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In this report, CoFe2O4/Polypyrrole (PPy)/Pd ternary composite nanofibers are fabricated through a one-step redox reaction between pyrrole and Na2PdCl4 in the presence of electrospun CoFe2O4 nanofibers in ethylene glycol (EG). The generation of Pd nanoparticles is accompanied by the formation of PPy on the surface of electrospun CoFe2O4 nanofibers during the redox reaction. The as-prepared CoFe2O4/PPy/Pd composite nanofibers may be used as efficient catalysts for the p-nitrophenol hydrogenation with an apparent rate constant ( kapp) of about 13.2 × 10−3 s−1. The CoFe2O4/PPy/Pd composite nanofibers show good magnetic properties, which can be readily recycled under an external magnetic field. [ABSTRACT FROM AUTHOR]

Plasma alloying technique capable of producing metallic coatings with metallurgical bonding has attracted much attention in dental and orthopedic fields. In this study, the effects of temperature and time of plasma tantalum (Ta) alloying technique on the mechanical, electrochemical, and osteoblastic properties of Ta coatings were systematically investigated. Ta coatings prepared at 800 °C possess better interfacial strengths than those prepared at 750 and 850 °C, and the interfacial strength increases with prolonged alloying time (30–120 min). At 800 °C, however, the increased proportion of the soft Ta deposition layer with alloying time in the whole coating impairs the surface mechanical properties of the entire coating, as convinced by decreased microhardness and wear resistance. Moreover, Ta coatings exhibit better corrosion resistance than the Ti6Al4V substrate in Dulbecco's modified Eagle medium. The enhanced adhesion and extracellular matrix mineralization level of osteoblasts demonstrate the better cytocompatibility and osteogenic activity of the Ta coating. Ta30 (Ta coating prepared at 800 °C for 30 min) exhibits excellent mechanical, electrochemical, and osteoblastic behaviors and is promising in biomedical applications. [ABSTRACT FROM AUTHOR]

Corrosion—reactions occuring between engineering materials and their environment—can cause material failure and catastrophic accidents, which have a serious impact on economic development and social stability. Recently, super-hydrophobic coatings have received much attention due to their effectiveness in preventing engineering materials from further corrosion. In this paper, basic principles of wetting properties and corrosion protection mechanism of super-hydrophobic coatings are introduced firstly. Secondly, the fabrication methods by electrochemical surface engineering—including electrochemical anodization, micro-arc oxidation, electrochemical etching, and deposition—are presented. Finally, the stabilities and future directions of super-hydrophobic coatings are discussed in order to promote the movement of such coatings into real-world applications. The objective of this review is to bring a brief overview of the recent progress in the fabrication of super-hydrophobic coatings by electrochemical surface methods for corrosion protection of engineering materials. [ABSTRACT FROM AUTHOR]

Because of its excellent wear resistance and corrosion resistance, CoCrFeNi-based HEA has been selected as the coating prepared on steels to improve its service life. This paper presents single-track CoCrFeNiMo 0.2 Nb 0.2 HEA cladding layers fabricated at different laser scanning speeds on an AISI H13 steel substrate. The grain morphology, microstructure and elemental distribution are illustrated. The phase constituents of the fusion zone (FZ) and middle section of the coatings were analyzed. The outcomes of this research showed that as the laser scanning speed increased, the grains in the cladding layers were refined, while the variation in the Fe elemental content first increased and then decreased. In the FZ, Mo and Nb, as strong carbide-forming elements, preferentially combined with the carbides in the substrate, forming a new (Mo)NbC phase with a grain size of 600 nm at the retained austenite grain boundary. During the process of laser cladding, the thermal Marangoni flow of multiple principal components and the solidification of the molten pool, which are influenced by the scanning speed, determine the microstructure of the (Mo)NbC in the FZ and eutectic in the in-between section of the cladding layer. The illustration of the microstructure evolution and solidification mechanism in this study can provide a foundation for the potential applications of HEA coatings. [Display omitted] • The single-track CoCrFeNiMo 0.2 Nb 0.2 HEA cladding layers were prepared on an AISI H13 steel. • The Mo, Nb elements in fusion zone prefer to form (Mo)NbC with a size of 600 nm at the retained-austenite grain boundaries. • The microstructure evolution from substrate to cladding layer is austenite, retained-austenite + (Mo)NbC, and eutectic. [ABSTRACT FROM AUTHOR]

Highlights: [•] SnS2/rGO has been successfully synthesized through a one-pot hydrothermal method. [•] SnS2 nanoflakes along with a small amount of SnS were well decorated on rGO sheets. [•] SnS2 nanoflakes have small sizes of 50–100nm in length and 5–10nm in thickness. [•] The SnS2/rGO nanocomposite showed enhanced adsorption ability for RhB. [ABSTRACT FROM AUTHOR]

