273 research outputs found

    Two-dimensional Quasi-bessel beam synthesis and frequency-scanning leaky-wave launchers

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    In this paper, a technique to synthesize a 2D frequency-scanned high order Bessel beam in a parallel plates waveguide (PPW) scenario is presented. This technique is based on a one dimensional beam launcher, rather than the more typical axicons or the more recent metasurfaces and antenna arrays for 3D Bessel beam synthesis. With this launcher, it is possible to generate a 2D Bessel beams whose direction can be controlled by changing the frequency of the feeding signal in the Ku band from 14.5 GHz to 15 GHz. It is demonstrated how this can be done by combination of two leaky waves (LW), which can be created by the same 1D structure, scanning at different angles and launched to the PPW region. The beams are generated in a triangular area, with one of its sides being the launcher itself and the other sides are defined by the direction of radiation of each of the forming leaky wave

    The noni anthraquinone damnacanthal is a multi-kinase inhibitor with potent anti-angiogenic effects

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    Este es el manuscrito que fue aceptado y que finalmente se publicó en Cancer Letters con el DOI: 10.1016/j.canlet.2016.10.037The natural bioactive compound damnacanthal inhibits several tyrosine kinases. Herein, we show that -in fact- damancanthal is a multi kinase inhibitor. A docking and molecular dynamics simulation approach allows getting further insight on the inhibitory effect of damnacanthal on three different kinases: vascular endothelial growth factor receptor-2, c-Met and focal adhesion kinase. Several of the kinases targeted and inhibited by damnacanthal are involved in angiogenesis. Ex vivo and in vivo experiments clearly demonstrate that, indeed, damnacanthal is a very potent inhibitor of angiogenesis. A number of in vitro assays contribute to determine the specific effects of damnacanthal on each of the steps of the angiogenic process, including inhibition of tubulogenesis, endothelial cell proliferation, survival, migration and production of extracellular matrix remodeling enzyme. Taken altogether, these results suggest that damancanthal could have potential interest for the treatment of cancer and other angiogenesisdependent diseases.Supported by grants BIO2014-56092-R (MINECO and FEDER), P12-CTS-1507 (Andalusian Government and FEDER) and funds from group BIO-267 (Andalusian Government). The "CIBER de Enfermedades Raras" is an initiative from the ISCIII (Spain). JAGV had the financial support of Vicerrectorado de Investigación y Transferencia (University of Málaga, Spain). The funders had no role in the study design, data collection and analysis, decision to publish or preparation of the manuscript

    The enzymatic determination of glucose in carbonated beverages: a useful tool for the undergraduate students to learn the basis of enzymatic analysis and the comparison of two analytical methods

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    The importance of enzymatic analysis in biochemistry, clinical chemistry and food chemistry is undoubted. The course "Applied Biochemistry" in our Faculty is aimed to undergraduate students of Chemistry and Biochemistry. In this subject, the principles and applications of enzymatic analysis are presented to the students, who receive a theoretical introductory lecture in the classroom before they carry out an experiment that should be feasible to be solved in a short laboratory period. The experimental protocol here presented, based on the enzymatic determination of glucose in carbonated beverages, has been implemented at the University of Málaga and it has been optimized according to the students’ results and commentaries along the last years. It aims to illustrate basic issues relating enzymatic analysis, including its potential application to food chemistry. Although there are several enzymatic methods that can be used for the determination of glucose, we selected the one based on the coupled reactions of glucose oxidase (GOD; EC 1.1.3.4.) and peroxidase (POD; EC 1.11.1.7.) because the kinetic constants of glucose oxidase allow the mentioned enzymatic reactions to be used in both, the end point and the kinetic enzymatic analysis methods. In this way, data for two different protocols for the determination of glucose concentration are obtained by the students from a single reaction mixture. Students construct a calibration curve for each method using a glucose standard solution, and use them to determine the glucose concentration in the problem solutions. The inclusion of replicate samples in the determination of the glucose concentration of an “ideal problem” (glucose in purified water) is used to illustrate the principles of statistics in the lab, and comparison with the “real value” allows an estimation of the accuracy of each method. The evaluation of glucose concentration in four carbonated beverages: coloured coke and uncoloured tonic sodas (regular or sugarless in both cases) makes student to recognise the appearance of interferences that should be either avoided or eliminated. Since all samples are analysed by means of end-point and kinetic methods, students can discuss the applicability of each method to these specific analytical problems. They are also encouraged to compare both analytical methods in terms of sensitivity, selectivity, accuracy, and time consumed. Chemistry and Biochemistry undergraduate students having performed this experiment in our laboratories have found it formative, interesting and challenging.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    A practice project to prevent the cookbook model as modus operandi for biochemistry laboratory learning

