1. Department of Microbiology, Immunology, and Cell Biology, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, West Virginia 26506-9177
2. Department of Oral Biology, State University of New York at Buffalo, Buffalo, New York 14214
3. Prefectural University of Hiroshima, Department of Life Sciences, 562 Nanatsuka, Shobara, Hiroshima, 727-0023, Japan
4. CREST Soft-Nano Machine Project, Innovation Plaza, Hiroshima, 3-10-23 Kagamiyama, Higashi-Hiroshima, 739-0046, Japan