Search Results (332)

A series of Ni_xCo_3−xO₄ (x = 0.75, 1, 1.5, 2, 2.25) catalysts with different Ni/Co molar ratios was fabricated via the co-precipitation method. The catalytic performance for CO oxidation and SO₂ resistance of the prepared catalysts was systematically investigated, and their physicochemical properties were characterized by XRD, SEM, BET, H₂-TPR, CO-TPD and in situ DRIFTS. The experimental results reveal that the Ni₂.₂₅Co₀.₇₅O₄ catalyst exhibits the optimal CO oxidation activity, achieving a CO conversion of 93.25% at 120 °C. The superior catalytic performance can be attributed to its large specific surface area, low reduction temperature, and easily activated lattice oxygen species. When exposed to SO₂ at a concentration 10 times the industrial emission limit, all catalysts exhibited varying degrees of activity loss. Among them, NiCo₂O₄ exhibited the slowest deactivation rate and showed the greatest recovery in CO conversion after SO₂ was cut off, suggesting relatively better sulfur tolerance and recoverability among the investigated catalysts. In conclusion, tuning the Ni/Co molar ratio can effectively optimize the low-temperature CO oxidation activity and sulfur resistance of Ni-Co composite oxides. This work provides a useful reference for the structural composition design and practical application of such catalysts in flue gas purification. Full article

Layered cathodes (LiNi_xCo_yMn_zO₂, NCM) have emerged as critical materials for batteries and energy storage fields by virtue of their high energy density. However, NCM materials undergo rapid performance degradation and severe capacity fading under harsh conditions of long-term cycling and high voltage. Currently, research regarding spent NCM materials mainly concentrates on failure analysis and modification processes at the macroscopic scale. Nevertheless, the failure mechanisms of NCM, the intrinsic processes during repair and modification, and the fundamental origins of performance improvement are generally embedded in structural evolution at the nanoscale or even atomic scale. This review first discusses the failure mechanisms of NCM. Particularly, the main content focuses on lattice distortion and layered structural instability at the lattice level, migration of nanoscale species together with performance degradation induced by side reactions at the interface level, and generation of nanocracks at the particle level. Moreover, this paper reviews the characterization methods applied at the nanometer scale, and two modification strategies are summarized, namely nanoscale coating and elemental doping. It is expected to provide theoretical references and technical insights for constructing efficient and controllable targeted modification strategies of layered NCM cathodes and developing high-performance ternary cathode materials. Full article

Background/Objectives: Drug resistance is a major challenge in cancer therapy, and mitochondria contribute to this process by controlling both metabolic adaptability and cell survival signaling. Mitophagy, the selective lysosomal removal of dysfunctional mitochondria, has been implicated in therapy resistance, yet its role in sunitinib-resistant renal cancer remains poorly defined. Methods: In this study, acquired sunitinib resistance was established in ACHN renal cancer cells through eight months of stepwise dose escalation. Initial selection conditions were determined using CCK-8 viability and crystal violet colony assays in parental ACHN cells, whereas sustained proliferation under continuous sunitinib exposure was used as the operational criterion for the resistant phenotype. Resistant and parental sensitive cells were treated with 25 µM and 50 µM succinic acid, alone or in combination with sunitinib. Gene expression of BNIP3, NIX, FUNDC1, LC3, PINK1, Parkin, PGAM5, SRC, LONP1, and ATP5F1A was measured by RT-qPCR, and BNIP3 and NIX protein levels were assessed by ELISA. Results: Resistant cells showed significant upregulation of receptor-mediated mitophagy components BNIP3, NIX and FUNDC1 (p < 0.05), with no significant change in LC3, alongside suppression of PINK1, Parkin, and mitochondrial homeostasis-associated genes LONP1, PGAM5, and ATP5F1A (p < 0.05). Succinic acid predominantly reduced BNIP3 and NIX protein levels in both cell lines and suppressed BNIP3, NIX, and LC3 mRNA expression in resistant cells. In contrast, the sunitinib + 50 µM succinic acid combination selectively increased PARKIN, PGAM5, LONP1, and ATP5F1A expression in resistant cells (2.49- to 5.98-fold; p < 0.005), a pattern not observed in parental cells. Conclusions: These findings indicate that sunitinib resistance in ACHN cells is associated with upregulated transcription of receptor-mediated mitophagy components and downregulated transcription of PINK1/Parkin pathway genes, and that exogenous succinic acid selectively upregulates PARKIN and other mitochondrial homeostasis-related gene expression in resistant, but not parental, cells. Full article

