New liquid supports in the development of integrated platforms for the reuse of oxidative enzymes and polydopamine production

Polydopamine (PDA), a bioinspired polymer from mussel adhesive proteins, has attracted impressive attention as a novel coating for (nano) materials with an adequate conformal layer and adjustable thickness. Currently, PDA is obtained from dopamine chemical oxidation under alkaline conditions, limiting its use in materials sensible to alkaline environments. Envisaging a widespread use of PDA, the polymerization of dopamine by enzymatic catalysis allows the dopamine polymerization in a large range of pHs, overcoming thus the limitations of conventional chemical oxidation. Moreover, the conventional method of polymerization is a time-consuming process and produces PDA films with poor stability, which restricts its applications. On the other hand, the main bottleneck of enzyme-based biocatalytic processes is the high cost of the single use of the enzyme. In this work, laccase was used to catalyse dopamine polymerization. To improve its performance, a liquid support for integrating the laccase and its reuse together with the PDA production and recovery was developed using aqueous biphasic systems (ABS). Firstly, dopamine polymerization by laccase was optimized in terms of pH, temperature and initial dopamine concentration. It was demonstrated that the highest enzymatic polymerization of dopamine was achieved at pH 5.5, 30°C and 2 mg ml−1 of dopamine. Then, ABS composed of polymers, salts and ionic liquids were evaluated to optimize the laccase confinement in one phase while PDA is recovered in the opposite phase. The most promising ABS allowing the separation of laccase from the reaction product is composed of polypropylene glycol (400 g mol−1) and K2HPO4. The polymerization of dopamine in ABS leads to a remarkable improvement of polymerization of 3.9-fold in comparison to the conventional chemical PDA polymerization. The phase containing the confined laccase was reused for four consecutive reaction cycles, with a relative polymerization of 68.9% in the last cycle. The results of this work proved that ABS are a promising approach to create a liquid support for enzyme reuse allowing the process intensification efforts. The use of biocatalysts in ABS emerges as sustainable and alternative platforms from environmental and techno-economic points of view.publishe

Periodic vehicle routing problem in a health unit

In logistics of home health care services in the Health Units, the managers and nurses need to carry out the schedule and the vehicles routes for the provision of care at the patients' homes. Currently, in Portugal, these services are increasingly used but the problem is still, usually, solved manually and without computational resources. The increased demand for home health care due to the boost of the elderly people number entails a high associated cost which, sometimes, does not guarantee the quality of the service. In this sense, the periodic vehicle routing problem is a generalization of the classical vehicle routing problem in which routes are determined for a time horizon of several days. In this work, it is provided a periodic vehicle routing problem applied in the Health Unit in Bragança. An integer linear programming formulation for the real database, allowed to solve the problem in an efficient and optimized way using the CPLEXR software.Programa Operacional Temático Factores de Competitividade(POCI-01-0145-FEDER-007043

A step for the valorization of spent yeast through production of iron–peptide complexes — a process optimization study

Given the importance of iron in human nutrition and the significance of waste and by-product valorisation in a circular economy environment, we investigated the effects of protein and iron concentration on the production yield of iron–peptide complexes from spent Saccharomyces cerevisiae. For this purpose, different amounts of protein and iron were used in the complexation process. The results have shown that higher concentrations, although permitting a faster and larger scale process, provide a significantly lower complexation yield, which deems the process less feasible. This is corroborated by fluorescence analysis, which shows a lower degree of complexation with higher protein concentration. In addition, varying the concentration of iron does not change the quality of formed complexes, as evidenced by Fourier transform infrared spectroscopy (FT-IR) analysis. The morphology of all samples was also evaluated using scanning electron microscopy (SEM). Therefore, further studies are needed to optimize the process and to evaluate the best conditions for an economically sound valorization process for iron–peptide complexes. Nonetheless, current results in the development of a new process for the valorisation of spent yeast, in the form of iron-peptide complexes, look promising.info:eu-repo/semantics/publishedVersio

