Oxidation Resistance Research Articles

Brucellosis, a globally significant zoonotic disease caused byBrucellainfection, relies on the pathogen's ability to invade and replicate within host cells. This intracellular replication is tightly regulated by transcriptional networks, including the LysR-family regulator VtlR, which is critical forB. abortusvirulence but whose role in B. melitensis remains unclear. Here, we constructedvtlRmutant and complemented strains in B. melitensis M5 and demonstrated that VtlR is essential for virulence. Phenotypic assays revealed that vtlR deletion impaired bacterial growth on L-fucose, D-glucose, and meso-erythritol, increased sensitivity to hydrogen peroxide and sodium nitroprusside, and reduced intracellular survival in RAW264.7 macrophages while triggering reactive oxygen species (ROS) production. RNA-seq and RT-qPCR analysis indicated that VtlR positively regulates small RNA AbcR2 and three DUF1127-domain proteins (RS13565, RS04310, RS13280), mirroring its regulatory role inB. abortus. However, overexpression of these targets failed to restore virulence in thevtlRmutant. Notably, the mutant strain elicited protective immunity in mice, suggesting its potential as a live-attenuated vaccine candidate. Collectively, this study elucidates the VtlR regulon inB. melitensis, advancing our understanding ofBrucellapathogenesis and vaccine development.

This study developed a method of fabricating heatable textiles using silver (Ag) and copper (Cu) nanowires (NWs) and various textile substrates (knit silk, rayon, silk scarf, poplin and polyester) using a repeated dip-and-dry process. The effects of substrate type, nanowire material, and processing conditions on electrical and thermal performance were systematically investigated. Among the five tested fabrics, poplin—characterized by its plain weave structure and high fabric density—exhibited the lowest sheet resistance and was selected for detailed thermal analysis. Cu nanowires showed rapid degradation due to surface oxidation, resulting in a complete loss of conductivity within 18 seconds of ambient exposure. In contrast, Ag nanowires formed uniform conductive networks with excellent oxidation resistance, enabling stable and reliable Joule heating. The AgNW-coated poplin demonstrated a rapid thermal response, reaching 90% of the target temperature within 12 seconds under 5?V, with less than 0.5% deviation during steady-state operation. The heating behavior remained stable over repeated on/off cycles and during 10,000 minutes of continuous operation, with only minor decreases of 3.5% in temperature and 4.0% in current. Furthermore, consistent heating performance was maintained under mechanical deformation such as twisting and folding. In this study, AgNW-coated poplin demonstrated the most stable Joule heating performance among the tested textile substrates, which is attributed to the intrinsic oxidation resistance of Ag and the plain weave structure of the poplin substrate.

ABSTRACT Refractory high‐entropy alloys (RHEAs) offer high strength at extreme temperatures but suffer from poor oxidation resistance. The Ta‐Mo‐Cr‐Ti‐Al system shows promising oxidation resistance due to protective (Cr,Ti,Ta)O₂ scale formation. This study investigates how varying Cr:Ti ratios (2:1, 1:2, and equimolar) affect microstructure and oxidation behavior in Ar‐5 vol.%H₂O and Ar‐2.5 vol.%O₂ atmospheres at 1000°C. Titanium influences oxide defect structure through its valence state, controlling oxygen transport kinetics. Results demonstrate strong atmosphere‐dependent performance: Cr‐rich alloys excel in dry oxygen due to continuous chromia formation and reduced oxygen diffusion zones, while Ti‐rich alloys perform superior in humid conditions, likely due to hydrogen uptake effects and reduced chromium volatilization. The study reveals that optimal oxidation resistance requires atmosphere‐specific compositions, with microstructural factors (Laves phase distribution) playing equally important roles as oxide defect chemistry in determining overall performance.

Titanium is widely used in aerospace and medical industries for its high strength-to-weight ratio and corrosion resistance, while Inconel 718 is favored in aerospace and power generation for its exceptional mechanical strength and oxidation resistance at high temperatures. It’s challenging to directly combine the Inconel 718 and the titanium, so the interlayer of vanadium is used which causes the strengthening of the bond by the formation of inter-metallics (TiaNib, NixVy). In this study, the RVE model was developed in order to examine the mechanical properties (i.e. Modulus, Poisson ratio) of the inter-metallics, by examining their microstructures. Furthermore, nanoindentation techniques are employed across different zones of the weldment to determine the modulus and hardness values. At the vanadium-Inconel interface, hardness and modulus values were observed to range from 2 to 8.5GPa and 130 to 205GPa respectively. The maximum error in hardness between the experimental and simulation was 3.75%. The pile up behavior was also examined in the simulation setup to determine the amount of plastic zone in the indent.

