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   620篇
  免费   56篇
耳鼻咽喉   5篇
儿科学   14篇
妇产科学   21篇
基础医学   91篇
口腔科学   6篇
临床医学   53篇
内科学   125篇
皮肤病学   9篇
神经病学   34篇
特种医学   32篇
外科学   47篇
综合类   8篇
预防医学   141篇
眼科学   29篇
药学   21篇
肿瘤学   40篇
  2023年   3篇
  2021年   5篇
  2019年   7篇
  2018年   8篇
  2017年   12篇
  2016年   7篇
  2015年   11篇
  2014年   8篇
  2013年   19篇
  2012年   34篇
  2011年   28篇
  2010年   16篇
  2009年   12篇
  2008年   28篇
  2007年   33篇
  2006年   35篇
  2005年   33篇
  2004年   37篇
  2003年   28篇
  2002年   36篇
  2001年   41篇
  2000年   26篇
  1999年   15篇
  1998年   13篇
  1997年   4篇
  1996年   11篇
  1993年   4篇
  1992年   10篇
  1991年   10篇
  1990年   10篇
  1989年   10篇
  1988年   6篇
  1987年   5篇
  1986年   6篇
  1985年   17篇
  1984年   8篇
  1983年   6篇
  1982年   6篇
  1981年   3篇
  1979年   5篇
  1978年   6篇
  1976年   4篇
  1973年   3篇
  1972年   7篇
  1971年   7篇
  1970年   3篇
  1969年   4篇
  1967年   5篇
  1966年   4篇
  1935年   2篇
排序方式: 共有676条查询结果,搜索用时 15 毫秒
1.
To test hypotheses of opposing roles of dopamine and serotonin in prolactin secretion in seasonal affective disorder, the authors determined basal serum prolactin concentrations for premenopausal women, eight with and 14 without seasonal affective disorder, in late afternoon during the follicular phase of the menstrual cycle (and a subgroup during the luteal phase) in winter and summer. Despite their significantly higher Hamilton depression scale scores in winter than in summer, the patients had significantly lower prolactin concentrations than the control subjects in both seasons. These results suggest that low prolactin secretion may be a trait characteristic in seasonal affective disorder.  相似文献   
2.
3.
4.
5.
Using a model of group care practice that identifies seven areas of child care worker activity and skill, this paper shows how these skills can be used in work with parents and other family members of children in placement. The emphasis is on the child care worker’s role as parent educator. This approach transforms the 24-hour-per day group care environment, and the living unit in particular, into a classroom for teaching and learning parenting skills. The educational, policy, and resource consequences of this proposal are then discussed. Finally, this model of practice is linked to psychoeducational, family resource, and competency-based approaches to family intervention and social work practice. All of these models de-emphasize family pathology in favor of practice that views parents and family members as partners in the care and treatment process. The author thanks Karen Kayser of Boston College and Henry Maier of the University of Washington, Seattle, for their comments on an earlier draft of this article.  相似文献   
6.
7.
The purpose of this study was to compare the phagocytosis of Aeromonas hydrophila, Edwardsiella ictaluri, Edwardsiella tarda and Micrococcus luteus by channel catfish neutrophils. Various aspects of opsonization effect and bactericidal ability of channel catfish neutrophils were investigated. Percent phagocytosis ranged from a low of 1% to a high of 91%. The highest percent phagocytosis and phagocytic indices routinely occurred with normal serum and were highest for M. luteus (91.78%, 55.25) and A. hydrophila (87.52%, 43.60). In all cases, the percent phagocytosis and phagocytic index was lowest in assays without serum. Channel catfish neutrophils displayed a bactericidal/static ability for each bacterium tested except E. tarda. Neutrophils exhibited a greater inhibitory capacity for A. hydrophila and M. luteus than for the other bacteria when in the presence of normal or inactivated catfish serum.  相似文献   
8.
Sputum specimens culture positive for Moraxella (Branhamella) catarrhalis were Gram stained with three decolorizer solutions (slow, 95% ethyl alcohol; intermediate, 1:1 ratio of 95% ethyl alcohol and acetone; and fast, acetone alone) for 5, 10, 20, and 30 s. Optimal results were obtained with acetone alone after 10 s or with a 1:1 mixture of acetone and ethanol after 20 s. Inadequate decolorization of M. catarrhalis in sputa is likely if the decolorization solution and exposure time are not optimal and may contribute to underreporting of this organism.  相似文献   
9.
Alcohol and the Psychophysiological Detection of Deception   总被引:1,自引:0,他引:1  
Psychophysiological detection of deception examinations were conducted on 40 subjects. Of these, 32 were “guilty” of a mock crime and 8 were innocent. Sixteen guilty subjects committed the crime while intoxicated and the remaining 16 committed the crime sober. These two groups of guilty subjects were subdivided such that half of each group was examined with the polygraph while intoxicated and the other half was examined while sober. Two questioning techniques were used in the examination, a Control Question Test and the Guilty Knowledge Test. Measures of skin resistance, heart rate and respiration were recorded. The principal findings were that alcohol intoxication during the crime reduced detectability with detection scores derived from the measurement of skin resistance responses on the Control Question Test and on the Guilty Knowledge Test. The analyses of guilt/innocent classifications, based on the detection scores, showed these classifications to be affected by alcohol intoxication.  相似文献   
10.
Crypts of Lieberkuhn are radiosensitive: the technique of crypt counting is an established method of assessing radiation induced changes in the small intestine. However, there has been little work done on the surface contours of the crypts, as they open into the intervillous cleft. The current paper describes the structure of control mouse crypt mouths as unobtrusive openings approximately 5 microns in diameter. After radiation with heavy ion particles, the crypt mouths are substantially larger (up to 10 microns in diameter) with a marked collar which is similar to that sometimes seen in coeliac disease. The shape and incidence of the collared crypts is described for specimens irradiated with neon, silicon and iron ions, with treatment with iron producing the most marked collars: it is suggested that the size and incidence of the collared crypts may be related to the LET of the beam used. It is of interest that the abnormal crypts are not produced after single doses of X-irradiation. The consideration of the structure of the collared crypts may require a redefinition of the terms crypt and villus with priority being given to the position of subepithelial vessels rather than surface shape. Finally, although the collared crypts can not be directly equated with 'tunnel' or 'channel' lesions, it is pointed out that they do represent localised damage with a specific position and shape.  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