5,640 research outputs found
Hacia productos saludables elaborados con arroces ricos en melatonina.
El arroz (Oryza sativa) es un cereal fundamental para más de la mitad de la población mundial. Como alimento básico es un aporte calórico en la dieta, adicionalmente contiene melatonina, compuesto beneficioso para la salud. En resultados previos, los arroces; integral, negro y rojo poseen mayor nivel de melatonina comparándolos con otras muestras analizadas, por lo que estos fueron seleccionados para iniciar un estudio de desarrollo de nuevos productos con arroces ricos en melatonina. En esta etapa, se analizó el efecto de la cocción sobre el contenido en melatonina, manteniéndose ésta en niveles aun elevados: 138 µg/kg-1 en el arroz rojo, 95 µg/kg-1 en el arroz negro y 22 µg/Kg-1 en el arroz integral; en el arroz blanco apenas alcanzó 6 µg/kg-1. La evaluación sensorial mediante prueba de calificación hedónica de los atributos globales aspecto, olor, sabor y textura mostró que no hay diferencia en la aceptación entre las 4 variedades de arroz. Mediante encuestas se analizaron otros factores que a priori podrían influir en la aceptabilidad del producto por los consumidores, tales como, la información en el etiquetado del contenido de melatonina y su origen, los mensajes sobre su efecto beneficioso en el metabolismo, y la familiaridad con la marca
Interaction of Staphylococcus aureus and Host Cells upon Infection of Bronchial Epithelium during Different Stages of Regeneration
The primary barrier that protects our lungs against infection by pathogens is a tightly sealed layer of epithelial cells. When the integrity of this barrier is disrupted as a consequence of chronic pulmonary diseases or viral insults, bacterial pathogens will gain access to underlying tissues. A major pathogen that can take advantage of such conditions is Staphylococcus aureus, thereby causing severe pneumonia. In this study, we investigated how S. aureus responds to different conditions of the human epithelium, especially nonpolarization and fibrogenesis during regeneration using an in vitro infection model. The infective process was monitored by quantification of the epithelial cell and bacterial populations, fluorescence microscopy, and mass spectrometry. The results uncover differences in bacterial internalization and population dynamics that correlate with the outcome of infection. Protein profiling reveals that, irrespective of the polarization state of the epithelial cells, the invading bacteria mount similar responses to adapt to the intracellular milieu. Remarkably, a bacterial adaptation that was associated with the regeneration state of the epithelial cells concerned the early upregulation of proteins controlled by the redox-responsive regulator Rex when bacteria were confronted with a polarized cell layer. This is indicative of the modulation of the bacterial cytoplasmic redox state to maintain homeostasis early during infection even before internalization. Our present observations provide a deeper insight into how S. aureus can take advantage of a breached epithelial barrier and show that infected epithelial cells have limited ability to respond adequately to staphylococcal insults
Novel spatial domain integral equation formulation for the analysis of rectangular waveguide steps close to arbitrarily shaped dielectric and/or conducting posts
[EN] In this paper, a novel integral equation formulation expressed in the spatial domain is
proposed for the analysis of rectangular waveguide step discontinuities. The important novelty of the
proposed formulation is that which allows to easily take into account the electrical influence of a given
number of arbitrarily shaped conducting and dielectric posts placed close to the waveguide discontinuity.
For the sake of simplicity, and without loss of generality, the presented integral equation has been
particularized and solved for inductive rectangular waveguide geometry. In this case, the integral equation
mixed-potentials kernel is written in terms of parallel plate Green¿s functions with an additional ground
plane located on the waveguide step. Therefore, the unknowns of the problem are reduced to an equivalent
magnetic surface current on the step aperture and equivalent magnetic and electric surface currents on
the dielectric and conducting posts close to the discontinuity. The numerical solution of the final integral
equation is efficiently computed after the application of acceleration techniques for the slowly convergent
series representing the Green¿s functions of the problem. The numerical method has been validated through
several simulation examples of practical microwave devices, including compact size band-pass cavity filters
and coupled dielectric resonators filters. The results have been compared to those provided by commercial
full-wave electromagnetic simulation software packages, showing in all cases a very good agreement, and
