633 resultados para José Carlos de Magalhães
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OBJETIVO: Apresentar um software que permita uma análise detalhada da dinâmica da deglutição. MATERIAIS E MÉTODOS: Participaram deste estudo dez indivíduos após acidente vascular encefálico, sendo seis do gênero masculino, com idade média de 57,6 anos. Foi realizada videofluoroscopia da deglutição e as imagens foram digitalizadas em microcomputador, com posterior análise do tempo do trânsito faríngeo da deglutição, por meio de um cronômetro e do software. RESULTADOS: O tempo médio do trânsito faríngeo da deglutição apresentou-se diferente quando comparados os métodos utilizados (cronômetro e software). CONCLUSÃO: Este software é um instrumento de análise dos parâmetros tempo e velocidade da deglutição, propiciando melhor compreensão da dinâmica da deglutição, com reflexos tanto na abordagem clínica dos pacientes com disfagia como para fins de pesquisa científica.
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OBJETIVO: Demonstrar a apresentação mais freqüente das lesões mamárias císticas utilizando a elastografia e discutir a sua aplicabilidade. MATERIAIS E MÉTODOS: A casuística compôs-se de 150 pacientes encaminhadas para realização de biópsia mamária percutânea com 175 lesões. Foram excluídas as lesões com diagnóstico histológico de lesões sólidas (153 lesões) e incluídas as lesões com características císticas à histologia (22 lesões), incluindo cistos complicados, lesões papilíferas, lesões inflamatórias, hiperplasia de células colunares típica e ectasia ductal. Estas lesões foram classificadas de forma retrospectiva por meio da elastografia, conforme escores criados pelos autores, variando de 1 a 4. RESULTADOS: Das 22 lesões encaminhadas, 13 (59%) correspondiam a cistos, uma (4,6%) a ectasia ductal, duas (9,2%) a lesões inflamatórias, cinco (22,6%) a lesões papilíferas e uma (4,6%) a hiperplasia de células colunares. Foram encontrados 17 escores 2, quatro escores 3, um escore 4 e nenhum escore 1, com especificidade de 95%. CONCLUSÃO: As lesões císticas mamárias têm diferentes apresentações à elastografia, conforme o resultado histológico, sendo este um método útil para a sua diferenciação e de fácil aplicabilidade na clínica diária.
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OBJETIVO: A nefropatia por contraste é a terceira causa de insuficiência renal aguda em pacientes hospitalizados. O objetivo deste estudo foi avaliar a ação da n-acetilcisteína e do alopurinol na proteção renal em ratos de ambos os sexos que receberam diatrizoato. MATERIAIS E MÉTODOS: Ratos Wistar adultos jovens, uninefrectomizados e submetidos a restrição hídrica, receberam solução salina (grupo 1: machos; grupo 2: fêmeas), diatrizoato (grupo 3: machos; grupo 4: fêmeas), diatrizoato e n-acetilcisteína (grupo 5: machos), diatrizoato e alopurinol (grupo 6: machos) e diatrizoato e n-acetilcisteína + alopurinol (grupo 7: machos). A filtração glomerular foi avaliada pela creatinina. O teste t de Student e o teste do sinal foram utilizados para análises estatísticas. RESULTADOS: Ratos que receberam diatrizoato apresentaram elevação estatisticamente significante da creatinina sérica, quando comparados aos controles, porém não houve diferença entre os sexos. Os animais que receberam alopurinol não mostraram aumento significante da creatinina, enquanto a administração de n-acetilcisteína não impediu a elevação da creatinina. CONCLUSÃO: O alopurinol mostrou-se mais efetivo que a n-acetilcisteína na proteção funcional renal ao dano induzido pelo diatrizoato de sódio. Não houve diferença entre os sexos na intensidade do dano renal pelo diatrizoato de sódio.
