Porcine hemagglutinating encephalomyelitis virus(PHEV)is one of the coronaviruses susceptible to swine populations.The non-structural protein 2(NS2)encoded by its genome is fre-quently deleted during the epidemic transmission of the virus,but its biological significance re-mains unclear.In order to explore the structure and function of the NS2 protein,this study utilized platforms such as ProtParam,TMHMM,NetPhos3.1,and ExPASy to analyze its physicochemical properties,spatial structure,genetic evolution,and post-translational modification characteristics.Meanwhile,the NS2 protein was expressed in eukaryotes and transcriptome sequencing was per-formed to clarify the biological processes it participates in.The results showed that the NS2 protein consists of 233 amino acids,with a molecular weight of 26.735 kDa,and a half-life of approximately 30 hours in mammals.It includes 13 phosphorylation sites,2 N-glycosylation sites,and 1 O-glyco-sylation site,with no signal peptide and strong hydrophilicity.The a-helix accounts for the highest proportion in NS2(43.78％),followed by random coils(36.05％).The homology of the NS2 pro-tein between the epidemic strains PHEV-CC14 and PHEV-JL/2008 in Northeast China is 99.57％.The NS2 protein is widely involved in the regulation of nerve-related functions,such as axon guid-ance and synaptic development.This study preliminarily clarified the biological function of the NS2 protein,providing a new perspective for understanding the pathogenic mechanism of PHEV.

Porcine hemagglutinating encephalomyelitis virus(PHEV)is one of the coronaviruses susceptible to swine populations.The non-structural protein 2(NS2)encoded by its genome is fre-quently deleted during the epidemic transmission of the virus,but its biological significance re-mains unclear.In order to explore the structure and function of the NS2 protein,this study utilized platforms such as ProtParam,TMHMM,NetPhos3.1,and ExPASy to analyze its physicochemical properties,spatial structure,genetic evolution,and post-translational modification characteristics.Meanwhile,the NS2 protein was expressed in eukaryotes and transcriptome sequencing was per-formed to clarify the biological processes it participates in.The results showed that the NS2 protein consists of 233 amino acids,with a molecular weight of 26.735 kDa,and a half-life of approximately 30 hours in mammals.It includes 13 phosphorylation sites,2 N-glycosylation sites,and 1 O-glyco-sylation site,with no signal peptide and strong hydrophilicity.The a-helix accounts for the highest proportion in NS2(43.78％),followed by random coils(36.05％).The homology of the NS2 pro-tein between the epidemic strains PHEV-CC14 and PHEV-JL/2008 in Northeast China is 99.57％.The NS2 protein is widely involved in the regulation of nerve-related functions,such as axon guid-ance and synaptic development.This study preliminarily clarified the biological function of the NS2 protein,providing a new perspective for understanding the pathogenic mechanism of PHEV.

Objective:To explore the difference and clinical significance of paraspinal muscle degeneration between single-segment degenerative lumbar spondylolisthesis and degenerative lumbar spinal stenosis.Methods:From January 2014 to October 2020, a retrospective analysis of 30 patientswere diagnosed with L 4,5 degenerative lumbar spondylolisthesis, aged 61.63±8.42 years old (range 44 to 82 years old), body mass index 24.07±3.17 kg/m 2 and 30 patientswere diagnosed with L 4,5 degenerative lumbar spinal stenosis, aged 59.67±12.89 years old (range 31 to 80 years old), body mass index 25.29±3.48kg/m 2, both of them went on surgery in department of spine surgery, shengjing hospital, China Medical University.30 healthy people were selected from outpatient physical examination in the control group, aged 58.33±7.36 years old (range 52 to 83 years old), body mass index 25.72±2.58 kg/m 2. These three groups were all male. Select all patients with L 3,4, L 4,5 and L 5S 1 disc level axial MRI images, and use the deep learning automatic segmentation measurement system developed by our hospital and Shenyang Institute of Automation Chinese Academy of Sciences to measure multifidus muscle cross sectional area (MMCSA), erector spinae cross sectional area (ESCSA), multifidus muscle fatty infiltration rate (MMFIR) and erector spinae fatty infiltration rate (ESFIR). One-way ANOVA was used to test the imaging parameters of multifidus and erector spinae of the three groups, and LSD- t test was used to compare the imaging parameters in each segment of paraspinal muscles. Results:The gender of three groups were male, there was no significant difference in age ( H=5.303, P>0.05), and there was no significant difference in body mass index ( F=2.267, P>0.05). Multifidus muscle cross-sectional area in L 3,4: degenerative lumbar spondylolisthesis groupincreased 189.11 mm 2 compared with degenerative lumbar spinal stenosis group ( P=0.010). Multifidus muscle cross-sectional area in L 4,5: compared with healthy people group, degenerative lumbar spondylolisthesis group decreased 205.52 mm 2 ( P=0.002), while degenerative lumbar spinal stenosis group decreased 184.14 mm 2 ( P=0.006). Multifidus muscle cross-sectional area in L 5S 1: compared with degenerative lumbar spinal stenosis group, degenerative lumbar spondylolisthesis group decreased 174.93 mm 2 ( P=0.018); compared with healthy people group, degenerative lumbar spondylolisthesis group decreased 406.06 mm 2 ( P<0.001), while degenerative lumbar spinal stenosis group decreased 231.13 mm 2 ( P=0.002). Erector spinae cross sectional area in L 4,5: compared with healthy people group, degenerative lumbar spinal stenosis group decreased 398.70 mm 2 ( P=0.006). Erector spinae cross sectional area in L 5S 1: compared with degenerative lumbar spinal stenosis group, degenerative lumbar spondylolisthesis group decreased 500.02 mm 2 ( P<0.001); compared with healthy people group, degenerative lumbar spinal stenosis group decreased 455.37 mm 2 ( P<0.001). Compared with healthy group, the multifidus muscle fatty infiltration rate of degenerative lumbar spondylolisthesis group in L 3,4 increased 4.96% ( P=0.001). Compared with degenerative lumbar spinal stenosis group, the erector spinae fatty infiltration rate of degenerative lumbar spondylolisthesis group in L 5S 1 decreased 5.41% ( P=0.004). Compared with healthy group, the erector spinae fatty infiltration rate of degenerative lumbarspinal stenosis group in L 5S 1 increased 5.02% ( P=0.008) . Conclusion:Paraspinal muscle cross sectional area of each segment in degenerative lumbar spondylolisthesis group and degenerative lumbar spinal stenosis group decreased in different degrees. In degenerative lumbar spondylolisthesis group, the degree of multifidus muscle fat infiltration was more significant, while indegenerative lumbar spinal stenosis group,the degree of erector spinal fat infiltration was higher.

Objective To observe the in vivo degradation of poly-DL-lactic acid ureteral stent in canine and the pathological change in canine ureter.Methods Poly-DL-lactic acid ureteral stent was inserted into 19 canine ureters,respectively.The stents were taken out every two weeks with their degradation observed with electronic microscopy and their molecular weight change detected by gel permeation chromatography.Pathological change in ureteral tissue specimens stained with hematoxylin and eosin was observed by light microscopy.Results The molecular weight of poly-DL-lactic acid ureteral stent was decreased to 8 033 seven weeks after degradation from 68 900 before degradation,with a degradation rate of 88.3%.Electronic microscopy showed that the number of pores in stent was gradually increased and their diameter became larger.The stent was degraded.The main pathological change observed in canine ureter tissue was non-specific inflammation.Conclusion Poly-DL-lactic acid ureteral stent is good in degradation property and tissue compatibility in vivo.