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   1466631篇
  免费   101177篇
  国内免费   4318篇
耳鼻咽喉   21065篇
儿科学   48017篇
妇产科学   41994篇
基础医学   222399篇
口腔科学   39160篇
临床医学   135384篇
内科学   284232篇
皮肤病学   32348篇
神经病学   120933篇
特种医学   53825篇
外国民族医学   366篇
外科学   204710篇
综合类   29209篇
现状与发展   1篇
一般理论   464篇
预防医学   118786篇
眼科学   34236篇
药学   103193篇
  6篇
中国医学   3242篇
肿瘤学   78556篇
  2019年   11671篇
  2018年   16491篇
  2017年   12457篇
  2016年   13486篇
  2015年   18323篇
  2014年   24493篇
  2013年   36851篇
  2012年   47809篇
  2011年   50268篇
  2010年   30801篇
  2009年   28701篇
  2008年   46392篇
  2007年   48590篇
  2006年   49100篇
  2005年   47043篇
  2004年   44744篇
  2003年   41156篇
  2002年   38757篇
  2001年   61578篇
  2000年   63216篇
  1999年   53137篇
  1998年   15638篇
  1997年   14336篇
  1996年   14514篇
  1995年   13998篇
  1994年   13181篇
  1993年   12411篇
  1992年   43159篇
  1991年   42125篇
  1990年   40680篇
  1989年   38466篇
  1988年   35633篇
  1987年   34792篇
  1986年   33180篇
  1985年   31497篇
  1984年   24006篇
  1983年   20376篇
  1982年   12741篇
  1981年   11194篇
  1979年   21707篇
  1978年   15841篇
  1977年   12857篇
  1976年   12546篇
  1975年   12903篇
  1974年   15603篇
  1973年   15315篇
  1972年   14055篇
  1971年   13058篇
  1970年   12056篇
  1969年   11143篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
Psychometric data are presented which examine the validity of using the concentration of benzoylecgonine in urine, a major metabolite of cocaine, as a measure of drug use, in studies of drug abuse treatments. In such research the standard biological indicator of drug use is usually a qualitative urine drug test, which merely indicates the presence or absence of a drug or its metabolite. A quantitative (i.e. continuous) outcome measure, such as the concentration of a drug or its metabolite in a biological fluid, has substantially more statistical power than a dichotomous measure and should, therefore, prove a more sensitive measure of drug use when viewed from a measurement perspective. Data from two placebo-controlled clinical trials of fluoxetine as an adjunct to treatment for cocaine abuse are analyzed to address this issue. Results indicate that urine benzoylecgonine level is closely related to self-reports of drug use and is independent of levels of anxiety, depression and hopelessness.  相似文献   
142.
The objectives of this study were to investigate (1) changes in consumption of alcohol among pregnant women over a period of 5 years (1984/85–1990), (2) changes of attitudes towards drinking during pregnancy in the general population over the same period of time, and (3) possible connections between (1) and (2). The investigation was designed as a cross-sectional study. Our subjects were two representative samples of pregnant women in Oslo, n = 577 and 425, and two representative samples of the Norwegian population, n = 1004 and 1204. The main outcome measures were a self-completed questionnaire for the pregnant women and a personal interview for the general population sample. There was a significant reduction (50% decrease) in alcohol consumption among the second cohort of pregnant women compared with the first. Furthermore, we found an increase during the 5-year period in the number of persons with a restrictive attitude towards alcohol use during pregnancy. There seems to be a connection between these two phenomena, but with our present state of knowledge it is hard to say anything about the causal relationship between them.  相似文献   
143.
Results of arthroscopic acromioplasty related to rotator cuff lesions   总被引:1,自引:1,他引:0  
Summary Seventy-nine patients with a history of the subacromial impingement syndrome were treated by arthroscopic acromioplasty. The results were evaluated with a new scoring system designed to assess subjective symptoms before and after operation. The outcome was related to the pathological lesions of the rotator cuff seen at arthroscopy and graded by our modification of the Neer classification. The overall results were satisfactory in 67%, with men having better results than women. Those with a history of injury did better than those without, and the results in those with partial or total cuff tears were better than those with intact cuffs. Since the state of the cuff affects the result, arthroscopy should precede acromioplasty.
