A study of catalytic metals and alkaline metal oxides leading to the development of a stable Ru-doped Ni Dual Function Material for CO2 capture from flue gas and in-situ catalytic conversion to methane

Atmospheric CO2 concentrations are at their highest level on record. Scientific evidence has demonstrated a direct correlation between the rise of CO2 levels and an increase of the global median temperature (~1°C higher than compared to the pre-industrial revolution times) due to the greenhouse gas effect. The change in climate due to this rapid increase of CO2 levels is already negatively affecting our ecosystem and lives, with unpredictable consequences in the future. The main source of anthropogenic CO2 emissions is attributed to the combustion of fossil fuels for energy production and transportation. Global indicators signal that carbon-intensive fuels will continue to be utilized as a main energy source despite the rising implementation of renewable energy sources. In order to curb CO2 emissions, several carbon dioxide capture, utilization and sequestration (CCUS) technologies have been suggested. The current state-of-the-art CO2 capture technology utilizes toxic and corrosive aqueous amine solutions that capture CO2 at room temperature but require heating above the water boiling point temperatures to separate CO2 from the amine solution; the latter of which is to be recycled. Once the CO2 is purified, it is necessary to transport it to its sequestration site or an upgrading processing plant. These are complicated schemes that involve many energy-intensive and costly processes. To address the shortcomings of these technologies, we propose a Dual Function Material (DFM) that both captures CO2 and catalytically converts it to methane in-situ. The DFM consists of a catalytic metal intimately in contact with an alkaline metal oxide supported on a high surface area carrier. The process operates within the flue gas at 320°C for both CO2 capture and methane generation upon the addition of renewable H2. The catalyst is required to methanate the adsorbed CO2 after the capture step is carried out in an O2 and steam-containing flue gas. Ruthenium, rhodium, and nickel are known CO2 methanation catalysts, provided they are in the reduced state. All three were compared for performance under DFM flue gas conditions. Ni is a preferred methanation catalyst based on price and activity; however, its inability to be reduced to its active state after experiencing O2-containing flue gas during the capture step was an outcome determined in this thesis. The performance of a variety of alkaline adsorbents (“Na2O”, CaO, “K2O” and MgO) and carriers (Al2O3, CeO2, CeO2/ZrO2 (CZO), Na-Zeolite-X (Na-X-Z), H-Mordenite Zeolite (H-M-Z), SiC, SiO2 and ZrO2-Y) were also studied. Selection of the best materials was based on CO2 capture capacity, net methane production and hydrogenation rates that were evaluated with thermogravimetric analysis and in fixed bed reactor tests. Rh and Ru DFMs were effective methanation catalysts with Ru being superior based on capture capacity, hydrogenation rate and price. Ru remained active towards methanation even after exposure to O2 and steam-containing simulated flue gas. Alkaline adsorbents, in combination with reduced Ru, were tested for adsorption and methanation. Ru – “Na2O”/Al2O3 DFMs showed the highest rates for methanation although CaO is also a reasonable candidate with slightly lower methanation kinetics. To date, we have demonstrated that -Al2O3 is the most suitable carrier for DFM application relative to other materials studied. The Ni-containing DFM, pre-reduced at 650°C, was highly active for CO2 methanation. However, the hydrogenation with 15% H2/N2 is completely inactive after exposure to O2 and steam, in a flue gas simulation, during the CO2 capture step at 320oC. This thesis reports that small amounts of precious metal (≤ 1% Pt, Pd or Ru) enhance the reduction (at 320°C) and activation of Ni-containing DFM towards methanation even after O2 exposure in a flue gas. While ruthenium is most effective, Pt and Pd all enhance reduction of oxidized Ni. Another objective of this thesis was to investigate whether a portion of the Ru, at its current loading of 5%, could be replaced with less expensive Ni while maintaining its performance. The findings show that the main advantage of the presence of Ni is a small increase in CO2 adsorption and increase in methane produced, at the expense of a lower methanation rate. Extended cyclic aging studies corroborate the stable performance of 1% Ru, 10% Ni, 6.1% “Na2O”/Al2O3. Characterization methods were used to monitor physical and chemical changes that may have occurred during aging studies. Measurements of the BET surface area, H2 chemisorption, XRD pattern, TEM images and STEM-EDS mapping were utilized to study and compare the structural and chemical changes between fresh and aged Ru doped Ni DFM samples. While similar BET surface areas were observed for the fresh and aged samples, some redispersion of the Ru and Ni sites was confirmed via H2 uptake and the observed decreases in Ru and Ni cluster size in the aged sample in comparison to the fresh. XRD patterns confirm an almost complete disappearance of the NiOx and RuOx species and the appearance of catalytically active Ru0 and Ni0 peaks on the aged sample compared to the fresh one. Further details of these methods, findings and conclusions are described in this thesis

