6,120 research outputs found
Left-right symmetric model with symmetry
We analyze the leptonic sector in the left-right symmetric model dressed with
a discrete symmetry which realizes, after weak spontaneous
breaking, a small broken \mu\lra\tau symmetry that is suggested to explain
observable neutrino oscillation data. \mu\lra\tau symmetry is broken at tree
level in the effective neutrino mass matrix due to the mass difference
in the diagonal Dirac mass
terms, whereas all lepton mixings arise from a Majorana mass matrix. In the
limit of a small breaking we determined , and the deviation from
the maximal value of , in terms of the light neutrino hierarchy
scale, , and a single free parameter of the model.Comment: 9 pages, 4 figures. Title changed and we have added one new section:
CP phase contribution. Minor corrections and references updated. Published
versio
Functional changes induced by extrusion during cocoa alkalization
[EN] Polyphenols, a group of secondary metabolites, have well-known relevant effects on human health. During traditional alkalization, this content dramatically lowers. We aimed to evaluate an alternative alkalization method based on extrusion on cocoa functional characteristics. The results showed that the antioxidant capacity and total phenolic values increased as alkali concentration and temperature did, and these values doubled under less extreme conditions. Comparing the functional properties between extruded and traditionally produced powders revealed that catechin, epicatechin and dimers B1 and B2 contents were 43%, 33%, 54% and 34% lower in the extruded samples, respectively. However, this reduction was partially balanced by increased clovamide content up to 50%. Thus the total phenol content and antioxidant capacity of the extruded samples were statistically above those of the commercial one. Hence extrusion alkalization should be considered a new processing alternative to avoid markedly reducing functional properties.This work was funded by the Spanish Government and European Regional Development Fund (Project RTC-2016-5241-2).Valverde-Garcia, D.; Behrends, B.; Pérez-Esteve, É.; Kuhnert, N.; Barat Baviera, JM. (2020). Functional changes induced by extrusion during cocoa alkalization. Food Research International. 136:1-10. https://doi.org/10.1016/j.foodres.2020.10946911013
Functional Ag-Exchanged Zeolites as Biocide Agents
"This is the peer reviewed version of the following article: Cerrillo, José Luis, Antonio Eduardo Palomares, Fernando Rey, Susana Valencia, María Bernardita Pérez-Gago, Diana Villamón, and Lluís Palou. 2018. Functional Ag-Exchanged Zeolites as Biocide Agents. ChemistrySelect 3 (17). Wiley: 4676 82. doi:10.1002/slct.201800432, which has been published in final form at https://doi.org/10.1002/slct.201800432. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."[EN] Materials based on silver are used for controlling different pathogenic microorganisms. However, the influence of the silver carrier in the biocidal activity of the material has been scarcely reported. The present research is focused on studying the influence of zeolite properties on the biocidal activity of silver-exchanged zeolites, acting as reservoirs of silver species. The biocidal action of Ag-Faujasite (Ag-FAU) and Ag-Linde Type A (Ag-LTA) zeolites, containing different silver contents, is studied against different types of bacteria and fungi. Importantly, zeolite structure is found to be a significant parameter for controlling the antibacterial activity of Ag-exchanged zeolites. The results show that Ag-FAU presents a higher activity than Ag-LTA, because the topology of FAU combined with its highest Si/Al ratio favors the formation and release of silver species with important biocidal activity. Some insights on the bactericidal mechanism of Ag-zeolites are envisaged by means of high resolution transmission electron microscopy, showing the multi-targeted biocidal action of Ag species released from zeolites. Besides, it is shown that Ag-zeolites are more active against bacteria than fungi. Antifungal activity is highly dependent on the fungi species and the structure of the zeolite is not as determinant as it is for the antibacterial activity.The authors thank the Spanish Ministry of Economy and Competitiveness through MAT-2015-71842-P and SEV-2016-0683 for the financial support and J.L. Cerrillo wish to thank Spanish Ministry of Economy and Competitiveness for the Severo Ochoa PhD fellowship (SVP-2014-068600).Cerrillo, JL.; Palomares Gimeno, AE.; Rey Garcia, F.; Valencia Valencia, S.; Pérez-Gago, MB.; Villamón-Pérez, D.; Palou-Valls, L. (2018). Functional Ag-Exchanged Zeolites as Biocide Agents. ChemistrySelect. 