Search Results (776)

Starch–polyphenol interactions play a critical role in regulating the structural organization and thermal behavior of starch-based systems. In this study, maize starches with different amylose contents were used to systematically investigate how tea polyphenol (TP) complexation influences starch structure and thermal stability. Starch–TP complexes were prepared under thermal-induced conditions and characterized using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). TGA results showed that increasing amylose content slightly reduced the thermal stability of native starches, whereas TP incorporation significantly enhanced thermal resistance, particularly in high-amylose systems. XRD analysis indicated that TP complexation did not affect the crystal structure of starch but led to a pronounced reduction in relative crystallinity, with low-amylose complexes exhibiting predominantly amorphous behavior and high-amylose complexes retaining partial nanocrystalline organization. FTIR spectra revealed reduced short-range molecular order and strengthened hydrogen bonding interactions after TP binding. DSC analysis demonstrated increased gelatinization temperatures accompanied by decreased enthalpy changes, reflecting restricted molecular mobility and delayed solvation of nanocrystalline domains. SEM observations further showed a transition toward denser and more interconnected micro–nano structures with increasing amylose content. Overall, TP preferentially interacts with amylose-rich regions through non-covalent interactions, promoting structural reorganization and enhanced thermal stability of the starch matrix. These findings provide new insight into amylose-dependent starch–polyphenol interactions and offer guidance for designing thermally stable starch-based functional materials. Full article

Lignin from Phaleria macrocarpa (Mahkota Dewa) fruit, a bioactive-rich cultivated medicinal biomass, was employed as a renewable precursor for lignin quantum dots (LQDs). A simple, aqueous, catalyst-free two-step route (lignin to lignin nanoparticles to LQDs) is demonstrated, enabling the valorization of non-food lignin into photoluminescent nanomaterials. The resulting LQDs were predominantly amorphous with short-range graphitic ordering and a narrow particle size distribution (3–5 nm). Structural and chemical analyses indicated a partially graphitized carbon framework enriched with oxygenated surface functionalities, which is consistent with their bright blue–green emission (λ_em of 490 nm; average fluorescence lifetime of 4.51 ns). Hydrothermal carbonization induced a blue shift in the UV–Vis absorption profile, resulting in a main band at 288 nm with a shoulder at 312 nm. The LQDs exhibited high cytocompatibility toward L929 mouse fibroblasts (93.1 ± 6.5% viability at 24 h) and were readily internalized by cells, facilitating green fluorescence live-cell imaging as a proof-of-concept. Antibacterial activity was observed against both Gram-positive and Gram-negative strains, supporting dual biofunctional performance. Overall, this study established a green and scalable route for converting P. macrocarpa fruit lignin into multifunctional LQDs, with potential applications in circular-bioeconomy such as antimicrobial/active coatings and optical sensing in agro-industrial contexts. Full article

There are many stories in the Hebrew Bible that depict prominent Jews in the epicentre of a foreign imperia, and biblical scholarship essentially classifies every such narrative as court tales in terms of genre. Notwithstanding nuances and sub-categorisations (e.g., court contest and court conflict, wisdom court legend, success story of the wise courtier), to have one catch-all genre designation is imprudent and amorphous. This paper argues, using Formkritik and Gattungskritik, for three subgenres whereby foreign royal stories may be distinguished. One type of tale involves a foreign king who is either sleepless (Dan 6, Esth 6) or dreams (Gen 41, Dan 2 and 4); in the former, a king intervenes favourably for Jews in distress, while in the latter, the king’s dreams are interpreted by a wise Jewish courtier. Another type of tale is the imperial banquet, where an intoxicated gentile king orders the death of a high official (Dan 5, Esth 1, 5/7); this is wrought by a woman who exploits the king’s wine-induced disposition to effect lethal action with disastrous repercussions for the kingdom. Still another type of tale is the court tale proper; these episodes, however, are restricted to the courtly etiquette and decorum of courtiers who sagaciously advise the king, alongside its tensions with monotheism (Dan 3; Esth 3). As a result of this preliminary investigation, the typical setting of the political centre of the foreign imperium in Hebrew Bible narratives comprises three subgenres: court tales, banquet tales, and bedchamber tales. Since genres are determined by the common story forms, each distinct genre is scientifically determined by corresponding distinct narrative structures, vocabulary, and outcomes. Thus, what is proposed is a more illuminating distinction to the wide array and nebulous conglomeration of biblical stories involving Jews in prominent spaces within the foreign king’s court. Furthermore, the implications of the contended three subgenres involve calcifying religious practices, which become vital expressions of Judaism in the Second Temple period. Full article

