Search Results (1,309)

The quantitative analysis of cardio selective beta-blockers, such as the antihypertensive and antiarrhythmic medication acebutolol (ABT), is critical for biomedical and environmental monitoring. This study describes the development of a high-performance electrochemical sensing platform for ABT based on a screen-printed carbon electrode (SPCE) modified with a silver nanoparticle/hexagonal boron nitride (Ag NPs/h-BN) nanocomposite. The morphological and structural properties of the synthesized materials were examined by using a microscopic and spectroscopic techniques. The Ag NPs/h-BN/SPCE demonstrated exceptional electrocatalytic activity toward ABT oxidation, characterized by a significant reduction in overpotential and a substantial enhancement in peak current relative to unmodified and mono-component electrodes. This superior performance is attributed to the synergistic integration of Ag NPs and h-BN, which provides a high density of active sites, an expanded electroactive surface area, and accelerated charge transfer kinetics. Under optimized experimental conditions, the sensor exhibited a broad linear dynamic range of 0.01–284 μM, a remarkably low limit of detection (LOD) of 0.0049 μM, and a high sensitivity of 0.873 µA µM⁻¹ cm⁻² for ABT detection. Furthermore, the platform displayed excellent selectivity in the presence of common interfering species and robust reproducibility (RSD of 4.8%). The practical utility of the Ag NPs/h-BN/SPCE was successfully validated through the precise quantification of ABT in complex biological and environmental matrices. This work provides a versatile strategy for the rational design of metal nanocatalysts confined within h-BN frameworks for the development of advanced electrochemical diagnostic tools. Full article

Luminescent cellulose-based fibers are promising materials for anti-counterfeiting applications because they can provide covert and spectrally distinguishable optical signatures compatible with paper- and textile-based authentication systems. In this study, Lyocell fibers modified with selected inorganic and organic luminescent compounds were subjected to accelerated xenon-lamp aging in order to evaluate their functional durability under simulated environmental exposure. The effects of aging on the mechanical properties and luminescent behavior of the fibers were investigated. The results showed that accelerated aging led to a reduction in tensile strength and elongation at break for all fiber variants, although the extent of these changes depended on the type of modifier. Spectroscopic analysis indicated that, despite changes in emission intensity, the characteristic luminescent responses of the modified fibers remained detectable after aging. These findings suggest that luminescent Lyocell fibers can retain their practical identification potential under the applied test conditions and may be considered promising candidates for use as covert security elements. The observed stability is attributed to the immobilization of luminophores within the cellulose matrix and the intrinsic photostability of the applied luminescent systems. At the same time, the study highlights the need for further investigations into the structural and photophysical stability of such systems under long-term environmental exposure. Full article

Fibroin-based films represent a promising platform for sustainable and bio-derived materials. Existing literature has mainly focused on isolated molecules, plasticizers, or chemical cross-linkers, and the function of complex, multi-component natural extracts as structure-modulating agents in fibroin films remains poorly understood. In this study, edible films containing mulberry leaf extract (MLE; 2–8 wt%) and fibroin (8 wt%) were prepared by solution casting, and their structures were investigated using spectroscopic, morphological, thermal, mechanical, and barrier property analyses. The results reveal that MLE induces concentration-dependent changes in film performance through multicomponent, non-covalent interactions with the fibroin. An approximately 187% increase in tensile strength was achieved at high MLE concentration, confirming effective physical reinforcement. The water vapor transmission rate decreased markedly from 0.888 to 0.170 g·h⁻¹·m⁻², indicating an enhanced moisture barrier, whereas oxygen permeability increased at higher extract loadings, suggesting localized chain rearrangements. High optical transparency in the visible region was maintained (79.95–83.77%), while UV response was selectively altered with extract concentration. Overall, the 8MLE formulation exhibited the most balanced performance. This study demonstrates that plant-derived extracts can serve as effective natural modifiers for tailoring fibroin film properties without inducing crystallization, offering a sustainable strategy for designing bio-based and edible protein film systems. Full article

