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   1733276篇
  免费   126414篇
  国内免费   3900篇
耳鼻咽喉   22136篇
儿科学   56835篇
妇产科学   47215篇
基础医学   246428篇
口腔科学   49189篇
临床医学   157066篇
内科学   340732篇
皮肤病学   39295篇
神经病学   134967篇
特种医学   64574篇
外国民族医学   243篇
外科学   260183篇
综合类   39656篇
现状与发展   4篇
一般理论   573篇
预防医学   128696篇
眼科学   40978篇
药学   126297篇
  7篇
中国医学   4541篇
肿瘤学   103975篇
  2021年   13564篇
  2019年   14206篇
  2018年   20777篇
  2017年   15851篇
  2016年   17327篇
  2015年   19816篇
  2014年   27352篇
  2013年   39698篇
  2012年   55361篇
  2011年   58206篇
  2010年   34214篇
  2009年   32076篇
  2008年   54085篇
  2007年   57488篇
  2006年   58057篇
  2005年   55297篇
  2004年   53436篇
  2003年   50673篇
  2002年   48699篇
  2001年   92110篇
  2000年   93855篇
  1999年   77277篇
  1998年   20146篇
  1997年   17615篇
  1996年   17717篇
  1995年   17055篇
  1994年   15511篇
  1993年   14331篇
  1992年   57554篇
  1991年   55450篇
  1990年   53123篇
  1989年   50908篇
  1988年   46299篇
  1987年   45056篇
  1986年   42341篇
  1985年   40120篇
  1984年   29515篇
  1983年   25079篇
  1982年   14104篇
  1981年   12548篇
  1979年   25629篇
  1978年   17671篇
  1977年   15009篇
  1976年   13954篇
  1975年   14627篇
  1974年   17698篇
  1973年   17003篇
  1972年   15724篇
  1971年   14480篇
  1970年   13463篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
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   
72.
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   
73.
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   
74.
75.
76.
77.
78.
79.
80.
AIMS: To establish all-cause and cause-specific death rates, and risk factors for mortality in insulin-treated diabetic individuals living in the province of Canterbury, New Zealand. METHODS: Insulin-treated diabetic subjects (n = 995) on the Canterbury Diabetes Registry were followed up over 15 years and vital status determined. Death rates were standardized and hazard regression was used to model the effects of demographic covariates on relative survival time. RESULTS: There were 419 deaths in 11 226.3 person-years of follow-up with a standardized mortality ratio (SMR) of 2.0 (95% confidence interval (CI) 1.8-2.2). Relative mortality was greatest for the group aged 0-29 years (SMR 3.0 (95% CI 2.4-3.7)). After controlling for diabetes duration and gender, a 10-year increment in age of onset was associated with a 33% decrease in relative hazard (95% CI 29-36%), indicating that excess mortality due to diabetes declines with rising age of onset. After controlling for age of onset and gender, each 10-year increment in duration of diabetes is associated with a 26% decrease in relative hazard (95% CI 24-29%), indicating that with longer survival the mortality hazard approaches the general population hazard. Relative mortalities were increased for cardiovascular, renal and respiratory disease, but not malignancy. Relative mortality from acute metabolic complications was increased in the subgroup with age of onset of diabetes < 30 years and requiring insulin within 1 year of diagnosis. CONCLUSIONS: Mortality rates are high for insulin-treated diabetic individuals relative to the general population.  相似文献   
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