2,025 research outputs found

    Elaboración de bioplástico usando la cáscara de Musa × paradisiaca (plátano) recolectada del mercado Modelo, Chiclayo

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    El presente trabajo de investigación tuvo como objetivo principal, elaborar bioplástico usando cáscara de Musa × paradisiaca (plátano) recolectada del mercado Modelo, Chiclayo. Se utilizó este residuo orgánico, ya que, es una de las frutas que más se comercia en dicho lugar, siendo un desecho útil para la elaboración de bioplástico. El tipo de investigación fue descriptiva, la población está conformada por todos los desechos de cáscara de Musa × paradisiaca (plátano), la muestra está conformada por 2.5 Kg de Musa × paradisiaca. Primero se recolectó los 2.5 kg de plátano, luego se descascaró consiguiendo 468g de cáscaras, por consiguiente, se ejecutó 3 procedimientos para elaborar bioplásticos; 145 g, 154g y 169g respectivamente usando materiales como glicerina, vinagre blanco, maicena y agua. El bioplástico producido por el tercer procedimiento obtuvo mejor calidad de resistencia y flexibilidad ya que se le redujo la cantidad de agua. Por consiguiente, se realizó ensayos de biodegradabilidad del producto del bioplástico por un periodo de 7 días, se pusieron 3 muestras de 5 cm de largo y ancho cada una en agua, suelo húmedo y temperatura ambiente respectivamente. Finalmente, con el producto de elaboración se fabricó un envase de bioplástico en forma de sobre con unas medidas de 20 cm de largo y 8.5 cm de ancho, concluyendo que los residuos de la cáscara de Musa × paradisiaca (plátano) son eficientes para la elaboración de bioplástico, ya que, proporciona buena resistencia, elasticidad y flexibilidad

    Structural, optical and vibrational properties of ZnO:M (M=Al3+ and Sr2+) nano and micropowders grown by hydrothermal synthesis

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    Powders of ZnO and ZnO:M (M = Al3+ and Sr2+) with 1 and 4% of M nominal content were synthetized by a hydrothermal method in a diethanolamine (DEA) medium. The samples were studied by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), micro-Raman and photoluminescence (PL). The powder particles were spherical with average radius decreasing from 1 μm down to 70 nm with increasing Al3+ nominal content but nearly independent on the Sr2+ nominal content. The XRD and micro-Raman results indicate that both Al3+ and Sr2+ mostly incorporated substitutionally into the ZnO lattice, giving rise to compressive and tensile strain, respectively, as a result of ionic radii differences. The PL spectra for ZnO:Al exhibit a dopant-induced contribution at ∼3.1 eV, which is not observed for ZnO:Sr, due to radiative transitions involving trapping of photocarriers at theoretically expected substitutional Al3+ donor states or at Zn interstitial defects.Fil: Marín Ramírez, Oscar Alonso. Universidad Nacional de Tucumán. Instituto de Física del Noroeste Argentino. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Física del Noroeste Argentino; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Laboratorio de Física del Sólido; ArgentinaFil: Soliz, Tania. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología; ArgentinaFil: Gutierrez, Jorge Andrés. Universidad del Quindío. Facultad de Ciencias Básicas y Tecnológicas; ColombiaFil: Tirado, Monica Cecilia. Universidad Nacional de Tucumán. Instituto de Física del Noroeste Argentino. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Física del Noroeste Argentino; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Física. Departamento de Nanomateriales y Propiedades Dieléctricas; ArgentinaFil: Figueroa, Carlos. Universidad Nacional de Tucumán. Instituto de Física del Noroeste Argentino. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Física del Noroeste Argentino; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Laboratorio de Física del Sólido; ArgentinaFil: Comedi, David Mario. Universidad Nacional de Tucumán. Instituto de Física del Noroeste Argentino. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Física del Noroeste Argentino; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Laboratorio de Física del Sólido; Argentin

