Publications

Abstract The biphasic transfer of Eu(NO3)3 by trioctylphosphine oxide (TOPO) diluted in a molecular diluent or as a component of a hydrophobic eutectic solvent (HES) was studied by two-phase isothermal titration calorimetry and complemented by XAS, FTIR, and NMR spectroscopy. In HES, the solvent intermolecular interactions introduce an enthalpic penalty, which is overcompensated by a reduction of the entropic cost of Eu(III) phase transfer, resulting in enhanced metal partitioning.

Abstract Concrete structures require precise temperature and humidity monitoring during curing to ensure optimal strength and to prevent defects such as cracking. A compact optical sensing system was developed using a single fiber that can be embedded directly within the concrete. When paired with a spectral interrogation unit operating in the low-loss single-mode communications band of 1500-1600 nm, the system functions as both a temperature and relative humidity (RH) sensor. Temperature monitoring is achieved using a Fiber Bragg Grating, while humidity sensing is provided by a Fabry-Perot interferometer (FPI) at the fiber tip. The interferometer cavity is formed with a layer of polyvinylpyrrolidone (PVP), an RH-sensitive polymer. The system exhibited a response time of approximately 3 h and operated over a relative humidity range of 50-95% RH and a temperature range of 30-60 degrees C, with normalized free spectral range sensitivities of the FPI up to 35 m(-1)/%RH at high humidity levels. The system was validated using a small-scale 50-day in-concrete test.

Abstract Introduction Staphylococcus aureus is an important opportunistic pathogen whose ability to form biofilms and acquire multidrug resistance limits the effectiveness of conventional antibiotics. Although some antibiotic combinations have shown promise, their clinical use is limited by pharmacokinetic and pharmacodynamic issues, chemical instability and formulation challenges. Objectives This study aimed to develop novel hybrid molecules combining ciprofloxacin with plant-derived monoterpenoids to improve antibacterial and antibiofilm efficacy against S. aureus strains. Methods Based on preliminary antibiotic-terpenoids combination studies in S. aureus CECT 976, citronellol and geraniol were selected for hybrid synthesis. The minimum inhibitory concentration (MIC) of the hybrids was evaluated in ciprofloxacin-susceptible ( S. aureus CECT 976) and resistant strains ( S. aureus 8093). Furthermore, the antibiofilm efficacy was analysed in the prevention and eradication of pre-established biofilms by quantifying biomass, metabolic activity and culturability. Moreover, their impact on biofilm structure and membrane integrity was investigated using optical coherence tomography, flow cytometry and epifluorescence microscopy, respectively. Furthermore, matrix components were analysed by spectrophotometry and confocal laser scanning microscopy (CLSM). The cytotoxic and haemolytic profile of the hybrids were evaluated using mammalian cells and red blood cells, respectively. Results For the resistant strain (ciprofloxacin MIC > 1024 µg mL−1), the hybrids showed MICs of 16 µg mL−1, indicating a limited shift in activity compared to the susceptible strain (MIC = 8 µg mL−1). For pre-established biofilms of the S. aureus resistant strain, where ciprofloxacin was ineffective, the hybrids reduced up to 40 % of biomass, inhibited 90 % of metabolic activity and reduced culturability by ∼ 2.3 log(CFU cm−2). They also disrupted the biofilm structure, with an average thickness of less than 10 µm in both strains tested. Furthermore, the hybrids caused significant damage to the cell membrane (90 % in the susceptible strain and about 35 % in the resistant strain) and exhibited low toxicity in HepG2 cells. Consistent with confocal observations, alterations in matrix composition were also observed in the presence of the hybrid compounds. Conclusion This study highlights the potential of monoterpenoid-ciprofloxacin hybrids that combine the antibacterial effects of ciprofloxacin with the bioactive properties of monoterpenes, potentially affecting S. aureus biofilms through multiple mechanisms. Copyright © 2026. Published by Elsevier B.V.

Abstract Antimicrobial photodynamic inactivation (aPDI) is a promising strategy for combating chronic wound infections, particularly those involving biofilms. However, its efficacy against Pseudomonas aeruginosa biofilms is limited by poor light penetration and photosensitisers through the biofilm matrix. This study explores, for the first time, the combination of subinhibitory colistin (Col) concentrations with berberine/curcumin (Ber/Cur) and gentamicin (Gen) to enhance aPDI activity against P. aeruginosa biofilms, including a clinical strain from a diabetic foot ulcer. Membrane integrity changes induced by Col were assessed by flow cytometry with propidium iodide. Synergistic concentrations of Ber/Cur-Gen-Col were determined via checkerboard assay. The effects of blue light (420 nm, 30 mW/cm(2), 10 min) on these combinations were evaluated for both biofilm prevention and eradication assays. For established biofilms, one or three irradiation cycles were applied at 24 h intervals, followed by an assessment of regrowth after 48 and 72 h. Biomass, metabolic activity, and culturability were quantified using crystal violet, resazurin, and colony-forming units (CFU). The mode of action was investigated via ROS production, membrane disruption, and biofilm structural changes using fluorometry, microscopy, and optical coherence tomography. Col at subinhibitory concentrations reduced membrane integrity (approximate to 30 %), enhancing Ber/Cur-Gen efficacy. Photoactivated Ber/Cur-Gen-Col inhibited biofilm formation (>90% reduction in biomass and metabolic activity and 6-log reduction in CFU). Against pre-formed biofilms, this combination achieved a 7-log reduction in CFU and a 90% reduction in biomass and metabolic activity. Three irradiation cycles sustained inhibition for up to 72 h. Ber-Gen-Col showed superior performance, highlighting the synergistic potential of subinhibitory Col in enhancing aPDI as a promising strategy for managing persistent wound infections.

