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   2374068篇
  免费   176962篇
  国内免费   3760篇
耳鼻咽喉   32632篇
儿科学   76339篇
妇产科学   63317篇
基础医学   352106篇
口腔科学   64038篇
临床医学   213646篇
内科学   463398篇
皮肤病学   52616篇
神经病学   187187篇
特种医学   89466篇
外国民族医学   489篇
外科学   357582篇
综合类   47974篇
现状与发展   12篇
一般理论   863篇
预防医学   183856篇
眼科学   55136篇
药学   177541篇
  11篇
中国医学   4908篇
肿瘤学   131673篇
  2021年   19876篇
  2019年   20269篇
  2018年   27906篇
  2017年   20978篇
  2016年   23588篇
  2015年   26795篇
  2014年   37443篇
  2013年   55477篇
  2012年   76901篇
  2011年   81733篇
  2010年   48455篇
  2009年   45762篇
  2008年   76256篇
  2007年   81060篇
  2006年   81697篇
  2005年   79140篇
  2004年   75502篇
  2003年   72799篇
  2002年   70366篇
  2001年   109284篇
  2000年   111923篇
  1999年   93967篇
  1998年   27185篇
  1997年   23844篇
  1996年   24211篇
  1995年   22852篇
  1994年   21015篇
  1993年   19780篇
  1992年   72214篇
  1991年   70228篇
  1990年   68579篇
  1989年   65852篇
  1988年   60477篇
  1987年   59262篇
  1986年   55335篇
  1985年   53121篇
  1984年   39413篇
  1983年   33472篇
  1982年   19922篇
  1979年   35958篇
  1978年   25708篇
  1977年   21286篇
  1976年   20362篇
  1975年   21858篇
  1974年   26195篇
  1973年   24837篇
  1972年   23234篇
  1971年   22071篇
  1970年   20280篇
  1969年   19330篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
151.
152.
153.
Eccrine naevus (EN) is a rare skin hamartoma included in the organoid group of epidermal naevi, histologically defined as focal hyperplasia and/or hypertrophy of eccrine glands. Clinically, EN usually presents as hyperhidrotic patches with no visible skin changes, frequently located on the forearms. The decision to treat EN or not usually depends on the grade of hyperhidrosis, but there is no therapeutic consensus because of the rarity of this condition. We present a case diagnosed as EN in an adult patient with severe localized hyperhidrosis, which was successfully treated with botulinum toxin.  相似文献   
154.
155.
156.
157.
Alterations in autophagy are increasingly being recognized in the pathogenesis of proteinopathies like Alzheimer's disease (AD). This study was conducted to evaluate whether melatonin treatment could provide beneficial effects in an Alzheimer model related to tauopathy by improving the autophagic flux and, thereby, prevent cognitive decline. The injection of AAV‐hTauP301L viral vectors and treatment/injection with okadaic acid were used to achieve mouse and human ex vivo, and in vivo tau‐related models. Melatonin (10 μmol/L) impeded oxidative stress, tau hyperphosphorylation, and cell death by restoring autophagy flux in the ex vivo models. In the in vivo studies, intracerebroventricular injection of AAV‐hTauP301L increased oxidative stress, neuroinflammation, and tau hyperphosphorylation in the hippocampus 7 days after the injection, without inducing cognitive impairment; however, when animals were maintained for 28 days, cognitive decline was apparent. Interestingly, late melatonin treatment (10 mg/kg), starting once the alterations mentioned above were established (from day 7 to day 28), reduced oxidative stress, neuroinflammation, tau hyperphosphorylation, and caspase‐3 activation; these observations correlated with restoration of the autophagy flux and memory improvement. This study highlights the importance of autophagic dysregulation in tauopathy and how administration of pharmacological doses of melatonin, once tauopathy is initiated, can restore the autophagy flux, reduce proteinopathy, and prevent cognitive decline. We therefore propose exogenous melatonin supplementation or the development of melatonin derivatives to improve autophagy flux for the treatment of proteinopathies like AD.  相似文献   
158.
159.
160.
Objective: Report measured resting energy expenditure (REE) in wheelchair rugby athletes and evaluate agreement between REE and the prediction models of Chun, Cunningham, Harris-Benedict, Mifflin, Nightingale and Gorgey, and Owen.

Design: Cohort-based validation study.

Setting. Paralympic team training camp.

Participants: Fourteen internationally competitive athletes who play wheelchair rugby, 13 of whom had cervical spinal cord injuries (SCI).

Outcome Measures: A portable metabolic analyzer was used to measure REE following an overnight fast and dual-energy X-ray absorptiometry (DXA) was used to assess lean body mass for the prediction equations.

Results: REE in the current sample was 1735?±?257?kcal?×?day?1 ranging from 1324 to 2068?kcal?×?day?1 Bhambhani Y. Physiology of wheelchair racing in athletes with spinal cord injury. Sports Med 2002;32(1):2351.[Crossref], [PubMed], [Web of Science ®] [Google Scholar]. Bland–Altman analyses revealed negative mean bias but similar limits of agreement between measured REE and scores predicted by Chun, Cunningham, Mifflin, Nightingale and Gorgey, and Owen models in elite athletes who play wheelchair rugby.

Conclusion: Prediction models regressed on persons with and without SCI under-predicted REE of competitive wheelchair rugby athletes. This outcome may be explained by the higher REE/fat-free mass (FFM) ratio of current athletes compared to less active samples. Findings from the current study will help practitioners to determine nutrient intake needs on training days of varied intensity.  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