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   4943篇
  免费   303篇
  国内免费   10篇
耳鼻咽喉   26篇
儿科学   172篇
妇产科学   163篇
基础医学   551篇
口腔科学   64篇
临床医学   839篇
内科学   877篇
皮肤病学   82篇
神经病学   466篇
特种医学   82篇
外科学   488篇
综合类   38篇
一般理论   7篇
预防医学   670篇
眼科学   58篇
药学   249篇
中国医学   6篇
肿瘤学   418篇
  2024年   4篇
  2023年   25篇
  2022年   33篇
  2021年   77篇
  2020年   63篇
  2019年   106篇
  2018年   116篇
  2017年   92篇
  2016年   98篇
  2015年   111篇
  2014年   160篇
  2013年   261篇
  2012年   394篇
  2011年   380篇
  2010年   233篇
  2009年   184篇
  2008年   332篇
  2007年   369篇
  2006年   352篇
  2005年   333篇
  2004年   329篇
  2003年   313篇
  2002年   253篇
  2001年   43篇
  2000年   50篇
  1999年   49篇
  1998年   49篇
  1997年   54篇
  1996年   47篇
  1995年   40篇
  1994年   33篇
  1993年   39篇
  1992年   24篇
  1991年   16篇
  1990年   20篇
  1989年   21篇
  1988年   18篇
  1987年   16篇
  1986年   10篇
  1985年   11篇
  1984年   10篇
  1983年   10篇
  1982年   8篇
  1981年   15篇
  1980年   14篇
  1978年   5篇
  1966年   3篇
  1964年   3篇
  1963年   3篇
  1962年   3篇
排序方式: 共有5256条查询结果,搜索用时 15 毫秒
1.
2.
Maternal and Child Health Journal -  相似文献   
3.
4.
Research investigating predictors of risky sexual behavior of rural MSM is sparse, even though the prevalence of HIV in rural areas has increased. This study explored two sets of predictors of 93 rural MSM's levels of risky sexual behavior: mental health variables and stigma emanating from men's family members, health care professionals, and people in the rural communities in which they live. Over 47% of the men were found to be at modified high to high risk. Logistic regression using a continuation logit model was used to test the relationship of the predictor variables and the four levels of risk. Findings indicate that self-esteem was predictive of the highest sexual risk behavior but not lower levels of risk. Stigma was predictive of modified high sexual risk when compared to low and no risk categories. No variables differentiated men at low risk from men at no risk.  相似文献   
5.
Background:  Melatonin is gaining popularity as a sedative agent with children. This study sought to characterise this practice more precisely as well as examine aspects of its safety and efficacy in order to develop treatment guidelines.
Method:  Postal surveys of two groups of psychiatrists: generic child psychiatrists and psychiatrists who regularly treat learning disabled children.
Results:  Both groups (all of the specialists and 81% of the non-specialists) reported regular but not frequent use of melatonin in their usual practice, mostly for night-settling sleep problems refractory to behavioural modification strategies, commonly in the context of neurodevelopmental disability (especially autism). Treatment was described as being 'usually successful' and side-effects were highly infrequent and mild in nature. Variations in most prescribing practices were identified (dosage, timing).
Conclusions:  Melatonin appears to represent a useful and relatively safe drug when used in specific circumstances; however, the evidence-base underpinning its use, particularly over the long-term, remains modest. Thus caution and clinical audit of practice is required.  相似文献   
6.
7.
This study evaluated the effectiveness of early orthodontic treatment with the Twin-block appliance for the developing Class II Division 1 malocclusion. This multicenter trial was carried out in the United Kingdom. A total of 174 children, aged 8 to 10 years old, with Class II Division 1 malocclusion were randomly allocated to receive treatment with a Twin-block appliance or to an untreated, control group. Data were collected at the start of the study and 15 months later. Results showed that early treatment with Twin-block appliances resulted in reduction of overjet, correction of molar relationships, and reduction in severity of malocclusion. Most of this correction was due to dentoalveolar change, but some was due to favorable skeletal change. Early treatment with the Twin-block appliance is effective in reducing overjet and severity of malocclusion. The small change in the skeletal relationship might not be considered clinically significant.  相似文献   
8.
A novel gene therapy approach for treating damaged cartilage is proposed that involves placing endotoxin-free cDNA containing the gene for bone morphogenetic protein-2 (BMP-2) in type I collagen sponges and then transferring the naked plasmid DNA construct to the injury site. A full-thickness cartilaginous defect in rabbits implanted with plasmid containing a marker gene (beta-galactosidase) showed expressed protein as detected by immunostaining. At 1 week postimplantation, mesenchymal cells subjacent to the defect had incorporated the implanted naked plasmid DNA and, once transfected, served as local bioreactors, transiently producing the gene product. Plasmids containing the gene for BMP-2 implanted in collagen sponges in cartilage lesions stimulated hyalinelike articular cartilage repair at 12 weeks postimplantation, nearly equivalent in quality to that induced by collagen sponges with recombinant BMP-2 protein. Our approach circumvents the risks of inflammation and immunogenic response associated with the use of viral vectors. Naked plasmid DNA as a vehicle for transferring therapeutic genes has been shown to be effective in a therapeutic model within rabbit articular cartilage and appears to be safe and cost effective.  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