Bistability, softening, and quenching of magnetic moments in Ni-filled carbon nanotubes

The authors apply first-principles calculations to investigate the interplay between structural, electronic, and magnetic properties of nanostructures composed of narrow nanotubes filled with metallic nanowires. The focus is on the structural and magnetic responses of Ni-filled nanotubes upon radial compression. Interestingly, metastable flattened structures are identified, in which radially deformed nanotubes are stabilized by the interactions with the encapsulated wire. Moreover, our results indicate a quenching of the magnetic moment of the wire upon compression, as a result of the transfer of charge from the $s$ to the $d$ orbitals of the atoms in the wire.Comment: 4 pages, 4 figure

Evaluation of the biocontrol potential of a commercial yeast starter against fuel-ethanol fermentation contaminants

ABSTRACT: Lactic acid bacteria (LAB) and Brettanomyces bruxellensis are the main contaminants of bioethanol fermentations. Those contaminations affect Saccharomyces cerevisiae performance and reduce ethanol yields and productivity, leading to important economic losses. Currently, chemical treatments such as acid washing and/or antibiotics are used to control those contaminants. However, these control measures carry environmental risks, and more environmentally friendly methods are required. Several S. cerevisiae wine strains were found to secrete antimicrobial peptides (AMPs) during alcoholic fermentation that are active against LAB and B. bruxellensis strains. Thus, in the present study, we investigated if the fuel-ethanol commercial starter S. cerevisiae Ethanol Red (ER) also secretes those AMPs and evaluated its biocontrol potential by performing alcoholic fermentations with mixed-cultures of ER and B. bruxellensis strains and growth assays of LAB in ER pre-fermented supernatants. Results showed that all B. bruxellensis strains were significantly inhibited by the presence of ER, although LAB strains were less sensitive to ER fermentation metabolites. Peptides secreted by ER during alcoholic fermentation were purified by gel-filtration chromatography, and a bioactive fraction was analyzed by ELISA and mass spectrometry. Results confirmed that ER secretes the AMPs previously identified. That bioactive fraction was used to determine minimal inhibitory concentrations (MICs) against several LAB and B. bruxellensis strains. MICs of 1-2 mg/mL were found for B. bruxellensis strains and above 2 mg/mL for LAB. Our study demonstrates that the AMPs secreted by ER can be used as a natural preservative in fuel-ethanol fermentations.info:eu-repo/semantics/publishedVersio

Environmental licensing of major undertakings : possible connection between health and environmentResumo

A perspectiva de uma avaliação multidisciplinar, que considere os impactos da modificação do meio ambiente sobre a saúde da população, durante a implantação de projetos de desenvolvimento potencialmente poluidores, é incipiente no Brasil. Considerando o cenário de grandes empreendimentos no país, ampliar o olhar sobre a relação saúde-ambiente a partir dos processos sociais e econômicos de desenvolvimento, visando projetos ecologicamente sustentáveis, é uma estratégia fundamental. O artigo explora o debate sobre as relações entre o modelo de desenvolvimento vigente, os riscos, o ambiente e a saúde e discute a importância da participação do setor saúde nos processos de licenciamento ambiental, instrumento da Avaliação de Impacto Ambiental (AIA). Visando à construção de territórios mais sustentáveis, ambientalmente e socialmente, o setor saúde vem buscando oportunidades para participar dos processos de licenciamento de grandes empreendimentos, na perspectiva da AIA. Resultados de uma pesquisa realizada no âmbito do Ministério da Saúde demonstrou a forma de participação nesses processos, apontando para as potencialidades e fragilidades que favorecem ou dificultam o fortalecimento de ações preventivas em saúde pública, na implementação de grandes projetos de desenvolvimento no Brasil.The prospect of multidisciplinary assessment that considers the environmental impacts on the health of the population during the implementation of potentially polluting projects is incipient in Brazil. Considering the scenario of major undertakings in the country, broadening the outlook on the health and environment relationship based on social and economic development processes striving for environmentally sustainable projects is a key strategy. This article examines the debate on the relationship between the current development model, the risks, the environment and health and discusses the importance of the participation of the health sector in the environmental licensing procedures, which is the instrument of the Environmental Impact Assessment (EIA). Seeking to create more environmentally and socially sustainable territories, the health sector has been looking for opportunities to participate in the licensing processes of major undertakings from the EIA standpoint. Results of research conducted by the Ministry of Health have demonstrated the form of participation in these processes, highlighting the strengths and weaknesses that favor or hinder the increase of preventive actions in public health in the implementation of major undertakings in Brazil

