The usefulness of diffusion‐weighted readout‐segmented EPI and fast spin echo with BLADE (PROPELLER) k‐space sampling: A comparison with single‐shot EPI for diffusion‐weighted imaging in ischemic stroke patients

We evaluated the value of diffusion‐weighted readout‐segmented EPI (DW rs‐EPI) and diffusion‐weighted fast spin echo images with BLADE (PROPELLER) k‐space sampling (DW BLADE) in patients with ischemic stroke through intra‐individual comparisons with diffusion‐weighted single‐shot EPI (DW ss‐EPI). Forty‐four patients with acute ischemic stroke who had undergone three different types of diffusion weighted imaging (DWI) (b = 1000 s/mm²) were included. Two reviewers assessed the three types of DWI for diagnostic confidence based on a five‐point confidence score (CS). The inter‐ and intra‐observer agreements for the CS were assessed. The DWI signal ratio to the contralateral normal area and the apparent diffusion coefficient (ADC) of DWI lesions were compared. The CSs of the three DWI methods were significantly different (P < 0.001). A post hoc analysis showed a significantly higher CS with DW rs‐EPI than with DW ss‐EPI (P = 0.022). There were significant increases in the CSs for DW rs‐EPI compared to DW ss‐EPI, for patients who underwent DWI within 24 h of symptom onset, and for patients with DWI lesions ≤ 50 mm². The inter‐observer and intra‐observer agreements of the CS were good. DW rs‐EPI increased the diagnostic confidence of ischemic stroke compared to DW ss‐EPI, particularly for patients with small lesions and for those who underwent DWI within 24 h of symptom onset. DW BLADE showed a similar level of diagnostic confidence to DW ss‐EPI. © 2016 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 26, 216–224, 2016     

Acute Phase Response as a Biological Mechanism‐of‐Action of (Nano)particle‐Induced Cardiovascular Disease

Inhaled nanoparticles constitute a potential health hazard due to their size‐dependent lung deposition and large surface to mass ratio. Exposure to high levels contributes to the risk of developing respiratory and cardiovascular diseases, as well as of lung cancer. Particle‐induced acute phase response may be an important mechanism of action of particle‐induced cardiovascular disease. Here, the authors review new important scientific evidence showing causal relationships between inhalation of particle and nanomaterials, induction of acute phase response, and risk of cardiovascular disease. Particle‐induced acute phase response provides a means for risk assessment of particle‐induced cardiovascular disease and underscores cardiovascular disease as an occupational disease.     

Influence of the Al(Co,Ni) layer on the corrosion resistance of a cobalt based alloy (Mar‐M‐509®)

In the present work, the results of studies on the structure and corrosion resistance of Al(Co, Ni) layer are shown. The diffusion Al(Co, Ni) layer was created on the cobalt alloy Mar‐M‐509 substrate by chemical vapor deposition (CVD) method with aluminum trichloride (AlCl₃) under the hydrogen atmosphere. The scanning electron microscope (SEM) observations and microtomography measurements of layers were performed. Also an analysis of the chemical (energy‐dispersive X‐ray spectroscopy (EDS)) and phase (X‐ray diffraction (XRD)) composition was carried out. By the X‐ray diffraction method (sin² φ) also the residual stresses were calculated in the matrix of the material. The corrosion resistance was tested with impedance and potentiodynamic methods in 0.1 M Na₂SO₄, 0.1 M H₂SO₄ solutions and acidulous 0.1 M NaCl solution (pH = 4.2) at room temperature. The results indicate that the analyzed layer with a thickness of about 14 μm have a similar corrosion resistance compared to the base material – Mar‐M‐509^® cobalt alloy. Only in the strongly acidic environments, the corrosion resistance of the layer is remarkably decreased.     

Out‐of‐Plane Strain Induced in a Moiré Superstructure of Monolayer MoS2 and MoSe2 on Au(111)

Making contact of transition metal dichalcogenides (TMDCs) with a metal surface is essential for fabricating and designing electronic devices and catalytic systems. It also generates strain in the TMDCs that plays significant role in both electronic and phonon structures. Therefore, detailed understanding of mechanism of the strain generation is important to fully comprehend the modulation effect for the electronic and phonon properties. Here, MoS₂ and MoSe₂ monolayers are grown on Au surface by chemical vapor deposition and it is demonstrated that the contact with a crystalline Au(111) surface gives rise to only out‐of‐plane strain in both MoS₂ and MoSe₂ layers, whereas no strain generation is observed on polycrystalline Au or SiO₂/Si surfaces. Scanning tunneling microscopy analysis provides information regarding consequent specific adsorption sites between lower S (Se) atoms in the S? Mo? S (Se? Mo? Se) structure and Au atoms via unique moiré superstructure formation for MoS₂ and MoSe₂ layers on Au(111). This observation indicates that the specific adsorption sites give rise to out‐of‐plane strain in the TMDC layers. Furthermore, it also leads to effective modulation of the electronic structure of the MoS₂ or MoSe₂ layer.     

A cell‐based smoothed discrete shear gap method (CS‐FEM‐DSG3) based on the C0‐type higher‐order shear deformation theory for dynamic responses of Mindlin plates on viscoelastic foundations subjected to a moving sprung vehicle

A cell‐based smoothed discrete shear gap method (CS‐FEM‐DSG3) based on the first‐order shear deformation theory (FSDT) was recently proposed for static and dynamic analyses of Mindlin plates. In this paper, the CS‐FEM‐DSG3 is extended to the C⁰‐type higher‐order shear deformation plate theory (C⁰‐HSDT) and is incorporated with damping–spring systems for dynamic responses of Mindlin plates on viscoelastic foundations subjected to a moving sprung vehicle. At each time step of dynamic analysis, one four‐step procedure is performed including the following: (1) transformation of the weight of a four‐wheel vehicle into the sprung masses at wheels; (2) dynamic analysis of the sprung mass of wheels to determine the contact forces; (3) transformation of the contact forces into loads at nodes of plate elements; and (4) dynamic analysis of the plate elements on viscoelastic foundations. The accuracy and reliability of the proposed method are verified by comparing its numerical solutions with those of other available numerical results. Copyright © 2014 John Wiley & Sons, Ltd.     

