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71.
Professor Luciano Bovicelli Nicola Rizzo Vera Montacuti Raffaella Morandi Calogero Vullo Cristina Toffoli Anna Venturoli 《黑龙江环境通报》1988,8(7):495-500
We report a series of 350 patients submitted to transabdominal chorionic villus sampling (CVS). A technique using two ultrasound-guided needles and a suction pump was used. In most cases, the procedure was performed between 9 and 13 weeks. Twenty-one pregnancies were selectively terminated; nine spontaneous abortions followed the procedure and one fetal loss after 28 weeks was recorded; 153 pregnancies are in progress and 169 delivered fetuses are alive and well. Transabdominal biopsy is a feasible and effective technique for CVS. 相似文献
72.
A case of spontaneous abortion after transcervical CVS is presented. Despite no evidence of bacteria in the vagina and cervix prior to sampling and the prophylactic use of Metronidazole, pathological evidence of chorioamnionitis was found. The implications of this are discussed. 相似文献
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由于可吸入颗粒物严重影响大气环境质量和人体健康,对其研究愈来愈受到重视.我国北京、南京、重庆等城市对可吸入颗粒物均做过系统的研究,而目前在淮南市仍是空白.总结近年来可吸入颗粒物方面的研究成果,对淮南市在此方面的研究提出若干建议,供研究者参考. 相似文献
75.
Demonstration of Line Transect Methodologies to Estimate Urban Gray Squirrel Density 总被引:2,自引:0,他引:2
Eric W. Hein 《Environmental management》1997,21(6):943-947
Sciurus carolinensis ) have been labor intensive and costly, I demonstrate the use of line transect surveys to estimate gray squirrel density and
determine the costs of conducting surveys to achieve precise estimates. Density estimates are based on four transects that
were surveyed five times from 30 June to 9 July 1994. Using the program DISTANCE, I estimated there were 4.7 (95% CI = 1.86–11.92)
gray squirrels/ha on the Clemson University campus. Eleven additional surveys would have decreased the percent coefficient
of variation from 30% to 20% and would have cost approximately $114. Estimating urban gray squirrel density using line transect
surveys is cost effective and can provide unbiased estimates of density, provided that none of the assumptions of distance
sampling theory are violated. 相似文献
76.
J. V. Bonta C. R. Amerman T. J. Harlukowicz W. A. Dick 《Journal of the American Water Resources Association》1997,33(4):907-917
ABSTRACT: A study was conducted to determine the effects of mining and reclaiming originally undisturbed watersheds on surface-water hydrology in three small experimental watersheds in Ohio. Approximately six years of data were collected at each site, with differing lengths of premining (Phase 1), mining and reclamation (Phase 2), and post-reclamation (Phase 3) periods. Mining and reclamation activities showed no consistent pattern iii base-flow, and caused slightly more frequent higher daily flow volumes. Phase 2 activities can cause reductions in seasonal variation in double mass curves compared with Phase 1. Restoration of seasonal variations was noticeably apparent at one site during Phase 3. The responses of the watersheds to rainfall intensities causing larger peak flow rates generally decreased due to mining and reclamation, but tended to exceed responses observed in Phase 1 during Phase 3. Natural Resources Conservation Service (NRCS) curve numbers increased due to mining and reclamation (Phase 2), ranging from 83 to 91. During Phase 3, curve numbers remained approximately constant from Phase 2, ranging from 87 to 91. 相似文献
77.
环境保护要依靠公众参与——关于环境保护主要依靠力量的市民调查 总被引:2,自引:1,他引:2
环境问题和环境保护已日益深入到社会政治、经济、文化、生活各个领域。在呼吁公众参与的条件下,依靠谁去搞好环境保护?公众是如何看待自己在环境保护中的作用的呢?对这些问题的回答将有助于了解公众关于环境保护的心态,有助于环境保护公众参与政策更具有针对性的实施。本文就这一话题进行了城市居民的抽样调查。调查表明,公众普遍认为,政府和公众参与是搞好环保的主要依靠力量;而公众对环境宣传教育和污染企业的治理以及技术进步的期望较低。本文进一步分析了不同年龄、文化程度、职业和人均月收入带来的影响,以期把握不同层次公众的心态。在此基础上本文就环境宣传教育如何促进公众参与提出了一些思考。 相似文献
78.
矿井通风系统模糊可靠性研究 总被引:2,自引:1,他引:2
定义模糊可靠度为一个服从正态分布的模糊数,并以模糊数作为通风系统的各风路可靠度,进而提出了矿井通风系统的模糊可靠度计算方法。同时在置信水平上,确定矿井通风系统的普通可靠度置信区间。若=1,则模糊可靠度计算转化为可靠度计算。 相似文献
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