238 research outputs found

    Notes on Leibniz n-algebras

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    We analyze behaviors of generalized forgetful and Daletskii-Takhtajan’s functors on perfect objects and crossed modules of Leibniz n-algebras. Then we give applications to homology and universal central extensions of Leibniz n-algebrasAgencia Estatal de Investigación | Ref. PID2020-115155GB-I00Xunta de Galicia | Ref. ED431C 2023/3

    Methodological refinement of the submillimeter galaxy magnification bias. Paper iI: cosmological analysis with a single redshift bin

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    The main goal of this work, the second in a three-paper series, is to test the impact of a methodological improvement in measuring the magnification bias signal on a sample of submillimeter galaxies and its implications for constraining cosmological parameters. The analysis considers the angular cross-correlation function between a foreground sample of GAMA galaxies (0.2<z<0.80.2<z<0.8) and a background sample of H-ATLAS submillimeter galaxies (1.2<z<4.01.2<z<4.0). A refined methodology, discussed extensively in Paper I, is used. By interpreting the weak lensing signal within the halo model and employing an MCMC algorithm, the posterior distribution of the halo occupation distribution (HOD) and cosmological parameters is obtained for a flat Λ\LambdaCDM model. The analysis incorporates the foreground angular auto-correlation function to account for galaxy clustering. The results demonstrate a remarkable improvement in uncertainties for both HOD and cosmological parameters compared to previous studies. However, when using the cross-correlation data alone, the estimation of σ8\sigma_8 depends on prior knowledge of β\beta, the logarithmic slope of the background number counts. Assuming a physically motivated prior distribution for β\beta, mean values of Ωm=0.18+0.030.03\Omega_m=0.18^{+0.03}{-0.03} and σ8=1.04+0.110.07\sigma_8=1.04^{+0.11}{-0.07} are obtained. These results may however be subject to an inherent bias in the data due to anomalous behavior observed in the G15 field. After excluding the G15 region, the mean values shift to Ωm=0.30+0.050.06\Omega_m=0.30^{+0.05}{-0.06} and σ8=0.92+0.070.07\sigma_8=0.92^{+0.07}{-0.07}. This becomes more apparent when adding the clustering of the foreground sample, but the dependence on β\beta information disappears, mitigating the aforementioned issue. Excluding the G15 region, the joint analysis yields mean values of Ωm=0.36+0.030.07\Omega_m=0.36^{+0.03}{-0.07}, σ8=0.90+0.030.03\sigma_8=0.90^{+0.03}{-0.03}, and h=0.760.14+0.14h=0.76^{+0.14}_{-0.14}.Comment: This work is the second one of a three-paper series. Submitted to A&

    Improving a Deep Learning Model to Accurately Diagnose LVNC

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    ©2023. This manuscript version is made available under the CC-BY 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ This document is the Published Manuscript version of a Published Work that appeared in final form in Journal of Clinical Medicine. To access the final edited and published work see https://doi.org/10.3390/jcm12247633Accurate diagnosis of Left Ventricular Noncompaction Cardiomyopathy (LVNC) is critical for proper patient treatment but remains challenging. This work improves LVNC detection by improving left ventricle segmentation in cardiac MR images. Trabeculated left ventricle indicates LVNC, but automatic segmentation is difficult. We present techniques to improve segmentation and evaluate their impact on LVNC diagnosis. Three main methods are introduced: (1) using full 800 × 800 MR images rather than 512 × 512; (2) a clustering algorithm to eliminate neural network hallucinations; (3) advanced network architectures including Attention U-Net, MSA-UNet, and U-Net++.Experiments utilize cardiac MR datasets from three different hospitals. U-Net++ achieves the best segmentation performance using 800 × 800 images, and it improves the mean segmentation Dice score by 0.02 over the baseline U-Net, the clustering algorithm improves the mean Dice score by 0.06 on the images it affected, and the U-Net++ provides an additional 0.02 mean Dice score over the baseline U-Net. For LVNC diagnosis, U-Net++ achieves 0.896 accuracy, 0.907 precision, and 0.912 F1-score outperforming the baseline U-Net. Proposed techniques enhance LVNC detection, but differences between hospitals reveal problems in improving generalization. This work provides validated methods for precise LVNC diagnosis

    A Review of the Commercial Uses of Sulphate Minerals from the Titanium Dioxide Pigment Industry: The Case of Huelva (Spain)

