Publications

Abstract Structural health monitoring (SHM) of reinforced concrete structures (RCS) is crucial for mitigating the consequences of their deterioration. By identifying and addressing the issues early, SHM helps reduce environmental impact, safeguard lives, and enhance economic resilience. Rebar corrosion is a leading cause of early RCS decay and optical fibre sensors (OFS) have been employed for its monitoring. Reflection optrodes using optical fibres where the tip is coated with iron (Fe) thin films offer a robust, long-lasting and straightforward solution. This study investigates the tracking of spectral changes during the Fe thin film corrosion, which has been neglected in the literature, in favour of tracking reflection changes from thin film spalling. A multimode fibre tip, coated with a thin Fe layer embedded in concrete, allows spectral changes to be observed during corrosion. A 100 nm thick Fe film was deposited using radio frequency magnetron sputtering on polished fibre tips. Corrosion was induced by applying salted water drops and allowing the fibre tip to dry. Corrosion monitoring was successful for both air-exposed and cement-embedded tips, with results compared to reflection simulations of Fe, Fe2O3, and Fe2O3 thin films. This study supports monitoring at different wavelengths, enhancing robustness, cost-effectiveness and earlier detection. © The Authors.

Abstract This work studies the formation of deep eutectic solvents formed by one active pharmaceutical ingredient (quinine, pyrimethamine, or 2-phenylimidazopyridine) and a second component potentially acting as an excipient (betaine, choline chloride, tetramethylammonium chloride, thymol, menthol, gallic acid, vanillin, acetovanillone, 4-hydroxybenzaldehyde, syringaldehyde, propyl gallate, propylparaben, or butylated hydroxyanisole), aiming to address challenges regarding drug solubility, bioavailability, and permeability. A preliminary screening was carried out using the thermodynamic model COSMO-RS, narrowing down the search to three promising excipients (thymol, propyl gallate, and butylated hydroxyanisole). Nine solid-liquid equilibrium (SLE) phase diagrams were experimentally measured combining the three model drugs with the screened excipients, and using a combination of a visual melting method and differential scanning calorimetry. Negative deviations from thermodynamic ideality were observed in all nine systems. Furthermore, a total of four new cocrystals were found, with powder and single crystal X-ray diffraction techniques being employed to verify their unique diffraction patterns. In the thermodynamic modelling of the SLE diagrams, two COSMO-RS parametrizations (TZVP and TZVPD-FINE) were also applied, though neither consistently delivered a better description over the other.

Abstract Herein, the conjugation of carbon dots (CDs) with TiO2 nanoparticles is reported to prepare a photocatalytic nanocomposite for an enhanced visible-light-driven photodegradation of methylene blue (MB). CDs are prepared from citric acid (CA) and ethylenediamine (EDA) via hydrothermal treatment. Using MB as a model pollutant, it is observed that, under visible-light irradiation, the nanocomposite presents an increment of the catalytic performance of 367% when compared to bare TiO2. This is achieved because the addition of CDs leads to increased visible-light absorption and hinders the recombination of photogenerated charge carriers. Thus, CDs are capable of bridging some of the limitations posed by TiO2. Tests using reactive species scavengers indicate that the main active species involved in the photodegradation by the nanocomposites are superoxide radicals followed by hydroxyl radicals, which differs from bare TiO2. Lastly, a life cycle assessment (LCA) study shows that, when accounting for performance, the nanocomposites have lower relative environmental impacts than bare TiO2. In addition, the safety of the produced CDs is shown by in vitro assays. In summary, due to conjugation with CDs, a relevant increment in the catalytic performance of TiO2 is achieved; providing an important step toward the sustainable rational design of active visible-light-driven photocatalysts.

Abstract The possible fabrication of porous anodic oxide films on aluminium in ionic liquids based on choline dihydrogen citrate eutectic mixtures both with oxalic acid and isopropyl alcohol and ethylene glycol, has been investigated. The anodisation has been carried out in either potentiostatic or galvanostatic regime, at temperatures of 45-80 degrees C, for different process durations. Quite compact, uniform anodic alumina layers have been obtained. Based on AFM and SEM investigations, pore diameters between 50 and 80 nm and interpore distances in the range of 160-200 nm have been estimated, with values influenced by the electrolyte type and anodisation conditions. The highest anodisation rate of about 0.4 mu m min(-1) has been determined by applying operation temperatures of 60 degrees C. The recorded EIS spectra showed a pure capacitive behaviour and high anodic oxide resistances of 10(6)-10(7) omega cm(2) order.

