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Experimental and numerical characterization of 3D‑printed scaffolds under monotonic compression with the aid of micro‑CT volume reconstruction

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Bio-Design and Manufacturing 2021年第2期4卷 222-242页

作者： r.Baptista M.F.C.pereira A.Maurício D.rechena V.Infante M.Guedes CDP2T Departamento de Engenharia MecanicaEscola Superior de Tecnologia de SetúbalInstituto Politécnico de Setúbal2910‑761 SetúbalPortugal CErENA DECivilInstituto Superior TécnicoUniversidade de LisboaAv.Rovisco Pais11049‑001 LisbonPortugal IDMEC Instituto Superior TécnicoUniversidade de LisboaAv.Rovisco Pais11049‑001 LisbonPortugal IPFN Instituto Superior TécnicoUniversidade de Lisboa1049‑001 LisbonPortugal CeFEMA Instituto Superior TécnicoUniversidade de LisboaAv.Rovisco Pais11049‑001 LisbonPortugal

Even when damaged by injury or disease bone tissue has the remarkable ability to *** this process is limited by large size bone defects,tissue engineering is responsible for restoring,maintaining or improving tissue *** are support structures,designed to be implanted in the damaged site,supporting mechanical loads and protecting the regenerating bone *** this paper,3D-printed PLA scaffolds with three different porosity values and two different geometries were experimentally and numerically ***-CT analysis showed that fused filament fabrication can be used to produce scaffolds with the desired porosity and 100%of interconnected *** monotonical compression,scaffolds apparent compressive modulus increased from 89 to 918 MPa,while yield stress increased from 2.9 to 27.5 MPa as porosity decreased from 70 to 30%.Open porosity decreased up to 8%on aligned scaffolds and 14%on staggered scaffolds,after compression,while scaffold’s surface-to-volume ratio highest reduction(7.48 to 4.55 mm−1)was obtained with aligned low porosity ***-CT volume reconstruction allowed for scaffold simplified numerical models to be built and *** agreement was found when predicting scaffold’s apparent compressive ***,it can be concluded that 3D printing is a viable scaffold manufacturing technique for trabecular bone replacement.

关键词： Scaffold Pore design Mechanical behavior Micro-CT analysis Finite element method

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Native and exotic seed dispersal by the stone marten(Martes foina):implications for the regeneration of a relict climactic forest in central Portugal

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Integrative Zoology 2019年第3期14卷 280-292页

作者： Lúcia pereira Ana VASQUES Paula MAIA Maria João rAMOS pereira Carlos FONSECA Milena MATOS CESAM-Centre for Environmental and Marine Studies-Wildlife research Unit Department of BiologyUniversity of AveiroAveiroPortugal CESAM-Centre for Environmental and Marine Studies-Department of Environment and Planning University of AveiroAveiroPortugal Erasmus University College Life Sciences DepartmentRotterdamthe Netherlands Institute of Biosciences PPGBANDepartment of ZoologyUniversidade Federal do Rio Grande do SulBrazil BioLiving Association FrossosAlbergaria-a-VelhaPortugal

The stone marten(Martes foina)is a carnivorous mammal that often consumes fleshy fruits,thus potentially promoting seed *** present study was developed in Bussaco National Forest,central Portugal,and aimed to assess the potential role of the stone marten in dispersing native and exotic plants in different forest landscape *** from stone marten scats and fleshy fruits were collected monthly and were thereafter identified and sowed in a nursery,following a randomized experimental *** emergence was monitored *** linear models were used to test for differences in time and success of emergence between seeds from scats and fruits of 3 native species(rubus ulmifolius,Arbutus unedo and Celtis australis)and 1 exotic plant species with invasive behavior(Prunus laurocerasus).Fruit consumption by the stone martens significantly increased and accelerated the germination of the native *** but had no effect on the other 2 native species or on the invasive *** suggested that stone martens contribute to gene flow and forest regeneration by dispersing native plant ***,although the germination was not enhanced in the invasive species,the preference of stone martens for these fruits may potentially contribute to the proliferation of *** study represents a contribution to better understanding the fauna and flora interactions,enabling for a more conscious and effective decision-making in forest management.

