An eukaryotic expression system of Congjiang pigs IFN-λ1 was constructed to obtain its expression in CHO-K1 cells and the inhibition effect of Congjiang pig IFN-λ1 on PRRSV proliferation was verified. The eukaryotic expression plasmid pEGFP-PoIFN-λ1 was constructed from the pig IFN-λ1 gene fragment and transfected into CHO-K1 cells. Expression was detected by fluorescence microscopy and Western blotting. The influence on the proliferation of PRRSV was assessed. The results of the study showed that the recombinant plasmid pEGFP-PoIFN-λ1 was constructed correctly. After transfection, green fluorescent signal was detected in CHO-K1 cells by fluorescence microscopy. Western blot analysis revealed that in cells at different time periods after transfection, porcine IFN-λ1 was expressed, with the highest expression observed 36 h after transfection. The antiviral activity of the supernatant after 36 h of transfection was determined by the micro cytopathic inhibition method, and the biological activity was 2.1×103 U/mL. Quantitative PCR was used to detect the proliferation of PRRSV, and the results showed that Congjiang pigs IFN-λ1 significantly inhibited the mRNA expression of PRRSV and viral proliferation in a dose- and time-dependent manner. This study established a Congjiang pig IFN-λ1 eukaryotic expression system, and the quantitative PCR method showed that it has a significant inhibitory effect on the proliferation of PRRSV, which lays a foundation for the future production of antiviral drugs and clinical application.

As the most recent video coding standard, High Efficiency Video Coding (HEVC) adopts various novel techniques, including a quad-tree based coding unit (CU) structure and additional angular modes used for intra encoding. These new techniques achieve a notable improvement in coding efficiency at the penalty of significant computational complexity increase. Thus, a fast HEVC coding algorithm is highly desirable. In this paper, we propose a fast intra CU decision algorithm for HEVC to reduce the coding complexity, mainly based on a key-point detection. A CU block is considered to have multiple gradients and is early split if corner points are detected inside the block. On the other hand, a CU block without corner points is treated to be terminated when its RD cost is also small according to statistics of the previous frames. The proposed fast algorithm achieves over 62% encoding time reduction with 3.66%, 2.82%, and 2.53% BD-Rate loss for Y, U, and V components, averagely. The experimental results show that the proposed method is efficient to fast decide CU size in HEVC intra coding, even though only static parameters are applied to all test sequences.