特异性拟杆菌引物在珠江三角洲的适应性研究

在珠江三角洲地区采集人、猪、牛、狗以及家禽等33个粪便样品,高效提取基因组DNA,选取14种特异性拟杆菌引物进行检验分析,并进一步采用已知污染源类型的水样对其进行验证.结果表明:采用粪便样品DNA专属提取试剂盒和水体样品DNA专属提取试剂盒提取的基因组模版纯度和提取率均符合后续实验要求.拟杆菌通用引物2#(Bac32F/Bac708R)检出率为85%(28/33),特别是对哺乳类动物和鸡的粪便具有更高的检出率.人的拟杆菌特异性引物3#(HF134F/ Bac708R)和4#(HF183F/Bac708R)、反刍动物的拟杆菌特异性引物8#(CF128F/Bac708R)以及猪的拟杆菌特异性引物10#(PF163F/Bac708R)在珠江三角洲地区同时具有较高的灵敏度和较强的特异性.水体样品验证实验与实际污染类型相符,说明拟杆菌通用引物2#、人的特异性引物3# 和4# 以及猪的特异性引物10# 在珠江三角洲地区具有很好的适用性.     

西太湖秋季蓝藻水华过后细胞裂解对溶解性有机碳影响

从2009年7月~2010年3月每月采集西太湖表层水样,分析叶绿素含量﹑蓝藻细胞裂解速率﹑磷酸盐浓度的变化,并通过切向流超滤系统分离得到的高分子量(1kDa~0.5μm)溶解性有机物的碳氮比值和高分子量溶解性有机碳浓度的变化.结果表明,西太湖蓝藻细胞裂解速率在11月达到最大值(0.43d-1),而磷酸盐和高分子量溶解性有机碳浓度分别在12月与9月达到最大值.细胞裂解速率与磷酸盐﹑高分子量溶解性有机碳浓度之间没有相关性,说明水华过后影响磷酸盐浓度﹑高分子量溶解性有机碳的因素很多,蓝藻细胞裂解只是其中重要因素之一.藻类水华的出现可能导致水体中其它磷形态(如有机磷)与磷酸盐之间的迁移转化,而大型浅水湖泊扰动导致的沉积物再悬浮和水华过后频繁的细菌活动都可能是影响高分子量溶解性有机碳的因素.秋季水华过后蓝藻细胞裂解释放的有机碳进入微食物网循环,引起细菌活动频繁,而溶解性有机物中含碳化合物比含氮化合物容易降解,所以碳氮比值逐渐减少.此外细菌通过硝酸盐合成溶解性有机氮也可能是碳氮比值减少的一个重要原因.     

Effects of benzo(a)pyrene on blood components,tumor markers,and oxidative status in mice

This study was carried out to investigate the effect of long-term exposure to benzo(a)pyrene (B(a)P) in mice. Hemogram, tumor markers, oxidative status, and B(a)P residues in liver tissue were evaluated. Sixty albino Swiss mice were randomly distributed equally into three groups; the control was given 0.1?mL corn oil once a week for 8 weeks. The other two groups were given 20 and 40?mg B(a)P per kg body weight once a week orally for the same period. B(a)P-treated mice suffered from depression and ascites, and macrocytic normochromic anemia was recorded at the 16th and 30th week. There was marked leukocytosis with lymphocytosis at the early stage of the experiment, followed by leukopenia, lymphopenia, and neutropenia at the end of the experiment. Monocytes and arginase activity were elevated throughout the experiment. Alpha feto-protein was detected only in the experimental groups in the 30th week of the experiment. A marked increase in lipid peroxides associated with a decrease in reduced glutathione and glutathione-S-transferase (GST) activity was observed in liver homogenate of the B(a)P-exposed animals. Residues of B(a)P were detected in liver tissue with a concentration parallel to the B(a)P dose level. In conclusion, B(a)P caused abnormal changes in the hemogram, evidence of tumor formation through B(a)P-induced oxidative stress, and it was accumulated in the liver tissue of mice.     

Determination and QSPR analysis of log Kow and log Koc for fluorine containing benzene derivatives

Octanol‐water partition coefficients (Kow) and soil organic carbon sorption coefficients (Koc) were determined for 14 fluorinated benzene derivatives. Quantitative structure‐property relationships were developed using molecular connectivity indices and quantum chemical parameters to analyze the most significant factors influencing these physico‐chemical properties of the compounds. The substitution by F in benzene derivatives has greater influence on Koc than on Kow.     

发酵制药废水二级出水中溶解性有机物特性分析

溶解性有机物（DOM）是发酵制药废水二级生化尾水深度处理工艺的主要去除对象,深入解析废水中DOM的特性是将其有效去除的前提和关键.本研究采集氨基酸类、头孢类、抗生素类、维生素类、阿维菌素类5种发酵制药废水二级出水,通过XAD-8树脂亲疏水性分离、凝胶色谱分子量分级、傅里叶变换红外光谱和三维荧光表征对二级出水中的DOM进行特性分析.结果表明,5种发酵制药废水二级出水的盐度和色度高,废水中有机物浓度高、波动大（48.60~245.40 mg·L^-1）.DOM大多数以疏水性组分为主,分子量分布广泛（210~10000 Da）.二级出水DOM均含有大量的不饱和双键、苯环结构,同时含有—OH、—NH₂和C=O等发色团和助色基团,造成废水色度较高.通过对发酵制药废水二级出水进行EEM-PARAFAC分析确定了4种荧光组分特征峰,包括3种腐殖质类（C1、C3、C4）和1种类蛋白类组分（C2）.发酵制药废水二级出水中DOM主要是以类腐殖质有机物为主（C1、C3）.全方面识别和解析发酵制药废水DOM的组成,可为废水深度处理工艺的优化提供指导.     

