Microstructure and properties of Cu−2Cr−1Nb alloy fabricated by spark plasma sintering

Cu−2Cr−1Nb alloy was fabricated by spark plasma sintering(SPS)using close coupled argon-atomized alloy powder as the raw material.The optimal SPS parameters obtained using the L9(3^(4))orthogonal test were 950℃,50 MPa and 15 min,and the relative density of the as-sintered alloy was 99.8%.The rapid densification of SPS effectively inhibited the growth of the Cr_(2)Nb phase,and the atomized powder microstructure was maintained in the grains of the alloy matrix.Uniformly distributed multi-scale Cr_(2)Nb phases with grain sizes of 0.10−0.40μm and 20−100 nm and fine grains of alloy matrix with an average size of 3.79μm were obtained.After heat treatment at 500℃ for 2 h,the room temperature tensile strength,electrical conductivity,and thermal conductivity of the sintered Cu−2Cr−1Nb alloy were 332 MPa,86.7%(IACS),and 323.1 W/(m·K),respectively,and the high temperature tensile strength(700℃)was 76 MPa.

Correlation of Fibroscan parameter with serum inflammation indexes, collagen metabolism indexes and fibrosis indexes in patients with hepatitis b cirrhosis

Objective:To study the correlation of Fibroscan parameter with serum inflammation indexes, collagen metabolism indexes and fibrosis indexes in patients with hepatitis b cirrhosis. Methods:Patients who were diagnosed with hepatitis b cirrhosis in Dongfeng Hospital Affiliated to Hubei University of Medicine between June 2014 and August 2017 were selected as cirrhosis group for the research, patients who were diagnosed with chronic viral hepatitis b and without liver cirrhosis were selected as the HBV group, and healthy volunteers who received physical examination in Dongfeng Hospital Affiliated to Hubei University of Medicine during the same period were selected as the control group for the research;Fibroscan was performed to determine the liver stiffness measurement (LSM), and serum was collected to determine the inflammation indexes, collagen metabolism indexes and fibrosis indexes.Results:LSM levels as well as serum sICAM1, sP-selectin, MIF, MMP2, MMP9, CatS, TGFβ1, HA, LN, PC-III and IV-C contents of cirrhosis group and CHB group were significantly higher than those of control group whereas serum IL-21, IFN-γ, TIMP1 and TIMP2 contents were lower than those of control group;LSM level as well as serum sICAM1, sP-selectin, MIF, MMP2, MMP9, CatS, TGFβ1, HA, LN, PC-III and IV-C contents of cirrhosis group was significantly higher than those of CHB group whereas serum IL-21, IFN-γ, TIMP1 and TIMP2 contents lower than those of CHB group;LSM level in cirrhosis group was positively correlated with serum sICAM1, sP-selectin, MIF, MMP2, MMP9, CatS, TGFβ1, HA, LN, PC-III and IV-C contents, and negatively correlated with serum IL-21, IFN-γ, TIMP1 and TIMP2 contents.Conclusion: The Fibroscan parameter LSM of hepatitis b cirrhosis has evaluation value for inflammatory response, collagen metabolism and fibrosis process in the course of cirrhosis.