Evaluation of the human petrotympanic fissure using anatomized cadaveric specimens and multi-detector CT imaging.

PURPOSE: The purpose of the current study is twofold. First, to investigate the variability of the petrotympanic fissure's (PTF) morphology in anatomized human cadaveric specimens using multi-detector computed tomography (MDCT), and second, to compare the resulting measurements to investigate the possibilities of applying MDCT in the determination of PTF morphology in living humans. METHODS: Specimens (n = 15) containing the temporal bone and TMJ were obtained from embalmed adult female (53.3%) and male (46.7%) cadavers and imaged using a helical 16-row scanner. Afterwards, cryosections were obtained and morphometric parameters were measured. Degree of agreement between both determinations was investigated and morphometric variables were also compared between PTF types. RESULTS: Three different types of PTF were identified. Type 1 was a wide tunnel-shaped structure. It was found in 20% of the cases. Type 2 was wide in the entrance but gradually narrows to the tympanic cavity. It was found in 46.7% of specimens. Finally, type 3, which was observed in 33.3% of the cases, was wide at the entrance of the mandibular fossa, followed by a middle region with flat-shaped tunnel structure and a narrow exit. The PTF's vertical diameters at the mandibular fossa, midpoint, and tympanic cavity and the width at the mandibular fossa all were significantly greater in type 1 specimens. CONCLUSIONS: MDCT is suitable for investigating the variable morphology of human PTF and its association with middle ear's and TMJ pathologies.

CATALIZADORES DE Co, Fe Y Ni SOPORTADOS SOBRE COQUE PARA LA LICUEFACCIÓN DIRECTA DE CARBÓN / Co, Fe AND Ni CATALYSTS SUPPORTED ON COKE FOR DIRECT COAL LIQUEFACTION / CATALISADORES DE Co, Fe E Ni NUM SUPORTE DE COQUE PARA A LIQUEFAÇÃO DIRECTA DE CARVÃO

Se prepararon catalizadores de metales de transición soportados en coque por impregnación con una solución del complejo de metal-tiourea, obtenido a partir de las sales precursoras de cloruro de cobalto, cloruro de níquel o sulfato de hierro y amonio. La formación del sulfuro sobre la superficie del soporte se realizó mediante la descomposición del complejo. Los catalizadores producidos se usaron en la licuefacción directa de un carbón bituminoso medio volátil (Yerbabuena No 1) de Cundinamarca en un reactor Parr discontinuo de 250 mL a 723 K y una presión de hidrógeno de 8,0 MPa en presencia de tetralina como solvente donor de hidrógeno, con un tiempo de residencia de una hora. Los resultados de los ensayos catalíticos muestran, para todos los catalizadores, una buena conversión del carbón y rendimientos significativos en la fracción de aceites e indican que el método de preparación propuesto del catalizador es efectivo y, eventualmente, permitiría remplazar los procesos convencionales de sulfuración con H2S.

Transition metal catalysts supported on coke were prepared by impregnation with a solution of complex of metal-thiourea, that is produced from salt precursors of cobalt chloride, nickel chloride or iron sulfate and ammonium. Sulphide formation on the support surface was generated by decomposition of the metal complex. The catalysts obtained were used in direct coal liquefaction of a medium volatile bituminous coal (Yerbabuena No 1) from Cundinamarca using a 250 mL Parr reactor at 723 K, and a hydrogen pressure of 8.0 MPa, with a reaction time of 1 h and using tetralin as hydrogen-donor solvent. The catalytic results show, for all samples, both a good coal conversion and an enhancement of the yield of oils, this indicates that the proposed preparation method of catalyst is effective and, that eventually, the H2S sulphidation conventional process could be replaced.

Foram preparados catalisadores de metais de transição num suporte de coque por impregnação com uma solução do complexo de metal-tioureia, obtidos a partir dos sais precursores de cloreto de cobalto, cloreto de níquel ou sulfao de ferro y amônia. A formação de enxofre sobre a superfície do suporte foi realizado mediante a descomposição do complexo. Os catalisadores produzidos foram usados na liquefação directa de um carvão betuminoso meio volátil (Yerbabuena No1) de Cundinamarca num reactor Parr descontinuo de 250 ml a 723 K y uma pressão de hidrogênio de 8,0 MPa na presença de tetralina como solvente doador de hidrogênio, com um tempo de residência de 1 hora. Os resultados dos ensaios catalíticos mostram, para todos os catalisadores, uma boa conversão do carvão e rendimentos significativos na fracção orgânica e indicam que o método de preparação proposto do catalisador é efectivo e, eventualmente, permitiria substituir os processos convencionais de sulfuração com H2S.