Protocolo para sinterização de zircônia odontológica por energia de micro-ondas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Virulência de micro-organismos à Plutella xylostella (L.) (Lepidoptera: Plutellidae) e compatibilidade com inseticidas

Pós-graduação em Agronomia (Entomologia Agrícola) - FCAV

Intervenções para aumentar adesão às precauçôes padrão e/ou baseadas nas vias de transmissão de micro-organismos aos cuidados do paciente: revisão sistemática de ensaios clínicos randomizados e não randomizados, séries temporais e estudos controlados antes e depois

Pós-graduação em Enfermagem - FMB

Perfil global de expressão de micro-RNAS circulantes como marcadores de resposta terapêutica na leucemia mielóide crônica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Testes convencionais e empregando Micro-CT na avaliação de propriedades físico-químicas de materiais retrobturadores e cimentos endodônticos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Produção de enzimas lignocelulósicas por fermentação em estado sólido por espécimes do gênero Trichoderma para sacarificação do bagaço de cana de açúcar tratado com micro-ondas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Study of Micro Rotary Ultrasonic Machining

Product miniaturization for applications in fields such as biotechnology, medical devices, aerospace, optics and communications has made the advancement of micromachining techniques essential. Machining of hard and brittle materials such as ceramics, glass and silicon is a formidable task. Rotary ultrasonic machining (RUM) is capable of machining these materials. RUM is a hybrid machining process which combines the mechanism of material removal of conventional grinding and ultrasonic machining. Downscaling of RUM for micro scale machining is essential to generate miniature features or parts from hard and brittle materials. The goal of this thesis is to conduct a feasibility study and to develop a knowledge base for micro rotary ultrasonic machining (MRUM). Positive outcome of the feasibility study led to a comprehensive investigation on the effect of process parameters. The effect of spindle speed, grit size, vibration amplitude, tool geometry, static load and coolant on the material removal rate (MRR) of MRUM was studied. In general, MRR was found to increase with increase in spindle speed, vibration amplitude and static load. MRR was also noted to depend upon the abrasive grit size and tool geometry. The behavior of the cutting forces was modeled using time series analysis. Being a vibration assisted machining process, heat generation in MRUM is low which is essential for bone machining. Capability of MRUM process for machining bone tissue was investigated. Finally, to estimate the MRR a predictive model was proposed. The experimental and the theoretical results exhibited a matching trend.

Produção de enzimas lignocelulósicas por fermentação em estado sólido por espécimes do gênero Trichoderma para sacarificação do bagaço de cana de açúcar tratado com micro-ondas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Comparison Between Micro- and Macrosurgical Techniques for the Treatment of Localized Gingival Recessions Using Coronally Positioned Flaps and Enamel Matrix Derivative

Background: The aim of this study is to compare the macro- and microsurgery techniques for root coverage using a coronally positioned flap (CPF) associated with enamel matrix derivative (EMD). Methods: Thirty patients were selected for the treatment of localized gingival recessions (GRs) using CPF associated to EMD. Fifteen patients were randomly assigned to the test group (TG), and 15 patients were randomly assigned to the control group (CG). The microsurgical approach was performed in the TG, and the conventional macrosurgical technique was performed in the CG. The clinical parameters evaluated before surgery and after 6 months were GR, probing depth, relative clinical attachment level, width of keratinized tissue (WKT), and thickness of keratinized tissue (TKT). The discomfort evaluation was performed 1 week postoperative. Results: There were no statistically significant differences between groups for all parameters at baseline. At 6 months, there was no statistically significant difference between the techniques in achieving root coverage. The percentage of root coverage was 92% and 83% for TG and CG, respectively. After 6 months, there was a statistically significant increase of WKT and TKT in TG only. Both procedures were well tolerated by all patients. Conclusions: The macro- and microsurgery techniques provided a statistically significant reduction in GR height. After 6 months, there was no statistically significant difference between the techniques regarding root coverage, and the microsurgical technique demonstrated a statistically significant increase in WKT and TKT. J Periodontol 2010;81:1572-1579.

CHARACTERIZATION OF THE MICRO-SITE CONDITIONS FROM RESTORED AREAS WITH DIFFERENT AGES

Regeneration microsites are characterized by diverse combinations of attributes which assure the best conditions for seed germination and seedling establishment. By understanding these attributes, we can contribute to determining better management methodologies for reestablishing ecological process in sites under restoration. Thus, we sought to characterize and differentiate the micro-site conditions of restoration plantings to indentify likely physical-chemical limitations for the establishment of native tree species in the forest understory. This study was carried out in reforestation plantings with different ages (10, 22 and 55 years). The physical-chemical characterization of the micro-site of regeneration of the study areas was carried out by evaluating the soil compression level, porosity, humidity, organic matter and nutrients content and granulometry, as well as litter dry mass and canopy cover. An increase on the canopy cover and soil porosity, humidity, clay and organic matter content were observed in the oldest restored areas, as well as a decrease in soil compression. Thus, these findings demonstrated that the evaluated microsite properties are in process of restoration. Therefore, microsite conditions for seedling establishment become even more similar to reference ecosystems as restoration planting evolve.

