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   14206篇
  免费   977篇
  国内免费   48篇
耳鼻咽喉   76篇
儿科学   410篇
妇产科学   396篇
基础医学   1646篇
口腔科学   178篇
临床医学   2229篇
内科学   2914篇
皮肤病学   178篇
神经病学   1385篇
特种医学   241篇
外科学   1288篇
综合类   384篇
一般理论   18篇
预防医学   1994篇
眼科学   261篇
药学   632篇
中国医学   15篇
肿瘤学   986篇
  2023年   72篇
  2022年   34篇
  2021年   236篇
  2020年   152篇
  2019年   239篇
  2018年   284篇
  2017年   217篇
  2016年   229篇
  2015年   289篇
  2014年   430篇
  2013年   694篇
  2012年   976篇
  2011年   1123篇
  2010年   593篇
  2009年   522篇
  2008年   999篇
  2007年   1051篇
  2006年   1001篇
  2005年   1000篇
  2004年   976篇
  2003年   886篇
  2002年   832篇
  2001年   111篇
  2000年   93篇
  1999年   118篇
  1998年   161篇
  1997年   132篇
  1996年   106篇
  1995年   118篇
  1994年   102篇
  1993年   91篇
  1992年   71篇
  1991年   61篇
  1990年   63篇
  1989年   69篇
  1988年   57篇
  1987年   46篇
  1986年   52篇
  1985年   53篇
  1984年   65篇
  1983年   81篇
  1982年   73篇
  1981年   73篇
  1980年   61篇
  1979年   46篇
  1978年   51篇
  1977年   42篇
  1976年   37篇
  1975年   30篇
  1974年   29篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Background and objectivesPatients older than 75 years with ST-segment elevation myocardial infarction undergoing primary angioplasty in cardiogenic shock have high mortality. Identification of preprocedural predictors of short- and long-term mortality could be useful to guide decision-making and further interventions.MethodsWe analyzed a nationwide registry of primary angioplasty in the elderly (ESTROFA MI + 75) comprising 3576 patients. The characteristics and outcomes of the subgroup of patients in cardiogenic shock were analyzed to identify associated factors and prognostic predictors in order to derive a baseline risk prediction score for 1-year mortality. The score was validated in an independent cohort.ResultsA total of 332 patients were included. Baseline independent predictors of mortality were anterior myocardial infarction (HR 2.8, 95%CI, 1.4-6.0; P = .005), ejection fraction < 40% (HR 2.3, 95%CI, 1.14-4.50; P = .018), and time from symptom onset to angioplasty > 6 hours (HR 3.2, 95%CI, 1.6-7.5; P = .001). A score was designed that included these predictive factors (score “6-ANT-40”). Survival at 1 year was 54.5% for patients with score 0, 32.3% for score 1, 27.4% for score 2 and 17% for score 3 (P = .004, c-statistic 0.70). The score was validated in an independent cohort of 124 patients, showing 1-year survival rates of 64.5%, 40.0%, 28.9%, and 22.2%, respectively (P = .008, c-statistic 0.68).ConclusionsA preprocedural score based on 3 simple clinical variables (anterior location, ejection fraction < 40%, and delay time > 6 hours) may be used to estimate survival after primary angioplasty in elderly patients with cardiogenic shock and to guide preinterventional decision-making.  相似文献   
5.
6.
Identification of high-risk human papillomavirus genotypes causing cervical precancer is crucial for informing HPV vaccine development and efficacy studies, and for determining which types to include in next-generation genotyping assays. Co-occurrence of hrHPV infections is common and complicates carcinogenicity assessment; accurate attribution requires tissue-based genotyping of precancers. We included all women with cervical intraepithelial neoplasia Grade 2 or worse (CIN2+) from the Biopsy Study, an observational study of 690 women enrolled between 2009 and 2012 at the University of Oklahoma. Tissue-based genotyping, including whole tissue sections (WTS) and laser-capture microdissection (LCM), was performed on all precancers with multiple hrHPV infections detected in cytology, totaling over 1,800 HPV genotyping assays. Genotype attribution was compared to hierarchical and proportional hrHPV-type attribution models. Of 276 women with CIN2+, 122 (44.2%) had multiple hrHPV genotypes in cytology. Of 114 women with genotyping data, 94 had one or more hrHPV detected in tissue. Seventy-one women (75.5%) had a single causal hrHPV genotype, while 23 women had multiple hrHPV genotypes causing CIN2+. Ten women had multiple causal infections in a single biopsy, contrary to the previous notion that each lesion is caused by a single type only. While HPV16 was the predominant causal hrHPV genotype using all approaches, the hierarchical model overattributed HPV16, whereas other causal hrHPV genotypes, particularly HPV18 and HPV35, were underattributed. Understanding true causal genotypes is important for the evaluation of vaccine efficacy, to estimate the extent of unmasking, and for type-specific risk assessment in screening and management.  相似文献   
7.
8.
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