Interferon-γ induces immunoproteasomes and the presentation of MHC I-associated peptides on human salivary gland cells.

A prominent histopathological feature of Sjögren's syndrome, an autoimmune disease, is the presence of lymphocytic infiltrates in the salivary and lachrymal glands. Such infiltrates are comprised of activated lymphocytes and macrophages, and known to produce multiple cytokines including interferon-gamma (IFN-γ). In this study, we have demonstrated that IFN-γ strongly induces the expression of immunoproteasome beta subunits (β1i, β2i and β5i) and immunoproteasome activity but conversely inhibits the expression of proteasome beta subunits (β1, β2 and β5) in human salivary gland (HSG) cells. Mass spectrometric analysis has revealed potential MHC I-associated peptides on the HSG cells, including a tryptic peptide derived from salivary amylase, due to IFN-γ stimulation. These results suggest that IFN-γ induces immunoproteasomes in HSG cells, leading to enhanced presentation of MHC I-associated peptides on cell surface. These peptide-presenting salivary gland cells may be recognized and targeted by auto-reactive T lymphocytes. We have also found that lactacystin, a proteasome inhibitor, inhibits the expression of β1 subunit in HSG cells and blocks the IFN-γ-induced expression of β1i and immunoproteasome activity. However, the expression of β2i and β5i in HSG cells is not affected by lactacystin. These results may add new insight into the mechanism regarding how lactacystin blocks the action of proteasomes or immunoproteasomes

Concepto de desarrollo humano: Caritas in Veritate y programa de desarrollo de las naciones unidas

This paper tries to put on the table some important aspects –from the perspective of social sciences –on comprehensive human development by trying to answer the following questions: Why and for what is important to under stand such concept? Why want and hunger continues to strike around the world? To answer these questions, the interpretations on comprehensive human development havebeen described in two parts: the first is how Caritas in Veritate understands this concept, and the second are the UNDP contributions to development.Este artículo trata de dar a conocer algunos aspectos importantes del desarrollo humano integral, desde la perspectiva de las ciencias sociales, respondiendo a las preguntas: ¿Por qué y para qué es importante conocer el concepto?, ¿Por qué continúa el hambre y la pobreza en el mundo? Para dar respuesta a las interrogantes se ha considerado describir las formulaciones del desarrollo humano integral en dos partes: la primera trata de cómo es abordado el concepto en la encíclica Caritas in Veritate; la segunda, presenta los aportes del PNUD al desarrollo

Efecto del ácido perfluoroctanoico (PFOA) en la generación de estrés oxidante e inducción de muerte celular en la ovogénesis temprana de ratón, in vitro

