Browsing by Issue Date, starting with "2023-11-24"
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- Implementação de Metodologia para Controlo Estatístico do Processo na Inspeção Tridimensional de Peças Metálicas de AeronavesPublication . Domingues, Ana Laura Pedrosa; Lima, Tânia Daniela Felgueiras de Miranda; Silva, Jorge Miguel dos ReisAtualmente, na Aernnova Évora, cada peça inspecionada na máquina de medição por coordenadas (CMM) é analisada individualmente. Sendo esta análise individual e demorada, não existe uma ferramenta que permita estabelecer uma interligação dos dados de medição das diferentes peças nem que permita determinar se o processo de fabrico se encontra ou não estabilizado, através da análise da capacidade e capabilidade do mesmo. A presente dissertação surgiu da necessidade de tornar os dados resultantes da medição tridimensional de peças metálicas de aeronaves acessíveis, no que diz respeito às suas características geométricas, de modo a possibilitar uma análise real-time dos mesmos, permitindo visualizá-los enquanto informação útil substituindo a tomada de ações corretivas por ações preventivas. A metodologia foi implementada a 4 casos práticos, 2 longarinas e 2 revestimentos. Após a medição de cada peça é exportado um ficheiro de texto com os pontos e avaliações resultantes da medição tridimensional. Estes ficheiros são automaticamente transferidos para o software PowerBI, no qual se desenvolveu uma página com a representação gráfica dos dados existentes nestes ficheiros. Os resultados obtidos, no caso dos revestimentos, foram bastante satisfatórios, com valores de capacidade e capabilidade superiores a 2,00. No caso das longarinas, identificou-se a necessidade de realizar uma análise da causa raiz dos desvios, de modo a melhorar o cumprimento dos requisitos destas peças. A implementação das recomendações, no que diz respeito à frequência de medição das peças que se encontram estabilizadas permite uma poupança de 85.500 €, bem como de 3.075 horas de trabalho, considerando o plano de produção atualmente em vigor para o próximo ano.
- Cosméticos anti-estrias: estudo de mercadoPublication . Pinheiro, Júlia Tomás; Oliveira, Rita Manuela Palmeira de; Esteves, DianaO presente relatório foi realizado no âmbito da unidade curricular “Estágio” do Mestrado Integrado em Ciências Farmacêuticas. É constituído por dois capítulos que correspondem à vertente de investigação e à experiência de estágio em Farmácia comunitária. O capítulo I aborda o estudo de cosméticos comercializados em Portugal e intitula-se de “Produtos cosméticos anti-estrias: estudo de mercado”. O objetivo desta investigação foi efetuar um estudo de mercado dos cosméticos anti-estrias comercializados em Farmácias, Parafarmácias e Hipermercados do território português, analisando não só a lista de ingredientes, mas também as alegações quer das embalagens quer dos sites. Recolheu-se um total de 35 produtos cosméticos de 22 marcas diferentes. Após esta etapa concluída, foi feita a análise das seguintes informações: pessoa responsável, marca, nome comercial, lista INCI, ingredientes ativos, alegações presentes na embalagem, alegações presentes no site, estudos de eficácia realizados e tipologia de local de venda. A maioria (74%) dos produtos foram formulados para grávidas e/ou puberdade, sob a forma de óleos (43%) e cremes (34%). Apenas 3 produtos foram concebidos como multifuncionais (uso para outras marcas e cicatrizes além de estrias) e apenas 43% mencionaram a frequência adequada de aplicação (principalmente duas vezes ao dia). Verificou-se que 91% continham ingredientes de origem vegetal pela sua atividade ao nível da emoliência, ação direta na regeneração e nas fibras de colagénio. A combinação de ingredientes ativos foi encontrada em 22 produtos mostrando a importância do efeito aditivo/sinérgico para a eficácia. As alegações são suportadas por ensaios clínicos para 20 produtos (57%). Entre estes, 10 não especificam a população do estudo, enquanto 8 foram testados entre gestantes. Verificou-se que os produtos comercializados em farmácia combinam mais ingredientes ativos e apresentam mais estudos clínicos do que os encontrados em supermercados. Este estudo permitiu recolher informação que suportará o desenvolvimento de novos produtos anti-estrias com características diferenciadoras das do mercado existente. O Capítulo II refere-se à minha experiência de estágio em Farmácia Comunitária decorrida na Farmácia Lopes em Viana do Castelo entre 6 de fevereiro e 23 de junho de 2023, sob orientação da Dra. Sara Sobreiro.
