全文获取类型
收费全文 | 3875篇 |
免费 | 405篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 49篇 |
儿科学 | 49篇 |
妇产科学 | 71篇 |
基础医学 | 651篇 |
口腔科学 | 108篇 |
临床医学 | 376篇 |
内科学 | 871篇 |
皮肤病学 | 172篇 |
神经病学 | 308篇 |
特种医学 | 150篇 |
外科学 | 644篇 |
综合类 | 50篇 |
一般理论 | 1篇 |
预防医学 | 236篇 |
眼科学 | 40篇 |
药学 | 224篇 |
中国医学 | 1篇 |
肿瘤学 | 291篇 |
出版年
2022年 | 51篇 |
2021年 | 70篇 |
2020年 | 35篇 |
2019年 | 64篇 |
2018年 | 92篇 |
2017年 | 78篇 |
2016年 | 87篇 |
2015年 | 101篇 |
2014年 | 131篇 |
2013年 | 164篇 |
2012年 | 227篇 |
2011年 | 219篇 |
2010年 | 127篇 |
2009年 | 118篇 |
2008年 | 166篇 |
2007年 | 188篇 |
2006年 | 188篇 |
2005年 | 168篇 |
2004年 | 146篇 |
2003年 | 141篇 |
2002年 | 130篇 |
2001年 | 111篇 |
2000年 | 108篇 |
1999年 | 93篇 |
1998年 | 35篇 |
1997年 | 22篇 |
1996年 | 33篇 |
1995年 | 31篇 |
1994年 | 22篇 |
1992年 | 75篇 |
1991年 | 58篇 |
1990年 | 64篇 |
1989年 | 64篇 |
1988年 | 53篇 |
1987年 | 67篇 |
1986年 | 41篇 |
1985年 | 57篇 |
1984年 | 34篇 |
1983年 | 38篇 |
1979年 | 36篇 |
1978年 | 26篇 |
1976年 | 26篇 |
1975年 | 23篇 |
1974年 | 40篇 |
1973年 | 50篇 |
1972年 | 30篇 |
1971年 | 25篇 |
1970年 | 22篇 |
1969年 | 25篇 |
1967年 | 20篇 |
排序方式: 共有4292条查询结果,搜索用时 15 毫秒
141.
142.
143.
Adler Christoph Onur Oezguer A. Braumann Simon Gramespacher Hannes Bittner Stefan Falk Steffen Fink Gereon R. Baldus Stephan Warnke Clemens 《Journal of neurology》2022,269(3):1530-1537
Journal of Neurology - To test if the early kinetics of neurofilament light (NFL) in blood adds to the absolute values of NFL in the prediction of outcome, and to evaluate if NFL can discriminate... 相似文献
144.
Sage Hahn Scott Mackey Janna Cousijn John J. Foxe Andreas Heinz Robert Hester Kent Hutchinson Falk Kiefer Ozlem Korucuoglu Tristram Lett Chiang-Shan R. Li Edythe London Valentina Lorenzetti Luijten Maartje Reza Momenan Catherine Orr Martin Paulus Lianne Schmaal Rajita Sinha Zsuzsika Sjoerds Dan J. Stein Elliot Stein Ruth J. van Holst Dick Veltman Henrik Walter Reinout W. Wiers Murat Yucel Paul M. Thompson Patricia Conrod Nicholas Allgaier Hugh Garavan 《Human brain mapping》2022,43(1):555-565
To identify neuroimaging biomarkers of alcohol dependence (AD) from structural magnetic resonance imaging, it may be useful to develop classification models that are explicitly generalizable to unseen sites and populations. This problem was explored in a mega-analysis of previously published datasets from 2,034 AD and comparison participants spanning 27 sites curated by the ENIGMA Addiction Working Group. Data were grouped into a training set used for internal validation including 1,652 participants (692 AD, 24 sites), and a test set used for external validation with 382 participants (146 AD, 3 sites). An exploratory data analysis was first conducted, followed by an evolutionary search based feature selection to site generalizable and high performing subsets of brain measurements. Exploratory data analysis revealed that inclusion of case- and control-only sites led to the inadvertent learning of site-effects. Cross validation methods that do not properly account for site can drastically overestimate results. Evolutionary-based feature selection leveraging leave-one-site-out cross-validation, to combat unintentional learning, identified cortical thickness in the left superior frontal gyrus and right lateral orbitofrontal cortex, cortical surface area in the right transverse temporal gyrus, and left putamen volume as final features. Ridge regression restricted to these features yielded a test-set area under the receiver operating characteristic curve of 0.768. These findings evaluate strategies for handling multi-site data with varied underlying class distributions and identify potential biomarkers for individuals with current AD. 相似文献
145.
