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Influence of train speed and its mitigation measures in the short-and long-term performance of a ballastless transition zone

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铁道工程科学:英文版 2023年第4期31卷 309-324页

作者： Ana Ramos rui Calçada António Gomes correia Department of Civil Engineering Faculty of EngineeringUniversity of PortoCONSTRUCT-LESEPortoPortugal Department of Civil Engineering University of MinhoISISEGuimarãesPortugal

The ballastless track is nowadays the most popular railway system due to the required low number of maintenance opera-tions and costs,despite the high *** gradual change from ballasted to ballastless tracks has been occurring in Asia,but also in Europe,increasing the number of transition *** transition zones are a special area of the railway networks where there is an accelerated process of track degradation,which is a major concern of the railway infrastructure ***,the accurate prediction of the short-and long-term performance of ballastless tracks in transition zones is an important topic in the current paradigm of building/rehabilitating high-speed *** work purposes the development of an advanced 3D model to study the global performance of a ballastless track in an embankment-tunnel transition zone considering the influence of the train speed(220,360,500,and 600 km/h).Moreover,a mitigation measure is also adopted to reduce the stress and displacements levels of the track in the transition.A resilient mat placed in the tunnel and embank-ment aims to soften the *** behaviour of the track with the resilient mat is evaluated considering the influence of the train speed,with special attention regarding the critical *** used methodology is a novel and hybrid approach that allows including short-term and long-term performance,through the development of a powerful 3D model combined with the implementation of a calibrated empirical permanent deformation model.

关键词： Ballastless track Train speed Numerical modelling Transition zone Critical speed

Current advances in solid free-form techniques for osteochondral tissue engineering

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Bio-Design and Manufacturing 2018年第3期1卷 171-181页

作者： Joao Bebiano Costa Joana Silva-correia rui Luis Reis Joaquim Miguel Oliveira B's Research Group I3Bs - Research Institute onBiomaterials Biodegradables and Biomimetics University ofMinho Headquarters of the European Institute of Excellenceon Tissue Engineering and Regenerative Medicine AveParkParque de Ciencia e Tecnologia Zona Industrial da Gandra4805-017 Barco Guimaraes Portugal ICVS/3B's-PT Government Associate Laboratory Braga Guimarfies Portugal The Discoveries Centre for Regenerative and PrecisionMedicine Headquarters at University of MinhoAvepark 4805-017 Barco Guimaraes Portugal

Osteochondral (OC) lesions are characterized by defects in two different zones, the cartilage region and subchondral bone region. These lesions are frequently associated with mechanical instability, as well as osteoarthritic degenerative changes in the knee. The lack of spontaneous healing and the drawbacks of the current treatments have increased the attention from the scientific community to this issue. Different tissue engineering approaches have been attempted using different polymers and different scaffolds’ processing. However, the current conventional techniques do not allow the full control over scaffold fabrication, and in this type of approaches, the tuning ability is the key to success in tissue regeneration. In this sense, the researchers have placed their efforts in the development of solid free-form (SFF) techniques. These techniques allow tuning different properties at the micro–macro scale, creating scaffolds with appropriate features for OC tissue engineering. In this review, it is discussed the current SFF techniques used in OC tissue engineering and presented their promising results and current challenges.

关键词：软骨病变生物技术生物科学发展现状

Association between EGF +61A/G polymorphism and gastric cancer in Caucasians

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World Journal of Gastroenterology 2011年第4期17卷 488-492页

作者： Ana Paula Araújo Bruno M Costa Ana L Pinto-correia Maria Fragoso Paula Ferreira Mário Dinis-Ribeiro Sandra Costa rui M Reis rui Medeiros Molecular Oncology Group Portuguese Institute of Oncology of Porto Life and Health Sciences Research Institute (ICVS) School of Health Sciences Oncology Department Portuguese Institute of Oncology of Porto Gastroenterology Department Portuguese Institute of Oncology of Porto Portugal Cintesis/Faculty of Medicine University of Porto Centro de Estudos em Biomedicina Health Sciences Faculty-Fernando Pessoa University Instituto de Ciencias Biomédicas de Abel Salazar Abel Salazar Institute for the Biomedical Sciences

