Desenvolvimento de nanopartículas magnéticas para dispositivos biomédicos

In the last decades, magnetic nanoparticles have been developed for biomedical applications, such as medical treatment and imaging. In medical treatment, magnetic nanoparticles have been extensively used in hyperthermia, a treatment that requires the heating of cancer cells but lacks local temperature control, which often leads to damage in healthy cells. This thesis addresses this problem using Fe3Se4 nanoparticles that have a Curie temperature slightly above 40 °C. In medical imaging, the quest for contrast manipulation has been pursued during the last decades. The use of contrast agents is nowadays common when performing an MRI. These contrast agents are molecules, nanoparticles or compounds, that alter the magnetic environment and can later increase or decrease the contrast of the obtained image. Fe3Se4 nanoparticles here presented are also evaluated as contrast agents for MRI. In addition, the development of dual-mode contrast agents represents a new generation, which takes advantage of the two relaxation modes, allowing a higher contrast between healthy and unhealthy tissues. Regarding this, the present thesis also reports the development of a new synthesis approach to yield a dual-mode contrast agent that combines Fe3O4 nanoparticles and a Gadolinium based metal-organic complex. Synthesis and characterizations of all the nanoparticles and Gadolinium complexes are presented, as well as the ecotoxicological and cytotoxic evaluations of the nanoparticlesNas últimas décadas, as nanopartículas magnéticas têm vindo a ser desenvolvidas para aplicações biomédicas, tais como tratamento médico e imagiologia. Em relação ao tratamento médico, as nanopartículas magnéticas têm sido extensivamente utilizadas em hipertermia, um tratamento que requere o aquecimento de células cancerígenas mas que não possui controlo de temperatura local, o que habitualmente provoca danos em células saudáveis. Esta tese aborda este problema utilizando nanopartículas de Fe3Se4 cuja temperatura de Curie se encontra ligeiramente acima de 40 °C. No que toca à imagiologia médica, nas últimas décadas têm vindo a ser desenvolvidas novas maneiras que permitam a manipulação do contraste. Nos dias de hoje, a utilização de agentes de contraste é comum quando se realiza uma Ressonância Magnética (MRI). Estes agentes de contraste podem ser moléculas, nanopartículas ou compostos, que alteram o ambiente magnético e podem depois aumentar ou diminuir o contraste da imagem obtida. As nanopartículas de Fe3Se4 aqui apresentadas são também avaliadas como agentes de contraste para MRI. Para além disto, o desenvolvimento de agentes de contraste de modo duplo representa uma nova geração, que tira vantagemdos dois modos de relaxação, permitindo um maior contraste entre tecidos doentes e saudáveis. Neste sentido, a presente tese também reporta o desenvolvimento de um novo método de síntese que dá origem a agentes de contraste de modo duplo que combinam nanopartículas de Fe3O4 e complexos organometálicos de Gadolínio. As sínteses e caracterizações de todas as nanopartículas e complexos de Gadolínio são apresentadas, bem como avaliações ecotoxicológicas e citotóxicas das nanopartículasMestrado em Materiais e Dispositivos Biomédico

Electrochromic windows based on luminescent acrylate/ionosilicas

Funding Information: This work was funded by project I&D&I OBTain, operation no. NORTE-01-0145-FEDER-000084, co-financed by the European Regional Development Fund (FEDER) thought NORTE 2020 (Northern Regional Operational Programme 2014/2020), CENTRO2020 in the scope of the project PLANETa, CENTRO-01-0247-FEDER-181242, SOLPOWINS-Solar-Powered Smart Windows for Sustainable Buildings (PTDC/CTM/4304/2020), CQ-VR that is supported by FCT through the projects UIDB/00616/2020 and UIDP/00616/2020 and developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, Instituto de Telecomunicações (FCT Ref. UIDB/50008/2020) financed by national funds through the FCT/MCTES (PIDDAC), and CQ-University of Minho that is supported by FCT through the projects UIDB/00686/2020 and UIDP/00686/2020. DP acknowledges OBTain for post-doc grant BIPD/UTAD/19/2021. RFPP acknowledges FCT-UMinho for the contract in the scope of Decreto-Lei 57/2016 57/2017. SFHC thanks FCT for a research contract 2022.03740.CEECIND. Publisher Copyright: © The Author(s) 2024.Poly(methyl methacrylate) (PMMA)-based composite films doped with lanthanide-doped sol–gel derived imidazolium-based ionosilicas (IS-Ln) were recently proposed as active layers of luminescent down shifting (LDS) layers, but subsequent work demonstrated also their potential as electrolytes for electrochromic devices (ECDs) with foreseen application in smart windows of energy-efficient buildings. Nevertheless, some challenges remained to be addressed in the latter devices, the most critical one being the poor solubility of PMMA in the ionic liquid used in the formulation of these materials. To avoid this drawback, in the present work we propose novel lanthanide-containing acrylate/ionosilicas (AC/IS-Ln, Ln = Tb3+, Eu3+). The transparent, homogeneous, and luminescent hybrid materials synthesized are characterized by Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, atomic force microscopy, contact angle measurements, ionic conductivity, and photoluminescence spectroscopy. Optimized samples are successfully employed as electrolytes in luminescent ECD prototypes. The ECD device doped with AC/IS-Eu shows good cycling stability with reproducible bleaching/coloring over 50 chronoamperometry cycles, high coloration efficiency (CE) values CEin/CEout in the visible (−89/+98 cm2 C−1), and near-infrared (−126/138 cm2 C−1) spectral regions, and outstanding memory effect. Graphical Abstract: (Figure presented.)publishersversionepub_ahead_of_prin