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    This study was focused on the historical evolution of the waste management policy carried out by the Spanish industry devoted to titanium dioxide pigments manufacturing for minimising its environmental impact. This challenge was achieved by modifying the original chemical process and converting the originally dissolved sulphate and sulphuric acid present in the final streams of the factory into sulphate minerals (melanterite FeSO4 7H2O, szomolnokite FeSO4 H2O, and gypsum CaSO4 2H2O). These by-products were physicochemically, mineralogically and radiologically characterised in order to gain basic information for its subsequent commercial use. Some of the uses summarised in this study for both ferrous sulphates are as a supplier of iron to prevent chlorosis, animal food, manufacture of cement (to reduce Cr VI), primary flocculants for ferrous sulphates, magnetite nanoparticle and nano-Fe2O3 formation, production of magnetite concentrate, remediation of polluted soils with metals, and treatment of wastewaters. Red gypsum was analysed as a substitute for natural gypsum in the manufacture of cement, construction materials, inhibitor in soil erosion, and the immobilisation of heavy metals in agricultural soils and carbonation processes.This research was partially supported by the Spanish Government Department of Science and Technology (MINECO) through the project "Fluxes of Radionuclides Emitted by the Phosphogypsum Piles Located at Huelva; Assessment of the Dispersion, Radiological Risks and Remediation Proposals" (Ref. CTM, 2015-68628-R)), the Regional Government of Andalusia project called "Basic processes regulating the fractionations and enrichments of natural radionuclides under acid mine drainage conditions" (Ref.: UHU-1255876), and the University of Cadiz project called "New methodogy of radioisotope isolation with environmental interest for its measurement by alpha spectrometry" (Ref: PR2019-024). Documen

    Strong Metal-Support Interaction (SMSI) in Au/TiO2 photocatalysts for environmental remediation applications: Effectiveness enhancement and side effects

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    Strong Metal−Support Interaction (SMSI) is a well-known phenomenon of heterogeneous catalysis that have not been extensively investigated in photocatalytic applications. Moreover, the reactions previously studied for photocatalysts under SMSI state are mainly restricted to energy related uses. The present work seeks to explore the effect of SMSI induced by soft wet-chemistry in a Au/TiO2 photocatalyst with specific focus on photocatalytic environmental remediation. With this aim, the developed photocatalyst has been evaluated considering liquid, gas and solid pollutants in order to represent the wide range of environmental photocatalysis applications. These photooxidation scenarios were methylene blue dissolved in water, gaseous NO, and soot directly deposited on the photocatalyst. The results revealed that the SMSI induction has a generally positive effect on photoactivity promoting the MB and soot removal by 53% and 60%, respectively. However, the SMSI did not provide any additional benefit in the NOx elimination compared to the non-SMSI Au/TiO2 photocatalyst, because the enveloping of AuNPs limits the gold-pollutant interaction

    Chemical Modification of a Dehydratase Enzyme Involved in Bacterial Virulence by an Ammonium Derivative: Evidence of its Active Site Covalent Adduct

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    The first example of an ammonium derivative that causes a specific modification of the active site of type I dehydroquinase (DHQ1), a dehydratase enzyme that is a promising target for antivirulence drug discovery, is described. The resolution at 1.35 Å of the crystal structure of DHQ1 from Salmonella typhi chemically modified by this ammonium derivative revealed that the ligand is covalently attached to the essential Lys170 through the formation of an amine. The detection by mass spectroscopy of the reaction intermediates, in conjunction with the results of molecular dynamics simulations, allowed us to explain the inhibition mechanism and the experimentally observed differences between S. typhi and Staphylococcus aureus enzymes. The results presented here reveal that the replacement of Phe225 in St-DHQ1 by Tyr214 in Sa-DHQ1 and its hydrogen bonding interaction with the conserved water molecule observed in several crystal structures protects the amino adduct against further dehydration/aromatization reactions. In contrast, for the St-DHQ1 enzyme, the carboxylate group of Asp114, with the assistance of this water molecule, would trigger the formation of a Schiff base that can undergo further dehydration reactions until full aromatization of the cyclohexane ring is achieved. Moreover, in vitro antivirulence studies showed that the reported compound is able to reduce the ability of Salmonella Enteritidis to kill A459 respiratory cells. These studies have identified a good scaffold for the design of irreversible inhibitors that can be used as drugs and has opened up new opportunities for the development of novel antivirulence agents by targeting the DHQ1 enzymeFinancial support from the Spanish Ministry of Science and Innovation (SAF2013-42899-R), Xunta de Galicia (GRC2013-041), and the European Regional Development Fund (ERDF) is gratefully acknowledged. E.L. thanks the Xunta de Galicia for his postdoctoral fellowship. A.B. thanks the Miguel Servet Programme ISCIII-FEDER (CP13/00226) and the ISCIIIGeneral Subdirection of Assesment and Promotion of the Research (PI14/00059) for financial supportS

    Hydroxylammonium derivatives for selective active-site lysine modification in the anti-virulence bacterial target DHQ1 enzyme

