Browsing by Issue Date, starting with "2022-11-22"
Now showing 1 - 10 of 15
Results Per Page
Sort Options
- Study of Th17 cells in patients under peritoneal dialysisPublication . Barreto, Inês Rodrigues; Fonseca, Ana Mafalda Loureiro; Monteiro, Andreia Sofia ReisChronic Kidney Disease is a complex disease, with increasing prevalence in the world, and is defined by irreversible damage in the kidney structure and function. One of the most used treatments is peritoneal dialysis, that allows to preserve part of the renal function. However, in the long-term, it leads to peritoneal damage, that seems to be modulated by inflammatory processes and immune responses. Among these mediators, Th17 cells and IL-17A seem to play an important role in the pathogenesis of the disease. Therefore, this study aimed to quantify the populations of total lymphocytes, T cells, CD4+ and CD8+ T cells, Th17 and Th1 cells in peripheral blood and peritoneal effluent from 26 patients undergoing peritoneal dialysis and compare with peripheral blood from a control group, consisting of 10 healthy volunteers. The local IL-17A concentration in the serum and peritoneal effluent was also studied. The main differences were found in the frequencies of Th17 and Th1 cells, that were significantly lower in patients on peritoneal dialysis than in the control group. It was also observed that the frequency of Th1 cells was higher in the peritoneal effluent than in the blood. IL-17A concentration was significantly higher in the peritoneal effluent when compared to the serum. Although IL-17A levels do not follow the same pattern as some previous research, the results seem to suggest that in the patient's peritoneum, an inflammatory process is emerging, and further clarification is needed regarding the mechanisms of action of this cytokine in the pathology.
- Estudo da relação ecológica das espécies de leveduras com a Candida albicansPublication . Caetano, Cátia Filipa Torres; Mateus, Joana Rita Gonçalves Araújo Rolo; Gaspar, Carlos Alberto da SilvaO papel da comunidade fúngica, a micobiota, na saúde da mucosa vaginal é uma área de investigação muito atual. O aparecimento de novas tecnologias de sequenciação e avanços na bioinformática permitiram descobrir novas espécies de fungos neste nicho. Candida spp. constitui o grupo mais importante de fungos patogénicos oportunistas, sendo o mais prevalente em infeções vulvovaginais. Contudo fungos como a Rhodotorula spp., Cryptococcus spp. e Malassezia spp. têm vindo a emergir como potenciais patogénicos deste nicho, sendo por isso relevante, do ponto de vista cientifico, perceber qual a sua interação ecológica com a C. albicans quando estão presentes em co- cultura. O objetivo deste estudo foi avaliar qual o impacto das novas leveduras na patogenicidade da C. albicans, no crescimento in-vitro, na formação de biofilme invitro em diferentes momentos de colonização (mistos e pré- formados) e na formação de tubo germinativo. Os ensaios foram realizados com uma única espécie ou com coculturas de C. albicans ATCC10231 com uma outra espécie de levedura, R. mucilaginosa DSM13621, M. furfur DSM6170 e C. albidus DSM70215. Os resultados mostraram que a M. furfur cria uma relação de simbiose com a C. albicans demonstrando uma maior taxa de crescimento em co-cultura (aproximadamente 1/3), um aumento da biomassa do biofilme, quando misturadas (154,1%) e pré- formados (166,8%) e um aumento da formação de tubo germinativo da C. albicans (119,8%). Já para as leveduras R. mucilaginosa e C. albidus a relação é antagónica (com um decréscimo significativo em todos os ensaios), inibindo a patogenicidade da C. albicans.
- Um Clube de Ciências para a Química SustentávelPublication . Vale, Carla Antónia Marques; Santos, Amélia Rute Lima Dias dos; Ciríaco, Maria de Lurdes Franco; Parada, Paulo André de PaivaEste Relatório de Estágio Pedagógico começa por descrever uma componente pedagógica desenvolvida pela autora, enquanto docente da Escola EB Engº Manuel Rafael Amaro da Costa, do Agrupamento de Escolas de São Teotónio, durante o ano letivo 2021/2022. A prática profissional como professora de Física e Química é desempenhada por diversas funções dentro de uma escola que neste relatório estão descritas como: Atividades Curriculares; Atividades de Enriquecimento Curricular e Candidatura ao Clube de Ciência Viva na Escola. A referida candidatura serviu de inspiração à proposta apresentada como estudo de Investigação - Um Clube de Ciências para a Química Sustentável. Para desenvolver este tema começou por ser realizado um profundo trabalho de pesquisa que permitisse estabelecer uma relação direta entre a Carta da Terra, os ODS12 – Produção e Consumo Sustentável e a Hidroponia, aqui aplicada como Hidroponia Didática. Um Clube de Ciências apresenta uma educação não formal com grandes potencialidades para o desenvolvimento dos jovens. Esta forma de educação deve ser cada vez mais reconhecida para uma sociedade que pretende construir um Sistema Educativo moderno, holístico e inclusivo. Assim, tanto a educação formal como não formal proporcionam habilidades, valores e atitudes que são essenciais para a vivência no seculo XXI. A criação de um Sistema Hidropónico numa Horta Escolar promove aprendizagens da Química mais significativas que vão ao encontro das reais necessidades educativas dos jovens. Aqui sugere-se como metodologia a prática STEAM que permite um estudo transdisciplinar para jovens do 3º Ciclo do Ensino Básico, de modo a desenvolvê-los ao nível do seu conhecimento, aptidão e competências.
