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   217398篇
  免费   15743篇
  国内免费   774篇
耳鼻咽喉   2311篇
儿科学   5632篇
妇产科学   4483篇
基础医学   28084篇
口腔科学   4807篇
临床医学   20673篇
内科学   45993篇
皮肤病学   2886篇
神经病学   21069篇
特种医学   7178篇
外国民族医学   13篇
外科学   33861篇
综合类   3591篇
现状与发展   2篇
一般理论   299篇
预防医学   19697篇
眼科学   4433篇
药学   14921篇
  1篇
中国医学   376篇
肿瘤学   13605篇
  2023年   876篇
  2022年   1450篇
  2021年   3522篇
  2020年   2157篇
  2019年   3486篇
  2018年   4068篇
  2017年   3310篇
  2016年   3520篇
  2015年   4169篇
  2014年   6271篇
  2013年   9048篇
  2012年   13454篇
  2011年   14653篇
  2010年   8291篇
  2009年   7477篇
  2008年   13919篇
  2007年   14730篇
  2006年   14218篇
  2005年   14656篇
  2004年   14110篇
  2003年   13174篇
  2002年   12691篇
  2001年   2131篇
  2000年   1727篇
  1999年   2280篇
  1998年   2911篇
  1997年   2510篇
  1996年   2270篇
  1995年   2030篇
  1994年   1836篇
  1993年   1709篇
  1992年   1424篇
  1991年   1333篇
  1990年   1209篇
  1989年   1097篇
  1988年   1133篇
  1987年   1167篇
  1986年   1127篇
  1985年   1212篇
  1984年   1553篇
  1983年   1547篇
  1982年   1858篇
  1981年   1691篇
  1980年   1591篇
  1979年   881篇
  1978年   1025篇
  1977年   977篇
  1976年   876篇
  1975年   727篇
  1974年   730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