Worldwide trends in underweight and obesity from 1990 to 2022: a pooled analysis of 3663 population-representative studies with 222 million children, adolescents, and adults

Background Underweight and obesity are associated with adverse health outcomes throughout the life course. We estimated the individual and combined prevalence of underweight or thinness and obesity, and their changes, from 1990 to 2022 for adults and school-aged children and adolescents in 200 countries and territories. Methods We used data from 3663 population-based studies with 222 million participants that measured height and weight in representative samples of the general population. We used a Bayesian hierarchical model to estimate trends in the prevalence of different BMI categories, separately for adults (age ≥20 years) and school-aged children and adolescents (age 5–19 years), from 1990 to 2022 for 200 countries and territories. For adults, we report the individual and combined prevalence of underweight (BMI <18·5 kg/m2) and obesity (BMI ≥30 kg/m2). For schoolaged children and adolescents, we report thinness (BMI <2 SD below the median of the WHO growth reference) and obesity (BMI >2 SD above the median). Findings From 1990 to 2022, the combined prevalence of underweight and obesity in adults decreased in 11 countries (6%) for women and 17 (9%) for men with a posterior probability of at least 0·80 that the observed changes were true decreases. The combined prevalence increased in 162 countries (81%) for women and 140 countries (70%) for men with a posterior probability of at least 0·80. In 2022, the combined prevalence of underweight and obesity was highest in island nations in the Caribbean and Polynesia and Micronesia, and countries in the Middle East and north Africa. Obesity prevalence was higher than underweight with posterior probability of at least 0·80 in 177 countries (89%) for women and 145 (73%) for men in 2022, whereas the converse was true in 16 countries (8%) for women, and 39 (20%) for men. From 1990 to 2022, the combined prevalence of thinness and obesity decreased among girls in five countries (3%) and among boys in 15 countries (8%) with a posterior probability of at least 0·80, and increased among girls in 140 countries (70%) and boys in 137 countries (69%) with a posterior probability of at least 0·80. The countries with highest combined prevalence of thinness and obesity in school-aged children and adolescents in 2022 were in Polynesia and Micronesia and the Caribbean for both sexes, and Chile and Qatar for boys. Combined prevalence was also high in some countries in south Asia, such as India and Pakistan, where thinness remained prevalent despite having declined. In 2022, obesity in school-aged children and adolescents was more prevalent than thinness with a posterior probability of at least 0·80 among girls in 133 countries (67%) and boys in 125 countries (63%), whereas the converse was true in 35 countries (18%) and 42 countries (21%), respectively. In almost all countries for both adults and school-aged children and adolescents, the increases in double burden were driven by increases in obesity, and decreases in double burden by declining underweight or thinness. Interpretation The combined burden of underweight and obesity has increased in most countries, driven by an increase in obesity, while underweight and thinness remain prevalent in south Asia and parts of Africa. A healthy nutrition transition that enhances access to nutritious foods is needed to address the remaining burden of underweight while curbing and reversing the increase in obesit

A rotina da sesta numa sala de 3/4 anos: O olhar das crianças, dos pais e dos agentes educativos envolvidos

