312 resultados para Ressonância Transversa


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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Background: To establish the best methodology for diagnosis and management of patients with solid and complex renal masses by comparing the costs and benefits of different imaging methods and to improve differential diagnosis of these benign and malignant lesions, particularly by investigating tumour calcifications. Methods: We performed a prospective study on 31 patients with solid or complex masses by submitting them to Abdominal Ultrasonography (US), Doppler Ultrasonography of the renal mass (US Dop), Computed Tomography (CT), and Magnetic Resonance Imaging (MRI). Results: We found 28 patients with malignant and three with benign masses. Of the 28 malignant, 17 showed calcifications at CT; 16 central and one was of the pure peripheral curvilinear type (egg shell). Excretory Urography (IVP) had a significantly lower detection rate for central calcifications than both US and CT. Benign and malignant masses appeared as described in literature, with US, CT and MRI showing high sensitivity and specificity in renal tumor diagnosis. The exception was US Dop where we obtained lower sensitivity for the characterization of malignant tumor flow. Conclusions: In this series we were surprised to find that CT revealed central calcifications in 51.6% of patients, all with malignant lesions, while, literature reports a frequency of calcification in renal cell carcinoma between 8 and 22%, in studies using abdominal films and EU (IVP). This finding is of great importance when we consider that these calcifications occur particularly in malignant neoplasms. As a result of comparing these different imaging methods we have developed a better methodology for renal tumor investigation.

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

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Pós-graduação em Física - FEG

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Pós-graduação em Bases Gerais da Cirurgia - FMB

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Using the sol-gel process, organic-inorganic hybrid coatings were synthesized by incorporation of different concentrations of functionalized carbon nanotubes, to improve their mechanical strength and thermal resistance without changing its passivation character. The siloxane-PMMA hybrids were prepared by radical polymerization of methyl methacrylate (MMA) with 3-methacryloxipropiltrimethoxisilane (MPTS) using the thermal initiator benzoyl peroxide (BPO), followed by acid catalyzed hydrolysis and condensation of tetraethoxysilane (TEOS). The analysis of pristine and functionalized carbon nanotubes was carried out using Scanning Electron Microscopy, X-ray Photoelectron Spectroscopy and Raman Spectroscopy. Structural analysis of hybrids was performed by Nuclear Magnetic Resonance, Atomic Force Microscopy and Raman Spectroscopy. For analysis of mechanical strength and thermal stability were performed mechanical compression tests and thermogravimetric analysis, respectively. Electrochemical Impedance Spectroscopy was used to evaluate the corrosion resistance in saline environment. The results showed an effective functionalization of carbon nanotubes with carboxyl groups and conservation of its structure. The hybrids showed high siloxane network connectivity and roughness of approximately 0.3 nm. The incorporation of carbon nanotubes in the hybrid matrix did not change significantly their thermal stability. Samples containing carbon nanotubes exhibit good corrosion resistance (on the order of MΩ in saline environment), but the lack of complete dispersion of carbon nanotubes in the hybrid, resulted in a loss of mechanical and corrosion resistance compared to hybrid matrix.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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A expansão rápida da maxila cirurgicamente assistida (ERMCA) é realizada por meio de osteotomias nos pilares da maxila e na sutura palatina mediana, promovendo a correção da deficiência transversa da maxila. Técnicas menos invasivas foram descritas, visando à realização desses procedimentos sob anestesia local, eliminando os custos de internação hospitalar e trazendo maior conforto aos pacientes. A proposta deste trabalho foi discutir os aspectos envolvidos na simplificação da técnica da ERMCA sob anestesia local por meio do relato de caso clínico-cirúrgico de paciente com 27 anos de idade. Conclui-se que o diagnóstico por meio da avaliação clínica e dos modelos de estudo é essencial para a indicação da ERMCA e esse procedimento proporciona boa previsibilidade na correção da deficiência transversal, com mínima morbidade. Além disso, a utilização de uma técnica minimamente invasiva é efetiva no tratamento de maxilas atrésicas, com índices de recidiva semelhantes aos das técnicas mais invasivas.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)