Wang X, Yoon Y J, Ji H
Department of Mechanical Engineering and Biomechanics, The University of Texas at San Antonio, 6900 North Loop 1604 West, San Antonio, TX 78249, USA.
J Biomech. 2007;40(6):1401-4. doi: 10.1016/j.jbiomech.2006.06.005. Epub 2006 Aug 9.
A scratch test using a nanoindentation system was proposed in this study to assess the age-related changes in the in situ toughness of bone matrix at ultrastructural levels. A tissue removal energy density (u(r)) was defined and estimated as the work done by the scratch (U(T)) divided by the total volume of the scratch groove (u(s)). The value of u(s) was used as a relative measure of the in situ toughness of the tissue. Human cortical bone specimens obtained from middle-aged (between 49 and 59 years old) and elderly groups (over 69 years old) were tested using this technique. A significant difference in the estimated removal energy density (u(s)) in the secondary osteons was found between the middle-aged and elderly groups (5.49+/-0.696 vs. 4.09+/-1.30 N/mm(2), respectively).
本研究提出了一种使用纳米压痕系统的划痕试验，以在超微结构水平评估骨基质原位韧性的年龄相关变化。定义并估计了组织去除能量密度（u(r)），即划痕所做的功（U(T)）除以划痕凹槽的总体积（u(s)）。u(s)的值用作组织原位韧性的相对度量。使用该技术对从中年组（49至59岁）和老年组（69岁以上）获取的人类皮质骨标本进行了测试。中年组和老年组之间在次生骨单位中估计的去除能量密度（u(s)）存在显著差异（分别为5.49±0.696和4.09±1.30 N/mm²）。
