99 research outputs found

    Protic ionic liquids as electrolyte for electrochemical CO2 reduction [Resumo]

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    ABSTRACT: Ionic liquids have been considered a promising material under investigation for integration of CO2 capture and electrochemical reduction, due to their recognized sustainability and tunable properties. During previous works, the development of an electrochemical process to produce syngas (CO+H2) using electrolytes based on 1-ethyl-3-methyl-imidazolium trifluoromethanosulfate [EMIM][OTf] was reported [1-2]. A more recent work reported the effect of replacing the 1-ethyl-3-methyl-imidazolium cation [EMIM] by 1-ethyl-3-picolinium [C2-3-pic] and 1-ethyl-4-picolinium [C2-4-pic] cations as electrolyte for electrochemical reduction of CO2 at pressures higher than atmospheric [3]. The objective of this work is to study the influence of protic ionic liquids-based electrolytes in electrochemical CO2 reduction. In this context, protic ionic liquids prepared by direct protonation of different imidazolium compounds using suitable organic acids have been investigated. All electrolytes are characterized by cyclic voltammetry and electrochemical impedance spectroscopy to evaluate their electrochemistry behavior for CO2 electroreduction processes. Productivities of gaseous products resulting from the co-electrolysis of CO2 and water together with their faradaic efficiencies have been also determined.info:eu-repo/semantics/publishedVersio

    Imidazolium and picolinium-based electrolytes for electrochemical reduction of CO2 at high pressure

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    ABSTRACT: Ionic liquids (ILs) have been considered among one of the most promising materials under investigation for integration of CO2 capture and electrochemical reduction (ECR). In the design of an IL-based electrolyte that can be employed industrially, the understanding of the influence of IL structure on ECR was considered essential. In this context, electrolytes with trifluoromethanosulfonate (OTf) anion were investigated as aqueous electrolytes for electrochemical reduction of CO2 at high pressure and near room temperature with zinc electrodes. The effect of replacing the 1-ethyl-3-methyl-imidazolium cation [EMIM] by 1-ethyl-3-picolinium [C2(3)pic] and by 1-ethyl-4-picolinium [C2(4)pic] cations was studied. The use of picolinium-based electrolytes in ECR is for the first time reported. A high-pressure single compartment test bed was used for electrolyte screening. Carbon monoxide productivities and selectivities were determined for the several electrolytes with different water contents. The electrolytes were characterized by cyclic voltammetry and electrochemical impedance spectroscopy. Electrolyte conductivities and diffusion coefficients were estimated. The effect of the cations is complex as it affects conductivity, double layer structure, reaction reversibility and even the ionic liquid physical state. Notwithstanding, it is possible to tune these properties to achieve similar CO productions with reduced IL amounts, considering the nature of the cation and the water content, leading to the design of more cost effective electrolytes for efficient ECR process.info:eu-repo/semantics/publishedVersio

    Advances in electrochemical reduction of CO2 in ionic liquid-based electrolytes [Resumo]

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    ABSTRACT: Electrochemical reduction of CO2 was for the first time reported in 1870 [1], but it was only after 2010 that this field was the subject of intense research efforts. The use of renewable electricity to convert CO2 into products that are currently derived from fossil products and have high carbon footprint will certainly make this technology one pillar of a sustainable chemical industry. The scepticism towards the availability of cost effective products derived from CO2 electro-reduction that customers will be willing to buy has shifted to the belief that they can be commercially viable. Turning electrochemical CO2 reduction into a commercial technology will depend on economics, on the price of electricity, efficiency of the process and the value of the products. One way to improve the economics and improve the efficiency of the process is to integrate CO2 capture with conversion [2,3]. In this way the energy intensive regeneration step of the capture media can be eliminated and also CO2 transportation and storage. Ionic liquids are ideal media to achieve this integration, due to high CO2 adsorption capacity, high selectivity, wide electrochemical windows and nearly zero vapour pressure. The present work reports the progress of electrochemical reduction of CO2 in ionic liquids and the work of the authors in this field. It has been recognized that ionic liquids promote CO2 electro-reduction through lowering the reduction potential, the suppression of the competing hydrogen evolution reaction and by increasing the selectivity towards the target products. However, the understanding of the interactions between ionic liquids, CO2 and catalyst is still quite limited, but fundamental for synthetizing more efficient electrolytes for CO2 electro-reduction [4]. Thus, current cation and anion effects will be analysed and an overview of the current performance of heterogeneous electro-catalysts in ionic liquid- based electrolytes for CO2 electro-reduction will be provided.N/

    Structural Characterization of LRRK2 Inhibitors

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    Kinase inhibition is considered to be an important therapeutic target for LRRK2 mediated Parkinson's disease (PD). Many LRRK2 kinase inhibitors have been reported but have yet to be optimized in order to qualify as drug candidates for the treatment of the disease. In order to start a structure-function analysis of such inhibitors, we mutated the active site of Dictyostelium Roco4 kinase to resemble LRRK2. Here, we show saturation transfer difference (STD) NMR and the first cocrystal structures of two potent in vitro inhibitors, LRRK2-IN-1 and compound 19, with mutated Roco4. Our data demonstrate that this system can serve as an excellent tool for the structural characterization and optimization of LRRK2 inhibitors using X-ray crystallography and NMR spectroscopy

    Tecnologias e estratégias de comunicação online durante a pandemia covid-19: o caso das instituições de ensino superior em Portugal

