两种不同形态MnO2降解卡马西平的效果及途径对比

研究了两种不同形态MnO₂（δ-MnO₂和胶体MnO₂）对难降解有机药物卡马西平（carbamazepine,CBZ）的去除效果,并通过液相色谱质谱联用技术（LC/MS）分析了不同pH值条件下δ-MnO₂和胶体MnO₂氧化转化CBZ的产物,探究其氧化转化途径.结果表明,δ-MnO₂和胶体MnO₂能通过化学氧化作用在2h内去除约1mg/L CBZ,相比之下,胶体MnO₂受pH影响较小且单位质量Mn对CBZ具有更好的去除效果.δ-MnO₂和胶体MnO₂与CBZ反应过程中各检出7种和4种产物.胶体MnO₂具有更强的氧化能力,越过了多种中间产物的产生步骤,使CBZ的降解途径更加简明.     

2,3,7,8-Tetrachlorodibenzo-p-dioxin promotes migration ability of primary cultured rat astrocytes via aryl hydrocarbon receptor

Emerging evidence showed that 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) could induce expression of certain reactivation-associated genes in astrocytes, however, the consequent cellular effects and molecular mechanisms are still unclear. During the process of astrocyte reactivation, migration is a critical cellular event. In the present study, we employed wound-healing assay and Transwell® motility assay to explore the effects of TCDD on cell migration in primary cultured rat cortical astrocytes. We found that upon TCDD treatments at relative low concentrations (10^? 10 and/or 10^? 9?mol/L), the ability of primary astrocytes to migrate horizontally and vertically was promoted. In line with this cellular effect, the mRNA expression of two pro-migratory genes, including cell division cycle 42 (CDC42) and matrix metalloproteinase 2 (MMP2) was induced by TCDD treatment. Dioxin exerts its toxic effects mainly through aryl hydrocarbon receptor (AhR) pathway. So the role of AhR pathway in the pro-migratory effects of TCDD was examined using an AhR antagonist, CH223191. We found that application of CH223191 significantly reversed the pro-migratory effects of TCDD. Interestingly, the basal ability of horizontal migration as well as basal levels of CDC42 and MMP2 expression were dramatically reduced suggesting a possible physiological role of AhR in maintaining the endogenous migration ability of the primary astrocytes. These findings support the notion that dioxin promotes astrocyte reactivation at molecular and cellular levels.     

ANAMMOX富集与优化停曝比对MBR-SNAD工艺的影响

采用膜生物反应器（MBR）研究了厌氧氨氧化细菌在富集过程中的活性变化,在启动全程自养脱氮（CANON）工艺中以恒定曝气量,通过优化停曝比实现氨氧化细菌（AerAOB）和厌氧氨氧化细菌（AnAOB）协同脱氮并且有效抑制亚硝酸盐氧化菌（NOB）的活性,然后添加有机物（乙酸钠）逐步启动同步亚硝化-厌氧氨氧化耦合异养反硝化（SNAD）工艺.结果表明,在厌氧氨氧化细菌富集过程中,通过不断缩短水力停留时间（HRT）提高进水氮负荷的方式强化厌氧氨氧化细菌活性,其平均活性由0.603mgN/（h·gVSS）提高到了8.1mgN/（h·gVSS）;当恒定曝气量为50mL/min,停曝比为4：10（min：min）时,AerAOB和AnAOB对氨氮的去除量分别占总氨氮去除量的58.8%和41.2%,NOB氧化亚硝态氮的量占总硝态氮生成量的15.3%,成功抑制了NOB的活性;当C/N比为0.5,调整停曝比为4：15后,反硝化过程氮去除量占总氮去除率的20.9%,厌氧氨氧化过程氮去除量占总氮去除率的79.1%,实现了AerAOB、AnAOB和反硝化细菌（DNB）协同脱氮的目的.     