Background: Prostate cancer (PCa) is the leading male urinary malignancy globally. Our previous article demonstrated the anti-PCa activity of Euphorbia humifusa Willd water extract (EHW) and some of its compounds via downregulating AR expression, but the anti-PCa active compounds from Euphorbia humifusa Willd (EH) and their mechanisms of action are yet to be clarified. Thus, the current article studied the in vitro anti-PCa effects of 3,3′-di-O-methylellagic acid (3,3′-di-O-Me-EA) derived from EHW and the related mechanism involved. Methods: 3,3’-di-O-Me-EA was isolated from EHW applying bioassay-guided fractionation. The spectroscopic methods were used to determining the structure of 3,3′-di-O-Me-EA. The drug-likeness and ADMET properties (absorption, distribution, metabolism, excretion, and toxicity) of 3,3′-di-O-Me-EA were analyzed in silico. Molecular docking and real-time surface plasmon resonance (SPR) analysis were performed to measure the interaction of 3,3′-di-O-Me-EA and VDAC1 protein. The viability and apoptosis of 22RV-1 and DU145 PCa cells were determined using MTT and Annexin V-FITC staining assay, respectively. q-PCR and Western blot experiments were used to analyzing the gene and protein expressions of VDAC1. Results: 3,3′-di-O-Me-EA was isolated and purified from EHW with a purity of ≥90.06%, and its structure was identified by HRTOF mass, NMR, and an authentic standard. In silico ADMET analysis indicated its favorable drug-like and pharmacokinetic properties. Molecular docking and SPR results confirmed that 3,3′-di-O-Me-EA could bind with the VDAC1 protein. Moreover, 3,3′-di-O-Me-EA dose- and time-dependently inhibited 22RV-1 and DU145 PCa cell viability, and induced apoptosis in a dose-dependent manner (p < 0.05). RT-qPCR and Western blot results showed that 3,3′-di-O-Me-EA dose-dependently up-regulated VDAC1 gene and protein expression levels in 22RV-1 and DU145 cells (p < 0.05). Meanwhile, in VDAC1-depleted 22RV-1 and DU145 cells, 3,3′-di-O-Me-EA down-regulated VDAC1 gene and protein expression levels, increased cell viability, and inhibited apoptosis compared to 22RV-1 and DU145 cells (p < 0.05). Furthermore, 3,3′-di-O-Me-EA enhanced VDAC1 gene and protein expression levels, inhibited cell viability, and induced apoptosis in VDAC1-overexpressed 22RV-1 and DU145 cells compared with 22RV-1 and DU145 cells (p < 0.05). Overall, EH active compound 3,3′-di-O-Me-EA may inhibit viability and induce apoptosis of 22RV-1 and DU145 PCa cells via up-regulating VDAC1 gene and protein expression levels. Conclusion: The results indicated that the 22RV1 and DU145 PCa cell viability inhibitory effects of 3,3′-di-O-Me-EA isolated from EH may be mediated by induction of apoptosis through up-regulation of VDAC1 gene and protein expression levels. Full article

Water electrolysis has emerged as a strategically appealing route for the sustainable production of green hydrogen (H₂) via the hydrogen evolution reaction (HER), though the sluggish kinetics of the oxygen evolution reaction (OER) remains a bottleneck hindering large-scale practical applications. In this regard, an attractive solution is offered by the integration of the ethanol oxidation reaction (EOR) into hybrid water-splitting systems, favorably reducing anodic overpotentials. Nonetheless, an open challenge is related to the fabrication of eco-friendly and economically viable catalysts free from noble metals, combining efficiency and stability. Herein, we explore nickel-oxide-based nanostructures grown onto porous Ni foam scaffolds by a scalable hydrothermal (HT) approach as EOR electrocatalysts. Material properties arising from modulation of the sole HT growth time are investigated by complementary structural, microscopic, and spectroscopic techniques. Electrochemical tests demonstrate good durability and very attractive EOR performances, mainly influenced by the morphology and the NiOOH surface content of the target systems. Overall, the present work advances an attractive route to transition-metal-based electrocatalysts for efficient alcohol-oxidation-assisted water electrolysis. Full article

