Influência do laser terapêutico no reparo de defeito ósseo de ratos submetidos à ausência de carga

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

Utilização de materiais piezelétricos (PZTS) para coleta e armazenamento de energia

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação imuno-histoquímica da remodelação óssea alveolar em ratos diabéticos durante a movimentação ortodôntica associada à laserterapia

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desenvolvimento de um monitor de vibrações utilizando sensores de tecnologia micro-eletromecânica - MEMS

Pós-graduação em Engenharia Mecânica - FEG

Caracterização mineralógica, química e solubilização do potássio de glauconita modificada

Demand for potassium in Brazil is large and is constantly increasing, but only about 5% of all consumed potassium is produced in the country. This low domestic production implies high rate of potassium imports, leaving the country vulnerable in the event of any difficulty to import this product and currency fluctuations. The modified glauconite is a rock that has a high potential for potassium exploration, found in Minas Gerais state, its extraction is relatively cheap and the prospected rock volume is high. The difficulty for its use as a direct source of potassium is in its low solubility. Thus, the objective of this study was to perform a chemical and mineralogical characterization of the modified glauconite and evaluate the effectiveness of techniques and treatments in the potassium solubilization contained in the rock. For this study, it was used characterization techniques such as X-ray diffraction, scanning electron microscopy, diffraction by Synchrotron Light and chemical analysis of high and low power of potassium extraction. Also granulometric testing and thermal treatments with different forms of calcination were carried out. Overall, it was found that the modified glauconite is a compound of minerals, of the mica groups K-feldspar and quartz and calcination substantially alter the crystal structure of these minerals, increasing the potassium availability. While the natural solubility of glauconite modified be very low, rock calcination added with high fluxes of calcium and low magnesium content at 1200 °C led to potassium solubility increase in order of 100 times compared to that observed in the glauconite natural modified.

Estrutura e propriedades de filmes finos ferroelétricos do sistema PZT

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

Caracterização elétrica e microestrutural de cerâmicas varistoras de baixa tensão à base de ('SN IND.1-x''TI IND.x')'O IND.2' e 'SN''O IND.2' dopados com 'CO''O' e 'NB IND.2''O IND.5'

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeitos da terapia fotodinâmica na expressão dos genes SAP5, LIP9 e PLB2 em Candida albicans

Pós-graduação em Biopatologia Bucal - ICT

Contribuição da aplicação do ultrassom de baixa potência na prevenção de osteopenia em tíbias de ratos sob ausência de carga

Este trabalho objetivou verificar se o ultrassom de baixa potência (US) previne a ocorrência de osteopenia em tíbias de ratos sob ausência de carga. Foram utilizados 45 Rattus novergicus albinus, Wistar adultos, machos, distribuídos em cinco grupos iguais: C - animais-controle livres em gaiolas por 21 dias; S - animais suspensos pela cauda por 21 dias; ST - suspensos pela cauda por 21 dias e concomitantemente tratados com US; S→C - suspensos por 21 dias e depois permanecendo livres em gaiolas por mais 21 dias; S→CT - suspensos por 21 dias e depois permanecendo livres em gaiolas por mais 21 dias e concomitantemente tratados com US. O tratamento foi realizado com US de 1,5MHz, ciclo de trabalho 1:4, 30mW/cm², na tíbia direita, por 15 sessões de 20 minutos cada, cinco sessões por semana. Ainda vivos, os animais foram submetidos a exame de densitometria óssea para verificação da densidade mineral óssea (DMO) e do conteúdo mineral ósseo (CMO). Após a eutanásia dos animais, as tíbias foram desarticuladas, dissecadas e submetidas a ensaio mecânico destrutivo para análise da força máxima (Fmáx) e da rigidez (R). Foram avaliados também o comprimento (L) e o diâmetro (D) no ponto médio da tíbia. O grupo S apresentou valores de DMO, CMO, Fmáx, R, L e D menores em relação ao grupo C, demonstrando que a suspensão pela cauda é prejudicial a estas variáveis. O tratamento dos animais suspensos com o US, grupo ST, elevou os valores de CMO e DMO em relação aos do grupo S, igualando-os aos do grupo C. A Fmáx, R e L do grupo ST aumentou em relação ao grupo S e também em relação ao grupo C (p<0,05). Nenhuma diferença significativa foi encontrada entre as variáveis analisadas para os grupos S→CT e S→C (p>0,05). Os resultados obtidos neste estudo permitem concluir que o US de baixa potência contribuiu na prevenção e reversão da ocorrência da osteopenia nos animais submetidos à suspensão pela cauda, demonstrando que a ausência do estímulo mecânico causada pela impossibilidade da deambulação pode ser minimizada pela ação mecânica deste.

