El pertinaz agárico

El uso médico del hongo denominado antiguamente agárico fue continuo durante más de veinte siglos, a pesar desu inutilidad terapéutica casi total. Se resume aquí la historia de este medicamento

On the deactivation of Zr-loading P-containing mesoporous carbon catalyst during methanol dehydration

Dimethyl ether (DME) has received much attention in the last few years due to its potential use as a diesel substitute and it can be obtained from dehydration of biomass-based methanol. γ-Alumina, ZSM-5 and HPAs were tested as catalysts. A carbon-supported zirconium phosphate catalyst was synthesized and tested for methanol dehydration reaction in a high temperature range. Carbon matrix was produced by olive stone waste activated with phosphoric acid (mass acid to olive stone ratio of 2:1) at 800ºC for 2 h. Then, after washing with distilled water and sieving between 100-300μm, the obtained carbon was impregnated with ZrO(NO3)2 and thermal treated at 250ºC for 2 h. Reaction was performed in a fixed-bed reactor at a space time of 75 gcat·s/mmolCH3OH, a partial pressure of 0.04 atm of methanol and temperatures between 450-600ºC. Deactivated samples were exposed to air at 350ºC for 100 min to study the catalyst regeneration. The catalyst showed a high selectivity to DME (≥95%) and an acceptable conversion at Tª lower than 400ºC without noticeable deactivation. At T>400 ºC, deactivation was detected, due to coke deposition, whose rate increases with operating temperature. However, a high selectivity to DME was observed (above 65%) even at very long times on stream (tos). N2 adsorption results pointed out that deposition of coke took place mainly on the surface of the narrow micropores of the catalyst, blocking much of this narrow porosity at long tos. According to XPS analysis, superficial concentration of phosphorus and zirconium were also diminished with coke deposition, although zirconium was decreased to a larger extend. A kinetic model was developed for the catalyst deactivation during methanol dehydration under different reaction conditions, based on coke deposition.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Situación actual de la epidemia de Peste porcina africana en Rumanía y la UE

La Peste porcina africana (PPA) es una enfermedad infectocontagiosa que afecta a animales suidosdomésticos y silvestres de todas las edades. Cursa con fiebre alta, pérdida de apetito, hemorragias en piely órganos internos, y muerte entre 2 y 20 días postinfección, dependiendo de la cepa implicada. Estáincluida en el Código Sanitario para los Animales Terrestres de la Organización Mundial de Sanidad Animal(OIE) y es de declaración obligatoria, pero no es zoonótica ni afecta a la salud pública. (1)La importancia de la enfermedad, aparte de su alta letalidad, radica en la rápida expansión observada enlos últimos años, extendiéndose sin freno por Europa y Asia, a pesar de los mecanismos de controlaplicados, y convirtiéndose en una amenaza global contra la cual aún no existe vacuna. Desde el año 2014la UE se enfrenta a este virus y actualmente está presente en 9 de los 28 países que la componen. Entreellos preocupa especialmente la situación en Rumanía al tratarse de uno de sus países comunitarios másduramente golpeados por la epidemia desde su contagio en el año 2017.En el presente trabajo se realiza una descripción de la enfermedad y se analiza la situación en la que seencuentran actualmente los países comunitarios afectados por el virus, con atención especial a Rumanía.Asimismo, se exponen las consecuencias que ha conllevado este letal virus a la UE hasta el momento y loque se espera de la evolución de la epidemia en el futuro próximo.<br /

Fibrosarcoma esplénico primario en un perro

Se describe un caso de fibrosarcoma esplénico primario, con metástasis múltiples, en un perro mestizo macho, de ocho años de edad. Clínicamente el animal presentaba un cuadro de insuficiencia hepática. Mediante la necropsia y el estudio histológico se llegó al diagnóstico definitivo.A case of primary splenic fibrosarcoma, with multiple metastasis, in a male eight-year old mixed-breed dog is described. The animal showed clinical signs corresponding with an hepatic failure. Necropsy and a subsequent histopathologic study lead to the final diagnosis

Imagen ecográfica de la obstrucción biliar extrahepática en el perro : descripción de 7 casos

Se realizó un estudio ecográfico en siete perros que presentaban un cuadro de ictericia por obstrucción biliar extrahepática. Esta técnica permitió llegar al diagnóstico en seis de los casos. Se estudió la imagen ecográfica de la dilatación de las vías biliares intra y extrahepáticas, así como los signos asociados, tales como la presencia de una masa en el área pancreática, que pudiesen orientar sobre el origen de la obstrucción.An ultrasonographic examination was carried in out 7 dogs with icterus due to an extrahepatic biliary obstruction. This technique allowed the diagnosis in 6 of the dogs. The sonographic appearance of the dilated intra and extrahepatic biliary tree was assessed, as well as the associated lesions, such as the presence of a mass in the pancreatic area, which could guide towards the origin of the obstruction

MgO-containing porous carbon spheres derived from magnesium lignosulfonate as sustainable basic catalysts

