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   1700748篇
  免费   124257篇
  国内免费   3790篇
耳鼻咽喉   21764篇
儿科学   55849篇
妇产科学   46289篇
基础医学   241985篇
口腔科学   48818篇
临床医学   151904篇
内科学   334858篇
皮肤病学   38690篇
神经病学   131454篇
特种医学   64217篇
外国民族医学   242篇
外科学   258019篇
综合类   39064篇
现状与发展   4篇
一般理论   533篇
预防医学   124749篇
眼科学   40271篇
药学   124042篇
  7篇
中国医学   4484篇
肿瘤学   101552篇
  2021年   12867篇
  2019年   13617篇
  2018年   20037篇
  2017年   15282篇
  2016年   16675篇
  2015年   19040篇
  2014年   26333篇
  2013年   38114篇
  2012年   53007篇
  2011年   55686篇
  2010年   32919篇
  2009年   30832篇
  2008年   51760篇
  2007年   55032篇
  2006年   55505篇
  2005年   52780篇
  2004年   50975篇
  2003年   48383篇
  2002年   46636篇
  2001年   91982篇
  2000年   93778篇
  1999年   77085篇
  1998年   19781篇
  1997年   17336篇
  1996年   17453篇
  1995年   16795篇
  1994年   15333篇
  1993年   14118篇
  1992年   57489篇
  1991年   55386篇
  1990年   53066篇
  1989年   50852篇
  1988年   46228篇
  1987年   45048篇
  1986年   42306篇
  1985年   40073篇
  1984年   29435篇
  1983年   24957篇
  1982年   13943篇
  1979年   25588篇
  1978年   17629篇
  1977年   14954篇
  1976年   13924篇
  1975年   14611篇
  1974年   17696篇
  1973年   17004篇
  1972年   15714篇
  1971年   14485篇
  1970年   13471篇
  1969年   12543篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
The present study compared four different sites and conditions for the measurement of maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) in 38 spontaneous breathing tracheotomised patients. Of the patients, 28 had chronic obstructive pulmonary disease (COPD). The four different conditions were: 1) through a cuff inflated cannula (condition A); 2) through the mouth with a deflated cannula (condition B); 3) through the mouth with a phonetic uncuffed cannula (condition C); and 4) through the mouth after stoma closure (condition D). Five trials in each condition were performed using a standardised method. The measurement of both MIP and MEP differed significantly depending on the condition of measurement. MIP taken in condition A was significantly higher when compared with conditions B, C and D. MEP in condition A was significantly higher when compared with condition B and D. In condition A the highest frequency of the best measurement of MIP and MEP was observed at the fourth and fifth effort, respectively. The same results were obtained after the selection of only COPD patients. In conclusion, respiratory muscle assessment differs significantly depending on measurement condition. Measurement through inflated cannula tracheotomy yields higher values of both maximal inspiratory and maximal expiratory pressure.  相似文献   
32.
33.
背景/目的:从1978-2000年,有10对联体双胞胎成功接受了手术分离,结果14人存活。其中6对是因为他们的联体同胞死亡或濒临死亡而接受紧急分离手术。剩余的4对,每对至少一个同胞接受至少一次的急诊手术后,才接受联体分离手术。方法:对这一独特的队列进行包含6个项目的问卷调查。问题的设计是开放式的,为父母/家庭提供有关信息的最大机会。对每个家庭就相同的问题也进行了当面的问卷调查。医师询问了与身体健康和疾病相关的一些问题。而社会工作询问了与发育、教育、社会心理和家庭功能相关的问题。结果:前面提及的14人存活的双胞胎中,4人大学毕业,1人于1981年完成中学学业,剩余9人正在上学。14人在最初的手术后,还需要接受再次手术,尤其是需要矫正泌尿系统、畸形、神经外科和小儿外科的问题。结论:通过超声检查对联体双胎进行宫内诊断,可以使医师和胎儿父母在孕早期决定在终止妊娠时是进行双胎分离还是保全其中一个。这些病例报道通过描述14例手术存活的长期体格检查和心理学检查结果,为医师和父母在关键时刻做出决定提供了另外有助的依据。  相似文献   
34.
Summary: A female patient with isovaleric acidaemia had a successful outcome from pregnancy.  相似文献   
35.
36.
37.
38.
AIM: The innovations for disease management need to be thoroughly evaluated so that their benefits and potential downsides can be compared with the already existing approaches. Endovascular laser (EVL) treatment for varicose veins offers today several advantages over surgical standard stripping. The Italian Endovenous-laser Working Group (IEWG) is a homogeneous group of surgeons and phlebologists who have been using EVL since 1999 and has undertaken to examine EVL in a multicenter study starting from a well defined rationale, with the benefit of a single protocol to use. METHODS: In a cooperative, multicenter, clinical study, 1076 limbs in 1050 patients, mean age of 54.5 years, 241 males and 809 females affected by chronic venous insufficiency (CVI) were considered eligible for surgery and stratified by CEAP classification in a four-year period (January 1999 December 2003). Inclusion criteria were insufficiency of the great and/or small saphenous vein at various levels, beyond those accessory saphenous trunks with incompetence in the saphenofemoral junction. In all cases truncular reflux apparead up on duplex scan examination, with or without associated varicosities. All the patients underwent a surgery on the basis of the clinical assessment. All the centres involved performed treatment in conformity with the Food and Drug Administration (FDA) validated procedure, using an endo-laser venous system kit with a 810-980 nm diode. Duplex scan was performed in all patients after 36 months with very few lost to follow-up cases. RESULTS: In the immediate postoperative period the results have been impressive, with a very effective closure of incompetent great saphenous vein and the other treated varicose veins (the early occlusion rate has been 99%). Major complications have not been detected: in particular, no deep venous thrombosis (DVT) evaluated duplex ultrasound. The patients' acceptability and satisfaction regarding the procedure, have been measured by means of a questionnaire on the quality of life, and the result was 96.7%. After 36 months, the total occusion rate of saphenous trunks has been 97%. CONCLUSIONS: The first important Italian experience with EVL based on preoperative, perioperative and postoperative duplex control and which is also based on the patients' satisfaction at mid/long-term has indicated some advantages over the standard treatment with the stripping method. In terms of reduced postoperative pain, shorter sick leave, a faster resumption of the normal activities, and, in particular, the total absence of DVT, we can conclude that EVL is a good solution for all patients with anatomic and hemodinamic patterns for saphenous vein surgery.  相似文献   
39.

Background  

A public hospital in New Mexico required collection of 50% of estimated costs prior to elective surgeries for self-pay patients. This study assesses the impact of this policy on access to elective surgical procedures.  相似文献   
40.
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