134 research outputs found
Agua y desequilibrio geográfico: estudio sobre vulnerabilidad hídrica en la región tlaxcalteca
La vulnerabilidad hídrica es un tema poco estudiado en la región del Matlalcueye,Tlaxcala, México. Las diferencias en acceso que la caracterizan no son evidentes,razones que llevaron a la elaboración del presente trabajo, que muestra cómo este factor se presenta en una región aparentemente homogénea, pero donde el acceso al agua entre comunidades urbanas y rurales depende de la ubicación geográfica de las localidades, la densidad poblacional, la localización de fuentes de abastecimiento; todo ello con independencia de las características culturales y étnicas de su población
Yogur desnatado con transglutaminasa microbiana: evaluación de la aceptación del consumidor
The decrease in the fat content of yoghurt causes sensory modifications. Microbial transglutaminase (TG) has been proposed as an alternative for reducing the problems caused by the fat reduction. This work deals with the evaluation of the sensory profile, acceptance and preferences of skim yoghurt produced with TG at pilot scale. A group of 124 consumers of yoghurts were randomly selected. A lower firmness has been observed in yoghurt without TG (NoTG). TG Yoghurt has shown a lower whey odor and less acid taste than NoTG yoghurt. Free whey was not observed in the TG yoghurt. Despite of those differences, consumers only observed minor textural differences. In terms of overall acceptance and preference, no statistically significant differences were observed. The use of TG avoids the addition of milk protein or other texture additives into the yoghurt, decreasing production cost with the same overall acceptance and preference by consumers.La disminución del contenido graso del yogur provoca modificaciones sensoriales. La transglutami- nasa microbiana (TG) se ha propuesto como una alternativa para reducir los problemas causados por la reducción de grasa. Este trabajo trata sobre la evaluación del perfil sensorial, la aceptación y la preferencia del yogur desnatado producido con TG en una planta piloto. Un grupo de 124 consumidores de yogures fueron seleccionados al azar. Una menor firmeza se observó en el yogur sin TG (NoTG). EL yogur con TG mostró menor olor a suero, menor sabor ácido que el yogur NoTG. No se observó suero en el yogur con TG. A pesar de esas diferencias, los consumidores solo observaron pequeñas diferencias de textura. En términos de aceptación global y preferencia, no se observaron diferencias estadísticamente significativas. El uso de TG evita la adición de proteínas de la leche u otros aditivos para mejorar la textura del yogur, lo que reduce los costes de producción manteniéndose la aceptación y preferencia por parte de los consumidores.This research was supported by MICINN (Spain) [Project No. RTC2014- 1835-2] and Consellería de Cultura, Educación e Ordenación Universitaria, Xunta de Galicia (ES) [Project No. ED431B 2016/009]S
Double-template fabrication of three-dimensional porous nickel electrodes for hydrogen evolution reaction
[EN] Three-dimensional (3D) porous nickel structures were fabricated via a double-template electrochemical deposition process. The construction of the foam structures was achieved by means of a hydrogen bubble dynamic template, prepared from Cu electrodeposition at high current densities. Subsequently, a Ni layer was electrodeposited on the Cu 3D template. During the nickel coating, the typical finger-like microstructure of the Cu foam becomes denser and changes to a cauliflower microstructure. The hydrogen evolution reaction (HER) on these macroporous Ni electrodes was evaluated in 30 wt.% KOH solution by means of polarization curves and electrochemical impedance spectroscopy (EIS). Results demonstrate greater apparent activity of the developed electrodes towards HER in comparison with commercial smooth Ni electrode. The 3D porous Ni electrocatalyst obtained from Cu templates synthesized at the lowest current density and the highest electrodeposition time yielded the best electrochemical activity for HER. © 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.Isaac Herraiz-Cardona is grateful to the Ministerio de Educacion (Spain) for a postgraduate grant (Ref. AP2007-03737). This work was supported by Generalitat Valenciana (PROMETEO/2010/023) and Universidad Politecnica de Valencia (PAID-06-10-2227).Herraiz-Cardona, I.; Ortega Navarro, EM.; Vázquez-Gómez, L.; Pérez-Herranz, V. (2012). Double-template fabrication of three-dimensional porous nickel electrodes for hydrogen evolution reaction. International Journal of Hydrogen Energy. 37(3):2147-2156. https://doi.org/10.1016/j.ijhydene.2011.09.155S2147215637
