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We report the atomic-scale structures and fluctuatingdynamicalbehavior of size-selected Au55clusters obtained by aberration-correctedscanning transmission electron microscopy (STEM) coupled with systematicSTEM simulations. No high-symmetry structures (face-centered cubicpolyhedron, icosahedron, or decahedron) were observed in our statisticalinvestigation. We find Au55clusters that are characteristicof the theoretically predicted chiral structure and similar sisterisomers (which together we define as the chiral structural zone).The chiral structural zone was found to arise repeatedly in the time-lapsesequences of images we measured, though other amorphous-like structuresare also frequently observed. The approach demonstrated here can beapplied to identify specific low-symmetry atomic structures in othersmall clusters and distinguish them unambiguously from high-symmetryisomers. [ABSTRACT FROM AUTHOR]

A multi-level finite element (FE) method was developed to firstly study the mechanical responses and progressive damage behaviors of graded porous structures made of hydroxyapatite particle reinforced polymer biocomposite (HA/PEEK) under flexure load. In order to bridge the mechanical properties of the base material, damage and failure criteria of the building blocks for the graded porous structure, and macroscopic response of the structure, three-level FE models from micro-, meso- to macro-scale were established. A graded porous biocomposite implant was considered as a continuum structure with a solid section and a porous section with a gradient change in porosity from 29.5 to 80.9% in six equal steps. The macro-scale FE model of the implant was then constructed from the meso-scale unit cubic-shaped cell model, which was made of beam elements with a fixed length but a gradient change in their cross-section areas depending on the porosity level. The base material of the structure, HA/PEEK, was obtained from our previous work through a micro-scale unit cell model consisting of the particle and polymer matrix for predicting its stress-strain relation with dependence on variation of HA volume fraction. By adoption of the proposed method, a virtual three-point bending test was simulated to predict force-displacement relations of the implant and its damage initiation and propagation in both graded and uniform porous structures under flexural load. The trend of the predicted results agreed with those reported in open literature. [ABSTRACT FROM AUTHOR]

Abstract: Ceramic coatings containing TiO2 were formed on Ti6Al2Zr1Mo1V alloy surface by microarc oxidation (MAO) method. The microstructure, phase and chemical composition of the coatings were analyzed by SEM, XRD and EDS techniques. The coating mainly consists of rutile TiO2 and a small amount of anatase TiO2. The infrared emissivity values of coated and uncoated titanium samples when exposed to 700 °C were tested. It was found that the coating exhibits a higher infrared emissivity value (about 0.9) in the wavelength range of 8–14 μm than that of the uncoated titanium alloy, although which shows a slight increase from 0.1 to 0.3 with increasing exposure time at 700 °C. The relatively high infrared emissivity value of the MAO coating is possibly attributed to the photon emission from the as formed TiO2 phase. [Copyright &y& Elsevier]

Abstract: The density-functional theory (DFT) within the full potential linearized augmented plane wave (FPLAPW) method was applied to study the layered organic–inorganic hybrid Fe[CH3(CH2)2PO3(H2O)]. The relative stability of the ground state, the electronic band structure, the magnetic and the conducting properties were investigated. The calculations reveal that the compound has a stable ferromagnetic ground state and the spin magnetic moment per molecule is about 4.0 μ B, which is mainly from Fe(II) ion. By analysis of the band structure, we find that the compound has half-metallic properties. [Copyright &y& Elsevier]

Abstract: We report measurements of third-order optical nonlinearity of the 90GeS2–5Ga2S3–5CdS (in mol%) chalcogenide glass using the femtosecond time-resolved optical Kerr gate technique at 820 nm. The third-order nonlinear susceptibility was estimated to be as large as 1.0×10−12 esu. The full width at half maximum of the Kerr signal was 150 fs, implying that the sample had a response faster than 120 fs. Its response was dominantly assigned to the ultrafast distortion of the electron cloud. This glass sample is promising in future all-optical switching devices. [Copyright &y& Elsevier]

Examines the use of carbon nanotubes for nanometer-sized devices. Description of nanotube devices; Characteristics of the spatial modulation of the nanotube electronic bandgap; Response of the bandgap to metallofullerenes.

