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   3809397篇
  免费   315845篇
  国内免费   16565篇
耳鼻咽喉   51106篇
儿科学   120567篇
妇产科学   98689篇
基础医学   595318篇
口腔科学   102766篇
临床医学   345429篇
内科学   679835篇
皮肤病学   99089篇
神经病学   319883篇
特种医学   148127篇
外国民族医学   273篇
外科学   585350篇
综合类   119194篇
现状与发展   29篇
一般理论   2382篇
预防医学   315043篇
眼科学   89682篇
药学   264739篇
  59篇
中国医学   13398篇
肿瘤学   190849篇
  2021年   57488篇
  2020年   36835篇
  2019年   59742篇
  2018年   74140篇
  2017年   56811篇
  2016年   62581篇
  2015年   76791篇
  2014年   111363篇
  2013年   177151篇
  2012年   108612篇
  2011年   110641篇
  2010年   123169篇
  2009年   125539篇
  2008年   95906篇
  2007年   100539篇
  2006年   109687篇
  2005年   104265篇
  2004年   105416篇
  2003年   95282篇
  2002年   84507篇
  2001年   136480篇
  2000年   129946篇
  1999年   122256篇
  1998年   68794篇
  1997年   65477篇
  1996年   63136篇
  1995年   58663篇
  1994年   52644篇
  1993年   48992篇
  1992年   85130篇
  1991年   81038篇
  1990年   76730篇
  1989年   75170篇
  1988年   69085篇
  1987年   67236篇
  1986年   63570篇
  1985年   62785篇
  1984年   54896篇
  1983年   49593篇
  1982年   43635篇
  1981年   40995篇
  1980年   38465篇
  1979年   44859篇
  1978年   38253篇
  1977年   34931篇
  1976年   31966篇
  1975年   30789篇
  1974年   32483篇
  1973年   31183篇
  1972年   29036篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
Journal of Medical Ultrasonics - Chronic liver disease is still a major problem because disease progression will ultimately lead to liver cirrhosis. Portal hypertension is the hallmark in advanced...  相似文献   
13.
14.
15.
16.
Neoadjuvant programmed cell death protein 1 (PD-1) blockade exhibits promising efficacy in patients with mismatch repair deficient (dMMR) colorectal cancer (CRC). However, discrepancies between radiological and histological findings have been reported in the PICC phase II trial (NCT 03926338). Therefore, we strived to discern radiological features associated with pathological complete response (pCR) based on computed tomography (CT) images. Data were obtained from the PICC trial that included 36 tumors from 34 locally advanced dMMR CRC patients, who received neoadjuvant PD-1 blockade for 3 months. Among the 36 tumors, 28 (77.8%) tumors achieved pCR. There were no statistically significant differences in tumor longitudinal diameter, the percentage change in tumor longitudinal diameter from baseline, primary tumor sidedness, clinical stage, extramural venous invasion status, intratumoral calcification, peritumoral fat infiltration, intestinal fistula and tumor necrosis between the pCR and non-pCR tumors. Otherwise, tumors with pCR had smaller posttreatment tumor maximum thickness (median: 10 mm vs 13 mm, P = .004) and higher percentage decrease in tumor maximum thickness from baseline (52.9% vs 21.6%, P = .005) compared to non-pCR tumors. Additionally, a higher proportion of the absence of vascular sign (P = .003, odds ratio [OR] = 25.870 [95% CI, 1.357-493.110]), nodular sign (P < .001, OR = 189.000 [95% CI, 10.464-3413.803]) and extramural enhancement sign (P = .003, OR = 21.667 [2.848-164.830]) was observed in tumors with pCR. In conclusion, these CT-defined radiological features may have the potential to serve as valuable tools for clinicians in identifying patients who have achieved pCR after neoadjuvant PD-1 blockade, particularly in individuals who are willing to adopt a watch-and-wait strategy.  相似文献   
17.
18.
19.
20.
PurposeUnderstanding the value of genetic screening and testing for monogenic disorders requires high-quality, methodologically robust economic evaluations. This systematic review sought to assess the methodological quality among such studies and examined opportunities for improvement.MethodsWe searched PubMed, Cochrane, Embase, and Web of Science for economic evaluations of genetic screening/testing (2013-2019). Methodological rigor and adherence to best practices were systematically assessed using the British Medical Journal checklist.ResultsAcross the 47 identified studies, there were substantial variations in modeling approaches, reporting detail, and sophistication. Models ranged from simple decision trees to individual-level microsimulations that compared between 2 and >20 alternative interventions. Many studies failed to report sufficient detail to enable replication or did not justify modeling assumptions, especially for costing methods and utility values. Meta-analyses, systematic reviews, or calibration were rarely used to derive parameter estimates. Nearly all studies conducted some sensitivity analysis, and more sophisticated studies implemented probabilistic sensitivity/uncertainty analysis, threshold analysis, and value of information analysis.ConclusionWe describe a heterogeneous body of work and present recommendations and exemplar studies across the methodological domains of (1) perspective, scope, and parameter selection; (2) use of uncertainty/sensitivity analyses; and (3) reporting transparency for improvement in the economic evaluation of genetic screening/testing.  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