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Currently, the potential use of selective laser melting (SLM) technology to fabricate and optimise the performance of human bone implants with functionally graded scaffold (FGS) structures has drawn an increasing amount of attention. Magnesium alloy is a high-quality light metal that shows impressive potential in bioengineering; thus, it is chosen in this study. However, the defects that occur in magnesium during manufacturing may generate unexpected mechanical differences between the products and the ideal products, so there is a need to determine an efficient way to model actual products. In this article, samples were manufactured with different laser energy densities and subjected to compression experiments. The formation of spherical defects was analysed according to the principle of additive manufacturing. Hence, based on the observed characteristics, finite element (FE) models with different geometries were built, and changes in the stress distribution during compression were discussed. By comparing the mechanical properties obtained from compression tests and FE modelling, the simulation accuracy of each model was also estimated, from which the model that highlighted the stacking relationship was notable. Moreover, the expanded Hertzian contact stress theorem verified the influence of spherical defects on the compressive behaviour of the sample. The accuracy of the FE results was obviously improved by rectifying the equivalent bearing area.

Purpose: To investigate whether aloperine pretreatment ameliorates acute liver injury in carbon tetrachloride (CCl4)-treated mice.Methods: Mice were injected with CCl4 and orally administered aloperine. Blood samples and liver tissues were used for histopathological and biochemical analyses, respectively. Protein expression levels were determined by western blotting.Results: Histopathological analysis indicate that aloperine pretreatment significantly alleviated CCl4- induced mouse hepatic injury. CCl4 treatment induced the upregulation of aspartate aminotransferase (AST), alkaline phosphatase (ALP), alanine amino transferase (ALT), and total bilirubin (p < 0.05). However, these alterations were significantly inhibited by aloperine treatment. Moreover, aloperine pretreatment markedly decreased (p < 0.05) the CCl4-induced expression of oxidative stress biomarkers, including malondrialdeline (MDA), glutathione (GSH), catalase (CAT), and superoxide dismutase (SOD). Compared to the control group, the protein levels of Nrf2, HO-1, iNOS, and COX-2 were significantly increased in the CCl4 group, while Nrf2 and HO-1 were upregulated. Furthermore, iNOS and COX-2 were downregulated in mouse liver in CCl4 + aloperine group compared to CCl4 group in a concentration-dependent manner (p < 0.05).Conclusion: Aloperine pretreatment appears to markedly upregulate Nrf2 and HO-1 and downregulate iNOS and COX-2 to suppress hepatic injury in mice. Thus, aloperine is a promising treatment for acute liver injury. Keywords: Hepatic injury, Aloperine, Oxidative stress, Nrf2/HO-1 pathway