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   12649篇
  免费   632篇
  国内免费   73篇
耳鼻咽喉   114篇
儿科学   197篇
妇产科学   162篇
基础医学   1733篇
口腔科学   168篇
临床医学   769篇
内科学   3273篇
皮肤病学   212篇
神经病学   776篇
特种医学   549篇
外科学   2239篇
综合类   48篇
预防医学   321篇
眼科学   267篇
药学   816篇
中国医学   27篇
肿瘤学   1683篇
  2023年   75篇
  2022年   166篇
  2021年   293篇
  2020年   153篇
  2019年   211篇
  2018年   260篇
  2017年   212篇
  2016年   269篇
  2015年   307篇
  2014年   369篇
  2013年   469篇
  2012年   747篇
  2011年   834篇
  2010年   501篇
  2009年   391篇
  2008年   705篇
  2007年   771篇
  2006年   768篇
  2005年   807篇
  2004年   836篇
  2003年   807篇
  2002年   793篇
  2001年   222篇
  2000年   215篇
  1999年   230篇
  1998年   161篇
  1997年   138篇
  1996年   124篇
  1995年   116篇
  1994年   100篇
  1993年   115篇
  1992年   160篇
  1991年   142篇
  1990年   120篇
  1989年   132篇
  1988年   121篇
  1987年   87篇
  1986年   54篇
  1985年   63篇
  1984年   40篇
  1983年   34篇
  1982年   18篇
  1980年   13篇
  1979年   15篇
  1978年   16篇
  1977年   19篇
  1974年   14篇
  1969年   12篇
  1967年   16篇
  1966年   13篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Background and Aims: Video capsule endoscopy (VCE) has become increasingly important as a simple method for observing the entire small intestine. The indications for VCE are obscure gastrointestinal bleeding and investigation of Crohn’s disease (CD). However, the correlation between endoscopic findings obtained by VCE and clinical findings in known cases of CD is not clear, and we therefore investigated this in the present study. Patients and methods: In 30 patients with known CD (Crohn’s disease activity index [CDAI] 0–420; median = 158.3), double contrast enteroclysis (ENT) was performed 1–3 weeks prior to VCE. The relationship between the VCE findings and hematological analysis/CDAI was examined. Results: In 17 of 30 patients, the entire small intestine could be investigated by VCE, whereas in the remaining 13 patients the terminal ileum could not be investigated. The following exhibited positive correlations: total lesions and CDAI (correlation coefficient values: rs = 0.661, adjusted P < 0.0061), ulcers and C‐reactive protein (CRP) (rs = 0.607, adjusted P < 0.0061), total lesions and CRP (rs = 0.604, adjusted P < 0.0061). Conclusions: Analysis with VCE suggests that CDAI and CRP indicate the activity of intestinal lesions in patients with known CD, and that CRP, in particular, is associated with the activity of ulcerative lesions of the intestine. This may contribute to revised guidelines for VCE in the future.  相似文献   
5.
6.
7.
Mediastinal cystic tumors are well-marginated round lesions that comprise 12% to 18% of all mediastinal masses. These lesions include a variety of diseases with overlapping radiologic appearances and variable prognoses. Pathological examinations are almost always required for differential diagnosis. We encountered a case of anterior mediastinal tumor discovered in the process of investigation of Raynaud's phenomenon. Taking into account the tumor location, a pericardial cyst was initially suspected. However, the tumor was surgically resected and histopathological examinations demonstrated thymus-like tissue in the cyst walls. Raynaud's phenomenon greatly improved after surgery. These findings suggested that cystic thymoma originated from ectopic thymic tissue and is accompanied by paraneoplastic syndrome.  相似文献   
8.
In this study, we used a novel 4-fluid nozzle spray drier to prepare composite microparticles of a water-insoluble drug, flurbiprofen (FP), and a water-soluble drug, sodium salicylate (SS), for the purpose of improving the water solubility of FP. An ethanol solution of FP and an aqueous SS solution were simultaneously introduced through different liquid passages in the 4-fluid nozzle spray drier and then spray-dried. Quantitative elemental analysis suggested that the FP/SS ratio in each composite microparticle was nearly the same as the formulation ratio. We also found that SS and FP exist in a low crystallinity state in the composite particles. Release of FP from dissolved composite microparticles was markedly improved because of an increase in the effective surface area following rapid dissolution of SS. This study shows that it is possible to prepare FP-SS composite microparticles using a 4-fluid nozzle spray drier in single process and that this can improve the ability of FP to dissolve in water.  相似文献   
9.
10.
In order to treat fistulated esophageal cancer using a flexible stent, a covered flexible stent was constructed by wrapping a nitinol stent with a thin sheet of Gore-Tex, preserving the stents original advantages of flexibility and a low-profile introducer system. This stent was used to perform standard radiotherapy in a case of fistulated esophageal cancer.  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