Thesis (M.S.) in Chemical Engineering--University of Maine, 2007. / Includes vita. Includes bibliographical references (leaves 82-83).

Thesis (Ph. D.)--Montana State University--Bozeman, 2005. / Typescript. Chairperson, Graduate Committee: David L. Dickensheets. Includes bibliographical references (leaves 111-115).

Orientador: Americo Bortolazzo Correr / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-27T03:22:53Z (GMT). No. of bitstreams: 1 Sfalcin_RavanaAngelini_D.pdf: 1513616 bytes, checksum: bd6dc4a4843283522343b56a58ef8ec7 (MD5) Previous issue date: 2015 / Resumo: O objetivo neste trabalho foi avaliar as propriedades físico-químicas de infiltrantes resinosos com adição de partículas bioativas, bem como sua capacidade de penetração e dureza da profundidade em lesões subsuperficiais de esmalte. Uma blenda contendo TEGDMA (75% em peso) e BisEMA (25% em peso) foi manipulada e a partir dela foram incorporados 5 tipos de partículas bioativas (10% em peso): hidroxiapatita (HAp), fosfato de cálcio amorfo (ACP), vidro bioativo policarboxilato de zinco (BAG Zn), vidro bioativo 45S5 (BAG 45S5), cimento de silicato de cálcio modificado por ?-TCP (HCAT-?). Um material comercial foi utilizado (ICON®) como controle. Dez espécimes foram confeccionados para cada grupo de cada teste: rugosidade superficial (Ra) antes e após a escovação; Resistência à flexão por 3 pontos (RF) e módulo de elasticidade (ME); resistência coesiva à tração (RC); dureza Knoop (KHN); densidade de ligação cruzada (DLC); grau de conversão (GC); sorção (S) e solubilidade (SL) em água; e micro-dureza (KHN). Os dados foram submetidos a ANOVA e teste Tukey (?=0.05). A penetração dos infiltrantes resinosos no esmalte humano desmineralizado foi qualitativamente avaliada em Microscopia Confocal de Varredura a Laser (n=5). Os resultados mostraram que os menores valores de rugosidade (antes e após a escovação foram apresentados pelo ACP. Com relação à resistência a flexão e módulo de elasticidade, T+B apresentou o maior valor e ICON® mostrou o menor valor. ICON® também mostrou o menor valor de resistência coesiva à tração; não houve diferença significativa entre os grupos T+B, HAp, ACP, BAG Zn, BAG 45S5 e HCAT-?. Para o teste de dureza Knoop, ICON® obteve o menor valor e BAG Zn mostrou o maior valor. Para densidade de ligação cruzada, ICON® apresentou maior quantidade de ligação cruzada e HAp, menor quantidade de ligação cruzada. ICON® apresentou grau de conversão significantemente menor que os infiltrantes experimentais, que não diferiram entre eles. ICON® apresentou a maior sorção de água e HAp a menor. Não houve diferença significativa entre os demais grupos. Para solubilidade, ICON® apresentou os maiores valores, mas sem diferença de ACP. BAG 45S5 apresentou a menor solubilidade. Com relação a micro-dureza, não houve diferença estatisticamente significante entre as profundidades avaliadas (50 µm, 200 µm, 350 µm e 500 µm). BAG 45S5, BAG Zn e HCAT-? não mostraram diferença estatística entre eles. Entretanto, HCAT-? e BAG Zn foram similares ao ICON® e ACP. O grupo cariado mostrou menor valor quando comparado a todos os grupos testados. A análise em microscopia confocal mostrou que todos os materiais apresentaram boa capacidade de penetração nas lesões iniciais, exceto para FCA. Pôde ser concluído que adição de partículas bioativas em um infiltrante experimental melhorou as propriedades mecânicas e não afetou a capacidade de penetração dos infiltrantes. O infiltrante resinoso contendo fosfato de cálcio amorfo foi o que apresentou o melhor desempenho no teste de rugosidade de superfície antes e após a escovação / Abstract: The aim of this study was to evaluate the physical-chemical properties of the experimental infiltrants with the addition of bioactive particles as well as their capability of penetration and depth Knoop hardness into caries-like lesions. A control blend was made with TEGDMA (75 wt%) and BisEMA (25 wt%). Five bioactive fillers were added in the control blend (10 wt%): Hydroxyapatite (Hap), amorphous calcium phosphate (ACP), Zinc-polycarboxylated bioactive glass (BAG-Zn), bioactive glass 45S5 (BAG 45S5), and ?-TCP modified calcium silicate cements (HCAT-?). An available commercially material was used (ICON®). Ten specimens were comprised by each group for the following tests: Surface roughness (Ra) before and after brushing abrasion; flexural strength (FS) and elastic modulus (E-Modulus); tensile cohesive strength (TCS); Knoop hardness (KHN); softnening ratio (SR); degree of conversion (DC); water sorption (WS) and solubility (SL); and micro-hardness (micro-KHN). Data were subjected to ANOVA and Tukey¿s test (?=0.05). Confocal Scanning Laser Microscopy was used to evaluate qualitatively the penetration capability of resin infiltrants into demineralized human enamel. Results showed that ACP had the lowest Ra before and after brushing abrasion. Regarding to the FS and E-modulus, T+B showed the higher value and ICON® showed the lower value. Also, ICON® showed the lower value of TCS, but there was no significant statistically difference among the groups T+B, HAp, ACP, BAG Zn, BAG 45S5 e HCAT-?. To the KHN, ICON® obtained the lower value and BAG Zn showed the higher value. According to the SR, ICON® showed lower SR and HAp, the higher SR. ICON showed DC significantly lower than experimental resin infiltrants. Regarding to the WS, ICON® presented the highest water sorption and HAp the lowest one. There was no significant statistically difference among the other groups. ICON showed the highest SL results; however, the results were similar to ACP. The lowest SL was found for BAG 45S5. Regarding to the micro-KHN, there was no statistically difference among the analyzed depths (50 µm, 200 µm, 350 µm and 500 µm). BAG 45S5, BAG Zn and HCAT- ? did not show statistical difference among them. However, HCAT- ? and BAG Zn were similar to ICON® and ACP. Carious group showed lower value when compared to all the tested groups. Confocal microscopy analysis showed good capability of penetration into the initial lesions for all materials, except for ACP. It could be concluded that the addition of bioactive particles into an experimental infiltrant improved the mechanical properties and did not affect the capability of penetration into the experimental infiltrants. The resin infiltrant with amorphous calcium phosphate presented the best performance to the roughness surface before and after brushing abrasion / Doutorado / Materiais Dentarios / Doutora em Materiais Dentários

