RCIPL
Repositório Institucional do Politécnico de Lisboa
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Impact of high-performance sport on serum potassium values in athletes: a systematic review
Publication . Tavares, Ana Sofia; Bellém, Fernando; Vieira, Daniela; Miranda, Vasco; Pires, Mariana; Sá, César; Saraiva, Linda; Silva, Inês P.; Silva, Ana; Montoya-Fernández, Carlos; Pereira, Beatriz
Potassium is an alkali metal and the most abundant cation in the human body, measurable in serum, plasma, whole blood, and urine. The release of potassium from muscles into the bloodstream during intense exercise is related to the intensity of physical activity. Therefore, changes in serum potassium levels in individuals who regularly engage in sports can have significant consequences for the performance and health of athletes. Aims: To assess the impact of training on serum potassium levels in athletes by means of a broad systematic review. Following the PRISMA 2020 guidelines, a comprehensive search was conducted in electronic databases such as PubMed, Scopus, and Web of Science between April 21 and June 15, 2022. The methodological quality of the included studies was evaluated using the Effective Public Health Practice Project tool. A total of 12 primary research articles published in Portuguese, English, and Spanish were included. The study population consisted of athletes who were not taking potassium supplements. Criteria for eligibility, data sources, search strategies, study selection, and methods of analysis were meticulously followed to ensure a rigorous systematic review. Twelve studies (228 athletes, most of them football players) published between 2012 and 2020, mostly by Asia (n =6 studies; 50.0 %) and Europe (n =5; 33.4 %), and designed as longitudinal observational studies were synthesized. Out of the 12 included studies, 7 demonstrated an increase in potassium levels during exercise and a subsequent decrease after exercise. However, no definitive conclusions could be drawn, highlighting the need for further detailed studies to better understand the relationship between different sports and potassium level variations. Future studies are necessary to understand the effects of changes in potassium levels on the cardiac muscle due to the spurious correlation between potassium and cardiac arrest. This will help to establish more precise associations and implications for athlete health and performance.
Impacto de doses suprafisiológicas de esteroides anabolizantes nos níveis de glicose e insulina em atletas de bodybuilding do sexo masculino: revisão sistemática
Publication . Ferreira, Bárbara; Leite, Beatriz; Calixto, Carolina; Bellém, Fernando; Tavares, Ana Sofia; Sá, César; Saraiva, Linda; Silva, Inês P.; Silva, Ana; Montoya-Fernández, Carlos; Pereira, Beatriz
Os esteroides anabolizantes androgénicos são compostos sintéticos com estrutura química semelhante à testosterona. São frequentemente usados por atletas recreativos para aumentar a massa muscular, força e diminuir a massa gorda. No entanto, os esteroides anabolizantes androgénicos também podem ter efeitos adversos na saúde, incluindo alterações nos níveis de glicose e insulina. A presente revisão sistemática tem como objetivo a análise de estudos que avaliem o impacto da toma de esteroides anabolizantes androgénicos, em doses suprafisiológicas, nos níveis de glicose e insulina em bodybuilders do sexo masculino. Foram seguidas as diretrizes PRISMA, tendo sido incluídos 4 artigos com recurso às bases de dados eletrónicas PubMed, Scopus e B-on, sendo que a pesquisa foi realizada entre o dia 3 de abril e 1 de maio de 2024. Os estudos analisados apresentam resultados dos doseamentos de insulina e glicose num grupo experimental e num grupo controlo, permitindo-nos concluir que os esteroides anabolizantes androgénicos podem ter influência nestes parâmetros. Em particular, verificou-se que os esteroides anabolizantes androgénicos podem diminuir a sensibilidade à insulina, o que pode aumentar o risco de desenvolver diabetes tipo 2.
Fault-mediated magma propagation and triggered seismicity revealed by the 2022 São Jorge Azores unrest
Publication . Hicks, Stephen P.; Gonzalez, Pablo J.; Lomax, Anthony; Ferreira, Ana M. G.; Ramalho, Ricardo S.; Mitchell, Neil C.; Silveira, Graça; Dias, Nuno Afonso; Fontiela, João; Fernandes, Rui; Custódio, Susana; Tsekhmistrenko, Maria; Mendes, Virgílio; Pimentel, Adriano; Silva, Rita; Prates, Gonçalo; Sturgeon, William; Marignier, Augustin; Carrilho, Fernando; Marques, Rui; Miranda, Miguel; Garcia, Arturo M.
