Microwave-assisted, performance-advantaged electrification of propane dehydrogenation.

Nonoxidative propane dehydrogenation (PDH) produces on-site propylene for value-added chemicals. While commercial, its modest selectivity and catalyst deactivation hamper the process efficiency and limit operation to lower temperatures. We demonstrate PDH in a microwave (MW)-heated reactor over PtSn/SiO2 catalyst pellets loaded in a SiC monolith acting as MW susceptor and a heat distributor while ensuring comparable conditions with conventional reactors. Time-on-stream experiments show active and stable operation at 500°C without hydrogen addition. Upon increasing temperature or feed partial pressure at high space velocity, catalysts under MWs show resistance in coking and sintering, high activity, and selectivity, starkly contrasting conventional reactors whose catalyst undergoes deactivation. Mechanistic differences in coke formation are exposed. Gas-solid temperature gradients are computationally investigated, and nanoscale temperature inhomogeneities are proposed to rationalize the different performances of the heating modes. The approach highlights the great potential of electrification of endothermic catalytic reactions.

Infección osteoarticular multifocal en un recién nacido / Multifocal osteoarticular infection in a neonate / Infecção osteoarticular multi-focal num recém-nascido

Tanto la osteomielitis como la osteoartritis séptica en el período neonatal son patologías infrecuentes. La afectación ósea de la columna cervical es aún más rara, siendo excepcional en neonatos. Son patologías graves, con elevada morbimortalidad, donde el diagnóstico y tratamiento precoz agresivo son de suma importancia para el pronóstico vital y funcional. Presentamos el caso de un neonato que presentó una sepsis a S. Aureus multirresistente, asociada a una osteomielitis de la primera vértebra cervical y a una osteoartritis séptica de la cadera izquierda. Fue tratado precozmente de forma quirúrgica y con antibioticoterapia, presentando una buena evolución.

Both osteomyelitis and septic osteoarthritis in the neonatal period are infrequent pathologies. Bone involvement of the cervical spine is even rarer, being exceptional in neonates. These are serious pathologies, with high morbimortality, where early diagnosis and aggressive treatment are of utmost importance for the vital and functional prognosis. We present the case of a neonate who presented with sepsis due to multidrug-resistant S. Aureus, associated with osteomyelitis of the first cervical vertebra and septic osteoarthritis of the left hip. He was treated early surgically and with antibiotic therapy, presenting a good evolution

Tanto a osteomielite como a osteoartrose séptica no período neonatal são patologias raras. O envolvimento ósseo da coluna cervical é ainda mais raro, sendo excepcional nos recém-nascidos. Estas são patologias graves, com elevada morbimortalidade, onde o diagnóstico precoce e o tratamento agressivo são da maior importância para o prognóstico vital e funcional. Apresentamos o caso de um recém-nascido que apresentou sepse devido a S. Aureus multirresistente, associado a osteomielite da primeira vértebra cervical e osteoartrose séptica da anca esquerda. Foi tratado precocemente cirurgicamente e com terapia antibiótica, com uma boa evolução.

Fracturas de húmero distal en pacientes mayores de 65 años: ¿cuál es la mejor opción terapéutica? / Distal humerus fractures in patients over 65 years: what is the best therapeutic option? / Fraturas do úmero distal em pacientes maiores de 65 anos: qual é a melhor opção terapêutica?

Introducción: Las fracturas del húmero distal corresponden al 2% de todas las fracturas. Son los pacientes más añosos, los que presentan mayor desafío terapéutico. Suelen presentarse con huesos osteoporóticos, lo que conlleva a producir fracturas con mayor conminución articular y metafisaria; así como también dificultar una fijación estable y rígida de las mismas, que permita una movilidad precoz. Estas características generan controversia a la hora de elegir el tratamiento adecuado. El objetivo de este estudio es revisar la bibliografía de la última década, acerca de cuál es la mejor opción terapéutica para las fracturas de húmero distal en pacientes añosos. Materiales y métodos: Se realizó una búsqueda sistematizada a través de los buscadores electrónicos PubMed y Timbó en agosto 2019. La búsqueda llego a un total de 475 artículos, de los cuales se seleccionaron 24 según criterios de inclusión y exclusión. Discusión: La mayoría de los estudios analizados son estudios de serie de casos retrospectivos. En los trabajos revisados, existen fracturas tanto extra como intra-articulares. Se analizaron los resultados de los distintos tratamientos realizados según parámetros clínicos, scores funcionales y complicaciones. Conclusiones: El tratamiento conservador es una opción válida para aquellos pacientes en los que el terreno no permita una intervención quirúrgica. Para las fracturas tipo extra-articulares y parcialmente articulares, la reducción abierta y fijación interna es el tratamiento de elección. Para las fracturas articulares completas, no hay diferencias significativas en cuanto a scores utilizados entre la reducción abierta y fijación interna con la artroplastia de codo. Faltan estudios prospectivos que comparen ambos tratamientos.

