444 research outputs found

    Evaluation of the Magnetic Field Generated by the Inverter of an Electric Vehicle

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    In hybrid and electric vehicles, passengers sit very close to an electric system of significant power, which means that they may be subjected to high electromagnetic fields. The hazards of long-term exposure to these fields must be taken into account when designing electric vehicles and their components. Among all the electric devices present in the power train, the electronic converter is the most difficult to analyze, given that it works with different frequencies. In this paper, a methodology to evaluate the magnetic field created by a power electronics converter is proposed. After a brief overview of the recommendations of electromagnetic fields exposure, the magnetic field produced by an inverter is analyzed using finite element techniques. The results obtained are compared to laboratory measurements, taken from a real inverter, in order to validate the model. Finally, results are used to draw some conclusions regarding vehicle design criteria and magnetic shielding efficiency

    Energy Storage Systems for Electric Vehicles: Performance Comparison based on a Simple Equivalent Circuit and Experimental Tests

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    The decision to select the most suitable type of energy storage system for an electric vehicle is always difficult, since many conditionings must be taken into account. Sometimes, this study can be made by means of complex mathematical models which represent the behavior of a battery, ultracapacitor or some other devices. However, these models are usually too dependent on parameters that are not easily available, which usually results in nonrealistic results. Besides, the more accurate the model, the more specific it needs to be, which becomes an issue when comparing systems of different nature. This paper proposes a practical methodology to compare different energy storage technologies. This is done by means of a linear approach of an equivalent circuit based on laboratory tests. Via these tests, the internal resistance and the self-discharge rate are evaluated, making it possible to compare different energy storage systems regardless their technology. Rather simple testing equipment is sufficient to give a comparative idea of the differences between each system, concerning issues such as efficiency, heating and self-discharge, when operating under a certain scenario. The proposed methodology is applied to four energy storage systems of different nature for the sake of illustration

    Molecular characterization of autophagic and apoptotic signaling induced by sorafenib in liver cancer cells

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    Sorafenib is the unique accepted molecular targeted drug for the treatment of patients in advanced stage of hepatocellular carcinoma. The current study evaluated cell signaling regulation of endoplasmic reticulum (ER) stress, c-Jun-N-terminal kinase (JNK), Akt, and 5′AMP-activated protein kinase (AMPK) leading to autophagy and apoptosis induced by sorafenib. Sorafenib induced early (3–12 hr) ER stress characterized by an increase of Ser51P-eIF2α/eIF2α, C/EBP homologous protein (CHOP), IRE1α, and sXBP1, but a decrease of activating transcription factor 6 expression, overall temporally associated with the increase of Thr183,Tyr185P-JNK1/2/JNK1/2, Thr172P-AMPKα, Ser413P-Foxo3a, Thr308P-AKt/AKt and Thr32P-Foxo3a/Foxo3a ratios, and reduction of Ser2481P-mammalian target of rapamycin (mTOR)/mTOR and protein translation. This pattern was related to a transient increase of tBid, Bim EL, Beclin-1, Bcl-xL, Bcl-2, autophagy markers, and reduction of myeloid cell leukemia-1 (Mcl-1) expression. The progressive increase of CHOP expression, and reduction of Thr308P-AKt/AKt and Ser473P-AKt/AKt ratios were associated with the reduction of autophagic flux and an additional upregulation of Bim EL expression and caspase-3 activity (24 hr). Small interfering-RNA (si-RNA) assays showed that Bim, but not Bak and Bax, was involved in the induction of caspase-3 in sorafenib-treated HepG2 cells. Sorafenib increased autophagic and apoptotic markers in tumor-derived xenograft model. In conclusion, the early sorafenib-induced ER stress and regulation of JNK and AMPK-dependent signaling were related to the induction of survival autophagic process. The sustained drug treatment induced a progressive increase of ER stress and PERK-CHOP-dependent rise of Bim EL, which was associated with the shift from autophagy to apoptosis. The kinetic of Bim EL expression profile might also be related to the tight balance between AKt- and AMPK-related signaling leading to Foxo3a-dependent BIM EL upregulation.Ministerio de Economía y Competitividad BFU2016‐75352‐PInstituto de Salud Carlos III PI15/00034, PI13/ 00021, PI16/00090, PI14/01349Ministerio de Educación FPU16/05127, FPU12/01433, FPU13/01237Junta de Andalucía CTS-6264, PI-00025-2013, PI-0127-2013, PI-0198-201

    Integral Field Spectroscopy based H\alpha\ sizes of local Luminous and Ultraluminous Infrared Galaxies. A Direct Comparison with high-z Massive Star Forming Galaxies

