Cystic fibrosis (CF) is an autosomal recessive disorder affecting 70,000 individuals worldwide. This disease is characterized by the buildup of mucus in the airways leading to chronic lung infections resulting in pulmonary failure and death in 95% of CF patients. Routine surveillance of CF pathogens using traditional microbiology culture guides management and treatment of CF patients. Molecular profiling studies have revealed emerging pathogens that may play a role in CF lung disease by either directly causing infection or upregulating the virulence factors of classic CF pathogens, such as P. aeruginosa; however, routine CF culture protocols have not been modified to detect these organisms. The goal of this study was to expand the data relevant to the use of microbiology cultures for the management and treatment of CF patients at Virginia Commonwealth University Medical Center (VCUMC) by directly selecting for emerging CF pathogens in culture. This was accomplished by developing,optimizing, and implementing an agar to select for colistin-resistant non-fermenting Gram- negative rods (NF GNRS). In addition, McKay agar and anaerobic media were utilized to recover members of the Streptococcus anginosus group (SAG) and anaerobes in CF respiratory samples. The prevalences of SAG, anaerobes, and colistin-resistant NF GNRs recovered on study media from 75 adult and pediatric CF patients at VCUMC were 17.33%, 41.33%, and 4% respectively. Approximately 62% of patients culture-positive for SAG were also infected with P. aeruginosa and 53.8% of SAG recovered in culture were from CF patients experiencing PE. These findings further support the claim that interspecies interactions among emerging and classic CF pathogens may result in periods of clinical instability or PE. Twenty-eight of the 75 patients were culture-positive for Veillonella species, with the majority of samples collected during a period of surveillance. Four colistin-resistant NF GNRs were isolated on the study media alone. The selective nature of the study media prevented the mixed respiratory flora and classic CF pathogens from overgrowing and obscuring the growth of these colistin-resistant NF GNRs. The presence and role of emerging pathogens in the CF patient population at VCUMC warrants further investigation; therefore, the routine culture protocol needs to be revised to recover and select for those organisms thought to play a role in PE and lung function decline.

A neuropatia motora multifocal (NMM) é uma doença rara, que compromete as fibras nervosas motoras e que pode levar a incapacidades de gravidade variável, provavelmente na dependência do seu diagnóstico e tratamento precoces. O uso de imunoglobulina humana por via endovenosa em altas doses é considerado o tratamento mais eficaz para NMM. A objetivação das incapacidades funcionais que a NMM provoca e da sua reversão parcial ou completa em decorrência do tratamento ou de sua evolução não tem sido uniforme. Tais dificuldades se devem ao fato de que os instrumentos utilizados para a mensuração das incapacidades têm sido variados e não uniformes. A escala global de avaliação das incapacidades na neuropatia motora multifocal construída pelo método Rasch (GIR - MNN) ou Multifocal Motor Neuropathy - Rasch-built Overal Disability Scale (MMN-RODS©) foi desenvolvida especificamente para a avaliação das incapacidades funcionais dos pacientes com NMM. Em recente estudo, multicêntrico, foi verificado que a MMN-RODS©, originalmente desenvolvida em inglês, preenche as expectativas do modelo de Rasch. Para aplicação no Brasil, o presente trabalho realizou a tradução, a adaptação transcultural, conforme metodologia descrita na literatura, e a aplicação da escala em pacientes com Neuropatia Motora Multifocal / Multifocal Motor Neuropathy (MMN) is a rare disease that involves the motor nerve fibers. A better prognosis for MMN is probably linked to early diagnoses and treatment. Even so, MMN can lead to severe incapacities. The use of intravenous high doses of human immunoglobulin (IgIV) is considered efficacious to treat MMN. The objectification of the incapacities provoked by MNN, their evolution, and partial or complete deficits reversion due to the treatment has not been standardized. This lack of uniformity is due to the variety of tools used for the measurement of the deficits in MMN. The multifocal motor neuropathy - Raschbuilt overall disability scale (MMN-RODS©) was developed specifically for evaluation of the functional incapacities in MNN patients. In a recent multicentric study, it was verified that MMN-RODS© fulfill the expectations of the Rasch method. The present work realized the translation, transcultural adaptation and validation of the scale to the Brazilian Portuguese context aiming to use this tool to evaluate MMN patients living in Brazil

