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   1542759篇
  免费   115583篇
  国内免费   17997篇
耳鼻咽喉   21518篇
儿科学   42296篇
妇产科学   41383篇
基础医学   211958篇
口腔科学   43205篇
临床医学   142467篇
内科学   293165篇
皮肤病学   32193篇
神经病学   117933篇
特种医学   61485篇
外国民族医学   573篇
外科学   228509篇
综合类   65675篇
现状与发展   61篇
一般理论   454篇
预防医学   104672篇
眼科学   37768篇
药学   121871篇
  198篇
中国医学   15221篇
肿瘤学   93734篇
  2021年   18586篇
  2020年   13465篇
  2019年   15313篇
  2018年   19476篇
  2017年   16426篇
  2016年   16976篇
  2015年   21833篇
  2014年   28838篇
  2013年   35530篇
  2012年   48416篇
  2011年   52191篇
  2010年   30907篇
  2009年   28110篇
  2008年   44207篇
  2007年   47245篇
  2006年   48009篇
  2005年   46921篇
  2004年   41713篇
  2003年   40351篇
  2002年   38818篇
  2001年   67661篇
  2000年   69867篇
  1999年   60454篇
  1998年   17961篇
  1997年   16798篇
  1996年   15651篇
  1995年   14745篇
  1994年   13543篇
  1992年   44390篇
  1991年   42656篇
  1990年   41631篇
  1989年   40437篇
  1988年   37784篇
  1987年   37095篇
  1986年   35478篇
  1985年   33533篇
  1984年   25080篇
  1983年   21233篇
  1979年   24024篇
  1978年   17103篇
  1977年   14872篇
  1976年   13401篇
  1975年   15300篇
  1974年   18121篇
  1973年   17586篇
  1972年   16845篇
  1971年   15740篇
  1970年   14931篇
  1969年   14364篇
  1968年   13473篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
901.
The concentration of microsomal cytochromes P-450, and of protein in the homogenate, cytosol and microsomes were measured in the liver, kidney and duodenal mucosa of healthy well-fed male and female camels, sheep and goats. For comparison, data from the liver of male and female rats were also obtained. The protein concentrations in the tissues of adult animals were broadly similar in the four species. The concentration of cytochromes P-450 was highest in the liver, followed by the kidney, then the duodenal mucosa in all the species. No cytochromes P-450 were detected in the tissues of immature (less than 1 mo) male goats, whereas the female goat had the highest concentrations of these enzymes in the liver and kidney when compared with the respective tissues in the other species studied. Males had higher activity of cytochromes P-450 than females in the three tissues, except in the duodenal mucosa of sheep, where males had lower activity than females. In camel liver and sheep kidney, the amount of cytochromes P-450 were similar in the two sexes. The present results suggest that the mature female goat is the species best equipped to handle xenobiotics which are detoxified by the cytochromes P-450 and other drug metabolizing enzymes in diseased or malnourished animals is suggested as these two conditions are known to modify drug metabolizing enzymes.  相似文献   
902.
903.
904.
905.
906.
907.
908.
OBJECTIVE: To obtain consensus among a panel of experts on performance measures useful for evaluating the quality of hospital-based domestic violence (DV) programs. METHODS: The Delphi process of consensus development was used with a panel of 18 experts including DV researchers, program planners, and advocates. Three rounds were conducted over a period of six months, with each round involving the completion of a written questionnaire. Panelists were instructed to concentrate on structure and process measures of DV program performance. Health outcome measures were not considered. During each round, panelists rated (scale of 1-5) their level of agreement with each measure, in terms of the measure's usefulness for evaluating hospital-based DV programs. Data were entered into SPSS on a personal computer and frequency distributions, measures of central tendency, and variance were computed for each measure. Consensus development was defined as a reduction in the item-specific variance from one round to the next. RESULTS: A total of 37 performance measures were agreed upon. These measures fell within nine different domains of DV program activities, including: Policies and Procedures, Hospital Physical Environment, Hospital Cultural Environment, Training of Providers, Screening and Safety Assessment, Documentation, Intervention Services, Evaluation Activities, and Collaboration. CONCLUSIONS: A number of measures have been identified as useful for evaluating hospital-based DV programs. Use of these measures should assist researchers, program planners, and administrators in assessing the quality of hospital-based DV programs.  相似文献   
909.
Out of 36511 patients attending the ENT OHD of R. G,. Aur Medical Callege & Hospital. Kolkata, in one year 0.08% patients were found tuning naspharyngeal mass. 30 cases of nasopharyngeal mass were studied. The peak incidence of nasopharyngeal mass was in the age group between II to 20 years (40%). The incidence in males (73%) was more than females(27%). The maximum ineldence was found among students (74%). Commonest ntuopharyngeal nuns teas antrochoanal polyp (30%). Next commlon masses were adenoids (23%)Juvenile angwfibroma(20%) and nasophartngeal carcinoma (13%). Nasal obstruction was the main presenting symptom(83%) followed by epistaxis (40%).  相似文献   
910.
OBJECTIVE: To investigate the relationship of plasma homocysteine (Hcy) level to stroke and genetic factor to elevated plasma Hcy level. METHODS: The plasma Hcy level was measured by capillary electrophoresis-ultraviolet detection and the gene polymorphism of N5,N10-methylenetetrahydrofolate reductase (MTHFR) was studied with PCR-RFLP assay in 43 patients with cortical cerebral infarction and 42 healthy control. RESULTS: The plasma Hcy level of the patients (19.3 +/- 6.0 micromol/L) was markedly higher than that of the controls (13.7 +/- 5.4 micromol/L) (t = 4.16, P < 0.001). There are 3 genotypes, C/C, C/T and T/T, about base-variation of MTHFR gene at locus 677. The plasma Hcy level of the subjects with T/T genotype was higher than that of subjects with other genotypes. However, the frequencies of each genotype and allele were not significantly different between the patients and the controls. CONCLUSIONS: The elevated plasma Hcy level is a risk factor for atherothrombotic cerebral infarction, and is related to the C-->T mutation at locus 677 of MTHFR gene.  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