Discordant results between fetal karyotyping and non-invasive prenatal testing by maternal plasma sequencing in a case of uniparental disomy 21 due to trisomic rescue

Uniparental disomy (UPD) is an uncommon chromosome condition, but UPD involving chromosome 21 is rarely reported. We reported here a case who had first trimester screening test for Down syndrome, chorionic villus sampling for fetal karyotyping, quantitative fluorescence polymerase chain reaction (QF-PCR), as well as non-invasive prenatal testing (NIPT) by maternal plasma sequencing. There were discordant results between fetal karyotyping and NIPT due to UPD 21combined with confined placental mosaicism of trisomy 21. This demonstrated that it is possible to detect placental mosaicism by NIPT, but further studies are required to confirm its sensitivity. Therefore, all positive NIPT results must be confirmed by conventional invasive test and karyotyping. QF-PCR has the additional benefit in diagnosing UPD. © 2013 John Wiley & Sons, Ltd.     

一株对二甲苯降解菌的筛选鉴定及其降解特性

以对二甲苯为惟—碳源和能源,从某石化废水处理厂活性污泥中筛选得到一株对二甲苯降解菌株.生理生化实验、16S rDNA基因鉴定结果表明,该菌属于假单胞杆菌属(Pseudomonas sp.).通过对降解过程的动力学分析可知,该菌对底物的降解过程符合零级动力学特征,在初始对二甲苯质量浓度为800 mg/L时,降解速率常数最大,达18.43 mg/(L·h).在降解温度为30 ℃、废水pH为7.5、摇床转速为150 r/min的条件下,将5 mL菌液投加至32 mL对二甲苯质量浓度分别为840 mg/L和830 mg/L的焦化废水和石化废水中,降解84 h后基本无对二甲苯检出.     

Toluene decomposition performance and NOx by-product formation during a DBD-catalyst process

Characteristics of toluene decomposition and formation of nitrogen oxide (NOx) by-products were investigated in a dielectric barrier discharge (DBD) reactor with/without catalyst at room temperature and atmospheric pressure. Four kinds of metal oxides, i.e., manganese oxide (MnOx), iron oxide (FeOx), cobalt oxide (CoOx) and copper oxide (CuO), supported on Al₂O₃/nickel foam, were used as catalysts. It was found that introducing catalysts could improve toluene removal efficiency, promote decomposition of by-product ozone and enhance CO₂ selectivity. In addition, NOx was suppressed with the decrease of specific energy density (SED) and the increase of humidity, gas flow rate and toluene concentration, or catalyst introduction. Among the four kinds of catalysts, the CuO catalyst showed the best performance in NOx suppression. The MnOx catalyst exhibited the lowest concentration of O₃ and highest CO₂ selectivity but the highest concentration of NOx. A possible pathway for NOx production in DBD was discussed. The contributions of oxygen active species and hydroxyl radicals are dominant in NOx suppression.     

焦化废水生物脱氮半生产性试验启动研究

通过试验研究,探索了焦化废水生物脱氮半生产性启动条件,指出了顺利启动的关键技术是适宜的接种污泥及必须提供的环境条件。     

中国特色生产者责任延伸制度建设模式初探

概述了生产者责任延伸制度在发达国家的实施模式及其效果:探讨了建立中国PRO机构的可行性;提出了虚拟企业利用规模化资源共享来为群体用户提供信息化服务的设想:论述了"污染源"回收与无害化资源综合利用将成为下一轮投资热点的理由;简述了我国WEEE回收处理网络建设与推广项目的进展情况,以及发起单位下一步工作部署的部分内容.     

浅析生态文明理念对内蒙古草原旅游资源开发重要性

生态文明是继农业、工业文明之后,适应新形势而提出的.以直接解决与人类生存相关的生态问题为己任,用于指引人们实现可持续发展为目标.在内蒙古地区,草原是最具内蒙古特色和开发价值的资源,然而在近几十年的开发中严重违反了生态文明理念,以致出现草场退化、生物生存危机等状况.在当前内蒙古草原出现的严重问题的情况下,很有必要去探寻生态文明理念的重要价值.结合中国传统文化中天时地利人和的重要思想,实现在“因时制宜、因地制宜、以人为本及各方因素协调共促”理念下新的草原开发.     

三峡库区城镇建设用地驱动因子路径分析

随着三峡大坝的修建．三峡经济飞速发展．带动了利用三峡库区城镇建设用地的变化。本文以三峡库区21个县市1995—2005年城镇建设用用地的变化量为主要研究对象。结合1995-2005年期间第二产业与第三产业的集中指数与区位商的空间分布变化。采用路径分析建模的方法。奠立了城镇建设用地与固定资产投资、社会商品零售总额、第二产值、第三产值及城镇人口的路径模型．确定了备影响因子对蜮镇建设用地变化的影响程度。其中第二产值对城镇建设用地的变化影响最大．影响力最小的是城镇人口。此项研究进一步验证了路径分析模型在土地利用变化驱动力分析研究中的可行性．同时也为库区城镇建设用地的控制提供了参考。