[Display omitted] • The plasma reaction in the deposition of heavily boron-doped diamond films was in-situ diagnosed by OES. • Relationship between microstructure and plasma gas-phase reaction was investigated. • Revealed the mechanism of plasma gas-phase reaction in the deposition of heavily boron-doped diamond films. • Proved that the limit of boron doping for heavily boron doped diamond films is ∼30,000 ppm. • BH species in the plasma gas-phase strongly affect the microstructure of diamond films. The introduction of boron brings excellent electrical conductivity to diamond films, but also induces uncontrollability of the doping process. Therefore, it is crucial to the monitor of the growth and doping processes. In this work, to establish the correlation between the gas-phase chemical reactions and the microstructure characteristics of heavily boron-doped diamond (BDD) films, the plasma reactions in the chemical vapor deposition (CVD) process of BDD films were in-situ diagnosed and monitored using optical emission spectroscopy (OES), and the effect of different B/C ratios (from 10,000 to 60,000 ppm) on the microstructure, chemical composition were investigated comprehensively. As the B/C ratio increases, the insufficient gas-phase excitation and the "hydrogen abstraction" reaction of BH species lead to a massive loss of H species in the gas-phase of plasma, which is unfavorable for the diamond growth, weakens the etching on sp2 carbon, induces the development of defects and seriously damages the diamond films quality. The in-situ diagnostics and monitoring of the plasma state can realize the optimization of the growth and doping process for heavily doped polycrystalline BDD films, which is highly significant for its preparation and application. [ABSTRACT FROM AUTHOR]

Abstract: CNT/PPy/KxMnO2, a novel ternary core–shell nanowires, was successfully prepared by a two-step self-assembly method and utilized as an electrocatalyst for the oxidation of hydrogen peroxide. The as-synthesized products were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersive X-ray (EDX) spectroscopy and Fourier-transform infrared spectra (FTIR) measurements. The results exhibited that the KxMnO2 nanosheets were grown on the surface of CNT/PPy core–shell nanotubes. The planes of the KxMnO2 nanosheets were more or less perpendicular to the CNT/PPy nanotubes. Cyclic voltammetry (CV) results demonstrated that the CNT/PPy/KxMnO2 composite nanowires, as a nonenzyme catalyst, performed well with regards to the oxidation of hydrogen peroxide in 0.1M phosphate buffer solution (pH 7.0). The composite had a fast response with a linear range of 5.0μM to 9.7mM and a relatively low detection limit of 2.4μM (S/N=3). The sensitivity of the sensor for H2O2 was 114.6μAmM−1 cm−2. These excellent properties might be due to the large surface area of the composite nanowires and the quick electron transfer promoted by the combination of CNT and PPy. [Copyright &y& Elsevier]

Fine-tuning the surface structure of transition metal oxides at the atomic level is a promising way to improve the catalytic properties of materials. However, the influence of crystal surface structure on electrode reaction kinetics is still limited. In this study, we propose an in-situ synthesis strategy to obtain two-dimensional carbon/cerium oxide core-shell nanosheets by thermal decomposition of Ce-MOF nanosheets grown on the surface of carbon nanostructures, and fine-tuning the surface structure by introducing oxygen vacancies through defect engineering during the oxide nucleation process is conducted to obtain controllable exposed {111} and {110} surface CeO 2 @C composites. Both experiments and theoretical calculations show that the {110} -dominated nanocomplex (CeO 2 @C-350S) has better kinetic behavior and catalytic activity due to its abundant surface defects, which is manifested in higher active surface area, richer carrier concentration, and better promotion of diffusion and adsorption. In addition, CeO 2 @C-350S electrode has an extremely wide linear range and good stability in the electrochemical detection of nitrite. After 1000 times of the accelerated cycle experiments, CeO 2 @C-350S electrode still maintains 79.3 % of its initial current response, and recovers to 87.3 % after 10 min of stopping the test. The electrode stability is excellent, which is attributed to the clever carbon shell structure of the material. This synthesis strategy can be extended to other carbon-based oxide composite catalysts to improve the electrocatalytic performance and overall stability by adjusting the surface structure., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Background: Abnormal hyaluronic acid (HA) metabolism is a major factor in tumor progression, and the metabolic regulation of HA mainly includes HA biosynthesis and catabolism. In glioma, abnormal HA biosynthesis is intimately involved in glioma malignant biological properties and the formation of immunosuppressive microenvironment; however, the role of abnormal HA catabolism in glioma remains unclear., Methods: HA catabolism is dependent on hyaluronidase. In TCGA and GEPIA databases, we found that among the 6 human hyaluronidases (HYAL1, HYAL2, HYAL3, HYAL4, HYALP1, SPAM1), only HYAL2 expression was highest in glioma. Next, TCGA and CGGA database were further used to explore the correlation of HYAL2 expression with glioma prognosis. Then, the mRNA expression and protein level of HYAL2 was determined by qRT-PCR, Western blot and Immunohistochemical staining in glioma cells and glioma tissues, respectively. The MTT, EdU and Colony formation assay were used to measure the effect of HYAL2 knockdown on glioma. The GSEA enrichment analysis was performed to explore the potential pathway regulated by HYAL2 in glioma, in addition, the HYAL2-regulated signaling pathways were detected by flow cytometry and Western blot. Finally, small molecule compounds targeting HYAL2 in glioma were screened by Cmap analysis., Results: In the present study, we confirmed that Hyaluronidase 2 (HYAL2) is abnormally overexpressed in glioma. Moreover, we found that HYAL2 overexpression is associated with multiple glioma clinical traits and acts as a key indicator for glioma prognosis. Targeting HYAL2 could inhibit glioma progression by inducing glioma cell apoptosis and cell cycle arrest., Conclusion: Collectively, these observations suggest that HYAL2 overexpression could promote glioma progression. Thus, treatments that disrupt HA catabolism by altering HYAL2 expression may serve as effective strategies for glioma treatment., (© 2023. BioMed Central Ltd., part of Springer Nature.)