Abstract
Understanding failed volcanic eruptions is key to mapping magma plumbing and forecasting hazards. Faults and fractures guide magma, but their mechanisms remain unclear due to the lack of precise earthquake locations andlimited3-Dfaultmappinginvolcanicregions.The triple-junction setting of the Azores Archipelago, where volcanic systems and seismogenic faults coexist, offers a natural laboratory to study fault–magma interactions. We analysed ~18,000 earthquakes relocated to high precision using onshore and ocean-bottom seismometers, combined with geodetic data and seismic autocorrelation imaging, during a failed 2022 eruption on São Jorge Island. A magmatic dike ascended rapidly and mostly aseismically from the upper mantle, intruding a crustal fault before stalling ~1,600 m below the surface. Seismicity indicates that magma branching and lateral fluid escape along the fault triggered an intense, months-long swarm with rotated focal mechanisms. This study demonstrates the dual role of faults in facilitating and arresting magma ascent.
A moda, e não só, no final do milénio: revisões da matéria dada
Publication . Morais Alexandre, Paulo Jorge
Propõe-se uma análise panorâmica da evolução da moda, articulada com contextos históricos, sociais, culturais e artísticos do último quartel do século XX. Partindo da ideia de que a moda reflete o seu tempo, evidencia-se como fenómenos políticos (como o pós-25 de Abril em Portugal ou o fim da Guerra Fria), transformações sociais, avanços tecnológicos e movimentos culturais influenciaram diretamente as formas de vestir e os sistemas de gosto. Estabelece-se uma leitura interdisciplinar que cruza moda com música, cinema, televisão e comportamentos sociais, mostrando como estes universos contribuíram para a construção de identidades e tendências. Destaca-se a emergência de novos criadores, centros de produção e linguagens estéticas, bem como a crescente globalização da moda, com a afirmação de polos como Paris, Londres, Milão, Nova Iorque e Japão. Simultaneamente, analisa-se o desenvolvimento do sistema da moda em Portugal, evidenciando mudanças no consumo, na criação e na indústria.
Variants of the PKLR gene are associated with rates of hospitalization in Angolan children with sickle cell anemia
Publication . Manco, Licínio; Santos, Brígida; Faustino, Paula; Ginete, Catarina; Brito, Miguel; Arez, Ana Paula
Background: Sickle cell anemia (SCA), caused by the c.20 A > T (p.Glu6Val) mutation in the HBB gene, is one of the most prevalent hereditary diseases in Sub-Saharan Africa. Patients with the HbSS genotype exhibit variable phenotypic expressions and disease severity, often reflected in hospitalization rates. Reduced activity of pyruvate kinase (PKR, gene: PKLR), a key enzyme in glycolysis, impacts SCA pathophysiology through 2,3-DPG accumulation and ATP deficit. This study analyzed the association of three PKLR variants with hospitalization and clinical parameters in Angolan children with SCA. Material and methods: Sixty-three SCA children (3–12 years) were monitored in a prospective study (2019–2022). Polymorphisms rs8177970 and rs3020781 (intron 3) and rs1052177 (3' UTR) in the PKLR gene were analyzed via PCR-RFLP. Allele frequencies and Hardy-Weinberg equilibrium (HWE) were assessed using Arlequin 3.5, and SPSS 27 was used for statistical analyses. Association studies were performed using the Mann-Whitney U test, combining heterozygous and homozygous individuals for the minor allele into a single group. Results: Minor allele frequencies for rs8177970, rs3020781, and rs1052177 were 0.214, 0.221, and 0.377, respectively, with all genotype distributions consistent with the HWE. Polymorphism rs1052177 was significantly associated with hospitalization rates (p = 0.025), while rs8177970 showed a near-significant association (p = 0.068). No associations were found with hematological parameters. Conclusion: This study, conducted in SCA children from Angola, found potential links between two PKLR SNPs and hospitalization rates. The PKLR gene may act as a genetic modifier of the clinical progression of SCA, as these SNPs can affect gene expression levels.