Post-annealing treatments constitute a simple and cost-effective strategy to tailor the structure and photocatalytic performance of polymeric carbon nitride (PCN). In this work, PCNs synthesized from melamine and urea were subjected to post-annealing at 580 °C under air and CO₂ atmospheres to elucidate the role of hydrogen bonding, as well as other structural modifications induced by oxidizing atmospheres, on photocatalytic water splitting. Comprehensive structural, chemical, and textural characterization (XRD, FTIR spectroscopy, XPS, SSNMR, HRTEM, BET, TGA, and UV–Vis DRS) reveals that post-annealing induces markedly different effects depending on the precursor. For melamine-derived PCN, the treatment selectively disrupts hydrogen bonds between melon strands without introducing nitrogen vacancies, amorphization, or framework shortening. This structural rearrangement increases surface area, reduces particle size, slightly widens the band gap, and enhances water–framework interactions, resulting in a twofold improvement in the hydrogen evolution rate (HER), reaching ~3300 µmol h⁻¹ g·cat⁻¹ under visible-light irradiation. In contrast, urea-derived PCN undergoes only minor structural modifications, including slight exfoliation and possible nitrogen deficiency, which do not translate into a measurable enhancement of photocatalytic activity. These results demonstrate that selective hydrogen-bond disruption is a key factor governing charge transport and photocatalytic efficiency in PCN. Importantly, the optimized melamine-derived PCN achieves HER values comparable to those of urea-derived PCN while maintaining a substantially higher synthesis yield, highlighting its potential for scalable solar hydrogen production. Full article

Fe-based amorphous microwires were studied to examine the effect of partial surface nanocrystallization on their magnetic and electrical properties. Controlled annealing was used to induce nanocrystallization within the surface layer of the metallic core. The giant magnetoimpedance (GMI) was found to increase up to 150% compared to the as-cast microwires, which correlates with variations in the electromagnetic skin depth. Magnetic force microscopy (MFM) revealed a pronounced transformation of the magnetic domain structure: inclined and zigzag domains evolved into a ring domain configuration with radially oriented magnetization. This transformation of the domain structure occurred within the same magnetic field range where the maximum impedance response was observed. These results show a strong coupling between surface nanostructuring, domain configuration, and magnetoimpedance behavior, providing insights for optimizing Fe-based microwires for use in high-sensitivity magnetic and mechanical sensors. Full article

The biosynthesis of melanin in plants remains an enduring biochemical enigma. Unlike the well-characterized pathways of animals and fungi that produce the canonical “true melanins”, the enzymatic origins and physiological functions of melanin-like pigments in plants are poorly described. Recent advances in Juglans regia (walnut) have begun to illuminate this “dark metabolism,” revealing a dual polyphenol oxidase (PPO) system, constitutive JrPPO1 and stress-inducible JrPPO2, that orchestrates the oxidation of phenolics into amorphous, heterogeneous polymeric pigments. Functional studies demonstrate that JrPPO1 maintains tyrosine and redox homeostasis, while silencing triggers a lesion-mimic phenotype, highlighting the enzyme’s role in detoxifying reactive intermediates. In contrast, JrPPO2 responds to redox and pathogen stress, driving pigment formation as part of the defense response. The integration of biological evidence, encompassing genomics, genetics, and phenotyping, reveals that walnut pigmentation represents a genetically encoded, developmentally regulated adaptation balancing metabolic cost and oxidative protection. Decoding this system reframes melanin biosynthesis in plants as a strategic redox resilience mechanism, one that transforms potentially toxic phenolic oxidation into protective polymerization, bridging primary metabolism, defense, and evolution. Full article

