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   18965篇
  免费   1200篇
  国内免费   148篇
耳鼻咽喉   154篇
儿科学   375篇
妇产科学   273篇
基础医学   2354篇
口腔科学   602篇
临床医学   1956篇
内科学   4042篇
皮肤病学   385篇
神经病学   2334篇
特种医学   1278篇
外科学   3029篇
综合类   92篇
一般理论   7篇
预防医学   606篇
眼科学   402篇
药学   1095篇
中国医学   13篇
肿瘤学   1316篇
  2023年   149篇
  2022年   145篇
  2021年   517篇
  2020年   348篇
  2019年   410篇
  2018年   500篇
  2017年   443篇
  2016年   571篇
  2015年   644篇
  2014年   802篇
  2013年   920篇
  2012年   1451篇
  2011年   1454篇
  2010年   955篇
  2009年   874篇
  2008年   1309篇
  2007年   1420篇
  2006年   1195篇
  2005年   1224篇
  2004年   1165篇
  2003年   1071篇
  2002年   954篇
  2001年   170篇
  2000年   135篇
  1999年   174篇
  1998年   171篇
  1997年   132篇
  1996年   91篇
  1995年   73篇
  1994年   69篇
  1993年   68篇
  1992年   57篇
  1991年   44篇
  1990年   39篇
  1989年   48篇
  1988年   48篇
  1987年   30篇
  1986年   45篇
  1985年   39篇
  1984年   23篇
  1983年   25篇
  1982年   23篇
  1981年   23篇
  1980年   20篇
  1979年   18篇
  1978年   28篇
  1977年   27篇
  1974年   20篇
  1970年   13篇
  1966年   15篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Monitoring variations in the functioning of the autonomic nervous system may help personalize training of runners and provide more pronounced physiological adaptations and performance improvements. We systematically reviewed the scientific literature comparing physiological adaptations and/or improvements in performance following training based on responses of the autonomic nervous system (ie, changes in heart rate variability) and predefined training. PubMed, SPORTDiscus, and Web of Science were searched systematically in July 2019. Keywords related to endurance, running, autonomic nervous system, and training. Studies were included if they (a) involved interventions consisting predominantly of running training; (b) lasted at least 3 weeks; (c) reported pre- and post-intervention assessment of running performance and/or physiological parameters; (d) included an experimental group performing training adjusted continuously on the basis of alterations in HRV and a control group; and (e) involved healthy runners. Five studies involving six interventions and 166 participants fulfilled our inclusion criteria. Four HRV-based interventions reduced the amount of moderate- and/or high-intensity training significantly. In five interventions, improvements in performance parameters (3000 m, 5000 m, Loadmax, Tlim) were more pronounced following HRV-based training. Peak oxygen uptake () and submaximal running parameters (eg, LT1, LT2) improved following both HRV-based and predefined training, with no clear difference in the extent of improvement in . Submaximal running parameters tended to improve more following HRV-based training. Research findings to date have been limited and inconsistent. Both HRV-based and predefined training improve running performance and certain submaximal physiological adaptations, with effects of the former training tending to be greater.  相似文献   
3.
4.
5.
ABSTRACT

Objective: The purpose of this study was to examine the influence of a total knee arthroplasty (TKA) on linked cranial and caudal structures.

Methods: Thirty-five (14f/21m) subjects participated in this study: 15 subjects (9f, 6m) pre- and post- TKA and a control group of 20 subjects (5f, 15m). The measurements included: jaw condyle position and movement, back scan, plantar pressure distribution, and body sway.

Results: There were no significant differences in electronic position analysis of the jaw; however, the protrusion of the TKA group improved (p = 0.001). The test group had a more anteriorly inclined thoracic spine and a less pronounced lumbar lordosis. Before and after surgery, the body sway in the test group was larger.

Conclusion: The TKA affected most prominently the static mechanisms of the postural control and the spine position. The trajectories of the mandible during protrusion also changed slightly.  相似文献   
6.
7.
8.
9.
Liver-related death in human immunodeficiency virus (HIV)-infected individuals is about 10 times higher compared with the general population, and the prevalence of significant liver fibrosis in those with HIV approaches 15%. The present study aimed to assess risk factors for development of hepatic fibrosis in HIV patients receiving a modern combination anti-retroviral therapy (cART).This cross-sectional prospective study included 432 HIV patients, of which 68 (16%) patients were anti-hepatitis C virus (HCV) positive and 23 (5%) were HBsAg positive.Health trajectory including clinical characteristics and liver fibrosis stage assessed by transient elastography were collected at inclusion. Liver stiffness values >7.1 kPa were considered as significant fibrosis, while values >12.5 kPa were defined as severe fibrosis. Logistic regression and Cox regression uni- and multivariate analyses were performed to identify independent factors associated with liver fibrosis.Significant liver fibrosis was detected in 10% of HIV mono-infected, in 37% of HCV co-infected patients, and in 18% of hepatitis B virus co-infected patients. The presence of diabetes mellitus (odds ratio [OR] = 4.6) and FIB4 score (OR = 2.4) were independently associated with presence of significant fibrosis in the whole cohort. Similarly, diabetes mellitus (OR = 5.4), adiposity (OR = 4.6), and the FIB4 score (OR = 3.3) were independently associated with significant fibrosis in HIV mono-infected patients. Importantly, cumulative cART duration protected, whereas persistent HIV viral replication promoted the development of significant liver fibrosis along the duration of HIV infection.Our findings strongly indicate that besides known risk factors like metabolic disorders, HIV may also have a direct effect on fibrogenesis. Successful cART leading to complete suppression of HIV replication might protect from development of liver fibrosis.  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