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   410185篇
  免费   69297篇
  国内免费   23216篇
耳鼻咽喉   4551篇
儿科学   7937篇
妇产科学   5935篇
基础医学   56389篇
口腔科学   11098篇
临床医学   58316篇
内科学   73725篇
皮肤病学   10434篇
神经病学   31366篇
特种医学   14461篇
外国民族医学   215篇
外科学   47765篇
综合类   51020篇
现状与发展   77篇
一般理论   47篇
预防医学   24963篇
眼科学   11083篇
药学   39084篇
  341篇
中国医学   18658篇
肿瘤学   35233篇
  2024年   1024篇
  2023年   5161篇
  2022年   13368篇
  2021年   17965篇
  2020年   16979篇
  2019年   21199篇
  2018年   21214篇
  2017年   20952篇
  2016年   20964篇
  2015年   25938篇
  2014年   29417篇
  2013年   27459篇
  2012年   27514篇
  2011年   30473篇
  2010年   24848篇
  2009年   17645篇
  2008年   19652篇
  2007年   18557篇
  2006年   18593篇
  2005年   18066篇
  2004年   11888篇
  2003年   10905篇
  2002年   9686篇
  2001年   8620篇
  2000年   9358篇
  1999年   9659篇
  1998年   5681篇
  1997年   5677篇
  1996年   4491篇
  1995年   4064篇
  1994年   3367篇
  1993年   2231篇
  1992年   3033篇
  1991年   2657篇
  1990年   2362篇
  1989年   2096篇
  1988年   1752篇
  1987年   1528篇
  1986年   1273篇
  1985年   1067篇
  1984年   643篇
  1983年   479篇
  1982年   314篇
  1981年   309篇
  1980年   258篇
  1979年   339篇
  1978年   169篇
  1977年   168篇
  1974年   166篇
  1972年   148篇
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
31.
人体蠕形螨的生物学研究   总被引:4,自引:0,他引:4  
用透明胶带法观察蠕形螨在人体面部的寄生、逸出及其在体外的存活能力。结果表明:毛囊蠕形螨(Demod-exfoliculorum,D.f.)主要以颚体朝向毛囊底部寄生,且常常有多条群居现象,而皮脂蠕形螨,(Demodexbrevis,D.b.)一般为单条独居生活。两种人体蠕形螨昼夜均可主动爬出毛囊口出现在皮肤表面,D.f.以白天1000~1800为逸出高峰;D.b.则以夜间2200~200逸出最多。此外,蠕形螨在体外有较强的活动力和存活力。透明胶带法在人体蠕形螨的流行病学调查和生物学研究方面具有较高的应用价值  相似文献   
32.
33.
As an adjunct to a European multicentre prospective study, five quality assessment (QA) exercises, spanning a period of 2.5 years, were undertaken. In these, fifteen laboratories from eight countries each performed ten haemostatic factor assays. The design of the QA exercises allowed the between-duplicate, between-day and between-laboratory coefficients of variation (CVs) to be calculated. The between-duplicate CV decreased by a factor of one quarter, and the between-day CV by a factor of one third, over the five exercises. The activated partial thromboplastin time (APTT) assay consistently showed the lowest CVs, while there was notable improvement in the between-day CVs for von Willebrand factor related antigen (vWF R:Ag) and factor VIII clotting activity (VIII:C). However, the between-laboratory CV, assessing extent of agreement between the different laboratories, did not apparently improve over the five exercises. Thus, while QA exercises may be very useful in improving the performance of haemostatic assays according to criteria which an individual laboratory can assess, improving agreement on haemostatic assay results between laboratories may be more difficult to achieve.  相似文献   
34.
35.
The purpose of this study was to evaluate a new fluorescence polarization immunoassay, TDx, for digitoxin by comparing the results of this assay with those of a radioimmunoassay (RIA). Thirty-three serum samples were obtained from 15 patients during, and for 4 weeks after, a 4-week course of digitoxin therapy. Each sample was separated by centrifugation, coded, and frozen until analysis. At the time of analysis, each sample was divided and analyzed simultaneously by TDx and RIA. Nine samples yielded results less than 2 ng/ml (limit of assay sensitivity) by one or both methods and were excluded from further data analysis. Linear regression analysis of the results of the remaining 24 paired samples (x = TDx, y = RIA) revealed a strong correlation coefficient of r2 = 0.95, slope = 0.95, and a y intercept of -0.99 (y = -0.99 + 0.95x). Additionally, the TDx results were lower than the RIA values in only five of 33 paired samples; and these occurred in four patients who had a significantly lower mean estimated creatinine clearance than that of the other 11 patients (39.0 +/- 9.1 ml/min/1.73 m2 vs. 63.3 +/- 11.8 ml/min/1.73 m2, p less than 0.01). The TDx system is a comparable alternative to the RIA method, but differences in specificity and sensitivity may exist and should be evaluated more thoroughly.  相似文献   
36.
