A single-phase current-source converter combined with a hybrid converter for interfacing an electric vehicle and a renewable energy source

This paper presents a single-phase current-source converter (CSC) combined with a hybrid converter on the dc-link, allowing to interface an electric vehicle (EV) and a renewable energy source (RES). Therefore, the interface with the power grid is only performed through the CSC, which also permits the operation as shunt active power filter (SAPF), allowing to compensate power quality problems related with current and low power factor in the electrical installation. The whole system is composed by two main power stages, namely, the CSC that is responsible for compensating the current harmonics and low power factor, as well as operating as a grid-tied inverter or as an active rectifier, and the hybrid converter that is responsible for interfacing the dc-link of the CSC with the converters for the EV and the RES interfaces. As demonstrated along the paper, the CSC, combined with the hybrid converter on the dc-link, allows the operation as SAPF, as well as the operation in bidirectional mode, specifically for the EV operation, and also for injecting power from the RES. In the paper, the power electronics structure is described and the principle of operation is introduced, supported by the description of the control algorithms. The validation results show the proper operation of the CSC, combined with the hybrid converter on the dc-link, for the main conditions of operation, namely exchanging power with the power grid in bidirectional mode and operating as a SAPF.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 DAIPESEV PTDC/EEI-EEE/30382/2017

Effect of zeolite nanomaterials in methanogenic communities

Recently, the application of zeolite structures in methanogenic communities has attracted significant attention, since they may enhance the anaerobic digestion process, by affecting specifically the methanogenic activity of the sludges1. Zeolites are solid inorganic crystalline materials comprised of silicon, aluminum and oxygen in the three-dimensional structure. The building blocks become arranged in a periodic way to form channels and cages on a nano- and subnanometer scale of strictly regular dimensions, named micropores. The presence of the aluminum in the zeolite framework create a negative charge in the lattice, which can be balanced by the exchangeable cations, as sodium or metal ions.2 In this study, commercial zeolite structures (ZSM5, USY, NaX and NaY) with different particle sizes and different exchangeable cations (Co, Cu, Zn, Fe) were used in order to investigate their effect towards the specific methanogenic activity, both acetoclastic and hydrogenotrophic, of anaerobic sludge. In the acetoclastic methanogenic activity, NaY modified with Cobalt (CoY) decreased the activity in comparison with the control (without zeolite). The remaining zeolites (ZSM5, USY, NaX and NaY), even when modified with metal ions (Zn, Fe, Cu), seems to have no effect on this methanogenic pathway. On the other hand, the hydrogenotrophic methanogenesis was improved by the presence of NaY (109 %), which did not happen in the presence of ZSM5 and USY zeolites. Additionally, the effect of different zeolite concentration was accessed. Overall, the increase of zeolite concentration from 1 g/L to 5 g/L resulted in a higher inhibition towards the methanogenic activity. In addition, the application of these nanomaterials can be evaluated in pure cultures of methanogens, in order to understand and fine-tune the best zeolite nanomaterial concentration that may improve the specific methanogenic activity.We thank the Fundação para a Ciência e Tecnologia (FCT) for financial support through Centre of Chemistry (UID/QUI/00686/2013 and UID/QUI/0686/2016) and BioTecNorte (operation NORTE-01-0145-FEDER-000004), and through Centre of Biological -engineering (UIDB/04469/2020 unit). Cátia S. N. Braga holds a grant SFRH/BD/132003/2017 funded by FCT and European Union (EU), through the Portuguese State Budget and the European Social Fund under the scope of Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

Modulation of butyrate-degrading methanogenic communities by conductive materials

Butyrate is a volatile fatty acid commonly present in anaerobic bioreactors. Previous research showed that methane production (MP) rates from butyrate, by lake sediment microbiomes, doubled by addition of carbon nanotubes, which was accompanied by changes in the microbial community composition, with enrichment of typical fatty-acid degrading bacteria (Syntrophomonas spp.), well known to exchange electrons with methanogens via hydrogen or formate formation1. But the authors suggested that electrons exchange via conductive materials (CM) may take place instead. In our study, anaerobic butyrate-degrading enrichment cultures were developed with other CM, namely activated carbon (AC) and magnetite (Mag) at 0.5 g/L. MP started earlier in AC enrichment and complete degradation was achieved faster in Mag enrichment. Syntrophomonas spp. were enriched in all cultures (representing 60 to 80 % of the total bacterial community), but hydrogenotrophic methanogens were highly stimulated by AC (78 % of Methanomicrobiales), while the methanogenic community of Mag culture was more diverse in acetoclastic methanogens (43% of Methanosarcina and Methanosaeta). It is still unclear if the improvement on butyrate degradation is associated to the role of CM in interspecies electron transfer, but it is undoubtful that they differentially modulate the methanogenic communities towards faster MP.info:eu-repo/semantics/publishedVersio

Differential effects of carbon-based and iron-based conductive materials in anaerobic butyrate-degrading enrichments

Introduction Conductive materials (CM) accelerate methane production (MP), probably by promoting more efficient interactions between bacteria and methanogens. This work investigates the effects of activated carbon (AC) and magnetite (Mag) in microbial enrichments degrading butyrate. Three different butyrate-degrading enrichments were developed: 1) without CM, 2) with AC, or 3) with Mag. It was also investigated if the effect of CM persisted when CM-adapted enrichments were transferred to new medium without CM, and if CM affected the activity of stable enrichments without previous contact with CM. Methodology Enrichment series were initiated with granular anaerobic sludge as inoculum, butyrate (10 mmol/L) as substrate, and CM (0.5 g/L AC or 0.5 g/L Mag), or without CM, and incubated at 37 °C, under strict anaerobic conditions. The following parameters were monitored: methane by gas chromatography; butyrate and acetate by high performance liquid chromatography; oxidation-reduction potential; pH and conductivity. RNA was extracted and taxonomic composition of the microbial communities was obtained by 16S rRNA gene sequencing. Results During the first incubations, AC-enrichment consumed hydrogen derived from butyrate degradation within 4 days, which was much faster than the enrichments with Mag and without CM, which presented lag phases (LP), preceding MP, longer than 11 and 7 days, respectively. Thus, Mag probably inhibited butyrate-degrading bacteria and/or hydrogenotrophic methanogens. Conversely, after the lag phase, Mag-enrichment was the fastest converting acetate to methane (3 times faster than in AC-enrichment), suggesting a stimulatory effect of Mag towards acetoclastic methanogens. Nevertheless, once the enrichments were adapted to the growth conditions, more efficient butyrate conversion was observed by all enrichments, with lag phases lower than 4 days, even in the control-enrichment. No significant changes on butyrate degradation were observed when highly adapted CM-enrichments were transferred to fresh medium without CM. On the other hand, when active enrichments (without previous contact with CM), were incubated with AC, it became slightly faster (0.7 times shorter LP), and with Mag were greatly inhibited (12 times longer LP). Syntrophomonas spp. represented 60 to 80 % of the total bacterial communities in all enrichments. Hydrogenotrophs were more abundant in AC-enrichment (78 % of Methanomicrobiales) and Mag-enrichment was highly enriched in acetoclastic methanogens (43 % of microorganisms assigned to Methanosaeta and Methanosarcina). Conclusions The presence of CM affects the performance of butyrate-degrading communities, with AC accelerating particularly butyrate conversion to methane (via H2/CO2) and acetate, and Mag inhibiting that first step but stimulating acetate conversion to methane.info:eu-repo/semantics/publishedVersio

Unlocking the potential of snake venom-based molecules against the malaria, Chagas disease, and leishmaniasis triad

Funding Information: This work received financial support from PT national funds ( FCT/MCTES , Fundação para a Ciência e Tecnologia and Ministério da Ciência, Tecnologia e Ensino Superior) through the project CIRCNA/BRB/0281/2019 . Funding Information: This work received financial support from PT national funds (FCT/MCTES, Fundação para a Ciência e Tecnologia and Ministério da Ciência, Tecnologia e Ensino Superior) through the project CIRCNA/BRB/0281/2019.The authors further thank FCT/MCTES for supporting Research Units LAQV-REQUIMTE (UIDB/50006/2020), GHTM (UID/Multi/04413/2020). Publisher Copyright: © 2023 The AuthorsMalaria, leishmaniasis and Chagas disease are vector-borne protozoal infections with a disproportionately high impact on the most fragile societies in the world, and despite malaria-focused research gained momentum in the past two decades, both trypanosomiases and leishmaniases remain neglected tropical diseases. Affordable effective drugs remain the mainstay of tackling this burden, but toxicicty, inneficiency against later stage disease, and drug resistance issues are serious shortcomings. One strategy to overcome these hurdles is to get new therapeutics or inspiration in nature. Indeed, snake venoms have been recognized as valuable sources of biomacromolecules, like peptides and proteins, with antiprotozoal activity. This review highlights major snake venom components active against at least one of the three aforementioned diseases, which include phospholipases A2, metalloproteases, L-amino acid oxidases, lectins, and oligopeptides. The relevance of this repertoire of biomacromolecules and the bottlenecks in their clinical translation are discussed considering approaches that should increase the success rate in this arduous task. Overall, this review underlines how venom-derived biomacromolecules could lead to pioneering antiprotozoal treatments and how the drug landscape for neglected diseases may be revolutionized by a closer look at venoms. Further investigations on poorly studied venoms is needed and could add new therapeutics to the pipeline.publishersversionepub_ahead_of_prin

