315 research outputs found

    Bone fragility in postmenopausa women: a preliminar study

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    The aim of this work is to identify the prevalence of risks factors for bone fragility in postmenopausal women with hormonal replacement therapy (HRT) within two groups (with bone fracture history and without bone fracture history) and to evaluate the effect of modifiable risk factors on bone mineral density (BMD). The overall prevalence of osteoporosis in postmenopausal Portuguese women is high. A pattern identification of occurrences, in a group of patients submitted to this analysis, will enable the formulation of conclusions for knowledge improving of these different pathologies. This preliminary study will demonstrate that age, physical exercise and coffee consumption are associated with lower BMD and osteoporosis status in postmenopausal Portuguese woman

    Predicting the output dimensions, porosity and elastic modulus of additive manufactured biomaterial structures targeting orthopedic implants

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    This work was supported by FCT (Fundação para a Ciência e a Tecnologia) through the grant FRH/BD/128657/2017, the projects PTDC/EMS-TEC/5422/2014_ADAPTPROSTHESIS, POCI-01-0145-FEDER-030353 (SMARTCUT), NORTE 010145_FEDER-000018-HAMaBICo and UID/EEA/04436/2019.SLM accuracy for fabricating porous materials is a noteworthy hindrance when aiming to obtain biomaterial cellular structures owing precise geometry, porosity, open-cells dimension and mechanical properties as outcomes. This study provides a comprehensive characterization of seventeen biomaterial Ti6Al4V-based structures in which experimental and numerical investigations (compression stress-strain tests) were carried out. Monomaterial Ti6Al4V cellular structures and multi-material Ti6Al4V-PEEK cellular structures were designed, produced by SLM and characterized targeting orthopedic implants. In this work, the differences between the CAD design and the as-produced Ti6Al4V-based structures were obtained from image analysis and were used to develop predictive models. The results showed that dimensional deviations inherent to SLM fabrication are systematically found for different dimensional ranges. The present study proposes several mathematical models, having high coefficients of determination, that estimate the real dimensions, porosity and elastic modulus of Ti6Al4V-based cellular structures as function of the CAD model. Moreover, numerical analysis was performed to estimate the octahedral shear strain for correlating with bone mechanostat theory limits. The developed models can help engineers to design and obtain near-net shape SLM biomaterials matching the desired geometry, opencells dimensions, porosity and elastic modulus. The obtained results show that by using these AM structures design it is possible to fabricate components exhibiting a strain and elastic modulus that complies with that of bone, thus being suitable for orthopedic implants.info:eu-repo/semantics/publishedVersio

    Risco de fractura no tecido ósseo em pacientes do género feminino da zona litoral Norte de Portugal

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    Com este trabalho pretende-se obter estimativas do risco, associado a fracturas do tecido ósseo, função de alguma patologia, que se possa generalizar ou não para qualquer paciente, com base em determinados factores, nomeadamente, idade, estilo de vida, terapêutica associada, em função de dados clínicos obtidos em pacientes do género feminino na zona Litoral Norte de Portugal. No último triénio de 2010 foram avaliadas 125 pacientes na clínica Dr. Krug de Noronha, Radiologia/Imagem, com idades compreendidas entre os 30 e 85 anos para esse efeito. Foram obtidos e avaliados os exames densitométricos em relação à frequência de osteoporose ou osteopenia do colo do fémur e da coluna lombar destas pacientes. Simultaneamente foi elaborado um inquérito às pacientes com informações adicionais, dados pessoais, antropométricos, ginecológicos, considerando ainda a tipologia de factores de risco associados à osteoporose. Com base na amostra obtida serão apresentados diferentes gráficos por faixa etária para uma avaliação e discussão detalhada de cada factor de risco prevalente

    Análise da degradação em duas instalações fotovoltaicas, localizadas em Porto Alegre, Brasil

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    CIES2020 - XVII Congresso Ibérico e XIII Congresso Ibero-americano de Energia SolarRESUMO: Ao mesmo tempo em que o crescimento da energia solar fotovoltaica se expressa atingindo centenas de gigawatts instalados ao redor do mundo, a durabilidade dos módulos pode ser fator chave para manter a viabilidade da tecnologia. Este trabalho descreve o estado de duas instalações fotovoltaicas situadas no LABSOL (Laboratório de Energia Solar da UFRGS). A primeira instalação funciona há quinze anos e a mais recente há três anos. Para realizar esta avaliação aplicam-se algumas técnicas, destacando-se os registros de inspeções visuais, de imagens de eletroluminescência, de análises termográficas e principalmente resultados da caracterização elétrica do comportamento da curva I-V, refletindo então a degradação do material que compõe os módulos. Apesar dos danos revelados neste trabalho, pode-se afirmar que os sistemas continuam operando dentro das expectativas. A taxa de degradação da potência para o sistema mais antigo foi de 0,7% ao ano e na instalação de três anos, observou-se mínimo efeito visual da ação do ambiente, resultando taxa de degradação de 0,85% ao ano.ABSTRACT: At the same time that the growth of solar photovoltaic energy is expressed reaching hundreds of gigawatts installed around the world, the reliability of the modules can be a key factor to maintain the viability of the technology. This work describes the state of two photovoltaic installations located at LABSOL (Laboratory of Solar Energy at UFRGS). The first installation has been in operation for fifteen years and the most recent for three years. To carry out this evaluation some techniques are applied such as the records of visual inspections, electroluminescence images, thermographic analyzes and mainly results of the electrical characterization of the behavior of the I-V curve, thus revealing the degradation of the modules. Despite the damage revealed in this work, it can be said that the systems continue to operate within expectations. The rate of power degradation for the oldest system was 0.7% per year and in the three-year installation, a minimal visual effect of the action of the environment was observed, resulting in a rate of degradation of 0.85% per year.info:eu-repo/semantics/publishedVersio

