苯甲酸类化合物对发光菌的毒性及定量构效

测定了9种苯甲酸类化合物在pH=7时对发光菌的急性毒性(15min-EC50)。应用两种理化参数TSA和ELUMO对毒性数据进行了定量构效关系(QSARs)研究,并在此基础上初步探讨了苯甲酸类化合物的毒性机制。结果表明,苯甲酸类化合物对发光菌的毒性随取代基团的种类及取代位置不同而不同;苯甲酸类化合物对发光菌的致毒机制中可能有亲电作用发生,毒性可用TSA和ELUMO来联合描述。     

一种便携式荧光测油仪在海上溢油应急监测中的适用性研究

研究了一种便携式荧光测油仪在海上溢油应急监测中的适用性,并与现行仲裁标准方法进行比较分析。研究表明:该便携式荧光测油仪测定海水中油类样品仅需100 mL水样,平均每个样品所需的前处理时间约340 s,方法检出限为0.003 mg/L,测定下限为0.012 mg/L。测定用标准物质配制的不同浓度海水样品,相对标准偏差为0.08%~0.87%,测定标准样品的相对误差为0.49%~4.50%,实际样品加标回收率为90%~107%。对标准物质配制的海水样品进行检测,与现行仲裁标准方法在0.05水平下无显著性差异。在渤海中部海上监测中,连续6 d测定不同标准样品的相对标准偏差为0.26%~0.83%。研究结果表明,该便携式荧光测油仪适用于现场对油类的定量分析和水质评价。     

Duplex PCR for preimplantation genetic diagnosis (PGD) of spinal muscular atrophy

The main difficulty in developing a molecular diagnosis of spinal muscular atrophy (SMA) resides in the specific genomic structure of the locus. Indeed, two highly homologous survival motor neurone genes, SMN1 and SMN2, are present at the locus. The detection of the homozygous deletion of exons 7 and 8 of the SMN1 gene, which is present in 90 to 98% of the patients, is based on methods highlighting 1 of the 8 nucleotidic mismatches existing between these 2 genes. In order to offer preimplantation genetic diagnosis (PGD) for SMA, we developed a new allele-specific amplification method. The main disadvantage of our previously described strategy resided in the possibility of diagnosing, in case of amplification failure, an unaffected embryo as affected. We present here a new PGD-SMA method. We established the conditions for three different duplex PCRs, allowing the specific detection of the SMN1 gene and one polymorphic marker, either D5S629, D5S1977, or D5S641. Of the 60 to 90 single cells tested, the PCR efficiency varied from 98 to 100% with a complete genotype obtained in a range between 81 and 87% with a global allele drop-out rate of 9%. Such a test was used to perform 1 PGD cycle for which 7 embryos could be analysed. All the embryos were fully diagnosed, six as unaffected and one as affected. Four embryos were transferred, but no pregnancy ensued. Copyright © 2003 John Wiley & Sons, Ltd.     

Pitfalls in molecular diagnosis in a family with severe factor VII (FVII) deficiency—misdiagnosis by direct sequence analysis using a PCR product

Molecular diagnostic tests are becoming a routine analysis in many laboratories. These modern analyses are widely used in clinical medicine, forensic, genetic and prenatal diagnosis and also in preimplantation genetic diagnosis. The accuracy of analysis is highly dependent on the success achieved in minimising genotyping errors. The pitfalls in molecular diagnostic tests can be due to a simple technique such as the polymerase chain reaction (PCR) used universally. This technique is routinely used for its apparent accuracy, but it is also a well-known source of errors. We report an error introduced during PCR reaction that leads to a wrong sequence result and consequently to a ‘false’ molecular result in a next prenatal diagnosis in a family with severe factor VII (FVII) deficiency. This error was verified using an unsuitable primer design in a rich repetitive sequence of the FVII gene that leads to a false annealing and then to a wrong molecular diagnosis. It is essential to link closely molecular data with clinical and phenotype analysis in order to avoid false-negative or false-positive results, which is of great importance to diagnosis and molecular prevention. Copyright © 2003 John Wiley & Sons, Ltd.     