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    Targeted irreversible inhibitors bearing electrophiles that become activated towards covalent bond formation upon binding to a specific protein/enzyme is an emerging area in drug discovery. Targeting lysine residues is challenging due to the intrinsically low reactivity of the amino group at physiological pH. Herein we report the first example of a hydroxylammonium derivative that causes a specific covalent modification of an active-site and a sterically inaccessible lysine residue of an enzyme. The described ligands, compounds 1–3, were rationally designed to be activated towards covalent bond formation upon binding to the type I dehydroquinase (DHQ1) enzyme for the development of new anti-virulence agents to combat the widespread resistance to antibiotics. Evidence in atomic detail for the covalent modifications caused by the ligands to the catalytic Lys170 by the formation of a stable secondary amine is provided by the resolution at 1.08–1.25 Å of the crystal structures of DHQ1 from Salmonella typhi enzyme adducts. In addition, the first crystal structure of the addition intermediate adduct at 1.4 Å of a Schiff base formation reaction by using an analog of the natural substrate, compound 4, is also reported. Molecular dynamics simulation studies on non-covalent enzyme/ligand complexes and a two-dimensional QM/MM umbrella sampling simulation study suggested that a direct displacement by Lys170 with the release of NH2OH would be feasible. These studies might open up new opportunities for the development of novel lysine-targeted irreversible inhibitors bearing a methylhydroxylammonium moiety as a latent electrophile.Financial support from the Spanish Ministry of Economy and Competiveness (SAF2016-75638-R), the Xunta de Galicia [Centro singular de investigación de Galicia accreditation 2016-2019 (ED431G/09) and ED431B 2018/04] and theEuropean Union (European Regional Development Fund –ERDF) is gratefully acknowledged. MM and EL thank the Spanish Ministry of Education, Culture and Sport and the Xunta de Galicia for their respective FPU and postdoctoral fellowshipsS

    Insights into substrate binding and catalysis in bacterial type I dehydroquinase

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    Structural, biochemical and computational studies to study substrate binding and the role of the conserved residues of the DHQ1 (type I dehydroquinase) enzyme active site are reported in the present paper. The crystal structure of DHQ1 from Salmonella typhi in complex with (2R)-2-methyl-3-dehydroquinic acid, a substrate analogue, was solved at 1.5 Å. The present study reveals a previously unknown key role for conserved Glu, Phe and Met and Gln, Pro and Ala residues, with the latter three being located in the flexible substrate-covering loop. Glu was shown to be responsible for the folding of this loop and for the dramatic reduction of its flexibility, which triggers active site closure. Glu46 was found to be key in bringing the substrate close to the lysine/histidine catalytic pocket to initiate catalysis. The present study could be useful in the rational design of inhibitors of this challenging and recognized target for the development of novel herbicides and antimicrobial agentsThis work was supported by the Spanish Ministry of Science and Innovation (grant number SAF2010-15076) and via FPU fellowships to M.M. and A.P., the Xunta de Galicia (grant number GRC2013/041) and via postdoctoral fellowships to E.L. and J.M.O., and by the European Regional Development Fund (ERDF)S

    Los valores y su influencia en la satisfacción vital de los adolescentes entre los 12 y los 16 años: estudio de algunos correlatos

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    En esta investigación profundizamos en algunos aspectos de la calidad de vida entre los jóvenes a partir de factores como la autoestima, la percepción de control, el apoyo social percibido, los valores, etc. Se analizan las correlaciones entre factores que influyen en los valores y la satisfacción vital de los adolescentes entre los 12 y los 16 años. Se realiza un análisis exhaustivo de los datos obtenidos de los chicos y chicas por una parte, y de sus progenitores por otra, y se exploran las relaciones entre los factores y se analizan las concordancias y discrepancias de las respuestas de unos y otros.In this research we explore several aspects about the quality of life of youth from factors such as self-esteem, locus of control, the social perceived support, values, etc. In this article we study the correlations among factors the influence the values and vital satisfaction of adolescents aged 12-16 years old. We analize data from boys and girls and from their parents, we explore the relationship between the factors and we explore the concordances and discrepancies of their answers

    Exploring the Water-Binding Pocket of the Type II Dehydroquinase Enzyme in the Structure-Based Design of Inhibitors

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    Structural and computational studies to explore the WAT1 binding pocket in the structure-based design of inhibitors against the type II dehydroquinase (DHQ2) enzyme are reported. The crystal structures of DHQ2 from M. tuberculosis in complex with four of the reported compounds are described. The electrostatic interaction observed between the guanidinium group of the essential arginine and the carboxylate group of one of the inhibitors in the reported crystal structures supports the recently suggested role of this arginine as the residue that triggers the release of the product from the active site. The results of the structural and molecular dynamics simulation studies revealed that the inhibitory potency is favored by promoting interactions with WAT1 and the residues located within this pocket and, more importantly, by avoiding situations where the ligands occupy the WAT1 binding pocket. The new insights can be used to advantage in the structure-based design of inhibitorsFinancial support from the Spanish Ministry of Science and Innovation (Grant SAF2010-15076) and the Xunta de Galicia (Grant GRC2013/041) is gratefully acknowledged. B.B. and A.P. thank the Spanish Ministry of Education for their respective FPU fellowships. A.S. thanks the Spanish Ministry of Economy and Competitiveness for her FPI fellowship. J.M.O. thanks the Xunta de Galicia for a Plan I2C postdoctoral fellowshipS
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