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   60653篇
  免费   5412篇
  国内免费   1031篇
耳鼻咽喉   716篇
儿科学   1030篇
妇产科学   649篇
基础医学   5943篇
口腔科学   993篇
临床医学   7850篇
内科学   11962篇
皮肤病学   814篇
神经病学   3175篇
特种医学   747篇
外国民族医学   4篇
外科学   4088篇
综合类   7301篇
现状与发展   5篇
一般理论   23篇
预防医学   11635篇
眼科学   561篇
药学   4649篇
  58篇
中国医学   3759篇
肿瘤学   1134篇
  2024年   192篇
  2023年   1250篇
  2022年   1910篇
  2021年   2625篇
  2020年   2727篇
  2019年   2683篇
  2018年   2689篇
  2017年   2656篇
  2016年   2714篇
  2015年   2398篇
  2014年   4321篇
  2013年   6050篇
  2012年   3702篇
  2011年   3896篇
  2010年   3208篇
  2009年   2901篇
  2008年   2872篇
  2007年   2847篇
  2006年   2494篇
  2005年   1879篇
  2004年   1642篇
  2003年   1581篇
  2002年   1163篇
  2001年   1049篇
  2000年   835篇
  1999年   705篇
  1998年   522篇
  1997年   514篇
  1996年   373篇
  1995年   370篇
  1994年   329篇
  1993年   296篇
  1992年   247篇
  1991年   215篇
  1990年   189篇
  1989年   162篇
  1988年   120篇
  1987年   97篇
  1986年   45篇
  1985年   102篇
  1984年   87篇
  1983年   78篇
  1982年   78篇
  1981年   49篇
  1980年   65篇
  1979年   26篇
  1978年   38篇
  1977年   20篇
  1976年   21篇
  1974年   14篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
本文应用“冷沉淀”法制备纤维组织粘合剂。对纤维组织粘合剂中主要成份和含量进行了测定,并测定了主要理化性质,建立了动物实验模型,观察了实验兔对纤维粘合剂的反应。  相似文献   
42.
Abstract Essential fatty acid (FA) deficiency, which may accompany protein-energy malnutrition (PEM), has been associated with impaired inflammatory reactions. We evaluated this relationship by analysing FA profiles and delayed cutaneous hypersensitivity in 20 malnourished elderly non-cancer patients and in 20 age-matched control patients. As indicated by serum cholesterol and serum triglycerides, the lipid levels were decreased by about one-third in the subjects with PEM. In comparison with the controls, there was a reduction in the ω 3 FA (e.g. eicosapentanoate) in total serum lipids (mgl-1) and serum phospholipids (%) of 40% and 47%, respectively. Reductions in serum ω 6 FA (e.g. linoleate and arachidonate) levels corresponded to the drop in total FA concentrations (30%). The cutaneous hypersensitivity was impaired in 14 of the malnourished patients. The magnitude of the skin reaction was positively correlated ( P < 0·05) to the concentrations of eicosapentanoate in serum lipids and serum phospholipids, as well as to the linoleate concentration in total serum lipids. Six of the malnourished patients took part in a nutritional intervention programme for 3 months. In parallel with an improvement in the nutritional status there was a 35% increase ( P < 0·05) in the total ω 3 FA serum concentration. Negative skin tests became positive and the median skin induration enlarged threefold ( P < 0·05). Thus, deficiency of ω 3 FA might be one factor contributing to cutaneous anergy in elderly malnourished patients.  相似文献   
43.
Two hundred and thirty-five tenants living in sheltered housing in Scotland were surveyed to identify the extent of under-nutrition and the social factors which contribute to its development. A validated 24 h recall and the nutrient checklist published by NAGE were used to evaluate patterns of dietary intake. A questionnaire was developed which included scales designed to measure depression, social engagement, cognitive function, mobility and functional ability. The results show considerable evidence of a number of major nutrients in which there were low intakes. In order to express the extent of poor nutrition, a nutrient score was developed where points are awarded based on the number of nutrients falling below the Lower Reference Nutrient Intake, the Estimated Average Requirement or below half the daily Estimated Average Requirement.  相似文献   
44.
对28例青年人胃癌的临床及病理分析结果表明,其发病具有症状隐匿、病程短、进展快的特点,本组病例从出现症状到漏诊在6个月内为57.1%(16例),首发症状以上腹部疼痛、吐血、黑便多见,病理特征以结节蕈伞型、高分化腺癌多见。  相似文献   
45.