- NRF2 and Keap1 Genetic Polymorphisms in Breast CancerPublication . Costa, Diana Raquel Careano da; Granadeiro, Luiza Augusta Tereza Gil Breitenfeld; Patricio, Ana Cristina Ramalhinho Tavares; Almeida, Micaela Carina PereiraCancer is one of the diseases with the highest mortality rate, with breast cancer being the most frequent and with the highest mortality rate in females. Human exposure to oxidative stress may be correlated with the development of several pathologies, including cancer. The pathways involved in oxidative stress represent a risk factor for the development of breast cancer. One of the most important factors in oxidative stress regulation is the NF-E2-related factor 2 (Nrf2)-Kelch-like ECH-associated protein 1 (Keap1) (Nrf2-Keap1) complex. The regulation of this complex may be compromised, due to somatic mutations that influence the loss of negative regulation or the presence of Single Nucleotide Polymorphisms in the promoter region of the NRF2 gene, which may be related to changes in the expression of this transcription factor and its biological consequences. Genetic polymorphisms have become potential research targets in breast cancer due to their influence on carcinogenesis and their possible association becomes a key element for future research. The main objective of this work was to identify Single Nucleotide Polymorphisms not described in the literature in the polymorphic regions of the NRF2 and KEAP1 genes in 40 patients with histologically confirmed hormone-dependent breast cancer and to establish a possible association with the histological grade of the tumour. To identify the polymorphisms under study, PCR and Sanger sequencing were used. In order to be able to relate and compare the results obtained in the blood with the tumour tissue, the technique of extracting gDNA from mouse paraffin-embedded tissue was optimized, using 9 samples of mouse mammary tissue. Polymorphisms rs6721961, rs6706649, rs35652124 from NRF2 and rs1048290 from KEAP1 were identified in all samples, and de novo mutations were not identified. These results emphasize the need to study the tumour tissue and verify if it presents alterations in gene expression and appearance of new tumour-related mutations. The gDNA extraction from paraffin-embedded tissue samples from mouse mammary sections was successful, so the protocol was properly optimized, allowing it to be replicated, in future, in human samples.
- Avaliação do impacto dos níveis de expressão de RalGPS2 em cancro do pulmão e da próstataPublication . Diniz, Catarina Isabel da Poça; Santos, Adriana Oliveira dosO cancro da próstata é o que mais afeta homens, sendo de todos os tipos de cancro o segundo mais frequente a nível mundial. Por outro lado, o cancro do pulmão é o mais letal. O forte impacto destas doenças a nível mundial continua a impulsionar a investigação científica sobre o seu desenvolvimento e progressão, bem como sobre o seu tratamento. A sobreativação dos cofatores transcricionais YAP/TAZ, regulados negativamente pela via supressora tumoral Hippo, tem sido associada a diversos tipos de cancro, incluindo cancro da próstata, promovendo a proliferação celular. Além disso, RalGPS2 é um fator de troca de nucleotídeos de guanina e o seu silenciamento tem demonstrado ter a capacidade de diminuir a proliferação de células tumorais, mas o mecanismo não foi totalmente esclarecido. Recentemente, foi demonstrado que o aumento da sua expressão está associado a mau prognóstico dos doentes com adenocarcinoma do pulmão, o que reforça o interesse de prosseguir com a investigação do seu papel em células tumorais. Assim, este estudo teve como objetivos principais procurar evidências de uma possível interação entre RalGPS2 e os cofatores de transcrição YAP/TAZ no cancro da próstata. Este objectivo foi atingido quer por uma abordagem experimental, avaliando o silenciamento de RalGPS2 em combinação com tratamentos que levam à inativação de YAP/TAZ, quer através de uma abordagem bioinformática, explorando dados de transcriptómica de tumores de acesso livre. Na primeira abordagem, efetuou-se o silenciamento de RalGPS2 em linha celulares de cancro da próstata (DU145 e PC3) e de cancro do pulmão (A549) em combinação com ausência de soro fetal bovino (FBS) do meio de cultura e tratamentos com sinvastatina. Na 2ª abordagem, realizou-se uma análise de dados de transcriptómica