Os nervos periféricos são extensões do sistema nervoso central e responsável pela interação das atividades entre as extremidades, em suas funções sensitivas e motoras. São vulneráveis aos mesmos tipos de traumas que afetam outros tecidos: contusão, compressão, esmagamento, estiramento, avulsão e laceração. As lesões de nervos periféricos situam-se entre as mais incapacitantes que acometem indivíduos em idade produtiva, em face dos múltiplos aspectos concernentes às sequelas deste tipo de afecção. Desta forma, a interrupção de continuidade da estrutura do nervo, como no caso da neurotmese, por algum tipo de trauma, resulta na interrupção de transmissão dos impulsos nervosos e na desorganização de suas atividades funcionais. Por meio da utilização da microcirurgia foi possível desenvolver técnicas reparadoras que vão desde simples neurorrafia término-terminal até sofisticados procedimentos cirúrgicos com a utilização de enxertos de nervos, veias e artérias invertidas, tubos sintéticos de materiais variados, tais como silicone e polietileno. Outro aspecto que intriga pesquisadores de todo mundo é a utilização de fatores neurogênicos capazes de acelerar ou melhorar a regeneração de nervos periféricos. A gordura autóloga tem sido continuamente referenciada pela sua abundante oferta, no próprio sitio cirúrgico, apresentando resultados promissores, visto que a adventícia dos vasos é constituída por tecido conjuntivo frouxo, rico em adipócitos. Assim, em um trauma, os neuritos oriundos do coto proximal do nervo lesado, ficam diretamente em contato com esses adipócitos. Seguindo este raciocínio, e com base em trabalhos anteriores onde foi usada veia preenchida com músculo esquelético a fresco como enxerto, decidiu-se testar a possibilidade de crescimento axonal por meio de enxerto com tubo de polietileno preenchido por tecido adiposo autólogo associado a protocolo de imersão em câmara hiperbárica, por meio de um estudo Randomizado Controlado. Para tanto utilizou-se um tubo com 12 mm de comprimento por 0,25 mm de diâmetro, com poros de 80 μm de diâmetro, preenchido com tecido adiposo in natura retirado das adjacências do referido nervo, na tentativa de se recuperar o nervo isquiático. Os resultados morfométricos demonstraram que, os grupos experimentais com e sem preenchimento de gordura tiveram resultados, do ponto de vista morfométrico e funcional sem diferenças estatisticamente significantes, contudo, quando estes foram confrontados ao grupo controle final, apresentaram diferenças estatisticamente significantes. Já relevando a avaliação funcional, por meio do Catwalk, constatou-se que não houve diferença estatisticamente significante entre os grupos experimentais, mas teve diferença ao comparar com o grupo controle final, Diante das evidências encontradas e apoiados na literatura pode-se concluir que a câmara hiperbárica trouxe resultados positivos verificados pela aproximação dos resultados dos grupos experimentais tanto morfométrica como funcionalmente. / The peripheral nerves are extensions of the central nervous system and are responsible for the sensory and motor functions of the limbs. These nerves are vulnerable to the same types of traumas that affect other tissues: contusion, compression, crushing, stretching, avulsion, and laceration. Amongst the most disabling kinds of injuries that affect working-age individuals are those of the peripheral nerves; due to the multifaceted characteristics of the aftereffects of the injury. The break in continuity of the nerve structure due to trauma, as in the case of neurotmesis, results in the disruption of the transmission of nerve impulses and the disorganization of their functions. Through the use of microsurgery, it was possible to develop reconstructive techniques that range from a simple end-to-end neurorrhaphy to sophisticated surgical procedures that utilize nerve grafts, inverted veins and arteries, and synthetic rods of varied materials such as silicone or porous polyethylene. Another aspect that intrigues researchers around the world is the utilization of neurogenic factors capable of accelerating or improving the regeneration of peripheral nerves. Autologous fat has been a constant reference in this field of surgery due to its abundant supply at the surgical site itself. The results are promising, as the adventitia of vessels consists of loose connective tissue rich in adipocytes. Thus in a trauma, the neurites derived from the proximal stump of the damaged nerve are in direct contact with these adipocytes. Following this reasoning, and based on previous studies where veins grafted with fresh skeletal muscle were used, we decided to conduct a randomized controlled study to test the possibility of axonal growth by means of grating with a polyethylene rod filled with autologous adipocytes associated with immersion in a hyperbaric chamber. In an attempt to recover the sciatic nerve, a rod 12 mm in length, with a diameter of 0.25 mm, and with pores of 80 μm in diameter, filled with adipose tissue in natura removed from the surroundings of said nerve, was used. The morphometric results showed that the experimental groups with and without fat fillings had results that, from the morphometric and functional point of view, were of no statistically significant difference. However, when these results were compared with the final control group, statistically significant differences were noted. Highlighting the functional evaluation through the use of Catwalk, it was found that there were no statistically significant differences between the experimental groups, but there was indeed a difference in comparison to the final control group. In light of the evidence found and supported by literature, one can conclude that the use of the hyperbaric chamber brought positive results verified by the proximity of both the morphometric and functional results of the experimental groups.

