Since late 2011, porcine infections with highly virulent and antigenic variant of pseudorabies virus (PRV) cause great economic loss in the swine industry in China, and its emergence leads to variable protection efficacy of the commercially available PRV vaccine.

In the present study, the potential cross-protective efficacy of two live virus vaccines, includ- ing a commercial vaccine, and an attenuated low pathogenic PRV variant (rPRVTJ-delTK/gE/gI) against a PRV variant Tianjing (TJ) was evaluated in piglets. Vaccination of piglets with the live vaccine Bartha-K61 could not reduce the clinical signs, and was partially efficacious in the reduc- tion of viral loads upon PRV variant TJ challenge, indicating that this live vaccine provided limited cross-protection efficacy against the PRV variant infection. Additionally, rPRVTJ-delTK/gE/gI appeared to exert some beneficial efficiency in shortening the period of clinical fever and improv- ing the growth performance of the challenged pigs.

Our findings give a valuable guidance for the choice and use of PRV vaccines to control PRV variant infection in the field.

In order to predict the distribution of shrinkage porosity in steel ingot efficiently and accurately, a criterion R√L and a method to obtain its

threshold value were proposed. The criterion R√L was derived based on the solidification characteristics of steel ingot and pressure

gradient in the mushy zone, in which the physical properties, the thermal parameters, the structure of the mushy zone and the secondary

dendrite arm spacing were all taken into consideration. The threshold value of the criterion R√L was obtained with combination of

numerical simulation of ingot solidification and total solidification shrinkage rate. Prediction of the shrinkage porosity in a 5.5 ton ingot of

2Cr13 steel with criterion R√L>0.21 m･℃1/2･s

-3/2 agreed well with the results of experimental sectioning. Based on this criterion,

optimization of the ingot was carried out by decreasing the height-to-diameter ratio and increasing the taper, which successfully eliminated

the centreline porosity and further proved the applicability of this criterion.

In the current study, twenty lambs, aged 4 months, half male and half female, were classified into four groups, with five in each group. The experimental three groups of lambs were given intravenous (IV), intramuscular (IM) and subcutaneous (SC) administrations of recombinant ovine interferon-τ (roIFN-τ). The fourth group (normal control) of lambs was given normal saline injections in the same way. After administrations, blood samples were collected from the tested animals at different time points post injection, and the serum titers of roIFN-τ were measured using cytopathic effect (CPE) inhibition bioassay. The results of calculating pharmacokinetic (PK) parameters using DAS software showed that the PK characteristics of roIFN-τ through IV injection conformed to the two-compartment open model, whose half-life of distribution phases (T1/2α) was 0.33±0.034 h and the elimination half-life(T1/2β) was 5.01±0.24 h. However, the PK features of IM injection and SC injection of roIFN-τ conformed to the one compartment open model, whose Tmax were 3.11±0.26 h and 4.83±0.43 h, respectively, together with an elimination half life(T1/2β) of 9.11±0.76 h and 7. 43±0.58 h, and an absorption half-life (T1/2k(a)) of 1.13±0.31 h and 1.85±0.40 h, respectively. The bioavailability of roIFN-τ after IM administration reaches 73.57%, which is greater than that of SC administration (53.43%). These results indicate that the drug administration effect can be preferably obtained following a single dose IM administration of the roIFN-τ aqueous preparation. This study will facilitate the clinical application of roIFN-τ as a potential antiviral agent in future work.