Exploring blended learning tools to transform a laboratory course unit in engineering: Challenges, setbacks and rewards

To boost students engagement on learning outcomes, promote active peer learning, and adopt more dynamic teaching practices, a module of a laboratory course unit (TPL) in engineering was reformulated exploring blended learning. This reformulation was even more challenging than initially anticipated as it was implemented during the Covid-19 pandemic. As TPL learning practises are based on the operation of laboratory modules mimicking heat and mass transfer phenomena, asynchronous and on-line synchronous learning classes and face-to-face laboratory classes were outlined. To promote the asynchronous learning, a full script of TPL and pitch and longer videos presenting, respectively, each work and its practical operation process were formerly prepared and available online. Students were required to work in group to define the variables and conditions to be evaluated in each laboratory module, organize and plan the experimental activities, create data recording documents, and later present and argue their options in virtual synchronous classes. In the face-to-face classes, different activities were performed in a rotating system, scheduled and tuned in the online classes. It was also aimed in-situ promoting peer discussion of the data and reports elaboration, goals not attained due to the pandemic restrictions, as only two students of each group were present in each hands-on class and in sequential times. TPL reformulation was a tough and time-consuming task since 73 students were enrolled, divided into 3 shifts, each one with 5 groups of five students. Students individual learning evolution was inferred through online quizzes that were periodically made available. A final inquiry, launched to obtain students` opinion about this transformation endeavour highlighted the script, videos, and the prompt teachers feedback on the reports as the most fruitful and important aspects for students engagement and guide their learning pathway. The rationale behind this paper was to disclose this transformation experience and share information and strategies that can be used in the teaching/learning of laboratory classes. © 2021 University of Minho. All rights reserved.(undefined)info:eu-repo/semantics/publishedVersio

Effect of flow perfusion conditions in the chondrogenic differentiation of bone marrow stromal cells cultured onto starch based biodegradable scaffolds

Cartilage tissue engineering (TE) typically involves the combination of a 3-D biodegradable polymeric support material, with primary chondrocytes or other cell types able to differentiate into chondrocytes. The culture environment in which cell–material constructs are created and stored is an important factor. Various bioreactors have been introduced in TE approaches to provide specific culturing environments that might promote and accelerate cells’ potential for chondrogenic differentiation and enhance the production of cartilage extracellular matrix. The aim of the present study was to investigate the chondrogenic differentiation of goat bone marrow cells (GBMCs) under flow perfusion culture conditions. For that purpose, GBMCs were seeded into starch–polycaprolactone fiber mesh scaffolds and cultured in a flow perfusion bioreactor for up to 28 days using culture medium supplemented with transforming growth factor-b1. The tissue-engineered constructs were characterized after several end points (7, 14, 21 and 28 days) by histological staining and immunocytochemistry analysis, as well as by glycosaminoglycan and alkaline phosphatase quantification assays. In addition, the expression of typical chondrogenic markers was assessed by real-time reverse-transcription polymerase chain reaction analysis. In general, the results obtained suggest that a flow perfusion microenvironment favors the chondrogenic potential of GBMCs.EXPERTISSUES NMP3-CT-2004-500283Fundação para a Ciência e a Tecnologia (FCT) - Vivo Tissue (PTDC/CVT/67677/2006