Activated carbons are usually prepared from natural precursors (e.g., fruit stones or nutshells) by carbonization and activation processes carried out at 400–1000 °C. They exhibit well-developed porosity, and chemical activation introduces hydrophilic functional groups on their surface, providing excellent sorption properties. However, the high temperatures required during thermal treatment increase production costs. In this work, cost-reducing methods for preparing carbon sorbents are proposed. Carbonization of H₃PO₄ activated waste pistachio nutshells was performed using classical pyrolysis (500 or 550 °C, 30 min, N₂ atmosphere) and microwave treatment (power 1000 W, 20 min). The properties of the synthesized carbons were characterized using thermogravimetry and spectroscopic techniques including infrared (ATR), Raman, photoelectron (XPS) spectroscopies, and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS). Porous structure parameters were determined using nitrogen adsorption experiments. The efficiency of Pb²⁺ removal from spiked ultrapure, tap and river water was evaluated by batch sorption experiments and inductively coupled plasma–mass spectrometry. The most porous carbons were those prepared at 500 and 550 °C, with specific surface areas of 910 and 256 m²/g, respectively. Surface phosphates increased the Pb²⁺ sorption efficiency to 99% from ultrapure water, at an initial concentration of 300 µg Pb²⁺/L. The material obtained with the microwave method was not fully carbonized and remained nonporous, but it also exhibited 99% Pb²⁺ uptake from ultrapure water due to the presence of oxygen-containing surface groups. The Pb²⁺ removal from spiked tap and river water reached up to 84% and 94%, respectively, at the spiking level of 300 µg Pb²⁺/L. Full article

Background: In this study, type B gelatin was extracted from Oreochromis niloticus scales under hydrothermal conditions at 60 °C to evaluate the effect of ultrasound-assisted pretreatment on its structural, physicochemical, thermal, and functional properties. Methods: Gelatin obtained with and without ultrasound pretreatment was systematically characterized through molecular weight analysis, proteomic profiling, size determination, surface morphology, proximate composition, thermal behavior, and gelation-related functional properties in order to assess the influence of the extraction method on gelation performance. Results: Ultrasound pretreatment slightly increased gelatin yield from 1.46 to 1.70%, indicating enhanced collagen solubilization. Proteomic analysis confirmed the predominance of fibrillar collagen proteins in both samples, although differences in protein distribution were observed. Furthermore, weight-average molecular weight analysis revealed a reduction from 212.3 ± 11.8 to 170.9 ± 13.2 kDa in the ultrasound-treated sample, suggesting partial fragmentation of collagen chains induced by cavitation effects. Structural modifications were also reflected in increased porosity and surface changes, contributing to improved colloidal stability. However, these changes significantly affect the functional behavior of the gelatin. Ultrasound-treated sample exhibited limited gel-forming capacity and failed to form stable gels at the evaluated concentration, despite complete dissolution. In contrast, gelatin extracted without ultrasound treatment retained higher-molecular-weight fractions and formed stable gels at both 5 and 10% (w/w). Thermal and spectroscopic analyses suggested that the fundamental collagen structure was preserved in both samples, although differences were observed in thermal degradation behavior. Conclusions: These results highlight the importance of controlling ultrasound-assisted extraction conditions to balance collagen recovery with the preservation of molecular integrity required for gelation, providing insights for the development of sustainable fish-derived biomaterials for pharmaceuticals and biomedical applications. Full article

