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   3369952篇
  免费   273060篇
  国内免费   6035篇
耳鼻咽喉   48566篇
儿科学   107692篇
妇产科学   93107篇
基础医学   475324篇
口腔科学   99434篇
临床医学   306782篇
内科学   653063篇
皮肤病学   70428篇
神经病学   280893篇
特种医学   134410篇
外国民族医学   1247篇
外科学   507393篇
综合类   82981篇
现状与发展   4篇
一般理论   1428篇
预防医学   272153篇
眼科学   79797篇
药学   252457篇
  8篇
中国医学   6250篇
肿瘤学   175630篇
  2018年   33670篇
  2016年   28934篇
  2015年   33108篇
  2014年   47005篇
  2013年   71882篇
  2012年   96618篇
  2011年   102186篇
  2010年   60378篇
  2009年   57628篇
  2008年   97314篇
  2007年   103057篇
  2006年   104210篇
  2005年   101363篇
  2004年   98377篇
  2003年   94683篇
  2002年   93482篇
  2001年   153578篇
  2000年   159047篇
  1999年   135039篇
  1998年   39179篇
  1997年   35519篇
  1996年   35037篇
  1995年   33970篇
  1994年   31951篇
  1993年   29888篇
  1992年   109738篇
  1991年   106105篇
  1990年   102992篇
  1989年   99503篇
  1988年   92484篇
  1987年   91251篇
  1986年   86650篇
  1985年   83107篇
  1984年   63034篇
  1983年   54110篇
  1982年   32690篇
  1981年   29199篇
  1980年   27508篇
  1979年   59853篇
  1978年   42108篇
  1977年   35544篇
  1976年   33330篇
  1975年   35285篇
  1974年   43503篇
  1973年   41550篇
  1972年   38719篇
  1971年   36046篇
  1970年   33662篇
  1969年   31429篇
  1968年   28668篇
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
31.
32.
Gold nanoparticles (Au NPs) hold great promise in food, industrial and biomedical applications due to their unique physicochemical properties. However, influences of the gastrointestinal tract (GIT), a likely route for Au NPs administration, on the physicochemical properties of Au NPs has been rarely evaluated. Here, we investigated the influence of GIT fluids on the physicochemical properties of Au NPs (5, 50, and 100?nm) and their implications on intestinal epithelial permeability in vitro. Au NPs aggregated in fasted gastric fluids and generated hydroxyl radicals in the presence of H2O2. Cell studies showed that GIT fluids incubation of Au NPs affected the cellular uptake of Au NPs but did not induce cytotoxicity or disturb the intestinal epithelial permeability.  相似文献   
33.
Adjuvant irradiation is the standard treatment after breast conservative surgery. Normofractionated regimen with an overall treatment time of 5 to 6 weeks is often considered as a limiting factor for irradiation compliance. In order to answer this issue, moderate and more recently extreme hypofractionated protocols appeared. We report here oncological outcomes and toxicity of hypofractionated breast irradiation. After defining the frame of moderate and extreme hypofractionated breast irradiations based on overall treatment time, patient selection criteria were listed. According to their levels of proof, the results of moderate and extreme hypofractionated breast irradiation were analysed. Overall treatment time for moderate hypofractionated breast irradiation ranged from 3 to 4 weeks, while for extreme hypofractionated breast irradiation, it was less than 1 week. For moderate hypofractionated breast irradiation, whole breast irradiation was currently performed with or without lymph node irradiation. Moderate hypofractionated breast irradiation has proven to be as safe and as efficient as normofractionated breast irradiation with level IA evidence. For extreme hypofractionated breast irradiation, phase III randomized trials confirmed that accelerated partial breast irradiation was non-inferior in terms of local control compared to normofractionated whole breast irradiation (with external beam radiation therapy and multicatheter brachytherapy), with similar acute and late toxicity. While the use of intraoperative breast irradiation remains under debate, new very accelerated partial breast irradiation (overall treatment time not exceeding 2 days) protocols emerged with encouraging results. Accelerated partial breast irradiation is warranted for extreme hypofractionated breast irradiation and is indicated for low-risk breast cancers. Moderate and extreme hypofractionated breast irradiation regimens are validated and can be routinely proposed according to patient selection criteria.  相似文献   
34.
35.
36.
Secondary tricuspid regurgitation (TR) caused by right ventricular enlargement in the setting of left heart disease/pulmonary hypertension has been well described. In contrast, that associated with right atrial enlargement—atrial functional TR (AF‐TR)—remains largely underappreciated. AF‐TR most often occurs in the setting of lone atrial fibrillation, although it is also seen in its absence (idiopathic AF‐TR). Several recent studies have found that the prevalence, hemodynamic significance, and prognosis of AF‐TR are not inconsequential, suggesting increased physician awareness of this novel clinical entity is warranted. This article discusses the pathogenesis, echocardiographic findings, and treatment of this underappreciated cause of secondary TR.  相似文献   
37.
38.
39.
40.
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