Twin–twin transfusion syndrome—possible roles for doppler ultrasound and amniocentesis

A 29-year-old woman was referred for suspicion of twin-twin transfusion syndrome (TTTS). Several ultrasonographic and neonatal criteria of TTTS were encountered in this twin pregnancy. The peculiar observations in this case were, firstly, the demonstration of superficial anastomosis by Doppler ultrasound and, secondly, that one single therapeutic amniocentesis could have been sufficient to partially correct the progression of the syndrome, as after amniocentesis it was no longer possible to demonstrate the vascular communication. This observation suggests that superficial anastomoses could also have a role in the genesis of TTTS. Their effect could be monitored by Doppler ultrasound and could be more easily corrected by therapeutic amniocentesis.     

Human impact on current environmental state in Chinese lakes

Anthropogenic and natural disturbance to inland aquatic ecosystems displays a notable spatial difference, yet data to measure these differences are scarce. This study encompasses 217 lakes distributed over five lake regions of China and elucidates the environmental factors determining the spatial variability of the water quality and trophic status. A significant correlation between human modification index in surrounding terrestrial systems (HMT) and trophic status of lake ecosystems (TSI) was found, and the regression slope in each region was similar except in the Qinghai-Tibet Plateau region. It was further noted that the pattern of environmental factor network (EF network) differed among freshwater and saline lakes. The EF network was complex for freshwater lakes in less human-influenced areas, but intensive man-made influence disrupted most relationships except for those between total nitrogen, total phosphorus, chlorophyll-a, and water turbidity. As for regions including saline lakes, correlations among water salinity and organic forms of carbon and nitrogen were apparent. Our results suggest that HMT and EF network can be useful indicators of the ecological integrity of local lake ecosystems, and integrating spatial information on a large scale provides conservation planners the option for evaluating the potential risk on inland aquatic systems.     

沈阳市生活垃圾处理现状与对策

中国城市生活垃圾的产量不断增加,其组分也越来越复杂,处理难度和成本在逐渐加大,城市生活垃圾问题已越来越受到全世界的关注,文章简述了沈阳市生活垃圾的产量、成分、收集、运输和处理等概况,并就生活垃圾管理与处置过程中存在的问题,提出了相应的对策.     

化工厂区域土壤中砷的化学形态与分布特征

本文通过对大连化工厂区域土壤样品中砷的水溶态、碳酸铵交换态、盐酸溶解态、氢氧化钠溶解态、残渣态的析,以及各种形态中三价、五价砷的测定,评价该区砷的分布特征和污染现状,为研究砷在环境中的迁移规律和污染防治提供科学依据.     

Atmospheric Particle Hygroscopicity and the Influence by Oxidation State of Organic Aerosols in Urban Beijing

A hygroscopic tandem differential mobility analyser (H-TDMA) was used to observe the size-resolved hygroscopic characteristics of submicron particles in January and April 2018 in urban Beijing. The probability distribution of the hygroscopic growth factor (HGF-PDF) in winter and spring usually showed a bimodal pattern, with more hygroscopic mode (MH) being more dominant. The seasonal variation in particle hygroscopicity was related to the origin of air mass, which received polluted southerly air masses in spring and clean northwesterly air masses in winter. Particles showed stronger hygroscopic behaviour during heavy pollution episodes (HPEs) with elevated concentrations of secondary aerosols, especially higher mass fraction of nitrate, which were indicated using the PM_2.5 (particulate matter with diameter below 2.5 µm) mass concentration normalised by CO mass concentration. The hygroscopic parameter (κ) values were calculated using H-TDMA (κ_htdma) and chemical composition (κ_chem). The closure study showed that κ_chem was overestimated in winter afternoon when compared with κ_htdma, because the organic particle hygroscopic parameter (κ_org) was overestimated in the calculations. It was influenced by the presence of a high concentration of hydrocarbon-like organic aerosol (HOA) with a weak water uptake ability. A positive relationship was observed between κ_org and the ratio of oxygenated organic aerosol (OOA) and HOA, thereby indicating that the strong oxidation state enhanced the hygroscopicity of the particles. This study revealed the effect of local emission sources and secondary aerosol formation processes on particle hygroscopicity, which is of great significance for understanding the pollution formation mechanism in the North China Plain.     