Electrochemical characterization of a NiCo/Zn cathode for hydrogen generation
[EN] Hydrogen is considered to be the most promising candidate as a future energy carrier. One of the most used technologies for the electrolytic hydrogen production is alkaline water electrolysis. However, due to the high energy requirements, the cost of hydrogen produced in such a way is high. In continuous search to improve this process using advanced electrocatalytic materials for the hydrogen evolution reaction (HER), high area NiCo/Zn electrodes were prepared on AISI 304 stainless steel substrates by electrodeposition. After preparing, the alloys were leached of to remove part of the zinc and generate a porous layer (type Raney electrodes). The presence of a thin Ni layer between the substrate and the Raney coating favour the adherence of the latter. The porous NiCo/Zn electrode was characterized by SEM, EDX, confocal laser microscopy, and electrochemical impedance spectroscopy. HER on this electrode was evaluated in 30 wt.% KOH solution by means of polarization curves, hydrogen discharge curves, and galvanostatic tests. Results show that the developed electrode presents a most efficient behaviour for HER when comparing with the smooth Ni cathode. The high electrode activity was mainly attributed to the high surface area of the developed electrode. © 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.Isaac Herraiz-Cardona is grateful to the Ministerio de Ciencia e Innovacion (Spain) for a postgraduate grant (Ref. AP2007-03737). This work was supported by Generalitat Valenciana (Project PROMETEO/2010/023).Herraiz-Cardona, I.; Ortega Navarro, EM.; Vázquez-Gómez, L.; Pérez-Herranz, V. (2011). Electrochemical characterization of a NiCo/Zn cathode for hydrogen generation. International Journal of Hydrogen Energy. 36(18):11578-11587. https://doi.org/10.1016/j.ijhydene.2011.06.067S1157811587361
The HER in alkaline media on Pt-modified three-dimensional Ni cathodes
[EN] Electrodeposited porous Ni layers and commercial Ni foams were submitted to spontaneous deposition of Pt, achieved by immersing the Ni substrates in H2PtCl6 solutions, at open circuit, to produce Pt-modified 3D Ni electrodes. When using Ni foams, the immersion was prolonged until the whole amount of H2PtCl6 in the solution had reacted. Such an approach, which granted an easy control of the Pt loading, could not be used for Ni trodeposits, since they underwent significant corrosion. The true Pt surface area was determined by measuring, for each electrode, the hydrogen desorption charge according to methods described in the literature. The ratios between Pt surface area and Pt loading were higher for Ni foam electrodes than for porous Ni electrodeposits. Both kinds of Pt-modified Ni electrodes were used as cathodes for hydrogen evolution in 1 M KOH. Cathodes with Pt loading below 0.5 mg cm(-2) (referred to geometric surface area) evolved hydrogen at -100 mA cm(-2) with a -75 mV overpotential. The better activity of foam electrodes as compared to electrodeposits, especially at low Pt loading, was mainly due to their higher Pt surface area per unit Pt mass. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.The authors from IENI-CNR acknowledge the financial support of the Italian Ministry for Economic Development (MSE) - MSE-CNR Agreement on National Electrical System. I. Herraiz-Cardona is grateful to the Ministerio de Educacion of Spain for a post-graduate grant (Ref. AP2007-03737). The authors are indebted to Dr. Arianna Gambirasi, ICIS CNR, Padova, Italy for recording SEM images and to FILA INDUSTRIA CHIMICA SPA, San Martino di Lupari, Padova, Italy, owner of the Fei-ESem FEI Quanta 200 FEG instrument, for allowing its use for the research work described in this article.Fiameni, S.; Herraiz Cardona, I.; Musiani, M.; Pérez-Herranz, V.; Vázquez-Gómez, L.; Verlato, E. (2012). The HER in alkaline media on Pt-modified three-dimensional Ni cathodes. International Journal of Hydrogen Energy. 37(14):10507-10516. https://doi.org/10.1016/j.ijhydene.2012.04.100S1050710516371