    Intercultural and digital competence in teacher training from an international perspective: Poland Portugal, Slovakia, Spain and Russia

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    This article presents one of the studies from the European project IRNET, a network that pursues the development of new tools and methods for advanced pedagogical science in the field of ICT instruments, elearning and intercultural competences. We intend to explore the application of international and national policies of innovative, digital Education and intercultural competences in teacher training, as well as innovative educational practices. Another objective of the project is also to identify such practises and/or research projects in order to foster intercultural and digital competences in Spain, Poland , Slovak, Portugal and Russia. From a comparative perspective and on a qualitative paradigm, we have analyzed three comparative units that have allowed, among other things, us to look at the impact of projects financed with European or national funds as promoters of change and innovation related to intercultural training and technologies information. Finally, it has been observed that teaching trends point to a professorship endowed with skills that integrate intercultural models from the joint search for the school of the future, and for that online networks and virtual learning communities are key resources

    The UPMSat-2 Satellite: an academic project within aerospace engineering education

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    Today, project-based learning is a well-known methodology in engineering education. In the IDR/UPM Institute of Universidad Politécnica de Madrid (UPM), different lines of research have been developed to involve students into projects related to aerodynamics (both theoretical and experimental), fluid dynamics on low gravity, and space science (heat transfer).Although these lines of research were initially related to the Ph.D. programs integrated within the academic plan of the university, the increasing interest among the bachelor and master students on research and projects linked to the most advanced engineering techniques, prompted the IDR/UPM academic staff to offer some specific projects to these students as their final degree thesis. In the present work, the UPMSat-2 satellite project is analyzed as an academic tool to involve different groups of students into a big project,encouraging them not only to develop specific skills in relation to a single subsystem of the satellite, but also to harmonize their work with the results from other groups of students working on other different subsystems.The different groups of students were directed by the professors of the IDR/UPM Institute. These students being mainly from two different degrees at UPM: Bachelor’s Degree in Aerospace Engineering and Master’s Degree in Space Systems (MUSE). The main difference between these two groups being the amount of work carried out to fulfill the degree requirements. For the Bachelor’s Degree in Aerospace Engineering, a 300-hour average project is required, whereas for the Master’s Degree in Space Systems this limit increases to 450 hours. Taking into account the aforementioned figures, the importance of having motivated students is crucial. In this sense, a project like the UPMSat-2 has revealed itself as a formidable way to gather students and professors around a common engineering task. It should be pointed out that this kind of satellite, a 50-kg spacecraft, allows a more complex engineering management when compared to the cubesats (that is, engineering operations such as testing, integration or harnessing are closer to the ones related to commercial or military aircraft). Besides, as the UPMSat-2 is used as a platform to qualify space technologies for engineering enterprises (Iberespacio, Bartington, SSVB, Tecnobit, Arquimea…), students are in contact with commercial enterprises from the space sector, this fact being also important in order to increase their motivation. In the present work the educational benefits of the UPMSat-2 program in relation to the Master’s Degree in Space Systems (MUSE) are thoroughly described, some examples of the projects carried out by the students being summarized. satellite design, space technology, project-based learning, active learning

    Toward industrial production of isoprenoids in Escherichia coli: Lessons learned from CRISPR-Cas9 based optimization of a chromosomally integrated mevalonate pathway

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    Escherichia coli has been the organism of choice for the production of different chemicals by engineering native and heterologous pathways. In the present study, we simultaneously address some of the main issues associated with E. coli as an industrial platform for isoprenoids, including an inability to grow on sucrose, a lack of endogenous control over toxic mevalonate (MVA) pathway intermediates, and the limited pathway engineering into the chromosome. As a proof of concept, we generated an E. coli DH1 strain able to produce the isoprenoid bisabolene from sucrose by integrating the cscAKB operon into the chromosome and by expressing a heterologous MVA pathway under stress-responsive control. Production levels dropped dramatically relative to plasmid-mediated expression when the entire pathway was integrated into the chromosome. In order to optimize the chromosomally integrated MVA pathway, we established a CRISPR-Cas9 system to rapidly and systematically replace promoter sequences. This strategy led to higher pathway expression and a fivefold improvement in bisabolene production. More interestingly, we analyzed proteomics data sets to understand and address some of the challenges associated with metabolic engineering of the chromosomally integrated pathway. This report shows that integrating plasmid-optimized operons into the genome and making them work optimally is not a straightforward task and any poor engineering choices on the chromosome may lead to cell death rather than just resulting in low titers. Based on these results, we also propose directions for chromosomal metabolic engineering

