Umbilical cord blood mesenchymal stem cells traced and transfected by recombinant lentivirus vector with enhanced green fluorescent protein for treatment of ischemic necrosis of the femoral head in rabbits Chinese Journal of Tissue Engineering Research . 2011, (10): 1897 -1900 .  DOI: 10.3969/j.issn.1673-8225.2011.10.042