99 research outputs found

    Algunos aspectos cinéticos de las reacciones de sólidos con cloro

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    The present paper describes detailed kinetics investigations on some selected chlorine-solid reactions through thermogravimetric measurements. The solids studied in this article include chemical pure oxides and sulfides as well as their natural bearing materials. The chlorinating agents employed are gaseous mixtures of Cl2+N2 (chlorination), Cl2+O2 (oxychlorination), and Cl2+CO (carbochlorination). Results are presented as effects of various parameters on the reaction rate of these solids with these chlorinating agents. It was observed that the reactivity of these solids towards different chlorinating agents varied widely. Sulfides could be chlorinated at room temperature, while carbochlorination of chromium (III) oxide was possible only above 500 °C. The variation of the chlorination rate of these complex materials with respect to gas velocity, composition and temperature enabled us to focus some light on the plausible reaction mechanisms and stoichiometries. The obtained results were used for selective removal of iron from chromite concentrates, extraction of valuable metals from sulfide materials, purification of MgO samples, etc.Este trabajo describe detalladas investigaciones cinéticas en algunas reacciones seleccionadas de cloro-sólido a través de medidas termogravimétricas. Los sólidos estudiados en este artículo incluyen óxidos químicos puros y sulfuros, así como sus materiales naturales de soporte. Los agentes de cloración empleados son mezclas de gases de Cl2+N2 (cloración), Cl2+O2 (oxicloración) y Cl2+CO (carbocloración). Los resultados se presentan como efecto de varios parámetros en el porcentaje de reacción de estos sólidos con los agentes de cloración. Se ha observado que la reactividad de estos sólidos a través de diferentes agentes de cloración varía ampliamente. Los sulfuros se pudieron clorar a temperatura ambiente mientras que la carbocloración del óxido de cromo (III) sólo fue posible por encima de los 500 °C. La variación del porcentaje de cloración de estos materiales complejos con respecto a la velocidad del gas, composición y temperatura permitió arrojar alguna luz en los posibles mecanismos de reacción y estequiometrías. Los resultados obtenidos se han usado para la eliminación selectiva del hierro de concentrados de cromo, extracción de metales valiosos de materiales sulfhídricos, purificación de muestras de MgO, etc.Peer reviewe

    Study of antitumor activity in breast cell lines using silver nanoparticles produced by yeast

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    In the present article, we describe a study of antitumor activity in breast cell lines using silver nanoparticles (Ag NPs) synthesized by a microbiological method. These Ag NPs were tested for their antitumor activity against MCF7 and T47D cancer cells and MCF10-A normal breast cell line. We analyzed cell viability, apoptosis induction and endocytosis activity of those cell lines and we observed that the effects of the biosynthesized Ag NPs were directly related with the endocytosis activity. Moreover, Ag NPs had higher inhibition efficacy in tumor lines than in normal lines of breast, which is due to the higher endocytic activity of tumor cells comparing to normal cells. In this way, we are demonstrating that biosynthesized Ag NPs can be an alternative for the treatment of tumors.Fil: Ortega, Francisco Gabriel. Universidad de Granada. Centro de Genómica e Investigación Oncológica; EspañaFil: Fernández Baldo, Martín Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; ArgentinaFil: Fernández, Jorge Gastón. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; ArgentinaFil: Serrano, Maria J.. Universidad de Granada. Centro de Genómica e Investigación Oncológica; EspañaFil: Sanz Ferramola, Maria Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; ArgentinaFil: Diaz Mochón, Juan J.. Universidad de Granada. Centro de Genómica e Investigación Oncológica; EspañaFil: Lorente, José Antonio. Universidad de Granada. Centro de Genómica e Investigación Oncológica; EspañaFil: Raba, Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; Argentin

    A nutritional intervention for moderate altitude endurance preparation: A case report

