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Os websites de social media são principalmente impulsionados por conteúdos gerados pelos indivíduos e a sua popularidade exponenciou a capacidade de influência das comunicações interpessoais sobre produtos ou serviços no comportamento dos consumidores entre redes sociais online. Este estudo examinou os determinantes do Electronic Word-of-Mouth (eWOM) transmitido pela lista de contactos no Facebook que influenciam a intenção de compra dos consumidores. O modelo testado é adaptado do modelo Information Acceptance (IACM) de Erkan e Evans (2016). Os objetivos de pesquisa consistem na investigação de características da informação (qualidade e credibilidade de informação), do recetor (atitude em relação à informação e necessidades de informação) e do emissor (credibilidade da fonte) que exercem maior impacto na influência do eWOM no comportamento do consumidor. A utilidade da informação foi considerada como antecedente chave das respostas de comportamento (adoção da informação e intenção de compra). Dados recolhidos através de um questionário online a 294 utilizadores do Facebook residentes em Portugal foram analisados através da técnica de modelação de equações estruturais baseada no método de mínimos quadrados parciais (PLS-SEM). As características do recetor demonstraram ter o maior nível de influência na intenção de compra. A qualidade da informação não demonstrou efeito sobre a intenção de compra. Adicionalmente, a credibilidade da informação apresentou um efeito mediador total sobre a qualidade da informação e a credibilidade da fonte na perceção de utilidade de informação.

Funding Information: We are thankful to Sandrine Auger and Carolina Alves‐Feliciano for their helpful discussions. Part of the work described in this review was supported by grants from the Portuguese Funcação para a Ciência e Tecnologia (FCT), PTDC/BIA‐BQM/27959/2017 and PTDC/BIA‐BQM/0562/2020 and by ITQB MOSTMICRO (UIDB/04612/2020 and UIDP/04612/2020) Research Unit, co‐funded by FCT, through National funds, and by FEDER under the PT2020 Partnership Agreement. This work has also received funding from the European Union's Horizon 2020 research and innovation program under grant agreement 810856. The work described in this review was funded by Institut Pasteur, the Université de Paris and the ITN Marie Curie, Clospore (H2020‐MSCA‐ITN‐2014 642068). N.K. was a postdoctoral fellow from Université de Paris. Funding Information: We are thankful to Sandrine Auger and Carolina Alves-Feliciano for their helpful discussions. Part of the work described in this review was supported by grants from the Portuguese Funca??o para a Ci?ncia e Tecnologia (FCT), PTDC/BIA-BQM/27959/2017 and PTDC/BIA-BQM/0562/2020 and by ITQB MOSTMICRO (UIDB/04612/2020 and UIDP/04612/2020) Research Unit, co-funded by FCT, through National funds, and by FEDER under the PT2020 Partnership Agreement. This work has also received funding from the European Union's Horizon 2020 research and innovation program under grant agreement 810856. The work described in this review was funded by Institut Pasteur, the Universit? de Paris and the ITN Marie Curie, Clospore (H2020-MSCA-ITN-2014 642068). N.K. was a postdoctoral fellow from Universit? de Paris. Publisher Copyright: © 2021 Society for Applied Microbiology and John Wiley & Sons Ltd. ; Clostridia comprise bacteria of environmental, biotechnological and medical interest and many commensals of the gut microbiota. Because of their strictly anaerobic lifestyle, oxygen is a major stress for Clostridia. However, recent data showed that these bacteria can cope with O2 better than expected for obligate anaerobes through their ability to scavenge, detoxify and consume O2. Upon O2 exposure, Clostridia redirect their central metabolism onto pathways less O2-sensitive and induce the expression of genes encoding enzymes involved in O2-reduction and in the repair of oxidized damaged molecules. While Faecalibacterium prausnitzii efficiently consumes O2 through a specific extracellular electron shuttling system requiring riboflavin, enzymes such as rubrerythrins and flavodiiron proteins with NAD(P)H-dependent O2- and/or H2O2-reductase activities are usually encoded in other Clostridia. These two classes of enzymes play indeed a pivotal role in O2 tolerance in Clostridioides difficile and Clostridium acetobutylicum. Two main signalling pathways triggering O2-induced responses have been described so far in Clostridia. PerR acts as a key regulator of the O2- and/or reactive oxygen species–defence machinery while in C. difficile, σB, the sigma factor of the general stress response also plays a crucial role in O2 tolerance by controlling the expression of genes involved in O2 scavenging and repair systems. ; publishersversion ; published

