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   15463篇
  免费   1155篇
  国内免费   22篇
耳鼻咽喉   74篇
儿科学   619篇
妇产科学   523篇
基础医学   1854篇
口腔科学   163篇
临床医学   2377篇
内科学   2679篇
皮肤病学   182篇
神经病学   1490篇
特种医学   330篇
外科学   1293篇
综合类   318篇
一般理论   142篇
预防医学   2453篇
眼科学   234篇
药学   1021篇
  1篇
中国医学   22篇
肿瘤学   865篇
  2023年   160篇
  2022年   219篇
  2021年   408篇
  2020年   265篇
  2019年   422篇
  2018年   490篇
  2017年   308篇
  2016年   391篇
  2015年   410篇
  2014年   555篇
  2013年   757篇
  2012年   1217篇
  2011年   1260篇
  2010年   608篇
  2009年   541篇
  2008年   1016篇
  2007年   1045篇
  2006年   992篇
  2005年   933篇
  2004年   905篇
  2003年   804篇
  2002年   714篇
  2001年   182篇
  2000年   141篇
  1999年   168篇
  1998年   141篇
  1997年   101篇
  1996年   102篇
  1995年   96篇
  1994年   91篇
  1993年   89篇
  1992年   110篇
  1991年   91篇
  1990年   78篇
  1989年   83篇
  1988年   68篇
  1987年   72篇
  1986年   84篇
  1985年   65篇
  1984年   34篇
  1983年   36篇
  1982年   41篇
  1981年   41篇
  1980年   23篇
  1979年   33篇
  1977年   18篇
  1976年   19篇
  1975年   23篇
  1967年   16篇
  1966年   19篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
Book reviewed in this article: Ethics in Obstetrics and Gynecology . By Laurence B. McCullough and Frank A. Chervenak.  相似文献   
33.
? The paper describes a multiproject practice development programme undertaken over a period of 1 year. ? The background and development of the programme are outlined, whilst attention is paid to the innovatory nature of the work, particularly the use of inductive, deductive and integrated approaches to both change implementation and project supervision. ? The programme was monitored throughout using different data sources and the paper uses evaluative material retrospectively to provide answers to organizational and professional difficulties which arose during the course of the programme. ? The authors conclude that the use of combinations of different models for practice development has potential, but requires careful supervision. ? They also recommend that those involved in practice development are made fully aware of its local or micropolitics, and develop strategies to deal with change before it occurs, not after it has taken place.  相似文献   
34.
Ethics without abstraction: squaring the circle.   总被引:1,自引:0,他引:1  
  相似文献   
35.
Day cases: what are we counting?   总被引:1,自引:0,他引:1  
  相似文献   
36.
The concept of need and the practice of needs assessment are both subject to a wide range of interpretations, to the likely detriment of individual assessments and to multidisciplinary working. Clear definition is important for individual assessment, for the development of multidisciplinary tools and in gathering planning information. The concept of need is clarified, firstly by distinguishing between need and the difficulties that engender it, and secondly through a taxonomy of need. These assist clear definitions of both need and needs assessment when linked with a consideration of the current help a person receives and a specification of the type of help required by a person to meet their needs. Such definitions have implications for the role of needs assessment in individual assessment, service evaluation, service management and planning and in the development of multidisciplinary needs assessment tools.  相似文献   
37.
38.
The discriminative stimulus properties of (+)-lysergic acid diethylamide (LSD) and lisuride hydrogen maleate (LHM), were compared in a three-choice, water reinforced (FR 20) situation in which rats were required to press one lever following LSD (0.08 mg/kg), a second lever following LHM (0.04 mg/kg), and a third lever following saline. Reliable drug-appropriate responding was established in 72 sessions. Dose-response tests with LSD and LHM indicated that, as dose increased, the per cent of responding on the lever associated with the particular training drug also increased; little or no cross-transfer occurred between LSD and LHM. In generalization tests, the serotonin (5-HT) agonist quipazine substituted for LSD but not LHM while the dopamine (DA) agonist apomorphine mimicked LHM but not LSD; an unrelated compound, pentylenetetrazol (PTZ), produced responding on the saline-appropriate lever. In combination tests, 5-HT antagonists (e.g., BC-105 and low doses of pirenperone) blocked responding on the LSD lever while DA antagonists (e.g., haloperidol and much higher doses of pirenperone) blocked LHM-appropriate responding. These data suggest that the three-lever (D-D-N) procedure is similar to, but can be more sensitive than the two-lever (D-N) procedure (because it can differentiate between LSD and LHM); they therefore at least partially support the hypothesis that three-choice discriminations can be conceptualized as two separate, two-choice (D-N) discriminations (Jarbe and Swedberg 1982). The results also confirm suggestion that the stimulus effects of LSD and LHM are mediated by different mechanisms; the primary action of LSD is serotonergic (5-HT2), while that of LHM is dopaminergic (White 1986).Some of these data were presented at the meeting of the Society of Neuroscience, Toronto, 1988 (Satellite Session of the Society for the Stimulus Properties of Drugs). They were also submitted (in somewhat different form) to the Graduate School of the University of South Carolina in partial fulfillment of the requirements for an MA degree (in Experimental Psychology)  相似文献   
39.
40.
Summary The potential for induction of obesity during the preclinical phase of scrapie disease in mice was previously shown to be a function of both the strain of scrapie and the strain of inbred mouse. In the present study, host control of obesity induction by a scrapie strain was examined to determine if the effect were dependent on a single gene or multiple genes. The approach used was assessment of the pattern of weight induction in F1 and F2 crosses of parental inbred mouse strains that did or did not show a weight increase with a specific scrapie strain. Analyses of these data indicated that the induction of obesity was controlled by multiple host genes. In an unrelated observation, there was a correlation between the incubation period of a strain of scrapie in F2 generation mice and their coat color, i.e., the average incubation period of yellow-brown mice was significantly less than those of either black or white mice.  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