http://repositorio.ufc.br/handle/riufc/306 2026-04-16T10:51:10Z http://repositorio.ufc.br/handle/riufc/85484 Título: Estudo computacional da interação de fármacos anti-Parkinson com nanoestruturas de carbono Autor(es): Mendonça, Glaydson Leandro Farias Abstract: One of the consequences of increased life expectancy is the higher incidence of cases of neurodegenerative diseases, more common in older people. The most present in this category are: Alzheimer's disease and Parkinson's disease. The treatment of patients with Parkinsonism is often extremely exhausting, full of adverse effects; in certlin cares, the use of anti-Parkinson's drugs must cease so that individuals do not die or have permanent sequelae. Non-toxic nanostructured carbon particles interact with drugs, forming supramolecules capable of crossing the blood-brain barrier more easily, this show characteristics of good drug delivers. The present work aims to computationally study the interaction of the anti-Parkinson drugs Levodopa (LDP), Carbidopa (CDP), Entacapone (ECP) and Benserazide (BZD) with carbon nanostructures: Fullerane (C60), Single-walled carbon nanotube (NTCPS) and Fullerol (C60OH24) with the purpose of evaluating the application of these nanoparticles in a Drug delivery system. Molecular properties were obtained using DFT-level calculations, aiming to correlate them with pharmacological activity, as well as estimating the preferential adsorpition sites. The drug-nanostructure interactions were made using Monte Carlo and Molecular Dynamics Methods, obtaining the interaction energies and preferred orientations. It was observed that the interaction of drugs with C60 and NTCPS resulted in physical adsorption, where ECP binds more strongly to nanostructures, followed by LDP, BZD and CDP respectively, results attributed to molecular properties, such as LUMO and the electron density distribution in drugs. In the interaction of the molecules with C60OH24, chemisorption was observed, a consequence of the interaction of the heteroatoms of the drugs with the hydroxyl groups of the nanostructure, the interaction force undergoes a change and is shown as: ECP > BZD > CDP > LDP. As a final consideration, we have a potential suggestion for the treatment of Parkinson's disease would be the administration of LDP and CDP together with the carbon nanotube, making the drugs adhere to the carbon structure, facilitating the passage of drugs through the blood-brain barrier and potentially be released in the brain region, thus ensuring better use of the pharmacological effects of the drugs. Tipo: Tese 2017-01-01T00:00:00Z http://repositorio.ufc.br/handle/riufc/85345 Título: Computational study of water adsorption on iron surfaces and metallic alloys Autor(es): Castro, Gizele do Nascimento de Abstract: Uma das alternativas para reduzir a concentração de gases de efeito estufa (GEE) na atmosfera consiste na substituição dos combustíveis fósseis por fontes de energia limpas e renováveis, como o hidrogênio verde. Entretanto, o método empregado para sua produção, a eletrólise da água, ainda não é amplamente utilizado no mercado devido ao seu elevado custo, uma vez que esse processo requer eletrocatalisadores baseados em metais nobres, escassos na natureza, como irídio e platina. O presente estudo adota uma abordagem computacional para investigar a etapa de adsorção da água em ligas de ferro, ferro-cobalto e ferro-níquel. Foram realizadas otimização geométrica, dinâmica molecular e cálculos de propriedades eletrônicas com base na Teoria do Funcional da Densidade (DFT). Os resultados computacionais indicam que a energia de Gibbs de adsorção da água é mais espontânea na seguinte ordem dos planos cristalográficos: (110) > (100) > (111). A adição de um átomo de níquel à superfície metálica aumentou a densidade parcial de estados dos átomos de ferro adjacentes, favorecendo a adsorção da molécula de água, uma vez que foi na posição entre o átomo de ferro e o átomo de níquel que se observou maior disponibilidade de estados eletrônicos para a interação. Adicionalmente, a adsorção da molécula de água na superfície metálica promoveu a diminuição da densidade parcial de estados do átomo de ferro. Esse comportamento foi observado tanto para o ferro puro quanto para as ligas metálicas, quando a água interage com o sítio ativo mais favorável na superfície, indicando que o átomo de ferro doa densidade de estados à molécula de água durante o processo de adsorção. Tipo: Dissertação 2025-01-01T00:00:00Z http://repositorio.ufc.br/handle/riufc/85094 Título: Computational analysis of CO2 capture through deep eutectic solvents and silver nanoparticles Autor(es): Bezerra, Lucas Lima Abstract: The high levels of greenhouse gas (GHG) emissions