Oxide-oxide galvanic displacement reactions: Effect of the concentration of the ions released by the sacrificial oxide
Abstract Galvanic displacement reactions between a solid oxide and a dissolved metal cation are interesting processes for the preparation of oxide nanoparticles or electrocatalytic layers consisting of secondary mixed oxides. Their mechanism is not yet fully clarified. The composition of the secondary mixed oxides and their growth rate depend on many physical and chemical variables. In the present study, we have focused on the effects of the concentration of the ions released from the sacrificial oxide to the solution, when they are intentionally added to reaction media. We have studied the displacement of sacrificial PbO2 by either Mn2+ or Co2+ cations in acetate solution that contained variable concentrations of Pb2+, using electrochemical methods, SEM-EDS and XPS. The evolution of the open circuit potential of the systems was monitored during the reactions. We have found that, for both divalent cations, increasing concentrations of Pb2+ ions in the acetate solutions caused the formation of mixed oxides richer in Pb. Effects on growth rate and equilibrium potential were different for Mn2+ and Co2+
Bovine macrophages responses to the infection with virulent and attenuated Leptospira interrogans serovar Pomona
Leptospirosis is a zoonosis, caused by pathogenic spirochetes of the genus Leptospira. Although cattle are usually the maintenance hosts of serovar Hardjo, Pomona is the most frequent serovar circulating in Argentina. The understanding of bovine innate immune response and the virulence of this serovar is important for future control measures. This work compares infection of bovine macrophages with the virulent L. interrogans sv Pomona strain AKRFB (P1) and its attenuated counterpart (P19). First, we confirmed attenuation in the hamster model. Mortality and lung hemorrhages occurred after P1 inoculation, while the survival rate was 100% in P19-infected animals. Cells infected with both strains showed statistically upregulated gene expression of pro-inflammatory cytokines, IL-1β, IL-6 and TNFα. The level of expression of anti-inflammatory cytokine IL-10 was statistically different between strains. Increased expression of IL-10 was observed only in P1-infected cells. For the first time, we describe macrophages extracellular traps induced by infection of bovine macrophages (bMETs) with both, the virulent and attenuated Leptospira interrogans Pomona strains. P1 was found higher internalized when the phagocytosis was inhibited, suggesting a cell entrance of this strain also by an independent-phagocytosis pathway. Furthermore, P1 was higher colocalized with acidic and late endosomal compartments compared with P19. This data emphasizes the importance to deepen in Leptospira bovine macrophages particular invasion mechanisms and, furthermore, underline the value of studying the main hosts.Fil: Nagel, Ariel Gastón. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Vázquez, Cristina Lourdes. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Etulain, Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Blanco, Federico Carlos. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Gravisaco, Maria José. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Gómez, Ricardo Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Caimi, Karina Cynthia. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; Argentin
Sensory descriptive analysis and hedonic consumer test for Galician type breads
Bread consumption has declined in recent years due to the loss of its sensory quality. To identify the key sensory attributes for the consumer, in this study will provide to the bakery industry with a powerful tool to design products adapted to the consumer preferences will be provided to the bakery industry.
For identifying the key attributes 7 Galician breads were evaluated by a trained panel using 22 attributes using the Quantitative Descriptive Analysis. In addition, a sensory acceptance test carried out by 97 consumers provided hedonic evaluations.
The results of the joint analysis (trained panel and consumers) demonstrated that the loaves with the moistest bread crumb, with a predominance of large cells, and an alveolation with non-uniform distribution were the ones that presented the greatest acceptance.