Staphylococcus aureus, an opportunistic pathogen of global health concern, presents a significant clinical challenge due to its escalating antibiotic resistance and biofilm-forming capacity. The biofilm matrix of S. aureus is enriched with carotenoids, primarily staphyloxanthin (STX), which function as virulence factors by scavenging reactive oxygen species and inhibiting antimicrobial peptides. In this study, we examined the impact of the methanol extract of S. aureus (MES) on biofilm formation. Our findings revealed that MES enhanced biofilm formation in S. aureus strains with inherently weak biofilm-forming ability by upregulating key adhesion genes (fibronectin-binding protein A/fnbB, serine-aspartate repeat-containing protein D, clumping factors A/B, elastin-binding protein, and fib) and downregulating autolysis-associated genes (lytR and lrgA). Furthermore, MES augmented the resistance of these strains to whole blood-mediated killing and improved their antioxidant capacity. To elucidate the role of STX, methanolic extracts were prepared from crtM and crtN mutants of the USA300 LAC strain and applied to biofilm-impaired strains. These experiments provided indirect evidence that STX in the methanolic extract is a critical mediator of biofilm promotion in vitro. Collectively, our results suggest a potential mechanistic link between STX in S. aureus methanolic extract and biofilm formation, offering novel insights for therapeutic strategies against S. aureus infections.IMPORTANCEOur findings demonstrate that the methanolic extract of S. aureus, predominantly comprising STX, augments biofilm formation and antioxidant capacity in vitro. These results not only offer novel insights into potential therapeutic strategies for S. aureus infections but also underscore the potential role of microbial secondary metabolites in interstrain interactions.

Ti65 high-temperature titanium alloy, known for its exceptional high-temperature mechanical properties and oxidation resistance, demonstrates considerable potential for aerospace applications. Nevertheless, conventional manufacturing techniques are often inadequate for achieving high design freedom and fabricating complex geometries. This study presents a systematic investigation into the process optimization, microstructure characterization, and mechanical performance of Ti65 alloy produced by laser powder bed fusion (LPBF). Via meticulously designed single-track, multi-track, and bulk sample experiments, the influences of laser power (P), scanning speed (V), and hatch spacing (h) on molten pool behavior, defect formation, microstructural evolution, and surface roughness were thoroughly examined. The results indicate that under optimized parameters, the specimens attain ultra-high dimensional accuracy, with a near-full density (>99.99%) and reduced surface roughness (Ra = 3.9 ± 1.3 μm). Inadequate energy input (low P or high V) led to lack-of-fusion defects, whereas excessive energy (high P or low V) resulted in keyhole porosity. Microstructural analysis revealed that the rapid solidification inherent to LPBF promotes the formation of fine acicular α′-phase (0.236–0.274 μm), while elevated laser power or reduced scanning speed facilitated the development of coarse lamellar α′-martensite (0.525–0.645 μm). Tensile tests demonstrated that samples produced under the optimized parameters exhibit high ultimate tensile strength (1489 ± 7.5 MPa), yield strength (1278 ± 5.2 MPa), and satisfactory elongation (5.7 ± 0.15%), alongside elevated microhardness (446.7 ± 1.7 HV0.2). The optimized microstructure thereby enables the simultaneous achievement of high density and superior mechanical properties. The fundamental mechanism is attributed to precise control over volumetric energy density, which governs melt pool mode, defect generation, and solidification kinetics, thereby tailoring the resultant microstructure. This study offers valuable insights into defect suppression, microstructure control, and process optimization for LPBF-fabricated Ti65 alloy, facilitating its application in high-temperature structural components.

Copper nanowires (CuNWs) are promising for flexible transparent electrodes but suffer from lack of effective strategies to inhibit the oxidation-induced conductivity degradation, especially during large-area electrode preparation. Herein, a benzotriazole-functionalized ionic liquid ([BTAMMIM]TFSI) is introduced as an antioxidant layer to protect the CuNWs networks. Remarkably, the sheet resistance of the protected electrodes increases by only 0.54% compared to bare CuNWs after 60-day air exposure. Density functional theory (DFT) calculations and experiments reveal that the benzotriazole-functionalized cations and [TFSI] anions synergistically coordinate with copper, enabling exceptional oxidation resistance. By integrating with superwettability-assisted interfacial transfer strategy, large-area CuNWs@[BTAMMIM]TFSI composite electrodes (40 × 25 cm2) are fabricated with 37.2 Ω sq-1 sheet resistance and 88.2% transmittance (550nm). The electrodes maintain performance under acidic/alkaline conditions (pH 3/13) and high humidity (85% RH) at 85 °C. A demonstrated flexible smart window exhibits high transmittance modulation (6.1%-68.2%), fast response (< 0.2 s) and long-term stability, highlighting their potential in flexible optoelectronics.

