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   337908篇
  免费   22328篇
  国内免费   7381篇
耳鼻咽喉   4068篇
儿科学   9561篇
妇产科学   6618篇
基础医学   27449篇
口腔科学   7954篇
临床医学   37182篇
内科学   42409篇
皮肤病学   4574篇
神经病学   19304篇
特种医学   7851篇
外国民族医学   31篇
外科学   36373篇
综合类   50402篇
现状与发展   12篇
一般理论   29篇
预防医学   34383篇
眼科学   5270篇
药学   29957篇
  371篇
中国医学   30396篇
肿瘤学   13423篇
  2023年   5249篇
  2022年   9021篇
  2021年   13075篇
  2020年   12142篇
  2019年   18161篇
  2018年   15872篇
  2017年   12678篇
  2016年   10137篇
  2015年   9464篇
  2014年   19598篇
  2013年   21121篇
  2012年   18024篇
  2011年   19500篇
  2010年   15677篇
  2009年   14371篇
  2008年   14006篇
  2007年   14489篇
  2006年   12636篇
  2005年   10985篇
  2004年   8943篇
  2003年   7869篇
  2002年   6145篇
  2001年   5541篇
  2000年   4579篇
  1999年   3984篇
  1998年   3226篇
  1997年   3085篇
  1996年   2672篇
  1995年   2571篇
  1994年   2477篇
  1993年   1973篇
  1992年   2004篇
  1991年   1728篇
  1990年   1541篇
  1989年   1370篇
  1988年   1302篇
  1987年   1120篇
  1985年   3831篇
  1984年   4842篇
  1983年   3387篇
  1982年   3851篇
  1981年   3582篇
  1980年   3193篇
  1979年   2949篇
  1978年   2568篇
  1977年   1927篇
  1976年   2181篇
  1975年   1656篇
  1974年   1459篇
  1973年   1296篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
The paper gives an overview of today's knowledge of urinary tract infection in pregnancy and different treatment procedures. Three different studies of urinary tract infection (UTI) in pregnancy and the postpartum period are reported. Urinary screening of 1798 pregnant women showed a cumulative frequency of bacteriuria of 4.8%, recurrent infection in one-fifth of the cases, and pyelonephritis in 0.6%. Chlamydial infection was observed as a cause of dysuria in pregnancy. In the postpartum period bladder bacteriuria was demonstrated in 3.7%. The condition persisted in 27%, while short-course treatment had significant effect.Presented at the Zambon Symposium on Bacteriuria in Pregnancy, International Urogynecological Association Annual Meeting, Riva del Garda, Italy, September 13, 1989.  相似文献   
992.
Up to now, few analytical models have studied the incentives for cooperation in quality improvements among hospitals. Only those dealing with reimbursement systems have shown that, from the point of view of individual or competing hospitals, retrospective reimbursement is more likely to encourage quality improvements than prospective financing, while the reverse holds for efficiency improvements. This paper studies the incentives to improve the quality of hospital care, in an analytical model, taking into account the possibility of cooperative agreements, price besides non-price (quality) competition and quality improvements that may simultaneously increase demand, increase or reduce costs and spill over to rival hospitals. In this setting quality improvement efforts rise with the rate of prospective reimbursement, while the impact of the rate of retrospective reimbursement is ambiguous, but likely to be negative for quality improvements that are highly cost-reducting and create large spillovers. Cooperation may lead to more or less quality improvement than non-cooperative conduct, depending on the magnitude of spillovers and the degree of product market competition, relative to the net effect of quality on profits and the share of costs that is reimbursed retrospectively. Finally, the stability of cooperative agreements, supported by grim trigger strategies, is shown to depend upon exactly the opposite interaction between these factors.  相似文献   
993.
We report satisfactory results with a new operative treatment, conducted via an extensive anterolateral approach, involving 360 degree circumferential capsulotomy, for residual subluxation in congenital dislocation of the hip (CDH). Long-term radiographic results of this procedure (group A) were compared retrospectively with the results of partial capsulotomy (group B), which preserved the posteroinferior joint capsule. The mean center edge angle in group A (22.5°) was greater than that in group B (16.0°). Satisfactory results were achieved in 11 of 15 hips (73%) (Severin class I or II) in group A, and in 5 of 12 hips (42%) in group B. These results suggest that whole circumferential capsulotomy can remove obstacles to complete reduction, and that acetabular development can be expected in hips reduced by the procedure, without the performance of innominate osteotomy. We believe that our technique is a useful alternative for the treatment of residual subluxation in CDH.  相似文献   
994.
