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   71769篇
  免费   4871篇
  国内免费   201篇
耳鼻咽喉   529篇
儿科学   2091篇
妇产科学   1166篇
基础医学   9837篇
口腔科学   1505篇
临床医学   7523篇
内科学   15210篇
皮肤病学   981篇
神经病学   6850篇
特种医学   2227篇
外国民族医学   1篇
外科学   10043篇
综合类   878篇
一般理论   72篇
预防医学   6392篇
眼科学   1749篇
药学   4906篇
  1篇
中国医学   80篇
肿瘤学   4800篇
  2023年   376篇
  2022年   521篇
  2021年   1397篇
  2020年   839篇
  2019年   1364篇
  2018年   1659篇
  2017年   1237篇
  2016年   1356篇
  2015年   1582篇
  2014年   2366篇
  2013年   3210篇
  2012年   5236篇
  2011年   5367篇
  2010年   3001篇
  2009年   2666篇
  2008年   4873篇
  2007年   5332篇
  2006年   5237篇
  2005年   4969篇
  2004年   4765篇
  2003年   4309篇
  2002年   4204篇
  2001年   576篇
  2000年   405篇
  1999年   639篇
  1998年   899篇
  1997年   754篇
  1996年   634篇
  1995年   605篇
  1994年   490篇
  1993年   464篇
  1992年   349篇
  1991年   307篇
  1990年   258篇
  1989年   248篇
  1988年   266篇
  1987年   217篇
  1986年   236篇
  1985年   243篇
  1984年   311篇
  1983年   324篇
  1982年   385篇
  1981年   370篇
  1980年   343篇
  1979年   197篇
  1978年   239篇
  1977年   192篇
  1976年   133篇
  1975年   102篇
  1974年   106篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
The purpose of this paper is to provide an historical review of the progression of events within the jurisdiction of the province of Ontario related to the issue of laboratory diagnosis and the profession of chiropractic. The provisions of relevant legislation, task forces, Councils, reviews, consensus statements, Commissions and committees, are highlighted and discussed during respective time periods. Chiropractors had entitlement to order and perform laboratory tests until 1972 when a regulatory amendment, made without consultation with the chiropractic profession, precluded their continuing entitlement. Chiropractic patients require access to diagnostic laboratory services and equitable access to necessary laboratory services should be restored and preserved. This is consistent with the academic institutional accreditation standards of chiropractic education and the jurisdictional regulatory mechanisms of chiropractic practice and is consistent with both protecting and enhancing the public interest.  相似文献   
63.
64.
The first t-test     
The data with which Student illustrated the application of his famous distribution are examined from a number of aspects. Central to the discussion is the within-patient clinical trial at Kalamazoo whose results were published by Cushny and Peebles and misquoted by Student and Fisher. This trial is discussed from historical, pharmacological and statistical perspectives. Student's and Fisher's analyses and a more modern analysis by Preece are considered as is Cushny's and Peebles's interpretation. Brief biographies of the five physicians involved in running the trial are presented.  相似文献   
65.
A system was developed to expose macrophages to polyethylene in vitro. Exposure of macrophages to these particles in isolation led to the release of tumor necrosis factor alpha and prostaglandin E2. Exposure of macrophages in co-culture with osteoblasts to polyethylene particles increased the release of prostaglandin E2 and also led to the release of interleukin-6. Incubation of radiolabelled calvariae with conditioned medium from macrophages exposed to polyethylene particles alone or to particles in co-culture with osteoblasts led to bone resorption reflected by release of 45Ca. Incubation with pamidronate was effective in inhibiting resorption stimulated by conditioned medium from macrophages exposed to these particles alone or in co-culture with osteoblasts. This demonstrates that pamidronate, or other bisphosphonates, may be effective in inhibiting bone resorption at the implant/bone interface in association with the macrophage ressponse to particulate polyethylene. Further investigation into the possible use of pamidronate or other bisphosphonates in the treatment of aseptic loosening is warranted.  相似文献   
66.
Arthroscopic repair of rotator cuff tears is now possible. By using the biomechanical principles of margin convergenceand the balance of force couples, even large cuff defects can be repaired. Suture anchors are particularly suitable for arthroscopic repairs, and a corkscrew anchor design lends itself to a trans-tendon approach  相似文献   
67.
Objectives: To evaluate a group intervention to help individuals with psychiatric disorder stop smoking.
Method: A waitlist-treatment crossover design. Outcome measures included smoking cessation, motivation to stop, the Fagerstrom Test for Nicotine Dependence (FTND), urinary cotinine and psychiatric symptoms on the General Health Questionnaire.
Results: 38 subjects participated, of whom 19 completed the waitlist and intervention phases. There were no significant differences between subjects and dropouts. During the waitlist period there were no significant changes in tobacco use. At the end of the intervention, almost a quarter had stopped smoking, ( z = -2.24, p =0.02). Subjects also showed significant improvements on state of change, FTND score and urinary cotinine levels. These improvements were maintained at three-month follow-up (n=10). Psychiatric morbidity showed no change.
Conclusions: It is possible to reduce smoking in individuals with psychiatric disorder.
Implications: Larger randomised controlled trials are indicated to determine the relative contributions of nicotine replacement, bupropion and group interventions to smoking cessation in this population.  相似文献   
68.
We assessed the feasibility and psychometric properties of two commonly used health status questionnaires in Parkinson's disease (PD): the generic Nottingham Health Profile (NHP) and the disease-specific 39-item Parkinson's disease Questionnaire (PDQ-39), from a cross-sectional postal survey of PD patients (N = 81), using traditional and Rasch measurement methodologies. Overall response rate was 88%. Both questionnaires were found feasible, although the NHP performed less well. The PDQ-39 had fewer floor effects and was better able to separate respondents into distinct groups than the NHP, whereas the latter exhibited less ambiguous dimensionality and better targeting of respondents with non-extreme scores. Reliability and validity indices were similar, and potential differential item functioning by age and gender groups was found for both questionnaires. PDQ-39 response alternatives indicated ambiguity. With few exceptions, questionnaire scales were unable to meet recommended standards fully. While preliminary, this study illustrates the need for thorough evaluation of outcome measures and has implications beyond the questionnaires used here. Although promising, both questionnaires warrant further developmental work and stronger support of measurement validity before they could be considered fully suitable for valid use in PD, in particular in earlier stages of the disease.  相似文献   
69.
The expression of sodium channel α-subunit isoforms in astrocytes in adult rat spinal cord and optic nerve was examined utilizing immunocytochemical methods with antibodies generated against conserved and subtype-specific sequences of the sodium channel. In adult rat spinal cord, astrocytes within the dorsal and ventral funiculi were immunolabelled with antibody SP20, which recognizes a conserved sequence within sodium channel types I, II, and III. In addition, astrocytes within these spinal cord white matter tracts were immunostained with antibody SP11-II, which recognizes sodium channel type II. Antibodies SP11-I and SP32-III, which are directed against subtype-specific sequences in sodium channel types I and III, respectively, did not label astrocytes in the dorsal and ventral funiculi of the spinal cord. In optic nerves, astrocytes were immunostained with antibody SP20. However, no detectable labelling of cells within the optic nerve was observed with antibodies SP11-I, SP11-II, and SP32-III. These observations demonstrate that sodium channel II is expressed by astrocytes in spinal cord white matter. Moreover, these data suggest that regional factors regulate the level of sodium channel isoform expression in astrocytes.  相似文献   
70.
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