铁磁性纳米材料的制备及对17β-雌二醇的选择性富集——基于分子印迹技术

将铁磁性分离与分子印迹技术结合,以四氧化三铁纳米颗粒为核,以17β-雌二醇(E2)为模板分子,3-氨基丙基三乙氧基硅烷(APTES)为功能单体,利用表面聚合法制备了E2分子印迹纳米材料(MIPs)和不含E2的非印迹纳米材料(NIPs).通过傅里叶变换红外光谱(FT-IR)、X射线衍射(XRD)、X射线光电子能谱(XPS...     

油松叶绿体DNA间隔序列特点及系统学意义

对全国分布区12个天然油松种群进行取样,测定了叶绿体DNAtrnT-trnL、trnS-trnG、trnL-trnF基因间隔序列,分析了序列碱基组成特点及在松科系统分类中的意义.测序结果显示,3个片段碱基序列均富含A/T,长度依次为448bp、636bp和421bp,所测片段在种群水平上十分保守,没有发现具有种内鉴别意义的碱基变异.但此片段适合于松科属间和种间的系统学分析,运用PHYLIP软件构建松科植物的邻接系统树,支持松科分为两个亚科的分类系统,拓扑结构表明松属与银杉属的关系最近.由于叶绿体DNA序列长度适中,扩增和测序较为容易,适合作为研究松科植物系统进化较为理想的分子标记.图2表2参24     

监测水体重金属污染的分子生物标志物研究进展

水体重金属污染具有持久性、高度危害性和难治理性,如何快速、准确监测并对其进行科学评价,成为当今环境科学关心的热点问题。大量研究表明,水生生物体内某些生理指标的变化可以反映水体重金属的污染程度。综述了乙酰胆碱酯酶、抗氧化防御系统、腺苷三磷酸、DNA损伤以及金属硫蛋白等几种分子水平上的生物标志物监测重金属污染的原理、国内外研究进展以及应用现状。认为分子生物标志物具有特异性、敏感性等优势,可以较快指示水体重金属污染对生物体的影响,在实际应用中需注意各种干扰因素。在进行野外研究时,要注重混合重金属与多途径暴露下,分子生物标志物的变化规律。生物体之间差异性会导致标志物在同样暴露条件下产生不同的变化规律,需要加强＂离体＂标志物和＂标准化＂标志物的研究,确保监测结果的可靠性和可重复性。生物标志物较为敏感,容易受到外界环境及体内生理因素影响,可考虑综合运用多种生物标志物指示重金属污染。目前,有关重金属对水生生物毒性效应的研究较多,但重金属对生物体的致毒机理方面研究并不深入,这将是今后研究的重点问题之一。     

Degradation of chlorinated phenols by nanoscale zero-valent iron

Chlorophenols (CPs), as important contaminants in groundwater, are toxic and difficult to biodegrade. Recently nanoscale zero-valent iron received a great deal of attention because of its excellent performance in treating recalcitrant compounds. In this study, nanoscale zero-valent iron particles were prepared using chemical reduction, and the reductive transformations of three kinds of chlorinated phenols (2-CP, 3-CP, and 4-CP) by nanoscale zero-valent iron under different conditions were investigated. The transformation process of the CPs was shown to be dechlorination first, then cleavage of the benzene ring. The removal efficiency of the CPs varied as follows: 2-CP > 3-CP > 4-CP. The reactivity of CPs was associated with their energy of lowest unoccupied molecular orbit (E _LUMO). With the increase in initial concentrations of CPs, removal efficiency decreased a little. But the quantities of CPs reduced increased evidently. Temperature had influence on not only the removal efficiency, but also the transformation pathway. At higher temperatures, dechlorination occurred prior to benzene ring cleavage. At lower temperatures, however, the oxidation product was formed more easily. __________ Translated from China Environmental Science, 2006, 26(6): 698–702 [译自: 中国环境科学]     

链状高分子金属配合物催化氧化苯乙烯

利用链状Salen型高分子希夫碱金属配合物PLSBM(M:CoⅡ,MnⅡ,ZnⅡ,CuⅡ)作为催化剂,催化分子氧氧化苯乙烯.结果表明,在不添加任何助剂和共还原剂的条件下,氧化产物以苯甲醛(Ⅰ)和环氧苯乙烷(Ⅱ)为主,PLSBCuⅡ具有最佳的催化活性和产物选择性.考察了影响氧化反应的因素,发现在反应温度为90℃、反应时间为9h和催化剂与苯乙烯用量比为1mg∶2mL时,苯乙烯具有最优的转化率(61％)和产物选择性(Ⅰ:57％,Ⅱ:36％).