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   154881篇
  免费   10186篇
  国内免费   770篇
耳鼻咽喉   1417篇
儿科学   3917篇
妇产科学   2789篇
基础医学   20720篇
口腔科学   3481篇
临床医学   14995篇
内科学   33456篇
皮肤病学   2929篇
神经病学   14991篇
特种医学   6176篇
外国民族医学   6篇
外科学   23200篇
综合类   1915篇
现状与发展   2篇
一般理论   140篇
预防医学   11225篇
眼科学   3234篇
药学   10570篇
  14篇
中国医学   245篇
肿瘤学   10415篇
  2023年   908篇
  2022年   1289篇
  2021年   2929篇
  2020年   2066篇
  2019年   2857篇
  2018年   3456篇
  2017年   2685篇
  2016年   3059篇
  2015年   3537篇
  2014年   5066篇
  2013年   6851篇
  2012年   10595篇
  2011年   11202篇
  2010年   6380篇
  2009年   6082篇
  2008年   10255篇
  2007年   10928篇
  2006年   10408篇
  2005年   10659篇
  2004年   10059篇
  2003年   9537篇
  2002年   8949篇
  2001年   1518篇
  2000年   1153篇
  1999年   1625篇
  1998年   2123篇
  1997年   1653篇
  1996年   1437篇
  1995年   1298篇
  1994年   1148篇
  1993年   1126篇
  1992年   804篇
  1991年   807篇
  1990年   628篇
  1989年   612篇
  1988年   576篇
  1987年   582篇
  1986年   529篇
  1985年   544篇
  1984年   653篇
  1983年   586篇
  1982年   777篇
  1981年   707篇
  1980年   606篇
  1979年   381篇
  1978年   388篇
  1977年   413篇
  1976年   354篇
  1975年   305篇
  1974年   263篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
63.
64.
Bilateral ulnar agenesis is a rare abnormality. A total of 36 cases are analyzed: 35 of these are documented in the literature and 1 stillborn male is presented in this study. Most patients had one of the three conditions: Al-Awadi/Raas-Rothschild syndrome, syndrome of ulnar aplasia with split hand/split foot deformity, or the Brachmann—de Lange syndrome. Fifty percent of all cases with bilateral ulnar agenesis were associated with lower limb defects and these cases, for the most part, also belonged to the aforementioned syndromes. Nonskeletal, internal organ malformations were identified in 34% of all patients. Nine patients presented with isolated bilateral ulnar agenesis. The Al-Awadi/Raas-Rothschild syndrome and the split hand/split foot deformity are heritable disorders. There was no evidence for genetic etiology in most of the other cases. Bilateral ulnar agenesis in our fetus was part of the Brachmann—de Lange syndrome with associated cardiac defect, diaphragmatic hernia, and umbilical artery agenesis.  相似文献   
65.
66.
67.
68.
Oral mucosal lichen planus (OMLP) is a well recognized mucosal disease with unknown etiology. Considerable controversy exists as to whether OMLP is intrinsically premalignant, or if the disorder facilitates the development of oral mucosal squamous cell carcinoma (OMSCC) by external factors. The aim of the present study was to investigate the expression of c-erbB-2 protein in the keratinocytes of initial biopsies of oral mucosal disorders diagnosed as OMLP with no evidence of epithelial dysplasia. and to compare the results with the expression of c-erbB-2 protein in subsequent biopsies obtained from the same patients. These results were compared with the findings from control groups (patients with dysplasia with no evidence of OMLP, patients with OMSCC with no evidence of OMLP and normal oral mucosa). The expression of the c-erbB-2 protein was evaluated by immunohistochemical staining of the gene product with the avidin-biotin-complex method using paraffin-embedded tissue sections. Five of the initial biopsies from patients with OMLP expressed the c-erhB-2 protein and one did not. None of the OMLP cases that subsequently showed evidence of dysplasia expressed the c-erhB-2 protein, and of the three OMSCC specimens from the patients with OMLP. two were negative and one expressed c-erbB-2 protein. The specimens from the control groups all expressed the c-erhB-2 protein. The results indicated the probability of the absence of c-erbB-2 staining being an indication of a potential for neoplastic transformation in OMLP with dysplastic changes.  相似文献   
69.
70.
We have developed a guar wholemeal bread and tested its physiological efficacy and sensory qualities. The objective of the study was to estimate the optimum concentration of guar in bread required to reduce postprandial glycaemia and insulinaemia without adversely affecting the quality of the bread. Following overnight fasts, 15 normal weight, non-diabetic subjects consumed meals of wholemeal bread alone (controls) and supplemented with guar at three different concentrations (5, 10 and 15% replacement of wheat flour). Blood samples for glucose and insulin analysis were taken preprandially, and at 30 and 60 min after the start of each meal. The acceptability of the wholemeal control and guar breads was assessed using a hedonic scaling method. A significantly lower blood glucose rise at 30 min was found after the 15% guar bread meal compared to the control. Plasma insulin responses at 30 and 60 min were significantly lower after the 10 and 15% guar bread meals compared to the controls. Hedonic scores indicated that the subjects found the 5 and 10% guar breads acceptable and in the case of the 5% variety the mean score was identical to the control. We suggest that a guar concentration of between 5 and 10% replacement of wheat flour (wholemeal or white) should be used for the baking of guar wholemeal bread but further work is needed to define the precise quantity of guar required.  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