MARCADORES DE STRESS OXIDATIVO NA POLINEUROPATIA AMILOIDÓTICA FAMILIAR

MARCADORES DE STRESS OXIDATIVO NA POLINEUROPATIA AMILOIDÓTICA FAMILIAR Henrique Reguengo1,2, Maria Luís Cardoso2, Teresa Coelho3, Ana Martins3, Marta Novais3, Luísa Gomes1, Isabel Fonseca3, Berta Martins4, Franklim Marques2 1Serviço de Química Clínica, HSA/CHP, 2FFUP, 3Unidade Clínica de Paramiloidose, HSA/CHP, 4Laboratório de Imunogenética, ICBAS/UP. Hospital de Santo António, Centro Hospitalar do Porto (HSA/CHP), Porto. Faculdade de Farmácia, Universidade do Porto (FF/UP), Porto. Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto (ICBAS/UP), Porto. Introdução A Polineuropatia Amilóidotica Familiar (PAF) é uma amiloidose hereditária associada a variantes de transtirretina (TTR), em que ocorre deposição sistémica de amilóide, principalmente a nível dos nervos periféricos. Alguns estudos sugerem que o stress oxidativo pode estar envolvido na formação e modificação das fibrilas de amilóide. Fisiologicamente, o organismo defende-se das agressões mediadas pelos radicais livres utilizando diversas reservas antioxidantes celulares. Estudos realizados revelam diferentes respostas ao stress oxidativo envolvendo o malondialdeído (MDA), a capacidade antioxidante total (TAS), algumas vitaminas (A e E) e enzimas: glutationa reductase (GRed) e a superóxido dismutase (SOD). Objectivos Este estudo pretendeu quantificar alguns marcadores de stress oxidativo e analisar as diferenças entre doentes com PAF e portadores assintomáticos. Material e Métodos Foram incluídos 40 doentes com diagnostico de PAF e 45 portadores assintomáticos da mutação, procedentes da Unidade Clínica de Paramiloidose. Procedeu-se à avaliação da TAS da GRed e da SOD, respectivamente através dos Kit comerciais da Randox TAS NX2332, Glutationa Reductase ref. GR 2368, RANSOD ref. SD 125 e do MDA com o kit comercial da Zeptometrix, OXItek TBARS. Ref. 0801192. A comparação entre os grupos foi efectuada pelo teste t de student para amostras independentes e a relação entre as variáveis pela correlação de Pearson. Resultados Os valores de TAS e GRed foram significativamente mais elevados no grupo de doentes com PAF comparativamente aos portadores assintomáticos (P=0.02 e P=0.03, respectivamente). Entre os dois grupos, não se verificaram diferenças significativas no MDA, SOD e vitaminas A e E. No grupo de doentes com PAF, foi encontrada uma correlação significativa entre a TAS e a função renal avaliada pela creatinina sérica (r=0.60, P=0.01) e pela cistatina C (r=0.51, P=0.01). Nos portadores assintomáticos apenas a creatinina se correlacionou com a TAS, mas não a cistatina C. Apesar do grupo dos doentes com PAF apresentar valores mais elevados de creatinina sérica, as diferenças não foram significativas e o valor máximo apresentado foi de 1,46 mg/dl nos PAF e 1,02 mg/dl nos portadores assintomáticos. Conclusão Apesar do MDA não apresentar diferenças estatisticamente significativas, a capacidade antioxidante parece ser superior nos doentes com PAF comparativamente aos portadores assintomáticos. Os resultados revelam ainda uma correlação positiva significativa entre a TAS e os níveis séricos de creatinina e de cistatina C. É possível que o aumento dos valores de TAS reflicta um mecanismo de defesa ao aumento de stress oxidativo, geralmente associado à disfunção renal, avaliada pela creatinina e pela cistatina C. Apresentador: Henrique Reguengo, Técnico Superior de Saúde, Serviço de Quimica Clínica, HSA/CHP; Aluno de Doutoramento em Ciências Farmacêuticas, FF/UP

Xanthohumol-supplemented beer modulates angiogenesis and inflammation in a skin wound healing model. Involvement of local adipocytes

Angiogenesis and inflammation are two intermingled processes that play a role in wound healing. Nevertheless, whenever exacerbated, these processes result in nonhealing wounds. Xanthohumol (XN), a beer-derived polyphenol, inhibits these processes in many physiopathological situations. This study aimed at examining whether XN ingestion affects wound healing. Wistar rats drinking water, 5% ethanol, stout beer (SB) or stout beer supplemented with 10 mg/L XN (Suppl SB) for 4 weeks, were subjected to a 1.5 cm full skin-thickness longitudinal incision, and further maintained under the same beverage conditions for another week. No differences in beverage consumption or body weight were found throughout the study but food intake decreased in every group relative to controls. Consumption of Suppl SB resulted in decreased serum VEGF levels (18.42%), N-acetylglucosaminidase activity (27.77%), IL1β concentration (9.07%), and NO released (77.06%), accompanied by a reduced redox state as observed by increased GSH/GSSG ratio (to 198.80%). Also, the number of blood vessels within the wound granulation tissue seems to reduce in animals drinking Suppl SB (23.08%). Interestingly, SB and primarily Suppl SB showed a tendency to increase adipocyte number (to 194.26% and 156.68%, respectively) and reduce adipocyte size (4.60% and 24.64%, respectively) within the granuloma. Liver function and metabolism did not change among the animal groups as analyzed by plasma biochemical parameters, indicating no beverage toxicity. This study shows that XN intake in its natural beer context reduced inflammation, oxidative stress, and angiogenesis, ameliorating the wound healing process, suggesting that this polyphenol may exert beneficial effect as a nutritional supplement.info:eu-repo/semantics/publishedVersio

