À l'heure actuelle, le développement dans les piles à combustible gagne un regard considérable pour la cogénération de l'énergie propre. Plus particulièrement, les piles à combustible à conduction protonique dont leurs électrolytes sont des oxydes de type pérovskite. Nous nous sommes intéressés aux électrolytes des piles de type PCFC « Proton Ceramic Fuel Cell » dont la température de fonctionnement est intermédiaire. L'intérêt porté pour l'amélioration de la diffusion du proton au sein de ces matériaux implique une compréhension fondamentale de l'interaction du proton avec son environnement. Cette problématique a conduit à une étude systématique en appliquant l'approche de la théorie de la fonctionnelle de la densité sur les matériaux de BaMxZr1-xO3 (M=Y, In et Sc ; x=12,5, 25 et 37,5%). Dans un premier temps, la validation de la méthode appliquée sur le système idéal de BaZrO3 et BaZr0,625Y0,375O3 a été nécessaire afin de reproduire les propriétés électroniques, structurales et de vibration de phonon en bon accord avec les résultats expérimentaux. Dans un deuxième temps, la variation des propriétés électroniques et structurales en fonction de la nature du dopant accepteur (M=Y, In et Sc), sa répartition dans le réseau, et sa concentration ont été étudiées. Une distorsion locale autour de l'atome dopant dans le réseau a été obtenue. Par conséquent, une baisse de symétrie du réseau a été déterminée. Cette distorsion est remarquée quel que soit la nature du dopant. La différence la plus marquée de l'effet de la nature du dopant est trouvée sur les charges atomiques des ions oxygène selon trois environnement possible : Zr-O(1)-Zr, Zr-O(2)-M et M-O(3)-M. Une diminution de la charge (et donc diminution de la basicité) sur le site O3 est bien remarquée dans BaMxZr1-xO3. On attribue cette diminution de charge à la formation d'une liaison covalente à caractère anti-liant Y-O2 (O3). La liaison est ionique pour Sc-O2(O3) et covalente de faible caractère liant pour In-O2 (O3). Nous avons poursuivi nos investigations sur l'insertion d'hydrogène dans les matériaux étudiés. L'analyse des propriétés électroniques, structurales, des vibrations de phonon et l'énergie d'interaction de l'hydrogène des structures BaMxZr1-xO3H, nous ont permis d'établir une corrélation entre le caractère de la liaison chimique M-O, l'insertion du proton et la force de la liaison O-H. L'insertion de H sur le site O3 dans BaYxZr1-xO3 (x=0,25 et 0,375) n'est pas obtenue, probablement à cause de la faible basicité de l'ion oxygène dans la configuration Y-O3-Y. L'insertion du H sur le site O3 pour les deux configurations In-O-In et Sc-O-Sc est obtenue dans BaInxZr1-xO3 (x=0,25 et 0,375) et BaScxZr1-xO3 (x=0,25 et 0,375) respectivement. La variation de l'énergie d'interaction de l'hydrogène avec son environnement dévoile une stabilisation des défauts protoniques significativement plus importante dans le cas de l'atome dopant accepteur yttrium que dans le cas des dopants In et Sc. L'analyse des fréquences de vibration de valence de la liaison O-H a montrée que cette liaison est plus forte dans BaInxZr1-xO3 et BaScxZr1-xO3 que dans BaYxZr1-xO3. En conclusion, nos résultats démontrent que le matériau BaZrO3 dopé en Y favorise plus la formation des défauts protoniques avec une liaison O-H moins forte que dans les matériaux baryum zirconates dopés en In et Sc. / At the present, the development of fuel cells gains a significant interest for their application in clean energy technologies, more specifically, the proton conducting fuel cells. We are interested in the perovskite oxides electrolytes used in PCFC fuel cell “Proton Ceramic Fuel Cell” which operates at intermediate temperature. The interest for the improvement of proton diffusion in these materials necessitates a fundamental systematic understanding of the proton interaction with its environment. Therefore we applied Density Functional Theory based approach on ideal BaZrO3 and doped barium zirconates BaMxZr1-xO3 (M=Y, Sc and In ; x=12.5, 25 and 37.5%), currently known among the best candidates for PCFC electrolytes. First, the validation of the method applied to the ideal system and BaY0.375Zr0.625O3 was necessary in order to reproduce the electronic, structural and phonon vibration in good agreement with the experimental results. Second, the variation of electronic and structural properties and of the phonon vibration was studied as a function of acceptor dopant nature, positions in the lattice and concentration. A local distortion around the dopant atom in the lattice was obtained. Therefore a reduction of the symmetry system has been determined. This distortion is noticeable regardless of the nature of the dopant. The most striking difference due to the dopant nature is found for the atomic charges on three possible oxygen environments : Zr-O(1)-Zr, Zr-O(2)-M and M-O(3)-M. A decrease in the atomic charge of O3 site (decrease of basicity) is well observed in BaYxZr1-xO3. This decrease in the charge can be attributed to the formation of a covalent anti-binding Y-O2(O3) bond. The binding is ionic for Sc-O2 and slightly covalent with a maximum of 15% covalency for In-O2. Our next investigations were focused on the insertion of hydrogen in the studied materials. The analysis of the computed electronic and structural properties, phonon vibrations and hydrogen interaction energies allowed us to establish a correlation between the nature of the chemical bonding M-O, the insertion energy of the proton and the O-H bond strength. The insertion of hydrogen in O3 site in BaYxZr1-xO3 (x=0.25 and 0.375) is not obtained, probably due to the low basicity of the oxygen ion in the configuration Y-O-Y. The insertion of H at the oxygen site for both In-O3-In and Sc-O3-Sc configurations found to be energetically favored in BaInxZr1-xO3 (x=0.25 and 0.375) and BaScxZr1-xO3 (x=0.25 and 0.375) respectively. The variation of hydrogen interaction energy with its environment reveals a significantly stronger stabilization of proton defects in the case of yttrium acceptor dopant than in the two other barium zirconates doped with In and Sc. The analysis of O-H stretching vibration frequencies has shown that the O-H bond is stronger in BaInxZr1-xO3 and BaScxZr1-xO3 than in BaYxZr1-xO3. In conclusion, our results show that the Y doped barium zirconate material favors the formation of proton defects, with a weaker O-H bond than in In and Sc doped oxides.

