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   2351篇
  免费   207篇
耳鼻咽喉   57篇
儿科学   36篇
妇产科学   88篇
基础医学   308篇
口腔科学   12篇
临床医学   275篇
内科学   624篇
皮肤病学   15篇
神经病学   201篇
特种医学   86篇
外科学   336篇
综合类   50篇
预防医学   180篇
眼科学   42篇
药学   168篇
中国医学   7篇
肿瘤学   73篇
  2023年   18篇
  2022年   34篇
  2021年   69篇
  2020年   59篇
  2019年   70篇
  2018年   69篇
  2017年   65篇
  2016年   71篇
  2015年   74篇
  2014年   124篇
  2013年   133篇
  2012年   202篇
  2011年   208篇
  2010年   118篇
  2009年   87篇
  2008年   151篇
  2007年   182篇
  2006年   169篇
  2005年   136篇
  2004年   113篇
  2003年   87篇
  2002年   73篇
  2001年   23篇
  2000年   20篇
  1999年   17篇
  1998年   23篇
  1997年   17篇
  1996年   12篇
  1995年   17篇
  1994年   13篇
  1993年   7篇
  1992年   10篇
  1991年   11篇
  1990年   11篇
  1989年   6篇
  1988年   8篇
  1987年   3篇
  1986年   5篇
  1985年   2篇
  1984年   4篇
  1983年   2篇
  1982年   5篇
  1981年   5篇
  1980年   3篇
  1979年   7篇
  1976年   2篇
  1974年   2篇
  1970年   2篇
  1969年   2篇
  1882年   1篇
排序方式: 共有2558条查询结果,搜索用时 125 毫秒
1.
2.
Problem: The Leaders in Indigenous Medical Education (LIME) Network aims to improve the quality and effectiveness of Indigenous health in medical education as well as best practice in the recruitment, retention, and graduation of Indigenous medical students. Intervention: In this article we explore the utility of Etienne Wenger's “communities of practice” (CoP) concept in providing a theoretical framework to better understand the LIME Network as a form of social infrastructure to further knowledge and innovation in this important area of health care education reform. Context: The Network operates across all medical schools in Australia and New Zealand. Outcome: Utilizing a model of evaluation of communities of practice developed by Fung-Kee-Fung et al., we seek to analyze the outcomes of the LIME Network as a CoP and assess its approach and contribution to improving the implementation of Indigenous health in the medical curriculum and the graduation of Indigenous medical students. Lessons Learned: By reflecting on the Network through a community of practice lens, this article highlights the synthesis between the LIME Network and Wenger's theory and provides a framework with which to measure Network outputs. It also posits an opportunity to better capture the impact of Network activities into the future to ensure that it remains a relevant and sustainable entity.  相似文献   
3.
Rotary ventricular assist devices (VADs) are less sensitive to preload than the healthy heart, resulting in inadequate flow regulation in response to changes in patient cardiac demand. Starling‐like physiological controllers (SLCs) have been developed to automatically regulate VAD flow based on ventricular preload. An SLC consists of a cardiac response curve (CRC) which imposes a nonlinear relationship between VAD flow and ventricular preload, and a venous return line (VRL) which determines the return path of the controller. This study investigates the importance of a physiological VRL in SLC of dual rotary blood pumps for biventricular support. Two experiments were conducted on a physical mock circulation loop (MCL); the first compared an SLC with an angled physiological VRL (SLC‐P) against an SLC with a vertical VRL (SLC‐V). The second experiment quantified the benefit of a dynamic VRL, represented by a series of specific VRLs, which could adapt to different circulatory states including changes in pulmonary (PVR) and systemic (SVR) vascular resistance versus a fixed physiological VRL which was calculated at rest. In both sets of experiments, the transient controller responses were evaluated through reductions in preload caused by the removal of fluid from the MCL. The SLC‐P produced no overshoot or oscillations following step changes in preload, whereas SLC‐V produced 0.4 L/min (12.5%) overshoot for both left and right VADs. Additionally, the SLC‐V had increased settling time and reduced controller stability as evidenced by transient controller oscillations. The transient results comparing the specific and standard VRLs demonstrated that specific VRL rise times were improved by between 1.2 and 4.7 s ( = 3.05 s), while specific VRL settling times were improved by between 2.8 and 16.1 seconds ( = 8.38 s) over the standard VRL. This suggests only a minor improvement in controller response time from a dynamic VRL compared to the fixed VRL. These results indicate that the use of a fixed physiologically representative VRL is adequate over a wide variety of physiological conditions.  相似文献   
4.

