台州电子垃圾循环区域母乳中多氯联苯的污染现状

本文对浙江省台州市路桥和温岭两个电子垃圾循环区域母乳中多氯联苯(PCBs)污染现状进行了研究.路桥本地人群(n=16)、温岭本地人群(n=27)及在台州居住不足5年的外地人群(n=9)母乳中PCBs的中值浓度分别为195 ng·g-1脂重(lw)、138 ng·g-1lw和59.1 ng·g-1lw.路桥和温岭人群母乳中PCBs浓度显著高于在台州居住不足5年的外地人群(P<0.001),也远高于浙江省及中国背景区域水平.CB-118、CB-153和CB-138是台州母乳中最主要的3种同类物,与台州膳食样本中PCBs的指纹特征类似.路桥本地人群婴儿通过饮用母乳日摄入的PCBs量(EDI)(1024 ng·kg-1bw·d-1)略高于加拿大卫生部建议的成人对PCBs日耐受量(1000 ng·kg-1bw·d-1),温岭本地人群乳儿的EDI值(491 ng·kg-1bw·d-1)远高于我国12个省市EDI的均值(54.6 ng·kg-1bw·d-1),表明台州本地人群母乳喂养的婴儿处于较高的PCBs暴露风险中.母乳中PCBs浓度与母亲年龄、孕前体重指数、产次和婴儿的体重及性别无显著相关性.     

应用高效离子交换色谱分析青枯菌的致病力分

应用高效离子交换色谱和激光光散射仪检测器对不同致病力的青枯菌进行分析,建立了一种快速检测青枯菌致病力分化的新方法青枯菌纯培养物经过高效离子交换色谱分离得到3个致病力不同的特征峰,大小依次为峰3组分>峰2组分>峰1组分.对10株青枯菌进行色谱分析,并结合番茄组培苗感染试验检测其致病力,结果发现,强致病力菌株经过色谱分离只在峰3的保留时间位置出现单一特征峰,在9 d内即可引起100%的番茄组培苗发病;若菌株经过色谱分离形成3个特征峰,则峰3所占的面积比越大,该菌株的致病性相对就越强.25株不同致病力青枯菌的验证试验表明了该方法的可行性,番茄组培苗发病率x与峰3面积比y之间呈现出良好的线性关系,回归方程y=0.9581x+5.4984,相关系数r=0.986.通过对青枯菌色谱行为、致病力、细胞表而黏附的EPS Ⅰ含量三者之间相互关系的进一步研究,发现青枯菌的致病力越强,则细胞表面黏附的EPSⅠ越多,峰3所占的面积比就越大.图3表6参15     

青枯菌不同色谱峰组分的细胞表面特性

将高效离子交换色谱应用于植物重要致病菌——青枯菌的分离分析.青枯菌纯培养物经过色谱分离得到3个特征峰,收集3个色谱峰组分进行形态观察和生理生化鉴定,结果表明3个组分均属于青枯菌生化Ⅲ型;进一步分析发现,3个色谱峰组分在质粒DNA、细胞表面鞭毛菌毛蛋白含量和全细胞脂多糖成分方面无明显差异,但细胞表面黏附的胞外酸性多糖EPSⅠ含量差异显著;3个色谱峰青枯菌细胞表面疏水性的测定结果也证实了EPSⅠ是造成不同青枯菌细胞色谱行为差异的主要原因.高效离子交换色谱为细菌活细胞的研究提供了一种新方法.图4表2参15     

采用高效离子交换色谱分离分析动物肠道菌群方法初探

报道了利用高效离子交换色谱直接分离动物粪便肠道菌群的有关研究结果.人与兔的粪便样品稀释后经离心分离岀细菌,通过DEAE弱阴离子交换色谱(30cm×2cmi.d)进一步除去杂物,将所得细菌的完整细胞样品直接上样高效液相阴离子交换色谱进行分离.色谱柱采用TSKgelSuperQ-TOYOPEARL650C强阴离子交换树脂,平衡缓冲液为0.02mol/L的哌嗪-HCl缓冲液(pH8.0),吸附于色谱柱上的细菌完整细胞用0～1mol/LNaCl线性梯度进行洗脱,洗岀液由260nm紫外吸收与光散射强度检测器检测.人与兔粪便细菌样品分别获得8个与5个组分,经镜检与培养实验确认为细菌,并且光散射仪洗脱峰峰面积同细菌计数结果具有线性相关性.实验表明,高效离子交换色谱能够应用于肠道菌群这样的复杂细菌体系的分离分析.图5表2参11     

Identification methods of key contributing factors in crashes with high numbers of fatalities and injuries in China

Objectives: In China, serious road traffic crashes (SRTCs) are those in which there are 10–30 fatalities, 50–100 serious injuries, or a total cost of 50–100 million RMB (U.S.$8–16 M), and particularly serious road traffic crashes (PSRTCs) are those that are more severe or costly. Due to the large number of fatalities and injuries as well as the negative public reaction they elicit, SRTCs and PSRTCs have become of great concern to China during recent years. The aim of this study is to identify the main factors contributing to these road traffic crashes and to propose preventive measures to reduce their number.

Methods: 49 contributing factors of the SRTCs and PSRTCs that occurred from 2007 to 2013 were collected from the database “In-depth investigation and analysis system for major road traffic crashes” (IIASMRTC) and were analyzed through the integrated use of principal component analysis and hierarchical clustering to determine the primary and secondary groups of contributing factors.

Results: Speeding and overloading of passengers were the primary contributing factors, featuring in up to 66.3 and 32.6% of accidents, respectively. Two secondary contributing factors were road related: lack of or nonstandard roadside safety infrastructure and slippery roads due to rain, snow, or ice.

Conclusions: The current approach to SRTCs and PSRTCs is focused on the attribution of responsibility and the enforcement of regulations considered relevant to particular SRTCs and PSRTCs. It would be more effective to investigate contributing factors and characteristics of SRTCs and PSRTCs as a whole to provide adequate information for safety interventions in regions where SRTCs and PSRTCs are more common. In addition to mandating a driver training program and publicization of the hazards associated with traffic violations, implementation of speed cameras, speed signs, markings, and vehicle-mounted Global Positioning Systems (GPS) are suggested to reduce speeding of passenger vehicles, while increasing regular checks by traffic police and passenger station staff and improving transportation management to increase income of contractors and drivers are feasible measures to prevent overloading of people. Other promising measures include regular inspection of roadside safety infrastructure and improving skid resistance on dangerous road sections in mountainous areas.     

Research on the spatiotemporal evolution and influencing factors of green economic efficiency in the Yangtze River Economic Belt

Environmental Science and Pollution Research - In the Yangtze River Economic Belt (YREB), the green economy is an essential to sustainable economic development. In this study, we calculated a...