The activity of mitochondrial cytochrome c oxidase (COX) can be affected by either exogenous or endogenous factors. The most efficient and in the environment abundant compound that inhibits COX is cyanide. The very frequent cause of COX deficiency in humans is represented by a defect in the SURF1 gene. The mechanism of cyanide inhibitory effect on COX as well as the conditions for its recovery are not yet fully explained. Three parameters of COX function, namely the transport of electrons (oxygen consumption), the transport of protons (mitochondrial membrane potential, m) and the enzyme affinity to oxygen (p50 value), were studied with regard to the inhibition by KCN and its reversal by pyruvate. The function of COX was analysed in intact isolated rat liver mitochondria, both within the respiratory chain and as a sole enzyme, using succinate or an artificial electron donor ascorbate + TMPD as a substrate. 250 M KCN completely inhibited both electron- and proton-transporting function of COX, and this inhibition was reversible as proved with washing of mitochondria. The addition of 60 mM pyruvate induced the maximal recovery of both parameters to 60 - 80 % of original values. Using KCN in the low concentration range up to 5 M, a profound, 30-fold decrease of COX affinity to oxygen was observed....

Dans les alliages multiphasés, la cohérence des interfaces entre des phases en désaccord paramétrique génère des champs élastiques internes à longue distance et généralement anisotropes. L'interaction de ces champs affecte fortement la cinétique des transformations de phase diffusives, et influence la forme et l'arrangement spatial des précipités. Dans la microstructure des superalliages monocristallins à base de nickel, obtenue par précipitation de la phase γ’ ordonnée L12 dans la matrice CFC γ, l'élasticité conduit à la formation d'alignements quasi-périodiques des précipités γ’ cuboïdaux. La microstructure γ/ γ’ possède cependant des défauts systématiques d'alignement des précipités: des branches, des macro-dislocations et des motifs en chevrons. Nous nous intéressons à l'origine de ces défauts d'alignement. Nous conduisons des analyses de stabilité de l'arrangement périodique de précipités en interactions élastiques. Contrairement à la stabilité attendue, les calculs semi-analytiques ont révélé l'instabilité de la distribution périodique de précipités γ’ cubiques, vis-à-vis de certains modes de perturbation. Les principales instabilités sont le mode longitudinal [100] et le mode transverse [110], et leur domaine d'instabilité est analysé vis-à-vis de l'anisotropie élastique. Le développement de ces modes instables est étudié par une méthode de champ de phase classique, en simulant l'évolution de microstructures périodiques soumises à des légères perturbations initiales. Nous montrons que l'expression des instabilités d'arrangement procède essentiellement par l'évolution de la forme des précipités, et conduit à la formation de motifs qui ont pu être reliés à des microstructures expérimentales. En particulier, le mode transverse [110] conduit à la formation de motifs en chevrons. Nous étudions l'influence du taux de phase γ’ et de l'inhomogénéité du module élastique C’, et nous montrons le rôle qu'ils jouent dans la stabilisation de l'arrangement périodique. Dans des simulations réalisées dans des études antérieures, la dynamique des défauts est analysée au moyen de paramètres topologiques issus de la phénoménologie des structures hors-équilibre. Au cours d'un recuit isotherme, nous observons que les branches et les macro-dislocations migrent dans la microstructure selon des mécanismes de montée et de glissement. Nous utilisons ensuite une nouvelle formulation des modèles de champ de phase, intrinsèquement discrète, dans laquelle les interfaces sont résolues essentiellement avec un pas de grille sans friction de réseau et avec une invariance par rotation précise. Cette approche, appelée Sharp Phase Field Method (S-PFM), est implémentée sur une grille CFC, et avec une description des quatre variants de translation des précipités γ’. Nous montrons que la S-PFM permet la modélisation de microstructures à grande échelle, avec plusieurs milliers de précipités à deux et trois dimensions, et donne ainsi accès à des informations statistiques sur l'évolution de la microstructure et sur la dynamique des défauts d'alignement. Nous discutons finalement la perspective de modéliser l'évolution de la microstructure γ/γ’ à une échelle supérieure par une description de la dynamique des défauts d'alignement des précipités. / In multiphase alloys, internal elastic fields often arise as a result of a coherently adjusted misfit between the lattices of coexisting phases. Given their long-range and usually anisotropic nature, the interaction of these fields is known to significantly alter the kinetics of diffusion-controlled phase transformations, as well as influence the shapes and spatial arrangement of the misfitting precipitates. In the microstructure of single-crystal nickel-base superalloys, obtained by precipitation of the L12-ordered γ’ phase in the FCC γ matrix, elasticity leads to the formation of nearly periodic alignments of the cuboidal γ’ precipitates. However, the γ/γ’ microstructure systematically displays defects in the precipitate alignment: branches, macro-dislocations and chevron patterns. We first address the question of the origin of these alignment defects. Stability analyses of the periodic arrangement of elastically interacting precipitates are carried out. Contrary to the expected stability, the semi-analytical calculations revealed the periodic distribution of cubic γ‘ precipitates to be unstable against specific perturbation modes. The main instabilities are the [100] longitudinal mode and the [110] transverse mode, and their instability range is analyzed with respect to the elastic anisotropy. The consequences of these unstable modes are investigated using a classic phase field method, by modeling the evolution of periodic microstructures undergoing small initial perturbations. We show the expression of the instabilities mainly proceeds by the evolution of the precipitate shapes, and leads to the formation of patterns which were related to experimental microstructures. Specifically, the [110] transverse instability is responsible for the formation of chevron patterns. The effects of the volume fraction and of an inhomogeneity on the C’ shear modulus on the stability of the arrangement are studied, and we show the role they play in the partial stabilization of the periodic distribution, though the [100] longitudinal mode always remains unstable. In phase field calculations carried out in previous studies, the dynamics of alignment defects are analyzed by means of topological parameters derived from pattern formation theory. During annealing, branches and macro-dislocations were observed to migrate in the microstructure according to climbing and gliding mechanisms. We then use a new formulation of phase field models, intrinsically discrete, in which the interfaces are resolved with essentially one grid point with no pinning on the grid and an accurate rotational invariance. This approach, known as the Sharp Phase Field Method (S-PFM), is implemented on a FCC grid and accounts for the four translational variants of the γ’ precipitates. We show that the S-PFM allows for the modeling of large-scale microstructures, with several thousand precipitates both in two and three dimensions, and provides access to statistical information on the microstructure evolution and on the the dynamics of alignment defects. We finally discuss the perspective of modeling the evolution of the γ/γ’ microstructure at the macroscale by means of a description of the defect dynamics in the precipitate alignments.

