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   3643篇
  免费   220篇
  国内免费   30篇
耳鼻咽喉   44篇
儿科学   211篇
妇产科学   76篇
基础医学   433篇
口腔科学   74篇
临床医学   419篇
内科学   725篇
皮肤病学   74篇
神经病学   216篇
特种医学   524篇
外科学   307篇
综合类   57篇
预防医学   252篇
眼科学   43篇
药学   199篇
中国医学   12篇
肿瘤学   227篇
  2023年   15篇
  2022年   33篇
  2021年   73篇
  2020年   40篇
  2019年   55篇
  2018年   78篇
  2017年   51篇
  2016年   83篇
  2015年   91篇
  2014年   126篇
  2013年   191篇
  2012年   178篇
  2011年   172篇
  2010年   161篇
  2009年   140篇
  2008年   138篇
  2007年   133篇
  2006年   147篇
  2005年   104篇
  2004年   125篇
  2003年   109篇
  2002年   104篇
  2001年   48篇
  2000年   59篇
  1999年   52篇
  1998年   150篇
  1997年   131篇
  1996年   138篇
  1995年   100篇
  1994年   90篇
  1993年   87篇
  1992年   37篇
  1991年   28篇
  1990年   23篇
  1989年   66篇
  1988年   51篇
  1987年   59篇
  1986年   50篇
  1985年   51篇
  1984年   29篇
  1983年   37篇
  1982年   41篇
  1981年   23篇
  1980年   48篇
  1979年   18篇
  1978年   22篇
  1977年   22篇
  1976年   25篇
  1975年   25篇
  1971年   8篇
排序方式: 共有3893条查询结果,搜索用时 515 毫秒
1.
The aetiology of vitiligo has not been fully elucidated, and several hypotheses have been investigated; among them, the most explored assumes an autoimmune basis for the disease. Supporting this hypothesis is the frequent co-occurrence of autoimmune diseases with vitiligo. In addition, various genetic loci associated with vitiligo harbour key immune response genes. Our general hypothesis is that autoimmunity-associated genes participate in the control of vitiligo susceptibility. To investigate this hypothesis, we tested for association between vitiligo and genes CYP27B1, REL, TNFAIP3 and IL2/IL21, all previously related to autoimmune diseases associated with vitiligo. The study was performed using two independent population samples: a family-based discovery set (211 trios) and a replication set (131 cases/119 controls). Statistically significant association with vitiligo was detected between markers of the REL and IL2 gene in the family-based sample. Both association signals were concentrated among patients displaying autoimmune comorbidity and non-segmental vitiligo. Evidence for validation was detected for IL2 marker. Our findings suggest REL and IL2 as new vitiligo susceptibility genes and reinforce the hypothesis of a shared genetic mechanism controlling vitiligo and other autoimmune diseases.  相似文献   
2.
3.
Despite the introduction of microsurgical techniques into clinical practice, the results of surgical procedures involving the brachial plexus and peripheral nerves are still far from spectacular. We therefore studied the rat brachial plexus and its terminal branches in 203 rats. Detailed anatomic and morphologic analyses of the biceps brachii and musculocutaneous nerve, finger flexors, flexor carpi radialis, and the median nerve were performed. Various sources of conventional and vascularized nerve grafts were explored. After musculocutaneous nerve section or median nerve section, there were no articular contractures or automutilations, which constitutes an advantage for these experimental models over the sciatic nerve model. The brachial plexus and its terminal branches provide a good experimental model which can be used to assess the development and normal control of muscle function, examine the mechanisms underlying functional recovery, and test the effects of treatments to enhance recovery. © 1995 Wiley-Liss, Inc.  相似文献   
4.
The efficiency of two methods of detection of translocations induced in mouse stem cell spermatogonia by X-ray doses of 2, 5 and 7 Gy was compared: classical multivalent analysis at diakinesis-metaphase I of meiosis and observation via fluorescencein situ hybridization analysis of mitotic or meiotic stages. Specific DNA libraries for chromosomes 1, 11 and 13 were used. The results obtained indicate that (a) chromosomes 1, 11 and 13 are more involved in multivalent formation than expected on the basis of DNA content and (b) if the mitotic FISH analysis data are corrected for the observed over-representation, the frequencies of induced translocations are similar to those recorded in the classical multivalent studies, suggesting equal scoring efficiencies in both systems.  相似文献   
5.
6.
BACKGROUND: Our aims in the present study were to estimate the influences of pain and urinary symptoms on quality of life, and to determine which of these two variables has the most predictive power with respect to quality of life in young men with chronic prostatitis-like symptoms. METHODS: Chronic prostatitis-like symptoms were measured by the National Institutes of Health-Chronic Prostatitis Symptom Index. Of the 28,841 men aged 20 years who lived in the study community, 18,495 men (a response rate 64.1%) agreed to participate in the study. A total of 1057 men who complained of symptoms indicative of chronic prostatitis were included in the study. The influences of pain and urinary symptoms on quality of life were determined using logistic regression analysis. The receiver operating characteristic (ROC) curve was used to estimate the predictive ability of each of these variables with respect to quality of life. RESULTS: Results from multivariate analysis showed that both pain and urinary symptoms were associated with an increased likelihood of impaired quality of life, although pain contributed more to a reduced quality of life than urinary symptoms. Relative to men who experienced mild pain, men who experienced moderate pain had a 3.9-fold risk of poor quality of life (odds ratio [OR], 3.87; 95% confidence interval [CI], 2.86-5.23; P < 0.001) and those who experienced severe pain had a 15.7-fold risk of reduced quality of life (OR, 15.68; 95% CI, 6.59-37.35; P < 0.001). Moderate urinary symptoms were associated with a 1.4-fold risk of bother (OR, 1.41; 95% CI, 1.01-1.99; P < 0.001) and severe urinary symptoms were associated with 2.4-fold risk (OR, 2.39; 95% CI, 1.37-4.12; P < 0.001), relative to mild urinary symptoms. Comparison of the effects of pain and urinary symptoms showed that pain severity had the most predictive power for bother, quality of life, and quality-of-life impact. The areas under the ROC curves for bother, quality of life, and quality-of-life impact were 71.3%, 69.3% and 72.5%, respectively. CONCLUSION: Urinary symptoms and pain might be associated with an increased likelihood of impaired quality of life in young men with chronic prostatitis-like symptoms. In addition, our findings suggest that pain severity is the most influential variable for determining quality of life in this population.  相似文献   
7.
8.
9.
Evaluation of an on-line patient exposure meter in neuroradiology   总被引:1,自引:0,他引:1  
  相似文献   
10.
Pediatric knee MR imaging: pattern of injuries in the immature skeleton   总被引:3,自引:0,他引:3  
  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