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   2567258篇
  免费   196357篇
  国内免费   4200篇
耳鼻咽喉   36337篇
儿科学   85626篇
妇产科学   74168篇
基础医学   369866篇
口腔科学   74657篇
临床医学   224395篇
内科学   497708篇
皮肤病学   54774篇
神经病学   204721篇
特种医学   101168篇
外国民族医学   794篇
外科学   391922篇
综合类   59858篇
现状与发展   4篇
一般理论   830篇
预防医学   196228篇
眼科学   59792篇
药学   194400篇
  4篇
中国医学   4794篇
肿瘤学   135769篇
  2018年   24086篇
  2015年   24113篇
  2014年   33250篇
  2013年   50718篇
  2012年   69209篇
  2011年   73656篇
  2010年   43435篇
  2009年   41183篇
  2008年   70723篇
  2007年   75527篇
  2006年   76795篇
  2005年   74835篇
  2004年   73066篇
  2003年   70191篇
  2002年   69020篇
  2001年   115806篇
  2000年   119307篇
  1999年   101365篇
  1998年   28639篇
  1997年   25828篇
  1996年   25922篇
  1995年   24929篇
  1994年   23457篇
  1993年   22022篇
  1992年   83460篇
  1991年   81605篇
  1990年   80246篇
  1989年   77758篇
  1988年   72357篇
  1987年   71391篇
  1986年   67950篇
  1985年   65295篇
  1984年   49031篇
  1983年   42593篇
  1982年   25158篇
  1981年   22357篇
  1980年   21098篇
  1979年   46990篇
  1978年   32886篇
  1977年   28002篇
  1976年   26491篇
  1975年   28424篇
  1974年   34220篇
  1973年   33018篇
  1972年   30920篇
  1971年   28879篇
  1970年   26761篇
  1969年   25311篇
  1968年   23456篇
  1967年   21023篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
102.
103.
104.
105.
106.
107.
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   
108.
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   
109.
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   
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