Publications

Abstract An interaction between the hydrogen molecules and circumcoronenes (CCs) decorated with light transition metals, namely Sc, Ti, and V, is investigated using density functional theory and ab initio molecular dynamics. The systems under study show affinity to bind H2 molecules in two distinct ways: formation of i2-coordination, also called Kubas interaction, and dissociation of H2 molecule leading to so-called dihydride coordination. When considering the interaction of Sc-, Ti-, and V-decorated CCs with one H2 molecule only, the dihydride coordination is energetically preferred over the Kubas interaction by 114, 73, and 74 kJ mol- 1, respectively. However, when considering the interaction of Sc-, Ti-, and V-decorated CCs with a larger number of H2 molecules, the energy difference between these two types of systems decreases significantly (up to 1 kJ mol- 1). This finding points on the dynamic co-existence of these systems which is confirmed also by molecular dynamics simulations. The strongest H2 binding is found for V-decorated CC, followed by Ti-decorated CC and Sc-decorated CC. Calculated H2 binding energies of these Kubas interactions are in the interval of -40 to -80 kJ mol- 1, which is suitable for H2 storage applications. It is shown that Sc-, and Ti-decorated CCs are able to chemisorb four H2 molecules per one metal atom while V-decorated CC is able to chemisorb only three H2 molecules per one V atom. However, formed V-H bonds are significantly stronger than Ti-H and Sc-H ones. The hydrogen storage capacity of fully saturated Sc-decorated CC is sixteen H2 molecules, corresponding to a gravimetric density of 4.5 wt%.

Abstract Due to their distinctive combination of ionic liquid (IL) characteristics and magnetic susceptibility, magnetic ionic liquids (MILs) have emerged as promising materials for gas capture and separation. In this study, molecular dynamics (MD) simulations were employed to investigate the thermodynamic, transport, and structural properties of selected MILs and their interactions with environmentally relevant gases, including methane (CH4), ammonia (NH3), carbon dioxide (CO2) and sulfur dioxide (SO2). The study focused on both imidazolium-based ([C4C1im]+) and phosphonium-based ([P66614]+) cations paired with various anions, including [FeCl4]- , [FeBr4]-, [MnCl4]2- and [GdCl6]3-. Fixed-charge force field parameters were established and validated for phosphonium-based MILs for the first time in the area. Free energy calculations demonstrated that phosphoniumbased MILs with multivalent anions exhibit favorable solvation energies for CO2 and SO2 gases, indicating a high potential for selective gas capture. A reduction in gas mobility is observed in these multivalent-based MILs/gas systems. The molecular-level insights provided by radial distribution functions (RDFs) elucidate the critical role of anions in determining solvation behavior. This observation underscores the importance of these paramagnetic elements in the interactions between the gases and MILs. This study advances the understanding of gas-MIL interactions and offers a foundation for the rational design of advanced materials for industrial gas capture and environmental remediation processes.

Abstract Antibiotics have revolutionized medicine, with (fluoro)quinolones emerging as one of the most impactful classes of antibacterial agents. Since their introduction, four generations of (fluoro)quinolones have been developed, demonstrating a broad spectrum of activity, favourable pharmacokinetics, and clinical efficacy. However, the rise of multidrug-resistant pathogens has posed significant challenges to their continued effectiveness, particularly in healthcare settings. Among the main resistant species, Staphylococcus aureus, particularly methicillin-resistant strains (MRSA), Klebsiella pneumoniae, Enterococcus spp. (E. faecium and E. faecalis), Campylobacter spp., and Acinetobacter baumannii are the most important. This critical literature review provides an updated perspective on (fluoro)quinolones (old and new), encompassing their spectrum of activity, pharmacokinetics, mechanisms of resistance, and the role of antimicrobial stewardship in preserving their utility, to address the growing threat of resistance.

