Biocompatibilidade de resinas acrílicas para base e reembasamento de próteses após períodos de imersão em soluções desinfetantes: análise do metabolismo celular

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito do filme de carbono DLC aplicado por plasma como recobrimento em Polietileno de Ultra Densidade e Alto Peso Molecular (UHWPE) e planejamento virtual utilizando a técnica de elementos finitos em cirúrgias de próteses totais da ATM

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência da inalação da fumaça de cigarro na regeneração óssea guiada em enxertos autógenos onlay em ratas com deficiência estrogênica: estudo histomorfométrico

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo da resistência à corrosão de ligas Ni-Cr-Mo-Ta E Ni-Cr-Mo-W em solução NaF 0,08 mol/L, pH 4,7 para aplicações odontológicas

A large number of metal alloys are used in Dentistry for the manufacture of fixed and removable dentures. In the oral cavity, these structures are exposed to a chemically aggressive medium, like saliva and mechanical efforts, like mastication. In addition, acidic solutions containing fluoride ions are also frequently used in dental treatments to prevent dental plates and decays development. In this context, it was considered important to investigate the influence that a fourth element could exert when added to the ternary alloy Ni-Cr-Mo, largely used in Brazil. Therefore, electrochemical tests were done to evaluate the resistance to corrosion of quaternary alloy 65Ni-25Cr-5Mo-5Ta and 65Ni-25Cr-5Mo-5W in NaF solution 0,08mol / L, pH = 4.7. For greater understanding the microstructure and morphology of alloys were studied, through metallographic analysis, using optics microscopy and electron microscopy scanning. For the electrochemical tests were applied techniques traditionally used in corrosion researches, such as: potential measures in open circuit (OCP) and cyclic polarization (CP). It was found that both quaternary alloys showed very similar results. Comparing these quaternary alloys with the ternary 65Ni-25Cr-10Mo, it was found that the quaternary alloys exhibit greater resistance to corrosion, in other words, less passivation current density than the ternary alloy, showing that it is advantageous to add a fourth element in the alloy

Avaliação da atividade antifúngica de peptídeos derivados da histatina-5 para o tratamento de candidose bucal

Os peptídeos têm sido amplamente estudados e demonstrados como uma estratégia promissora no combate a micro-organismos patogênicos, devido aos inovadores mecanismos de ação que apresentam e a menor indução de resistência nos microorganismos. Os peptídeos da família das Histatinas, naturalmente presentes na saliva humana, são os principais agentes que auxiliam na cicatrização e oclusão de feridas, re-epitelização e, além disso, dispõem de mecanismos de ação contra microorganismos, em especial, a Candida albicans. O agente etiológico da Candidiose bucal é a Candida albicans, um patógeno de origem fúngica, que acomete indivíduos de todas as idades, indivíduos imunologicamente debilitados e, especialmente, os usuários de próteses dentárias. Um importante fator de virulência da Candida albicans é a habilidade de formar biofilmes, estrutura comunitária microbiana revestida por exopolissacarídeos, capaz de aderir-se a superfícies lisas. Os biofilmes associam-se com a capacidade de causar infecções, com o desenvolvimento de resistência contra o sistema imune do hospedeiro e contra os antifúngicos. O uso indiscriminado e a exposição prolongada aos antifúngicos induz o surgimento de resistência a esses medicamentos, além disso existem cepas de Candida albicans resistentes ao tratamento com antifúngicos azólicos. Devido a isso surge a necessidade de desenvolvimento de novos alvos terapêuticos. O objetivo desse estudo consiste no desenvolvimento de análogos da Histatina-5 com algumas modificações estruturais, a fim de potencializar a ação terapêutica já comprovada dos peptídeos da família das Histatinas. A Histatina-5GH apresenta maior carga positiva que os demais peptídeos devido a troca de duas glicinas na estrutura da Histatina-5 por duas histidinas. Por sua vez, a Histatina-5SC possui o resíduo de serina C-terminal substituído por...

Caracterização da liga Ti-15Zr visando aplicações biomédicas

With advances in health care, has been na increase of demand for material that could replace the functions of the human body parts, thus evolved biomedic prosthesis which today are responsible for the constant improvement of the quality of life. The Titanium alloys are widely used as implants due to its properties, like high mechanical resistance, biocompatibility and corrosion resistance, and the addition alloying elements like Zirconium, may improve some of those properties. Such properties are related to the microstructure and consequently to the type of processing performed. The purpose of this dissertation was to characterize the experimental alloy Ti15Zr after route of processsing and heat treatment in order to extend the knowledge about this alloy. The latter has been abtained by fusion of pure metals in a arc melting furnace with an inert argon atmosphere. The material has been homogenized in a tube furnace at 950ºC for 24h and cold worked by swaging, after that, bars with 10 mm of diameter were obtained by the process of rotary forging. The samples were solubilized at 900º C for 2 hours and quenched in water. After that, 4 samples were submitted to the aging, at 400º C, 450º C, 500º C and 550º C. The microstructure and phase analysis was done by optical microscopy and X-rays diffraction (XRD), the mechanical characterization was carried out by microhardness test and finally, evaluation of corrosion resistance of the alloy by electrochemical tests. The XRD and the optical microscopy made it possible to analyze that the heat treatment influenced the phase shifting from α to α', and probably affected the alloy hardness, at the first aged sample at 500º Chas been a sudden increase in the value of hardness, probably by appearance of omega phase, unwanted phase to the medical application duo to great fragility, and finally ... (Complete abstract click electronic access below)

APR e FMEA em trocador de calor de bomba

The modernization of the world made the speed, accuracy and reliability of all existing processes become increasingly necessary. For this evolution to occur every day, the evolution of the equipment was strategic, but not as much as needed. It is necessary for such equipment to ensure its function and, in case of failure, an early diagnosis to prevent loss. Therefore the evolution of maintainability and reliability in equipment is also paramount. Thus, the growth of forms of maintenance was driven by this scenario, forming maintenance philosophies. Among many, there is the RCM, which have its focus on the identification, parameters development and performance preview. One of those methodologies from this idea is the FMEA, process that has been studied and implemented this work, aiming the anticipation of failure modes and guidance for the use of a heat exchanger and a pump. This implementation has the aid of another process of RCM, the PHA, which was also shown and implemented, these results being used to start the FMEA process. The results show the activities with the highest chance of failure, presenting also the measures to be taken to avoid or minimize them. It is shown, in this paper, concern with the valves because they maintain control and system security, and its flaws related to accidents with possible danger to people and the whole system, emphasizing the priority of action

Aspectos estruturais e moleculares do músculo cardíaco durante a transição entre a disfunção e a insuficiência cardiaca

Pós-graduação em Biologia Geral e Aplicada - IBB

Efeito da inibição da NADPH oxidase sobre o estresse oxidativo e o fenótipo muscular esquelético de ratos com insuficiência cardíaca crônica induzida por estenose aórtica

Pós-graduação em Fisiopatologia em Clínica Médica - FMB