云南洱海沉积物中硫酸盐还原菌的时空分布特征

利用PCR扩增和荧光原位杂交方法分析了云南洱海沉积物中硫酸盐还原菌(Sulfate-reducing bacteria,SRB)类群和数量的时空分布特征。结果表明,秋季沉积物中检测出四个SRB类群(脱硫肠菌属、脱硫叶菌属、脱硫球菌属-脱硫线菌属-脱硫八叠菌属和脱硫弧菌属-脱硫微菌属),而春季沉积物中只检测出三个类群(脱硫肠菌属、脱硫叶菌属和脱硫球菌属-脱硫线菌属-脱硫八叠菌属)。相比春季,秋季沉积物检测出来的SRB类群具有更大的分布范围,同时,检测出的SRB类群主要分布在沉积物上部;从数量上来看,秋季沉积物SRB数量高于春季沉积物。上述结果指示秋季沉积物环境条件更适于SRB群落。此外,相比洱海秋季,洱海春季沉积环境溶解氧含量较高,且温度较低,这可能导致脱硫弧菌属-脱硫微菌属在洱海春季沉积物中处于不可育状态,由于其活性低而无法检测。     

西部煤矿建设项目土地资源影响量化评价研究

以煤矿建设项目对土地资源影响的特点和规律为基础,满足该类项目环境影响评价要求为指导,以陕西省黄陵建庄矿区建北矿井及选煤厂新建项目为例,介绍西部煤矿建设项目土地资源影响量化评价的方法与思路,是西部煤矿项目土地资源影响评价深化的一种研究,有利于协调煤炭资源开发与土地资源保护问题.     

天津沿岸海水中创伤弧菌的PCR检测和定量

采用普通PCR方法和SYBR Green实时定量PCR方法,根据创伤弧菌16S rDNA和23S rDNA基因间隔序列(internal transcribed spacer,ITS)设计引物,对渤海湾天津沿岸海水中的创伤弧菌进行了定性和定量检测.8个样品采集自天津市汉沽区沿岸海水,采集时间分别为2008年7月、10月和2009年3月、5月.PCR检测结果表明,这些样品都能扩增出276 bp的ITS序列,这些序列和GenBank上的同源序列(DQ462478)的相似性为96%～98%.用SYBR Green实时定量PCR方法测定了8个海水样品,样品中创伤弧菌的浓度为7.12×10~3～8.40×10~5 个/L,表明天津沿岸海水存在严重的创伤弧菌污染.     

天津市典型排污河水体中溶解性有机质的荧光分布特征分析

利用三维荧光光谱研究了天津市两条典型排污河(大沽排污河和北塘排污河)沿河水体中溶解性有机质(DOM)的荧光分布特征,并通过对荧光参数——紫外区类富里酸峰中心位置的荧光强度与可见区类富里酸峰中心位置的荧光强度比值(r(A,C))和激发光波长370nm时荧光发射光谱强度在450nm与500nm处的比值(f450/500)的分析,探讨了水体中DOM的来源.结果表明,大沽排污河除中游个别位置外,其它位置水体均能检出紫外区类富里酸、类蛋白、可见光区类腐殖质、紫外区类腐殖质,总体上呈中游少、上下游多的特点;而北塘排污河水体中DOM的荧光峰从上游到下游呈增多趋势,但检出数量比较少.两条排污河水体中DOM均以紫外区类腐殖质最强.两条排污河水体中DOM的荧光强度与其水质参数之间存在显著相关性,而大沽排污河的相关系数更大.结合荧光参数r(A,C)和f450/500的分析和现场对入河排污口的调研,发现两条排污河的溶解性有机质来源均以入河排污口排污汇入(陆源)为主,另外还有少量沉积物有机质释放(微生物作用).     

某货车侧翻水污染事件的环境损害评估方法探索

随着我国进入突发水污染事件高发期,面临的水环境形势日益严峻.为了震慑环境污染行为,保证受损的环境资源得到恢复和补偿,量化突发性水污染事件造成的经济损失显得至关重要.本文以重庆市某货车侧翻污染事件为例,构建了一套突发水污染事件环境损害的量化评估方法,并用该方法从财产损害、生态环境资源损害、应急处置行政事务投入费用和调查评估费用这4个方面量化了该事件造成的环境污染损害.