Avaliação de um recobrimento de baixa espessura processado pela deposição assistida por feixe iônico como alternativa para a incorporação de biocerâmicas em implantes dentários: estudo em cães

Thin-film bioceramic coatings are potential alternatives to overcome the limitations provided by other commercially available coating techniques like PSHA, where variable bioceramic dissolution added to a metalloceramic weak link are process- inherent. The purpose of this investigation was to determine the overall and site specific (to 0.5 mm from implant surface) levels of osseoactivity around a thin-film (IBAD processed) coated titanium alloy implant versus a non surface modified (sand-blasted/acid etched) titanium alloy implant in a canine model. The surgical model comprised the proximal tibiae epiphyses with four implants placed in each limb remaining for 2 and 4 weeks in-vivo. 10 mg/Kg oxytetracycline was administered 48 hours prior to euthanization. The limbs were retrieved by sharp dissection, reduced to blocks, and subsequently nondecalcified processed for fluorescent microscopy. Micrographs (20x mag) were acquired around the implant perimeter and merged for overall biological response evaluations, and four micrographs (40x mag. subdivided in rectangles) were acquired along one of the implant sides for tetracycline labeled area fraction quantification. The results showed biocompatible and osseoconductive properties for the thin-film coated and uncoated titanium alloy implants. Tetracycline labeled area fraction analyses showed that the thin-film coated implants presented significantly higher overall and site specific osseoactivity levels at 2 and 4 weeks. The site specific osseoactivity values were significantly higher compared to overall values for control and thin-film coated implants at both times in-vivo. According to the results obtained in this study, thin-film coated implants enhanced biological response at the early implantation times evaluated.Recobrimentos biocerâmicos de baixa espessura são potenciais alternativas para compensar as limitações de outros recobrimentos biocerâmicos disponíveis comercialmente como o plasma spray de hidroxiapatita, onde a dissolução desigual e a presença de uma fraca interface metal-cerâmica são problemas inerentes ao seu processamento. O propósito desta investigação foi determinar os níveis de atividade óssea total e específica a uma área (0.5 mm da superfície do implante) ao redor de um implante de liga de titânio (superficie jateada seguida de ataque ácido) recoberto com um filme biocerâmico de baixa espessura processado através de deposição auxiliada por feixe iônico, contra um implante de liga de titânio sem recobrimento biocerâmico em cães. O modelo cirúrgico utilizou a epífise proximal da tibia, com quatro implantes colocados em cada uma, onde permaneceram por um período de 2 e 4 semanas. Oxitetraciclina (10 mg/Kg) foi administrada 48 horas antes dos animais serem sacrificados. As tíbias foram dissecadas, reduzidas a blocos, e processadas para análise em microscópio ótico. Microfotografias com aumento de 20x foram obtidas da região perimetral do implante e foram alinhadas para análise da resposta biológica total. Subsequentemente, quatro micro-fotografias com aumento de 40x, sub- divididas em retângulos, foram obtidas de um dos lados do implante para quantificação da área marcada por tetraciclina. Os resultados mostraram biocompatibilidade e osseocondutividade dos implantes de liga de titânio com ou sem filme biocerâmico de baixa espessura. Análise da área marcada por tetraciclina mostrou que os implantes com recobrimento apresentaram uma maior atividade óssea total e específica ao redor do implante em 2 e 4 semanas. Os valores de atividade óssea específica à área adjacente à superfície do implante foram significantemente maiores comparados aos valores obtidos em regiões afastadas dos implantes com ou sem recobrimento biocerâmico. De acordo com os resultados obtidos neste estudo, concluímos que os implantes com recobrimento biocerâmico de baixa espessura aumentaram a resposta biológica após 2 e 4 semanas de tempo de implantação

Responsive materials in the design of transformable interactive surfaces

Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2008.Includes bibliographical references (p. 94-99).Materials that embody computational properties are reshaping the ways in which we design, interact and communicate. This thesis looks at the topic of form transformation and how to bring the programmability and versatility of digital forms into the physical world. The focus is placed on the relationship between materials, form and interaction, in particular how the behavior and properties of shape-changing materials can support the design of transformable interactive surfaces. Three design implementations are presented, each addressing a distinct subject area in the design of form transformation, namely topology, texture and permeability. Surflex is a composite that uses active and passive shape-changing materials to undergo large surface deformations. Sprout I/O implements small shape deformations and co-located input/output at a surface boundary to create a dynamic texture for communication. Shutters uses shape change to regulate a surface's permeability and control environmental exchanges between two distinct spaces. Drawing lessons from these projects, a soft mechanical alphabet and language for form transformation are derived, providing new formal possibilities for enriching human-computer interactions.Marcelo Coelho.S.M

O CONCEITO DE DISSOCIAÇÃO RÍTMICA APLICADO À IMPROVISAÇÃO IDIOMÁTICA NO CONTEXTO POLIMÉTRICO DA COMPOSIÇÃO SKETCH ON CANTOS VII:: ESTRATÉGIAS METODOLÓGICAS

O conceito de dissociação rítmica defendido pelo educador José Eduardo Gramani é usado nesta pesquisa como fundamentação teórica para o desenvolvimento de estratégias metodológicas voltadas à prática da improvisação idiomática em contextos polimétricos. A composição Sketch on Cantos VII foi usada como referência para a criação de tais estratégias, cujo resultado mostrouse satisfatório para o objetivo proposto. O trabalho tem estimulado reflexões sobre a vivificação do corpo para superação dos desafios que a polimetria e a polirritmia proporcionam, legitimando o conceito de dissociação rítmica

Tradução e repetição

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Materializing interaction

Thesis (Ph. D.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, February 2013.Cataloged from PDF version of thesis. "September 2012."Includes bibliographical references (p. 141-148).At the boundary between people, objects and spaces, we encounter a broad range of surfaces. Their properties perform functional roles such as permeability, comfort or illumination, while conveying information such as an object's affordances, composition, or history of use. However, today surfaces are static and can neither adapt to our changing needs, nor communicate dynamic information and sense user input. As technology advances and we progress towards a world imbued with programmable materials, how will designers create physical surfaces that are adaptive and can take full advantage of our sensory apparatus? This dissertation looks at this question through the lens of a three-tier methodology consisting of the development of programmable composites; their application in design and architecture; and contextualization through a broader material and surface taxonomy. The focus is placed primarily on how materials and their aggregate surface properties can be used to engage our senses. A series of design probes and four final implementations are presented, each addressing specific programmable material and surface properties. Surflex, Sprout 1/O, and Shutters are continuous surfaces which can change shape to modify their topology, texture and permeability, and Six-Forty by Four-Eighty is a light-emitting display surface composed of autonomous and reconfigurable physical pixels. The technical and conceptual objectives of these designs are evaluated through exhibitions in a variety of public spaces, such as museums, galleries, fairs, as well as art and design festivals. This dissertation seeks to provide contributions on multiple levels, including: the development of techniques for the creation and control of programmable surfaces; the definition of a vocabulary and taxonomy to describe and compare previous work in this area; and finally, uncovering design principles for the underlying development of future programmable surface aesthetics.by Marcelo Coelho.Ph.D