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   
5.
Abstract: Background: Fetal pulse oximetry improves the assessment of fetal well‐being during labor. The objective of this study was to evaluate women's satisfaction with their experience with this additional technology. Methods: We surveyed women participating in the FOREMOST trial, a randomized controlled trial comparing the addition of fetal pulse oximetry (FPO) to conventional cardiotocograph (CTG) monitoring (intervention group), versus CTG‐only (control group), in the presence of nonreassuring fetal status during labor. Our survey evaluated 3 aspects of women's experience: labor, fetal monitoring, and participation in the research. The survey was administered within a few days of giving birth and repeated 3 months later. Results: No differences were found between the intervention and control groups for women's evaluations of their labor, fetal monitoring, research, or overall experiences when surveyed on both occasions. Within each study group, a small but statistically significant decline occurred in women's scores for their experience of labor and overall experience from the initial survey close to the time of giving birth, to 3 months later. The magnitude of differences in responses over time was similar for the both groups. Women were more satisfied after a spontaneous or assisted vaginal birth than after cesarean section. Length of time the research midwife was present had a significant positive effect on women's ratings of their experience several days after giving birth (p = 0.006), but no effect at 3 months. Conclusions: The addition of fetal pulse oximetry for the assessment of fetal well‐being during labor did not affect childbearing women's perceptions of fetal monitoring or their labor. Women evaluated their experience in the research process positively overall. Small changes occurred in women's perception of their satisfaction over time. (BIRTH 33:2 June 2006)  相似文献   
6.
7.
Synovial sarcoma demonstrates epithelial differentiation, either by light microscopy (biphasic synovial sarcoma) or by immunohistochemical/ultrastructural methods only (monophasic) and poorly differentiated synovial sarcoma. Although the glands of synovial sarcoma are known to have tight junction-like structures, far less is known about junction formation in the spindled component of synovial sarcomas. Additionally, it is unknown whether the tight junctions of synovial sarcoma are normally constituted. The tight junction is a multiprotein complex consisting of numerous proteins that include ZO-1, claudin-1 and occludin. A total of 35 cases of synovial sarcoma (13 biphasic, 14 monophasic and eight poorly differentiated) were immunostained for ZO-1, claudin-1 and occludin using commercially available antibodies, heat-induced epitope retrieval and standard avidin-biotin technique. When available, corresponding electron micrographs were reviewed. For five cases, the presence of either an SYT-SSX1 (three cases) or SYT-SSX2 (two cases) gene fusion was known. Positive cases showed particulate membrane staining. The glands of biphasic synovial sarcomas expressed ZO-1 (13/13), claudin-1 (12/13) and occludin (11/13) in a manner identical to normal glandular epithelia, at the apical portion of the lateral membrane. The spindle cells of biphasic synovial sarcomas showed abnormal circumferential membranous expression of ZO-1 (12/13), claudin-1 (6/13) and occludin (3/13). Monophasic synovial sarcomas expressed ZO-1 in a circumferential pattern (13/14) but less often claudin-1 (4/14) or occludin (3/14). Poorly differentiated synovial sarcomas expressed ZO-1 (8/8) and claudin-1 (6/8) but only rarely occludin (2/8). By electron microscopy, recognizable tight junctions were seen only in glands. No correlation was seen between histologic subtype or fusion type and expression of tight junction proteins. We conclude that the glands of biphasic synovial sarcomas show well-organized, true epithelial tight junctions. In contrast, the spindled cells of all synovial sarcomas show significant abnormalities in the expression and localization of tight junction proteins, suggesting partial and/or aberrant epithelial differentiation.  相似文献   
8.
9.
10.
This study examined the relationship between psychological sense of community, social‐support networks, and care‐giver stress and satisfaction among firefighters. No significant gender differences were obtained, but zero‐order correlates demonstrated significant relationships among all four variables. In examining the mediating effects of social‐support satisfaction, partial mediation for psychological sense of community on care‐giver satisfaction was determined, as well as full mediation for psychological sense of community on care‐giver stress. Therefore, firefighters who are satisfied with the support they receive may experience less stress with their care giving than those who experience low levels of support satisfaction. Future studies should assess these relationships more extensively in other areas of civic responsibility among public‐service employees to delineate effective support avenues. © 2004 Wiley Periodicals, Inc. J Comm Psychol 32: 121–126, 2004.  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