La
2
O
3
is added into boriding agent considered as a role of boriding catalyst to improve the growth of TiB crystal whiskers in commercial purity titanium (CP-Ti) substrate by electrolytic ...boronising technology. The catalytic mechanism of boriding catalyst is discussed. The boriding of CP-Ti substrates is carried out in an electrochemical cell in which we use a mixture of sodium tetraborate and potassium carbonate as the base ingredients of molten electrolyte. Both TiB
2
and TiB phases in the borided titanium samples are confirmed by X-ray diffraction method (XRD). Scanning electron microscopy (SEM) images reveal the boride layers consist of a homogeneous TiB
2
phase on the top and TiB whiskers toward the substrate, and the result verify boriding catalyst promotes the growth of crystal whiskers significantly with an average boride layer thickness of 132 μm and a maximum thickness 338 μm.
Superelastic behavior is traditionally related to the martensitic transition with a collective transformation scenario in some shape memory alloys. A kind of quasi‐linear superelasticity accompanied ...by a finite avalanche or confined martensitic transformation was recently found in some alloy systems with strain glass state. Here, an in situ neutron diffraction technique was used to study the deformation behavior in an Ni43Fe18Ga27Co12 alloy with strain glass state in order to reveal the new intrinsic physical nature of the quasi‐linear superelasticity. A significant modulus softening prior to the stress‐induced martensitic transformation was observed during compression in the studied alloy, which is similar to the characteristics exhibited in the tweed precursor phenomena prior to temperature‐induced martensitic transformation. Moreover, the diffraction peak broadening was further shown during the elastic stage of deformation for both single‐crystal and polycrystalline samples, which mainly stems from the short‐range fluctuation in the strain field inside each grain based on Williamson–Hall analysis. The authors believe that there exists a spatial heterogeneity in the modulus of the confined martensitic transformation alloy.
Abstract Pure hydroxyapatite (HA) is brittle and it cannot be directly used for the load-bearing biomedical applications. The purpose of this investigation was to develop a new iron-containing ...HA/titanium composite via pressureless sintering at a relatively low temperature with particular emphasis on identifying the underlying toughening mechanisms. The addition of iron to HA/titanium composites led to a unique and favorable core/shell microstructure of Ti–Fe particles that consisted of outer titanium and inner iron, and good interfacial bonding with HA matrix. While the relative density, hardness and Young's modulus reduced, the flexural strength, fracture toughness, fatigue resistance, and the related fracture surface roughness increased significantly with increasing amount of Ti–Fe particles. Different toughening mechanisms including crack bridging, branching and deflection were observed in the composites, thus effectively increasing the crack propagation resistance and resulting in a substantial improvement in the mechanical properties of the composites.
Down-regulation of long non-coding RNA tumor suppressor candidate 7(TUSC7) contributes to tumorigenesis in several human cancers including glioma. However, the prognostic value of TUSC7 in glioma ...remains unclear. The present study aimed to investigate the clinicopathological and prognostic value of TUSC7.
The expression level of TUSC7 in glioma tissues and matched normal tissues were detected by qRT-PCR. Then, the association of serum TUSC7 expression level with various important clinicopathological parameters and survival rates was evaluated. The Cox regression analysis was used to evaluate the effect of independent prognostic factors on survival outcome.
The relative level of TUSC7 was significantly lower in glioma tissues compared to the adjacent normal brain tissues (p < 0.01). In addition, a lower expression of TUSC7 was observed in high-grade glioma tissues than in low-grade glioma tissues (p < 0.01). Furthermore, the low expression of TUSC7 was associated with poor clinicopathological characteristics of glioma, including WHO grade (p = 0.002) and KPS (p = 0.026). Then, the low TUSC7 level was correlated with shorter disease free survival (DFS) and overall survival (OS) than low level (both p = 0.05). Finally, univariate and multivariate Cox analysis showed that TUSC7 was an independent prognostic indicator for OS and DFS.
These results provided evidence that TUSC7 may be a potential biomarker in the prognosis of glioma.
Highlights • Blockade of Hcrtr1 within the mPFC inhibited the putative pyramidal neuron activity. • Hcrtr1 inactivation selectively reduced the power of the gamma oscillations. • The neuron activity ...and oscillations were not influenced after Hcrtr2 inactivation.
This paper theoretically and systematically investigates: (1) the effect of local transformed strains within deformation twinning on twin intersection; (2) the fracture mode based on type I co-zone ...tensile twin intersection in coarse-grained magnesium alloys, as well as the impacts of twin intersection and grain diameter on interfacial crack nucleation along twin boundaries; and (3) the influence of the local stresses arising from the encountered twin bands on crack growth. A novel dislocation-based strain nucleus model and a Green's function method, which are applicable to any material with local transformations in which elastic properties are reasonably approximated as isotropic, are specifically employed to model the concentrated transformed strain and calculate the local stress field resulting from deformation twinning and the stress intensity factors at crack tips in the magnesium alloys, respectively. In addition, an electron backscatter diffraction (EBSD) measurement is provided for crack nucleation originating from Type I co-zone tensile twin intersection. The theoretical modeling indicates: (i) the local strains within barrier twins strongly dictate the growth of incident twins and enhance the twin propagation stress; (ii) larger grains favor brittle fracture. More specifically, the dislocation reactions and pile-ups at the junctions between tensile twins can result in interfacial crack nucleation and growth along the twin boundaries, which is a brittle fracture mode based on lower twinning stress and stress concentration in the coarse-grained magnesium alloys; and (iii) the direction of crack propagation is easily changed by high-density twin bands and twin intersections owing to the local strains.
•The effects of local transformed strains within deformation twinning on twin intersection and cracking are considered.•To model the local stresses arising from the deformation twinning, a novel strain nucleus model are employed.•The fracture mode based on type I co-zone tensile twin intersection in coarse-grained Mg alloys is theoretically modeled.
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