Deposição e caracterização de filmes de óxido de cobalto por sputtering reativo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Tooth Discoloration Induced by Endodontic Phenothiazine Dyes in Photodynamic Therapy

Objective: This study sought to assess if discoloration of tooth structures occurs after photodynamic therapy (PDT) and to determine the efficacy of a protocol to remove the photosensitizers. Background data: PDT has been used in root canal treatment to enhance cleaning and disinfection of the root canal system. PDT uses a low power laser in association with a dye as a photosensitizer. Photosensitizers can induce staining of the dental structures, resulting in an unaesthetic appearance. Methods: Forty teeth were randomly divided into four groups according to the photosensitizer used and pre-irradiation time: 0.01% methylene blue for 5 min (MB5); 0.01% methylene blue for 10 min (MB 10); 0.01% toluidine blue for 5 min (TB5); and 0.01% toluidine blue for 10 min (TB 10). Specimens were irradiated with a 660 nm diode laser with a 300 mu m diameter optical fiber, at 40 mW power setting for 3 min. Immediately after, the photosensitizers were removed with Endo-PTC cream +2.5% sodium hypochlorite (NaOCl). The shade was measured by a Vita Easyshade spectrophotometer based on the CIELAB color system (L*a*b* values) at three different experimental times: before PDT (T0), immediately after PDT (T1), and after removal of the photosensitizer (T2). Results: The results showed a decrease in the averages of the L*a*b* coordinate values after PDT (T1) in all the groups, when compared with the number at T0, with a significant statistical difference in group MB10. After photosensitizer removal (T2), all the values of the coordinates increased with significant statistical differences (p < 0.05) between T1 and T2 in L* and a*. Conclusions: It can be concluded that both methylene blue and toluidine blue dyes cause tooth discoloration, and that Endo-PTC cream associated with 2.5% NaOCl effectively remove these dyes, regardless of the pre-irradiation time used for PDT.

Desenvolvimento de um sistema para caracterização de dispositivos eletroluminescentes

The materials designed to be used in electroluminescent (EL) devices construction are studied and improved since 1936. Great interests in the development of this kind of devices are mainly due to its low power consumption, flexibility, low cost and easy processing. One class of ELs devices with these characteristics are produced by employing a organic-polymeric/inorganic composite from a conductive polymer blend and an inorganic electroluminescent material (Zn2SiO4:Mn) dispersed in the polymeric matrix. This kind of device operates in d.c. or a.c. potentials, with EL of hundreds candela in the green region of the visible spectrum. However, few studies on the light emission were performed for these devices. In order to characterize devices made from composites, in this work is proposed a method of characterizing the electroluminescence associated with the impedance spectroscopy technique. To implement the technique of impedance spectroscopy was employ an experimental setup consisting of a source of a.c. voltage, an oscilloscope, and a reference resistor. Associated with this system, was use a photo diode and an analog electrometer to characterize the emitted light signal from the sample. The system was implemented allows characterization by impedance spectroscopy in the frequency range from 0.2 Hz up to 2 MHz and voltage amplitudes of 5 mV up to 20 kV. This system permits, at the same time, measurement of the RMS value of the luminance for devices in frequency range from 20 Hz up to 2 MHz. To test the system efficiency, an EL device was characterized showing analogous results to those reported in literature. By doing this, was demonstrated the efficiency of the system for electroluminescence characterization associated with the electrical characterization by impedance spectroscopy, for devices

Estudo da fotoisomerização em filmes de polímero triacrilato dopado com azocorante disperse red 1

Triacrylate resins are widely used to fabricate 3D microstructures, photonic crystals and optical devices. These resins can be doped with photosensitive materials like Disperse Red 1 (DR1), an Azo dye that changes its molecular configuration from trans to cis (photoisomerisation) with variations in their optical absorption spectrum when irradiated with ultraviolet or visible light. The reversibility of this process is thermally activated and occurs when the molecule remains at dark. In this work was prepared a 1:1 mixture of ethoxylated-6-trimethylolpropane (SR499) and tris-2-hydroxyethyl-isocyanurate (SR368) triacrylate resins, plus photoinitiator Lucirin TPOL, forming a UV curable polymeric matrix doped with DR1. Thin films were deposited onto glass slides by spin-coating technique. The films showed photochromic effect when illuminated with a low power diode laser (450 nm and 50mW/cm2). This effect is reversible after sample is left in dark. Thermochromic effect was evaluated by optical absorption measurements in the range of 40 to 140oC, heating the samples in-situ

Bancos de capacitores se corrente de Inrush

This work discusses about the effects and methods of control and elimination of the currents transients generated by switching capacitor banks, this currents are called inrush currents. Capacitor banks are widely used to compensate a low power factor generated by the widespread use of inductive loads. Currently many of these banks are automatic and therefore the capacitive cells are connected and disconnected according to the inductive loads on the network. However when connecting a capacitor bank to a bus can generate currents transients generated by electromagnetic transients. Aspects of the network, for example, the existence of a bank already connected to the bus, can influence the intensity of this phenomenon. This paper discusses some characteristics of the capacitors and the network to justify and explain the appearance of these transients and discusses its effects on the network and to other equipment. It is concluded that the main cause of this phenomenon is the voltage difference between the capacitor to be connected to the network and the bus, the results of the study were the bases to discuss the traditional methods to mitigate these currents and therefore its negative effects. Although in this paper is yet developed a method of electronic switching that can greatly reduce these transients

Introdução à gravitação de Brans-Dicke

The cosmological standard model needs a deep improvement when compared to recent observational data and also when contrasted with a broad theorical context. Al- ternative theories to General Relativity are possible candidates to reach the expectation Physics of Elementary Particles and Gravitation. Scalar-tensor theories seem to reappear from the ashes of the old work by Jordan corresponding appropriately low power limits of unifying theories. Being the Brans Dicke theory a scalar tensor is conducted a comprehensive study starting from its rst motivations to it s current one it is re flections