- Tempo ao Tempo: Processo criativo como reflexão sobre o cinema e a perdaPublication . Finotti, Lucas Messias; Nogueira, Luis Carlos da CostaNeste relatório tento revelar de maneira clara quais foram os principais fatores que me fizeram desenvolver esta ideia, a qual evoluiu para um projeto final em mestrado. Assim, num primeiro momento, tento buscar e refletir os verdadeiros motivos que desencadearam o crescimento do projeto, desde a narrativa aos locais, passando pelos personagens. Desta maneira, com uma cuidada reflexão, tento descrever e compreender todas as etapas que foram sendo desenvolvidas durante o projeto. Outro ponto abordado se relaciona com o fato de as vezes, sozinho, se ter uma ideia que, quando compartilhada, originando um trabalho em conjunto, pode chegar a um desfecho que jamais havíamos imaginado, nisto consistindo uma das grandes virtudes da atividade coletiva que é o cinema. Posteriormente, a fim de tentar descrever com mais detalhe toda a semana de filmagens, decidi usar como recurso uma escrita mais próxima de um diário, que contém grande parte dos problemas com que nos confrontámos, bem como as soluções encontradas e as grandes surpresas vividas, seja com atores ou com a equipa. Dessa forma, tento refletir sobre a forma como desempenhamos cada papel e como isso acaba sendo repercutido no resultado final. Após isto, num último momento, efetuo uma análise de todo o processo de montagem do projeto e de quais os caminhos seguidos nessa etapa. Outros aspetos abordados, e com muita importância na pós-produção, são a imagem e som. No entanto, merece especial destaque algo que me deixou mais apreensivo: a possibilidade de desenvolver uma música original para o projeto, tendo as conversas com o compositor sido cruciais para fazer o espectador sentir o filme da maneira como idealizava. Cada detalhe contribuiu para tornar este projeto uma história única, a qual se revelou fundamental para o meu crescimento pessoal e amadurecimento técnico, conceitual e artístico no cinema.
- Relevância do metaboloma do plasma para o diagnóstico e estudo etiológico do Acidente Vascular CerebralPublication . Santos, Celina Maria Serra; Fonseca, Carla Sofia Pais; Pérez, Francisco José AlvarezO acidente vascular cerebral (AVC) é a segunda principal causa de morte e a terceira principal causa de incapacidade em adultos em todo o mundo. Determinar a etiologia desta doença é importante para o diagnóstico e decisões terapêuticas, bem como a prevenção de AVC secundários. Contudo, é uma tarefa difícil e morosa, uma vez que são necessários exames complementares. A análise por ressonância magnética nuclear (RMN) de amostras de biofluidos, como é o caso do plasma humano, tornou-se fundamental para fornecer uma variedade de informações importantes para o diagnóstico e prognóstico, permitindo a monitorização da progressão da doença. Com esta técnica é possível estudar o metaboloma deste biofluido, investigar alterações nas vias metabólicas que podem estar subjacentes a vários processos da doença e identificar biomarcadores metabólicos associados ao AVC. Assim, o principal objetivo deste estudo foi investigar o perfil metabolómico do plasma obtido de indivíduos que sofreram um AVC e inferir se este pode ser útil para diferenciar tipos de AVC e correlacionar com a etiologia do AVC isquémico. Os espectros de RMN de 1H foram adquiridos e analisados utilizando uma análise estatística multivariada (PCA e PLS-DA) e univariada. Os resultados mostraram que foram observadas diferenças entre o metaboloma do plasma de indivíduos com AVC isquémico em comparação com indivíduos com AVC hemorrágico e entre as etiologias do AVC isquémico quando comparadas entre si (etiologia cardioembólica, aterosclerótica e lacunar). Metabolitos como a alanina, tirosina, histidina, glucose e fenilalanina estão de acordo com a literatura e poderão ser candidatos a biomarcadores dos tipos de AVC e suas etiologias. Estes resultados sugerem que uma abordagem metabolómica pode tornar-se útil, no futuro, no diagnóstico e na implementação de intervenções terapêuticas mais eficazes e preventivas.