Analyses the linkage between panic disorder and five adrenergic receptor loci, since several lines of investigation suggest that the nonadrenergic neurotransmitter system may be involved in the pathogenisis of panic disorder. Clinical methods; Laboratory methods; Statistical methods; Results; Discussion.

Abstract: SrMn2As2 single crystals were grown by the Sn flux method. Structural features of these crystals were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The XRD results show that the single crystal has a rhombohedral structure and grows along the c-axis direction. The microstructure and layered structural features of this material have been examined by SEM and high-resolution TEM observations. The measurements of in-plane resistivity as a function of temperature demonstrate that SrMn2As2 undergoes a phase transition of semiconductor–insulator at a low temperature; the active energies are estimated to be Δ=0.64 and 0.29eV for two distinct regions. Magnetic measurements show a clear antiferromagnetic (AFM) transition at about T N =125K. Therefore, the SrMn2As2 material is an AFM insulator at low temperatures and could be a potential parent compound for superconductors. [Copyright &y& Elsevier]

Highlights: [•] Fe80Ni20–O/TiO2n multilayer thin films were fabricated by magnetron sputtering. [•] In-plane magnetic anisotropy can be adjusted only by the thickness of TiO2 layer. [•] Excellent high-frequency characteristics in gigahertz range can be obtained. [•] Promote the application of the multilayer thin films in the GHz range. [Copyright &y& Elsevier]

Abstract: Through first-principles calculations within the framework of density functional theory, we have computed the electronic structures, mechanical elastic properties and thermodynamic properties of a series of Co-based Co3X (X = Ti, Ta, W, V and Al) intermetallic compounds with the cubic L12-type and hexagonal D019-type structures. The obtained lattice constants and formation energy are in good agreement with available experimental data. In terms of calculated mechanical elastic properties and Poisson’s ratio, most of these Co3X compounds are mechanically stable and exhibit a good ductile property. The calculations also have uncovered that the obtained elastic parameters including single-crystal elastic constants and polycrystalline moduli of Co3X compounds hold a linearly increasing trend as the melting point of the metallic element of X rises. Moreover, the quasi-harmonic Debye-Grüneisen approach has been turned out to be valid in describing the temperature-dependent thermodynamic properties including heat capacity, vibrational entropy, and thermal expansion coefficients of Co3X compounds. [Copyright &y& Elsevier]

Glasses compositions which can be expressed by (100-x)GeS2–xGa2S3 (x=0, 10, 20, 30 mol%), 70GeS2–(30-x)Ga2S3–xCdS (x=0, 10, 15, 20 mol%), and (100-x)GeS2–x[0.5Ga2S3–0.5CdS] (x=0, 10, 20, 30, 40 mol%), were obtained by the melt-quenching technique. Differential scanning calorimetry (DSC) and visible-IR transmission were used to characterize the thermal and optical properties of these glasses, together with refractive index and density measurements. These homogeneous glasses have relatively high glass transition temperatures (338–436 °C), good thermal stabilities, broad transparencies (0.45–11.5 μm), large refractive indices (2.01–2.25), and large densities (2.68–3.18 g cm-3). The long-wavelength cutoff edge is found near 12 μm due to the multiphonon Ge–S and Ga–S vibrations. The compositional dependences of selected properties were also discussed by making reference to the structural variation. [Copyright &y& Elsevier]

