全文获取类型
收费全文 | 5227篇 |
免费 | 359篇 |
国内免费 | 47篇 |
专业分类
耳鼻咽喉 | 45篇 |
儿科学 | 109篇 |
妇产科学 | 134篇 |
基础医学 | 826篇 |
口腔科学 | 84篇 |
临床医学 | 457篇 |
内科学 | 1333篇 |
皮肤病学 | 88篇 |
神经病学 | 621篇 |
特种医学 | 113篇 |
外科学 | 529篇 |
综合类 | 9篇 |
一般理论 | 3篇 |
预防医学 | 299篇 |
眼科学 | 78篇 |
药学 | 427篇 |
中国医学 | 9篇 |
肿瘤学 | 469篇 |
出版年
2024年 | 5篇 |
2023年 | 54篇 |
2022年 | 120篇 |
2021年 | 184篇 |
2020年 | 115篇 |
2019年 | 154篇 |
2018年 | 156篇 |
2017年 | 118篇 |
2016年 | 172篇 |
2015年 | 165篇 |
2014年 | 199篇 |
2013年 | 292篇 |
2012年 | 403篇 |
2011年 | 416篇 |
2010年 | 239篇 |
2009年 | 201篇 |
2008年 | 373篇 |
2007年 | 367篇 |
2006年 | 307篇 |
2005年 | 339篇 |
2004年 | 328篇 |
2003年 | 263篇 |
2002年 | 262篇 |
2001年 | 34篇 |
2000年 | 24篇 |
1999年 | 35篇 |
1998年 | 42篇 |
1997年 | 45篇 |
1996年 | 30篇 |
1995年 | 41篇 |
1994年 | 25篇 |
1993年 | 17篇 |
1992年 | 14篇 |
1991年 | 12篇 |
1990年 | 10篇 |
1989年 | 12篇 |
1988年 | 6篇 |
1987年 | 5篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1984年 | 8篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1981年 | 4篇 |
1980年 | 8篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1976年 | 4篇 |
1968年 | 1篇 |
排序方式: 共有5633条查询结果,搜索用时 15 毫秒
81.
82.
83.
Pietro Crivello Nina Lauterbach Laura Zito Federico Sizzano Cristina Toffalori Jessica Marcon Laura Curci Arend Mulder Lotte Wieten Elisabetta Zino Christien E.M. Voorter Marcel G.J. Tilanus Katharina Fleischhauer 《Human immunology》2013
The functional relevance of polymorphisms outside the peptide binding groove of HLA molecules is poorly understood. Here we have addressed this issue by studying HLA-DP3, a common antigen relevant for functional matching algorithms of unrelated hematopoietic stem cell transplantation (HSCT) encoded by two transmembrane (TM) region variants, DPB1*03:01 and DPB1*104:01. The two HLA-DP3 variants were found at a overall allelic frequency of 10.4% in 201 volunteer stem cell donors, at a ratio of 4.2:1. No significant differences were observed in cell surface expression levels of the two variants on B lymphoblastoid cell lines (BLCL), primary B cells or monocytes. Three different alloreactive T cell lines or clones showed similar levels of activation marker CD107a and/or CD137 upregulation in response to HLA-DP3 encoded by DPB1*03:01 and DPB1*104:01, either endogenously on BLCL or after lentiveral-vector mediated transfer into the same cellular background. These data provide, for the first time, direct evidence for a limited functional role of a TM region polymorphism on expression and allorecognition of HLA-DP3 and are compatible with the notion that the two variants can be considered as a single functional entity for unrelated stem cell donor selection. 相似文献
84.
Giorgia Bertazzoni Alessandro Sgambato Mario Migaldi Antonella Grottola Anna Maria Teresa Sabbatini Nadia Nanni Alberto Farinetti Francesco Iachetta Elisabetta Giacobazzi Monica Pecorari Luca Reggiani Bonetti 《Journal of medical virology》2013,85(1):105-109
Testicular germ cell tumors account for about 1% of all cancers. The incidence of these tumors is increasing and they represent the most common solid malignancies of young men aged 15–40 years with seminoma being one of the most common histotype. Pathogenesis of testicular germ cell tumors remains unknown and, although cryptorchidism is considered the main risk factor, there is evidence of an association with environmental and genetic risk factors. Human papillomaviruses (HPV) are a family of DNA viruses and represent a major risk factor for cervical cancer. In addition, they have been associated with other human non‐malignant and malignant diseases, including breast and head and neck cancer. HPV sequences have been detected throughout the male lower genitourinary tract as well as in seminal fluid and an increased testicular tumorigenesis has been reported in HPV transgenic mice. Aim of this study was to evaluate the potential involvement of HPV in human testicular tumorigenesis. Real‐time PCR employing GP5+/GP6+ consensus HPV primers was used to examine the presence of HPV sequences in a subset of human seminoma (n = 61) and normal testicles (n = 23). None of the specimens tested displayed the presence of HPV DNA. These findings do not support an association between HPV and human seminoma and warrant further studies to assess definitively the role of these viruses in human testicular tumorigenesis. J. Med. Virol. 85:105–109, 2012. © 2012 Wiley Periodicals, Inc. 相似文献
85.