Study of quantum dots (CdS, ZnS) toxicity in Danio rerio : preliminary results

Abstract in proceedings of the Fourth International Congress of CiiEM: Health, Well-Being and Ageing in the 21st Century, held at Egas Moniz’ University Campus in Monte de Caparica, Almada, from 3–5 June 2019.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.info:eu-repo/semantics/publishedVersio

Contributions of geography to environmental impact assessment in urban areas, based on the use of pressure state impact- response (P.S.I.R) methodology

A maior parte da população mundial vive em meio urbano, entretanto, diante da falta de organização, várias cidades no mundo têm problemas de degradação ambiental, especialmente nos países da América Latina e Caribe, onde a rápida urbanização é o principal vetor das pressões e conseqüentes impactos sofridos por essas cidades. Diante do quadro de piora da qualidade ambiental urbana, várias metodologias foram desenvolvidas para contribuir com a gestão ambiental, dentre elas a matriz P.E.I.R. (pressão-estado-impacto-resposta) desenvolvida pela Organização para Cooperação e Desenvolvimento Econômico (OCDE) que vem sendo utilizada pelo Programa das Nações Unidas para o Meio Ambiente (PNUMA) no projeto GEO Cidades. Ao lançar um olhar geográfico sobre a cidade o geógrafo tem muito a contribuir com esta metodologia, por seu objeto de estudo ser justamente o espaço geográfico, ou seja, aquele construído e continuamente transformado pelo homem ao longo do tempo. O objetivo desse artigo é mostrar como o geógrafo, ao fazer a análise da interação do homem com o meio, pode contribuir com os estudos através da matriz PEIR.Most part of the world population live in a urban environment, although with the lack of organization, several cities in the world have environmental problems, specially in the Latin America and Caribbean countries where the fast urbanization is the mainly cause of the pressure and its impacts in those cities. Based upon the diagnosis of an aggravation of environmental quality in the cities, many methodologies have been developed in a way to contribute to the environmental management, among then the PSIR matrix (pressure-state-impact-response) designed by the Organization for Economic Cooperation and Development (OECD), which UNEP (United Nations Environment Programme) has been using in the GEO Cities Project. The geographic point of view of the city has a lot to offer to the optimization of the results of such methodology. This argument is plausible because geographical studies, consider the broad aspects of the space in which human societies develop their ever changing activities through time. The aim of this paper is to show how the geographer, with the analysis of man's interaction with the environment, can contribute to studies by the PSIR matrix

Survey of biogenic amines (histamine and spermidine) in commercial seafood by enzyme linked immunosorbent assay (ELISA)

Abstract in proceedings of the Fourth International Congress of CiiEM: Health, Well-Being and Ageing in the 21st Century, held at Egas Moniz’ University Campus in Monte de Caparica, Almada, from 3–5 June 2019.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.info:eu-repo/semantics/publishedVersio

Umami taste in edible seaweeds: The current comprehension and perception

The fifth basic taste - umami, described as the essence of deliciousness, was discovered more than a century ago in Japan, after extraction of free glutamate from dashi, the Japanese broth prepared with brown seaweed Saccharina japonica (konbu). Although umami was accepted as a basic taste in the Eastern world a long time ago, umami gained recognition in the Western world very slowly. However, as the consumer's longing for delicious food is constantly growing, umami taste can be an important choice criterion. Moreover, in recent years, there has been an increasing demand for vegetarian and vegan products and edible seaweeds are a resource that has been used in the development of new food products. Consumption of edible seaweeds is becoming popular worldwide, not only due to their abundance and unique flavors but also because of their nutritional benefits and umami taste. In this review, the basic concepts of umami in seaweeds are described. The traditional consumption of seaweeds in the Eastern world, but also the more innovative approach in Western countries, are referred. The quantification of compounds responsible for the umami taste in aqueous extracts (broths) based on edible seaweeds was reviewed. Also, the influence of seaweed conservation techniques (drying techniques applied) and extraction conditions on umami potentials have been discussed, as well as the latest studies on metabolic pathways, including the biochemical reactions between glutamate and umami receptors.publishersversionpublishe

