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   104154篇
  免费   7674篇
  国内免费   377篇
耳鼻咽喉   1147篇
儿科学   2605篇
妇产科学   1677篇
基础医学   14776篇
口腔科学   2227篇
临床医学   10596篇
内科学   22070篇
皮肤病学   1800篇
神经病学   11025篇
特种医学   4239篇
外国民族医学   6篇
外科学   14909篇
综合类   1268篇
一般理论   73篇
预防医学   8033篇
眼科学   1747篇
药学   6979篇
中国医学   111篇
肿瘤学   6917篇
  2023年   582篇
  2022年   1092篇
  2021年   2151篇
  2020年   1336篇
  2019年   1989篇
  2018年   2449篇
  2017年   1807篇
  2016年   2171篇
  2015年   2500篇
  2014年   3296篇
  2013年   4351篇
  2012年   6708篇
  2011年   6781篇
  2010年   4004篇
  2009年   3645篇
  2008年   5985篇
  2007年   6479篇
  2006年   6036篇
  2005年   5977篇
  2004年   5579篇
  2003年   4953篇
  2002年   4942篇
  2001年   1940篇
  2000年   1832篇
  1999年   1705篇
  1998年   1256篇
  1997年   1018篇
  1996年   833篇
  1995年   844篇
  1994年   712篇
  1993年   649篇
  1992年   1207篇
  1991年   1113篇
  1990年   1046篇
  1989年   1010篇
  1988年   900篇
  1987年   840篇
  1986年   876篇
  1985年   873篇
  1984年   710篇
  1983年   606篇
  1982年   570篇
  1981年   456篇
  1980年   406篇
  1979年   536篇
  1978年   419篇
  1977年   383篇
  1975年   341篇
  1974年   369篇
  1973年   355篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
53.
54.
The loss of available iodine from povidone-iodine solution stored in contact with two different polyetherpolyurethane foams was monitored as a function of time and temperature. Statistical evaluation of the results for the four temperatures studied [ambient (25 degrees), 30, 45 and 55 degrees C] indicated the chemical equivalence of the two foams as storage and delivery systems for povidone-iodine solution in terms of solution stability. In addition, application of a first-order kinetic model to the data produced an acceptable fit. An Arrhenius-type evaluation of the resulting rate constants yielded a linear relationship which was shown to be useful for predicting loss of available iodine under ambient temperature conditions of storage.  相似文献   
55.
56.
Abstract: We describe the use of restriction analysis on PCR-amplified DNA for detecting all B*27 subtypes except B*2710 and B*2711 (i.e. from B*2701 to B*2709). After detecting B*27 by Sty I, double digestions consisting of Sty I plus another informative enzyme led to subtype assignment. We used mismatched primers to create restriction sites when necessary. The method avoids group-specific amplifications and other laborious optimization procedures. It was successfully tested on a panel of well characterized cell lines covering different B*27 subtypes. Then, we studied a group of 57 ankylosing spondyiitis patients and 746 controls from the south of Spain. B*27 showed a very strong association with the disease (OR=211.27, P=\0˜7). B*2702 and B*2705 distribution in controls (20% and 77.1%, respectively) differed from previously reported data in the Spanish population. We unexpectedly found the B*2707 allele in our population (one control).  相似文献   
57.
The anticancer agent temozolomide labeled with 13C (8-Carbamoyl-3-13C-methylimidazo-[5,1-d]-1,2,3,5-tetrazin-4-(3H)-one), was noninvasively detected in subcutaneous RIF-1 tumors by a selective cross polarization 13C NMR method, at a field strength of 9.4T. Pharmacokinetics of the drug, at a dose of 150 mg/kg, were determined for intravenous and intraperitoneal modes of administration (three animals per mode). The half-life of the drug in the tumors was approximately 60 min. The uptake and clearance of the drug, however, varied significantly between individual hosts, for both modes of administration. These results demonstrate the feasibility of obtaining pharmacokinetics of anticancer agents for individual tumors without the need for a label that might modify drug activity (e.g., fluorine). The variability of the in vivo measurements, even within the same tumor model, demonstrates the necessity of directly monitoring the tumor to evaluate drug pharmacokinetics.  相似文献   
58.
59.
60.
In child and youth care in the Netherlands, systematic planning of treatment is more and more considered to be a condition for effective and well founded treatment. Although workers are convinced of the benefits of treatment plans, treatment planning is not yet a natural and integrated part of residential care. There are several pressure points. In this article a model of treatment planning will be presented that contributes to an answer to these pressure points. The theoretical bases and the practical implications of this model will be discussed.  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