3(17):4676-4682. https://doi.org/10.1002/slct.201800432S46764682317Dai, D., Prussin, A. J., Marr, L. C., Vikesland, P. J., Edwards, M. A., & Pruden, A. (2017). Factors Shaping the Human Exposome in the Built Environment: Opportunities for Engineering Control. Environmental Science & Technology, 51(14), 7759-7774. doi:10.1021/acs.est.7b01097Klevens, R. M., Edwards, J. R., Richards, C. L., Horan, T. C., Gaynes, R. P., Pollock, D. A., & Cardo, D. M. (2007). Estimating Health Care-Associated Infections and Deaths in U.S. Hospitals, 2002. Public Health Reports, 122(2), 160-166. doi:10.1177/003335490712200205Busolo, M. A., Fernandez, P., Ocio, M. J., & Lagaron, J. M. (2010). Novel silver-based nanoclay as an antimicrobial in polylactic acid food packaging coatings. Food Additives & Contaminants: Part A, 27(11), 1617-1626. doi:10.1080/19440049.2010.506601Monteiro, D. R., Gorup, L. F., Takamiya, A. S., Ruvollo-Filho, A. C., Camargo, E. R. de, & Barbosa, D. B. (2009). The growing importance of materials that prevent microbial adhesion: antimicrobial effect of medical devices containing silver. International Journal of Antimicrobial Agents, 34(2), 103-110. doi:10.1016/j.ijantimicag.2009.01.017Jung, W. K., Koo, H. C., Kim, K. W., Shin, S., Kim, S. H., & Park, Y. H. (2008). Antibacterial Activity and Mechanism of Action of the Silver Ion in Staphylococcus aureus and Escherichia coli. Applied and Environmental Microbiology, 74(7), 2171-2178. doi:10.1128/aem.02001-07Sánchez, M. J., Mauricio, J. E., Paredes, A. R., Gamero, P., & Cortés, D. (2017). Antimicrobial properties of ZSM-5 type zeolite functionalized with silver. Materials Letters, 191, 65-68. doi:10.1016/j.matlet.2017.01.039Lalueza, P., Monzón, M., Arruebo, M., & Santamaría, J. (2011). Bactericidal effects of different silver-containing materials. Materials Research Bulletin, 46(11), 2070-2076. doi:10.1016/j.materresbull.2011.06.041Haile, T., Nakhla, G., Zhu, J., Zhang, H., & Shugg, J. (2010). Mechanistic study of the bactericidal action of silver-loaded chabasite on Acidithiobacillus thiooxidans. Microporous and Mesoporous Materials, 127(1-2), 32-40. doi:10.1016/j.micromeso.2009.06.030Saint-Cricq, P., Kamimura, Y., Itabashi, K., Sugawara-Narutaki, A., Shimojima, A., & Okubo, T. (2012). Antibacterial Activity of Silver-Loaded «Green Zeolites». European Journal of Inorganic Chemistry, 2012(21), 3398-3402. doi:10.1002/ejic.201200476Matsumura, Y., Yoshikata, K., Kunisaki, S., & Tsuchido, T. (2003). Mode of Bactericidal Action of Silver Zeolite and Its Comparison with That of Silver Nitrate. Applied and Environmental Microbiology, 69(7), 4278-4281. doi:10.1128/aem.69.7.4278-4281.2003Inglezakis, V. J. (2005). The concept of «capacity» in zeolite ion-exchange systems. Journal of Colloid and Interface Science, 281(1), 68-79. doi:10.1016/j.jcis.2004.08.082Fonseca, A. M., & Neves, I. C. (2013). Study of silver species stabilized in different microporous zeolites. Microporous and Mesoporous Materials, 181, 83-87. doi:10.1016/j.micromeso.2013.07.018Amorim, R., Vilaça, N., Martinho, O., Reis, R. M., Sardo, M., Rocha, J., … Neves, I. C. (2012). Zeolite Structures Loading with an Anticancer Compound As Drug Delivery Systems. The Journal of Physical Chemistry C, 116(48), 25642-25650. doi:10.1021/jp3093868Neves, I. C., Cunha, C., Pereira, M. R., Pereira, M. F. R., & Fonseca, A. M. (2010). Optical Properties of Nanostructures Obtained by Encapsulation of Cation Chromophores in Y Zeolite. The Journal of Physical Chemistry C, 114(24), 10719-10724. doi:10.1021/jp101001aGóra-Marek, K., Tarach, K. A., Piwowarska, Z., Łaniecki, M., & Chmielarz, L. (2016). Ag-loaded