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Orientador: Flávio Henrique Baggio Aguiar Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba Resumo: O objetivo deste estudo in vitro foi determinar a microdureza, rugosidade superficial, micromorfologia e alterações de cor de esmalte dental humano submetido a tratamentos clareadores caseiros com peróxidos de hidrogênio a 7,5% (PH) adicionados de cálcio, fosfato de cálcio amorfo (ACP), flúor e/ou hidroxiapatita (HA). Três agentes de tratamento comerciais: (Pola Day 7,5% (PD), Day White ACP 7,5% (DW), White Class Calcium 7,5% (WC)), três agentes clareadores experimentais (PH 7,5% + NaF (PHF), PH 7,5% + HA (PHH) e PH 7,5% + NaF + HA (PHFH)) e os grupos controle positivo (gel de peróxido de hidrogênio a 7,5% - PC) e controle negativo (gel sem peróxido de hidrogênio a 7,5% - NC), foram avaliados (n=10). Os agentes de tratamento comerciais foram aplicados pelo prazo recomendado pelos fabricantes e os agentes experimentais por 1,5 hora por dia. Todas as amostras foram imersas em solução de saliva artificial pelo resto do dia, num total de 21 dias de tratamento. Após, ficaram armazenados em saliva artificial por 14 dias. Ensaios de microdureza, rugosidade superficial, micromorfologia do esmalte e análise de alteração de cor foram realizados nos tempos baseline, 7, 14, 21 dias de tratamento, 7 e 14 dias de pós-tratamento. Para análise estatística, as médias foram comparadas utilizando o teste de Tukey-Kramer com um nível de significância de 5%. Como resultados, no teste de rugosidade superficial (Ra) foi observado aumento em todos os grupos experimentais (PHF, PHH e PHFH) e nos grupos comerciais DW e WC ao longo do tempo. No teste de microdureza (KHN) observou-se um aumento significativo para o grupo PHH e redução significativa do grupo DW, enquanto os outros grupos não apresentaram alteração significativa ao longo do tempo de estudo. Para o teste de análise de alteração de cor, todos os agentes apresentaram efeito clareador, exceto o grupo NC, sendo que o grupo PHH foi o único que apresentou valores similares aos agentes clareadores comerciais em todos os tempos de estudo. Na análise morfológica observou-se alterações como a presença de porosidades na maioria dos grupos, exceto no grupo NC, além de deposição de cristais de hidroxiapatita nos grupos PHH e PHFH. Concluiu-se que o tratamento clareador contendo hidroxiapatita proporcionou alterações de cor similares aos agentes clareadores comerciais, foi capaz de aumentar a microdureza, e que quando este componente é formulado com ou sem flúor, pode levar a um aumento da rugosidade superficial, devido a deposição de cristais de hidroxiapatita na superfície de esmalte, como observado pela análise de microscopia eletrônica de varredura Abstract: The aim of this in vitro study was to determine the microhardness, surface roughness, micromorphology and color change analysis of enamel submitted to with home-use bleaching treatment 7.5% hydrogen peroxide (HP) added with calcium, amorphous calcium phosphate (ACP), fluoride and/or hydroxyapatite (HA). Three commercial treatment agents: (Pola Day 7.5% (PD), Day White ACP 7.5% (DW), White Class 7.5% Calcium (WC)), three experimental bleaching agents (7.5% HP + NaF (PHF), HP + 7.5% HA (PHH) and PH + 7.5% NaF + HA (PHFH)), a negative control (Gel without 7.5% hydrogen peroxide - NC) and a positive control (Gel with 7.5% hydrogen peroxide - PC) groups were evaluated (n=10). The treatment agents were applied according to the manufacturer's recommendation and experimental agents were applied for 1,5 hour daily. Then all the specimens were immersed in artificial saliva for the rest of the day, in a total of 21 days of treatment. After the treatment phase, the specimens were stored in artificial saliva for 14 days. Microhardness tests, surface roughness, micromorphology of the enamel and color change analysis were performed at baseline, 7, 14, 21 days of treatment, 7 and 14 days post-treatment. For the statistical analysis, means were compared using the Tukey-Kramer test at a significance level of 5%. As results, the surface roughness test (Ra) presented increase in all experimental groups (PHF, PHH and PHFH) and commercial groups DW and WC in function of time. The microhardness test (KHN) showed a significant increase for the group PHH and a significant reduction on DW group, while the other groups did not show statistical difference in function of timespan study. For the color change analysis test, all the groups presented bleaching effectiveness, except the group NC, and the PHH group was the only one that showed similar values compared to the commercial bleaching agents at all times of study. In the morphological analysis, changes were observed as the presence of porosities in most groups, except on NC group, and deposition of hydroxyapatite crystals on groups PHH and PHFH. It was concluded that the bleaching treatment containing hydroxyapatite provided color changes similar to commercial bleaching agents, was able to increase the microhardness values, and that when this component is formulated with or without fluoride, it can lead to an increase in surface roughness due to deposition of hydroxyapatite crystals over the enamel surface, as observed by analysis of scanning electron microscopy Mestrado Dentística Mestre em Clínica Odontológica