High-density polyethylene (HDPE) is a valuable material, but its application under certain operational conditions is limited by oxidation resistance. To mitigate this, rice husk ash (RHA), a silica-rich (~95%) byproduct, was incorporated as a reinforcing filler. This study evaluates the effect of electron beam (EB) irradiation, at doses up to 100 kGy, on the properties of HDPE/RHA composites, focusing on mechanical performance and the polymer–filler interface. The results demonstrate that EB irradiation induces crosslinking and enhances interfacial interaction between the HDPE matrix and RHA filler. While the overall tensile strength of neat HDPE tended to decrease with irradiation dose (from 28.5 ± 1.2 MPa to 24.1 ± 1.5 MPa at 100 kGy), the optimization of dose and filler contents produced notable results: A maximum tensile strength of 29.0 ± 1.1 MPa was achieved in the composite containing 5 wt% RHA at 75 kGy. Furthermore, irradiation stabilized the material’s behavior, resolving the heterogeneous dispersion observed in non-irradiated samples with low RHA content. Regarding toughness, Izod’s impact resistance increased from 3.2 ± 0.2 kJ/m2 to 3.7 ± 0.3 kJ/m2 for the 10 wt% RHA composites irradiated at 50 kGy. Statistical analysis (ANOVA, p &lt; 0.05) confirmed the significance of these changes. In conclusion, electron beam irradiation is an effective tool for optimizing the mechanical properties and performance uniformity of HDPE/RHA composites, making them promising candidates for applications requiring enhanced durability and consistency, such as food packaging.

Enhancing the energy conversion efficiency of fuel cells necessitates optimization of oxygen reduction reaction (ORR) under high-voltage conditions through improved Pt catalysis. This study introduces an electrocatalyst that uniformly anchors a high loading (40 wt%) of small Pt nanoparticles (3.2nm) on a novel support: tellurium and nitrogen co-mediated graphitized mesoporous carbon (Te-N-GMC). The strong metal-support interactions arise from Pt─Te and Pt─N bonds. Density functional theory (DFT) calculations and operando X-ray absorption spectroscopy reveal that Te-N co-mediation enhances the high-voltage oxidation resistance of Pt via electron reverse transfer from the Te-N-GMC support to Pt. Consequently, the Pt valence state in Pt/Te-N-GMC increases by only +0.085 from open-circuit potential to 1.5V, resulting in exceptional durability over 100000 high-voltage cycles (1-1.5V) with negligible morphological aggregation. Moreover, the Te-N-GMC support effectively lowers the energy barrier of the rate-determining step, enabling Pt/Te-N-GMC to achieve outstanding activity (0.7V at 1.26 A cm-2 under H2-air conditions). This translates to an 18.6% increase in electrical efficiency compared with commercial Pt/C at the same output power density. These findings demonstrate the potential of Te-N-GMC as a robust cocatalyst for high-voltage ORR and highlight a promising strategy for enhancing Pt catalysis for high-efficiency fuel cells.

MXene represents a promising class of two-dimensional carbides and nitrides of transition metals. Due to their unique combination of high electrical conductivity, large specific surface area, hydrophilicity, and tunable surface chemistry, they have attracted significant scientific interest. These properties enable the application of MXenes in energy storage systems, sensors, electrocatalysis, filtration, and environmental remediation. However, their susceptibility to oxidation and insufficient long-term stability remain major challenges for practical use.To address these limitations, silicon-based modifications – specifically involving Si, SiO₂, and SiOx – are proposed as effective strategies for enhancing the structural stability of MXenes. This review analyzes functionalization methods employing silicon-containing components, including sol–gel synthesis, the Stöber method, chemical vapor deposition (CVD), atomic layer deposition (ALD), and sputtering techniques. Silicon modification improves oxidation resistance, thermal stability, surface area, and compatibility with composites. These enhanced properties contribute to improved performance of silicon-modified MXenes in lithium- and aluminum-ion batteries, supercapacitors, sensors, and catalysts. Additionally, their photocatalytic activity and pollutant adsorption capabilities support applications in environmental protection technologies. The review also explores sustainable and scalable strategies for integrating MXenes into future multifunctional systems.

