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   1373183篇
  免费   120380篇
  国内免费   1450篇
  2021年   17807篇
  2019年   16203篇
  2018年   18006篇
  2017年   16709篇
  2016年   28227篇
  2015年   42625篇
  2014年   50595篇
  2013年   77035篇
  2012年   36735篇
  2011年   25323篇
  2010年   43946篇
  2009年   45289篇
  2008年   24100篇
  2007年   22296篇
  2006年   27496篇
  2005年   28526篇
  2004年   27848篇
  2003年   25421篇
  2002年   23663篇
  2001年   33688篇
  2000年   30980篇
  1999年   31398篇
  1998年   25496篇
  1997年   25321篇
  1996年   24903篇
  1995年   23000篇
  1994年   22822篇
  1993年   21895篇
  1992年   27759篇
  1991年   26229篇
  1990年   25233篇
  1989年   26070篇
  1988年   24131篇
  1987年   22710篇
  1986年   21709篇
  1985年   23742篇
  1984年   23406篇
  1983年   20680篇
  1982年   20962篇
  1981年   20097篇
  1980年   18706篇
  1979年   19517篇
  1978年   18174篇
  1977年   17536篇
  1976年   16839篇
  1975年   16346篇
  1974年   16954篇
  1973年   17288篇
  1972年   14808篇
  1971年   13551篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
981.
Seven patients with “coeliac axis compression syndrome” are reported. Five were treated surgically, but only two did well. A survey of 200 healthy adults showed epigastric bruits in 6·5%; only one of these had dyspepsia, though dyspepsia was present in 12·5% overall.Caution is urged in attributing a causal relationship between coeliac axis compression and pain and in proceeding to arteriography when compression is suspected on clinical grounds.  相似文献   
982.
From experience in the Northampton/Kettering area 9 to 10% of all patients in a general hospital requiring care in an intensive therapy unit were aged 12 years or under. Fifty-nine children were admitted to the intensive therapy unit of Northampton General Hospital between May 1967 and August 1969. Of these, 22 had been injured in road traffic accidents, five were surgical emergencies, five had meningitis, four status epilepticus, and four respiratory infections.All of the 30 families interviewed were in favour of their child being admitted to the unit, and none considered that the experience had had any lasting adverse psychological effect on the child. It is suggested that certain carefully selected child patients do benefit from the facilities of an intensive therapy unit, and for this reason such units must be designed, equipped, and staffed with this in mind.  相似文献   
983.
984.
985.
986.
987.
S ummary . This paper describes the development and use of a selective diagnostic medium for the detection and enumeration of Clostridium perfringens in foods. The medium gives higher counts of Cl. perfringens and fewer false positives than existing media.  相似文献   
988.
989.
990.
Pieces of brain are fixed in formalin ammonium bromide for about 4 days at room temperature, and given the following treatment: After washing, dehydrating and clearing, embed in paraffin, section and mount. Deparaffinize sections and pass through graded alcohols to water. Sensitize in 5% sodium sulfite for 2 hours, wash in distilled water and impregnate with silver diamminohydroxide solution 2-5 minutes at room temperature. Reduce in 2% formalin, wash in distilled water and tone in gold chloride. Fix in 5% hypo, counterstain with 1% picric acid, dehydrate and cover in balsam. Equally good results are obtained by impregnating with Hortega's strong silver carbonate. The microglia, oligodendroglia, fibrous and protoplasmic astrocytes in the cat, rabbit, newborn and adult human are successfully stained by this method.  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