zeolites Y and USY as catalysts for selective ammonia oxidation. Catalysis Science & Technology, 6(6), 1651-1660. doi:10.1039/c5cy01446hDemirci, S., Ustaoğlu, Z., Yılmazer, G. A., Sahin, F., & Baç, N. (2013). Antimicrobial Properties of Zeolite-X and Zeolite-A Ion-Exchanged with Silver, Copper, and Zinc Against a Broad Range of Microorganisms. Applied Biochemistry and Biotechnology, 172(3), 1652-1662. doi:10.1007/s12010-013-0647-7Tekin, R., & Bac, N. (2016). Antimicrobial behavior of ion-exchanged zeolite X containing fragrance. Microporous and Mesoporous Materials, 234, 55-60. doi:10.1016/j.micromeso.2016.07.006Ferreira, L., Fonseca, A. M., Botelho, G., Aguiar, C. A.-, & Neves, I. C. (2012). Antimicrobial activity of faujasite zeolites doped with silver. Microporous and Mesoporous Materials, 160, 126-132. doi:10.1016/j.micromeso.2012.05.006Lalueza, P., Monzón, M., Arruebo, M., & Santamaria, J. (2011). Antibacterial action of Ag-containing MFI zeolite at low Ag loadings. Chem. Commun., 47(2), 680-682. doi:10.1039/c0cc03905eKawahara, K., Tsuruda, K., Morishita, M., & Uchida, M. (2000). Antibacterial effect of silver-zeolite on oral bacteria under anaerobic conditions. Dental Materials, 16(6), 452-455. doi:10.1016/s0109-5641(00)00050-6Bedi, R. S., Cai, R., O’Neill, C., Beving, D. E., Foster, S., Guthrie, S., … Yan, Y. (2012). Hydrophilic and antimicrobial Ag-exchanged zeolite a coatings: A year-long durability study and preliminary evidence for their general microbiocidal efficacy to bacteria, fungus and yeast. Microporous and Mesoporous Materials, 151, 352-357. doi:10.1016/j.micromeso.2011.10.012Chiericatti, C., Basílico, J. C., Basílico, M. L. Z., & Zamaro, J. M. (2014). Antifungal activity of silver ions exchanged in mordenite. Microporous and Mesoporous Materials, 188, 118-125. doi:10.1016/j.micromeso.2013.12.033Cerrillo, J. L., Palomares, A. E., Rey, F., Valencia, S., Palou, L., & Pérez-Gago, M. B. (2017). Ag-zeolites as fungicidal material: Control of citrus green mold caused by Penicillium digitatum. Microporous and Mesoporous Materials, 254, 69-76. doi:10.1016/j.micromeso.2017.03.036Mayoral, A., Carey, T., Anderson, P. A., & Diaz, I. (2013). Atomic resolution analysis of porous solids: A detailed study of silver ion-exchanged zeolite A. Microporous and Mesoporous Materials, 166, 117-122. doi:10.1016/j.micromeso.2012.04.033Kaur, B., Srivastava, R., Satpati, B., Kondepudi, K. K., & Bishnoi, M. (2015). Biomineralization of hydroxyapatite in silver ion-exchanged nanocrystalline ZSM-5 zeolite using simulated body fluid. Colloids and Surfaces B: Biointerfaces, 135, 201-208. doi:10.1016/j.colsurfb.2015.07.068Kwakye-Awuah, B., Williams, C., Kenward, M. A., & Radecka, I. (2008). Antimicrobial action and efficiency of silver-loaded zeolite X. Journal of Applied Microbiology, 104(5), 1516-1524. doi:10.1111/j.1365-2672.2007.03673.xSun, T., & Seff, K. (1994). Silver Clusters and Chemistry in Zeolites. Chemical Reviews, 94(4), 857-870. doi:10.1021/cr00028a001Sayah, E., Brouri, D., & Massiani, P. (2013). A comparative in situ TEM and UV–visible spectroscopic study of the thermal evolution of Ag species dispersed on Al2O3 and NaX zeolite supports. Catalysis Today, 218-219, 10-17. doi:10.1016/j.cattod.2013.06.003Satsuma, A., Shibata, J., Shimizu, K., & Hattori, T. (2005). Ag Clusters as Active Species for HC-SCR Over Ag-Zeolites. Catalysis Surveys from Asia, 9(2), 75-85. doi:10.1007/s10563-005-5993-1Hutson, N. D., Reisner, B. A., Yang, R. T., & Toby, B. H. (2000). Silver Ion-Exchanged Zeolites Y, X, and Low-Silica X: Observations of Thermally Induced Cation/Cluster Migration and the Resulting Effects on the Equilibrium Adsorption of Nitrogen. Chemistry of Materials, 12(10), 3020-3031. doi:10.1021/cm000294nFeng, Q. L., Wu, J., Chen, G. Q., Cui, F. Z., Kim, T. N., & Kim, J. O. (2000). A mechanistic study of the antibacterial effect of silver ions onEscherichia coli andStaphylococcus aureus. Journal of Biomedical Materials Research, 52(4), 662-668. doi:10.1002/1097-4636(20001215)52:43.0.co;2-3Compendium of Citrus Diseases 200
Reactivity Effects in a Very-High-Temperature Pebble-Bed Reactor
