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Background Both of American mink (Neovison vison) and wild rat (Rattus norvegicus) is considered reservoir hosts carrying many endoparasites. Trichinella is a successful parasitic nematode including nine species and three genotypes with a worldwide distribution. However, little is known about the prevalence of Trichinella infection in mink (Neovison vison) and rat (Rattus norvegicus) in China.Methods In total, 289 muscle samples of minks and 102 rat carcasses were collected between April 2017 and December 2019 in Weihai city of Shandong province, China. The food of minks including chicken skeleton and mashed marine products was also collected at 3 batches. All the samples were used to examine for the appearance of Trichinella by the pooled artificial HCl-pepsin digestion method. The isolates from minks and rats were identified as T. spiralis by multiplex PCR. Then, the phylogenetic tree was constructed based on the sequences of 5S rDNA inter-gene spacer regions.Results Muscle larvae were detected in 20 out of 289 minks (6.92%) and in 2 of 102 wild rats (1.96%), respectively. The intensity of Trichinella in mink samples was ranged from 0.025 to 0.815 lpg, while the larval burden in rats was 0.17 lpg. The isolates from minks and rats were identified as T. spiralis by multiplex PCR. Sequence analysis revealed a 100% identical alignment of the 5S rDNA inter-gene spacer regions from the two isolates. The phylogenetic tree confirmed the two isolates from minks and rats belonging to T. spiralis based on analysis of the 5S rDNA inter-gene spacer sequence.Conclusions The present study represents the first report of T. spiralis infection in American mink (Neovison vison) and wild rat (Rattus norvegicus) from Shandong province, China. The farmed minks would be vulnerable to Trichinella infection through exposure to the wild rats. The prevalence of T. spiralis in wild rats may raise a public health concern for the potential zoonotic risk for the domestic animals.

The types and contents of styrene-butadiene-styrene (SBS) modifier are two important factors of SBS modified asphalt mixtures. Nowadays, SBS are extensively utilized to modified asphalt in order to improve the performance of the flexible pavement. The objective of this study is to determine a best selection of types and contents of SBS modifier, which can improve high-temperature stability; low-temperature anti-cracking performance and moisture susceptibility of SBS modified asphalt mixture. The mixtures with four types of SBS (Linear A, Linear B, Star A, Star B) and the different contents of each type SBS including Linear SBS of 0%, 3%, 4%, 4.5% and Star SBS of 0%, 3%, 3.5%, 4%, were evaluated for the pavement performance of them under laboratory conditions. Wheel tracking test, beam bending test and freeze-thaw tensile strength test were chosen and carried out to determine high-temperature stability, low-temperature anti-cracking performance and the moisture susceptibility respectively. The laboratory testing results indicate that Star SBS show the more effective effects than Linear SBS to improve the high-temperature stability, low-temperature anti-cracking performance and moisture susceptibility of SBS modified asphalt mixture, and the optimum content of SBS can also play a key role the improvement of the pavement performance.