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   1284247篇
  免费   100554篇
  国内免费   2026篇
耳鼻咽喉   18513篇
儿科学   44610篇
妇产科学   35198篇
基础医学   183334篇
口腔科学   33800篇
临床医学   111894篇
内科学   259854篇
皮肤病学   28214篇
神经病学   101154篇
特种医学   51441篇
外国民族医学   660篇
外科学   197431篇
综合类   27089篇
现状与发展   1篇
一般理论   378篇
预防医学   96328篇
眼科学   28023篇
药学   95287篇
  2篇
中国医学   2439篇
肿瘤学   71177篇
  2018年   13390篇
  2017年   10129篇
  2016年   11092篇
  2015年   12575篇
  2014年   17429篇
  2013年   26567篇
  2012年   36477篇
  2011年   38516篇
  2010年   23074篇
  2009年   22030篇
  2008年   36991篇
  2007年   39620篇
  2006年   39887篇
  2005年   38792篇
  2004年   37915篇
  2003年   36698篇
  2002年   36064篇
  2001年   64225篇
  2000年   66702篇
  1999年   56591篇
  1998年   15206篇
  1997年   13831篇
  1996年   14261篇
  1995年   13523篇
  1994年   12822篇
  1993年   11828篇
  1992年   44698篇
  1991年   43591篇
  1990年   42345篇
  1989年   40237篇
  1988年   37014篇
  1987年   36323篇
  1986年   33704篇
  1985年   32363篇
  1984年   24209篇
  1983年   20317篇
  1982年   11758篇
  1981年   10718篇
  1980年   9543篇
  1979年   21386篇
  1978年   14845篇
  1977年   12559篇
  1976年   11718篇
  1975年   12646篇
  1974年   14695篇
  1973年   14149篇
  1972年   12963篇
  1971年   11752篇
  1970年   11068篇
  1969年   10046篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
901.
902.
903.
AIMS: Screening for diabetic retinopathy (DR) is highly inadequate in France because of insufficient infrastructure and increasing disease prevalence. We describe the results of the first systematic DR screening programme established in a university diabetes department. METHODS: In this cross-sectional study conducted over 1 year, consecutive adult patients underwent three-field retinal photography with the Topcon TRC NW6S digital fundus camera following pupillary dilatation with Tropicamide 1%. A questionnaire provided information on patients' systemic and ocular history. Glycated haemoglobin (HbA1c) was measured at the screening visit.Two ophthalmologists graded the retinal photographs in a masked fashion. RESULTS: Of 1157 patients attending the diabetes department, 1153 (99.7%)underwent photographic screening. Images were gradable in 96% patients.Diabetic retinopathy was detected in 522 (45%) patients and sight-threatening DR in 167 (14%). Of 704 (61%) patients previously believed to have no DR,254 (34%) screened positive. The presence of DR was associated with age,insulin use and non-Caucasian ethnicity in Type 2 patients, and with duration of diabetes and HbA1c in Type 1 and Type 2 patients. Associated ocular pathologies were diagnosed in 612 (53%) patients. CONCLUSIONS: Our photographic screening programme using pharmacological mydriasis provided a high screening coverage feasible in a hospital setting. We obtained information regarding prevalence and associated risk factors of DR inpatients attending a tertiary care centre. Screening was well accepted by patients and met with no protest from city ophthalmologists. It generated considerable interest among endocrinologists and feedback of results is expected to improve optimization of glycaemic control.  相似文献   
904.
905.
OBJECTIVE: The authors examined whether physicians' use of computerized decision aids affects patient satisfaction and/or blame for medical outcomes. METHOD: Experiment 1: Fifty-nine undergraduates read about a doctor who made either a correct or incorrect diagnosis and either used a decision aid or did not. All rated the quality of the doctor's decision and the likelihood of recommending the doctor. Those receiving a negative outcome also rated negligence and likelihood of suing. Experiment 2: One hundred sixty-six medical students and 154 undergraduates read negative-outcome scenarios in which a doctor either agreed with the aid, heeded the aid against his own opinion, defied the aid in favor of his own opinion, or did not use a decision aid. Subjects rated doctor fault and competence and the appropriateness of using decision aids in medicine. Medical students made judgments for themselves and for a layperson. RESULTS: Experiment 1: Using a decision aid caused a positive outcome to be rated less positively and a negative outcome to be rated less negatively. Experiment 2: Agreeing with or heeding the aid was associated with reduced fault, whereas defying the aid was associated with roughly the same fault as not using one at all. Medical students were less harsh than undergraduates but accurately predicted undergraduate's responses. CONCLUSION: Agreeing with or heeding a decision aid, but not defying it, may reduce liability after an error. However, using an aid may reduce favorability after a positive outcome.  相似文献   
906.
907.
A school microepidemic of tuberculosis.   总被引:1,自引:1,他引:0       下载免费PDF全文
C P Bredin  M Godfrey    J McKiernan 《Thorax》1991,46(12):922-923
BACKGROUND: Microepidemics of tuberculosis continue to occur in countries with a low incidence of tuberculosis. METHODS AND RESULTS: A microepidemic of tuberculosis in a secondary school with 604 girls in Cork city, Ireland, in 1986 with follow up to 1990 is described. Neonatal BCG vaccination was discontinued in the city in December 1972 so most of the 342 pupils who had received BCG were aged 14 years or more. Six active cases and 75 tuberculin positive cases were found. Four of the six girls with active disease had had neonatal BCG. The 75 pupils with a positive (grade 3 or 4) Heaf test response were given chemoprophylaxis with rifampicin and isoniazid for six months; none had developed active tuberculosis four years later. The brother of the girl who was the probable index case, however, developed active tuberculosis in 1988 despite similar chemoprophylaxis. CONCLUSION: The episode highlights the fact that children who have had neonatal BCG can develop active tuberculosis as teenagers.  相似文献   
908.
909.
910.
OBJECTIVES: Most obstetric clinics have a program for the identification of small-for-gestational age (SGA) fetuses because of the increased risk of fetal complications that they present. We have a structured model for the identification and follow-up of SGA pregnancies. We aimed to determine whether the recognition of SGA antepartum improves fetal outcome. METHODS: All pregnancies at Malm? University Hospital from 1990 to 1998 (n = 26 968) were reviewed. SGA fetuses identified prior to delivery (n = 681) were compared with those not identified (n = 573). Also, all pregnancies with SGA fetuses were compared with those appropriate-for-gestational age (AGA) (n = 24 585). The risk of serious fetal complications (hypoxic encephalopathy grade 2 or 3, intracranial hemorrhage, Apgar score <4 at 5 min, neonatal convulsions, umbilical pH <7.0, cerebral palsy, mental retardation, stillbirth, intrapartum or infant death) was assessed with cross-tabulation and logistic regression analysis, adjusted for gestational age and degree of SGA. RESULTS: When compared with SGA fetuses identified before delivery (54%), SGA fetuses not identified before delivery were characterized by a four-fold increased risk of adverse fetal outcome (odds ratio, 4.1; 95% CI, 2.5-6.8). Similarly, compared with AGA fetuses, SGA fetuses were associated with a four-fold increased risk of serious fetal complications. CONCLUSIONS: A structured antenatal surveillance program for fetuses identified as SGA results in a lower risk of adverse fetal outcome, compared with cases of SGA fetuses not identified antepartum.  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