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   2687724篇
  免费   204688篇
  国内免费   8507篇
耳鼻咽喉   34831篇
儿科学   88148篇
妇产科学   72938篇
基础医学   375107篇
口腔科学   76177篇
临床医学   243110篇
内科学   534664篇
皮肤病学   62517篇
神经病学   214080篇
特种医学   104918篇
外国民族医学   504篇
外科学   412595篇
综合类   63731篇
现状与发展   6篇
一般理论   902篇
预防医学   207700篇
眼科学   61451篇
药学   193365篇
  11篇
中国医学   5919篇
肿瘤学   148245篇
  2018年   29293篇
  2017年   22480篇
  2016年   25590篇
  2015年   29007篇
  2014年   40427篇
  2013年   60050篇
  2012年   78831篇
  2011年   83876篇
  2010年   50880篇
  2009年   48299篇
  2008年   77929篇
  2007年   83033篇
  2006年   84312篇
  2005年   80999篇
  2004年   77890篇
  2003年   74768篇
  2002年   71629篇
  2001年   134523篇
  2000年   138112篇
  1999年   114592篇
  1998年   32177篇
  1997年   28360篇
  1996年   29104篇
  1995年   28623篇
  1994年   26484篇
  1993年   24658篇
  1992年   90607篇
  1991年   87846篇
  1990年   84708篇
  1989年   81202篇
  1988年   74599篇
  1987年   73221篇
  1986年   68994篇
  1985年   65940篇
  1984年   49454篇
  1983年   41767篇
  1982年   24739篇
  1981年   22197篇
  1980年   20552篇
  1979年   43997篇
  1978年   31147篇
  1977年   26529篇
  1976年   24567篇
  1975年   25737篇
  1974年   30669篇
  1973年   29535篇
  1972年   27436篇
  1971年   25258篇
  1970年   23313篇
  1969年   21869篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
102.
Group A streptococcal meningitis is less common than other forms of meningitis; however, the occurrence of this infection is associated with high mortality and morbidity. Early recognition and a prompt treatment are therefore essential. We review one case of an Asian women admitted with group A streptococcal meningitis as a complication of otitis media.  相似文献   
103.
Liposarcomas are extremely rare in the mediastinum. They may achieve considerable size before causing any symptoms. Mediastinal liposarcomas may invade surrounding structures like the pericardium or the superior vena cava. Complete surgical excision is the optimal treatment in resectable cases. Excision of adjacent structures like the pericardium may be needed if the tumor infiltrates them. We report on a case of a giant liposarcoma of the mediastinum involving both hemithoraces and extending into the neck, which was successfully managed by complete surgical excision.  相似文献   
104.
For many parents stopping life-sustaining medical treatment on their dying infant is psychologically impossible. Dostoevsky's insights into human behavior, particularly the fact that individuals do not want the anxiety and guilt associated with responsibility for making difficult decisions, might change the way physicians approach parents for permission to withdraw life-prolonging medical interventions on dying infants.  相似文献   
105.
The authors discuss techniques for Monte Carlo (MC) cohort simulations that reduce the number of simulation replications required to achieve a given degree of precision for various output measures. Known as variance reduction techniques, they are often used in industrial engineering and operations research models, but they are seldom used in medical models. However, most MC cohort simulations are well suited to the implementation of these techniques. The authors discuss the cost of implementation versus the benefit of reduced replications.  相似文献   
106.
French asthma patients may be supervised by general practitioners (GPs) and/or specialists. Therefore, this study examined asthma management in patients exclusively supervised by specialists (SPE), GPs, (GP) and both (GP+SPE group), and compared the findings. Asthma patients were consecutively recruited in 348 pharmacies. Each patient completed a questionnaire providing data on personal characteristics, asthma management, perception of disease and asthma supervision. Asthma control was measured using the Asthma Control Test. Questionnaires were linked to computerised records of medications which had been dispensed before inclusion in the study. From the 1,256 patients (mean age = 36.1 yrs, 54.3% females), 11.4, 36.6, and 52.0% were placed in the SPE, GP, and GP+SPE groups, respectively. During the previous 4 weeks, most patients in the SPE group were properly controlled (52.2 versus 26.4 and 21.5% in GP and GP+SPE groups, respectively). The SPE group made more use of fixed combinations of long-acting beta agonist and inhaled corticosteroid, while receiving less short-acting beta agonists, antitussives and antibiotics. Striking differences in symptoms and asthma management were observed according to the type of asthma supervision. The current results strongly support the need to improve the management of asthma in primary care, and the coordination of care between general practitioners and specialists.  相似文献   
107.
Four clinical trials of porcine islet transplantation have been reported, and there are verbal reports that clinical trials on much larger scales are continuing in centers in China and Russia. The four reported trials are briefly reviewed and, in the light of the present status of experimental islet xenotransplantation, consideration is given to whether such trials are currently justified. The Ethics Committee of the International Xenotransplantation Association has (1) emphasized the need for encouraging studies in non-human primates before clinical trials should be undertaken, (2) mandatory monitoring for the transfer of porcine microorganisms, and (3) careful regulation and oversight by recognized bodies. Other aspects of the topic, such as the need for informed consent, are briefly discussed. We conclude that, at the present time, more data documenting convincing efficacy, focused on clinically applicable immunosuppressive regimens, are needed to justify the initiation of closely monitored clinical trials. A clinical trial may then be justified even though the potential risk to the patients, and possibly for society, will not be zero.  相似文献   
108.
Summary: The mosaic (Atp7a mo-ms ) is an X-linked, lethal mutation in mice. In mosaic mutant males, many clinical features characteristic of defective copper metabolism have been observed and they die at the age of 15 days, exhibiting strongsimilarities to the brindled and macular mutants. About 4% of the mutant males live to sexual maturity and some of them are fertile. In this paper, alterationsin the structure of the kidney from adult mutants are described. Owing to an inherited defect of efflux, copper is accumulated in the kidney of the mutants up to a toxic level and this leads to severe damage of the renal cortex. Pathological changes in the kidney mostly affected the structure of the renal corpuscle and renaltubules.  相似文献   
109.
110.
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