Publications

Abstract Recent advances in neuromorphic resistive switching have enabled us to start emulating biological synapses and neurons. A liquid switching medium brings these devices even closer to brain-like systems, being soft and flexible. Here, we propose copper solution-based artificial synapses that show both nonvolatile and volatile, and excitatory and inhibitory behavior, without an electroforming step. Different copper sulfate solutions, concentrations, electrode materials, and spacings were studied. Low operation voltage was achieved for the aqueous solution, showing high endurance and data retention. By changing solvation to glyceline, a change between nonvolatile and volatile dynamics occurred, while maintaining neuromorphic behavior and enhancing stability. This shows, for the first time, both potentiation and depression in a volatile device. Our results are promising for bio-voltage neuromorphic memristor-based interfaces.

Abstract The purpose of this article is to present and discuss a historical house project that was transposed into virtual reality, to be preserved as digital cultural heritage. The Matosinhos House, in Portugal, is part of a residential project designed by the architect Alvaro Siza Vieira in 1955-56, is the historical house that was chosen as case study. The article displays the historical significance of the project, as well as the method applied to transpose it into virtual reality. The goal is to promote access to digital cultural heritage based on reliable and accurate interpretation of the collected data.

Abstract The impact of nanostructuration on the transport properties of ionic liquids (ILs) was explored by a systematic and high-resolution study of the temperature dependence of the viscosity and electrical conductivity of seven ILs homolog series: [C(n)C(1)im]BF4, [C(n)C(1)im]PF6, [C(n)C(1)im][OTf], [C(n)C(1)im][FAP], [C(n)C(1)im][NTf2], [CnC(1)pyr][NTf2], [Cnpy][NTf2]. The increase of the alkyl chain length was found to increase the viscosity and decrease the molar conductivity due to a reduction of the overall mobility of the liquid and enhancement of the van der Waals interactions. The temperature dependency of transport properties was fitted to the Vogel-Fulcher-Tammann equation (VFT), and the energy barrier and pre-exponential coefficients were derived. The obtained results highlight the trendshift (n = 6-7) in the profile of the transport properties, which is a reflection of the intensification of nanostructuration and describes the transition from a liquid with a strong ionic character to a nanostructured liquid dominated by the hydrophobic domain. The derived energy barriers were found to correspond to around 0.2-0.35 of the cohesive interactions of the ionic liquids, with the spherical anions BF4- and PF6- showing a higher fraction than the more stretched and larger anions, such as NTf2. This fraction was found to not be affected by the alkyl chain length. The increase of the nonpolar region was also reflected in a more pronounced deviation from the ideal Walden relation. This highlights the increased complexity of the electric conductivity when compared with viscosity due to the heterogeneity of charge distribution, revealing the impact of ionic surface-volume ratio and anion-cation size ratio.

Abstract Halogenated benzaldehydes possess unique chemical properties that render them valuable in pharmaceutical synthesis, pesticide formulation, and dye production. However, thorough thermodynamic data for these compounds remain scarce. This study aims to fill this knowledge gap by investigating key physical properties of several halogenated benzaldehydes, namely 4-chlorobenzaldehyde, 4-bromobenzaldehyde, 2,3-dichlorobenzaldehyde, 2,4-dichlorobenzaldehyde, and 2,6-dichlorobenzaldehyde. The physical properties determined in this study include volatility, phase transitions, and water solubility, all of which are crucial for predicting the environmental fate of these compounds. The vapor pressures of both crystalline and liquid phases were measured using a reliable static method, allowing for the determination of standard molar enthalpies, entropies, and Gibbs energies of sublimation and vaporization, as well as their triple points. The melting temperature and molar enthalpy, along with the isobaric molar heat capacity of the crystalline phase, were assessed using differential scanning calorimetry. Water solubility was evaluated at 25 degrees C through the saturation shake-flask method, complemented by ultra-violet visible spectroscopy. By combining sublimation and solubility data, additional properties such as Gibbs energies of hydration and Henry's law constants were derived. The experimental results were integrated into existing databases, enhancing the predictive models for properties including melting temperature, vapor pressure, solubility, Gibbs energy of hydration, and Henry's constant. These findings significantly improve the environmental modeling capabilities, providing valuable insights into the mobility and fate of halogenated benzaldehydes in various environmental contexts.

Abstract <jats:title>Abstract</jats:title> <jats:p>In Portugal, open consultations (OCs) in primary health care address urgent medical needs, constituting 40–50% of family doctor activity. Frequent attenders (FAs), often presenting nonacute issues, significantly contribute to health care overuse. This study aimed to identify factors associated with frequent OC use in a primary health care unit during 2022. A retrospective cross-sectional analysis was conducted on 4,269 adult patients, with frequent attendance defined as four or more consultations (≥90th percentile). Sociodemographic and clinical factors, including age, sex, employment, chronic conditions, and multimorbidity, were examined using binomial logistic regression. FAs (n = 570, 13.4%) accounted for 36.2% of all consultations. Significant associated variables included female sex (OR = 1.417), economic insufficiency (OR = 1.323), and multimorbidity (OR = 1.678). Conditions such as musculoskeletal (OR = 2.146), psychological (OR = 2.040), and neurological (OR = 1.550) disorders were strongly linked to frequent attendance. While FAs represent a minority of patients, their disproportionate use of OC services underscores the need for targeted interventions, such as individualized care plans and resource optimization, to balance demand and availability. These findings highlight critical areas for policy and practice to enhance health care efficiency.</jats:p>