Surgical management of driveline infections in patients with left ventricular assist devices
下载免费PDF全文
![点击此处可从《Journal of cardiac surgery》网站下载免费的PDF全文](/ch/ext_images/free.gif)
146.
Augmentation of Transient Donor Cell Chimerism and Alloantigen‐Specific Regulation of Lung Transplants in Miniature Swine
下载免费PDF全文
![点击此处可从《American journal of transplantation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
W. Sommer B. Kruse S. Thissen K. Dreckmann A.‐K. Knoefel J. Salman C. Hafer J. Hecker G. Buechler J. H. Karstens D. Jonigk F. Länger V. Kaever C. S. Falk M. Hewicker‐Trautwein H. Ungefroren A. Haverich G. Warnecke 《American journal of transplantation》2016,16(5):1371-1382
Donor alloantigen infusion induces T cell regulation and transplant tolerance in small animals. Here, we study donor splenocyte infusion in a large animal model of pulmonary transplantation. Major histocompatibility complex–mismatched single lung transplantation was performed in 28 minipigs followed by a 28‐day course of methylprednisolone and tacrolimus. Some animals received a perioperative donor or third party splenocyte infusion, with or without low‐dose irradiation (IRR) before surgery. Graft survival was significantly prolonged in animals receiving both donor splenocytes and IRR compared with controls with either donor splenocytes or IRR only. In animals with donor splenocytes and IRR, increased donor cell chimerism and CD4+CD25high+ T cell frequencies were detected in peripheral blood associated with decreased interferon‐γ production of leukocytes. Secondary third‐party kidney transplants more than 2 years after pulmonary transplantation were acutely rejected despite maintained tolerance of the lung allografts. As a cellular control, additional animals received third‐party splenocytes or donor splenocyte protein extracts. While animals treated with third‐party splenocytes showed significant graft survival prolongation, the subcellular antigen infusion showed no such effect. In conclusion, minipigs conditioned with preoperative IRR and donor, or third‐party, splenocyte infusions may develop long‐term donor‐specific pulmonary allograft survival in the presence of high levels of circulating regulatory T cells. 相似文献
147.
148.
Freyschmidt EJ Mathias CB MacArthur DH Laouar A Narasimhaswamy M Weih F Oettgen HC 《The Journal of allergy and clinical immunology》2007,119(3):671-679
BACKGROUND: Atopic dermatitis (AD) is an inflammatory skin disorder occurring in genetically predisposed individuals with a systemic T(H)2 bias. Atopic dermatitis patients exposed to the smallpox vaccine, vaccinia virus (VV), occasionally develop eczema vaccinatum (EV), an overwhelming and potentially lethal systemic infection with VV. OBJECTIVE: To establish a murine model of EV and examine the effects of skin inflammation on VV immunity. METHODS: The skin of RelB(-/-) mice, like that of chronic AD lesions in humans, exhibits thickening, eosinophilic infiltration, hyperkeratosis, and acanthosis. RelB(-/-) and wild-type (WT) control mice were infected with VV via skin scarification. Viral spread, cytokine levels, IgG2a responses and VV-specific T cells were measured. RESULTS: Cutaneously VV-infected RelB(-/-), but not WT mice, exhibited weight loss, markedly impaired systemic clearance of the virus and increased contiguous propagation from the inoculation site. This was associated with a dramatically impaired generation of IFN-gamma-producing CD8(+) vaccinia-specific T cells along with decreased secretion of IFN-gamma by VV-stimulated splenocytes. The T(H)2 cytokines-IL-4, IL-5, IL-13, and IL-10-on the other hand, were overproduced. When infected intraperitoneally, RelB(-/-) mice generated robust T cell responses with good IFN-gamma production. CONCLUSION: Allergic inflammation in RelB(-/-) mice is associated with dysregulated immunity to VV encountered via the skin. We speculate that susceptibility of AD patients to overwhelming vaccinia virus infection is similarly related to ineffective T cell responses. CLINICAL IMPLICATIONS: The susceptibility of patients with AD to EV following cutaneous contact with VV is related to ineffective antiviral immune responses. 相似文献
149.