Human skin tone is an important consideration in pulse oximetry and evaluating skin health conditions. Various tools are available to measure skin tone, including visual scales, palette based estimations, and optical sensor based devices. The objective of this experimental study is to compare common skin tone measurement methods. We used Fitzpatrick Skin Type (self- and observer-reported), Pantone SkinTone Guide, Delfin SkinColorCatch, and Nix Spectro 2 devices to measure the forehead skin tone of 52 participants. We compared measurements in L*a*b color space and in individual typology angles (ITA). We observed statistically significant correlation between methods, including in specific color space components (L* and ITA). Between the device measurements, we observed discrepancies in ITA values. Such discrepancies, together with a lack of standard or ground truth method, show a need for further research into skin tone measurement. We suggest in the interim that research and clinical work adopt protocols that take current methodological limitations into consideration, for example through the parallel use of different methods if applicable. Further work is needed to develop validated, reliable and consistent skin tone measurement tools. Full article

Dry reforming of methane (DRM) represents a promising route for the valorization of CO₂ captured from industrial emissions through high-temperature catalytic conversion. In this work, a LaMn_1−xNi_xO₃ perovskite catalyst (x = 0.25, 6 wt% Ni) was synthesized as a powder by solution combustion synthesis and subsequently deposited onto γ-alumina supports to obtain a structured catalyst. X-ray diffraction confirmed the formation of the perovskite structure, characterized by corner-sharing BO₆ octahedra with Ni substitution at the B-site. H₂-temperature-programmed reduction (H₂-TPR) revealed the reduction of Mn⁴⁺ and Mn³⁺ species to MnO, accompanied by the complete reduction of oxidized Ni species to metallic Ni over the investigated temperature range. Raman spectroscopy of the spent catalyst indicated negligible carbon deposition after DRM. Moreover, the Mn–O stretching band shifted from 657 cm⁻¹ in the fresh catalyst to 643 cm⁻¹ after reaction, consistent with changes in the manganese oxidation state associated with the collapse of the perovskite structure and the formation of MnO. During a 25 h stability test at 700 °C, the powdered LaMn_1−xNi_xO₃ catalyst achieved a CH₄ conversion of 75% at a WHSV of 60 L g⁻¹ h⁻¹. DRM tests performed with the structured catalyst confirmed the catalytic performance under larger-scale operating conditions and different reaction parameters, including temperature, residence time, and CH₄/CO₂ feed ratio, reaching CH₄ conversions of up to 94% at 800 °C. Full article

Background and Objectives: Achieving optimal soft-tissue aesthetics is a paramount challenge during an apicoectomy of the maxillary central incisors. This article presents a novel modification of the Eskici Vertical Flap, designed to minimize scar formation, preserve the architectural integrity of the sub-mucosal fibers, and eliminate the risk of marginal gingival recession. Methods: The Transfrenular-Single Incision (TrSI) flap is elevated via a precise two-step process. First, a sagittal incision is carried out through the mucosa along the midline of the maxillary labial frenulum. Blunt lateral tunnel preparation is then performed toward the targeted tooth apex, and a subsequent deep periosteal incision with bony contact provides localized access to the periapical lesion. Following Paraendodontic Surgical Intervention (PSI), a two-layer suturing technique is implemented: the deep layer utilizes resorbable sutures to restore periosteal integrity and reposition the basal fibers of the frenular connective tissue, while the superficial layer promotes accurate mucosal edge adaptation. Results: The surgical access provided by the TrSI flap provides clinically sufficient exposure to perform precise osteotomy, retrograde root-end preparation, and biocompatible sealing. The evaluated clinical cases demonstrated optimal healing kinetics, the complete absence of visible scar tissue, and zero marginal gingival recession. Conclusions: The TrSI flap modification constitutes a highly predictable and effective option for PSI in the aesthetically critical anterior maxilla. Although its application spectrum is primarily limited to the central incisors, its capacity to prevent aesthetic deformities warrants its consideration in selected surgical protocols. Full article