with substantially enhanced numerical efficiencies.This research work has been financially supported by the Spanish Ministerio de Economia y Competitividad in the frame of the projects "Demostradores Tecnologicos de Filtros y Multiplexores con Respuestas Selectivas y Sintonizables en Nuevas Guias Compactas para Aplicaciones Espaciales (COMPASSES)" with Ref. TEC2016-75934-C4-1-R, and "Analisis y Diseno de Nuevos Componentes en Microondas y Milimetricas para Comunicaciones por Satelite (MILISAT)" with Ref. TEC2016-75934-C4-4-R. As an additional financial source we thank the regional agency Fundacion Seneca from Region de Murcia under the research project "Desarrollo de Antenas y Componentes Pasivos de Microondas para Sistemas Avanzados de Comunicaciones" with Ref. 19494/PI/14 and Ref. 20147/EE/17, and the PhD scholarship granted by the Spanish national Ministerio de Educacion, Cultura y Deporte with Ref. FPU15/02883. All results of this paper can be reproduced by using the data and information contained in the drawings and in the captions of the figures included in the paper.Quesada Pereira, FD.; Gomez Molina, C.; Alvarez Melcon, A.; Boria Esbert, VE.; Guglielmi, M. (2018). Novel spatial domain integral equation formulation for the analysis of rectangular waveguide steps close to arbitrarily shaped dielectric and/or conducting posts. Radio Science. 53(4):406-419. https://doi.org/10.1002/2017RS006429S406419534Arcioni , P. Bressan , M. Conciauro , G. Perregrini , L. 1997 Generalized Y-matrix of arbitrary H-plane waveguide junctions by the BI-RME method IEEE MTT-S International Microwave Symposium Digest 211 214 DenverCapolino, F., Wilton, D. R., & Johnson, W. A. (2005). Efficient computation of the 2-D Green’s function for 1-D periodic structures using the Ewald method. IEEE Transactions on Antennas and Propagation, 53(9), 2977-2984. doi:10.1109/tap.2005.854556Catina, V., Arndt, F., & Brandt, J. (2005). Hybrid surface integral-equation/mode-matching method for the analysis of dielectric loaded waveguide filters of arbitrary shape. IEEE Transactions on Microwave Theory and Techniques, 53(11), 3562-3567. doi:10.1109/tmtt.2005.857343Fructos, A. L., Boix, R. R., Mesa, F., & Medina, F. (2008). An Efficient Approach for the Computation of 2-D Green’s Functions With 1-D and 2-D Periodicities in Homogeneous Media. IEEE Transactions on Antennas and Propagation, 56(12), 3733-3742. doi:10.1109/tap.2008.2007281Guglielmi, M., & Newport, C. (1990). Rigorous, multimode equivalent network representation of inductive discontinuities. IEEE Transactions on Microwave Theory and Techniques, 38(11), 1651-1659. doi:10.1109/22.60012Hu, Y. L., Li, J., Ding, D. Z., & Chen, R. S. (2016). Analysis of Transient EM Scattering From Penetrable Objects by Time Domain Nonconformal VIE. IEEE Transactions on Antennas and Propagation, 64(1), 360-365. doi:10.1109/tap.2015.2501437Kalantari, M., & Paran, K. (2017). Analysing Metamaterial Layer by Simpler Approach Based on Mode Matching Technique. IET Microwaves, Antennas & Propagation, 11(5), 607-616. doi:10.1049/iet-map.2016.0687Mrvić, M., Potrebić, M., & Tošić, D. (2016). CompactEplane waveguide filter with multiple stopbands. Radio Science, 51(12), 1895-1904. doi:10.1002/2016rs006169Pérez-Soler, F. J., Quesada-Pereira, F. D., Cañete Rebenaque, D., Pascual-García, J., & Alvarez-Melcon, A. (2007). Efficient integral equation formulation for inductive waveguide components with posts touching the waveguide walls. Radio Science, 42(6). doi:10.1029/2006rs003591POGGIO, A. J., & MILLER, E. K. (1973). Integral Equation Solutions of Three-dimensional Scattering Problems. Computer Techniques for Electromagnetics, 159-264. doi:10.1016/b978-0-08-016888-3.50008-8Quesada Pereira , F. Boria , V. E. Gimeno , B. Cañete Rebenaque , D. Pascual Garcia , J. Alvarez Melcon , A. 2006 Investigation of multipaction phenomena in inductively coupled passive waveguide components for space applications IEEE MTT-S International Microwave Symposium Digest 246 249 San Francisco, CAPereira, F. D. Q., Esbert, V. E. B., Garcia, J. P., Ana Vidal Pantaleoni, Melcon, A. A., Tornero, J. L. G., & Gimeno, B. (2007). Efficient Analysis of Arbitrarily Shaped Inductive Obstacles in Rectangular Waveguides Using a Surface Integral-Equation Formulation. IEEE Transactions on Microwave Theory and Techniques, 55(4), 715-721. doi:10.1109/tmtt.2007.893673Quesada Pereira, F. D., Vera Castejón, P., Álvarez Melcón, A., Gimeno, B., & Boria Esbert, V. E. (2011). An efficient integral equation technique for the analysis of arbitrarily shaped capacitive waveguide circuits. Radio Science, 46(2), n/a-n/a. doi:10.1029/2010rs004458Stumpf, M., & Leone, M. (2009). Efficient 2-D Integral Equation Approach for the Analysis of Power Bus Structures With Arbitrary Shape. IEEE Transactions on Electromagnetic Compatibility, 51(1), 38-45. doi:10.1109/temc.2008.2009223Wei, X.-C., Li, E.-P., Liu, E.-X., & Cui, X. (2008). Efficient Modeling of Rerouted Return Currents in Multilayered Power-Ground Planes by Using Integral Equation. IEEE Transactions on Electromagnetic Compatibility, 50(3), 740-743. doi:10.1109/temc.2008.924392Huapeng Zhao, En-Xiao Liu, Jun Hu, & Er-Ping Li. (2014). Fast Contour Integral Equation Method for Wideband Power Integrity Analysis. IEEE Transactions on Components, Packaging and Manufacturing Technology, 4(8), 1317-1324. doi:10.1109/tcpmt.2014.232724
