全文获取类型
收费全文 | 56380篇 |
免费 | 4117篇 |
国内免费 | 139篇 |
专业分类
耳鼻咽喉 | 516篇 |
儿科学 | 1973篇 |
妇产科学 | 1665篇 |
基础医学 | 6749篇 |
口腔科学 | 1082篇 |
临床医学 | 9432篇 |
内科学 | 9827篇 |
皮肤病学 | 667篇 |
神经病学 | 5380篇 |
特种医学 | 1163篇 |
外科学 | 5058篇 |
综合类 | 944篇 |
一般理论 | 157篇 |
预防医学 | 7835篇 |
眼科学 | 1215篇 |
药学 | 3033篇 |
中国医学 | 40篇 |
肿瘤学 | 3900篇 |
出版年
2023年 | 282篇 |
2022年 | 395篇 |
2021年 | 896篇 |
2020年 | 674篇 |
2019年 | 1163篇 |
2018年 | 1245篇 |
2017年 | 956篇 |
2016年 | 1126篇 |
2015年 | 1285篇 |
2014年 | 1663篇 |
2013年 | 2706篇 |
2012年 | 3714篇 |
2011年 | 3837篇 |
2010年 | 2111篇 |
2009年 | 1879篇 |
2008年 | 3501篇 |
2007年 | 3890篇 |
2006年 | 3818篇 |
2005年 | 3703篇 |
2004年 | 3517篇 |
2003年 | 3316篇 |
2002年 | 3197篇 |
2001年 | 683篇 |
2000年 | 594篇 |
1999年 | 665篇 |
1998年 | 753篇 |
1997年 | 575篇 |
1996年 | 528篇 |
1995年 | 478篇 |
1994年 | 468篇 |
1993年 | 427篇 |
1992年 | 446篇 |
1991年 | 425篇 |
1990年 | 426篇 |
1989年 | 379篇 |
1988年 | 375篇 |
1987年 | 359篇 |
1986年 | 351篇 |
1985年 | 380篇 |
1984年 | 293篇 |
1983年 | 296篇 |
1982年 | 313篇 |
1981年 | 319篇 |
1980年 | 299篇 |
1979年 | 195篇 |
1978年 | 192篇 |
1977年 | 164篇 |
1976年 | 153篇 |
1975年 | 140篇 |
1974年 | 139篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Hannah C. Nordhues Anjali Bhagra Natya N. Stroud Jennifer A. Vencill Carol L. Kuhle 《Mayo Clinic proceedings. Mayo Clinic》2021,96(7):1907-1920
The coronavirus disease 2019 (COVID-19) pandemic has rapidly created widespread impacts on global health and the economy. Data suggest that women are less susceptible to severe illness. However, sex-disaggregated data are incomplete, leaving room for misinterpretation, and focusing only on biologic sex underestimates the gendered impact of the pandemic on women. This narrative review summarizes what is known about gender disparities during the COVID-19 pandemic and the economic, domestic, and health burdens along with overlapping vulnerabilities related to the pandemic. In addition, this review outlines recommended strategies that advocacy groups, community leaders, and policymakers should implement to mitigate the widening gender disparities related to COVID-19. 相似文献
2.
3.
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
4.
Osric A. Forrest Daniel M. Chopyk Yael Gernez Milton R. Brown Carol K. Conrad Richard B. Moss Vin Tangpricha Limin Peng Rabindra Tirouvanziam 《Journal of cystic fibrosis》2019,18(1):64-70
Background
Resistin is an immunometabolic mediator that is elevated in several inflammatory disorders. A ligand for Toll-like receptor 4, resistin modulates the recruitment and activation of myeloid cells, notably neutrophils. Neutrophils are major drivers of cystic fibrosis (CF) lung disease, in part due to the release of human neutrophil elastase- and myeloperoxidase-rich primary granules, leading to tissue damage. Here we assessed the relationship of resistin to CF lung disease.Methods
Resistin levels were measured in plasma and sputum from three retrospective CF cohorts spanning a wide range of disease. We also assessed the ability of neutrophils to secrete resistin upon activation in vitro. Finally, we constructed a multivariate model assessing the relationship between resistin levels and lung function.Results
Plasma resistin levels were only marginally higher in CF than in healthy control subjects. By contrast, sputum resistin levels were very high in CF, reaching 50–100 fold higher levels than in plasma. Among CF patients, higher plasma resistin levels were associated with allergic bronchopulmonary aspergillosis, and higher sputum resistin levels were associated with CF-related diabetes. Mechanistically, in vitro release of neutrophil primary granules was concomitant with resistin secretion. Overall, sputum resistin levels were negatively correlated with CF lung function, independently of other variables (age, sex, and genotype).Conclusions
Our data establish relationships between resistin levels in the plasma and sputum of CF patients that correlate with disease status, and identify resistin as a novel mechanistic link between neutrophilic inflammation and lung disease in CF. 相似文献5.
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
6.
7.
8.
9.
10.