苯酚、苯胺及其衍生物对斜生栅列藻的急性毒性及QSAR研究

本文应用ＯＥＣＤ标准方法测定了１８种酚类胺类化合物对斜生栅列藻的４８ｈ－ＥＣ６０值，选择参数ＥＬＵＭＯ和ｌｇＫｏｗ进行了ＱＳＡＲ分析，得到下列回归方程：－１ｇＥＣ５０＝２．５４１－０．６４９ＥＬＵＭＯ＋０．２９９ＬｇＫｏｗ，ｎ＝１８，ｒ＝０．９０３，ＳＥ＝０．３１４应用所得方程计算了化合物的毒性，探讨了毒机理。     

联苯代谢对微生物的生长胁迫及分裂抑制

以联苯/多氯联苯降解菌株R04（Rhodococcus sp.R04）和几种模式微生物为研究对象，利用高效液相色谱、荧光显微镜、扫描电子显微镜等分析微生物在联苯及其代谢物培养条件下细胞分裂和形态的变化.结果表明联苯及其代谢产物对红球菌R04和几种模式微生物细胞的分裂有抑制作用，并对部分微生物形态有影响.与前体-联苯及其代谢产物2-羟基-6-酮基-6-苯基-2，4-己二烯酸相比，2，3-二羟基联苯对G⁺、G^-细菌，或是酵母细胞分裂都有较强的抑制和形态的改变.2，3-二羟基联苯导致R.R04和缺陷型R.R04细胞形成不完整隔膜的比例增加；造成96.4%的大肠杆菌BL21细胞表面凹陷，胞质内容物流失，菌体体积缩小；导致枯草芽孢杆菌89.6%的细胞体积明显缩小；导致金黄色葡萄球菌基本没有细胞能形成完整的分裂隔膜；导致红酵母细胞能进行出芽生殖的比例从64.2%降低到19.3%，但对其细胞形态无明显改变.联苯代谢物2，3-二羟基联苯对红球菌R04及其它微生物细胞分裂和增殖的抑制作用比其前体-联苯强，建议在研究环境化合物与微生物互作时，应考虑环境化合物代谢的毒性效应.     

Regulation (EC) No. 1107/2009 and upcoming challenges for exposure assessment of plant protection products--Harmonisation or national modelling approaches?

In the new European Pesticide Regulation (EC) No. 1107/2009, the harmonisation of approaches for estimation of the environmental exposure of pesticides is considered a major goal. Several member states currently require their own models for the calculation of predicted environmental concentrations (PEC) in surface water. The variety of methods makes risk evaluations rather time-consuming for both notifiers and evaluating authorities. In the present study we compare surface water concentrations of 19 compounds using EU and country-specific models and risk assessment approaches to evaluate to which extent the resulting estimated exposure concentrations differ. Our results show that EU and country specific approaches and the resulting surface water concentrations differ considerably regarding basic model assumptions and assessment methods. The results indicate that the aimed harmonisation of risk assessment approaches within the EU will be difficult based on current models. New scenarios may help to achieve a harmonisation taking country-specific features into account.     

Hydroxytyrosol, the phenolic compound of olive oil protects human PBMC against oxidative stress and DNA damage mediated by 2,3,7,8-TCDD

The protective effect of hydroxytyrosol (HT), a strong antioxidant compound from extra virgin olive oil, against TCDD induced toxicity was investigated in human peripheral blood mononuclear cells (PBMC). PBMC (1 × 10⁶ cells mL⁻¹) were divided into four groups and were incubated in a CO₂ incubator (5% CO₂) for 12 h with vehicle, TCDD (10 nM), TCDD + HT (10 nM + 100 μM) and HT alone (100 μM) respectively. To clarify the role of HT against TCDD induced cytotoxicity, oxidative stress and the levels of antioxidant enzymes were assessed. Incubation of PBMC with TCDD significantly decreased cell viability, catalase (CAT) and glutathione peroxidase (GPx) and increased the levels of superoxide dismutase (SOD), glutathione reductase (GR) and oxidative stress markers such as lipid peroxidation products (LPO), protein carbonyl content (PCC) and reactive oxygen species (ROS). Whereas, HT had an effective antioxidant property as observed by the increased cell viability, normalization of antioxidant enzymes and decreased levels of LPO, PCC and ROS in PBMC co-treated with HT and TCDD. Apoptosis detection and comet assay results shows that HT, by acting as an antioxidant, prevents the damage to DNA induced by TCDD. In addition light microscopic and histopathological observations revealed that the cells are apoptotic and degenerated during TCDD treatment, whereas cells showed intact morphology during co-treatment with HT. On the whole, the results reveal that HT exerts a promising antioxidant potential in protecting the PBMC against TCDD induced oxidative stress, which might be due to the presence of catechol moiety in its structure.     

阿特拉津在土壤中的生物降解研究

运用恒温培养法研究了阿特拉津在河北省白洋淀地区农田土壤中的生物降解动力学，并从中分离鉴定了土壤中降解阿特拉津的优势菌种，研究结果表明，该土壤对阿特拉津具有一定的降解能力，非生物＋生物的降解、非生物降解和生物降解的速率分别为０．０２６２ｄ＾－１，０．００５５４８ｄ＾－１和０．００８１９４ｄ＾－１，半衰期分别为２６ｄ，１２５ｄ和８５ｄ，发现土壤中降解阿特拉津的优势菌种为蜡状芽孢杆菌（Ｂａｃｉｌｌｕｓ     

The relationship between diversity profiles,evenness and species richness based on partial ordering

Problems with the notion of evenness, such as ambiguity, proliferation of indices, choice of indices, etc. can be overcome by a more fundamental, mathematical approach. We show that the Lorenz curve is an adequate representation of evenness. The corresponding Lorenz order induces a partial order in the set of equivalent abundance vectors. Also diversity can adequately be studied through a partial order and represented by a curve derived from the classical Lorenz curve. This curve is known as the intrinsic diversity profile (or k-dominance curve) and was introduced by Patil and Taillie (1979) and Lambshead et al. (1981).     

纤维藻(Ankistrodesmus sp.)对镍的吸附、吸收作用及镍对其细胞形态结构影响

纤维藻（Ankistrodesmussp.）对镍毒作用反应敏感，对Ni     

强化混凝去除微污染原水胶体颗粒的研究

对珠江水系统进行了强化混凝处理，燕利用准弹性激光散射技术（PCS）对常规混凝和强化混凝前后水中胶体颗粒（小于0.45um)的大小与分布进行了测定,探讨了搅拌条件对混凝效果的影响。     

对硝基苯酚在沉积物上的吸附特性1

研究了沉积物吸附对硝基苯酚的作用机理及影响因素.结果表明,对硝基苯酚在沉积物上的吸附由其中的有机质含量和结构决定,体系的pH值对对硝基苯酚的吸附有较大的影响,其主要原因是体系的pH值控制着沉积物中有机质的溶出量.在实验浓度范围内,分配作用在沉积物吸附对硝基苯酚中占主导地位.     

苯蒸气在有机膨润土上的吸附动力学

本文研究了苯蒸气在溴化十六烷基三甲基胺（CTMAB）系列单阳离子有机膨润土上的吸附动力学过程。结果表明，苯蒸气在有机膨润土上的吸附符合一级动力学方程，即：r＝KvCo；在12h内，吸附反应均可达到平衡，吸附速率常数（Kv）与温度（T）成正相关，吸附反应的活化能在9．50－17．92kJ.mol^-1之间。