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    Laboratory learning is a crucial component of chemistry and biochemistry instruction and should be conceived as a way to develop students’ reasoning, technical or practical skills, introducing them into the scientific method principles. Nevertheless, the heavily criticized “expository instruction style”, characterized by a cookbook nature, is still the most widespread style of laboratory instruction in our universities. Alternative learning styles based in the inquiry, discovery and problem-based pedagogical approaches, have been reported to promote students’ problem solving skills, critical thought and self-confidence development. We are currently involved in the Educative Innovation Project PIE17-065, funded by University of Malaga, aimed to improve the teaching practice of Biochemistry laboratory to undergraduate students. Based on an enzymatic analysis of glucose in soft-drinks we have developed a laboratory protocol as a part of a full practice project where students must work before and after the lab session, in order to prevent the cookbook model as modus operandi, therefore preventing the situation where the students get a first glimpse of the experiment protocol whereas they put on their lab coat. The learning activities have been designed to move our students from the passive role that characterizes the step-by-step procedures, to an active and critical attitude that starts before and remains after their laboratory session, also minimizing time, space, and equipment resources. Our results have shown that this experiment has improved the learning of both, future biochemists and chemists, which showed a very positive perception of the whole practical project.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. PIE 17-06

    Firing behaviour of Tertiary, Cretaceous and Permo-Triassic clays from Castellon ceramic cluster (Spain)

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    This study is focused on the knowledge of clays historically used in manufacturing of ceramic pavement and coatings from the province of Castellon (NE, Spain) with a large ceramic industry. This research began in the early 1980s in the research group led by Professor T. Sanfeliu and continues today. This review paper and the last advances in knowledge have been written in honor of Professor E. Galán, one of the pioneers in the study of ceramic clays and kaolin in Spain. The objective of this paper is to extract conclusions about mineralogy, porosity and bending strength in ceramic test bodies manufactured using Tertiary-age, Cretaceous and Permo–Triassic local clays. Tertiary clays show a high CaO content and their predominant mineral phases are calcite and quartz. Cretaceous clays show a scarce CaO content. These Cretaceous raw materials are clays with high quartz and illite percentages. Permo–Triassic clays present a difference in the K2O and Fe2O3 content. The mineralogical composition is mainly formed by quartz, clay minerals and hematites. Ceramic test bodies were molded by extrusion and undergoing a firing process. Characterization of the fired clays was accomplished by TOM and XRD. Granular texture and porphyry structure, quartz phenocrysts and opaque hematite crystals were observed. Illitic clays rich in carbonates form plagioclases, wollastonite and gehlenite from 950 °C. In samples with low content in calcite and dolomite, the predominant mineral phases are quartz and hematite from 1000 °C onwards. A mercury porosimeter was used for determining the porous texture of ceramic matrix. A progressive reduction in open porosity and an increase of bending strength are observed with increasing temperature. The essays for bending strength were carried out by an INSTRON. A decline in porosity was observed when temperature rise associated with an increase in bending strength. Establishing relations between bending strength and the seven parameters studied link to the porous behaviour of the ceramic tests it was not possible because empirical equations do not fit experimental results

    Propuesta para la integración de expresiones temporales procedentes de patrimonio documental en un SIG

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    En este artículo se propone una metodología para la integración de un corpus histórico procedente de textos originales en un Sistema de Información Geográfica (SIG), donde destaca la incorporación de los aspectos temporales del corpus en la base de datos de un SIG. Para ello, se ha utilizado el lenguaje de marcado TimeML que facilita la comunicación entre los SIG y la información procedente de patrimonio cultural. Al amparo de este campo de estudio, el presente trabajo tiene dos objetivos fundamentales: por un lado, la identificación y normalización de expresiones temporales, y por otro lado, la incorporación de la variable temporal extraída de corpus históricos en los SIG

    Learning contract, co-operative and flipped learning as useful tools for studying metabolism