Abstract Background and aim: Pregnancy after the age of 35 is correlated with an increased risk of impaired placentation and the development of pregnancy-associated complications. Changes in uterine redox balance seem to play a role in these settings. In this work, we hypothesized that local redox dysregulation impacts the placenta metabolic profile. Thus, we aimed to study the expression of enzymes/transporters related to nutrient uptake during reproductive aging and the effect of antioxidant supplementation. Methods: Placenta samples were collected from pregnant women aged between 22 and 41 years, and from mice of different reproductive ages (8-12 and 38-42 weeks). A subgroup of 38-42 weeks-old mice was treated with apocynin (5 mM) in the drinking water. Real-time PCR was carried out to assess gene expression, and immunohistochemistry or western blotting to assess protein expression. Results: A significant age-related decrease in the expression of glucose transporter type 1 (GLUT-1) was observed in both species. Regarding lipid metabolism, there was a strong negative and significant correlation between the gene expression of fatty-acid transporter type 4 and maternal age, in the human placenta. Perilipin isoform 2 (PLIN-2) decreased significantly with maternal age, in both models. Additionally, a significant age-related decrease in the gene expression of large neutral amino acid transporter type 4 with reproductive age was observed in the mice placenta. Supplementation with apocynin attenuated the observed alterations in GLUT-1 and PLIN-2. The observed changes suggest an age-related placenta metabolic dysfunction, likely associated with oxidative stress, that may negatively impact fetal and placental development.

Abstract In the original publication [1], there was an error in the Discussion section in Figure 3, entitled “Thermochemical cycle of the vaporization of dimer and monomer of furfurylamine”. The arrow representing (Formula presented.) was incorrectly labeled. The corrected Figure 3 is provided below: Additionally, there were errors in the Discussion section following Figure 3 in the original publication. In accordance with the revised Figure 3, the value (Formula presented.) = 24 kJ·mol−1 [30] was replaced with (Formula presented.) = −24 kJ·mol−1 [30]. Equation (5) of the original publication is related to Figure 3 and was therefore incorrect. The corrected Equation (5) is shown below: (Formula presented.) In the original publication, there was also an error in Table 5 (Discussion section), titled “Vaporization enthalpies according to Equations (4) and (5) for furfurylamine”. The values of (Formula presented.) calculated in this work for furfurylamine (dimer) were incorrect. The corrected values are now presented in the revised Table 5. The authors state that the scientific conclusions are unaffected. This correction was approved by the Academic Editor. The original publication has also been updated. © 2025 by the authors.

Abstract <jats:p>In the original publication [...]</jats:p>

Abstract As the demand for more efficient energy storage solutions grows, emerging battery chemistries are being developed to complement or potentially replace conventional lithium-ion technologies. This review explores the circular economy potential of sodium (Na), magnesium (Mg), zinc (Zn), and aluminum (Al) battery systems as alternative post-lithium configurations. Through a comparative literature analysis, it identifies key barriers related to material complexity, recovery efficiency, and regulatory gaps, while highlighting opportunities for design improvements and policy alignment to enhance sustainability across battery life cycles. However, end-of-life (EoL) material recovery remains constrained by complex chemistries, low technology readiness levels, and fragmented regulatory frameworks. Embedding materials/battery design principles, transparent life cycle assessment (LCA) data (e.g., publishing LCAs in open repositories using a standard functional unit), and harmonized policy early could close material loops and transform the rising post-lithium battery stream into a circular-economy resource rather than a waste burden.

Abstract This study presents a comprehensive investigation of the morphological and photocatalytic properties of electrochemically synthesized titanium dioxide (TiO2), both in its amorphous (non-calcined) and crystalline (calcinated) forms and its composite with biomass-derived carbon (TiO2@C). The TiO2 materials were synthesized using a deep eutectic solvent (DES)-based electrochemical method, and their properties were compared with commercial TiO2 nano-powder (TiO2_NP). Characterization techniques such as BET, SEM/EDX, XRD, Raman, ATR-FTIR, and XPS were employed to elucidate the structural, textural, and surface chemical properties of the materials. The amorphous TiO2 (TiO2@DES) exhibited significantly higher surface area and pore volume compared to commercial TiO2, while the calcined TiO2 (TiO2@DES_400) displayed enhanced crystallinity with an anatase structure. The TiO2@C composite was prepared via an in-situ decoration of biomass-derived carbon during the TiO2 electrochemical synthesis. This resulted in a material with a high specific surface area (2214 m(2) g(-1)) and porous structure. This composite demonstrated superior photocatalytic performance for the degradation of crystal violet dye under both UV and visible light irradiation, achieving degradation efficiencies of similar to 98 % after 5 h. The TiO2@C composite was further applied to degrade wastewater from leather dye processing, demonstrating its efficacy in real-world applications. These results underscore the potential of the TiO2@C composite as a sustainable and high-performance photocatalyst for environmental remediation, particularly in wastewater treatment.