Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Selenium (Se) is an oligoelement crucial for various biological processes. Se has anti-inflammatory and antioxidant properties and plays a key role in brain development. Adenosine deaminase (ADA, EC 3.5.4.4) is a key enzyme in purine metabolism because it helps in the regulation of intracellular and extracellular levels of adenosine, an important nucleoside that acts in the neuromodulation of the immune and nervous systems. Oxidative stress occurs when there is an imbalance between the production of reactive species and their detoxification by systems that remove or repair the resulting damage. In this context, several Se compounds have been developed and studied, among them the 3-methyl-1-phenyl-2-(phenylseleno)oct-2-en-1-one (C12H2HOSe), which is an α, β-unsaturated ketone functionalized vinyl chalcogenide, and sodium selenate (Na2SeO4), the main inorganic form of Se found in animals and plants. The aim of this study was to compare the effects of C12H2HOSe (organic Se) and Na2SeO4 (inorganic Se) on the cell viability, lipoperoxidation and ADA activity in cortex slices of young rats. The results showed that only organic Se caused a reduction in ADA activity at the concentrations of 1, 10 and 30μM in the cerebral cortex slices of the rats tested. However, this result is not related to the oxidation of the thiol groups, since this compound did not alter the NP-SH and LDH levels. Both compounds did not affect the lipoperoxidation levels, although the organic Se was capable of sequestering NO radicals at the highest concentration tested. The inorganic Se protected the cerebral cortex slices against the sodium nitroprusside-induced damage and increased the NP-SH levels. The tests used to evaluate cell viability (LDH and MTT) suggest the maintenance of the cell integrity of the cortex slices exposed to Se compounds. Therefore, our results suggest that organic Se has immunomodulatory properties, due to the reduction in ADA activity, and acted in the maintenance of the cell integrity. In turn, the antioxidant activity of inorganic Se was reaffirmed. Hence, the results of this study paved the way to explore both Se compounds in the CNS. / O selênio (Se) é um oligoelemento essencial em vários processos biológicos. Possui propriedades antiinflamatórias, antioxidantes e desempenha um papel fundamental no desenvolvimento do cérebro. A adenosina deaminase (ADA, E.C. 3.5.4.4) é uma enzima chave no metabolismo das purinas, pois auxilia na regulação dos níveis intra e extracelulares de adenosina, um importante nucleosídeo que atua na neuromodulação dos sistemas nervoso e imune. O estresse oxidativo ocorre quando há desequilíbrio entre a produção de espécies reativas e sua desintoxicação através de sistemas que removem ou reparem os danos por elas causados. Nesse contexto, vários compostos de Se vêm sendo desenvolvidos e estudados, entre eles podemos citar o 3-metil-1-fenil-2-(fenilseleno)oct-2-en-1-um(C12H2HOSe),um organocalcogênio com uma cetona α, β- insaturada funcionando como um vinil calcogênio e o selenato de sódio (Na2SeO4), principal Se inorgânico encontrado em animais e plantas. Este estudo teve como objetivo comparar os efeitos do C12H2HOSe (Se orgânico) e Na2SeO4 (Se inorgânico) na viabilidade celular, parâmetros relacionados ao estresse oxidativo e atividade da ADA em fatias de córtex de ratos jovens. Os resultados demonstraram que apenas o Se orgânico provocou a diminuição na atividade da ADA nas concentrações de 1, 10 e 30μM nas fatias de córtex cerebral dos ratos testados. No entanto, esse resultado não tem relação com a oxidação de seus grupamentos tióis, já que esse composto não alterou os níveis de NP-SH e de LDH. Apesar de ambos os compostos não alteraram os níveis de lipoperoxidação, o Se orgânico apresentou capacidade de sequestrar radicais NO na maior concentração testada. Já o composto inorgânico de Se protegeu as fatias de córtex cerebral contra o dano induzido pelo nitroprussiato de sódio e aumentou os níveis de NP-SH. Os testes de viabilidade celular (LDH e MTT) sugerem a manutenção da integridade celular em fatias de córtex de ratos jovens quando expostos aos compostos de Se. Assim, nossos resultados sugerem que o Se orgânico apresenta propriedades imunomoduladoras por reduzir a atividade da ADA, além de atuar na manutenção da integridade celular. Já o Se inorgânico teve sua atividade antioxidante confirmada. Portanto, os resultados obtidos neste estudo destacam um caminho promissor a ser explorado por ambos os compostos no SNC.