Les matériaux à changement de phase montrent la combinaison exceptionnelle d’un contraste énorme dans leurs propriétés physiques entre la phase amorphe et cristalline allié à une cinétique de changement de phase extrêmement rapide. La grande différence en résistivité permet leur application dans les mémoires numériques. De plus, cette classe de matériaux montre dans leur état vitreux des phénomènes de transport électronique caractéristiques. Le seuil de commutation dénote la chute de la résistivité dans l’état amorphe au delà d’un champ électrique critique. Le phénomène de seuil de commutation permet la transition de phase en appliquant des tensions relativement faibles. Au-dessous de cette valeur critique l’état désordonné montre une conductivité d’obscurité activée en température ainsi qu’une résistance - dans les cellules mémoires et les couches minces également – qui augmente avec le temps. Cette évolution de la résistivité amorphe entrave le stockage à plusieurs niveaux, qui offrirait la possibilité d'accroître la capacité ou la densité de stockage considérablement. Comprendre les origines physiques de ces deux phénomènes est crucial pour développer de meilleures mémoires à changement de phase. Bien que ces deux phénomènes soient généralement attribués aux défauts localisés, la connaissance de la distribution de défauts dans les matériaux amorphes à changement de phase est assez limitée. Cette thèse se concentre sur la densité des défauts mesurée dans différents verres chalcogénures présentant l’effet de seuil de commutation. Sur la base d’expériences de photo courant modulé (MPC) et de spectroscopie par déviation photothermique, un modèle sophistiqué des défauts a été développé pour GeTe amorphe (a-GeTe) mettant en évidence les états de la bande de valence et plusieurs défauts. Cette étude sur a-GeTe montre que l’analyse des données MPC peut être grandement améliorée en prenant en compte la variation de la bande de l’énergie interdite avec la température. Afin de mieux appréhender l’évolution de la résistivité amorphe, la présente étude porte sur l’évolution avec les recuits et le vieillissement de la résistivité, de l’énergie d’activation du courant d’obscurité, de la densité des défauts, du stress mécanique, de l'environnement atomique et de l’énergie de la bande interdite mesurée par des méthodes optiques sur les couches minces de a-GeTe. Le recuit d’un échantillon entraîne un élargissement de la bande interdite et de l’énergie d’activation du courant d’obscurité. De plus, la technique MPC a révélé une diminution des défauts profonds dans les couches minces de a-GeTe vieillies. Ces résultats illustrent l’impact de l’annihilation des défauts et de l’élargissement de la bande interdite sur l’évolution de la résistivité des matériaux à changement de phase amorphe. Cette thèse présente également une étude sur les alliages à changement de phase GeSnTe. En augmentant la concentration d’étain, on observe une décroissance systématique de la résistivité amorphe, de l’énergie d’activation du courant d’obscurité, de la largeur de bande interdite et de la densité des défauts, qui conduisent à une résistivité amorphe plus stables dans les compositions riches en étain comme a-Ge2Sn2Te4. L’étude sur les alliages GeSnTe montre que les matériaux à changement de phase ayant une résistivité amorphe plus stable présentent une faible énergie d’activation du courant d’obscurité. À l’exemple du Ge2Sn2Te4 et GeTe la présente étude montre un lien étroit entre l’évolution de la résistivité et la relaxation du stress mécanique. L’étude sur les verres chalcogénures montrent que les matériaux ayant un grand champ d’électrique de seuil, bien connu d’après la littérature, présentent aussi une grande densité de défauts. Ce résultat implique que l’origine du phénomène de seuil de commutation se trouve dans un mécanisme de génération à travers la bande interdite et de recombinaison dans les défauts profonds comme proposé par D. Adler. / Phase change materials combine a pronounced contrast in resistivity and reflectivity between their disordered amorphous and ordered crystalline state with very fast crystallization kinetics. Due to this exceptional combination of properties phase-change materials find broad application in non-volatile optical memories such as CD, DVD or Bluray Disc. Furthermore, this class of materials demonstrates remarkable electrical transport phenomena in their disordered state, which have shown to be crucial for their application in electronic storage devices. The threshold switching phenomenon denotes the sudden decrease in resistivity beyond a critical electrical threshold field. The threshold switching phenomenon facilitates the phase transitions at practical small voltages. Below this threshold the amorphous state resistivity is thermally activated and is observed to increase with time. This effect known as resistance drift seriously hampers the development of multi-level storage devices. Hence, understanding the physical origins of threshold switching and resistance drift phenomena is crucial to improve non-volatile phase-change memories. Even though both phenomena are often attributed to localized defect states in the band gap, the defect state density in amorphous phase-change materials has remained poorly studied. This thesis presents defects state densities measured on different amorphous phase-change materials and chalcogenides showing electrical threshold switching. On the basis of Modulated Photo Current (MPC) Experiments and Photothermal Spectroscopy a sophisticated band model for a-GeTe has been developed, which is shown to consist of defect bands and band tail states. This study on a-GeTe has shown that the data analysis within MPC experiments can be drastically improved by taking the temperature dependence of the optical band gap into account. To get a better understanding of resistance drift phenomena this study focuses on the evolution of resistivity on heating and ageing, activation energy of electronic conduction, optical band gap, defect state density, mechanical stress and nearest neighbour ordering in a-GeTe thin films. After heating the samples one hour at 140°C the activation energy for electric conduction increases by 30 meV, while the optical band gap increases by 60 meV. Additionally, MPC experiments revealed a decreasing concentration of mid gap states in aged a-GeTe thin films. These findings demonstrate the impact of band gap opening and defect annihilation on resistance drift. Furthermore, the stoichiometric dependence of resistance drift phenomena in a-GeSnTe phase-change alloys is studied in this thesis. A systematic decrease in the amorphous state resistivity, activation energy for electric conduction, optical band gap and defect density is observed with increasing tin content resulting in a low resistance drift for tin rich compositions such as a-Ge2Sn2Te4. This study on GeSnTe systems demonstrates, that phase change alloys showing a more stable amorphous state resistivity are characterized by a low activation energy of electronic conduction. This finding found in GeSnTe alloys holds also true for GeSbTe and AgInSbTe systems. On the example of a-Ge2Sn2Te4 and a-GeTe exhibiting a strong resistance drift, the evolution of the amorphous state resistivity is shown to be closely linked to the relaxation of internal mechanical stresses resulting in an improving structural ordering of the amorphous phase. For the investigated alloys showing electrical switching, the measured density of midgap states is observed to decreases with decreasing threshold field known from literature. This result favours a generation-recombination model behind electrical switching in amorphous chalcogenides as originally proposed by Adler.

