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   1370596篇
  免费   120354篇
  国内免费   1449篇
  2021年   17764篇
  2019年   16185篇
  2018年   17984篇
  2017年   16682篇
  2016年   28194篇
  2015年   42584篇
  2014年   50538篇
  2013年   76994篇
  2012年   36635篇
  2011年   25225篇
  2010年   43897篇
  2009年   45262篇
  2008年   23989篇
  2007年   22190篇
  2006年   27373篇
  2005年   28443篇
  2004年   27799篇
  2003年   25360篇
  2002年   23605篇
  2001年   33676篇
  2000年   30970篇
  1999年   31390篇
  1998年   25490篇
  1997年   25312篇
  1996年   24906篇
  1995年   22997篇
  1994年   22822篇
  1993年   21896篇
  1992年   27745篇
  1991年   26191篇
  1990年   25146篇
  1989年   25978篇
  1988年   24074篇
  1987年   22659篇
  1986年   21653篇
  1985年   23741篇
  1984年   23399篇
  1983年   20676篇
  1982年   20959篇
  1981年   20099篇
  1980年   18712篇
  1979年   19518篇
  1978年   18176篇
  1977年   17538篇
  1976年   16840篇
  1975年   16351篇
  1974年   16952篇
  1973年   17291篇
  1972年   14808篇
  1971年   13550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