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   52187篇
  免费   6540篇
  国内免费   1689篇
耳鼻咽喉   435篇
儿科学   540篇
妇产科学   682篇
基础医学   4866篇
口腔科学   218篇
临床医学   4288篇
内科学   2701篇
皮肤病学   301篇
神经病学   291篇
特种医学   2789篇
外国民族医学   94篇
外科学   7762篇
综合类   7797篇
现状与发展   7篇
一般理论   1篇
预防医学   1867篇
眼科学   109篇
药学   2589篇
  25篇
中国医学   682篇
肿瘤学   22372篇
  2024年   61篇
  2023年   684篇
  2022年   1031篇
  2021年   2262篇
  2020年   2176篇
  2019年   1949篇
  2018年   1848篇
  2017年   1862篇
  2016年   2126篇
  2015年   2498篇
  2014年   3273篇
  2013年   3292篇
  2012年   2780篇
  2011年   3097篇
  2010年   2540篇
  2009年   2561篇
  2008年   2664篇
  2007年   2952篇
  2006年   2890篇
  2005年   2537篇
  2004年   2180篇
  2003年   2028篇
  2002年   1762篇
  2001年   1637篇
  2000年   1275篇
  1999年   1029篇
  1998年   857篇
  1997年   797篇
  1996年   532篇
  1995年   494篇
  1994年   404篇
  1993年   319篇
  1992年   274篇
  1991年   256篇
  1990年   183篇
  1989年   146篇
  1988年   150篇
  1987年   135篇
  1986年   133篇
  1985年   155篇
  1984年   111篇
  1983年   76篇
  1982年   98篇
  1981年   94篇
  1980年   53篇
  1979年   54篇
  1978年   38篇
  1977年   28篇
  1976年   20篇
  1975年   9篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
《Cancer radiothérapie》2022,26(4):611-615
In order to provide more convenient irradiation regimens for patient comfort, radiation facility organization and health expenses, new hypofractionated protocols have been evaluated. Moderately (dose/fraction: 2.3 to 3 Gy), then ultra (dose/fraction: 5.2 to 6.1 Gy) hypofractionated irradiations were first validated. The current question is: is it possible to go forward using extreme hypofractionated regimens (EHR) based on 1 to 3 fractions. Different irradiation techniques are under investigation. However, brachytherapy remains the smartest way to deliver a high dose in a small volume. We report prospective and retrospective study results which evaluated EHR for breast and prostate brachytherapy. While oncological outcome and toxicity profile appear extremely encouraging for low-risk breast cancer after a 1 to 4 fractions (6.25 to 20 Gy/fraction), the use of a single fraction of 19 to 23 Gy appears debatable for prostate cancer. Brachytherapy represents an emblematic example of EHR but longer follow-up and more mature results are awaited in order to specify the right indications and refine the EQD2 calculation method including new biological and technical factors.  相似文献   
2.
3.
4.
5.
Breast core biopsies are a standard component of the triple approach that includes clinical examination, imaging and tissue sampling. Conventional cores, diagnostic vacuum assisted biopsy and vacuum assisted excisions are established methods for sampling and managing breast lesions. It is important to be aware of the potential pitfalls in the technical handling and interpretation of the limited core biopsy samples. Here, we present a clinically oriented, well illustrated overview of the common diagnostic pitfalls based on the author's diagnostic and second opinion practice, emphasize the value of clinicopathological correlation and provide histological tips and clues with useful immunohistochemistry to aid the reporting pathologists in their daily interpretation of breast core biopsies.  相似文献   
6.
7.
8.
神经内分泌肿瘤(neuroendocrine neoplasm,NEN)是一类起源于肽能神经元和神经内分泌细胞,具有神经内分泌分化并表达神经内分泌标志物的少见肿瘤,可发生于全身各处,以肺及胃肠胰NEN(gastroenteropancreatic neuroendocrine neoplasm, GEP-NEN)最常见。国内外研究数据均提示,NEN的发病率在不断上升。美国流行病学调查结果显示,与其他类型肿瘤相比,NEN的发病率上升趋势更为显著。中国抗癌协会神经内分泌肿瘤专委会在现有循证医学证据基础上,结合已有国内外指南和共识,制订了首版中国抗癌协会神经内分泌肿瘤诊治指南,为临床工作者提供参考。  相似文献   
9.
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   
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