Abstract The worldwide increase in antifungal resistance, particularly in Candida sp., requires the exploration of novel therapeutic agents. Natural compounds have been a rich source of antimicrobial molecules, where peptides constitute the class of the most bioactive components. Therefore, this study looks into the target-specific binding efficacy of insect-derived antifungal peptides (n = 37) as possible alternatives to traditional antifungal treatments. Using computational methods, namely the HPEPDOCK and HDOCK platforms, molecular docking was performed to evaluate the interactions between selected key fungal targets, lanosterol 14-demethylase, or LDM (PDB ID: 5V5Z), secreted aspartic proteinase-5, or Sap-5 (PDB ID: 2QZX), N-myristoyl transferase, or NMT (PDB ID: 1NMT), and dihydrofolate reductase, or DHFR, of C. albicans. The three-dimensional peptide structure was modelled through the PEP-FOLD 3.5 tool. Further, we predicted the physicochemical properties of these peptides through the ProtParam and PEPTIDE 2.0 tools to assess their drug-likeness and potential for therapeutic applications. In silico results show that Blap-6 from Blaps rhynchopeter and Gomesin from Acanthoscurria gomesiana have the most antifungal potential against all four targeted proteins in Candida sp. Additionally, a molecular dynamics simulation study of LDM-Blap-6 was carried out at 100 nanoseconds. The overall predictions showed that both have strong binding abilities and are good candidates for drug development. In in vitro studies, Gomesin achieved complete biofilm eradication in three out of four Candida species, while Blap-6 showed moderate but consistent reduction across all species. C. tropicalis demonstrated relative resistance to complete eradication by both peptides. The present study provides evidence to support the antifungal activity of certain insect peptides, with potential to be used as alternative drugs or as a template for a new synthetic or modified peptide in pursuit of effective therapies against Candida spp.

Abstract European legislation defines cosmetics as substances or mixtures designed to contact external body parts for cleaning, protection, fragrance, maintenance, or appearance modification. Cosmetic regulation has become increasingly important in recent years, as the number of consumers continues to grow. One of the major challenges of the cosmetic industry is effectively communicating to consumers the critical need to avoid using expired products for several safety reasons, with microbial contamination being among the most significant concerns. A key research priority involves understanding how bacterial and fungal populations commonly proliferate within cosmetic formulations. Regulatory standards strictly prohibit specific microorganisms in finished cosmetic products, as specified in EMA guidelines, making microbiological assessment an essential component of product evaluation. This review examines the prevalence, risks, and control measures associated with microbial contamination in cosmetic products. Special attention is given to the most isolated microorganisms, factors contributing to contamination, and current preservation strategies in the cosmetic industry. © 2025 Elsevier B.V., All rights reserved.

Abstract The rapid spread of generative artificial intelligence (GenAI) in contemporary society calls for a rethinking of education. This study investigates Portuguese secondary students' perceptions of chat generative pre-trained transformer (ChatGPT) in education. In 2024, we surveyed 114 students (aged 16-17) from one school in 2024 using a 15-item questionnaire (closed- and openended items) covering five dimensions: (1) knowledge of AI and ChatGPT; (2) use of ChatGPT; (3) perceived accuracy of ChatGPT-generated outputs; (4) the potential of ChatGPT for teaching; and (5) ethics and academic integrity. Responses to closed-ended items were analyzed descriptively and open-ended responses underwent content analysis. The results indicate that, although most students are familiar with AI and ChatGPT, their demonstrated knowledge is largely utilitarian and superficial. Students predominantly use ChatGPT for schoolwork and attribute high reliability to its outputs, often without the necessary critical evaluation. We also identified weaknesses in their ethical understanding, particularly regarding academic integrity and plagiarism. We argue for critical AI literacy and teacher professional development to support pedagogically grounded and ethical integration of GenAI. Education for the ethical and responsible use of these technologies proves essential to prepare young people for future challenges.

Abstract The metabolic remodeling occurring in carcinogenesis cells is firmly established. However, to understand the connection between the cellular metabolic profile and carcinogenesis, an accurate measurement of metabolic fluxes is required. In order to quantify the fluxes in these metabolic pathways, stable isotope tracers and nuclear magnetic resonance (NMR) techniques were employed. For that purpose, two human non-small lung cancer cell lines (A549 and H1299) were used. For the quantification of carbon intermediary metabolism cells were grown in 13C labelled glucose while for de novo lipogenesis (DNL) assessment 2H2O was supplemented to the culture media. To better understand and characterize cellular bioenergetics, mitochondrial membrane potential, oxygen consumption, and energy charge were also assessed. Finally, to establish a bridge between metabolic fluxes and cancer proliferation, substrate dependency studies were performed. Several metabolic inhibitors were also tested, targeting glycolysis, TCA cycle, pentose phosphate pathway (PPP) and transaminases. Our results showed the occurrence of metabolic heterogeneity between the two non-small lung cancer cell lines: H1299 exhibited a relatively active TCA cycle, while A549 showed a more glycolytic phenotype. The overall mitochondrial bioenergetic parameters were in agreement with the metabolic profiles. The mitochondrial network was polarized and active in all cell lines, although the H1299 cell line exhibited higher basal oxygen consumption and spare respiratory capacity. Nonetheless, DNL rate did not differ in H1299 and A549 lung cancer cell lines. Additionally, alpha-ketoglutarate availability was proven a key determinant for H1299 non-small cell lung cancer cells survival and proliferation. In conclusion, this work revealed that cells derived from a lymph node metastasis (H1299) have a more active TCA cycle and altered oxidative stress levels when compared to cells derived from a primary tumor (A549). In the process, we successfully implemented a new 2H enrichment method for DNL assessment for the first time in in vitro cancer research.