The very-high-temperature reactor (VHTR) is one of the most promising and innovative designs selected by the Generation IV International Forum. Although previous papers have focused on the study and optimization of several parameter of a VHTR conceptual design, there is still much work needed to achieve the commercial introduction of this technology. The primary aim of this study is to obtain the reactivity effects of such parameters as the temperature of the fuel, moderator, and reflector, and the poisoning by 135Xe and 149Sm in the VHTR critically. To reach this goal, the widely-used MCNP6 code was employed in order to simulate the neutronics of the VHTR. The viability of the utilization of the MCNP6 code and the developed model for the study of the physics of the VHTR core was confirmed through the calculation and comparison with benchmarks provided by the IAEA. Based on the results of the temperature coefficients of reactivity obtained, a negative reactivity effect on the system of about 12 pcm/K was found, as is expected in all the nuclear fission reactors, while the combined effect of fission products 135Xe and 149Sm implies a negative reactivity of 3475 pcm
Lepton Number Violation from Colored States at the LHC
The possibility to search for lepton number violating signals at the Large
Hadron Collider (LHC) in the colored seesaw scenario is investigated. In this
context the fields that generate neutrino masses at the one-loop level are
scalar and Majorana fermionic color-octets of SU(3). Due to the QCD strong
interaction these states may be produced at the LHC with a favorable rate. We
study the production mechanisms and decays relevant to search for lepton number
violation signals in the channels with same-sign dileptons. In the simplest
case when the two fermionic color-octets are degenerate in mass, one could use
their decays to distinguish between the neutrino spectra. We find that for
fermionic octets with mass up to about 1 TeV the number of same-sign dilepton
events is larger than the standard model background indicating a promising
signal for new physics.Comment: minor corrections, added reference
Overlapping of acoustic bandgaps using fractal geometries
The transmission of acoustic waves in a fractal distribution of rigid scatterers embedded in air is reported in this work. The Sierpinsky fractal is used to produce a compact small device containing several periodicities, therefore the fractal distribution contains several finite sonic crystals. The attenuation band produced by the fractal distribution results from the sum of the Bragg peaks of each periodicity. On the other hand, bandgaps of sonic crystal depend on the well-known filling fraction, thus the radii of the scatterers in the fractal distribution has been optimized using genetic algorithm in order to overlap the bandgaps of each periodicity obtaining a wide and full attenuation band.This work was supported by MCI (Spanish Government) and FEDER funds, under Grant Nos. MAT2009-09438 and MTM2009-14483-C02-02. The authors would like to thank Prof. K. ATTENBOROUGH and Dr. E. A. SANCHEZ-PEREZ for their suggestions and for the revision of the manuscript.Castiñeira Ibáñez, S.; Romero García, V.; Sánchez Pérez, JV.; García-Raffi, LM. (2010). Overlapping of acoustic bandgaps using fractal geometries. EPL. 92(2):240071-240073. doi:10.1209/0295-5075/92/24007S24007124007392
G Protein-Coupled Estrogen Receptor Immunoreactivity Fluctuates During the Estrous Cycle and Show Sex Differences in the Amygdala and Dorsal Hippocampus
G protein-coupled estrogen receptor (GPER) in the amygdala and the dorsal hippocampus mediates actions of estradiol on anxiety, social recognition and spatial memory. In addition, GPER participates in the estrogenic regulation of synaptic function in the amygdala and in the process of adult neurogenesis in the dentate gyrus. While the distribution of the canonical estrogen receptors α and β in the amygdala and dorsal hippocampus are well characterized, little is known about the regional distribution of GPER in these brain regions and whether this distribution is affected by sex or the stages of the estrous cycle. In this study