362 research outputs found

    Effect of Oak Chip Addition at Different Winemaking Stages on Phenolic Composition of Moravia Agria Red Wines

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    This study compared changes in the phenolic composition of Moravia Agria wine and its effect on colour,co-pigmentation as well as on physicochemical properties, such as antioxidant capacity, caused by addingoak chips at different stages of the winemaking process. Moravia Agria control wine was made followingtraditional winemaking processes, without oak chips. Oak chips were added to the rest of the wines attwo dose rates (3 and 6 g/L) at different stages of the winemaking process: for one week during alcoholicfermentation, during malolactic fermentation and in young red Moravia Agria wine. Only slight significantdifferences were found in phenolic composition, antioxidant activity and chromatic characteristics betweenthe Moravia Agria wines treated with oak chips and the control wine. However, oak chip addition slightlydecreased the content of non-polymeric red pigments (monomeric anthocyanins and pyranoanthocyanins)and also of resveratrol-monomer stilbenes. It is suggested that oak chip addition to Moravia Agria winescan be selected as part of the targeted sensory profile (relative intensity of sensory descriptors providedby grape and oak wood), since only a few changes have been observed in the phenolic profiles, antioxidantcapacity value and colour characteristics

    MicroRNA Profiling and Bioinformatics Target Analysis in Dorsal Hippocampus of Chronically Stressed Rats: Relevance to Depression Pathophysiology

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    Indexación: Scopus.1Laboratory of Neuroplasticity and Neurogenetics, Faculty of Chemical and Pharmaceutical Sciences, Department of Biochemistry and Molecular Biology, Universidad de Chile, Santiago, Chile, 2National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Durham, NC, United States, 3Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago, Chile, 4Millennium Institute for Integrative Biology (iBio), FONDAP Center for Genome Regulation, Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, Santiago, Chile, 5Department of Kinesiology, Faculty of Health Sciences, Universidad Católica del Maule, Talca, Chile, 6Escuela de Química y Farmacia, Facultad de Medicina, Universidad Andres Bello, Santiago, Chile.This study was supported by the following grants: FONDECYT 1120528 (JLF), Fondo Central de Investigación, Universidad de Chile ENL025/16 (JLF), ES090079 (JAC). Research in RG and EV laboratories is funded by Instituto Milenio iBio – Iniciativa Científica Milenio MINECON.Studies conducted in rodents subjected to chronic stress and some observations in humans after psychosocial stress, have allowed to establish a link between stress and the susceptibility to many complex diseases, including mood disorders. The studies in rodents have revealed that chronic exposure to stress negatively affects synaptic plasticity by triggering changes in the production of trophic factors, subunit levels of glutamate ionotropic receptors, neuron morphology, and neurogenesis in the adult hippocampus. These modifications may account for the impairment in learning and memory processes observed in chronically stressed animals. It is plausible then, that stress modifies the interplay between signal transduction cascades and gene expression regulation in the hippocampus, therefore leading to altered neuroplasticity and functioning of neural circuits. Considering that miRNAs play an important role in post-transcriptional-regulation of gene expression and participate in several hippocampus-dependent functions; we evaluated the consequences of chronic stress on the expression of miRNAs in dorsal (anterior) portion of the hippocampus, which participates in memory formation in rodents. Here, we show that male rats exposed to daily restraint stress (2.5 h/day) during 7 and 14 days display a differential profile of miRNA levels in dorsal hippocampus and remarkably, we found that some of these miRNAs belong to the miR-379-410 cluster. We confirmed a rise in miR-92a and miR-485 levels after 14 days of stress by qPCR, an effect that was not mimicked by chronic administration of corticosterone (14 days). Our in silico study identified the top-10 biological functions influenced by miR-92a, nine of which were shared with miR-485: Nervous system development and function, Tissue development, Behavior, Embryonic development, Organ development, Organismal development, Organismal survival, Tissue morphology, and Organ morphology. Furthermore, our in silico study provided a landscape of potential miRNA-92a and miR-485 targets, along with relevant canonical pathways related to axonal guidance signaling and cAMP signaling, which may influence the functioning of several neuroplastic substrates in dorsal hippocampus. Additionally, the combined effect of miR-92a and miR-485 on transcription factors, along with histone-modifying enzymes, may have a functional relevance by producing changes in gene regulatory networks that modify the neuroplastic capacity of the adult dorsal hippocampus under stress. © 2018 Muñoz-Llanos, García-Pérez, Xu, Tejos-Bravo, Vidal, Moyano, Gutiérrez, Aguayo, Pacheco, García-Rojo, Aliaga, Rojas, Cidlowski and Fiedler.https://www.frontiersin.org/articles/10.3389/fnmol.2018.00251/ful