Durante el siglo XX, se ha producido un aumento de los productos en el medio ambiente que pueden ser perjudiciales para la función reproductiva en humanos. Por lo tanto, al comenzar el siglo XXI, es conveniente evaluar las futuras direcciones en el campo de la toxicología reproductiva. En las últimas décadas, millones de toneladas de productos químicos sintéticos se han fabricado y liberado al ambiente. Los humanos han estado expuestos constantemente a agentes potencialmente tóxicos ya sea de una manera directa o indirecta, y poco se sabe sobre los efectos adversos que estos pueden causar sobre las células germinales. Se ha reportado que niveles elevados de ácido perfluorooctanoico (PFOA) están relacionados con subfecundidad, en tanto que niveles elevados de compuestos perfluorados en el suero humano se han asociado con una reducción en el número de espermatozoides normales por eyaculado. Sin embargo, los efectos del PFOA en la ovogénesis de mamíferos no se ha explorado. En este estudio se determinó la toxicidad del PFOA en la ovogénesis temprana de ratón, la viabilidad de los ovocitos se determinó mediante el conteo de éstos en los explantes y con tinción de MTT. Se determinó la concentración letal 50 (CL50) de PFOA en ovocitos de ratón la cual fue de 112.86µM. Además de la viabilidad se estudiaron dos parámetros, la generación de especies reactivas de oxígeno (ERO) y el tipo de muerte celular causados por PFOA. En el caso de los dos parámetros anteriores (ERO y muerte celular) se observó que son dependientes de la concentración, generándose ERO, y muerte celular tanto necrosis como apoptosis en la concentración de 28µM (¼ de la CL50); En la concentración 112.86µM se incrementaron ambos parámetros. Este estudio aporta datos acerca del riesgo que representa este compuesto perfluorado para la ovogénesis de varias especies de mamíferos, incluida la especie humana, en tanto que el investigar el tipo de muerte celular causado por PFOA en los ovocitos será útil para entender los mecanismos moleculares por los que este xenobiótico causa daño celular.During the 20th century, there has been an increase in environmental products that may be detrimental to human reproductive function. Therefore, at the beginning of the 21st century, it is convenient to evaluate future directions in the field of reproductive toxicology. In the last decades, millions of tons of synthetic chemicals have been manufactured and released to the environment. Humans have been constantly exposed to potentially toxic agents either directly or indirectly, and little is known about the adverse effects these can cause on germ cells. Elevated levels of perfluorooctanoic acid (PFOA) have been reported to be related to subfeeding, while elevated levels of perfluorinated compounds in human serum have been associated with a reduction in the number of normal spermatozoa per ejaculate. However, the effects of PFOA on mammalian oogenesis have not been explored. In this study, we determined the toxicity of PFOA in early oogenesis of mouse, the viability of the oocytes was determined by counting them in the explants and MTT staining. The lethal 50 (LC50) concentration of PFOA in mouse oocytes was 112.86 µM. To determine the toxicity of PFOA, in addition to viability two parameters were studied: generation of reactive oxygen species (ROS) and type of cell death. In the case of the two previous parameters (ERO and cell death), they were found to be concentration dependent, generating ROS and necrotic and apoptotic cell death in the concentration of 28 µM (¼ of the LC50); At 112.86 µM both parameters were increased. This study provides data on the risk of this perfluorinated compound for oogenesis of several mammalian species, including the human species, while investigating the type of cell death caused by PFOA in oocytes will be useful for understanding the molecular mechanisms by which this xenobiotic causes cellular damage

Aplicación del programa Reggio Emilia para mejorar el pensamiento creativo en niños de 5 años de la I.E.I N°022 Semillitas del Futuro, Los Olivos 2017

La presente investigación tuvo como objetivo demostrar la eficacia de la aplicación del programa Reggio Emilia para potenciar el pensamiento creativo en niños de 5 años de una I.E. de nivel inicial del distrito de los Olivos, enfoque cuantitativo, tipo aplicada, diseño experimental, cuasi experimental propiamente dicho y de corte transversal; con una población de 36 niños y una muestra de 36 niños, para la recolección de datos se aplicó la técnica de la observación y el instrumento fue un test que midió el pensamiento creativo, la validez del instrumento se hizo a través del juicio de expertos que dieron un resultado aplicativo y la confiabilidad se determinó utilizando la “r” de Pearson. Los resultados fueron que el 75% de los niños tienen un logro previsto frente al pensamiento creativo y solo el 15% obtuvieron un logro destacado, lo que significa que el programa Reggio Emilia si influye en la mejora del pensamiento creativo