Il été prouvée dans plusieurs études de la littérature que la taille d'un composant affecte sa tenue en fatigue et cette tendance est plus prononcée dans le régime de fatigue à grand nombre de cycles. Plus précisément, une baisse de la limite de fatigue est observée et est souvent expliquée par l’augmentation, avec l’augmentation du volume sollicité, de la probabilité de trouver un défaut critique ou une zone plus faible dans le matériau. Le présent mémoire fait partie d'un projet de recherche français (QUAUSI) regroupant plusieurs partenaires industriels et académiques qui vise à contrôler la qualité d'usinage des composants structuraux d'avions. Un des défis consiste à définir un critère approprié d'acceptabilité de défauts pour la conception en FGNC. Le critère doit être capable de prendre en compte une large gamme de défauts de surface et de composants de tailles et de géométries différentes. L'objectif principal étant de mieux comprendre l'impact des états de surface périodiques (caractéristique du type d'usinage utilisé) sur la limite de fatigue, Il a fallu d'abord vérifier si un effet de taille peut être observé quand un nombre croissant de défauts de surface simples sont introduits à la surface d'échantillons polis. Le matériau d’étude est l’alliage d'aluminium 7050 (Al Zn6CuMgZr). Une grande campagne d'essais de fatigue sous charge de flexion plane à R=-1 est effectuée sur des éprouvettes présentant des défauts hémisphériques, de différents tailles et nombres, et des états de surface usinés. Les résultats des essais ont permis de caractériser à la fois l'effet Kitagawa et l'effet d'échelle sur la tenue fatigue. Une approche probabiliste basée sur le concept du maillon le plus faible associé à un critère d'amorçage de fissure de fatigue approprié est utilisée pour prendre en compte la répartition des contraintes et la taille du volume fortement sollicité. Les prédictions utilisant des simulations EF montrent un bon accord avec les résultats expérimentaux et illustrent l'importance de prendre en compte l'effet d'échelle lors de la conception de composants contenant différents types de défauts de surface ou de motifs de rugosité.Mots-clés : Défaut de surface, fatigue à grand nombre de cycles, diagramme de Kitagawa-Takahashi, Le plus faible concept de lien, alliage AA7050 / The size of a component has been proved in several studies of the literature to affect the fatigue strength and this trend is known to be more pronounced in the High Cycle Fatigue regime. More exactly a drop of the fatigue limit is observed and this evolution is very often explained by the probability to find a critical defect or a weakest zone in the material as the stressed volume rises. The present manuscript is part of a French research project gathering several industrial and academic partners that aims to control the machining quality of aircraft structural components. For one part of the project the challenge is to define a proper defect acceptability criterion for HCF design purpose. It must be able to account for a large range of surface defects and of component sizes and geometries. Even though the primary objective was to better understand the impact of periodic surface micro-geometry patterns (characteristic of the type of machining used) on the fatigue limit, we thought that it was first necessary to check if a size effect can be observed when an increasing number of artificial simplified surface defects are introduced at the surface of smooth specimens. The aeronautical material under investigation is a 7050 Aluminum alloy (Al Zn6CuMgZr). A large fatigue testing campaign under fully reversed plane bending loading is undertaken on specimens with artificial surface hemispherical defects. Defect number varies from 1 to 44 per specimen whereas their size ranges from 60 µm to 800 µm. Testing results allow the characterization of both Kitagawa effect and scale effect on the fatigue response. A probabilistic approach based on the weakest link concept together with a proper fatigue crack initiation criterion is used to account for the stress distribution and the size of the highly stressed volume. Predictions using FE simulations show a good agreement with experimental results and illustrate the importance of taking the scale effect into account while designing components containing different types of surface defects or roughness patterns.Keywords : Surface defect, HCF, Kitagawa-Takahashi diagram, Weakest link concept, AA7050 alloy.