The effect of pit size and density on the fatigue behaviour of a pre‐corroded martensitic stainless steel

UNS S17400 steel is used in turbines for the aerospace and utility industries. While it is generally corrosion resistant, it is susceptible to pitting when exposed to aqueous chloride environments. Effects of pitting characteristics, such as depth, width, and local density on fatigue life, have been studied in this work to better inform criteria for component replacement or repair. While pit depth correlates well with cracking, the deepest pit never initiated the crack that ultimately led to failure. The clustering of pits, or local pitting density, also correlated well with crack initiation location; however, the densest region of pitting was not always the location where cracking occurred. There is likely no single metric that directly correlates pitting with fatigue cracking, rather there is a combination of pitting characteristics that ultimately lead to cracking. The results from this work suggest that pit depth and local pitting density are among the more important metrics.     

Effects of l‐carnitine supplement on serum inflammatory cytokines,C‐reactive protein,lipoprotein (a), and oxidative stress in hemodialysis patients with Lp (a) hyperlipoproteinemia

Inflammation, oxidative stress, and high concentration of serum lipoprotein (a) [Lp (a)] are common complications in hemodialysis patients. The present study was designed to investigate the effects of l ‐carnitine supplement on serum inflammatory cytokines, C‐reactive protein (CRP), Lp (a), and oxidative stress in hemodialysis patients with Lp (a) hyperlipoproteinemia [hyper Lp (a)]. This was an unblinded, randomized clinical trial. Thirty‐six hyper Lp (a) hemodialysis patients (23 men and 13 women) were randomly assigned to either a carnitine or control group. Patients in the carnitine group received 1000 mg/d oral l ‐carnitine for 12 weeks, whereas patients in the control group did not receive any l ‐carnitine supplement. At baseline and the end of week 12, 5 mL of blood were collected after a 12‐ to 14‐hours fast and serum free carnitine, CRP, interleukin‐1β, interleukin‐6 (IL‐6), tumor necrosis factor‐α, Lp (a), and oxidized low‐density lipoprotein were measured. Serum free carnitine concentration increased significantly by 86% in the carnitine group at the end of week 12 compared with baseline (P<0.001), while serum CRP and IL‐6 showed a significant decrease of 29% (P<0.05) and 61% (P<0.001), respectively. No significant changes were observed in serum free carnitine, CRP, and IL‐6 in the control group. There were no significant differences between the two groups in mean changes of serum interleukin‐1β, tumor necrosis factor‐α, Lp (a), and oxidized low‐density lipoprotein concentrations. l ‐carnitine supplement reduces inflammation in hemodialysis patients, but has no effect on hyper Lp (a) and oxidative stress.     

Epitaxial Growth of 6 in. Single‐Crystalline Graphene on a Cu/Ni (111) Film at 750 °C via Chemical Vapor Deposition

The future electronic application of graphene highly relies on the production of large‐area high‐quality single‐crystal graphene. However, the growth of single‐crystal graphene on different substrates via either single nucleation or seamless stitching is carried out at a temperature of 1000 °C or higher. The usage of this high temperature generates a variety of problems, including complexity of operation, higher contamination, metal evaporation, and wrinkles owing to the mismatch of thermal expansion coefficients between the substrate and graphene. Here, a new approach for the fabrication of ultraflat single‐crystal graphene using Cu/Ni (111)/sapphire wafers at lower temperature is reported. It is found that the temperature of epitaxial growth of graphene using Cu/Ni (111) can be reduced to 750 °C, much lower than that of earlier reports on catalytic surfaces. Devices made of graphene grown at 750 °C have a carrier mobility up to ≈9700 cm² V^?1 s^?1 at room temperature. This work shines light on a way toward a much lower temperature growth of high‐quality graphene in single crystallinity, which could benefit future electronic applications.     

The Influence of Carbon Nitride Nanosheets Doping on the Crystalline Formation of MIL‐88B(Fe) and the Photocatalytic Activities

In this research, bulk graphitic carbon nitride (g‐C₃N₄) is exfoliated and transferred to the carbon nitride nanosheets (CNNSs), which are then coupled with MIL‐88B(Fe) to form the hybrid. From the results of the powder X‐ray diffraction, scanning electronic microscopy and thermogravimetric analysis, it is found that the doping of CNNSs on the surface of MIL‐88(Fe) could maintain the basic structure of MIL‐88B(Fe), and the smaller dimension of CNNSs might influence the crystallization process of metal‐organic frameworks (MOFs) compared to bulk g‐C₃N₄. Besides, the effects of the CNNSs incorporation on photocatalysis are also investigated. Through the photoluminescence spectra, electrochemical measurements, and photocatalytic experiments, the hybrid containing 6% CNNSs is certified to possess the highest catalytic activity to degrade methylene blue and reduce Cr(VI) under visible light. The improvement of the photocatalytic performance can be attributed to the matched energy level which favors the formation of the heterojunctions. Besides, it promotes the charge migration such that the contact between MOFs and CNNSs is more intimate, which can be inferred from the electronic microscopy images. Finally, a possible photocatalytic mechanism is put forward by the relative calculation and the employment of the scavengers to trap the active species.