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    Aims. We study the analogy between local U/LIRGs and high-z massive SFGs by comparing basic H{\alpha} structural characteristics, such as size, and luminosity (and SFR) surface density, in an homogeneous way (i.e. same tracer and size definition, similar physical scales). Methods. We use Integral Field Spectroscopy based H{\alpha} emission maps for a representative sample of 54 local U/LIRGs (66 galaxies). From this initial sample we select 26 objects with H{\alpha} luminosities (L(H{\alpha})) similar to those of massive (i.e. M\ast \sim 10^10 M\odot or larger) SFGs at z \sim 2, and observed on similar physical scales. Results. The sizes of the H{\alpha} emitting region in the sample of local U/LIRGs span a large range, with r1/2(H{\alpha}) from 0.2 to 7 kpc. However, about 2/3 of local U/LIRGs with Lir > 10^11.4 L\odot have compact H{\alpha} emission (i.e. r1/2 < 2 kpc). The comparison sample of local U/LIRGs also shows a higher fraction (59%) of objects with compact H{\alpha} emission than the high-z sample (25%). This gives further support to the idea that for this luminosity range the size of the star forming region is a distinctive factor between local and distant galaxies of similar SF rates. However, when using H{\alpha} as a tracer for both local and high-z samples, the differences are smaller than the ones recently reported using a variety of other tracers. Despite of the higher fraction of galaxies with compact H{\alpha} emission, a sizable group (\sim 1/3) of local U/LIRGs are large (i.e. r1/2 > 2 kpc). These are systems showing pre-coalescence merger activity and they are indistinguishable from the massive high-z SFGs galaxies in terms of their H{\alpha} sizes, and luminosity and SFR surface densities.Comment: Accepted for publication in A&A. (!5 pages, 7 figures, 2 tables

    Síntesis y aplicación de nuevas nanopartículas de plata biocompatibles para el control del crecimiento de bacterias lácticas y acéticas en vinos

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    Este libro recoge el amplio y significativo elenco de estudios (microbiología) recientemente realizados por los grupos de investigación de la red GIENOL (Grupos de investigación enológica).-- et al.Es bien conocido que la plata tiene propiedades antimicrobianas muy potentes. Actualmente, la nanoplata es el nanomaterial más utilizado, representando aproximadamente la cuarta parte de todos los nanomateriales comercializados en el mercado. El presente trabajo tiene por objetivo explorar la potencial utilización de nuevas nanopartículas de plata como agentes antimicrobianos en enología, como una alternativa al empleo de los sulfitos. En primer lugar, se ha llevado a cabo la síntesis y caracterización de dos materiales de plata: PEG‐Ag NPs 1, nanopartículas sólidas soportadas sobre polietilenglicol, y GSH‐Ag NPs 2, nanopartículas en solución soportadas sobre glutatión. A continuación, se ha evaluado su actividad antimicrobiana frente a un total de 11 especies, que incluyen bacterias lácticas y bacterias acéticas. Se han establecido los parámetros de inhibición bacteriana, comprobándose que los nanomateriales con recubrimientos a base de ambos polímeros solubles (polietilenglicol y glutatión), son capaces de inhibir el crecimiento de ambos tipos de bacterias, y en concreto, el efecto inhibidor sobre las bacterias acéticas, fue superior al del metabisulfito potásico. También se ha estudiado el mecanismo de acción antimicrobiano de las nanopartículas de plata, en el que parece que están implicados cambios en la membrana plasmática de la célula bacteriana con pérdida de la viabilidad celular y de las funciones vitales de la célula.Los autores agradecen la financiación recibida del Ministerio de Economía y Competitividad (MINECO) a través de los proyectos PRI‐PIBAR‐2011‐1358 y AGL2012‐40172‐C02‐01.Peer Reviewe

    The impact of environmental effects on AGN: a decline in the incidence of ionized outflows

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    AGN have been generally considered to be less frequent in denser environments due to the lower number of galaxy-galaxy interactions and/or the removal of their gas-rich reservoirs by the dense intergalactic medium. However, recent observational and theoretical works suggest that the effect of ram-pressure stripping might reduce the angular momentum of their gas, causing it to infall towards the super massive black hole (SMBH) at their centre, activating the AGN phase. In this work we explore the connection between environment and nuclear activity by evaluating the variation in the incidence of ionized outflows in AGN across different environments. We select a sample of 3300\sim3300 optical AGN from the Sloan Digital Sky Survey Data Release 13 that we match with the group catalogue from Lim et al. 2017. We further probe their environment through the projected distance to the central galaxy of the group/cluster and the projected surface density to the 5th neighbour (δ5\delta_5). We find that at lower masses (<1010.3<10^{10.3}M_{\odot}), the fraction of ionized outflows is significantly lower in satellite (7\sim7%) than in isolated (22\sim22%) AGN. The fraction of outflows in all satellite AGN decreases towards closer distances to the central, whereas only the lower-mass ones display a significant decline with δ5\delta_5. Although this study does not include AGN in the densest regions of galaxy clusters, our findings suggest that AGN in dense environments accrete less gas than those in the field potentially due to the removal of the gas reservoirs via stripping or starvation, consistent with a negative connection between environment and AGN activity. We propose that the observed change in the incidence of outflows towards denser regions of groups and clusters could contribute to the higher gas metallicities of cluster galaxies compared to field ones, especially at lower masses.Comment: 9 pages, 6 figures, Accepted for publication in Astronomy and Astrophysic

    Volatile and phenolic composition of a Chardonnay wine treated with antimicrobial plant extracts before malolactic fermentation

