Search Results (565)

The truncated octagonal cuprous oxide photocatalysts were synthesized in the presence of polyvinylpyrrolidone. Zn-doped Cu₂O photocatalysts were successfully synthesized with different ZnSO₄/CuSO₄ ratios. The effects of Zn doping on the light absorption, morphology, separation of photogenerated charge carriers, and hydrogen production performance of the photocatalyst were investigated. The size and morphology of the Zn-doped Cu₂O-based nanomaterials change with increasing dosages of zinc sulfate dopant. Zn doping resulted in a reduction in crystallite size, a change in morphology, and a decrease in the size of the nanomaterial. The hydrogen production activity of the Zn-Cu₂O photocatalyst Zn-Cu₂O-2 with optimized dopant content can reach 9690 μmol h⁻¹g⁻¹. The enhanced photocatalytic activity of Zn-doped Cu₂O photocatalyst is achieved through significantly improved electron-hole separation, which is maximized at an optimal Zn dopant concentration. Full article

To develop a cost-effective titanium alloy tailored for laser powder bed fusion (LPBF), a novel Ti-5.2Al-5Fe (wt.%) dual-phase alloy was designed and fabricated in this study. The composition was optimized for low density (4.4 g/cm³), high yield strength (1052 MPa), and suitable β-phase stability ([Mo]_eq = 9.3%). The alloy demonstrated excellent formability, achieving high densification (porosity ≤ 2%) and hardness (>400 HV) over a wide volumetric energy density range (48–204 J/mm³). The Al element inhibited balling by improving melt pool wettability, while the Fe element synergistically promoted densification by lowering the liquidus temperature. The as-built microstructure comprised α and β phases, with the α-phase content increasing significantly from 25.4% to 60.8% with higher energy density. While all samples exhibited high tensile strength (>1290 MPa), ductility was limited (<2.6%). EBSD analysis identified the α-phase as the primary carrier of micro-residual stress, with a high density of “zero-solution” points, low-angle grain boundaries, and KAM values. This indicates severe stress concentration from rapid solidification and phase transformation, elucidating the fundamental reason for the low ductility. This study provides systematic insights from composition design to microscopic mechanisms for designing LPBF-dedicated titanium alloys with a wide process window. Full article

Triaxial electrospinning was used to fabricate fiber membranes composed of polycaprolactone (PCL), poly(lactic-co-glycolide) (PLGA), and gelatin (GT), designed as carriers for curcumin (Cur) delivery. Here, synthetic polyesters acted as core and shell layers, while GT formed the middle layer containing Cur at varying concentrations. This paper aimed to demonstrate the effect of a shell layer by rearranging the core and shell layers on the kinetics of model drug delivery. In vitro release results indicated the shell layer considerably affected the release behavior, reducing the initial burst release by up to 28% in triaxial fibers compared to coaxial fibers in PLGA-shell forms. The release kinetics were interpreted using the Gallagher–Corrigan model. The membranes were also evaluated for their morphological properties. PLGA-shell-layered triaxial fibers exhibited pore sizes up to approximately 11 µm, small enough to prevent cell migration, while providing higher permeability. The surface wettability analysis of the developed fibers showed that all forms exhibited hydrophilic properties. Furthermore, the cytocompatibility of the fiber membranes was confirmed with the relative cell viability of over 80%. Triaxial fibers with different shell layers displayed similar release trends, yet fibers with the PLGA shell layer demonstrated more favorable performance, attributed to its layer configuration. These findings suggest that the strategic positioning of polymers in triaxial electrospun membranes could be pivotal in optimizing drug delivery systems. Full article