The competitiveness and sustainability of Scale-ups in Latin America
Este estudio es una revisión bibliográfica
centrada en la relación de la competitividad y
sostenibilidad de las Scale-Up en
Latinoamérica, concepto entendido como la
dinámica de crecer aceleradamente en función
de la habilidad de mantener un desempeño
similar o mayor en el modelo de negocio, ya
sea incrementando o reduciendo los
componentes y recursos. Se describe su
tipología, en las cuales se encuentran la
competitividad de las naciones, la
competitividad empresarial y la competitividad
industrial y se abordan sus diferentes
dimensiones, la sostenibilidad económica,
social y ecológica, dando alcance a una
comprensión general y punto de vista global
acerca de sus conceptualizaciones de manera
unificada; dentro de este estudio también se
analiza el emprendimiento asociado a la
competitividad y a la dinámica empresarial
Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV
A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay
channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7
TeV is presented. The data were collected at the LHC, with the CMS detector,
and correspond to an integrated luminosity of 4.6 inverse femtobarns. No
significant excess is observed above the background expectation, and upper
limits are set on the Higgs boson production cross section. The presence of the
standard model Higgs boson with a mass in the 270-440 GeV range is excluded at
95% confidence level.Comment: Submitted to JHE
Search for anomalous t t-bar production in the highly-boosted all-hadronic final state
A search is presented for a massive particle, generically referred to as a
Z', decaying into a t t-bar pair. The search focuses on Z' resonances that are
sufficiently massive to produce highly Lorentz-boosted top quarks, which yield
collimated decay products that are partially or fully merged into single jets.
The analysis uses new methods to analyze jet substructure, providing
suppression of the non-top multijet backgrounds. The analysis is based on a
data sample of proton-proton collisions at a center-of-mass energy of 7 TeV,
corresponding to an integrated luminosity of 5 inverse femtobarns. Upper limits
in the range of 1 pb are set on the product of the production cross section and
branching fraction for a topcolor Z' modeled for several widths, as well as for
a Randall--Sundrum Kaluza--Klein gluon. In addition, the results constrain any
enhancement in t t-bar production beyond expectations of the standard model for
t t-bar invariant masses larger than 1 TeV.Comment: Submitted to the Journal of High Energy Physics; this version
includes a minor typo correction that will be submitted as an erratu
Combined search for the quarks of a sequential fourth generation
Results are presented from a search for a fourth generation of quarks
produced singly or in pairs in a data set corresponding to an integrated
luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in
2011. A novel strategy has been developed for a combined search for quarks of
the up and down type in decay channels with at least one isolated muon or
electron. Limits on the mass of the fourth-generation quarks and the relevant
Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a
simple extension of the standard model with a sequential fourth generation of
fermions. The existence of mass-degenerate fourth-generation quarks with masses
below 685 GeV is excluded at 95% confidence level for minimal off-diagonal
mixing between the third- and the fourth-generation quarks. With a mass
difference of 25 GeV between the quark masses, the obtained limit on the masses
of the fourth-generation quarks shifts by about +/- 20 GeV. These results
significantly reduce the allowed parameter space for a fourth generation of
fermions.Comment: Replaced with published version. Added journal reference and DO
Measurement of the t t-bar production cross section in the dilepton channel in pp collisions at sqrt(s) = 7 TeV
The t t-bar production cross section (sigma[t t-bar]) is measured in
proton-proton collisions at sqrt(s) = 7 TeV in data collected by the CMS
experiment, corresponding to an integrated luminosity of 2.3 inverse
femtobarns. The measurement is performed in events with two leptons (electrons
or muons) in the final state, at least two jets identified as jets originating
from b quarks, and the presence of an imbalance in transverse momentum. The
measured value of sigma[t t-bar] for a top-quark mass of 172.5 GeV is 161.9 +/-
2.5 (stat.) +5.1/-5.0 (syst.) +/- 3.6(lumi.) pb, consistent with the prediction
of the standard model.Comment: Replaced with published version. Included journal reference and DO
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