Effect of the number of abutments on biomechanics of Branemark prosthesis with straight and tilted distal implants

OBJECTIVE: This study aimed to evaluate the bending moments, and compressive and tensile forces in implant-supported prostheses with three, four or five abutments. MATERIAL AND METHODS: Ten Pd-Ag frameworks were tested over two master models with: 1) parallel vertical implants, and 2) tilted distal implants. Strain gauges were fixed on the abutments of each master model to measure the deformation when a static load of 50 N was applied on the cantilever (15 mm). The deformation values were measured when the metallic frameworks were tested over three, four or five abutments, and transformed into force and bending moment values. Data were analyzed by ANOVA and Tukey's test for multiple comparisons at 5% level of significance. RESULTS: Abutment #1 (adjacent to the cantilever) had the highest values of force and sagittal bending moment for all tests with three, four or five abutments. Independently from the number of abutments, axial force in abutment #1 was higher in the vertical model than in the tilted model. Total moment was higher with three abutments than with four or five abutments. Independently from the inclination of implants, the mean force with four or five abutments was lower than that with three abutments. CONCLUSION: The results suggest that in the set-ups with four or five abutments tilted distal implants reduced axial force and did not increase bending moments

ANÁLISE DA CAPACIDADE DE PROPULSÃO DE UM PROTÓTIPO ELÉTRICO

Há mais de um século que os automóveis fazem parte do cotidiano da humanidade, e ano após ano o número de usuários aumenta. São feitos esforços no mundo todo para tornar os veículos mais eficientes e menos poluentes. O presente trabalho vem ao encontro deste objetivo, no qual foi realizado o estudo da capacidade de propulsão de um protótipo elétrico como alternativa aos veículos com motores a combustão interna. A partir de um conjunto pré-selecionado, composto por dois motores elétricos, gerenciados por módulos de controle programáveis, foi realizada a instalação e configuração dos diversos componentes elétricos e mecânicos que compõem o sistema. Num segundo momento foram definidas as resistências que se opõem ao movimento do protótipo, permitindo especificar dados de desempenho e consequentemente avaliar sua capacidade de transitar nas vias dos grandes centros. Concluiu-se que o conjunto propulsor possui características que tornam o protótipo apto a transitar em vias urbanas com restrição a ângulos de aclive maiores que 10º

O fenómeno das fake news no contexto das relações públicas

Dissertação de mestrado apresentada à Escola Superior de Comunicação Social como parte dos requisitos para obtenção de grau de mestre em Gestão Estratégica das Relações Públicas.As fake news não são novas. Ao olhar-se para o passado da comunicação, consegue-se perceber que há fenómenos muito semelhantes: a desinformação, o boato, a pós-verdade e os pseudo-eventos. Contudo, atualmente, apresentam uma importância acrescida: têm os social media ao seu dispor, que lhes proporciona uma maior velocidade de propagação e, consequentemente, permite que se multipliquem e se tornem globais. É neste ponto que nos situamos, e é a partir deste contexto que se pretende compreender a natureza da relação entre as Relações Públicas e as fake news. Percebe-se que os profissionais desta área não podem ignorar a existência de fake news, sendo necessário monitorizar, avaliar e delinear estratégias de prevenção e de reação, tal como se torna imperativa a aposta na veracidade dos factos que se transmite aos media e na criação de relações com os stakeholders e públicos. Questiona-se a possibilidade de as Relações Públicas contribuírem para a literacia mediática e explora-se a relação entre os profissionais do setor e os jornalistas, tendo como base o panorama de fake news atual, verificando-se uma maior relevância da mesma. A sustentar a parte empírica desta dissertação estão as visões de 17 profissionais da área das Relações Públicas, que trabalham em agências de comunicação nacionais.ABSTRACT : What we call fake news are not new. Looking at the past of communication, one can see that there are very similar phenomena’s: misinformation, rumours, post-truths and socalled events. Today, however, they have an added importance: they have social media at their disposal, which gives them a faster spread and therefore allows them to multiply and become global. This is where we stand and it is from this context that we want to understand the nature of the relationship between Public Relations and fake news. We realize that professionals in this area cannot ignore on the existence of fake news, with much necessity to monitor, evaluate and outline prevention and reaction strategies, as it is imperative to bet on the truth of the facts transmitted to the media and the creation of relationships with stakeholders and audiences. We question the possibility of Public Relations contributing to media literacy and explore the relationship between industry professionals and journalists, based on the current fake news landscape, with a greater relevance. Supporting the empirical part of this dissertation are the views of 17 PR professionals working in national media agencies.N/

A atuação da Área Industrial do BNDES na Região Sul

Bibliografia: p. 102-103.Neste capítulo, são apresentados resumos setoriais, cases empresariais e discussões prospectivas relativos a alguns dos vários setores em que a Área Industrial (AI) do BNDES atua, por exemplo, automotivo, sucroenergético, complexo industrial da saúde, de tecnologias de informação e comunicação (TICs), de bens de capital, comércio, serviços e cultura. Defende-se que o peso da indústria na Região Sul dá origem a um quadro complexo e diversificado, o que faz com que a AI do BNDES atue de modo igualmente complexo em seu esforço de promoção do desenvolvimento econômico.In this chapter, we present sectorial summaries, corporate case studies and prospective discussions on some of the many sectors in which the BNDES’ Industrial Division (AI) operates, for example, automotive, sugar-based ethanol, industrial health, information and communication technologies (ICTs), capital goods, trade, services and culture. It defends that the strength of industry in the South region of Brazil gives rise to complex and diversified circumstances, which result in the AI division operating in an equally complex manner in its efforts to boost economic development

Effect of removal and reinsertion of force-closed stems on deformation of total hip arthroplasty

ABSTRACT OBJECTIVES: This study investigated removal of a force-closed stem, done in order to improve acetabular exposure during revision, with reinsertion afterwards. It is unknown how much this procedure modifies the stem/cement interface. METHODS: Three tapered stem models were implanted into composite femurs. Strain gauges were embedded in the medial aspect of the cement mantle and in several positions on the outer surface of the femurs. The deformation was measured during static loading, which was applied at two different times: after implantation and after one million loading cycles, followed by stem removal and reinsertion. The t test was performed. The differences in deformation were compared (at p ≤ 0.05) between the two static loading times and among the three stem designs. RESULTS: No significant differences in deformation were found after the two loading times for the three models. No significant differences in the initial deformations of the three models were found for most of the gauges attached to the femurs. CONCLUSIONS: Reinsertion of the force-closed stem does not alter the load transmission from the stem to the cement and to the surface of the femur, even after one million loading cycles

Migration and strains induced by different designs of force-closed stems for THA

ABSTRACT Objectives: Subtle differences in stem design can result in different mechanical responses of the total hip arthroplasty. Tests measuring migration of the stem relative to the femur, as well as the strains in the cement mantle and on the femur can detect different mechanical behavior between stems. Methods: In this article, conical, double and triple tapered stems were implanted in composite femurs and subjected to static and cyclic loads. Stems differed mainly on taper angle, calcar radius and proximal stiffness. Stem migration and strains on the femur and in the cement mantle were achieved. Results: Significant differences (p < 0.05) were noted in the permanent rotation between double and triple tapers, in the strains on the proximal medial femur between triple and both conical and double tapers, and in the strains on the lateral proximal femur between double tapers and both conical and triple tapers. Conclusion: The proposed mechanical tests were able to detect significant differences in the behavior of these resembling stems. Stem proximal stiffness and the calcar radius of the stem influence its rotational stability and the strain transmission to the femur

Projetos diversos em biomecânica

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