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    The suspension of classroom classes from March 2020, determined by the Portuguese government in response to the CoViD-19 pandemic, imposed on educational institutions an unprecedented urgency of innovative pedagogical practices facilitated by technology. Among the many challenges, teachers had to adapt and reinvent their teaching strategies and methodologies. Having additional difficulties such as the lack of access to technologies that facilitate online classes and a concern about the possible decrease in the quality of learning due to the sudden switch to emergency remote learning (ERE). This communication proposal is an integral part of a broader study, still in progress, and from which we will present the results regarding the use of technologies for synchronous and asynchronous communication, in Portuguese higher education institutions, during the period of social confinement. The main objective of the investigation was to understand how higher education professors and students experienced the digital transition to the ERE, the pedagogical practices and the communication strategies adopted during this period. The investigation used mixed methods and, in order to respond to the proposed objectives and describe the pedagogical practices implemented and the communication strategies, specific instruments were built for data collection. A questionnaire was developed, aimed at students, and interviews aimed at both students and teachers, focusing on the technological, pedagogical and emotional dimensions, as well as on the evaluation of the experience. Data collection was carried out after the first confinement, at the end of the first semester of 2020, and took place in eight Portuguese higher education institutions (four Universities and four Polytechnic Institutes). In this communication, we will present a preliminary analysis of the results obtained and that are related to the pedagogical strategies adopted and the use of technology in synchronous and asynchronous online communication. We will also discuss the impacts of remote teaching on teaching work, evaluating whether they can bring positive and/or negative consequences to the pedagogical activity.info:eu-repo/semantics/publishedVersio

    Identification of Autophagy as a Functional Target Suitable for the Pharmacological Treatment of Mitochondrial Membrane Protein-Associated Neurodegeneration (MPAN) In Vitro

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    Mitochondrial membrane protein-associated neurodegeneration (MPAN) is a relentlessly progressive neurodegenerative disorder caused by mutations in the C19orf12 gene. C19orf12 has been implicated in playing a role in lipid metabolism, mitochondrial function, and autophagy, however, the precise functions remain unknown. To identify new robust cellular targets for small compound treatments, we evaluated reported mitochondrial function alterations, cellular signaling, and autophagy in a large cohort of MPAN patients and control fibroblasts. We found no consistent alteration of mitochondrial functions or cellular signaling messengers in MPAN fibroblasts. In contrast, we found that autophagy initiation is consistently impaired in MPAN fibroblasts and show that C19orf12 expression correlates with the amount of LC3 puncta, an autophagy marker. Finally, we screened 14 different autophagy modulators to test which can restore this autophagy defect. Amongst these compounds, carbamazepine, ABT-737, LY294002, oridonin, and paroxetine could restore LC3 puncta in the MPAN fibroblasts, identifying them as novel potential therapeutic compounds to treat MPAN. In summary, our study confirms a role for C19orf12 in autophagy, proposes LC3 puncta as a functionally robust and consistent readout for testing compounds, and pinpoints potential therapeutic compounds for MPAN.</p

    Identification of Autophagy as a Functional Target Suitable for the Pharmacological Treatment of Mitochondrial Membrane Protein-Associated Neurodegeneration (MPAN) In Vitro

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    Mitochondrial membrane protein-associated neurodegeneration (MPAN) is a relentlessly progressive neurodegenerative disorder caused by mutations in the C19orf12 gene. C19orf12 has been implicated in playing a role in lipid metabolism, mitochondrial function, and autophagy, however, the precise functions remain unknown. To identify new robust cellular targets for small compound treatments, we evaluated reported mitochondrial function alterations, cellular signaling, and autophagy in a large cohort of MPAN patients and control fibroblasts. We found no consistent alteration of mitochondrial functions or cellular signaling messengers in MPAN fibroblasts. In contrast, we found that autophagy initiation is consistently impaired in MPAN fibroblasts and show that C19orf12 expression correlates with the amount of LC3 puncta, an autophagy marker. Finally, we screened 14 different autophagy modulators to test which can restore this autophagy defect. Amongst these compounds, carbamazepine, ABT-737, LY294002, oridonin, and paroxetine could restore LC3 puncta in the MPAN fibroblasts, identifying them as novel potential therapeutic compounds to treat MPAN. In summary, our study confirms a role for C19orf12 in autophagy, proposes LC3 puncta as a functionally robust and consistent readout for testing compounds, and pinpoints potential therapeutic compounds for MPAN.</p

    Identification of Autophagy as a Functional Target Suitable for the Pharmacological Treatment of Mitochondrial Membrane Protein-Associated Neurodegeneration (MPAN) In Vitro

    Get PDF
    Mitochondrial membrane protein-associated neurodegeneration (MPAN) is a relentlessly progressive neurodegenerative disorder caused by mutations in the C19orf12 gene. C19orf12 has been implicated in playing a role in lipid metabolism, mitochondrial function, and autophagy, however, the precise functions remain unknown. To identify new robust cellular targets for small compound treatments, we evaluated reported mitochondrial function alterations, cellular signaling, and autophagy in a large cohort of MPAN patients and control fibroblasts. We found no consistent alteration of mitochondrial functions or cellular signaling messengers in MPAN fibroblasts. In contrast, we found that autophagy initiation is consistently impaired in MPAN fibroblasts and show that C19orf12 expression correlates with the amount of LC3 puncta, an autophagy marker. Finally, we screened 14 different autophagy modulators to test which can restore this autophagy defect. Amongst these compounds, carbamazepine, ABT-737, LY294002, oridonin, and paroxetine could restore LC3 puncta in the MPAN fibroblasts, identifying them as novel potential therapeutic compounds to treat MPAN. In summary, our study confirms a role for C19orf12 in autophagy, proposes LC3 puncta as a functionally robust and consistent readout for testing compounds, and pinpoints potential therapeutic compounds for MPAN
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