Shear Softening in a Metallic Glass: First-Principles Local-Stress Analysis.

Metallic glasses deform elastically under stress. However, the atomic-level origin of elastic properties of metallic glasses remain unclear. In this Letter using ab initio molecular dynamics simulations of the Cu_{50}Zr_{50} metallic glass under shear strain, we show that the heterogeneous stress relaxation results in the increased charge transfer from Zr to Cu atoms, enhancing the softening of the shear modulus.

Muscle activation patterns in acceleration-based phases during reach-to-grasp movement.

[Purpose] An earlier study divided reaching activity into characteristic phases based on hand velocity profiles. By synchronizing muscle activities and the acceleration profile, a phasing approach for reaching movement, based on hand acceleration profiles, was attempted in order to elucidate the roles of individual muscle activities in the different phases of the acceleration profile in reaching movements. [Subjects and Methods] Ten healthy volunteer subjects participated in this study.

Microrelief suppresses large wrinkling appearance: an in silico study.

Background And Purpose: Extensive skin wrinkling during facial expressions is one of the considerable problems in aesthetic dermatology. Although a few in silico studies have been performed with the aim of revealing the mechanism of a wrinkled appearance, there have been few studies that take into account the influence of skin roughness (i.e.

Si segregation at Fe grain boundaries analyzed by ab initio local energy and local stress.

Using density-functional theory calculations combined with recent local-energy and local-stress schemes, we studied the effects of Si segregation on the structural, mechanical and magnetic properties of the Σ3(1 1 1) and Σ11(3 3 2) Fe GBs formed by rotation around the [1 1 0] axis. The segregation mechanism was analyzed by the local-energy decomposition of the segregation energy, where the segregation energy is expressed as a sum of the following four terms: the local-energy change of Si atoms from the isolated state in bulk Fe to the GB segregated state, the stabilization of replaced Fe atoms from the GB to the bulk, the local-energy change of neighboring Fe atoms from the pure GB to the segregated GB and the local-energy change of neighboring Fe atoms from the system of an isolated Si atom in the bulk Fe to the pure bulk Fe. The segregation energy and value of each term greatly depends on the segregation site and Si concentration.

[Objective and subjective measures of sleep of shift-working nurses].

Objectives: To objectively evaluate sleep quality of shift-working nurses, we used an Actiwatch 2, a watch-like actigraphy device designed to measure sleep and wakefulness based on the amount of movement. Subjective sleep quality was also assessed using the St. Mary's Hospital Sleep Questionnaire.