Uncovering biodegradability and biocompatibility of betaine-based deep eutectic systems

Funding Information: Open access funding provided by FCT|FCCN (b-on). This project has received funding from the European Union’s Horizon 2020 (European Research Council) under the grant agreement No ERC-2016-CoG 725034. This work was further supported by the Associate Laboratory for Green Chemistry- LAQV which is financed by national funds from FCT/MCTES (UIDB/50006/2020) and by the Applied Molecular Biosciences Unit UCIBIO which is financed by national funds from FCT (UIDP/04378/2020 and UIDB/04378/2020). Alexandre Paiva acknowledges FCT for the financial support through IF/01146/2015. Publisher Copyright: © 2023, The Author(s).Deep eutectic systems (DES) have shown increasing popularity in last decade; however, the number of studies on the potential toxicity towards living organisms remains scarce. These studies are of the utmost importance to infer on the claimed non-toxicity and biocompatibility of DES. Most articles published, at this moment, only evaluate the toxicity towards a cell model or in different strains of bacteria. For this purpose, in this work, the effect of two DES (betaine:sorbitol:water 1:1:3 and betaine:glycerol 1:2) and their individual components were evaluated at different concentrations after administered via intraperitoneal injection in zebrafish (Danio rerio). The total antioxidant capacity, lipoperoxidation, and the activity of various enzymes that work in different antioxidant pathways (superoxide dismutase, glutathione peroxidase, catalase, and glutathione S-transferase) were assessed. The results show no significant toxicity within the tested concentrations: up to 5000 µM and 3000 µM, for the assays using the system betaine:sorbitol:water 1:1:3 and for betaine:glycerol 1:2, respectively. The toxicity of individual components was studied up to 1000 µM. Based on the encouraging results that have been obtained, it is safe to conclude that these two deep eutectic systems can be used as the new class of environmentally friendly solvents. Graphical Abstract: [Figure not available: see fulltext.]publishersversionpublishe

Study of the effects of nanoplastics ingestion in a freshwater fish (Danio rerio)

Abstract in proceedings of the Fourth International Congress of CiiEM: Health, Well-Being and Ageing in the 21st Century, held at Egas Moniz’ University Campus in Monte de Caparica, Almada, from 3–5 June 2019.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.info:eu-repo/semantics/publishedVersio

Marine fish primary hepatocyte isolation and culture: New insights to enzymatic dissociation pancreatin digestion

PTDC/CTA-AMB/29173/2017 UIDB04292/2020 UIDP/04292/2020 UIDB04378/2020 UIDP/04378/2020 UIDB/04138/2020 UIDP/04138/ 2020 PTDC/CTA-AMB/29173/2017, NO-VAID39 grant 2020.09005. BD. DL57/2016/CP1376/CT002 CEECINST/00102/2018Primary cell cultures from wild organisms have been gaining relevance in ecotoxicology as they are considered more sensitive than immortalized cell lines and retain the biochemical pathways found in vivo. In this study, the efficacy of two methods for primary hepatocyte cell isolation was compared using liver from two marine fish (Sparus aurata and Psetta maxima): (i) two-step collagenase perfusion and (ii) pancreatin digestion with modifications. Cell cultures were incubated in L-15 medium at 17 ± 1 °C and monitored for up to six days for cell viability and function using the trypan blue exclusion test, MTT test, lactate dehydrogenase (LDH) activity, and ethoxyresorufin O-deethylase (EROD) activity after Benzo[a]Pyrene exposure. The results showed significant differences between the number of viable cells (p < 0.05), the highest number being obtained for the pancreatin digestion method (average = 4.5 ± 1.9 × 107 cells). Moreover, the hepatocytes showed solid adherence to the culture plate and the rounded shape, changing into a triangular/polygonal shape. The cell viability and function obtained by pancreatin digestion were maintained for five days, and the EROD induction after exposure to the B[a]P showed that cells were metabolically active. This study shows that the optimized pancreatin digestion method is a valid, cost-effective, and simple alternative to the standard perfusion method for the isolation of primary hepatocytes from fish and is suitable for ecotoxicological studies involving marine pollutants, such as PAHs.publishersversionpublishe