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   37846篇
  免费   2945篇
  国内免费   102篇
耳鼻咽喉   370篇
儿科学   1142篇
妇产科学   973篇
基础医学   5784篇
口腔科学   501篇
临床医学   5265篇
内科学   6587篇
皮肤病学   767篇
神经病学   4703篇
特种医学   930篇
外科学   3514篇
综合类   300篇
现状与发展   1篇
一般理论   35篇
预防医学   3953篇
眼科学   636篇
药学   2417篇
中国医学   42篇
肿瘤学   2973篇
  2023年   263篇
  2022年   433篇
  2021年   938篇
  2020年   627篇
  2019年   945篇
  2018年   1131篇
  2017年   890篇
  2016年   979篇
  2015年   1044篇
  2014年   1461篇
  2013年   1877篇
  2012年   2975篇
  2011年   3047篇
  2010年   1672篇
  2009年   1519篇
  2008年   2586篇
  2007年   2651篇
  2006年   2434篇
  2005年   2479篇
  2004年   2246篇
  2003年   2068篇
  2002年   1945篇
  2001年   379篇
  2000年   231篇
  1999年   389篇
  1998年   432篇
  1997年   369篇
  1996年   268篇
  1995年   276篇
  1994年   219篇
  1993年   201篇
  1992年   176篇
  1991年   164篇
  1990年   144篇
  1989年   147篇
  1988年   112篇
  1987年   111篇
  1986年   98篇
  1985年   88篇
  1984年   101篇
  1983年   81篇
  1982年   74篇
  1981年   78篇
  1980年   72篇
  1979年   45篇
  1978年   42篇
  1977年   47篇
  1976年   41篇
  1974年   32篇
  1972年   30篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Community pharmacists contribution to the management of drug problems is considerable. As the use of illicit drugs has increased, pharmacists have come under increasing pressure to offer services to problem drug users. However, there is concern among some pharmacists that offering such services may deter other customers. There is particular concern among some pharmacists about needle exchange services. Only 9.5% of Scottish pharmacies offer needle exchange services compared to 69% which are dispensing methadone (57% of which supervise methadone consumption). Qualitative interviews were used in a purposive sample of 10 pharmacies in Scotland. Eight customers were interviewed in each pharmacy to ascertain pharmacy customers’ views on these services. The majority of customers were supportive of these services. Customers were often unaware that the pharmacy they were interviewed in was offering services for people with drug problems. Pharmacy customers were more knowledgeable about, and more supportive, of needle exchange services than they were of methadone. This was because they believed needle exchange services helped to reduce the amount of discarded needles in public places. Pharmacy customers also recognised that needle exchange helped reduce the spread of disease. These findings should be used to encourage more pharmacists to offer needle exchange services.  相似文献   
52.
53.
54.
Evidence that genetic disposition for adult lactose intolerance significantly affects calcium intake, bone density, and fractures in postmenopausal women is presented. PCR-based genotyping of lactase gene polymorphisms may complement diagnostic procedures to identify persons at risk for both lactose malabsorption and osteoporosis. INTRODUCTION: Lactase deficiency is a common autosomal recessive condition resulting in decreased intestinal lactose degradation. A -13910 T/C dimorphism (LCT) near the lactase phlorizin hydrolase gene, reported to be strongly associated with adult lactase nonpersistence, may have an impact on calcium supply, bone density, and osteoporotic fractures in the elderly. MATERIALS AND METHODS: We determined LCT genotypes TT, TC, and CC in 258 postmenopausal women using a polymerase chain reaction-based assay. Genotypes were related to milk intolerance, nutritional calcium intake, intestinal calcium absorption, bone mineral density (BMD), and nonvertebral fractures. RESULTS: Twenty-four percent of all women were found to have CC genotypes and genetic lactase deficiency. Age-adjusted BMD at the hip in CC genotypes and at the spine in CC and TC genotypes was reduced by -7% to -11% depending on the site measured (p = 0.04). LCT(T/C-13910) polymorphisms alone accounted for 2-4% of BMD in a multiple regression model. Bone fracture incidence was significantly associated with CC genotypes (p = 0.001). Milk calcium intake was significantly lower (-55%, p = 0.004) and aversion to milk consumption was significantly higher (+166%, p = 0.01) in women with the CC genotype, but there were no differences in overall dietary calcium intake or in intestinal calcium absorption test values. CONCLUSION: The LCT(T/C-13910) polymorphism is associated with subjective milk intolerance, reduced milk calcium intake, and reduced BMD at the hip and the lumbar spine and may predispose to bone fractures. Genetic testing for lactase deficiency may complement indirect methods in the detection of individuals at risk for both lactose malabsorption and osteoporosis.  相似文献   
55.
56.
We cared for a patient with methicillin-resistant Staphylococcus aureus bacteremia who experienced clinical failure with daptomycin. The failure was accompanied by progressive elevation of the daptomycin minimum inhibitory concentration during treatment. DNA fingerprinting confirmed that the minimum inhibitory concentration elevation occurred within the same strain of methicillin-resistant Staphylococcus aureus. This observation provides important new information to clinicians who adopt this promising drug for treatment of serious infections caused by methicillin-resistant Staphylococcus aureus.  相似文献   
57.
58.

Objective: To summarize changes in folic acid awareness, knowledge, and behavior among women of childbearing age in the United States since the U.S. Public Health Service (USPHS) 1992 folic acid recommendation and later fortification. Methods: Random-digit dialed telephone surveys were conducted of approximately 2000 women (per survey year) aged 18–45 years from 1995–2005 in the United States. Results: The percentage of women reporting having heard or read about folic acid steadily increased from 52% in 1995 to 84% in 2005. Of all women surveyed in 2005, 19% knew folic acid prevented birth defects, an increase from 4% in 1995. The proportion of women who reported learning about folic acid from health care providers increased from 13% in 1995 to 26% in 2005. The proportion of all women who reported taking a vitamin supplement containing folic acid increased slightly from 28% in 1995 to 33% in 2005. Among women who were not pregnant at the time of the survey in 2005, 31% reported taking a vitamin containing folic acid daily compared with 25% in 1995. Conclusions: The percentage of women taking folic acid daily has increased modestly since 1995. Despite this increase, the data show that the majority of women of childbearing age still do not take a vitamin containing folic acid daily. Health care providers and maternal child health professionals must continue to promote preconceptional health among all women of childbearing age, and encourage them to take a vitamin containing folic acid daily.

  相似文献   
59.
60.
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