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Inflammation is a common manifestation of body immunity and mediates a cascade of cytokines. Tumor necrosis factor-α (TNF-α), as a multi-effect cytokine, plays an important role in the inflammatory response by interacting with its receptor (TNFR). In this study, Pf_TNF-α, Pf_TNFR1 and Pf_TNFR2 genes were cloned from yellow catfish (Pelteobagrus fulvidraco), and bioinformatics analyses showed that the three genes were conserved and possessed similar sequence characteristics as those of other vertebrates. The qPCR results showed that Pf_TNF-α, Pf_TNFR1 and Pf_TNFR2 mRNAs were constitutively expressed in 14 tissues and the lymphocytes of four tissues from healthy adults. The mRNA expression levels of Pf_TNF-α and Pf_TNFR1 genes were significantly up-regulated in the spleen, liver, trunk kidney, head kidney and gill after Edwardsiella ictaluri infection, while the mRNA expression of Pf_TNFR2 was significantly up-regulated in the spleen, and down-regulated in the liver and gill. In the isolated peripheral blood leukocytes (PBLs) of yellow catfish, the expression of Pf_TNF-α mRNA was notably up-regulated and the two Pf_TNFR transcripts were distinctly down-regulated after stimulation with lipopolysaccharides (LPS), peptidoglycan (PGN), polyinosinic-polycytidylic acid (Poly I:C) and phytohaemagglutinin (PHA). After stimulated by recombinant (r) Pf_sTNF protein, the mRNA expressions of various inflammatory factors genes were up-regulated in the PBLs. Meanwhile, rPf_sTNF promoted the phagocytic activity of leukocytes, whereas the activity mediated by rPf_sTNF could be inhibited by rPf_TNFR1CRD2/3 and rPf_TNFR2CRD2/3. The up-regulation of TNF-α and IL-1β mRNAs expression triggered by rPf_sTNF could be inhibited by MAPK inhibitor (VX-702) and NF-κB inhibitor (PDTC). rPf_sTNF induced the expression of FADD mRNA in PBLs and increased the apoptotic rate of PBLs, and inhibiting the NF-κB and MAPK signal pathways could enhance the apoptosis of PBLs. The results indicate that Pf_TNF-α, Pf_TNFR1 and Pf_TNFR2 play important roles in the immune response of yellow catfish to bacterial invasion.

The acquisition of elastic resistance coefficient is crucial for the design of shallow hydraulic tunnel. In this paper, the resistance coefficient of the tunnel in the test section of the South Main Canal Project is monitored and analyzed. Considering the actual load mode of the tunnel lining, the load value acting on the lining is measured by the measurement instrument on the spot, and the elastic resistance acting on the tunnel lining is obtained. The elastic resistance coefficient acting on the tunnel lining is obtained through the deformation around the tunnel on the measuring side. The research conclusions and methods can provide reference for the support design of shallow hydraulic tunnel in loose soil layer.

As a polymer material, UPR anchoring material has pyrolysis at high temperature, which directly affect its mechanical stability. Using micro-CT scans and 3D image reconstruction to analysis pyrolysis characteristics and the pore structure evolution of UPR anchoring material at high temperatures, and the results showed that the thermal decomposition cause obvious changes in internal microstructure at high temperatures; the average gray attenuated 20.7%, pore groups number increased 47.5% and pore group size increased 201.5% between 350 °C and 500 °C; organic cemented body corresponding to attenuation coefficient ranges from 0.0163 to 0.0373, the inner pore increased significantly after organic pyrolysis, and connected with each other to form larger pores group; the pyrolysis critical temperature is 350 °C, pyrolysis affects significantly to the internal structure and the density of the material. Mechanical properties decayed significantly at high temperature (400 °C), compressive strength decreased by 95% and pull-out strength decreased by 68.3%.