AIM: To investigate the association between epidermal growth factor (EGF) +61A/G polymorphism and susceptibility to gastric cancer, through a cross-sectional study. METHODS: Polymerase chain reaction resctriction fragment lenght polymorphism analyses were used to genotype EGF +61 in 207 patients with gastric lesions (162 patients with gastric adenocarcinomas, 45 with atrophy or intestinal metaplasia) and 984 controls. All subjects were Caucasian. RESULTS: Genotype distribution was 23.5% for GG and 76.5% for GA/AA in the control group, 18.4% for GG and 68.6% for GA/AA in the entire group with gastric lesions and 17.9% for GG and 82.1% for GA/AA in the group with gastric adenocarcinoma. No statistically significant associations were found between EGF +61 variants and risk for developing gastric cancer [odds ratios (OR) = 1.41, 95% confidence intervals (CI): 0.90-2.21, P = 0.116]. However, the stratification of individuals by gender revealed that males carrying A alleles (EGF +61A/G or AA) had an increased risk for developing gastric cancer as compared to GG homozygous males (OR = 1.55, 95% CI: 1.05-2.28, P = 0.021). CONCLUSION: In summary, we found that males who were A carriers for EGF +61 had an increased risk for developing gastric cancer. This result may be explained by the suggestion that women secrete less gastric acid than men.

关键词：多态性分析 EGF 白种人胃癌表皮生长因子协会聚合酶链反应片段长度

Indirect printing of hierarchical patient-specific scaffolds for meniscus tissue engineering

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Bio-Design and Manufacturing 2019年第4期2卷 225-241页

作者： Joao BCosta Joana Silva-correia Sandra Pina Alain da Silva Morais Sílvia Vieira Hélder Pereira Joao Espregueira-Mendes rui LReis Joaquim M.Oliveira B′s Research Group I3Bs-Research Institute on BiomaterialsBiodegradables and BiomimeticsUniversity of MinhoHeadquarters of the European Institute of Excellence on Tissue Engineering and Regenerative MedicineAveParkZona Industrial da Gandra4805-017 Barco GmrPortugal ICVS/3B’s-PT Government Associate Laboratory Braga/GuimaraesPortugal The Discoveries Centre for Regenerative and Precision Medicine Headquarters at University of MinhoAvepark4805-017 BarcoGuimar'sPortugal Ripoll y De Prado Sports Clinic:Murcia-Madrid FIFA Medical Centre of Excellence MurciaSpain Orthopedic Department Centro Hospitalar Póvoa de Varzim Vila do CondePortugal Clínica do Dragao Espregueira-Mendes Sports CentreFIFA Medical Centre of ExcellencePortoPortugal Dom Henrique Research Centre PortoPortugal Orthopedic Department University of MinhoBragaPortugal

The complex meniscus tissue plays a critical role in the knee. The high susceptibility to injury has led to an intense pursuit for better tissue engineering regenerative strategies, where scaffolds play a major role. In this study, indirect printed hierarchical multilayered sca ffolds composed by a silk fibroin (SF) upper layer and an 80/20 (w/w) ratio of SF/ionic-doped β-tricalcium phosphate (TCP) bottom layer were developed. Furthermore, a comparative analysis between two types of sca ffolds pro- duced using di fferent SF concentrations, i.e., 8% (w/v) (Hi8) and 16% (w/v) (Hi16) was performed. In terms of architecture and morphology, the produced sca ffolds presented homogeneous porosity in both layers and no di fferences were observed when comparing both sca ffolds. A decrease in terms of mechanical performance of the sca ffolds was observed when SF concentration decreased from 16 to 8% (w/v). Hi16 revealed a static compressive modulus of 0.66 ± 0.05 MPa and dynamical mechanical properties ranging from 2.17 ± 0.25 to 3.19 ± 0.38 MPa. By its turn, Hi8 presented a compressive modulus of 0.27 ± 0.08 MPa and dynamical mechanical properties ranging from 1.03 ± 0.08 MPa to 1.56 ± 0.13 MPa. In vitro bioactivity studies showed formation of apatite crystals onto the surface of Hi8 and Hi16 bottom layers. Human meniscus cells (hMCs) and human primary osteoblasts were cultured separately onto the top layer (SF8 and SF16) and bottom layer (SF8/TCP and SF16/TCP) of the hierarchical sca ffolds Hi8 and Hi16, respectively. Both cell types showed good adhesion and proliferation as denoted by the live/dead staining, Alamar Blue assay and DNA quanti fication analysis. Subcutaneous implantation in mice revealed weak in flammation and sca ffold’s integrity. The hierarchical indirect printed SF sca ffolds can be promising candidate for meniscus TE sca ffolding applications due their suitable mechanical properties, good biological performance and possibility of being applied in a patie

关键词： Patient-specific Indirect printing Hierarchical Silk fibroin Enzymatic-cross-linking Meniscus

Epstein-Barr virus is associated with gastric carcinoma: The question is what is the significance?