High-entropy alloys (HEAs) represent one of the most promising emerging material families, particularly for advanced surface engineering applications. In this work, a near-high-entropy alloy (near-HEA) coating was produced on a 316L stainless steel substrate using laser metal deposition (LMD) from a powder mixture of Inconel 625, Cr and Mo, without the intentional addition of Fe. Due to dilution from the substrate, the resulting alloy contained elevated Fe content while maintaining Cr, Ni and Mo concentrations within the generally accepted compositional range of HEAs. The deposited layer exhibited a dual-phase microstructure consisting of a face-centered cubic (FCC) phase and a highly distorted tetragonal phase forming a periodic network with a characteristic length scale of several hundred nanometers. The hardness of the coating increased to approximately three times that of the substrate, reaching values of 600–700 HV. To further modify the surface properties, laser-induced periodic surface structures (LIPSS) were generated on the polished coating using femtosecond pulsed laser irradiation at different energy densities. The morphology and subsurface structure of the resulting periodic patterns were investigated by scanning electron microscopy. LIPSS with characteristic dimensions ranging from the micrometer to nanometer scale were successfully produced. Cross-sectional analyses revealed that the underlying dual-phase microstructure remained continuous within the laser-structured regions, indicating that LIPSS formation occurred predominantly via metallic ablation without significant phase transformation or amorphization. These results demonstrate the combined applicability of LMD and femtosecond laser structuring for producing mechanically enhanced, micro- and nanostructured near-HEA coatings with potential for advanced surface-related functionalities. Full article

p-Nitrophenol (PNP), a highly toxic and recalcitrant organic pollutant prevalent in industrial wastewater, poses severe challenges to traditional Fenton treatment technologies. In this study, a novel nanoporous catalyst is synthesized via a combined annealing–dealloying strategy. Annealing at 550 °C and 600 °C induces partial crystallization, generating α-Fe and Fe₂B phases that serve as preferential corrosion sites during chemical dealloying. This process results in a three-dimensionally interconnected nanoporous structure, which significantly increases the specific surface area of the catalyst to 2.642 m²/g. The optimized nanoporous catalyst exhibits excellent degradation performance, achieving complete removal of PNP within 30 min under room temperature reaction conditions. Notably, kinetic analysis reveals a degradation mechanism involving adsorption and Fenton-like catalysis. The high specific surface area provides abundant active sites for PNP adsorption, while the enhanced Fe²⁺ dissolution synergistically accelerates the degradation. The adsorption kinetic follows a pseudo-second-order model, and the degradation kinetic conforms to a first-order model, with activation energy analysis further confirming a surface-reaction-controlled process. This work provides a feasible approach and technical reference for designing efficient porous catalysts based on amorphous alloys for advanced treatment of refractory organic wastewater. Full article

The present work investigates the effect of phosphorous-acid-induced pH variation on the electrodeposition of Ni–P coatings and examines how changes in electrolyte composition influence current efficiency, deposition behaviour, microstructure, optical properties, tribological response and wettability. In addition, the study assesses the potential of a post-deposition surface modification using stearic acid to enhance the hydrophobic character of the coatings. Ni and Ni–P layers were electrodeposited on 316L stainless steel using electrolytes containing 0–40 g/L of H₃PO₃, resulting in progressively lower bath pH and significant changes in deposition kinetics. The introduction of H₃PO₃ caused a sharp reduction in cathodic current efficiency and deposition rate, producing ultrathin Ni–P films with 20–24 at.% P. XRD and SEM analyses showed a transition from highly crystalline Ni to amorphous, nodular Ni–P structures. Tribological tests revealed a pronounced improvement in sliding performance for all Ni–P coatings compared to pure Ni, with sample S2 (5 g/L of H₃PO₃) exhibiting the lowest and most stable friction coefficient (~0.30). Wettability studies indicated that all as-deposited Ni–P surfaces were weakly hydrophobic, with surface energies dominated by the dispersive component. A stearic acid post-treatment produced a measurable increase in the water contact angle, indicating successful surface functionalization of the coatings. Overall, this study provides a comprehensive assessment of how phosphorous acid concentration governs the functional behaviour of electrodeposited Ni–P coatings. Full article