关键词： germination invasive species Martes foina Prunus laurocerasus relict climactic forest

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Clinical/Behavioral Monitoring of rodents and rabbits Undergoing Scientific Experiments

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Open Journal of Veterinary Medicine 2024年第5期14卷 91-109页

作者： Luiz Cesar Cavalcanti pereira Jhônata Willy rocha Coelho Hyago da Silva Medeiros Elidio rita de Cássia dos Passos Ferraz Da Silva João Gabriel regis Sobral Bárbara Alves de Brito Soledade Leandro Thomaz Vilela Isabele Barbieri Dos Santos Institute of Science and Technology in Biomodels (ICTB) Oswaldo Cruz Foundation (FIOCRUZ) Rio de Janeiro Brazil Laboratory Animal Facility of the Carlos Chagas Pavilion of the Animal Experimentation Center (CEA) Oswaldo Cruz Institute (IOC) Oswaldo Cruz Foundation (FIOCRUZ) Rio de Janeiro Brazil

Background: We currently have international and national guidelines regarding the assessment and monitoring of clinical signs and humane endpoints in animals used in teaching and research, which make the performance of these activities mandatory for any experiment and professional working in this area. Assigning the severity of a research experiment is the result of an analysis of records of observations of the animal’s behavior, and clinical signs. The aim of this study was to describe the importance of carrying out a severity assessment associated with clinical and behavioral monitoring of rodents and rabbits during experimentation to maintain the welfare of these animals undergoing scientific research. Methods: The literature search was carried out using the following terms: “Monitoring”;“Humane endpoints”;“Animal welfare”, “rodents”;“rabbits”, and as connectors “and”;“or”, in the following databases: PubMed;LILACS/BIrEME and SciELO. results: A total of 987 articles were identified in the databases, and 20 of these studies were included in this review. Conclusions: Humane endpoint protocols and procedure severity tables are of the utmost importance, both from an ethical point and to refine the results of research conducted on laboratory animals. They should be drawn up jointly by the teams responsible for the project and the maintenance of the animals during the research period, and the data obtained should be published so that the scientific community can have access to it, helping to disseminate these practices, as well as helping to draw up new procedures. Monitoring and evaluating the welfare and clinical condition of animals undergoing scientific research procedures is the responsibility of the professors, researchers, veterinarians, and animal facility coordinators. The Ethics Committee on the Use of Animals must monitor all the activities conducted with the animals, by inspecting the experimental procedures and the physical environment of the laboratory an

关键词： Monitoring Humane Endpoints Animal Welfare Experimental Design Laboratory Animals’ Investigations

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Analysis of the Hypervariable regions(HVrs)of the wsp Gene of Wolbachia from Solenopsis invicta Ants in Southeastern Brazil

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Advances in Entomology 2014年第3期2卷 135-143页

作者： rodrigo Fernando de Souza Cintia martins roberto Manoel pereira Odair Correa Bueno Centro de Estudos de Insetos Sociais Instituto de BiocienciasUniversidade Estadual Paulista Julio de Mesquita FilhoCampus Rio ClaroSao PauloBrazil Universidade Federal do Piauí(Federal University of Piauí) Campus ParnaíbaPiauíBrazil Urban Entomology Laboratory Entomology&Nematology DepartmentUniversity of FloridaGainesvilleUSA

Wolbachia is a bacterium that infects many arthropods with horizontal or vertical transmission. The introduction and spreading of Solenopsis invicta in new areas may have influenced the acquisition of Wolbachia as this ant species spread from its South America origin to other parts of the globe. The wsp gene of Wolbachia was analyzed using the WSP Typing and a similarity analysis was conducted to analyse the sharing of the symbiont among nests of S. invicta ants. The analyses revealed the presence of two groups of Wolbachia: strain A belonging to InvA S. invicta subgroup, and the strain B belonging to Acromyrmex insinuator. The wsp gene and its hypervariable regions are shared among the Wolbachia present in different types of ants inhabiting in the New World. Wolbachia strains found in the nests of S. invicta are ant-specialist symbionts which may have spread by several means among the ant population.

关键词： Ant recombination Horizontal Transmission Symbiont

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Mechanical characterization of sisal reinforced cement mortar

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Theoretical & Applied Mechanics Letters 2014年第6期4卷 26-30页

作者： r.Fujiyama F.Darwish M.V.pereira Department of Mechanical Engineering Para Federal University Department of Civil Engineering Fluminense Federal University Department of Materials Engineering Catholic University of rio de Janeiro

This work aims at evaluating the mechanical behavior of sisal fiber reinforced cement mortar. The composite material was produced from a mixture of sand, cement, and water. Sisal fibers were added to the mixture in different lengths. Mechanical characterization of both the composite and the plain mortar was carried out using three point bend, compression, and impact tests. Specimens containing notches of different root radii were loaded in three point bending in an effort to determine the effect of the fibers on the fracture toughness of the material. The results obtained indicate that, while fiber reinforcement leads to a decrease in compressive strength, J-integral calculations at maximum load for the different notch root radii have indicated, particularly for the case of long fibers, a significant superiority of the reinforced material in comparison with the plain cement mortar, in consistence with the impact test data.

