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   4952篇
  免费   293篇
  国内免费   25篇
耳鼻咽喉   51篇
儿科学   135篇
妇产科学   63篇
基础医学   735篇
口腔科学   449篇
临床医学   342篇
内科学   1127篇
皮肤病学   109篇
神经病学   434篇
特种医学   66篇
外国民族医学   1篇
外科学   536篇
综合类   20篇
预防医学   495篇
眼科学   63篇
药学   337篇
中国医学   24篇
肿瘤学   283篇
  2024年   5篇
  2023年   54篇
  2022年   78篇
  2021年   165篇
  2020年   126篇
  2019年   164篇
  2018年   170篇
  2017年   135篇
  2016年   135篇
  2015年   185篇
  2014年   237篇
  2013年   271篇
  2012年   433篇
  2011年   495篇
  2010年   287篇
  2009年   234篇
  2008年   357篇
  2007年   316篇
  2006年   267篇
  2005年   255篇
  2004年   227篇
  2003年   195篇
  2002年   145篇
  2001年   36篇
  2000年   35篇
  1999年   38篇
  1998年   29篇
  1997年   21篇
  1996年   18篇
  1995年   15篇
  1994年   13篇
  1993年   15篇
  1992年   7篇
  1991年   9篇
  1990年   9篇
  1989年   17篇
  1988年   6篇
  1987年   5篇
  1986年   5篇
  1985年   3篇
  1984年   5篇
  1983年   4篇
  1982年   5篇
  1981年   4篇
  1980年   4篇
  1979年   6篇
  1978年   3篇
  1977年   4篇
  1976年   4篇
  1971年   2篇
排序方式: 共有5270条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.

Background  

Due to marginalization, trafficking violence, conflicts with the police and organic and social psychological problems associated with the drug, crack is one of the most devastating drugs currently in use. However, there is evidence that some users manage to stay alive and active while using crack cocaine for many years, despite the numerous adversities and risks involved with this behavior. In this context, the aim of the present study was to identify the strategies and tactics developed by crack users to deal with the risks associated with the culture of use by examining the survival strategies employed by long-term users.  相似文献   
7.
The implantation of chondrocytes, seeded on matrices such as hyaluronic acid or collagen membranes, is a method that is being widely used for the treatment of chondral defects. The aim of the present study was to evaluate the distribution, viability and phenotype expression of the cells seeded on a collagen membrane just at the time of the implantation. Twelve patients who were suffering from articular cartilage lesions were treated by the MACI® procedure. The residual part of each membrane was tested by colorimetric assay (MTT) and histochemical and ultrastructural analyses were carried out. In all of the samples a large number of viable cells, quite homogenously distributed, was detected. The cells expressed the markers of the differentiated hyaline chondrocytes. These data reassure in that the MACI procedure provides a suitable engineered tissue for cartilage repair, in line with the clinical evidences emerging in the literature.  相似文献   
8.
PURPOSE: Current treatment for febrile neutropenia (FN) includes hospitalization for evaluation, empiric broad-spectrum antibiotics, and other supportive care. Clinical trials have reported conflicting results when studying whether the colony-stimulating factors (CSFs) improve outcomes in patients with FN. This Cochrane Collaboration review was undertaken to further evaluate the safety and efficacy of the CSFs in patients with FN. METHODS: An exhaustive literature search was undertaken including major electronic databases (CANCERLIT, EMBASE, LILACS, MEDLINE, SCI, and the Cochrane Controlled Trials Register). All randomized controlled trials that compare CSFs plus antibiotics versus antibiotics alone for the treatment of established FN in adults and children were sought. A meta-analysis of the selected studies was performed. RESULTS: More than 8,000 references were screened, with 13 studies meeting eligibility criteria for inclusion. The overall mortality was not influenced significantly by the use of CSF (odds ratio [OR] = 0.68; 95% CI, 0.43 to 1.08; P = .1). A marginally significant result was obtained for the use of CSF in reducing infection-related mortality (OR = 0.51; 95% CI, 0.26 to 1.00; P = .05). Patients treated with CSFs had a shorter length of hospitalization (hazard ratio [HR] = 0.63; 95% CI, 0.49 to 0.82; P = .0006) and a shorter time to neutrophil recovery (HR = 0.32; 95% CI, 0.23 to 0.46; P < .00001). CONCLUSION: The use of the CSFs in patients with established FN caused by cancer chemotherapy reduces the amount of time spent in hospital and the neutrophil recovery period. The possible influence of the CSFs on infection-related mortality requires further investigation.  相似文献   
9.
10.
We examined 334 legs in 167 consecutive patients with advanced peripheral ischemic disease using color Doppler sonography and angiography. Angiography revealed 714 lesions (369 nonsignificant stenoses, 297 significant stenoses, and 48 occlusions) in the 334 legs examined. Overall, color Doppler sonography revealed diagnostic agreement with angiography in 668 of 714 lesions (93.5%), including 343 of 369 (92.9%) nonsignificant stenoses, 279 of 297 (93.9%) significant stenoses, and 46 of 48 (95.8%) occlusions. Overestimation occurred in 26 of 369 (7%) nonsignificant stenoses and 3 of 297 (1%) significant stenoses. Underestimation was observed in 15 of 297 (5%) significant stenoses and in 2 of 48 (4.2%) occlusions. Peak systolic velocity ratio correlated better (P < 0.01) than peak systolic velocity with diameter reduction percentage as assessed at angiography. Color Doppler sonography is an accurate noninvasive method for evaluating patients with peripheral ischemic disease.  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