2,116 research outputs found

    Early Detection with Pulse Oximetry of Hypoxemic Neonatal Conditions. Development of the IX Clinical Consensus Statement of the Ibero-American Society of Neonatology (SIBEN)

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    This article reviews the development of the Ninth Clinical Consensus Statement by SIBEN (the Ibero-American of Neonatology) on “Early Detection with Pulse Oximetry (SpO2) of Hypoxemic Neonatal Conditions”. It describes the process of the consensus, and the conclusions and recommendations for screening newborns with pulse oximetry

    The dynamics of the β-propeller domain in Kelch protein KLHL40 changes upon nemaline myopathy-associated mutation

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    Evolutionarily widespread, functionally and structurally diverse and still largely unexplored, Kelch proteins, characterized by the presence of a conserved C-terminal β-propeller, are implicated in a number of diverse fundamental biological functions, including cytoskeletal arrangement, regulation of cell morphology and organization, and protein degradation. Mutations in the genes encoding for Kelch superfamily members are being discovered as the cause of several neuromuscular diseases and cancer. The E528K mutation in Kelch protein KLHL40, which regulates skeletal muscle myogenesis, has been identified as a frequent cause of severe autosomal-recessive nemaline myopathy (NM). We use all-atom molecular dynamics simulations to characterize the dynamic behaviour of the β-propeller of the wild-type protein and identify correlated motions underlying the in vivo functionality. We also modelled the NM-associated mutation and we found that it does not lead to dramatic disruption of the β-propeller architecture; yet, residue 528 is a hub in the correlated motions of the domain, and mutation-induced local structural alterations are propagated to the whole protein, affecting its dynamics and physicochemical properties, which are fundamental for in vivo interaction with partners. Our results indicate that rational design of drugs can be envisioned as a strategy for restoring the internal network of communication and resetting KLHL40 to its physiological state

    Direito das Novas Tecnologias de Informação na Jurisprudência Brasileira

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    Though the Brazilian law still have no systematic statute on internet and digital legal aspects, the case law and precedents of superior courts have been establishing some important guidelines to both the interpretation of existing norms to embrace digital questions, as well as the discussion of the civil regulatory framework of internet in public opinion and the legislative houses. This article presents the most important decisions from Brazilian superior courts on the law of information technologies in order to identify the most polemical questions as well as the solutions found so far.Sociedad Argentina de Informática e Investigación Operativ

    Direito das Novas Tecnologias de Informação na Jurisprudência Brasileira

    Get PDF
    Though the Brazilian law still have no systematic statute on internet and digital legal aspects, the case law and precedents of superior courts have been establishing some important guidelines to both the interpretation of existing norms to embrace digital questions, as well as the discussion of the civil regulatory framework of internet in public opinion and the legislative houses. This article presents the most important decisions from Brazilian superior courts on the law of information technologies in order to identify the most polemical questions as well as the solutions found so far.Sociedad Argentina de Informática e Investigación Operativ

    Direito das Novas Tecnologias de Informação na Jurisprudência Brasileira

    Get PDF
    Though the Brazilian law still have no systematic statute on internet and digital legal aspects, the case law and precedents of superior courts have been establishing some important guidelines to both the interpretation of existing norms to embrace digital questions, as well as the discussion of the civil regulatory framework of internet in public opinion and the legislative houses. This article presents the most important decisions from Brazilian superior courts on the law of information technologies in order to identify the most polemical questions as well as the solutions found so far.Sociedad Argentina de Informática e Investigación Operativ

    Assessing the functional and structural stability of the Met80Ala mutant of cytochrome c in dimethylsulfoxide

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    The Met80Ala variant of yeast cytochrome c is known to possess electrocatalytic properties that are absent in the wild type form and that make it a promising candidate for biocatalysis and bi-osensing. The versatility of an enzyme is enhanced by the stability in mixed aqueous/organic solvents that would allow poorly water-soluble substrates to be targeted. In this work, we have evaluated the effect of dimethylsulfoxide (DMSO) on the functionality of the Met80Ala cyto-chrome c mutant, by investigating the thermodynamics and kinetics of electron transfer in mixed water/DMSO solutions up to 50% DMSO v/v. In parallel, we have monitored spectroscop-ically the retention of the main structural features in the same medium, focusing on both the overall protein structure and the heme center. We found that the organic solvent exerts only minor effects on the redox and structural properties of the mutant mostly as a result of the mod-ification of the dielectric constant of the solvent. This would warrant proper functionality of this variant also under these potentially hostile experimental conditions, that differ from the physi-ological milieu of cytochrome c

