全文获取类型
收费全文 | 3336篇 |
免费 | 265篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 38篇 |
儿科学 | 84篇 |
妇产科学 | 72篇 |
基础医学 | 491篇 |
口腔科学 | 68篇 |
临床医学 | 367篇 |
内科学 | 697篇 |
皮肤病学 | 77篇 |
神经病学 | 353篇 |
特种医学 | 57篇 |
外科学 | 359篇 |
综合类 | 27篇 |
预防医学 | 412篇 |
眼科学 | 61篇 |
药学 | 233篇 |
中国医学 | 16篇 |
肿瘤学 | 196篇 |
出版年
2024年 | 11篇 |
2023年 | 72篇 |
2022年 | 120篇 |
2021年 | 232篇 |
2020年 | 140篇 |
2019年 | 149篇 |
2018年 | 182篇 |
2017年 | 108篇 |
2016年 | 114篇 |
2015年 | 102篇 |
2014年 | 145篇 |
2013年 | 167篇 |
2012年 | 258篇 |
2011年 | 265篇 |
2010年 | 146篇 |
2009年 | 121篇 |
2008年 | 158篇 |
2007年 | 157篇 |
2006年 | 144篇 |
2005年 | 137篇 |
2004年 | 125篇 |
2003年 | 90篇 |
2002年 | 77篇 |
2001年 | 20篇 |
2000年 | 29篇 |
1999年 | 21篇 |
1998年 | 13篇 |
1997年 | 14篇 |
1996年 | 12篇 |
1995年 | 15篇 |
1993年 | 13篇 |
1992年 | 12篇 |
1991年 | 20篇 |
1990年 | 21篇 |
1989年 | 13篇 |
1988年 | 15篇 |
1987年 | 20篇 |
1986年 | 14篇 |
1985年 | 12篇 |
1983年 | 10篇 |
1982年 | 6篇 |
1981年 | 12篇 |
1979年 | 6篇 |
1978年 | 7篇 |
1977年 | 9篇 |
1975年 | 8篇 |
1974年 | 10篇 |
1973年 | 7篇 |
1972年 | 6篇 |
1965年 | 6篇 |
排序方式: 共有3608条查询结果,搜索用时 15 毫秒
31.
32.
33.
34.
35.
36.
Olivia Fletcher Lorna Gibson Nichola Johnson Dan R Altmann Jeffrey M P Holly Alan Ashworth Julian Peto Isabel Dos Santos Silva 《Cancer epidemiology, biomarkers & prevention》2005,14(1):2-19
We reviewed all English-language articles on associations among circulating levels of the insulin-like growth factors (IGF) and their binding proteins (IGFBP), polymorphisms in their genes, and breast cancer risk. In premenopausal women, five of eight IGF-I studies and four of six IGFBP-3 studies of circulating levels found that women in the highest quantile had more than twice the risk of developing breast cancer of those in the lowest, although in some this effect was only apparent at young ages. In postmenopausal women, however, there was no consistent effect. A simple sequence length polymorphism 1 kb 5' to IGF-I was examined in relation to circulating levels of IGF-I (12 studies) or breast cancer risk (4 studies), but there was no convincing evidence of any effect. For an A/C polymorphism 5' to IGFBP-3, all three studies were consistent with a modest effect on circulating levels, but no evidence of a direct effect on breast cancer risk was seen in the only relevant study. Variation within the reference range of IGF-I and IGFBP-3 may confer only modest increases in breast cancer risk, and any single polymorphism may only account for a small proportion of that variation. Nevertheless, population attributable fractions for high circulating levels of IGF-I and IGFBP-3 and for common genetic variants could be substantial. Further large studies, or combined analysis of data from existing studies, are needed to quantify these effects more precisely. 相似文献
37.
38.
