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   3533661篇
  免费   297597篇
  国内免费   16010篇
耳鼻咽喉   47581篇
儿科学   113182篇
妇产科学   92455篇
基础医学   562244篇
口腔科学   94660篇
临床医学   327695篇
内科学   622960篇
皮肤病学   91533篇
神经病学   304633篇
特种医学   136501篇
外国民族医学   395篇
外科学   533274篇
综合类   107023篇
现状与发展   23篇
一般理论   2347篇
预防医学   308071篇
眼科学   80184篇
药学   242929篇
  27篇
中国医学   10542篇
肿瘤学   169009篇
  2021年   55913篇
  2020年   35608篇
  2019年   58806篇
  2018年   72730篇
  2017年   55411篇
  2016年   61035篇
  2015年   74958篇
  2014年   109414篇
  2013年   175328篇
  2012年   102122篇
  2011年   103457篇
  2010年   120174篇
  2009年   123258篇
  2008年   88768篇
  2007年   92438篇
  2006年   102603篇
  2005年   97616篇
  2004年   98601篇
  2003年   88793篇
  2002年   78321篇
  2001年   108256篇
  2000年   101636篇
  1999年   100215篇
  1998年   65963篇
  1997年   63749篇
  1996年   61426篇
  1995年   56998篇
  1994年   51172篇
  1993年   47769篇
  1992年   71299篇
  1991年   68383篇
  1990年   64911篇
  1989年   63258篇
  1988年   58834篇
  1987年   57427篇
  1986年   54792篇
  1985年   54706篇
  1984年   49569篇
  1983年   45117篇
  1982年   42143篇
  1981年   39697篇
  1980年   37347篇
  1979年   41090篇
  1978年   36138篇
  1977年   32626篇
  1976年   30473篇
  1975年   28709篇
  1974年   30212篇
  1973年   29094篇
  1972年   27231篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
992.

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   
993.
994.

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   
995.
996.
997.
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   
998.
999.
Trichotillomania is a form of traction alopecia resulting from repetitive and compulsive hair pulling and plucking. Trichotillomania and patchy alopecia areata may have similar clinical and dermoscopic features in some cases. On trichoscopic examination, the presence of black dots, coiled or hook hair, shafts of varying lengths with fraying or split ends (trichoptilosis), and an absence of exclamation mark hairs and yellow dots are suggestive of trichotillomania.  相似文献   
1000.
Objective: The objective of this study was to gain greater insight into individuals’ quality of life (QOL) definitions, appraisals, and adaptations following spinal cord injury (SCI).

Design: A mixed-methods design, applying the Schwartz and Sprangers response shift (RS) model. RS is a cognitive process wherein, in response to a change in health status, individuals change internal standards, values, or conceptualization of QOL

Setting: Community-dwelling participants who receive medical treatment at a major Midwestern medical system and nearby Veterans’ Affairs hospital.

Participants: A purposive sample of participants with SCI (N?=?40) completed semi-structured interviews and accompanying quantitative measures.

Interventions: Not applicable.

Outcome Measures: Qualitative data were analyzed using content analysis to identify themes. Analysis of variance were performed to detect differences based on themes and QOL, well-being, and demographic and injury characteristics.

Results: Four RS themes were identified, capturing the range of participant perceptions of QOL. The themes ranged from complete RS, indicating active engagement in maintaining QOL, to awareness and comparisons redefining QOL, to a relative lack of RS. Average QOL ratings differed as a function of response shift themes. PROMIS Global Health, Anxiety, and Depression also differed as a function of RS themes.

Conclusion: The RS model contextualizes differences in QOL definitions, appraisals, and adaptations in a way standardized QOL measures alone do not.  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