Search Results (373)

Psoriasis is a common inflammatory skin disease with chronic manifestation in which the role of neutrophil extracellular traps (NETs) and alarmins are increasingly recognized as contributors to systemic and cutaneous inflammation. However, the interaction between alarmins and NET-driven immune responses remains poorly defined. The main aim of this study is to define the role of target alarmins (i.e., IL-33 and TSLP) in NETs induction and its subsequent impact on oxidative stress and inflammation in the peripheral blood. In the present study, we recruited active psoriasis patients (n = 56) and control (n = 56) subjects. The frequency of circulating neutrophils, the levels of NET-associated markers (MPO (myeloperoxidase)–DNA complex, CitH3 (citrullinated histone H3), PAD4 (peptidyl arginine deiminase4), NADPH oxidase, and NE (neutrophil elastase)), and alarmin transcripts (IL (interleukin)-33, TSLP (thymic stromal lymphopoietin), S100A7, S100B, HSP (heat shock protein) 60/70 were quantified using flow cytometry, ELISA (Enzyme-linked immunosorbent assay), and qPCR (quantitative polymerase chain reaction), respectively, in each group. The NET formation potential of isolated neutrophils was assessed in the presence or absence of rhIL-33 and rhTSLP by immunocytofluorescence. The effect of rhIL-33- and rhTSLP-primed NETs in augmenting oxidative stress and inflammation was evaluated on peripheral blood mononuclear cells (PBMCs) by ELISA. Significantly higher circulating neutrophils (p < 0.001) and levels of NET-associated markers (i.e., MPO–DNA complex, CitH3, PAD4, NADPH oxidase, and NE) were observed in active psoriasis patients compared to controls. Lesional skin exhibited strong expression of MPO (p < 0.001) compared to normal skin. The alarmins, IL-33 and TSLP, were markedly upregulated in the blood and skin (p < 0.05). The rhIL-33 and rhTSLP treated neutrophils demonstrated enhanced NETosis in patients (p < 0.001). Increased expression of inflammatory cytokines and oxidative stress markers were reported in PBMCs when incubated with rhIL-33- and rhTSLP-primed NETs. Taken together, our investigation demonstrated the novel mechanism wherein the alarmins IL-33 and TSLP exacerbate NET formation that may drive enhanced inflammation and oxidative stress in psoriasis. Full article

The optical and vibrational responses of Gd₃Ga₅O₁₂ (GGG) single crystals to 147 MeV Kr-ion irradiations were systematically investigated to clarify defect formation pathways and their influence on luminescence mechanisms. Absorption spectra measured at room temperature reveal a stepwise redshift of the fundamental edge and the progressive development of a broad sub-band-gap tail between 4.4 and 5.3 eV, indicating the accumulation of F- and F⁺-type oxygen-vacancy centers and increasing structural disorder. Raman spectroscopy shows that, despite substantial track overlap at fluences up to 10¹⁴ ions/cm², the crystal preserves its phonon frequencies and linewidths, while peak intensities decrease due to a growing disordered volume fraction. Low-temperature (13 K) photoluminescence demonstrates the persistence of a dominant broad band near 2.4 eV and the emergence of an additional irradiation-induced band at ~2.75 eV whose width increases with fluence, reflecting the formation of vacancy-related defect complexes. Excitation spectra transform from band-edge-dominated behavior in the pristine crystal to defect-tail-mediated excitation in heavily irradiated samples. These results provide a consistent spectroscopic picture of ion-track-induced disorder in GGG and identify the defect states governing its luminescence under extreme irradiation conditions. Full article

Cesium lead chloride (CsPbCl₃) is a stable, wide-bandgap perovskite with significant potential for ultraviolet (UV) photodetection and blue light-emitting diodes (LEDs). However, the dynamical mechanisms of ferroelastic domain walls associated with the dielectric relaxations in a single-crystal have rarely been reported. In this work, we observed reversible phase transitions from cubic to tetragonal, and further to orthorhombic symmetry, accompanied by the formation and evolution of strip-like ferroelastic domain walls, using in situ X-ray diffraction (XRD), differential scanning calorimetry (DSC), polarized optical microscopy (POM), and dielectric measurements. Notably, the dielectric studies revealed low temperature (~170–180 K) frequency-dependent loss peaks that we attribute to the pinning of polarized domain walls by chloride vacancies. We also found that the formation or disappearance of ferroelastic domain walls near the octahedral tilting transition temperatures leads to pronounced anomalies in the dielectric permittivity. These findings clarify the intrinsic phase behavior of CsPbCl₃ single crystals and underscore the significant contribution of ferroelastic domain walls to its dielectric response, providing insights for optimizing its optoelectronic performance. Full article

