In the present study, 89 porcine reproductive and respiratory syndrome virus (PRRSV) isolates in China during 2007 to 2012 were randomly selected from the GenBank genetic sequence database. Evolutionary characteristics of these isolates were analyzed based on the sequences of non-struc-tural protein 2 (Nsp2) and glycoprotein 5 (GP5). The genetic variations of the isolates were also compared with six representative strains. The results showed that a high degree of genetic diversity exists among the PRRSV population in China. Highly pathogenic PRRSV isolates, with a discon-tinuous deletion of a 30 amino acid residue in the Nsp2 region, remained the most dominant virus throughout 2007-2012 in China. Owing to the extensive use of representative vaccine strains, natu-ral recombination events occurred between strains. Three isolates-HH08, DY, and YN-2011-were more closely related to vaccine strains than the other isolates. Both YN-2011 and DY were the evolu-tionary products of recombination events between strains SP and CH-1R. The results of the present study provide useful information for the epidemiology of PRRSV as well as for vaccine development.

OBJECTIVE: To develop a self deep breathing training device which can improve lung function compliance and blood oxygen saturation. METHODS: The device consists of four parts:flow tube, measuring cylinder, mobile phone holder and meridian guidance audio-visual synthesis training software. The flow tube measures the flow rate of inhaled gas, the metering cylinder measures the total amount of inhaled gas, and the mobile phone rack is equipped with a mobile phone storing the meridian guidance audio-visual synthesis training software. RESULTS: The device is reasonable in structure and flexible in operation, which can meet the requirements of self deep inspiration training under the guidance of training module. CONCLUSIONS Deep inspiration training under the guidance of guidance training module can form "deep and slow" abdominal breathing, and then improve lung function.
Cell Phone ; Lung ; Meridians ; Software