3,514 research outputs found

    Bis(cyanato-κN)bis­(5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine-κN 3)zinc

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    In the title complex, [Zn(NCO)2(C7H8N4)2], the ZnII ion exhibits a distorted tetra­hedral coordination geometry. The coordination environment is formed by two 5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine (dmtp) ligands, coordinated through the N atom in position 3, and two cyanate anions inter­acting by their N atoms. Supra­molecular dimers are generated by stacking inter­actions between the pyrimidine rings of two ligands related by an inversion center [centroid–centroid distance = 3.5444 (18) Å]

    Bis(7-amino-1,2,4-triazolo[1,5-a]pyrimidin-4-ium) bis­(oxalato-κ2 O 1,O 2)cuprate(II) dihydrate

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    The structure of the title ionic compound, (C5H6N5)2[Cu(C2O4)2]·2H2O, consists of a centrosymmetric copper(II) oxalate dianion, two monoprotonated mol­ecules of the adenine analog 7-amino-1,2,4-triazolo[1,5-a]pyrimidine (7atp) and two water mol­ecules of crystallization. The CuII ion, located on an inversion center, exhibits a sligthly distorted square-planar coordination geometry, in which two oxalate anions bind in a bidentate fashion. The triazolopyrimidine ligand is protonated at the N atom in position 4, instead of its most basic N atom in position 3. This fact may be explained by the network stability, which is provided through the formation of a two-dimensional wave-like network parallel to (50) by N—H⋯O, O—H⋯N and O—H⋯O hydrogen bonds. These nets are further connected via C—H⋯O inter­actions

    Differences and similarities of stellar populations in LAEs and LBGs at z~3.4-6.8

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    Lyman alpha emitters (LAEs) and Lyman break galaxies (LBGs) represent the most common groups of star-forming galaxies at high z, and the differences between their inherent stellar populations (SPs) are a key factor in understanding early galaxy formation and evolution. We have run a set of SP burst-like models for a sample of 1558 sources at 3.4 < z < 6.8 from the Survey for High-z Absorption Red and Dead Sources (SHARDS) over the GOODS-N field. This work focuses on the differences between the three different observational subfamilies of our sample: LAE–LBGs, no-Ly α LBGs, and pure LAEs. Single and double SP synthetic spectra were used to model the spectral energy distributions, adopting a Bayesian information criterion to analyze under which situations a second SP is required. We find that the sources are well modelled using a single SP in ∼79 per cent of the cases. The best models suggest that pure LAEs are typically young low-mass galaxies (⁠t∼26+41−25 Myr; Mstar∼5.6+12.0−5.5×108 M⊙⁠), undergoing one of their first bursts of star formation. On the other hand, no-Ly α LBGs require older SPs (t ∼ 71 ± 12 Myr), and they are substantially more massive (Mstar ∼ 3.5 ± 1.1 × 109 M⊙). LAE–LBGs appear as the subgroup that more frequently needs the addition of a second SP, representing an old and massive galaxy caught in a strong recent star-forming episode. The relative number of sources found from each subfamily at each z supports an evolutionary scenario from pure LAEs and single SP LAE–LBGs to more massive LBGs. Stellar mass functions are also derived, finding an increase of M* with cosmic time and a possible steepening of the low-mass slope from z ∼ 6 to z ∼ 5 with no significant change to z ∼ 4. Additionally, we have derived the SFR–Mstar relation, finding an SFR∝Mβstar behaviour with negligible evolution from z ∼ 4 to z ∼ 6

    Support effects on NiO-based catalysts for the oxidative dehydrogenation (ODH) of ethane

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    [EN] We report on the effect of NiO-support interactions on the chemical nature of Ni species in a series of supported NiO catalysts for the ODH of ethane. SiO2, TiO2-anatase, a high surface area TiO2 and a porous clay hetero-structure (PCH) with TiO2 and SiO2 pillars were used as supports, which led to a selectivity to ethylene in the range 30-90% over supported NiO catalysts. The catalysts were characterized by means of XRD, N-2-Adsorption, H-2-TPR, XPS and in situ (under H-2 reductive atmosphere) and ex situ XAS spectroscopy. The catalytic performance of supported materials is discussed in terms of their reducibility and specific reduction kinetics, but also taking into account the specific chemical nature of Ni species on each catalyst. The influence of the particle size and the presence of Ni and O vacancies on the catalytic performance in the ODH of ethane is inferred.Authors would like to thank the DGICYT in Spain CTQ2015-68951-C3-1-R, CTQ2015-68951-C3-3-R, CTQ2012-37925-C03-2 and ENE2017-88818-C2-1-R. Also authors want to acknowledge the ALBA Synchrotron Light Source (Project ID: 2015021258 at CLAESS beamline). Authors from ITQ thank Project SEV-2016-0683 for financial support. D. D. also thanks MINECO and Severo Ochoa Excellence Program for his fellowship (SVP-2014-068669). Authors from UV thank the University of Valencia (UV-INV-AE16-484416 project) and MINECO (MAT2017-84118-C2-1-R project) for funding.Delgado-Muñoz, D.; Sanchís, R.; Cecilia, JA.; Rodríguez-Castellón, E.; Caballero, A.; Solsona, B.; López Nieto, JM. (2019). Support effects on NiO-based catalysts for the oxidative dehydrogenation (ODH) of ethane. Catalysis Today. 333:10-16. https://doi.org/10.1016/j.cattod.2018.07.010S101633

