Publications

Abstract This paper investigates a proposal for teaching Green Chemistry concepts through the implementation of a Problem-Based Learning (PBL) approach in a specific and optional course on the subject in higher education. The main objective was to analyze the effect of implementing Problem-Based Learning (PBL) didactics on understanding Green Chemistry principles within a course with 8 university students. Through this methodology, students analyzed case studies involving the identification of GC principles in industrial redesign processes and the problematization of controversial situations related to the importance of discussions on chemical processes. Two specific cases, bio-based butylene glycol and enzymatic treatment of paper, were used to test students' ability to recognize and justify the relevance of these principles. Additionally, another activity about the synthesis of acetanilide allowed students to identify which of four methodologies could be considered the greenest, considering different aspects. The research revealed that although the PBL approach effectively engaged students and deepened their understanding of GC principles, some concepts presented challenges. Certain principles of Green Chemistry, such as atom economy and catalysis, proved complex for some students, leading to confusion and challenges in assessing the greenness of processes. Nonetheless, students demonstrated improved knowledge and practical application of GC principles, linking them to industrial processes like bio-based material production and analyzing the benefits and drawbacks of different methods for producing the same substance. This study highlighted the value of a dedicated PBL approach with adequate resources to foster discussions and understanding. However, elective courses often attract only those already familiar with the subject, limiting broader engagement and field expansion. Disparities in case material quality, particularly for bio-based butylene glycol and acetanilide production, underscored the need for well-structured resources. Future research should include larger sample sizes for statistical validation and more class time for discussions and supplemental activities. This study contributes to the literature on active learning strategies, showcasing PBL's potential to enhance sustainable chemical education.

Abstract This study demonstrates the efficacy of ionic liquid (IL)-assisted vapor deposition in achieving high-quality and distinctive crystal film growth of two organic semiconductors (OSCs): a carbazole derivative (TCB) and a phenylamine derivative (TDAB). ILs with different wetting properties (short-chain [C2C1im][NTf2] and long-chain [C8C1im][NTf2]) and engineered shapes (microdroplets and coalesced film) were utilized as solvents in a vacuum. Through a meticulously designed experimental strategy, encompassing both sequential and simultaneous deposition of the IL and the OSC, this study unveils the pivotal role of ILs in shaping the crystallization behavior of the organic compound. Differential scanning calorimetry, polarized light microscopy, high-resolution scanning electron microscopy, and X-ray diffraction were employed for the films' thermal, morphological, and structural characterization. Thin films of TDAB exhibit crystallinity and a greater tendency to grow tridimensionally, forming giant pillars. However, the typical vertical growth of TDAB on solid substrates is altered when deposition occurs on surfaces coated with ILs. The IL promotes the lateral growth of nanostructures. The experimental results reveal variations in film morphology and coverage influenced by the cation alkyl chain length of the IL. In contrast to TDAB, TCB films are amorphous when thermally evaporated on solid substrates. Notably, IL-assisted vapor deposition induces the crystallization of TCB. Furthermore, TCB films deposited on coalesced IL films exhibit enhanced crystallinity and homogeneous horizontal growth, representing a significant finding in the context of thin film deposition and semiconductor device fabrication.

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 The Mediterranean basin is highly susceptible to climate change, with soil salinization and the increase in average temperatures being two of the main factors affecting crop productivity in this region. Following our previous studies on describing the detrimental effects of heat and salt stress co-exposure on tomato plants, this study aimed to understand if substrate supplementation with a combination of arbuscular mycorrhizal fungi (AMF) and biochar could mitigate the negative consequences of these stresses. Upon 21 days of exposure, stressed tomato plants grown under supplemented substrates showed increased tolerance to heat (42 degrees C for 4 h/ day), salt (100 mM NaCl), and their combination, presenting increased biomass and flowering rate. The beneficial effects of AMF and biochar were associated with a better ionic balance (i.e. lower sodium accumulation and higher uptake of calcium and magnesium) and increased photosynthetic efficiency. Indeed, these plants presented higher chlorophyll content and improved CO2 assimilation rates. Biochemical data further supported that tomato plants grown with AMF and biochar were capable of efficiently modulating their defence pathways, evidenced by the accumulation of proline, ascorbate, and glutathione, coupled with a lower dependency on energy-costly enzymatic antioxidant players. In summary, the obtained data strongly point towards a beneficial role of combined AMF and biochar as sustainable tools to improve plant growth and development under a climate change scenario, where soil salinization and heat peaks often occur together.

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.