Abstract PFASs are a class of highly persistent chemicals that are slowly infiltrating soils and waterways. Thus, there is a great need for fast, sensitive, and reliable techniques to detect PFASs. Conventional methods, such as LC-MS/SPE, allow high sensitivities. However, such methods can be complex and expensive. Considering this, it is not surprising that the scientific community has turned their attention to the search for alternatives. New types of PFAS sensors have been reported over the years, being generally part of three classes: optical, electrochemical, or hybrid sensors. Carbon dots (CDs) are new alternative fluorescent sensors that can present great affinity towards PFASs, while allowing for a fast response and promising sensitivity and selectivity. Furthermore, CDs have more attractive properties than traditional fluorophores and even metal-based nanomaterials that make them better candidates for sensing applications. Thus, CDs display great potential for permitting a fast and accurate quantification of PFASs. This review aims to serve as a basis for the future development and optimization of CD-based fluorescent sensors for PFASs.

Abstract A sustainable matrix based on eucalyptol essential oil/sawdust was developed and applied on laminated plywood. This finish aims to serve as a eucalyptol odor slow release. Eucalyptol odor release was monitored with gas chromatography coupled with a flame ionization detector (GC-FID: Limits of Detection and Quantification of 0.70 g/m3 and 2.11 g/m3, respectively, and with linearity up to 18.6 g/m3). Measurement of the eucalyptol odor released was performed during a six-month period, and it was found that the release followed a first-order exponential decay with a decay rate constant of 0.0169 per day. The half-life was determined to be of 48 days. The granulometry and particle size porosity of sawdust were analyzed by Scanning Electron Microscopy. A sawdust size fraction of 112-200 mu m showed the best eucalyptol absorption capacity, with 1:3 masses ratio (sawdust:eucalyptol). The release duration of eucalyptol is influenced by the quantity of the eucalyptol-sawdust composite and the aperture size for release. Through the determination of this relationship, it was found that applying 15.0 g of the composite through a 0.8 mm diameter aperture resulted in a 6-month eucalyptol release period. This outcome is regarded as highly favorable, considering the inherent high volatility of eucalyptol and the relatively small amount of composite required for future product applications. The new product is characterized by a carbon footprint (considering the industry frontiers) of 5.94 kg CO2eq/m2 of plywood floor.

Abstract The mode of action toward gastric cancer cells of brominated Coelenteramine, an analogue of a metabolic product of a marine bioluminescent reaction, was investigated by synchrotron radiation-based Fourier Transform Infrared spectrocopy (FTIR). This method revealed that the anticancer activity of brominated Coelenteramine is closely connected with cellular lipids, by affecting their organization and composition. More specifically, there is an increasing extent of oxidative stress, which results in changes in membrane polarity, lipid chain packing and lipid composition. However, this effect was not observed in a noncancer cell line, helping to explain its selectivity profile. Thus, synchrotron radiation-based FTIR helped to identify the potential of this Coelenteramine analogue in targeting membrane lipids, while proving to be a powerful technique to probe the mechanism of anticancer drugs.

Abstract This paper examines the determinants of FDI in small states, as only a small number of studies have analyzed the determinants of FDI in these countries. Small states have particular features that justify the need for a deeper analysis. Based on a panel data for 42 small states between 2005 and 2019, results clearly indicate the importance of the quality of human capital and the availability of infrastructures as the strongest drivers of FDI in small states. The country's level of openness, the availability of natural resources, the level of corporate tax and control of corruption also seems to play a relevant role therein. Moreover, the results suggest that the determinants differ depending on the region to which the country belongs and differ between island and non-island countries. These results can help small countries in defining policies that help them to attract FDI, which is crucial for their sustainable development.