Abstract The multifaceted nature of the neurodegenerative diseases, as Alzheimer's disease (AD) and Parkinson's disease (PD) with several interconnected etiologies, and the absence of effective drugs, led herein to the development and study of a series of multi-target directed ligands (MTDLs). The developed RIV-IND hybrids, derived from the conjugation of an approved anti-AD drug, rivastigmine (RIV), with melatonin analogues, namely indole (IND) derivatives, revealed multifunctional properties, by associating the cholinesterase inhibition of the RIV drug with antioxidant activity, biometal (Cu(II), Zn(II), Fe(III)) chelation properties, inhibition of amyloid-/3 (A/3) aggregation (self- and Cu-induced) and of monoamine oxidases (MAOs), as well as neuroprotection capacity in cell models of AD and PD. In particular, two hybrids with hydroxyl-substituted indoles ( 5a2 and 5a3) ) could be promising multifunctional compounds that inspire further development of novel anti-neurodegenerative drugs.

Abstract An experimental and computational thermochemical study is reported focus on the relationship between the energetic properties, the structural characteristics and the inherent reactivity of three thiothiadiazoles: 2-amino5-(methylthio-)-1,3,4-thiadiazole, 2-amino-5-(ethylthio-)-1,3,4-thiadiazole and 2-mercapto-5-methylthio-1,3,4thiadiazole. From the DSC measurements, the enthalpies of fusion and the respective onset temperatures were determined. The standard molar energies of combustion of the (alkylthio)-1,3,4-thiadiazoles were determined by rotating bomb combustion calorimetry. The corresponding standard molar enthalpies of sublimation, at T = 298.15 K, were derived from high-temperature Calvet microcalorimetry measurements and the study of the dependence of the compound's vapour pressures with the temperature, using the Knudsen-effusion technique. The combination of these experimental results enables the calculation of the standard molar enthalpies of formation in the gaseous state, at T = 298.15 K, which are discussed in terms of structural contributions. The latter property was also determined from high-level ab initio molecular orbital calculations at the G3(MP2)//B3LYP level of theory. The computed values are in good agreement with the experimental ones. In addition, a conformational and tautomeric study was conducted using the same approach, in order to provide insight on the amino/imino and thiol/thione tautomerism of the compounds studied. The amino form predominates in aminothiadiazoles, while the thione form prevails in mercaptothiadiazole. Moreover, the relative thermodynamic stability of each compound was also evaluated showing that in both solid and gas phases, the most stable species is the mercaptothiadiazole (in its thione form). The thermochemical results of the (alkylthio)-1,3,4-thiadiazoles show a good agreement with the NBO (natural bond orbitals) analysis results.

Abstract Given the challenges associated with understanding electrochemistry content by engaging in prediction, observation, and explanation, laboratory activities can foster active participation and critical thinking, enabling individuals to proactively confront and revise their understanding. Since pre-service teachers should gain firsthand experience with predict-observe-based on a predict-observe-explain strategy, we propose a laboratory activity presented as a mystery box related to concentration cells coupled with an Arduino-based electronic data measurement system to identify how pre-service chemistry teachers move from observations to inferences in a qualitative research. Data was collected by written records and oral explanations during the practical interactions. Results suggest that the proposed laboratory activity allows pre-service chemistry teachers to access data and correct inferences related to electrochemistry content, promoting critical thinking. Data also showed a connection between the macroscopic and symbolic domains, and pre-service teachers recognized concepts associated with the activity, such as solution conductivity and the potential difference in chemical reactions, interpreting the system with prior knowledge, like electron flow direction and concentration cell components. However, additional strategies are needed for detailed and consistent observation and inference recording, enhancing the potential of such activities in favoring electrochemistry education in high schools.