Application of benzo[a]phenoxazinium chlorides in antimicrobial photodynamic therapy of Candida albicans biofilms

The use of Antimicrobial Photodynamic Therapy (APDT) as a new approach to treat localized Candida infections is an emerging and promising field nowadays. The aim of this study was to verify the efficacy of photodynamic therapy using two new benzo[a]phenoxazinium photosensitizers against Candida albicans biofilms: N-[5-(3-hydroxypropylamino)-10-methyl-9H-benzo[a]phenoxazin-9-ylidene]ethanaminium chloride (FSc) and N-(5-(11-hydroxyundecylamino)-10-methyl-9H-benzo[a]phenoxazin-9-ylidene)ethanaminium chloride (FSd). The photodynamic activity of dyes against C. albicans biofilms was evaluated by incubating biofilms with dyes in the range of 100-300 μM for 3 or 18 h followed by illumination at 12 or 36 J cm-2, using a xenon arc lamp (600 ± 2 nm). A total photoinactivation of C. albicans biofilm cells was achieved using 300 μM of FSc with18 h of incubation, followed by illumination at 36 J cm-2. Contrarily, FSd had insignificant effect on biofilms inactivation by APDT. The higher uptake of FSc than FSd dye by biofilms during the dark incubation may explain the greater photodynamic effectiveness achieved with FSc. The results obtained stresses out the FSc-mediated APDT potential use to treat C. albicans infections.This work was supported by the research grant SFRH/BD/72742/2010 from "Fundacao para a Ciencia e Tecnologia" (FCT), Portugal. The authors also thank the Project "BioHealth - Biotechnology and Bioengineering approaches to improve health quality", Ref. NORTE-07-0124-FEDER-000027, co-funded by the Programa Operacional Regional do Norte (ON.2 - 0 Novo Norte), QREN, FEDER and the FCT Strategic Project PEst-OE/EQB/LA0023/2013. In addition, financial to Centre of Chemistry and Centre of Physics through CQ/UM [PEst-C/QUI/UI0686/2013 (FCOMP-01-0124FEDER-037302)] and CFUM [PEst-C/FIS/UI0607/2013 (F-COMP-01-0124-FEDER-037291)], as well as a post-doctoral grant to B.R. Raju (SFRH/BPD/62881/2009) is also acknowledged to FCT, POPH-QREN, FSE

Nanoencapsulation of bovine lactoferrin for oral hygiene applications

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Novel hydroxyapatite/chitosan bilayered scaffold for osteochondral tissue-engineering applications : scaffold design and its performance when seeded with goat bone marrow stromal cells

Recent studies suggest that bone marrow stromal cells are a potential source of osteoblasts and chondrocytes and can be used to regenerate damaged tissues using a tissue-engineering (TE) approach. However, these strategies require the use of an appropriate scaffold architecture that can support the formation de novo of either bone and cartilage tissue, or both, as in the case of osteochondral defects. The later has been attracting a great deal of attention since it is considered a difficult goal to achieve. This work consisted on developing novel hydroxyapatite/chitosan (HA/CS) bilayered scaffold by combining a sintering and a freeze-drying technique, and aims to show the potential of such type of scaffolds for being used in TE of osteochondral defects. The developed HA/CS bilayered scaffolds were characterized by Fourier transform infra-red spectroscopy, X-ray diffraction analysis, micro-computed tomography, and scanning electron microscopy (SEM). Additionally, the mechanical properties of HA/CS bilayered scaffolds were assessed under compression. In vitro tests were also carried out, in order to study the water-uptake and weight loss profile of the HA/CS bilayered scaffolds. This was done by means of soaking the scaffolds into a phosphate buffered saline for 1 up to 30 days. The intrinsic cytotoxicity of the HA scaffolds and HA/CS bilayered scaffolds extract fluids was investigated by carrying out a cellular viability assay (MTS test) using Mouse fibroblastic-like cells. Results have shown that materials do not exert any cytotoxic effect. Complementarily, in vitro (phase I) cell culture studies were carried out to evaluate the capacity of HA and CS layers to separately, support the growth and differentiation of goat marrow stromal cells (GBMCs) into osteoblasts and chondrocytes, respectively. Cell adhesion and morphology were analysed by SEM while the cell viability and proliferation were assessed by MTS test and DNA quantification. The chondrogenic differentiation of GBMCs was evaluated measuring the glucosaminoglycans synthesis. Data showed that GBMCs were able to adhere, proliferate and osteogenic differentiation was evaluated by alkaline phosphatase activity and immunocytochemistry assays after 14 days in osteogenic medium and into chondrocytes after 21 days in culture with chondrogenic medium. The obtained results concerning the physicochemical and biological properties of the developed HA/CS bilayered scaffolds, show that these constructs exhibit great potential for their use in TE strategies leading to the formation of adequate tissue substitutes for the regeneration of osteochondral defects

