Since May 2015, outbreaks of hydropericardium-hepatitis syndrome (HHS) caused by fowl adenovirus 4 (FAdV-4) with a novel genotype have been reported in China, causing significant economic losses to the poultry industry. A previous comparative analysis revealed that highly virulent FAdV-4 isolates contain various genomic deletions and multiple distinct mutations in the major structural genes fiber2 and hexon. To identify the genes responsible for the virulence of HHS-associated novel FAdV-4 isolates, FAdV-4 infectious clones were constructed by directly cloning the whole genome of a highly pathogenic FAdV-4 isolate (CH/HNJZ/2015) and that of a nonpathogenic strain (ON1) into a p15A-cm vector using the ExoCET method. Subsequently, the fiber2, hexon, and 1966-bp fragment-replaced mutant/recombinant viruses were constructed using Redαβ recombineering and ccdB counter-selection techniques. The pathogenicity of the rescued viruses was compared with that of the rescued parent viruses rHNJZ and rON1 in 3-week-old SPF chickens. Chickens infected with the rescued viruses carrying the fiber2 and/or hexon gene of the HNJZ strain developed similar clinical signs to the natural infection, with distinctive gross lesions and characteristic histological signs indicative of HHS observed in sick/dead chickens. Our results clearly demonstrated that the virulence of the novel highly pathogenic FAdV-4 strain was independent of the 1966-bp deletion and that the fiber2 and hexon genes have crucial roles in FAdV-4 pathogenicity. The data presented in this report will provide further insights into the crucial factors determining the pathogenicity of FAdV strains. Furthermore, the infectious clones generated based on the FAdV-4 genome can be used as a platform for studies of gene function and for the development of recombinant vaccines.

It was demonstrated that gel-free styrene−butadiene−styrene triblock copolymer (SBS) latex with a molecular weight about 90 kg/mol and styrene composition about 34% could be synthesized by reversible addition−fragmentation chain transfer miniemulsion polymerization. The resulted SBS might be an excellent thermoplastic elastomer as indicated by its mechanical properties with ultimate tensile strength of 16 MPa and about 800% elongation at break.

Dihydroartemisinin is a potent compound against LLC cell line in vitro. In vivo, the combination strategy of DHA and chemotherapeutics holds promise for the treatment of relatively large and rapidly growing lung cancers.

Highlights► DHA induced K562 cells autophagy followed by LC3-II protein expression. ► The DHA-induced autophagy might be ROS dependent. ► Inhibition of K562 cell proliferation by DHA was also dependent upon iron decrease.