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   60640篇
  免费   6759篇
  国内免费   1385篇
耳鼻咽喉   621篇
儿科学   1308篇
妇产科学   1439篇
基础医学   6432篇
口腔科学   1617篇
临床医学   5507篇
内科学   2982篇
皮肤病学   373篇
神经病学   3188篇
特种医学   2623篇
外国民族医学   75篇
外科学   8657篇
综合类   7899篇
现状与发展   6篇
一般理论   1篇
预防医学   2392篇
眼科学   496篇
药学   3815篇
  36篇
中国医学   1269篇
肿瘤学   18048篇
  2024年   136篇
  2023年   837篇
  2022年   1669篇
  2021年   2692篇
  2020年   2455篇
  2019年   2196篇
  2018年   2074篇
  2017年   2151篇
  2016年   2345篇
  2015年   2744篇
  2014年   3671篇
  2013年   4134篇
  2012年   3215篇
  2011年   3514篇
  2010年   2827篇
  2009年   2783篇
  2008年   2782篇
  2007年   2824篇
  2006年   2857篇
  2005年   2571篇
  2004年   2154篇
  2003年   1963篇
  2002年   1609篇
  2001年   1458篇
  2000年   1203篇
  1999年   1084篇
  1998年   908篇
  1997年   891篇
  1996年   806篇
  1995年   726篇
  1994年   615篇
  1993年   524篇
  1992年   455篇
  1991年   437篇
  1990年   372篇
  1989年   316篇
  1988年   316篇
  1987年   282篇
  1986年   268篇
  1985年   374篇
  1984年   288篇
  1983年   188篇
  1982年   248篇
  1981年   234篇
  1980年   145篇
  1979年   126篇
  1978年   115篇
  1977年   72篇
  1976年   50篇
  1973年   24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.
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.
10.
孙莉  赵毅 《现代肿瘤医学》2019,(13):2420-2424
三阴性乳腺癌(triple negative breast cancer,TNBC)是雌激素受体(estrogen receptor,ER)、孕激素受体(progesterone receptor,PR)及人类表皮生长因子受体(human epidermal growth factor-2,HER-2)均不表达的乳腺癌。按其功能特征可归纳为5类分子分型:以DNA修复缺陷或生长因子为途径的基底细胞样三阴性乳腺癌;以上皮-间充质转化和肿瘤干细胞为特征的间质样三阴性乳腺癌;免疫调节型三阴性乳腺癌;雄激素受体过表达的管腔/分泌型三阴性乳腺癌;HER-2富集型三阴性乳腺癌。三阴性乳腺癌恶性程度高且异型性较大,其治疗困难且预后较差,内分泌治疗及靶向治疗不敏感。目前很多学者对于三阴性乳腺癌的治疗各有研究,并有临床试验证实下述治疗有效。  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