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   8371篇
  免费   611篇
  国内免费   62篇
耳鼻咽喉   91篇
儿科学   253篇
妇产科学   236篇
基础医学   859篇
口腔科学   351篇
临床医学   803篇
内科学   1943篇
皮肤病学   295篇
神经病学   486篇
特种医学   349篇
外国民族医学   3篇
外科学   1338篇
综合类   245篇
现状与发展   30篇
一般理论   5篇
预防医学   527篇
眼科学   173篇
药学   522篇
中国医学   43篇
肿瘤学   492篇
  2024年   26篇
  2023年   277篇
  2022年   230篇
  2021年   409篇
  2020年   289篇
  2019年   330篇
  2018年   456篇
  2017年   262篇
  2016年   248篇
  2015年   307篇
  2014年   416篇
  2013年   445篇
  2012年   639篇
  2011年   603篇
  2010年   392篇
  2009年   338篇
  2008年   448篇
  2007年   384篇
  2006年   356篇
  2005年   346篇
  2004年   285篇
  2003年   245篇
  2002年   204篇
  2001年   73篇
  2000年   66篇
  1999年   70篇
  1998年   58篇
  1997年   69篇
  1996年   65篇
  1995年   52篇
  1994年   50篇
  1993年   47篇
  1992年   31篇
  1991年   52篇
  1990年   31篇
  1989年   54篇
  1988年   41篇
  1987年   43篇
  1986年   20篇
  1985年   30篇
  1984年   21篇
  1983年   15篇
  1982年   20篇
  1981年   20篇
  1980年   24篇
  1979年   16篇
  1978年   19篇
  1976年   17篇
  1975年   18篇
  1974年   19篇
排序方式: 共有9044条查询结果,搜索用时 15 毫秒
31.
32.
33.

Background  

We present the design of an open randomized multi-centre study on surgical versus conservative treatment of acute Achilles tendon ruptures. The study is designed to evaluate the effectiveness of conservative treatment in reducing complications when treating acute Achilles tendon rupture.  相似文献   
34.
Glatiramer acetate is an immunomodulating drug used in the treatment of multiple sclerosis. It consists of a copolymer of amino acid residues in the same stoichiometric proportions as in myelin basic protein. Its mechanism of action is not entirely known and is probably multifaceted, with deletion of some immune cell populations and stimulation of others in these patients. Some mechanisms involve neuroprotectant effects. There is ample evidence of its efficacy in relapsing-remitting disease, using both clinical and imaging measures of disease activity, and in this paper we review the clinical and basic studies of this drug. Finally we discuss how some of its neuroprotectant effects may be useful in neurodegeneration such as is seen in more advanced cases of multiple sclerosis and other diseases such as amyotrophic lateral sclerosis and Parkinson’s disease.  相似文献   
35.
BACKGROUND: The mainstay of treatment for pemphigus is systemic corticosteroids. Different adjuvants have been used to reduce side-effects of long-term corticotherapy. Gold is an anti-inflammatory drug used in autoimmune diseases, whose use has waned with the advent of new immunosuppressive agents. OBJECTIVE: To study the outcome of the use of intramuscular gold treatment of pemphigus vulgaris refractory to previous therapies. METHODS: Thirteen patients with pemphigus vulgaris who had failed to respond to several prior therapies were treated with aurothiomalate, as a steroid-sparing agent. Patients were monitored to assess disease activity and gold toxicity. RESULTS: Seven patients achieved complete remission. Four patients were able to taper prednisone doses, although pemphigus flared when prednisone was discontinued or reduced. Toxicity was observed in the other two patients. CONCLUSIONS: In 53.4% of the patients, the use of chrysotherapy resulted in the complete clearing of the disease, discontinuation of all systemic therapies and induced a long-term clinical remission. Prednisone doses were able to be reduced in the remaining 46.6%. Any side-effects were reversible with drug discontinuation. Gold therapy showed efficacy as a secondary line treatment in refractory pemphigus vulgaris.  相似文献   
36.
OBJECTIVE: Our objective was to determine whether the observed relaxation to lactate and other agents in placental vessels of normal pregnancies is altered in severe preeclampsia.STUDY DESIGN: Isolated placental arteries and veins from women with severe preeclampsia and uncomplicated term pregnancies were precontracted with prostaglandin F under 5% oxygen and 5% carbon dioxide with the balance nitrogen (Po2 35 to 38 torr) and then exposed to lactate (1 to 10 mmol/L, pH 7.4, n = 8 to 15), arachidonic acid (0.01 to 10 μmol/L, n = 6 to 13), nitroglycerin (1 nmol to 1 μmol/L, n = 4 to 12), or forskolin (0.01 to 10 μmol/L, n = 6 to 9). The response to lactate was also examined in placental vessels from appropriate-for-gestational-age preterm deliveries (n = 8) for comparison with a similar group with severe preeclampsia (n = 8). The t test and analysis of variance statistics were used.RESULTS: Relaxation to lactate was markedly inhibited in both placental arteries and veins of women with severe preeclampsia compared with vessels from uncomplicated term or preterm pregnancies. Responses to the other relaxing agents were not altered in the severely preeclampsia vessels.CONCLUSIONS: In severe preeclampsia absence of lactate-induced dilatation of placental vessels may contribute to the fetal complications associated with impaired blood flow and vasospasm.  相似文献   
37.
The heat shock/oxidative stress connection   总被引:2,自引:0,他引:2  
Involvement of free-radical oxidations in the aging process has been a topic of interest since Harman's original contribution. Because of the close association between aging and Alzheimer disease (AD) and the qualitative similarity in the neuropathology of both conditions, it has been proposed by many investigators that oxidative stress may be important in AD. If such modality of injury was indeed involved, one should expect to find markers of oxidation and heat shock (since free radicals are key mediators of heat-shock induction) in brains of patients with AD. In fact, several studies documented abnormal expression of antioxidant enzymes and heat-shock proteins (HSP) along with other markers of oxidation in AD brains. We showed that abnormally expressed antioxidant enzymes are topographically associated with senile plaques and neurofibrillary tangles, and that the activity of these enzymes is (contrary to what one would expect) markedly reduced. These findings have recently been confirmed by other investigators. Despite a large amount of evidence that suggests an association between oxidative stress and the pathogenesis of AD, it is not yet known whether oxidative stress is a cause or consequence of the disorder. Future research efforts regarding the oxidative stress hypothesis of AD should include attempts, at generating AD pathology by oxidative means in laboratory animals, determining the role and integrity of the heat-shock response in AD, as well as that of various antioxidant systems, growth factors, and hormones with antioxidant and neuroprotective properties.  相似文献   
38.
One-hundred and six male children aged 6-23 months with a history of acute watery diarrhoea of less than 72 h duration were randomized to receive either folic acid in a dose of 5 mg at 8-h intervals or placebo for 5 d. There were 54 children in the folic acid group and 52 in the placebo group. The admission characteristics were comparable between the two groups. No significant differences were observed in the intake of oral rehydration solution or stool output between the groups. The mean ± SD of total stool output (g kg−1) was 532 ± 476 vs 479 ± 354 and the duration (h) of diarrhoea was 108 ± 68 vs 103 ± 53 in the folic acid vs placebo group, respectively. The findings, therefore, should have a positive influence on preventing the inappropriate use of folic acid in acute diarrhoea.  相似文献   
39.
40.
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