In a sample of 55 consecutive methadone maintenance admissions to our clinic, 42% were diagnosed with antisocial personality disorder (ASPD) using the National Institute of Mental Health Diagnostic Interview Schedule NIMH DIS. Individuals with ASPD exhibited greater risk for HIV infection as defined by more sexual contacts, needle use and equipment sharing. Data at 1 year follow-up were obtained on this group of patients. The objective was to compare the ASPD and non-ASPD groups with regards to demographics, drug abuse history, outcome and retention in treatment. There were no significant differences between the groups on any demographic or treatment outcome variables. Survival analysis indicated that there were no group differences in treatment retention. In conclusion, although there were no differences in treatment outcome between ASPD and non-ASPD groups it is possible that ASPD patients who drop out of treatment will be at higher risk for contracting and spreading HIV within the IV drug using population. These data also suggest that in this population the diagnosis of ASPD using primarily behavioral traits as measured in the NIMH-DIS-III, has little utility in predicting treatment outcome.  相似文献   
46.
Back pain among nurses is a common problem. Prior studies of this problem have been based on cross-sectional or retrospective data. This 18-month prospective study involving nurses newly graduated from nursing school investigated personal, worksite, and training factors associated with future risk of back pain. Each nurse underwent a preliminary interview and periodic follow-ups to identify those with back injuries. Contingency tables and logistic regression analyses demonstrated that prior significant back pain episodes (evidenced by previous job changes because of back pain, frequent medication use, etc.) were associated with increased future risk. Training at nursing school or on the job did not have a protective effect. This pilot study therefore suggests factors useful in placement and counseling of new nurses and indicates the need for further implementation of mechanical lift assist device use. © 1994 Wiley-Liss, Inc.  相似文献   
47.
崔玉中 《现代预防医学》2007,34(1):101-102,104
目的 为了解我市高中学生性心理发展及性教育状况。[方法] 对淄博市6所高中的高一学生进行了问卷调查,并对调查结果采用SPS统计软件进行卡方检验统计分析。[结果](1)男生和女生与异性交往的程度按所占比例高低依次为:一般朋友-约会-接吻;(2)有41%的男生表示爱上过异性,其中最小是在13岁;56%的女生表示爱上过异性,其中最小是在9岁,使爱上的异性成为自己恋人的男生有72%,女生占66.7%;(3)异性交往没有采取进一步行动的首要原因排在前5位的分别为:感情还没有到地步(17.1%),怕影响自己的前途(15.4%),我没有进一步欲望(8%),违背家庭的期望(7.95),不愿意勉强对方(6.85),[结论] 在高中阶段应加强性教育工作,指导学生与异性的正常交往.  相似文献   
48.
1‐Benzyl‐4‐hydroxy[2‐14C]piperidine, a useful intermediate in labeled compound synthesis, was prepared from [14C]formaldehyde in high yield. The distribution pattern of 14C in the product is consistent with a mechanism involving reversible iminium ion formation and rapid equilibration of the iminium ion through a cationic aza‐Cope rearrangement. These steps precede the rate‐determining intramolecular cyclization step. SCH 351125 is a potent, selective CCR5 receptor antagonist with potential as a treatment for HIV infection. [14C]SCH 351125, required for metabolism studies, was prepared from 1‐benzyl‐4‐hydroxy[2‐14C]piperidine in six steps. [14C]SCH 351125 is a mixture of four atropisomers. Preparation of [14C]SCH 351125 besylate salt of the desired atropisomer pair is also described. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   
49.
转型期的文学艺术总体格局出现了引人注目的变化 ,电视剧已成为百姓日常文化消费的主要对象 ;在艺术风格上呈现世俗化、平民化趋向的电视剧创作 ,同样要“代表先进文化的前进方向” ,这就要求创作者更新并优化观念。现代观念的涵义是丰富的 ,与时俱进的 ;一些电视剧的缺失都可以从中找到原因。而近几年涌现的一批在大众化、精品化方面取得重大进展的多种题材的电视剧 ,关键在于观念的突破带动了思想和艺术的创新  相似文献   
50.
中药泡洗治疗糖尿病足90例疗效分析   总被引:1,自引:0,他引:1  
目的为了观察中药泡洗对糖尿病足的疗效。方法对90例糖尿病足患者用中药(方剂组成:桃仁、红花、桂枝、没药、乳香、花椒、川芎等各10g)水煎制后分为2袋各300ml配合足浴仪泡洗,2次,d,30min/次,10d为1疗程。结果全组90例患者显效66例,有效24例,总有效率100%。结论中药泡洗治疗糖尿病足疗效确切。  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