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   666061篇
  免费   35531篇
  国内免费   619篇
耳鼻咽喉   8973篇
儿科学   21619篇
妇产科学   15799篇
基础医学   113141篇
口腔科学   16634篇
临床医学   59905篇
内科学   119873篇
皮肤病学   15964篇
神经病学   47910篇
特种医学   25582篇
外国民族医学   53篇
外科学   99127篇
综合类   8317篇
现状与发展   2篇
一般理论   149篇
预防医学   46216篇
眼科学   14924篇
药学   50768篇
  1篇
中国医学   1335篇
肿瘤学   35919篇
  2021年   5179篇
  2019年   5335篇
  2018年   8653篇
  2017年   6621篇
  2016年   8081篇
  2015年   8131篇
  2014年   10250篇
  2013年   16048篇
  2012年   22595篇
  2011年   25287篇
  2010年   14469篇
  2009年   11877篇
  2008年   23739篇
  2007年   25905篇
  2006年   25126篇
  2005年   24335篇
  2004年   23530篇
  2003年   23018篇
  2002年   22379篇
  2001年   27333篇
  2000年   29227篇
  1999年   22416篇
  1998年   6715篇
  1997年   5576篇
  1996年   5366篇
  1995年   4945篇
  1992年   15099篇
  1991年   16405篇
  1990年   16538篇
  1989年   16225篇
  1988年   14804篇
  1987年   14784篇
  1986年   13643篇
  1985年   13374篇
  1984年   10063篇
  1983年   8589篇
  1982年   4805篇
  1979年   9429篇
  1978年   6836篇
  1977年   5622篇
  1976年   5922篇
  1975年   7040篇
  1974年   7820篇
  1973年   7507篇
  1972年   6865篇
  1971年   6628篇
  1970年   6165篇
  1969年   5693篇
  1968年   5401篇
  1967年   4859篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
Journal of Behavioral Medicine - Evidence supports the use of graphic warnings to educate the public about the health harms of smoking and suggests warnings eliciting negative emotional responses...  相似文献   
4.
The adrenal cortex gives rise to a biologically heterogenous group of neoplasms, each with a distinct morphology, antigen expression and molecular profile. Adrenal cortical adenomas have excellent prognosis and are usually cured by surgical resection alone, while adrenal cortical carcinomas are very aggressive tumors with a poor prognosis regardless of therapy. These tumors are rare and often challenging for a pathologist to diagnose, as significant overlap exists between benign and malignant lesions in some cases. In this review, we attempt to summarize most important histologic and clinical features of adrenal cortical adenomas and carcinomas, clarify the use of different grading systems, the use of special stains and the differential diagnosis for practicing pathologists. Most relevant hereditary syndromes associated with adrenal cortical tumors are listed. Updates in molecular alterations in adrenal cortical neoplasms and hyperplastic diseases as well as their clinical significance and potential therapeutic implications are also discussed.  相似文献   
5.
6.
7.
Journal of Immigrant and Minority Health - COVID-19 has disproportionally affected underrepresented minorities (URM) and low-income immigrants in the United States. The aim of the study is to...  相似文献   
8.
Tamoxifen prevents recurrence of breast cancer and is suggested for preventive risk-reducing therapy. Tamoxifen reduces mammographic density, a proxy for therapy response, but little is known about its effects in remodelling normal breast tissue. Our study, a substudy within the double-blinded dose-determination trial KARISMA, investigated tamoxifen-specific changes in breast tissue composition and histological markers in healthy women. We included 83 healthy women randomised to 6 months daily intake of 20, 10, 5, 2.5, 1 mg of tamoxifen or placebo. The groups were combined to “no dose” (0-1 mg), “low-dose” (2.5-5 mg) or “high-dose” (10-20 mg) of tamoxifen. Ultrasound-guided biopsies were collected before and after tamoxifen exposure. In each biopsy, epithelial, stromal and adipose tissues was quantified, and expression of epithelial and stromal Ki67, oestrogen receptor (ER) and progesterone receptor (PR) analysed. Mammographic density using STRATUS was measured at baseline and end-of-tamoxifen-exposure. We found that different doses of tamoxifen reduced mammographic density and glandular-epithelial area in premenopausal women and associated with reduced epithelium and increased adipose tissue. High-dose tamoxifen also decreased epithelial ER and PR expressions in premenopausal women. Premenopausal women with the greatest reduction in proliferation also had the greatest epithelial reduction. In postmenopausal women, high-dose tamoxifen decreased the epithelial area with no measurable density decrease. Tamoxifen at both low and high doses influences breast tissue composition and expression of histological markers in the normal breast. Our findings connect epithelial proliferation with tissue remodelling in premenopausal women and provide novel insights to understanding biological mechanisms of primary prevention with tamoxifen.  相似文献   
9.
Microbial co-infections are another primary concern in patients with coronavirus disease 2019 (COVID-19), yet it is an untouched area among researchers. Preliminary data and systematic reviews only show the type of pathogens responsible for that, but its pathophysiology is still unknown. Studies show that these microbial co-infections are hospital-acquired/nosocomial infections, and patients admitted to intensive care units with invasive mechanical ventilation are highly susceptible to it. Patients with COVID-19 had elevated inflammatory cytokines and a weakened cell-mediated immune response, with lower CD4+ T and CD8+ T cell counts, indicating vulnerability to various co-infections. Despite this, there are only a few studies that recommend the management of co-infections.  相似文献   
10.
Troppmair  Teresa  Egger  J.  Krösbacher  A.  Zanvettor  A.  Schinnerl  A.  Neumayr  A.  Baubin  M. 《Der Anaesthesist》2022,71(4):272-280
Die Anaesthesiologie - Die Qualität eines Rettungssystems zeichnet sich auch durch den effizienten Einsatz seiner personellen und Fahrzeugressourcen aus. So können im berechtigten Fall...  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