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    Es el Abstract de una comunicación a un congreso internacional sobre educaciónUndergraduate students in Biology identify Metabolic Biochemistry as a particularly difficult subject. This is due to the fact that students need to interconnect properly all the contents of its syllabus throughout their study of the subject in order to get a global insight of the complex regulatory features controlling metabolic pathways within the metabolic network under different physiologic and pathologic conditions, as well as metabolism as a whole. Due to these objective difficulties, a high percentage of our students face the study of this subject as a very hard task beyond their forces and capacities. This perception leads to high rates of premature dropout. In previous years, less than 40% of all the registered students attended the examinations of Metabolic Biochemistry (a subject in the second year of the Degree of Biology at our University). Even worse, less than 25% of our students passed the exams. From the academic year 2015/16 on, we are developing innovative teaching projects (PIE15-163 and PIE17-145, funded by University of Malaga) aimed to increase our student loyalty to the subject (and hence to increase their attendance to exams) and to help them to learn more effectively metabolism and its regulation. These innovative teaching projects are based on the use of several powerful tools: a learning contract and problem-based learning within the framework of group tasks promoting an actual collaborative learning in a flipped classroom. The present communication will show the implementation of the PIE15-163 and PIE17-145 projects and some results obtained from them.This work was supported by Malaga University funds granted to the educational innovation project PIE17-145. The attendance to the END2018 International Conference on Education and New Developments (June 2018, Budapest, Hungary) has received a grant from "I Plan Propio Integral de Docencia. Universidad de Málaga"]

    A mobile terminal leaky-wave antenna for efficient 5G communication

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    The millimeter-wave 37 –43.5GHz band is proposed to provide the requested multigigabit-per-second (Gb/s) data rates for future 5G cellular communications. As a total wireless-link gain of 37 dBi may be required, the mobile terminal antennas should provide 12 dBi gain –being the remaining 25 dBi for the base station antennas. This high gain is linked to the synthesis of narrow directive radiated beam, which must somehow be scanned into space over a wide field of view (FoV), and thus satisfy the mobility and coverage conditions. Such high-gain beam-scanning antenna design is very challenging, taking into account that high radiation efficiency, compact size/volume, and low-cost are key features for mass-market mm-wave applications. In this sense, most of the proposed 5G mobile-antenna solutions are based on phased arrays, which rely on active scanning/beam-forming networks which might be impractical due to an increase cost and manufacturing complexity. However, owning to their characteristics of high-gain, simple-feeding, planar structure, and inherent frequency-beam-scanning behavior, leaky-wave antennas (LWAs) might offer an interesting solution for high-gain low-cost scanning

    RSSI-Based direction-of-departure estimation in bluetooth low energy using an array of frequency-steered leaky-wave antennas

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    This paper presents a novel advanced Bluetooth Low Energy (BLE) beacon, which is based on an array of frequency-steered leaky-wave antennas (LWAs), as a transmitter for a Direction-of-Departure (DoD) estimation system. The LWA array is completely passive, fabricated in a low-cost FR4 printed-circuit board and designed to multiplex to different angular directions in space each one of the three associated BLE advertising channels that are used for periodically transmitting the ID of the beacon. This way, the use of more expensive hardware associated to electronic phased-array steering/beam-switching is avoided. Four commercial BLE modules are connected to the four ports of the array, producing an advanced BLE beacon that synthesizes twelve directive beams (one per each port and advertising channel) distributed over a wide Field of View (FoV) of 120 degrees in the azimuthal plane. Then, any BLE enabled IoT device located within this FoV can scan the messages from the beacon and obtain the corresponding Received Signal Strength Indicator (RSSI) of these twelve beams to estimate the relative DoD by using amplitude-monopulse signal processing, thus dispensing from complex In-phase/Quadrature (IQ) data acquisition or high computational load.We propose an angular windowing technique to eliminate angular ambiguities and increase the angular resolution, reporting a root mean squared angular error of 3.7º in a wide FoV of 120º.This work was supported in part by the Spanish National projects TEC2016-75934-C4-4-R and TEC2016-76465-C2-1-R, and in part by the 2018 UPCT Santander Research Grant

    Incorporating TimeML into a GIS

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    This study approaches a methodology for the integration of temporal information belonging to a historical corpus in a Geographic Information System (GIS), with the purpose of analyzing and visualizing the textual information. The selected corpus is composed of business letters of the Castilian merchant Simón Ruiz (1553-1597), in the context of the DynCoopNet Project (Dynamic Complexity of Cooperation-Based Self-Organizing Commercial Networks in the First Global Age), that aims to analyze the dynamic cooperation procedures of social networks. The integration of historical corpus into a GIS has involved the following phases: (1) recognition and normalization of temporal expressions and events in 16th century Castilian following the TimeML annotation guidelines and (2) storage of tagged expressions into a Geodatabase. The implementation of this process in a GIS would allow to later carrying out temporal queries, dynamic visualization of historical events and thus, it addresses the recognition of human activity patterns and behaviours over tim
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