Preferential oxidation of CO over Au/CuOx-CeO2 catalyst in microstructured reactors studied through CFD simulations

A computational fluid dynamics (CFD) simulation study of the preferential oxidation of CO (CO-PROX) in microstructured reactors consisting in square and semicircular microchannels coated with anAu/CuOx¿CeO2catalyst is presented. The CO content of the feed stream was set at 1 vol.%. A parametricsensitivity analysis has been performed under isothermal conditions revealing that an optimal reactiontemperature exists that leads to a minimum CO content at the microreactor exit. The influence of thespace velocity, CO2concentration and oxygen-to-CO molar ratio in the feed stream (), catalyst loading,and microchannel characteristic dimension (d) on the microreactor performance has been investigated.Under suitable conditions, the CO concentration can be reduced below 10 ppm at relatively low tem-peratures within the 155¿175¿C range. A negative effect of the increase of d from 0.35 mm to 2.8 mmon the CO removal efficiency has been found and attributed to a more detrimental effect of the masstransport limitations on the oxidation of CO than that of H2. Non-isothermal CFD simulations have beenperformed to investigate the cooling of the CO-PROX reactor with air or a fuel cell anode off gas surrogatein parallel microchannels. Due to the very rapid heat transfer allowed by the microreactor and the stronginfluence of the reaction temperature on the exit CO concentration, a careful control of the coolant flowrate and inlet temperature is required for proper reactor operation. The microreactor behavior is virtuallyisothermal.Ministerio de Ciencia e Innovación ENE2009-14522-C04Ministerio de Economía y Competitividad ENE2012-37431-C0

Preferential oxidation of CO over Au/CuOx-CeO2 catalyst in microstructured reactors studied through CFD simulations

A computational fluid dynamics (CFD) simulation study of the preferential oxidation of CO (CO-PROX) in microstructured reactors consisting in square and semicircular microchannels coated with anAu/CuOx¿CeO2catalyst is presented. The CO content of the feed stream was set at 1 vol.%. A parametricsensitivity analysis has been performed under isothermal conditions revealing that an optimal reactiontemperature exists that leads to a minimum CO content at the microreactor exit. The influence of thespace velocity, CO2concentration and oxygen-to-CO molar ratio in the feed stream (), catalyst loading,and microchannel characteristic dimension (d) on the microreactor performance has been investigated.Under suitable conditions, the CO concentration can be reduced below 10 ppm at relatively low tem-peratures within the 155¿175¿C range. A negative effect of the increase of d from 0.35 mm to 2.8 mmon the CO removal efficiency has been found and attributed to a more detrimental effect of the masstransport limitations on the oxidation of CO than that of H2. Non-isothermal CFD simulations have beenperformed to investigate the cooling of the CO-PROX reactor with air or a fuel cell anode off gas surrogatein parallel microchannels. Due to the very rapid heat transfer allowed by the microreactor and the stronginfluence of the reaction temperature on the exit CO concentration, a careful control of the coolant flowrate and inlet temperature is required for proper reactor operation. The microreactor behavior is virtuallyisothermal.Peer Reviewe

Multipotent adult progenitor cells sustain function of ischemic limbs in mice

Despite progress in cardiovascular research, a cure for peripheral vascular disease has not been found. We compared the vascularization and tissue regeneration potential of murine and human undifferentiated multipotent adult progenitor cells (mMAPC-U and hMAPC-U), murine MAPC-derived vascular progenitors (mMAPC-VP), and unselected murine BM cells (mBMCs) in mice with moderate limb ischemia, reminiscent of intermittent claudication in human patients. mMAPC-U durably restored blood flow and muscle function and stimulated muscle regeneration, by direct and trophic contribution to vascular and skeletal muscle growth. This was in contrast to mBMCs and mMAPC-VP, which did not affect muscle regeneration and provided only limited and transient improvement. Moreover, mBMCs participated in a sustained inflammatory response in the lower limb, associated with progressive deterioration in muscle function. Importantly, mMAPC-U and hMAPC-U also remedied vascular and muscular deficiency in severe limb ischemia, representative of critical limb ischemia in humans. Thus, unlike BMCs or vascular-committed progenitors, undifferentiated multipotent adult progenitor cells offer the potential to durably repair ischemic damage in peripheral vascular disease patients

Biodiversity loss in a Mediterranean ecosystem due to an extreme warming event unveils the role of an engineering gorgonian species

Stochastic perturbations can trigger major ecosystem shifts. Marine systems have been severely affected in recent years by mass mortality events related to positive thermal anomalies. Although the immediate effects in the species demography affected by mortality events are well known, information on the mid- to long-term effects at the community level is much less documented. Here, we show how an extreme warming event replaces a structurally complex habitat, dominated by long-lived species, by a simplified habitat (lower species diversity and richness) dominated by turf-forming species. On the basis of a study involving the experimental manipulation of the presence of the gorgonian Paramuricea clavata, we observed that its presence mitigated the effects of warming by maintaining the original assemblage dominated by macroinvertebrates and delaying the proliferation and spread of the invasive alga Caulerpa cylindracea. However, due to the increase of sediment and turf-forming species after the mortality event we hypothesize a further degradation of the whole assemblage as both factors decrease the recruitment of P.clavata, decrease the survival of encrusting coralligenous-dwelling macroinvertebrates and facilitate the spreading of C. cylindracea