Bidentate ligands, derived from the 1,3-dicarbonyl framework, play a central role in coordination chemistry, catalysis, and materials science due to their tuneable donor properties and structural versatility. This review examines and compares three closely related ligand classes, β-diketones (O,O′ donors), imino-β-diketones or enaminones (N,O donors), and di-imino-β-diketones or β-diketiminates (N,N′ donors), to elucidate how systematic substitution of oxygen by nitrogen affects structure and properties. The discussion integrates spectroscopic data (NMR and IR), crystallographic findings, electrochemical measurements, and density functional theory (DFT) calculations reported in the literature. Across these systems, tautomerism plays a decisive role, with conjugation-stabilized enol or enamine forms generally preferred in solution and the solid state. Frontier molecular orbital analyses show extensive delocalization over the chelate backbone and, when present, aromatic substituents. Electrochemical studies reveal consistent correlations between experimental reduction potentials and calculated LUMO energies for O,O′-, N,O-, and N,N′-bidentate ligands. Overall, the comparison demonstrates that donor atom substitution within a conserved conjugated scaffold provides a systematic approach to tuning acidity, coordination behaviour, and redox properties, offering a coherent framework for understanding structure–property relationships in 1,3-dicarbonyl-derived chelating ligands. Full article

Moringa oleifera leaves are recognized as a nutrient-dense plant material of compositional and nutritional interest. This study aimed to characterize the nutritional and physicochemical properties of M. oleifera dried leaves through nutritional assessment and spectroscopic fingerprinting. Amino acid profiling, antioxidant activity assessment using ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and oxygen radical absorbance capacity (ORAC) assays, chromatographic analysis of organic acids and sugars, color measurement, techno-functional characterization, and vibrational spectroscopy including Fourier Transform infrared with attenuated total reflectance (FT-IR/ATR) and Raman were employed. The crude protein content was 16.13 ± 0.43%. Moringa leaves contained all essential amino acids, with notably high tryptophan content (amino acid score, AAS = 200.00%). The amino acids limiting the nutritional value of the protein were primarily sulfur-containing amino acids (AAS = 49.57%) and lysine (AAS = 49.79%). Histidine, leucine, and valine also showed levels below the reference protein. Antioxidant activity exhibited solvent-dependent patterns: the 80% ethanolic extract demonstrated significantly higher FRAP activity (27.05 ± 1.05 mg Trolox Equivalent (TxE)/g dry matter (DM)) and ORAC values (107.24 ± 6.80 mg TxE/g DM), while no statistically significant differences between extracts were observed for DPPH, ABTS, or total phenolic content. Chromatographic profiling identified fructose and glucose as the predominant sugars, alongside citric, succinic, lactic, and acetic acids. The leaves exhibited favorable techno-functional properties, including high water holding capacity and water solubility index. Spectroscopic analysis revealed bands consistent with proteins, lipids, carbohydrates, and glycoside-related structures, while the preserved green-yellow coloration (hue angle 101.68°) indicated retention of pigment-related features during processing. These findings provide compositional and physicochemical characteristics of Moringa leaves relevant to their evaluation as a plant-derived food material. Full article