Este trabalho apresenta um procedimento de avaliação para a determinação da Integral J e do CTOD para dutos com trincas circunferenciais em sua superfície externa e interna submetidos à flexão pura para uma ampla faixa de geometrias de trinca e propriedades (encruamento) de material baseados em soluções das componentes plásticas de J e CTOD. Uma descrição da metodologia sobre a qual J e CTOD são determinados estabelece o contexto necessário para a determinação das funções adimensionais h1 e h2 aplicáveis a uma grande faixa de geometrias de trinca e propriedades de material características de aços estruturais para a construção de dutos e vasos de pressão. As extensivas análises numéricas não-lineares 3-D fornecem um conjunto completo de soluções para J e CTOD, os quais entram diretamente em procedimentos avançados para a avaliação de defeitos em dutos e cilindros submetidos à flexão. Este estudo também examina uma comparação exploratória entre os resultados do procedimento proposto e os resultados de análises numéricas por elementos finitos de dutos com trincas superficiais submetidos ao processo de enrolamento. / This work provides an estimation procedure to determine the J-integral and CTOD for pipes with circumferential surface cracks subjected to bending load for a wide range of crack geometries and material (hardening) based upon fully-plastic solutions. A summary of the methodology upon which J and CTOD are derived sets the necessary framework to determine nondimensional functions h1 and h2 applicable to a wide range of crack geometries and material properties characteristic of structural, pressure vessel and pipeline steels. The extensive nonlinear, 3-D numerical analyses provide a definite full set of solutions for J and CTOD which enters directly into fitness-for service (FFS) analyses and defect assessment procedures of cracked pipes and cylinders subjected to bending load. The study also examines an exploratory comparison between the resulting fully-plastic solutions and finite element analyses of circumferentially cracked pipes subjected to reeling.

Introdução: As grandes perdas de maxila condicionam grande defeito oral que afetam a qualidade de vida do paciente em diversos domínios. Porém, não há na literatura um questionário específico para esta condição. Proposição: Desenvolver e validar um instrumento de qualidade de vida para as grandes perdas de maxila sem envolvimento facial. Material e Método: Elaboração de um questionário piloto baseado nos achados de outros estudos e seleção de perguntas de instrumentos já existentes que trabalham com domínios semelhantes. Em seguida, clínicos avaliaram estas questões, que poderiam sugerir a inclusão e exclusão de questões. A seguir, pacientes pontuaram os itens gerados numa escala de 0 a 10 segundo a relevância e importância para redução de itens segundo o método de impacto. Por fim, dois pesquisadores agruparam os itens em domínios e se determinou a consistência interna pelo coeficiente alfa de Cronbach. Resultados e Discussão: O questionário preliminar contou inicialmente com 60 questões que, após a entrevista com pacientes, foi reduzido a 33. O alfa de Cronbach foi de 0,92 e os itens foram separados em oito domínios: relações sociais; fala e voz; alimentação; emocional; bem estar material; dor; estética; e halitose. Apenas uma questão, que não obteve índice de impacto suficiente, foi incluída devido aos achados de outros estudos e falta de outra pergunta similar. O instrumento gerado necessita de um processo de validação final. Conclusões: Obtenção de um questionário preliminar sobre qualidade de vida nas grandes perdas de maxila sem envolvimento facial com validade de conteúdo. / Introduction: Maxilla defects affect patients quality of life on several domains. There is not a specific instrument to this condition. Proposition: Develop and validate a disease-specific health related quality of life questionnaire for acquired maxilla defect. Materials and Methods: To elaborate a pilot questionnaire based on other studies results and select questions using instruments that deal with similar domains. Then, experts assessed these items and could suggest including or excluding questions. After that, patients scored the items according to relevance and importance in order to reduce the number of questions using the impact method. At last, two researchers grouped the questions into domains and the internal consistency was calculated using the Cronbachs alpha coefficient. Results and Discussion: The pilot questionnaire contained 60 questions and after we performed the impact method it was reduced to 33 items. The Cronbachs alpha coefficient was 0,92. The researchers compiled the items into eight domains: social relationships; speech and voice; feeding; emotional; material wellbeing; pain; aesthetics ;and halitosis. Only one question did not reach the minimum impact score was included in the questionnaire due to findings in others studies and lack of a similar items. The preliminary instrument presented here needs to undergo a complete validation process in to assess the psychometric properties and to decide on the final version. Conclusions: A preliminary version of the instrument with content validity was obtained.

Introdução: As comunicações interatriais do tipo ostium secundum (CIA-OS) são tratadas por fechamento percutâneo (FP) ou intervenção cirúrgica (IC). Estudos comparando ambos métodos são escassos e avaliações de custo-efetividade inexistem na literatura nacional. Objetivos: Realizar uma avaliação da segurança e eficácia (ASE) clínica seguida de uma análise de custo-efetividade (ACE) incremental comparando o FP e IC sob a perspectiva do Sistema Único de Saúde (SUS). Materiais e métodos: ASE - Estudo observacional, não randomizado de 2 coortes de crianças e adolescentes < 14 anos com CIA-OS tratadas por FP ou IC. A coleta dos dados foi prospectiva no FP e retrospectiva no IC. ACE - Realizada revisão sistemática de estudos clínicos disponíveis no MEDLINE e a Cochrane Central. Estudos com mais de 50 pacientes e com idade média abaixo de 14 anos foram incluídos. A análise foi baseada em uma árvore de decisão computando os custos e consequências no longo prazo de ambas as opções. Foi utilizado valor da prótese de R$ 16.000 e estipulado valor de honorário médico de R$ 2.355. A efetividade foi estimada em anos de vida. A avaliação utilizou uma taxa de desconto de 5% ao ano e uma disposição a pagar de 3 vezes o PIB per capita no