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    This work is licensed under a Creative Commons Attribution 3.0 License.Previous studies have proven the potential of antimicrobial plant extracts to delay malolactic fermentation (MLF) in red wines. With the final end of extending their applicability in oenology, the aim of this study was to investigate whether the addition of antimicrobial extracts (from eucalyptus leaves and almond skins) to white wines (i.e., Chardonnay wine), as a way to control MLF, would affect wine organoleptic properties, in particular those related to their volatile and phenolic composition. Although addition of both extracts led to statistically significant changes (p<0.05) in the concentration of several volatile and phenolic compounds, only few of them showed contents higher than their sensory thresholds, meaning that the changes observed in their concentration could slightly affect the final wine aroma and astringency. However, use of the extracts in the elaboration of white wines needs to be assessed in future experiments at winery scale, including wine sensorial analysis.This work has been funded by the Spanish Ministry for Science and Innovation (AGL2006-04514, AGL2009-13361-C02-00 and CSD2007-00063 Consolider Ingenio 2010 FUN-C-FOOD Projects), and the Comunidad de Madrid (ALIBIRD P2009/AGR-1469 Project). JJRB and AGR are the recipients of a fellowship from the JAE-Doc Program (CSIC) and DANONE Institute, respectively.Peer Reviewe

    Slower growth during lactation rescues early cardiovascular and adipose tissue hypertrophy induced by fetal undernutrition in rats

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    Low birth weight (LBW) and accelerated growth during lactation are associated with cardiometabolic disease development. LBW offspring from rats exposed to undernutrition during gestation (MUN) develops hypertension. In this rat model, we tested if slower postnatal growth improves early cardiometabolic alterations. MUN dams were fed ad libitum during gestation days 1–10, with 50% of the daily intake during days 11–21 and ad libitum during lactation. Control dams were always fed ad libitum. Pups were maintained with their own mother or cross-fostered. Body weight and length were recorded weekly, and breastmilk was obtained. At weaning, the heart was evaluated by echocardiography, and aorta structure and adipocytes in white perivascular fat were studied by confocal microscopy (size, % beige-adipocytes by Mitotracker staining). Breastmilk protein and fat content were not significantly different between groups. Compared to controls, MUN males significantly accelerated body weight gain during the exclusive lactation period (days 1–14) while females accelerated during the last week; length growth was slower in MUN rats from both sexes. By weaning, MUN males, but not females, showed reduced diastolic function and hypertrophy in the heart, aorta, and adipocytes; the percentage of beige-type adipocytes was smaller in MUN males and females. Fostering MUN offspring on control dams significantly reduced weight gain rate, cardiovascular, and fat hypertrophy, increasing beige-adipocyte proportion. Control offspring nursed by MUN mothers reduced body growth gain, without cardiovascular modifications. In conclusion, slower growth during lactation can rescue early cardiovascular alterations induced by fetal undernutrition. Exclusive lactation was a key period, despite no modifications in breastmilk macronutrients, suggesting the role of bioactive components. Our data support that lactation is a key period to counteract cardiometabolic disease programming in LBW and a potential intervention window for the mothe

    Bioaccessibility of phenolic compounds from cocoa shell subjected to in vitro digestion and its antioxidant activity in intestinal and hepatic cells

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    The cocoa shell is a by-product generated by the cocoa processing industry that could be used as a nutraceutical owing to the significant amounts of bioactive compounds it contains. This work aimed to study the bioaccessibility of phenolic compounds present in the flour (CSF) and an aqueous extract (CSE) from cocoa shells through an in vitro simulated digestion and to assess their antioxidant capacity in vitro by using intestinal and hepatic cell culture models (IEC-6 and HepG2 cells). The bioaccessibility of phenolic compounds was determined using a simulated in vitro digestion model (INFOGEST). Total phenolic compounds (TPC) and antioxidant activity were measured using in vitro techniques. Reactive oxygen species (ROS) were evaluated in IEC-6 and HepG2 cells after t-BOOH stimulation. TPC present in CSE were more bioaccessible than phenolic compounds present in CSF. During digestion, the bioaccessibility of phenolic compounds from CSF fluctuated in the gastric (2.8 mg/g), intestinal (7.6 mg/g), and colonic (5.7 mg/g) phases. Similarly, for the phenolics of CSE, the bioaccessibility increased from 50.6 mg/g in the gastric phase to 53.4 mg/g in the intestinal phase and decreased in the colonic phase to 37.2 mg/g. The in vitro antioxidant capacity followed a similar behavior, increasing throughout the digestion in CSF (8.8- to 10.6-fold) and CSE (6.0- to 7.4-fold). Digested CSF and CSE were not cytotoxic for IEC-6 and HepG2 cells and protected their viability under oxidative stress conditions (93–100%). t-BOOH-induced ROS were prevented by CSF (72–88%) and CSE (81–94%) bioaccessible fractions in both intestinal and hepatic cells. In conclusion, cocoa shells are a source of potentially bioavailable antioxidant phenolic compounds that may protect cells from oxidative stress
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