Medical students are allocated little curriculum time for exposure to expert systems. ESTA, a computer model of an expert system, was developed to make best use of this time. The nature of the students' interaction with ESTA is described, and their reactions to the expert system concepts and the place of expert systems in medicine are presented. A discussion of these reactions draws some conclusions about teaching expert systems in particular, and computers in general, in the basic medical course.  相似文献   
995.
A structured clinical examination has been an integral component of the final-year examinations conducted by the Departments of Medicine and Surgery at the University of Adelaide for the last 8 years. It has been used as an alternative to the traditional clinical examination. This paper describes the results of ongoing student and examiner surveys carried out to determine their views and satisfaction with this new approach. It also briefly discusses the feasibility of introducing such an examination into a conventional medical school environment. The surveys showed a remarkable level of acceptance and support by both students and examiners. This positive reaction has been maintained over the 8-year period. The main reasons seem to be its perceived relevance and fairness. Students also appear to be directing their learning in a direction thought desirable by teachers. No significant problems have been encountered with the practical implementation of the method.  相似文献   
996.
200例择期胆囊切除+术中胆道造影患者分二组;芬太尼17ug/kg静注(F组,n=100)、哌替啶1mg/kg静注。评价两种麻醉性镇痛药致Oddi括约肌痉挛的发生率,结果:8例病人造影剂不能通过Oddi括约肌、十二指肠不显影,胆总管下端显示“鸟嘴样”或“假结石”影像,后者3例病人胆总管探查阴性,静注纳络酮0.4mg后,全部病例造影剂顺利进入十二指肠。结论:硬膜外麻醉辅用小剂量芬太尼/哌替啶时Odd  相似文献   
997.
芸香甙对大鼠内囊血肿的治疗作用   总被引:2,自引:0,他引:2  
芸香甙是黄酮类化合物,就其对大鼠内囊血肿的保护作用进行了初步研究。在内囊血肿大鼠模型上,芸香甙50、100mg.kg^-1可以明显改善大鼠的神经症状,降低神经症状和评分;芸香甙显著降低脑组织的丙二醛含量和提高超氧化物歧化酶的活性。  相似文献   
998.
报告5例对胰岛素抵抗的糖尿病特殊类型病例,其均具有胰岛素应用指征,但使用胰岛素后血糖却反而上升,逐渐增加胰岛素用量,则血糖值亦呈上升趋势。对该类病人的治疗,首先停用胰岛素,改用自制中药制剂及优降糖、降糖灵治疗,取得了良好效果。  相似文献   
999.
This paper reports an attempt to develop self-directed learning skills in second-year medical students by introducing case-based projects into the gross anatomy course at a long-established medical school. The programme and students' responses to a questionnaire completed at the end of the year are presented. Information on the various resources used by students to find information is given. The performance of students in the case-based components of the course has been evaluated and also in the more traditional end-of-year written examination. The data confirm that students have recognized that the projects were about obtaining a deeper understanding of the anatomy, and the programme appears to have promoted the use and study of library texts.  相似文献   
1000.
Polyclonal antibodies recognizing the pyridyloxobutyl (POB) moiety of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) were produced in rabbits immunized either with POB-bovine albumin or POB-Sepharose. The POB intermediates necessary to modify the protein were generated by alkaline (pH 9.0) treatment of the synthetic precursor 4-(carbethoxynitrosamino)-1-(3-pyridyl)-1-butanone. In a competitive enzyme linked immunoabsorbent assay (ELISA), 70 pmole NNK inhibited 50% of the binding of the anti-POB antibodies to POB-protein absorbed on microtiterplates. This 50% inhibition varied from 70 pmole to 200 nmole using a series of NNK analogues, depending on the integrity of the POB moiety. Immunological techniques initiated in this study detect NNK-protein conjugates or measure the quantity of POB groups liberated upon alkaline or acid treatment of NNK modified protein.  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