Abstract Surface water is used for a variety of purposes, including agriculture, drinking water, and other services. Therefore, its quality is crucial for irrigation, human welfare, and health. Thus, the main objective is to improve surface water quality assessment and geochemical analysis to evaluate anthropogenic activities' impact on surface water quality in the Oued Laou watershed, Northern Morocco. Thirteen surface water samples were characterized for 26 physicochemical and biological parameters. In this aspect, emerging techniques such as multivariate statistical approaches (MSA), water quality indices (WQI), irrigation water quality (IWQI), and Geographic Information System (GIS) were employed to identify the sources of surface water pollution, their suitability for consumption, and the distribution of surface water quality. The results showed that the major ion concentrations were reported in the following order: Ca2+, Na+, Mg2+, and K+; and HCO3- > CO32- > Cl- > SO42- > NO3- > F- > PO43- > NO2-. It was also demonstrated that almost all parameters had concentrations lower than World Health Organization (WHO) limits, except for bicarbonate ions (HCO3-) and the biochemical oxygen demand for five days (BOD5), which exceeded the WHO limits at 120 mg/L and 3 mg/L, respectively. Furthermore, the types of Ca2+-HCO3- (Calcium-Bicarbonate) and Ca2+-Mg2+-HCO3- (Calcium-Magnesium-Bicarbonate) predominated in surface water. The Principal Component Analysis (PCA) indicates that the Oued Laou river was exposed to two forms of contamination, the first being attributed to anthropogenic activities such as agriculture, while the second reflects the water-sediment interaction. The Hierarchical Cluster Analysis (HCA), reflecting the mineralization in the study area, has classified the samples into four clusters. The Inverse Distance Weighting (IDW) of the WQI indicates that 7.69% and 38.46% of the surface water represent, respectively, excellent and good quality for drinking. At the same time, the IWQI revealed that 92.30% of the water surface is good for irrigation. As a result, the combination of WQIs, PCA, IWQI, and GIS techniques is effective in providing clear information for assessing the suitability of surface water for drinking and its controlling factors and can also support decision-making in susceptible locations such as the Oued Laou river in northern Morocco.

Abstract Simple Summary Cancer is a dramatic illness that ranks among the most pressing health concerns facing humanity and necessitates a proactive approach to treatment. Phytochemicals are regarded as interesting molecules for the development of anticancer drugs due to their pleiotropic effects on broad targets. The actions of phytochemicals are focused on tumor cells alone, with no negative effects on normal cells. The intricate process of carcinogenesis involves numerous signaling cascades. This study examined the effects of four organ extracts from a Mediterranean endemic plant, Cladanthus mixtus, on human tumor cells. To the best of our knowledge, this is the first study on this plant from northern Morocco showing relevant antiproliferative activity against two cancer cell lines and one non-tumoral cell line. Many of the chemotherapeutic drugs for the treatment of cancer are molecules identified and isolated from plants or their synthetic derivatives. This work aimed to identify the bioactive compounds using LC-MS and GC-MS and to evaluate the anticancer activity of the methanolic extracts of roots, stems, leaves, and flowers from Cladanthus mixtus. The anticancer activity was evaluated in vitro against two cancer cell lines: human breast carcinoma (MCF-7) and human prostate carcinoma (PC-3), using the MTT assay and microscopic observation. A human normal lung fibroblast (MRC-5) was included to determine the extract's safety for non-tumoral cells. The chemical composition results by LC-MS analysis revealed the presence of 24 phenolic compounds. Furthermore, GC-MS analysis allowed the identification of many biomolecules belonging to terpenoids, esters, alcohols, alkanes, fatty acids, organic acids, benzenes, phenols, ketones, carbonyls, amines, sterols, and other groups. The findings suggest that the majority of C. mixtus extracts have antiproliferative activity against two cancer cell lines, MCF-7 and PC-3, and one non-tumoral cell line, MRC-5. The activity was dose-dependent, and the highest effect was obtained with leaf extract in the two cancer cell lines. Moreover, these extracts demonstrated an acceptable toxicological profile against normal cells. Overall, C. mixtus extracts revealed promising antitumor properties provided by their phytochemical composition.