Patients with severe mental illness and hepatitis C virus infection benefit from new pangenotypic direct-acting antivirals: Results of a literature review

Hepatitis C virus (HCV) infection is a global health problem that can results in cirrhosis, hepatocellular carcinoma and even death. HCV infection is 3–20-fold more prevalent among patients with versus without severe mental illness (SMI), such as major depressive disorder, personality disorder, bipolar disorder and schizophrenia. Treatment options for HCV were formerly based on pegylated interferon alpha, which is associated with neuropsychiatric adverse events, and this contributed to the exclusion of patients with SMI from HCV treatment, elimination programmes, and clinical trials. Moreover, the assumption of poor adherence, scant access to healthcare and the stigma and vulnerability of this population emerged as barriers and contributed to the low rates of treatment and efficacy. This paper reviews the literature published between December 2010 and December 2020 exploring the epidemiology of HCV in patients with SMI, and vice versa, the effect of HCV infection, barriers to the management of illness in these patients, and benefits of new therapeutic options with pangenotypic direct antiviral agents (DAAs). The approval of DAAs has changed the paradigm of HCV infection treatment. DAAs have proven to be an equally efficacious and safe option that improves quality of life (QoL) in patients SMI. Knowledge of the consequences of the HCV infection and the benefits of treatment with new pangenotypic DAAs among psychiatrists can increase screening, referral and treatment of HCV infection in patients with SM

Arnold Heim (1882-1965) geólogo-naturalista suizo: El primer Miembro Correspondiente de la Sociedad Geológica Argentina

The intense geological and naturalistic activity of Dr. Arnold Heim in various parts of the world, lead him to become an outstanding personality for the time. He obtained a PhD at the University of Zürich. The detailed manuscripts of the Precordillera, Patagonia and other sectors published by A. Heim during his stays in Argentina and Chile are well known. He was designed in 1946, as the first Corresponding Member of the Argentine Geological Society. In addition to his activity in oil prospecting, about 300 scientific publications are recorded; descriptions of the trips are included with complete accounts of flora and fauna and of the inhabitants of the visited regions and their customs, as well as maps and geographical works. An important milestone in his life was the possibility of being part of the first Swiss scientific expedition to the Himalayas, where he head with his disciple A. Gansser. The results were relevant stratigraphic and tectonic observations with the discovery of ophiolitic rocks of the ancient Tethys Sea and the interpretation of a continental collision. In all cases, he has left valuable documentation such as photos, maps and correspondence preserved in the ETH Bibliothek in Zürich. In 1939 with 57 years old arrived in South America. Upon arriving, he is surprised by the overwhelming nature offered by the southern Chilean-Argentine region. The initial objective of his trip was to explore the area of the Northern Patagonian Ice Field and the final destination, ascend Mount San Valentín. He was then hired by the ‘Dirección de Minas’ of Buenos Aires for various geotechnical studies in San Juan and La Rioja, among others. The detailed structural schemes of Barreal, Rinconada, and the San Juan river, are still valid. Along his life Heim was a tireless traveling geologist, who came to mention him as the “Swiss Humboldt”.La intensa actividad geológica y de naturalista multifacético en diversas partes del mundo, convirtieron al Dr. Arnold Heim en una destacada personalidad para la época. Se formó académicamente en la escuela geológica suiza de Zúrich. Son conocidos los detallados trabajos en la Precordillera, Patagonia y otros sectores publicados durante su estadía en Sudamérica. Fue seleccionado en 1946, como el primer Miembro Correspondiente de la Sociedad Geológica Argentina. Además de la actividad en la prospección de petróleo, publicó unos 300 trabajos científicos, incluyendo descripciones de sus viajes con relatos completos de flora y fauna, y de los habitantes de la región visitada y sus costumbres. Formó parte de la primera expedición científica suiza a los Himalayas, donde realizó junto a su discípulo A. Gansser relevantes observaciones estratigráficas y tectónicas, con el descubrimiento de rocas ofiolíticas como relictos del antiguo Mar de Tethys y la interpretación de una colisión continental. Ha dejado una valiosa documentación de fotos, mapas y correspondencia preservada en la Biblioteca ETH de Zúrich. En 1939 con 57 años llega a Sudamérica, donde se siente sorprendido por la desbordante naturaleza del sur chileno-argentino. El objetivo era explorar la zona del Lago General Carrera-Buenos Aires, el Campo de Hielo Patagónico Norte y el destino final, ascender el Monte San Valentín. Luego fue contratado por la Dirección de Minas de Buenos Aires para estudios geotécnicos en San Juan y La Rioja, entre otros. Sus detallados esquemas estructurales de Barreal, Rinconada y el río San Juan, aún tienen vigencia. Fue un geólogo viajero incansable, a quien se lo llegó a conocer como el "Humboldt suizo"

