Physiology and cell biology of acupuncture observed in calcium signaling activated by acoustic shear wave

This article presents a novel model of acupuncture physiology based on cellular calcium activation by an acoustic shear wave (ASW) generated by the mechanical movement of the needle. An acupuncture needle was driven by a piezoelectric transducer at 100 Hz or below, and the ASW in human calf was imaged by magnetic resonance elastography. At the cell level, the ASW activated intracellular Ca 2+ transients and oscillations in fibroblasts and endothelial, ventricular myocytes and neuronal PC-12 cells along with frequency-amplitude tuning and memory capabilities. Monitoring in vivo mammalian experiments with ASW, enhancement of endorphin in blood plasma and blocking by Gd 3+ were observed; and increased Ca 2+ fluorescence in mouse hind leg muscle was imaged by two-photon microscopy. In contrast with traditional acupuncture models, the signal source is derived from the total acoustic energy. ASW signaling makes use of the anisotropy of elasticity of tissues as its waveguides for transmission and that cell activation is not based on the nervous system. © 2011 The Author(s).published_or_final_versionSpringer Open Choice, 21 Feb 201

Investigation on the thermal effects during nanometric cutting process while using nanoscale diamond tools

In this paper, large scale molecular dynamics simulations are carried out to investigate the thermal effect on nanometric cutting of copper while using a single tip and a multi-tip nanoscale diamond tool. A new concept of atomistic equivalent temperature is proposed and used to characterize the temperature distribution in the cutting zone. The results show that the cutting heat generated while using a multi-tip tool is larger than that of using a single tip tool. The local temperature is found to be higher at the inner sides of the multi-tip tool cutting edges than the outer sides. Applying centro-symmetry parameters and radius distribution function, the local annealing process and its effect on the integrity of the machined nanostructures are analyzed. It is observed that the local annealing at the machined surface can improve the surface integrity of the machined nanostructures, especially in the multi-tip diamond tool cutting process. There exists a great potential to control the thickness of residual atomic defect layer through an optimal selection of the cutting speed with designed depth of cut

The structural basis of autotransporter translocation by TamA

TamA is an Escherichia coli Omp85 protein involved in autotransporter biogenesis. It comprises a 16-stranded transmembrane β-barrel and three POTRA domains. The 2.3-Å crystal structure reveals that the TamA barrel is closed at the extracellular face by a conserved lid loop. The C-terminal β-strand of the barrel forms an unusual inward kink, which weakens the lateral barrel wall and creates a gate for substrate access to the lipid bilayer