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   1114篇
  免费   80篇
  国内免费   5篇
耳鼻咽喉   9篇
儿科学   67篇
妇产科学   24篇
基础医学   113篇
口腔科学   13篇
临床医学   80篇
内科学   226篇
皮肤病学   14篇
神经病学   76篇
特种医学   103篇
外科学   143篇
综合类   66篇
预防医学   61篇
眼科学   35篇
药学   90篇
肿瘤学   79篇
  2022年   16篇
  2021年   27篇
  2020年   19篇
  2019年   19篇
  2018年   22篇
  2017年   14篇
  2016年   16篇
  2015年   24篇
  2014年   27篇
  2013年   34篇
  2012年   55篇
  2011年   58篇
  2010年   41篇
  2009年   46篇
  2008年   47篇
  2007年   57篇
  2006年   54篇
  2005年   59篇
  2004年   37篇
  2003年   25篇
  2002年   32篇
  2001年   26篇
  2000年   17篇
  1999年   21篇
  1998年   35篇
  1997年   29篇
  1996年   19篇
  1995年   16篇
  1994年   14篇
  1993年   11篇
  1992年   17篇
  1991年   20篇
  1990年   18篇
  1989年   24篇
  1988年   20篇
  1987年   25篇
  1986年   20篇
  1985年   7篇
  1984年   8篇
  1983年   14篇
  1982年   10篇
  1981年   7篇
  1980年   7篇
  1979年   6篇
  1978年   6篇
  1976年   6篇
  1975年   10篇
  1973年   6篇
  1972年   10篇
  1971年   6篇
排序方式: 共有1199条查询结果,搜索用时 375 毫秒
1.
2.
The purpose of this study is to show the spectrum of adjacent organ invasion and to make a brief review of hepatic alveolar hydatid disease (AHD), using CT and MR imaging. We retrospectively reviewed CT and MR images of three patients with various adjacent organ invasions surgically and histologically proven to be AHD. Local invasion to right kidney and adrenal, right hemidiaphragm and lung were detected in one patient, right adrenal in another patient and gall bladder, duodenum, gastric wall and pancreas invasion in the other. AHD may rarely extend to the gall bladder, stomach, duodenum, pancreas, right adrenal and kidney, diaphragm, pleura and lung. The extension of the disease outside the liver is usually encountered in patients with large, peripherally located masses in the advanced stage of the disease.  相似文献   
3.
In an effort to evaluate whether differences exist in the hypothalamic-pituitary-thyroid axis of depressed children, a thyrotropin releasing hormone (TRH) stimulation test was administered to 55 prepubertal subjects who were divided into three groups matched for age and sex: a depressed group (endogenous N = 15, nonendogenous N = 15), a psychiatric nondepressed control group (N = 16), and a normal control group (N = 9). Each subject was tested at two dosages of TRH, 2 micrograms/kg and 7 micrograms/kg. Increasing age and female sex were positively correlated with a greater thyroid stimulating hormone (TSH) response. TSH response to TRH was examined with subjects reclassified by severe suicidal ideation, severe aggression, and parental history of alcoholism. Results of this study are contrasted with the adult psychiatric literature.  相似文献   
4.
5.
Reference values are proposed for the concentrations of As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Pb, Se, and Zn in whole blood, blood serum, urine, milk, liver, and hair from adult human subjects. For F, I, and Ni, it was not possible to evaluate reference intervals for all the specimens mentioned above. For several elements, including Al, B, Br, Cs, Li, Rb, U, and V, the present status of the literature does not provide an adequate basis for formulating baseline concentrations; therefore, results from selected investigations are listed for information only. For elements such as Cu, Fe, and Zn, which are known to be homeostatically controlled, the concentrations in whole blood and blood serum follow a gaussian-like frequency distribution, and we could consider both median and mean values for evaluation. On the other hand, elements whose concentrations in tissues and body fluids are influenced by dietary availability (e.g., As and Se) or environmental factors (e.g., Cd, Hg, and Pb) show wide scatter. In these cases, the median appeared to be a better indicator of the central tendency than the mean, when different populations are involved. These points are illustrated.  相似文献   
6.
7.
Deprivation of form vision by the fitting of translucent occluders suppressed the diurnal cycling of enkephalinergic amacrine cells (the ENSLI amacrine cells), in the chicken. Daily periods of normal vision or enforcing temporal contrast using strobe lighting appeared to restore normal functioning of the ENSLI cells. These results suggest that the ENSLI cells are involved in retinal circuits that assess the quality of the visual image and control eye growth.  相似文献   
8.
Dihydrostreptomycin analogues with structural variations in their guanidino groups were prepared. The analogue with a methyl group on the guanidine at C-1 was nearly as active as dihydrostreptomycin against bacteria. However, the 2-imidazolin-2-ylamino substituent at C-1 eliminated activity. No analogue with a substituent on the C-3 guanidino group was active.  相似文献   
9.
Colour Doppler flow imaging (CD) is a well-established method of assessing valvular and congenital disease of the heart. The technique has proven useful intraoperatively in patients undergoing valve repair or replacement or intracardiac reconstruction. In 21 patients with various cardiac anomalies, colour Doppler flow imaging was used intraoperatively, before cardiac cannulation and again after cardiopulmonary bypass. Previously undisclosed features were demonstrated preoperatively in two patients and important residual defects after cardiopulmonary bypass in three others. Adequacy of valve replacement was confirmed in four patients and small leaks in ventricular septal defect patches were shown in another three. The procedure facilitated repair of complex cardiac fistulas in two patients. There were no apparent complications from CD. As intracardiac repairs become more complex, the role of intraoperative CD will expand.  相似文献   
10.
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