Pierre Delabie ric Baudin Olivia Hentic Pauline Afchain Timofei Rusu Franoise Montravers 《Medicine》2022,101(47)
The main purpose of this retrospective study was to determine the diagnostic performance of [68Ga]Ga-DOTA-D-Phe1-Try3-octreotide(DOTA-TOC) positron emission tomography/computed tomography (PET/CT) in patients with well-differentiated colorectal Neuroendocrine Tumours (NETs) originating from the hindgut. The other aims were to assess the impact of the examination on patient management and to analyze the results of 2-[18F]FDG and/or 6-[18F]FDOPA PET/CT when they were performed. [68Ga]Ga-DOTA-TOC PET/CT and clinical data from 30 patients with biopsy-proven well-differentiated NETs originating from the hindgut were retrospectively reviewed and analyzed by comparing the [68Ga]Ga-DOTA-TOC PET/CT findings with pathological and/or follow-up data. We also compared the [68Ga]Ga-DOTA-TOC PET/CT results with 2-[18F]FDG and/or 6-[18F]FDOPA PET/CT results in 6 patients. The impact on management was determined in hindsight by comparing the patient management decided before and after the TEP examination based on data from multidisciplinary team meetings. On a patient basis, [68Ga]Ga-DOTA-TOC PET/CT was accurate in 30 of the 30 examinations. [68Ga]Ga-DOTA-TOC PET/CT correctly identified the primary tumor in all patients with primary tumors not resected before the examination and allowed the detection of unexpected distant metastases in 36% of the patients referred for initial staging. [68Ga]Ga-DOTA-TOC PET/CT findings affected patient management in 57% of cases with generally major intermodality changes. Intraindividual comparison of the results of the different PET radiopharmaceuticals showed a clear superiority of [68Ga]Ga-DOTA-TOC PET/CT considering both the number of lesions and the intensity of uptake. [68Ga]Ga-DOTA-TOC PET/CT is an accurate imaging modality for the assessment of well-differentiated colorectal NETs that highly impact patient management. Thus, we suggest that [68Ga]Ga-DOTA-TOC PET/CT be employed as a first choice for the assessment of these tumors in nuclear medicine. 相似文献
39.
The study of intra and interlayer excitons in 2D semiconducting vdW heterostructures is a very hot topic not only from a fundamental but also an applicative point of view. Due to their strong light–matter interaction, Transition Metal Dichalcogenides (TMD) and group-III nitrides are particularly attractive in the field of opto-electronic applications such as photo-catalytic and photo-voltaic ultra-thin and flexible devices. Using first-principles ground and excited-state simulations, we investigate here the electronic and excitonic properties of a representative nitride/TMD heterobilayer, the . We demonstrate that the band alignment is of type I, and low energy intralayer excitons are similar to those of a pristine monolayer. Further, we disentangle the role of strain and AlN dielectric screening on the electronic and optical gaps. These results, although they do not favor the possible use of AlN/ in photo-catalysis, as envisaged in the previous literature, can boost the recently started experimental studies of 2D hexagonal aluminum nitride as a good low screening substrate for TMD-based electronic and opto-electronic devices. Importantly, our work shows how the inclusion of both spin-orbit and many-body interactions is compulsory for the correct prediction of the electronic and optical properties of TMD/nitride heterobilayers. 相似文献
40.
Prerna Sharma Kajal Shah Johanna Loomba Arti Patel Indika Mallawaarachchi Olivia Blazek Sarah Ratcliffe Khadijah Breathett Amber E. Johnson Angela M. Taylor Michael Salerno Michael Ragosta Nishtha Sodhi Daniel Addison Selma Mohammed Kenneth C. Bilchick Sula Mazimba 《Clinical cardiology》2022,45(10):1070
BackgroundThe implications of coronavirus disease 2019 (COVID‐19) infection on outcomes after invasive therapeutic strategies among patients presenting with acute myocardial infarction (AMI) are not well studied.HypothesisTo assess the outcomes of COVID‐19 patients presenting with AMI undergoing an early invasive treatment strategy.MethodsThis study was a cross‐sectional, retrospective analysis of the National COVID Cohort Collaborative database including all patients presenting with a recorded diagnosis of AMI (ST‐elevation myocardial infarction (MI) and non‐ST elevation MI). COVID‐19 positive patients with AMI were stratified into one of four groups: (1a) patients who had a coronary angiogram with percutaneous coronary intervention (PCI) within 3 days of their AMI; (1b) PCI within 3 days of AMI with coronary artery bypass graft (CABG) within 30 days; (2a) coronary angiogram without PCI and without CABG within 30 days; and (2b) coronary angiogram with CABG within 30 days. The main outcomes were respiratory failure, cardiogenic shock, prolonged length of stay, rehospitalization, and death.ResultsThere were 10 506 COVID‐19 positive patients with a diagnosis of AMI. COVID‐19 positive patients with PCI had 8.2 times higher odds of respiratory failure than COVID‐19 negative patients (p = .001). The odds of prolonged length of stay were 1.7 times higher in COVID‐19 patients who underwent PCI (p = .024) and 1.9 times higher in patients who underwent coronary angiogram followed by CABG (p = .001).ConclusionThese data demonstrate that COVID‐19 positive patients with AMI undergoing early invasive coronary angiography had worse outcomes than COVID‐19 negative patients. 相似文献