Aluminum-doped zinc oxide electrode for robust (Pb,La)(Zr,Ti)O3 capacitors: effect of oxide insulator encapsulation and oxide buffer layer

Conductive aluminum-doped zinc oxide (AZO) was deposited by pulsed laser deposition as top electrodes for chemical solution deposition derived lanthanum modified lead zirconate titanate (PLZT) capacitors. Compared with PLZT capacitors with Pt top electrodes (Pt/PLZT/Pt), PLZT capacitors with AZO as top electrodes (AZO/PLZT/Pt) showed improved fatigue endurance after cycles of 200 kV/cm (10 V) were applied with a 100 μs pulse width at 1 ms intervals. By using a combination of AZO as the top electrode and as a thin buffer layer (10 nm) under PLZT thin films (AZO/PLZT/AZO/Pt), fatigue behavior was also improved compared with the case without an AZO buffer layer. The addition of either an Al₂O₃ or HfO₂ encapsulation layer increased the remnant polarization ratio of PLZT capacitors (after annealing at 200 °C, 1 Torr, 3 % hydrogen atmosphere) to 0.80 and 0.57, respectively, comparing with 0.52 without an encapsulation layer.     

Near-infrared reflection from periodically aluminium-doped zinc oxide thin films

Multilayers of aluminium-doped zinc oxide (Al:ZnO) as a heat-reflection material were prepared by a reactive sputtering method with intermittent Al doping or Al content modulation. A drop in the refractive indices n around the plasma wavelength λ_p of 1456 nm for the optimally-doped Al:ZnO layers formed the periodic distribution of n in the multilayers. The periodic n provided selective reflection of approximately 60% under λ_p and shielded near-infrared solar radiation containing high energy, which was impossible to be reflected from the Al:ZnO monolayer. The selective reflection was accompanied by infrared reflection above λ_p, low emissivity and no subsequent visible reflection, which allowed the multilayers to achieve compatibility between the solar heat gain coefficient of 0.6 and the visible transmittance of nearly 80%.     

Eviprostat Activates cAMP Signaling Pathway and Suppresses Bladder Smooth Muscle Cell Proliferation

Eviprostat is a popular phytotherapeutic agent for the treatment of lower urinary tract symptoms (LUTS). At present, the signaling mechanisms underlying its therapeutic effects are still poorly understood. Given that cAMP has been reported to suppress cell hyperplasia and hypertrophy in various pathological situations, we asked whether the effect of Eviprostat could be ascribed to the activation of the cAMP signaling pathway. In the study, exposure of cAMP response element (CRE)-secreted alkaline phosphatase (SEAP) (CRE-SEAP)-reporter cells to Eviprostat elevated SEAP secretion, which was associated with an increased phosphorylation of vasodilator-stimulated phosphoprotein (VASP) and cAMP-response element-binding protein (CREB), as well as enhanced expression of CRE-regulated protein connexin43, indicating an activation of the cAMP signaling pathway. Consistent with these observations, Eviprostat-induced expression of Cx43 was abolished in the presence of adenylyl cyclase inhibitor SQ22536 or PKA inhibitor H89, whereas it was mimicked by adenylyl cyclase activator, forskolin. Further analysis demonstrated that Eviprostat significantly potentiated the effect of phosphodiesterase 3 (PDE3) inhibitor, but not that of PDE4 inhibitor, on CRE activation. Moreover, Eviprostat suppressed PDGF-induced activation of ERK and Akt and inhibited cell proliferation and hillock formation in both mesangial cells and bladder smooth muscle cells. Collectively, activation of the cAMP signaling pathway could be an important mechanism by which Eviprostat exerts its therapeutic effects for LUTS.     

A General Analytical Method for a Three‐Phase Line‐Start Permanent‐Magnet Synchronous Motor

A line‐start permanent‐magnet synchronous motor (LSPMM) consists of a stator with symmetrical three‐phase armature windings and a salient pole rotor with a permanent magnet for excitation and a starting winding similar to the squirrel‐cage winding of an induction motor. In this paper, a general analytical method based on tensor analysis is proposed for practical performance calculation of a three‐phase LSPMM. The general equation for the currents of the three‐phase LSPMM is derived from the transient impedance tensor expressed in polyphase symmetry axes, and the general equation for vibratory and nonvibratory torques is derived from the current equation. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 185(4): 60–68, 2013; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21284     

Caged multiwalled carbon nanotubes as the adsorbents for affinity-based elimination of ionic dyes

