Rapid detection of numerical aberrations of chromosomes 13, 18 and 21 in chorionic mesenchymal cells

We have devised and evaluated a rapid screening method for the detection of numerical aberrations of chromosomes13, 18 and 21 in chorionic villus cells. We used non-radioactive in situ hybridization (ISH) with three chromosome-specific probes on overnight-attached mesenchymal cells from chorionic villi. A blind study was performed of 47 karyotypically normal samples, one triploid sample, two samples trisomic for chromosome 21, and two samples from a fetus with putative mosaicism (46/47, +21). All samples were hybridized with the chromosome 18- and 21-specific probes. Thirty samples were additionally hybridized with the chromosome 13-specific probe. The test could be completed within 3-4 days of sampling. In samples disomic with respect to the probed chromosomes, an average of 2 per cent (range 0-9 per cent) had three hybridization signals. By contrast, in the samples trisomic for the probed chromosome(s), 57 per cent (chromosome 13), 51 per cent (chromosome 18), and an average of 74 per cent (55-86 per cent) (chromosome 21) of the nuclei exhibited three signals. In the putative mosaic samples, the number of nuclei with three chromosome 21-specific signals ranged from 41 to 69 per cent. We conclude that this technique rapidly and clearly distinguishes between normal and trisomic/triploid samples, and consequently may be of use in future prenatal diagnosis.     

四川盆地土壤微量元素生态类型研究

本研究从生态学观点出发,根据土壤缺乏微量元素的临界值指标,探究了四川盆地土壤微量元素的生态类型,按其土壤供给有效态微量元素的丰缺程度,将本区土壤微量元素分为五种生态类型:严重缺乏、缺乏、适中、丰富和很丰富。统计结果表明,四川盆地各类土壤的微量元素生态类型特点为:有效硼含量很低,普遍严重缺硼;有效锌含量亦低,近半数土壤缺锌;多数土壤有效锰含量丰富,仅少部分土壤供锰不足;有效铜和铁的含量丰富。     

论环境质量管理在线监控指挥系统建设

本文着重阐述在原有的“污染源在线监控系统”的基础上，通过架构更高层次的“环境质量管理在线监控指挥系统”，在环境监察行政执法上突破原有的“运动式”执法和宏观表面管理，实现在环境监察行政执法上的“点对点”数字化精确管理与在线指挥，在环境质量管理上突破原有的人工行政审批制，实现“以人为本”的环境质量管理电子政务行政许可制，以及由此带来环境质量管理理念、管理机制和环境监察行政执法工作模式的创新。提高行政效能，服务经济建设。     

“十五”环境规划编制方法的改革

在分析中长期环境规划发展趋势的基础上,结合可持续发展的要求,从6个方面探讨了“十五”环境规划编制方法的改革与创新的具体方案。     

关于中国生活垃圾渗滤液排放标准的探讨

介绍了美国、德国、日本等国的渗滤液排放标准,并与中国现行的<生活垃圾填埋污染控制标准>(GB16889-1997)中的渗滤液排放标准相比较,指出了其存在的排放标准统一化、限值过于严格、控制项目不足等问题,并针对这些问题提出了相关的建议.     

独立学院教学中的四忌

独立学院的学生与母体高校学生相比有一定的特殊性。独立学院的教学如若完全沿用母体高校的方法和要求,势必会出现一些问题和矛盾。为此,在独立学院教学中,教师应注意四忌。