    Production of jet fuel precursor monoterpenoids from engineered Escherichia coli

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    Monoterpenes (C10 isoprenoids) are the main components of essential oils and are possible precursors for many commodity chemicals and high energy density fuels. Monoterpenes are synthesized from geranyl diphosphate (GPP), which is also the precursor for the biosynthesis of farnesyl diphosphate (FPP). FPP biosynthesis diverts the carbon flux from monoterpene production to C15 products and quinone biosynthesis. In this study, we tested a chromosomal mutation of Escherichia coli's native FPP synthase (IspA) to improve GPP availability for the production of monoterpenes using a heterologous mevalonate pathway. Monoterpene production at high levels required not only optimization of GPP production but also a basal level of FPP to maintain growth. The optimized strains produced two jet fuel precursor monoterpenoids 1,8-cineole and linalool at the titer of 653 mg/L and 505 mg/L, respectively, in batch cultures with 1% glucose. The engineered strains developed in this work provide useful resources for the production of high-value monoterpenes. Biotechnol. Bioeng. 2017;114: 1703-1712. © 2017 Wiley Periodicals, Inc

    Renewable production of high density jet fuel precursor sesquiterpenes from <i>Escherichia coli</i>

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    Abstract Background Aviation fuels are an important target of biofuels research due to their high market demand and competitive price. Isoprenoids have been demonstrated as good feedstocks for advanced renewable jet fuels with high energy density, high heat of combustion, and excellent cold-weather performance. In particular, sesquiterpene compounds (C15), such as farnesene and bisabolene, have been identified as promising jet fuel candidates. Results In this study, we explored three sesquiterpenes—epi-isozizaene, pentalenene and α-isocomene—as novel jet fuel precursors. We performed a computational analysis to calculate the energy of combustion of these sesquiterpenes and found that their specific energies are comparable to commercial jet fuel A-1. Through heterologous MVA pathway expression and promoter engineering, we produced 727.9 mg/L epi-isozizaene, 780.3 mg/L pentalenene and 77.5 mg/L α-isocomene in Escherichia coli and 344 mg/L pentalenene in Saccharomyces cerevisiae. We also introduced a dynamic autoinduction system using previously identified FPP-responsive promoters for inducer-free production and managed to achieve comparable amounts of each compound. Conclusion We produced tricyclic sesquiterpenes epi-isozizaene, pentalenene and α-isocomene, promising jet fuel feedstocks at high production titers, providing novel, sustainable alternatives to petroleum-based jet fuels

    Design and rationale of a multicentre, randomised, double-blind, placebo-controlled clinical trial to evaluate the effect of vitamin D on ventricular remodelling in patients with anterior myocardial infarction: the VITamin D in Acute Myocardial Infarction (VITDAMI) trial

