全文获取类型
收费全文 | 5197篇 |
免费 | 369篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 78篇 |
儿科学 | 199篇 |
妇产科学 | 101篇 |
基础医学 | 670篇 |
口腔科学 | 89篇 |
临床医学 | 457篇 |
内科学 | 1273篇 |
皮肤病学 | 344篇 |
神经病学 | 351篇 |
特种医学 | 163篇 |
外科学 | 724篇 |
综合类 | 39篇 |
一般理论 | 7篇 |
预防医学 | 366篇 |
眼科学 | 63篇 |
药学 | 309篇 |
中国医学 | 2篇 |
肿瘤学 | 345篇 |
出版年
2023年 | 50篇 |
2022年 | 27篇 |
2021年 | 107篇 |
2020年 | 103篇 |
2019年 | 151篇 |
2018年 | 145篇 |
2017年 | 121篇 |
2016年 | 145篇 |
2015年 | 121篇 |
2014年 | 199篇 |
2013年 | 277篇 |
2012年 | 334篇 |
2011年 | 355篇 |
2010年 | 180篇 |
2009年 | 199篇 |
2008年 | 354篇 |
2007年 | 311篇 |
2006年 | 332篇 |
2005年 | 293篇 |
2004年 | 255篇 |
2003年 | 265篇 |
2002年 | 247篇 |
2001年 | 63篇 |
2000年 | 41篇 |
1999年 | 59篇 |
1998年 | 40篇 |
1997年 | 30篇 |
1996年 | 29篇 |
1995年 | 45篇 |
1994年 | 31篇 |
1993年 | 23篇 |
1992年 | 27篇 |
1991年 | 27篇 |
1990年 | 28篇 |
1989年 | 23篇 |
1988年 | 17篇 |
1987年 | 15篇 |
1986年 | 29篇 |
1985年 | 16篇 |
1984年 | 23篇 |
1983年 | 26篇 |
1982年 | 15篇 |
1981年 | 20篇 |
1980年 | 17篇 |
1979年 | 13篇 |
1973年 | 14篇 |
1972年 | 13篇 |
1971年 | 11篇 |
1970年 | 14篇 |
1967年 | 19篇 |
排序方式: 共有5580条查询结果,搜索用时 15 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.
Familial risk and heritability of intellectual disability: a population-based cohort study in Sweden
3.
Nicole Martinez-Martin Sarah Wieten David Magnus Mildred K. Cho 《The Hastings Center report》2020,50(3):43-46
Digital contact tracing, in combination with widespread testing, has been a focal point for many plans to “reopen” economies while containing the spread of Covid-19. Most digital contact tracing projects in the United States and Europe have prioritized privacy protections in the form of local storage of data on smartphones and the deidentification of information. However, in the prioritization of privacy in this narrow form, there is not sufficient attention given to weighing ethical trade-offs within the context of a public health pandemic or to the need to evaluate safety and effectiveness of software-based technology applied to public health. 相似文献
4.
5.
6.
Lamberto Torralba‐Raga Bianca Tesi Samuel C. C. Chiang Heinrich Schlums Magnus Nordenskjld AnnaCarin Horne Jan‐Inge Henter Marie Meeths Mohamed Abdelhaleem Sheila Weitzman Yenan Bryceson 《Pediatric blood & cancer》2020,67(4)
Mutations in SH2D1A, encoding the intracellular adaptor signaling lymphocyte activation molecule associated protein (SAP), are associated with X‐linked lymphoproliferative disease type 1 (XLP1). We identified a novel hemizygous SH2D1A c.49G > A (p.E17K) variant in a 21‐year‐old patient with fatal Epstein‐Barr virus infection–associated hemophagocytic lymphohistiocytosis. Cellular and biochemical assays revealed normal expression of the SAP variant protein, yet binding to phosphorylated CD244 receptor was reduced by >95%. Three healthy brothers carried the SH2D1A c.49G > A variant. Thus, data suggest that this variant represents a pathogenic mutation, but with variable expressivity. Importantly, our results highlight challenges in the clinical interpretation of SH2D1A variants and caution in using functional flow cytometry assays for the diagnosis of XLP1. 相似文献
7.
Femoral access‐related complications during percutaneous transcatheter aortic valve implantation comparing single versus double Prostar XL device closure 下载免费PDF全文
8.
Validation of a fast method for quantification of intra‐abdominal and subcutaneous adipose tissue for large‐scale human studies 下载免费PDF全文
Magnus Borga E Louise Thomas Thobias Romu Johannes Rosander Julie Fitzpatrick Olof Dahlqvist Leinhard Jimmy D. Bell 《NMR in biomedicine》2015,28(12):1747-1753
Central obesity is the hallmark of a number of non‐inheritable disorders. The advent of imaging techniques such as MRI has allowed for a fast and accurate assessment of body fat content and distribution. However, image analysis continues to be one of the major obstacles to the use of MRI in large‐scale studies. In this study we assess the validity of the recently proposed fat–muscle quantitation system (AMRATM Profiler) for the quantification of intra‐abdominal adipose tissue (IAAT) and abdominal subcutaneous adipose tissue (ASAT) from abdominal MR images. Abdominal MR images were acquired from 23 volunteers with a broad range of BMIs and analysed using sliceOmatic, the current gold‐standard, and the AMRATM Profiler based on a non‐rigid image registration of a library of segmented atlases. The results show that there was a highly significant correlation between the fat volumes generated by the two analysis methods, (Pearson correlation r = 0.97, p < 0.001), with the AMRATM Profiler analysis being significantly faster (~3 min) than the conventional sliceOmatic approach (~40 min). There was also excellent agreement between the methods for the quantification of IAAT (AMRA 4.73 ± 1.99 versus sliceOmatic 4.73 ± 1.75 l, p = 0.97). For the AMRATM Profiler analysis, the intra‐observer coefficient of variation was 1.6% for IAAT and 1.1% for ASAT, the inter‐observer coefficient of variation was 1.4% for IAAT and 1.2% for ASAT, the intra‐observer correlation was 0.998 for IAAT and 0.999 for ASAT, and the inter‐observer correlation was 0.999 for both IAAT and ASAT. These results indicate that precise and accurate measures of body fat content and distribution can be obtained in a fast and reliable form by the AMRATM Profiler, opening up the possibility of large‐scale human phenotypic studies. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
9.
Ingigerður S. Sverrisdóttir Sigrún H. Lund Ingemar Turesson Magnus Björkholm Lynn R. Goldin Ola Landgren Sigurður Y. Kristinsson 《British journal of haematology》2019,186(1):37-44
Parental longevity is associated with an increased life expectancy; results with regard to specific diseases are conflicting. There are limited data focusing on host characteristics and their effect on survival among multiple myeloma (MM) patients and individuals with monoclonal gammopathy of undetermined significance (MGUS). Therefore, our aim was to evaluate the impact of parental longevity on survival of patients with MM and MGUS. A total of 4675 patients with MM, 6812 MGUS patients and 13 398 population-based controls for MM as well as 19 110 controls for MGUS, from 1988 to 2013, were included in the study. Longevity was defined as >90 years of age. Among MM patients, parental longevity was associated with a decreased risk of death [hazard ratio (HR) = 0·92, 95% confidence interval (CI) 0·84–0·99] and the same was true for MGUS patients (HR = 0·87, 95% CI 0·78–0·96). Having one long lived parent significantly decreased the risk of death in both groups, but was not statistically significant when both parents exceeded 90 years of age. In conclusion, parental longevity decreases the risk of death for patients with MM and MGUS which may reflect the importance of the host's genetic and environmental factors in relation to survival. 相似文献
10.