Results from the portuguese register

Objective Our aims were to evaluate the correlation between Juvenile Arthritis Disease Activity Score 27-joint reduced count (JADAS27) with erythrocyte sedimentation rate (ESR) and JADAS27 with C-reactive protein (CRP) scores and to test the agreement of both scores on classifying each disease activity state. We also aimed at verifying the correlation of the 2 scores across juvenile idiopathic arthritis (JIA) categories and to check the correlation between JADAS27-ESR and clinical JADAS27 (JADAS27 without ESR). Methods A nationwide cohort of patients with JIA registered in the Portuguese Register, Reuma.pt, was studied. JADAS27-CRP was adapted by replacing ESR with CRP level as the inflammatory marker. JADAS27-CRP was calculated similarly to JADAS27-ESR as the simple linear sum of its 4 components. Pearson's correlations and K statistics were used in the analyses. Results A total of 358 children had full data to calculate JADAS27; 65.4% were female and the mean ± SD disease duration was 11.8 ± 9.1 years. The correlation coefficient between JADAS27-ESR and JADAS27-CRP was 0.967 (P < 0.0001), although the correlation coefficient between ESR and CRP level was 0.335 (P < 0.0001). The strong correlation between JADAS27-ESR and JADAS27-CRP was maintained when compared within each JIA category. The agreement between JADAS27-ESR and JADAS27-CRP across the 4 activity states was very good, showing 91.1% of the observations in agreement; K = 0.867 (95% confidence interval 0.824-0.91). The correlation between JADAS27 with ESR and JADAS27 without ESR was high (r = 0.97, P < 0.0001). Conclusion JADAS27 based on CRP level correlated closely with JADAS27-ESR across all disease activity states and JIA categories, indicating that both measures can be used in clinical practice. Moreover, the correlation of JADAS27 with and without ESR was also high, suggesting that this tool might be useful even in the absence of laboratorial measures.publishersversionpublishe

Influence of the different “patient global assessment” formulations on disease activity score by different indices in rheumatoid arthritis

© 2018, International League of Associations for Rheumatology (ILAR). Patient global assessment (PGA) is included in almost all rheumatoid arthritis (RA) composite disease activity indices and definitions of remission. However, different PGA formulations exist and are used interchangeably in research and clinical practice. We investigated how five different PGA formulations used in four disease indices affect the remission rates. This was an ancillary analysis of data from a cross-sectional study in patients with RA. The data comprised the following: 28-joint counts, C-reactive protein, and five PGA formulations. Remission rate variation was assessed using five PGA formulations in each index (ACR/EULAR Boolean, CDAI, SDAI, and DAS28-CRP). PGA agreement was assessed by the following: Pearson’s correlation; Bland-Altman plots; paired samples t test; and establishing the proportion of patients who scored (i) all formulations within an interval of 20mm and (ii) each formulation ≤ 10mm. This analysis included 191 patients. PGA formulations presented good correlations (≥ 0.65), but Bland-Altman plots showed clinically significant differences, which were statistically confirmed by comparison of means. Just over a half (51.8%) of patients scored all PGA formulations within a 20-mm interval. The proportion of those scoring ≤ 10mm varied from 11.5 to 16.2%. When different formulations of PGA were used in each index, remission differences of up to 4.7, 4.7, 6.3, and 5.2% were observed. When formulations were used in their respective indices, as validated, the remission rates were similar (13.1, 13.6, 14.1, and 18.3%). Using PGA formulations interchangeably may have implications in the assessment of disease activity and in the attainment of remission, and this can impact upon management decisions

The Portuguese Rheumatoid Arthritis Impact of Disease (RAID) score and its measurement equivalence in three countries: validation study using Rasch Models

© 2018, The Author(s). Purpose: The Rheumatoid Arthritis Impact of Disease (RAID) score assesses seven impact domains of interest for people with RA. This study aimed to test patients’ understanding of the Portuguese RAID and evaluate its cross-cultural validity for use in Portugal. Methods: This was a mixed methods study comprising two phases: (i) cognitive debriefing to determine patient’s comprehension of the Portuguese RAID and (ii) cross-cultural validation using Rasch analysis. Construct validity was determined by fit to the model, invariance culture (compared with France and UK datasets) and evidence of convergent and divergent validity. Results: Patients’ input (n = 38) led to minor changes in the phrasing of two items to ensure conceptual equivalence between the Portuguese and the original RAID. In Rasch analysis (n = 288), two items ‘Sleep’ and ‘Physical well-being’ in the Portuguese dataset did not adequately fit the model specifications, suggesting multidimensionality (sleep—not necessarily associated with RA) and redundancy (physical well-being overlapping with functional disability). Despite the imperfections, the scale had high internal consistency, evidence of convergent and divergent validity and invariance to culture (compared to France n = 195 and UK n = 205 datasets). The scale was well targeted for patients with different levels of disease impact. Conclusions: The RAID has been successfully adapted into Portuguese and it can be used with confidence in clinical practice. Further research will be required to ensure it captures the full range of sleep problems in RA. Meanwhile, data across the three countries (Portugal, France and the UK) are comparable except for the two items (sleep and physical well-being)