Objective To assess the ability of quantitative ultrasound index to predict the severity of CCl4?induced liver fibrosis in a rat model us?ing logistic regression analysis. Methods In a rat model of 40%CCl4?induced liver fibrosis,ultrasound detected the portal vein diameter,blood flow velocity,and Young's modulus. The degree of hepatic fibrosis was determined using a light microscope after hematoxylin and eosin staining of tissue. Results Portal vein diameter and Young's modulus were useful predictors of the severity of liver fibrosis,with statistical significance(P<0.05). Young's modulus was most effective with an R2 value 0.788. Young's modulus combined with the distal diameter of portal vein effectively improved the predictive ability,showing an R2 value 0.821. Conclusion Young's modulus is the most predictive index to assess the severity of liver fibrosis. A combination of multiple indices can improve the ability to predict the severity of liver fibrosis.

African swine fever(ASF)is a highly contagious and pathogenic disease affecting both domestic and wild pigs,which is caused by African swine fever virus(ASFV).In European epidem-ics,low-virulence strains of ASFV,which do not have hemadsorbing properties,have been identi-fied.Following the identification of highly virulent genotype Ⅱ ASFV strains in China in 2018,subsequently,low-virulence strains of genotype Ⅱ and genotype Ⅰ emerged.Recombination be-tween genotypes Ⅰ and Ⅱ has also led to the occurrence of high-virulence strains.This indicates a complex and diverse genetic evolution of ASFV during the epidemiological transmission,which po-ses significant challenges for vaccine development and disease surveillance.Here,we provide an o-verview of the novel epidemiological characteristics of ASFV,with a focus on genetic variations and pathogenic differences during the outbreaks of ASF.We also explore how ASFV genetic varia-tions impact immune escape and pathogenicity of the virus,and the challenges they pose for vac-cine development,disease diagnosis,and surveillance.The aim of this review is to enhance our un-derstanding of the genetic evolution and mutation mechanisms of ASFV,providing a theoretical basis for the development of vaccines and research on diagnostic technologies.