1. Institute for Hepatitis and Virus Research, Hepatitis B Foundation,
Doylestown, Pennsylvania 18902, United States
2. Drexel Institute for Biotechnology and Virology
Research, Drexel University College of Medicine, Doylestown, Pennsylvania
18902, United States
3. School
of Pharmaceutical Science and Technology, Tianjin University, Tianjin
300072, P. R. China