Search Results (15,705)

The development of titanium-based surface alloys and coatings that combine extreme hardness with sufficient toughness remains a major challenge for components operating under severe friction and wear conditions. In this work, titanium–boride composite coatings were synthesized on commercially pure titanium by scanning electron beam surface alloying of preplaced boron. The influence of beam power (900, 1200, and 1500 W) on phase formation, microstructural evolution, and mechanical performance was systematically investigated. At 900 W, insufficient melting resulted in chemically and structurally heterogeneous coatings containing unreacted boron. Increasing the beam power to 1200 W promoted the formation of TiB and TiB₂ phases, leading to a maximum microhardness of approximately 5500 HV_0.2. At 1500 W, complete boron incorporation produced a graded architecture consisting of a Ti/TiB surface layer and a TiB₂-rich sublayer. This hierarchical microstructure exhibited a favorable combination of high hardness and the lowest coefficient of friction (0.21), representing a reduction of more than 50% compared with the untreated titanium substrate. These findings establish a clear relationship between electron beam processing conditions, microstructural development, and mechanical performance, demonstrating that scanning electron beam surface alloying is an effective strategy for tailoring high-performance Ti–B composite surfaces. The developed coatings show strong potential for aerospace and other advanced engineering applications requiring lightweight materials with high hardness and low friction. Full article

Ni–Mo alloy claddings were fabricated on low-carbon steel substrates using powder metallurgy combined with hot isostatic pressing (PM-HIP). The interfacial microstructure, elemental interdiffusion, phase composition and microhardness distribution of the bimetallic composite were investigated systematically. The results show that sound metallurgical bonding without pores, cracks and element dilution is achieved under the HIP process of 1100 °C, 120 MPa and 4 h holding time. Interdiffusion of Fe, Ni and Mo atoms forms a 20–50 μm thick interfacial transition layer, and Mo exhibits a relatively low diffusion capacity due to its large atomic radius. Two intermetallic phases, Ni₄Mo and NiMo, are formed in the cladding layer because of the inhomogeneous distribution of Mo. A prominent microhardness gradient is observed throughout the composite, and the interfacial layer presents the highest hardness of 905 HV resulting from multiple strengthening mechanisms. As an effective alternative to traditional welding and cladding technologies, the PM-HIP process exhibits great potential for manufacturing complex bimetallic components with prospective service prospects in severe corrosive environments. Full article

Traditional fermented foods are important reservoirs of wild microorganisms with technological, sensory, protective, and functional potential. However, the performance of these isolates in controlled or compositionally different food matrices remains fragmented across microbial groups and food systems. This systematic review synthesized evidence on using wild microbial isolates from traditional fermented foods and beverages as starters or potential probiotic cultures. The conducted a systematic search exclusively in Scopus, following PRISMA 2020, to include original research articles published between 2021 and 2026, yielding 68 eligible studies. The included studies were analyzed by geographical origin, isolation source, recipient matrix, microbial group, and key physicochemical, technological, sensory, microbiological, nutritional, and functional outcomes. The evidence was organized into wild yeasts and filamentous fungi, lactic acid bacteria (LAB), Bacillus isolates, and defined mixed microbial cultures. Across food matrices, microbial incorporation frequently accelerated acidification, shortened fermentation time, modified volatile compound profiles, and altered texture, color, enzymatic activity, or substrate utilization. Sensory responses improved aroma, flavor, texture, and acceptance, whereas others produced profiles that deviated from the characteristic product and reduced overall liking. Functional effects included increases in phenolic compounds, antioxidant activity, GABA, folate, peptides, and resistant starch, along with reductions in phytates, nitrites, biogenic amines, aflatoxins, and nondigestible oligosaccharides. Researchers also reported antimicrobial, antifungal, protective, and preliminary probiotic properties. Defined mixed microbial cultures often provided complementary metabolic effects, although true synergistic interactions were demonstrated only sporadically. Overall, wild isolates from traditional fermentations represent promising resources for food bioprocessing; however, their performance varies widely across strains, recipient matrices, experimental conditions, and outcomes evaluated. Consequently, their application requires strain–matrix validation, comprehensive sensory assessment, safety characterization, and evaluation under processing and storage conditions relevant to industrial production. Full article