Brasil (63.000). Análises de limiares também foram conduzidas. Resultados: ASE - De Abr/09 a Out/11 foram alocados 75 pacientes (pts) no FP e entre Jan/06 e Jan/11 105 pts na IC. A idade e o peso foram maiores no FP e o diâmetro da CIA foi semelhante entre os grupos. Sucesso técnico foi observado em todos os procedimentos e não houve óbitos. Complicações (a maioria menores) foram encontradas em 68% na IC e em 4% do FP (p<0,001). As taxas de fluxo residual não significativo ou de oclusão total do defeito foram semelhantes nos 2 grupos. A mediana de internação foi de 1,2 dias após o FP e 8,4 dias após a IC (p< 0,001). ACE - A estratégia de busca retornou 2.957 referências, das quais 34 foram incluídas. A taxa de mortalidade foi semelhante nos 2 grupos. O FP teve discreta maior efetividade, menor taxa de complicações moderadas/graves e menor tempo de internação, mas com maior probabilidade de um segundo procedimento. A relação de custo-efetividade incremental (RCEI) do tratamento percutâneo foi de R$ 230.641 por ano de vida salvo. Considerando-se este cenário, seria necessário que o custo indireto associado à cirurgia fosse de R$ 4.960, ou que o valor pago pelo dispositivo percutâneo sofresse redução de R$ 4.960 para que o FP se tornasse aceitável do ponto de vista econômico. Conclusões: Ambos tratamentos são seguros e eficazes com ótimos desfechos, porém o FP apresenta menor morbidade e tempo de internação. Usando os valores diretos estipulados neste estudo, a RCEI foi elevada limitando a incorporação do FP pelo SUS neste momento. Estudos considerando também os custos indiretos são necessários para a adequada ACE de ambas estratégias. / Introduction: Atrial septal defects of the secundum type (ASD-OS) are treated by percutaneous closure (PC) or surgical intervention (SI). Comparative studies are scarce and there is no cost-effectiveness assessment in the Brazilian literature. Objectives: To perform a clinical safety and efficacy (ASE) assessment followed by an incremental cost-effectiveness (CEE) analysis comparing PC and SI under the Brazilian Unified Health System perspective. Materials and methods: ASE - Observational, non-randomized study of two cohorts of children and adolescents under 14 years with ASD-OS treated by PC or SI. Data was collected prospectively in PC and retrospectively in SI. CEE - A systematic review of clinical studies available in MEDLINE and Cochrane Central was performed. Studies with more than 50 patients and mean age under 14 years were included. Analysis was based on a decision tree that took into account costs and consequences during long-term follow-up for both options. The cost of the device and medical honorarium were estimated at R$ 16.000 and R$ 2.355, respectively. Effectiveness was estimated in years of life. Assessment was performed using a discount tax of 5% and a willingness to pay of 3 times the GID in Brazil (63.000). Threshold analyses were also conducted. Results: ASE - From Apr/09 to Oct/11 75 patients (pts) were enrolled in PC and from Jan/06 to Jan/11 105 pts in SI. Age and weight were greater in PC and the ASD diameter was similar. Technical success was achieved in all procedures and there were no deaths. Complications (most minor) occurred in 68% of SI and 4% of PC (p<0,001). The rate of total occlusion or non-significant residual shunts was similar in both groups. Median hospitalization time was 1.2 days in PC and 8.4 days in SI (p<0,001). CEE - Search strategy returned 2957 references and 35 were included. Mortality was similar in both groups. PC was associated with slightly better effectiveness, lower rates of moderate/severe complications and reduced hospital stay despite a higher probability of a second procedure. Incremental cost-effectiveness ratio (ICER) was R$ 230.641 for life-year gained. In this scenario, PC would be acceptable from the economic point of view if the indirect costs of the SI was R$ 4.960 or the cost of the device was reduced by R$ 4.960. Conclusions: Both methods are safe and effective with excellent outcomes, however PC is associated with less morbidity and in-hospital time. Using the direct costs stipulated in this study, the ICER was high limiting the incorporation of PC by the Brazilian Unified Health System (SUS) at this moment. Studies also considering the indirect costs should be performed for better CEE assessment of both strategies.

Defeitos de cartilagem e a mais comum doença articular, a osteoartrite, são caracterizadas pela destruição da cartilagem articular, e consequentemente na perda da função articular em humanos e animais. As estratégias atuais de tratamento, conservativas e cirúrgicas, são insuficientes: não resultam em restauração total da cartilagem hialina, e, portanto trazem um prognóstico reservado a longo prazo. O presente estudo tem por objetivo avaliar os efeitos do administração conjunta de concentrado de medula óssea, plasma rico em plaqueta sobre lesões condrais experimentalmente induzidas e tratadas com microfraturas e ácido hialuronico. Foram utilizadas as articulações metacarpofalangeana de 6 éguas, as quais foram divididas em 2 grupos aleatoriamente e cego. Foram feitos defeitos condrais totais através de artroscopia e, todos foram tratados com microfraturas e ácido hialurônico no transoperatório (M 0) sendo, esse repetido após 15 dias (M 15) e 30 dias (M 30). Grupo C (controle) e grupo T (tratado). O grupo T foi tratado com aspirado concentrado de células tronco de medula óssea adicionada ao plasma rico em plaquetas (PRP), os quais foram injetados na articulação no final da cirurgia (M0). O grupo T recebeu ainda 2 aplicações articulares adicionais de PRP em 15 dias (M 15) e 30 dias (M 30). As seguintes avaliações foram realizadas: exame clínico de claudicação, ultrassonografia, estudo radiográfico, avaliações de líquido sinovial (físico, bioquímico e citológico). As avaliações foram realizadas antes da cirurgia (M 0), com 3, 5 e 7 dias. Posteriormente a cada 15 dias (M 15, M 30, M 45 e M 60) e os 3 últimos momentos foram aos 90 (M90), 120 (M120) e 210 (M210) dias. Ao final do experimento os animais foram enviados para abate comercial. Foram verificadas diferenças estatísticas (p<0,05) entre o grupo tratado e controle para avaliação de proteínas no líquido sinovial corrigido por uréia em 3, 5 e 7 dias; para PGE2 no líquido sinovial em 3 e 5 dias onde para ambas as variáveis com maiores valores para o grupo tratado. Já a concentração de ácido hialurônico apresentou maiores valores (p<0,05) em 3, 45 e 90 dias no grupo controle. Para as demais variáveis não houve diferença estatística entre o grupo tratado e controle. Porém, notou-se medianas maiores para condroitin sulfato em 3 e 5 dias no grupo controle. Notavelmente, o grupo tratado apresentou melhor escore macroscópico na avaliação do tecido de reparo. Contudo, a administração intra-articular de concentrado de medula óssea e plasma rico em plaquetas sobre lesões condrais induzidas e tratadas com microfraturas e ácido hialurônico produziu uma reação articular transitória, principalmente nos primeiros 60 dias, e foi evidenciado pelo aumento de PGE2 e proteínas no líquido sinovial, bem como, claudicação, dor a flexão passiva, diminuição da mobilidade articular e aumento de volume articular. No entanto, o tratamento produziu um efeito condroprotetor e anabólico sobre tecido de reparo formado, uma vez que o grupo tratado apresentou menor concentração de ácido hialurônico 3, 45 e 90 dias e melhor escore macroscópico ICRS aos 210 dias / Cartilage defects and the most common joint disease, osteoarthritis, are characterized by destruction of articular cartilage, and consequently in loss of joint function in humans and animals. Current strategies of conservative and surgical treatment are insufficient: they don&rsquo;t result in complete restoration of hyaline cartilage, and bring a poor prognosis on the long term. This study aims to evaluate the effects of co-administration of bone marrow concentrate, platelet rich plasma on experimentally induced chondral lesions and treated with microfractures and hyaluronic acid. The metacarpophalangeal joints of 6 mares were used, which were divided into 2 groups at random and blind. Total chondral defects were made using arthroscopy, and all were treated with microfractures and hyaluronic acid during surgery (M 0) and the hyaluronic acid was repeated after 15 days (M 15) and 30 days (M 30). Group C (control) and T group (treated). Group T was treated with concentrated aspirated bone marrow stem cells added to the platelet rich plasma (PRP), which were injected into the joint at surgery (M0). The T group had another 2 additional joint PRP applications in 15 days (M 15) and 30 days (M 30). The following evaluations were performed: clinical examination of lameness, ultrasound, radiographic studies and synovial fluid analysis (physical, biochemical and cytological). The evaluations were performed before surgery (M 0), 3, 5 and 7 days. Then, every 15 days (M 15, M 30, M 45 and M 60) and the last 3 evaluation were at 90 (M90), 120 (M120) and 210 (M210) days. At the end of the experiment the animals were sent to commercial slaughter. Statistical differences were found (p <0.05) between the treated and control group for evaluation of protein in synovial fluid corrected by urea at 3, 5 and 7 days; for PGE2 in the synovial fluid in 3 to 5 days where both variables had higher values for the treated group. The hyaluronic acid concentration was higher (p <0.05) at 3, 45 and 90 days in the control group. For the other variables there were no statistical difference between the treated and control groups. However, greater medians were noticed for chondroitin sulfate in 3 to 5 days in the control group. Notably, the treated group showed better macroscopic score in the evaluation of the repair tissue. In conclusion, intra-articular administration of bone marrow concentrate and platelet-rich plasma on induced chondral lesions and treated with microfractures and hyaluronic acid produced a transient response joint, especially during the first 60 days, and it was evidenced by the increase in PGE2 and proteins of the synovial fluid, as well as lameness, pain passive flexion, decreased joint mobility and joint swelling. Besides that, the treatment produced an anabolic chondroprotective effect on repair tissue formed once the treated group showed lower concentration of hyaluronic acid 3, 45 and 90 days, and better ICRS macroscopic scoring at 210 days

Einen Orbitadefekt mit Verlust des Auges und der filigranen Lidstrukturen kann eine implantatverankerte Silikonepithese im Halt sicher und bei geöffnetem Auge ästhetisch mit gutem Ergebnis abdecken. Bei Lidschluß fällt allerdings die Starrheit der Lider in der Epithese auf. Ziel der Entwicklung war es, das künstliche Oberlid in der Orbitaepithese beweglich zu gestalten und so durch die gewonnene Dynamik ein natürlicheres Aussehen beim Patienten zu erreichen. In der Epithese sollten alle Komponenten integriert sein, um das künstliche Oberlid synchron zum gesunden Auge zu bewegen. Als bewegliches Oberlid erwies sich gegossene Latexmilch als Material am geeignetsten. Dieses Material war elastisch, einfärbbar und konnte den Belastungen der ungefähr 30 unwillkürlichen Lidschlagbewegungen pro Minute standhalten. Das künstliche Oberlid wurde analog dem natürlichen Vorbild des Lidöffners nach dem Prinzip der Zuggurtung über die Augenprothese nach oben hinten gezogen. Als Antrieb wurde ein DC-Mikromotor eingesetzt, der das Oberlid mit Hilfe eines kleinen Polyamidfadens, welcher an der inneren verstärkten Lidkante befestigt war, nach kranial bewegte. Der Faden wurde über eine Kanülenführung auf eine Seilrolle gewickelt. Nachdem sich ein aufgebautes Tischmodell im Test bewährt hatte, wurde eine einbaufähige elektronische Schaltung in SMD-(Surface Mounted Device) Technik entwickelt, die einerseits den Antrieb steuerte und andererseits die zur Synchronisation erforderlichen Muskelpotentiale verarbeitete. Diese zwei doppelseitig bestückten Platinen wurden direkt hinter die individuell aus Glas vom Okularisten hergestellte Augenprothese positioniert. Über fünf integrierte einstellbare Potentiometer konnten die abgeleiteten Muskelsignale für eine verzögerungsfreie Lidbewegnung beim Patienten individuell verändert werden. Die Energiebereitstellung für die Elektronik und den Motor konnte aufgrund der zu niedrigen Nennkapazitäten nicht durch Akkumulatoren erfolgen, sondern wurde durch eine kleine leicht auswechselbare Batterie erreicht, die hochgerechnet Strom für 7 bis 14 Tage lieferte. Da die einzelnen Komponenten nicht frei in der Epithese liegen konnten, wurde als Schutz ein Gehäuse in hartem Acrylatkunststoff konzipiert. Da die Anordnung der Batterie unter oder hinter dem Motor möglich war und auch die Elektronik versetzt zu Batterie und Motor angebracht werden konnte, konnte so die Geometrie des Gehäuses in Grenzen dem individuellen Orbitadefekt angepaßt werden. In