全文获取类型
收费全文 | 6251篇 |
免费 | 573篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 57篇 |
儿科学 | 174篇 |
妇产科学 | 214篇 |
基础医学 | 823篇 |
口腔科学 | 112篇 |
临床医学 | 720篇 |
内科学 | 1314篇 |
皮肤病学 | 117篇 |
神经病学 | 628篇 |
特种医学 | 149篇 |
外科学 | 848篇 |
综合类 | 110篇 |
一般理论 | 3篇 |
预防医学 | 685篇 |
眼科学 | 72篇 |
药学 | 376篇 |
中国医学 | 1篇 |
肿瘤学 | 428篇 |
出版年
2023年 | 58篇 |
2022年 | 38篇 |
2021年 | 151篇 |
2020年 | 132篇 |
2019年 | 185篇 |
2018年 | 195篇 |
2017年 | 141篇 |
2016年 | 171篇 |
2015年 | 143篇 |
2014年 | 223篇 |
2013年 | 322篇 |
2012年 | 467篇 |
2011年 | 469篇 |
2010年 | 271篇 |
2009年 | 214篇 |
2008年 | 339篇 |
2007年 | 386篇 |
2006年 | 339篇 |
2005年 | 345篇 |
2004年 | 299篇 |
2003年 | 250篇 |
2002年 | 211篇 |
2001年 | 103篇 |
2000年 | 105篇 |
1999年 | 111篇 |
1998年 | 63篇 |
1997年 | 41篇 |
1996年 | 39篇 |
1995年 | 56篇 |
1994年 | 44篇 |
1993年 | 54篇 |
1992年 | 89篇 |
1991年 | 73篇 |
1990年 | 62篇 |
1989年 | 56篇 |
1988年 | 50篇 |
1987年 | 66篇 |
1986年 | 39篇 |
1985年 | 43篇 |
1984年 | 45篇 |
1983年 | 37篇 |
1982年 | 22篇 |
1981年 | 23篇 |
1980年 | 21篇 |
1979年 | 24篇 |
1978年 | 33篇 |
1977年 | 24篇 |
1976年 | 16篇 |
1975年 | 21篇 |
1971年 | 17篇 |
排序方式: 共有6831条查询结果,搜索用时 31 毫秒
1.
Dongbing Lai Emma C. Johnson Sarah Colbert Gayathri Pandey Grace Chan Lance Bauer Meredith W. Francis Victor Hesselbrock Chella Kamarajan John Kramer Weipeng Kuang Sally Kuo Samuel Kuperman Yunlong Liu Vivia McCutcheon Zhiping Pang Martin H. Plawecki Marc Schuckit Jay Tischfield Leah Wetherill Yong Zang Howard J. Edenberg Bernice Porjesz Arpana Agrawal Tatiana Foroud 《Alcoholism, clinical and experimental research》2022,46(3):374-383
2.
3.
W. Jeffrey Zabel Jessica L. Conway Adam Gladwish Julia Skliarenko Giulio Didiodato Leah Goorts-Matthews Adam Michalak Sarah Reistetter Jenna King Keith Nakonechny Kyle Malkoske Muoi N. Tran Nevin McVicar 《Practical radiation oncology》2021,11(1):e80-e89
PurposeAuto-contouring may reduce workload, interobserver variation, and time associated with manual contouring of organs at risk. Manual contouring remains the standard due in part to uncertainty around the time and workload savings after accounting for the review and editing of auto-contours. This preliminary study compares a standard manual contouring workflow with 2 auto-contouring workflows (atlas and deep learning) for contouring the bladder and rectum in patients with prostate cancer.Methods and MaterialsThree contouring workflows were defined based on the initial contour-generation method including manual (MAN), atlas-based auto-contour (ATLAS), and deep-learning auto-contour (DEEP). For each workflow, initial contour generation was retrospectively performed on 15 patients with prostate cancer. Then, radiation oncologists (ROs) edited each contour while blinded to the manner in which the initial contour was generated. Workflows were compared by time (both in initial contour generation and in RO editing), contour similarity, and dosimetric evaluation.ResultsMean durations for initial contour generation were 10.9 min, 1.4 min, and 1.2 min for MAN, DEEP, and ATLAS, respectively. Initial DEEP contours were more geometrically similar to initial MAN contours. Mean durations of the RO editing steps for MAN, DEEP, and ATLAS contours were 4.1 min, 4.7 min, and 10.2 min, respectively. The geometric extent of RO edits was consistently larger for ATLAS contours compared with MAN and DEEP. No differences in clinically relevant dose-volume metrics were observed between workflows.ConclusionAuto-contouring software affords time savings for initial contour generation; however, it is important to also quantify workload changes at the RO editing step. Using deep-learning auto-contouring for bladder and rectum contour generation reduced contouring time without negatively affecting RO editing times, contour geometry, or clinically relevant dose–volume metrics. This work contributes to growing evidence that deep-learning methods are a clinically viable solution for organ-at-risk contouring in radiation therapy. 相似文献
4.
