首页 | 官方网站   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   14390篇
  免费   904篇
  国内免费   71篇
医药卫生   15365篇
  2023年   151篇
  2022年   117篇
  2021年   490篇
  2020年   307篇
  2019年   430篇
  2018年   476篇
  2017年   382篇
  2016年   379篇
  2015年   472篇
  2014年   616篇
  2013年   796篇
  2012年   1236篇
  2011年   1161篇
  2010年   691篇
  2009年   583篇
  2008年   989篇
  2007年   993篇
  2006年   947篇
  2005年   863篇
  2004年   830篇
  2003年   769篇
  2002年   618篇
  2001年   74篇
  2000年   62篇
  1999年   97篇
  1998年   110篇
  1997年   96篇
  1996年   64篇
  1995年   63篇
  1994年   54篇
  1993年   59篇
  1992年   46篇
  1991年   39篇
  1990年   22篇
  1989年   23篇
  1988年   25篇
  1987年   23篇
  1986年   18篇
  1985年   24篇
  1984年   24篇
  1983年   18篇
  1982年   17篇
  1981年   10篇
  1980年   15篇
  1979年   10篇
  1978年   10篇
  1977年   9篇
  1973年   5篇
  1972年   7篇
  1971年   6篇
排序方式: 共有10000条查询结果,搜索用时 281 毫秒
1.
2.
BackgroundLittle is known about the extent of ordering low-value services by.PurposeTo compare the rates of low-value back images ordered by primary care physicians (PCMDs) and primary care nurse practitioners (PCNPs).MethodWe used 2012 and 2013 Medicare Part B claims for all beneficiaries in 18 hospital referral ?regions (HRRs) and a measure of low-value back imaging from Choosing Wisely. Models included random clinician effect and fixed effects for beneficiary age, disability, Elixhauser comorbidities, clinician sex, the emergency department setting, back pain visit volume, organization, and region (HRR).FindingsPCNPs (N = 231) and PCMDs (N = 4,779) order low-value back images at similar rates (NP: all images: 26.5%; MRI/CT: 8.4%; MD: all images: 24.5%; MRI/CT: 7.7%), with no detectable significant difference when controlling for covariates.DiscussionPCNPs and PCMDs order low-value back images at an effectively similar rate.  相似文献   
3.
4.
5.
6.
7.
8.
Colorectal cancer (CRC) screening programs help diagnose cancer precursors and early cancers and help reduce CRC mortality. However, currently recommended tests, the fecal immunochemical test (FIT) and colonoscopy, have low uptake. There is therefore a pressing need for screening strategies that are minimally invasive and consequently more acceptable to patients, most likely blood based, to increase early CRC identification. MicroRNAs (miRNAs) released from cancer cells are detectable in plasma in a remarkably stable form, making them ideal cancer biomarkers. Using plasma samples from FIT-positive (FIT+) subjects in an Italian CRC screening program, we aimed to identify plasma circulating miRNAs that detect early CRC. miRNAs were initially investigated by quantitative real-time PCR in plasma from 60 FIT+ subjects undergoing colonoscopy at Fondazione IRCCS Istituto Nazionale dei Tumori, then tested on an internal validation cohort (IVC, 201 cases) and finally in a large multicenter prospective series (external validation cohort [EVC], 1121 cases). For each endoscopic lesion (low-grade adenoma [LgA], high-grade adenoma [HgA], cancer lesion [CL]), specific signatures were identified in the IVC and confirmed on the EVC. A two-miRNA-based signature for CL and six-miRNA signatures for LgA and HgA were selected. In a multivariate analysis including sex and age at blood collection, the areas under the receiver operating characteristic curve (95% confidence interval) of the signatures were 0.644 (0.607–0.682), 0.670 (0.626–0.714) and 0.682 (0.580–0.785) for LgA, HgA and CL, respectively. A miRNA-based test could be introduced into the FIT+ workflow of CRC screening programs so as to schedule colonoscopies only for subjects likely to benefit most.  相似文献   
9.
10.
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-23

京公网安备 11010802026262号