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   2557篇
  免费   188篇
  国内免费   5篇
耳鼻咽喉   16篇
儿科学   96篇
妇产科学   52篇
基础医学   429篇
口腔科学   31篇
临床医学   380篇
内科学   487篇
皮肤病学   22篇
神经病学   235篇
特种医学   106篇
外科学   204篇
综合类   37篇
一般理论   6篇
预防医学   266篇
眼科学   33篇
药学   167篇
中国医学   2篇
肿瘤学   181篇
  2023年   20篇
  2022年   21篇
  2021年   59篇
  2020年   26篇
  2019年   50篇
  2018年   58篇
  2017年   51篇
  2016年   47篇
  2015年   67篇
  2014年   61篇
  2013年   114篇
  2012年   185篇
  2011年   210篇
  2010年   129篇
  2009年   94篇
  2008年   171篇
  2007年   197篇
  2006年   163篇
  2005年   166篇
  2004年   165篇
  2003年   136篇
  2002年   144篇
  2001年   20篇
  2000年   18篇
  1999年   12篇
  1998年   27篇
  1997年   22篇
  1996年   20篇
  1995年   15篇
  1994年   14篇
  1993年   19篇
  1992年   10篇
  1991年   8篇
  1989年   10篇
  1988年   7篇
  1987年   7篇
  1986年   10篇
  1985年   14篇
  1984年   7篇
  1983年   11篇
  1982年   13篇
  1981年   11篇
  1980年   19篇
  1979年   11篇
  1978年   12篇
  1977年   7篇
  1976年   9篇
  1972年   8篇
  1964年   8篇
  1962年   9篇
排序方式: 共有2750条查询结果,搜索用时 15 毫秒
91.
The aim of this study was to evaluate the clinical, therapeutic, laboratory, and radiological differences between respiratory syncytial virus (RSV) and non-RSV bronchiolitis in order to assess if the prior knowledge of viral etiology changed management decisions and would be able to predict outcomes. Medical charts of children <1 year admitted to the emergency department with bronchiolitis during two RSV seasons (2010–2012) were reviewed. We analyzed 221 episodes of bronchiolitis. The percentage of exams performed (95 % confidence interval (CI) 0.74–2.52), abnormal laboratory and radiological findings (95 % CI 0.53–16.89) did not differ between groups. RSV bronchiolitis had a more severe clinical course. However, virologic testing for RSV had low specificity in identifying at-risk patients for hospitalization, longer hospital length of stay, and need of oxygen therapy and nasogastric tube (44, 40, 42, and 35 %, respectively), and while statistically significant, the positive likelihood ratios were only slightly greater than 1. Conclusion: Although RSV bronchiolitis has a more severe clinical course, virologic testing does not help in management decisions, and at an individual level, as a performance test, it seems insufficient to precisely predict outcomes.  相似文献   
92.
93.
A proton magnetic resonance spectral editing technique is presented that uses PRESS excitation to achieve spatially localized measurements of brain gamma-aminobutyric acid (GABA). The homonuclear difference spectroscopy technique employs a frequency selective inversion pulse to suppress the creatine resonance at 3.0 ppm. The timing of this pulse is optimized to maximize the suppression of creatine by minimizing the effect of the editing pulse on the 3.0 ppm resonances. The PRESS excitation achieves three dimensional spatial localization in a single acquisition making it less sensitive to patient motion than multiple acquisition techniques. The performance and utility of this technique were evaluated by phantom experiments and by in vivo measurements of brain GABA concentration in 10 normal subjects.  相似文献   
94.
95.
96.
97.
A series of intracellular events occurring after treatment of rabbit synovial fibroblasts with 0.01 μg/ml phorbol myristate acetate (PMA) were measured. Ten minutes after addition of PMA, there was a temporary increase in intracellular cyclic AMP levels, followed by a transient decrease in incorporation of 3H-thymidine into DNA. Approximately 500 ng/mg cell protein of PGE2 were found in culture medium from the 12- to 24- hour incubation period, but significant collagenase was not detectable until 24 to 36 hours. Treatment with aspirin or indomethacin abolished PGE2 production but did not affect collagenase levels. Production of enzyme was associated with a cessation of cell proliferation, measured by protein content/culture and cell number. No enzyme was detectable in untreated cultures. Synovial fibroblasts treated with phorbol myristate acetate may provide a good model for studies on the mechanism of induction of collagenase production.  相似文献   
98.
99.
This Conversations Starter article presents a selected research abstract from the 2017 Association of American Medical Colleges Southern Region Group on Educational Affairs annual spring meeting. The abstract is paired with the integrative commentary of 4 experts who shared their thoughts stimulated by the study. These thoughts explore the value of the Observed Structured Teaching Encounter in providing structured opportunities for medical students to engage with the complexities of providing peer feedback on professionalism.  相似文献   
100.
Aims   This paper aimed to assess whether the increase of social differentiation of smoking is observed in France.
Design and setting   Five cross-sectional telephone surveys conducted in France between 2000 and 2007.
Participants   The surveys were conducted among national representative samples of French subjects aged 18–75 years ( n  = 12 256, n  = 2906, n  = 27 499, n  = 2887, n  = 6007 in 2000, 2003, 2005, 2006 and 2007, respectively). We focused on three groups: executives, manual workers and the unemployed.
Measurements   Time trends of smoking prevalence were assessed, and socio-economic factors (especially occupation and job status) associated with smoking were identified and compared in 2000 and 2005. We also computed respondents' equivalized household consumption (EHI) and their cigarette budget to assess the financial burden of smoking.
Findings   Between 2000 and 2007, smoking prevalence decreased by 22% among executive managers and professionals and by 11% among manual workers, and did not decrease among the unemployed. Indicators of an underprivileged social situation were associated more markedly with smoking in 2005 than in 2000. In addition, the falling-off of smoking initiation occurred later and was less marked among manual workers than it was among executive managers and professionals. Finally, in 2005 15% of French smokers devoted at least 20% of their EHI to the purchase of cigarettes, versus only 5% in 2000, and smoking weighted increasingly heavily on the poorest smokers' budgets.
Conclusions   While these results point out an increased social differentiation in tobacco use, they underline the need to design and implement other forms of action to encourage people to quit, in particular targeting individuals belonging to underprivileged groups.  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