Background: Guanine-rich DNA regions can fold into G-quadruplex (G4) structures, which are prevalent in telomeres and oncogene promoters, making them attractive targets for anticancer therapeutics. Small molecules capable of selectively stabilizing G4 DNA can disrupt telomerase activity and oncogene expression, offering a promising strategy for cancer intervention. Methods: A rationally designed series of DPPZ–anhydride-conjugated ligands (1 and 2) and their corresponding quaternized derivatives (1-q and 2-q) were synthesized to investigate the combined effects of π-extension, bromine substitution, and cationic modification on DNA recognition. The synthetic strategy relied on the incorporation of a highly planar DPPZ–anhydride scaffold to enhance π-surface area, followed by selective quaternization to introduce permanent positive charge and reinforce electrostatic interactions with the DNA backbone. All compounds were fully characterized by NMR and spectroscopic methods. The DNA-binding properties of the ligands were systematically evaluated toward duplex (ds-DNA) and G-quadruplex (G4-DNA) structures using UV–Vis absorption titration, fluorescence intercalator displacement (FID) assays, and competitive dialysis experiments. Quaternization markedly enhanced intrinsic binding constants and significantly reduced DC₅₀ values, particularly for G4-DNA. While bromine substitution increased overall binding affinity, it did not substantially improve topology selectivity. Among the series, compound 1-q exhibited the most favorable balance between affinity and G4 selectivity. Results: The interaction of the compounds with BSA was quantified using Stern–Volmer quenching constants, which demonstrated a clear trend of enhanced quenching efficiency upon modification. The binding strength followed a descending order of 1-q > 2-q > 1 > 2, highlighting the superior performance of the first series over the second. These findings indicate that the structural features of 1-q facilitate a more robust interaction within the hydrophobic pockets of the protein. Conclusions: Overall, the results demonstrate that strategic π-conjugation combined with electrostatic reinforcement provides an effective approach for the development of topology-selective DNA-binding ligands. Full article

This work reports a systematic study concerning the synthesis of pure polyaniline ultrafine nanofibers (PANI-NFs) and their nanocomposites with oxygen-functionalized carbon nanotubes (PANI-NFs/O-MWCNTs) using diluted chemical polymerization and hydrothermal processes. We investigated the synergistic effects of various synthesis parameters, such as the concentration of the ammonium persulfate oxidant agent and growth temperature, on the physical, chemical, and electrochemical properties of the resulting products through structural, morphological, spectroscopic, and electrochemical characterization. Our study revealed the successful synthesis of thermally resistant polyaniline ultrafine nanofibers (PANI-NFs) in the form of emeraldine salt (ES), exhibiting a mean diameter in the range of 8–17 nm. The PANI-NFs and PANI-NFs/O-MWCNT nanocomposites demonstrated excellent electrochemical properties, with specific capacitances of up to 0.94–1.23 F cm⁻² and 1410–2074 F/g, respectively, and with good rate capability. These characteristics are confirmed by the relaxation time constant τ₀ (41 and 8 ms, respectively) and lower internal R₀/interfacial charge transfer R_Փ resistances of around 0.2 Ω, as well as diffusion coefficients of around 10⁻⁷ and 3.7 × 10⁻⁷ cm²/s. This breakthrough in nanofiber synthesis paves the way for practical applications in diverse domains, from high-performance energy storage to biosensing and beyond, where the unique electroactive properties of the nanocomposites can be leveraged to achieve exceptional results. Full article

The control of oxygen stoichiometry via topochemical reduction offers a powerful route to manipulate the functional properties of complex oxides. Here, we investigate the chemical and structural evolution of epitaxial BiFeO₃ (BFO) thin films under CaH₂ treatment in a sealed tube, using a representative reduction condition of 365 °C for 2 h and a temperature window of 345 to 380 °C to probe the reduction dependent evolution. The inherent sensitivity of BFO’s multiferroic properties to oxygen vacancy formation and cation valence states makes it an ideal platform to probe reduction pathways. The aim of this work is to elucidate the detailed reduction pathway, including phase stability, valence changes in Bi and Fe, and the morphological consequences of oxygen extraction. Using a combination of spectroscopic, diffraction, and microscopic techniques, it was demonstrated that CaH₂ annealing does not yield a homogeneous oxygen-deficient perovskite. Instead, it triggers a decomposition into Bi₂O₃, metallic Bi, and FeO_x secondary phases, accompanied by severe surface roughening. This chemical reconstruction leads to a strong suppression of the ferromagnetic-like response and a redshift in the optical absorption edge. Full article