Lipid Peroxidation in Meat and Meat Products

The meat and meat products present a considerable amount of lipid in their composition. The lipid composition of these foods is diversified. Thus, depending on the type of meat, which can be rich in unsaturated fatty acid, there is an increase in the disposition for lipid oxidation. Oxidation reactions not only reduce the shelf life and nutritional value of food products but also can generate harmful compounds. Thus, having in view that many types of new technologies are applied to these foods, the proposal of this chapter of how these new methodologies have affected the lipid peroxidation of these foods. Moreover, the aim is to evaluate what impacts on the chemical characteristics of these foods

Vaginal prevention of Candida albicans: synergistic effect of lactobacilli and mannan oligosaccharides (MOS)

Vulvovaginal candidiasis (VVC) affects approximately 30-50% of women at least once during their lifetime, causing uncomfortable symptoms and limitations in their daily quality of life. Antifungal therapy is not very effective, does not prevent recurrencies and usually causes side effects. Therefore, alternative therapies are urgently needed. The goal of this work was to investigate the potential benefits of using mannan oligosaccharides (MOS) extracts together with a Lactobacillus sp. pool, composed by the most significant species present in the vaginal environment, to prevent infections by Candida albicans. Microbial growth of isolated strains of the main vaginal lactobacilli and Candida strains was assessed in the presence of MOS, to screen their impact upon growth. A pool of the lactobacilli was then tested against C. albicans in competition and prophylaxis studies; bacterial and yeast cell numbers were quantified in specific time points, and the above-mentioned studies were assessed in simulated vaginal fluid (SVF). Finally, adhesion to vaginal epithelial cells (HeLa) was also evaluated, once again resorting to simultaneous exposure (competition) or prophylaxis assays, aiming to measure the effect of MOS presence in pathogen adherence. Results demonstrated that MOS extracts have potential to prevent vaginal candidiasis in synergy with vaginal lactobacilli, with improved results than those obtained when using lactobacilli alone. KEY POINTS: Potential benefits of MOS extracts with vaginal lactobacilli to prevent C. albicans infections. MOS impacts on growth of vaginal lactobacilli pool and C. albicans in SVF. MOS extracts in synergy with L. crispatus inhibit C. albicans adhesion in HeLa cells.info:eu-repo/semantics/publishedVersio

Laboratório de Jogos

Laboratório de Jogos é um projeto de divulgação de ciência aprovado e financiado pelo Ciência Viva ‐ Agência Nacional para a Cultura Científica e Tecnológica. O Laboratório de Jogos tem como objetivo disponibilizar jogos matemáticos e atrair as pessoas de uma forma lúdica e desafiante, nomeadamente os alunos com dificuldades e repulsa pela matemática. Pretende‐se que alunos e professores usem os jogos como ferramentas de ensino que lhes permitam a manipulação e a visualização de conceitos e a estruturação de raciocínios e estratégias para atingir determinados objetivos. A matemática é fascinante e a chave que desvenda os seus mistérios está ao alcance de todos, mesmo dos que se creem incapazes. O Laboratório de Jogos contribui, desta forma, para desmistificar a atitude socialmente generalizada de receio ante a necessidade de resolver um problema ou compreender um conceito de matemática. O Laboratório de Jogos é constituído por quatro temas distintos: jogos de cartas, jogos de contagem, jogos abstratos e jogos determinísticos. Os jogos possuem características distintas dependendo da idade dos possíveis jogadores e, como tal, foram delineados para poderem ser jogados por crianças com idade superior a três anos. O Laboratório de jogos está, também, associado ao projeto de divulgação matemática EureKit (eurekit.ipb.pt), do Instituto Politécnico de Bragança. Este projeto disponibiliza, gratuitamente, à população em geral uma exposição itinerante com diversos jogos matemáticos. Esta exposição já esteve patente em diversos locais de Portugal – desde escolas básicas/secundárias, Câmaras Municipais e Centros de Ciência Viva.info:eu-repo/semantics/publishedVersio

