Trisomy 7 in chorionic villi: Follow-up studies of pregnancy,normal child,and placental clonal anomalies

Cytogenetic study of chorionic villi sampled because of advanced maternal age revealed, after overnight culture, an apparently non-mosaic trisomy 7. Amniocentesis showed exclusively normal mitoses, and the pregnancy continued normally. One hundred mitoses from cord blood of the normal newborn revealed a non-mosaic 46,XX complement. No cells with a proven trisomy 7 were found in cultures from either of two biopsies of the morphologically normal placenta, but the peripheral biopsy showed in multiple cultures an abnormal clone: 47,XX, + 20,-2,-21, + t(2;21)(p13;q22). To our knowledge, this is the first case of non-mosaic trisomy 7 detected on CVS which has had follow-up studies of amniotic fluid, cord blood, and term placenta.     

Quantitative structure-property relationship of aromatic sulfur-containing carboxylates

IntroductionItiswidelyrecognizedthatthephysicochemicalprofileoforganicchemicalslargelydeterminestheirdistributionbetweenenvironmentalmedia .Fortheenvironmentalbehaviorsoforganiccontaminants,watersolubility(SW)andoctanol waterpartitioncoefficient(KOW)aretremendouslyimportant.Octanol waterpartitioncoefficienthasbeenwidelyrelatedtobiochemicaland orbiologicalactivityinquantitativestructure activityrelationships(QSARs) (Leo ,1 971 ) .Watersolubilitycorrespondstothedispersiontendencyandtothereca…     

含湿Ca(OH)2颗粒脱硫反应特性的模型研究

在半干法脱硫装置中脱反应主要表现为湿Ｃａ（ＯＨ）２颗粒与ＳＯ２的反应，在液相反应溶解和传质理论基础上，通过对含湿Ｃａ（ＯＨ）２颗粒内反应机理的研究分析提出了含湿Ｃａ（ＯＨ）２颗粒相比发生明显变化。     

有机气溶胶的来源与形成研究现状

介绍了有机气溶胶来源与形成的研究现状,从有机气溶胶的化学组成特征、一次有机气溶胶的来源和二次有机气溶胶的形成机制论述其研究进展.一次有机气溶胶主要来源于烹调油烟、机动车排放、生物质燃烧、工业或民用燃油锅炉释放出的有机物,还有道路扬尘、沥青、刹车尘、轮胎屑、室外香烟烟雾、以及高等植物蜡、细菌活动和草本植物等.大气中的半挥发性有机物可通过物理和化学吸附形成二次有机气溶胶,一些挥发性有机物可通过气相化学反应转化为低挥发性的物质并形成二次有机气溶胶,其主要前体物是芳香族化合物,如苯、甲苯、二甲苯,以及烯烃、烷烃、环烷烃、萜烯和生物排放的非饱和氧化物.     

Influence of chlorsulfuron herbicide on size of microbial biomass in the soil

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Methods for project-based mechanisms (JI/CDM)—relevance of IPCC inventory guidelines

A baseline for a project consists of estimates of annual emissions of greenhouse gases (GHG) for a given time period without implementing the project. A general three-step process for determining the baseline is suggested. The emission reduction of the project is given by the difference between the baseline and the monitored annual emissions. A preferred method, direct measurement of the emission reduction, is possible for some types of projects. Methods for estimating the annual baseline emissions are not necessary for the latter category, and a definition of this project category is suggested. IPCC Guidelines for National GHG Inventories categorise the emission sources so that only direct emissions from consumption of fuel and feedstock are calculated. There are thus no emission factors for indirect emissions (e.g. electricity consumption or km transported) or emission factors that depend on technology only, independent of consumption of fuel and feedstock. Technology-dependent emission factors may thus need to be developed for estimating indirect emissions and multi-project baselines. Consistency should be sought with the IPCC Guidelines when estimating annual baseline emissions and in monitoring project emissions to ensure comparability with the National Inventories.     

Enhanced cyanogen chloride formation after UV/PS and UV/H2O2 pre-oxidation and chlorination in natural river water

Ultraviolet/persulfate (UV/PS) and Ultraviolet/hydrogen peroxide (UV/H₂O₂) have attracted much attention in recent years as advanced oxidation processes for water treatment. However, it is not all clear how these two methods affect the formation of cyanogen chloride (CNCl) in the subsequent water chlorination process. In this study, it was found that both UV/H₂O₂ and UV/PS pre-oxidation promoted the formation of CNCl in six actual water samples collected from urban rivers. Glycine, uric acid, arginine and histidine were investigated as the model compounds to explore the effects of different methods on the production of CNCl. The results showed that compared with chlorination alone, pre-oxidation by UV/H₂O₂ and UV/PS can reduce the production of CNCl for glycine and uric acid by up to 95% during post-chlorination process. However, they can greatly promote the formation of CNCl for arginine and histidine by up to 120-fold. In a more detailed investigation, pre-oxidation of histidine formed highly reactive intermediates to chlorine, leading to increased CNCl formation and chlorine consumption. The results showed that the precursors of CNCl was altered after pre-oxidation, and need to be re-evaluated.     

PVC附载TiO_2光催化剂的制备与评价

研究以PVC颗粒为载体、利用加热法制备附载型TiO2 光催化剂 ,并对其进行牢固性、附载率、使用寿命及活性等方面的评价     

DPIV技术测量流冰速度应用研究

基于数字信号分析原理,对连续两幅图像进行互相关分析,寻找互相关函数的峰值;应用数字粒子图像测速(digital particle image velocimetry)技术,并通过计算机VC编程,解决了用于雷达测量单点流冰速度的不足;为大范围区域内流冰场瞬时速度的计算,实时雷达测量辽东湾海上流冰速度场提供了有应用价值的方法.     

上海市在用车推行I/M制度中检测方法的研究

对在用车实施I/M制度，采用底盘测功机模拟道路工况检测汽车排放污染物，按美国国家环保局（EPA）推荐的方法有3种：瞬态短工总法（IM240）、稳态加速模拟工况法（ASM）和瞬态短工部简易质量分析检测法（VMAS）。根据上海市的试验结果，对上述3种方法的检测精度、设备投资以及运行维护诸方面进行分析比较，阐明上海市采用VMAS方法的依据和应注意的问题，并对应采用的模拟道路工况提出了看法。