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   210526篇
  免费   15183篇
  国内免费   750篇
耳鼻咽喉   2288篇
儿科学   5489篇
妇产科学   4306篇
基础医学   27128篇
口腔科学   4513篇
临床医学   20023篇
内科学   44902篇
皮肤病学   2754篇
神经病学   20312篇
特种医学   6958篇
外国民族医学   13篇
外科学   33005篇
综合类   3416篇
现状与发展   2篇
一般理论   291篇
预防医学   19079篇
眼科学   4373篇
药学   14405篇
  1篇
中国医学   374篇
肿瘤学   12827篇
  2023年   843篇
  2022年   1405篇
  2021年   3442篇
  2020年   2106篇
  2019年   3391篇
  2018年   3973篇
  2017年   3216篇
  2016年   3412篇
  2015年   4070篇
  2014年   6097篇
  2013年   8824篇
  2012年   13132篇
  2011年   14323篇
  2010年   8099篇
  2009年   7307篇
  2008年   13591篇
  2007年   14429篇
  2006年   13927篇
  2005年   14397篇
  2004年   13814篇
  2003年   12902篇
  2002年   12443篇
  2001年   1881篇
  2000年   1462篇
  1999年   2052篇
  1998年   2834篇
  1997年   2440篇
  1996年   2210篇
  1995年   1958篇
  1994年   1759篇
  1993年   1664篇
  1992年   1217篇
  1991年   1159篇
  1990年   1067篇
  1989年   964篇
  1988年   1019篇
  1987年   1025篇
  1986年   1012篇
  1985年   1085篇
  1984年   1486篇
  1983年   1466篇
  1982年   1816篇
  1981年   1639篇
  1980年   1558篇
  1979年   812篇
  1978年   958篇
  1977年   933篇
  1976年   831篇
  1975年   683篇
  1974年   666篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
The aim of the study was to determine the effect of β-glucan on the cytotoxicity and genotoxicity of polypectomized patient's fecal water (FW). Polypectomized volunteers (n = 69) were randomly assigned to consume bread with or without β-glucan, for 3 months. FW was collected at the beginning (t = 0), the 30th and 90th day and 2 wk after the intervention. Cytotoxicity and genotoxicity were estimated on Caco-2 cells, using trypan blue exclusion test and comet assay, respectively. Gastrointestinal symptoms were recorded and subjects kept a 3-day food diary at baseline and after completion. Trypan blue exclusion test revealed cell survival of approximately 87% after incubation with FW. The FW samples showed 49% genotoxicity at the baseline. Genotoxicity in the intervention group decreased during the trial reaching statistical significance on the 90th day compared to control. An increase was noticed 2 wk after the trial, but it still remained significantly lower compared to control. Group-specific analysis for β-glucan also revealed significant decrease in the genotoxicity on the 90th day compared to baseline. β-glucan ingestion in polypectomized patients significantly decreased the genotoxicity of their FW. Our findings suggest that β-glucan consumption could possibly provide protection against colon cancer development.  相似文献   
3.
4.
5.
6.
7.
8.
9.

Objectives

To investigate whether functional overreaching affects locomotor system behaviour when running at fixed relative intensities and if any effects were associated with changes in running performance.

Design

Prospective intervention study.

Methods

Ten trained male runners completed three training blocks in a fixed order. Training consisted of one week of light training (baseline), two weeks of heavy training designed to induce functional overreaching, and ten days of light taper training designed to allow athletes to recover from, and adapt to, the heavy training. Locomotor behaviour, 5-km time trial performance, and subjective reports of training status (Daily Analysis of Life Demands for Athletes (DALDA) questionnaire) were assessed at the completion of each training block. Locomotor behaviour was assessed using detrended fluctuation analysis of stride intervals during running at speeds corresponding to 65% and 85% of maximum heart rate (HRmax) at baseline.

Results

Time trial performance (effect size ±95% confidence interval (ES): 0.16 ± 0.06; p < 0.001), locomotor behaviour at 65% HRmax (ES: ?1.12 ± 0.95; p = 0.026), and DALDA (ES: 2.55 ± 0.80; p < 0.001) were all detrimentally affected by the heavy training. Time trial performance improved relative to baseline after the taper (ES: ?0.16 ± 0.10; p = 0.003) but locomotor behaviour at 65% HRmax (ES: ?1.18 ± 1.17; p = 0.048) and DALDA (ES: 0.92 ± 0.90; p = 0.045) remained impaired.

Conclusions

Locomotor behaviour during running at 65% HRmax was impaired by functional overreaching and remained impaired after a 10-day taper, despite improved running performance. Locomotor changes may increase injury risk and should be considered within athlete monitoring programs independently of performance changes.  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