Jogos matemáticos como ferramenta para motivar os estudantes para aprender matemática

Despertar nos alunos o gosto pela Matemática é uma tarefa exigente para os educadores e professores. É uma evidência para os professores de todos os níveis de ensino que a maioria dos estudantes demonstra receios e carrega preconceitos sobre a natureza do pensamento matemático e, consequentemente, sobre a sua própria capacidade para a disciplina. A introdução de jogos matemáticos nas rotinas da sala de aula é uma contribuição promissora para ajudar a superar tais equívocos já que todos os estudantes, não importa a sua idade ou nível educacional, são mais facilmente cativados para aprender se puderem fazê-lo de uma forma divertida. Portanto, jogar jogos desde as primeiras fases do percurso escolar promove interações agradáveis que podem ser a base de um relacionamento saudável e gratificante com a Matemática. A exposição EureKit dispõe de uma vasta coleção de jogos - alguns clássicos bem conhecidos, como o Mancala ou diversas variações do Solitário, e outros totalmente concebido no âmbito do projeto. A coleção está organizada em quatro categorias diferentes: jogos abstratos, jogos de cartas, jogos de contagem e jogos determinísticos. Os jogos EureKit são um recurso que pode ser usado por todos os professores e profissionais de divulgação científica, a fim de motivar a visualização e compreensão de muitos conceitos matemáticos. Para tal, é importante que aos professores seja disponibilizada formação adicional que lhes permita fazer um uso proveitoso de tais ferramentas e avaliar o impacto desta abordagem na sua dinâmica de sala de aula. O objetivo deste trabalho é orientar os professores e outros educadores interessados numa utilização rentável dos recursos disponíveis (em particular os jogos na exposição EureKit) e apresentar alguns exemplos de temas cuja introdução pode ser feita recorrendo a jogos matemáticos. A abordagem descrita é facilmente implementável uma vez que o projeto Eurekit torna acessíveis aos professores os recursos que constituem a exposição (jogos), bem como cursos de formação pedagógica para docentes de todos os níveis de ensino - da Educação Pré-Escolar ao Secundário.info:eu-repo/semantics/publishedVersio

MathE - Improve mathematical skills in higher education

Higher education students of scientific subjects often lack the basic mathematical skills to follow lectures and make the most of the lecturer’s teachings. It is necessary to identify the gaps in each students’ understanding of the concepts and offer teachers adequate resources to motivate and provide their students the skills and competences they miss. The main goal of MathE - Improve Maths Skills in Higher Education is to encourage training and exchange in order to enhance and strengthen the quality of teaching and to support the use of digital and online technologies to improve pedagogies and assessment methods. MathE also aims to set up transnational teacher training courses and strengthen cooperation between universities that already offer such courses.info:eu-repo/semantics/publishedVersio

Effect of mannan oligosaccharides extracts in uropathogenic escherichia coli adhesion in human bladder cells

info:eu-repo/semantics/publishedVersio

Chitosan and polyethylene glycol based membranes with antibacterial properties for tissue regeneration

The prevention of microbial infections associated with implantable medical devices and superficial wounds represents one of the main research strategies in the field of biomaterials. The present study reports on the development of composite membranes of Chitosan (CS)-Polyethylene glycol (PEG) matrix, incorporating particles of biphasic calcium phosphate (BCP), zinc oxide (ZnO) and copper oxide (CuO). The properties that are relevant for intended applications in tissue regeneration and antibacterial coatings of implants were assessed. It was found that the addition of 1% (w/w - relative to the mass of CS) of each metal oxide promoted satisfactory bacteriostatic activity and exhibited no cytotoxic effects towards the Vero cell line. The formation of bonds between the CS/PEG matrix and ionic species from the powders enhanced the cross-linking degree and mechanical properties of composite membranes in comparison to the non-doped membrane with the same polymer matrix (CS/PEG = 70/30%). A gradual degradation of the composite membranes over the immersion time in simulated body fluid (SBF) was accompanied by a continuous surface deposition of uniform apatite layer.publishe