Bioactivity of chitosan-based particles loaded with plant-derived extracts for biomedical applications: emphasis on antimicrobial fiber-based systems

Marine-derived chitosan (CS) is a cationic polysaccharide widely studied for its bioactivity, which is mostly attached to its primary amine groups. CS is able to neutralize reactive oxygen species (ROS) from the microenvironments in which it is integrated, consequently reducing cell-induced oxidative stress. It also acts as a bacterial peripheral layer hindering nutrient intake and interacting with negatively charged outer cellular components, which lead to an increase in the cell permeability or to its lysis. Its biocompatibility, biodegradability, ease of processability (particularly in mild conditions), and chemical versatility has fueled CS study as a valuable matrix component of bioactive small-scaled organic drug-delivery systems, with current research also showcasing CS's potential within tridimensional sponges, hydrogels and sutures, blended films, nanofiber sheets and fabric coatings. On the other hand, renewable plant-derived extracts are here emphasized, given their potential as eco-friendly radical scavengers, microbicidal agents, or alternatives to antibiotics, considering that most of the latter have induced bacterial resistance because of excessive and/or inappropriate use. Loading them into small-scaled particles potentiates a strong and sustained bioactivity, and a controlled release, using lower doses of bioactive compounds. A pH-triggered release, dependent on CS's protonation/deprotonation of its amine groups, has been the most explored stimulus for that control. However, the use of CS derivatives, crosslinking agents, and/or additional stabilization processes is enabling slower release rates, following extract diffusion from the particle matrix, which can find major applicability in fiber-based systems within ROS-enriched microenvironments and/or spiked with microbes. Research on this is still in its infancy. Yet, the few published studies have already revealed that the composition, along with an adequate drug release rate, has an important role in controlling an existing infection, forming new tissue, and successfully closing a wound. A bioactive finishing of textiles has also been promoting high particle infiltration, superior washing durability, and biological response.FCT. Portuguese Foundation for Science and Technology (FCT), FEDER funds by means of Portugal 2020 Competitive Factors Operational Program (POCI) and the Portuguese Government (OE), grant number PTDC/CTMTEX/28074/2017 (POCI-01-0145- FEDER-028074). Authors also acknowledge project UID/CTM/00264/2021 of Centre for Textile Science and Technology (2C2T), funded by national funds through FCT/MCTES. J.D. and C.S.M. also acknowledge FCT for PhD grants 2020.07387.BD and 2020.08547.BD, respectivel

Phase Competitions behind the Giant Magnetic Entropy Variation: Gd5Si2Ge2 and Tb5Si2Ge2 Case Studies

Magnetic materials with strong spin-lattice coupling are a powerful set of candidates for multifunctional applications because of their multiferroic, magnetocaloric (MCE), magnetostrictive and magnetoresistive effects. In these materials there is a strong competition between two states (where a state comprises an atomic and an associated magnetic structure) that leads to the occurrence of phase transitions under subtle variations of external parameters, such as temperature, magnetic field and hydrostatic pressure. In this review a general method combining detailed magnetic measurements/analysis and first principles calculations with the purpose of estimating the phase transition temperature is presented with the help of two examples (Gd5Si2Ge2 and Tb5Si2Ge2). It is demonstrated that such method is an important tool for a deeper understanding of the (de)coupled nature of each phase transition in the materials belonging to the R5(Si,Ge)4 family and most possibly can be applied to other systems. The exotic Griffiths-like phase in the framework of the R5(SixGe1-x)4 compounds is reviewed and its generalization as a requisite for strong phase competitions systems that present large magneto-responsive properties is proposed