    Mandibular solitary plasmocytoma of the jaw : a case report

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    Plasma cell tumors are lymphoid neoplasms with an uncontrolled proliferation of B cells. These are divided into localized forms (solitary bone plasmocytoma -SBP- and extramedullary plasmocytoma -EP-) and disseminated forms (multiple myeloma-MM-). The SBP is a rare and controversial disease. The aim of this article is the analysis of this entity based on the presentation of a 64-year-old man without previous medical history, with a mass in the left mandibular angle extending to the parotid region on the same side. The panoramic radiography, computed tomography and magnetic resonance imaging showed an osteolytic lesion 6.5 x 5 x 6.7 cm in the mandibular angle with infiltration of the masticator space and left parotid region. The normality of the extension study, and histopathological examination confirmed the diagnosis of SBP. The patient received treatment with radiotherapy with good outcome. © Medicina Oral

    Methods to study adult hippocampal neurogenesis in humans and across the phylogeny

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    The hippocampus hosts the continuous addition of new neurons throughout life—a phenomenon named adult hippocampal neurogenesis (AHN). Here we revisit the occurrence of AHN in more than 110 mammalian species, including humans, and discuss the further validation of these data by single-cell RNAseq and other alternative techniques. In this regard, our recent studies have addressed the long-standing controversy in the field, namely whether cells positive for AHN markers are present in the adult human dentate gyrus (DG). Here we review how we developed a tightly controlled methodology, based on the use of high-quality brain samples (characterized by short postmortem delays and ≤24 h of fixation in freshly prepared 4% paraformaldehyde), to address human AHN. We review that the detection of AHN markers in samples fixed for 24 h required mild antigen retrieval and chemical elimination of autofluorescence. However, these steps were not necessary for samples subjected to shorter fixation periods. Moreover, the detection of labile epitopes (such as Nestin) in the human hippocampus required the use of mild detergents. The application of this strictly controlled methodology allowed reconstruction of the entire AHN process, thus revealing the presence of neural stem cells, proliferative progenitors, neuroblasts, and immature neurons at distinct stages of differentiation in the human DG. The data reviewed here demonstrate that methodology is of utmost importance when studying AHN by means of distinct techniques across the phylogenetic scale. In this regard, we summarize the major findings made by our group that emphasize that overlooking fundamental technical principles might have consequences for any given research fieldAssociation for Frontotemporal Degeneration; Banco de Santander; Center for Networked Biomedical Research on Neurodegenerative Diseases; Consejo Nacional de Ciencia y Tecnología (CONACYT), Grant/Award Number: 385084; European Research Council, Grant/Award Number: ERC-CoG2020-101001916; Fundacion Ram on Areces; Secretaria de Educacion, Ciencia Tecnología e Innovacion (SECTEI) of the Regional Government of Ciudad de México (CDMX), Grant/Award Number: SECTEI/159/2021; Spanish Ministry of Economy and Competitiveness, Grant/Award Numbers: PID2020-113007RB-I00, RYC-2015-171899, SAF-2017-82185-R; The Alzheimer's Association, Grant/Award Numbers: 2015-NIRG-340709, AARG-17-528125, AARG-17-528125-RAPI

    Effect of animal mixing as a stressor on biomarkers of autophagy and oxidative stress during pig muscle maturation

