首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   653篇
  免费   2篇
  国内免费   3篇
安全科学   8篇
环保管理   1篇
综合类   631篇
基础理论   8篇
污染及防治   3篇
评价与监测   2篇
社会与环境   3篇
灾害及防治   2篇
  2021年   6篇
  2020年   1篇
  2018年   2篇
  2017年   3篇
  2016年   2篇
  2013年   4篇
  2012年   5篇
  2011年   31篇
  2010年   32篇
  2009年   34篇
  2008年   26篇
  2007年   37篇
  2006年   40篇
  2005年   54篇
  2004年   42篇
  2003年   43篇
  2002年   57篇
  2001年   25篇
  1999年   1篇
  1996年   1篇
  1995年   27篇
  1994年   43篇
  1993年   22篇
  1992年   14篇
  1991年   25篇
  1990年   11篇
  1989年   11篇
  1988年   14篇
  1987年   11篇
  1986年   4篇
  1985年   11篇
  1984年   10篇
  1983年   3篇
  1982年   2篇
  1981年   4篇
排序方式: 共有658条查询结果,搜索用时 15 毫秒
101.
We report a case of prenatal diagnosis of trisomy 20p resulting from a maternal pericentric inversion. The diagnosis was confirmed on both chorionic villi and amniotic cells. This case underlines the fact that prenatal ultrasound diagnosis of this structural anomaly is difficult. The only early sonographic feature was increased nuchal translucency. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
102.
103.
104.
105.
106.
107.
108.
109.
Maternal serum unconjugated oestriol (uE3) was measured in 15 375 pregnancies during 2 years of second-trimester risk assessment for Down syndrome using biochemical markers. Very low levels of uE3 (<0·1 MOM) were detected in 22 serum samples (0·14 per cent). Very low uE3 was associated with an adverse outcome in 13 pregnancies including fetal death and miscarriage (N=11), anencephaly (N=1), and Meckel—Gruber syndrome (N=1). Dry scales on the skin appeared in the first year of life in four boys. From dermatological diagnosis, prenatal uE3 levels, and pedigree analysis, it is concluded that at least 5 in approximately 7500 male births in the study population are affected by steroid sulphatase deficiency, which is the biochemical defect in X-linked ichthyosis. Very low uE3 levels in the second trimester are indicative of this disease in pregnancies with normal ultrasound findings.  相似文献   
110.
Adult respiratory distress syndrome (ARDS) is a clinical syndrome which occurs due to various direct or indirect noxious agents and pyhsical mechanisms. One of the etiological factors is ingested chemicals (e.g. paraquat, ethylene glycol). The organophosphorous (OP) insecticides are the most toxic and frequently encountered chemicals that produce poisoning in humans. Studies were undertaken to investigate whether OP insecticides may produce ARDS. Fifteen autopsy cases due to suicidal OP insecticide poisoning were investigated. Toxicological analyses were performed with a gas chromatography-nitrogen phosphorous detector (GC-NPD). Methamidophos, dimefox and dichlorvos were the detected OP. Lungs were examined macroscopically. Two cases showed features compatible with ARDS in which the only cause of death was OP poisoning. Due to the severity of ARDS it is important to assess insecticidal exposure in an attempt to enhance survival patterns following OP poisoning in patients in order to initiate therapy.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号