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   5604篇
  免费   268篇
  国内免费   18篇
耳鼻咽喉   46篇
儿科学   67篇
妇产科学   65篇
基础医学   715篇
口腔科学   144篇
临床医学   361篇
内科学   1385篇
皮肤病学   38篇
神经病学   363篇
特种医学   174篇
外科学   1145篇
综合类   23篇
预防医学   152篇
眼科学   227篇
药学   353篇
中国医学   13篇
肿瘤学   619篇
  2023年   27篇
  2022年   72篇
  2021年   103篇
  2020年   44篇
  2019年   81篇
  2018年   109篇
  2017年   79篇
  2016年   105篇
  2015年   122篇
  2014年   148篇
  2013年   209篇
  2012年   316篇
  2011年   354篇
  2010年   203篇
  2009年   161篇
  2008年   279篇
  2007年   286篇
  2006年   316篇
  2005年   330篇
  2004年   279篇
  2003年   249篇
  2002年   269篇
  2001年   180篇
  2000年   179篇
  1999年   166篇
  1998年   63篇
  1997年   45篇
  1996年   49篇
  1995年   43篇
  1994年   31篇
  1993年   29篇
  1992年   84篇
  1991年   87篇
  1990年   99篇
  1989年   85篇
  1988年   91篇
  1987年   68篇
  1986年   67篇
  1985年   49篇
  1984年   45篇
  1983年   32篇
  1982年   17篇
  1981年   19篇
  1980年   15篇
  1979年   17篇
  1978年   19篇
  1974年   17篇
  1973年   15篇
  1972年   24篇
  1969年   18篇
排序方式: 共有5890条查询结果,搜索用时 15 毫秒
1.
2.
3.
In order to examine the cholecystohepatic circulation of trichloroethylene (TRI) and its metabolites, we injected the gallbladder with TRI and its metabolites, i.e. chloral hydrate (CH), free-trichloroethanol (F-TCE), trichloroacetic acid (TCA) and conjugated-trichloroethanol (Conj-TCE), using anesthetized dogs. The absorption rates of water from the gallbladder were 25-30% 2 h after administration for all substances. The absorption rates of substances were 65-70% in the CH, F-TCE and TRI groups, and 40-50% in the Conj-TCE and TCA groups 2 h after the administration. Conj-TCE in the blood absorbed from the gallbladder has a tendency to be directly transported to the venous system rather than to be taken into hepatocytes in the liver. All of the administered substances, in particular, F-TCE might be metabolized to other substances in the gallbladder.  相似文献   
4.
The requirement for endoscopic access to a stricture is a major limitation of the endoscopic dilatation for the treatment of strictures in the gastrointestinal tract. We have developed the double‐balloon enteroscopy method that enables visualization of the entire small bowel. In addition, double‐balloon enteroscopy has a potential for the interventional therapy including dilatation of strictures. We present here a case of jejunal strictures in a 47‐year‐old woman with Crohn's disease successfully treated with a balloon catheter in combination with double‐balloon enteroscopy. Balloon dilation with double‐balloon enteroscopy is a promising method for the treatment of small bowel strictures in Crohn's disease.  相似文献   
5.
6.
FR112123 is a new oligopeptide antibiotic produced by Streptomyces viridochromogenes No. 7587. The structure of FR112123 is elucidated as N-(N6-(N2-glycyl-L-glutaminyl)-D-lysyl)-D-alanine (1) by spectroscopic and chemical evidence. It resembles a partial structure of peptidoglycan in bacteria. The compound has a superior activity against an Escherichia coli mutant sensitive to inhibitors of cell wall synthesis, although it has a weak activity against the parent strain. These suggest that FR112123 might act on the biosynthesis of bacterial cell wall.  相似文献   
7.
We report the case of an infant with a cerebellar astrocytoma that showed marked calcification within only 6 months. In general, only slow-growing tumors tend to calcify. To our knowledge, no other case of such rapid calcification in cerebellar astrocytoma has been reported.  相似文献   
8.
A 22-year-old man was urgently admitted for pneumothorax. He continued complaining of exertional dyspnea and dry cough after the pneumothorax healed. About three months later, an atypical pulmonary mycobacteriosis by mycobacterium kansasii was identified. Exertional dyspnea increased after chemotherapy was administered, and the patient was readmitted because of difficulty in daily life activities. Chest radiographs and CT scans showed bilateral pulmonary hyperinflation and a narrowed heart shadow. There was also marked combined ventilatory impairment, as identified by a respiratory function test. Furthermore, the histological findings of surgically removed lung tissue revealed accumulation of lymphocytes in the wall of a small bronchus. Idiopathic bronchiolitis obliterans was diagnosed from the clinical course and clinical findings. The patient is now being monitored and is awaiting lung transplantation.  相似文献   
9.
10.
We have investigated the effects of short-contact topical application of tretinoin using 16 male db/db mice by creating two full-thickness wounds on the skin of the back. A 0.1% tretinoin aqueous gel was applied to one wound for five minutes daily for five successive days while only aqueous gel was applied to the other (control). The mean (SD) percentage surface area unhealed before and after treatment were 0.88 (0.3) and 0.64 (0.15). In tretinoin-treated mice and non-treated mice (controls), the mean (SD) thicknesses of granulation were 1.383 (697) micro m and 683 (413) micro m, the density of capillary vessels in granulation was 12.2 (5.5)% and 5.7 (3.9)%, respectively. Differences between the two groups were significant for each variable. Wound healing was accelerated with short-contact topical application of tretinoin in db/db mice.  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