in the atmosphere, especially CO2, are driving global warming, which is causing several problems for society, such as droughts, hurricanes, heat waves, and floods. Therefore, it is urgent to capture CO2 gas. In this thesis, the first work analyzed the effect of increased temperature on CO2 absorption using a deep eutectic solvent (DES) based on urea and choline chloride (reline) through molecular dynamics (MD) simulations and non-covalent interactions (NCI). Posteriorly, the second work analyzed the synergistic effect of three DESs (ethaline, reline, and glyceline) and a silver nanoparticle (AgNP) in the CO2 capture process through MD simulations. In the first work, it was observed that the increased temperature effect occasioned the reduction of the hydrogen bond (HB) number between the CO2 molecules and the urea molecules, resulting in the highest total interaction potential energy (IPE), indicating that the CO2 absorption process is more indicated at 303 K, with an average IPE value of -3872.54 kJ mol-1. On the other hand, the NCI results indicated that the increased temperature effect resulted in increased repulsion interactions and reduced the strong interactions in the systems simulated. Therefore, both computational approaches suggested that the CO2 absorption process is more indicated at the temperature of 303 K. In the second work, it was registered that the AgNP presence increases the HB number between the CO2 gas and the molecules that act as hydrogen bond donors (HBD), resulting in the lowest total IPE values for this group, occasioning a better CO2 capture process, especially for the AgNP-reline-CO2 system, with an average IPE value of -757.68 kJ mol 1. The radial distribution function (RDF) analysis indicated that ethylene glycol and urea are key species in the CO2 capture process for the AgNP-ethaline-CO2 and AgNP-reline CO2 systems, respectively. Furthermore, the AgNP is the key species in the CO2 capture process for the AgNP-glyceline-CO2 system. Tipo: Tese 2026-01-01T00:00:00Z http://repositorio.ufc.br/handle/riufc/85068 Título: Insights acerca da deposição e da dinâmica molecular de microplásticos em ambientes estuarinos: um comparativo entre o teórico e o experimental Autor(es): Parente, Guilherme de Sandes Abstract: Microplastics (MPs) are persistent and ubiquitous contaminants capable of interacting with various environmental components, particularly natural organic matter, such as humic acid (HA) present in sediments. In estuarine environments, this interaction is particularly critical, as estuaries are known to be areas of MP deposition, ant the presence of HA is frequently reported in extraction procedures. Thus, understanding the interaction between MPs and HA, and the mechanisms involved is highly relevant from an environmental perspective. In this study, experimental and computational approaches were employed to investigate the tendency of interaction between MPs of the types polyethylene (PE), polypropylene (PP), and polystyrene (PS) and HA. The experimental approach, associated with Principal Component Analysis (PCA), was applied to evaluate the correlation between MPs, HA, and different studied estuarine environmental parameters, such as granulometry (sand, gravel and silt), organic matter (OM), and organic carbon (OC). The PCA revealed a positive correlation between MPs and HA, evidencing their affinity and ability of HA to influence the distribution of MPs in estuarine sediments To further investigate these interactions, the Molecular Dynamics (MD) computational technique was applied. This method provided a important details about the interaction, such as the predominance of van der Waals interactions in the stabilization of the systems (HA-PE, HA-PP, and HA-PS), with a higher affinity between HA and PS compared to the others, due to the more negative IPE value. In addition, a more significant reduction in the number of hydrogen bonds involving HA-H2O was observed for the system containing PS, suggesting a more favorable HA-PS interaction. Through the Independent Gradient Model (IGM), it was possible to visualize the interactions and confirm the presence of van der Waals interactions in all systems, as well as to verify strong interactions between HA and PS, mainly near the oxygen atoms of HA. Therefore, the high affinity directly impacts the environmental dynamics of these contaminants in estuarine environments, favoring their retention and deposition in sediments. These results highlight the strong affinity between HA and MPs, especially PS, emphasizing the need to further environmental studies further environmental studies on MPs to better understand their impacts on estuarine environments. Tipo: Dissertação 2025-01-01T00:00:00Z