por forma a perceber qual a expressão de RALGPS2 e o seu valor prognóstico em cancro da próstata. Para além disso, avaliou-se o nível de correlação existente entre os níveis de expressão dos genes RalGPS2, YAP1 e WWTR1 em adenocarcinoma da próstata e em tumores neuroendócrinos da próstata. Tanto a ausência de FBS como a adição de sinvastatina a 10 ou 30 µM tiveram efeito na distribuição do ciclo celular na linha DU145, induzindo o aumento do número de células em fase G1 e sua diminuição na fase S. No que respeita à indução de apoptose, apenas a concentração mais elevada a induziu nesta linha, mas a sua combinação com ausência de soro teve um efeito sinérgico. Nas condições de transfeção usadas, o silenciamento de RalGPS2 não teve um efeito claro no crescimento celular das células estudadas, apesar de se poder ter devido parcialmente a ter sido usad0 um controlo de transfeção com elevada toxicidade inespecífica, e parte devido ao silenciamento incompleto do gene alvo. Quanto à sua combinação com a remoção de soro ou sinvastatina, o efeito foi maioritariamente aditivo. Contudo, este efeito não foi específico se comparado com o siRNA usado como controlo, ficando a dúvida se por não se ter usado o controlo correto. Na linha A549 verificou-se que a combinação do silenciamento com a uma baixa concentração de sinvastatina, sem efeito por si só, teve um ligeiro efeito sinérgico de inibição do crescimento celular, apesar de não se terem detetado efeitos sinérgicos na indução e apoptose ou na distribuição do ciclo celular. No que respeita à análise de transcriptómica realizada, não se detetou valor prognóstico significativo na expressão de RalGPS2 em cancro da próstata, mas verificou-se existirem evidências de uma correlação muito forte entre a expressão de YAP1 e RalGPS2 específica quer de tecido saudável, adenocarcinomas e tumores neuroendócrinos da próstata.
- The sociodemographic challenge in human-centred production systems – a systematic literature reviewPublication . Alves, Joel; Lima, Tânia M.; Gaspar, Pedro Dinisindustries are currently struggling with ageing workforce in modern production systems associated with industry 4.0. The industrial socio-demographic problem is more and more present as the increas-ing of the ageing population results in the prolongation of the work-ing life and the consecutively in the ageing of the workforce in industries. This paper aims to conduct a systematic literature review on the challenges and concerns of ageing operators, including the physical, cognitive, ergonomic, and well-being conditions of the age-ing workforce in the industry 4.0 environment. The ScienceDirect, Scopus, web of Science and PubMed scientific databases were used to survey the studies and selected using PRiSMA guidelines. This paper was structured and analysed by clusters: Ageing, industry 4.0, Human Factors, and ergonomics. These clusters were developed as research lines: Ageing as the socio-demographic challenge, industry 4.0 as the technological development, Human Factors as the individual charac-teristics of the operator, and ergonomics as the work environment. Thus, human-centric approaches and ideas are discussed with the insights and issues of industry 4.0 technologies, Human Factors, and ergonomics to achieve a sustainable system at the engineering and social level.
- Modelização e análise de desempenho de geradores termoelétricos aplicados no aproveitamento da energia do corpo humanoPublication . Manuel, Joice Magna Castelo Francisco; Calado, Maria do Rosario AlvesO elevado custo de energia, a poluição ambiental e o aquecimento global são alguns dos grandes problemas que a humanidade tem enfrentado atualmente. Para minimizar, de alguma forma, estes problemas, os cientistas têm concentrado as suas atividades na procura de formas alternativas de obtenção de energia e de realizar a sua captura. O efeito termoelétrico converte energia térmica em eletricidade. Na Bioengenharia, é possível conceber aplicações com módulos termoelétricos que aproveitam a energia térmica do corpo humano para a converter em energia elétrica, que possam alimentar dispositivos microeletrónicos e sensores autónomos. Os desempenhos dos módulos termoelétricos dependem dos vários parâmetros. A correta avaliação e simulação desses desempenhos é fundamental tanto no seu desenvolvimento quanto na sua aplicação em sistemas completos.
