作者单位:Univ Georgia, Coll Vet Med, Athens, GA 30602 USA[1]Georgia Inst Technol, Wallace H Coulter Dept Biomed Engn, Kennesaw, GA USA[2]Univ Calif San Diego, Atlanta, GA USA[3]Georgia Inst Technol, Wallace H Coulter Dept Biomed Engn, Atlanta, GA 30332 USA[4]