Coiled tubing (CT) has been widely used for oil and gas exploitation, however corrosion of CT under high pressure and high temperature (HPHT) environment was often reported, also corrosion induced failures of CT welds were often observed to occur during service. Corrosion related behaviors of CT welds are not clear. Therefore, a study of the corrosion resistance of CT welds under HPHT environment is carried out. In order to efficiently evaluate the corrosion resistance of welds, some test samples were obtained by linear cutting out of a CT110 in service on the site. The water samples from gas field were used as the test reagent to simulate the actual corrosive medium. Based on the results of weight loss test under HPHT corrosive environment and tensile test under room conditions, the corrosion sensitivities of the welding seam and base material under various temperatures and partial pressures of CO2 as well as the mechanical properties of the corroded CT were compared and evaluated quantitatively, the corrosion morphologies and material products of the test samples were analyzed by scanning electron microscope (SEM). The test results showed that the corrosion rates of the welding seam in a HPHT caldron were 1.7, 2.0 and 1.2 times of the base metal’s when the total pressure is 4MPa, and the temperature is 30°C, 60°C and 90°C, respectively. The corrosion rates of the welding seam is 2.0, 2.1 and 2.0 times of the base metal’s when the partial pressure of CO2 is 0.1MPa, 0.2MPa and 0.3MPa, respectively. The yield strength of the weld seam after corrosion test was found to be reduced by 4.8% (the yield strength of the base metal was reduced by 4.0%) and its tensile strength was reduced by 8.2% (the base metal was reduced by 7.1%). This indicates that CT weld seam is more susceptible to corrosion than CT base material under service condition.

The morphology and distribution of the antennal sensilla of adult diving beetle Cybister japonicus Sharp (Dytiscidae, Coleoptera), have been examined. Five types of sensilla on the antennae were identified by scanning electron microscope (SEM) and transmission electron microscope (TEM). Sensilla placodea and elongated s. placodea are the most abundant types of sensilla, distributing only on the flagellum. Both these types of sensilla carry multiple pore systems with a typical function as chemoreceptors. Three types of s. coeloconica (Type I-III) were also identified, with the characterization of the pit-in-pit style, and carrying pegs externally different from each other. Our data indicated that both type I and type II of s. coleconica contain two bipolar neurons, while the type III of s. coleconica contains three dendrites in the peg. Two sensory dendrites in the former two sensilla are tightly embedded inside the dendrite sheath, with no space left for sensilla lymph. There are no specific morphological differences in the antennal sensilla observed between males and females, except that the males have longer antennae and more sensilla than the females.

We describe low-cost fabrication, size control and characterization of borosilicate glass nanopores for sensing of single biomolecules. Nanopores with pore diameters down to ∼100nm were fabricated in borosilicate glass capillaries using table-top carbon-di-oxide laser assisted glass capillary puller. We further achieve controlled reduction in pore diameter by sculpting of glass capillaries under constant electron beam exposure of a scanning electron microscope. We confirm successful fabrication of sub-10nm pores by SEM imaging. We further show electrical characterization and low-noise behavior of these borosilicate nanopores and compare various geometries of pulled conical glass nanopores. We show, for the first time, a comprehensive characterization of glass nanopore conductance across a wide range (1M-1μM) of salt conditions. We show the conditions for the conical pore conductance model to fit to this extended salt range. We also experimentally show, for the first time, the role of buffer conditions in this wide salt range measurement. Finally, we demonstrate single molecule sensing capabilities of these devices with real-time translocation experiments of individual λ-DNA molecules. We observe distinct current blockage signatures of single and multiply folded DNA molecules as they undergo voltage-driven translocation through the glass nanopores. We find increased signal to noise for single molecule detection for higher trans-nanopore driving voltages.

Scanning Electron Microscope (SEM) as one of the major research and industrial equipment for imaging of micro-scale samples and surfaces has gained extensive attention from its emerge. However, the acquired micrographs still remain two-dimensional (2D). In the current work a novel and highly accurate approach is proposed to recover the hidden third-dimension by use of multi-view image acquisition of the microscopic samples combined with pre/post-processing steps including sparse feature-based stereo rectification, nonlocal-based optical flow estimation for dense matching and finally depth estimation. Employing the proposed approach, three-dimensional (3D) reconstructions of highly complex microscopic samples were achieved to facilitate the interpretation of topology and geometry of surface/shape attributes of the samples. As a byproduct of the proposed approach, high-definition 3D printed models of the samples can be generated as a tangible means of physical understanding. Extensive comparisons with the state-of-the-art reveal the strength and superiority of the proposed method in uncovering the details of the highly complex microscopic samples.

The objective of this study was to improve the stability and water-solubility of patchouli alcohol by complexing with β-cyclodextrin (β-CD). The interactions between patchouli alcohol and β-CD were characterized by differential scanning calorimetry (DSC), Fourier transformation-infrared (FT-IR) spectroscopy, powder X-ray diffraction (PXRD), and Scanning electron microscope (SEM), respectively. According to molecular modeling method, the enthalpy formation of host-guest illustrated the predominant configuration and the lowest value ΔbGo was -10.8174±1.9235 kcal/mol, suggesting the complex could reduce the energy of the system. The characterization analysis confirmed the formation of PA-CD inclusion complex, and the results indicated the advantage of the inclusion complex in stability and dissolution rates. These results identified PA-CD inclusion complex an effective way for the storage of PA, and better inclusion method still needed to be studied.

The macro-epibiotic communities of sea turtles have been subject to growing interest in recent years, yet their micro-epibiotic counterparts are almost entirely unknown. Here, we provide the first evidence that diatoms are epibionts for all seven extant species of sea turtle. Using Scanning Electron Microscopy, we inspected superficial carapace or skin samples from a single representative of each turtle species. We distinguished 18 diatom taxa from these seven individuals, with each sea turtle species hosting at least two diatom taxa. We recommend that future research is undertaken to confirm whether diatom communities vary between sea turtle species and whether these diatom taxa are facultative or obligate commensals.