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   13220篇
  免费   863篇
  国内免费   39篇
耳鼻咽喉   140篇
儿科学   328篇
妇产科学   403篇
基础医学   1882篇
口腔科学   195篇
临床医学   1203篇
内科学   3030篇
皮肤病学   223篇
神经病学   1490篇
特种医学   360篇
外科学   1606篇
综合类   210篇
一般理论   13篇
预防医学   899篇
眼科学   305篇
药学   1030篇
中国医学   26篇
肿瘤学   779篇
  2022年   127篇
  2021年   272篇
  2020年   119篇
  2019年   174篇
  2018年   225篇
  2017年   186篇
  2016年   222篇
  2015年   262篇
  2014年   341篇
  2013年   478篇
  2012年   674篇
  2011年   714篇
  2010年   350篇
  2009年   371篇
  2008年   676篇
  2007年   700篇
  2006年   706篇
  2005年   679篇
  2004年   675篇
  2003年   602篇
  2002年   606篇
  2001年   321篇
  2000年   295篇
  1999年   262篇
  1998年   127篇
  1997年   107篇
  1996年   104篇
  1995年   92篇
  1994年   98篇
  1993年   96篇
  1992年   245篇
  1991年   236篇
  1990年   203篇
  1989年   203篇
  1988年   183篇
  1987年   173篇
  1986年   176篇
  1985年   134篇
  1984年   141篇
  1983年   118篇
  1982年   110篇
  1981年   77篇
  1980年   85篇
  1979年   107篇
  1978年   91篇
  1977年   80篇
  1976年   86篇
  1975年   99篇
  1974年   84篇
  1971年   80篇
排序方式: 共有10000条查询结果,搜索用时 15 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.
4.
5.
6.
7.
Nutcracker fracture of the cuboid is a rare injury usually caused by forced abduction of the forefoot on a fixed hindfoot. We report a case of this fracture in a 58-year-old man who was treated on the principle of ligamentotaxis and the position being held with Kirchner wires for a period of 5 weeks. He recovered without any complications and with good ankle and subtalar movements. At 5 months following the injury he had returned to his previous occupation. We think this novel way of treating this rare fracture is simple and gave a good result in this patient.  相似文献   
8.
BACKGROUND: Few data are currently available investigating neurosteroids (NS) in Alzheimer's disease (AD). The NS allopregnanolone may be decreased in serum and plasma in patients with AD, but it is unclear if allopregnanolone is also reduced in brain. Because a number of NS exhibit neuroprotective effects and impact cognitive performance in rodent models, these molecules may be relevant to the pathophysiology of neurodegenerative disorders. We therefore investigated prefrontal cortex (PFC) NS levels in AD. METHODS: Neurosteroid levels (allopregnanolone, pregnenolone, dehydroepiandrosterone [DHEA]) were determined in postmortem PFC in 14 male subjects with AD and 15 cognitively intact male control subjects by gas chromatography/mass spectrometry preceded by high-performance liquid chromatography purification. RESULTS: Subjects with AD exhibit significant reductions in allopregnanolone compared with cognitively intact control subjects (median levels = 2.50 ng/g vs. 5.59 ng/g, respectively; p = .02). Allopregnanolone levels are inversely correlated with neuropathological disease stage (Braak), r = -.49, p = .007. Median DHEA levels are elevated in subjects with AD (p = .01). CONCLUSIONS: Subjects with AD demonstrate significant reductions in PFC allopregnanolone levels, a finding that may be relevant to neuropathological disease stage severity. Neurosteroids may have utility as candidate biomarkers in AD.  相似文献   
9.
Case report A 28-year-old female patient was admitted because of painlessmacroscopic haematuria. Past history included severe mentalretardation and nystagmus. At age 17, a computed tomography(CT) scan of the brain showed an absent cerebellar vermis andcerebellar hypoplasia. There was no  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