    Thermodynamics and Kinetics of Electron Transfer of 2 Electrode-Immobilized Small Laccase from Streptomyces coelicolor

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    The thermodynamic and kinetic properties for the heterogeneous electron transfer (ET) were measured for the electrode-immobilized small laccase (SLAC) from Streptomyces coelicolor subjected to different electrostatic and covalent protein-electrode linkages, using cyclic voltammetry. Once immobilized electrostatically onto a gold electrode using mixed carboxyl- and hydroxy-terminated alkane-thiolate SAMs or covalently exploiting the same SAM subjected to N-hydroxysuccin-imide+1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide (NHS-EDC) chemistry, the SLAC-electrode electron flow occurs through the T1 center. The E°’ values (from +0.2 to +0.1 V vs. SHE at pH 7.0) are lower by more than 0.2 V compared to the protein either in solution or immobilized with different anchoring strategies using uncharged SAMs. For the present electrostatic and covalent binding, this effect can respectively be ascribed to the negative charge of the SAM surfaces and to deletion of the positive charge of Lys/Arg residues due to amide bond formation which both selectively stabilize the more positively charged oxidized SLAC. Observation of enthalpy/entropy compensation within the series indicates that the immobilized proteins experience different reduction-induced solvent reorganization effects. The E°’ values for the covalently attached SLAC are sensitive to three acid base equilibria, with apparent pKa values of pKa1ox =5.1, pKa1red=7.5, pKa2ox=8.4, pKa2red=10.9, pKa2ox=8.9, pKa2red=11.3 possibly involving one residue close to the T1 center and two residues (Lys and/or Arg) along with moderate protein unfolding, respectively. Therefore, the E°’ value of immobilized SLAC turns out to be particularly sensitive to the anchoring mode and me-30 dium conditions

    EFFICIENT ELECTROCATALYTIC H2 PRODUCTION BY IMMOBILIZED Co(III)-MYOGLOBIN

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    The thermodynamics and kinetics of heterogeneous electron transfer (ET) for Co-substituted horse myoglobin (Co-Mb) and its derivatives with ammonia and imidazole as heme axial ligands were studied with cyclic voltammetry on a pyrolytic graphite electrode along with their ability to mediate the electrocatalytic production of H2 . All the proteins experience a non-diffusive electrochemical regime as electrode-bound species. The adsorbed Co-Mb construct was found to carry out the electrocatalytic reduction of water protons to H2 with a good efficiency under anaerobic conditions thus yielding a simple and tunable system for H2 production. Replacement of H2O as Co axial ligand by ammonia and imidazole significantly lowers the catalytic currents for H3O+/H2O reduction to H2. The E°’ values of the Co(III)/Co(II) redox couple for all species are mainly determined by the enthalpic contribution. Differences were found in the kinetics of ET for the different protein adducts due to changes in the activation enthalpies. However, all species share the same distance of about 14 Å from the electrode surface to the Co(III)/Co(II) center determined using the Marcus model, consistent with a non-denaturing adsorption of the protein

    How to Turn an Electron Transfer Protein into a Redox Enzyme for Biosensing

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    Cytochrome c is a small globular protein whose main physiological role is to shuttle electrons within the mitochondrial electron transport chain. This protein has been widely investigated, especially as a paradigmatic system for understanding the fundamental aspects of biological electron transfer and protein folding. Nevertheless, cytochrome c can also be endowed with a non-native catalytic activity and be immobilized on an electrode surface for the development of third generation biosensors. Here, an overview is offered of the most significant examples of such a functional transformation, carried out by either point mutation(s) or controlled unfolding. The latter can be induced chemically or upon protein immobilization on hydrophobic self-assembled monolayers. We critically discuss the potential held by these systems as core constituents of amperometric biosensors, along with the issues that need to be addressed to optimize their applicability and response
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