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   11091篇
  免费   727篇
  国内免费   32篇
耳鼻咽喉   104篇
儿科学   538篇
妇产科学   351篇
基础医学   1516篇
口腔科学   234篇
临床医学   1354篇
内科学   2208篇
皮肤病学   252篇
神经病学   991篇
特种医学   161篇
外国民族医学   1篇
外科学   1014篇
综合类   164篇
一般理论   23篇
预防医学   1227篇
眼科学   273篇
药学   646篇
中国医学   23篇
肿瘤学   770篇
  2023年   102篇
  2022年   124篇
  2021年   344篇
  2020年   220篇
  2019年   321篇
  2018年   325篇
  2017年   255篇
  2016年   295篇
  2015年   308篇
  2014年   428篇
  2013年   592篇
  2012年   875篇
  2011年   913篇
  2010年   528篇
  2009年   486篇
  2008年   701篇
  2007年   819篇
  2006年   688篇
  2005年   667篇
  2004年   630篇
  2003年   590篇
  2002年   539篇
  2001年   58篇
  2000年   59篇
  1999年   79篇
  1998年   94篇
  1997年   78篇
  1996年   60篇
  1995年   73篇
  1994年   51篇
  1993年   49篇
  1992年   33篇
  1991年   37篇
  1990年   35篇
  1989年   29篇
  1988年   25篇
  1987年   26篇
  1986年   19篇
  1985年   34篇
  1984年   24篇
  1983年   21篇
  1982年   29篇
  1981年   22篇
  1980年   18篇
  1979年   19篇
  1978年   23篇
  1977年   19篇
  1976年   11篇
  1975年   9篇
  1973年   9篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
INTRODUCTION: Autoimmune hepatitis (AIH) is a well-defined entity in the West but there are sparse Indian data on this disease. AIM: To study the clinical profile and response to treatment of Indian patients with AIH. METHODS: This is a part retrospective and part prospective study of 50 patients (median age 48 years, range 11-82; 43 women) seen between 1995 to 2001, diagnosed to have AIH as per the revised scoring system. Clinical and laboratory profile, response to treatment, and complications of treatment were analyzed. RESULTS: AIH accounted for 6% of all patients with liver disease seen during the period. The presenting symptoms were gastrointestinal in 43 and non-gastrointestinal in 7, with median symptom duration of 6 months (range 2 weeks to 40 years). Forty patients (80%) had chronic liver disease. Associated illnesses were present in 28 patients. Twenty-six patients were classified as definite and the rest as probable AIH. Forty-nine patients had Type 1 AIH. Five patients had overlap syndrome. Forty-five patients (90%) received immunosuppressive therapy. Twelve of 18 patients receiving only prednisolone and 21 of 27 patients receiving prednisolone and azathioprine combination responded. Thirteen (26%) patients had therapy-related complications (infectious 5, non infectious 8) with two treatment-related deaths. CONCLUSION: Type 1 AIH was the predominant type of AIH. The majority of patients with AIH presented with chronic liver disease. There was good response to immunosuppressive therapy. Therapy-related complications occurred in one-fourth of patients.  相似文献   
2.
This study compared the predictive value of the theory of planned behavior in university students in South Africa (N = 251) and the United States (N = 160) who completed an anonymous self-administered questionnaire. Multiple regression analyses revealed that condom use and intention were significantly predicted by positive condom attitude, subjective norm, self-efficacy, and attending university in South Africa. Significant interactions between country and predictors indicated that subjective norm predicted condom use and intention more strongly in the American sample than in the South African sample; attitude predicted intention more strongly in the American sample than in the South African sample; but self-efficacy predicted intention more strongly in the South African sample than in the American sample. The theory of planned behavior may provide a useful framework for interventions to reduce South African students' risk of HIV/and sexuality transmitted diseases. Such interventions should especially focus on building self-efficacy to use condoms.  相似文献   
3.
4.
Background: Neuraxial blockade is used as primary anesthetic technique in one third of surgical procedures. The authors tested whether bisoprolol would protect patients at risk for cardiovascular complications undergoing surgery with spinal block.

Methods: The authors performed a double-blinded, placebo-controlled, multicenter trial to compare the effect of bisoprolol with that of placebo on 1-yr composite outcome including cardiovascular mortality, nonfatal myocardial infarction, unstable angina, congestive heart failure, and cerebrovascular insult. Bisoprolol was given orally before and after surgery for a maximum of 10 days. Adrenergic receptor polymorphisms and safety outcome measures of bisoprolol therapy were also determined.

Results: A total of 224 patients were enrolled. Spinal block could not be established in 5 patients. One hundred ten patients were assigned to the bisoprolol group, and 109 patients were assigned to the placebo group. The mean duration of treatment was 4.9 days in the bisoprolol group and 5.1 days in the placebo group. Bisoprolol therapy reduced mean heart rate by 10 beats/min. The primary outcome was identical between treatment groups and occurred in 25 patients (22.7%) in the bisoprolol group and 24 patients (22.0%) in the placebo group during the 1-yr follow-up (hazard ratio, 0.97; 95% confidence interval, 0.55-1.69; P = 0.90). However, carriers of at least one Gly allele of the [beta]1-adrenergic receptor polymorphism Arg389Gly showed a higher number of adverse events than Arg homozygous (32.4% vs. 18.7%; hazard ratio, 1.87; 95% confidence interval, 1.04-3.35; P = 0.04).  相似文献   

5.
The leaf essential oil of Eugenia zuchowskiae from Monteverde, Costa Rica, has been obtained by hydrodistillation and analyzed by GC–MS. The principal constituents of E. zuchowskiae leaf oil were α-pinene (28.3%), β-caryophyllene (13.2%), α-humulene (13.1%), and α-copaene (8.1%). The leaf essential oil of E. zuchowskiae showed pronounced in-vitro cytotoxic activity against MCF-7, MDA-MB-468, and UACC-257 human tumor cell lines. The major components showed cytotoxic activities comparable to doxorubicin (LC50 14–70 μg/ml).  相似文献   
6.
BACKGROUND AND OBJECTIVES: An eight-member group consisting of Canadian infectious disease and immunology specialists and a family physician with significant experience in HIV management was convened to update existing recommendations, specifically intended for use by Canadian HIV-treating physicians, on the appropriate use of enfuvirtide in HIV/AIDS patients with resistance to other antiretroviral drugs. METHODS: Evidence from the literature and expert opinions of the group members formed the basis of the guidelines. Comments on the draft guidelines were obtained from other physicians across Canada with HIV expertise. The final guidelines represent the group's consensus agreement. RESULTS AND CONCLUSIONS: The recommendations were developed to guide physicians in optimal practices in patient selection for enfuvirtide treatment and subsequent patient management. The issues considered include positive predictors of response to enfuvirtide, stage of disease, optimization of the background regimen, early indicators of enfuvirtide response, and patient education and support.  相似文献   
7.
8.
At the present time, there are many fundamental issues coming from the Department of Health or from other national organizations, which will have an effect on the future development of the dietetic profession. The British Diatetic Association (BDA) Professional Development Committee will consider these issues, as and when appropriate, and will publish the information in the form of Briefing Papers.
The first Briefing Paper on 'Quality Assurance' was published by the BDA in November 1989. The second on 'Measuring clinical outcome' is published below. In each case the opinion of BDA members and specialist groups has been sought and the Professional Development Committee wishes to thank individuals and the specialist groups for their comments.
The Briefing Papers are intended to provide information and promote discussion among the membership. I would welcome further comments from readers, which may be directed to the British Dietetic Association Office.  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