To optimize the performance of indium oxide (In₂O₃)-based thermoelectric materials, this study prepared Nb-doped In₂O₃ via mechanical alloying and spark plasma sintering (SPS), investigating its regulatory mechanism on the crystal structure, as well as on thermoelectric and mechanical properties. X-ray diffraction (XRD) showed that Nb was incorporated into the In₂O₃ lattice; with increasing Nb doping, the lattice constant decreased due to the ionic radius difference between Nb (64 pm) and In³⁺ (80 pm) plus Nb’s strong polarization effect. In electrical properties, Nb doping significantly improved conductivity: pure In₂O₃ had ~53.42 S/cm, reaching 272.07 S/cm (over 5x increase) at x = 0.005, which is attributed to Nb releasing free electrons and increasing the carrier concentration; though carrier mobility slightly decreased, carrier concentration growth dominated conductivity improvement. The absolute Seebeck coefficient decreased (from −185.24 μV/K to −120.12 μV/K at x = 0.005), but electrical conductivity increased and far exceeded the decrease in the square of the Seebeck coefficient, leading to a high-temperature power factor of 5.10 μW/(cm·K²). In terms of thermal properties, Nb doping reduced thermal conductivity and lattice thermal conductivity. Collectively, the x = 0.004 sample achieved a ZT value of 0.302 at 800 K, which is over 5 times higher than that of pure In₂O₃ (0.055 at 973 K); meanwhile, Nb doping enhanced the Vickers hardness, realizing the optimization of thermoelectric and mechanical properties. Full article

Cu₂O solar cells are regarded as a promising emerging inorganic photovoltaic technology due to their power conversion efficiency (PCE) potential and material sustainability. While previous studies primarily focused on the band offset between n-type buffer layers and Cu₂O optical absorption, this work systematically investigated an ETL/buffer/p-Cu₂O/HTL heterojunction structure using SCAPS-1D simulations. Key design parameters, including bandgap (Eg) and electron affinity (χ) matching across layers, were optimized to minimize carrier transport barriers. Furthermore, the doping concentration and thickness of each functional layer (ETL: transparent conductive oxide; HTL: hole transport layer) were tailored to balance electron conductivity, parasitic absorption, and Auger recombination. Through this approach, a maximum PCE of 14.12% was achieved (V_oc = 1.51V, J_sc = 10.52 mA/cm², FF = 88.9%). The study also identified candidate materials for ETL (e.g., GaN, ZnO:Mg) and HTL (e.g., ZnTe, NiO_x), along with optimal thicknesses and doping ranges for the Cu₂O absorber. These findings provide critical guidance for advancing high-performance Cu₂O solar cells. Full article

Silver selenide (Ag₂Se) is a promising n-type thermoelectric material for near-room-temperature energy harvesting due to its high electrical conductivity and low lattice thermal conductivity. In this study, Ag₂Se-based composites were synthesized using a cold sintering process (CSP), enabling densification at low temperature under applied pressure. Reduced graphene oxide (RGO) was incorporated into the Ag₂Se matrix in small amounts (0.25–1.0 wt.%) to enhance thermoelectric performance. Structural analysis confirmed phase-pure β-Ag₂Se, while SEM and TEM revealed homogeneous RGO dispersion and strong interfacial adhesion. RGO addition led to a reduced carrier concentration due to carrier trapping by oxygen-bearing functional groups, resulting in decreased electrical conductivity. However, the absolute Seebeck coefficient increased with RGO content, maintaining a balanced power factor. Simultaneously, RGO suppressed thermal conductivity to below 0.75 W m⁻¹ K⁻¹ at room temperature. The optimal composition, 0.75 wt.% RGO, exhibited the highest average zT of 0.98 across the temperature range from room temperature to 383 K. These results demonstrate that combining the CSP with RGO incorporation offers a scalable and cost-effective strategy for enhancing the thermoelectric performance of Ag₂Se-based materials. Full article

Background: Amlodipine besylate (AML) is recognized as a calcium channel blocker curative for hypertension. However, the drug emerged recently as an antibacterial cure that competently prevails over resistant strains. Methods: Incorporating amlodipine into zein nanoparticles was employed to innovate a suitable carrier for loading and targeting deep corneal infection. The Box–Behnken design was adopted to produce various formulations of amlodipine-loaded zein nanoparticles (AML-ZNs) with diversity in composition concentration (% w/v), comprising zein, Labrafac, and poloxamer 407. Results: Relying on the optimization criterion, the chosen preference formulation concentration (% w/v) consists of 2.068 for zein, 0.75 for Labrafac, and 1.0 for Poloxamer. Morphological micrography of AML-ZNs showed regular spherical particles in the nanometric scale, and physicochemical characterization procedures confirmed system suitability. While tracking eyedrop optimum features, sodium alginate was selected for coating nanoparticles to improve stability and system viscosity. Both pH and sterility were also considered and maintained. Comparative studies were conducted pre- and post-coating, and the assessed features for the final selected formulation were 349.9 ± 5.8 nm, 0.2186 ± 0.0271, −55.45 ± 1.84 mV, 81.293 ± 0.9%, and 19.3 ± 0.19 cp for size, PDI, surface charge, entrapment, and viscosity, respectively. The AML-ZNs-Alg formulation demonstrates a more controlled pattern of release of roughly 40% of the drug released after 48 h, while the permeation profile shows 37 ± 3.52% permeated after 24 h, confirmed visually. In vitro microbial assay alongside the corneal in vivo microbial and histological pathology evaluation proved the efficacy of amlodipine as an antibacterial agent. Conclusions: These findings highlighted that the prepared AML-ZNs-Alg eyedrop can be a promising system as an antibacterial therapy. Full article