长更号轮客舱内空气质量跟踪调查

对上海海运局所属长更轮进行了４个航次的客轮舱内的空气质量跟踪调查，主要监测了ＣＯ２、ＣＯ２、ＮＯｘ、ＣＨ２Ｏ和ＩＰ等污染因子，调查结果表现，三、四、五等客舱的室内空气均受到污染，相对而言，前两者污染较轻，而后者较严重，空气综合质量指数，甲板上的数据远小于１，三、四等客舱略大于１，五等客舱则远大于１。     

Collagen biosynthesis in cell culture from chorionic villi

After chorionic villus biopsy of human placenta, cell cultures were propagated with Ham's F10 medium or Eagle's minimum essential medium (MEM). It was possible to study the morphology of the cells by transmission electron microscopy (TEM) after a special culture of the cells in a collagen gel. The cells embedded in a collagen gel were able to contract the gel and to organize collagen fibres, as fibroblast cultures do. TEM showed vacuolization and well-developed cisternae of the endoplasmic reticulum, especially in the case of MEM culture. The aim was to determine whether cells cultivated from early placenta were able to synthesize enough collagen for a metabolic study. A high level of collagen biosynthesis could be quantified. Types I and III collagen can be determined which is useful for studying the abnormalities of collagen synthesis in suspected cases of osteogenesis imperfecta or Ehlers–Danlos type IV syndrome. The hydroxylation of lysine can also be studied with respect to Ehlers–Danlos type VI syndrome. Moreover, these cells, in contrast to fibroblast cultures, made it possible to study the biosynthesis of type IV collagen.     

我国若干湖泊水库的营养状态指数TSI_c及其与各参数的关系

基于我国２０多个湖泊水库的不同营养状态特征，首次得出了适用于我国若干湖泊的营养状态指数ＴＳＩｃ及其与各参数的关系，通过对这些湖泊的ＴＳＩｃ与ＴＳＩｍ值比较，指出ＴＳＩｃ比ＴＳＩｍ更适合于描述生物量与营养盐呈线性响应的我国这类湖泊的营养状态，此外还提出用相关加权法综合不同参数的营养状态指数，并用一个“综合”状态式来表示湖泊的营养状态。     

静态混合器在污水处理装置上的应用

介绍了螺旋式管道静态混合器的结构和原理．在PTA污水处理装置上，采用三级静态混合器进行得水混合，代替了均质池加搅拌机的传统混合方法．收到了良好的效果．实现了投资省、耗能低、维修容易、混合效果好的目的．为污水处理领域进行污水混合提供了新的行之有效的方法．     

Amylo-1,6-glucosidase activity in cultured cells: A deficiency in type III glycogenosis with prenatal studies

Deficiency of amylo-1,6–glucosidase activity was expressed in parallel in liver and skin fibroblasts from a patient with type III glycogenosis. In crude extracts of control liver and muscle, amylo-1, 6–glucosidase (M.W. 164000) was identified by immunoprecipitation; no cross-reacting material was found in the patient's liver. Assay of amylo-1,6–glucosidase activity in cultured skin fibroblasts from the affected family revealed less than 10 per cent of control value in mutant homozygous cells whereas in cells from the parents, activity was reduced to 40–60 per cent of the control value. Activity in cultured amniotic fluid cells was similar to that of control fibroblasts. In cultured amniotic fluid cells obtained during the mother's subsequent pregnancy, the normal amylo–1,6–glucosidase activity measured, predicted correctly the outcome of this pregnancy prior to the 20th week of gestation.