The use of an artisanal production process (sourdough and long fermentation time) and the incorporation into the recipe of indigenous flour (around 40%) improved the acceptance of the Galician breadS
Percepción de los estudiantes de Kinesiología y Fisioterapia sobre la calidad del aula virtual
Introduction: The COVID-19 pandemic has caused teaching in higher education institutions around the world to drastically change from physical to virtual mode. Objective: To know the perception of Kinesiology and Physiotherapy students in Paraguay about the quality of the virtual classroom in the context of the COVID-19 pandemic. Methodology: observational, exploratory, descriptive, cross-sectional, prospective study, with non-probability sampling, of consecutive cases. An online instrument was shared through social networks and messaging applications, in order to study sociodemographic and socioeconomic characteristics, as well as those related to educational quality. For the latter, the “Cuestionario de Evaluación de la Calidad de los cursos virtuales de Educación Social, Calidad General del Entorno y de la Metodología Didáctica” by Santoveña Casal was used. Results: 331 students participated in the research. 74.62% were female with a mean age of 23.06±4.9. 93.35% used the virtual classroom for the first time. Regarding the quality of the virtual classroom, 45.62% of the participants stated that “some” attention is paid to the teaching-learning process and 47.43% mentioned that it is “somewhat” effective and efficient. 32.63% of the participants responded that “very little” is compensated for the economic investment with the quality of the course. Conclusion: Today there is a new task in the teaching work, and where elements of virtuality have begun to be used with the aim of not slowing down the teaching-learning processes. Our research shows that most of the participants have used a virtual classroom for the first time during this pandemic and, in addition, it allows us to have a preliminary reading on the quality of it in these complex times.Introducción: la pandemia de COVID-19 ha hecho que la enseñanza en instituciones de educación superior de casi todo el mundo cambié drásticamente de la modalidad física presencial a la virtual. Objetivo: conocer la percepción que tienen los estudiantes de Kinesiología y Fisioterapia de Paraguay sobre la calidad del aula virtual en el contexto de la pandemia de COVID-19. Metodología: estudio observacional, exploratorio, descriptivo de corte transverso, prospectivo, con muestreo no probabilístico, de casos consecutivos. Un instrumento en línea fue compartido a través de las redes sociales y aplicaciones de mensajería, con el fin de estudiar características sociodemográficas y socioeconómicas, así como aquellas relacionadas a la calidad educativa. Para esto último se utilizó el “Cuestionario de Evaluación de la Calidad de los cursos virtuales de Educación Social, Calidad General del Entorno y de la Metodología Didáctica” de Santoveña Casal. Resultados: 331 estudiantes participaron de la investigación. El 74,62 % fue del sexo femenino con una edad media de 23,06±4,9. El 93,35 % utilizó por primera vez el aula virtual. Respecto a la calidad del aula virtual, el 45,62 % de los participantes manifestó que se presta “algo” de atención al proceso de enseñanza-aprendizaje y el 47,43 % mencionó que es “algo” eficaz y eficiente. 32,63 % de los participantes respondió que “muy poco” se compensa la inversión económica con la calidad del curso. Conclusión: hoy en día existe un nuevo quehacer en las labores docentes, y donde elementos de la virtualidad han comenzado a utilizarse con el objetivo de no frenar los procesos de enseñanza-aprendizaje. Nuestra investigación pone de manifiesto que la mayoría de los participantes ha utilizado por primera vez un aula virtual durante esta pandemia y, además, nos permite tener una lectura preliminar sobre la calidad de la misma en estos tiempos tan complejos
Lysyl oxidase-like 3 is required for melanoma cell survival by maintaining genomic stability
Lysyl oxidase-like 3 (LOXL3) is a member of the lysyl oxidase family comprising multifunctional enzymes with depicted roles in extracellular matrix maturation, tumorigenesis, and metastasis. In silico expression analyses followed by experimental validation in a comprehensive cohort of human cell lines revealed a significant upregulation of LOXL3 in human melanoma. We show that LOXL3 silencing impairs cell proliferation and triggers apoptosis in various melanoma cell lines. Further supporting a pro-oncogenic role in melanoma, LOXL3 favors tumor growth in vivo and cooperates with oncogenic BRAF in melanocyte transformation. Upon LOXL3 depletion, melanoma cells display a faulty DNA damage response (DDR), characterized by ATM checkpoint activation and inefficient ATR activation leading to the accumulation of double-strand breaks (DSBs) and aberrant mitosis. Consistent with these findings, LOXL3 binds to proteins involved in the maintenance of genome integrity, in particular BRCA2 and MSH2, whose levels dramatically decrease upon LOXL3 depletion. Moreover, LOXL3 is required for efficient DSB repair in melanoma cells. Our results reveal an unexpected role for LOXL3 in the control of genome stability and melanoma progression, exposing its potential as a novel therapeutic target in malignant melanoma, a very aggressive condition yet in need for more effective treatment options
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