The presence of alkalis in lignosulfonate allows an easy preparation of sustainable MgO-containing carbon catalysts with surface basicity by carbonization of magnesium lignosulfonate and/or further partial gasification of the produced char with CO2. Carbon spheres with different chemical and physical properties were obtained from lignosulfonate treated at temperatures ranging from 500 to 900 ºC. Carbonization at 900 °C generates hollow porous carbon spheres (pore volume of 0.20 cm3/g and apparent surface area of 465 m2/g) with magnesium content of 12%. A kinetic study of CO2 gasification of the carbon spheres obtained at 900 °C at temperatures in the range of 700 – 800 °C revealed that the gasification rate can be accurately described by the random pore model up to conversion values of 0.5. Based on this study, in order to develop additional porosity on the carbon spheres obtained at 900 °C, a partial gasification with CO2 at 750 °C for 30 min was carried out, reaching surface areas higher than 700 m2/g and 15.3% of Mg loading, with an overall preparation yield of 30%. All the obtained carbon materials were tested as catalyst for 2-propanol decomposition, showing a high selectivity to acetone, evidencing the basic character of these carbon catalysts. The highest activity and selectivity were shown by the CO2-activated carbon spheres (conversion and acetone selectivity higher than 90% at 420 °C), indicating that magnesium lignosulfonate is an attractive raw material for the preparation of sustainable carbon catalysts for biorefinery applicationsThe authors wish to thank MICINN (RTI2018-097555-B-100) and Junta de Andalucía (UMA18-FEDERJA-110 and P18-RT-4592) for financial support. M.G.R. acknowledges the assistance of MICINN through an FPU Grant (FPU 18/01402). // Funding for open access charge: Universidad de Málaga / CBU

Deactivation of a Biomass-Derived Zirconium-Doped Phosphorus-Containing Carbon Catalyst in the Production of Dimethyl Ether from Methanol Dehydration

Dehydration of methanol to produce dimethyl ether (DME) was studied at relatively high temperatures (400–600 °C) on biomass-derived phosphorus-containing carbon impregnated with a zirconium salt. Highly thermally stable zirconium phosphate surface groups could be obtained on the final catalyst, which were responsible for the high stability and selectivity to DME of the catalyst at temperatures lower than 400 °C. However, harder operation conditions, closer to those of the industrial process, were evaluated to analyze the changes of the catalyst surface properties with the reaction temperature and the possible causes of deactivation. Thus, high methanol conversion and selectivity to DME were also observed in the temperature range of 400–600 °C, although deactivation was detected. Coke deposition was responsible for a decrease in microporosity and surface concentration of zirconium and phosphorus of the catalyst. Temperature-programmed desorption, 31P magic angle spinning nuclear magnetic resonance, and X-ray photoelectron spectroscopy results suggest that the Zr–O–P groups from zirconium phosphate species were responsible for the long-term stability of the catalyst and that the C–O–P-type active sites were deactivated very fast. However, coke deposition on Zr–O–P-type active sites caused a slow and irreversible deactivation, while deposited coke on the C–O–P-type active sites was easily eliminated by the oxidative treatment in air. A reaction scheme that accounted for the gas product distribution and the production of coke was proposed. A kinetic model for coke formation as a function of time on stream that successfully represents the experimental results was also propounded, which yielded a value for the activation energy for the production of coke of 124 kJ/mol.Funding for open access charge: Universidad de Málaga / CBUA. This work was supported by the Spanish Ministry of Economy and Competitiveness and Junta de Andalucia through CTQ2015-68654-R, RTI2018-097555-B-I00, and UMA18- FEDERJA-110 projects. Javier Torres-Liñán also acknowledges the assistance of the Spanish Ministry of Economy, Industry and Competitiveness for the award of a predoctoral contract to become a Ph.D. (BES-2016-079237)

Preparación de carbones activados de porosidad controlada por activación química de lignosulfonato de sodio

La lignina es uno de los biopolímeros más abundantes en la naturaleza. La industria papelera (y la bio-refinera, en un futuro), genera (y, probablemente, generará) una importante cantidad de lignina, como subproducto o residuo, que, a pesar de su elevado potencial como materia prima, se emplea, principalmente, para la generación de energía en las plantas donde es aislada del resto de biopolímeros que la contienen. En este trabajo se propone, como alternativa, la valorización de lignina técnica obtenida mediante el método del bisulfito a través de la preparación de carbones activos mediante la activación química de un lignosulfonato de sodio con ácido fosfórico. Así, empleando distintas relaciones de impregnación H3PO4/masa lignosulfonato, entre 0 y 3 y temperaturas de activación, entre 400 y 800 °C, se pueden producir carbones activados con un gran desarrollo poroso (ABET 1290 m2/g) y alta contribución de mesoporos (Vmes 1.86 cm3/g). Sin embargo, si se realiza al lignosulfonato un tratamiento térmico a 250 °C, seguido de un lavado ácido, previo a la impregnación, sin modificar las condiciones de activación (temperatura de carbonización y relación agente activante: precursor carbonoso), se obtiene un carbón activado con un elevado desarrollo de la microporosidad, con ABET=2175 m2/g. De esta manera, es posible modular la porosidad resultante a partir del mismo precursor, con ligeras variaciones en el método de preparación.Junta de Andalucía (UMA18-FEDERJA-110 y P18-RT-4592) Ministerio de Ciencia, Innovación y Universidades (RTI2018-097555B-I00). Ministerio de Ciencia, Innovación y Universidades (FPU 18/01402). Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech