Dehydropeptide supramolecular hydrogels and nanostructures as potential peptidomimetic biomedical materials

Supramolecular peptide hydrogels are gaining increased attention, owing to their potential in a variety of biomedical applications. Their physical properties are similar to those of the extracellular matrix (ECM), which is key to their applications in the cell culture of specialized cells, tissue engineering, skin regeneration, and wound healing. The structure of these hydrogels usually consists of a di- or tripeptide capped on the N-terminus with a hydrophobic aromatic group, such as Fmoc or naphthalene. Although these peptide conjugates can offer advantages over other types of gelators such as cross-linked polymers, they usually possess the limitation of being particularly sensitive to proteolysis by endogenous proteases. One of the strategies reported that can overcome this barrier is to use a peptidomimetic strategy, in which natural amino acids are switched for non-proteinogenic analogues, such as D-amino acids, β-amino acids, or dehydroamino acids. Such peptides usually possess much greater resistance to enzymatic hydrolysis. Peptides containing dehydroamino acids, i.e., dehydropeptides, are particularly interesting, as the presence of the double bond also introduces a conformational restraint to the peptide backbone, resulting in (often predictable) changes to the secondary structure of the peptide. This review focuses on peptide hydrogels and related nanostructures, where α,β-didehydro-α-amino acids have been successfully incorporated into the structure of peptide hydrogelators, and the resulting properties are discussed in terms of their potential biomedical applications. Where appropriate, their properties are compared with those of the corresponding peptide hydrogelator composed of canonical amino acids. In a wider context, we consider the presence of dehydroamino acids in natural compounds and medicinally important compounds as well as their limitations, and we consider some of the synthetic strategies for obtaining dehydropeptides. Finally, we consider the future direction for this research area.This work was supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding of CQUM (UID/QUI/00686/2019). FCT, FEDER, PORTUGAL2020 and COMPETE2020 are also acknowledged for funding under research project PTDC/QUI-QOR/29015/2017 (POCI-01-0145-FEDER-029015)

Um contributo da análise estatística na gestão de uma Estação de Tatamento de Águas Residuais (ETAR)

A deterioração progressiva dos recursos hídricos e a grande quantidade de água poluída gerada pelas sociedades modernas faz com que as estações de tratamento de águas residuais (ETAR) tenham uma extrema importância na prevenção e controlo da qualidade da água. Numa ETAR, o processo de lamas activadas é a tecnologia mais comumente usada para remover poluentes orgânicos das águas residuais (por meio de suspensão de biomassa bacteriana). Esta é a tecnologia com melhor custo- benefício, é muito flexível e pode ser adaptada a diferentes tipos de águas residuais. Por conseguinte, é muito importante compreender e modelar os processos biológicos utilizados numa ETAR, por forma a estimar os custos de tratamento com maior precisão e estabelecer uma melhor relação custo-eficácia. Neste trabalho a discussão centra-se no estabelecimento de análises e modelos estatísticos a fim de quantificar e caracterizar padrões de interacção entre as águas residuais dos afluentes que são tributários para as ETAR, as variáveis hidro-meteorológicas, as variáveis físico- químicas e as variáveis de custos associados aos tratamentos. O procedimento de modelação estatística foi aplicado a um conjunto de ETAR localizadas na região Noroeste de Portugal, em que os dados foram observados num período de dois anos (de Janeiro de 2015 até Dezembro de 2016). As metodologias desenvolvidas contribuíram para o aumento da eficiência de gestão, em particular da eficiência energética e da sustentabilidade dos sistemas de tratamento e exploração de águas residuais

A comparative thermoacoustic insulation study of silica aerogels reinforced with reclaimed textile fibres: cotton, polyester and wool

