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   48166篇
  免费   7314篇
  国内免费   131篇
耳鼻咽喉   313篇
儿科学   1426篇
妇产科学   2443篇
基础医学   3920篇
口腔科学   583篇
临床医学   20137篇
内科学   7255篇
皮肤病学   526篇
神经病学   3424篇
特种医学   759篇
外科学   3400篇
综合类   469篇
一般理论   69篇
预防医学   5784篇
眼科学   383篇
药学   1755篇
中国医学   27篇
肿瘤学   2938篇
  2023年   911篇
  2022年   300篇
  2021年   725篇
  2020年   1015篇
  2019年   934篇
  2018年   1799篇
  2017年   1865篇
  2016年   2036篇
  2015年   2165篇
  2014年   2411篇
  2013年   3169篇
  2012年   2475篇
  2011年   2724篇
  2010年   2149篇
  2009年   2349篇
  2008年   2560篇
  2007年   2638篇
  2006年   2635篇
  2005年   2441篇
  2004年   2256篇
  2003年   2143篇
  2002年   1969篇
  2001年   755篇
  2000年   512篇
  1999年   695篇
  1998年   975篇
  1997年   983篇
  1996年   911篇
  1995年   831篇
  1994年   640篇
  1993年   565篇
  1992年   427篇
  1991年   390篇
  1990年   364篇
  1989年   334篇
  1988年   269篇
  1987年   239篇
  1986年   262篇
  1985年   286篇
  1984年   235篇
  1983年   227篇
  1982年   232篇
  1981年   233篇
  1980年   200篇
  1979年   147篇
  1978年   129篇
  1977年   131篇
  1976年   135篇
  1975年   101篇
  1972年   119篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Patient navigation is a strategy for overcoming barriers to reduce disparities and to improve access and outcomes. The aim of this umbrella review was to identify, critically appraise, synthesize, and present the best available evidence to inform policy and planning regarding patient navigation across the cancer continuum. Systematic reviews examining navigation in cancer care were identified in the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase, Cumulative Index of Nursing and Allied Health (CINAHL), Epistemonikos, and Prospective Register of Systematic Reviews (PROSPERO) databases and in the gray literature from January 1, 2012, to April 19, 2022. Data were screened, extracted, and appraised independently by two authors. The JBI Critical Appraisal Checklist for Systematic Review and Research Syntheses was used for quality appraisal. Emerging literature up to May 25, 2022, was also explored to capture primary research published beyond the coverage of included systematic reviews. Of the 2062 unique records identified, 61 systematic reviews were included. Fifty-four reviews were quantitative or mixed-methods reviews, reporting on the effectiveness of cancer patient navigation, including 12 reviews reporting costs or cost-effectiveness outcomes. Seven qualitative reviews explored navigation needs, barriers, and experiences. In addition, 53 primary studies published since 2021 were included. Patient navigation is effective in improving participation in cancer screening and reducing the time from screening to diagnosis and from diagnosis to treatment initiation. Emerging evidence suggests that patient navigation improves quality of life and patient satisfaction with care in the survivorship phase and reduces hospital readmission in the active treatment and survivorship care phases. Palliative care data were extremely limited. Economic evaluations from the United States suggest the potential cost-effectiveness of navigation in screening programs.  相似文献   
2.
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   
3.
4.
5.
6.
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