The integration of silica nanoparticles (NS) into cementitious composites has emerged as a promising strategy to refine the microstructure and enhance concrete performance. Beyond their chemical role in accelerating hydration and promoting additional C–S–H gel formation, silica nanoparticles act as physical fillers, reducing porosity and improving interfacial bonding within the matrix. These dual effects result in a denser and more resilient composite, whose mechanical and dynamic responses differ from those of conventional concrete. However, studies addressing the vibrational and modal behavior of nano-reinforced concretes, particularly under elastic and viscoelastic foundation conditions, remain limited. This study investigates the dynamic response of NS-reinforced concrete slabs using a refined quasi-3D plate deformation theory with five (05) unknowns. Different foundation configurations are considered to represent various soil interactions and assess structural integrity under diverse supports. The effective elastic properties of the nanocomposite are obtained through Eshelby’s homogenization model, while Hamilton’s principle is used to derive the governing equations of motion. Navier’s analytical solutions are applied to simply supported slabs. Quantitative results show that adding 30 wt% NS increases the Young’s modulus of concrete by about 26% with only ~1% change in density; for simply supported slender slabs, this results in geometry-dependent increases of up to 18% in the fundamental natural frequency. While the Winkler and Pasternak foundation parameters reduce this frequency, the damping parameter of the viscoelastic foundation enhances the dynamic response, yielding frequency increases of up to 28%, depending on slab geometry. Full article

Against the backdrop of intensifying global climate change and human activities, the increasing frequency and evolution of major wildfire events pose severe challenges to global disaster prevention and mitigation systems. Systematically understanding their disaster characteristics, spatiotemporal patterns, and societal response efficacy is an urgent scientific requirement for formulating effective coping strategies. This study constructed a comprehensive database covering 137 major global wildfire events from 2018 to 2024, with data sourced from GFED, EM-DAT, and official national reports. Utilizing a synthesis of methods including descriptive statistics, spatiotemporal clustering analysis, K-means pattern recognition, and non-parametric tests, a multi-dimensional quantitative analysis was conducted on disaster characteristics, evolutionary trends, casualty patterns, and policy effectiveness. Despite potential reporting biases and heterogeneous data standards across countries, the analysis reveals the following: (1) All key wildfire metrics (e.g., burned area, casualties, evacuation scale) exhibited extreme right-skewed distributions, indicating that a minority of catastrophic events dominate the overall risk profile; (2) Global wildfire hotspots demonstrated dynamic expansion, spreading from traditional regions in North America and Australia to emerging areas such as Mediterranean Europe, Chile, and the Russian Far East, forming three significant spatiotemporal clusters; (3) Four distinct casualty patterns were identified: “High-Lethality”, “Large-Scale Evacuation”, “Routine-Control”, and “Ecological-Destruction”, revealing the differentiated formation mechanisms under various disaster scenarios; (4) A substantial gap of nearly 65 times in emergency evacuation efficiency—defined as the ratio of evacuated individuals to total casualties—was observed between developed and developing countries, highlighting a significant “development gap” in emergency management capabilities. This study finds evidence of increasing extremization, expansion, and polarization in global wildfire risk within the 2018–2024 event sample. The conclusions emphasize that future risk management must shift from addressing “normal” events to prioritizing preparedness for “catastrophic” scenarios and adopt refined strategies based on casualty patterns. Simultaneously, the international community needs to focus on bridging the emergency response capability gap between nations to collectively build a more resilient global wildfire governance system. Full article

