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21.
The most widely used method for fetocide in late termination of pregnancy for fetal abnormalities (TOPFA) consists of injecting of potassium chloride (KCl) into the fetal heart and is likely to be painful after 22 weeks of gestation. We studied ten consecutive women undergoing TOPFA between 22 and 38 weeks. This technique for fetocide consisted of a single umbilical vein puncture under ultrasound guidance with injections of sufentanil 5 µg followed by KCl 2 g. No electrocardiographic modifications could be observed and maternal plasma potassium levels did not show any significant variation throughout the procedure. Fetal umbilical phlebotomy for fetal analgesia followed by fetocide therefore appears to be a safe procedure for the mother and allows the fetus to die without pain when late termination of pregnancy (TOP) is indicated. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   
22.
中国可持续发展综合评价研究   总被引:19,自引:3,他引:16  
可持续发展作为一个动态、开放的复杂巨系统。人口、资源、经济、环境和科技构成了其关键要素。本文基于PREEST系统模型。首先提出了一套中国可持续发展综合评价指标体系:同时。借助于主成分分析法和隶属度分析法。就中国1987~2001年度的综合发展指数与协调发展指数进行了实证分析;最后。基于研究成果。对中国未来的可持续发展提出了若干政策建议。  相似文献   
23.
The structure of the choroid plexus was studied in five normal human embryos, three normal fetuses and three fetuses with choroid plexus cysts. These were detected by ultrasound and the fetuses were karyotypically normal. The choroid plexus appears in the lateral cerebral ventricles at the seventh developmental week. The early structure is lobulated with vessels running in the mesenchymal stroma and forming capillary nets under the single-layered ependymal epithelium. This embryonal structure is converted into the fetal type during the ninth developmental week as the embryonal capillary net is replaced by elongated loops of wavy capillaries that lie under regular longitudinal epithelial folds. The choroid plexus cysts exhibited accumulation of fluid within distended mesenchymal stroma and did not show the wavy folds on this surface, which was smooth. Within this connective tissue of the cyst wall were distended angiomatous interconnecting thin-walled capillaries. Therefore, filled cavities were not lined by any epithelium. We suggest that fetal choroid plexuses cysts (at least in many cases) are in fact pseudocysts exhibiting angiomatous patterns of capillaries in their walls. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   
24.
防灾预案研究   总被引:1,自引:0,他引:1  
陆立德  徐旭初 《灾害学》1992,7(2):17-20
本文提出了防御灾害预案的五要素和逻辑结构,进而讨论了防灾预案的优化准则、制定程序等问题。  相似文献   
25.
A case of type III congenital cystic adenomatoid malformation of the lung was successfully diagnosed prenatally by fetal lung biopsy. We performed this procedure at 22 weeks of gestation, using a biopsy gun system under ultrasound guidance. The pregnancy was undisturbed by the procedure but as the condition was incompatible with life, an abortion was performed. The diagnosis was confirmed at post-mortem examination. Fetal lung biopsy appears to be a useful method for prenatal diagnosis of fetal lung disorders.  相似文献   
26.
27.
岷江上游崩塌滑坡分布规律研究   总被引:1,自引:0,他引:1  
岷江为长江—级支流,上游长330km,自1986年以来,发生崩塌滑坡200余处,体积约2.1亿m ̄3。作者研究了岷江上游崩塌滑坡的分布规律。采用统计指标法,将岷江上游分为三种不同的崩塌滑坡分布密度区:①UXS.高密度区;②MXS,中密度区;③LXS_3低密度区。  相似文献   
28.
三峡工程与长江中游沿江产业带建设   总被引:3,自引:0,他引:3  
讨论了长江中游沿江产业带发展条件、限制因素和未来发展,指出三峡工程的建设将对长江中游产业的布局和经济发展带来深刻的变化;防洪作用促进中游两岸大型工业项目的兴建,调整现有沿江城镇的布局,使之结构趋于合理化;电力供应经解能源的紧张状态,改善航运条件,发挥长江黄金水道的综合效益。当然,由于坝下河道冲刷,对现有的码头带来一定的影响,由于冬季水位抬升引起两岸低湖田地下水位上升,加剧两岸土壤潜育化和沼泽化。  相似文献   
29.
Ligustrum lucidum Ait. f. tricolor (Rehd.) Rehd. in relation to atmospheric pollutants in Córdoba city, Argentina. The study area receives regional pollutants and was categorized taking into account traffic level, industrial density, type of industry, location of the sample point in relation to the street corner, treeless condition, and topographic level. Dried weight/fresh weight ratio (DW/FW) and specific leaf area (SLA) were calculated, and concentrations of chlorophylls, carotenoids, total sulfur, soluble proteins, malondialdehyde (MDA), and hydroperoxy conjugated dienes (HPCD) were determined in leaf samples. Sulfur content correlates positively with traffic density and SLA correlates negatively with some combinations of the categorical variables; MDA correlates positively with topographic level and total protein concentration correlates negatively with treeless condition. On the basis of our results, traffic, location of trees, type of industry, situation of a tree with respect to others, and topographic level are the environmental variables to bear in mind when selecting analogous sampling points in a passive monitoring program. An approximation to predict tree injury may be obtained by measuring DW/FW ratio, proteins, pigments, HPCD, and MDA as they are responsible for the major variability of data.  相似文献   
30.
Benthic macroinvertebrate communities in streams adjacent to cornfields, streams where cows had unrestricted access, and reference locations without agriculture were compared to examine the effects of local land use and land use/land cover in the watershed. At each local site, macroinvertebrates and a variety of habitat parameters were measured upstream, adjacent, downstream, and farther downstream of the local land use. A geographic information system (GIS) was used to calculate drainage basin area, land use/land cover percentages in each basin, and the distance from sample sites to the stream source. Three‐way analysis of covariance (ANCOVA) tests with date, site type, and sampling location as main effects were used to explore differences in macroinvertebrate metrics using median substrate size, percent hay/pasture area, and stream depth as covariates. The covariates significantly improved model fit and showed that multiple contributing factors influence community composition. Local impacts were greatest at sites where cows had access, probably because of sedimentation and embeddedness in the substrate. Differences between the upstream and the adjacent and downstream locations were not as great as expected, perhaps because upstream recolonization was reduced by agricultural impacts or because of differences in the intensity or proximity of agriculture to riparian areas in the watershed. The results underscore the importance of both local and watershed factors in controlling stream community composition.  相似文献   
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