Role of deep sponge grounds in the Mediterranean Sea: a case study in southern Italy

The Mediterranean spongofauna is relatively well-known for habitats shallower than 100 m, but, differently from oceanic basins, information upon diversity and functional role of sponge grounds inhabiting deep environments is much more fragmentary. Aims of this article are to characterize through ROV image analysis the population structure of the sponge assemblages found in two deep habitats of the Mediterranean Sea and to test their structuring role, mainly focusing on the demosponges Pachastrella monilifera Schmidt, 1868 and Poecillastra compressa (Bowerbank, 1866). In both study sites, the two target sponge species constitute a mixed assemblage. In the Amendolara Bank (Ionian Sea), where P. compressa is the most abundant species, sponges extend on a peculiar tabular bedrock between 120 and 180 m depth with an average total abundance of 7.3 +/- 1.1 specimens m(-2) (approximately 230 gWW m(-2) of biomass). In contrast, the deeper assemblage of Bari Canyon (average total abundance 10.0 +/- 0.7 specimens m(-2), approximately 315 gWW m(-2) of biomass), located in the southwestern Adriatic Sea between 380 and 500 m depth, is dominated by P. monilifera mixed with living colonies of the scleractinian Madrepora oculata Linnaeus, 1758, the latter showing a total biomass comparable to that of sponges (386 gWW m(-2)). Due to their erect growth habit, these sponges contribute to create complex three-dimensional habitats in otherwise homogenous environments exposed to high sedimentation rates and attract numerous species of mobile invertebrates (mainly echinoderms) and fish. Sponges themselves may represent a secondary substrate for a specialized associated fauna, such zoanthids. As demonstrated in oceanic environments sponge beds support also in the Mediterranean Sea locally rich biodiversity levels. Sponges emerge also as important elements of benthic-pelagic coupling in these deep habitats. In fact, while exploiting the suspended organic matter, about 20% of the Bari sponge assemblage is also severely affected by cidarid sea urchin grazing, responsible to cause visible damages to the sponge tissues (an average of 12.1 +/- 1.8 gWW of individual biomass removed by grazing). Hence, in deep-sea ecosystems, not only the coral habitats, but also the grounds of massive sponges represent important biodiversity reservoirs and contribute to the trophic recycling of organic matter

A dual epigenomic approach for the search of obesity biomarkers: DNA methylation in relation to diet-induced weight loss

Epigenetics could help to explain individual differences in weight loss after an energy-restriction intervention. Here, we identify novel potential epigenetic biomarkers of weight loss, comparing DNA methylation patterns of high and low responders to a hypocaloric diet. Twenty-five overweight or obese men participated in an 8-wk caloric restriction intervention. DNA was isolated from peripheral blood mononuclear cells and treated with bisulfite. The basal and endpoint epigenetic differences between high and low responders were analyzed by methylation microarray, which was also useful in comparing epigenetic changes due to the nutrition intervention. Subsequently, MALDI-TOF mass spectrometry was used to validate several relevant CpGs and the surrounding regions. DNA methylation levels in several CpGs located in the ATP10A and CD44 genes showed statistical baseline differences depending on the weight-loss outcome. At the treatment endpoint, DNA methylation levels of several CpGs on the WT1 promoter were statistically more methylated in the high than in the low responders. Finally, different CpG sites from WT1 and ATP10A were significantly modified as a result of the intervention. In summary, hypocaloric-diet-induced weight loss in humans could alter DNA methylation status of specific genes. Moreover, baseline DNA methylation patterns may be used as epigenetic markers that could help to predict weight loss

The Metabolic and Hepatic Impact of Two Personalized Dietary Strategies in Subjects with Obesity and Nonalcoholic Fatty Liver Disease: The Fatty Liver in Obesity (FLiO) Randomized Controlled Trial

The prevalence of nonalcoholic fatty liver disease (NAFLD) is increasing worldwide. NAFLD management is mainly focused on weight loss, but the optimal characteristics of the diet demand further investigation. This study aims to evaluate the effects of two personalized energy-restricted diets on the liver status in overweight or obese subjects with NAFLD after a 6 months follow-up. Ninety-eight individuals from the Fatty Liver in Obesity (FLiO) study were randomized into two groups and followed different energy-restricted diets. Subjects were evaluated at baseline and after 6 months. Diet, anthropometry, body composition, and biochemical parameters were evaluated. Liver assessment included ultrasonography, Magnetic Resonance Imaging, elastography, and determination of transaminases. Both dietary groups significantly improved their metabolic and hepatic markers after the intervention, with no significant differences between them. Multivariate regression models evidenced a relationship between weight loss, adherence to the Mediterranean Diet (MedDiet), and a decrease in liver fat content, predicting up to 40.9% of its variability after 6 months. Moreover, the antioxidant capacity of the diet was inversely associated with liver fat content. Participants in the group with a higher adherence to the MedDiet showed a greater reduction in body weight, total fat mass, and hepatic fat. These results support the benefit of energy-restricted diets, high adherence to the MedDiet, and high antioxidant capacity of the diet for the management of NAFLD in individuals with overweight or obesity