Predicted VO2 on 6 minutes walk test for FAP liver transplanted patients

Physical function is limited post-liver transplantation and exercise training can improve exercise capacity following transplantation but previously assessment of functional capacity is necessary. The 6 minute walk test (6MWT) is routinely used for studying patient’s exercise capacity and is less expensive and time consuming than a Cardiopulmonary Exercise Test (CPXT). There have been some studies looking at the relationship between 6MWT and peak VO2 in patients but few presented an adequate equation for predicted peak VO2 from 6MWT to transplanted patients and none for Familial Amyloidotic Polyneuropathy (FAP) liver transplanted patients (FAPTx). The aim of this study was to compare the validity of 6 equations as predictors of VO2 from the 6MWT and compare it with directly measured VO2 in patients FAPTx

Improvement in efficiency of the electrocatalytic reduction of hydrogen peroxide by prussian blue produced from the [Fe(CN)5(mpz)]2– complex

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Hydrogen peroxide is one of the most important molecules in chemical signaling in living organisms. Because of this, its sensing is indispensable for the diagnosis of many diseases. Among the materials used for the detection and quantification of H2O2, Prussian Blue (PB) has been highlighted due to its performance. Therefore, the search for alternatives or the improvement of PB performance is a challenge. In this context, our motivation was to evaluate how the ligand N-methylpyrazinium affects the structure and reactivity of Prussian Blue films produced from [Fe(CN)(5)(mpz)](2-) (PB-mpz). Based on the results, it was possible to conclude that the ligand is coordinated to the complex inside the PB framework and consequently contributes to the generation of a noncrystalline structure. The ions contained in buffer solutions can react with Prussian Blue by binding to Fe3+ and breaking the structure. In addition, a PB-mpz film in HCl/KCl showed higher sensitivity towards H2O2 than a PB film.Hydrogen peroxide is one of the most important molecules in chemical signaling in living organisms. Because of this, its sensing is indispensable for the diagnosis of many diseases. Among the materials used for the detection and quantification of H2O2, Pr20171319791988CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)459923/2014‐52013/22127‐2sem informaçãoThe authors acknowledge the financial support of the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) (grant no. 459923/2014‐5), the Fundo de Apoio ao Ensino, à Pesquisa e à Extensão – Universidade Estadual de Campinas (FAEPEX‐UNICAMP

Power electronics converters for an electric vehicle fast charging station with energy storage system and renewable energy sources

Fast Charging Stations (FCS) are a key element for the wide spreading of Electric Vehicles (EVs), by reducing the charging time to a range between 20 to 40 minutes. However, the integration of FCS causes some adverse impacts on the Power Grid (PG), namely the huge increase in the peak demand during short periods of time. This paper addresses the design of power electronics converters for an EV DC FCS with local storage capability and easy interface of renewables. In the proposed architecture, the energy storage capability is used to smooth the peak power demand and contributes to stabilize the PG. When integrated in a smart grid, the proposed architecture may even return some of the stored energy back to the PG. The accomplishment of the aforementioned objectives requires a set of different power electronics converters, described and discussed along the paper. In order to demonstrate the potentialities of the proposed EV DC FCS architecture, four different case studies were analysed.This work has been supported by FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2019. This work is financed by the ERDF – COMPETE 2020 Programme, and FCT within project SAICTPAC/0004/2015-POCI-01-0145-FEDER-016434 and FCT within project PTDC/EEI-EEE/28813/2017. Mr. Luis A. M. Barros is supported by the doctoral scholarship PD/BD/143006/2018 granted by the Portuguese FCT agency. Mr. Tiago Sousa is supported by the doctoral scholarship SFRH/BD/134353/2017 granted by the Portuguese FCT agency

Toxicological assessment of anthropogenic Gadolinium in seawater: biochemical effects in mussels Mytilus galloprovincialis