UV和UV/H2O2工艺对水中二嗪磷的降解

在低压汞灯（LPUV,253.7nm）光照条件下,研究了过氧化氢（H₂O₂）加入量对二嗪磷降解动力学、产物生成和降解途径的影响规律与作用机理.结果表明,二嗪磷水溶液在单独UV和UV/H₂O₂工艺中的降解反应均符合准一级反应动力学,且反应速率常数（k）随H₂O₂加入量的增加而增大,H₂O₂加入量为0,5,10mg/L时的k分别为0.0234,0.0301,0.0341min-1.在UV光照处理条件下,二嗪磷水溶液中的溶解性有机碳（DOC）随H₂O₂加入量的增加而降低,但其矿化度均相对较低（光照120min时的DOC去除率均低于20%）.此外,UV光照处理时,H₂O₂的加入对二嗪磷光氧化降解产物的种类及生成量均存在显著影响.二嗪磷水溶液单独UV光照处理60min时检出了8种中间/降解产物,但经UV/H₂O₂工艺处理60min时仅检出了6种中间/降解产物,且不同H₂O₂加入量时的光氧化降解产物生成量或浓度及随UV光照处理时间的变化幅度与趋势均存在较大程度的差别.基于二嗪磷及其降解产物的定性、（半）定量分析结果,提出了二嗪磷水溶液在单独UV和UV/H₂O₂工艺中的降解途径与机理.     

Heterogeneous photocatalytic degradation of diuron on zinc oxide: Influence of surface-dependent adsorption on kinetics, degradation pathway, and toxicity of intermediates

Heterogeneous photocatalytic reaction has been generally applied for degradation of toxic contaminants. Degradations of a compound using the same kind of catalyst that was synthesized differently are commonly found in literature. However, the reported degradation intermediates are normally inconsistent. This issue is especially important for the degradation of toxic compounds because intermediates may be more toxic than their parent compounds and understanding the reason is necessary if appropriate catalysts are to be designed. This work systematically compares the photocatalytic degradation of diuron, a toxic recalcitrant herbicide, on two forms of zinc oxide (ZnO), i.e., conventional particles with zinc- and oxygen-terminated polar surfaces as the dominating planes, and nanorods with mixed-terminated nonpolar surfaces. Experimental and theoretical results indicate that both the rate of reaction and the degradation pathway depend on the adsorption configuration of diuron onto the surface. Diuron molecules adsorb in different alignments on the two surfaces, contributing to the formation of different degradation intermediates. Both the aliphatic and aromatic sides of diuron adsorb on the polar surfaces simultaneously, leading to an attack by hydroxyl radicals from both ends. On the other hand, on the mixed-terminated surface, only the aliphatic part adsorbs and is degraded. The exposed surface is therefore the key factor controlling the degradation pathway. For diuron degradation on ZnO, a catalyst confined to mixed-terminated surfaces, i.e., ZnO nanorods, is more desirable, as it avoids the formation of intermediates with potent phytotoxicity and cytogenotoxicity.     

Prenatal diagnosis of NADH:ubiquinone oxidoreductase deficiency

NADH:ubiquinone oxidoreductase (complex I of the mitochondrial respiratory chain) deficiency is a severe disorder with an often early fatal outcome. Prenatal diagnosis for complex I defects currently relies mainly on biochemical assays of complex I in fetal tissues such as chorionic villi (CV), and is only in a minority of cases possible by means of mutational analysis of nuclear-encoded genes of complex I. We report on our experience to date with prenatal diagnosis in pregnancies at risk for complex I deficiency. We measured complex I activity in native CV and/or cultured CV in 23 pregnancies in 15 families. In accordance with the results of the investigations in CV, 15 children were born clinically unaffected. Two prenatally diagnosed unaffected fetuses and two prenatally diagnosed affected fetuses were lost prematurely with spontaneous or provoked abortions, respectively. Two affected children were born (prenatally found to be affected). In two pregnancies a discrepancy between native and cultured cells was found. We conclude that prenatal diagnosis for complex I deficiency can be reliably performed. Pitfalls were encountered in using cultured CV as a result of maternal cell contamination (MCC). Future research on pathogenic nuclear mutations underlying complex I deficiency will extend the possibilities for prenatal diagnosis at the molecular level. Copyright © 2001 John Wiley & Sons, Ltd.     

