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   4216297篇
  免费   329979篇
  国内免费   13860篇
耳鼻咽喉   58601篇
儿科学   134718篇
妇产科学   110320篇
基础医学   650651篇
口腔科学   113410篇
临床医学   381787篇
内科学   759655篇
皮肤病学   105880篇
神经病学   349759篇
特种医学   163565篇
外国民族医学   503篇
外科学   646602篇
综合类   119212篇
现状与发展   23篇
一般理论   2562篇
预防医学   352713篇
眼科学   98766篇
药学   294360篇
  26篇
中国医学   11297篇
肿瘤学   205726篇
  2021年   55699篇
  2020年   35460篇
  2019年   58400篇
  2018年   73617篇
  2017年   56245篇
  2016年   62278篇
  2015年   75326篇
  2014年   109654篇
  2013年   174784篇
  2012年   120533篇
  2011年   126023篇
  2010年   125149篇
  2009年   126495篇
  2008年   112338篇
  2007年   119701篇
  2006年   128474篇
  2005年   123653篇
  2004年   123927篇
  2003年   114345篇
  2002年   103592篇
  2001年   149681篇
  2000年   144542篇
  1999年   134300篇
  1998年   70080篇
  1997年   66199篇
  1996年   64411篇
  1995年   59687篇
  1994年   53772篇
  1993年   50041篇
  1992年   96047篇
  1991年   92649篇
  1990年   89064篇
  1989年   86820篇
  1988年   80020篇
  1987年   78513篇
  1986年   73860篇
  1985年   72977篇
  1984年   61664篇
  1983年   55428篇
  1982年   46019篇
  1981年   43116篇
  1980年   40503篇
  1979年   53102篇
  1978年   44031篇
  1977年   38886篇
  1976年   36264篇
  1975年   36271篇
  1974年   39407篇
  1973年   37634篇
  1972年   35245篇
排序方式: 共有10000条查询结果,搜索用时 0 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