Nasal Staphylococcus aureus carriage is not a risk factor for lower-airway infection in young cystic fibrosis patients
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Ridder-Schaphorn S Ratjen F Dübbers A Häberle J Falk S Küster P Schuster A Mellies U Löwe B Reintjes R Peters G Kahl BC 《Journal of clinical microbiology》2007,45(9):2979-2984
Staphylococcus aureus is one of the first pathogens which often persistently infect the airways of cystic fibrosis (CF) patients. Nasal S. aureus carriage is a risk factor for S. aureus infections in non-CF patients. Topical treatment strategies successfully eradicate nasal S. aureus carriage, thereby decreasing S. aureus infection. A prospective longitudinal multicenter study was conducted to assess whether nasal carriage represents a risk factor for S. aureus colonization of the oropharynx in young CF patients. Cross-sectional analysis revealed a significantly higher prevalence of S. aureus-positive nasal (28/80 [35%] versus 20/109 [18%]; P < 0.01) and oropharyngeal (35/80 [44%] versus 20/109 [18%]; P < 0.001) cultures in children with CF compared to a control group. The first site of S. aureus detection was the nose in 6 patients and the oropharynx in 14 patients, respectively. Longitudinal analysis demonstrated a significantly higher S. aureus prevalence (61/62 [98%] versus 47/62 [76%]; P < 0.001) and persistence (46/62 [74%] versus 31/62 [50%]; P < 0.01) in the oropharynx than in the nose. In CF patients, the oropharynx, and not the nose, was the predominant site of S. aureus infection and persistence. Hence, it is unlikely that CF patients will benefit from topical treatment strategies to eradicate nasal carriage. 相似文献
150.
Alternative complement pathway in the pathogenesis of disease mediated by anti-neutrophil cytoplasmic autoantibodies
下载免费PDF全文
![点击此处可从《The American journal of pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Xiao H Schreiber A Heeringa P Falk RJ Jennette JC 《The American journal of pathology》2007,170(1):52-64
Clinical and experimental data indicate that anti-neutrophil cytoplasmic autoantibodies (ANCAs) cause glomerulonephritis and vasculitis. Here we report the first evidence that complement is an important mediator of ANCA disease. Transfer of anti-myeloperoxidase (MPO) IgG into wild-type mice or anti-MPO splenocytes into immune-deficient mice caused crescentic glomerulonephritis that could be completely blocked by complement depletion. The role of specific complement activation pathways was investigated using mice with knockout of the common pathway component C5, classic and lectin binding pathway component C4, and alternative pathway component factor B. After injection of anti-MPO IgG, C4-/- mice developed disease comparable with wild-type disease; however, C5-/- and factor B-/- mice developed no disease. To substantiate a role for complement in human ANCA disease, IgG was isolated from patients with myeloperoxidase ANCA (MPO-ANCA) or proteinase 3 ANCA (PR3-ANCA) and from controls. Incubation of MPO-ANCA or PR3-ANCA IgG with human neutrophils caused release of factors that activated complement. IgG from healthy controls did not produce this effect. The findings suggest that stimulation of neutrophils by ANCA causes release of factors that activate complement via the alternative pathway, thus initiating an inflammatory amplification loop that mediates the severe necrotizing inflammation of ANCA disease. 相似文献