Chiral Interactions and Sensing at Liquid|Liquid Interface

Chiral interactions of compounds with therapeutic interest and its study predicting and interpreting transport process across biological barriers represents one of the most important topics in research. This thesis is devoted to the study of chiral ion transfer at the interface between two immiscible electrolytes solutions (ITIES), as a promising method of simplifying chiral detection and separation. As a proof of concept, for the study of chiral compounds at liquid|liquid interface, three different approaches were used: i) chiral stationary phases based on modified cyclodextrins, AcαCD and AcβCD, ii) chiral acute phase protein, α1-acid-glycoprotein (AGP) and iii) thick film electrode modified with an ethylated cyclodextrin ferrocene (EtCDFc). The chiral selectors used, AcαCD, AcβCD, AGP and EtCDFc display complex three-dimensional structures that are capable of recognising specifically the enantiomers of a drug molecule, with different affinity. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to investigate the enantioselective interaction between the chiral molecules. In the study of chiral ion transfer using AcαCD and AcβCD, as a chiral organic phase, it was observed that the two lipophilic CDs facilitated the transfer of ephedrine ions by the formation of inclusion complexes. The enantioselectivity was achieved as the complexes between the protonated ephedrine ions and the CDs lead two different signal responses as a result of different affinities in the complex formation. Furthermore, the positive enantiomer (+)EPH+ showed to be consistently the cation being transferred at less positive potentials suggesting that it binds preferentially with the chiral selectors, in comparison with (-)EPH+, indicating that its transfer is more facile. The difference in stability constant between the (+)EPH+ and (-)EPH+ complexes was found to be 1.41±0.1 for AcβCD and 1.20±0.1 for AcαCD. When investigating the chiral interactions between the AGP and the three basic drugs (propranolol, lidocaine and procaine hydrochloride), it was found, that the plasma protein binds to the protonated drugs with clear different affinities. The formation of a complex between the drugs and AGP was shown as a decrease in the CV and DPV responses, corresponding to the reduction in the transfer of the cationic drugs, as only the unbound (free) drug was able to be transferred across the liquid|liquid interface. The bound and unbound drug concentration was estimated in a different range of concentrations based on the responses obtained in the presence and absence of the protein. The differences in current responses, observable in the measurements, lead to chiral discrimination between R- and S-propranolol. Scatchard analysis was employed to calculate the association constant and the number of binding sites of the drugs with AGP. The calculated association constants were 2.7x105 M-1 for S- and 1.3x105 M-1 for R-propranolol, which were significantly higher than those for lidocaine, 1.2x104 M-1, and for procaine,8.4x103 M-1. This showed that AGP has more affinity for R- and S-propranolol than lidocaine or procaine hydrochloride. A thick film modified electrode with a chiral redox probe, ethylated ferrocene cyclodextrin (EtCDFc) was used to study chiral ion transfer across the liquid|liquid interface coupled to a redox reaction. EtCDFc has a dual role, a redox active moiety and a cyclodextrin moiety which is able to form chiral complexes. Thus, the redox reaction of EtCdF was accompanied by the complexation of mandelic acid enantiomers with the cyclodextrin part of EtCDFc, with the two reactions mutually influencing each other. In addition the thick film ensured that the generated product of the molecular probe was within the diffusion layer and away from the aqueous|organic solvent interface, so that the charge neutrality of the organic film was only maintained by the presence of ions from the aqueous phase

The impact of an online mathematics education project (MATACTIVA) on higher education students

The Online Mathematics Education Project (MatActiva) is an exciting new initiative which aims to support and enhance mathematics education. The project is led by the Institute of Accounting and Administration of Porto (ISCAP), part of the Polytechnic Institute of Porto (IPP). It provides innovative resources and carefully constructed materials around themes such as Elementary Mathematics, Calculus, Algebra, Statistics and Financial Mathematics to help support and inspire students and teachers of mathematics. The goal is to increase mathematical understanding, confidence and enjoyment, enrich the mathematical experience of each person, and promote creative and imaginative approaches to mathematics. Furthermore the project can be used to deliver engaging and effective mathematics instruction through the flipped classroom model. This paper also presents the findings of a large survey, whose propose was to study the student’s reaction to the project

Relationship between the ratio of the cervical muscles and non-specific neck pain in the school community

Neck disorders appear more often associated with pain and muscle fatigue, both in young individuals and in individuals of middle age. Sustained muscle contraction needed to maintain the head in several positions and fatigue caused by muscle weakness are some of the factors for the arising of neck pain.info:eu-repo/semantics/publishedVersio

Influence of exercise on functional capacity and in the lumbar and thoracic disability in ankylosing spondylitis

Ankylosing Spondylitis (AS) is a chronic inflammatory disease, associated to spine moblity limitations. Until today it isn’t known an efficient treatment; although, there are therapeutic strategies, like exercise, that can alleviate and delay the disease complications.info:eu-repo/semantics/publishedVersio

Educação para os media nas sociedades multimediáticas

A passagem da cultura de massas à cultura multimediática é marcada pela propagação, global e altamente veloz, de uma “pandemia”: a disseminação do “vírus da informação”, especialmente por via digital e em rede. As sociedades contemporâneas são learning cultures (Buckingham), potencialmente geradoras de indivíduos (cada vez mais) dependentes de informação: são os novos infoadictos, os junkies de informação. A proliferação de meios de comunicação multiplataforma e a multiplicação de receptores-produtores-receptores (utilizadores-participantes) e das suas mensagens mediáticas, potenciadas pelo desenvolvimento e integração com as Tecnologias da Informação e Comunicação (TIC), parecem estar na base de um novo paradigma sociocomunicacional de grande complexidade. Neste contexto, ter ou não ter acesso à informação e, simultaneamente, ter ou não ter competências interpretativas, analíticas, críticas e comunicativas que permitam descodificar e codificar eficazmente essa mesma informação num “tempo-espaço comprimido” (Harvey) parece determinante para a integração social plena. É por isso que faz todo o sentido falar em educação para os media.The transition from mass culture to multimedia culture has been marked by the global and high-speed spread of a “pandemic”: the dissemination of the “information virus”, especially by digital means and on-line. Contemporary societies are learning cultures (Buckingham) that potentially produce (increasingly) information-dependent individuals: they are the new info-addicts, the information junkies. The proliferation of multiplatform-based means of communication and the multiplication of receivers-producers-receivers (users-participants) and their media messages, boosted by development of and integration with ICT (Information and Communication Technology), appears to form the basis of a new highly complex socio-communicational paradigm. In this situation, having or not having access to information and, at the same time, having or not having interpretative, analytical, critical and communicative skills that allow an individual to effectively encode and decode this same information in “compressed time-space” (Harvey) seem decisive for full social integration. For this reason, it makes complete sense to talk about education for the media

Prevalence of cervical pain and functional disability in the school community

The school community is exposed to numerous risk factors for the occurrence of neck pain. These symptoms may cause restrictions on their functional capacity and there’s a need to make a proper measurement of this phenomenon, in a valid and reproducible manner. For this, the most recommended instrument is the Neck Disability Index (NDI); however its use in Portugal requires an analysis of its psychometric properties.info:eu-repo/semantics/publishedVersio

Effect of exercise on quality of sleep in patients with ankylosing spondylitis

Ankylosing spondylitis (AS) is an inflammatory rheumatic disease, associated with limited mobility of the spine, sleep disturbance, and fatigue. The exercise aims are to preserve mobility and decrease sleep disorders.info:eu-repo/semantics/publishedVersio

Creating interactive learning materials to promote statistical skills in higher education

Novas oportunidades de aprendizagem ao longo da vida, currículos alternativos no ensino pré-universitário e políticas bastante “abertas” de acesso ao Ensino Superior (ES) têm potenciado, nas últimas décadas, o problema da falta de homogeneização de saberes e competências dos alunos “calouros” em Instituições de Ensino Superior (IES). Este problema torna-se avassalador quando se trata de unidades curriculares básicas "construtivas", como a Matemática ou a Estatística, em licenciaturas não matemáticas, em áreas como a Administração, Contabilidade ou Gestão. Esta é uma “luta” diária que os docentes destas unidades curriculares enfrentam ao tentarem falar de disciplinas mais avançadas a um público muito heterogéneo, com diferenças significativas na formação matemática, promovendo a participação de todos os alunos e evitando o abandono precoce de alguns . Neste sentido, Neste artigo serão apresentadas algumas dessas estratégias, desenvolvidas no Politécnico do Porto (P.PORTO) e baseadas na criação e utilidade dos materiais interativos de ensino e aprendizagem. Sentiu-se a real necessidade de inovar no processo de ensino-aprendizagem e a procura de um bom software de apoio, que permitisse desenvolver todos os materiais e implementar interações reais, culminou com a escolha do iSpring Suite 9. Este software é um poderoso kit de ferramentas de eLearning para PowerPoint que permite desenvolver cursos, videoaulas e avaliações de qualidade que funcionarão em qualquer desktop, laptop e plataforma móvel. Portanto, o uso do iSpring Suite 9 será descrito...info:eu-repo/semantics/publishedVersio