Investigation of the microcrack evolution in a Ti-based bulk metallic glass matrix composite

AbstractThe initiation and evolution behavior of the shear-bands and microcracks in a Ti-based metallic-glass–matrix composite (MGMC) were investigated by using an in-situ tensile test under transmission electron microscopy (TEM). It was found that the plastic deformation of the Ti-based MGMC related with the generation of the plastic deformation zone in crystalline and shear deformation zone in glass phase near the crack tip. The dendrites can suppress the propagation of the shear band effectively. Before the rapid propagation of cracks, the extending of plastic deformation zone and shear deformation zone ahead of crack tip is the main pattern in the composite

Cu-7Cr-0.1Ag Microcomposites Optimized for High Strength and High Condutivity

This paper (i) investigated how the microstructure, conductivity, and mechanical properties of Cu-7Cr-0.1Ag microcomposites were changed by cold drawing and subsequent heat treatment, and (ii) produced the Cu-7Cr-0.1Ag microcomposite with an optimum combination of strength and conductivity. The figure of merit Z (combining strength and conductivity) of the Cu-7Cr-0.1Ag microcomposite was larger than that of the microcomposite without silver for each heat treatment. The value of Z of the Cu-7Cr-0.1Ag microcomposite was a maximum after heat treatment for 1 h at 600 °C, indicating that this was the optimum intermediate heat treatment. The following combinations of conductivity, strength and ductility (measured as elongation to fracture) were obtained by the Cu-7Cr-0.1Ag microcomposite with η = 8: (i) 77.9% IACS (International Annealed Copper Standard), 920 MPa and 3.1%; (ii) 79.3% IACS, 880 MPa and 3.3%; and (iii) 79.9% IACS, 798 MPa and 3.5%. These values for the Cu-7Cr-0.1Ag microcomposite were larger than those of the Cu-7Cr microcomposite

Serotype specific epitopes identified by neutralizing antibodies underpin immunogenic differences in Enterovirus B

So far no vaccine or antiviral therapy is available for Echovirus 30 (E30) that causes aseptic meningitis. Here, the authors generate and characterise two E30-specific monoclonal antibodies that block binding of the virus to its attachment receptor CD55 and uncoating receptor FcRn, and determine the cryo-EM structures of E30 with the bound neutralizing antibodies

Cu-7Cr-0.1Ag Microcomposites Optimized for High Strength and High Condutivity

This paper (i) investigated how the microstructure, conductivity, and mechanical properties of Cu-7Cr-0.1Ag microcomposites were changed by cold drawing and subsequent heat treatment, and (ii) produced the Cu-7Cr-0.1Ag microcomposite with an optimum combination of strength and conductivity. The figure of merit Z (combining strength and conductivity) of the Cu-7Cr-0.1Ag microcomposite was larger than that of the microcomposite without silver for each heat treatment. The value of Z of the Cu-7Cr-0.1Ag microcomposite was a maximum after heat treatment for 1\ua0h at 600\ua0°C, indicating that this was the optimum intermediate heat treatment. The following combinations of conductivity, strength and ductility (measured as elongation to fracture) were obtained by the Cu-7Cr-0.1Ag microcomposite with η\ua0=\ua08: (i) 77.9% IACS (International Annealed Copper Standard), 920\ua0MPa and 3.1%; (ii) 79.3% IACS, 880\ua0MPa and 3.3%; and (iii) 79.9% IACS, 798\ua0MPa and 3.5%. These values for the Cu-7Cr-0.1Ag microcomposite were larger than those of the Cu-7Cr microcomposite

Manual acupuncture as prophylaxis for migraine without aura: study protocol for a multi-center, randomized, single-blinded trial

Abstract Background Migraine is a highly prevalent neurological disorder. It is the third most prevalent disorder and the seventh highest cause of disability worldwide. Acupuncture may be a viable prophylactic treatment option for frequent or uncontrolled migraine. Clinical studies comparing acupuncture and placebo acupuncture have not reached a consistent conclusion in confirming whether acupuncture is effective in migraine prophylaxis. The effect of acupuncture mainly depends on acupoints and needles operation. We found that the design of the placebo acupuncture in previous studies included shallow needling at sham acupoints, non-penetrating needling at sham acupoints, and needling at inactive acupuncture points to achieve the inert effect of control group, but the non-penetrating needling at true acupoints was ignored. This randomized controlled trial aims to use true acupoints for non-penetrating acupuncture as control to evaluate the efficacy of manual acupuncture for the prophylaxis of migraine without aura (MWoA). Methods/design This is a single-blinded, randomized, controlled, prospective, multi-center trial with two parallel treatment groups. A total of 198 eligible patients with MWoA will be randomly divided into two groups (1:1 allocation ratio). The intervention group will receive manual acupuncture and the control group will receive placebo acupuncture (non-penetrating). Patients will receive three acupuncture treatment sessions per week for 4 consecutive weeks. All patients will then receive a 12-week follow-up. Discussion In this study, we are evaluating the efficacy and safety of manual acupuncture in the prophylaxis of MWoA. The placebo control is using non-penetrating needling verum acupoints. It is essential to determine an appropriate control method to ensure the methodological quality of a randomized controlled trial. Trial registration The trial has been registered in the Chinese Clinical Trial Registry (approval no. ChiCTR2000032308 ) in April 2020

Substrate Facet Effect on the Growth of Monolayer MoS₂ on Au Foils

MoS₂ on polycrystalline metal substrates emerges as an intriguing growth system compared to that on insulating substrates due to its direct application as an electrocatalyst in hydrogen evolution. However, the growth is still indistinct with regard to the effects of the inevitably evolved facets. Herein, we demonstrate for the first time that the crystallography of Au foil substrates can mediate a strong effect on the growth of monolayer MoS₂, where large-domain single-crystal MoS₂ triangles are more preferentially evolved on Au(100) and Au(110) facets than on Au(111) at relative high growth temperatures (>680 °C). Intriguingly, this substrate effect can be weakened at a low growth temperature (∼530 °C), reflected with uniform distributions of domain size and nucleation density among the different facets. The preferential nucleation and growth on some specific Au facets are explained from the facet-dependent binding energy of MoS₂ according to density functional theory calculations. In brief, this work should shed light on the effect of substrate crystallography on the synthesis of monolayer MoS₂, thus paving the way for achieving batch-produced, large-domain or domain size-tunable growth through an appropriate selection of the growth substrate