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   8502篇
  免费   550篇
  国内免费   1篇
  2023年   42篇
  2022年   88篇
  2021年   171篇
  2020年   97篇
  2019年   157篇
  2018年   213篇
  2017年   157篇
  2016年   271篇
  2015年   404篇
  2014年   469篇
  2013年   576篇
  2012年   732篇
  2011年   651篇
  2010年   425篇
  2009年   424篇
  2008年   553篇
  2007年   512篇
  2006年   452篇
  2005年   472篇
  2004年   415篇
  2003年   384篇
  2002年   367篇
  2001年   73篇
  2000年   56篇
  1999年   76篇
  1998年   92篇
  1997年   67篇
  1996年   67篇
  1995年   45篇
  1994年   66篇
  1993年   46篇
  1992年   44篇
  1991年   37篇
  1990年   28篇
  1989年   28篇
  1988年   21篇
  1987年   15篇
  1986年   11篇
  1985年   13篇
  1984年   21篇
  1983年   13篇
  1982年   20篇
  1981年   16篇
  1980年   13篇
  1979年   9篇
  1978年   17篇
  1977年   13篇
  1976年   14篇
  1975年   10篇
  1938年   8篇
排序方式: 共有9053条查询结果,搜索用时 593 毫秒
191.
192.
193.

Background

The ability to apply standard and interoperable solutions for implementing and managing medical registries as well as aggregate, reproduce, and access data sets from legacy formats and platforms to advanced standard formats and operating systems are crucial for both clinical healthcare and biomedical research settings.

Purpose

Our study describes a reproducible, highly scalable, standard framework for a device registry implementation addressing both local data quality components and global linking problems.

Methods and Results

We developed a device registry framework involving the following steps: (1) Data standards definition and representation of the research workflow, (2) Development of electronic case report forms using REDCap (Research Electronic Data Capture), (3) Data collection according to the clinical research workflow and, (4) Data augmentation by enriching the registry database with local electronic health records, governmental database and linked open data collections, (5) Data quality control and (6) Data dissemination through the registry Web site. Our registry adopted all applicable standardized data elements proposed by American College Cardiology / American Heart Association Clinical Data Standards, as well as variables derived from cardiac devices randomized trials and Clinical Data Interchange Standards Consortium. Local interoperability was performed between REDCap and data derived from Electronic Health Record system. The original data set was also augmented by incorporating the reimbursed values paid by the Brazilian government during a hospitalization for pacemaker implantation. By linking our registry to the open data collection repository Linked Clinical Trials (LinkedCT) we found 130 clinical trials which are potentially correlated with our pacemaker registry.

Conclusion

This study demonstrates how standard and reproducible solutions can be applied in the implementation of medical registries to constitute a re-usable framework. Such approach has the potential to facilitate data integration between healthcare and research settings, also being a useful framework to be used in other biomedical registries.  相似文献   
194.
195.
Coral Reefs - Coral bleaching represents the most serious threat to contemporary coral reefs. In response, focus is being laid on understanding the cellular processes involved in the response of...  相似文献   
196.
Molecular Biology Reports - Serotoninergic system is one of the most important neurotransmission systems investigated in the field of psychiatry. Extensive evidence reveals how alterations of this...  相似文献   
197.
We report 24 records of giant armadillo roadkill on Brazilian highways in the Cerrado, Pantanal and Amazon biomes illustrating that highways are a threat to this species. However, we also documented the species using underpasses, demonstrating that these structures could help to reduce the risk of roadkill for giant armadillos.  相似文献   
198.
Camellia japonica L. (Theaceae, Theales) is an acidophilic evergreen flowering shrub and is traded worldwide. Symbiotic associations between the roots of this plant species and arbuscular mycorrhizal fungi (AMF), commonly recognized as natural biofertilizers and biocontrol agents, have been poorly studied so far. The aim of our study was to verify whether the application of nonspecific commercial AMF-based inocula could succeed and improve the growth of C. japonica. An experiment was conducted concerning the application of commercial inocula constituted by a specific AMF isolate (Funneliformis mosseae) or a consortium of different fungi and bacteria as alternatives to fertilization in pot cultivated C. japonica ‘Dr. Burnside’. Several growth parameters, plant nutrition and mycorrhization levels were monitored at the end of plant cultivation. Generally, increases in some macroelements (Ca, Mg, K) and microelements (Cu, Mn, Fe, Zn) were detected in the root system of inoculated camellias, while only Cu and Mn accumulation was increased in the leaves. Plants inoculated with the consortium inoculum exhibited increased chlorophyll content and foliage diameter while plants inoculated with F. mosseae exhibited increased number of flowers. Based on the polymorphism of an 18S rDNA region, we assessed the inoculated AMF that colonized C. japonica roots. The experiments showed that the applied AMF poorly colonized the root system of C. japonica. We suggest that commercial AMF formulations should be more targeted and host-specific in order to successfully colonize the host root and, potentially, fully express their benefits.  相似文献   
199.
200.
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