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    Introduction:Decreased plasma vitamin D (VD) levels are linked to cardiovascular damage. However, clinical trials have not demonstrated a benefit of VD supplements on left ventricular (LV) remodelling. Anterior ST-elevation acute myocardial infarction (STEMI) is the best human model to study the effect of treatments on LV remodelling. We present a proof-of-concept study that aims to investigate whether VD improves LV remodelling in patients with anterior STEMI. Methods and analysis:The VITamin D in Acute Myocardial Infarction (VITDAMI) trial is a multicentre, randomised, double-blind, placebo-controlled trial. 144 patients with anterior STEMI will be assigned to receive calcifediol 0.266 mg capsules (Hidroferol SGC)/15 days or placebo on a 2:1 basis during 12 months. Primary objective:to evaluate the effect of calcifediol on LV remodelling defined as an increase in LV end-diastolic volume >= 10\% (MRI). Secondary objectives:change in LV end-diastolic and end-systolic volumes, ejection fraction, LV mass, diastolic function, sphericity index and size of fibrotic area; endothelial function; plasma levels of aminoterminal fragment of B-type natriuretic peptide, galectin-3 and monocyte chemoattractant protein-1; levels of calcidiol (VD metabolite) and other components of mineral metabolism (fibroblast growth factor-23 (FGF-23), the soluble form of its receptor klotho, parathormone and phosphate). Differences in the effect of VD will be investigated according to the plasma levels of FGF-23 and klotho. Treatment safety and tolerability will be assessed. This is the first study to evaluate the effect of VD on cardiac remodelling in patients with STEMI. Ethics and dissemination: This trial has been approved by the corresponding Institutional Review Board (IRB) and National Competent Authority (Agencia Espanola de Medicamentos y Productos Sanitarios (AEMPS)). It will be conducted in accordance with good clinical practice (International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use-Good Clinical Practice (ICH-GCP)) requirements, ethical principles of the Declaration of Helsinki and national laws. The results will be submitted to indexed medical journals and national and international meetings.The VITDAMI trial is an investigator initiated study, sponsored by the Instituto de Investigacion Sanitaria Fundacion Jimenez Diaz (IIS-FJD). Funding has been obtained from Fondo de Investigaciones Sanitarias (PI14/01567; http://www.isciii.es/) and Spanish Society of Cardiology (http://secardiologia.es/). In addition, the study medication has been provided freely by the pharmaceutical Company FAES FARMA S.A. (Leioa, Vizcaya, Spain; http://faesfarma.com/). This company was the only funder who collaborated in study design (IG-H).S

    Salt lakes of La Mancha (Central Spain): A hot spot for tiger beetle (Carabidae, Cicindelinae) species diversity

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    The tiger beetle assemblage of the wetlands of La Mancha (central Spain) comprises nine species: Calomera littoralis littoralis, Cephalota maura maura, Cephalota circumdata imperialis, Cephalota dulcinea, Cicindela campestris campestris, Cicindela maroccana, Cylindera paludosa, Lophyra flexuosa flexuosa, and Myriochila melancholica melancholica. This assemblage represents the largest concentration of tiger beetles in a single 1º latitude / longitude square in Europe. General patterns of spatial and temporal segregation among species are discussed based on observations of 1462 specimens registered during an observation period of one year, from April to August. The different species of Cicindelini appear to be distributed over space and time, with little overlapping among them. Three sets of species replace each other phenologically as the season goes on. Most of the species occupy drying or dried salt lakes and salt marshes, with sparse vegetation cover. Spatial segregation is marked in terms of substrate and vegetation use. Calomera littoralis and M. melancholica have been observed mainly on wet soils; C. circumdata on dry open saline flats; C. dulcinea and C. paludosa in granulated substrates with typical halophytic vegetation; C. maura is often present in man-modified areas. Cephalota circumdata and C. dulcinea are included as species of special interest in the list of protected species in Castilla–La Mancha. Conservation problems for the Cicindelini assemblage arise from agricultural activities and inadequate use of sport vehicles. Attempts at restoring the original habitat, supressing old semi-industrial structures, may affect the spatial heterogeneity of the lakes, and have an effect on Cicindelinae diversity.This study was possible thanks to the support from the Fundación Global Nature through the European Life European Community Project Humedales de La Mancha (LIFE10 NAT/ES/000563), Spanish Ministry of Agriculture, Food and Environment and to the facilities provided by the Museo Nacional de Ciencias Naturales (MNCN-CSIC).Peer reviewe
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