Direct ink writing (DIW) is a promising additive manufacturing technique for flexible electronics; however, lateral spreading of conventional silver inks often limits printing resolution and geometric fidelity. To address this limitation, an in situ UV-assisted DIW strategy using photocurable silver inks was developed for the fabrication of high-resolution conductive features. The effects of Ag loading, TPO photoinitiator concentration, and dispersant type on the rheological behavior, photocuring response, and stability of the inks were systematically investigated. Excessive TPO concentrations were found to induce rheological instability, whereas an optimized formulation enabled a stable photocuring response. Among the dispersants investigated, AH100 provided the most favorable balance between ink flowability and controlled substrate wetting, thereby suppressing excessive lateral spreading. During printing, in situ UV irradiation rapidly promoted crosslinking of the resin matrix, increasing the structural rigidity of the deposited filament and restricting capillary-driven spreading. Using the optimized printing conditions and a photocurable silver ink with a Ag powder-to-photosensitive resin mass ratio of 4:1, the post-sintering line width was reduced from 269.8 to 72.57 μm, corresponding to a reduction of approximately 73%. After sintering at 800 °C, the printed tracks exhibited an electrical conductivity on the order of 10⁷ S/m, demonstrating that the substantial improvement in printing resolution was achieved without significantly compromising electrical performance. This in situ UV-assisted DIW strategy therefore provides an effective route for fabricating fine conductive features with improved dimensional fidelity and competitive electrical performance, showing promise for high-resolution flexible electronics and sensor applications. Full article

Podocytes and their foot processes form a functional layer of the glomerular filtration barrier. Due to their unique morphology and function, podocytes employ distinct nutrient pathways to maintain the bioenergetic balance, with lactate being one of several available energy substrates. Enhanced lactate intake modulates the redox state of the cell by increasing mitochondrial respiration and reactive oxygen species production. Monocarboxylate transporter 1 (MCT1) is the primary lactate transporter, and alterations in its surface expression may contribute to the regulation of lactate uptake in podocytes. Beyond its metabolic role, lactate also acts as a crucial signaling molecule by binding to G-protein-coupled receptor 81 (GPR81), mediating a wide range of physiological effects through the inhibition of protein kinase A (PKA). The present study investigated novel regulatory mechanisms of MCT1 internalization, which depend on GPR81 signaling and PKA activity in primary rat podocytes, through the biotinylation assay. Surprisingly, both PKA inhibition (with H89 and PKI 14–22) and activation (with 8-bromo-cAMP and H₂O₂) increased MCT1 internalization. GPR81 was also found to regulate MCT1 membrane trafficking, likely through the modulation of PKA activity but also potentially through PKA-independent mechanism. Additionally, general dynamic changes in endocytic activity were detected under the present conditions with pHrodo-dextran fluorescence analysis. These results suggest that the modulation of PKA activity and GPR81 signaling may regulate lactate transport via MCT1, thereby ensuring its proper metabolic function in podocytes. Full article

Clays are increasingly incorporated as feed additives for ruminants, partly inspired by animals’ natural geophagic behaviour. However, their effects on rumen function and productivity remain inconsistent in the literature. This meta-analysis synthesised 39 controlled studies (73 treatment means) to quantitatively evaluate the effects of clay supplementation on fermentation, digestibility, metabolic health, and productivity. Clay supplementation improved rumen fermentation efficiency, as indicated by reductions in methane emissions (−20.45%; p < 0.001) and ammonia-N (−11.51%; p = 0.033), along with an increase in propionate production (+4.35%; p = 0.046). These findings are consistent with proposed mechanisms not directly evaluated in this meta-analysis. Total volatile fatty acid concentration (+3.25%; p = 0.20) and rumen pH (+0.25%; p = 0.75) were not significantly altered by clay supplementation. Digestibility responses were moderately improved, particularly for neutral detergent fibre (+7.32%; p = 0.011) and organic matter (+3.06%; p < 0.001). These improvements may reflect enhanced microbial colonisation and substrate utilisation. Blood urea nitrogen decreased (−5.64%; p = 0.002) with minimal systemic effects, consistent with a primarily rumen-localised mode of action. These responses were associated with increases in weight gain (+7.96%; p = 0.002) and milk fat yield (+9.19%; p = 0.030). Meta-regression identified inclusion level and clay type as significant sources of variability (p < 0.05 for multiple outcomes). The findings indicate that clay supplementation supports methane abatement while improving rumen fermentation, digestibility, health, and productivity in ruminants. Full article

