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   19078篇
  免费   1491篇
  国内免费   53篇
耳鼻咽喉   354篇
儿科学   1096篇
妇产科学   554篇
基础医学   2396篇
口腔科学   350篇
临床医学   1931篇
内科学   3515篇
皮肤病学   509篇
神经病学   1418篇
特种医学   523篇
外科学   2754篇
综合类   757篇
一般理论   11篇
预防医学   1919篇
眼科学   318篇
药学   1196篇
  1篇
中国医学   17篇
肿瘤学   1003篇
  2021年   136篇
  2019年   155篇
  2018年   198篇
  2017年   173篇
  2016年   168篇
  2015年   225篇
  2014年   295篇
  2013年   451篇
  2012年   619篇
  2011年   620篇
  2010年   380篇
  2009年   454篇
  2008年   561篇
  2007年   675篇
  2006年   631篇
  2005年   558篇
  2004年   458篇
  2003年   443篇
  2002年   469篇
  2001年   443篇
  2000年   408篇
  1999年   415篇
  1998年   315篇
  1997年   319篇
  1996年   312篇
  1995年   260篇
  1994年   276篇
  1993年   282篇
  1992年   371篇
  1991年   332篇
  1990年   331篇
  1989年   352篇
  1988年   282篇
  1987年   296篇
  1986年   249篇
  1985年   242篇
  1984年   199篇
  1983年   185篇
  1982年   139篇
  1979年   146篇
  1977年   131篇
  1976年   130篇
  1959年   356篇
  1958年   762篇
  1957年   871篇
  1956年   773篇
  1955年   806篇
  1954年   784篇
  1949年   183篇
  1948年   128篇
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
1.
2.
Animal models have traditionally provided the basis for preliminary investigation of new techniques prior to trials taking place in human subjects. The timing of when to proceed with human trials is difficult, as the accuracy of preclinical models can only be determined with hindsight. This review outlines the progression from transplantation in animal models to man. Now that many transplant procedures are well established, it is possible to assess the predictive value and limitations of animal models. These results are of great importance in the current debate about composite tissue allotransplantation (CTA) and in particular facial transplantation. This progression of CTA from animal models to man is outlined and compared with early renal, cardiac, and liver transplants. There is some evidence to suggest that animal models may have been misleading in CTA and that this has effectively delayed the transition to humans. The role for animal models in facial transplantation, which is currently making the step to clinical trials, is discussed.  相似文献   
3.

Background  

Hospital episode statistics (HES) is a UK national database for the National Health Service (NHS), now available online. The purpose of this study was to observe trends in ophthalmic operations performed during the period from 1998 to 2004, using this data.  相似文献   
4.
5.
Restriction fragment length polymorphism (RFLP) of human mitochondrial DNA was analysed in a sample of 87 subjects from Apulia (South Italy) by the restriction enzymes Hpa I, Bam HI, Hae II, Msp I, Ava II, and Hinc II using total blood cell DNA probed by human mtDNA from placenta. Five BamHI morphs were observed, two of which are new ( Bam HI-4 and -5), as well as one new Ava II morph ( Ava II-28). The association Bam HI-4/ Ava II-28 enables us to demonstrate for the first time two polymorphic Bam HI sites present together in the same mtDNA molecule. In agreement with historical data the Apulian sample has been shown to be the most heterogeneous Italian population so far tested.  相似文献   
6.
The synthesis of TPH-13 (Glp-Glu-Lys-Pro-Tyr-Trp-Pro-Pro-Pro-Ile-Tyr-Pro-Met-OH), a tridecapeptide isolated from the skin of the South American frog Phyllomedusa rohdei, is described and alternative approaches are discussed.  相似文献   
7.
8.
Abstract:  In Sweet's syndrome, the essential features are the characteristic morphology of the lesions, their histologic appearance, the dramatic response to corticosteroids and the absence of scarring. We report an 8-month-old infant in whom Sweet's syndrome was diagnosed and who developed acquired cutis laxa in the skin lesions.  相似文献   
9.
10.
Intubating conditions have been assessed at 60 s following administration of vecuronium 0.1 mg kg-1 or atracurium 0.5 mg kg-1 given either as a single dose after induction of anaesthesia with thiopentone or in divided doses; vecuronium 0.015 mg kg-1 followed 4 or 6 min later by 0.085 mg kg-1, or atracurium 0.075 mg kg-1 followed 4 or 6 min later by 0.425 mg kg-1. In the divided dose groups the smaller initial (priming) dose was given prior to induction of anaesthesia. Onset and duration of clinical relaxation were assessed using a peripheral nerve stimulator. The intubating conditions at 60 s improved significantly, with the use of relaxants in divided doses being acceptable in 80 and 70% of patients, respectively, with vecuronium and atracurium, but the conditions are not as good as those commonly found using suxamethonium. Priming at 6 min has no advantage over priming at 4 min. The onset of complete block was accelerated with priming, but the difference was not significant. The duration of clinical relaxation of vecuronium was significantly prolonged by giving it in divided doses. Unpleasant awareness of muscle weakness was observed in 15 patients, requiring early induction of anaesthesia in five of them.  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