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   5589篇
  免费   341篇
  国内免费   26篇
耳鼻咽喉   120篇
儿科学   130篇
妇产科学   98篇
基础医学   882篇
口腔科学   98篇
临床医学   488篇
内科学   1290篇
皮肤病学   170篇
神经病学   621篇
特种医学   432篇
外国民族医学   4篇
外科学   681篇
综合类   47篇
一般理论   2篇
预防医学   258篇
眼科学   70篇
药学   218篇
中国医学   3篇
肿瘤学   344篇
  2021年   65篇
  2020年   61篇
  2019年   63篇
  2018年   87篇
  2017年   68篇
  2016年   101篇
  2015年   112篇
  2014年   133篇
  2013年   174篇
  2012年   224篇
  2011年   259篇
  2010年   165篇
  2009年   167篇
  2008年   225篇
  2007年   258篇
  2006年   221篇
  2005年   255篇
  2004年   228篇
  2003年   191篇
  2002年   159篇
  2001年   161篇
  2000年   176篇
  1999年   150篇
  1998年   79篇
  1997年   77篇
  1996年   63篇
  1995年   52篇
  1994年   43篇
  1993年   43篇
  1992年   111篇
  1991年   98篇
  1990年   121篇
  1989年   110篇
  1988年   104篇
  1987年   118篇
  1986年   107篇
  1985年   87篇
  1984年   69篇
  1983年   62篇
  1982年   39篇
  1981年   42篇
  1979年   51篇
  1978年   46篇
  1975年   38篇
  1974年   45篇
  1973年   42篇
  1972年   43篇
  1971年   41篇
  1970年   43篇
  1969年   37篇
排序方式: 共有5956条查询结果,搜索用时 375 毫秒
1.
2.
Apoptotic cells, e.g. postinflammatory neutrophils, were reported to be engulfed by phagocytes without induction of an inflammatory response. We investigated the humoral immune response of BALB/c mice after repeated injection of viable or apoptotic human T cells. Following interleukin-2 (IL-2) deprivation, phytohaemagglutinin (PHA)/IL-2 expanded human T-cell lines were irradiated with UV-B light to induce apoptosis, confirmed by propidium iodide staining of Triton X-100-lysed cells. Indirect immunofluorescence was used to detect antilymphocyte antibodies 7 days after each injection. We found high levels of antilymphocyte antibodies in all animals immunized with viable T cells, whereas animals injected with apoptotic cells showed a significantly reduced humoral immune response. We conclude that apoptotic cells induce poor xenoreactive T-cell responses when compared with viable cells.  相似文献   
3.
A new range of stand magnifiers has been released by the COIL company in the United Kingdom. Examination of these magnifiers reveals that they fail to deliver the rated magnifications labelled prominently on the appliances, as a result of the manufacturer's conformance with the requirements of the German DIN standard and the use of back vertex power (F'v) rather than equivalent dioptric power (Fm) of the magnifier. In this study we provide information on the optometric parameters of these new stand magnifiers that will assist the more accurate specification of improvements in vision expected from their use.  相似文献   
4.
PURPOSE: To compare tests for intestinal function with clinical scores after abdominal irradiation. PATIENTS AND METHODS: At the Department of Radiotherapy, Erfurt, Germany, intestinal changes were studied in 91 patients receiving abdominal radiotherapy between 1992 and 1996. Conventional fractionation (1.8-2 Gy per fraction, total doses 30.6-62.5 Gy) was applied. Before and at weekly intervals during radiotherapy, the clinical response was scored according to RTOG/EORTC for the upper and lower gastrointestinal (GI) tract. Resorption tests for vitamin B(12) and D-xylose were performed before the onset and immediately after treatment. RESULTS: The clinical response displayed a well-defined dose-effect relationship with grade 1 effects in 5% and 50% of the patients at about 10 Gy and 50 Gy, respectively. For grade 2 reactions, 5%- and 50%-effective doses were 20-30 Gy and 60-80 Gy. Effects in the upper and lower GI tract were highly correlated. Changes in body weight did not show a correlation with other clinical symptoms. Changes in resorption also displayed a significant dose effect. However, no correlation was found with the clinical symptoms in the individual patient. CONCLUSION: In the present study, the clinical manifestation of intestinal side effects according to RTOG/EORTC criteria was reflected by neither the vitamin B(12) nor by the D-xylose resorption test. Hence, these tests cannot be regarded as useful for objective quantitation of intestinal radiation injury.  相似文献   
5.
6.
7.
Information on the relative incidence of Crohn's disease and ulcerative colitis was obtained by a prospective investigation at six Melbourne teaching hospitals. One hundred and eleven patients who presented with chronic inflammatory bowel diseases between 1980-1981 were admitted to the study. Forty (36%) patients were diagnosed as having Crohn's disease and 63 (57%) patients as having ulcerative colitis. The type of chronic inflammatory bowel disease could not be determined in eight (7%) patients. These findings suggest that the relative frequency of Crohn's disease and ulcerative colitis in Melbourne hospitals is within the range that is reported for northern Europe and the United States.  相似文献   
8.
9.
10.
The development of in vitro blood tests that measure the delayed hypersensitivity reaction developed after contact with Mycobacterium tuberculosis will change progressively the diagnosis of M. tuberculosis infection. These blood assays (Quantiferon TB Gold, Cellestis, Australia; T-SPOT.TB, Oxford Immunotec, United Kingdom) use specific, complex M. tuberculosis antigens (ESAT-6 and CFP-10), whereas the intra-dermal Mantoux test is done with tuberculin, a complex mixture of more than 200 antigens. ESAT-6 and CFP-10 are absent from all the BCG vaccine strains used throughout the world. Significant improvement in the specificity with equivalent or increased sensitivity of the in vitro tests compared to the Mantoux test will lead eventually to replacement of the latter.  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