Este trabalho tem por objetivo propor um método eficiente para avaliar gestão de estoque, aplicando conjuntamente a Teoria de Controle Ótimo (OCT), para obter funções de estocagem dinamicamente ótimas, e Análise Envoltória de Dados (DEA), para calcular as eficiências relativas. Tendo em vista esse objetivo foi desenvolvido um modelo integrado DEA-OCT para calcular a eficiência de custo otimizada ao longo do tempo, quando o sistema possui variáveis relacionadas entre si, como no caso de sistemas de controle de estoque, e para analisar produção e demanda (assim como a variável estoque, oriunda dessa relação), estendendo o modelo variacional. Este trabalho aplica o modelo proposto a 647 empresas das Américas do Sul e do Norte, depois faz uma comparação entre Brasil e Chile (países emergentes economicamente), posteriormente focando no setor de comércio, considerando seus sistemas produção-estoque com dados de variáveis contábeis. Os modelos minimizam os custos de produção e de estoque para calcular a eficiência de custo ao longo do tempo. O output (produto, ou variável de saída) é a demanda; o input (insumo, ou variável de entrada) é a produção, e o intermediate (variável intermediária) é o estoque. Seus custos são considerados na função objetivo. É acrescentada uma restrição variacional da OCT para descrever a relação entre demanda, produção e estoque. Em resumo, o modelo é relevante por calcular eficiência prevenindo a possibilidade de obter uma projeção que ignora a relação entre as variáveis, uma vez que essa relação sempre ocorre, na prática, em sistemas de controle de estoque. As principais contribuições são: possibilitar o uso de OCT como a ferramenta de benchmarking DEA no contexto de eficiência dinâmica, estender o modelo DEA variacional de Sengupta (1995), incluindo restrições de modelos mais recentes e possibilitar o cálculo de eficiência quando há relação entre as variáveis. / This work aims to propose an efficient method to evaluate inventory management, jointly applying optimal control theory (OCT), obtaining dynamically optimal production and inventory functions, and data envelopment analysis (DEA), calculating the relative efficiencies. With this objective in mind, it was developed a DEA-OCT integrated model to calculate allocative efficiency optimized over time, when systems have variable with relationship among themselves, like in the case of inventory control systems, and for analyzing production and demand (as the inventory variable obtained from this relationship), extending the variational model. This paper applies the proposed model to 647 companies from South and North America, after that it was made a comparison between Brazil and Chile (economically emerging countries), then focusing on the commercial sector, considering its production-inventory systems and data from accounting variables. The model minimizes the inventory and production costs to calculate the allocative efficiency over time. The output is demand; the input is production, and the intermediate variable is inventory. Their costs are considered in the objective function. A variational constraint OCT is added to describe the relationship among demand, production, and inventory. In summary, the model is relevant to calculate efficiency by preventing the possibility of finding a projection that ignores the relationship among variables, since this relationship always occur in practice in inventory control systems. The main contributions are: using OCT as the benchmarking tool DEA in the context of dynamic efficiency, extending the Sengupta (1995) variational DEA model, including constraints from recent model and making it possible to calculate efficiency when there is a relationship among variables.

