INTRODUCTION The purpose of the study is to compare the effects of genistein, estradiol, estradiol/progesterone combination on the bone mineral density and biomechanical properties of ovariectomized rats' bone. METHODS 50 female adult Sprague-Dawley rats were divided into five groups. Bilaterally ovaeriectomy were performed in all groups except the sham-operated group. Groups were a sham-oper...

The Multi-DOF forceps manipulator we developed has two additional DOF of bending on the tip of forceps, and provides new surgical fields and techniques for surgeons. The most remarkable characteristics of the prototype described in this paper are: 1) the small diameter and the small radius of curvature of bending; 2) the confirmation of perfect cleanness and sterilization of this manipulator. I...

We use the cyclization of small DNA molecules, approximately 200 bp in length, to study conformational properties of DNA fragments with single-stranded gaps. The approach is extremely sensitive to DNA conformational properties and, being complemented by computations, allows a very accurate determination of the fragment's conformational parameters. Sequence-specific nicking endonucleases are use...

PURPOSE The aim of this in vitro study was to evaluate the mechanical properties (bending strength and hardness) of seven different fiber reinforced composite posts, in relation to their microstructural characteristics. MATERIALS AND METHODS Two hundred eighty posts were divided into seven groups of 40, one group for each type of post analyzed. Within each group, 15 posts were subjected to th...

Bundles of filamentous actin (F-actin) form primary structural components of a broad range of cytoskeletal processes including filopodia, sensory hair cell bristles and microvilli. Actin-binding proteins (ABPs) allow the cell to tailor the dimensions and mechanical properties of the bundles to suit specific biological functions. Therefore, it is important to obtain quantitative knowledge on the...

An analytic expression is derived for the distribution G(~ R) of the end-to-end distance ~ R of semiflexible polymers in external potentials to elucidate the effect of confinement on the mechanical and statistical properties of biomolecules. For parabolic confinement the result is exact whereas for realistic potentials a self-consistent ansatz is developed, so that G(~ R) is given explicitly ev...

Strand length, free-fall distance (FFD), and plate spacing was varied to control the strand alignment distribution of strandboard. To determine the strand angle distribution, photographs of strands were recorded as digital image data, and strand angle analysis was conducted using a modified von Mises distribution function. A part of this measurement was used as a reference for the alignment in ...

In order to replicate the fracture behavior of the intact human skull under impact it becomes necessary to develop a material having the mechanical properties of cranial bone. The most important properties to replicate in a surrogate human skull were found to be the fracture toughness and tensile strength of the cranial tables as well as the bending strength of the three-layer (inner table-dipl...