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   25520篇
  免费   1184篇
  国内免费   122篇
耳鼻咽喉   226篇
儿科学   426篇
妇产科学   433篇
基础医学   3364篇
口腔科学   464篇
临床医学   1606篇
内科学   6001篇
皮肤病学   448篇
神经病学   2195篇
特种医学   1069篇
外科学   4112篇
综合类   95篇
一般理论   5篇
预防医学   827篇
眼科学   649篇
药学   1634篇
中国医学   41篇
肿瘤学   3231篇
  2022年   211篇
  2021年   429篇
  2020年   229篇
  2019年   332篇
  2018年   409篇
  2017年   333篇
  2016年   377篇
  2015年   433篇
  2014年   567篇
  2013年   722篇
  2012年   1185篇
  2011年   1209篇
  2010年   677篇
  2009年   601篇
  2008年   1059篇
  2007年   1220篇
  2006年   1159篇
  2005年   1105篇
  2004年   1031篇
  2003年   1022篇
  2002年   1068篇
  2001年   819篇
  2000年   892篇
  1999年   805篇
  1998年   325篇
  1997年   252篇
  1996年   246篇
  1995年   226篇
  1994年   226篇
  1993年   201篇
  1992年   750篇
  1991年   651篇
  1990年   625篇
  1989年   629篇
  1988年   593篇
  1987年   548篇
  1986年   487篇
  1985年   487篇
  1984年   283篇
  1983年   244篇
  1979年   259篇
  1978年   141篇
  1977年   115篇
  1975年   119篇
  1974年   108篇
  1973年   115篇
  1972年   108篇
  1970年   118篇
  1969年   131篇
  1968年   112篇
排序方式: 共有10000条查询结果,搜索用时 218 毫秒
1.
Animal and human studies suggest fish oil and green tea may have protective effect on prostate cancer. Fatty acid synthase (FAS) has been hypothesized to be linked to chemoprotective effects of both compounds. This study evaluated the independent and joint effects of fish oil (FO) and green tea supplement (epigallocatechin-3-gallate, EGCG) on FAS and Ki-67 levels in prostate tissue. Through a double-blinded, randomized controlled trial with 2 × 2 factorial design, 89 men scheduled for repeat prostate biopsy following an initial negative prostate biopsy were randomized into either FO alone (1.9 g DHA + EPA/day), EGCG alone (600 mg/day), a combination of FO and EGCG, or placebo. We used linear mixed-effects models to test the differences of prostate tissue FAS and Ki-67 by immunohistochemistry between pre- and post-intervention within each group, as well as between treatment groups. Results did not show significant difference among treatment groups in pre-to-post-intervention changes of FAS (P = 0.69) or Ki-67 (P = 0.26). Comparing placebo group with any of the treatment groups, we did not find significant difference in FAS or Ki-67 changes (all P > 0.05). Results indicate FO or EGCG supplementation for a short duration may not be sufficient to produce biologically meaningful changes in FAS or Ki-67 levels in prostate tissue.  相似文献   
2.
3.
We report a case of a diaphragmatic hernia after a heart transplant operation. A 43-year-old woman, who underwent orthotropic heart transplantation for hypertrophic cadiomyopathy two year earlier, presented with vomiting and epigastric pain. A computed tomography scan showed that the stomach and transverse colon were dislocated in the left thoracic cavity. We diagnosed left diaphragmatic hernia incarceration and performed laparoscopic repair of the diaphragmatic hernia. A 12 × 8 cm diaphragmatic defect was found intraoperatively on the ventrolateral aspect of the left diaphragm, and the stomach with volvulus had herniated into the thorax through the defect. The hernia was considered to be iatrogenic. The diaphragmatic defect was large, and the diaphragm was thinning. We closed the defect by mesh repair. Laparoscopic mesh repair of the diaphragmatic hernia could be performed safely and with minimal invasiveness.  相似文献   
4.
5.
6.
7.
8.
9.
OBJECTIVES: To reveal the frequency and the clinical characteristics of dystrophic calcification that occurs in children with juvenile dermatomyositis, multi-center analysis was constructed. METHOD: Fifty children with JDM were enrolled, and 14 of them (28.0%) were complicated with calcinosis. Clinical symptoms and laboratory tests at onset, initial therapy and disease course were compared in children with and without calcinosis. RESULTS: The mean age of the onset of calcinosis was 4.78 +/- 3.33 years, and it was younger than those of children without calcinosis (8.66 +/- 3.85 years) (P = 0.0017). No differences of clinical manifestation except Gower's sign were observed. The frequency of positive anti-nuclear antibody was 7.1% in children with calcinosis and 52.9% without calcinosis (P = 0.0112). The initial therapy of methylprednisolon pulses gave no effects on prognosis of calcium deposition. The calcinosis appeared in 1.56 +/- 1.91 year after the onset of the disease. The various types of calcium deposition including large tumorous clumps, subcutaneous plaques or nodules, sheet-type calcification were deserved. They appeared over knee joints (64.3%), elbow joint (64.3%), and hip processes (50.0%). Calcinosis affecting the subcutaneous tissues frequently resulted in painful superficial ulceration of the overlying skin (42.9%), local infection (50.0%), and limitation of joint movement (14.3%). Although aluminum phosphate was effective in 2 children among 7, no other effective treatment was recommended. In 5 cases, surgical removal of tumorous clumps was operated. Thus, juvenile dermatomyositis is frequently complicated with calcinosis. This type of calcinosis was found to be unlikely to resolve completely, and resulted in severe disability in children.  相似文献   
10.
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