关键词： composite material impact energy fracture initiation J-integral

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role of Helicobacter pylori in gastric mucosa-associated lymphoid tissue lymphomas

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World Journal of Gastroenterology 2014年第3期20卷 684-698页

作者： Marta-Isabel pereira José Augusto Medeiros Clinical Hematology Department Coimbra University Hospital Center Institute of Physiology Faculty of MedicineUniversity of CoimbraAzinhaga de Santa Comba

Mucosa-associated lymphoid tissue (MALT) lymphoma is an indolent extranodal marginal zone B-cell lymphoma, originating in acquired MALT that is induced in mucosal barriers as part of a normal adaptive immune response to a chronic immunoinflammatory stimulus, most notably chronic infection by Helicobacter pylori (H. pylori). This antigenic stimulation initially leads to lymphoid hyperplasia; the acquisition of additional genetic aberrations culminates in the activation of intracellular survival pathways, with disease progression due to proliferation and resistance to apoptosis, and the emergence of a malignant clone. There are descriptions of MALT lymphomas affecting practically every organ and system, with a marked geographic variability partially attributable to the epidemiology of the underlying risk factors; nevertheless, the digestive system (and predominantly the stomach) is the most frequently involved location, reflecting the gastrointestinal tract’s unique characteristics of contact with foreign antigens, high mucosal permeability, large extension and intrinsic lymphoid system. While early-stage gastric MALT lymphoma can frequently regress after the therapeutic reversal of the chronic immune stimulus through antibiotic eradication of H. pylori infection, the presence of immortalizing genetic abnormalities, of advanced disease or of eradication-refractoriness requires a more aggressive approach which is, presently, not consensual. The fact that MALT lymphomas are rare neoplasms, with a worldwide incidence of 1-1.5 cases per 105 population, per year, limits the ease of accrual of representative series of patients for robust clinical trials that could sustain informed evidence-based therapeutic decisions to optimize the quality of patient care.

关键词： Mucosa-associated lymphoid tissue lymphoma Marginal zone lymphoma Helicobacter pylori Gastric lymphoma Eradication therapy Nuclear factor-kappa B pathway

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Fluidization of binary mixtures of sisal residue and sand:A new model for deriving the final fluidization velocity

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Particuology 2018年第5期16卷 10-22页

作者： David Vasconcelos Gabriele Batalha Luis Gabriel pereira Carlos Augusto Pires Chemical reaction Engineering Laboratory Federal University of Bahia40.210-910SalvadorBABrazil

The influence of different factors on the fiuidization of a binary mixture of sisal residue and sand was *** particle sizes of the sand and sisal residue were varied from 0.2to 0.8mm and the biomass mass fractions from 2% to 9%.Some segregation was noted,and a significant relationship was found among the final fluidization velocity (Uff),the biomass and sand sizes,and the biomass mass fraction.A novel model was developed for predicting Uff,leading to an average discrepancy of 12.69% between the measured and predicted Uff compared with the best match of 15.32% when using a model from a previous *** new model was applied to data from studies using other biomass and a broad range of particle *** average divergences from measured values when using the new model were 7.9% for corn cob and walnut shell,and 20.5% for sweet sorghum bagasse,tobacco residue, and soy *** were superior to the values derived using other *** results confirm the accuracy of the model developed in this work and show that it represents a viable alternative way to calculate Uff for a binary mixture of sand and biomass.

关键词： Fluidization Binary mixture Sisal residue Final fluidization velocity model

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Production of bio-fertilizer from Ascophyllum nodosum and Sargassum muticum (Phaeophyceae)

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Journal of Oceanology and Limnology 2019年第3期37卷 918-927页

作者： SILVA Luís Daniel BAHCEVANDZIEV Kiril pereira Leonel Faculty of Science and Technology University of CoimbraCoimbra 3000-456Portugal Polytechnic Institute of Coimbra Agricultural CollegeⅡA-Institute of Applied ResearchCERNAS-Research Centre for Natural ResourcesEnvironmentand SocietyBencantaCoimbra 3045-601Portugal Faculty of Science and Technology University of CoimbraCoimbra 3000-548Portugal

