Thermodynamic Analyses of Fuel Production Via Solar-Driven Ceria-Based Nonstoichiometric Redox Cycling: A Case Study of the Isothermal Membrane Reactor System

A thermodynamic model of an isothermal ceria-based membrane reactor system is developed for fuel production via solar-driven simultaneous reduction and oxidation reactions. Inert sweep gas is applied on the reduction side of the membrane. The model is based on conservation of mass, species, and energy along with the Gibbs criterion. The maximum thermodynamic solar-to-fuel efficiencies are determined by simultaneous multivariable optimization of operational parameters. The effects of gas heat recovery and reactor flow configurations are investigated. The results show that maximum efficiencies of 1.3% (3.2%) and 0.73% (2.0%) are attainable for water splitting (carbon dioxide splitting) under counter- and parallel-flow configurations, respectively, at an operating temperature of 1900 K and 95% gas heat recovery effectiveness. In addition, insights on potential efficiency improvement for the membrane reactor system are further suggested. The efficiencies reported are found to be much lower than those reported in literature. We demonstrate that the thermodynamic models reported elsewhere can violate the Gibbs criterion and, as a result, lead to unrealistically high efficiencies. The present work offers enhanced understanding of the counter-flow membrane reactor and provides more accurate upper efficiency limits for membrane reactor systems. © 2019 by ASME.Australian Research Council (Wojciech Lipiński, Future Fellowship, Award No. FT140101213, Funder ID. 10.13039/501100000923). China Scholarship Council (Sha Li, Grant No. [2015] 3022, 201506020092, Funder ID. 10.13039/501100004543)

High ferritin levels have major effects on the morphology of erythrocytes in Alzheimer's disease

Introduction: Unliganded iron both contributes to the pathology of Alzheimer's disease (AD) and also changes the morphology of erythrocytes (RBCs). We tested the hypothesis that these two facts might be linked, i.e., that the RBCs of AD individuals have a variant morphology, that might have diagnostic or prognostic value. Methods: We included a literature survey of AD and its relationships to the vascular system, followed by a laboratory study. Four different microscopy techniques were used and results statistically compared to analyze trends between high and normal serum ferritin (SF) AD individuals. Results: Light and scanning electron microscopies showed little difference between the morphologies of RBCs taken from healthy individuals and from normal SF AD individuals. By contrast, there were substantial changes in the morphology of RBCs taken from high SF AD individuals. These differences were also observed using confocal microscopy and as a significantly greater membrane stiffness (measured using force-distance curves). Conclusion: We argue that high ferritin levels may contribute to an accelerated pathology in AD. Our findings reinforce the importance of (unliganded) iron in AD, and suggest the possibility both of an early diagnosis and some means of treating or slowing down the progress of this disease

Profound Morphological Changes in the Erythrocytes and Fibrin Networks of Patients with Hemochromatosis or with Hyperferritinemia, and Their Normalization by Iron Chelators and Other Agents

It is well-known that individuals with increased iron levels are more prone to thrombotic diseases, mainly due to the presence of unliganded iron, and thereby the increased production of hydroxyl radicals. It is also known that erythrocytes (RBCs) may play an important role during thrombotic events. Therefore the purpose of the current study was to assess whether RBCs had an altered morphology in individuals with hereditary hemochromatosis (HH), as well as some who displayed hyperferritinemia (HF). Using scanning electron microscopy, we also assessed means by which the RBC and fibrin morphology might be normalized. An important objective was to test the hypothesis that the altered RBC morphology was due to the presence of excess unliganded iron by removing it through chelation. Very striking differences were observed, in that the erythrocytes from HH and HF individuals were distorted and had a much greater axial ratio compared to that accompanying the discoid appearance seen in the normal samples. The response to thrombin, and the appearance of a platelet-rich plasma smear, were also markedly different. These differences could largely be reversed by the iron chelator desferal and to some degree by the iron chelator clioquinol, or by the free radical trapping agents salicylate or selenite (that may themselves also be iron chelators). These findings are consistent with the view that the aberrant morphology of the HH and HF erythrocytes is caused, at least in part, by unliganded (‘free’) iron, whether derived directly via raised ferritin levels or otherwise, and that lowering it or affecting the consequences of its action may be of therapeutic benefit. The findings also bear on the question of the extent to which accepting blood donations from HH individuals may be desirable or otherwise

Site-Specific Nutrient Management: Implementation guidance for policymakers and investors

Site-Specific Nutrient Management (SSNM) provides guidance relevant to the context of farmers' fields. SSNM maintains or enhances crop yields, while providing savings for farmers through more efficient fertilizer use. By minimizing fertilizer overuse, greenhouse gas emissions can be reduced, in some cases up to 50%. SSNM optimizes the supply of soil nutrients over space and time to match crop requirements. SSNM increases crop productivity and improves efficiency of fertilizer use. SSNM mitigates greenhouse gases from agriculture in areas with high nitrogen fertilizer use. Incentives for adoption of SSNM depend strongly on fertilizer prices

Characteristics of survivors: growth and nutritional condition of early stages of the hake species <i>Merluccius paradoxus</i> and <i>M. capensis</i> in the southern Benguela ecosystem

Larval mortality in marine fish is strongly linked to characteristic traits such as growth and condition, but the variability in these traits is poorly understood. We tried to identify the variability in growth in relation to conditions leading to greater survival chances for early stages of Cape hake, Merluccius paradoxus and M. capensis, in the Benguela upwelling ecosystem. During two cruises in 2007 and one cruise in 2008, hake larvae and juveniles were caught. Otolith microstructures revealed a larval age ranging from 2 to 29 days post-hatching (dph), whereas juvenile age was 67–152 dph. RNA:DNA ratios, used to evaluate nutritional condition, were above the relevant threshold level for growth. No strong coupling between growth and condition was detected, indicating a complex relationship between these factors in the southern Benguela ecosystem. Merluccius paradoxus juveniles caught in 2007 (the surviving larvae of 2006) had significantly higher larval growth rates than larvae hatched in 2007 and 2008, possibly indicating selection for fast growth in 2006. High selection pressure on growth could be linked to predation avoidance, including cannibalism

Ajo selenizado: ¿un alimento funcional futuro o actual?

