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   4295篇
  免费   401篇
  国内免费   12篇
耳鼻咽喉   120篇
儿科学   245篇
妇产科学   78篇
基础医学   565篇
口腔科学   49篇
临床医学   431篇
内科学   909篇
皮肤病学   81篇
神经病学   334篇
特种医学   60篇
外科学   526篇
综合类   92篇
一般理论   2篇
预防医学   592篇
眼科学   59篇
药学   237篇
中国医学   1篇
肿瘤学   327篇
  2023年   77篇
  2022年   107篇
  2021年   200篇
  2020年   156篇
  2019年   188篇
  2018年   194篇
  2017年   125篇
  2016年   120篇
  2015年   149篇
  2014年   198篇
  2013年   242篇
  2012年   318篇
  2011年   342篇
  2010年   188篇
  2009年   134篇
  2008年   226篇
  2007年   225篇
  2006年   210篇
  2005年   207篇
  2004年   160篇
  2003年   133篇
  2002年   127篇
  2001年   31篇
  2000年   40篇
  1999年   36篇
  1998年   31篇
  1997年   21篇
  1996年   19篇
  1995年   19篇
  1994年   18篇
  1993年   14篇
  1992年   30篇
  1991年   28篇
  1990年   36篇
  1989年   35篇
  1988年   13篇
  1987年   16篇
  1986年   26篇
  1985年   16篇
  1984年   25篇
  1983年   21篇
  1982年   20篇
  1980年   13篇
  1979年   16篇
  1978年   12篇
  1976年   14篇
  1975年   12篇
  1973年   16篇
  1972年   16篇
  1971年   11篇
排序方式: 共有4708条查询结果,搜索用时 15 毫秒
1.
2.
3.
Castrated or sham-operated male athymic mice were inoculated with cells from the human hepatocellular carcinoma cell line PLC/PRF/5. There were no significant differences between the two groups with respect to the number of animals developing tumors, the time to tumor development, or the subsequent rate of increase in either tumor base area or mouse serum alpha-fetoprotein concentration. Androgen receptors were assayed in nuclei obtained from three separate liver cancer cell lines and from normal adult human liver. Similar concentrations, ranging from 235 to 550 fmol/mg DNA, of nuclear androgen receptors were detected in all tissues. Low percentages of androgen receptors were retained on DNA-cellulose. Although the presence of receptors implies the potential for metabolic effects of androgens in normal and malignant liver, our in vivostudies suggest that castration does not alter significantly the growth of liver cancer xenografts in athymic mice.  相似文献   
4.
Blood alcohol level among emergency room patients: a multivariate analysis   总被引:2,自引:0,他引:2  
This article examines the distribution of positive blood alcohol levels (BALs) among emergency room patients and the relationship between intoxication and other variables. Approximately one-quarter of the 640 subjects had positive blood alcohol levels and 16.3% had BAL readings above 0.10%, the legal limit for operating a motor vehicle in most states. Chi-square tests and logistic regression analysis indicated a significant relationship between employment status, gender, educational attainment, age and BAL. There were no significant racial differences. Analysis of the role of the presenting problem with BAL revealed that being involved in an accident was significantly predictive of a high BAL in a multivariate context. However, patients presenting with psychiatric problems had overall higher levels of intoxication than other patients. These findings have major implications for public policy formulation vis-à-vis public health delivery.  相似文献   
5.
6.
7.
8.
There is a dearth of research examining treatment engagement and attendance among runaway youth and their families. Such research is needed in order to inform treatment providers on factors associated with engagement and maintenance of these difficult to engage families into counseling. This study examined differential treatment attendance for alcohol abusing runaway youth residing at a local shelter. A traditional office-based family systems approach, Functional Family Therapy (FFT), was compared to a non-traditional, home-based, multi-systemic family therapy approach, Ecologically Based Family Therapy (EBFT). As expected, treatment engagement and attendance was significantly higher for those assigned to EBFT (N = 37) compared to FFT (N = 40). Predictors of treatment attendance (income, family chaos, externalization problems and level of youth substance use) were examined within each treatment modality. Findings suggest that home-based (compared to office-based) treatment modalities may significantly increase treatment attendance and engagement of runaway youth and their families. Non-traditional forms of treatment may need to be considered in order to best meet the needs of highly chaotic and disorganized family systems.  相似文献   
9.
ATVs: a new safety hazard?   总被引:2,自引:2,他引:0       下载免费PDF全文
  相似文献   
10.
An important methodological issue in depressionanalog research is whether individuals who scoreextremely low on self-report measures like the BeckDepression Inventory (BDI) should be included innondepressed control groups. Joiner, Schmidt, and Metalsky(1994) found that college students with BDI scores of 0or 1 evidenced a fake-good test taking style as measuredby the MMPI validity scales. The present study investigated whether very low BDI scores (BDI= 0 or 1; n = 21) might be associated with an elevatedpositive mood state, extreme optimism, positiveattributional style or social desirability. Resultsindicated that the very low scoring BDI subjects scoredhigher on social desirability than the low scoring group(BDI = 2 9, n = 63). Significant differences on mood,symptom and cognitive measures disappeared when social desirability was entered as a covariate.Findings support Kendall, Hollon, Beck, Hammen, andIngram's (1987) recommendation that subjects who score0 or 1 on the BDI should be excluded from a nondepressed control group.  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