Sobre a (in)visibilidade da aprendizagem

Neste relatório pretendo abordar algumas questões da camuflagem/invisibilidade da aprendizagem. Ao longo deste ano tive a oportunidade de estagiar na Escola Secundária de Ermesinde com o professor cooperante Pedro Casal. Durante o estágio acompanhei a turma de décimo segundo ano do curso profissional de Design Gráfico, tendo realizado a minha proposta de aula com a mesma. Ao longo do período de estágio fui-me apercebendo de que muitos alunos iam para a escola com muitas intenções sem que a aprendizagem fizesse parte das mesmas. Na sala de aula, todos os assuntos eram tratados à exceção da aprendizagem. Após perceber este desencanto pela escola, percebi que existia uma revolta para com esta, consequente da disciplina imposta e que resulta na invisibilidade da aprendizagem, ou seja, os alunos não conseguem percecionar as vantagens que a aprendizagem fornece tornando-a sem utilidade. A aprendizagem torna-se invisível. Contudo, quando os alunos não encontram um propósito na escola e esta se torna um local obrigatório a frequentar é necessário arranjar estratégias que contrariem este processo de desmotivação para com a escola. Através desta temática realizei a proposta de aula de forma a que a invisibilidade da aprendizagem possa ser usada como auxílio à aprendizagem

Intake of nanoparticles and impact on gut microbiota: in vitro and animal models available for testing

The oral delivery of compounds associated with diet or medication have an impact on the gut microbiota balance, which in turn, influences the physiologic process. Several reports have shown significant advances in clarifying the impact, interactions and outcomes of oral intake of nanoparticles and the human gut. These interactions may affect the bioavailability of the delivered compounds. In addition, there is a considerable breakthrough in the development of antimicrobial nanoparticles for intestinal pathogenic bacteria. Several in vitro fermentation and in vivo models have been developed throughout the years and were used to test these systems. The methodologies and studies carried out so far on the modulation of human and animal gut microbiome by oral delivery nanosized materials were reviewed. Overall, the available in vitro studies mimic the real physiological events enabling to select the best production conditions of nanoparticulate systems in a preliminary stage of research. On the other hand, animal studies can be used to access the dosage effect, safety and correlation between haematological, biochemical and symptoms, with gut microbiota groups and metabolites.info:eu-repo/semantics/publishedVersio

Chitosan microparticles oral delivery system of relaxing peptides

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Development and characterization of chitosan microparticles-in-films for buccal delivery of bioactive peptides

Nowadays, bioactive peptides are used for therapeutic applications and the selection of a carrier to deliver them is very important to increase the efficiency, absorption, release, bioavailability and consumer acceptance. The aim of this study was to develop and characterize chitosan-based films loaded with chitosan microparticles containing a bioactive peptide (sequence: KGYGGVSLPEW) with antihypertensive properties. Films were prepared by the solvent casting method, while the microparticles were prepared by ionic gelation. The final optimized chitosan microparticles exhibited a mean diameter of 2.5 m, a polydispersity index of 0.46, a zeta potential of +61 mV and a peptide association efficiency of 76%. Chitosan films were optimized achieving the final formulation of 0.79% (w/v) of chitosan, 6.74% (w/v) of sorbitol and 0.82% (w/v) of citric acid. These thin ( 0.100 mm) and transparent films demonstrated good performance in terms of mechanical and biological properties. The oral films developed were flexible, elastic, easy to handle and exhibited rapid disintegration (30 s) and an erosion behavior of 20% when they came into contact with saliva solution. The cell viability (75–99%) was proved by methylthiazolydiphenyl-tetrazolium bromide (MTT) assay with TR146 cells. The chitosan mucoadhesive films loaded with peptide–chitosan microparticles resulted in an innovative approach to perform administration across the buccal mucosa, because these films present a larger surface area, leading to the rapid disintegration and release of the antihypertensive peptide under controlled conditions in the buccal cavity, thus promoting bioavailability.info:eu-repo/semantics/publishedVersio

Edible films as oral delivery systems for xanthines extracted from medicinal plants: an experimental design approach

Two formulations of edible films intended for oral delivery of therapeutic xanthines were developed, following an experimental design approach. Gelatin type A and sodium carboxymethylcellulose were used as polymeric matrices with different physico-chemical nature. Caffeine, a well-known methylxhanthine, was used as model bioactive molecule, representing overall xanthines (e.g. caffeine, theophylline, theobromine) extracted from medicinal plants. Fourier-transform infrared spectroscopy (FTIR) analysis was performed to outwit the formation of covalent bonds between caffeine and the matrix of edible films. Scanning electron microscopy (SEM) was performed to assess if caffeine was homogeneously dispersed on the matrix of edible films. Simulation of gastrointestinal tract and ex vivo permeability studies across intestinal mucosa were performed to predict the delivery profile of caffeine from developed formulations of edible films. Gelatin type A-based edible films offered a slow release of caffeine whereas sodium carboxymethylcellulose-based edible films promote an immediate release of caffeine.info:eu-repo/semantics/publishedVersio