Nichtglaukomatöse Optikusatrophien führen nicht nur zu einer Verminderung der Dicke der retinalen Nervenfaserschicht (RNFL) sondern auch zu einer Reduktion des Makulavolumens. In dieser Arbeit wurde mit Hilfe der optischen Kohärenztomographie (OCT) untersucht, welche Schichten der Makula von Dickenveränderungen als Folge einer Optikusatrophie betroffen sind. Es wurden 27 Patienten mit nichtglaukomatösen Optikusatrophien unterschiedlicher Ätiologie (postneuritische, hereditäre und traumatische Atrophien) und 21 augengesunde Kontrollpersonen untersucht. OCT-Scans der RNFL und der Makula wurden mit Hilfe des Stratus OCT 3000 (Carl Zeiss Meditec) durchgeführt. Die axialen Reflektivitätsprofile der radialen Scans wurden aus den exportierten JPEG-Bildern an zwölf Punkten in je 1,5mm Entfernung von der Foveola vermessen und gemittelt. Das charakteristische Reflektivitätsprofil mit fünf Intensitätsmaxima und vier Intensitätsminima wurde der Lokalisation der einzelnen Makulaschichten zugeordnet. Die von nichtglaukomatöser Optikusatrophie betroffenen Augen wiesen im Vergleich zu den Augen der augengesunden Normalpersonen signifikant (p<0,05) reduzierte RNFL-Dicken (um 35,5% reduziert) und Makulavolumen-Werte (um 11,8% reduziert) auf. Bei allen untersuchten Formen der Optikusatrophie waren nicht nur die makuläre Nervenfaserschicht (MNFL) sondern alle inneren Schichten der Makula verdünnt. Die mittlere Reduktion betrug 21,2% für die MNFL, 39,7% für die Ganglienzellschicht, 33,2% für die innere plexiforme Schicht und 9,4% für die innere Körnerzellschicht im Vergleich zu den Werten der Normalpersonen. Veränderungen der äußeren Netzhautschichten traten nur bei den posttraumatischen Atrophien auf. Eine Beurteilung der Dicke aller einzelnen Netzhautschichten aus OCT-Scans ist mit Hilfe geräteintegrierter Software bisher noch nicht möglich. Die quantitative Analyse der axialen Reflektivitätsprofile aus exportierten OCT-Bildern stellt eine geeignete Methode zur Beschreibung des Verlaufs und der Lokalisation von Makulaveränderungen bei Optikusatrophien verschiedener Genese dar.

The early non-invasive diagnosis of epithelial tissue alterations in daily clinical routine is still challenging. Since optical coherence tomography (OCT) shows the potential to differentiate between benign and malignant tissue of primal endothelium, OCT could be beneficial for the early diagnosis of malignancies in routine health checks. In this research, a new handheld endoscopic scanning unit was designed and connected to a spectral domain OCT system of our workgroup for the in vivo imaging of the human oral mucosa.

[pt] Foram desenvolvidas fontes ópticas para obtenção de imagens por tomografia de coerência óptica com alta resolução. Dois tipos de abordagens foram realizados, uma com um laser contínuo sintonizável, que neste trabalho foi instrumentado com marcadores de frequência óptica, outra com uma fonte óptica pulsada de banda larga. Mediante um processo de calibricação desenvolvido neste trabalho, a fonte contínua forneceu resoluções de 8 μm e alcances até 0,5 mm, enquanto que a fonte pulsada forneceu resoluções de 3 μm e alcances de 300 μm. A fonte pulsada permitiu ainda a obtenção de imagens em tempo real com capacidade de captura de movimento do objeto. / [en] Optical sources to obtain images through high resolution optical coherence tomography were developed. Two approaches were taken, one with a continuously tunable external cavity laser which, in this work, was modified to produce optical frequency markers, the other with an ultra-wideband pulsed source. Using a calibration process we developed in this work the continuously tunable source continued to achieve resolutions 8 μm and ranges of 0.5 mm, while the pulsed source achieved resolutions of 3.3 μm and ranges of 300 μm. The pulsed source has the capacity to capture real time images.

Glaucoma is the second leading cause of blindness in the world. The disease is characterized by irreversible damage to retinal ganglion cells. Once glaucoma is detected, further vision loss can be prevented by pharmacological or surgical treatment. However, current diagnostic methods lack the necessary sensitivity and up to 40% of vision maybe irreversibly lost before detection occurs. A Swept Source Polarization-Sensitive Optical Coherence Tomography (SS-PSOCT) instrument for high sensitivity cross-sectional imaging of optical anisotropy in turbid media has been designed, constructed, and verified. A multiple-state nonlinear fitting algorithm was used to measure birefringence of the retinal nerve fiber layer with less than 1%± average uncertainty. To perform eye imaging efficiently a slit-lamp based interface for the SS-PSOCT instrument with a Line Scanning Laser Ophthalmoscope (LSLO) was used. This interface allowed for repeatable, stable, and registered measurements of the retina. A fixation target was used to stabilize the volunteer’s eye and image desired areas of the retina. The LSLO allowed for an optimization of the location of OCT scans on the retina and provided a fundus blood vessel signature for registration between different imaging sessions. The SS-PSOCT system was used to measure depth-resolved thickness, birefringence, phase retardation and optic axis orientation of the retinal nerve fiber layer in normal volunteers. The peripapillary area around the optic nerve head (ONH) is most sensitive to glaucoma changes and hence data was acquired as concentric ring scans about the ONH with increasing diameters from 2mm to 5mm. Imaging of normal patients showed that higher values of phase retardation occurred superior and inferior to the optic nerve head especially next to blood vessels and thicker parts of the retinal nerve fiber layer. / text