Introduction: Distal humerus fractures account for 2% of all fractures. It is the elderly patients who present the greatest therapeutic challenge. Osteoporotic bones, more common in this population, lead to the production of fractures with greater joint and metaphyseal comminution. As a result, stable and rigid fixation becomes more difficult, hindering early mobility. These characteristics generate controversy when choosing the appropriate treatment. The aim of this study is to review the literature of the last decade regarding the best therapeutic option for distal humerus fractures in elderly patients. Methods: A systematized search was performed through the electronic search engines PubMed and Timbó in august 2019. The search reached a total of 475 articles, of which 24 were selected according to inclusion and exclusion criteria. Discussion: Most of the studies analyzed are retrospective case series studies. In the articles reviewed, there are both extra and intra-articular fractures. The results of the different treatments performed were analyzed according to clinical parameters, functional scores and complications. Conclusions: Conservative treatment is a valid option for those patients where the terrain does not allow surgical intervention. For extra-articular and partial-articular fractures, open reduction and internal fixation is the treatment of choice. For complete articular fractures, there are no significant differences in scores used between open reduction and internal fixation and elbow replacement. There is a lack of prospective studies comparing both treatments.

Introdução: Fraturas do úmero distal correspondem a 2% de todas as fraturas. São os pacientes mais idosos os que apresentam maior desafio terapêutico. Geralmente apresentam-se com ossos osteoporóticos, o que implica produzir fraturas com maior cominuição articular e metafisária; assim como também dificultar uma fixação estável e rígida das mesmas, que permita uma mobilidade precoce. Estas características geram controvérsia na escolha do tratamento adequado. O objetivo deste estudo é rever a bibliografia da última década, sobre qual é a melhor opção terapêutica para fraturas de úmero distal em pacientes idosos. Materiais e métodos: Foi realizada uma pesquisa sistematizada através dos buscadores eletrônicos Pubmed e Timbó em agosto 2019. A pesquisa chegou a um total de 475 artigos, dos quais 24 foram selecionados segundo critérios de inclusão e exclusão. Discussão: A maioria dos estudos analisados são estudos de série de casos retrospectivos. Nos trabalhos revisados, existem fraturas tanto extra como intra-articulares. Foram analisados os resultados dos diferentes tratamentos realizados segundo parâmetros clínicos, scores funcionais e complicações. Conclusões: O tratamento conservador é uma opção válida para os pacientes em que o terreno não permita uma intervenção cirúrgica. Para fraturas tipo extra-articulares e parcialmente articulares, a redução aberta e fixação interna é o tratamento de escolha. Para fracturas articulares completas, não há diferenças significativas em termos de scores utilizados entre a redução aberta e a fixação interna com artroplastia do cotovelo. Faltam estudos prospectivos que comparem os dois tratamentos.

Microwave-Assisted Catalytic Combustion for the Efficient Continuous Cleaning of VOC-Containing Air Streams.

A microwave-heated adsorbent-reactor system has been used for the continuous cleaning of air streams containing n-hexane at low concentrations. Both, a single catalytic bed (PtY zeolite) and a double (adsorptive DAY zeolite + catalytic PtY zeolite) fixed-bed reactor configurations were studied under dry and humid conditions. The zeolites were selectively heated by short periodic microwave pulses that caused the desorption of n-hexane and its subsequent catalytic combustion. The double bed configuration was attractive because it allowed nearly the same performance with only half of the catalyst load. The operation was especially efficient under realistic humid gas conditions that favored more intense microwave absorption, producing a faster heating of the adsorptive and catalytic beds. Under these conditions, continuous gas cleaning could be achieved with short (3 min, 30 W) microwave heating pulses every 5 min.

Optic neuritis in pregnancy after Tdap vaccination: Report of two cases.

Two pregnant women developed one-eye blurring vision within three weeks after Tdap vaccination. Neurophtalmologic and MR examination confirmed an unilateral optic neuritis without evidence of underlying disease. Both patients had a full recovery, one after intravenous metilprednisolone. This is the first report of optic neuritis related with Tdap vaccination in pregnancy.

Pd-Ag Membrane Coupled to a Two-Zone Fluidized Bed Reactor (TZFBR) for Propane Dehydrogenation on a Pt-Sn/MgAl2O4 Catalyst.

Several reactor configurations have been tested for catalytic propane dehydrogenation employing Pt-Sn/MgAl2O4 as a catalyst. Pd-Ag alloy membranes coupled to the multifunctional Two-Zone Fluidized Bed Reactor (TZFBR) provide an improvement in propane conversion by hydrogen removal from the reaction bed through the inorganic membrane in addition to in situ catalyst regeneration. Twofold process intensification is thereby achieved when compared to the use of traditional fluidized bed reactors (FBR), where coke formation and thermodynamic equilibrium represent important process limitations. Experiments were carried out at 500-575 °C and with catalyst mass to molar flow of fed propane ratios between 15.1 and 35.2 g min mmol-1, employing three different reactor configurations: FBR, TZFBR and TZFBR + Membrane (TZFBR + MB). The results in the FBR showed catalyst deactivation, which was faster at high temperatures. In contrast, by employing the TZFBR with the optimum regenerative agent flow (diluted oxygen), the process activity was sustained throughout the time on stream. The TZFBR + MB showed promising results in catalytic propane dehydrogenation, displacing the reaction towards higher propylene production and giving the best results among the different reactor configurations studied. Furthermore, the results obtained in this study were better than those reported on conventional reactors.