In the last years, functional foods have awakened consumer, scientific and business interest. A commonly found vegetable in such kind of foods includes garlic (Allium sativum). By its ability for selenium (Se) bio-accumulation, garlic can turn into an attractive option of selenized food. Selenium is an essential micronutrient for many organisms including plants, animals, and humans. It is an important trace element due to its antioxidant properties and plays a main role in prevention of cancer and cardiovascular diseases. Nowadays, there is an increasing interest in the study of Se speciation due to the different roles that each species manifests in toxicological and nutrition fields. However, Se exhibits a narrow interval between toxicity and essentiality, which is puzzling toxicologists and alarming nutritionists and legislators. In the present review, an overview on the development of selenized garlic studies and its potential implementation in Argentine production is exposed. The development of novel foods with added value such us selenized garlic could be an attractive alternative for local market. Moreover, it becomes a good offering for factory owners, considering that Mendoza represents about 85% of total garlic production in the country.En los últimos años, los alimentos funcionales han despertado el interés de consumidores, científicos y empresarios. El ajo (Allium sativum) puede ser un ejemplo de ello. Gracias a su capacidad de bioacumular selenio (Se), dicha hortaliza puede convertirse en una atractiva opción de alimento enriquecido con Se. El Se es un micronutriente esencial para numerosos organismos, incluyendo plantas, animales y humanos. Este micronutriente es de gran importancia debido a sus propiedades antioxidantes, y actúa, en consecuencia, como protector de numerosas enfermedades, tales como cáncer y problemas cardiovasculares. Actualmente, existe un mayor interés en el estudio de especiación de Se debido a los distintos roles que cada especie manifiesta en los campos nutricionales y toxicológicos. Sin embargo, las concentraciones de Se poseen un estrecho intervalo entre toxicidad y esencialidad, desconcertando a toxicólogos y alarmando a nutricionistas y legisladores. En este trabajo, se presenta un panorama del grado de avance sobre el estudio de fortificación de ajo con Se y sus perspectivas de aplicación en el sistema productivo de la República Argentina. Este tipo de producción, con un significativo valor agregado, representa una atractiva oportunidad de mercado para la provincia de Mendoza, considerando además que la misma posee cerca del 85% de la producción nacional.Fil: Escudero, Leticia B.. Consejo Nacional de Investigaciones Científicas y TécnicasFil: Monasterio, Romina P.. Consejo Nacional de Investigaciones Científicas y TécnicasFil: Lipinski, Víctor M.. Instituto Nacional de Tecnología Agropecuaria (Argentina)Fil: Filippini, María Flavia. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Ingeniería AgrícolaFil: Wuilloud, Rodolfo Germán. Consejo Nacional de Investigaciones Científicas y Técnica

Selenized garlic: a future prospect or already a current functional food?

In the last years, functional foods have awakened consumer, scientific and business interest. A commonly found vegetable in such kind of foods includes garlic (Allium sativum). By its ability for selenium (Se) bio-accumulation, garlic can turn into an attractive option of selenized food. Selenium is an essential micronutrient for many organisms including plants, animals, and humans. It is an important trace element due to its antioxidant properties and plays a main role in prevention of cancer and cardiovascular diseases. Nowadays, there is an increasing interest in the study of Se speciation due to the different roles that each species manifests in toxicological and nutrition fields. However, Se exhibits a narrow interval between toxicity and essentiality, which is puzzling toxicologists and alarming nutritionists and legislators. In the present review, an overview on the development of selenized garlic studies and its potential implementation in Argentine production is exposed. The development of novel foods with added value such us selenized garlic could be an attractive alternative for local market. Moreover, it becomes a good offering for factory owners, considering that Mendoza represents about 85% of total garlic production in the country.In the last years, functional foods have awakened consumer, scientific and business interest. A commonly found vegetable in such kind of foods includes garlic (Allium sativum). By its ability for selenium (Se) bio-accumulation, garlic can turn into an attractive option of selenized food. Selenium is an essential micronutrient for many organisms including plants, animals, and humans. It is an important trace element due to its antioxidant properties and plays a main role in prevention of cancer and cardiovascular diseases. Nowadays, there is an increasing interest in the study of Se speciation due to the different roles that each species manifests in toxicological and nutrition fields. However, Se exhibits a narrow interval between toxicity and essentiality, which is puzzling toxicologists and alarming nutritionists and legislators. In the present review, an overview on the development of selenized garlic studies and its potential implementation in Argentine production is exposed. The development of novel foods with added value such us selenized garlic could be an attractive alternative for local market. Moreover, it becomes a good offering for factory owners, considering that Mendoza represents about 85% of total garlic production in the country

Selectivity of DNA polymerases toward α and β nucleotide substrates of d and l series

AbstractThe substrate properties of four carbocyclic d and l nucleoside 5′-triphosphate analogs toward HIV and AMV reverse transcriptases and terminal deoxynucleotidyl transferase were evaluated. The compounds of the d-β and l-β series were found to be terminating substrates for these enzymes, while the derivatives of the d-α and l-α series were recognized only by terminal deoxynucleotidyl transferase, suggesting that for the template-independent enzyme the mutual orientation of the two fragments is of no significance. A hypothesis for binding of nucleotides to the DNA polymerase active center was proposed