Recently, anthropogenic enrichment of rare earth elements (REE) have been reported in natural environments, due to increasing use and discharges of hospital/industrial wastewaters. Gadolinium (Gd), which is mainly used as contrast agent for magnetic resonance imaging in medical exams, may reach concentrations in water up to two orders of magnitude larger than baseline levels. Nevertheless, in marine systems scarce information is available concerning the toxicity of REE towards inhabiting organisms. This study aimed to evaluate the biochemical impact of anthropogenic Gd in the Mediterranean mussel Mytilus galloprovincialis, which is a species of commercial interest and one of the most accepted pollution bioindicator. Organisms were exposed to different concentrations of Gd (0, 15, 30, 60, 120 µg/L) for 28 days. At the end of the experiments, biomarkers related to mussels’ metabolic (electron transport system activity and energy reserves content), oxidative stress status (cellular damage and the activity of antioxidant and biotransformation enzymes) and neurotoxic effects (activity of the enzyme Acetylcholinesterase) were measured, as well as Gd bioconcentration in organisms. Results showed a high content of Gd (2.5±0.50 µg/g) in mussels exposed to the highest concentration, contrary to those at control condition and at 15 and 30 μg/L of Gd (levels below 0.38 µg/g). Although no mortality was observed during the experimental period, exposure to Gd strongly affected the biochemical performance of M. galloprovincialis, including the decrease on mussels’ metabolism, induction of oxidative stress and neurotoxicity, particularly evidenced at intermediate concentrations. These results may indicate that up to certain stressful levels, although lowering their metabolism, organisms may be able to activate defense strategies to avoid cellular injuries which, on the other hand, may compromise mussels physiological performance such as growth and reproduction success. Nevertheless, our findings support that the widespread utilization of Gd may represent an environmental risk in the future.publishe

Three-phase three-level current-source converter for EVs fast battery charging systems

This paper presents a three-phase three-level fast battery charger for electric vehicles (EVs) based in a current-source converter (CSC). Compared with the traditional voltage-source converters used for fast battery chargers, the CSC can be seen as a natural buck-type converter, i.e., the output voltage can assume a wide range of values, which varies between zero and the maximum instantaneous value of the power grid phase-to-phase voltage. Moreover, using the CSC it is not necessary to use a dc-dc back-end converter in the battery side, and it is also possible to control the grid current in order to obtain a sinusoidal waveform, and in phase with the power grid voltage (unitary power factor). Along the paper is described in detail the proposed CSC for EVs fast battery charging systems: the circuit topology, the power control theory, the current control strategy and the grid synchronization algorithm. Several simulation results of the EV fast battery charger operating with a maximum power of 50 kW are presented

The enthalpies of dissociation of the N-O bonds in two quinoxaline derivatives

The present work reports the first experimental thermochemical study of mono-N-oxides derived from quinoxaline, namely, 3-methoxycarbonyl-2-methyl-quinoxaline N-oxide and 3-ethoxycarbonyl-2-methyl-quinoxaline N-oxide. The values of the enthalpies of formation, in the condensed state, and of the enthalpies of sublimation, derived from static bomb calorimetry and Calvet microcalorimetry measurements, respectively, are combined to derive the standard molar enthalpies of formation in the gaseous phase for these two compounds. From the latter values, the first and second N-O bond dissociation enthalpies for the corresponding di-N-oxides have been obtained. The gas-phase experimental results are also compared with calculated data obtained with a density functional theory approach. Copyright (c) 2008 John Wiley & Sons, Ltd

Can water remediated by manganese spinel ferrite nanoparticles be safe for marine bivalves?

In the last few years the use of nanoparticles (NPs) such as the manganese spinel ferrite (MnFe2O4) has been increasing, with a vast variety of applications including water remediation from pollutants as metal(oid)s. Although an increasing number of studies already demonstrated the potential toxicity of NPs towards aquatic systems and inhabiting organisms, there is still scarce information on the potential hazard of the remediated water using NPs. The present study aimed to evaluate the ecotoxicological safety of Pb contaminated seawater remediated with MnFe2O4, NPs, assessing the toxicity induced in mussels Mytilus galloprovincialis exposed to contaminated seawater and to water that was remediated using MnFe2O4, NPs. The results obtained demonstrated that seawater contaminated with Pb, NPs or the mixture of both (Pb + NPs) induced higher toxicity in mussels compared to organisms exposed to Pb, NPs and Pb + NPs after the remediation process. In particular, higher metabolic depression, oxidative stress and neurotoxicity were observed in mussels exposed to contaminated seawater in comparison to mussels exposed to remediated seawater.publishe

