全文获取类型
收费全文 | 36488篇 |
免费 | 2986篇 |
国内免费 | 75篇 |
专业分类
耳鼻咽喉 | 275篇 |
儿科学 | 1227篇 |
妇产科学 | 976篇 |
基础医学 | 4544篇 |
口腔科学 | 749篇 |
临床医学 | 6068篇 |
内科学 | 6839篇 |
皮肤病学 | 457篇 |
神经病学 | 3279篇 |
特种医学 | 785篇 |
外科学 | 3434篇 |
综合类 | 504篇 |
一般理论 | 69篇 |
预防医学 | 4805篇 |
眼科学 | 490篇 |
药学 | 2309篇 |
中国医学 | 40篇 |
肿瘤学 | 2699篇 |
出版年
2023年 | 176篇 |
2022年 | 248篇 |
2021年 | 656篇 |
2020年 | 496篇 |
2019年 | 869篇 |
2018年 | 931篇 |
2017年 | 695篇 |
2016年 | 809篇 |
2015年 | 890篇 |
2014年 | 1153篇 |
2013年 | 1809篇 |
2012年 | 2521篇 |
2011年 | 2525篇 |
2010年 | 1384篇 |
2009年 | 1279篇 |
2008年 | 2334篇 |
2007年 | 2488篇 |
2006年 | 2462篇 |
2005年 | 2354篇 |
2004年 | 2229篇 |
2003年 | 2067篇 |
2002年 | 2032篇 |
2001年 | 391篇 |
2000年 | 339篇 |
1999年 | 405篇 |
1998年 | 473篇 |
1997年 | 365篇 |
1996年 | 340篇 |
1995年 | 322篇 |
1994年 | 287篇 |
1993年 | 271篇 |
1992年 | 249篇 |
1991年 | 216篇 |
1990年 | 208篇 |
1989年 | 220篇 |
1988年 | 197篇 |
1987年 | 170篇 |
1986年 | 187篇 |
1985年 | 208篇 |
1984年 | 188篇 |
1983年 | 191篇 |
1982年 | 217篇 |
1981年 | 203篇 |
1980年 | 182篇 |
1979年 | 118篇 |
1978年 | 102篇 |
1977年 | 103篇 |
1976年 | 109篇 |
1975年 | 80篇 |
1974年 | 91篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Marike Gabrielson Mattias Hammarström Magnus Bäcklund Jenny Bergqvist Kristina Lång Ann H Rosendahl Signe Borgquist Roxanna Hellgren Kamila Czene Per Hall 《International journal of cancer. Journal international du cancer》2023,152(11):2362-2372
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
2.
Factors predicting the development of pressure ulcers in an at‐risk population who receive standardized preventive care: secondary analyses of a multicentre randomised controlled trial
下载免费PDF全文
![点击此处可从《Journal of advanced nursing》网站下载免费的PDF全文](/ch/ext_images/free.gif)
3.
Y. Ermias I.A. Morgan K.M. Curtis M.K. Whiteman L.G. Horton L.B. Zapata 《Contraception》2019,99(5):300-305
ObjectiveIdentify factors associated with healthcare providers' frequency of depot medroxyprogesterone acetate (DMPA) provision to adolescents.Study designWe analyzed data from surveys mailed to a nationally representative sample of public-sector providers and office-based physicians (n=1984). We estimated adjusted odds ratios (aORs) and 95% confidence intervals (CIs) of factors associated with frequent DMPA provision to adolescents in the past year.ResultsAlthough most providers (>95%) considered DMPA safe for adolescents, fewer reported frequent provision (89% of public-sector providers; 64% of office-based physicians). Among public-sector providers, factors associated with lower odds of frequent provision included working in settings without Title X funding (aOR 0.44, 95% CI 0.30–0.64), reporting primary care as their primary clinical focus versus reproductive or adolescent health (aOR 0.42, 95% CI 0.28–0.61), and providing fewer patients with family planning services. Among office-based physicians, factors associated with lower odds of frequent provision included specializing in obstetrics/gynecology (aOR 0.50, 95% CI 0.27–0.91) and family medicine (aOR 0.21, 95% CI 0.09–0.47) versus adolescent medicine, completing training ≥15 versus <5 years ago (aOR 0.27, 95% CI 0.09–0.83), and reporting that 0–24% of patients pay with Medicaid or other government healthcare assistance versus ≥50% (aOR 0.23, 95% CI 0.09–0.61). The reason most commonly reported by providers for infrequent DMPA provision was patient preference for another method.ConclusionsWhile most providers reported frequently providing DMPA to adolescents, training on evidence-based recommendations for contraception, focused on subgroups of providers with lower odds of frequent DMPA provision, may increase adolescents' access to contraception.ImplicationsAlthough >95% of providers considered depot medroxyprogesterone (DMPA) a safe contraceptive for adolescents, only 89% of public-sector providers and 64% of office-based physicians reported frequently providing DMPA to adolescents. Provider training on evidence-based recommendations for contraception counseling and provision may increase adolescents' access to DMPA and all methods of contraception. 相似文献
4.
5.
6.
7.
8.
9.
10.