Chromium coatings with excellent corrosion resistance and strong Zr interfacial bonding are economical candidates for accident-tolerant fuel claddings. Irradiation-triggered elemental interdiffusion and interfacial voids severely degrade their service reliability. Ni alloying was introduced into the Cr matrix to obtain composite coatings with improved mechanical properties and irradiation resistance. CrNi coatings with different Ni contents were deposited using magnetron sputtering, whose microstructural features, phase composition, mechanical properties and irradiation behavior were comprehensively characterized by XRD, SEM, TEM and mechanical measurements. The pristine CrNi coatings display compact and uniform microstructural morphologies. Increasing Ni concentration significantly refines the columnar grain architecture and diminishes grain dimensions. Post-irradiation microstructural characterization reveals distinct structural evolution features of CrNi coatings with different Ni contents. Pure Cr and low-Ni coatings present enhanced XRD diffraction intensities and contain high-density irradiation-induced dislocation loops. The 27 at.% Ni coating after irradiation is indicative of irradiation-triggered local recrystallization and defect annihilation. Mechanical tests confirm that moderate Ni alloying (~17 at.%) achieves improved resistance to irradiation-induced hardening through solute–defect interaction effects, whereas excessive Ni (~27 at.%) degrades mechanical properties owing to aggravated lattice disorder, increased free volume, and soft Ni-phase dilution effects. Full article

Fuzz buttons are formed by interweaving and compacting fine metallic wires, resulting in a highly porous architecture with complex internal contact interactions. Their compressive behavior is governed by the evolution of wire–wire contacts, frictional sliding, local bending, and plastic deformation, which cannot be adequately captured by conventional homogenized models. To address this limitation, a process-informed finite element modeling approach based on virtual fabrication is proposed. First, the spatial trajectories of 24 beryllium copper wires are generated using a parametric three-dimensional weaving algorithm and smoothed by cubic spline interpolation to obtain continuous wire centerlines. The resulting preform is then virtually compacted to reconstruct the densified wire network and its contact topology. The model employs a globally controlled solid-element mesh, a penalty-based general contact algorithm, a Coulomb friction model, and an explicit quasi-static solution scheme. The size-dependent plastic response of the fine wires is further incorporated through a Nix–Gao-based correction to the constitutive relation. The model is validated against quasi-static compression experiments at compressive strains of 15%, 20%, and 25%. The relative errors in the predicted peak forces are 2.12%, 5.65%, and 6.81%, respectively, while the corresponding coefficients of determination for the force–displacement curves are 0.984, 0.970, and 0.973. The model successfully reproduces the nonlinear loading–unloading response and hysteretic energy dissipation over the investigated strain range. The proposed approach provides a physically grounded numerical framework for predicting the compressive behavior of fuzz buttons and investigating the mesoscopic mechanics of complex interwoven wire networks. Full article

Tuning the d-band electronic structure of non-noble-metal catalysts is a central strategy for an alkaline hydrogen evolution reaction (HER), yet how composition controls the d orbital in multi-Wyckoff-site layered systems remains insufficiently understood. Here, layered (Fe_1-xNi_x)₃GaTe₂ single crystals (x = 0.2–1.0) were synthesized by the self-flux method as a platform to address this question. Single-crystal XRD and EDS confirm that Ni is uniformly incorporated into the parent P6₃/mmc framework while inducing a composition-dependent lattice evolution. Electrochemical measurements in 1.0 M KOH reveal a clear volcano-shaped composition dependence, peaking at x = 0.6, where the lowest overpotential, the smallest Tafel slope (94 mV dec⁻¹), the lowest charge-transfer resistance and the largest double-layer capacitance are simultaneously reached. First-principles calculations show that Ni doping reshapes the Fe-site d orbital strongly composition-dependent rate: the Fe d-band center upshifts rapidly by ~0.5 eV between x = 0.4 and x = 0.6, while the Ni d-band center stays nearly fixed in the same composition range. The maximum of HER activity therefore aligns with a steep upshift of the Fe d-band center rather than with the Ni content itself. Charge-density mapping of (Fe_0.4Ni_0.6)₃GaTe₂ further demonstrates that the electron-enriched regions are located on the Fe and interlayer Ni3 sublattices that dominate the d states near E_F. Full article