Hydrogenated amorphous silicon (a-Si:H) is a mature thin-film technology for large-area devices and thin-film sensors, and its low-temperature growth via Plasma-Enhanced Chemical Vapor Deposition (PECVD) makes it particularly suitable for biomedical flexible and wearable platforms. However, the reliable integration of a-Si:H sensors on polymer substrates requires a quantitative assessment of their electrical stability under mechanical stress, since bending-induced variations may affect sensor accuracy. In this work, we provide a quantitative, direction-dependent evaluation of the static-bending robustness of both single-doped a-Si:H layers and complete p-i-n junction stacks on polyimide (Kapton^®), thereby linking material-level strain sensitivity to device-level functionality. First, n- and p-doped a-Si:H layers were deposited on 50 µm thick Kapton^® and then structured as two-terminal thin-film resistors to enable resistivity extraction under bending conditions. Electrical measurements were performed on multiple samples, with the current path oriented either parallel (longitudinal) or perpendicular (transverse) to the bending axis, and resistance profiles were determined as a function of bending radius. While n-type layers exhibited limited and mostly gradual variations, p-type layers showed a stronger sensitivity to mechanical stress, with a critical-radius behavior under transverse bending and a more progressive evolution in the longitudinal one. This directional response identifies a practical bending condition under which doped layers, particularly p-type films, are more susceptible to strain-induced degradation. Subsequently, a linear array of a-Si:H p-i-n sensors was fabricated on Kapton^® substrates with two different thicknesses (25 and 50 µm thick) and characterized under identical bending conditions. Despite the increased strain sensitivity observed in the single-layers, the p-i-n diodes preserved their rectifying behavior down to the smallest radius tested. Indeed, across the investigated radii, the reverse current at −0.5 V remained consistent, confirming stable junction operation under bending. Only minor differences, related to substrate thickness, were observed in the reverse current and in the high-injection regime. Overall, these results demonstrate the mechanical robustness of stacked a-Si:H junctions on polyimide and support their use as sensors for wearable biosensing architectures. By establishing a quantitative, orientation-aware stability benchmark under static bending, this study supports the design of reliable a-Si:H flexible sensor platforms for curved and wearable surfaces. Full article

To obtain data on the effects of ozonolysis on the structural and dynamic parameters of ultrafine fibers based on the binary compositions of poly-(3-hydroxybutyrate) (PHB) and polyvinylpyrrolidone (PVP) with varying ratios of polymer components ranging from 0/100 to 100/0 mass%, produced by electrospinning, a study was conducted. The morphology and structural–dynamic characteristics of the ultrafine fibers were examined. Comprehensive research was carried out, combining thermophysical measurements (DSC), dynamic measurements using an electron paramagnetic resonance (EPR) technique, scanning electron microscopy, and infrared spectroscopy. The influence of the mixture’s composition and ozonolysis on the degree of crystallinity of PHB and the molecular mobility of the TEMPO radical (tetramethylpiperidine-1-oxyl) in the amorphous regions of the PHB/PVP fiber material was demonstrated. The low-temperature maximum on the DSC thermograms provided information about the fraction of hydrogen bonds in the mixed compositions, allowing for the enthalpy of thermal destruction of these bonds in both the original and oxidized samples to be determined. The study showed significant changes in the degree of crystallinity of PHB, the enthalpy of hydrogen bond destruction, molecular mobility, moisture absorption of the compositions, and the activation energy of rotational diffusion in the amorphous regions of the PHB/PVP mixed compositions. It was established that within the 50/50% PHB/PVP ratio, an inversion transition occurs from the dispersion material to the dispersion medium. Ozonolysis induces a sharp change in the material’s structure. The conducted research provided the first opportunity to assess the impact of ozonolysis on the structural and dynamic characteristics of PHB/PVP ultrafine fibers at a molecular level. These materials may serve as a therapeutic system for controlled drug delivery. Full article

Colloidal amorphous structures comprise short-range ordered arrays of monodisperse submicrometer-sized particles. They exhibit angle-independent structural color and hence are expected to be promising candidates for advanced color materials. In particular, non-close-packed colloidal amorphous structures embedded in soft polymers can alter the angle-independent color through stimuli-induced volume changes in the polymer. Consequently, such materials should have significant potential for application in sensor devices. This paper reports the preparation of an elastomer-immobilized non-close-packed colloidal amorphous film with an angle-independent color using a hydrogel-immobilized non-close-packed colloidal amorphous film as the starting material. The swelling solvent (i.e., water) in the hydrogel film was replaced with a hydrophilic elastomer precursor solution, which was photopolymerized to immobilize the colloidal amorphous structure with the separated particles within the elastomer film. The color of the elastomer-immobilized non-close-packed colloidal amorphous film was angle-independent and was easily altered under stretching. Furthermore, hydrophilic carbon black dispersed well in the hydrophilic elastomer precursor solution, improving the saturation of the resultant elastomer-immobilized non-close-packed colloidal amorphous film. The flexible nature of the prepared film should allow it to be attached to curved surfaces, thereby promoting its application as a simple strain sensor to express invisible strains through color changes. Full article