Hipoxia y las grandes alturas: el nobel de fisiología 2019

Hace casi un siglo que un peruano, renombrado investigador y catedrático de la Universidad Nacional Mayor de San Marcos, describió el mal de altura crónico(1). La descripción que realizó el doctor Carlos Monge se basó en sus hallazgos clínicos, con una profundización bastante certera para los métodos fisiológicos y bioquímicos a su alcance en dicha época. Con el transcurrir de los años, muchos investigadores estudiaron cuáles son los mecanismos que subyacen ante la hipoxia y cómo las células responden ante ella, dentro de este grupo de Investigadores se encuentra el doctor Gregg L. Semenza, quien luego de un acucioso trabajo logró describir que existía un grupo de proteínas que eran inducidas por la hipoxia, que llamó factor inducido por hipoxia HIF(2), dichas proteínas juegan un rol importante en la respuesta a la hipoxia y en procesos de adaptación que se produce en los habitantes de las grandes alturas

Alfabetización Digital: ¿Qué y para qué?

Título: Alfabetización Digital: ¿Qué y para qué?, Capítulo I, II y III, Evaluación Total, Autores y Referencia

Posttransplant Thrombopoiesis Predicts Survival in Patients Undergoing Autologous Hematopoietic Progenitor Cell Transplantation

AbstractThe frequency and clinical significance of secondary thrombocytopenia following initial engraftment in autologous hematopoietic progenitor cell transplantation (HPCT) is unknown. An institutional review board approved retrospective study of thrombopoiesis was performed in 359 patients transplanted with autologous blood (97%) or marrow (3%) who achieved platelet engraftment to >50,000/μL. Idiopathic secondary posttransplant thrombocytopenia (ISPT) was defined as >50% decline in blood platelets to <100,000/μL in the absence of relapse or sepsis. ISPT occurred at a median of day +35 posttransplant in 17% of patients. Patients with ISPT had similar initial platelet engraftment (median 17 days) versus non-ISPT patients (18 days; P = NS) and recovered platelet counts (median 123,00 K/μL) by day 110 posttransplant. Four factors were independently associated with post-transplant death in a multivariate model: disease status at transplant; the number of prior chemotherapy regimens, failure to achieve a platelet count of >150,000/μL posttransplant, and the occurrence of ISPT. A prognostic score was developed based upon the occurrence of ISPT and posttransplant platelet counts of <150,000/μL. Survival of patients with both factors (n = 25) was poor (15% alive at 5 years); patients with 1 factor (n = 145) had 49% 5-year survival; patients with 0 factors (n = 189) had 72% 5-year survival. Patients who failed to achieve a platelet count of >150,000/μL received significantly fewer CD34+ cells/kg (P < .001), whereas patients with ISPT received fewer CD34+CD38− cells/kg (P = .0006). The kinetics of posttransplant thrombopoiesis is an independent prognostic factor for long-term survival following autologous HPC. ISPT and lower initial posttransplant platelet counts reflect poor engraftment with long-term and short-term repopulating CD34+ hematopoietic stem cells, respectively, and are associated with an increased risk of death from disease relapse

Seguridad alimentaria en México: reforma del estado y modernización administrativa

El presente trabajo tiene por objetivo el dar respuesta a la pregunta: ¿De qué manera la estructura y el funcionamiento del Estado y la Administración Pública se relacionan con la Seguridad Alimentaria en México? Ello se logrará a través de un enfoque de investigación mixto/holístico que permitirá llevar a cabo el análisis de las Reformas del Estado Mexicano y de los procesos más relevantes implementados para la Modernización Administrativa en materia de Seguridad Alimentaria. Así como también, se podrá observar que las acciones emprendidas han generado que la producción interna de alimentos se incremente y que la balanza agroalimentaria se encuentre en una etapa superavitaria, lo cual da como resultado que exista el acceso físico de alimentos al interior del país, tal y como lo plantean los preceptos de la Seguridad Alimentaria