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   1549365篇
  免费   108151篇
  国内免费   3782篇
耳鼻咽喉   22063篇
儿科学   45779篇
妇产科学   42781篇
基础医学   213776篇
口腔科学   43947篇
临床医学   134632篇
内科学   306505篇
皮肤病学   33196篇
神经病学   128261篇
特种医学   62920篇
外国民族医学   450篇
外科学   241239篇
综合类   33450篇
现状与发展   7篇
一般理论   602篇
预防医学   107741篇
眼科学   36342篇
药学   114222篇
  28篇
中国医学   3273篇
肿瘤学   90084篇
  2019年   12507篇
  2018年   17161篇
  2017年   13594篇
  2016年   14984篇
  2015年   17030篇
  2014年   24063篇
  2013年   35391篇
  2012年   48390篇
  2011年   50893篇
  2010年   29808篇
  2009年   28525篇
  2008年   47818篇
  2007年   51525篇
  2006年   51693篇
  2005年   50323篇
  2004年   48596篇
  2003年   46358篇
  2002年   45396篇
  2001年   65466篇
  2000年   66733篇
  1999年   57244篇
  1998年   17156篇
  1997年   15461篇
  1996年   14677篇
  1995年   13803篇
  1994年   12837篇
  1992年   43760篇
  1991年   42218篇
  1990年   41341篇
  1989年   40285篇
  1988年   37658篇
  1987年   37036篇
  1986年   35523篇
  1985年   33805篇
  1984年   25709篇
  1983年   21797篇
  1982年   13599篇
  1981年   12432篇
  1979年   24385篇
  1978年   17550篇
  1977年   15279篇
  1976年   13781篇
  1975年   15581篇
  1974年   18406篇
  1973年   17835篇
  1972年   16993篇
  1971年   15878篇
  1970年   15041篇
  1969年   14451篇
  1968年   13549篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
In a prospective study, we sought to determine acceptability of linkage of administrative and clinical trial data among Canadian patients and Research Ethics Boards (REBs). The goal is to develop a more harmonized approach to data, with potential to improve clinical trial conduct through enhanced data quality collected at reduced cost and inconvenience for patients. On completion of the original LY.12 randomized clinical trial in lymphoma (NCT00078949), participants were invited to enrol in the Long-term Innovative Follow-up Extension (LIFE) component. Those consenting to do so provided comprehensive identifying information to facilitate linkage with their administrative data. We prospectively designed a global assessment of this innovative approach to clinical trial follow-up including rates of REB approval and patient consent. The pre-specified benchmark for patient acceptability was 80%. Of 16 REBs who reviewed the research protocol, 14 (89%) provided approval; two in Quebec declined due to small patient numbers. Of 140 patients invited to participate, 115 (82%, 95% CI 76 to 88%) from across 9 Canadian provinces provided consent and their full name, date of birth, health insurance number and postal code to facilitate linkage with their administrative data for long-term follow-up. Linkage of clinical trial and administrative data is feasible and acceptable. Further collaborative work including many stakeholders is required to develop an optimized secure approach to research. A more coordinated national approach to health data could facilitate more rapid testing and identification of new effective treatments across multiple jurisdictions and diseases from diabetes to COVID-19.  相似文献   
73.
locStra is an ‐package for the analysis of regional and global population stratification in whole‐genome sequencing (WGS) studies, where regional stratification refers to the substructure defined by the loci in a particular region on the genome. Population substructure can be assessed based on the genetic covariance matrix, the genomic relationship matrix, and the unweighted/weighted genetic Jaccard similarity matrix. Using a sliding window approach, the regional similarity matrices are compared with the global ones, based on user‐defined window sizes and metrics, for example, the correlation between regional and global eigenvectors. An algorithm for the specification of the window size is provided. As the implementation fully exploits sparse matrix algebra and is written in C++, the analysis is highly efficient. Even on single cores, for realistic study sizes (several thousand subjects, several million rare variants per subject), the runtime for the genome‐wide computation of all regional similarity matrices does typically not exceed one hour, enabling an unprecedented investigation of regional stratification across the entire genome. The package is applied to three WGS studies, illustrating the varying patterns of regional substructure across the genome and its beneficial effects on association testing.  相似文献   
74.
75.
76.
77.
Background MMR proficient (pMMR) colorectal cancer (CRC) is usually unresponsive to immunotherapy. Recent data suggest that ibrutinib may enhance the anti-tumour activity of anti-PD-1 immunotherapy. In this study, we evaluated the safety and efficacy of ibrutinib plus pembrolizumab in refractory metastatic CRC.Methods This was a phase 1/2 study in patients with refractory metastatic pMMR CRC. The primary endpoints for phases 1 and 2 were maximum tolerated dose (MTD) and disease control rate, respectively. The secondary endpoints were safety, progression-free survival (PFS) and overall survival (OS).Results A total of 40 patients were enrolled. No dose-limiting toxicity was observed, and MTD was not identified. The highest tested dose of ibrutinib, 560 mg once daily, was combined with a fixed dose of pembrolizumab 200 mg every 3 weeks for the phase 2 portion. The most common grade 3/4 treatment-related adverse events were anaemia (21%), fatigue (8%) and elevated alkaline phosphatase (8%). Among 31 evaluable patients, 8 (26%) achieved stable disease, and no objective response was observed. The median PFS and OS were 1.4 and 6.6 months, respectively.Conclusion Ibrutinib 560 mg daily plus pembrolizumab 200 mg every 3 weeks appears to be well tolerated with limited anti-cancer activity in metastatic CRC.ClinicalTrials.gov identifier NCT03332498.Subject terms: Cancer immunotherapy, Colorectal cancer  相似文献   
78.
79.
80.
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