Background: Extracellular vesicles, particularly exosomes, play a crucial role in cell–cell communication and as carriers of biomarkers. However, their use in clinical settings is limited due to a lack of standardized isolation and characterization. Ultracentrifugation (UC) is considered a gold standard for exosome isolation but presents several limitations. Size-exclusion chromatography (SEC) has recently gained attention as a superior method, which offers better yield, purity, and protection of exosome physical properties. This study focused on optimizing the SEC method for isolation of exosomes from seminal plasma and comparing yield, quality, and proteome profiles with those obtained by UC. Methods: In this SEC method, seminal plasma (0.5 mL) was loaded onto a SEC column and collected in 13 fractions of 0.4 mL each. The physical and molecular characterization of exosomes was carried out using a ZetaView analyzer and Western blot, respectively. Further, SEC-isolated exosomes were used for proteomic profiling and functional bioinformatic analysis. Results: The second and third fractions had the highest concentration of exosomes with uniform size and strong expression of exosome markers. Also, comparative proteomic analysis identified 3315 proteins in SEC-isolated exosomes and 931 in UC-isolated exosomes, with 709 proteins in common. SEC-isolated exosomes showed greater overlap with Vesiclepedia’s and ExoCarta’s top 100 lists than UC-isolated exosomes (Vesiclepedia: 91 vs. 77 proteins, ExoCarta: 94 vs. 79). Proteins from SEC- and UC-isolated exosomes showed similar enrichment profiles across all three gene ontology categories. Conclusions: Overall, this optimized SEC protocol is a reliable alternative method to isolate seminal exosomes with high purity, supporting its potential applications in clinical and basic research. Full article

Planetary gearbox serves as a key transmission component in planetary ball screw actuator systems. Under the action of alternating loads, the stress concentration locations of the planet carrier in actuators with planetary gear trains are prone to fatigue cracks, which can lead to catastrophic system breakdowns. However, due to the complex vibration transmission path and the interference of uninterested vibration components, the characteristic modulation signal is ambiguous, so it is challenging to diagnose this fault. Therefore, this paper proposes a new fault diagnosis method. Firstly, a vibration signal model is established to accurately characterize the amplitude and phase modulation effects caused by cracked carriers, providing theoretical guidance for fault feature identification. Subsequently, three novel sideband evaluators of the modulation signal bispectrum (MSB) and their parameter selection ranges are proposed to efficiently locate the optimal fault-related bifrequency signatures and reduce computational cost, leveraging the effects identified by the model. Finally, a novel health indicator, the mean absolute root value (MARV), is used to monitor the state of the planet carrier. The effectiveness of this method is verified by experiments on the planetary gearbox test rig. The results show that the robustness of the amplitude and phase modulation effect of the cracked carrier in the low-frequency band is significantly higher than that in the high-frequency band, and the initial carrier crack can be accurately identified using this phenomenon under different operating conditions. This study provides a reliable solution for the condition monitoring and health management of the actuation system, which is helpful to improve the safety and reliability of operation. Full article