Funding Information: Funding: This study was financially supported by the Portuguese Fundação para a Ciência e Tec-nologia (FCT), grants PTDC/BIA-BQM/27959/2017 and PTDC/BIA-BQM/0562/2020, and Project MOSTMICRO-ITQB with references UIDB/04612/2020 and UIDP/04612/2020. This project has also received funding from the European Union's Horizon 2020 research and innovation program under grant agreement 810856. MCM is the recipient of FCT grant SFRH/BD/143651/2019. BAS is the recipient of FCT grant DFA/BD/8066/2020. Funding Information: This study was financially supported by the Portuguese Funda??o para a Ci?ncia e Tecnologia (FCT), grants PTDC/BIA-BQM/27959/2017 and PTDC/BIA-BQM/0562/2020, and Project MOSTMICRO-ITQB with references UIDB/04612/2020 and UIDP/04612/2020. This project has also received funding from the European Union?s Horizon 2020 research and innovation program under grant agreement 810856. MCM is the recipient of FCT grant SFRH/BD/143651/2019. BAS is the recipient of FCT grant DFA/BD/8066/2020. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. ; Flavodiiron proteins (FDPs) are a family of modular and soluble enzymes endowed with nitric oxide and/or oxygen reductase activities, producing N2O or H2O, respectively. The FDP from Escherichia coli, which, apart from the two core domains, possesses a rubredoxin-like domain at the C-terminus (therefore named flavorubredoxin (FlRd)), is a bona fide NO reductase, exhibiting O2 reducing activity that is approximately ten times lower than that for NO. Among the flavorubredoxins, there is a strictly conserved amino acids motif,-G[S,T]SYN-, close to the catalytic diiron center. To assess its role in FlRd's activity, we designed several site-directed mutants, replacing the conserved residues with hydrophobic or anionic ones. The mutants, which maintained the general characteristics of the wild type enzyme, including cofactor content and integrity of the diiron center, revealed a decrease of their oxygen reductase activity, while the NO reductase activity—specifically, its physiological function—was almost completely abolished in some of the mutants. Molecular modeling of the mutant proteins pointed to subtle changes in the predicted structures that resulted in the reduction of the hydration of the regions around the conserved residues, as well as in the elimination of hydrogen bonds, which may affect proton transfer and/or product release. ; published

Funding Information: We are grateful to Cristina Leit?o (ITQB-NOVA) for expert technical assistance on the HPLC assays. We thank the Diamond Light Source for access to beamline B21 (proposal mx20161) and the technical support from Katsuaki Inoue, that contributed to the results presented here.This work was supported by FEDER and Funda??o para a Ci?ncia e a Tecnologia, I. P. through national funds (Projects UIDB/04138/2020 and UIDP/04138/2020 and research project PTDC/MED-QUI/29712/2017). This work has received funding from the European Union?s Horizon 2020 research and innovation programme under the Marie-Sklodowska Curie grant agreement No [675007], LISBOA-01-0145-FEDER-029967 and PTDC/QUI-QOR/29967/2017. Principal Researcher grant CEECIND/03143/2017 (Funda??o para a Ci?ncia e a Tecnologia) is acknowledged by L.M.D.G. European Union?s Horizon 2020 research and innovation programme (grant agreement No 810856) is acknowledged by M.T. iNOVA4Health Research Unit (LISBOA-01-0145-FEDER-007344), which is cofunded by Funda??o para a Ci?ncia e a Tecnologia/Minist?rio da Ci?ncia, Tecnologia e Ensino Superior, through national funds, and by FEDER under the PT2020 Partnership Agreement, is acknowledged by J.B.V. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. Copyright: Copyright 2021 Elsevier B.V., All rights reserved. ; Phenylketonuria (PKU) is a genetic disease caused by deficient activity of human pheny-lalanine hydroxylase (hPAH) that, when untreated, can lead to severe psychomotor impairment. Protein misfolding is recognized as the main underlying pathogenic mechanism of PKU. Therefore, the use of stabilizers of protein structure and/or activity is an attractive therapeutic strategy for this condition. Here, we report that 3-hydroxyquinolin-2(1H)-one derivatives can act as protectors of hPAH enzyme activity. Electron paramagnetic resonance spectroscopy demonstrated that the 3-hydroxyquinolin-2(1H)-one compounds affect the coordination of the non-heme ferric center at the enzyme active-site. Moreover, surface plasmon resonance studies showed that these stabilizing compounds can be outcompeted by the natural substrate L-phenylalanine. Two of the designed compounds functionally stabilized hPAH by maintaining protein activity. This effect was observed on the recombinant purified protein and in a cellular model. Besides interacting with the catalytic iron, one of the compounds also binds to the N-terminal regulatory domain, although to a different location from the allosteric L-Phe binding site, as supported by the solution structures obtained by small-angle X-ray scattering. ; publishersversion ; published