Anaerobic phenanthrene biodegradation with four kinds of electron acceptors enriched from the same mixed inoculum and exploration of metabolic pathways

Anaerobic phenanthrene biodegradation enriched process was described in detail. The enriched bacterial communities were characterized under four redox conditions. The enriched archaeal communities were stated under high percentage conditions. Relatively intact pathways of anaerobic phenanthrene biodegradation were proposed. Polycyclic aromatic hydrocarbons (PAHs) are widespread and persistent contaminants worldwide, especially in environments devoid of molecular oxygen. For lack of molecular oxygen, researchers enhanced anaerobic zones PAHs biodegradation by adding sulfate, bicarbonate, nitrate, and iron. However, microbial community reports of them were limited, and information of metabolites was poor except two-ring PAH, naphthalene. Here, we reported on four phenanthrene-degrading enrichment cultures with sulfate, bicarbonate, nitrate, and iron as electron acceptors from the same initial inoculum. The high-to-low order of the anaerobic phenanthrene biodegradation rate was the nitrate-reducing conditions>sulfate-reducing conditions>methanogenic conditions>iron-reducing conditions. The dominant bacteria populations were Desulfobacteraceae, Anaerolinaceae, and Thermodesulfobiaceae under sulfate-reducing conditions; Moraxellaceae, Clostridiaceae, and Comamonadaceae under methanogenic conditions; Rhodobacteraceae, Planococcaceae, and Xanthomonadaceae under nitrate-reducing conditions; and Geobacteraceae, Carnobacteriaceae, and Anaerolinaceae under iron-reducing conditions, respectively. Principal component analysis (PCA) indicated that bacteria populations of longtime enriched cultures with four electron acceptors all obtained significant changes from original inoculum, and bacterial communities were similar under nitrate-reducing and iron-reducing conditions. Archaea accounted for a high percentage under iron-reducing and methanogenic conditions, and Methanosarcinaceae and Methanobacteriaceae, as well as Methanobacteriaceae, were the dominant archaea populations under iron-reducing and methanogenic conditions. The key steps of phenanthrene biodegradation under four reducing conditions were carboxylation, further ring system reduction, and ring cleavage.     

植物线粒体基因转录水平表达研究方法的建立

以茎瘤芥雄性不育系为材料,在已有文献的基础上,对常规方法进行改进,使植物线粒体分离、线粒体切片观察、线粒体RNA提取、反转录方法、PCR扩增、northern杂交等方法系统化,建立了一整套比较有效的适合于植物线粒体基因转录水平表达分析的方法.图4参12     

细胞凋亡的线粒体途径调控

细胞凋亡是近年来研究的一个热点问题，涉及到细胞内许多复杂的生化过程．线粒体是真核生物能量和代谢的中心，也是细胞凋亡信号传导途径中起关键调节作用的细胞器，对细胞凋亡的线粒体途径调控机制进行研究具有重要意义．本文综述了细胞凋亡过程中线粒体途径的信号传导及其调控机制、线粒体对细胞凋亡信号的反应、细胞凋亡过程中线粒体功能丧失几方面的研究进展．图1参43     

Alcaligenes sp.YF11菌对杀灭菊酯的降解机理

测定了降解菌Alcaligenessp.YF11对不同浓度杀灭菊酯的降解及其降解途径。在纯培养系统中,Alcaligenessp.YF11对100mg／L的杀灭菊酯的降解符合零级动力学特征,其降解速率为2．1mg／L·h;50mg／L的杀灭菊酯在24h的降解率为87.5％;10mg／L的杀灭菊酯10h的降解率为71．0％。Alcaligenesso．YF11对杀灭菊酯的降解为矿化作用。