CAD/CAM polymer-based dental materials are increasingly used as metal-free alternatives for fixed and implant-supported restorations. High-performance polymers such as polyetheretherketone (PEEK), fiber-reinforced composites, and graphene-reinforced polymers have been introduced to improve material stability; however, evidence regarding the effects of thermal aging on their physicochemical and biological properties remains limited. In this study, PEEK, a fiber-reinforced composite (FRC), and a graphene-reinforced PMMA-based polymer (G-CAM) were evaluated. Twenty-seven disc-shaped specimens (10 × 2 mm; n = 9 per material) were fabricated and subjected to 10,000 thermal cycles between 5 and 55 °C. Color change (ΔE₀₀), surface roughness (Ra), and Vickers microhardness (VHN) were measured before and after aging. Chemical stability was assessed using FTIR and Raman spectroscopy, surface morphology by SEM analysis, and biological safety by cytotoxicity testing. Material-dependent differences were observed in color stability, surface roughness, and microhardness after thermal aging (p < 0.05). Microhardness decreased in the fiber-reinforced and graphene-reinforced materials, whereas PEEK showed no significant change. Spectroscopic analyses indicated preserved chemical structure, and all materials demonstrated acceptable cytocompatibility. Thermal aging influenced material behavior while chemical stability and biological safety were maintained, highlighting the importance of considering aging behavior during material selection for prosthetic restorations. Full article

Carnosine (or β-alanyl-L-histidine) is an endogenous compound playing very important roles in human organisms as antiglycation and antioxidant agents, and, in addition, helping to mitigate illnesses such as cancer and neurodegenerative diseases. Aiming to explore the chelating ability of carnosine, based on its coordinating possibilities, we started to investigate the metal complexes of essential copper(II), zinc(II), and iron(II) ions coordinated to this dipeptide. Different compounds were isolated in the solid state by adding stoichiometric amounts of metal salts to carnosine at controlled pH or under a controlled atmosphere, with the formation of mono-, bi- and polynuclear species. These complexes were subsequently characterized mainly by spectroscopic techniques (UV–Vis, IR, EPR), in addition to elemental analysis. A binuclear species was isolated with copper(II) and had its structure determined by X-ray diffraction, improving previously reported data in the literature. Two insoluble correlated trinuclear species were isolated with zinc(II) ions, using perchlorate or chloride as counter-ions. In the case of iron, a mononuclear species was verified with Fe(II) ions, obtained under an inert atmosphere. Further, the antioxidant properties of free carnosine and the copper–carnosine complex were verified by their scavenging activity toward the ABTS^•+ radical, using Trolox as a reference, showing significant activity. The carnosine–metal complexes were also tested as potential antineoplastic agents, in comparison to the free ligand, after 24 h of incubation at 37 °C, using malignant HeLa, SKMEL 28 and SKMEL 147, and non-tumor fibroblast cells. Results indicated neglected or poor anti-proliferative properties of these metal complexes, when compared to other similar compounds described in the literature. Full article

The usage of magnetic nanoparticles (MNPs), particularly iron oxide-based systems such as magnetite (${\mathrm{Fe}}_3$${\mathrm{O}}_4$) and maghemite ($\gamma$-${\mathrm{Fe}}_2$${\mathrm{O}}_3$), has significantly advanced the field of theranostics. These nanoparticles unite therapeutic and diagnostic capabilities due to their favorable magnetic properties and surface engineering potential. However, the path from synthesis to clinical application poses substantial challenges, including optimization of structure–property–function relationships, biocompatibility issues, and effective surface functionalization. Various synthesis methods, such as co-precipitation and thermal decomposition, aim to achieve specific nanoparticle characteristics, although they encounter obstacles related to scalability and reproducibility. Furthermore, characterizing these systems through structural, microstructural and spectroscopic techniques is vital to determine their functional efficacy and ensure their safe biomedical usage. This review comprehensively examines recent advancements and identifies existing challenges in the clinical translation of MNPs, highlighting the need for refined methods and standardized protocols to effectively exploit their theranostic potential. It outlines future directions, emphasizing the importance of green synthesis and robust characterization frameworks to enhance the integration of MNPs in personalized medicine. Full article