This work reports the electrochemical behavior of a nickel hydroxide electrode, electrodeposited in a deep eutectic solvent (DES), in alkaline solutions of varying composition, aiming to elucidate the influence of the cation (Na⁺ vs. K⁺), urea, and carbonate ions on the mechanism and kinetics of anodic processes. Cyclic voltammetry and electrochemical impedance spectroscopy were employed to analyze the electrochemical responses of electrode processes in alkaline water electrolysis systems. For the urea oxidation reaction (UOR), the frequency-dependent characteristics were thoroughly characterized, and the impedance response was simulated according to the Armstrong–Henderson equivalent circuit. It was found that the addition of urea significantly transforms the impedance structure, sharply reducing the polarization resistance and increasing the pseudo-capacitive component of the constant phase element at low frequencies, indicating activation of the slow steps of urea oxidation via a direct mechanism and the formation of an extended adsorptive surface. It was demonstrated that, unlike conventional alkaline electrolysis where KOH-based systems are generally more effective, urea-assisted systems exhibit superior performance in NaOH-based electrolytes, which provides more favorable kinetics for the electrocatalytic urea oxidation process. Furthermore, the accumulation of carbonate ions was shown to negatively affect UOR kinetics by increasing polarization resistance and partially blocking surface sites, highlighting the necessity of controlling electrolyte composition in practical systems. These findings open new opportunities for the rational design of efficient urea-assisted electrolyzers for green hydrogen generation. Full article

This study investigates vibration signals generated during end milling of thin-walled EN AW-7075 aluminum alloy components using a set of 24 tools with distinct cutting edge microgeometries. Five characteristic parameters describing the dynamic response of the process, including both energy-related and statistical indicators, were extracted and analyzed. The results clearly demonstrate the critical influence of tool microgeometry on process dynamics. In particular, the introduction of an additional zero-clearance flank land at the cutting edge proved decisive in suppressing vibrations. For the most favorable geometries, the root mean square (RMS) value of vibration was reduced by more than 50%, while the spectral power density (PSD) decreased by up to 70–75% compared with the least favorable configurations. Simultaneously, both time- and frequency-domain responses exhibited complex and irregular patterns, highlighting the limitations of intuitive interpretation and the need for multi-parameter evaluation. To enable a synthetic comparison of tools, the Vibration Severity Index (VSI), which integrates RMS and kurtosis into a single composite metric, was introduced. VSI-based ranking allowed the clear identification of the most dynamically stable geometry. For the selected tool, additional analysis was conducted to evaluate the influence of cutting parameters, namely feed per tooth and radial depth of cut. The results showed that the most favorable dynamic behavior was achieved at a feed of 0.08 mm/tooth and a radial depth of cut of 1.0 mm, whereas boundary conditions resulted in higher kurtosis and a more impulsive signal structure. Overall, the findings confirm that properly engineered cutting-edge microgeometry, especially the formation of additional zero-clearance flank land significantly enhances the dynamic of thin-wall milling, demonstrating its potential as an effective strategy for vibration suppression and process optimization in precision machining of lightweight structural materials. Full article

This study investigated the dielectric and photocatalytic properties of green-synthesized titanium dioxide nanoparticles (TiO₂ NPs), which are widely utilized semiconductor materials known for their excellent optical, structural, and electronic characteristics. The TiO₂ NPs were synthesized via a green precipitation method from the aqueous extract of Cymbopogon proximus. A comprehensive set of analytical techniques—UV–Vis spectroscopy, XRD, FTIR, TEM, EDX, and DLS—was employed to determine their optical response, crystalline structure, functional groups, morphology, elemental composition, and particle size distribution. UV–Vis analysis revealed a characteristic absorption peak at 327 nm, and the band gap energy, calculated via the Tauc plot method, was 3.16 eV. The XRD results confirmed the formation of a tetragonal TiO₂ phase with an average crystallite size of approximately 4 nm. TEM images further supported the spherical to quasitetragonal morphology and revealed that the aggregated clusters formed conjoint nanostructures. The photocatalytic activity of the TiO₂ NPs was evaluated using a 0.5 mM RhB dye solution under UV–visible irradiation. The synthesized nanoparticles achieved a photodegradation efficiency of 97% after 50 h, with a corresponding rate constant of 0.073402 h⁻¹, indicating their potential for effective photocatalytic pollutant removal. Furthermore, the dielectric behavior of the TiO₂ NPs was examined at room temperature. The material exhibited a high dielectric constant at low frequencies due to interfacial (Maxwell–Wagner) polarization, along with frequency-dependent AC conductivity attributed to charge-carrier hopping mechanisms. These dielectric properties, combined with strong photocatalytic performance, underscore the suitability of green-synthesized TiO₂ NPs for applications in environmental remediation, energy-storage devices, and advanced technologies. Full article

