African swine fever (ASF) was officially reported in Vietnam in February 2019 and spread across the whole country, affecting all 63 provinces and cities.
Material and Methods
In this study, ASF virus (ASFV) VN/Pig/HaNam/2019 (VN/Pig/HN/19) strain was isolated in primary porcine alveolar macrophage (PAM) cells from a sample originating from an outbreak farm in Vietnam’s Red River Delta region. The isolate was characterised using the haemadsorption (HAD) test, real-time PCR, and sequencing. The activity of antimicrobial feed products was evaluated via a contaminated ASFV feed assay.
Phylogenetic analysis of the viral p72 and EP402R genes placed VN/Pig/HN/19 in genotype II and serogroup 8 and related it closely to Eastern European and Chinese strains. Infectious titres of the virus propagated in primary PAMs were 106 HAD50/ml. Our study reports the activity against ASFV VN/Pig/HN/19 strain of antimicrobial Sal CURB RM E Liquid, F2 Dry and K2 Liquid. Our feed assay findings suggest that the antimicrobial RM E Liquid has a strong effect against ASFV replication. These results suggest that among the Sal CURB products, the antimicrobial RM E Liquid may have the most potential as a mitigant feed additive for ASFV infection. Therefore, further studies on the use of antimicrobial Sal CURB RM E Liquid in vivo are required.
Our study demonstrates the threat of ASFV and emphasises the need to control and eradicate it in Vietnam by multiple measures.
Molybdenum (Mo) films (~1 μm) as back contacts for chalcopyrite solar cells are usually deposited onto the glass substrate by DC-sputtering because of their high deposition rate with a column structure. During selenization, selenium (Se) is infiltrated deeply into the column structure of Mo films. Although the difference in sheet resistance and resistivity values before and after selenization is negligible, the selenized Mo films are easily peeled off from the glass substrate even with the tape testing. The existence of Se in Mo films with a column structure was investigated by scanning electron microscopy cross-section, energy-dispersive X-ray spectroscopy, and X-ray diffraction measurement. To overcome this obstacle, a 200-nm-thick Mo compact layer was deposited by RF-sputtering on top of the Mo film to prevent Se infiltration. Finally, the bilayer of Mo was passed with tape testing for both films before and after selenization. The results may be helpful to further achieve highly stable fabrication processes of chalcopyrite solar cells.