- Molecular docking tools for the screening of affinity ligands for pre-miRNA-29b purificationPublication . Almeida, Paulo Ricardo Esteves; Sousa, Fani Pereira de; Pereira, Matheus Mendonça; Freire, Mara GuadalupeOver the years, the interest in using nucleic acids as biopharmaceuticals to establish alternatives to traditional treatments for diseases such as cancer and neurodegenerative disorders has been increasing. The ability to regulate gene expression may lead to new forms of treatment for diseases with ineffective therapies, such as Alzheimer's disease. To further study these biomolecules and make them usable as biopharmaceuticals, they need to have a high degree of purity and preserved biological activity. Through biotechnology, the recombinant production of these biomolecules is rapid, cost-effective, and applicable on an industrial scale. However, subsequent steps related to separation and purification make the process costly. The main purification technique currently used in the biopharmaceutical industry is chromatography. But if a more specific strategy is expected, affinity chromatography must be considered, where the selection of more selective ligands is the greatest challenge. In this context, the present work aims to identify ligands for the purification of premiRNA-29b, which has potential as a biopharmaceutical for Alzheimer's disease treatment. This identification and selection of ligands was carried out through in silico methods, making the work less costly, time-saving, and environmentally friendly. Initially, 13 oligonucleotides (oligos) were designed to interact with the pre-miRNA-29b through base complementarity with one of three possible binding sites: the 5' end, the 3' end, or the hairpin structure. Each of these oligos has a carbon chain linked to the 5' end and an amino group to allow the immobilization of the ligand onto the chromatographic support. This chain can have either six or twelve carbons, resulting in two versions of each oligonucleotide, summing up to a total of 26 different ligands. After designing the oligo sequences and pre-miRNA-29b, they were submitted to a server for molecular docking analysis, and the results regarding the affinity energy and interaction capability were subsequently analyzed. Following the analysis of the docking score, the number of connections between the ligand and the target, and the site of interaction, 4 oligos were selected as the most promising. These ligands will help understand the influence of the carbon chain and the potential differences for the pre-miRNA-29b purification between versatile oligos, which can interact with more than one target site, and selective oligos, which only interact with the site they were designed for. The results indicated that approximately 80% of the interactions established between the ligand and pre-miRNA-29b are hydrogen bonds, which can provide some stability to the complex. To obtain more information about the stability of the interaction between the ligands and the receptor, molecular dynamics assays were performed, demonstrating that the formed complex is quite stable (RMSD < 1 Å). This way, it was possible to select the best ligands for the purification of pre-miRNA-29b from the initial group, as well as to confirm their stability with the target.
- Validation of LoggerOne system’s 5-lead ECGPublication . Daniel, Lisana Moniz de Sousa; Santos, Nuno Manuel Garcia dos; Felizardo, Virginie dos SantosValidation studies are becoming increasingly crucial as technology advances and the number of electrocardiography (ECG) wearables grows. Existing validation studies, however, are limited and particular to the approach in question. The primary purpose of this dissertation is to provide a standard validation method that can be used for a wide range of validation studies. To that purpose, the LoggerOne system will be compared against the COMEN system, an established gold standard. ECG signals will be recorded using both devices at the same time, with the assistance of an ECG signal simulator. The simulator used is a CE certified device that can simulate both pediatric and adult ECG signals, as well as different types of arrhythmia’s. The recorded signals will be processed using Python’s ECG and data manipulation toolboxes. Prior to validation, signals from both devices will be normalized, and a number of filters and algorithms for feature extraction for each lead will be tested. The optimized algorithms will then extract relevant signal properties such as the P and T wave, QRS complex, RR, PR, ST, and QT intervals, and ST and PR segments. This intervals and segments from each device will be analyzed using statistical analysis methods such as Bland-Altman limits of agreement (LoA), intraclass correlation coefficient (ICC), and morphological comparison to validate the device. This work results can be divided into two components: algorithm optimization results and validation results. Regarding algorithm results, only some leads presented P wave bounds and the T onset with values of sensitivity (Se) and positive predictive value (+P) below 95% , whereas most results present values above 98%. Standard deviation (SD) values for P bounds and QRS onset exceeded the reference values in some leads, whereas all other values remained within the range of reference. The mean values remained below the reference value imposed. Regarding validation results, almost all results for each lead show good agreement and reliability, except for intervals and segments computed using the T onset.