Entre os produtos confeccionados com polímeros reforçados com fibras, as hastes pultrudadas têm sido utilizadas em um número crescente de aplicações devido a características como baixa massa, elevada resistência mecânica, baixo custo de manutenção e alta resistência à corrosão, em particular quando comparadas com hastes confeccionadas em materiais convencionais equivalentes. Porém, os mecanismos de envelhecimento e de degradação dos compósitos poliméricos reforçados com fibras precisam ser mais bem compreendidos, particularmente os mecanismos de dano em condições de serviço, em aplicações de engenharia civil ou em águas profundas. Neste trabalho, foi avaliada a exposição de hastes pultrudadas produzidas a partir de fibras de carbono e vidro e resinas epóxi e éster-vinílica após 3000 horas em diferentes ambientes, como exposição à radiação UV, exposição à água do mar e exposição à água a 60 °C. Os principais aspectos microestruturais, físicos, térmicos, químicos, mecânicos e de vida útil das hastes foram avaliados antes e após as exposições. As hastes com fibras de carbono apresentaram maior resistência residual de forma geral quando comparadas às hastes de fibra de vidro, as quais perderam mais de 50% da sua resistência original após exposições de curta duração (744 h). Quando expostas à radiação UV, as hastes com fibras de carbono apresentaram maior resistência residual à tração, assim como quando submetidas a esforços combinados nos ensaios de SBS. O ambiente mais agressivo entre os estudados definitivamente foi a imersão em água destilada. Os resultados dos ensaios de short-beam apresentaram melhor relação com os efeitos de degradação do que os ensaios de resistência à tração. Através das análises microestruturais (MO e MEV) foi possível identificar alguns tipos de mecanismos de degradação atuantes em cada condição de envelhecimento acelerado. Após analisar uma combinação de fatores envolvidos, a resina epóxi, dentre as resinas estudas, foi a que apresentou melhores propriedades de interface quando utilizada com fibras de carbono. / Among products made with fiber-reinforced polymers, pultruded rods have been used in an increasing number of applications, due to such features as low weight, high strength, low maintenance costs, and high corrosion resistance, particularly when compared with rods manufactured with equivalent conventional materials. However, the ageing and degradation mechanisms of these polymer composite materials still need to be better understood, particularly the damage mechanisms under various service conditions, such as civil engineering or in deep water applications. This thesis presents an experimental study that evaluates the ageing of pultruded rods produced from reinforced carbon and glass fibers and epoxy and vinyl ester resin matrices when exposed to UV radiation, seawater and distilled water at 60 °C for 3000 hours. The degradation assessment in the different environments was made by analyzing and comparing the microstructural, physical, chemical, thermal and mechanical aspects and the lifespan of the pultruded composite rods before and after accelerated ageing. The carbon fiber rods presented a higher residual resistance considering all the aforementioned aspects when compared to the glass fibers rods, which lost more than 50% of their original resistance after short exposure (744 h) to weathering. When exposed to UV radiation, the carbon fiber rods showed higher residual resistance as compared with other types of degrading conditions. Distilled water was undoubtedly the most aggressive ageing factor in respect to all the evaluated properties and characteristics of the tested rods. The short-beam test results showed higher correlation with the degradation effects than the results of the tensile test. By means of microstructural analysis (SEM and OM), it was possible to identify some types of degradation mechanisms for each kind of applied accelerated ageing. After analyzing a combination of factors involved, it was possible to reach the conclusion that the epoxy resin incorporated with carbon fibers displayed the best overall performance among all possible resin/fiber couples

Tese de mestrado integrado. Engenharia Electrotécnica e de Computadores. Faculdade de Engenharia. Universidade do Porto. 2010

No description available.

No description available.

