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   3231565篇
  免费   279186篇
  国内免费   13719篇
耳鼻咽喉   44288篇
儿科学   103900篇
妇产科学   82961篇
基础医学   522003篇
口腔科学   87003篇
临床医学   291669篇
内科学   564834篇
皮肤病学   88354篇
神经病学   279101篇
特种医学   127401篇
外国民族医学   329篇
外科学   501531篇
综合类   100688篇
现状与发展   23篇
一般理论   2263篇
预防医学   274532篇
眼科学   73889篇
药学   220471篇
  23篇
中国医学   9328篇
肿瘤学   149879篇
  2021年   54861篇
  2020年   35036篇
  2019年   57983篇
  2018年   70804篇
  2017年   54013篇
  2016年   59598篇
  2015年   73746篇
  2014年   107931篇
  2013年   173181篇
  2012年   86840篇
  2011年   86373篇
  2010年   115338篇
  2009年   120036篇
  2008年   73399篇
  2007年   75547篇
  2006年   86693篇
  2005年   81980篇
  2004年   84308篇
  2003年   75311篇
  2002年   65062篇
  2001年   94429篇
  2000年   86973篇
  1999年   88674篇
  1998年   64300篇
  1997年   62362篇
  1996年   60129篇
  1995年   55672篇
  1994年   49943篇
  1993年   46513篇
  1992年   62369篇
  1991年   59470篇
  1990年   56577篇
  1989年   55965篇
  1988年   51625篇
  1987年   51029篇
  1986年   48136篇
  1985年   48646篇
  1984年   45284篇
  1983年   41557篇
  1982年   40685篇
  1981年   38492篇
  1980年   36202篇
  1979年   37060篇
  1978年   33761篇
  1977年   30959篇
  1976年   28457篇
  1975年   26803篇
  1974年   27576篇
  1973年   26534篇
  1972年   24642篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.

Background

Physicians treating nonvalvular atrial fibrillation (AF) assess stroke and bleeding risks when deciding on anticoagulation. The agreement between empirical and physician-estimated risks is unclear. Furthermore, the association between patient and physician sex and anticoagulation decision-making is uncertain.

Methods

We pooled data from 2 national primary care physician chart audit databases of patients with AF (Facilitating Review and Education to Optimize Stroke Prevention in Atrial Fibrillation and Coordinated National Network to Engage Physicians in the Care and Treatment of Patients with Atrial Fibrillation Chart Audit) with a combined 1035 physicians (133 female, 902 male) and 10,927 patients (4567 female and 6360 male).

Results

Male physicians underestimated stroke risk in female patients and overestimated risk in male patients. Female physicians estimated stroke risk well in female patients but underestimated the risk in male patients. Risk of bleeding was underestimated in all. Despite differences in risk assessment by physician and patient sex, > 90% of patients received anticoagulation across all subgroups. There was modest agreement between physician estimated and calculated (ie, CHADS2 score) stroke risk: Kappa scores were 0.41 (0.35-0.47) for female physicians and 0.34 (0.32-0.36) for male physicians.

Conclusions

Our study is the first to examine the association between patient and physician sex influences and stroke and bleeding risk estimation in AF. Although there were differences in agreement between physician estimated stroke risk and calculated CHADS2 scores, these differences were small and unlikely to affect clinical practice; further, despite any perceived differences in the accuracy of risk assessment by sex, most patients received anticoagulation.  相似文献   
994.
995.

Background

Inflammation and infections have been associated with prostate cancer progression. We assessed whether elevated serum cytokines or T. vaginalis seropositivity at the time of diagnosis was associated with higher grade or lethal prostate cancer.

Patients and Methods

Men with localized or metastatic prostate cancer were included in this study. Cytokine serum levels including interleukin (IL)-1α, IL-1β, IL-2, IL-6, IL-8, monocyte chemotactic protein 1 (CCL-2), tumor necrosis factor α, and growth-regulated oncogene α (CXCL-1) using a multiplex enzyme-linked immunosorbent assay and T. vaginalis serology were measured in blood samples at diagnosis.

Results

A total of 324 patients were identified at time of localized disease and 118 at time of metastatic disease. Of the 189 patients with localized disease and clinical follow-up data (median, 73 months), 28 developed lethal disease. There was no association between circulating cytokine levels above median concentrations nor T. vaginalis seropositivity and risk of intermediate- to high-risk or lethal prostate cancer.

Conclusion

Higher levels of serum cytokine levels and T. vaginalis seropositivity at diagnosis are not associated with high-grade or lethal prostate cancer and do not aid risk stratification of localized prostate cancer.  相似文献   
996.
997.
998.
999.
ABSTRACT

Forest workers, including loggers, foresters, and wildland firefighters, are regularly exposed to some of the most fatal occupational environments in the United States. These hazardous work environments may become even more complex and dynamic when subject to bark beetle outbreaks that have resulted in significant tree mortality. The impacts of tree death from bark beetles are significant, with the cumulative 17-year (2000–2016) footprint for bark beetle caused tree mortality estimated at 54 million acres. However, how workers think about and act in these environments is understudied. This study, therefore, approaches the issue of beetle kill and forest worker safety by examining the perspectives or workers themselves. Its contribution is to leverage ethnographic research to provide insights that can generate new research questions, better inform outreach, and ultimately improve worker safety outcomes. The resulting insights show that beetle kill was understood by workers as a hazard that increased the complexity and dynamism of the work environment, making situational awareness both more necessary and more difficult to maintain. While much research about situational awareness focuses on hazardous situations, it is suggested that building adequate situational awareness should also include broader considerations of organizational communication, as well as training and experience considered over the course of entire careers.  相似文献   
1000.
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