全文获取类型
收费全文 | 1555450篇 |
免费 | 130105篇 |
国内免费 | 4455篇 |
专业分类
耳鼻咽喉 | 25643篇 |
儿科学 | 52607篇 |
妇产科学 | 44079篇 |
基础医学 | 210037篇 |
口腔科学 | 41635篇 |
临床医学 | 144239篇 |
内科学 | 317974篇 |
皮肤病学 | 36954篇 |
神经病学 | 126125篇 |
特种医学 | 63263篇 |
外国民族医学 | 390篇 |
外科学 | 259192篇 |
综合类 | 27622篇 |
现状与发展 | 73篇 |
一般理论 | 340篇 |
预防医学 | 106503篇 |
眼科学 | 35819篇 |
药学 | 108891篇 |
1篇 | |
中国医学 | 2756篇 |
肿瘤学 | 85867篇 |
出版年
2018年 | 21106篇 |
2017年 | 17819篇 |
2016年 | 20625篇 |
2015年 | 22341篇 |
2014年 | 33669篇 |
2013年 | 43781篇 |
2012年 | 45992篇 |
2011年 | 48112篇 |
2010年 | 34999篇 |
2009年 | 36773篇 |
2008年 | 47171篇 |
2007年 | 49325篇 |
2006年 | 52147篇 |
2005年 | 49149篇 |
2004年 | 46488篇 |
2003年 | 44452篇 |
2002年 | 43928篇 |
2001年 | 66543篇 |
2000年 | 67264篇 |
1999年 | 57697篇 |
1998年 | 18247篇 |
1997年 | 16303篇 |
1996年 | 16219篇 |
1995年 | 15970篇 |
1994年 | 14185篇 |
1993年 | 12859篇 |
1992年 | 44297篇 |
1991年 | 43721篇 |
1990年 | 42937篇 |
1989年 | 41691篇 |
1988年 | 38690篇 |
1987年 | 37793篇 |
1986年 | 36063篇 |
1985年 | 34308篇 |
1984年 | 25621篇 |
1983年 | 22197篇 |
1982年 | 13431篇 |
1981年 | 11823篇 |
1979年 | 24078篇 |
1978年 | 17017篇 |
1977年 | 14817篇 |
1976年 | 13816篇 |
1975年 | 15366篇 |
1974年 | 17853篇 |
1973年 | 17144篇 |
1972年 | 16441篇 |
1971年 | 15251篇 |
1970年 | 14188篇 |
1969年 | 13479篇 |
1968年 | 12676篇 |
排序方式: 共有10000条查询结果,搜索用时 16 毫秒
1.
2.
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
3.
Kara S. Tanaka MD Veronica R. Andaya BA Steven W. Thorpe MD Kenneth R. Gundle MD James B. Hayden MD Yee-Cheen Duong MD Raffi S. Avedian MD David G. Mohler MD Lee J. Morse MD Melissa N. Zimel MD Richard J. O'Donnell MD Andrew Fang MD Robert Lor Randall MD Tina H. Tran BS Christin New BA Rosanna L. Wustrack MD other members of Study Group FORCE 《Journal of surgical oncology》2023,127(1):148-158
4.
5.
6.
Jos B. Poell Leon J. Wils Arjen Brink Ralf Dietrich Christine Krieg Eunike Velleuer Ilkay Evren Elisabeth R. Brouns Jan G. de Visscher Elisabeth Bloemena Bauke Ylstra Ruud H. Brakenhoff 《International journal of cancer. Journal international du cancer》2023,152(2):227-238
Oral squamous cell carcinomas (OSCCs) develop in genetically altered epithelium in the mucosal lining, also coined as fields, which are mostly not visible but occasionally present as white oral leukoplakia (OL) lesions. We developed a noninvasive genetic assay using next-generation sequencing (NGS) on brushed cells to detect the presence of genetically altered fields, including those that are not macroscopically visible. The assay demonstrated high accuracy in OL patients when brush samples were compared with biopsies as gold standard. In a cohort of Fanconi anemia patients, detection of mutations in prospectively collected oral brushes predicted oral cancer also when visible abnormalities were absent. We further provide insight in the molecular landscape of OL with frequent changes of TP53, FAT1 and NOTCH1. NGS analysis of noninvasively collected samples offers a highly accurate method to detect genetically altered fields in the oral cavity, and predicts development of OSCC in high-risk individuals. Noninvasive genetic screening can be employed to screen high-risk populations for cancer and precancer, map the extension of OL lesions beyond what is visible, map the oral cavity for precancerous changes even when visible abnormalities are absent, test accuracy of promising imaging modalities, monitor interventions and determine genetic progression as well as the natural history of the disease in the human patient. 相似文献
7.
8.
Buket Bakan Fatih Oltulu Yeliz Y?ld?r?m Altu? Yava?o?lu Sinan Akg?l Nefise ülkü Karabay Yava?o?lu 《Arhiv za higijenu rada i toksikologiju》2023,74(3):207
The aim of this safety study in mice was to determine in vivo toxicity and biodistribution potential of a single and multiple doses of L-glutamic acid-g-p(HEMA) polymeric nanoparticles as a drug delivery system. The single dose did not cause any lethal effect, and its acute oral LD50 was >2.000 mg/kg body weight (bw). Multiple doses (25, 50, or 100 mg/kg bw) given over 28 days resulted in no significant differences in body and relative organ weights compared to control. These results are supported by biochemical and histological findings. Moreover, nanoparticle exposure did not result in statistically significant differences in micronucleus counts in bone marrow cells compared to control. Nanoparticle distribution was time-dependent, and they reached the organs and even bone marrow by hour 6, as established by ex vivo imaging with the IVIS® spectrum imaging system. In conclusion, L-glutamic acid-g-p(HEMA) polymeric nanoparticles appear biocompatible and have a potential use as a drug delivery system.KEY WORDS: biocompatibility, blood biochemistry, genotoxicity, histology, in vivo toxicity, micronucleus test, polymers 相似文献
9.
10.
Jones type fifth metatarsal fractures pose a challenge to the foot and ankle surgeon, given documented high nonunion rates as well as high complication rates including hardware prominence, nerve injury, and screw breakage for existing treatment modalities including screw and plantar plate fixation. We call for the design of innovative Jones-fracture specific implants which contour to the natural curve of the fifth metatarsal. Future research should aim to expand upon existing literature for Jones fracture fixation and evaluate efficacy of novel implants which are designed to address unacceptably high complication rates for existing treatment modalities. 相似文献