No description available.

The validity of corneal confocal microscopy (CCM) in assessing peripheral neuropathy has been studied extensively in several studies with a large cohort of subjects with diabetes and in a handful of studies with small sample sizes in subjects with other systemic conditions. The non-invasive nature of this technique as well as its high reproducibility, moderate to high sensitivity and specificity, and ease of use make it an ideal biomarker for diagnosing onset, severity and progression of peripheral neuropathy. This thesis aims to further investigate the potential of CCM by evaluating abnormalities in the corneal sub-basal nerve plexus, Langerhans Cells (LCs) and epithelial cells in neuropathy related to diabetes and cancer. This thesis has established that evaluating the sub-basal nerve plexus in the centre and at the inferior whorl increases the diagnostic performance of CCM. In addition to diagnosing clinical and subclinical neuropathy in children and adults with diabetes CCM can also identify sub-clinical nerve damage in patients with upper gastrointestinal cancer and assess the effects of chemotherapy. CCM also identifies differences in small fibre pathology between diabetic patients with and without painful neuropathy. Although there was an increased prevalence and severity of dry eye and LCs' density, this was not related to an abnormality of corneal nerves in diabetic patients with no or mild neuropathy. Epithelial cell morphology was not associated with corneal nerve damage and did not alter in patients with Type 1 diabetes. In conclusion, CCM has been shown to be an ideal marker for quantifying early small fibre pathology and assessing peripheral neuropathies.

Colloidal crystallization in sedimenting systems is an incompletely understood process, where the influence of interparticle forces on the three-dimensional (3-D) microstructure remains to be fully elucidated. This dissertation outlines work that is intended to improve our knowledge of this subject by studying sedimentation equilibrium and phase behavior for electrostatically repulsive systems, as well as the interfacial crystallization of attractive depletion systems. Towards this end, several analytical and experimental tools have been developed to explore the thermodynamic behavior of these systems. For example, the experimental challenges necessitated the development and implementation of the following in this work: (1) core/shell silica particles incorporating molecular fluorophores or semiconductor nanocrystals; (2) modification of silica particle surfaces; (3) the design of specialized sedimentation cells; and (4) the development of a novel fluorescent intensity-based approach to quantifying colloidal sediments. Analysis of the experimental data required the use of the following tools: (1) location of particle centers from images; (2) deconvolution of intensity profiles using a novel Monte Carlo-type algorithm; and (3) prediction of colloidal phase diagrams using perturbation theory. On the basis of this work’s experimental and simulation data, it is concluded that competing orientations of crystal grains may suppress crystallization at grain boundaries, resulting in a non-uniform depth of the fluid/solid transition. Also, it was demonstrated that the grain size in depletion crystals formed from quantum dot-coated silica particles can be increased by localized annealing with the confocal microscope’s laser. Additional findings include the ability of the intensity-based approach to measure interparticle forces in colloidal sediments, as well as the inability to use perturbation theory to predict two-dimensional colloidal fluid/solid transitions. While significant progress has been achieved, work on 3-D imaging of colloidal depletion crystals in a refractive index-match medium is ongoing. This work improves our understanding of 3-D colloidal crystallization at interfaces, as well as provides new tools for future research. Also, this work demonstrates a potential route for zone refining of colloidal crystals, a technique that may be important in the search for low-defect 3-D arrays that can be used as templates for photonic bandgap materials.

Thesis (Ph. D.)--University of Texas at Austin, 2003. / Vita. Includes bibliographical references. Available also from UMI Company.

Thesis (MS)--Montana State University--Bozeman, 2008. / Typescript. Chairperson, Graduate Committee: Jean Starkey. Includes bibliographical references (leaves 70-76).

Thesis (Ph. D.)--University of Texas at Austin, 2004. / Supervisor: Michael C. Downer. Vita. Includes bibliographical references.

Thesis (Ph. D.)--Montana State University--Bozeman, 2007. / Typescript. Chairperson, Graduate Committee: Anne Camper. Includes bibliographical references (leaves 104-113).