Dissertação de Mestrado apresentada no ISPA – Instituto Universitário para obtenção de grau de Mestre na especialidade em Educação Pré-EscolarÉ prática comum as crianças até aos 3 anos de idade fazerem a sesta nos estabelecimentos de ensino. Em alguns desses estabelecimentos as crianças deixam de fazer a sesta aquando a entrada no pré-escolar; contudo, alguns outros optam por dar continuidade a esta rotina. Tendo presente as minhas vivências neste âmbito, e de modo, a aprofundar o tema da sesta em contexto de Jardim de Infância, a minha escolha para este relatório final recaiu nesta prática. Tentei entender toda a dinâmica da prática da sesta e para sustentar este estudo de cariz qualitativo, procurei autores de referência como Assunção Folque, Mário Cordeiro, Teresa Paiva entre outros, de modo, a fundamentar as boas práticas do sono (noturno e diurno) nomeadamente, de crianças em idade pré-escolar. Este estudo teve como público-alvo as crianças do pré-escolar da instituição onde realizei o meu estágio. Escolhi como instrumentos de recolha de dados, a observação e o questionário, de modo a recolher a maior informação possível que me permitisse analisar e perceber aquela prática no referido local. Observei as crianças na mencionada rotina e estabeleci com elas algumas conversas informais sobre o que pensavam da sesta. Também a opinião da equipa pedagógica e dos encarregados de educação, recolhida através de questionários, foi tida em conta de modo a perceber com encaram o tempo de sesta nas crianças desta faixa etária, e quais as suas convicções relativamente a esta rotina praticada no jardim-de-infância. Com a informação possível de ser recolhida, bem como, toda a pesquisa realizada na literatura de referência, consegui compreender melhor todos os aspetos que se entrecruzam antes da tomada de decisão de fazer, ou não, as crianças dormir a sesta.ABSTRACT: It is common practice for children up to the age of 3 to have naps whilst at a educational setting, however in some of these establishments they are now stopping this, whilst continuing it in others. Bearing in mind my experience in this area and so to delve deeper into the practice of napping during preschool hours, my final report will be undertaken in this subject. I have done my best to understand the dynamics of naps and to sustain this study to a qualitative nature by referencing authors; Assunção Folque, Mário Cordeiro and Teresa Paiva amounts others to better support the practice of nighttime/ daytime sleep with particular interest in preschool aged children. This study used children from the preschool where I conducted my internship as its target audience. I have used my knowledge gained here for data collection alongside observations and questionnaire to gather as much information for me to thought be able to analyze and understand this practice used. I watched the children in their setting whilst having informal discussions on their thoughts on nap time. A view from a pedagogical team as well as parents and guardians has been collected and taken into account on their thoughts and beliefs through the use of questionnaires in regard of nap time within this age range. With the information that`s can be collected alongside the reference literature I am able to better understand all aspects of this before coming to a conclusion on if nap time benefits or hinders the children using the practice in an educational setting

Worldwide trends in underweight and obesity from 1990 to 2022: a pooled analysis of 3663 population-representative studies with 222 million children, adolescents, and adults

Background: Underweight and obesity are associated with adverse health outcomes throughout the life course. We estimated the individual and combined prevalence of underweight or thinness and obesity, and their changes, from 1990 to 2022 for adults and school-aged children and adolescents in 200 countries and territories. Methods: We used data from 3663 population-based studies with 222 million participants that measured height and weight in representative samples of the general population. We used a Bayesian hierarchical model to estimate trends in the prevalence of different BMI categories, separately for adults (age ≥20 years) and school-aged children and adolescents (age 5-19 years), from 1990 to 2022 for 200 countries and territories. For adults, we report the individual and combined prevalence of underweight (BMI <18·5 kg/m2) and obesity (BMI ≥30 kg/m2). For school-aged children and adolescents, we report thinness (BMI <2 SD below the median of the WHO growth reference) and obesity (BMI >2 SD above the median). Findings: From 1990 to 2022, the combined prevalence of underweight and obesity in adults decreased in 11 countries (6%) for women and 17 (9%) for men with a posterior probability of at least 0·80 that the observed changes were true decreases. The combined prevalence increased in 162 countries (81%) for women and 140 countries (70%) for men with a posterior probability of at least 0·80. In 2022, the combined prevalence of underweight and obesity was highest in island nations in the Caribbean and Polynesia and Micronesia, and countries in the Middle East and north Africa. Obesity prevalence was higher than underweight with posterior probability of at least 0·80 in 177 countries (89%) for women and 145 (73%) for men in 2022, whereas the converse was true in 16 countries (8%) for women, and 39 (20%) for men. From 1990 to 2022, the combined prevalence of thinness and obesity decreased among girls in five countries (3%) and among boys in 15 countries (8%) with a posterior probability of at least 0·80, and increased among girls in 140 countries (70%) and boys in 137 countries (69%) with a posterior probability of at least 0·80. The countries with highest combined prevalence of thinness and obesity in school-aged children and adolescents in 2022 were in Polynesia and Micronesia and the Caribbean for both sexes, and Chile and Qatar for boys. Combined prevalence was also high in some countries in south Asia, such as India and Pakistan, where thinness remained prevalent despite having declined. In 2022, obesity in school-aged children and adolescents was more prevalent than thinness with a posterior probability of at least 0·80 among girls in 133 countries (67%) and boys in 125 countries (63%), whereas the converse was true in 35 countries (18%) and 42 countries (21%), respectively. In almost all countries for both adults and school-aged children and adolescents, the increases in double burden were driven by increases in obesity, and decreases in double burden by declining underweight or thinness. Interpretation: The combined burden of underweight and obesity has increased in most countries, driven by an increase in obesity, while underweight and thinness remain prevalent in south Asia and parts of Africa. A healthy nutrition transition that enhances access to nutritious foods is needed to address the remaining burden of underweight while curbing and reversing the increase in obesity. Funding: UK Medical Research Council, UK Research and Innovation (Research England), UK Research and Innovation (Innovate UK), and European Union