- Fluxos de mão-de-obra na economia-mundo capitalistaPublication . Cerdeira, Mariana Clemente; Madeira, Luis Filipe da SilvaDesenvolvida da década de 1970 pelo renomado sociólogo Immanuel Wallerstein, a análise dos sistemas-mundo propõe-se compreender o processo de mudança social através do estudo de totalidades económicas e sistémicas. No que respeita ao mundo moderno, na perspetiva do sistema-mundo, o capitalismo desenvolve-se no quadro de uma economiamundo cuja divisão social do trabalho, estruturada por relações centro/periferia, atravessa as fronteiras políticas dos múltiplos Estados que alberga. Com o propósito epistemológico de superar o Estado-nação como unidade de análise da ação social, esta perspetiva fornece um enquadramento analítico com utilidade para compreender melhor os fluxos de mão-de-obra, que assim podem ser perspetivados como um processo influenciado pelas dinâmicas estruturais da economia-mundo capitalista. Deste modo, além de perspetivar as migrações, em particular os fluxos de mão-de-obra, de acordo com a perspetiva do sistema-mundo, esta dissertação pretende também demonstrar a superioridade analítica desta perspetiva face às insuficiências das perspetivas convencionais, maioritariamente herdeiras da economia neoclássica.
- Development of RNA-based nanoparticles for cancer therapyPublication . Simões, Pedro Miguel Baltazar; Cruz, Carla Patricia Alves Freire Madeira da; Tomaz, Cândida Ascensão Teixeira; Nunes, Jéssica LopesOral cancer is increasingly recognized as two distinct diseases, mouth and oropharyngeal cancer. Its incidence and mortality are increasing, and it is expected in the year of 2040 a number of 553000 new cases and a total of 263000 deaths, worldwide. Treatment options depend on the stage of cancer, the location of the tumor, patient age, associated illnesses, among others. The most common therapy for oral cancers in early stages is surgery, to remove the top layers of malignant tissue. In more advanced stages, when there is still no metastasis, the most used therapies are surgery and radiotherapy, either used alone or combined. When the cancer has already spread to other parts of the body, a combined modality approach integrating surgery, and radiotherapy with or without chemotherapy is the golden choice. For some patients, immunotherapy, alone or with chemotherapy can be also an option. Although there are several therapeutic options, none of them are completely effective and in addition, there are several side effects associated with the therapies. To overcome these limitations, researchers have been trying to reduce these drawbacks by using drug delivery systems that carry drugs to be delivered at cancer cells. In this dissertation, we synthesized, characterized, and evaluated the biological potential of nanoparticles, namely liposomes and gold nanoparticles, coated with a RNA to selectively deliver the ligands C8, and dexamethasone, to oral cancer cells. Firstly, the RNA structure and binding interaction between the RNA sequence and ligands C8, dexamethasone and nucleolin (NCL) were evaluated by CD, TDS, NMR and fluorescence titrations. The biophysical assays evidenced the formation of an RNA hairpin and duplex structure and the ligands C8 and dexamethasone did not stabilize this structure. It was also shown that the RNA interacts and has a KD to NCL of 1.8 × 10-6 M, which increases with the addition of C8 and dexamethasone, and C8 showing a more pronounced effect. Then, RNA-coated gold nanoparticles and liposomes were produced and characterized. The functionalized gold nanoparticles and liposomes presented a size close to 20 nm and 160 nm, respectively, as observed by the DLS technique. The PAGE and NMR techniques showed that the liposomes were effectively coated with the RNA. Additionally, the UVvis spectroscopy revealed that the ligands C8 and dexamethasone were efficiently encapsulated in the liposomes. Finally, in vitro effects on oral cancer cell line (SCC-154) versus healthy cells (NHDF) of RNA gold nanoparticles and liposomes loading the ligands C8 and dexamethasone and the capacity of internalization of the RNA on oral cancer cells were evaluated. By MTT assay the RNA functionalized liposomes loaded with C8, or dexamethasone presented a significant reduction in the cell viability of malignant SCC-154 cells, while maintaining viable the non-malignant NHDF cells. With respect to the confocal fluorescence microscopy assays, the results proved that the RNA was able to internalize the majority of SCC-154 cells after 2 h of incubation, and mainly localize the nucleus and cytoplasm of cells. We also verified that the RNA did not internalize cells via NCL. Overall, the results obtained in this dissertation can contribute to the development of new drug delivery systems for sustained and effective targeted oral cancer therapy.
