Curved mineral platelets in bone.

Bone is a composite material principally made up of a mineral phase (apatite) and collagen fibrils. The mineral component of bone occurs in the form of polycrystalline platelets 2-6 nm in thickness. These platelets are packed and probably glued together in stacks of two or more, ranging up to >30 platelets.

Effect of plate orientation on apparent thickness of mineral plates by transmission electron microscopy.

Purpose: Transmission electron microscopy (TEM) is widely used to study the ultrastructure of bone. The mineral of bone occurs as polycrystalline mineral plates about 3 to 6 nm in thickness. A problem in using TEM to make quantitative analyses of bone is that the orientation of the plates with respect to the plane of the section being imaged is expected to affect their apparent thickness.

Ashing of bone: errors due to loss of CO and their correction.

Introduction: Ashing is widely used to determine weight fraction of water-free bone that is mineral, but no standard procedure exists and the range of techniques used spans a range of temperatures and times over which the amount of weight loss is variable. We show that variability is largely due to progressive loss of CO from CO ions in the apatite crystal lattice, beginning at 600 ℃, typically used for ashing. We test the effect of varying temperature, time, and weight of sample and develop a reliable method, using small samples.

Dataset of oxygen, carbon, and strontium isotope values from the Imperial Roman site of Velia (ca. 1st-2nd c. CE), Italy.

The oxygen (δO), strontium (Sr/Sr), and previously unpublished carbon (δC) isotope data presented herein from the Imperial Roman site of Velia (ca. 1st to 2nd c. CE) were obtained from the dental enamel of human permanent second molars (M2).

Modeling of bending and torsional stiffnesses of bone at sub-microscale: Effect of curved mineral lamellae.

Recent transmission electron microscopy images of transverse sections of human cortical bone showed that mineral lamellae (polycrystalline sheets of apatite crystals) form arcuate multi-radius patterns around collagen fibrils. The 3-6 nm thick mineral lamellae are arranged in stacks of 3-20 layers and curve around individual fibrils, few fibrils, and higher numbers of collagen fibrils. We evaluate the effect of these stacked mineral lamellae with various radius of curvature patterns on the elastic bending and torsional responses of bone at the sub-microscale using a finite element method.