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   5162篇
  免费   434篇
  国内免费   17篇
耳鼻咽喉   17篇
儿科学   168篇
妇产科学   76篇
基础医学   635篇
口腔科学   196篇
临床医学   574篇
内科学   1045篇
皮肤病学   56篇
神经病学   517篇
特种医学   242篇
外科学   433篇
综合类   229篇
一般理论   3篇
预防医学   616篇
眼科学   59篇
药学   438篇
中国医学   1篇
肿瘤学   308篇
  2022年   40篇
  2021年   74篇
  2020年   43篇
  2019年   72篇
  2018年   78篇
  2017年   60篇
  2016年   70篇
  2015年   81篇
  2014年   118篇
  2013年   157篇
  2012年   273篇
  2011年   237篇
  2010年   158篇
  2009年   170篇
  2008年   254篇
  2007年   218篇
  2006年   181篇
  2005年   203篇
  2004年   174篇
  2003年   173篇
  2002年   208篇
  2001年   156篇
  2000年   170篇
  1999年   141篇
  1998年   94篇
  1997年   79篇
  1996年   72篇
  1995年   56篇
  1994年   57篇
  1993年   56篇
  1992年   111篇
  1991年   98篇
  1990年   108篇
  1989年   91篇
  1988年   98篇
  1987年   99篇
  1986年   102篇
  1985年   88篇
  1984年   63篇
  1983年   61篇
  1982年   58篇
  1981年   42篇
  1980年   36篇
  1979年   55篇
  1978年   54篇
  1977年   36篇
  1976年   38篇
  1974年   41篇
  1970年   42篇
  1968年   41篇
排序方式: 共有5613条查询结果,搜索用时 15 毫秒
1.
ABSTRACT

Measuring hope reliably and accurately remains an important research objective, not least in less prosperous settings where ‘holding on to hope’ may be critically important in the struggle against adverse life conditions. The State Hope Scale was designed for use in the US. Despite reported application in diverse cultures and using translations the scale has not been extensively validated outside US populations. This study contributes to a larger project exploring the measurement of hope and provides a critique of Snyder’s scale as used in a Tanzanian female population of 1021 urban microfinance participants. We evaluate the scale’s validity through assessment of the empirical distribution of scores, item response profiles, internal consistency and discriminatory ability. Participants mostly scored very high and many reached very near the maximum attainable score. Hardly any endorsed the negative half of the response scale. Several problems are discussed including poor discrimination and strong evidence of acquiescence response bias. We also found little association of the scale scores with hypothesised correlates of hope. Future improvements on the measurement of hope are recommended, especially in studies outside the narrow Western context in which the scale was devised.  相似文献   
2.
Background: Gastrointestinal stromal tumors (GIST) are one of the most common mesenchymal tumors of the gastrointestinal tract. GIST are defined by positive immunohistochemical staining for KIT or CD34 and thus are generally diagnosed after surgery. Because small GIST are rarely diagnosed before surgery, the clinical course of these small tumors is not clear. The aim of the present study was to follow changes in size and configuration of small GIST that were pathologically confirmed using endoscopic ultrasonography‐guided fine‐needle aspiration biopsy (EUS‐FNAB). Methods: Between July 1997 and December 2003, 16 tumors in 16 patients (10 men and 6 women) with an immunohistochemical diagnosis of GIST were regularly followed in our hospital. The median patient age when EUS‐FNAB was performed was 62 years (range 26–82 years) and the median follow‐up period was 4.9 years (range 0.5–9.6 years). Results: Fourteen tumors showed no remarkable changes in size and shape during follow up compared with the initial diagnosis. Two tumors enlarged: one tumor approximately doubled its diameter in 8 years and the other tumor increased from 1.8 cm at diagnosis to up to 10 cm after only 2 years. Doubling time of the latter tumor was calculated as 3.1 months. Conclusions: We conclude that EUS‐FNAB might be a good modality for final diagnosis of GIST without surgery, and that GIST without rapid growth on follow up can be endoscopically followed.  相似文献   
3.
颈动脉内膜切除术的恰当应用   总被引:2,自引:0,他引:2  
在颈动脉内膜切除术(CEA)首创的头30年里,一直没有明确的标准来确定哪些颈内动脉疾病患者适合这一手术.最近,从7项临床随机试验中得出了哪些有症状与无症状患者适合行CEA的结论.对于颈内动脉狭窄70%以上的患者,卒中的危险性最大,手术的益处也最大.在这些研究中,CEA对以下患者最有益半球短暂性脑缺血发作、颅内外联合病灶和无侧支循环且除此之外身体状况良好的老年患者.下列患者虽然能从手术中获益,但围手术期卒中和死亡的危险性较高广泛白质疏松、对侧颈内动脉闭塞和腔内有血栓者.狭窄50%~69%的患者较少获益,包括女性和仅有一过性单眼盲在内的一些患者行CEA甚至可能有害.腔隙性卒中和一侧颈内动脉接近闭塞的患者有手术指征,但益处不大;狭窄<50%的患者不能从手术中获益.在最大的一项无症状患者随机试验中,围手术期卒中和死亡的危险性非常小(1.5%),但要在2年内防止1例卒中发生需要相当多的病例(83例)接受CEA治疗.以后的文献报道围手术期危险性较高(2.8%~5.6%).近一半无症状患者的卒中是心源性栓塞和小血管疾病所致.这些局限性抵消了任何潜在的益处.其他试验正在进行,并可能确认哪些无症状患者亚组可从手术中获益.同时,大多数无症状患者内科治疗效果也较好.  相似文献   
4.
5.
6.
Coronary artery bypass grafts: visualization with MR imaging   总被引:1,自引:0,他引:1  
Gomes  AS; Lois  JF; Drinkwater  DC  Jr; Corday  SR 《Radiology》1987,162(1):175
  相似文献   
7.
The present study evaluated the use of psychologic measures, in particular, the relatively new Million Behavioral Health Inventory (MBHI), in predicting change in physical function of chronic low back pain patients undergoing a functional restoration program. The first 134 consecutive patients completing this program were assessed. Results demonstrated that various clinical scales of the MBHI were predictive of improvement in physical function. In addition, various scales enabled discrimination between patients who completed the program and those who prematurely dropped out. Although this inventory shows promise in helping to predict response to treatment, no single psychologic test can reliably be used as the sole predictor in clinical cases.  相似文献   
8.
9.
This article is designed to help dentists make better decisions regarding capitation programs. It focuses on approaches to costs that can be useful. An example is given that illustrates how these cost concepts might be used to analyze a capitation proposal.  相似文献   
10.
Due to recent public debate and newly imposed resident work hour restrictions, we decided to investigate the relationship of resident call status to their ambulatory patients' satisfaction. Resident continuity clinic patients were asked to rate their level of satisfaction on a 10-point Likert-type scale. Using multiple regression approaches, these data were then assessed as a function of resident call status. We found that in 646 patient encounters, patient satisfaction scores were significantly less when the resident was postcall, 8.99 ± 1.8, than when not postcall, 9.31 ± 1.3. We herein discuss etiologies and implications of these findings for both patient care and medical education.  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