Merkel cell carcinoma (MCC) is a rare neuroendocrine carcinoma of the skin, for which the exact mechanisms of carcinogenesis remain unknown. Therapeutic options for this highly aggressive malignancy have historically been limited in both their initial response and response durability. Recent improvements in our understanding of MCC tumor biology have expanded therapeutic options for these patients, namely through the use of immunotherapies such as immune checkpoint inhibitors. Further elucidation of the tumor mutational landscape has identified molecular targets for therapies, which have demonstrated success in other cancer types. In this review, we discuss both current and investigational immune and molecular targets of therapy for MCC. 相似文献
5.
Katherine T. Flynn-O’Brien Morgan K. Richards Davene R. Wright Frederick P. Rivara Wren Haaland Leah Thompson Keith Oldham Adam Goldin 《Journal of pediatric surgery》2019,54(4):621-627
Background
There is a movement to ensure that pediatric patients are treated in appropriately resourced hospitals through the ACS Children’s Surgery Verification (CSV) program. The objective of this study was to assess the potential difference in care provision, health outcomes and healthcare and societal costs after implementation of the CSV program.Methods
All 2011 inpatient admissions for selected complex pediatric patients warranting treatment at a hospital with Level I resources were evaluated across 6 states. Multivariate regressions were used to analyze differences in healthcare outcomes (postoperative complications including death, length of stay, readmissions and ED visits within 30 days) and costs by CSV level. Recycled predictions were used to estimate differences between the base case scenario, where children actually received care, and the optimized scenario, where all children were theoretically treated at Level I centers.Results
8,006 children (mean age 3.06 years, SD 4.49) met inclusion criteria, with 45% treated at Level I hospitals, 30% at Level II and 25% at Level III. No statistically significant differences were observed in healthcare outcomes. Readmissions within 30 days were higher at Level II compared to Level I centers (adjusted IRR 1.61; 95% CI 1.11, 2.34), with an estimated 24 avoidable readmissions per 1000 children if treatment were shifted from Level II to Level I centers. Overall, costs per child were not significantly different between the base case and the optimized scenario.Conclusion
Many complex surgical procedures are being performed at Level II/III centers. This study found no statistically significant increase in healthcare or societal costs if these were performed instead at Level I centers under the optimized scenario. Ongoing evaluation of efforts to match institutional resources with individual patient needs is needed to optimize children’s surgical care in the United States.Level of evidence
II. 相似文献6.
Early loss of vision produces dramatic changes in the functional organization and connectivity of the neocortex in cortical areas that normally process visual inputs, such as the primary and second visual area. This loss also results in alterations in the size, functional organization, and neural response properties of the primary somatosensory area, S1. However, the anatomical substrate for these functional changes in S1 has never been described. In the present investigation, we quantified the cortical and subcortical connections of S1 in animals that were bilaterally enucleated very early in development, prior to the formation of retino-geniculate and thalamocortical pathways. We found that S1 receives dense inputs from novel cortical fields, and that the density of existing cortical and thalamocortical connections was altered. Our results demonstrate that sensory systems develop in tandem and that alterations in sensory input in one system can affect the connections and organization of other sensory systems. Thus, therapeutic intervention following early loss of vision should focus not only on restoring vision, but also on augmenting the natural plasticity of the spared systems. 相似文献
7.
8.
Leah H. Cobb Emily M. McCabe Lauren B. Priddy 《Journal of orthopaedic research》2020,38(10):2091-2103
Osteomyelitis, or the infection of the bone, presents a major complication in orthopedics and may lead to prolonged hospital visits, implant failure, and in more extreme cases, amputation of affected limbs. Typical treatment for this disease involves surgical debridement followed by long-term, systemic antibiotic administration, which contributes to the development of antibiotic-resistant bacteria and has limited ability to eradicate challenging biofilm-forming pathogens including Staphylococcus aureus—the most common cause of osteomyelitis. Local delivery of high doses of antibiotics via traditional bone cement can reduce systemic side effects of an antibiotic. Nonetheless, growing concerns over burst release (then subtherapeutic dose) of antibiotics, along with microbial colonization of the nondegradable cement biomaterial, further exacerbate antibiotic resistance and highlight the need to engineer alternative antimicrobial therapeutics and local delivery vehicles with increased efficacy against, in particular, biofilm-forming, antibiotic-resistant bacteria. Furthermore, limited guidance exists regarding both standardized formulation protocols and validated assays to predict efficacy of a therapeutic against multiple strains of bacteria. Ideally, antimicrobial strategies would be highly specific while exhibiting a broad spectrum of bactericidal activity. With a focus on S. aureus infection, this review addresses the efficacy of novel therapeutics and local delivery vehicles, as alternatives to the traditional antibiotic regimens. The aim of this review is to discuss these components with regards to long bone osteomyelitis and to encourage positive directions for future research efforts. 相似文献
9.
10.