Beta-gallium oxide (β-Ga₂O₃) is a semiconductor with an ultra-wide bandgap, high optical transparency, and excellent electrical properties, which can be finely tuned for a wide range of electronic devices. This study optimized the process conditions for fabricating β-Ga₂O₃ thin films with desired electrical characteristics. β-Ga₂O₃ films were deposited on (100) Si substrates via RF magnetron sputtering with varying O₂ flow rates and post-annealed at temperatures ranging from 600 °C to 800 °C. The structural and electrical properties of the films were analyzed using X-ray diffraction (XRD) spectroscopy, scanning electron microscopy (SEM), and Hall effect measurements. The XRD results confirmed the formation of nanocrystalline β-Ga₂O₃, with variations in peak intensities and shifts observed based on O₂ flow rates. The films exhibited carrier concentrations exceeding 5 × 10²² cm⁻³, mobilities ranging from 50 to 115 cm²/Vs, and resistivity around 1 × 10⁻⁶ Ω⋅cm. This study demonstrates that the electrical properties of β-Ga₂O₃ thin films can be modulated during the deposition and post-annealing processes. The ability to control these properties underscores the potential of β-Ga₂O₃ for advanced applications in high-performance high-power devices and optoelectronic devices such as deep ultraviolet photodetectors. Full article

To overcome the production bottleneck induced by the high viscosity of extra-heavy oil and resolve the issues of limited efficiency in traditional thermal oil recovery methods (including cyclic steam stimulation (CSS), steam flooding, and steam-assisted gravity drainage (SAGD)) as well as the fragmentation of existing viscosity reducer evaluation systems, this study establishes a multi-dimensional evaluation system for the effectiveness of viscosity reducers, with stage-averaged remaining oil saturation as the core benchmarks. A “1D static → 2D dynamic → 3D synergistic” progressive sequential experimental design was adopted. In the 1D static experiments, multi-gradient concentration tests were conducted to analyze the variation law of the viscosity reduction rate of viscosity reducers, thereby screening out the optimal adapted concentration for subsequent experiments. For the 2D dynamic experiments, sand-packed tubes were used as the experimental carrier to compare the oil recovery efficiencies of ultimate steam flooding, viscosity reducer flooding with different concentrations, and the composite process of “steam flooding → viscosity reducer flooding → secondary steam flooding”, which clarified the functional value of viscosity reducers in dynamic displacement. In the 3D synergistic experiments, slab cores were employed to simulate the SAGD development process after multiple rounds of cyclic steam stimulation, aiming to explore the regulatory effect of viscosity reducers on residual oil distribution and oil recovery factor. This novel evaluation system clearly elaborates the synergistic mechanism of viscosity reducers, i.e., “chemical empowerment (emulsification and viscosity reduction, wettability alteration) + thermal amplification (steam carrying and displacement, steam chamber expansion)”. It fills the gap in the existing evaluation chain, which previously lacked a connection from static performance to dynamic displacement and further to multi-process synergistic adaptation. Moreover, it provides quantifiable and implementable evaluation criteria for steam–chemical composite flooding of extra-heavy oil, effectively releasing the efficiency-enhancing potential of viscosity reducers. This study holds critical supporting significance for promoting the efficient and economical development of extra-heavy oil resources. Full article

In this study, barium-doped lanthanum copper oxide (LaCuO) thin films were deposited onto quartz glass substrates using a radio frequency (RF) magnetron sputtering system. The deposited films were subsequently subjected to a selenization annealing process to convert them into barium-doped lanthanum copper oxyselenide (LaCuOSe:Ba) thin films. Selenization was conducted at annealing temperatures of 750 °C, 800 °C, 850 °C, and 900 °C to determine the optimal processing conditions for achieving high-quality LaCuOSe:Ba films. Structural and compositional analyses were performed using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results indicated that the primary phase of the films under all conditions was LaCuOSe. However, at annealing temperatures above 850 °C, secondary phases, such as Cu₂Se and La₂O₂Se, were formed, indicating partial decomposition or phase separation at elevated temperatures. Among the conditions tested, the film annealed at 850 °C exhibited the most favorable optoelectronic properties. It demonstrated an average visible light transmittance of 59%, an electrical resistivity of 6.37 × 10⁻³ Ω·cm, a carrier mobility of 5.87 cm²/V·s, and a carrier concentration of 2.15 × 10²⁰ cm⁻³. These values yielded the highest calculated figure of merit for transparent conducting films, reaching 1.6 × 10⁻⁵ Ω⁻¹, signifying an optimal balance between transparency and conductivity under these processing conditions. Full article