Abstract The high costs of equipment and maintenance for Chemistry laboratories are a barrier to quality education in this science. However, the emergence of user-friendly and low-cost technological tools helps to mitigate this problem. This paper presents a STEM proposal for exploring distillation collaboratively in a remote laboratory with live data transmission and sharing online. The approach was analyzed by four teachers from Mozambique who, in that context, highlighted the positive potential for knowledge exchange between schools and cultures and the negative lack of technological means in schools for its implementation. They recognize great potential for implementation in higher education, as institutions have better resources. Thus, richer learning experiences can be promoted for all participants.

Abstract Student-centred learning requires a variety of approaches, such as inquiry-based learning and the tackling of authentic and problem-based learning activities, to make the teaching and learning process more meaningful and to encourage students to participate more actively in class. The inquiry approach enables students to investigate solutions to real problems, awakening their need to ask questions, design and conduct research, collect and analyse data, interpret results and present them in a structured way. This study investigates the influence of an inquiry-based science education (IBSE) module on the development of oral and written communication skills among 10th grade students. The study is set in a secondary school context and focuses on a problem-based learning approach centred around gases and dispersions. A total of 111 students participated in this one-group post-assessment qualitative study, where evaluation rubrics were applied to assess students' written and oral communication, focusing on correctness, clarity and mastery of scientific language. The results showed that the majority of students performed well in both written and oral tasks, demonstrating improved scientific communication skills. This suggests that IBSE, particularly in the context of secondary education, can be an effective approach to fostering students' abilities to communicate scientific concepts. The study has implications for enhancing pedagogical practices and encourages further research on the long-term effects of IBSE on student learning.

Abstract An acid-base titrator connected to the Internet was developed for conducting remote investigative experiments. The experiment was broadcasted in a high school senior classroom, with the presence of a facilitating teacher. The activity required students to determine the indicator present in the solution. To carry out the activity, students added acid or base to sweep the pH range from 0 to 14 and noted the corresponding coloration to the pH through video analysis. The results obtained were very satisfactory, both in the identification of the indicator and in the acceptance and engagement of the students in the activity.

Abstract Educators cannot overlook the affect's potential for students’ educational success. In this study, affective analogies are proposed as a didactic resource to foster students’ affect for chemistry learning and positive attitudes towards the physics-chemistry subject. To examine the influence of the affective analogies on it, we grouped contents of this subject into three modules (Kinetic-molecular theory; Quantum model of the atom; Chemical elements and their isotopes) and developed analogies between chemistry and music for each (affective analogies), which were then compared to homologous undifferentiated analogies (familiar analogues without affective qualities in addition) and teaching strategies without analogies. An explanatory mixed-method design was used. Data were collected through questionnaires and interviews, with a convenience sample of 147 students attending the 7th grade of a middle school music course. The results show that the affective dimension of analogies promotes positive affect for learning at much higher levels than the familiar dimension. We proposed a mechanism through which this occurs. However, if analogies are familiar, it seems that their positive affective dimension is not as important for students’ learning levels. More than interesting, analogies should perhaps be non-aversive. As for attitudes towards physics-chemistry, teaching with affective analogies is the most beneficial strategy. This results from students’ perception that this teaching approach promoted positive affect for the study of physics-chemistry, compared to undifferentiated analogies and without analogies. Furthermore, it favoured learning and achievement in physics-chemistry, compared to the absence of analogies, because without analogies it is more difficult to understand abstract or difficult concepts. © 2025 Fırtına Akademi A.Ş. All rights reserved. This article published by TUSED is released under the CC BY-NC-ND license.

Abstract New psychoactive substances (NPS) are designed to evade legal regulation while mimicking the effects of classic illicit drugs such as 3,4-methylenedioxymethamphetamine (MDMA). This category includes phenethylamine derivatives, such as the psychedelic 2C and NBOMe drugs. Given the lack of data regarding the toxicological profile of these substances, the goal of this study was to evaluate the neurotoxicity of 2C-I and 25I-NBOMe and explore their neurotoxic pathways. Lower EC50 values, in both NR uptake and MTT reduction assays in differentiated SH-SY5Y cells and primary rat cortical cultures, revealed that 25I-NBOMe is significantly more cytotoxic than 2C-I, likely due to its higher lipophilicity. Both drugs triggered severe mitochondrial dysfunction, characterized by decreased intracellular ATP levels and mitochondrial membrane depolarization, although no significant changes in intracellular ROS/RNS levels were observed. Additionally, 25I-NBOMe increased the intracellular Ca2* levels. Apoptosis was an observed mechanism of cell death for both drugs, as demonstrated by a significant increase in the number of cells undergoing early apoptosis (AnV+/PI-) and late apoptosis/necrosis (AnV+/PI+). However, only 2C-I induced autophagy and strongly triggered caspase-3 activation. This suggests that 2C-I induces caspase-3-dependent apoptosis, whereas 25I-NBOMe may also induce apoptosis through a caspase-3-independent pathway, possibly involving increased intracellular Ca2* levels and direct mitochondrial damage. These findings underscore the complex interplay between mitochondrial dysfunction, calcium dysregulation, and cell death pathways, highlighting the central role of mitochondria in the cytotoxicity of 2C-I and 25INBOMe.