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OBJETIVO: Caracterizar os aspectos mamográficos de cancerização de lóbulos associados a carcinoma ductal in situ (CDIS), por meio de correlação entre achados de imagem e histológicos. MATERIAIS E MÉTODOS: O presente estudo retrospectivo foi baseado em uma revisão de laudos histopatológicos de 135 pacientes submetidas a biópsia de mama. O diagnóstico de cancerização de lóbulos associada a CDIS foi confirmado em 12 das pacientes. Dois casos foram excluídos porque os cortes histopatológicos não estavam disponíveis para correlação da patologia com a mamografia. Todas as imagens mamográficas foram retrospectivamente analisadas às cegas quanto aos resultados histológicos e classificados por dois experientes radiologistas especializados em mama. RESULTADOS: Nove casos (90%) apresentavam microcalcificações redondas agrupadas e um (10%) apresentava calcificações lineares. A distribuição das calcificações foi definida como lobular em todos os casos. A análise histopatológica demonstrou quatro casos de CDIS cribriforme, dois casos de comedocarcinoma, um caso de CDIS sólido, um caso de CDIS cribriforme associado com sólido e um caso de CDIS cribriforme associado com sólido e comedocarcinoma. No caso em que havia calcificações redondas e lineares, o subtipo histológico era de CDIS cribriforme. Com relação ao número de microcalcificações, nove casos apresentavam mais do que 20 e apenas um caso apresentava menos do que 10 microcalcificações. CONCLUSÃO: Na presente coorte, a avaliação mamográfica de pacientes com CDIS apresentando cancerização de lóbulos demonstrou agrupamentos de microcalcificações redondas com distribuição lobular. Embora agrupamentos de calcificações redondas sejam normalmente associados a um processo benigno, a cancerização de lóbulos por CDIS pode produzir um padrão similar, mimetizando, assim, uma condição benigna.
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Os autores relatam um caso de abordagem mista para o tratamento endovascular de doença oclusiva da artéria tibial anterior por acesso pedioso retrógrado, no qual a abordagem tradicional anterógrada foi inadequada em vencer uma oclusão. A técnica parece oferecer uma opção para procedimentos endovasculares, que objetivam o tratamento de lesões da artéria tibial anterior em que a via anterógrada convencional mostre-se inadequada.
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Objective To construct a Portuguese language index of information on the practice of diagnostic radiology in order to improve the standardization of the medical language and terminology. Materials and Methods A total of 61,461 definitive reports were collected from the database of the Radiology Information System at Hospital das Clínicas – Faculdade de Medicina de Ribeirão Preto (RIS/HCFMRP) as follows: 30,000 chest x-ray reports; 27,000 mammography reports; and 4,461 thyroid ultrasonography reports. The text mining technique was applied for the selection of terms, and the ANSI/NISO Z39.19-2005 standard was utilized to construct the index based on a thesaurus structure. The system was created in *html. Results The text mining resulted in a set of 358,236 (n = 100%) words. Out of this total, 76,347 (n = 21%) terms were selected to form the index. Such terms refer to anatomical pathology description, imaging techniques, equipment, type of study and some other composite terms. The index system was developed with 78,538 *html web pages. Conclusion The utilization of text mining on a radiological reports database has allowed the construction of a lexical system in Portuguese language consistent with the clinical practice in Radiology.
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The authors present a case of a neuroendocrine carcinoma in an asymptomatic 75-year-old woman, detected in routine breast screening. The lesion was visible at mammography as a well circumscribed, medium density nodule, with no associated microcalcifications, and at ultrasonography as a hypoechoic nodule, with irregular shape and ill-defined margins. Magnetic resonance imaging revealed findings consistent with malignancy.
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This review gives a critical idea on the importance of intramolecular reactions as models for enzymatic catalysis. Intramolecular lactonizations, ester and amide hydrolysis studies result in theories which try to explain the difference between intermolecular, intramolecular and enzyme reactions and rationalize the enhancement promoted by these biological catalyst.
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The catalytic decomposition of soybean oil was studied in a fix bed reactor at 673 and 773 K and using amorphous silica-alumina and the zeolites USY, H-Mordenite and H-ZSM-5 as catalysts. Both the selectivity and the catalytic activity were determined by studying the product composition resulting from the chemical reactions. Physicochemical characteristics of the catalysts were obtained by X-ray fluorescence, Fourier Transform infrared spectroscopy, 29Si and 27Al Nuclear Magnetic Ressonance and textural analysis. The zeolites USY and H-ZSM-5, showing higher Brönsted acidity, yielded products with higher concentration in aromatic hydrocarbons, whereas with both H-Mordenite and amorphous silica-alumina the main products were paraffins.
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In the last years, several research groups have been working on the synthesis of new steroidal plant hormones called brassinosteroids (BS), which promote plant growth and better crops. Many synthetic targets and applications of these compounds and their analogues have been described in the literature. From Solanum species of the Distrito Federal, we isolated the steroidal alkaloid solasodine, which was then converted into our starting material, vespertiline. By functionalization of rings A and B, we have synthesized a new analogue of BS, with a 2alpha,3alpha-dihydroxy-6-one structure, typical of the naturally occurring BS castasterone, the immediate biosynthetic precursor of brassinolide.