Silica aerogels are highly porous materials with exceptional thermal insulation performance. They become even more attractive if combined thermal and acoustic insulation is achieved. Silica aerogel composites reinforced with fibres are an ingenious way to surpass the fragility stemmed from the aerogel’s intrinsic porosity, and textile fibres are good sound absorption materials. Reclaimed fibres are a relatively low-cost feedstock and were obtained in this work exclusively through mechanical processes from textile wastes, thus promoting the concept of circular economy, namely for cotton, polyester and wool fibres. These reclaimed fibres were used as reinforcement matrices for silica aerogel composites obtained from sol–gel transformation of tetraethyl orthosilicate and isobutyltriethoxysilane/or vinyltrimethoxysilane precursors and dried at ambient pressure after silylation. Silica aerogel composites reinforced with reclaimed cotton fibres had the best sound absorption coefficient (a peak value of 0.89), while the polyester-reinforced composite exhibited the lowest thermal conductivity (k = ~24 mW m−1 K−1, Hot Disk). The better combined results on thermal and acoustic insulation were achieved by the wool-reinforced composites. The thermal conductivity values were less than 27 mW m−1 K−1, and the sound absorption coefficient achieved a peak value of 0.85. Therefore, the aerogel composites developed here can be selected for thermal or/and acoustic barriers by choosing a suitable type of fibre. Their design and preparation protocol followed environmental-friendly and cost-effective approaches.Teresa Linhares acknowledges the PhD grant Ref. SFRH/BD/131819/2017, attributed by Fundação para a Ciência e Tecnologia, I.P. (FCT, Portugal), funded by national funds from MCTES (Ministério da Ciência, Tecnologia e Ensino Superior) and, when appropriate, co-funded by the European Commission through the European Social Fund. Consumables for the syntheses and characterizations performed at CIEPQPF and 2C2T research units were funded by the European Regional Development Fund (ERDF), through COMPETE 2020 Operational Programme for Competitiveness and Internationalization, combined with Portuguese National Funds, through FCT, I.P. under the projects POCI-01-0145-FEDER-006910 and POCI-01-0145-FEDER-007136 (FCT Refs. UIDB/EQU/00102/2020 and UID/CTM/00264/2020, respectively)

Avaliação de técnicas de oxidação avançada no tratamento de água para consumo humano

Face ao aparecimento de contaminantes emergentes e altos custos associados às novas tecnologias de remoção destes contaminantes e matéria orgânica natural (MON), é necessário e essencial o desenvolvimento de tecnologias de tratamento igualmente eficientes, ambientalmente mais sustentáveis e de baixo custo. Deste modo, o presente artigo tem como principal objetivo o desenvolvimento e avaliação da eficiência de técnicas de oxidação avançada na remoção de MON, baseada na utilização de nanopartículas de dióxido de titânio (TiO2) imobilizadas. São condensados resultados quantitativos e qualitativos de ensaios de fotocatálise heterogénea (FH) com TiO2imobilizado e suspenso de água de alimentação à ETA de Areias de Vilar. É documentada a relação entre a MON e a absorvância através de curvas de calibração. Apresenta-se ainda uma análise comparativa entre os três processos de oxidação avançada (FH com TiO2 suspenso, imobilizado e pré-ozonização) que permitiu aferir o potencial de oxidação de MON do sistema fotocatalítico heterogéneo com TiO2imobilizado. O estudo realizado é um contributo na evolução e otimização do sistema fotocatalítico com TiO2 imobilizado, podendo mesmo se tratar futuramente de uma etapa de tratamento (principal ou complementar) económica, sustentável e eficaz com aplicabilidade em ETA

Coffee consumption has no acute effects on glucose metabolism in healthy men : a randomized crossover clinical trial

We investigate the effect of coffee (caffeinated and decaffeinated) on glucose effectiveness and insulin sensitivity using the stable isotope minimal model protocol with oral glucose administration in healthy men

Chromium (VI) ion adsorption features of chitosan film and its chitosan/zeolite conjugate 13X film

This research evaluated the importance of the adsorption properties of chitosan a chitosan/zeolite conjugate film for the removal of Cr(VI) ions from solutions in the 5–260 mg/L concentration range, when the pH was adjusted to 4.0 and 6.0. The uptake capacities of the films formed by chitosan and by the chitosan/zeolite conjugate were calculated by mass balance. The equilibrium isotherms were fitted to the Langmuir, Freundlich and Redlich-Peterson models. The chitosan film seems to be a good sorbent for Cr(VI) at pH 4, but its physical instability suggests the need for a more resilient support. Due to this fact zeolite was added to the chitosan matrix in solution and a chitosan/zeolite (CS/Zeo) film was thus formed. The solubility of the film and the characterization of the different matrices by FTIR, TGA and X-Ray showed that a cross-linked structure was formed between the chitosan and zeolite and the solubility of the film increased. In this study, the low manufacturing cost of the CS/Zeo matrix, the good uptake of Cr(VI) at acidic pH (17.28 mg/g) and the non desorption of Cr(VI) from the film in water suggests this combination should be tested in industrial environment.The authors are grateful for the Coordination of Improvement of Higher Education Personnel (CAPES - Brazil) for PhD fellowship and the financial support received from Financier of Studies and Projects (FINEP - Brazil), National Council for Scientific and Technological Development (CNPq - Brazil), Catholic University of Pernambuco (UNICAP - Brazil), University of Minho (UMINHO - Portugal). They also acknowledge Antonio Soares Vicente (UMINHO - Portugal) who kindly supplied the chitosan