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World Journal of Gastroenterology 2008年第27期14卷 4347-4351页

作者： Hugo Sousa Ana L Pinto-correia rui Medeiros Mario Dinis-Ribeiro Molecular Oncology Group and Molecular Virology Laboratory Portuguese Institute of Oncology of Porto Gastroenterology Department Portuguese Institute of Oncology of Porto

AIM: To examine the possible role of the Epstein- Barr Virus (EBV) in the development of gastric adenocarcinoma (GC). It is unclear whether EBV is involved in GC development or is a consequence of gastric inflammation secondary to immunosuppressive treatments. METHODS: A systematic review was carried out of all published observational studies on the temporal association between EBV and GC, with a view to determine a causal relationship. RESULTS: The present study showed that the worldwide crude prevalence of EBV in gastric adenocarcinoma was 8.29%. The prevalence varied from 7.08% for intestinal type and 9.82% for diffuse type of GC. It was observed that Western and Central Asian countries had a significantly higher frequency of EBV positive cases compared to South-Eastern countries. America had the highest EBV-GC prevalence whereas Europe had the lowest. CONCLUSION: The present review has demonstrated a high prevalence of EBV in gastric adenocarcinoma. However, studies designed to assess a temporal relationship and histological association using sensitive techniques should be carried out to establish the role of EBV in GC carcinogenesis.

关键词：胃癌 Epstein-Barr病毒系统观查胃炎

Frequency-Domain Receivers for Rate-1 Space-Time Block Codes

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International Journal of Communications, Network and System Sciences 2009年第9期2卷 845-861页

作者： Mário Marques da Silva rui Dinis Américo M. C. correia 不详

This paper considers iterative frequency-domain receivers for block transmission techniques with rate-1 Space Time Block Coding (STBC) for two and four transmit antennas using both Orthogonal Frequency Division Multiplexing (OFDM) and Single-Carrier (SC) schemes. The proposed receiver includes an interference canceller which enhances the performance of the non-orthogonal STBC scheme with 4 transmit antennas, allowing performances close to those of orthogonal codes. Our performance results show that combining STBC with block transmission techniques allows excellent performances.

关键词： SC-FDE Turbo Equalization STBC OFDM

Fatigue Strength Evaluation of Resin-Injected Bolted Connections Using Statistical Analysis

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Engineering 2017年第6期3卷 795-805页

作者： Jose Antonio Fonseca de Oliveira correia Bruno Alexandre Silva Pedrosa Patricia Cordeiro Raposo Abilio Manuel Pinho De Jesus Helena Maria dos Santos Gervisio Grzegorz Stanislaw Lesiukc Carlos Alberto da Silva Rebelo rui Artur Bartolo Calcada Luis Alberto Proenca Simoes da Silva Faculty of Engineering University of Porto Porto 4200-465 Portugal Institute for Sustainability and Innovation in Structural Engineering (ISISE) Department of Civil Engineering University of Coimbra Coimbra 3030-788 Portugal Department of Mechanics Materials Science and Engineering Faculty of Mechanical Engineering Wroclaw University of Technology Wroctaw 50-370 Poland

在对老旧的螺栓和铆接金属桥进行修补和加固时可以使用不同的方案。由于铆接链接技术目前并不常用,连接它需要特定的设备和熟练的工人。另一种解决方案是使用焊接。但是,老旧钢材的可焊性较差。螺栓是一种非常可行的替代解决方案,并且... 详细信息

在对老旧的螺栓和铆接金属桥进行修补和加固时可以使用不同的方案。由于铆接链接技术目前并不常用,连接它需要特定的设备和熟练的工人。另一种解决方案是使用焊接。但是,老旧钢材的可焊性较差。螺栓是一种非常可行的替代解决方案,并且常用于修复旧金属桥。装配螺栓的解决方案成本高昂,另一种方法是使用树脂灌注式螺栓。带有预紧力的树脂灌注式老旧螺栓连接的受力性能已经用准静态和蠕变试验进行了研究,然而,关于这些连接节点的滑移和疲劳行为的文献很少。本文概述了几位研究者的实验项目,旨在评估单侧受剪和双侧受剪的树脂灌注式螺栓连接的疲劳行为。对有预紧力的标准螺栓和有预紧力的树脂灌注式螺栓的连接节点的实验数据进行比较分析,显示后者的疲劳强度较低。但欧洲规范3(EC3)对树脂灌注式螺栓和标准螺栓的连接节点提出的疲劳强度曲线大致相同,这应得到足够的重视。此外,本研究还展示了使用黏结螺栓连接的可行性研究。最后的研究是用高强度低合金结构钢板和用于金属黏结的丙烯酸结构黏结剂进行的。针对两个实际工程案例,使用线性化边界及Castillo和Fernández-Canteli模型对疲劳实验数据进行统计分析。最终提出疲劳设计曲线,并与欧洲和北美规范中的几个设计建议进行比较。

