Publications

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 Bioluminescence (BL) and chemiluminescence (CL) are remarkable processes in which light is emitted due to (bio)chemical reactions. These reactions have attracted significant attention for various applications, such as biosensing, bioimaging, and biomedicine. Some of the most relevant and well-studied BL/CL systems are that of marine imidazopyrazine-based compounds, among which Coelenterazine is a prime example. Understanding the mechanisms behind efficient chemiexcitation is essential for the optimization and development of practical applications for these systems. Here, the CL of a fluorinated Coelenterazine analog was studied using experimental and theoretical approaches to obtain insight into these processes. Experimental analysis revealed that CL is more efficient under basic conditions than under acidic ones, which could be attributed to the higher relative chemiexcitation efficiency of an anionic dioxetanone intermediate over a corresponding neutral species. However, theoretical calculations indicated that the reactions of both species are similarly associated with both electron and charge transfer processes, which are typically used to explain efficiency chemiexcitation. So, neither process appears to be able to explain the relative chemiexcitation efficiencies observed. In conclusion, this study provides further insight into the mechanisms behind the chemiexcitation of imidazopyrazinone-based systems.

Abstract Micro- and nanoplastics (MNPs) are an important atmospheric aerosol constituent. However, there still needs to be a standard procedure for their sampling and size fractionation, which is an obstacle to the aggregation and critical analysis of results obtained by different research groups. This review focuses on the sampling and fractionation methodologies used for MNPs. Moreover, a streamlined, simplified methodology for sampling and fractionation is proposed.

Abstract <jats:p>Green carbon-based materials (GCM), i.e. carbon materials produced using renewable biomass or recycled wastes, ought to be used in order to processes become sustainable and carbon neutral. Carbon nanomaterials, like for example carbon dots and nanobichar families, and carbon materials, like for example activated carbon and biochar substances, are sustainable materials with great potential to be used in different technology applications. In this review, the following four applications were selected, and the works published in the last two years (since 2022) critically reviewed: agriculture; water treatment; energy management; and, carbon dioxide reduction and sequestration. GCM improved the performance of the technological applications under revision and play an important role in the sustainability of the processes, contributing to the mitigation of the climate change, namely by reducing emission and increase sequestration of CO2eq..</jats:p>

Abstract Green carbon-based materials (GCM), i.e., carbon materials produced using renewable biomass or recycled waste, ought to be used to make processes sustainable and carbon-neutral. Carbon nanomaterials, like carbon dots and the nanobichar families, and carbon materials, like activated carbon and biochar substances, are sustainable materials with great potential to be used in different technological applications. In this review, the following four applications were selected, and the works published in the last two years (since 2022) were critically reviewed: agriculture, water treatment, energy management, and carbon dioxide reduction and sequestration. GCM improved the performance of the technological applications under revision and played an important role in the sustainability of the processes, contributing to the mitigation of climate change, by reducing emissions and increasing the sequestration of CO2eq.

Abstract The pharmacological interest in mitochondria is very relevant since these crucial organelles are involved in the pathogenesis of multiple diseases, such as cancer. In order to modulate cellular redox/oxidative balance and enhance mitochondrial function, numerous polyphenolic derivatives targeting mitochondria have been developed. Still, due to the drug resistance emergence in several cancer therapies, significant efforts are being made to develop drugs that combine the induction of mitochondrial metabolic reprogramming with the ability to generate reactive oxygen species, taking into consideration the varying metabolic profiles of different cell types. We previously developed a mitochondria-targeted antioxidant (AntiOxCIN6) by linking caffeic acid to lipophilic triphenylphosphonium cation through a 10-carbon aliphatic chain. The antioxidant activity of AntiOxCIN6 has been documented but how the mitochondriotropic compound impact energy metabolism of both normal and cancer cells remains unknown. We demonstrated that AntiOxCIN6 increased antioxidant defense system in HepG2 cells, although ROS clearance was ineffective. Consequently, AntiOxCIN6 significantly decreased mitochondrial function and morphology, culminating in a decreased capacity in complex I-driven ATP production without affecting cell viability. These alterations were accompanied by an increase in glycolytic fluxes. Additionally, we demonstrate that AntiOxCIN6 sensitized A549 adenocarcinoma cells for CIS-induced apoptotic cell death, while AntiOxCIN6 appears to cause metabolic changes or a redox pre-conditioning on lung MRC-5 fibroblasts, conferring protection against cisplatin. We propose that length and hydrophobicity of the C10-TPP+ alkyl linker play a significant role in inducing mitochondrial and cellular toxicity, while the presence of the antioxidant caffeic acid appears to be responsible for activating cytoprotective pathways.