    Synthesis and characterization of polymer/silica/QDs fluorescent nanocomposites with potential application as printing toner

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    In this work cadmium telluride quantum dots (CdTeQDs) were prepared via one-pot synthesis microwave assisted. Afterwards, CdTeQDs/silica (SiO2)/nigrosine (nigro)/poly (styrene co-methyl methacrylate) (PSCMM) fluorescent nanocomposite (CSNP) powders were prepared via ultrasonic treatment and post drying at 60 °C. The samples were characterized by UV-vis absorbance, x-ray diffraction (XRD) and transmission electron microscopy (TEM). Finally, successful printing tests were performed on security paper at 130 °C. These results show the potential of this nanocomposite to be used as security toner. This printing toner configuration is reported for first time

    Recent Trends in SST, Chl-a, Productivity and Wind Stress in Upwelling and Open Ocean Areas in the Upper Eastern North Atlantic Subtropical Gyre

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    The global upper ocean has been warming during the last decades accompanied with a chlorophyll-a (Chl-a) and productivity decrease. Whereas subtropical gyres show similar trends, Eastern Boundary Upwelling Systems are thought to increase in productivity due to increased trade winds. This study analyzes recent trends in sea surface temperature (SST), Chl-a, net primary production (NPP) and meridional wind stress in the Eastern North Atlantic subtropical gyre (NASE) in order to examine if the global trends can be detected in open ocean and upwelling areas and how the ocean biota responds. Satellite data of such variables of the last 15–40 years were analyzed to calculate mean trends in upwelling areas in the Canary upwelling system and open ocean areas around the Azores, Madeira and the Canary Islands. Our results show significant warming in the area with a maximum of 2.7°C per century for the Azores. Moreover, a general decreasing trend for Chl-a and NPP seems to be more evident in the permanent upwelling areas, which will be responsible for a loss of 0.13% of the global NPP per century. Our results also highlight a significant expansion of the oceanic desert area of 10% with an increase in unproductive days of up to 84 days in the last 20 years. The competitive relationship of stratification and wind stress in the Canary upwelling system might be a more plausible explanation for the decrease in Chl-a and NPP in upwelling areas linked to the increase in upwelling favorable wind stress and the surface warming.En prens

    Microstructure, magnetic and mechanical properties of Ni-Zn ferrites prepared by Powder Injection Moulding

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    Nowadays, the electronic industry demands small and complex parts as a consequence of the miniaturization of electronic devices. Powder injection moulding (PIM) is an emerging technique for the manufacturing of magnetic ceramics. In this paper, we analyze the sintering process, between 900 °C and 1300 °C, of Ni–Zn ferrites prepared by PIM. In particular, the densification behaviour, microstructure and mechanical properties of samples with toroidal and bar geometry were analyzed at different temperatures. Additionally, the magnetic behaviour (complex permeability and magnetic losses factor) of these compacts was compared with that of samples prepared by conventional powder compaction. Finally, the mechanical behaviour (elastic modulus, flexure strength and fracture toughness) was analyzed as a function of the powder loading of feedstock. The final microstructure of prepared samples was correlated with the macroscopic behaviour. A good agreement was established between the densities and population of defects found in the materials depending on the sintering conditions. In general, the final mechanical and magnetic properties of PIM samples were enhanced relative those obtained by uniaxial compaction