    Development of β-TCP-Ti6Al4V structures: Driving cellular response by modulating physical and chemical properties

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    Acknowledgments This work was supported by FCT (Fundação para a Ciência e Tecnologia) through the grants SFRH/BD/140191/2018; SFRH/BPD/112111/2015, SFRH/BD/128657/2017, SFRH/BD/141056/2018; SFRH/BPD/97701/2013, PD/BDE/127836/2016, and the projects PTDC/EMS-TEC/5422/2014_ADAPTPROSTHESIS and NORTE-01- 0145-FEDER-000018-HAMaBICo. Additionally, this work was supported by FCT with the reference project UID/EEA/04436/2013, by FEDER funds through the COMPETE 2020 – Programa Operacional Competitividade e Internacionalização (POCI) with the reference project POCI-01-0145-FEDER-006941.Load-bearing implants success is strongly dependent on several physical and chemical properties that are known to drive cellular response. In this work, multi-material β-TCP-Ti6Al4V cellular structures were designed to combine Ti6Al4V mechanical properties and β-Tricalcium Phosphate bioactivity, in order to promote bone ingrowth as the bioactive material is being absorbed and replaced by newly formed bone. In this sense, the produced structures were characterized regarding roughness, wettability, β-TCP quantity and quality inside the structures after fabrication and the pH measured during cell culture (as consequence of β-TCP dissolution) and those aspects were correlated with cellular viability, distribution, morphology and proliferation. These structures displayed a hydrophilic behavior and results showed that the addition of β-TCP to these cellular structures led to an alkalization of the medium, aspect that significantly influences the cellular response. Higher impregnation ratios were found more adequate for lowering the media pH and toxicity, and thus enhance cell adhesion and proliferation.info:eu-repo/semantics/publishedVersio

    45S5 BAG-Ti6Al4V structures: The influence of the design on some of the physical and chemical interactions that drive cellular response

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    This work was supported by FCT (Fundação para a Ciência e Tecnologia) through the grants SFRH/BPD/112111/2015, SFRH/BD/128657/2017, PD/BDE/127836/2016, SFRH/BPD/97701/2013, SFRH/ BD/141056/2018, SFRH/BD/140191/2018 and the projects PTDC/EMSTEC/5422/2014 and NORTE-01-0145-FEDER-000018-HAMaBICo. Additionally, this work was supported by FCT with the reference project UID/EEA/04436/2013, by FEDER funds through the COMPETE 2020 – Programa Operacional Competitividade e Internacionalização (POCI) with the reference project POCI-01-0145-FEDER-006941.Multi-material Ti6Al4V cellular structures impregnated with 45S5 bioactive glass were designed and produced using Selective LaserMelting (SLM), an additive manufacturing technique, combinedwith Press and Sintering focusing on load bearing components like hip implants. These structures were designed to combine Ti6Al4V mechanical properties and promote bone ingrowth into the structure as the bioactive material (45S5) is being absorbed and replaced by newly formed bone. The influence of these structures design on some of the physical and chemical aspects that drive cellular response was assessed. Roughness, wettability, bioactive glass quantity and quality on the structures after processing and the pH measured during cell culture (as a consequence of bioactive glass dissolution) were evaluated and correlated with cellular viability, cellular distribution, morphology and proliferation on the surface and inside the structures.info:eu-repo/semantics/publishedVersio

    From forensics to clinical research: expanding the variant calling pipeline for the precision ID mtDNA whole genome panel

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    Despite a multitude of methods for the sample preparation, sequencing, and data analysis of mitochondrial DNA (mtDNA), the demand for innovation remains, particularly in comparison with nuclear DNA (nDNA) research. The Applied Biosystems™ Precision ID mtDNA Whole Genome Panel (Thermo Fisher Scientific, USA) is an innovative library preparation kit suitable for degraded samples and low DNA input. However, its bioinformatic processing occurs in the enterprise Ion Torrent Suite™ Software (TSS), yielding BAM files aligned to an unorthodox version of the revised Cambridge Reference Sequence (rCRS), with a heteroplasmy threshold level of 10%. Here, we present an alternative customizable pipeline, the PrecisionCallerPipeline (PCP), for processing samples with the correct rCRS output after Ion Torrent sequencing with the Precision ID library kit. Using 18 samples (3 original samples and 15 mixtures) derived from the 1000 Genomes Project, we achieved overall improved performance metrics in comparison with the proprietary TSS, with optimal performance at a 2.5% heteroplasmy threshold. We further validated our findings with 50 samples from an ongoing independent cohort of stroke patients, with PCP finding 98.31% of TSS’s variants (TSS found 57.92% of PCP’s variants), with a significant correlation between the variant levels of variants found with both pipelines

    Discovery and integration of Web 2.0 content into geospatial information infrastructures: a use case in wild fire monitoring

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    Efficient environment monitoring has become a major concern for society to guarantee sustainable development. For instance, forest fire detection and analysis is important to provide early warning systems and identify impact. In this environmental context, availability of up-to-date information is very important for reducing damages caused. Environmental applications are deployed on top of GeospatialInformation Infrastructures (GIIs) to manage information pertaining to our environment. Suchinfrastructures are traditionally top-down infrastructures that do not consider user participation. This provokes a bottleneck in content publication and therefore a lack of content availability. On the contrary mainstream IT systems and in particular the emerging Web 2.0 Services allow active user participation that is becoming a massive source of dynamic geospatial resources. In this paper, we present a webservice, that implements a standard interface, offers a unique entry point for spatial data discovery, both in GII services and web 2.0 services. We introduce a prototype as proof of concept in a forest fire scenario, where we illustrate how to leverage scientific data and web 2.0 conten
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