This study presents a numerical investigation of a slit fin-enhanced phase change material (PCM)-based battery thermal management system (BTMS) for an 18650 cylindrical LiNi_xCo_γMnzO₂ lithium-ion battery. The proposed design modifies the conventional solid rectangular external fins by introducing four longitudinal slit fins with uniformly distributed rectangular through-thickness slot cutouts along the fin height. This modification increases the PCM-fin interfacial contact area and creates additional natural convective heat dissipation pathways from the PCM region to the ambient environment while maintaining the same BTMS envelope, PCM thickness, fin count, housing geometry, and material selection as the validated rectangular-fin baseline. The lumped-capacitance thermal model was used for battery heat generation, while the enthalpy-porosity approach was employed to model PCM melting. Simulations were performed in ANSYS Fluent 2024/R2 at 1C, 3C, 5C, and 7C discharge rates at an ambient temperature of 308.15 K. Paraffin wax PCM with a latent heat of approximately 240,000 J/kg was used. The rectangular fin model was first validated against the baseline study, achieving an average cell wall temperature error of 1.03% and a maximum error of 1.47% at 5C, while the total temperature and liquid fraction deviations remained below 0.73%, confirming the reliability of the numerical model. Mesh independence and temporal convergence studies further confirmed that the selected 0.50 mm polyhedral mesh and 0.5 s time step provided accurate and stable results. The results demonstrate that the slit fin geometry provides metric-dependent improvements in PCM utilization, thermal protection duration, and high-rate latent-heat activation rates. At 1C, both configurations remained well below the 318.15 K safety threshold, but the slit fin configuration maintained approximately 0.7 K lower total temperature at 2500 s and delayed PCM melting by about 300 s compared with rectangular fins, preserving more latent heat capacity for later thermal loading. At 3C, the slit fin design extended the thermal protection duration from 1650 s to 2500 s, corresponding to a 51.5% improvement, and increased PCM latent heat utilization from LF = 0.42 to LF = 0.49, representing a 16.7% increase. At 5C, slit fins initiated PCM melting approximately 3.5 times earlier, around 100 s, compared with 350–400 s for rectangular fins, and reached LF = 0.50 at 620 s, whereas rectangular fins reached only LF = 0.37 at 1480 s. This corresponds to approximately 2.87 times faster PCM utilization and 35.1% greater PCM melting. At 7C, the slit fin system again showed stronger PCM engagement, corresponding to 35.7% greater PCM utilization. Temperature and liquid fraction contours confirmed that the slit openings intensify localised PCM melting near the heat source, improve heat spreading through the PCM domain, and support natural convection-assisted melting. Overall, the slit-fin geometry provides a geometry-based enhancement for PCM utilization and thermal protection without changing system size or material selection for PCM-based BTMSs, improving latent heat utilization and thermal protection without increasing system size, PCM volume, or material complexity. Full article

Camelliasaponins, bioactive constituents abundant in the by-products of Camellia oleifera oil production, exhibit diverse biological activities. However, their potential in regulating neuroprotective mitophagy remains largely unexplored. This study identifies camelliasaponin B1 (CSB1) as an abundant component in C. oleifera seeds and investigates its cytoprotective mechanisms against oxidative stress. Using an in vitro model of H₂O₂-induced oxidative damage in PC12 cells, we found that CSB1 pretreatment significantly alleviated oxidative stress, as evidenced by reduced reactive oxygen species (ROS) accumulation and enhanced antioxidant enzyme activities (SOD, CAT, GSH-Px). CSB1 also preserved mitochondrial function, restoring membrane potential (ΔΨm), ultrastructure, and respiratory capacity. Mechanistically, CSB1 reduces the expression of BNIP3/NIX-LC3B pathway-related proteins, suggesting a modulatory effect on mitophagy, as supported by transcriptomic analysis, Western blotting, and immunofluorescence. Molecular docking computationally predicted potential interactions between CSB1 and BNIP3/NIX proteins, which require experimental validation. Collectively, these findings suggest that CSB1 acts as a cytoprotective agent that enhances antioxidant defenses, safeguards mitochondrial integrity, and is associated with reduced BNIP3/NIX-LC3B expression and co-localization, offering a potential molecular basis for its development as a neuroprotective agent targeting oxidative stress-related mitochondrial dysfunction. Full article