Synthesis and structural characterization of new Piano-stool Ruthenium(II) complexes bearing 1-Butylimidazole heteroaromatic ligand

New cationic ruthenium(II) complexes with the formula [Ru(eta(5)-C5H5)(LL)(1-BuIm)] [Z], with (LL) = 2PPh(3) or DPPE, and Z = CF3SO3-, PF6-, BPh4-, have been synthesized and fully characterized. Spectroscopic and electrochemical studies revealed that the electronic properties of the coordinated 1-butylimidazole were clearly influenced by the nature of the phosphane coligands (LL) and also by the different counter ions. The solid state structures of the six complexes determined by X-ray crystallographic studies, confirmed the expected distorted three-legged piano stool structure. However the geometry of the 1-butylimidazole ligand was found considerably different in all six compounds, being governed by the stereochemistry of the mono and bidentate coligands (PPh3 or DPPE)

Asymmetrical subcortical plasticity entails cognitive progression in older individuals

Structural brain asymmetries have been associated with cognition. However, it is not known to what extent neuropsychological parameters and structural laterality covary with aging. Seventy-five subjects drawn from a larger normal aging cohort were evaluated in terms of MRI and neuropsychological parameters at two moments (M1 and M2), 18 months apart. In this time frame, asymmetry as measured by structural laterality index (ΔLI) was stable regarding both direction and magnitude in all areas. However, a significantly higher dispersion for this variation was observed in subcortical over cortical areas. Subjects with extreme increase in rightward lateralization of the caudate revealed increased M1 to M2 Stroop interference scores, but also a worsening of general cognition (MMSE). In contrast, subjects showing extreme increase in leftward lateralization of the thalamus presented higher increase in Stroop interference scores. In conclusion, while a decline in cognitive function was observed in the entire sample, regional brain asymmetries were relatively stable. Neuropsychological trajectories were associated with laterality changes in subcortical regions.This work was supported by the project NORTE‐01‐0145‐FEDER‐000013 through the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER), and funded by the European Commission (FP7) “SwitchBox ‐ Maintaining health in old age through homeostasis” (Contract HEALTH‐F2‐2010‐259772), and co‐financed by the Portuguese North Regional Operational Program (ON.2 – O Novo Norte), under the National Strategic Reference Framework (QREN), through FEDER, and by the Fundação Calouste Gulbenkian (Portugal) (Contract grant number: P‐139977; project “TEMPO ‐ Better mental health during ageing based on temporal prediction of individual brain ageing trajectories”) and by “PANINI ‐ Physical Activity and Nutrition INfluences In ageing” (European Commission (Horizon 2020), Contract GA 675003). Individual authors were supported under: "SwitchBox" to PM and NCS; Fundação para a Ciência e a Tecnologia (FCT) grants SFRH/BD/52291/2013 to ME and PD/BD/106050/2015 to CPN via Inter‐University Doctoral Programme in Ageing and Chronic Disease (PhDOC), PDE/BDE/113601/2015 to PSM and PDE/BDE/113604/2015 to RM via PhD Program in Health Sciences (Applied) (Phd‐iHES), SFRH/BD/90078/2012 to TCC, SFRH/BD/101398/2014 to LA and SFRH/BPD/80118/2011 do HLAinfo:eu-repo/semantics/publishedVersio

The BALA project: A pioneering monitoring of Azorean forest invertebrates over two decades (1999–2022)

Globally, there is a concerning decline in many insect populations, and this trend likely extends to all arthropods, potentially impacting unique island biota. Native non-endemic and endemic species on islands are under threat due to habitat destruction, with the introduction of exotic, and potentially invasive, species, further contributing to this decline. While long-term studies of plants and vertebrate fauna are available, long-term arthropod datasets are limited, hindering comparisons with better-studied taxa. The Biodiversity of Arthropods of the Laurisilva of the Azores (BALA) project has allowed gathering comprehensive data since 1997 in the Azorean Islands (Portugal), using standardised sampling methods across islands. The dataset includes arthropod counts from epigean (pitfall traps) and canopy-dwelling (beating samples) communities, enriched with species information, biogeographic origins, and IUCN categories. Metadata associated with the sample protocol and events, like sample identifier, archive number, sampled tree species, and trap type are also recorded. The database is available in multiple formats, including Darwin Core, which facilitates the ecological analysis of pressing environmental concerns, such as arthropod population declines and biological invasions.info:eu-repo/semantics/publishedVersio

