Mateus Aquino Gonçalves

This study approaches the characterization of Ferroxite and Hematite and the test of their magnetic properties on the degradation and adsorption of Atrazine, an herbicide of the triazine class. This herbicide was compared with a sample of Ferroxite in the absence of a magnetic field and with Hematite, a non-magnetic material which should not be attracted by the magnet. In the sample, the Atrazine determination was carried out by Fenton analysis. Preliminary results were satisfactory, gathering a reduction rate up to 85% for Ferroxite in the presence of a magnetic field and 53% for Hematite. The Fenton reaction, however, showed an 87% reduction rate for Ferroxite in the presence of a magnetic field, and 56% for Hematite. These findings have shown that there is a relation between the magnetic field intensity and the adsorption capacity for these materials.

Molecularly imprinted polymers (MIPs) are synthetic polymers designed to exhibit selective recognition and binding capabilities toward target molecules and have been widely combined with advanced ceramic-based materials toward better performance in many catalytic applications of interest and beyond. What sets MIPs apart is their molecularly imprinted cavities, which are formed during polymerization in the presence of a template molecule. Upon template removal, these cavities retain the shape, size, and chemical functionality of the template molecule, allowing for highly specific recognition and binding of target molecules. In recent years, there has been a growing interest in leveraging these molecularly imprinted cavities not only for molecular recognition and sensing but also as catalytic sites and supports. Complementary to experimental studies, density functional theory (DFT) calculations are increasingly used to elucidate the molecular interactions, catalytic mechanisms, and optimize the design of MIP–ceramic catalysts. This review aims to provide a comprehensive overview of the current state of research on advanced ceramic-based catalysts supported by MIPs for environmental applications. Additionally, the review will discuss challenges and future directions in the field, focusing on enhancing the catalytic efficiency, stability, and scalability of MIP-based ceramic catalysts. By exploring these aspects, this review seeks to illustrate the promising role of MIP-modified ceramic materials in advancing the field of catalysis and catalytic supports.

The study approaches the characterization of Ferroxite and Hematite and the test of their magnetic properties on the degradation and adsorption of Atrazine, an herbicide of the triazine class. This herbicide was compared with a sample of Ferroxite in the absence of magnetic field and with Hematite, a non-magnetic material which should not be attracted by the magnet. In the sample, the Atrazine determination was carried out by Fenton analysis. Preliminary results were satisfactory, gathering reduction rate up to 85% for Ferroxite in the presence of magnetic field and 53% for Hematite. The Fenton reaction, however, showed 87% reduction rate for Ferroxite in the presence of magnetic field, and 56% for Hematite. These findings have shown that there is a relation between the magnetic field intensity and the adsorption capacity for these materials.

In this paper the effect of different solvents (ethanol, acetone, dichloromethane and hexane) in the surface treatment of graphite for the construction of voltammetric sensors was evaluated. During voltammetric experiments of the graphite powder‐based sensor treated with ethanol, it was possible to observe a significant increase in current signals for the redox process of the model analyte (acetaminophen), as well as an increase in the area density of this sensor compared to its unmodified electrode. Theoretical studies involving Density Functional Theory (DFT) and Quantum Theory of Atoms in Molecules (QTAIM) showed greater interaction and stability when graphite was treated with ethanol solvent. Moreover, the theoretical calculations indicated that treating the voltammetric sensor with ethanol offers improvements in the electrochemical response of the model analyte mainly due to a higher spin density, and a partially covalent interaction between solvent and graphite surface. Therefore, graphite powder‐based sensors treated with ethanol were used for determination of acetaminophen in pharmaceutical samples and their results were in good agreement with those obtained by using spectrophotometric method recommended by Pharmacopoeia.

The absence of adequate force field (FF) parameters to describe certain metallic complexes makes new and deeper analyses impossible. In this context, after a group of researchers developed and validated an AMBER FF for a platinum complex (PC) conjugated with AHBT, new possibilities emerged. Thus, in this work, we propose an improved path to obtain NMR spectroscopic parameters, starting from a specific FF for PC, allowing to obtain more reliable information and a longer simulation time. Initially, a docking study was carried out between a PC and PI3K enzyme, aiming to find the most favorable orientation and, from this pose, to carry out a simulation of classical molecular dynamics (MD) with an explicit solvent and simulation time of 50 ns. To explore a new PC environment, a second MD simulation was performed only between the complex and water molecules, under the same conditions as the first MD. After the results of the two MDs, we proposed strategies to select the best amino acid residues (first MD) and water molecules (second MD) through the analyses of hydrogen bonds and minimum distance distribution functions (MDDFs), respectively. In addition, we also selected the best frames from the two MDs through the OWSCA algorithm. From these resources, it was possible to reduce the amount and computational cost of subsequent quantum calculations. Thus, we performed NMR calculations in two chemical environments, enzymatic and aqueous, with theory level GIAO–PBEPBE/NMR-DKH. So, from a strategic path, we were able to obtain more reliable chemical shifts and, therefore, propose safer spectroscopic probes, showing a large difference between the values of chemical shifts in the enzymatic and aqueous environments.

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Wavepress is a signal processing software that has a simple and friendly interface that can be used by researchers, professors and students. The program uses the wavelet transform, which is a signal processing tool, being used to handle a signal in the time-scale space. In this way, the program can be used for signal processing capable of reducing, without losing important information, the amount of information. Thus, it is possible to obtain graphs and tables to explore the results in a comprehensive and satisfying way. In this work, the main features of Wavepress are explored with applications in computational chemistry, and drug design, all examples are illustrated with graphs and tables got with Wavepress.

New tools for cancer diagnosis are being studied since early diagnosis can be crucial for a successful treatment. In this context, the use of NMR probes constitutes an efficient method of diagnosis. In this study, we investigated the use of ciprofloxacin to indirectly label the overexpression of topoisomerase-II enzymes by changes in ¹⁹F NMR chemical shifts of ciprofloxacin. Increased topoisomerase-II expression has been associated with cancer occurrence, mainly with aggressive forms of breast cancer, thus constituting a promising molecular target for new tumor cell identifiers. Using DFT calculations, we performed a spectroscopy analysis of ciprofloxacin in different chemical environments and evaluated the solvent and enzymatic effects. Our results show that ciprofloxacin forms a stable complex with the enzyme, and the main intermolecular interactions between ciprofloxacin and human topoisomerase-IIβ are hydrogen bonds, followed by π-π stacking and electrostatic interactions. Additionally, a shift of 6.04 ppm occurs in the ¹⁹F NMR signal when ciprofloxacin interacts with the human topoisomerase-IIβ enzyme, and this parameter may be an indirect marker indicating the overexpression of these enzymes in the body.

Introdução: A química computacional é uma ferramenta importante no estudo de propriedades microscopicas Assim, podemos destacas a Teoria do Funcional de Densidade (TFD) que é considerado um método muito importante da química computacional. Métodos: Esse artigo mostra as principais caracteristicas da TFD e suas aplicações em agentes de constraste. Resultados: Os agentes de contraste têm como característica serem paramagnéticos.Estes compostos podem ser classificados de acordo com o grau de mudança na intensidade do sinal, ou do brilho na imagem de ressonância. Conclusão: A TFD é um método presente na química computacional muito importante, esse método consegue obter resutados satisfatorios com um custo computacional relativamente baixo.