Atrial fibrillation (AF) and heart failure (HF) frequently coexist, but the clinical relevance of AF may differ according to whether it appears to be a potentially reversible contributor, an aggravating factor in established HF, or a marker of advanced substrate. The driver–modifier–marker lens used in this review is a provisional, nonvalidated aid to clinical reasoning and should not be interpreted as a treatment score. This narrative review was informed by dated searches of PubMed/MEDLINE, the Cochrane Library, and OpenAlex through 29 July 2026, followed by a targeted update on 30 July 2026. It considers HF with reduced, mildly reduced, and preserved ejection fraction together with AF timing, burden, ventricular-rate exposure, myocardial substrate, and reversibility. Early rhythm control may be particularly relevant when AF is recent or temporally associated with ventricular dysfunction, symptoms, decompensation, or inadequate cardiac resynchronization therapy delivery. Evidence supporting catheter ablation is most direct in suspected AF-mediated cardiomyopathy and selected HFrEF populations, whereas evidence in HFpEF more consistently supports symptom relief, improved exercise hemodynamics, and AF-burden reduction than mortality reduction. Pulmonary vein isolation remains the procedural foundation. Radiofrequency, cryoballoon, and pulsed-field ablation are effective in broad AF populations, but HF phenotype-specific prognostic superiority has not been established for any energy source. Clinical decisions should reflect the design and directness of the evidence together with expected benefit, rhythm durability, procedural risk, patient-reported outcomes, stroke prevention, guideline-directed HF therapy, risk-factor management, and patient preference. Full article

We investigate the dynamic magnetic properties of an epitaxial Co₂₅Fe₇₅ thin film grown on a MgAl₂O₄ (001) substrate using broadband ferromagnetic resonance (VNA-FMR). The film exhibits a pronounced fourfold symmetry of the resonance field, characteristic of cubic magnetocrystalline anisotropy. By combining broadband and angular-dependent FMR measurements, we determined a spectroscopic g-factor of 2.083 ± 0.017, an effective magnetization of 1655 ± 31 kA/m, and a cubic magnetocrystalline anisotropy field of 28.25 ± 0.22 mT. Beyond the expected angular dependence of the resonance field, we experimentally demonstrated a pronounced flattening of the frequency versus magnetic field dependence for magnetic field direction located between the principal crystallographic axes. The effect, predicted by conventional ferromagnetic resonance theory but not previously investigated in detail, originates from the equilibrium rotation of the magnetization and is quantitatively described within the Stoner–Wohlfarth framework. For ${\varphi }_H$ = 34°, the resonance frequency remained nearly constant over the magnetic field interval from 6.8 to 26.2 mT at room temperature. A comparison with other (001)-oriented epitaxial magnetic films revealed that similar frequency plateaus can occur over frequencies ranging from 0.9 to 12.35 GHz and over magnetic field intervals from 0.5 to 63 mT. These findings establish a route toward microwave devices that are insensitive to fluctuations in the applied magnetic field and motivate further studies of spin-wave dynamics in this regime. Full article

Superhydrophobic SiO₂ nanofibers were deposited on copper foam substrates via micro/nano surface modification to improve the pool boiling heat transfer performance of porous copper media. By adopting an electrospinning technique, uniform and robust superhydrophobic SiO₂ nanofibers were firmly deposited on copper foam skeletons, forming interconnected porous structures with intrinsic superhydrophobic characteristics. The fabricated superhydrophobic nanofiber structures greatly reduce bubble nucleation resistance and provide sufficient stable vaporization sites, effectively promoting boiling heat transfer enhancement. Experimental results verify that surface modification with superhydrophobic SiO₂ nanofibers significantly improves the overall boiling performance of copper foam. The sample with a nanofiber loading of 1.8 mg achieves the optimal thermal performance, presenting lower wall superheat, higher critical heat flux, and an improved heat transfer coefficient. CFD simulations were conducted, and the numerical results exhibit good consistency with experimental measurements. Full article

