The in vitro biomechanical properties of three methods for internal fixation of femoral neck fractures were evaluated. Fifty cadaveric femura from Beagle dogs were used. Ten intact femora served as controls. In 40 femura, an osteotomy of the femoral neck was performed to simulate a transverse fracture. With the remaining 30 femura, three repair methods (two medium Orthofix pins, a 2.7 mm cort...

We investigate shear strength properties of wet granular materials in the pendular state (i.e., the state where the liquid phase is discontinuous) as a function of water content. Sand and glass beads were wetted and tested in a direct shear cell and under various confining pressures. In parallel, we carried out three-dimensional molecular dynamics simulations by using an explicit equation expre...

mechanical properties of non-split pistachio nuts are among the lada required for the design of equipment needed for processing of the nut. unsplit pistachio nut samples were uniaxially loaded to determine the nut’s needed splitting force and energy, as well as poisson’s ratio and young’s modulus of elasticity. the tests were carried out at four moisture contents (5, 10, 15 and 20% wb), under f...

The mechanical compressive properties of individual thin-wall and thick-wall TiO(2) nanotubes were directly measured for the first time. Nanotubes with outside diameters of 75 and 110 nm and wall thicknesses of 5 and 15 nm, respectively, were axially compressed inside a 400 keV high-resolution transmission electron microscope (TEM) using a new fully integrated TEM-atomic force microscope (AFM) ...

Perfringolysin O (PFO) is a prototypical member of a large family of pore-forming proteins that undergo a significant reduction in height during the transition from the membrane-assembled prepore to the membrane-inserted pore. Here, we show that targeted application of compressive forces can catalyze this conformational change in individual PFO complexes trapped at the prepore stage, recapitula...

The ability of a spatial population of cutaneous, Adelta, and C mechano-nociceptors to encode the location and intensity of a noxious, cutaneous indentation was examined using an isolated preparation in a rat model. Skin and its intact innervation were harvested from the medial thigh of the rat hindlimb and placed in a dish, with the corium side down, containing synthetic interstitial fluid. Th...

The tarsi of the cricket Tettigonia viridissima bear flexible attachment pads that are able to deform, replicating the profile of a surface to which they are apposed. This attachment system is supplemented by a secretion produced by epidermal cells and transported onto the surface of the pad through the pore canals of the pad cuticle. This study shows that the secretion alone is necessary, but ...

As a cementitious material, geopolymers show a high quasi-brittle behavior and a relatively low fracture energy. To overcome such a weakness, incorporation of fibers to a brittle matrix is a well-known technique to enhance the flexural properties. This study comprehensively evaluates the short and long term impacts of different volume percentages of polypropylene fiber (PPF) reinforcement on fl...

Safety standard requirements must be implemented for lumbar support robots, which are mainly used preventing low back pain (LBP) in caregivers. Usually, simulations to mimic actions that not allowed a real person. However, comprehensive validation of simulator dynamic conditions has been conducted. In this study, an ergonomic is validated through forward flexion invasive experiments. The corres...

This study investigated cell survival and gene expression under various compressive stress conditions mimicking orthodontic force by using a newly developed in vitro model of human periodontal ligament-like tissue (HPdLLT). The HPdLLT was developed by three-dimensional culturing of human periodontal ligament fibroblasts in a porous poly-L-lactide matrix with threefold increased culture media pe...