- Design and Engineering of Tissue Papers using Cellulose-based Fibrous Materials 3D Simulations: an approach for Furnish OptimizationPublication . Morais, Flávia Pinto; Curto, Joana Maria Rodrigues; Amaral, Maria Emília da Costa Cabral; Carta, Ana Margarida Martins SalgueiroIn recent years, the tissue paper industry has been exposed to several challenges related to the growing relevance and demand for raw materials (furnish) and sustainable products. Cellulose fibers are excellent raw materials, due to their intrinsic characteristics, leading to their use in various products, such as tissue papers. These materials serve multiple purposes, combining cost-effectiveness with increasingly demanding hygiene criteria. The knowledge of the different types of pulp fibers and the results of their modifications by engineering processes contributes to the design of tissue paper materials with the best combination of furnish, for the several types of final products. This work explores the furnish optimization of tissue products, through the development and application of advanced computational tools. A methodology that combines experimental and computational planning was implemented to establish relationships between the key fiber and structure properties, the process steps that modify them, and the structural and functional tissue paper properties. This led to the development of a simulator for furnish optimization and management, the SimTissue. This work presents a significant and innovative contribution in the 3D fiber characterization and modeling, in the application of experimental and computational approaches to evaluate the engineering of fiber and structure modification processes, and in the optimization using advanced computational tools to design soft, resistant, and absorbent tissue materials. The characterization of the fiber dimensions in the paper structure, in the three dimensions (3D), was fundamental to model them, using SEM images methodologies and advanced computational tools for fiber and structure modeling. As a result of this strategy, 3D fiber models were developed, implemented, and used as input variables in computational simulations to predict the structural properties. A representative set of cellulose pulps of industrial interest were selected and characterized, obtained from hardwood and softwood species with different cooking and bleaching processes. The contribution of these pulp fibers with different morphological, chemical and water interaction properties to the tissue properties was accessed through several correlations. Therefore, a planning was implemented from the point of view of engineering fiber and structure modification process variables, influencing the design of tissue paper materials. The pulps were subjected to enzymatic and mechanical treatment, and incorporation of additives in suspension, including micro/nanofibrillated cellulose (MFC/NFC) and biopolymers. All these sets of trials were investigated to quantify their influence, singular or in combination, on the key tissue properties: softness, strength, and absorption. A production methodology of laboratory-made isotropic structures of 20 g/m2 instead of 60 g/m2, with pressing step suppression, was proposed following an adaptation of ISO 5269-1, in order to mimic tissue papers and evaluate these tissue properties. The establishment of relationships between these pulp fibers, the multiple changes resulting from the different processes, and the functional tissue properties was obtained using several computational tools, such as decision/regression trees, multiple linear regressions, artificial neural networks, among others, used as models to support planning and decision-making in industrial production. Therefore, the validation of computational models with these structures was an innovative and irreplaceable milestone to obtain a 3D computational simulator with predictive capacity for tissue structures. This entire process allowed the computational implementation of the SimTissue through the programming of algorithms for the calculation engine and database integration, to be used in specific cases to support industrial furnish management. The design of tissue fibrous materials using these computational tools allowed the development of furnish combinations and process parameters that led to the optimization of each tissue paper. This assisted in the decision of which pulps were most suitable for a given product and which enzymatic and mechanical treatments or additives incorporation enabled an optimized tissue material. By applying this methodology, it was possible to produce tissue structures with maximization of eucalyptus fibers, minimizing the incorporation of softwood pulp fibers, and quantifying the implications of the choices on the final end-use tissue properties. Hence, SimTissue predicts the influence of various types of raw materials used in formulations to produce tissue materials, the influence of modification processes, and the incorporation of additives. The validation of the properties’ prediction was performed with experimental and simulated structures. Each simulation performed can also be compared with formulations with 100% eucalyptus fiber pulps, or with different percentages of other hardwood and softwood fiber pulps, which reflects the ratio used by the tissue paper industry. The present work describes an experimental and computational approach, with the design and development of a predictive capacity tool, with the integration of fundamental variables, to optimize innovative furnish formulations, saving laboratory and industrial resources. This multiscale system, with multiple inputs and multiple outputs, was integrated using computational tools, modeling, and optimization methods. The development of the SimTissue was an innovative milestone to obtain the predictive capability of tissue structures, to support industrial production in furnish management and optimization. The materials design strategy using this computational tool can also be applied to the development of value-added fibrous materials based on eucalyptus fiber and including additives and fibers with micro and nanoscale.