Entre os produtos confeccionados com polímeros reforçados com fibras, as hastes pultrudadas têm sido utilizadas em um número crescente de aplicações devido a características como baixa massa, elevada resistência mecânica, baixo custo de manutenção e alta resistência à corrosão, em particular quando comparadas com hastes confeccionadas em materiais convencionais equivalentes. Porém, os mecanismos de envelhecimento e de degradação dos compósitos poliméricos reforçados com fibras precisam ser mais bem compreendidos, particularmente os mecanismos de dano em condições de serviço, em aplicações de engenharia civil ou em águas profundas. Neste trabalho, foi avaliada a exposição de hastes pultrudadas produzidas a partir de fibras de carbono e vidro e resinas epóxi e éster-vinílica após 3000 horas em diferentes ambientes, como exposição à radiação UV, exposição à água do mar e exposição à água a 60 °C. Os principais aspectos microestruturais, físicos, térmicos, químicos, mecânicos e de vida útil das hastes foram avaliados antes e após as exposições. As hastes com fibras de carbono apresentaram maior resistência residual de forma geral quando comparadas às hastes de fibra de vidro, as quais perderam mais de 50% da sua resistência original após exposições de curta duração (744 h). Quando expostas à radiação UV, as hastes com fibras de carbono apresentaram maior resistência residual à tração, assim como quando submetidas a esforços combinados nos ensaios de SBS. O ambiente mais agressivo entre os estudados definitivamente foi a imersão em água destilada. Os resultados dos ensaios de short-beam apresentaram melhor relação com os efeitos de degradação do que os ensaios de resistência à tração. Através das análises microestruturais (MO e MEV) foi possível identificar alguns tipos de mecanismos de degradação atuantes em cada condição de envelhecimento acelerado. Após analisar uma combinação de fatores envolvidos, a resina epóxi, dentre as resinas estudas, foi a que apresentou melhores propriedades de interface quando utilizada com fibras de carbono. / Among products made with fiber-reinforced polymers, pultruded rods have been used in an increasing number of applications, due to such features as low weight, high strength, low maintenance costs, and high corrosion resistance, particularly when compared with rods manufactured with equivalent conventional materials. However, the ageing and degradation mechanisms of these polymer composite materials still need to be better understood, particularly the damage mechanisms under various service conditions, such as civil engineering or in deep water applications. This thesis presents an experimental study that evaluates the ageing of pultruded rods produced from reinforced carbon and glass fibers and epoxy and vinyl ester resin matrices when exposed to UV radiation, seawater and distilled water at 60 °C for 3000 hours. The degradation assessment in the different environments was made by analyzing and comparing the microstructural, physical, chemical, thermal and mechanical aspects and the lifespan of the pultruded composite rods before and after accelerated ageing. The carbon fiber rods presented a higher residual resistance considering all the aforementioned aspects when compared to the glass fibers rods, which lost more than 50% of their original resistance after short exposure (744 h) to weathering. When exposed to UV radiation, the carbon fiber rods showed higher residual resistance as compared with other types of degrading conditions. Distilled water was undoubtedly the most aggressive ageing factor in respect to all the evaluated properties and characteristics of the tested rods. The short-beam test results showed higher correlation with the degradation effects than the results of the tensile test. By means of microstructural analysis (SEM and OM), it was possible to identify some types of degradation mechanisms for each kind of applied accelerated ageing. After analyzing a combination of factors involved, it was possible to reach the conclusion that the epoxy resin incorporated with carbon fibers displayed the best overall performance among all possible resin/fiber couples