we performed a morphometric analysis of GPER immunoreactivity in the posterodorsal medial, anteroventral medial, basolateral, basomedial and central subdivisions of the amygdala and in all the histological layers of CA1 and the dentate gyrus of the dorsal hippocampal formation. The number of GPER immunoreactive cells was estimated in these different structures. GPER immunoreactivity was detected in all the assessed subdivisions of the amygdaloid nucleus and dorsal hippocampal formation. The number of GPER immunoreactive cells was higher in males than in estrus females in the central (P = 0.001) and the posterodorsal medial amygdala (P < 0.05); higher in males than in diestrus females in the strata orients (P < 0.01) and radiatum-lacunosum-moleculare (P < 0.05) of CA1-CA3 and in the molecular layer of the dentate gyrus (P < 0.01); higher in diestrus females than in males in the basolateral amygdala (P < 0.05); higher in diestrus females than in estrus females in the central (P < 0.01), posterodorsal medial (P < 0.01) and basolateral amygdala (P < 0.01) and higher in estrus females than in diestrus females in the strata oriens (P < 0.05) and radiatum-lacunosum-moleculare (P < 0.05) of CA1-CA3 and in the molecular layer (P < 0.05) and the hilus of the dentate gyrus (P < 0.05). The findings suggest that estrogenic regulation of the amygdala and hippocampus through GPER may be different in males and in females and may fluctuate during the estrous cycle.This study was supported by Ministero dell'Istruzione, dell'Università e della Ricerca, Italy (MIUR project Dipartimenti di Eccellenza 2018–2022) to Department of Neuroscience Rita Levi Montalcini, Agencia Estatal de Investigación, Spain (BFU2017-82754-R, PSI2017-86396-P), Centro de Investigación Biomédica en Red Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid and Fondos FEDER, GRUPOS UCM-BSCH 951579. MM fellowship was generously granted by Prof. G. C. Bergui
Long-range correlations in non-equilibrium systems: Lattice gas automaton approach
In systems removed from equilibrium, intrinsic microscopic fluctuations
become correlated over distances comparable to the characteristic macroscopic
length over which the external constraint is exerted. In order to investigate
this phenomenon, we construct a microscopic model with simple stochastic
dynamics using lattice gas automaton rules that satisfy local detailed balance.
Because of the simplicity of the automaton dynamics, analytical theory can be
developed to describe the space and time evolution of the density fluctuations.
The exact equations for the pair correlations are solved explicitly in the
hydrodynamic limit. In this limit, we rigorously derive the results obtained
phenomenologically by fluctuating hydrodynamics. In particular, the spatial
algebraic decay of the equal-time fluctuation correlations predicted by this
theory is found to be in excellent agreement with the results of our lattice
gas automaton simulations for two different types of boundary conditions.
Long-range correlations of the type described here appear generically in
dynamical systems that exhibit large scale anisotropy and lack detailed
balance.Comment: 23 pages, RevTeX; to appear in Phys. Rev.
Stability of Attractive Bose-Einstein Condensates in a Periodic Potential
Using a standing light wave trap, a stable quasi-one-dimensional attractive
dilute-gas Bose-Einstein condensate can be realized. In a mean-field
approximation, this phenomenon is modeled by the cubic nonlinear Schr\"odinger
equation with attractive nonlinearity and an elliptic function potential of
which a standing light wave is a special case. New families of stationary
solutions are presented. Some of these solutions have neither an analog in the
linear Schr\"odinger equation nor in the integrable nonlinear Schr\"odinger
equation. Their stability is examined using analytic and numerical methods.
Trivial-phase solutions are experimentally stable provided they have nodes and
their density is localized in the troughs of the potential. Stable
time-periodic solutions are also examined.Comment: 12 pages, 18 figure
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