1. Section on Tissue Biophysics and Biomimetics, Program in Pediatric Imaging and Tissue Science, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, 13 South Drive, Bethesda, Maryland 20892, United States
2. Laboratoire Interdisciplinaire de Physique CNRS UMR 5588, Université J. Fourier de Grenoble, B.P.87, 38402 St Martin d’Hères cedex, France