Trophoblast-like cells sorted from peripheral maternal blood using flow cytometry: A multiparametric study involving transmission electron microscopy and fetal dna amplification

Three monoclonal antibodies (MAbs) against trophoblast (GB17, GB21, and GB25) and flow cytometry were used to sort trophoblast-like cells (TLCs) from peripheral blood of pregnant women. Sorted TLCs were processed for electron microscopy and fetal DNA amplification of the Y-specific sequences from mothers carrying male fetuses. At the ultra-structural level, most of the nucleated cells had the morphology of leucocytes, suggesting maternal contaminants, and we did not find the characteristic features of the free inter-villous trophoblast cells. Nevertheless, polymerase chain reaction (PCR) analysis showed an amplification of Y-specific sequences in two out of three samples of sorted TLCs. These results suggest that besides the maternal leucocytes, sufficient trophoblast nucleated fetal cells can be obtained using cell enrichment by sorting. This sensitive method holds promise for non-invasive prenatal diagnosis of fetal sex and if sufficient Y(positive) nuclei are found, for the diagnosis of selected numerical chromosome abnormalities.     

Gold mining in Siberia and the Far East as a source of mercury contamination of the environment

ＩｎｔｒｏｄｕｃｔｉｏｎＳｉｂｅｒｉａａｎｄｔｈｅＦａｒＥａｓｔａｒｅｔｈｅｏｌｄｅｓｔａｎｄｔｈｅｒｉｃｈｅｓｔｇｏｌｄ ｍｉｎｉｎｇａｒｅａｓｏｆＲｕｓｓｉａ .Ｉｎｔｅｎｓｉｖｅｇｏｌｄ ｍｉｎｉｎｇｈｅｒｅｓｔａｒｔｅｄｉｎｔｈｅｂｅｇｉｎｎｉｎｇｏｆｔｈｅ 19ｔｈｃｅｎｔｕｒｙ(Ｖｙａｚｅｌｓｈｃｈｉｋｏｖ ,1963) .Ｆｏｒｔｈｅｍｏｓｔｐａｒｔｇｏｌｄ ｂｅａｒｉｎｇｏｒｅｓａｎｄｓａｎｄｓｗｅｒｅｐｒｏｃｅｓｓｅｄｗｉｔｈｔｈｅｕｓｅｏｆａｍａｌｇａｍａｔｉｏｎｍｅｔｈｏｄｆｏｒｇｏｌｄｅ…     

关于农业污染纠纷综合处理的思考

揭示了农业污染纠纷的内涵,提出了处理农业污染纠纷的４个“支撑点”,即运用农业技术先行界定,运用监测数据科学鉴证;运用因果关系逻辑推定,强化环境管理,疏通综合处理渠道等。     

一种新结构静电除油雾器的电场分析

文章分析了一种新结构静电除油雾器的电场结构.结果表明改进电极板形状和组合形式是提高电场处理能力的途径之一.在传统的针一板结构电极的后端增加一组特殊形状极板,可以收到明显效果.这种结构电场在满足一定处理效率的基础上提高了电场风速,并减小设备体积、降低成本.     

自然条件下石羊河终闾湖泊模拟研究

石羊河流域史前曾存在大面积的终闾湖泊---猪野泽。自西汉开拓河西以后的两千多年以来,受人类活动影响,石羊河流域土地覆盖发生了显著的变化。灌溉农田取代了天然绿洲,而且面积逐步扩大,农业用水急剧增加,猪野泽逐渐退缩成许多小湖,并于近代干涸。在假设人类活动（主要是灌溉）对水资源未加利用的条件下（理想状态）,通过确定流域的水量收支和改进水量平衡模型,对石羊河流域现代自然条件下“终闾湖”的面积进行了模拟重建,得出现代终闾湖的面积至少应为５８０ｋｍ^２。     

Review of information on pesticide residues in the Canadian environment

Summary Pesticide residues in soil, water, food, wildlife and other media have been analysed in several monitoring studies. The purpose was to establish the distribution of these residues across a defined area, ascertain their trend over a specific period and use the results to assess environmental compliance and safety. In the present review the availability of information on pesticide residues in various Canadian environmental components was sought. With the possible exception of localized pesticide contamination of some private water supply wells, ground and surface water, most analyses revealed concentrations below guideline limits. Only a few cases were reported of mishandling, misuse and poisoning from pesticides. Continuing surveillance programmes and in-depth and well-organized monitoring studies, with special focus on areas that are vulnerable to contamination, by both provincial and federal governments, are largely responsible for the encouraging results. This experience in the control of pesticide use and monitoring of residues in the environment should be of particular interest in developing countries.Dr A.Y. Sangodoyin is a senior lecturer in the Department of Agricultural Engineering at the University of Ibadan. He was recently involved in a study visit to the University of Alberta, Edmonton, Alberta, Canada T6G 2G7, where his co-author Dr D.W. Smith is a member of staff in the Department of Civil-Engineering.     

Enzyme-Retted Flax Fiber and Recycled Polyethylene Composites

Municipal solid wastes generated each year contain potentially useful and recyclable materials for composites. Simultaneously, interest is high for the use of natural fibers, such as flax (Linum usitatissimum L.), in composites thus providing cost and environmental benefits. To investigate the utility of these materials, composites containing flax fibers with recycled high density polyethylene (HDPE) were created and compared with similar products made with wood pulp, glass, and carbon fibers. Flax was either enzyme- or dew-retted to observe composite property differences between diverse levels of enzyme formulations and retting techniques. Coupling agents would strengthen binding between fibers and HDPE but in this study fibers were not modified in anyway to observe mechanical property differences between natural fiber composites. Composites with flax fibers from various retting methods, i.e., dew- vs. enzyme-retting, behaved differently; dew-retted fiber composites resulted in both lower strength and percent elongation. The lowest level of enzyme-retting and the most economical process produces composites that do not appear to differ from the highest level of enzyme-retting. Flax fibers improved the modulus of elasticity over wood pulp and HDPE alone and were less dense than glass or carbon fiber composites. Likely, differences in surface properties of the various flax fibers, while poorly defined and requiring further research, caused various interactions with the resin that influenced composite properties.     

电网建设项目竣工环保验收初探

电网建设项目竣工环保验收工作,在我国还处于起步阶段,江苏省电力公司根据电网建设项目数量多,工程类型相似,污染因子单一,环境影响较小的特点,在组织环保验收的工作中,摸索出建立环保验收档案,选择典型线路和监测点,“打包”进行运行期环境影响评价等方法,2年内成功地完成了300多项110～220 kV电网建设项目的环保验收,这种大批量电网建设项目环保监测和验收的模式,得到了地方环保部门的肯定.