TY  - JOUR
AU  - Krauss, S.
AU  - Fratzl, P.
AU  - Seto, J.
AU  - Currey, J. D.
AU  - Estevez, J. A.
AU  - Funari, S. S.
AU  - Gupta, H. S.
AU  - DESY
TI  - Inhomogeneous fibril stretching in antler starts after macroscopic yielding: Indication for a nanoscale toughening mechanism
JO  - Bone
VL  - 44
SN  - 8756-3282
CY  - Amsterdam [u.a.]
PB  - Elsevier Science
M1  - PHPPUBDB-11774
SP  - 1105-1110
PY  - 2009
N1  - © Published by Elsevier Inc.; Post referee fulltext in progress 2; Embargo 12 months from publication
AB  - Antler is a unique mineralized tissue, with extraordinary toughness as well as an ability to annually regenerate itself in its entirety. The high fracture resistance enables it to fulfill its biological function as a weapon and defensive guard during combats between deer stags in the rutting season. However, very little is quantitatively understood about the structural origin of the antler's high toughness. We used a unique combination of time-resolved synchrotron small angle X-ray diffraction together with tensile testing of antler cortical tissue under physiologically wet conditions. We measured the deformation at the nanoscale from changes in the meridional diffraction pattern during macroscopic stretch-to-failure tests. Our results show that on average fibrils are strained only half as much as the whole tissue and the fibril strain increases linearly with tissue strain, both during elastic and inelastic deformation. Most remarkably, following macroscopic yielding we observe a straining of some fibrils equal to the macroscopic tissue strain while others are hardly stretched at all, indicating an inhomogeneous fibrillar strain pattern at the nanoscale. This behavior is unlike what occurs in plexiform bovine bone and may explain the extreme toughness of antler compared to normal bone.
KW  - Animals
KW  - Antlers: physiology
KW  - Biomechanics
KW  - Bone and Bones: physiology
KW  - Deer
KW  - Scattering, Small Angle
KW  - Stress, Mechanical
KW  - Tensile Strength: physiology
KW  - X-Ray Diffraction
LB  - PUB:(DE-HGF)16
C6  - pmid:19236962
UR  - <Go to ISI:>//WOS:000266347700012
DO  - DOI:10.1016/j.bone.2009.02.009
UR  - https://bib-pubdb1.desy.de/record/93861
ER  -