Accommodation is the change in the dioptric power of the eye altering the focus from distance to near. Presbyopia is the loss of accommodative function that occurs with age. There are many techniques used to measure accommodation, however, there is little consensus as to how clinical data should be collected and analysed. The overarching theme of this thesis is the in vivo examination of accommodation and how lifestyle can affect the onset of presbyopia. An open-field autorefractor with badal adaption was used to examine accommodative dynamic profiles under varying demands of vergence. From this data a new metric for assessing the time for accommodative change was derived. Furthermore this thesis describes a bespoke automated accommodative facility instrument that was developed to provide further assessment of accommodative speeds. Defocus curves are used for assessing accommodation and depth-of-focus; the work presented explores the use of non-linear regression models to define the most appropriate method of assessing defocus curves in phakic subjects, and pseudophakic subjects implanted with an extended depth-of-focus intraocular lens. Using an absolute cut-off criteria of +0.30logMAR improved the repeatability and reliability of the depth-of-focus metrics over a cut-off criteria relative to the best corrected visual acuity. A swept-source anterior segment optical coherence tomographer (AS-OCT) was used to image the morphology of the ciliary muscle during accommodation. The accuracy of ciliary muscle measurements was improved when using reference points on the sclera to align the AS-OCT scan. The use of a ciliary muscle area metric demonstrated poor repeatability and reliability when compared to the traditional assessment of muscle morphology via thickness measurements. Physiological ageing in the crystalline lens occurs in line with ageing in other structures in the body. The methods for assessing accommodative function examined in previous chapters, were used to examine whether lifestyle factors which affect the rate of systemic ageing, such as smoking, also affect accommodative function. Although being a current smoker and having greater central adiposity was associated with a slower time for accommodative change, further research is required before these findings can be applied to the target population.

Os materiais restauradores estão evoluindo rapidamente e novas técnicas de inserção do compósito na cavidade restauradora estão sendo propostos. Dependendo da técnica, poderá ocorrer maior ou menor formação de bolhas na restauração final. A incorporação de bolhas entre as camadas do material restaurador pode gerar uma maior degradação da restauração em virtude da menor obtenção de propriedades físico-mecânicas do material. Assim, a necessidade de estudos sobre a prevalência de bolhas em restaurações confeccionadas com diferentes técnicas de inserção se faz necessária para a melhor compreensão do uso e do manuseio dos materiais. O objetivo desse trabalho foi analisar a ocorrência de bolhas e o volume de espaços presentes no interior de restaurações com resina composta, inserida na cavidade dental através das técnicas restauradoras: incremental e bulk fill. Quarenta e oito dentes molares humanos (n=24, duas restaurações por dente) foram selecionados e, nestes, foram confeccionados dois preparos por dente, um em cada região proximal, com profundidade de 4mm, largura de 4mm e distância axio-proximal de 2mm. Posteriormente, foram restaurados de acordo com os grupos: FiltekTM One Bulk Fill Restorative (FOB; 3M Oral Care); FiltekTM Z350 XT (FXT; 3M Oral care); FiltekTM Bulk Fill Flowable Restorative (FBF+FXT; 3M Oral care) e FiltekTM Z350 XT Flow (FF+FXT; 3M Oral care) . As resinas fluidas foram cobertas com a resina FiltekTM Z350 XT (3M Oral Care). Após 24 horas, os dentes restaurados foram submetidos à ciclagem térmica (5.000 ciclos) e posteriormente foi realizada a Tomografia de Coerência Ótica (OCT). Através da análise das imagens obtidas pelo OCT foram medidos os valores de quantidade de bolhas e porcentagem de espaços presentes nas restaurações. Os dados da presença de bolhas foram analisados estatisticamente com o teste Qui-Quadrado, os dados de número de bolhas e porcentagem de espaços obtidos foram analisados com o teste de Kruskall Wallis e a comparação entre os grupos foi feita pelo método de Dunn , com nível de significância de 5%. FF+FXT, apresentou bolhas em todas as restaurações e foi significativamente maior quando comparado a FXT (p=0,015). FF+FXT apresentou quantidade significativamente maior de bolhas (p<0,05) quando comparada com os outros três grupos. FBF+FXT apresentou a maior porcentagem de porosidade, devido ao maior tamanho de bolhas, porém esta porcentagem foi significantemente maior apenas quando comparada com FXT (p<0,05). Todos os grupos apresentaram bolhas. As técnicas restauradoras que apresentaram o pior desempenho, considerando o número de bolhas e a porcentagem de porosidade, foram aquelas realizadas com resina composta fluída. Não houve diferença estatisticamente significante quanto ao número de bolhas e à porcentagem de espaços entre as restaurações confeccionadas somente com resinas de alta viscosidade para as diferentes técnicas utilizadas neste estudo. / Dental restorative materials are quickly evolving, and new techniques are being proposed to change the way of filling dental cavities. Depending on the technique, a different number of voids could be generated inside the restauration. The appearance of these voids between layers of resin composite can significate a greater degradation of the material determined by low mechanical and physical properties. Therefore, to investigate voids prevalence at different restorative techniques is needed, in order to get a better understanding of the resin composites and their best handling. The objective of this project was to analyze the voids frequency inside and between the layers of the resin composite, filling class II cavities using incremental technique and bulk fill technique. Forty eight human teeth (n=24, two restorations per tooth) were selected and two cavities per tooth were made, one per each proximal area, 4mm of depth, 4mm height and 2mm of axio-proximal distance. After, they were divided in four groups and restored using FiltekTM One Bulk Fill Restorative (FOB; 3M Oral Care); FiltekTM Z350 XT (FXT; 3M Oral care); FiltekTM Bulk Fill Flowable Restorative (FBF+FXT; 3M Oral care) e FiltekTM Z350 XT Flow (FF+F; 3M Oral care), handled according to manufacturer instructions. Flowable resin composite was covered with FiltekTM Z350 (3M Oral Care). 24 hours later, thermocycling was conducted (5,000 cycles) and later Optical Coherence Tomography was performed. By analyzing the OCT images, number of voids and percentage of void volume were calculated. Presence of voids were analyzed by Chi-squared test, number of voids and percentage of void volume were analyzed by Kruskall Wallis test, and comparisons were performed by Dunn Method, at significance level of 5%.. FF+FXT had voids in all the restorations of the group, and it was significantly greater when compared with FXT (p=0.015). FF+FXT had statistically significant more number of voids (p<0.05) when compared with the others 3 groups. FBF+FXT had the highest percentage of voids volume, because the size of its voids, but this percentage was significantly different only when compared with FXT (p<0,05). All groups had voids. Restorative techniques that presented worst performance, considering number of voids and percentage of voids volume, were the ones made with flowable resin composite. Non statistical differences referred to a number of voids, neither percentage of voids volume among restorations made using only high viscosity resin.