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    Background: Moderate altitudes carry physiological and metabolic changes that can dampen exercise performance. Fortunately, these changes can be modulated by an optimal nutritional intervention. This case study represents the first nutritional intervention of a moderate altitude athlete. These results may help to establish well-designed nutritional guidelines for moderate altitude sports athletes. Case presentation: This case study examined the effects of a 11- week nutritional intervention on body composition, muscle strength, cardiorespiratory fitness, resting and exercise nutrient oxidation, and subjective sleep quality, in a male high-level moderate altitude athlete with a very light non-exercise activity thermogenesis. During the 11-week of nutritional intervention, 2800-3500 kcal/day, 6.8-8.9 g/kg/day of carbohydrates, 1.2-1.7 g/kg/day of protein, and 1-2.5 g/kg/day of fat were prescribed. Different specific considerations were also included, such as: iron supplementation, antioxidants increment in different phases, and ergogenic aids (i.e. creatine and beta-alanine). Our results demonstrated a decrease in adiposity and an increase in fat-free mass. In parallel, the athlete improved muscle strength, and therefore endurance adaptations after a maximal effort test (i.e. enhancement of the heart rate recovery). After the intervention, the athlete not only increased the carbohydrate oxidation during exercise and resting conditions but also improved his subjective sleep quality. Conclusions: Our results suggest that a nutritional intervention based on the endurance nutritional recommendations and adapted to the altitude physiological peculiarities can induce body recomposition, improve physiological adaptations to effort, and upgrade the substrate oxidation in a moderate altitude high-level athletes.Spanish Government FPU19/01609Redes Tematicas de Investigacion Cooperativa RETIC Red SAMID RD16/0022University of Granada Plan Propio de InvestigacionJunta de Andalucia, Consejeria de Conocimiento, Investigacion y Universidades (ERDF) SOMM17/6107/UGR DOC 01151University of Granada, Plan Propio de Investigacion 2020 Programa de Contratos Puent

    Study of antitumor activity in breast cell lines using silver nanoparticles produced by yeast

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    In the present article, we describe a study of antitumor activity in breast cell lines using silver nanoparticles (Ag NPs) synthesized by a microbiological method. These Ag NPs were tested for their antitumor activity against MCF7 and T47D cancer cells and MCF10-A normal breast cell line. We analyzed cell viability, apoptosis induction, and endocytosis activity of those cell lines and we observed that the effects of the biosynthesized Ag NPs were directly related with the endocytosis activity. Moreover, Ag NPs had higher inhibition efficacy in tumor lines than in normal lines of breast cells, which is due to the higher endocytic activity of tumor cells compared to normal cells. In this way, we demonstrate that biosynthesized Ag NPs can be an alternative for the treatment of tumors.Support from Universidad Nacional de San Luis, to the Agencia Nacional de Promoción Científica y Tecnológica, from Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Argentina), and from GENYO, Centre for Genomics and Oncological Research: Pfizer-University of Granada, Andalusian Regional Government, Granada, Spain are acknowledged

    Novel purine chemotypes with activity against Plasmodium 2 falciparum and Trypanosoma cruzi

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    Malaria and Chagas disease, caused by Plasmodium spp. and Trypanosoma cruzi parasites, remain important global health problems. Available treatments for those diseases present several limitations, such as lack of efficacy, toxic side effects, and drug resistance. Thus, new drugs are urgently needed. The discovery of new drugs may be benefited by considering the significant biological differences between hosts and parasites. One of the most striking differences is found in the purine metabolism, because most of the parasites are incapable of de novo purine biosynthesis. Herein, we have analyzed the in vitro anti-P. falciparum and anti-T. cruzi activity of a collection of 81 purine derivatives and pyrimidine analogs. We firstly used a primary screening at three fixed concentrations (100, 10, and 1 µM) and progressed those compounds that kept the growth of the parasites < 30% at 100 µM to dose–response assays. Then, we performed two different cytotoxicity assays on Vero cells and human HepG2 cells. Finally, compounds specifically active against T. cruzi were tested against intracellular amastigote forms. Purines 33 (IC50 = 19.19 µM) and 76 (IC50 = 18.27 µM) were the most potent against P. falciparum. On the other hand, 6D (IC50 = 3.78 µM) and 34 (IC50 = 4.24 µM) were identified as hit purines against T. cruzi amastigotes. Moreover, an in silico docking study revealed that P. falciparum and T. cruzi hypoxanthine guanine phosphoribosyltransferase enzymes could be the potential targets of those compounds. Our study identified two novel, purine-based chemotypes that could be further optimized to generate potent and diversified anti-parasitic drugs against both parasites.SAF2016-76080-R (Spanish Ministry of Economy (AEI/FEDER, UE))PID2019-110810RB-I00 (Spanish Ministry of Science and Innovation)Generalitat of Catalonia Universities and Research Department, Spain (AGAUR; 2017SGR00924)Carlos III Health Institute (ISCIII)RICET Network for Cooperative Research in Tropical Diseases (ISCIII; RD12/0018/0010)Generalitat of Catalonia Department of Health (PERIS 2016–2010 SLT008/18/00132)Spanish Ministry of Education, Culture, and Sports (FPU grant ref. 14/00818)Spanish Ministry of Science, Innovation, and Universities through the “Centro de Excelencia Severo Ochoa 2019–2023” Program (CEX2018-000806-S)CERCA Progra

