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An iron alloy coating with gradient transition was sprayed on F304 stainless steel substrate by plasma spraying method and with a gradient material obtained by the material performance simulation software, and the effect of gradient transition on the microstructure, hardness and wear resistance of the coating was analyzed by comparing with the non gradient transition coating. The results show that both the gradient coating and the non gradient coating have wavy layered structure and are formed by highly flattened deformed particles overlapping each other. Micro metallurgical bonding was observed between the coating particles, and oxides were observed between the coating and the substrate, between the flat particles and inside the flat layer. The coating microstructure includes austenite phase, ferrite phase and carbides. The surface hardness of the gradient coating and the non gradient transition coating are basically similar, but there are obvious steep drop steps between the section hardness of the non gradient coating and the substrate hardness, while the section hardness of the gradient coating and the substrate hardness change gently, and the section hardness of the gradient coating is slightly lower than that of the non gradient coating. The wear rate of gradient coating is similar to that of non gradient coating at 400 °C, but it is lower than that of non gradient transition coating at 350 °C. The reason for reducing hardness changes and improving wear resistance of the coating may be related to the improvement of the microstructure and plasticity of the coating by the gradient layer, but more research is needed. [ABSTRACT FROM AUTHOR]

The material performance simulation software JMatPro was used to simulate and calculate equilibrium phase structure and properties of a mixture formed by mixing different proportions of Norem02 alloy and F304 stainless steel. The results show that in the range of 500-1300 °C, equilibrium phases of the mixture include Austenite and Ferrite, and the carbides include M2(C,N), M6C, M7C3 and M23C6. As the content of F304 in the mixture increases, the phase transition temperature A1 of the mixture decreases, and A3 first decreases and then increases; in the equilibrium phase, the content of Austenite and Ferrite increases, and the content of carbide decreases until the carbides M7C3 and M6C gradually disappear. Density, coefficient of linear expansion, thermal conductivity, Young's modulus, Poisson's ratio and specific heat capacity of different mixture materials vary with temperature in a complex manner. Strength and hardness of the mixture formed when the content of F304 is 20 % is the highest. The finer the grain size of the mixture, the higher the strength and hardness of the material. Comparing standard physical property data of F304 stainless steel at room temperature with the simulation calculation results, it is found that the error is small, which verifies the accuracy of the simulation calculation results. [ABSTRACT FROM AUTHOR]

Myopalladin (MYPN) is a striated muscle-specific immunoglobulin domain-containing protein located in the sarcomeric Z-line and I-band. MYPN gene mutations are causative for dilated (DCM), hypertrophic, and restrictive cardiomyopathy. In a yeast two-hybrid screening, MYPN was found to bind to titin in the Z-line, which was confirmed by microscale thermophoresis. Cardiac analyses of MYPN knockout (MKO) mice showed the development of mild cardiac dilation and systolic dysfunction, associated with decreased myofibrillar isometric tension generation and increased resting tension at longer sarcomere lengths. MKO mice exhibited a normal hypertrophic response to transaortic constriction (TAC), but rapidly developed severe cardiac dilation and systolic dysfunction, associated with fibrosis, increased fetal gene expression, higher intercalated disc fold amplitude, decreased calsequestrin-2 protein levels, and increased desmoplakin and SORBS2 protein levels. Cardiomyocyte analyses showed delayed Ca2+ release and reuptake in unstressed MKO mice as well as reduced Ca2+ spark amplitude post-TAC, suggesting that altered Ca2+ handling may contribute to the development of DCM in MKO mice. [ABSTRACT FROM AUTHOR]