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   1082983篇
  免费   73517篇
  国内免费   1652篇
耳鼻咽喉   15648篇
儿科学   30030篇
妇产科学   27227篇
基础医学   154638篇
口腔科学   32347篇
临床医学   92057篇
内科学   210687篇
皮肤病学   23364篇
神经病学   86290篇
特种医学   44658篇
外国民族医学   103篇
外科学   176742篇
综合类   19093篇
现状与发展   1篇
一般理论   271篇
预防医学   69020篇
眼科学   25565篇
药学   83406篇
  3篇
中国医学   2497篇
肿瘤学   64505篇
  2018年   11572篇
  2017年   9153篇
  2016年   10696篇
  2015年   12168篇
  2014年   15457篇
  2013年   22392篇
  2012年   31639篇
  2011年   32147篇
  2010年   18986篇
  2009年   17681篇
  2008年   31548篇
  2007年   33429篇
  2006年   34153篇
  2005年   33506篇
  2004年   32253篇
  2003年   31275篇
  2002年   30633篇
  2001年   59444篇
  2000年   61383篇
  1999年   51221篇
  1998年   12065篇
  1997年   10576篇
  1996年   10425篇
  1995年   9626篇
  1994年   8914篇
  1993年   8207篇
  1992年   37481篇
  1991年   35853篇
  1990年   34715篇
  1989年   33705篇
  1988年   30621篇
  1987年   29856篇
  1986年   27818篇
  1985年   26624篇
  1984年   18991篇
  1983年   16082篇
  1982年   8445篇
  1981年   7360篇
  1979年   17079篇
  1978年   11544篇
  1977年   9857篇
  1976年   8567篇
  1975年   9660篇
  1974年   11527篇
  1973年   10830篇
  1972年   10332篇
  1971年   9802篇
  1970年   9270篇
  1969年   8712篇
  1968年   7957篇
排序方式: 共有10000条查询结果,搜索用时 812 毫秒
171.
172.
Peacekeeping missions involve experiences that may impact the mental health of participating soldiers. However, research on the long-term mental health consequences of peacekeeping is sparse. The present study aimed to find the prevalence of mental health problems (MHPs), possible MHP predictors, and associations between predictors and MHPs in Norwegian peacekeepers 18–38 years after deployment to a United Nations peacekeeping mission. We used data from a cross-sectional, postdeployment survey of Norwegian peacekeepers who served in Lebanon between 1978 and 1998 (N = 10,605). Participants were assessed for posttraumatic stress disorder (PTSD); anxiety; depression; insomnia; alcohol misuse; drug misuse; and exposure to pre-, peri-, and postdeployment stressors. Logistic regressions were executed to explore key variables associated with MHPs. Total MHP prevalence was 15.1%, 95% CI [14.4, 15.8]. The estimates for specific disorders were 0.1% for drug misuse, 3.4% for alcohol misuse, 4.0% for depression, 6.2% for PTSD, 6.4% for anxiety, and 9.3% for insomnia. Postdeployment stressors, OR = 1.91, 95% CI [1.79, 2.04]; employment status, OR = 1.41, 95% CI [1.33, 1.48]; and traumatic exposure during deployment, OR = 1.11, 95% CI [1.09, 1.12], were positively related to PTSD, χ2(17, N = 8,568) = 1,791.299, p < .001. Similar patterns were found for the other MHPs. Considering that most participants (84.9%) reported low symptom levels, our findings challenge the widespread public perception that most peacekeepers have MHPs. Moreover, our results indicate that future peacekeepers should be prepared for challenges they may face not only during deployment but also in the years following their homecoming.  相似文献   
173.
174.