Résumé Soixante dix-neuf patients, présentant depuis 3.5 ans (±1.8) un syndrome de conflit sousacromial, ont été traités par acromioplastie arthroscopique. Les résultats ont été évalués au moyen d'une nouvelle cotation, mesurant la symptomatologie subjective avant et 17 mois en moyenne après l'intervention chirurgicale. On a étudié le rapport entre ces résultats et la morphologie pathologique de la coiffe des rotateurs, constatée lors de l'arthroscopie et classée conformément à notre version modifiée, décrite précédemment, de la classification de Neer. Les résultats globaux étaient satisfaisants dans 67% des cas. Les résultats étaient nettement meilleurs chez les hommes que chez les femmes. Ils étaient significativement meilleurs chez les patients pour qui la symptomatologie était apparue après un traumatisme violent, de même lorsqu'il existait une rupture totale ou partielle de la coiffe des rotateurs. L'état de la coiffe influence les résultats de l'acromioplastie, pour pouvoir le déterminer il faut pratiquer une arthroscopie préalable.
  相似文献   
144.
The synopsis of neurogenic lower urinary tract dysfunctions aims to be practical and tries to give some simple algorithms to the physician to help his understanding of the pathophysiology and to guide him towards an easy, functional, preventive and chronological exploration and treatment.  相似文献   
145.
A study was carried out in order to document any abnormalities in the electro-encephalogram (EEG) that might appear in young adolescents who have deliberately inhaled the range of volatile substances loosely referred to as 'glue'. The EEGs of a group of 'street children' being assisted in a Johannesburg shelter were examined. The records were analysed for any clinical abnormalities and also subjected to spectral analysis in order to examine the overall characteristics of frequency, power and spatial distribution. The EEGs clearly revealed that, although at the time of the examination the subjects were ostensibly abstinent, both clinical and normative evidence of continuing brain disturbance was present. It was concluded that glue sniffing is likely to have long term electrocerebral sequelae.  相似文献   
146.
The results of the in vitro fertilisation programme at Tygerberg Hospital for the period April 1983 to January 1988 are presented. Of the 1117 laparoscopies performed, 825 patients reached the transfer stage. A live-birth rate of 9.3% was achieved. The pregnancy rate after transfer of 4 embryos was 25.9% compared with 15.4% after 2 embryos and 10.8% after 3 embryos (P = less than 0.0001). The multiple pregnancy rate was 2.8% in the group receiving 2 embryos and 11.7% and 10.4% in those receiving 3 and 4 embryos, respectively. Of the 77 successful pregnancies (90 babies), 1 baby died at 34 weeks' gestation as the result of abruptio placentae due to preeclampsia and 1 cot death occurred. The only congenital abnormality encountered was a cleft palate.  相似文献   
147.
Nine hundred and three patients undergoing diagnostic peritoneal lavage (DPL) over a 6-year period were retrospectively reviewed to evaluate the utility of the white blood cell (WBC) count in the lavage fluid. Eleven patients (1.2%) had dialysate WBC counts greater than 500/mm3, with erythrocyte counts less than 10(5)/mm3. Nine of these patients who were lavaged within 4 hours of injury had no intra-abdominal pathology. Two patients, lavaged after 4 hours, demonstrated intra-abdominal injury. Two hundred twenty-three patients (24.7%) had grossly clear dialysate which was not sent for laboratory analysis. None of these patients required laparotomy. We conclude that the WBC count in DPL fluid is of no diagnostic value in victims of blunt abdominal trauma who are lavaged within 4 hours of injury. In addition, laboratory analysis of clear dialysate is not required in these patients.  相似文献   
148.
We report a case of recurrent calculi in a Kock pouch continent urinary diversion. An open operation was avoided by successfully excising the Marlex mesh and removing it with the associated calculi in an endoscopic fashion.  相似文献   
149.
150.
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