Intravenous administration of human bone marrow stromal cells (hMSCs) after middle cerebral artery occlusion (MCAo) in rats provides functional benefit. We tested the hypothesis that these functional benefits are derived in part from hMSC production of growth and trophic factors. Quantitative sandwich enzyme‐linked immunosorbent assay (ELISA) of hMSCs cultured with normal and MCAo brain extracts were performed. hMSCs cultured in supernatant derived from ischemic brain extracts increased production of brain‐derived neurotrophic factor (BDNF), nerve growth factor (NGF), vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF). These neurotrophins and angiogenic growth factors increased in a post‐ischemia time‐dependent manner. The hMSC capacity to increase expression of growth and trophic factors may be the key to the benefit provided by transplanted hMSCs in the ischemic brain.  相似文献   
37.
OBJECTIVE: To investigate the characteristics of the early stage treponema pallidum infected tissue in ear, nose, oropharynx and larynx and to raise relevance ratio of syphilis in nose and oropharynx and enhance doctor's self-protection awareness. METHODS: The histopathologic characteristics were studied by using HE staining, Warthin-Starry (W-S) staining was adopted to examine the treponema pallidum(TP) in lesion issue and its exudates smear for 12 cases biopsy tissues of suspicious syphilis. The diagnosis was confirmed by venereal disease research laboratory (VDRL), rapid plasma reagin circle test(RPR), treponema pallidum hemagglutination test(TPHA) and fluorescent treponemal antibody-absorption test (FTA-ABS). Treat with curing syphilis methods which published by nation. RESULTS: In the 12 cases mucous membrane specimen, the squamous epithelium proliferated, neutrophilic granulocyte infiltrated, within inherent membrane generous plasmacyte and lymphocyte infiltrated. W-S staining: plenty of treponema pallidum were found inside mucous membrane epithelium and exudate smear. Serology examination: 11 cases VDRL(++++), 7 cases RPR (+), 11 cases TPHA(+), 1 case FTA-ABS(+). After systemic treatment, 11 cases are clinically recovered. All patients serology become negative. CONCLUSION: W-S staining method can directly demonstrate histopathologic characteristics in early syphilis, in intrinsic membrane numerous plasmacyte infiltration. Combining with specific syphilis serology examination could increase diagnosis rate of syphilis in nose and oropharynx.  相似文献   
38.
Dry skin (xerosis) is a common dermatosis affecting people of varying skin types and ages and various areas of the body. It is associated with both skin thickening and skin thinning and is triggered by both exogenous (e.g. climate, environment, lifestyle) and endogenous (e.g. medication, hormone fluctuations, organ diseases) factors. Skin requires a water content of 10–15% to remain supple and intact. This water is either ‘static’ (i.e. bound) or ‘dynamic’. The predominance of hydrophobic substances in intercellular constituents is a means of regulating the humidity of the skin. Emollients, highly effective treatment adjuncts in the management of all dry skin disorders, help to restore damaged intercorneocyte lipid structures and increase the water content of the skin, helping to reduce scaling and improving its barrier function.  相似文献   
39.
40.
王翠玲 《护理研究》2006,20(11):1016-1017
质量管理是医院生存和发展的战略战术。质量就是生命,质量就是效益,21世纪护理质量的起步要求是护理质量管理者应在缺陷预防和质量持续改进方面做出尝试,护理管理者应在推行精细化管理,强化护理过程控制方面做出努力,以满足广大病人的健康服务需求。1质量发展及其概念1.1护理质量管理的发展阶段美国护理质量管理大体经历了3个历史性发展阶段:20世纪70年代“质量控制阶段”,20世纪80年代“质量保证阶段”,20世纪90年代“质量促进阶段”。质量控制阶段的主要特点:①由质量管理人员发现已出现的质量问题,然后做出处理;②技师评价方式为依照标准…  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