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   771篇
  免费   25篇
  国内免费   5篇
耳鼻咽喉   15篇
儿科学   17篇
妇产科学   53篇
基础医学   175篇
口腔科学   7篇
临床医学   78篇
内科学   96篇
皮肤病学   24篇
神经病学   37篇
特种医学   47篇
外科学   49篇
综合类   4篇
预防医学   73篇
眼科学   14篇
药学   90篇
肿瘤学   22篇
  2021年   12篇
  2020年   8篇
  2019年   9篇
  2018年   9篇
  2017年   8篇
  2015年   7篇
  2014年   9篇
  2013年   16篇
  2012年   33篇
  2011年   34篇
  2010年   20篇
  2009年   14篇
  2008年   30篇
  2007年   30篇
  2006年   33篇
  2005年   19篇
  2004年   24篇
  2003年   18篇
  2002年   20篇
  2001年   20篇
  2000年   21篇
  1999年   24篇
  1998年   23篇
  1997年   8篇
  1996年   18篇
  1995年   7篇
  1994年   12篇
  1993年   8篇
  1992年   10篇
  1991年   8篇
  1990年   19篇
  1989年   19篇
  1988年   15篇
  1987年   14篇
  1986年   19篇
  1985年   8篇
  1984年   11篇
  1983年   8篇
  1982年   7篇
  1980年   7篇
  1979年   17篇
  1978年   11篇
  1977年   17篇
  1975年   17篇
  1974年   10篇
  1973年   11篇
  1971年   10篇
  1970年   9篇
  1969年   8篇
  1968年   8篇
排序方式: 共有801条查询结果,搜索用时 15 毫秒
1.
2.
Vitiligo and psoriasis are both common skin disorders. However, psoriasis strictly confined to pre-existing vitiligo areas is rare and suggests a causal relationship. We report here on two patients with a strict anatomical colocalization of vitiligo and psoriasis. The histopathological examinations showed typical changes for both diseases together with a dense infiltrate of CD4+ and CD8+ T cells. By immunohistochemistry, intracytoplasmatic granzyme B and tumour necrosis factor alpha (TNF-alpha) were detected within the T-cell population, suggesting the functional activity of these cells and the creation of a local T helper 1 (Th1)-cytokine milieu. Additionally, in one patient we could identify anti-melanocytic T cells by tetramer staining and enzyme-linked immunospot (ELISPOT) analysis. These skin-infiltrating lymphocytes might trigger, by the local production of Th-1 cytokines such as TNF-alpha and interferon-gamma (IFN-gamma), the eruption of psoriatic plaques in patients with a genetic predisposition for psoriasis.  相似文献   
3.
A quantitative spectrophotometric method has been developed for determining the impurity of isonaphthazarin in samples of tetraxolin. The relative error of determination is about 1.0% at a confidence probability of P = 0.95%. The procedure is recommended for the quantitative control of the possible impurity of isonaphthazarin in the parent substance of tetraxolin. __________ Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 41, No. 1, pp. 38–40, January, 2007.  相似文献   
4.
5.
Damage to the genetic component of spermatozoa seems to play the main role in a majority of cases where current approaches fail to reveal the specific cause of male infertility. In this study, we compared semen quality in men assigned to two defined groups: men from couples with unexplained infertility – idiopathic infertility (A) and young men with no experiences of infertility (B). All samples were examined by standard ejaculate analysis and sperm chromatin structure assay (SCSA). Sperm chromatin damage was significantly higher in men from group A than in those from group B. Similar results were obtained by comparison of men from group A (all men were normozoospermic) with normozoospermic men from group B. According to these results, we can suppose that chromatin disorders may be the causal factor of subfertility or infertility in some of these men. No evidence for a strong association between chromatin disorders and standard parameters of ejaculates was found. We failed to confirm a relationship between smoking and sperm quality in men from any of the investigated groups. SCSA is a method that facilitates the identification of infertile men who otherwise show normal semen variables.  相似文献   
6.
7.
Medial border of the perirenal space: CT and anatomic correlation   总被引:11,自引:0,他引:11  
  相似文献   
8.
Circannual variation in lymphocyte subsets, revisited   总被引:2,自引:0,他引:2  
BACKGROUND: Circadian and circannual variations in lymphocyte subsets, especially CD8+ T-lymphocytes, have been reported. This study focuses on CD4+ T-lymphocyte seasonal variation over a 6-year 8-month period. STUDY DESIGN AND METHODS: Lymphocyte subsets were quantitated monthly for four healthy individuals from 1986 through 1992 as part of a flow cytometry quality-control program. RESULTS: In general, there were no significant seasonal changes in the total number of white cells or in total lymphocyte counts. The absolute numbers of CD4+ T-lymphocytes were lowest in summer when the CD8+ T-lymphocytes were highest. Mean CD4+ T-lymphocyte counts were 846, 967, 618, and 695 per microL for Subjects 1 through 4, respectively, in winter and 432, 670, 355, and 766 per microL, respectively, in summer. Two healthy subjects had CD4+ T-lymphocyte counts lower than 300 per microL on one or more occasions during the study period. In three of the four subjects, the percentage of B-lymphocytes in winter was almost double that in summer. In one of the four subjects, no circannual rhythm was observed in these lymphocyte subpopulations. CONCLUSION: The seasonal variation in CD4+ T- lymphocyte counts demonstrated in three healthy individuals over almost 7 years is again of interest in light of renewed consideration of using surrogate tests, such as CD4+ T-lymphocyte counts, to screen for AIDS- like diseases that may be in the blood supply.  相似文献   
9.
A comprehensive study of blood lipid composition and microcirculatory indices was performed in 88 patients with diabetes mellitus (DM) combined with coronary heart disease (CHD). A "syndrome" of mutual aggravation was shown to develop in the combination of DM and CHD. As a result of it the above indices were changed depending on clinical signs of each of the two diseases. Lipid metabolic and microcirculatory derangements depended mostly on a degree of compensation of carbohydrate metabolism. a DM type, the presence of diabetic angiopathies and CHD gravity.  相似文献   
10.
A rapid microagglutination test has been developed which can be performed in 30 minutes. Ninety-seven percent of 96 patients diagnosed as having Legionella pneumophila (serogroup 1) infection by indirect immunofluorescence were also detected by the rapid microagglutination test.  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