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   154700篇
  免费   32939篇
  国内免费   2421篇
耳鼻咽喉   5222篇
儿科学   5438篇
妇产科学   2516篇
基础医学   3836篇
口腔科学   1680篇
临床医学   27222篇
内科学   48260篇
皮肤病学   7530篇
神经病学   15201篇
特种医学   6954篇
外科学   42005篇
综合类   259篇
现状与发展   72篇
预防医学   7233篇
眼科学   3465篇
药学   1175篇
中国医学   8篇
肿瘤学   11984篇
  2024年   517篇
  2023年   4858篇
  2022年   1229篇
  2021年   3354篇
  2020年   6184篇
  2019年   2407篇
  2018年   7632篇
  2017年   7511篇
  2016年   8617篇
  2015年   8649篇
  2014年   15792篇
  2013年   15899篇
  2012年   5935篇
  2011年   5945篇
  2010年   10625篇
  2009年   14506篇
  2008年   6088篇
  2007年   4306篇
  2006年   6693篇
  2005年   3948篇
  2004年   3164篇
  2003年   2143篇
  2002年   2161篇
  2001年   3871篇
  2000年   3052篇
  1999年   3270篇
  1998年   3653篇
  1997年   3488篇
  1996年   3374篇
  1995年   3204篇
  1994年   1944篇
  1993年   1568篇
  1992年   1375篇
  1991年   1427篇
  1990年   1066篇
  1989年   1189篇
  1988年   1043篇
  1987年   862篇
  1986年   909篇
  1985年   737篇
  1984年   562篇
  1983年   529篇
  1982年   522篇
  1981年   408篇
  1980年   362篇
  1979年   334篇
  1978年   337篇
  1977年   400篇
  1975年   289篇
  1972年   286篇
排序方式: 共有10000条查询结果,搜索用时 531 毫秒
961.
962.
Background: We examined alternative methods of delivering cytokines as an adjunct for priming lymph node (LN) cells draining sites of vaccine inoculation for the purpose of generating immune cells for adoptive immunotherapy. Methods: Using syngeneic murine tumors we examined the ability of IL-2, IL-4, or GM-CSF delivered locally to a site of tumor inoculum to induce antitumor reactive draining LN cells. Mice were inoculated subcutaneously with tumor cells transduced to secrete cytokine; tumor cells admixed with fibroblasts transduced to secrete cytokine; or intralesional inoculation of cytokine in established tumor to induce sensitized LN cells capable of mediating tumor regression in adoptive transfer. Results: Both IL-4 and GM-CSF cytokines were effective in enhancing the antitumor reactivity of vaccine-primed LN cells compared to IL-2, which was ineffective. The local delivery of GM-CSF by autocrine or paracrine secretion of genetically engineered cells, as well as direct intratumoral delivery was capable of upregulating LN sensitization compared to systemic administration, which did not. Conclusions: The local delivery of GM-CSF as an adjuvant for tumor vaccination can be accomplished by various methods, including direct injection, which avoids the need for gene transfer.  相似文献   
963.
R Philipp  N Wood 《World health forum》1992,13(2-3):237-239
In order to clarify the housing and settlements component of the European health-for-all programme and to identify perceived priorities with a view to the preparation of training materials, members of WHO's Rural and Urban Development and Housing Network were invited to complete a questionnaire. The results are reported below. The questionnaire can be used in identifying local development priorities, comparing attitudes, and studying perceived needs. Intended as a tool for policy-makers, course organizers and public health professionals, it is available from the authors of the present article.  相似文献   
964.
965.
966.
We report studies on the complement sensitivity of four strains of Yersinia enterocolitica , serotypes O:3, O:9, O:5,27, and O:20, isolated from blood units involved in transfusion fatalities. Complement in fresh CPD plasma killed Y. enterocolitica within 4 h at 22°C in 100% of the experiments. The bactericidal action was serotype and complement activation pathway dependent. Both classic and alternate pathways seemed to be active, but the latter to a lesser degree. When the classic pathway was blocked by chelation of Ca2+ no complete killing was obtained. Complement did not enhance or condition Yersinia for leucocyte filter retention. Direct removal of Yersinia by filtration was also related to serotype; all strains were reduced by filtration in heat-inactivated plasma, and all except serotype O:5,27 were reduced in Ca2+ -chelated plasma. Our findings may explain why plasma products and platelet concentrates are rarely involved in Yersinia sepsis related to transfusion.  相似文献   
967.
968.
Limited randomized clinical trial data favor the use of anticoagulation in patients with cerebral venous thrombosis. We present a patient with deep cerebral venous thrombosis in whom anticoagulation was withheld because of coexistent intraventricular hemorrhage. She had a benign clinical course without anticoagulation, suggesting that close observation may be a management option in these patients.  相似文献   
969.
970.
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