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   874篇
  免费   37篇
  国内免费   22篇
耳鼻咽喉   2篇
儿科学   53篇
妇产科学   12篇
基础医学   77篇
口腔科学   11篇
临床医学   85篇
内科学   106篇
皮肤病学   9篇
神经病学   81篇
特种医学   165篇
外科学   88篇
综合类   79篇
预防医学   40篇
眼科学   31篇
药学   58篇
中国医学   1篇
肿瘤学   35篇
  2021年   7篇
  2020年   8篇
  2019年   8篇
  2018年   10篇
  2017年   12篇
  2016年   11篇
  2015年   23篇
  2014年   23篇
  2013年   30篇
  2012年   33篇
  2011年   24篇
  2010年   20篇
  2009年   19篇
  2008年   27篇
  2007年   33篇
  2006年   50篇
  2005年   22篇
  2004年   27篇
  2003年   17篇
  2002年   17篇
  2001年   29篇
  2000年   20篇
  1999年   18篇
  1998年   36篇
  1997年   27篇
  1996年   29篇
  1995年   26篇
  1994年   26篇
  1993年   33篇
  1992年   18篇
  1991年   12篇
  1990年   21篇
  1989年   19篇
  1988年   11篇
  1987年   14篇
  1986年   28篇
  1985年   13篇
  1984年   17篇
  1983年   11篇
  1982年   12篇
  1981年   15篇
  1980年   16篇
  1979年   5篇
  1978年   10篇
  1977年   8篇
  1976年   7篇
  1974年   3篇
  1971年   3篇
  1970年   3篇
  1966年   5篇
排序方式: 共有933条查询结果,搜索用时 31 毫秒
111.

Background:

We derived estimates of overdiagnosis by polygenic risk groups and examined whether polygenic risk-stratified screening for prostate cancer reduces overdiagnosis.

Methods:

We calculated the polygenic risk score based on genotypes of 66 known prostate cancer loci for 4967 men from the Finnish section of the European Randomised Study of Screening for Prostate Cancer. We stratified the 72 072 men in the trial into those with polygenic risk below and above the median. Using a maximum likelihood method based on interval cancers, we estimated the mean sojourn time (MST) and episode sensitivity. For each polygenic risk group, we estimated the proportion of screen-detected cancers that are likely to be overdiagnosed from the difference between the observed and expected number of screen-detected cancers.

Results:

Of the prostate cancers, 74% occurred among men with polygenic risk above population median. The sensitivity was 0.55 (95% confidence interval (CI) 0.45–0.65) and MST 6.3 (95% CI 4.2–8.3) years. The overall overdiagnosis was 42% (95% CI 37–52) of the screen-detected cancers, with 58% (95% CI 54–65) in men with the lower and 37% (95% CI 31–47) in those with higher polygenic risk.

Conclusion:

