoluene by O3/H2O2 process in a bubble contact column was investigated. Effects of the molar ratio of hydrogen peroxide to ozone,pH value and t-butanol on the oxidation process were discussed. It was found that the proper H2O2/O3 molar ratio for the degradation of p-nitrotoluene was around 0.6, different pH values and the presence of t-butanol highly influenced the removal efficiency of p-nitrotoluene. 5-methyl-2-nitrophenol, 2-methyl-5-nitrophenol, (4-nitrophenyl) methanol, 5-(hydroxymethyl)-2-nitro phenol, acetic acid, 2-methylpropane diacid and 2-(hydroxylmethyl)propane diacid were identified as degradation intermediates and products through GC-MS. Radical reaction mechanism and degradation pathway were proposed based on the results of experiments. It is deduced that the benzene ring of p-nitrotoluene can be only destroyed by hydroxyl radicals through a polyhydroxy intermediate pathway. Then unstable polyhydroxy intermediates can be oxidized to different acids with low molecular weight rapidly.

Photoelectrocatalytic hydrogen peroxide production based on transition‐metal‐oxide semiconductors

As a kind of valuable chemicals,hydrogen peroxide(H2O2)has aroused growing attention in many fields.However,H2O2 production via traditional anthraquinone process suffers from challenges of large energy consumption and heavy carbon footprint.Alternatively,photoelectrocatalytic(PEC)production of H2O2 has shown great promises to make H2O2 a renewable fuel to store solar energy.Transition‐metal‐oxide(TMO)semiconductor based photoelectrocatalysts are among the most promising candidates for PEC H2O2 production.In this work,the fundamentals of H2O2 synthesis through PEC process are briefly introduced,followed by the state‐of‐the‐art of TMO semiconductor based photoelectrocatalysts for PEC production H2O2.Then,the progress on H2O2 fuel cells from on‐site PEC production is presented.Furthermore,the challenges and future perspectives of PEC H2O2 production are discussed.This review aims to provide inspiration for the PEC production of H2O2 as a renewable solar fuel.

Effect of Iron on Growth, Pigmentation and Antioxidative Activity of Bloom Forming Cyanobacteria

Cyanobacterial blooms are ubiquitous in fresh and brackish eutrophic waters in India. The cyanotoxins produced by many bloom forming cyanobacteria severely affect the health of animals, fishes, birds and human beings. Different physical and chemical factors contribute towards bloom formation. Ten bloom forming cyanobacteria were isolated from natural blooms of northern India. The strains were purified and enriched in the laboratory. The aim of this study was to understand the influence of iron on growth, pigmentation and antioxidative activity of enzymes-catalase and ascorbate peroxidase of bloom forming cyanobacteria. Results show that different strains of bloom forming cyanobacteria attain optimum growth at varied concentration of iron. The cyanobacterial strains like Synechocystis aquatalis, Merismopedia glauca, Anabaena variabilis and Anabaena iyengarii exhibit maximum growth at low iron concentration （2 pM） while some species require higher concentration of iron for their optimum growth namely, Arthrospira platensis show optimum growth at 10uM, and Nostocpaludosum shows maximum growth at 100uM concentration of iron. It was also noticed that chlorophyll and phycobiliprotein content also varies with change in iron concentration. The activity of antioxidative enzymescatalase and ascorbate peroxidase was noticed in all ten cyanobacterial strains. In the light of the findings, it seems that Arthrospira platensis possess maximum catalase and ascorbate peroxidase activity. Increment in concentration beyond optimum value leads to deterioration in the growth, pigment content and enzymatic activity of the cyanobacterial strains. Knowledge about the factors influencing growth of bloom forming cyanobacteria will help to work out ways for eradication of hazardous cyanobacterial blooms.

Experimental and model comparisons of H_2O_2 assisted UV photodegradation of Microcystin-LR in simulated drinking water

The degradation of Microcystin-LR (MC-LR) in water by hydrogen peroxide assisted ultraviolet (UV/H2O2) process was investigated in this paper. The UV/H2O2 process appeared to be effective in removal of the MC-LR. MC-LR decomposition was primarily ascribed to production of strong and nonselective oxidant-hydroxyl radicals within the system. The intensity of UV radiation, initial concentration of MC-LR, MC-LR purity, dosages of H2O2, the initial solution pH, and anions present in water, to some extent, influenced the degradation rate of MC-LR. A modified pseudo-first-order kinetic model was developed to predict the removal efficiency under different experimental conditions.