SLAM Project - Long Term Ecological Study of the Impacts of Climate Change in the natural forests of Azores: V - New records of terrestrial arthropods after ten years of SLAM sampling

BACKGROUND: A long-term study monitoring arthropods (Arthropoda) is being conducted since 2012 in the forests of Azorean Islands. Named "SLAM - Long Term Ecological Study of the Impacts of Climate Change in the natural forest of Azores", this project aims to understand the impact of biodiversity erosion drivers in the distribution, abundance and diversity of Azorean arthropods. The current dataset represents arthropods that have been recorded using a total of 42 passive SLAM traps (Sea, Land and Air Malaise) deployed in native, mixed and exotic forest fragments in seven Azorean Islands (Flores, Faial, Pico, Graciosa, Terceira, São Miguel and Santa Maria). This manuscript is the fifth data-paper contribution, based on data from this long-term monitoring project. NEW INFORMATION: We targeted taxa for species identification belonging to Arachnida (excluding Acari), Chilopoda, Diplopoda, Hexapoda (excluding Collembola, Lepidoptera, Diptera and Hymenoptera (but including only Formicidae)). Specimens were sampled over seven Azorean Islands during the 2012-2021 period. Spiders (Araneae) data from Pico and Terceira Islands are not included since they have been already published elsewhere (Costa and Borges 2021, Lhoumeau et al. 2022). We collected a total of 176007 specimens, of which 168565 (95.7%) were identified to the species or subspecies level. For Araneae and some Hemiptera species, juveniles are also included in this paper, since the low diversity in the Azores allows a relatively precise species-level identification of this life-stage. We recorded a total of 316 named species and subspecies, belonging to 25 orders, 106 families and 260 genera. The ten most abundant species were mostly endemic or native non-endemic (one Opiliones, one Archaeognatha and seven Hemiptera) and only one exotic species, the Julida Ommatoiulus moreleti (Lucas, 1860). These ten species represent 107330 individuals (60%) of all sampled specimens and can be considered as the dominant species in the Azorean native forests for the target studied taxa. The Hemiptera were the most abundant taxa, with 90127 (50.4%) specimens. The Coleoptera were the most diverse with 30 (28.6%) families. We registered 72 new records for many of the islands (two for Flores, eight for Faial, 24 for Graciosa, 23 for Pico, eight for Terceira, three for São Miguel and four for Santa Maria). These records represent 58 species. None of them is new to the Azores Archipelago. Most of the new records are introduced species, all still with low abundance on the studied islands. This publication contributes to increasing the baseline information for future long-term comparisons of the arthropods of the studied sites and the knowledge of the arthropod fauna of the native forests of the Azores, in terms of species abundance, distribution and diversity throughout seasons and years.AMCS is supported by the Ramón y Cajal program (RYC2020-029407-I), financed by the Spanish Ministerio de Ciencia e Innovación. IRA and MB were funded by Portuguese funds through FCT – Fundação para a Ciência e a Tecnologia, I.P., under the Norma Transitória – DL 57/2016/CP1375/CT0003 and DL 57/2016/CP1375/CT0001, respectively. Several projects supported the acquisition of traps during the last ten years, namely: EUFCT-NETBIOME –ISLANDBIODIV grant 0003/2011 (between 2012 and 2015); Portuguese National Funds, through FCT – Fundação para a Ciência e Tecnologia, within the project UID/BIA/00329/2013-2020; Direcção Regional do Ambiente - PRIBES (LIFE17 IPE/PT/ 000010) (2019); Direcção Regional do Ambiente – LIFE-BETTLES (LIFE18 NAT_PT_000864) (2020); AZORESBIOPORTAL – PORBIOTA (ACORES-01-0145- FEDER-000072) (2019); (FCT) - MACRISK-Trait-based prediction of extinction risk and invasiveness for Northern Macaronesian arthropods (FCT-PTDC/BIA-CBI/0625/2021) (2021-2022). Data curation and open Access of this manuscript were supported by the project MACRISK-Trait-based prediction of extinction risk and invasiveness for Northern Macaronesian arthropods (FCT-PTDC/BIA-CBI/0625/2021).info:eu-repo/semantics/publishedVersio