Experimental validation of a current-source converter with reduced dc-link operating as shunt active power filter

Nowadays, the majority of electronic equipment behaves as nonlinear loads, introducing power quality problems into the power grid, namely, current harmonics and low power factor. These problems contribute to reduce the efficiency of the power grid and can cause malfunctioning of sensitive loads connected to the power grid. Therefore, it is important to develop power electronics solutions capable to mitigate these power quality problems. In this context, this paper presents a novel single-phase shunt active power filter (SAPF) based on a current-source converter, where the key differencing factor, when compared with the conventional approach, is the reduced dc-link. As the proposed topology requires a reduced dc-link, it represents a relevant advantage, requiring a less bulky inductance in the dc-link, reducing the losses, cost, and volume. The proposed SAPF with reduced dc-link is introduced in detail along the paper, and a comprehensive comparison with the conventional SAPF is established based on computer simulations. Besides, an experimental validation is carried out with a developed laboratory prototype, validating the main advantages of the proposed SAPF with reduced dc-link.This work has been supported by FCT – Fundação para a Ciência e Tecnologia with-in the Project Scope: UIDB/00319/2020. This work has been supported by the FCT Project newERA4GRIDs PTDC/EEI-EEE/30283/2017 and the FCT Project QUALITY4POWER PTDC/EEI-EEE/28813/2017, and by. Mr. Luis A. M. Barros is supported by the doctoral scholarship PD/BD/143006/2018 granted by the Portuguese FCT foundation

Remediation of Arsenic from contaminated seawater using manganese spinel ferrite nanoparticles: ecotoxicological evaluation in Mytilus galloprovincialis

In the last decade different approaches have been applied for water remediation purposes, including the use of nanoparticles (NPs) to remove metals and metalloids from water. Although studies have been done on the toxic impacts of such NPs, very scarce information is available on the impacts of water after decontamination when discharged into aquatic environments. As such, in the present study we aimed to evaluate the ecotoxicological safety of seawater previously contaminated with arsenic (As) and remediated by using manganese-ferrite (MnFe2O4-NPs) NPs. For this, mussels Mytilus galloprovincialis were exposed for 28 days to different conditions, including clean seawater (control), As (1000 μg L−1) contaminated and remediated (As 70 μg L−1) seawater, water containing MnFe2O4- NPs (50 mg L−1) with and without the presence of As. At the end of exposure, concentrations of As in mussels tissues were quantified and biomarkers related to mussels’ metabolism and oxidative stress status were evaluated. Results revealed that mussels exposed to water contaminated with As and to As + NPs accumulated significantly more As (between 62% and 76% more) than those exposed to remediated seawater. Regarding biomarkers, our findings demonstrated that in comparison to remediated seawater (conditions a, b, c) mussels exposed to contaminated seawater (conditions A, B, C) presented significantly lower metabolic activity, lower expenditure of energy reserves, activation of antioxidant and biotransformation defences, higher lipids and protein damages and greater AChE inhibition. Furthermore, organisms exposed to As, NPs or As + NPs revealed similar biochemical effects, both before and after water decontamination. In conclusion, the present study suggests that seawater previously contaminated with As and remediated by MnFe2O4-NPs presented significantly lower toxicity than As contaminated water, evidencing the potential use of these NPs to remediate seawater contaminated with As and its safety towards marine systems after discharges to these environments.publishe

Effects of Enteral Fluid Therapy in Continuous Flow Administered by Nasogastric Tube in Buffalo Calves

To investigate the employment of enteral fluid therapy in continuous flow administered by a nasogastric tube in buffalo calves; toassesstheeffectsof a hypotonic and an isotonic electrolyte solutionon: vital functions, blood count and serum andurinary biochemistry profile of buffalo calves. Seven buffalo calves, clinically healthy, were submitted to two treatments. The solutions were administered in continuous flow through a nasogastric tube at a dose of 15 mL/kg/hr for 12 hours. The serum biochemistry profile showed an increase in chloride concentration, decrease in serumurea and osmolarity. In urine, anincrease in sodium and chloride concentrations and a decrease in calcium, creatinine and urea were observed. Enteral fluid therapy in continuous flow proved to beeasy to use and effective in maintaining volemia and concentration of electrolytes in buffalo calves