Abstract: Thin film materials with excellent high-frequency, magnetic and electrical properties are in great demand in modern electromagnetic devices operating in GHz range. In this letter, we fabricated [Fe80Ni20–O/SiO2] n multilayer thin films with different SiO2 interlayer thicknesses (t=0.5–4nm) and fixed Fe80Ni20–O layer thickness by controlling the sputtering time at room temperature. In these films, the in-plane uniaxial magnetic anisotropy fields can be adjusted in a broad range (from 26 to 107Oe) by just changing the thickness of each SiO2 interlayer without applying any inducing field. Excellent high-frequency performances in GHz range have been observed in the typical sample. [Copyright &y& Elsevier]

Abstract: The tetragonal orthophosphates, YbPO4 and LuPO4, were studied by in situ X-ray diffraction (XRD) at pressures up to 52 and 43GPa, respectively. A reversible phase transition from the zircon structure-type to the scheelite structure-type was found at ∼22GPa for YbPO4 and 19GPa for LuPO4. Coinciding with the transition from the zircon structure-type to the scheelite structure-type, there is a ∼10% reduction in volume and a significant increase in the bulk modulus for both compounds. [Copyright &y& Elsevier]

Abstract: In order to study the stability and the magnetic properties of the molecule-based magnetic compound [Mn2(dpp)2(H2O)2Cl4]⋅2H2O,dpp=2, 3-bis(2-pyridyl) pyrazine, we employ the full potential linearized augmented plane-wave method within the generalized gradient approximation (GGA) to calculate the total energy, the magnetic moments and the electronic structure for the title compound. The calculations reveal that the compound [Mn2(dpp)2(H2O)2Cl4]⋅2H2O,dpp=2,3-bis(2-pyridyl) pyrazine has stable ferromagnetic ground state, and the spin magnetic moment per molecule is about , which mainly comes from the Mn. There exists a dominant intra-molecule ferromagnetic interaction through the double chloro-bridge between Mn2+ ions. The total density of states show this compound is a semiconductor. The computation is in agreement with the experiment. [Copyright &y& Elsevier]

Abstract: N-doped carbon films were prepared on Si(100) and Ti–6Al–4V substrates using direct current magnetically filtered cathodic arc deposition (DC-MFCAD) at room temperature for various different N2 pressures. The structure and composition of the films were characterized by Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Ball-on-disk and microhardness tests were used to characterize the mechanical properties of the films, and Hall effect tests were employed to study the electrical properties. [Copyright &y& Elsevier]

Abstract: The present work studies the AISI304 weld cracking mechanism of AISI321 austenite stainless steel of flue gas pipe, which served up to 60,000 h at 650–700 °C. The performance and microstructure of failed material were characterized by impact test, optical microscopy, scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS), X-ray diffraction (XRD). The results show that cracks ware caused by embrittlement of weld metal and thermal stress. Needle like σ-phase precipitation during service is primarily responsible for significant degradation in mechanical properties and microstructures of weld metal. Needle type σ-phase is a severe stress-raiser and plays a role as crack initiator at the interface with matrix. In addition, maximum equivalent stress is about 175 MPa in the elbow which is near to the yield stress of the steel. It is highly possible that a crack will be initiated under above stress condition and will propagate faster along embrittled σ-phase. Several approaches should be employed to control σ-phase precipitation in weld. These approaches include: decreasing content of ferrite and M23C6 carbide in weld and selecting Nb added weld wire during welding. [Copyright &y& Elsevier]

An advanced hydrothermal modification method was developed to synthesis Ni/Al2O3 catalyst with perfect activity. SEM, XRD, DTA–TG and XPS were used to characterize the textural properties of the materials obtained after each synthesis step. The experimental results indicated that the modification of the impregnation samples at elevated temperatures enhanced the absorption of Ni(NO3)2·xH2O on the surface of supporters which were composed mainly of Al(OH)3 and AlOOH, leading to the formation of the porous sintering products (NiAl2O4/Al2O3) with bigger specific surface areas and higher Ni contents. The conversion of CH4 increased a lot by using the hydrothermal-modified catalyst instead of using the catalyst prepared via the traditional impregnation–sintering route. [Copyright &y& Elsevier]