In this study, an electrochemical system for methane conversion was developed, employing Ni- and Ce-doped LaCoO₃ perovskite as the anode catalyst in an Na₂CO₃ electrolyte. Structural characterization revealed that the La_1−yCe_yCo_1−xNi_xO₃ (x = 0–0.5, y = 0–0.12) synthesized by the sol–gel method maintains the perovskite structure, but is rich in oxygen vacancies. Electrochemical studies revealed that the performance of methane activation is related to the presence of Ni(III) in the catalyst, and reactive oxygen species (•OH and HOO⁻) are provided through water oxidation reactions (WOR) in the Na₂CO₃ electrolyte. The electrocatalytic performance of the synthesized La_0.92Ce_0.08Co_0.5Ni_0.5O₃ during methane conversion was verified in an electrolysis cell, and ethanol and acetic acid were identified as the methane conversion oxygenates. Under ambient conditions, the formation rate of ethanol reached 577.0 μmol g_cat⁻¹ h⁻¹ at 0.90 V (vs. Ag/AgCl) in 0.5 mol L⁻¹ Na₂CO₃. The catalyst was found to retain structural integrity and sustain catalytic activity over multiple reaction cycles. Full article

Oxidative stress is a major contributor to neuronal apoptosis and subsequent neurofunctional deficits. This study investigates the dual role of the mitochondrial membrane-anchored protein NIX in PC12 cells, a model for mature neurons. We demonstrate that both overexpression and knockdown of NIX attenuate apoptosis under oxidative stress, albeit through distinct mechanisms. Overexpression of NIX promotes cell survival by activating NIX-mediated mitophagy, which clears damaged mitochondria and intracellular reactive oxygen species (ROS), thereby maintaining redox homeostasis. Conversely, knockdown of NIX reduces apoptosis primarily by diminishing the intrinsic pro-apoptotic function of the protein. Collectively, these findings reveal that NIX expression levels critically gate PC12 cell fate under oxidative stress by differentially activating pro-survival or anti-apoptotic pathways. Full article

The development of high-performance cathode materials represents a crucial strategy for enhancing the overall electrochemical performance of aqueous alkaline zinc batteries. The rational design of electrode microstructure and chemical composition can synergistically boost the electrochemical reaction activity, ion/electron transport kinetics, and structural stability. In this work, a composite cathode material, FLG@Ni_xS₆/Co₄S₃/Ni-Co(OH)₂, was successfully synthesized via an electrochemical codeposition method. The engineered architecture offers abundant electrochemically active sites, well-defined ion diffusion pathways, and continuous electron conduction networks. Moreover, the strong interaction among the constituent phases effectively regulates and accelerates the redox reaction kinetics. When integrated into an aqueous alkaline zinc battery, the device attains a high specific capacity of 385 mAh g⁻¹ at 2 A g⁻¹, excellent rate capability (287 mAh g⁻¹ at 80 A g⁻¹), a gravimetric energy density of 590 Wh kg⁻¹, a power density of 128.57 kW kg⁻¹, and remarkable cycling stability, with 100% capacity retention maintained after 20,000 cycles. Overall, this study proposes a scalable and rational composite strategy for designing high-performance electrode materials for next-generation electrochemical energy storage systems. Full article

Metallic glasses can be transformed into nanocrystalline–amorphous alloys via controlled crystallisation with fast nucleation and slow grain growth. This can be achieved either through appropriate chemical composition of amorphous precursors or by applying ultra-rapid annealing (URA). Typically, heating between preheated copper blocks is used to ensure the URA conditions. In this work, ribbons were heated by an electric current flowing along their length, and the temperature was monitored using pyrometers. The investigated alloys were Fe_86-xNi_xB₁₄ (at. %), where x = 4, 6 or 10. Properly adjusted isothermal annealing at 380–410 °C for 1–20 s induced crystallisation, with the nanocrystalline bcc-Fe(Ni) phase occupying 0–55% of the volume. With increasing annealing time, the coercive field increased from 9 A/m in the amorphous state to 25 A/m and 17 A/m for x = 4 and x = 10, respectively. Transmission electron microscopy confirmed that samples annealed at higher temperatures for shorter times exhibited smaller grain sizes compared to those annealed at lower temperatures for longer times, which resulted in improved magnetic softness. An increase in nickel content reduced coercivity, improved ductility, and offered a wider window for the choice of annealing temperature. Full article