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   2400篇
  免费   197篇
  国内免费   9篇
耳鼻咽喉   38篇
儿科学   84篇
妇产科学   49篇
基础医学   330篇
口腔科学   25篇
临床医学   295篇
内科学   499篇
皮肤病学   25篇
神经病学   173篇
特种医学   57篇
外科学   327篇
综合类   25篇
一般理论   1篇
预防医学   237篇
眼科学   22篇
药学   140篇
中国医学   1篇
肿瘤学   278篇
  2023年   17篇
  2022年   34篇
  2021年   72篇
  2020年   36篇
  2019年   63篇
  2018年   65篇
  2017年   45篇
  2016年   63篇
  2015年   78篇
  2014年   93篇
  2013年   122篇
  2012年   185篇
  2011年   198篇
  2010年   107篇
  2009年   88篇
  2008年   171篇
  2007年   156篇
  2006年   151篇
  2005年   145篇
  2004年   136篇
  2003年   134篇
  2002年   123篇
  2001年   21篇
  2000年   27篇
  1999年   29篇
  1998年   26篇
  1997年   23篇
  1996年   11篇
  1995年   7篇
  1994年   17篇
  1993年   17篇
  1992年   11篇
  1991年   13篇
  1990年   6篇
  1989年   12篇
  1988年   9篇
  1987年   11篇
  1986年   7篇
  1985年   13篇
  1984年   8篇
  1983年   10篇
  1982年   6篇
  1981年   4篇
  1979年   5篇
  1977年   3篇
  1975年   5篇
  1972年   3篇
  1971年   3篇
  1957年   2篇
  1954年   2篇
排序方式: 共有2606条查询结果,搜索用时 15 毫秒
71.
72.
73.
Controversy exists over whether the lower airway inflammation that characterizes cystic fibrosis (CF) is initiated primarily by the genetic defect. To determine if inflammation precedes infection, we examined bronchoalveolar lavage (BAL) fluid cytology, cytokines (interleukin (IL)-1beta, IL-4, IL-5, IL-6, IL-8, IL-10, and tumor necrosis factor-alpha), and free neutrophil elastase activity from 70 CF (aged 1.5-71 months) children detected by newborn screening and 19 (aged 2.0-48 months) controls with chronic stridor. CF subjects were selected and categorized as pristine (13 aged /= 10(5) colony-forming units/ml of pathogenic bacteria in BAL), and uninfected (15 aged > 6 months, asymptomatic, not taking antibiotics at bronchoscopy, and free of pathogens in their BAL). To further resolve if inflammation develops without infection, inflammatory mediators in paired annual BAL samples from 38 CF subjects were measured, and results were grouped according to whether BAL showed persistence (n = 6), acquisition (n = 8), clearance (n = 13), or absence (n = 11) of infection. While pristine, uninfected, and control subjects had similar BAL profiles, infected patients showed elevated inflammatory indices, including increased IL-10 (P < 0.001). Pristine subjects had the fewest signs of inflammation. Analysis of BAL pairs found differences between the four infection groups for changes in neutrophil percentages, IL-8 (P < 0.001), and free neutrophil elastase (P = 0.009). Infection was associated with elevated inflammatory mediators in BAL fluid. In contrast, minimal or reduced signs of inflammation accompanied absence of eradication of infection from BAL fluid. We conclude that in CF, infection initiates and sustains airway inflammation.  相似文献   
74.
75.
76.
Heparin-induced thrombocytopenia is a well-recognized complication of anticoagulation with heparin. We present the case of a patient with recent heparin-induced thrombocytopenia who subsequently needed surgery on an emergency basis for acute type A aortic dissection. This article reports the successful use of bivalirudin, a direct thrombin inhibitor, as an alternative to heparin throughout cardiopulmonary bypass and deep hypothermic circulatory arrest. We contend that bivalirudin is a safe alternative to heparin when performing surgery for aortic dissection and should be considered as an option for use in patients who present with heparin-induced thrombocytopenia.  相似文献   
77.
78.
79.
Atypical visual processing in children with autism spectrum disorder (ASD) does not seem to reside in an isolated processing component, such as global or local processing. We therefore developed a paradigm that requires the interaction between different processes—an identification task with Gaborized object outlines—and applied this to two age groups of 6-to-10 and 10-to-14 year old children with and without ASD. Event history analyses demonstrated an identification disadvantage in the ASD group, which remained quite stable during the temporal unfolding of the outline. The typically developing group particularly outperformed the ASD group when more complex contours were shown. Together, our results suggest that the interplay between local and global processes and between bottom-up and top-down processes is disturbed in ASD.  相似文献   
80.
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