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   1642464篇
  免费   126651篇
  国内免费   27838篇
耳鼻咽喉   20965篇
儿科学   47053篇
妇产科学   41925篇
基础医学   226574篇
口腔科学   41352篇
临床医学   160261篇
内科学   300255篇
皮肤病学   30477篇
神经病学   116763篇
特种医学   63442篇
外国民族医学   590篇
外科学   229567篇
综合类   95973篇
现状与发展   87篇
一般理论   330篇
预防医学   119707篇
眼科学   39588篇
药学   137680篇
  436篇
中国医学   26775篇
肿瘤学   97153篇
  2022年   17330篇
  2021年   25568篇
  2020年   19097篇
  2019年   19592篇
  2018年   23758篇
  2017年   20440篇
  2016年   20643篇
  2015年   28217篇
  2014年   36635篇
  2013年   43099篇
  2012年   61368篇
  2011年   67290篇
  2010年   42466篇
  2009年   37284篇
  2008年   55863篇
  2007年   58597篇
  2006年   58224篇
  2005年   56650篇
  2004年   48741篇
  2003年   47324篇
  2002年   44677篇
  2001年   66061篇
  2000年   67356篇
  1999年   58583篇
  1998年   19386篇
  1997年   17786篇
  1996年   16944篇
  1995年   15980篇
  1994年   14836篇
  1993年   12831篇
  1992年   43209篇
  1991年   42314篇
  1990年   41526篇
  1989年   40099篇
  1988年   37263篇
  1987年   36391篇
  1986年   34557篇
  1985年   32726篇
  1984年   24242篇
  1983年   21046篇
  1979年   22752篇
  1978年   15943篇
  1977年   13774篇
  1976年   13003篇
  1975年   14226篇
  1974年   16715篇
  1973年   16106篇
  1972年   15352篇
  1971年   14247篇
  1970年   13230篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
We previously reported poorer survival among non-Hispanic blacks and Hispanics with idiopathic pulmonary fibrosis (IPF) compared to non-Hispanic whites at our center. In the current study, we hypothesized that these disparities would exist in a nationwide cohort of wait-listed patients with IPF. We performed a retrospective cohort study of 2635 patients with IPF listed for lung transplantation between 1995 and 2003 at 94 transplant centers in the United States. The age-adjusted mortality rate was higher among non-Hispanic blacks [hazard ratio (HR) = 1.24, 95% confidence interval (CI) 1.06-1.45, p = 0.009] and Hispanics (HR = 1.29, 95% CI 1.06-1.56, p = 0.01) compared to non-Hispanic whites. These findings persisted after adjustment for transplantation, medical comorbidities and socioeconomic status. Worse lung function at the time of listing appeared to explain some of these differences (HR for non-Hispanic blacks after adjustment for forced vital capacity percent predicted = 1.16, 95% CI 0.98-1.36, p = 0.09; HR for Hispanics = 1.21, 95% CI 0.99-1.48, p = 0.056). In summary, black and Hispanic patients with IPF have worse survival than whites after listing for lung transplant.  相似文献   
62.
Leocani  L.  Comi  G. 《Neurological sciences》2006,27(1):s27-s29
Neurological Sciences - Brain plasticity, intended as the pattern of functional and structural changes in responses to environmental physiological or pathological events, is underlined by several...  相似文献   
63.
64.
65.
66.
CONTEXT: Although the nonmedical use of stimulant drugs such as cocaine and methamphetamine is increasingly common in many rural areas of the United States, little is known about the health beliefs of people who use these drugs. PURPOSE: This research describes illicit stimulant drug users' views on health and health-related concepts that may affect their utilization of health care services. METHODS: A respondent-driven sampling plan was used to recruit 249 not-in-treatment, nonmedical stimulant drug users who were residing in 3 rural counties in west central Ohio. A structured questionnaire administered by trained interviewers was used to collect information on a range of topics, including current drug use, self-reported health status, perceived need for substance abuse treatment, and beliefs about health and health services. FINDINGS: Participants reported using a wide variety of drugs nonmedically, some by injection. Alcohol and marijuana were the most commonly used drugs in the 30 days prior to the interview. Powder cocaine was used by 72.3% of the sample, crack by 68.3%, and methamphetamine by 29.7%. Fair or poor health status was reported by 41.3% of the participants. Only 20.9% of the sample felt they needed drug abuse treatment. Less than one third of the sample reported that they would feel comfortable talking to a physician about their drug use, and 65.1% said they preferred taking care of their problems without getting professional help. CONCLUSIONS: Stimulant drug users in rural Ohio are involved with a range of substances and hold health beliefs that may impede health services utilization.  相似文献   
67.
PURPOSE: In children with locally advanced or recurrent malignant tumours, prognosis can be improved by regional deep hyperthermia (RHT) in combination with platin-based chemotherapy. However, because of the increasing number of patients that achieve long-time remission with this therapy, it is necessary to evaluate long-term sequelae of thermochemotherapy. During the years 1993-2004 one has observed avascular osteonecrosis (AON) of the femoral head after RHT in seven children with pelvic germ cell tumours or rhabdomyosarcomas. METHODS: Although AON may develop in patients with malignancies treated with chemo- or radiotherapy alone, RHT might nevertheless contribute to the occurrence of AON. In order to determine potential risk factors for AON after RHT, this study analysed the relationship of AON to the patient's age, medical history and treatment parameters such as thermal dose equivalent and power output. RESULTS AND CONCLUSIONS: In the present study AON was associated with young age as well as intensity of hyperthermia indicated by high power levels that exceed 20 W per kg body weight and/or application of eight or more heat sessions as well as additional radiotherapy. Based on this observation, it was assumed that an optimized three dimensional thermal field modelling may be helpful to avoid hazardous temperatures in the femoral heads during RHT treatment and to reduce AON of the femoral heads.  相似文献   
68.
Cell physiology and molecular biology typically follow a reductionistic approach in science. In the last decade, molecular principles and pathogenetic factors involved in the development of many diseases have been successfully discovered. Therefore, early biological concepts based on systemic and cybernetic thoughts have been largely overshadowed by these more recent molecular and pathogenetic factors. This review highlights discoveries on bone development and hypothalamic controlled feeding and eating behavior with a cybernetic and systemic perspective. Interestingly, ancient ideas on bone development and hypothalamic function are still reasonable considerations to embed new molecular discoveries into a systemic concept of principles organizing nature.  相似文献   
69.
70.
医改尚未成功,路在何方?   总被引:3,自引:0,他引:3  
目前我国医疗制度改革尚未取得成功,这与计划经济向市场经济转轨这历史时期及卫生工作的特殊性有关,出现问题,甚至失误,在所难免。提出(1)医改的目的是确保全国人民健康,人人享有医疗保健。(2)把卫生系统推向市场,医疗机构商业化,不是医改的方向。(3)预防为主,健全预防医学制系。(4)国家增加投入。(5)制定公立及私立医院各项制度,保护医务人员的合法权益。(6)加强社区基层医疗机构的建设。  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