http://hdl.handle.net/11422/15 2026-05-06T18:26:39Z 2026-05-06T18:26:39Z Moreno Vera, Felipe Adrian http://hdl.handle.net/11422/29139 2026-05-06T18:26:14Z 2024-12-02T00:00:00Z

Title: Automated detection of vulnerability exploitation in underground hacking forums Author(s)/Inventor(s): Moreno Vera, Felipe Adrian Advisor: Menasché, Daniel Sadoc Abstract: This work proposes a machine learning-based approach to identify and classify vulnerability exploitation, the scope, and the impact of malicious software through the monitoring of underground hacker forums. The growing volume of posts discussing vulnerability exploitation demands an automated approach to process topics and posts that may trigger alarms based on their content. To illustrate the proposed system, we used the CrimeBB dataset, which contains data extracted from various underground forums, and developed a supervised machine learning model capable of filtering topics that cite CVEs and labelingthem as proof of concept (PoC), weaponization, exploitation, among others. We applied machine learning and natural language processing techniques to preprocess the texts and then trained several linear and non-linear models. To evaluate the models’ effectiveness and accuracy and compare results, we used metrics such as accuracy, precision, and recall. Additionally, to gain a better understanding and explanation of why the model can differentiate between classes, we employed model explanation methods to determine the relevance of words in predictions. Overall, this work highlights the differences in the nature of the labeled posts and their importance in vulnerability analysis. Publisher: Universidade Federal do Rio de Janeiro Type: Dissertação

2024-12-02T00:00:00Z Costa, Marília Ladeira Alves e http://hdl.handle.net/11422/29138 2026-05-06T18:25:17Z 2026-01-01T00:00:00Z

Title: Uso de métodos DFT e de docking molecular para avaliar a quelação de átomos de Ferro em grupos [Fe4S4(Cys)4]-2 Author(s)/Inventor(s): Costa, Marília Ladeira Alves e Advisor: Lima, Camilo Henrique da Silva Abstract: This work aims to perform a critical analysis of the ability of molecular docking methods to describe electronic interactions in metalloenzymes containing [4Fe–4S] clusters. The study employs Density Functional Theory (DFT) calculations and docking simulations to investigate systems in which metal–ligand interactions require explicit consideration of electronic effects, which are often neglected by classical methods. The methodology initially involved DFT calculations on [4Fe–4S] cluster models coordinated by cysteine residues to evaluate the energetic favorability of ligand coordination. Subsequently, docking studies were carried out on different protein systems using AutoDock4, LeDock, AutoDock Bias, and Metalloprotein Bias Docking, under RESP and AM1-BCC partial charge schemes, in addition to cavity analyses to assess site accessibility. The results demonstrate that, although the search algorithms generate poses with low RMSD values in redocking protocols, the scoring functions consistently fail to reproduce realistic coordination geometries. Excessively short metal–oxygen distances and incorrect orientations of coordinating atoms were favored, regardless of the applied bias or charge scheme. It is concluded that the main limitations of classical docking methods in metalloprotein systems are intrinsically associated with deficiencies in the scoring functions. Publisher: Universidade Federal do Rio de Janeiro Type: Dissertação

2026-01-01T00:00:00Z Oliveira, Heldis Beloni de http://hdl.handle.net/11422/29137 2026-05-06T18:05:53Z 2026-02-27T00:00:00Z

Title: Avaliação de glifosato e ácido aminometilfosfônico (AMPA) Em urina de gestantes e puérperas na cidade do Rio de Janeiro por cromatografia líquida de alta eficiência acoplada a detector de fluorescência (CLAE-FLD) Author(s)/Inventor(s): Oliveira, Heldis Beloni de Advisor: Padilha, Monica Costa Abstract: Glyphosate is a pesticide widely used in Brazil and worldwide, whose presence in environmental and biological matrices has raised scientific interest, particularly in the context of human biomonitoring studies. In this regard, the present study aimed to develop, optimize, validate, and apply an analytical method for the determination of glyphosate and its main metabolite, aminomethylphosphonic acid (AMPA), in urine samples from pregnant women. The method is based on high-performance liquid chromatography coupled with a fluorescence detector (HPLC-FLD), following derivatization with 9-fluorenylmethoxycarbonyl chloride (FMOC-Cl). Sample preparation involved liquid–liquid extraction clean-up, derivatization, and solid-phase extraction steps, which were systematically optimized in terms of solvents, volumes, reaction time, and temperature. Method validation was carried out in accordance with national and international guidelines, including the Brazilian National Institute of Metrology, Quality and Technology (INMETRO), evaluating selectivity, linearity, limits of detection and quantification, precision, accuracy, repeatability, and intermediate precision. The method showed linear behavior over the concentration range of 0.5–10 μg L⁻¹ for both analytes, no significant matrix effect, and limits of detection of 0.03 μg L⁻¹ for glyphosate and 0.15 μg L⁻¹ for AMPA, with limits of quantification of 0.11 μg L⁻¹ and 0.50 μg L⁻¹, respectively. Recovery assays performed at different concentration levels within the established linear range yielded recoveries between 107–109% for glyphosate and 97–100% for AMPA, with low relative standard deviation values. After validation, the method was applied to the analysis of 10 urine samples from pregnant women residing in the state of Rio de Janeiro, Brazil. Glyphosate and AMPA concentrations in all analyzed samples were below the method detection limits. The analytical performance in real matrix was confirmed by fortified control samples at 2.5 μg L⁻¹, which demonstrated the robustness and reliability of the method. These results indicate that the developed method is suitable for the determination of glyphosate and AMPA in urine and presents strong potential for application in human biomonitoring studies. Publisher: Universidade Federal do Rio de Janeiro Type: Dissertação

2026-02-27T00:00:00Z Souza, Flávia Rodrigues Simão de http://hdl.handle.net/11422/29136 2026-05-06T17:35:19Z 2025-01-01T00:00:00Z

Title: Da joia à bijuteria, uma viagem ao mundo da química Author(s)/Inventor(s): Souza, Flávia Rodrigues Simão de Advisor: Peres, Rosa Cristina Dias Abstract: An analysis of the Basic Education Development Index (IDEB) in the state of Rio de Janeiro in 2019 revealed that it presented the lowest performance among the states in the Southeast region of Brazil. Regarding Chemistry education, this low achievement appears to be mainly associated with studest’s lack of interest in content-centered teaching approaches, in which the teacher assumes the role of the sole knowledge holder and central figure in the classroom. In this context, the present work proposes the development of a didactic tool containing everyday examples with a focus on Chemistry, aiming to support Chemistry teachers in their classes by promoting greater student engagement and improved understanding of chemical phenomena. To this end, the instructional material produced an e-book discusses the electrochemical processes involved in the production and use of costume jewelry, while also providing more comprehensive content on these topics, including mineral extraction, metallic bonding, and the general chemical properties of these accessories. The final material was developed with the collaboration of high school Chemistry teachers, based on their responses to a qualitativequantitative questionnaire. As a result of their contributions, both visual and content-related adjustments were made. Additionally, the material demonstrated potential to enhance student engagement and contribute to more effective learning in secondary education, as teachers expressed interest in adopting it in their teaching practice. It is concluded that the e-book produced represents an innovative and useful tool for Chemistry learning in basic education. Publisher: Universidade Federal do Rio de Janeiro Type: Dissertação

2025-01-01T00:00:00Z