O TRABALHO PEDAGÓGICO COM WEB RÁDIO: UM RELATO DE EXPERIÊNCIA EM CONTEXTO DE ENSINO REMOTO

The Information and Communication Technologies (ICT) applied to education represent innovations that facilitate pedagogical work. In the context of remote teaching due to the Covid-19 pandemic, educational systems have been forced to adopt creative paths and experiences involving ICT in their educational processes. Thus, the objective of this article is to present an experience report in remote teaching at a Public University about the use of web radio for educational purposes. The methodology used in the reported experience is the qualitative research approach with the technical procedure of action research. The article describes the technical procedures of assembly, transmission, process management, content production, as well as audience data and impressions of Pedagogy students in two disciplines. Among the results and conclusions, the educational potential of using web radio can be highlighted, as well as the research paths that can derive from it.Las Tecnologías de la Información y la Comunicación (TIC) aplicadas a la educación representan innovaciones que facilitan el trabajo pedagógico. En los contextos de enseñanza remota debido a la pandemia de Covid-19, los sistemas educativos se vieron obligados a adoptar caminos y experiencias creativas que involucran TIC en sus procesos educativos. Por lo tanto, el objetivo de este artículo es presentar un informe de experiencia en la enseñanza remota en una universidad pública sobre el uso de la radio web con fines educativos. Como metodología del informe de experiencia, se utiliza el enfoque cualitativo de investigación con un procedimiento técnico de investigación-acción. En el artículo se describen los procedimientos técnicos de montaje, transmisión, gestión de procesos, producción de contenidos, así como datos de audiencia e impresiones de estudiantes del curso de Pedagogía en dos disciplinas. Entre los resultados y conclusiones se puede señalar el potencial educativo del uso de la radio web, así como los caminos de investigación que pueden derivar.  As Tecnologias de Informação e Comunicação (TIC) aplicadas à educação representam inovações que facilitam o trabalho pedagógico. Nos contextos de ensino remoto em função da pandemia de Covid-19 os sistemas educacionais foram forçados a adotar caminhos e experiências criativas envolvendo TIC em seus processos educativos. Destarte o objetivo desse artigo é apresentar um relato de experiência no ensino remoto em uma Universidade Pública sobre a utilização de web rádio com fins educacionais. Como metodologia da experiência relatada se utiliza o enfoque qualitativo de pesquisa com procedimento técnico de pesquisa-ação. No artigo se descreve os procedimentos técnicos de montagem, transmissão, gestão de processos, produção de conteúdos, bem como dados de audiência e impressões de estudantes de curso de Pedagogia em duas disciplinas. Entre os resultados e conclusões pode-se apontar para o potencial educativo do uso de web rádio, bem como os caminhos de pesquisa de que podem derivar

The role of α2,3- and α2,6-sialylation

RESUMO: Os glicoconjugados que decoram a superfície celular e os lípidos e proteínas secretados ocupam o ponto de encontro onde normalmente ocorrem interacções críticas homólogas (hospedeiro-hospedeiro) e heterólogas (hospedeiro-patogénio). Apesar de ser largamente aceite que os glicanos são parte integrante do processo de imunidade, continua a não ser claro qual o papel que os glicanos, em toda a sua diversidade, tomam no quadro geral da imunidade. Os glicanos, que são frequentemente terminados por resíduos de ácido siálico, podem ser alterados por factores externos, tais como patogénios, ou por acontecimentos fisiológicos celulares específicos. Normalmente em posição terminal, as glico-estruturas que contêm ácido siálico assumem um papel fundamental numa quantidade substancial de receptores imunes envolvidos na adesividade e tráfico celular, tal como as Selectinas e as Siglecs, das quais se sabe apresentarem uma relevante função imune. À altura do início desta tese, era sabido que os ácidos siálicos expressos à superfície das células poderiam modular mecanismos importantes nas respostas imunes adaptativas. Considerando a posição de charneira que as células dendríticas (DCs) ocupam na transição da resposta imune inata para a adaptativa, antecipámos que os ácidos siálicos poderiam também modular mecanismos relevantes nas DCs humanas. As DCs têm uma função muito relevante na verificação e captura antigénica, migração para os gânglios linfáticos e apresentação antigénica aos linfócitos, uma sequência de funções que conduz, em ultima instância, à indução da resposta inata adaptativa. Considerando estas premissas, a nossa hipótese principal foi que os ácidos siálicos podem influenciar funções relevantes das DCs, tais como captura de antigénios, maturação, migração para os gânglios linfáticos e apresentação antigénica às células Para testar esta hipótese, dividimos o trabalho em quatro partes: 1) Analisámos os glicanos sialilados de superfície, expressos durante a diferenciação de monócitos humanos em DCs (moDCs). Os nossos dados mostraram que a expressão dos glicanos com ligações em O (O-glicanos) e sialilados em α2,3, assim como glicanos com ligações em N (N-glicanos) sialilados em α2,6 e α2,3 aumentou durante o processo de diferenciação das moDCs. Contribuindo para esta nova configuração glicosídica, três sialiltransferases (STs) poderão estar envolvidas: a ST6Gal-1 correlaciona-se com a expressão aumentada de N-glicanos sialilados em α2,6; a ST3Gal-1 contribui para a sialilação em α2,3 de O-glicanos, em especial de antigénios T; e a ST3Gal-4 poderá ser responsável pelo aumento de N-glicanos sialilados em α2,3. Após estímulo e consequente maturação das moDCs, ambos os níveis de expressão génica de ST6Gal-1 e ST3Gal-4 são negativamente modificados sendo, também, que a expressão de ST3Gal-1 varia consoante o estímulo. 2) Estudámos posteriormente as consequências da modulação dos ácidos siálicos de superfície nas funções das DCs. Observámos que a remoção dos ácidos siálicos de superfície diminui significativamente a capacidade de macropinocitose e endocitose mediada por receptores nas moDCs. Em contrapartida, o tratamento com sialidase aumentou significativamente a capacidade das moDCs para fagocitar Escherichia coli. Determinou-se também que este mecanismo requer a existência de ácido siálico presente nas E. coli indicando um mecanismo de interacção hospedeiro-patogénio dependente de ácido siálico em ambas as partes envolvidas. As moDCs tratadas com sialidase também apresentam um nível superior de expressão de moléculas de MHC e moléculas co-estimulatórias, sugerindo um fenótipo celular mais maduro. Recorrendo ao modelo de ratinho, utilizaram-se DCs derivadas de células da medula (BMDCs) de ratinhos deficientes em ST3Gal-1 e ST6Gal-1. Estes ensaios revelaram que quer a endocitose quer a maturação são influenciadas por modificações 37 nos glicanos sialilados em α2,3 ou α2,6. A detecção e quantificação de proteínas Nglicosiladas e sialiladas em α2,6 apontou para um potencial envolvimento de integrinas β2 nestes mecanismos. 3) O efeito da sialilação em α2,6 na migração das DCs para os gânglios linfáticos foi também analisado. Observámos que BMDCs deficientes para ST6Gal-1 apresentam uma redução de cerca de 50% nos níveis de migração das DCs para os gânglios linfáticos, tal como aferido em ensaios de inflamação in situ e estudos de transferência adoptiva de células. Uma redução dos níveis deste tipo de migração foi também observada quando BMDCs nativas foram transferidas para ratinhos receptores deficientes em ST6Gal-1. São, contudo, necessários mais ensaios de forma a identificar as moléculas envolvidas neste processo. 4) Por último, analisámos o impacto da sialilação na estimulação antigénica das DCs às células T. Assim, concluiu-se que moDCs tratadas com sialidase apresentam um nível de expressão superior de IL-12, TNF-ɑ, IL-6 e IL-10, e activação do factor de transcrição nuclear kappa B (NF-κB). As DCs tratadas com sialidase induziram uma maior proliferação nas células T, com expressão correspondente de interferão-γ. Este dado sugere que a remoção de ácidos siálicos de superfície contribui para o desenvolvimento de uma resposta pro-inflamatória do tipo 1 por células T auxiliares (resposta Th1). Considerando estes dados no seu todo, concluímos que o ácido siálico tem um papel marcante nas funções imunes das DCs. Alterações à concentração de ácido siálico à superfície das células podem alterar a endocitose/fagocitose, maturação, migração para os tecidos e gânglios linfáticos e capacidade estimulatória para com as células T. Complementando estes dados, as ligações glicosídicas de ácidos siálicos criados por ST6Gal-1 e ST3Gal-1 são funcionalmente relevantes. A modulação programada da sialilação do glicocálice, mediada por sialidases individuais ou sialiltransferases é uma possibilidade aceitável para a melhoria da fagocitose por DCs e da sua potência imunológica. Este facto tem um significado particular para imunoterapias baseadas em DCs, podendo provar-se decisivo para a sua eficiência e aplicabilidade num futuro muito próximo.-------------------------------ABSTRACT: Glycans decorating cell surface and secreted proteins and lipids occupy the junction where critical host–host and host-pathogen interactions occur. In spite of the wide acceptance that glycans are centrally implicated in immunity, exactly how glycans and their variety and variability contribute to the overall immune response remains poorly defined. Glycans, frequently terminated by sialic acid residues, may be modified by external factors such as pathogens or upon specific physiological cellular events. The terminal, privileged positions of sialic acid-modified structures makes them key, fundamental determinants for a number of immune receptors with known involvement in cellular adhesiveness and cell trafficking, such as Selectins and Siglecs, with known relevant immune functions. At the time this thesis was initiated, it was established that sialic acids expressed at cell surface could modulate important mechanisms of the adaptive immune responses. Given the key role of dendritic cells (DCs) in the transition from innate to the adaptive immune responses, we anticipated that sialic acids could also modulate important mechanisms of human DCs. DCs have a relevant role in antigen screening and uptake, migration to lymph nodes and antigen presentation to lymphocytes, ultimately triggering the adaptive immune response. Therefore, our primary hypothesis was that sialic acids may modulate DC functions, such as antigen uptake, maturation, homing to lymph nodes and antigen presentation to T cells. To test this hypothesis, we divided our work in four parts. 1) Surface sialylated glycans expressed during differentiation from human monocytes to DCs (moDCs) were analyzed. Our data showed that α2,3-sialylated O-glycans and α2,6- and α2,3-sialylated N-glycans expression increased during moDC differentiation. Three main sialyltransferases (STs) are committed with this new glycan configuration: ST6Gal- 1 correlates with the increased expression of α2,6-sialylated N-glycans; ST3Gal-1 32 contributes for the α2,3-sialylation of O-glycans, especially T antigens; and ST3Gal-4 may contribute for the increased α2,3-sialylated N-glycans. Upon moDC maturation, ST6Gal-1 and ST3Gal-4 are downregulated and ST3Gal-1 is altered in a stimulus dependent manner. 2) We subsequently analyzed the consequences of the modulation of cell surface sialic acids in DC functions. We observed that removing surface sialic acid by sialidase significantly decreased the capacity of moDCs to micropinocytose and receptormediated endocytose. In contrast, treatment with a sialidase significantly improved the capacity of moDCs to phagocytose Escherichia coli. The improved phagocytosis mechanism required E. coli sialic acids, indicating a mechanism of host–pathogen interaction dependent on sialic acid moieties. Sialidase-treated moDCs have increased expression of MHC and co-stimulatory molecules, suggesting a more mature phenotype. Experiments using mouse bone marrow-derived DCs (BMDCs) from ST3Gal-1-/- and ST6Gal-1-/- strains indicated that endocytosis and maturation are influenced by changes in either α2,3 or α2,6-sialylated glycans. The analysis of α2,6-sialylated, N-glycosylated proteins, strongly suggested the potential involvement of β2 integrins, underlying these mechanisms. 3) The effect of α2,6-sialylation in DC homing to lymph nodes was also analyzed. We observed that BMDCs deficient for ST6Gal-1 have an almost 50% reduction in DC homing, as assayed by in situ inflammation and adoptive transfer studies. A reduction in DC homing was also observed when wild type BMDCs were transferred into ST6Gal-1-/- recipient mice. Further investigations are necessary to identify the molecules involved in this process. 4) Finally, we also analyzed the impact of sialylation on DCs ability to prime T cells. Sialidase-treated moDCs show increased gene expression of IL-12, TNF-α, IL-6 and IL- 10 cytokines, and activation of the transcription factor nuclear factor-κB. Sialidase33 treated DCs induced a higher proliferative response of T cells with concomitant higher expression of interferon-γ, suggesting that the clearance of cell surface sialic acids contributes to the development of a T helper type 1 proinflammatory response. Together, our data strongly support sialic acid’s relevance in DC immune functions. Alterations of cell surface sialic acid content can alter the endocytosis/phagocytosis, maturation, migration/homing and the ability for T cell priming in human DCs. Moreover, sialic acid linkages created by ST6Gal-1 and ST3Gal-1 are functionally relevant. The engineering of cell surface sialylation, mediated by individual sialidases or sialyltransferases is a likely possibility to fine tune DC phagocytosis and immunological potency, with particular significance to DC-based therapies

Serviço de vídeo a pedido através da Internet

O presente téxto tem o objectivo de introduzir os conceitos relacionados com a transmissão de vídeo através da Internet. Através da realização, implementação e estudo de uma plataforma de suporte ao serviço de vídeo a pedido, analisam-se os principais problemas inerentes à concepção de um serviço deste tipo. Apresenta-se uma solução para um clube de vídeo on-line, mostrando uma implementação possível para o serviço de vídeo em tempo real. Por fim fazem-se as conclusões e enumeram-se algumas direcções para melhorar a qualidade do serviço

As informações e investigação criminal na GNR

O presente trabalho está subordinado ao tema: "As informações e investigação criminal na GNR." As informações e a investigação criminal são duas áreas que assumem actualmente grande importância na estrutura da GNR. Estas articulam-se em estruturas ramificadas pelos escalões hierárquicos da organização e têm como órgãos máximos responsáveis a Direcção de Informações e a Direcção de Investigação Criminal. A recente reestruturação da GNR provocou alterações nas referidas estruturas que apesar de trabalharem autonomamente por vezes o seu objecto de estudo incide em matérias comuns às duas. Neste contexto desenvolveu-se um estudo a partir da pergunta de partida "Face à reestruturação da GNR de que meios de coordenação carecem as Direcções de informações e de investigação criminal?." Os principais objectivos são res ponder à pergunta de partida bem como identificar dificuldades de coordenação e apresentar soluções para suprimir essas dificuldades. A metodologia para o trabalho consistiu na análise documental de textos, livros, sítios na internet, diplomas legais e na interpretação das entrevistas realizadas a pessoas directamente ligadas ao tema. Após a análise dos dados concluiu-se que as Direcções carecem dos seguintes meios de coordenação: contacto permanente entre os Oficiais das Direcções, realização de reuniões conjuntas, partilha de informações. Existem algumas lacunas no que respeita à coordenação entre as Direcções, que serão resolvidas com a implementação do Sistema Integrado de Informações Operacionais de Polícia. Concluiu-se ainda que não está a ser assegurada a análise de informações ao nível das Unidades Territoriais. O presente trabalho foi realizado entre Janeiro e Março 2009.Abstract This work is related to the topic: "Intelligence and criminal investigation in the GNR‖. Intelligence and criminal investigation are two areas of great importance in the National Republican Guard organisation. These areas are divided according to hierarchical echelons of the organisation which have as their responsible organs the Direction of Intelligence and the Direction of Criminal Investigation. The recent restructuring of the National Republican Guard caused several changes in the above-mentioned structures that in spite of working independently they sometimes share the same purpose. Bearing this in mind it was carried out a study to answer the following question: "In view of restructuring the National Republican Guard which resources do the coordination of Direction of Intelligence and of Criminal Investigation need?." The main aims are not only to answer this question but also to identify difficulties of coordination and to present solutions to avoid these difficulties. The methodology for this work consisted in the analysis of documentary texts, books, sites on the Internet, legal certificates and it was also based on the understanding of the personal interviews made to the people acquainted to this issue. Thereupon the analysis of the data we can conclude that both Directions stand in need of the following resources of coordination: constant contact between the Direction Officers; the accomplishment of meetings between them; share of intelligence. There are some gaps in what concerns the coordination between the Directions, which will be solved by the implementation of the Integrated System of Operational Intelligence of the Police. We also reached out to the conclusion that the analysis of intelligence is not reassured at the Territorial Units level yet. This work was carried out through January until March 2009

Cholesterol-based compounds: Recent advances in synthesis and applications

This review reports on the latest developments (since 2014) in the chemistry of cholesterol and its applications in different research fields. These applications range from drug delivery or bioimaging applications to cholesterol-based liquid crystals and gelators. A brief overview of the most recent synthetic procedures to obtain new cholesterol derivatives is also provided, as well as the latest anticancer, antimicrobial, and antioxidant new cholesterol-based derivatives. This review discusses not only the synthetic details of the preparation of new cholesterol derivatives or conjugates, but also gives a short summary concerning the specific application of such compoundsThanks are due to the University of Aveiro, Instituto Politécnico de Bragança, FCT/MEC for financial support of the QOPNA (FCT UID/QUI/00062/2013) and CIMO (UID/AGR/00690/2013) research units, through national funds, and where applicable cofinanced by the FEDER, within the PT2020 Partnership Agreement; and also to the Portuguese NMR Network. This work was also supported by the Integrated Programme of SR&TD “pAGE–Protein aggregation Across the Lifespan” (reference CENTRO-01-0145-FEDER-000003), co-funded by the Centro 2020 program, Portugal 2020, European Union, through the European Regional Development Fund. H. M. T. Albuquerque thanks the pAGE project for his Post-Doc grant (BPD/UI98/4861/2017).info:eu-repo/semantics/publishedVersio

Chromones as versatile building blocks in cycloaddition reactions

4H-Chromen-4-ones commonly referred as chromones are a class of naturally occurring heterocyclic compounds implicated in a series of biological and pharmacological properties.[1] It is also an interesting scaffold involved in a range of chemical transformations for the preparation of novel and more complex oxygen-containing heterocyclic derivatives.[2] Following our interest in the chemistry of chromones, we design two different building blocks, 2- [(1E,3E)-4-arylbuta-1,3-dien-1-yl]-4H-chromen-4-ones 1 and (E)-2-(4-arylbut-1-en-3-yn-1-yl)-4Hchromen- 4-ones 2, and explore the reactivity of the unsaturated systems in cycloaddition reactions. In the former case, chromones 1 were used as dienes in microwave-assisted Diels–Alder (DA) reactions with various electron-poor and electron-rich dienophiles to provide flavone-type compounds 3.[3] In the latter case, the diene system of chromones 2 was involved in DA reactions with N-methylmaleimide whereas the acetylene moiety react with sodium azide, via 1,3-dipolar cycloaddition reaction, to afford xanthene-1,2,3-triazole dyads 4.[4] In this communication, we will present and discuss the synthetic details and spectroscopic characterization of the main products and some interesting byproducts, as well as the intermediate compounds isolated in each case.Thanks are due to University of Aveiro and FCT/MEC for the financial support of the QOPNA research unit (FCT UID/QUI/00062/2013) through national founds and, where applicable, co-financed by the FEDER, within the PT2020 Partnership Agreement, and to the Portuguese NMR Network, as well as to the Instituto Politécnico de Bragança. H.M.T.A. is grateful to FCT for their PhD grant (SFRH/BD/86277/2012).info:eu-repo/semantics/publishedVersio

Synthesis of xanthone-1,2,3-triazole dyads

Xanthones and 1,2,3-triazoles are known to exhibit several biological, pharmacological and biocidal properties[1]. The potential applications of these two classes of heterocycles led us to develop new strategies to synthesize xanthone-1,2,3-triazole dyads, aiming to get potentially improved therapeutic agents[2]. With this rational in mind we designed and synthesized novel chromone derivatives 1a-d to be used as building motifs and to explore the reactivity of the two unsaturated systems (the diene and the alkyne). In the present communication we will present a new synthetic route towards the synthesis of xanthone-1,2,3-triazole dyads 7a-d using consecutively the azide-alkyne Huisgen 1,3-dipolar cycloaddition and Diels-Alder reaction. Our approach involves the synthesis chromone-triazole derivatives 2a-d using the reaction of 1a-d with sodium azide, followed by the methylation of the NH of the triazole moiety. The methylation afforded three isomers 3a-d, 4a-d and 5a-d, as expected. The major isomers 3a-d were used in the Diels-Alder reaction with N-methylmaleimide, and the adducts obtained 6a-d were oxidized to afford the xanthone-1,2,3-triazole dyads 7a-d. All the synthetic details as well as the structural characterization (by 1D and 2D NMR studies) of the new synthesised compounds will be presented and discussed