Enhancing the oxidation resistance of copper nanoparticles (CuNPs) is a crucial objective in plasmonic photocatalytic reactions. In this study, a series of Cu/X catalysts was synthesized using semiconductor nanomaterials (X = TiO2, ZnO, BN, TiN, SiC, and C3N4) as supports for CuNPs. These catalysts were systematically evaluated in visible-light-driven photocatalytic oxidative homocoupling of phenylacetylene (OHA). Comprehensive characterization revealed distinct metal-support interactions and nanostructure evolution during repeated catalytic cycles. The photocatalytic performance, copper leaching, and structural stability of the catalysts were compared. Cu/TiO2 achieved the highest 1,3-diyne yield (up to 93%) in the first two cycles. In contrast, Cu/ZnO showed minimal copper leaching and excellent recyclability, retaining high activity over three consecutive cycles without the need for reduction pretreatment. Comparative studies revealed that the combination of localized surface plasmon resonance (LSPR) and efficient electron transfer within the Cu0-Cu2O-CuO composite was a key factor in enhancing the photocatalytic activity and stability. These findings provide new insights into the rational design of durable CuNP-based photocatalysts for visible-light-driven organic transformations.

Brass components are widely used in heat dissipation and thermal emission devices due to their high thermal conductivity and ease of processing. However, these applications demand good thermal oxidation resistance, high emissivity, and excellent corrosion resistance. In this study, nickel coatings were deposited on brass substrates by direct current electroplating, and the effects of current density and cathode configuration on the microstructure, emissivity, and corrosion resistance of the coatings were systematically investigated. The results show that the emissivity of the coatings first increased and then decreased with increasing current density. Optimal performance was achieved when the cathode and anode were positioned perpendicular to the horizontal plane at a current density of 3.0 A·dm−2. Under these conditions, the coatings exhibited a smooth, uniform, and dense microstructure, with evenly distributed metallic grains. Electrochemical polarization and impedance measurements further confirmed the superior corrosion resistance of this coating, with a minimum corrosion current density of 0.259 μA·cm−2, a maximum polarization resistance of 6381.55 Ω·cm2, and a minimum corrosion rate of 0.023 mm/a. These findings demonstrate a simple and effective approach to enhancing both the emissivity and corrosion resistance of brass substrates, offering practical value for thermal management applications.

Abstract Collagen plays a critical role in wound repair. Current recombinant collagen therapies provide exogenous collagen to the wound site; however, they fail to stimulate endogenous collagen production, which is crucial for achieving structurally integrated and durable tissue repair. To overcome this critical limitation, ionizable lipid nanoparticles (LNPs) are engineered containing nucleotide‐modified messenger RNA (mRNA) that encodes collagen. In immortalized human keratinocytes, these mRNA‐LNPs successfully expressed collagen. Functional assays of the mRNA‐LNP‐treated keratinocytes revealed cell migration rates tripled, superoxide dismutase activity increased by 40%, and proliferation is slightly enhanced. In mice, subcutaneous delivery of luciferase mRNA‐LNP showed rapid fluorescence generation (4 h postinjection) with sustained expression up to 144 h. In an 8‐mm full‐thickness wound model, collagen mRNA‐LNP‐treated tissue saw a wound area reduction of 40% at day 3 compared with 10% reduction in the control. A histological evaluation demonstrated a significant increase in neovascularization density and higher collagen depositioncompared to the control. These findings demonstrate that collagen mRNA‐LNPs accelerated wound healing through coordinated mechanisms that enhanced cell migration, oxidative stress resistance, angiogenesis, and extracellular matrix remodeling. The technology overcomes limitations of existing collagen‐based therapies by enabling endogenous protein biosynthesis, offering translational potential for dermatological applications.

The microstructural evolution and oxidation resistance at 1500 °C of Mo-Si-Cr-B coating with a Cr2Nb4Si5 layer

The oxidation resistance and plasma ablation performance at 3000 K of HfC-TiC ultra-high temperature ceramics

Improving the resistance to high-temperature oxidation of 254SMo super-austenitic stainless steel welds using ultrasonic shot peening-induced gradient nanostructures.

A new outlet for traditional antioxidants: multifunctional additives based on ionic liquid strategy toward excellent lubrication and oxidation resistance

Improved chemical and gastrointestinal stability of natural proanthocyanidins encapsulated in hydrolyzed soy protein-based nanoparticles.

Fabrication, mechanical properties, and oxidation resistance of (Nb,Ti)CN-Ni cermets with different TiC0.7N0.3 contents

Enhanced high-temperature oxidation resistance of Ni-based single crystal superalloys by laser shock peening