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   21112篇
  免费   6394篇
  国内免费   76篇
耳鼻咽喉   370篇
儿科学   528篇
妇产科学   514篇
基础医学   889篇
口腔科学   1451篇
临床医学   6447篇
内科学   4782篇
皮肤病学   581篇
神经病学   2683篇
特种医学   728篇
外科学   3161篇
综合类   120篇
现状与发展   2篇
一般理论   2篇
预防医学   2859篇
眼科学   370篇
药学   418篇
  1篇
中国医学   5篇
肿瘤学   1671篇
  2024年   243篇
  2023年   1384篇
  2022年   412篇
  2021年   762篇
  2020年   1162篇
  2019年   538篇
  2018年   1556篇
  2017年   1682篇
  2016年   1685篇
  2015年   1707篇
  2014年   1980篇
  2013年   2010篇
  2012年   904篇
  2011年   923篇
  2010年   1204篇
  2009年   1563篇
  2008年   721篇
  2007年   556篇
  2006年   604篇
  2005年   426篇
  2004年   360篇
  2003年   307篇
  2002年   289篇
  2001年   409篇
  2000年   262篇
  1999年   348篇
  1998年   313篇
  1997年   336篇
  1996年   323篇
  1995年   303篇
  1994年   196篇
  1993年   176篇
  1992年   211篇
  1991年   170篇
  1990年   180篇
  1989年   184篇
  1988年   141篇
  1987年   130篇
  1986年   124篇
  1985年   112篇
  1984年   86篇
  1983年   62篇
  1982年   53篇
  1981年   48篇
  1979年   52篇
  1978年   42篇
  1977年   32篇
  1974年   39篇
  1972年   31篇
  1971年   30篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
63.
The widespread use and misuse of alcohol, drug and other psychoactive substances are major health and social concerns that affect the lives of many The social and health sequelae of psychoactive drugs and alcohol are preventable and manageable with minimal interventions Nurses and other health workers can effectively respond to substance misuse problems and their existing generic skills can be easily adapted in working with substance misusers This paper considers some of the issues such as the extent of the problem, attitudinal considerations, response to substance misusers and a brief outline of the role of the nurse The urgent need for education and training in substance misuse and addictive behaviour for nurse practitioners is also addressed  相似文献   
64.
This study was designed to assess the accuracy of end-tidalPco 2 and transcutaneousPco 2 as measurements of arterialPco 2 in extubated, spontaneously breathing patients recovering from general anesthesia. In 30 patients, measurement of arterial transcutaneous, and end-tidalPco 2 were taken simultaneously with body temperature approximately every 15 minutes over a 2-hour period. ArterialPco 2 values were corrected for body temperature. Values for Paco 2 were compared with those forPetCO2 and Psco 2 by linear regression analysis and by calculation of bias ± precision. Thirty-six percent of the capnogram tracings obtained did not develop a plateau phase. We found poor correlation between end-tidal and arterialPco 2 regardless of the shape of the capnogram tracing, as well as poor correlation between transcutaneous and arterialPco 2. Although the measurements of bias and precision of noninvasivePco 2 monitors in this population are comparable to studies in other populations, we advise caution in relying on the routine use ofPetCO2 or Psco 2 for the noninvasive assessment of respiratory depression in extubated, spontaneously breathing patients recovering from general anesthesia.  相似文献   
65.
66.
Artificial neural networks are being investigated in the field of medical imaging as a means to facilitate pattern recognition and patient classification. In the work reported here, the effects of internal structure and the nature of input data on the performance of neural networks were investigated systematically using computer-simulated data. Network performance was evaluated quantitatively by means of receiver operating characteristic analysis and compared with the performance of an ideal statistical decision maker. We found that the relatively simple neural networks investigated in this study can perform at the level of an ideal decision maker. These simple networks were also found to learn accurately even when the training data are extremely unbalanced with respect to the prevalence of actually positive cases and to differentiate input data patterns by recognizing their unique characteristics.  相似文献   
67.
This review examines some of the questions and current literature regarding psychological factors as they affect pulmonary and rheumatologic diseases. Recommendations are made concerning directions for future research in these areas.  相似文献   
68.
69.
The ability of hemagglutinating and poorly hemagglutinating strains of the gastroduodenal pathogen Helicobacter pylori to bind 125I-radiolabelled laminin was quantitated in a liquid phase assay. Although all strains bound laminin, some hemagglutinating strains were good binders of laminin (maximum of 31% binding), whereas poorly hemagglutinating strains bound intermediate to small amounts of laminin (minimum of 6% binding). Since a hydrophobic component of the bacterium has been reported to be involved in binding of laminin (T. J. Trust, P. Doig, L. Emödy, Z. Kienle, T. Wadström, and P. O'Toole, Infect. Immun. 59:4398-4404, 1991), we investigated the role of lipopolysaccharide (LPS) in the interaction of both types of strains with laminin. Although the extent of inhibition varied among strains, laminin binding to hemagglutinating and poorly hemagglutinating strains was inhibited with homologous and heterologous smooth-form LPS. The ability of heterologous rough-form LPS to produce inhibition comparable to that shown by smooth-form LPS indicated that the O side chain of H. pylori LPS was not involved in the interaction. Further inhibition experiments with dephosphorylated LPS, isolated core oligosaccharide, and free lipid A suggested that a phosphorylated structure in the core oligosaccharide mediates the interaction of a hemagglutinating strain of H. pylori with laminin, whereas a conserved nonphosphorylated structure in the core oligosaccharide mediates the interaction of a poorly hemagglutinating strain. Furthermore, we showed that the interaction of H. pylori LPS with 125I-radiolabelled laminin in a solid phase assay was saturable, specific, and inhibitable with unlabelled laminin. It was postulated that the initial recognition and binding of laminin by H. pylori may occur through LPS and that subsequently a more specific interaction with a lectin-like adhesin on the bacterial surface occurs.  相似文献   
70.
An acid-insoluble, methacrylic acid, methyl methacrylate copolymer (Eudragit L-100) was used to give an enteric coating to a grass pollen extract in order to protect it against gastric degradation. Substantial protection against the degradative effects of simulated gastric secretion was demonstrated using this preparation which was well tolerated by grass pollen-allergic volunteers. The enteric-coated allergen induced a greater secondary antibody response than did an aqueous presentation when administered orally to guinea pigs which had been primed previously by subcutaneous injection. This result indicates that an effective hyposensitisation regimen could consist of a short series of initial parenteral injections, followed by an oral course of the protected allergen.  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