    Protein crystallization in short-peptide supramolecular hydrogels: A versatile strategy towards biotechnological composite materials

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    Protein crystallization in hydrogels has been explored with the main purpose of facilitating the growth of high quality crystals while increasing their size to enhance their manipulation. New avenues are currently being built for the use of protein crystals as source materials to create sensors and drug delivery vehicles, to name just a few. In this sense, short-peptide supramolecular hydrogels may play a crucial role in integrating protein crystals within a wider range of applications. In this article, we show that protein crystallization in short-peptide supramolecular hydrogels is feasible and independent of the type of peptide that forms the hydrogel and/or the protein, although the output is not always the same. As a general trend, it is confirmed that hydrogel fibers are always incorporated within crystals so that novel composite materials for biotechnological applications with enhanced properties are produced.This research was funded by the MICINN (Spain) projects BIO2010-6800 (JAG), CTQ2012-34778 (JJDM), and “Factoría Española de Cristalización” Consolider-Ingenio 2010 (JAG & MCM), and by Junta de Andalucía (Spain) project P12-FQM- 2721 (LAC). EDRF funds JAG, LAC & JMC. JJDM thanks MICINN for a Ramon y Cajal Fellowship and MCM thanks CSIC for her JAE Fellowshi

    Influence of the chirality of short peptide supramolecular hydrogels in protein crystallogenesis

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    For the first time the influence of the chirality of the gel fibers in protein crystallogenesis has been studied. Enantiomeric hydrogels 1 and 2 were tested with model proteins lysozyme and glucose isomerase and a formamidase from B. cereus. Crystallization behaviour and crystal quality of these proteins in both hydrogels are presented and compared.MICINN (Spain) projects BIO2010-16800 (JAG), CTQ-2011.22455 (LAC & JMC), CTQ2012-34778 (JJDM & ALG), “Factoría Española de Cristalización” Consolider-Ingenio 2010 (JAG & MCM) and EDRF Funds (JAG, LAC & JMC), P12-FQM-2721 (LAC) Junta de Andalucía.MINECO,Project No. FIS2013-41821-R

    Control of the flame front advance in a sintering bed of iron ores

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    11 páginas, 15 figuras, 4 tablas.[EN] A sintering pan of 40 cm cubed is loaded with a mixture of iron ores, limestone and coke weighing 110 kg in a sintering pilot plant. In this sintering pan, a series of thermocouples have been introduced at different depths. Tests have been carried out to study the width of the combustion zone and the maximum temperature of the flame front across the sintering bed. For the analysis of the results, a data acquisition system was used. This consisted of two modules connected in serie, for performing the analogue-digital conversion. The analogue entry point is the exit point of the thermocouples and the digital exit point was the temperature average. A computer was used for conserving and storing the data and for carrying out interpolations, simulating the state and evolution of the flame front across the bed.[ES] En una planta piloto de sinterización se cargan, en la paila cúbica de 40 cm de lado, 110 kg de una mezcla de minerales de hierro, caliza y coque, donde se han introducido una serie de termopares a diferentes profundidades. Se realizan ensayos para estudiar la evolución del ancho de la zona de combustión y de la temperatura máxima del frente de llama a través del lecho de sinterización. Para el análisis de los resultados se utiliza un sistema de adquisición de datos formado por dos módulos conectados en serie, encargados de realizar la conversión analógico-digital. La entrada analógica es la salida de los termopares y la salida digital es la medida de la temperatura. Se dispone de un ordenador para la conservación y almacenamiento de los datos y para realizar interpolaciones que simulan el estado y evolución del frente de llama a través del lecho.Peer reviewe
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