Oceans and seas form a large body of water that contains a natural *** humans,represents a resource,which makes this a point of interest,from researches to improve the *** produce many compounds and secondary metabolites that can be used in different fi elds of industry such as food,agricultural,pharmaceutical and *** though seaweeds are ancestral resources,recently it was notorious a global interest in knowing more about its potentials,where biotechnology plays an important role in *** showed that seaweed has many bioactive compounds benefi cial to plant development,giving them a great potential as an agricultural *** seaweeds to the soil provides organic matter,minerals,trace elements,growth plant regulator,metabolites,vitamins,and amino acids and it can work as a soil *** Portugal,the use of seaweeds for agriculture is important since long time *** the past,populations that lived near coastal zone depended on the seaweeds as a family subsistence but,throughout the years,synthetic fertilizers replaced *** work aimed to assess the potential of the extracts obtained from Ascophyllum nodosum and from Sargassum muticum as an agricultural *** evaluation was carried out with rice plants(Oryza sativa)and lettuce(Lactuca sativa),in germination bioassays,the culture of rice and lettuce plants in pots,and culture of lettuce plants in *** that,seaweed liquid extracts were used in different concentrations in different *** show that extracts obtained from two seaweeds,*** and ***,can be promissory plant biofertilizer at a concentration of 25% and had a positive effect on seed germination,plant development,and production.

关键词： fertilizer bioactive compounds Ascophyllum nodosum Sargassum muticum Oryza sativa Lactuca sativa

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Aspects of Fretting Fatigue Finite Element Modelling

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Computers, Materials & Continua 2020年第7期64卷 97-144页

作者： Kyvia pereira Libardo VVanegas-Useche Magd Abdel Wahab Soete Laboratory Faculty of Engineering and ArchitectureGhent UniversityZwijnaardeB-9052Belgium Facultad de Ingeniería Mecánica Universidad Tecnológica de PereiraPereira660003Colombia Division of Computational Mechanics Ton Duc Thang UniversityHo Chi MinhVietnam Faculty of Civil Engineering Ton Duc Thang UniversityHo Chi MinhVietnam

Fretting fatigue is a type of failure that may affect various mechanical components,such as bolted or dovetail joints,press-fitted shafts,couplings,and *** to its importance,many researchers have carried out experimental tests and analytical and numerical modelling,so that the phenomena that govern the failure process can be understood or appropriately ***,the performance of systems subjected to fretting fatigue can be predicted and *** paper discusses different aspects related to the finite element modelling of fretting *** presents common experimental configurations and the analytical solutions for cylindrical ***,it discusses aspects of fretting fatigue crack initiation,such as crack location,orientation,and length,as well as stress averaging ***,it deals with the propagation stage;crack face interaction,orientation criteria,and crack growth rate are ***,additional aspects of recent research on fretting fatigue are reviewed:out-of-phase loading,cohesive zone modelling,wear effects,heterogeneity,and crystal *** fatigue is a phenomenon not well understood,and much more research is needed so that its understanding is increased and proper criteria and laws may be available for different cases.

关键词： Fretting fatigue FEM modelling crack initiation crack growth

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Amprolium exposure alters mice behavior and metabolism in vivo

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Animal Models and Experimental Medicine 2018年第4期1卷 272-281页

作者： Juliana Oliveira Moraes Samara Dias Cardoso rodrigues Leidiano martins pereira rita de Cássia Noronha Medeiros Clarissa Amorim Silva de Cordova Fabiano Mendes de Cordova Programa de Pós-Gradua??o em Sanidade Animal e Saúde Pública nos Trópicos Universidade Federal do Tocantins Curso de Medicina Veterinária Universidade Federal do Tocantins Curso de Medicina Universidade Federal do Tocantins

Background: Thiamine deficiency(TD) models have been developed, mainly using the thiamine analog pyrithiamine. Other analogs have not been used in rodents. We aimed to evaluate the effects and mechanisms of intraperitoneal(ip) amprolium-induced TD in mice. We also evaluated the associated pathogenesis using antioxidant and anti-inflammatory compounds(Trolox, dimethyl sulfoxide).Methods: Male mice were separated into two groups, one receiving a standard diet(control animals), and the other a TD diet(deficient groups) for 20 days. Control mice were further subdivided into three groups receiving daily ip injections of saline(NaCl0.9%; Cont group), Tolox(Tr group) or dimethyl sulfoxide(DMSO; Dmso group). The three TD groups received amprolium(Amp group), amprolium and Trolox(Amp+Tr group), or amprolium and DMSO(Amp+Dmso group). The animals were subjected to behavioral tests and then euthanized. The brain and viscera were ***: Amprolium exposure induced weight loss with hyporexia, reduced the behavioral parameters(locomotion, exploratory activity, and motor coordination), and induced changes in the brain(lower cortical cell viability) and liver(steatosis). Trolox co-treatment partially improved these conditions, but to a lesser extent than ***: Amprolium-induced TD may be an interesting model, allowing the deficiency to develop more slowly and to a lesser extent. Amprolium exposure also seems to involve oxidative stress and inflammation, suggested as the main mechanisms of cell dysfunction in TD.

关键词： brain dimethyl sulfoxide thiamine deficiency Trolox

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