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   22896篇
  免费   1368篇
  国内免费   139篇
耳鼻咽喉   290篇
儿科学   438篇
妇产科学   356篇
基础医学   3651篇
口腔科学   463篇
临床医学   1908篇
内科学   4243篇
皮肤病学   915篇
神经病学   2511篇
特种医学   1545篇
外科学   3181篇
综合类   104篇
一般理论   10篇
预防医学   894篇
眼科学   371篇
药学   1996篇
中国医学   31篇
肿瘤学   1496篇
  2023年   97篇
  2022年   94篇
  2021年   324篇
  2020年   264篇
  2019年   343篇
  2018年   375篇
  2017年   346篇
  2016年   452篇
  2015年   592篇
  2014年   673篇
  2013年   908篇
  2012年   1373篇
  2011年   1520篇
  2010年   954篇
  2009年   919篇
  2008年   1494篇
  2007年   1598篇
  2006年   1488篇
  2005年   1434篇
  2004年   1416篇
  2003年   1418篇
  2002年   1374篇
  2001年   289篇
  2000年   214篇
  1999年   295篇
  1998年   349篇
  1997年   302篇
  1996年   249篇
  1995年   219篇
  1994年   202篇
  1993年   207篇
  1992年   135篇
  1991年   122篇
  1990年   111篇
  1989年   107篇
  1988年   121篇
  1987年   105篇
  1986年   83篇
  1985年   81篇
  1984年   110篇
  1983年   96篇
  1982年   110篇
  1981年   105篇
  1980年   115篇
  1979年   62篇
  1978年   61篇
  1977年   87篇
  1976年   73篇
  1975年   66篇
  1974年   69篇
排序方式: 共有10000条查询结果,搜索用时 904 毫秒
51.
52.
目的 了解核因子-κB(NF-κB)在耳蜗的表达情况.方法 小鼠皮下注射卡那霉素(KA),鼓室注射脂多糖(LPS),以注射等量生理盐水作为对照,用多克隆兔抗体NF-κB p50免疫组化染色,观察NF-κB p50在小鼠耳蜗的表达.结果 NF-κB p50主要定位在耳蜗的螺旋缘、盖膜、血管纹、螺旋韧带、螺旋神经节和神经纤维.整个耳蜗各圈均可观察到免疫反应,而螺旋韧带、盖膜、螺旋突、螺旋神经节和神经纤维均可观察到较强的免疫反应,Corti器的免疫反应比上述结构要弱一些.Corti器的内、外毛细胞,内、外柱细胞,Deiter细胞和Claudious细胞均可观察到NF-κB p50的免疫反应,这些免疫反应在内沟细胞、Hensen细胞和Claudious细胞较弱,而在螺旋神经节可观察到较强的免疫反应,内、外毛细胞核未见免疫反应.结论 注射脂多糖和卡那霉素可使NF-κB p50在小鼠耳蜗产生急性反应.  相似文献   
53.
54.
Positron emission tomography (PET) using [(11)C]PK 11195, a ligand for peripheral benzodiazepine receptor binding sites, offers the opportunity to image activated microglia in vivo. This tool may therefore be used to display the occurrence of microglial activation in the course of neurodegeneration. A patient with the clinical diagnosis of corticobasal degeneration (CBD) and left-sided symptoms was studied using fluorodeoxyglucose (FDG) and [(11)C]PK 11195 PET. We found a marked right hemispheric hypometabolism and asymmetric microglial activation in corresponding areas of the basal ganglia and right temporal and parietal cortex. [(11)C]PK 11195 PET suggests involvement of microglial activation in the pathogenesis of CBD.  相似文献   
55.
56.
57.
The chasm between the supply and demand of donated organs and tissues continues to grow despite widespread public awareness of transplantation and numerous efforts to educate the public about organ donation. It is fast becoming a significant public health problem in this country. The need for more effective public education is well documented in the literature on transplantation and is a primary objective of organizations in the transplant field. In response to this need, the Division of Organ Transplantation in the Health Resources and Services Administration of the Public Health Service initiated a project to examine the nature and scope of donation education initiatives throughout the country, to identify shortcomings, and to suggest ways the Federal Government could contribute to the effectiveness of public education in organ and tissue donation. The project resulted in the development of a protocol that also is applicable to other health education programs. Its major steps consisted of assessing the status of donation-related public education in the United States, identifying existing needs in donation education by applying principles learned from other public health education programs, and identifying roles that could be assumed to help strengthen the American public''s commitment to organ and tissue donation. These roles, which could be adopted by an transplant-related organization, were as broker of knowledge, producer of educational strategies, energizer through communications research, and catalyst by bringing together other groups. This approach to needs assessment and planning may provide useful insights both for those concerned with transplants and for professionals conducting education campaigns related to other public health issues.  相似文献   
58.
59.
The purpose of this study was to test the feasibility of MR-guided percutaneous ethanol ablation of liver tissue on a .2-T open MR scanner. Needles were placed by MR guidance first into an ex vivo sheep liver and then into livers of three anesthetized pigs, and injection of 10 ml of 96% alcohol was performed. T1 fast low-angle shot (FLASH), T2 turbo spin echo (TSE), and T1 spin echo (SE) images were obtained after incremental volumes of injection. In one pig, simultaneous injection of saline into normal liver was also performed with subsequent pathological correlation. Ethanol-infiltrated liver was hypointense to liver on all sequences, whereas saline caused no tissue signal changes on T1 SE and either isointense or hyperintense changes on T2 TSE images. Pathological examination confirmed ethanol-induced acute liver changes as compared with the control. MR guidance of needle placement and monitoring of ethanol effects on liver tissue is feasible. This may have implications for potential MR-guided hepatic tumor ablation.  相似文献   
60.
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