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    The objective of this work was to study the postmortem evolution of potential biomarkers of autophagy (Beclin 1, LC3-II/LC3-I ratio) and oxidative stress (total antioxidant activity, TAA; superoxide dismutase activity, SOD and catalase activity, CAT) in the Longissimus dorsi muscle of entire male ((Large White × Landrace) × Duroc) pigs subjected to different management treatments that may promote stress, such as mixing unfamiliar animals at the farm and/or during transport and lairage before slaughter. During the rearing period at the farm, five animals were never mixed after the initial formation of the experimental groups (unmixed group at the farm, UF), whereas 10 animals were subjected to a common routine of being mixed with unfamiliar animals (mixed group at the farm, MF). Furthermore, two different treatments were used during the transport and lairage before slaughter: 10 pigs were not mixed (unmixed group during transport and lairage, UTL), whereas five pigs were mixed with unfamiliar animals on the lorry and during lairage (mixed group during transport and lairage, MTL). These mixing treatments were then combined into three pre-slaughter treatments – namely, UF-UTL, MF-UTL and MF-MTL. The results show that MF-UTL and MF-MTL increased significantly the muscle antioxidant defense (TAA, SOD and CAT) at short postmortem times (4 and 8 h; P < 0.001), followed by an earlier depletion of the antioxidant activity at 24 h postmortem (P < 0.05). We also found that mixing unfamiliar animals, both at the farm and during transport and lairage, triggers postmortem muscle autophagy, which showed an earlier activation (higher expression of Beclin 1 and LC3-II/LC3-I ratio at 4 h postmortem followed by a decreasing pattern of this ratio along first 24 h postmortem) in the muscle tissues of animals from the MF-UTL and MF-MTL groups, as an adaptive strategy of the muscle cells for counteracting induced stress. From these results, we propose that monitoring the evolution of the main biomarkers of autophagy (Beclin 1, LC3-II/LC3-I ratio) and muscle antioxidant defense (TAA, SOD, CAT) in the muscle tissue within the first 24 h postmortem may help the detection of animal stress and its potential effect on the postmortem muscle metabolism.info:eu-repo/semantics/publishedVersio

    Instituto Internacional de Investigaci ́on e Innovaci ́on del Envejecimiento

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    El Instituto Internacional de Investigaci on e Innovaci on del Envejecimiento es un proyecto transfronterizo y multidisciplinar centrado en la mejora de la calidad de vida de los ancianos mediante el uso de la tecnolog a. En este proyecto colaboran la Universidad de Evora, el Instituto Polit ecnico de Porto Alegre, el Instituto Polit ecnico de Beja, la Administraci on Regional de Salud de Alentejo y la Universidad de Extremadura. Los objetivos del proyecto se centran en comprender los aspectos biom edicos, funcionales y psicol ogicos del envejecimiento; generar nuevos modelos y procesos de cuidado a ancianos y desarrollar soluciones tecnol ogicas que contribuyan a la salud y calidad de vida de los ancianos y a la sostenibilidad de los servicios

    MUSE view of Arp220: Kpc-scale multi-phase outflow and evidence for positive feedback

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    Arp220 is the nearest and prototypical ULIRG, and shows evidence of pc-scale molecular outflows in its nuclear regions and strongly perturbed ionised gas kinematics on kpc scales. It is therefore the ideal system for investigating outflows and feedback phenomena in details. We investigate the feedback effects on the Arp220 ISM, deriving a detailed picture of the atomic gas in terms of physical and kinematic properties, with a spatial resolution never obtained before (0.56", i.e. ~ 210 pc). We use optical IFS observations from VLT/MUSE-AO to obtain spatially resolved stellar and gas kinematics, for both ionised ([N II]6583) and neutral (Na ID5891,96) components; we also derive dust attenuation, electron density, ionisation conditions and hydrogen column density maps to characterise the ISM properties. Arp220 kinematics reveal the presence of a disturbed, kpc-scale disk in the innermost nuclear regions, and highly perturbed, multi-phase (neutral and ionised) gas along the minor-axis of the disk, which we interpret as a galactic-scale outflow emerging from the Arp220 eastern nucleus. This outflow involves velocities up to ~ 1000 km/s at galactocentric distances of ~ 5 kpc, and has a mass rate of ~ 50 Msun/yr, and kinetic and momentum power of ~ 1e43 erg/s and ~ 1e35 dyne, respectively. The inferred energetics do not allow us to distinguish the origin of the outflows, i.e. whether they are AGN-driven or starburst-driven. We also present evidence for enhanced star formation at the edges of - and within - the outflow, with a star formation rate SFR ~ 5 Msun/yr (i.e. ~ 2% of the total SFR). Our findings suggest the presence of powerful winds in Arp220: they might be capable of removing or heating large amounts of gas from the host ("negative feedback"), but could be also responsible for triggering star formation ("positive feedback").STFC ER

    Use of sonic tomography to detect and quantify wood decay in living trees.

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    Premise of the studyField methodology and image analysis protocols using acoustic tomography were developed and evaluated as a tool to estimate the amount of internal decay and damage of living trees, with special attention to tropical rainforest trees with irregular trunk shapes.Methods and resultsLiving trunks of a diversity of tree species in tropical rainforests in the Republic of Panama were scanned using an Argus Electronic PiCUS 3 Sonic Tomograph and evaluated for the amount and patterns of internal decay. A protocol using ImageJ analysis software was used to quantify the proportions of intact and compromised wood. The protocols provide replicable estimates of internal decay and cavities for trees of varying shapes, wood density, and bark thickness.ConclusionsSonic tomography, coupled with image analysis, provides an efficient, noninvasive approach to evaluate decay patterns and structural integrity of even irregularly shaped living trees
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