- Plasmid DNA-loaded calcium phosphate functional nanocomplexes: innovative approach against cervical cancerPublication . Costa, Matilde Bogalheiro; Sousa, Ângela Maria Almeida de; Valente, Joana Filipa Abreu Pereira; Patrício, Tatiana Marisa FernandesCancer is among the leading causes of death worldwide. By 2040 it is expected that the number of new cancer cases will rise to 29.5 million and the number of cervical cancerrelated deaths to 16.4 million. Generally, cancer incidence rate increases in countries with highest life expectancy, education level and standard of living. However, for cervical cancer the reverse happens, its incidence is higher in less developed countries, due to the lack of proper awareness, screening programs, inaccessibility to proper diagnosis and efficient treatment procedures, these facts lead to a late diagnosis and consequently low survival rates. Human Papillomavirus (HPV), a highly sexually transmissible virus, is the main agent in cervical cancer. Around 79 % of the diagnosed causes are attributed to HPV-16 and -18. The severity of symptoms is usually associated with the affinity presented by oncoproteins E6 and E7 within each HPV type toward the target protein, p53, a tumour suppressor, and pRb, a retinoblastoma protein, respectively. Thus, the deregulation of these proteins’ expression leads to invasion, proliferation, and survival of cancer cells. A plethora of strategies are being developed to detect and prevent the disease, with antiHPV vaccines being at the front. However, in less developed countries, with poor health resources, the preventative measures do not always work, and new therapies are being developed to treat this type of cancer. Gene therapy has been increasingly used since it allows the correction of a genetic effect while also facilitating for an induced cell death. Thus, plasmid DNA that encodes the p53 gene can be a promising approach to combat cervical cancer. However, pDNA use is limited since it is easily degraded by various agents, so a delivery system is needed to carry pDNA to the target cells. Calcium phosphate nanoparticle are promising delivery systems since they are composed of ions that naturally exist in the human body, and its degradation does not entail negative consequences for the patient. In this context, the present work’s focus is the development of plasmid DNA-loaded calcium phosphate nanoparticles and further functionalization with folic acid for a targeted delivery to HPV positive cancer cells. Initially, the delivery system formulation was optimized resulting in delivery systems presenting a size of 76.34 ± 34.08 nm, with a polydispersity index (PdI) of 0.40 ± 0.09 and a surface charge of – 20.90 ± 0.90 mV. pDNA inclusion was performed through an adsorption approach yielding a size of 133.13 ± 58.12 nm, PdI of 0.65 ± 0.17 and a surface charge of – 23.70 ± 1.10 mV with an encapsulation efficiency of approximately 100 %. Folic acid loading was investigated, and two methods were chosen, firstly when folic acid is added in the precursor calcium solution (CaP-NP/FACa) and also when folic acid is added through adsorption (CaP-NP/FAAd), which exhibited a folic acid loading efficiency of approximately 92 and 70 %, respectively. The CaP-NP/pDNA/FAAd achieved an efficiency of approximately 100 % for pDNA encapsulation and approximately 99.6 % for folic acid loading, with a size of 112.63 ± 19.81 nm, PdI of 0.50 ± 0.22 and a surface charge of – 27.40 ± 0.69 mV. The CaP-NP/pDNA/FACa presented an encapsulation efficiency of pDNA in the nanoparticles of 100 % and an efficiency of approximately 73 % for the loading of folic acid, with a size of 110.42 ± 65.71 nm, PdI of 0.50 ± 0.07 and a charge of – 22.20 ± 0.60 mV. Overall, the in vitro assays showed no inherent cytotoxicity for the CaP-NPs, with viability reduction only in higher concentrations (500 and 1000 µg/mL). The delivery systems did not affect the healthy cells viability but decreased the viability in the cancer cell line. Cell internalization was evaluated through confocal microscopy, which showed significant uptake in both cell lines. The formulations presenting pDNA and folic acid, in the calcium solution (CaP-NP/pDNA/FACa) and adsorbed after the nanoparticle formulation (CaP-NP/pDNA/FAAd), presented high accumulation in cancer cells. PCR evaluation seems to present increased expression values of p53 when the cancer cell line was transfected with both CaP-NP/pDNA and CaP-NP/pDNA/FACa. The present work demonstrated that CaP-NPs, loaded with pDNA and modified with folic acid, show a therapeutic effect, and represents a promising treatment for cervical cancer.
- Effects of G-quadruplex structures formation in miRNA expression associated with lung cancerPublication . Polido, Joana Curado; Cruz, Carla Patricia Alves Freire Madeira da; Baptista, Pedro Viana; Alexandre, Daniela de JesusLung cancer (LC) is a growing health issue. Characterized by the aggressive profile and late presentation, it ranks first as the deadliest cancer worldwide, requiring novel therapeutic approaches and biomarkers to improve the prognosis. MicroRNAs (miRNAs or miR) are actively implicated in the inhibition of gene expression, leading to pathologies when dysregulated. In this way, they are promising targets in diagnosis but also therapy by restoring the endogenous levels. MiR-3196 and miR-193a-5p/3p are aberrantly expressed in LC, affecting the cancer cell’s apoptosis, proliferation, and migration. The G-quadruplex (G4) is a non-canonical secondary structure capable of structurally interfering with the enzymatic maturation and target binding in miRNAs, acting as a potential tool for miRNA silencing. The current dissertation determines the expression and therapeutic potential of miR-3196 and miR-193a-3p/5p in peripheral blood mononuclear cells (PBMCs) and LC cell lines and evaluates the miRNA-silencing by the G4 structure stabilization within the precursor sequences. Overall, the abnormal profile of both miRNAs and their suitability as targets was observed. Biophysical evidence confirmed the folding of stable parallel G4 structures in the pre-miRNAs, greatly stabilized by the ligand C8-NH2. In cells, incubation with the ligand did not reveal a G4-mediated effect on the maturation. Hence, further research is required to validate the results and assess this hypothesis as an anti-cancer strategy.
