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During the preparation and service process of micro-arc oxidation coatings，phenomena such as uneven growth or surface wear and peeling emerged，so the micro-arc oxidation coatings should be removed to achieve the purpose of secondary preparation and reuse.Aiming at the bottleneck problem of difficulty to remove micro-arc oxidation coating with high bonding strength，a novel plasma electrolytic removal(PER) technique was presented in this work.By comparing and analyzing the coating removal rates at different voltages，thickness change，and microstructure after coating removal at different times，it was found that the coating removal efficiency was the lowest with the applied voltage of 260 V，and the coating was completely removed after 11 min.When the voltage was increased to 320 V，the coating was completely removed in only 6 min.This was due to the large applied voltage，which made it easier to generate multiple and stable plasma discharge channels，thus realizing rapid removal of micro-arc oxidation coating.Furthermore，a synergistic mechanism of peeling，thinning，and dissolution in the removal of coatings by plasma electrolysis was proposed.The PER technique exhibits high efficiency and environmental protection，which has broad application prospects in the fields of aerospace，medical instruments and so on.

In order to improve the high temperature oxidation resistance of TC4 alloy，an anti-oxidation ceramic coating was prepared on the surface of titanium alloy by micro-arc oxidation in the NaAlO2+ Na3PO4 electrolyte system.The phase composition and microstructure of the coating were characterized by XRD，SEM and EDS，respectively.The hardness and elastic modulus of the coating were tested by nano indenter.In addition，the high temperature oxidation resistance and thermal shock resistance of the micro-arc oxidation coating were studied.Results showed that the surface of the micro-arc oxidation coating was porous.The coating was mainly composed of Al2TiO5 and rutile TiO2 phase.The nano hardness of microarc oxidation coating was (7.8 ± 0.6) GPa，significantly higher than that of TC4 alloy [(4.0 ± 0.2) GPa].After cyclic oxidation at 700 ℃for 80 h，the weight gain per unit area of micro-arc oxidation coating was only 0.73 mg/cm2，which was far less than the weight gains of TC4 alloy (20 mg/cm2)，showing good high temperature oxidation resistance.After 25 thermal shocks at 700 ℃，the coating had no scaling，indicating excellent thermal shock resistance.Hence，it could be seen that micro-arc oxidation coating could effectively prevent the diffusion of oxygen，significantly reducing the oxidation rate of titanium alloy and improving the high temperature oxidation resistance of titanium alloy.

Constructing heterojunctions and hollow multi‐shelled structures can render materials with fascinating physicochemical properties, and have been regarded as two promising strategies to overcome the severe shuttling and sluggish kinetics of polysulfide in lithium–sulfur (Li–S) batteries. However, a single strategy can only take limited effect. Modulating catalytic hosts with synergistic effects are urgently desired. Herein, Mn3O4‐MnS heterogeneous multi‐shelled hollow spheres are meticulously designed by controlled sulfuration of Mn2O3 hollow spheres, and then applied as advanced encapsulation hosts for Li–S batteries. Benefiting from the separated spatial confinement by hollow multi‐shelled structure, ample exposed active sites and built‐in electric field by heterogeneous interface, and synergistic effects between Mn3O4 (strong adsorption) and MnS (fast conversion) components, the assembled battery achieves prominent rate capability and decent cyclability (0.016% decay per cycle at 2 C, 1000 cycles). More crucially, satisfactory areal capacity reaches up to 7.1 mAh cm−2 even with high sulfur loading (8.0 mg cm−2) and lean electrolyte (E/S = 4.0 μL mg−1) conditions. This work will provide inspiration for the rational design of hollow multi‐shelled heterostructure for various electrocatalysis applications. [ABSTRACT FROM AUTHOR]

Dielectric tunability is widely used in numerous electronic devices, including wavelet filters, lens antennae, and varactors. However, a dielectric device often has only one tunable dielectric constant range, confining the integration of a multi‐frequency electronic circuit. Herein, a new kind of dielectric tunable textured BaTi0.99Fe0.01O3−δ ceramics with micro‐twin boundaries is proposed for the dual‐channel controllable dielectric constants. The relative tunability with the acceptable figure of merit is as large as 76% in the crossover channel, which is superior to that of the most state‐of‐the‐art BaxSr1 −xTiO3 counterparts. This new design strategy offers the possibility of dual‐channel filters in one dielectric device controlled by external electric fields. The required external electric field is moderate with the help of reversible micro twins, which is confirmed by first‐principles studies. The static magnetic field interference on the dielectric constant is also evaluated, showing the frequency stability of dielectric tunability in a range between 5k and 1 m Hz. [ABSTRACT FROM AUTHOR]

Objectives: To conduct an umbrella review to extensively evaluate and summarise the evidence regarding the relationship between risk factors and the occurrence of brain metastasis in lung cancer., Design: Umbrella review of systematic reviews and meta-analyses., Data Sources: Four databases (PubMed, EMBASE, Web of Science and Cochrane Library) were searched from inception to 10 November 2024., Eligibility Criteria: Systematic reviews and meta-analyses that assessed the relationship between risk factors and brain metastasis in lung cancer were included. Only English language studies were considered., Data Extraction and Synthesis: Two authors independently extracted data and assessed the methodological quality and risk of bias of the included studies. Certainty of evidence was evaluated and summarised for each identified risk factor., Results: Six systematic reviews/meta-analyses were included. The quality of these studies varied, with most having low or critically low methodological quality. Epidermal growth factor receptor mutations, female gender, lung adenocarcinoma and advanced tumour stage were associated with an increased risk of brain metastasis. Prophylactic cranial irradiation and older age were associated with reduced risk., Conclusions: This umbrella review suggests that several risk factors may be associated with brain metastasis in lung cancer, but the overall quality of evidence is low. Future studies with improved methodologies are needed to validate these findings., Prospero Registration Number: CRD42023484563., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2025. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ Group.)