Targeting screening to men at higher polygenic risk could reduce the proportion of cancers overdiagnosed.  相似文献   
112.
113.
A murine hybridoma clone is described that grows continuously in culture and produces a monoclonal antibody we have called Royal Free Monoclonal Antibody to factor IX No. 1 (RFF-IX/1). This has high affinity for a coagulation site on factor IX. RFF-IX/1 immobilised on sepharose can be used to deplete factor IX from normal human plasma. This immunoaffinity depleted plasma is indistinguishable from severe Christmas disease plasma and can be used as the substrate in a one stage coagulation assay for factor IX. The affinity column has high capacity and can be regenerated so that large scale production from normal plasma of factor IX deficient plasma as a diagnostic reagent is now feasible.  相似文献   
114.
The effect of hemodialysis and C5a des arg on neutrophil subpopulations   总被引:1,自引:0,他引:1  
Klempner  MS; Gallin  JI; Balow  JE; Van Kammen  DP 《Blood》1980,55(5):777-783
Alterations in neutrophil subpopulations during human hemodialysis or following injection of C5a des arg into rabbits were studied. Whereas baseline peripheral blood neutrophils contained approximately 80% of cells that formed rosettes with IgG-sensitized erythrocytes, neutrophils harvested at the granulocyte nadir (20 min after initiating hemodialysis or the injection of C5a des arg) were markedly depleted of this population. This was seen in a change in ratio of rosette-forming neutrophils (RFN) to non-rosette-forming neutrophils (non-RFN) from 4:1 at 0 time to 1:2 at 20 min. Since non-RFN are less active in assays of adherence and chemotaxis, these alterations in circulating neutrophil populations were reflected in abnormal functional capacity of neutrophils harvested at 20 min. To study the mechanism of RFN depletion, we investigated the ability of C5a des arg to aggregate various human neutrophil suspensions. Unfractionated neutrophils and RFN demonstrated prompt in vitro aggregation in response to C5a des arg, whereas this activated complement fragment induced little aggregation in a population enriched for non-RFN. These results may explain the alterations in neutrophil adherence, chemotaxis, phagocytosis, and bactericidal activity, which have been reported to accompany clinical disorders characterized by in vivo complement activation (i.e., hemodialysis or gram-negative sepsis).  相似文献   
115.
116.
Smoking prevalence among patients with posttraumatic stress disorder (PTSD) is over 40%. Baseline data from the VA Cooperative Studies Program trial of integrated versus usual care for smoking cessation in veterans with PTSD (N = 863) were used in multivariate analyses of PTSD and depression severity, and 4 measures of smoking intensity: cigarettes per day (CPD), Fagerström Test for Nicotine Dependence (FTND), time to first cigarette, and expired carbon monoxide. Multivariate regression analysis showed the following significant associations: CPD with race (B = ?7.16), age (B = 0.11), and emotional numbing (B =0 .16); FTND with race (B = ?0.94), education (B = ?0.34), emotional numbing (B = 0.04), significant distress (B = ?0.12), and PHQ‐9 (B = 0.04); time to first cigarette with education (B = 0.41), emotional numbing (B = ?0.03), significant distress (B = 0.09), and PHQ‐9 (B = ?0.03); and expired carbon monoxide with race (B = ?9.40). Findings suggest that among veterans with PTSD, White race and emotional numbing were most consistently related to increased smoking intensity and had more explanatory power than total PTSD symptom score. Results suggest specific PTSD symptom clusters are important to understanding smoking behavior in patients with PTSD.  相似文献   
117.

Background

Optic neuritis is an inflammatory demyelinating condition of the optic nerve that causes subacute visual loss. It is often the result of an underlying systemic condition, such as multiple sclerosis. Due to the possible long-term morbidity associated with this condition, it is essential that the emergency physician recognizes the diagnosis and expedites treatment.

Objective

This case report describes optic neuritis diagnosed at the bedside by emergency physician−performed ultrasound.

Case Report

This is a case report of a young man presenting with unilateral painful vision loss. Optic neuritis must be considered in the differential diagnosis of any young patient who presents with visual complaints without any other neurologic findings. This report is unique because there are very few cases describing the findings of optic neuritis on emergency physician−performed bedside ultrasound in the literature.

Conclusions

This article presents the case, describes diagnostic modalities, especially the use of ultrasound in its diagnosis, and the course of treatment for this particular condition.  相似文献   
118.
For academic pediatricians, social media has become an important avenue for professional development through continuing education, professional networking, and academic collaboration. Pediatric residency program directors have recognized additional benefits of social media engagement via program promotion and resident recruitment. The novel coronavirus disease 2019 (COVID-19) pandemic and subsequent move to virtual interviews for the 2020–2021 residency interview season have created a new urgency for pediatric program directors to establish an active social media presence, primarily as a means to engage applicants and provide them with information in lieu of cancelled away rotations and in-person interviews. Twitter is a free microblogging and social networking platform that allows real-time engagement among academic pediatricians. Here, we make the case that all pediatric program directors should have an active presence on Twitter.  相似文献   
119.
Summary Ossification of the posterior longitudinal ligament is a potentially curable cause of thoracic myelopathy. As this case illustrates, MRI can confirm the diagnosis, demonstrate other concomitant pathology such as disc herniation, and help assess the clinical significance of OPLL by showing spinal word compression.  相似文献   
120.
Chondroma of falx: CT findings   总被引:1,自引:0,他引:1  
  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