klinischen Versuchen an gesunden Probanden und Patienten mit implantatverankerten Orbitaepithesen zeigte sich, daß Muskelpotentiale vom M. orbicularis oculi aus dem gesunden Oberlid oder teilweise der exenterierten Orbita mit Restaktivität des Lidschließers mit Nadelelektroden bipolar abgeleitet zur Ansteuerung des Motors geeignet waren. Mit diesen Biopotentialen wurde das reibungslose Funktionieren der synchronen Lidbewegung des Prototypen an einer freiwilligen gesunden Versuchsperson getestet. Nach umfangreichen Labortestungen wurden zwei Patienten mit dieser neuartigen Orbitaepithese rehabilitiert. Bei den Patienten wurde das passende Gehäuse mit den gekapselten Funktionseinheiten individuell hergestellt und dieses in eine Silikonepithese eingearbeitet. Gehalten wurde die Silikonepithese über implantatfixierte Magnetabutments. Die Muskelpotentialableitung zur Triggerung der synchronen Lidbewegung erfolgte durch eine intramuskuläre EMG - Ableitung des M. orbicularis oculi. Beim ersten Patienten gelang dieses über eine sterile Nadelelektrode, die allerdings beim Tragen der neuen Orbitaepithese jedes Mal neu in den Muskel eingestochen werden mußte. Beim zweiten Patienten wurden die Muskelpotentiale über eine subcutan implantierte dünne EMG - Elektrode aufgenommen. Die Myosignale wurden bei beiden Patienten bipolar abgeleitet. Die zweite differente Elektrode kontaktierte einen implantatfixierten Magneten. Die Neutralelektrode war mit einem weiteren implantatverankerten Magneten verbunden. Die abgeleiteten Muskelimpulse beim Lidschlag konnten so bei den Patienten eine zum gesunden Oberlid synchrone künstliche Lidbewegung initiieren. Da die Bauteile zur künstlichen Lidbewegung noch nicht beliebig klein zu gestalten sind, können zur Zeit noch nicht alle Orbitaepithesenträger mit der neuartigen Epithese rehabilitiert werden. Um bei Patienten mit kleineren Orbitadefekten die Epithese eingliedern zu können, muß sich die zukünftige Forschung auf eine noch weitere Größenreduktion der einzelnen Komponenten konzentrieren. Durch die Entwicklung von telemetrischen Verfahren wird es möglich sein, die von einer intramuskuären implantierten, für diese Anwendung optimierten EMG - Elektrode emfangenen Signale ohne infektionsgefährdete Hautdurchleitung zur Epithese zu übertragen. / An orbit defect with loss of the eye and its delicate lid structures can be concealed with an implant anchored silicon facial prosthesis. This method assures secure retention and good esthetic results as long as the eye remains open. However, when the healthy lid closes, the immobility of the prosthesis becomes conspicuous. The aim of this development was to animate the artificial lid in the orbita prosthesis to give the patient a much more natural appearance. All components in the prosthesis were integrated to create an artificial lid that would blink in synchrony with that of the healthy eye. The material which proved to be most suited for the moveable eyelid was cast latex milk. It was elastic, would take dyes and was robust enough to withstand approximately 30 involuntary lid movements per minute. The artificial upper lid was pulled up behind the eye prosthesis by means of a fine thread, analogous to the natural lid opener. This is driven by a DC micromotor which lifts the upper lid in a cranial direction with a polyamid thread attached to the reinforced rim of the lid. The thread was wound onto a minute pulley. After a successful model had been constructed, an electronic circuit was developed in SMD (Surface Mounted Device) technique which drove the motor and processed the muscle potential necessary for the synchronization. These two double-sided circuit boards were positioned directly behind the artificial eye, which had been created specially by an ophthalmologist. By means of five integrated potentiometers, the muscle signals picked up were individually modified and adjusted to eliminate any delays in the lid movement. The low nominal capacity provided by accumulators ruled them out as a possible power supply for the electronics and motor, and instead, a small, light replaceable battery, capable of powering the motor for 7 to 14 days, was chosen. The individual components were then assembled and housed in a case of rigid acrylate plastic. It was possible to position the battery either under or behind the motor and to and stagger the electronics parts to the position of the battery and motor. This enhanced the adaptability of the case's geometric form to the individual orbit defect. Clinical tests with healthy test persons and patients with implant-anchored orbital prostheses demonstrated that muscle potentials from the orbicularis oculi muscle could be picked up from the healthy upper lid with bipolar needle electrodes. This was also possible in some cases when after exenteration the orbicularis oculi muscle remained partially active and continued to emit muscle potentials. With these biopotentials, the synchronic lid movement of the prototype was tested on a voluntary healthy test person. It functioned flawlessly. After extensive laboratory tests, two patients were rehabilitated with the new orbita prosthesis. For each patient a case for the components was designed and fitted into a silicone prosthesis retained with implant-anchored magnet abutments. The muscle potentials were conducted by an intramuscular electromyography (EMG) to trigger synchronous lid movement. With the first patient, a sterile needle electrode was used, but this had to be reinserted into the muscle each time the prosthesis was fitted. In the second patient the muscle potentials were picked up via a thin EMG-electrode implanted subcutaneously. In both cases bipolar conduction was taken. The second different electrode was attached to one implant-anchored magnet; the neutral electrode to another. In both patients, the muscle impulses emitted during lid closure initiated an artificial lid movement in synchrony with the healthy eyelid. Since the component parts cannot be reduced beyond a certain minimum size, not all orbit prosthesis wearers can be rehabilitated with the new prosthesis. In order to fit patients with smaller defects, future research will have to concentrate on a further reduction in component size. With further developments in telemetric procedures it will become possible to transmit signals received from a EMG electrode implanted in the muscle to the prosthesis without the dangers of infection inherent in conducting them through the skin.