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Laser excitation of 0.01 M solutions of 1-indanone (Ia), 1-tetralone (Ib), 1-benzosuberone (Ic), and their a,a -dimethyl derivatives IIa-c, respectively, in benzene, produced transients with maximum absorption at 425 nm, and lifetimes ranging from 62 ns (IIa) to 5.5ms (Ic). Quenching studies using well known triplet quenchers such as 1,3-cyclohexadiene and oxygen demonstrated the triplet nature of these transients. In the presence of hydrogen donors, such as 2-propanol, the triplet state decay of the ketones Ia-c leads to the formation of the corresponding ketyl radicals, i.e. IIIa-c, which show absorption spectra very similar to the parent ketone, with lmax at 430 nm and lifetime in excess of 20 ms. Steady state irradiations show that the a,a -dimethyl ketones IIa and IIc form ortho-alkyl benzaldehydes probably derived from an initial a-cleavage of the corresponding triplet excited states.
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The solution fluorescence of N-alkyl-2,3-naphthalimides (1-4) in polar protic and aprotic solvents was compared to the emission from solid samples resulting from the imide complexation with b-cyclodextrin or adsorption on the surface of microcrystalline cellulose. Solid samples of the inclusion complex 2,3-naphthalimides/b-cyclodextrin show maximum for fluorescence emission significantly different to the observed in methanolic solution. Beside this, a clear effect on the alkyl chain length could be observed for these samples which is probably due to differences in probe location inside the cyclodextrin cavity. The constancy for fluorescence quantum yield and fluorescence lifetime for the imides 1 - 4 adsorbed on microcrystalline cellulose suggests that, independently of the polarity of the solvent used for sample preparation, the probe is preferentially located on the cellulose surface. An increase of fluorescence quantum yield and fluorescence lifetime for solid samples, when compared to the values obtained in solution for the different solvents employed in this study (acetonitrile, methanol and water), is fully in accordance with a decrease of the probe mobility due to inclusion in b-cyclodextrin or to adsorption on cellulose.
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Polychlorinated biphenyls (PCBs) are a class of 209 chemical compounds with the molecular formula C12H10-nCl n, where 1 <= n <= 10. They were commercially produced as complex mixtures for various uses, being employed principally as dielectric fluids in capacitors and transformers. They are not easily degraded due their chemical and physical stability and tend to bioaccumulate in the organisms. After the discovery of their xenobiotic activity, restrictions were imposed for their use, as well as for their discards. Nowadays the development of recovery processes for contaminated environment urges to be done due to the extension of reached areas.
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Chalcone (1) and its fluorinated derivatives 2-4, as well as their cyclic analogues 5-10, were synthesized through an aldol condensation reaction between the corresponding ketone and aldehyde. These compounds were characterized by IR, EIMS and ¹H and 13C NMR spectral data. Modern NMR techniques allowed us to conclude that the compounds obtained show E configuration. These techniques were also employed to investigate the equilibrium involving the s-cis and s-trans conformations of 1-4, with this equilibrium being dependent on the fluorine substitution on both aromatic rings, A or B. IR studies indicated that the yield of the s-cis conformation in the fluorinated derivatives is 57.4±1.4; 88.1±0.4 and 66.4±0.7%, for 2, 3 and 4, respectively, based on previous ¹H NMR calculations for chalcone. Theoretical calculations, using the MMX method, were employed to justify the variation of chemical shifts for the fluorinated derivatives and cyclic analogues. These chemical shifts are consequence of the anisotropic effect showed by the carbonyl group on these compounds.
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Chalcone and its fluorinated derivatives were synthesized and photolyzed in the solid state. UV irradiation of chalcone and its monosubstituted fluorine derivatives (3- and 4-fluorchalcone) resulted in a mixture of anti-head-head (gamma-truxinic), sin-head-tail (alpha-truxilic) and anti-head-tail (epsilon-truxilic) dimers. On the other hand, upon irradiation of 3,4- and 3,5-difluorchalcone a stereoselective formation of the alpha-truxilic photodimer was observed, whereas for 2-substituted chalcones (2,3difluorchalcone, 2,5-difluorchalcone, 2,6-difluorchalcone and 2,3,4-trifluorchalcone) the beta-truxilic dimer was stereoselectively obtained. 2',3',4',5',6'-pentafluorchalcone was the less reactive of all chalcones studied and at least one of the possible photodimers, i.e the anti-head-head isomer, was identified. Irradiation of polyfluorinated chalcones such as 2,3,5,6-tetrafluor-, 2,3,4,5,6-pentafluor-, and 2,2',3,3',4,4',5,5',6,6'-decafluorchalcone led only to polymerization and/or decomposition products.