The development of bioactive hybrid coatings for biomedical implants requires materials exhibiting suitable thermal stability, bioactivity, and biocompatibility. In this study, hybrid organic–inorganic sol–gel coatings based on silica (SiO₂) and polyethylene glycol (PEG, 24 wt%) were functionalized with different concentrations of caffeic acid (CafA 5, 10, and 15 wt%) and deposited onto AISI 304 and AISI 316 stainless steel substrates by dip-coating without surface pre-treatment. The proposed approach enabled the formation of homogeneous hybrid coatings on untreated stainless steel substrates through a simple and scalable deposition process. A thermal analysis demonstrated the stability of the hybrid network and the effective integration of the organic and inorganic phases. Bioactivity was evaluated by in vitro immersion in simulated body fluid (SBF), while SEM observations revealed the formation of mineral deposits on the coating surface, and an EDX analysis confirmed the presence of calcium and phosphorus within the deposited layer. The formation of crystalline hydroxyapatite (HA) was subsequently confirmed by X-ray diffraction (XRD), confirming that all investigated formulations retained their ability to induce apatite formation after SBF immersion. In addition, in vitro biocompatibility assays confirmed that the developed materials exhibited concentration-dependent cytocompatibility, with the cellular response being influenced by the amount of incorporated CafA. Overall, the results demonstrate that the proposed hybrid materials combine thermal stability, bioactivity, and cytocompatibility, highlighting their potential as bioactive coatings for biomedical applications. Full article

Fe-Al intermetallic coatings were fabricated on 0Cr21Al6Nb stainless steel by pack cementation to systematically investigate the effects of temperature (650–800 °C) and holding time (2–16 h) on the coating microstructure, phase constitution, and hardness. The coatings primarily consisted of Fe₂Al₅, with a minor amount of FeAl₃ confined to the outermost surface. The coating/substrate interface exhibited a characteristic serrated or tongue-like morphology, which became increasingly pronounced with increasing temperature and holding time, indicating enhanced interdiffusion across the interface. Both increasing temperature and prolonging holding time markedly promoted coating growth and increased the coating thickness, while simultaneously facilitating the enrichment of FeAl₃ in the near-surface region. Despite these microstructural variations, the coating hardness remained relatively stable at approximately 960 HV, which was substantially higher than that of the substrate; meanwhile, the substrate exhibited a slight reduction in hardness after aluminizing. Thermodynamic analysis revealed that Fe₂Al₅ was preferentially formed owing to its relatively lower Gibbs free energy, and its formation remained thermodynamically favored during subsequent coating growth, whereas FeAl₃ was restricted to the coating surface. Kinetic analysis demonstrated that coating growth followed a parabolic law, indicating a diffusion-controlled growth mechanism, with an apparent activation energy of 107.5 kJ·mol⁻¹ for Al diffusion. Furthermore, temperature exerted a more pronounced influence on coating growth than holding time, highlighting temperature as the dominant kinetic parameter governing the formation and thickening of the Fe-Al intermetallic coating. Full article

To investigate how the position and thickness of ultrathin Al interfacial layers regulate the optoelectronic properties and temporal stability of AZO/Cu/AZO multilayer films, AZO/Cu/AZO (ACA), AZO/Al/Cu/AZO (AACA), and AZO/Al/Cu/Al/AZO (AACAA) multilayers were deposited on glass substrates by magnetron sputtering. For clarity, the stack notation is given from the film surface toward the substrate. AACA contains a 1 nm Al interfacial layer above Cu, whereas AACAA-1 and AACAA-2 contain Al layers on both sides of Cu with top/bottom thicknesses of 1/1 and 2/1 nm, respectively. The effects of Al layer insertion position and thickness on the microstructure, optoelectronic properties, and temporal stability were systematically investigated. The ACA and AACA films exhibited ZnO and Cu phases with preferred ZnO (002) and Cu (111) diffraction, respectively. The AACA film showed the best initial optoelectronic performance, with the average transmittance increasing from 75.9% to 85.7% and the sheet resistance decreasing from 18.5 to 6.7 Ω/sq, yielding a figure of merit (F_OM) of 3.2 × 10⁻² Ω⁻¹. After the additional Al layer was introduced beneath Cu, the Cu (111) signal became very weak and the sheet resistance increased markedly, indicating a substantial change in the structural and interfacial state of the ultrathin Cu layer. After two years of air exposure, pronounced Cu-O-rich particles were observed on the ACA surface, and the relative changes in average transmittance and sheet resistance reached 10.7% and 95.7%, respectively. In contrast, the corresponding changes for AACAA-2 were only 1.2% and 2.7%, demonstrating the best temporal stability. These results reveal a clear trade-off between initial optoelectronic performance and long-term stability and show that dual Al interfacial modification is an effective route for stabilizing AZO/Cu/AZO multilayer electrodes. Full article