关键词：疲劳连接结构加强 S-N曲线树脂灌注式螺栓

Gastric cancer in a Caucasian population: Role of pepsinogen C genetic variants

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World Journal of Gastroenterology 2006年第31期12卷 5033-5036页

作者： Ana L Pinto-correia Hugo Sousa Maria Fragoso Luís Moreira-Dias Carlos Lopes rui Medeiros Mário Dinis-Ribeiro Molecular Oncology GroupPortuguese Institute of Oncology of Porto Portugal Oncology DepartmentPortuguese Institute of Oncology of Porto Portugal Gastroenterology DepartmentPortuguese Institute of Oncology of Porto Portugal and ICBAS Abel Salazar Institute for the Biomedical SciencesPortoPortugal and CINTESIS/Faculty of Medicine University of Porto PortoPortugal

瞄准：在胃蛋白酶原 C (PGC ) 基因学习插入 / 删除多型性的角色，为胃粘膜的终端区别的一个有效标记，在到胃的损害的开发的危险性。方法：没有肿瘤的疾病的证据，学习与已知的胃的损害的 99 件样品和 127 件样品被执行。PCR 被采用，... 详细信息

瞄准：在胃蛋白酶原 C (PGC ) 基因学习插入 / 删除多型性的角色，为胃粘膜的终端区别的一个有效标记，在到胃的损害的开发的危险性。方法：没有肿瘤的疾病的证据，学习与已知的胃的损害的 99 件样品和 127 件样品被执行。PCR 被采用， 6 多态的等位基因被放大：等位基因 1 (510 bp ) ，等位基因 2 (480 bp ) ，等位基因 3/4 (450/460 bp ) ，等位基因 5 (400 bp ) 并且等位基因 6 (310 bp ) 。结果：我们的结果表明等位基因 6 搬运人似乎对任何胃的损害的发展有保护(或 = 0.34；P<0.001 ) ，与象萎缩或肠的组织变形那样的胃的腺癌联系的 non-dysplastic 损害(或 = 0.28；P<0.001 ) 或侵略 GC (或 = 0.39；P = 0.004 ) 。结论：我们的学习表明等位基因 6 搬运人地位在胃的损害的发展有一个保护的角色，可能由于它有 PGC 的更高的表示的协会。而且，在控制组的等位基因 6 搬运人的频率比在亚洲人口获得了高是远的，它可能代表在白种人和亚洲人口之间的基因差距。

关键词：胃癌胃蛋白酶原遗传疾病病理机制

Web-based system for training and dissemination of a magnification chromoendoscopy classification

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世界胃肠病学杂志：英文版 2008年第46期14卷 7086-7092页

作者： Mário Jorge Dinis-Ribeiro Ricardo Cruz correia Cristina Santos Sónia Fernandes Ernesto Palhares rui Almeida Silva Pedro Amaro Miguel Areia Altamiro Costa-Pereira Luis Moreira-Dias Gastroenterology Department Portuguese Oncology Institute Center for Research in Information Systems and Health Technologies (CINTESIS)/Department of Biostatistics and Medical Informatics Porto Faculty of Medicine Gastroenterology Department Coimbra University Hospital

AIM:To evaluate the use of web-based technologies to assess the learning curve and reassess reproducibility of a simplified version of a classification for gastric magnification chromoendoscopy (MC). METHODS: As part of a multicenter trial, a hybrid approach was taken using a CD-ROM, with 20 films of MC lasting 5 s each and an "autorun" file triggering a local HTML frameset referenced to a remote questionnaire through an Internet connection. Three endoscopists were asked to prospectively and independently classify 10 of these films randomly selected with at least 3 d apart. The answers were centrally stored and returned to participants together with adequate feedback with the right answer. RESULTS: For classification in 3 groups, both intra- [Cohen's kappa (κ) = 0.79-1.00 to 0.89-1.00] and inter-observer agreement increased from 1st (moderate) to 6th observation (κ = 0.94). Also, agreement with reference increased in the last observations (0.90, 1.00 and 1.00, for observers A, B and C, respectively). Validity of 100% was obtained by all observers at their 4th observation. When a 4th (sub)group was considered, inter-observer agreement was almost perfect (κ=0.92) at 6th observation. The relation with reference clearly improved into κ (0.93-1.00) and sensitivity (75%-100%) at their 6th observations. CONCLUSION: This MC classification seems to be easily explainable and learnable as shown by excellent intra-and inter-observer agreement, and improved agreement with reference. A web system such as the one used in this study may be useful for endoscopic or other image based diagnostic procedures with respect to definition, education and dissemination.

关键词：色原体再现性学习曲线性临床医学胃镜检查