    Rate-equation calculations of the current flow through two-site molecular device and DNA-based junction

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    Here we present the calculations of incoherent current flowing through the two-site molecular device as well as the DNA-based junction within the rate-equation approach. Few interesting phenomena are discussed in detail. Structural asymmetry of two-site molecule results in rectification effect, which can be neutralized by asymmetric voltage drop at the molecule-metal contacts due to coupling asymmetry. The results received for poly(dG)-poly(dC) DNA molecule reveal the coupling- and temperature-independent saturation effect of the current at high voltages, where for short chains we establish the inverse square distance dependence. Besides, we document the shift of the conductance peak in the direction to higher voltages due to the temperature decrease.Comment: 12 pages, 6 figure

    Dietary glycemic index and glycemic load are positively associated with risk of developing metabolic syndrome in middle-aged and elderly adults

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    © 2015, Copyright the Authors Journal compilation © 2015, The American Geriatrics Society. Objectives To evaluate how glycemic index (GI) and glycemic load (GL) are associated with the metabolic syndrome (MetS) and its features in middle-aged and elderly adults at high cardiovascular risk. Design Prospective, longitudinal, population-based cohort. Setting PREvenciõn con DIeta MEDiterránea study. Participants Men and women (N = 6,606) divided into three age groups (<65, 65-74, ≥75). Measurements Energy and nutrient intake was evaluated using a validated 137-item food frequency questionnaire. MetS and its features were defined in accordance with the criteria of the American Heart Association and National Heart, Lung, and Blood Institute. Results A positive association was observed between GI and MetS prevalence in the youngest and middle age groups for participants without diabetes mellitus, but no relationship was found for those with diabetes mellitus. During the median follow-up of 4.8 years, higher GI and GL were related to greater risk of MetS in the middle age group, independent of the presence of diabetes mellitus. Changes in dietary GI were associated with risk of developing the high fasting glucose component of the MetS in the oldest age category, and changes in dietary GL were associated with risk of developing abdominal obesity, hypertriglyceridemia, low high-density lipoprotein cholesterol, and high blood pressure in the youngest age category. Conclusion Dietary GI and GL have a potential role in the development of MetS and associated clinical features, with particular age-dependent considerations.Funded by: Centro Nacional de Investigaciones Cardiovasculares. Grant Number: 06/2007; Instituto de Salud Carlos III; Fondo de Investigación Sanitaria PI. Grant Number: 07/0473; Ministerio de Ciencia e Innovación. Grant Numbers: AGL-2009–13906-C02, AGL2010–22319-C03; Ministerio de Sanidad-Plan Nacional de Drogas. Grant Number: 2010/087; Fondo de Investigaciones Sanitarias. Grant Number: PI1002658 Fundación Mapfre 2010 Government of the Basque Country. Grant Number: IT386–10 University of the Basque Country. Grant Number: UFI 11/32 Catalan government Miguel Servet. Grant Number: 06/00100Peer Reviewe

    Green function techniques in the treatment of quantum transport at the molecular scale

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    The theoretical investigation of charge (and spin) transport at nanometer length scales requires the use of advanced and powerful techniques able to deal with the dynamical properties of the relevant physical systems, to explicitly include out-of-equilibrium situations typical for electrical/heat transport as well as to take into account interaction effects in a systematic way. Equilibrium Green function techniques and their extension to non-equilibrium situations via the Keldysh formalism build one of the pillars of current state-of-the-art approaches to quantum transport which have been implemented in both model Hamiltonian formulations and first-principle methodologies. We offer a tutorial overview of the applications of Green functions to deal with some fundamental aspects of charge transport at the nanoscale, mainly focusing on applications to model Hamiltonian formulations.Comment: Tutorial review, LaTeX, 129 pages, 41 figures, 300 references, submitted to Springer series "Lecture Notes in Physics
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