Postoperative pulmonary complications are associated with an increase in mortality, morbidity and healthcare utilisation. The Agency for Healthcare Research and Quality recommends risk assessment for postoperative respiratory complications in patients undergoing surgery. In this hospital registry study of adult patients undergoing non-cardiac surgery between 2005 and 2017 at two independent healthcare networks, a prediction instrument for early postoperative tracheal re-intubation was developed and externally validated. This was based on the development of the Score for Prediction Of Postoperative Respiratory Complications. For predictor selection, stepwise backward logistic regression and bootstrap resampling were applied. Development and validation cohorts were represented by 90,893 patients at Partners Healthcare and 67,046 patients at Beth Israel Deaconess Medical Center, of whom 699 (0.8%) and 587 (0.9%) patients, respectively, had their tracheas re-intubated. In addition to five pre-operative predictors identified in the Score for Prediction Of Postoperative Respiratory Complications, the final model included seven additional intra-operative predictors: early post-tracheal intubation desaturation; prolonged duration of surgery; high fraction of inspired oxygen; high vasopressor dose; blood transfusion; the absence of volatile anaesthetic use; and the absence of lung-protective ventilation. The area under the receiver operating characteristic curve for the new score was significantly greater than that of the original Score for Prediction Of Postoperative Respiratory Complications (0.84 [95%CI 0.82–0.85] vs. 0.76 [95%CI 0.75–0.78], respectively; p < 0.001). This may allow clinicians to develop and implement strategies to decrease the risk of early postoperative tracheal re-intubation.  相似文献   
175.
176.
Schizophrenia is a chronic and severe psychiatric disorder that has profound impact on an individual’s life and on society. Thus, developing more effective therapeutic interventions is essential. Over the past quarter‐century, an abundance of evidence from pharmacologic challenges, post‐mortem studies, brain imaging, and genetic studies supports the role of glutamatergic dysregulation in the pathophysiology of schizophrenia, and the results of recent randomized clinical trials based on this evidence have yielded promising results. In this article, we review the evidence that alterations in glutamatergic neurotransmission, especially focusing on the N‐methyl‐d ‐aspartate receptor (NMDAR) function, may be a critical causative feature of schizophrenia, how this contributes to pathologic circuit function in the brain, and how these insights are revealing whole new avenues for treatment development that could reduce treatment‐resistant symptoms, which account for persistent disability.  相似文献   
177.
This paper reviews the published literature on a group of developmental disorders of the retina and retinal pigment epithelium which result in focal abnormalities in one or both eyes. They are often asymptomatic, found on routine examination and are generally non-progressive. Some are associated with other systemic abnormalities.Subject terms: Retinal diseases, Eye abnormalities  相似文献   
178.
179.
Congenital heart disease is a rare but important finding in adults who experience sudden death. Examination of the congenitally malformed heart has historically been considered esoteric and best left to those with expertise. The Cardiac Risk in the Young cardiovascular pathology laboratory based at St George's University of London has now received over 6,000 cases. Of these, 21 congenitally malformed hearts were retained for research and educational purposes. Hearts were assessed using sequential segmental analysis, and causes of death were adjudicated based on thorough macroscopic examination and histology. Congenital malformations that were encountered included atrial septal defects, ventricular septal defects, tetralogy of Fallot, and transposition of the great arteries in both its regular and congenitally corrected variants. Findings also included hearts with mirror-imaged and isomeric atrial appendages. Direct causes of death included myocardial fibrosis, pulmonary hypertension, and hemorrhage. A small but notable proportion did not reveal a substrate for arrhythmia, raising the question of whether the terminal event was due to the congenital heart disease itself, or an underlying channelopathy. Here, we demonstrate the value of simple sequential segmental analysis in describing and categorizing the cases, with the concept of the “morphological method” serving to identify the distinguishing features of the cardiac components. Clin. Anat. 33:394–404, 2020. © 2019 Wiley Periodicals, Inc.  相似文献   
180.
ABSTRACT

Purpose

To investigate the effect of 1% tropicamide on anterior chamber aqueous flare (ACAF) measurements acquired with laser flare meter in patients with pseudoexfoliation.  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