Les structures fibreuses, formées d'une assemblée d'objets longilignes flexibles, sont très présentes dans notre environnement quotidien, notamment dans des systèmes biologiques tels que les végétaux ou les cheveux. Ces dernières années ont vu se développer diverses techniques de numérisation de la géométrie de fibres, soit par synthèse manuelle, soit par capture automatique. Parallèlement, de nombreux modèles physiques de simulation dynamique de fibres enchevêtrées ont été créés pour animer automatiquement ces objets complexes. Le but de cette thèse est d'établir un pont entre ces deux domaines: la géométrie de fibres d'une part, leur simulation dynamique d'autre part. Plus précisément, nous nous intéressons à la mise en correspondance d'une géométrie de fibres donnée en entrée, représentant un système mécanique à l'équilibre stable sous l'action de forces extérieures (gravité, forces de contact), avec les paramètres d'un modèle physique de fibres en contact. Notre objectif est de calculer les paramètres physiques des fibres de manière à garantir l'état d'équilibre de la géométrie donnée. Nous proposons de résoudre ce problème en choisissant comme modèle physique de fibres une assemblée de super-hélices en contact frottant. Nous proposons deux contributions principales. La première répond au besoin de convertir la géométrie d'une fibre numérisée quelconque, représentée comme une courbe 3d, en la géométrie du modèle des super-hélices, à savoir une courbe $G^1$ en hélices par morceaux. Nous proposons pour cela l'algorithme des tangentes flottantes 3d, qui consiste, en s'appuyant sur la condition de co-hélicité récemment énoncée par Ghosh, à interpoler N+1 tangentes réparties sur la courbe d'origine par N morceaux d'hélice, tout en minimisant l'écart en position. Par ailleurs nous complétons la démonstration partielle de Ghosh pour prouver la validité de notre algorithme dans le cas général. L'efficacité et la précision de notre méthode sont ensuite mises en évidence sur des jeux de données variés, d'abord synthétiques, créés par une artiste, puis issus de la capture de données réelles telles que des cheveux, des fibres musculaires ou des lignes de champ magnétique stellaire. Notre seconde contribution est le calcul de la géométrie au repos du modèle physique d'une assemblée de super-hélices, de sorte que la configuration de ce système à l'équilibre sous l'action des forces extérieures corresponde à la géométrie d'entrée. D'abord, nous considérons une fibre isolée soumise à des forces dérivant d'un potentiel, et montrons que le calcul est trivial dans ce cas. Nous proposons alors un critère simple permettant de décider si l'état d'équilibre est stable, et dans le cas contraire, de le stabiliser. Ensuite, nous considérons une assemblée de fibres soumises à des forces de contact frottant, modélisées par la loi non-régulière de Signorini-Coulomb. En considérant le matériau homogène, de masse et de raideur connues, et en nous appuyant sur une estimation de la géométrie au repos, nous construisons un problème d'optimisation quadratique convexe avec contraintes du second ordre. Nous montrons que ce problème inverse peut être résolu efficacement en utilisant un solveur conçu initialement pour le problème dynamique direct. Pour une géométrie d'entrée constituée de quelques milliers de fibres soumises à plusieurs dizaines de milliers de contacts frottants, nous calculons en quelques secondes une approximation plausible de la géométrie au repos des fibres, ainsi que des forces de contact en jeu. Nous appliquons finalement la combinaison de nos deux contributions à la synthèse automatique de coiffures physiques. Notre méthode permet d'initialiser un moteur physique de cheveux avec la géométrie issue des captures de coiffures réelles les plus récentes, et d'animer ensuite ces coiffures. / Fibrous structures, which consist of an assembly of flexible slender objects, are ubiquitous in our environment, notably in biological systems such as plants or hair. Over the past few years, various techniques have been developed for digitalizing fibers, either through manual synthesis or with the help of automatic capture. Concurrently, advanced physics based models for the dynamics of entangled fibers have been introduced in order to animate these complex objects automatically. The goal of this thesis is to bridge the gap between those two areas: on the one hand, the geometric representation of fibers; on the other hand, their dynamic simulation. More precisely, given an input fiber geometry assumed to represent a mechanical system in stable equilibrium under external forces (gravity, contact forces), we are interested in the mapping of such a geometry onto the static configuration of a physics-based model for a fiber assembly. Our goal thus amounts to computing the parameters of the fibers that ensure the equilibrium of the given geometry. We propose to solve this inverse problem by modeling a fiber assembly physically as a discrete collection of super-helices subject to frictional contact. We propose two main contributions. The first one deals with the problem of converting the digitalized geometry of fibers, represented as a space curve, into the geometry of the super-helix model, namely a $G^1$ piecewise helical curve. For this purpose we introduce the 3d floating tangents algorithm, which relies upon the co-helicity condition recently stated by Ghosh. More precisely, our method consists in interpolating N+1 tangents distributed on the initial curve by N helices, while minimizing points displacement. Furthermore we complete the partial proof of Ghosh for the co-helicity condition to prove the validity of our algorithm in the general case. The efficiency and accuracy of our method are then demonstrated on various data sets, ranging from synthetic data created by an artist to real data captures such as hair, muscle fibers or lines of the magnetic field of a star. Our second contribution is the computation of the geometry at rest of a super-helix assembly, so that the equilibrium configuration of this system under external forces matches the input geometry. First, we consider a single fiber subject to forces deriving from a potential, and show that the computation is trivial in this case. We propose a simple criterion for stating whether the equilibrium is stable, and if not, we show how to stabilize it. Next, we consider a fiber assembly subject to dry frictional contact (Signorini-Coulomb law). Considering the material as homogeneous, with known mass and stiffness, and relying on an estimate of the geometry at rest, we build a well-posed convex quadratic optimization problem with second order cone constraints. For an input geometry consisting of a few thousands of fibers subject to tens of thousands frictional contacts, we compute within a few seconds a plausible approximation of both the geometry of the fibers at rest and the contact forces at play. We finally apply the combination of our two contributions to the automatic synthesis of natural hairstyles. Our method is used to initialize a physics hair engine with the hair geometry taken from the latest captures of real hairstyles, which can be subsequently animated physically.

Made available in DSpace on 2014-10-09T12:51:05Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:04:29Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP