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Browsing by Issue Date, starting with "2022-11-08"

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  • Total ion chromatogram and total ion mass spectrum as alternative tools for detection and discrimination (A review)
    Publication . Barea-Sepúlveda, Marta; Duarte, Hugo; Aliaño-González, María José; Romano, Anabela; Medronho, Bruno
    Gas chromatography (GC) and mass spectrometry (MS) are widely used techniques in the analysis of complex mixtures due to their various advantages, such as high selectivity, reproducibility, precision, and sensitivity. However, the data processing is often complex and time-consuming and requires a great deal of experience, which might be a serious drawback in certain areas, such as quality control, or regarding research in the field of medicine or forensic sciences, where time plays a crucial role. For these reasons, some authors have proposed the use of alternative data processing approaches, such as the total ion chromatogram or total mass spectrum, allowing these techniques to be treated as sensors where each retention time or ratio m/z acts as a sensor collecting total intensities. In this way, the main advantages associated with both techniques are maintained, but the outcomes from the analysis can be reached in a faster, simpler, and an almost automated way. In this review, the main features of the GC- and MS-based analysis methodologies and the ways in which to apply them are highlighted. Moreover, their implementation in different fields, such as agri-food, forensics, environmental sciences, or medicine is discussed, highlighting important advantages as well as limitations.
    2022-11-08Journal article Open Access Show more
  • Avaliação ergonómica dos postos de trabalho dos funcionários administrativos da Universidade do Algarve: perceção de risco
    Publication . Lopes, Ailine Ariana Gomes Ferreira; Cavaco, Adriana
    Contexto: As lesões musculosqueléticas (LME) consistem num conjunto de doenças comuns relacionadas com o trabalho. Afetam milhões de trabalhadores europeus, com um custo de milhares de milhões de euros para as entidades patronais. Combater as LME contribui para melhorar a vida dos trabalhadores, e justifica-se plenamente do ponto de vista económico. Objetivo: O presente trabalho empírico tem como objetivo geral a análise e caraterização das condições de trabalho existentes nos postos de trabalho com computadores dos funcionários administrativos da UAlg e na identificação das Lesões musculoesqueléticas relacionadas com o trabalho (LMERT) e ainda na avaliação da perceção de risco. Metodologia: O estudo consistiu numa avaliação única á 31 trabalhadores pertencentes a 6 departamentos administrativos da UAlg, com cerca de 30 a 35 minutos de duração total, presencial e no posto de trabalho respetivo dos funcionários. Foram aplicados 4 questionários: o CHECK LIST “Lima e Coelho (2011)” (para a avaliação ergonómica dos postos de trabalho), Quick DASH (para avaliação da incapacidade do ombro, do braço e da mão); o Questionário Nórdico Músculo-esquelético (mensuração de sintomas de lesões músculo-esqueléticas) e o Questionário de Perceção de Riscos (desenvolvido pelo investigador no âmbito de Segurança e Saúde no Trabalho). Resultados: a grande maioria dos participantes queixaram-se de problemas como dor, desconforto e dormências no pescoço (71%) e na região lombar (64,5%). Pode estar na causa, o fato de que mais de metade dos participantes (61,3%) não utiliza o apoio lombar mantendo a cabeça alinhada com o corpo.
    2022-11-08Master thesis Open Access Show more
  • Efeitos da COVID-19 no marketing de museus de pequena escala
    Publication . Cardoso, Ana Catarina Goulão Dias; Guerreiro, Manuela; Sequeira, Bernardete
    O objetivo desta pesquisa é identificar medidas adotadas em museus de pequena escala durante os confinamentos motivados pela COVID-19, explorando tendências no regresso à normalidade. O decrescente interesse do público pelos museus e a tendência para a diminuição das visitas, trazem para o diálogo a necessidade de equacionar estratégias que pretendem reconectar as instituições museológicas com os públicos. Este estudo exploratório assenta em pesquisa qualitativa. A recolha de dados utiliza a entrevista semiestruturada junto de uma amostra intencionada, constituída por profissionais em museus de pequena escala, membros da Rede de Museus do Algarve. Os resultados permitem concluir que os profissionais entrevistados estão atentos a novas necessidades de interação com os seus públicos. A relevância das tecnologias e o fortalecimento das relações entre ambientes offline e online suscitam a necessidade de maior investimento em conteúdos digitais e a criação de novas plataformas. Além disso, a pandemia causada pela COVID-19 contribuiu para transformar e digitalizar os museus, atualizar formatos e discursos expositivos, interagir e comunicar com os visitantes em novos formatos. São discutidas sugestões para investigação futura, nomeadamente o interesse em aprofundar o conhecimento sobre a temática incluindo a perspetiva de públicos, com diferentes caraterísticas e distribuídos por meios online e offline. Estudos futuros devem também ser alargados a outras latitudes e tipologias de museus. Alavancado em lacunas identificadas na literatura, este estudo contribui para o conhecimento ao explorar as medidas adotadas durante os confinamentos motivados pela COVID-19 e tendências no regresso à normalidade em museus de pequena escala.
    2022-11-08Master thesis Open Access Show more
  • Halophyte plants as potential sources of Anticancer agents: a comprehensive review
    Publication . Custódio, Luísa; Garcia-Caparros, Pedro; Pereira, Catarina Guerreiro; Castelo-Branco, Pedro
    Salt-tolerant plants (halophytes) are widely distributed worldwide in several environments such as coastal salt marshes, sand dunes, and inland deserts. To cope with the harsh conditions that characterize those habitats, which include high salinity and radiation levels, such plants have developed morphological and physiological traits, the latter including the synthesis and accumulation of important secondary metabolites such as alkaloids and polyphenols. While essential in maintaining plant homeostasis, these compounds are highly valued in the medical field for the treatment of several human diseases, including cancer. Cancer is one of the most life-threatening disorders worldwide, which accentuates the need to improve current cancer therapies and minimize potential adverse secondary side-effects. In this context, the pharmacological evaluation of natural compounds has attracted growing interest since nature has already provided some important anti-cancer drugs. This review compiles, for the first time, research regarding the anticancer activity of halophytes from different families, including, whenever possible, the bioactive molecules involved in such therapeutical properties along with possible mechanisms of action. The introduction section provides some pertinent information regarding cancer and a summary of the most important characteristics of halophytes. The next section gives information regarding the in vitro and in vivo cytotoxic properties of several halophyte species, grouped by families, including contents in bioactive metabolites and proposed modes of action, if possible. Lastly, the conclusion presents the most relevant metabolites and/or promising species and extracts that could be further explored in anticancer drug research.
    2022-11-08Journal article Open Access Show more
  • Comparing the response of Citrus ×limon and Citrus ×sinensis to Trioza erytreae infestation using a proteomic approach
    Publication . Magalhães, Tomás; Dandlen, Susana; L, Anjos; Power, Deborah; Pereira, José Alberto; Duarte, Amilcar; Marques, Natália
    Citrus production is on high alert because of the devastating disease Huanglongbing (HLB), caused by the bacteria Candidatus Liberibacter spp.. With no viable treatment, current management practices rely on the control of its vectors, such as the African citrus psyllid,Trioza erytreae (Del Guercio 1918), which is already in the Mediterranean region (Portugal and north of Spain). This vector develops better in some citrus hosts, with Citrus ×limon described as the preferred host. To better understand the molecular response of citrus hosts to the psyllid, the phloem proteome of lemon (Citrus ×limon) and orange (Citrus ×sinensis) plants infested with T. erytreae was compared with equivalent non infested plants. Infestation was established with isolated plants by exposing them to 10 T. erytreae adults. Nymphs of T. erytreae at the 4-5th instar stage were removed from plants and infested leaf phloem was extracted. In control plants phloem was extracted from leaves of a similar size and developmental stage. The experiment was done under controlled conditions of temperature, light and humidity. Phloem was analyzed by nanoLC-MS/MS. A total of 48 and 1265 differentially abundant proteins (DAP) were identified in lemon and orange plants, respectively, with 18 proteins common to both species. The topmost enriched GO terms retrieved for upregulated proteins in lemon plants were assigned to organic acid and cellular amino acid metabolic processes. The topmost enriched GO terms in orange plants included organonitrogen compound metabolic process, cellular component assembly, establishment of protein localization, while downregulated terms were associated with carbohydrate metabolic process. This study revealed that T. erytreae infestation promoted distinct modifications in the phloem proteome of lemon and orange plants. This work is part of a group of studies that focus on this insect-plant interaction that aims for more informed and improved T. erytreae control.
    2022-11-08Conference object Restricted Show more