Preparation of a high-efficiency, low-cost, and environmentally friendly non-precious metal catalyst for the oxygen reduction reaction (ORR) is highly desirable in fuel cells. Herein, a Fe–Fe 3 C-functionalized few-layer graphene sheet (Fe/Fe 3 C/FLG) nanocomposite was fabricated through the vacuum heat treatment technique using ferric nitrate and glucose as the precursors and exhibited a high-performance ORR electrocatalyst. Multiple characterizations confirm that the nanosized Fe particles with the Fe 3 C interface are uniformly distributed in the FLGs. Electrocatalytic kinetics investigation of the nanocomposite indicates that the electron transfer process is a four-electron pathway. The formation of the Fe 3 C interface between the Fe nanoparticles and FLGs may promote the electron transfer from the Fe to FLGs. Furthermore, the Fe/Fe 3 C/FLG nanocomposite not only exhibits high ORR catalytic activity but also displays desirable stability. Consequently, the obtained Fe/Fe 3 C/FLG nanocomposite might be a promising non-precious, cheap, and high-efficiency catalyst for fuel cells.

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Porcine circovirus type 3 (PCV3) is a highly contagious virus belonging to the family Circoviridae that causes the severe dermatitis and nephropathy syndrome. To date, PCV3 has a worldwide distribution and bring huge economic loss in swine industry. Replicase protein (Rep) and capsid protein (Cap) are two major proteins of PCV3. Considering that the large number of new PCV3 isolates were reported in the past few years and the research for the codon usage pattern of Rep and Cap genes was still a gap, phylogenetic and codon usage analysis of these two genes was performed. Phylogenetic analysis with all strains showed no clear clusters were displayed, but almost all strains of one genotype were separated into same clade. Relative synonymous codon usage (RSCU) analysis revealed that the codon usage bias existed and effective number of codon (ENC) analysis showed that the bias was slight low. ENC-GC3s plot indicated that mutational pressure and other factors both play a role in PCV3 codon usage and neutrality plot analysis showed that natural selection was the main force in uencing the codon usage pattern. In summary, the results provided the important basic data on codon usage pattern of Rep and Cap genes, and a better understanding of the evolution and potential origin of PCV3.

Congenital tremor (CT) type A-II in piglets is a worldwide disease caused by an emerging atypical porcine pestivirus (APPV). Preparation and evaluation of vaccines in laboratory animals is an important preliminary step toward prevention and control of the disease. Here, virus-like particles (VLPs) of APPV were prepared and VLPs vaccine was evaluated in BALB/c mice. Purified E rns and E2 proteins expressed in E. coli were allowed to self-assemble into VLPs, which had the appearance of hollow spherical particles with a diameter of about 100 nm by transmission electron microscopy (TEM). The VLPs induced strong antibody responses and reduced the viral load in tissues of BALB/c mice. The data from animal challenge experiments, RT-PCR, and immunohistochemical analysis demonstrated that BALB/c mice are an appropriate laboratory model for APPV. These results suggest the feasibility of using VLPs as a vaccine for the prevention and control of APPV and provide useful information for further study of APPV in laboratory animals.

The H5N1 and H9N2 avian in uenza viruses (AIVs) seriously endanger the poultry industry and threaten human health. Characteristic in ammatory responses caused by H5N1 and H9N2 AIVs in birds and mammals result in unique clinical manifestations. The role of anti-in ammatory regulators, PTX3, Del-1 and GDF-15, in H5N1 and H9N2-AIV-mediated in ammation in birds and mammals has not yet been veri ed. Here, the expression of PTX3, Del-1 and GDF-15 in DF-1 and MDCK cells infected with H5N1 and H9N2 AIVs and their effect on in ammatory cytokines were analyzed. Infection with both AIVs increased PTX3, Del-1 and GDF-15 expression in DF-1 and MDCK cells. Infection with H9N2 or H5N1 AIV in DF-1 and MDCK cells with overexpression of all three factors, either alone or in combination, inhibited the expression of tested in ammatory cytokines. Furthermore, co-expression of PTX3, Del-1 and GDF-15 enhanced the inhibition, irrespective of the cell line. The ndings from this study offer insight into the pathogenic differences between H5N1 and H9N2 AIVs in varied hosts. Moreover, our ndings can be used to help screen for host-speci c anti-in ammatory agents.