Abstract Travel writing reflects placed subjective human experience and participates in the collective processes of assembling stable, consensual, or polemical geographical entities and identities. In this chapter, we reflect on the contributions of Critical Digital Humanities to the communication of travel writing studies. Using R language, we are exploring the Anglophone Travelers in Portugal databases—which provide annotated information on almost 200 foreigner travel accounts in English published since the eighteenth century—to visualize geographical entities, analyze topics, and design visualization tools for non-expert audiences. In the process, four contributions of Critical Digital Humanities became evident. First, toponymical and semantic sources of ambiguity require us to develop a strong understanding of data as an artifact or capta (Drucker, Digital Humanities Quarterly, vol. 5, no. 1, pp. 1–21, 2011) construed in the annotating process that may affect the accuracy of automatic geocoding and processing based on named entity recognition. Critical digital humanist scholars, even if aware of such issues, lack creative solutions to express ambiguity as informative per se of the liquid nature of social labeling. Second, digital humanities open doors to enhanced interactivity (for instance, web applications) but require thoughtful, parsimonious solutions to express complexity which raises issues related to minimal computing (Risam and Gil, Digital Humanities Quarterly, vol. 16, no. 2, 2022). Third, Critical Digital Humanities helped to understand that communicating foreign perspectives may impact the audiences’ understanding of the traveled territory, but also of the travelers as an exogroup, a social category built on stereotyped views. Fourth, Critical Digital Humanities allowed us to better communicate the entangled nature of traveling and socio-historical circumstances. The challenge is to use such information to promote meaningful, centrifugal travel experiences rather than centripetal, massive travel itineraries. In the future, the project aims to grow via participatory citizen science (crowdsourcing) and to extend its scope to online digital sources related to travel (for instance, blogs). These new steps will foster the need to examine web scraping and text cleaning techniques and develop suitable storytelling approaches to engage people and create narratives that reflect their inputs in a critical way. © The Editor(s) (if applicable) and The Author(s), under exclusive licence to Springer Nature Switzerland AG 2024.

Abstract The thermodynamic properties of ionic liquids (ILs) bearing alkylsilane and alkylsiloxane chains, as well as their carbon-based analogs, were investigated. Effects such as the replacement of carbon atoms by silicon atoms, the introduction of a siloxane linkage, and the length of the alkylsilane chain were explored. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to study the thermal and phase behavior (glass transition temperature, melting point, enthalpy and entropy of fusion, and thermal stability). Heat capacity was obtained by high-precision drop calorimetry and differential scanning microcalorimetry. The volatility and cohesive energy of these ILs were investigated via the Knudsen effusion method coupled with a quartz crystal microbalance (KEQCM). Gas phase energetics and structure were also studied to obtain the gas phase heat capacity as well as the energy profile associated with the rotation of the IL side chain. The computational study suggested the existence of an intramolecular interaction in the alkylsiloxane-based IL. The obtained glass transition temperatures seem to follow the trend of chain flexibility. An increase of the alkylsilane chain leads to a seemingly linear increase in molar heat capacity. A regular increment of 30 JK-1mol(-1) in the molar heat capacity was found for the replacement of carbon by silicon in the IL alkyl chain. The alkylsilane series was revealed to be slightly more volatile than its carbon-based analogs. A further increase in volatility was found for the alkylsiloxane-based IL, which is likely related to the decrease of the cohesive energy due to the existence of an intramolecular interaction between the siloxane linkage and the imidazolium headgroup. The use of Si in the IL structure is a suitable way to significantly reduce the IL's viscosity while preserving its large liquid range (low melting point and high thermal stability) and low volatilities.

Abstract The Periodic Table of the Elements of Green and Sustainable Chemistry (PT-GSC) represents a potentially meaningful tool for teaching and learning Green Chemistry. However, there is a lack of studies exploring the application of the PT-GSC in educational contexts. To contribute to filling this gap, a qualitative and participant approach was developed to examine the effects of using the PT-GSC in a high school setting, with a focus on analyzing the associated challenges and opportunities. Over a five-week period, 23 high school students enrolled in a chemistry course at a public school in Brazil worked in small groups to develop solutions for a case study addressing socio-scientific issues related to water scarcity in the local region using elements from the PT-GSC. Results from both the pre- and post-questionnaires, along with the written case study resolutions, provide evidence of the students' knowledge gains, particularly in critical scientific literacy for Green and Sustainable Chemistry Education. The findings showed that the PT-GSC is an interdisciplinary tool for introducing students to Green Chemistry concepts within the broader societal and scientific ecosystem. The implementation of novel case studies incorporating elements from the PT-GSC is a way to support our ongoing work with students and the public, contributing to a sustainable future.

Abstract The Beer-Lambert law is a fundamental relationship in chemistry that helps connect macroscopic experimental observations (i.e., the amount of light exiting a solution sample) to a symbolic model composed of system-level parameters (e.g., concentration values). Despite the wide use of the Beer-Lambert law in the undergraduate chemistry curriculum and its applicability to analytical techniques, students' use of the model is not commonly investigated. Specifically, no previous work has explored how students connect the Beer-Lambert law to absorption phenomena using submicroscopic-level reasoning, which is important for understanding light absorption at the particle level. The incorporation of visual-conceptual tools (such as animations and simulations) into instruction has been shown to be effective in conveying key points about particle-level reasoning and facilitating connections among the macroscopic, submicroscopic, and symbolic domains. This study evaluates the extent to which a previously reported simulation-based virtual laboratory activity (BLSim) is associated with students' use of particle-level models when explaining absorption phenomena. Two groups of analytical chemistry students completed a series of tasks that prompted them to construct explanations of absorption phenomena, with one group having completed the simulation-based activity prior to the assessment tasks. Student responses were coded using Johnstone's triad. When comparing work from the two student groups, chi-square tests revealed statistically significant associations (with approximately medium to large effect sizes) between students using the simulation and employing particle-level reasoning. That said, submicroscopic-level reasoning did not always provide more explanatory power to students' answers. Additionally, we observed the productive use of a variety of submicroscopic light-matter interaction models. We conjecture that engaging with BLSim provided new submicroscopic-level resources for students to leverage in explanations and predictions of absorption phenomena.