Nanocrystalline Fe-Gd-B alloys were successfully synthesized via Gd alloying in a binary Fe-B system using a single-roller melt-spinning technique. A systematic investigation of Gd content variation (0–4.35 at.%) reveals its critical role in tuning microstructure evolution, thermal stability, and magnetic properties. Crucially, the Fe_90.70Gd_2.32B_6.98 alloy ribbon exhibits optimized magnetic performance, achieving a high saturation magnetic induction (B_s) of 1.67 T and a low coercivity (H_c) of 2.737 kA/m. This enhancement is attributed to the suppression α-Fe grain growth through Gd-induced elevation of the thermal stability of the amorphous matrix, which confines the average crystallite size to 26.3 nm. The refined α-Fe phase contributes to elevated B_s through an increased ferromagnetic fraction, while its nanoscale grain structure, combined with wide magnetic domain configurations, effectively reduces H_c by limiting domain wall pinning sites. These findings establish that the synergistic effect of Gd alloying and Fe/B ratio adjustment is a viable strategy for designing high-performance Fe-based magnetic alloys. Full article

Solar-blind ultraviolet (UV) photodetectors based on wide-bandgap oxide semiconductors are highly desirable for environmental monitoring, flame sensing, and secure optical communication. Among them, Ga₂O₃ has attracted extensive attention due to its ultra-wide bandgap and intrinsic solar-blind response; however, its high dark current, weak built-in electric field, and defect-induced instability remain critical challenges, particularly for amorphous films prepared by scalable sputtering processes. Herein, a self-powered solar-blind UV photodetector based on a NiO/Ga₂O₃ heterojunction is demonstrated, in which the oxygen-vacancy concentration and band structure of sputtered Ga₂O₃ are systematically regulated by tailoring the Ar/O₂ sputtering atmosphere. Combined X-ray photoelectron spectroscopy, UV photoelectron spectroscopy, and optical measurements reveal that the variation in oxygen-vacancy concentration simultaneously modulates the Fermi-level position, band-edge alignment, and built-in potential at the NiO/Ga₂O₃ interface. As a result, the optimized heterojunction device exhibits a low dark current, pronounced rectifying behavior, and efficient carrier separation under zero bias, enabling self-powered operation. The photodetector delivers a responsivity of 47 mA W⁻¹, a detectivity of 7.52 × 10¹¹ Jones, and a high rejection ratio exceeding 10⁴ between 254 and 365 nm. Furthermore, stable and high-contrast UV imaging is successfully demonstrated, highlighting the practical applicability of the device. This work provides an effective methodology for modulating defects and band structure in high-performance solar-blind UV photodetectors based on sputtered wide-bandgap oxide heterojunctions. Full article

This study provides an original insight into the synergistic mechanism through which TM-104 and Vanlube 672 facilitate the in situ formation of a nanoscale bilayer tribofilm in ethylene glycol-based hydraulic fluid. By optimizing the additive formulation to 0.5 wt.% TM-104 and 2.0 wt.% Vanlube 672, a structurally graded tribofilm was autonomously assembled at the friction interface, comprising a 6 nm-thick P_xO_y-rich inner layer and a 140 nm-thick amorphous carbon outer layer. This engineered interlayer delivers exceptional tribological enhancements, with a 31% improvement in lubricity, a 71% increase in wear resistance, and a remarkable 577% enhancement in extreme-pressure load capacity. The first discovery was that there were differences in the mechanisms between these two layers: the inner P_xO_y layer establishes strong chemisorption bonds with the substrate, while the outer carbon layer facilitates energy dissipation through shear-induced graphitization. These findings establish a new paradigm for designing multi-functional lubricant additives and provide a scientific basis for developing high-performance fire-resistant hydraulic fluids operable under extreme conditions. Full article