Chalcones as versatile synthons for the synthesis of 5- and 6-membered nitrogen heterocylces

Chalcones belong to the flavonoid family which constitutes one of the major classes of naturally occurring oxygen heterocyclic compounds. The alpha,beta-unsaturated carbonyl system of chalcones possesses two electrophilic reactive centers allowing them to participate in addition reactions via attack to the carbonyl group (1,2-addition) or involving the beta-carbon (1,4-conjugate addition), leading to the synthesis of promising bioactive heterocyclic compounds. The purpose of this review is to present a systematic survey of the most recent literature that uses chalcones in the synthesis of biologically active 5- and 6-membered nitrogen heterocycles such as pyrroles, indoles, isoxazoles, imidazoles, pyrazoles, indazoles, triazoles, tetrazoles, pyridines and pyrimidines. Efficiency, easy-to-handle and cheap reagents, alternative heating conditions and greener protocols will be highlighted. In this review we will cover the literature since the beginning of the 21st century in more than 400 publications.PEst-C/QUI/UI0062/2013 FCOMP-01-0124-FEDER-03729

Synthesis of 2-{2-[5(4)-aryl-2H-[1,2,3]-triazol-4(5)-yl]vinyl}chromen-4-ones

Chromones are a family of oxygen-containing heterocyclic compounds that have been shown particular relevant biological activity. In what concerns to 2-methylchromones, their reactivity is well-known and allowed to exploit many different kinds of chemical reactions. The acidic character of the 2-methyl group, due to the low electron density at C-2 caused by carbonyl group enable this class of compounds to undergo oxidation, photolysis, cycloaddition and condensation reactionsUniversity of Aveiro, Funda9ao para a Ciencia e Tecnologia (FCT, Portugal), European Union, QREN, FEDER and COMPETE for funding the QOPNA Research Unit (project PEst-C/QUI/UI0062/2011) and the Portuguese National NMR Network. Hello Albuquerque also thanks FCT for his fellowship (SFRH/Bl/51556/2011 )

Nitromethane conjugate addition to 2-[(1E,3E)-4-arylbuta-1,3-dien-1-yl]-4Hchromen- 4-ones

Chromone are a group of oxygen-containing heterocycles, which are often associated to important biological activities.1 Chromone derivatives are also seen as interesting scaffolds to input further functionalizations,2 most of them through chemical transformations such as oxidation, condensation, Diels-Alder or conjugate addition. Conjugate addition of carbon nucleophiles to electron-deficient alkenes is one of the most important methods available for carbon–carbon bond-forming reactions. A wide range of carbon nucleophiles easily undergo conjugate addition with various substrates such as chalcones, cinnamylideneacetophenones or styrylchromones. Following previous work of our research group involving the 1,6-conjugate addition of nitromethane to (E)-2- styrylchromones,3 herein we report the first reactivity studies in the nitromethane conjugate addition to the extended unsaturated π-system of 2-[(1E,3E)-4-arylbuta-1,3-dien-1-yl]-4H-chromen-4-ones 1 (Scheme 1). The DBU catalyzed nitromethane addition reaction afforded the corresponding β-(nitromethyl)chromones 2 (1,6-conjugate addition) as major products. (E)-5'-(Nitromethyl)-3'-styryl-[1,1'-biphenyl]-2-ol 3 and 3'-aryl-2'-nitro-5'-(nitromethyl)spiro [chromane- 2,1'-cyclohexan]-4-one 4 derivatives were also isolated as minor products, which result from the addition of two nitromethane molecules, through tandem processes.info:eu-repo/semantics/publishedVersio