Nous présentons d'abord un système de tomographie optique fonctionnant en lumière blanche, avec un interféromètre de Linnik. La résolution tomographique obtenue est de l'ordre de 1,2 m dans l'air. Les capacités de l'instrument sont illustrées par des images tomographiques d'intérêt biomédical. D'autre part, nous présentons un polarimètre de Mueller à cristaux liquides nématiques optimisé pour la propagation des erreurs de mesures brutes aux images finales. Les mesures sont rapides (de l'ordre de la seconde) et précises (erreurs de l'ordre de 1%). Les images polarimétriques de coupes histologiques montrent l'intérêt de ce dispositif pour l'étude microscopique d'échantillons contenant des macromolécules fibreuses (collagène). Enfin, des images en degré de polarisation (DOP) de cols de l'utérus humains ex vivo viennent confirmer les possibilités de l'imagerie polarimétrique pour la détection de dysplasies (DOP plus élevé que dans les zones saines).

Une peinture est un matériau complexe composé de plusieurs couches picturales. Ce travail de recherche poursuit un double but : comprendre et modéliser l'aspect visuel d'un tel milieu stratifié et développer des méthodes non destructives permettant d'identifier les différents constituants présents dans une œuvre d'art. L'équation de transfert radiatif, résolue par la méthode de la fonction auxiliaire, permet de modéliser l'aspect visuel des couches picturales stratifiées. Cette modélisation est validée par comparaison avec des spectres expérimentaux de réflexion diffuse. Expérimentalement, la reconnaissance des pigments et des colorants à partir d'un appareil déjà opérationnel au laboratoire a été étendue à celle des constituants d'un mélange de pigments. De plus, la tomographie optique cohérente (OCT), développée au cours de cette thèse, permet d'imager les pigments et d'obtenir une information spectrale permettant d'envisager une identification non destructive des composants de couches picturales stratifiées.