- Determination of amphetamines in hair samples using microextraction by packaged sorbent and gas chromatography coupled to mass spectrometryPublication . Pires, Bruno Miguel Pinheiro; Simão, Ana Aysa da Rocha; Rosado, Tiago Alexandre Pires; Alba, Maria Eugénia GallardoDifferent extraction and clean-up protocols have been used for Amphetamine-type psychostimulants (ATS) determination in hair. Microextraction by packed sorbent (MEPS) is a miniaturized version of solid-phase extraction (SPE) which has been applied to determine a number of drugs in hair (e.g., opiates, cocaine, ketamine, etc.). However, concerning Amphetamine-type psychostimulants, MEPS has only been used in hair for the determination of amphetamine (AMP) and methamphetamine (MAMP). The aim of this work was the development and validation of a method to determine AMP, MAMP, 3,4-methylenedioxyamphetamine (MDA), 3,4- methylenedioxymethamphetamine (MDMA), 1-(1,3-benzodioxol-5-yl)propan-2- yl(ethyl)amine (MDE) and N-methyl-1-(1,3-benzodioxol-5-yl)-2-aminobutane (MBDB) in hair using MEPS for sample clean-up. Hair (50 mg) was incubated with NaOH 1M at 45 ºC overnight, after which HCl 10M was added for neutralization and the solution was centrifuged. The MEPS procedure for extract clean-up was optimized using the Design of Experiments (DoE) approach, and the final steps were: conditioning (1 x 250 µL of methanol and 1 x 250 µL of deionized water); loading (18 x 100 µL); and elution (7 x 100 µL of 2% NH4OH in acetonitrile). To the eluted extract, 30 µL of MBTFA was added, and extracts were evaporated to dryness, following microwave-assisted derivatization with 50 µL of MBTFA. A gas chromatography coupled to mass spectrometry (GC-MS) system was used for determination. The MEPS procedure resulted in recoveries of 8-14% for AMP, 14-20% for MAMP, 10-15% for MDA, 18-28% for MDMA, 25-43% for MDE and 34-52% for MBDB, in the linear range of 0.2 - 5.0 ng/mg. Precision and accuracy of the developed method were in accordance with the statements of international guidelines for method validation. This is the first analytical method using MEPS coupled to GC-MS to determine the selected amphetamines in hair samples, proving to be a great alternative to the classic procedures, being rapid, ecofriendly and less expensive.
- Invariants and Code Contracts in an Online Classroom EnvironmentPublication . Barata, Rui Pedro de Almeida; Sousa, Simão Patricio Melo deProgramming education has evolved significantly with the advent of online classroom environments, offering both advantages and challenges. This dissertation explores the integration of code contracts and invariants into programming education, with a focus on the OCaml language. The primary objective is to develop a tool that translates student-written code contracts and invariants into executable assertions, enhancing software reliability and correctness. In the pursuit of this objective, several key contributions are presented. First, an in-depth analysis of online classroom environments, highlighting the importance of addressing software reliability in this context. The Learn-OCaml platform is introduced as a valuable educational resource, offering a unique blend of contest-like challenges and comprehensive lessons. The dissertation delves into code contracts and invariants, elucidating their significance in ensuring code behaves as intended. It surveys existing code contract tools and the relevance of online classroom environments. The research demonstrates how a modified Gospel specification language can be harnessed to integrate code contracts into OCaml programs. The implementation phase of the project is detailed, outlining the process of translating components like preconditions, postconditions, invariants, and variants from Gospel specifications into actionable OCaml code. Limitations of the tool, especially in handling quantifiers, are acknowledged. The dissertation concludes with a summary of achievements and contributions, addressing the research problem of enhancing software reliability and correctness in online programming education. Future work is proposed, including the addition of quantifier support and the incorporation of the developed tool into the Learn-OCaml platform, fostering automated grading and assertion comparison. This work represents a significant step toward improving the quality of programming education in online classrooms, empowering students to write more reliable and correct code while offering educators enhanced tools for assessment and feedback.