Alpine habitats, characterized by their high degree of environmental heterogeneity and harsh climatic conditions, support a diverse array of plants with unique adaptive strategies. However, the mechanisms underlying the formation of these adaptive strategies, as well as their intrinsic links to species diversification, remain unclear. In this study, we investigated the evolution of life history traits, fruit characteristics, and variation in the karyotype of alpine species, and their roles in shaping their adaptability to high-altitude environments. We performed a comprehensive analysis of trait diversification, adaptive trait evolution, and their associations with environmental factors in the genus Meconopsis on the Qinghai-Xizang Plateau. Our results revealed that ancestral floral traits were characterized by solitary inflorescences and blue-purple pigmentation, features that have re-evolved at multiple points throughout the evolutionary history of the genus. We found that increased ploidy levels promoted perennial growth and semelparity (single-time fruiting), suggesting that life history strategies and fruiting frequency are strongly coupled. Furthermore, karyotypic variation and abiotic factors such as altitude, soil pH, and climate were found to accelerate the evolution of a perennial fruiting reproductive strategy. Our findings provide new insights into the evolution of adaptive traits in alpine plants and reveal how these species adjust their life history strategies in response to environmental pressures. Our findings enhance our understanding of resource allocation trade-offs in plants in extreme environments and shed light on the relationship between species diversification and adaptive evolution in alpine ecosystems. Full article

This study presents an in-depth investigation of an eccentric double-ring microwave resonator comprising two asymmetrically coupled conductive loops connected at a single point. The configuration was systematically analyzed using analytical modeling, full-wave electromagnetic simulations (Ansys HFSS), and experimental characterization. Analytical formulations based on the resonant condition of thin conductive rings provided theoretical estimates of the fundamental and higher-order eigenmodes, while simulations yielded accurate resonance frequencies, transmission responses, and electric field distributions. The transmission coefficient (S₂₁) exhibited two distinct resonance dips at 436 MHz and 708 MHz, confirming strong inter-ring coupling and hybrid mode formation. Electric field mapping revealed pronounced confinement within the resonator region (E > 170 V/m) and substantial attenuation of the transmitted field (E < 13 V/m), demonstrating efficient electromagnetic energy suppression. Experimental results showed excellent consistency with theoretical predictions. This paper aims to establish a compact, low-cost, and tunable resonant structure capable of frequency-selective attenuation and field confinement without using lossy materials. Unlike conventional symmetric resonators, the eccentric configuration enables enhanced coupling control and modal diversity, making it highly relevant for the design of next-generation electromagnetic shielding, filtering, and sensing systems. Full article

This study systematically investigated the electrorheological (ER) behavior of four aqueous smectite clay dispersions—fluorinated hectorite (Ht-F), stevensite (Stv), hectorite (Ht), and saponite (Sap)—with emphasis on transparency, rheological responses, and interparticle interactions. Optical observations revealed that the transparency of the aqueous dispersions followed the order Ht-F > Stv > Ht > Sap, which corresponded well to the finer network structures previously observed in Cryo-SEM images. Whereas micrometer-sized poly(methyl methacrylate) (PMMA) dispersions exhibited electrically induced rapid and reversible separation (ERS) due to sedimentation, the nanosized clays, which do not settle, developed ER effects through field-driven flocculation and subsequent network formation. Under low-frequency AC fields, Ht-F showed highly reversible responses similar to Stv, whereas Sap exhibited irreversible stress increases, accompanied by suspected ion release under the field. Dynamic rheological measurements showed that application of electric fields enhanced the loss modulus (G″) more prominently than the storage modulus (G′), clearly indicating a strengthening of viscous behavior. Derjaguin–Landau–Verwey–Overbeek theory (DLVO) potential analysis yielded a barrier-height sequence (Stv < Ht-F < Ht < Sap) that directly paralleled the order of ER responsiveness. These results demonstrate that the ER hierarchy of aqueous smectites can be rationalized by DLVO interactions and provide design guidelines for environmentally compatible ER fluids. Full article