Arachidonic acid (AA) is a high-value long-chain polyunsaturated fatty acid commonly produced by submerged fermentation of oleaginous fungi. Solid-state fermentation (SSF) using low-cost agro-industrial by-products represents a promising alternative approach for sustainable microbial lipid production. In this study, spent malt, a by-product of the brewing industry, was evaluated as a solid substrate for AA production by Mortierella alpina under SSF conditions. Four M. alpina strains were screened for growth, lipid accumulation, and AA production, and M. alpina 959 was selected as the most promising strain. The effects of nitrogen supplementation and oil incorporation on biomass formation, lipid accumulation, and AA productivity were subsequently investigated. Sunflower oil incorporation into spent malt-based substrates improved AA productivity under the most favorable conditions, resulting in an AA proportion of 38.6% of total fatty acids and 102.5 mg AA g⁻¹ of final dry mass of the SSF system (FDW-SC). Comparison of selected vegetable oils further demonstrated that the lipid source affected AA production, while having only a limited effect on fungal growth and total lipid accumulation. Overall, this study demonstrates the feasibility of spent malt-based SSF for AA production by M. alpina and highlights the valorization of brewery spent malt as a low-cost agro-industrial by-product for the production of value-added microbial lipids. Full article

Mechanical force offers a distinctive nonequilibrium mode of energy input for lignocellulosic biomass valorization through localized, transient action. This review systematically examines the multiscale physicochemical effects of mechanical force, its synergistic coupling with chemical pretreatments, and its role in enhancing enzymatic hydrolysis. The principal contribution of mechanical force is not merely particle-size reduction, but the exposure of active sites and improvement in substrate accessibility at the molecular level. Coupling mechanical force with chemical pretreatment enables the efficient component fractionation under mild conditions while mitigating irreversible lignin condensation. In high-solids enzymatic hydrolysis, a periodic mechanical energy input can tear fiber bundles, release constrained water, and renew reaction interfaces, thereby allowing enzymes to sustain a high catalytic efficiency at extremely low liquid-to-solid ratios and reducing the dependence on large amounts of free water. An economic analysis indicates that feedstock and enzyme costs dominate the overall process economics. Accordingly, mechanical-force strategies should prioritize the maximized sugar yield and reduced enzyme loading under a controlled energy input. Future research should focus on continuous operation, the balance between mechanical deconstruction and lignin structural integrity, and multidimensional evaluation frameworks that integrate the energy consumption, sugar yield, enzyme dosage, and full-process energy balance. Full article

Embedded 3D printing of hydrophilic hydrogels in aqueous support baths often suffers from filament deformation, positional deviation, and diffusion before complete cross-linking, while practical parameter-selection guidelines for specific material systems remain limited. In this work, an integrated engineering evaluation method was developed to characterize filament formation and early-stage evolution during embedded printing of gelatin/sodium alginate inks in Carbomer support baths. Filament quality was assessed using cross-sectional geometry, contour irregularity, deposition position, and early-stage diffusion ratio. The effects of printing kinematics and material rheology are systematically examined to establish a practical process window for this hydrophilic ink–bath system. The results show that the speed ratio between substrate and ink is a primary factor controlling filament geometry and deposition position, and a ratio close to 1 yields the most balanced cross-sectional morphology without position shift from the printed nozzle. Ink with high viscosity maintains contour irregularity within a narrow range of 0.005–0.009 and suppresses early diffusion, whereas a support bath with high viscosity and ink with high viscosity combination further slows diffusional evolution by about 70%. Based on the identified process window, several three-dimensional hydrogel structures were fabricated successfully. The proposed workflow provides a practical route for process evaluation and parameter selection in hydrophilic embedded printing, especially for continuous filament and tubular structures, and offers engineering guidance for bio-soft material fabrication in applications. Full article