A palaeobiologist's guide to 'virtual' micro-CT preparation

This paper provides a brief but comprehensive guide to creating, preparing and dissecting a 'virtual' fossil, using a worked example to demonstrate some standard data processing techniques. Computed tomography (CT) is a 3D imaging modality for producing 'virtual' models of an object on a computer. In the last decade, CT technology has greatly improved, allowing bigger and denser objects to be scanned increasingly rapidly. The technique has now reached a stage where systems can facilitate large-scale, non-destructive comparative studies of extinct fossils and their living relatives. Consequently the main limiting factor in CT-based analyses is no longer scanning, but the hurdles of data processing (see disclaimer). The latter comprises the techniques required to convert a 3D CT volume (stack of digital slices) into a virtual image of the fossil that can be prepared (separated) from the matrix and 'dissected' into its anatomical parts. This technique can be applied to specimens or part of specimens embedded in the rock matrix that until now have been otherwise impossible to visualise. This paper presents a suggested workflow explaining the steps required, using as example a fossil tooth of Sphenacanthus hybodoides (Egerton), a shark from the Late Carboniferous of England. The original NHMUK copyrighted CT slice stack can be downloaded for practice of the described techniques, which include segmentation, rendering, movie animation, stereo-anaglyphy, data storage and dissemination. Fragile, rare specimens and type materials in university and museum collections can therefore be virtually processed for a variety of purposes, including virtual loans, website illustrations, publications and digital collections. Micro-CT and other 3D imaging techniques are increasingly utilized to facilitate data sharing among scientists and on education and outreach projects. Hence there is the potential to usher in a new era of global scientific collaboration and public communication using specimens in museum collections.

Water-in-Oil Micro-Emulsion Enhances the Secondary Structure of a Protein by Confinement

A scheme is presented in which an organic solvent environment in combination with surfactants is used to confine a natively unfolded protein inside an inverse microemulsion droplet. This type of confinement allows a study that provides unique insight into the dynamic structure of an unfolded, flexible protein which is still solvated and thus under near-physiological conditions. In a model system, the protein osteopontin (OPN) is used. It is a highly phosphorylated glycoprotein that is expressed in a wide range of cells and tissues for which limited structural analysis exists due to the high degree of flexibility and large number of post-translational modifications. OPN is implicated in tissue functions, such as inflammation and mineralisation. It also has a key function in tumour metastasis and progression. Circular dichroism measurements show that confinement enhances the secondary structural features of the protein. Small-angle X-ray scattering and dynamic light scattering show that OPN changes from being a flexible protein in aqueous solution to adopting a less flexible and more compact structure inside the microemulsion droplets. This novel approach for confining proteins while they are still hydrated may aid in studying the structure of a wide range of natively unfolded proteins.

Effects of curing protocol and storage time on the micro-hardness of resin cements used to lute fiber-reinforced resin posts

Objectives: To determine the micro-hardness profile of two dual cure resin cements (RelyX - U100 (R), 3M-ESPE and Panavia F 2.0 (R), Kuraray) used for cementing fiber-reinforced resin posts (Fibrekor (R) - Jeneric Pentron) under three different curing protocols and two water storage times. Material and methods: Sixty 16mm long bovine incisor roots were endodontically treated and prepared for cementation of the Fibrekor posts. The cements were mixed as instructed, dispensed in the canal, the posts were seated and the curing performed as follows: a) no light activation; b) light-activation immediately after seating the post, and; c) light-activation delayed 5 minutes after seating the post. The teeth were stored in water and retrieved for analysis after 7 days and 3 months. The roots were longitudinally sectioned and the microhardness was determined at the cervical, middle and apical regions along the cement line. The data was analyzed by the three-way ANOVA test (curing mode, storage time and thirds) for each cement. The Tukey test was used for the post-hoc analysis. Results: Light-activation resulted in a significant increase in the microhardness. This was more evident for the cervical region and for the Panavia cement. Storage in water for 3 months caused a reduction of the micro-hardness for both cements. The U100 cement showed less variation in the micro-hardness regardless of the curing protocol and storage time. Conclusions: The micro-hardness of the cements was affected by the curing and storage variables and were material-dependent.

Medindo a temperatura de um gás no regime de micro-Kelvin

O desenvolvimento científico nos permite trabalhar hoje com gases em temperaturas muito inferiores aos 10-6 K. Estes gases, uma vez obtidos por técnicas de resfriamento óptico, precisam ser caracterizados com relaçãao às suas propriedades termodinâmicas. a a medida da temperatura. Dentre tais propriedades está a medida da temperatura. Neste trabalho mostramos de forma tutorial como são medidas tais baixas temperaturas, através de técnicas de tempo de voo. Tais técnicas combinam conhecimento básico de mecânica, termodinâmica dentre outros tópicos convencionalmente estudados nos cursos básicos de física.

Micro-mechanical bond strength tests for the assessment of the adhesion of GIC to dentine

Background. The aim of this study is to critically evaluate the bond strength (BS) of Glass-Ionomer Cements (GIC) to dentine with microtensile (mu TBS) and microshear (mu SBS) BS tests by assessing their rankings and failure patterns. Methods. Samples were made on flat dentine surfaces and submitted to mTBS and mSBS. The materials used were: high viscosity GIC (Ketac (TM) Molar Aplicap-KM), resin-modified GIC (Fuji II-FII), nano-filled resin-modified GIC (Ketac (TM) N100-N100) and an etch-and-rinse adhesive system with a composite resin (Adper (TM) Single Bond 2 and Z100 (TM)-Z100). All tests were performed with a Universal Testing Machine (24 h water storage, crosshead speed of 1 mm/min). Debonded surfaces were examined with a stereomicroscope (x40) to identify the failure mode. The data was analyzed with two-way ANOVA (p < 0.05) and LSD test. Results. Means were statistically different regarding the tests and materials, indicating that values for BS obtained for each material depend on the test performed. Failure analysis revealed that failures produced by mTBS were mainly cohesive for KM and FII. mu SBS failures were mainly adhesive or mixed for all materials. For the mTBS, the rank was Z100 > FII > KM = N100, whereas for the mSBS it was Z100 = FII = KM > N100. Conclusion: It may be concluded that distinct micro-mechanical tests present different failure patterns and rankings depending on the material to be considered.