The current research presents the synthesis, characterization, and application of a novel gas sensor based on polypyrrole/strontium titanate (PPy/STO) nanocomposites for the selective detection of CO₂. Utilizing chemical oxidative polymerization, PPy and PPy/STO nanocomposites with varying STO (10–50) wt.% were synthesized and characterized. The structural and morphological analysis confirms the formation of spherical structure and well-dispersed PPy nanoparticles with increasing crystallinity and interaction of STO in PPy chain particle compactness as the STO content increases. The integration of perovskite STO within the conducting polymer matrix enhances the electronic structure, porosity, and surface area of the composite, promoting improved gas sensing performance. Electrical impedance spectroscopy reveals that the composites exhibit a frequency-dependent dielectric response and conduction attributed to charge carrier mobility and interfacial polarization effects. PPy/STO 20% exhibits highest conductivity and dielectric constants of 0.03604 Scm⁻¹ and 1.074 × 10⁴, respectively. Real-time CO₂ sensing experiments conducted at 50 °C demonstrate good sensitivity, stability, and rapid response/recovery characteristics, particularly for the PPy/STO 10% and 40% composites. These findings highlight the potential of PPy/STO nanocomposites as flexible, lightweight, and efficient materials for portable CO₂ gas sensors, addressing the growing needs for environmental and health monitoring. Full article

Drop hammer impact tests were conducted to study crack features and the ductile–brittle transition in sea ice under low-speed impact. Crack images were analyzed using Hessian filtering and Hough transform methods, and a finite element model was created. Material parameters were validated using the crack tip strength factor. Energy dissipation, focusing on kinetic energy, was analyzed to understand energy conversion and crack propagation in sea ice during low-speed impact. The results indicate that the angular distribution of the crack mode exhibits central symmetry, with the peak frequency at each angle approximately 5°. As the initial impact kinetic energy increases, the dynamic response of the sea ice plate transitions from toughness to brittleness; the kinetic energy dissipation increases linearly, while its utilization efficiency declines. The variation in the kinetic energy conversion rate (η) is associated with the mode of ice plate failure. The crack propagation rate follows a normal distribution in relation to changes in time and kinetic energy. The stress wave effect predominates in the fracture formation mode, further elucidating the ductile–brittle transition behavior of sea ice. This research holds significant implications for ice-breaking operations. Full article

Due to their long wavelengths and low attenuation characteristics, seismic waves pose serious threats to engineering structures, resulting in an urgent need to develop effective vibration mitigation strategies. Locally resonant phononic crystals provide a novel approach to controlling seismic wave propagation, while auxetic materials have attracted considerable attention for their excellent energy absorption capabilities. To achieve broadband low-frequency seismic isolation, this study proposes a seismic metamaterial composed of embedded dual resonators combined with auxetic materials. The bandgap characteristics of the structure are calculated using the finite element method, and the mechanism of bandgap formation is elucidated through vibrational mode analysis. A parametric study is conducted to investigate the influence of mass block substitution on bandgap tunability, and complex band analysis is employed to evaluate seismic wave attenuation within the bandgap range. Furthermore, a graded composite structure is designed, and its seismic isolation performance is validated through frequency- and time-domain simulations. The results show that the proposed composite structure exhibits significant isolation effects within the 2.7–5 Hz bandgap range. Even under excitation with the Chi-Chi earthquake, whose dominant frequency lies outside the bandgap, the peak ground acceleration is reduced by approximately 42%, and the overall acceleration response is effectively suppressed. These findings provide a promising new design strategy for achieving broadband and low-frequency seismic protection in engineering applications. Full article

Agricultural machinery components suffer from severe soft abrasive wear when interacting with flexible materials like rice stalks. To address this, we investigate the friction-reduction mechanism, parameter optimization, and experimental validation of a biomimetic non-smooth surface inspired by the dung beetle’s microstructure. The bionic design was first established by characterizing the beetle’s unique micro-bump array. To ensure simulation accuracy, the critical bonding parameters of a flexible rice stalk DEM model were precisely calibrated via three-point bending tests combined with Response Surface Methodology (RSM). Subsequent DEM simulations revealed that the bionic surface disrupts continuous sliding by reducing the contact area and inducing high-frequency micro-vibrations in the stalk. Using RSM, the bump geometry was systematically optimized, yielding an optimal combination of a 2.975 mm diameter and a 1.0 mm spacing, which theoretically reduces the average normal contact force by 69.3%. Finally, reciprocating wear tests confirmed that the optimized bio-inspired surface exhibited significantly lower mass loss and effectively suppressed the formation of plowing grooves compared to a smooth surface, showing high agreement with simulation predictions. This study provides both a fundamental understanding of the friction-reduction mechanism and precise quantitative guidance for engineering wear-resistant agricultural components. Full article