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   4215754篇
  免费   329945篇
  国内免费   13858篇
耳鼻咽喉   58599篇
儿科学   134704篇
妇产科学   110307篇
基础医学   650613篇
口腔科学   113393篇
临床医学   381738篇
内科学   759594篇
皮肤病学   105869篇
神经病学   349714篇
特种医学   163550篇
外国民族医学   503篇
外科学   646511篇
综合类   119211篇
现状与发展   23篇
一般理论   2562篇
预防医学   352646篇
眼科学   98756篇
药学   294322篇
  26篇
中国医学   11295篇
肿瘤学   205621篇
  2021年   55691篇
  2020年   35451篇
  2019年   58387篇
  2018年   73602篇
  2017年   56235篇
  2016年   62267篇
  2015年   75310篇
  2014年   109638篇
  2013年   174762篇
  2012年   120465篇
  2011年   125948篇
  2010年   125125篇
  2009年   126483篇
  2008年   112296篇
  2007年   119653篇
  2006年   128441篇
  2005年   123617篇
  2004年   123897篇
  2003年   114312篇
  2002年   103562篇
  2001年   149672篇
  2000年   144521篇
  1999年   134296篇
  1998年   70076篇
  1997年   66201篇
  1996年   64409篇
  1995年   59684篇
  1994年   53772篇
  1993年   50039篇
  1992年   96051篇
  1991年   92641篇
  1990年   89049篇
  1989年   86821篇
  1988年   80022篇
  1987年   78514篇
  1986年   73861篇
  1985年   72979篇
  1984年   61666篇
  1983年   55434篇
  1982年   46019篇
  1981年   43115篇
  1980年   40503篇
  1979年   53098篇
  1978年   44034篇
  1977年   38885篇
  1976年   36269篇
  1975年   36273篇
  1974年   39412篇
  1973年   37634篇
  1972年   35249篇
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
991.
992.
The aim of the present study was to investigate the long-term incidence rate of Lyme borreliosis and, additionally, to determine whether a correlation exists between climatic factors and summer-season variations in the incidence of Lyme borreliosis. Climatic variability acts directly on tick population dynamics and indirectly on human exposure to Lyme borreliosis spirochetes. In this study, conducted in primary healthcare clinics in southeastern Sweden, electronic patient records from 1997–2003 were searched for those that fulfilled the criteria for erythema migrans. Using a multilevel Poisson regression model, the influence of various climatic factors on the summer-season variations in the incidence of erythema migrans were studied. The mean annual incidence rate was 464 cases of erythema migrans per 100,000 inhabitants. The incidence was significantly higher in women than in men, 505 and 423 cases per 100,000 inhabitants, respectively (p<0.001). The summer-season variations in the erythema migrans incidence rate correlated with the monthly mean summer temperatures (incidence rate ratio 1.12; p<0.001), the number of winter days with temperatures below 0°C (incidence rate ratio 0.97; p<0.001), the monthly mean summer precipitation (incidence rate ratio 0.92; p<0.05), and the number of summer days with relative humidity above 86% (incidence rate ratio 1.04; p<0.05). In conclusion, Lyme borreliosis is highly endemic in southeastern Sweden. The climate in this area, which is favourable not only for human tick exposure but also for the abundance of host-seeking ticks, influences the summer-season variations in the incidence of Lyme borreliosis.  相似文献   
993.
994.
995.
996.
997.
Primary chemotherapy administered to breast cancer patientsis the best model to identify baseline features able to predictwhich patients may be most likely to benefit or not from a cytotoxicregimen. In the March issue of Annals of Oncology two papersevaluated the predictive role of immunohistochemical p53 expressionon  相似文献   
998.
999.
1000.
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   
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