Filippo Morando Silvia Rosi Silvano Fasolato Marta Cavallin Elisabetta Gola Angelo Gatta Paolo Angeli MD PhD 《Journal of medical virology》2013,85(2):210-213
This is a case of 62 years old Caucasian treatment‐naïve patient who developed a severe acute hepatitis B infection soon after a trip to Thailand. The infection was due to genotype C HBV which was found to be resistant to lamivudine and telbivudine. The patient was treated with tenofovir resulting in complete suppression of viral replication and complete clinical and laboratory remission of acute hepatitis. Later the patient also developed seroconversion of HBeAg to anti‐HBe and of HBsAg to anti‐HBs. This case demonstrates that mutations of HBV polymerase associated with lamivudine, telbivudine, and adefovir resistance can be present also in untreated patients with severe acute hepatitis B. This suggests that in the clinical context, which represents a life threatening condition, a baseline resistance‐testing should be an additional marker in the diagnostic evaluation process. Finally, this case report seems to support the use of tenofovir for the immediate treatment of severe acute hepatitis B. J. Med. Virol. 85:210–213, 2013. © 2012 Wiley Periodicals, Inc. 相似文献
86.
Carmen Barba Massimo Cossu Renzo Guerrini Giancarlo Di Gennaro Flavio Villani Luca De Palma Laura Grisotto Alessandro Consales Domenica Battaglia Nelia Zamponi Piergiorgio dOrio Martina Revay Michele Rizzi Sara Casciato Vincenzo Esposito Pier Paolo Quarato Roberta Di Giacomo Giuseppe Didato Chiara Pastori Giusy Carfi Pavia Simona Pellacani Giulia Matta Mattia Pacetti Gianpiero Tamburrini Elisabetta Cesaroni Gabriella Colicchio Giampaolo Vatti Sofia Asioli Massimo Caulo Carlo Efisio Marras Laura Tassi 《Epilepsia》2021,62(1):128-142
87.
Bucello Sebastiano Annovazzi Pietro Ragonese Paolo Altieri Marta Barcella Valeria Bergamaschi Roberto Bianchi Alessia Borriello Giovanna Buscarinu Maria Chiara Callari Graziella Capobianco Marco Capone Fioravante Cavalla Paola Cavarretta Rosella Cortese Antonio De Luca Giovanna Di Filippo Massimiliano Dattola Vincenzo Fantozzi Roberta Ferraro Elisabetta Filippi Maria Maddalena Gasperini Claudio Grimaldi Luigi Maria Edoardo Landi Doriana Re Marianna Lo Mallucci Giulia Manganotti Paolo Marfia Girolama Alessandra Mirabella Massimiliano Perini Paola Pisa Marco Realmuto Sabrina Russo Margherita Tomassini Valentina Torri-Clerici Valentina Liliana Adriana Zaffaroni Mauro Zuliani Cristina Zywicki Sofia Filippi Massimo Prosperini Luca 《Journal of neurology》2021,268(8):2922-2932
Journal of Neurology - To identify baseline factors associated with disease activity in patients with relapsing–remitting multiple sclerosis (RRMS) under teriflunomide treatment. This was an... 相似文献
88.
Marcello Maggio Elena Colizzi Alberto Fisichella Giorgio Valenti Graziano Ceresini Elisabetta Dall’Aglio Livia Ruffini Fulvio Lauretani Liborio Parrino Gian Paolo Ceda 《Maturitas》2013
Cognition can be deteriorated in older persons because of several potential mechanisms including the hormonal changes occurring with age. Stress events cause modification in hormonal balance with acute and chronic changes such as increase in cortisol and thyroid hormones, and simultaneous alterations in dehydroepiandrosterone sulphate, testosterone and insulin like growth factor-1 levels. The ability to cope with stress and regain previous healthy status, also called resiliency, is particularly impaired in older persons Thus, stressful conditions and hormonal dysregulation might concur to the onset of cognitive impairment in this population. 相似文献
89.
Stefania Clemente Maria Daniela Falco Elisabetta Cagni Cinzia Talamonti Mafalda Boccia Eva Gino Elena Lorenzini Federica Rosica Serenella Russo Alessandro Alparone Daniele Zefiro Christian Fiandra 《The British journal of radiology》2021,94(1119)
Objectives:This multicentric study was carried out to investigate the impact of small field output factors (OFs) inaccuracies on the calculated dose in volumetric arctherapy (VMAT) radiosurgery brain plans.Methods:Nine centres, realised the same five VMAT plans with common planning rules and their specific clinical equipment Linac/treatment planning system commissioned with their OFs measured values (OFbaseline). In order to simulate OFs errors, two new OFs sets were generated for each centre by changing only the OFs values of the smallest field sizes (from 3.2 × 3.2 cm2 to 1 × 1 cm2) with well-defined amounts (positive and negative). Consequently, two virtual machines for each centre were recommissioned using the new OFs and the percentage dose differences ΔD (%) between the baseline plans and the same plans recalculated using the incremented (OFup) and decremented (OFdown) values were evaluated. The ΔD (%) were analysed in terms of planning target volume (PTV) coverage and organs at risk (OARs) sparing at selected dose/volume points.Results:The plans recalculated with OFdown sets resulted in higher variation of doses than baseline within 1.6 and 3.4% to PTVs and OARs respectively; while the plans with OFup sets resulted in lower variation within 1.3% to both PTVs and OARs. Our analysis highlights that OFs variations affect calculated dose depending on the algorithm and on the delivery mode (field jaw/MLC‐defined). The Monte Carlo (MC) algorithm resulted significantly more sensitive to OFs variations than all of the other algorithms.Conclusion:The aim of our study was to evaluate how small fields OFs inaccuracies can affect the dose calculation in VMAT brain radiosurgery treatments plans. It was observed that simulated OFs errors, return dosimetric calculation accuracies within the 3% between concurrent plans analysed in terms of percentage dose differences at selected dose/volume points of the PTV coverage and OARs sparing.Advances in knowledge:First multicentre study involving different Planning/Linacs about undetectable errors in commissioning output factor for small fields. 相似文献