Abstract: Polycrystalline and single crystalline samples of CaFe2As2 were prepared by using different fabrication routes. These samples show evident differences in both phase transition temperatures and transport properties depending on fabrication conditions. TEM observations reveal a rich variety of structural phenomena in these materials, such as a tweed-like pattern in self-flux samples, a structural modulation along the 〈110〉tetra direction in the polycrystalline sample, and complex dislocation networks in the Sn-flux samples. Careful analysis shows that the twinning domains arising from the tetragonal-to-orthorhombic phase transition belong to the δ-type. [Copyright &y& Elsevier]

In the synthesis of carbon nanotubes from ethylene decomposition by a Fe/Mo/Al2O3 catalyst at 823 K, the long and continuous coaxial carbon–metal nanowires up to 540 nm is observed. And for the first time, it is observed that the coaxial carbon–metal nanowires can grow in tip and base growth mode simultaneously. A detailed formation mechanism is proposed, where the aggregation of metal particles, lift-up of nanotubes obeying different growth modes and the deformation of metal particles by nanotubes are considered as the necessary steps for the formation of the nanowires. [Copyright &y& Elsevier]

CoCrMo alloy is one of the leading joint replacement biomaterials. However, the wear and corrosion of CoCrMo alloys may release metal ions into the physiological environment and cause failure of the joint implant surgery. In this work, a Cr-doping graphite-like carbon (Cr-GLC) nanocomposite film is coated on the wrought CoCrMo alloy to improve its biotribological properties and corrosion resistance, which can prolong the implant lifespan. Experimental results show that the CoCrMo alloy coated with the Cr-GLC nanocomposite film exhibits a nanocrystalline/amorphous microstructure, which owns excellent mechanical properties and wettability. Moreover, its biotribological properties are found to be 5 times better than those of CoCrMo substrates, due to high hardness of amorphous carbon film and strengthening of Cr 7 C 3 nanoparticles and the corrosion resistance is also improved with two orders of magnitude in the simulated body fluid condition, due to chemical inertness of Cr-GLC nanocomposite films. Thus, it is suggested that CoCrMo alloy coated by the Cr-GLC nanocomposite film is a good candidate for joint replacement applications. • Biotribological properties and corrosion resistance of a Cr-GLC film were studied. • The Cr-GLC film has high hardness and strong adhesion force. • Wear resistance of CoCrMo in NCS solution was improved by 5 times. • Corrosion resistance of CoCrMo was improved by two orders of magnitude. • CoCrMo coated by Cr-GLC film is a good candidate for joint replacement applications. [ABSTRACT FROM AUTHOR]

Hyperhomocysteinemia (hHcys) is an important independent risk factor for the development of cardiovascular disease and end-stage renal disease. Although multiple approaches lowering the levels of homocysteine have been used in experimental studies and clinical trials, there is no effective therapy available to fully prevent homocysteine-induced injury. Therefore, identifying key molecules in the pathogenic pathways may provide clues to develop new therapeutic strategies for the treatment of hHcys-associated injury beyond lowering the plasma homocysteine levels. In this study, we found that the levels of progranulin (PGRN), an autocrine growth factor, were significantly reduced in the kidney and heart from a mouse model of hHcys. We further observed that in hHcys, PGRN-deficient mice significantly exacerbated cardiorenal injury as evidenced by higher levels of urinary albumin excretion, more severe renal morphological injuries, including pronounced glomerular basement membrane thickening and podocyte foot process effacement, and adverse myocardial remodeling versus wild-type mice. Mechanistically, we found that PGRN-medicated Wnt/β-catenin signaling was one of the critical signal transduction pathways that links homocysteine to cardiorenal injury. Importantly, we finally provided direct evidence for the therapeutic potential of PGRN in mice with hHcys by pretreatment with recombinant human PGRN. Collectively, our results suggest that PGRN may be an innovative therapeutic strategy for treating patients with hHcys., (© 2016 American Heart Association, Inc.)