Periodontite apical e fatores de risco associados: estudo transversal

Objectives: The aim of this cross-sectional study was to investigate an association between the prevalence of root-filled teeth (RFT) or apical periodontitis (AP) and some systemic conditions or smoking habits in an adult Portuguese population. Methods: Medical histories, including age, gender, presence of cardiovascular disease (CVD), diabetes mellitus (DM), allergies, smoking status, and endodontic treatment data of 421 patients (10,540 teeth) were recorded. The prevalence of root filled teeth and the periapical status were assessed through panoramic radiographies. Periapical status was classified according to the Periapical index and AP was defined as PAI-score ≥3. Statistic analysis was performed with PASW Statistics 20.0 using qui-square tests, odds-ratio and confidence intervals (95%). Results: The overall prevalence of AP and RFT was 2.2% and 4.2%, respectively. RFT increased the possibility of having AP (p< 0.0001). Men's group showed a higher percentage of teeth with AP (p< 0.0001), less RFT (p = 0.05) and more residual roots (2.3%). Smoking increased the probability of having AP (p = 0.002) and RFT (p = 0.045). A positive correlation was observed between RFT and DM (p = 0.040). No statistically significant difference was found between AP and CVD, DM or allergies neither between RTF and CVD or allergies. Conclusions: The higher prevalence of AP and/or RFT in smoker subjects and in diabetic patients can suggest a relationship between oral and systemic health. More epidemiological studies are required before definitive conclusions can be made.Objetivos: O objetivo deste estudo transversal foi investigar a associação entre a prevalência de dentes com tratamento endodôntico (RFT) ou periodontite apical (AP) e algumas condições sistémicas ou hábitos tabágicos numa população adulta portuguesa. Métodos: Histórias médicas, incluindo idade, género, presença de doenças cardiovasculares (CVD), diabetes mellitus, alergias e hábitos tabágicos, e registos dos tratamentos endodônticos de 421 pacientes (10.540 dentes) foram recolhidos. A prevalência de dentes com tratamento endodôntico e status apical foram avaliados através de radiografias panorâmicas. O status apical foi classificado de acordo com o índice periapical e a AP definida para valores PAI≥3. A análise estatística foi realizada através do PASW Statistics 20.0 utilizando os testes chi-quadrado, valores odds-ratio e intervalos confiança (95%). Resultados: A prevalência da AP e RFT foi de 2,2% e 4,2%, respectivamente. RFT aumentou a possibilidade de ter AP (p<0,0001). Os homens revelaram uma maior percentagem de dentes com AP (p<0,0001), menos RFT (p=0,05) e mais raízes residuais (2,3%). Fumar aumentou a probabilidade de ter AP (p=0,002) e RFT (p=0,045). Uma relação positiva foi observada entre RFT e DM (p = 0,040). Não se encontraram diferenças estatisticamente significativas entre AP e CVD, DM ou alergias nem entre RTF e CVD ou alergias. Conclusões: Uma maior percentagem de AP e/ou RFT nos fumadores e nos pacientes com diabetes sugere uma relação entre a saúde oral e sistémica. Mais estudos epidemiológicos são necessários antes de se fazerem conclusões definitivas.info:eu-repo/semantics/publishedVersio

Management of fruit industrial by-products - a case study on circular economy approach

The management of industrial fruit by-products is important not only to decrease the volume of food waste accumulated in the landfills but also to develop strategies through reuse with the purpose to valorise and add economic value. The disposal of food waste leads to di erent global issues in di erent sectors, such as social, environmental and economical. These by-products represent a rich source of valuable compounds (polyphenols) with high antioxidant activity, which can be extracted through biotechnological methodologies for future industrial applications. In this context, the management of fruit by-products is challenged to move from a linear economy to a circular economy. Therefore, the purpose of this review is to provide a critical view of an integrated valorisation of fruit by-products to overcome a global issue, via the production of antioxidant extracts with high economic value. A case study of pineapple processing industrialization in a circular economy is explored and discussed.info:eu-repo/semantics/publishedVersio

Optimization of hemicellulose extraction from sugarcane straw by autohydrolysis

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Apical periodontitis and related risk factors: cross-sectional study

Objectives: The aim of this cross-sectional study was to investigate an association between the prevalence of root-filled teeth (RFT) or apical periodontitis (AP) and some systemic conditions or smoking habits in an adult Portuguese population. Methods: Medical histories, including age, gender, presence of cardiovascular disease (CVD), diabetes mellitus (DM), allergies, smoking status, and endodontic treatment data of 421 patients (10,540 teeth) were recorded. The prevalence of root filled teeth and the periapical status were assessed through panoramic radiographies. Periapical status was classified according to the Periapical index and AP was defined as PAI-score ≥3. Statistic analysis was performed with PASW Statistics 20.0 using qui-square tests, odds-ratio and confidence intervals (95%). Results: The overall prevalence of AP and RFT was 2.2% and 4.2%, respectively. RFT increased the possibility of having AP (p < 0.0001). Men’s group showed a higher percentage of teeth with AP (p < 0.0001), less RFT (p = 0.05) and more residual roots (2.3%). Smoking increased the probability of having AP (p = 0.002) and RFT (p = 0.045). A positive correlation was observed between RFT and DM (p = 0.040). No statistically significant difference was found between AP and CVD, DM or allergies neither between RTF and CVD or allergies. Conclusions: The higher prevalence of AP and/or RFT in smoker subjects and in diabetic patients can suggest a relationship between oral and systemic health. More epidemiological studies are required before definitive conclusions can be made.info:eu-repo/semantics/publishedVersio