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   14361篇
  免费   1564篇
  国内免费   19篇
耳鼻咽喉   176篇
儿科学   507篇
妇产科学   242篇
基础医学   2171篇
口腔科学   192篇
临床医学   1572篇
内科学   2619篇
皮肤病学   154篇
神经病学   1534篇
特种医学   459篇
外科学   2049篇
综合类   497篇
一般理论   16篇
预防医学   1439篇
眼科学   191篇
药学   1034篇
中国医学   18篇
肿瘤学   1074篇
  2023年   88篇
  2022年   122篇
  2021年   242篇
  2020年   192篇
  2019年   265篇
  2018年   314篇
  2017年   198篇
  2016年   228篇
  2015年   273篇
  2014年   401篇
  2013年   534篇
  2012年   787篇
  2011年   774篇
  2010年   449篇
  2009年   445篇
  2008年   706篇
  2007年   816篇
  2006年   765篇
  2005年   691篇
  2004年   644篇
  2003年   588篇
  2002年   595篇
  2001年   413篇
  2000年   399篇
  1999年   367篇
  1998年   198篇
  1997年   157篇
  1996年   124篇
  1995年   123篇
  1994年   133篇
  1993年   134篇
  1992年   292篇
  1991年   246篇
  1990年   239篇
  1989年   252篇
  1988年   201篇
  1987年   210篇
  1986年   183篇
  1985年   194篇
  1984年   144篇
  1983年   138篇
  1982年   96篇
  1979年   121篇
  1978年   103篇
  1977年   94篇
  1976年   96篇
  1974年   100篇
  1973年   95篇
  1972年   92篇
  1971年   88篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.

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   
2.
3.
4.
5.
6.
Animal models have traditionally provided the basis for preliminary investigation of new techniques prior to trials taking place in human subjects. The timing of when to proceed with human trials is difficult, as the accuracy of preclinical models can only be determined with hindsight. This review outlines the progression from transplantation in animal models to man. Now that many transplant procedures are well established, it is possible to assess the predictive value and limitations of animal models. These results are of great importance in the current debate about composite tissue allotransplantation (CTA) and in particular facial transplantation. This progression of CTA from animal models to man is outlined and compared with early renal, cardiac, and liver transplants. There is some evidence to suggest that animal models may have been misleading in CTA and that this has effectively delayed the transition to humans. The role for animal models in facial transplantation, which is currently making the step to clinical trials, is discussed.  相似文献   
7.
PINK1 mutations in sporadic early-onset Parkinson's disease.   总被引:5,自引:0,他引:5  
Pathogenic PINK1 mutations have been described in PARK6-linked Parkinson's disease (PD) patients of Asian origin. However, data on the frequency of PINK1 mutations in sporadic early-onset Parkinson's disease (EOPD) Asian patients are lacking. The objectives of this study were to report the frequency of PINK1 mutations of sporadic EOPD in an Asian cohort comprising of ethnic Chinese, Malays, and Indians, and to highlight a PINK1-positive patient who presented with restless legs symptoms. Eighty consecutive sporadic EOPD patients from the movement disorder clinics of two major tertiary institutions in the country were included. We performed sequence analysis of all the coding and exon-intron junctions of the PINK1 using specific primer sets. In addition, we genotyped polymorphisms detected from the analysis in a group of sporadic PD patients and controls. Three different mutations (two homozygous nonsense and one heterozygous missense) in the putative kinase domain were found in three patients, giving a 3.7% frequency of PINK1 mutations in our EOPD cohort. All the mutations were absent in 200 healthy controls. One patient with a novel homozygous nonsense PINK1 mutation presented unusually with restless legs symptoms. Separately, analysis of the frequency of four PINK1 polymorphisms in a group of sporadic PD and controls did not reveal any significant differences. We highlight a 3.7% frequency of PINK1 mutations in an Asian cohort (ethnic Chinese, Malay, and Indian) of EOPD. The phenotypic spectrum associated with PINK1-positive patients may be wider than previously reported. Polymorphisms of PINK1 do not appear to modulate risk of PD in our population.  相似文献   
8.

Background  

Hospital episode statistics (HES) is a UK national database for the National Health Service (NHS), now available online. The purpose of this study was to observe trends in ophthalmic operations performed during the period from 1998 to 2004, using this data.  相似文献   
9.
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