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   2345篇
  免费   172篇
  国内免费   75篇
耳鼻咽喉   1篇
儿科学   174篇
妇产科学   27篇
基础医学   264篇
口腔科学   58篇
临床医学   311篇
内科学   621篇
皮肤病学   78篇
神经病学   96篇
特种医学   394篇
外科学   151篇
综合类   45篇
预防医学   133篇
眼科学   19篇
药学   91篇
  2篇
肿瘤学   127篇
  2023年   7篇
  2022年   8篇
  2021年   19篇
  2020年   16篇
  2019年   25篇
  2018年   41篇
  2017年   29篇
  2016年   34篇
  2015年   54篇
  2014年   70篇
  2013年   83篇
  2012年   60篇
  2011年   60篇
  2010年   101篇
  2009年   99篇
  2008年   70篇
  2007年   94篇
  2006年   65篇
  2005年   65篇
  2004年   39篇
  2003年   26篇
  2002年   40篇
  2001年   51篇
  2000年   41篇
  1999年   38篇
  1998年   131篇
  1997年   161篇
  1996年   134篇
  1995年   112篇
  1994年   116篇
  1993年   98篇
  1992年   38篇
  1991年   42篇
  1990年   47篇
  1989年   65篇
  1988年   52篇
  1987年   50篇
  1986年   51篇
  1985年   46篇
  1984年   26篇
  1983年   16篇
  1982年   25篇
  1981年   30篇
  1980年   25篇
  1979年   7篇
  1978年   10篇
  1977年   19篇
  1976年   25篇
  1975年   14篇
  1968年   4篇
排序方式: 共有2592条查询结果,搜索用时 93 毫秒
21.
22.
23.
Dumas  JM; Edde  DJ 《Radiology》1986,160(2):453-456
In a prospective study conducted over a 12-month period, 30 patients underwent double-contrast arthrography of the knee followed by arthroscopic study. An 80% correlation rate was found between results. Arthrography had a higher rate of accuracy (93%) than arthroscopy (84%) and had a 7% false-positive and 0% false-negative rate. A commonly overlooked arthrographic sign--the triple-S or stuck sail sign--was 91% accurate in the prediction of meniscal tears. The complementary nature of the two examinations is discussed.  相似文献   
24.
25.
26.
Patellofemoral joint: kinematic MR imaging to assess tracking abnormalities   总被引:4,自引:0,他引:4  
Shellock  FG; Mink  JH; Fox  JM 《Radiology》1988,168(2):551-553
The patellofemoral joint was imaged with magnetic resonance (MR) in the axial plane while the knee was positioned from 0 degrees to 32 degrees of flexion (nine positions). These multiple sequential images obtained within the early phases of flexion of the knee were viewed in a "cine-loop" format, producing a kinematic study that clearly demonstrated the relationship of the patella to the trochlear groove. Four healthy subjects and one patient with known bilateral subluxing patellae were studied. The preliminary results suggest that kinematic MR imaging of the patellofemoral joint is potentially useful for the evaluation of patellar tracking abnormalities.  相似文献   
27.
We report an instance of critical ovarian hyperstimulation syndrome in a highly responsive in-vitro fertilization patient despite the preventive measure of a 4 day 'coast' interval during which no gonadotrophins were administered while gonadotrophin-releasing hormone agonist therapy continued until serum oestradiol concentrations fell below 3000 pg/ml.   相似文献   
28.
BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a major health problem with an estimated prevalence of 10-15% among smokers. The incidence of moderate COPD, as defined by the Global Initiative for Chronic Obstructive Lung Disease (GOLD), is largely unknown. AIM: To determine the cumulative incidence of moderate COPD (forced expiratory volume in 1 second/forced vital capacity ratio [FEV1/FVC] <0.7 and FEV1 <80% predicted) and its association with patient characteristics in a cohort of male smokers. DESIGN: Prospective cohort study. SETTING: The city of IJsselstein, a small town in the Netherlands. METHOD: Smokers aged 40-65 years who were registered with local GPs, participated in a study to identify undetected COPD. Baseline measurements were taken in 1998 of 399 smokers with normal spirometry (n = 292) or mild COPD (FEV1/FVC <0.7 and FEV1 >or=80% predicted, n = 107) and follow-up measurements were conducted in 2003. RESULTS: After a mean follow-up of 5.2 years, 33 participants developed moderate COPD (GOLD II). This showed an estimated cumulative incidence of 8.3% (95% CI = 5.8 to 11.4) and a mean annual incidence of 1.6%. No participant developed severe airflow obstruction. The risk of developing moderate COPD in smokers with baseline mild COPD (GOLD I) was five times higher than in those with baseline normal spirometry (one in five versus one in 25). CONCLUSIONS: In a cohort of middle-aged male smokers, the estimated cumulative incidence of moderate COPD (GOLD II) over 5 years was relatively high (8.3%). Age, childhood smoking, cough, and one or more GP contacts for lower respiratory tract problems were independently associated with incident moderate COPD.  相似文献   
29.
30.
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