Background and Clinical Significance: Granulomatous reactions are rare but clinically significant complications of aesthetic procedures involving dermal fillers, particularly in individuals with underlying immune dysregulation. These reactions present diagnostic and therapeutic challenges, especially when associated with undiagnosed or latent autoimmune diseases. This case illustrates the interaction between filler composition, immune status, and the risk of delayed inflammatory responses, underscoring the need for thorough patient evaluation and individualized management strategies. Case Presentation: A 49-year-old woman developed delayed-onset subcutaneous nodules following midface augmentation with two filler types: a monophasic, cross-linked hyaluronic acid gel (concentration 20 mg/mL, 1.0 mL per side) injected into the deep malar fat pads, and a calcium hydroxyapatite suspension (30% CaHA microspheres in a carboxymethylcellulose carrier, 0.5 mL per side) placed in the subdermal plane along the zygomatic arch. The procedure was performed in a single session using a 22 G blunt cannula, with no immediate adverse events. High-resolution ultrasound demonstrated hypoechoic inflammatory nodules without systemic symptoms. A retrospective review of her medical history revealed a latent, previously undisclosed diagnosis of granulomatosis with polyangiitis (GPA). The immune-adjuvant properties of calcium hydroxyapatite likely triggered a localized pro-inflammatory response in this predisposed patient. A conservative, staged, non-invasive therapeutic protocol—saline infiltration, intradermal polynucleotide injections, and manual lymphatic drainage—achieved complete clinical and radiological resolution without systemic immunosuppression or surgical intervention. Conclusions: This case highlights the critical importance of pre-procedural immunological assessment in aesthetic medicine. Subclinical autoimmune conditions may predispose patients to delayed granulomatous reactions after filler injections. An individualized, conservative management strategy can effectively resolve such complications while minimizing the risks associated with aggressive treatment. Greater awareness of immune-mediated responses to dermal fillers is essential to ensure patient safety and optimize clinical outcomes. Full article

This study introduces an efficient, all-aqueous emulsion-templating strategy for fabricating highly tunable yeast immobilization carriers with superior biocatalytic performance. Utilizing cellulose nanocrystals (CNCs) to stabilize dextran/polyethylene glycol (Dex/PEG) water-in-water emulsions, an architecture-controlled void is obtained by crosslinking the PEG-rich phase with variable concentrations of polyethylene glycol diacrylate (PEGDA) (10–25 wt%). This approach successfully yielded macroporous networks, enabling precise tuning of void diameters from 10.4 to 6.6 μm and interconnected pores from 2.2 to 1.4 μm. The optimally designed carrier, synthesized with 15 wt% PEGDA, featured 9.6 μm voids and robust mechanical strength (0.82 MPa), and facilitated highly efficient yeast encapsulation (~100%). The immobilized yeast demonstrated exceptional fermentation activity, remarkable storage stability (maintaining > 95% productivity after 4 weeks), and high reusability (85% activity retention after seven cycles). These enhancements are attributed to the material’s excellent water retention capacity and the provision of a stable microenvironment. This green and straightforward method represents a significant advance in industrial cell immobilization, offering unparalleled operational stability, protection, and design flexibility. Full article

The degradation of the electronic properties of semiconductor materials and electronic devices under neutron irradiation is a critical issue for the development of electronic systems intended for use in nuclear and thermonuclear energy facilities. This study presents a methodology for real-time measurement of the electrical parameters of semiconductor structures during neutron irradiation in a high-flux reactor environment. A specially designed irradiation fixture with an electrical measurement system was developed and implemented at the WWR-K research reactor. The system enables simultaneous measurement of electrical conductivity and the Hall effect, with automatic temperature control and remote data acquisition. The sealed fixture, equipped with radiation-resistant wiring and a temperature control, allows for continuous measurement of remote material properties at neutron fluences exceeding 10¹⁸ cm⁻², eliminating the limitations associated with post-irradiation handling of radioactive samples. The technique was successfully applied to the two different InGaAs-based heterostructures, revealing distinct mechanisms of radiation-induced modification: degradation of mobility and carrier concentration in the InGaAs quantum well structure on GaAs substrate, and transmutation-induced doping effects in the heterostructure on InP substrate. The developed methodology provides a reliable platform for evaluating radiation resistance and optimizing materials for magnetic sensors and electronic components designed for high-radiation environments. Full article