Multiwalled carbon nanotubes (MWCNTs) were used as the active elements for the first time for affinity-based elimination of ionic dyes. MWCNTs were encapsulated in cross-linked alginate (ALG) microvesicles using Ba2+ as the bridging ion. The Ba2+-alginate matrix constitutes a cage which holds the physically trapped MWCNTs. The cage carries negative charges on its surface. The cage restricts the access of anions of large molecular weight, such as humic acids, because of electrostatic repulsion. The cage also restricts the access of colloids of large size, because of size exclusion. Ionic dyes partition into the cage and then are captured by MWCNTs probably on the basis of van der Waals interactions occurring between the hexagonally arrayed carbon atoms in the graphite sheet of MWCNTs and the aromatic backbones of the dyes. As a result of these interactions the target species, namely, the ionic dyes, are eliminated efficiently by the MWCNTs of Ba2+-ALG/MWCNT composite adsorbents. The adsorptive capacities for elimination of acridine orange, ethidium bromide, eosin bluish, and orange G (the model species used for this study) were found as high as 0.44, 0.43, 0.33, and 0.31 micromol, respectively, for 1.0 mg of the caged MWCNTs. Adsorptive experiments with carbon nanofibers and activated carbons as the adsorbents were also performed. The MWCNT-based adsorbents provided the best capability for the affinity-based elimination of these targeted species. Biocompatibility experiments performed in vitro and in vivo provided promising results, suggesting potential applications of the caged MWCNTs in in situ environmental remediation.     

Synthesis of spherical LiMn2O4 microparticles by a combination of spray pyrolysis and drying method

Lithium manganese oxide (LiMn₂O₄) has been synthesized by a spray pyrolysis method from the precursor solution; LiNO₃ and Mn(NO₃)₂·6H₂O were stoichiometrically dissolved into distilled water. The synthesized LiMn₂O₄ particles exhibited a pure cubic spinel structure in the X-ray diffraction (XRD) patterns, however they were spherical hollow spheres for various concentrations of precursor solution. Thus, the as-prepared LiMn₂O₄ particles were then ground in a mortar and dispersed into distilled water. To make a well dispersed slurry solution, a dispersion agent was also added into the slurry solution. The LiMn₂O₄ microparticles with a spherical nanostructure were finally prepared by a spray drying method from the slurry solution. The tap density of the LiMn₂O₄ microparticle prepared by a combination of spray pyrolysis and drying method was larger than that by a conventional spray pyrolysis method.The as-prepared samples were sintered at 750 °C for 1 h in air and used as cathode active materials for lithium batteries. Test experiments in the electrochemical cell Li|1 M LiClO₄ in EC:DEC = 1:1|LiMn₂O₄ demonstrate that the sample prepared by the present method is a promising cathode active material for 4 V lithium-ion batteries at high-charge-discharge and elevated temperature operation. The LiMn₂O₄ compounds by the combination of spray pyrolysis and drying method are superior to that by the conventional spray pyrolysis method in terms of electrochemical characteristics and tap density.     

Microbial conversion of palmitoleic acid to 9,12-hexadecadienoic acid (16:2ω4) by Trichoderma sp. AM076

Trichoderma sp. AM076, isolated from a freshwater sample, was found to accumulate 9,12-cis-hexadecadienoic acid (16:2ω4), when grown with palmitoleic acid (16: 1ω7). Methyl myristate was the best carbon source for the conversion of palmitoleic acid to 16:2ω4. The mycelial 16:2ω4 content reached 17.4 mg/g dry mycelia (443 mg/L) when the fungus was grown in a medium that contained 2.0% methyl myristate, 1.5% yeast extract, and 2.0% methyl palmitoleate, pH 6.0, for 5 d at 28°C with shaking. In both nonpolar and polar lipids from the mycelia, 16:2ω4 was detected as one of the major fatty acids when 16:1ω7 was added. It is probable that 16:1ω7 is converted to 16:2ω4 through the Δ12 desaturation reaction.     

Efficient preparation of novel fluoroalkyl end‐capped oligomers/titanium dioxide nanocomposites

Novel fluoroalky end‐capped oligomers/titanium dioxide nanocomposites were prepared by the hydrolysis of titanium isopropoxide in the presence of fluoroalkyl end‐capped N‐(1,1‐dimethyl‐3‐oxobutyl)acrylamide oligomer [R_F‐(DOBAA)_n‐R_F], fluoroalkyl end‐capped N,N‐dimethylacrylamide oligomer [R_F‐(DMAA)_n‐R_F], and fluoroalkyl end‐capped acrylic acid oligomer [R_F‐(ACA)_n‐R_F] in tetrahydrofuran under mild conditions. In these fluorinated oligomers, R_F‐(ACA)_n‐R_F oligomer is more effective for the preparation of the corresponding oligomers/titanium dioxide nanocomposites, and this oligomer can afford the expected fluorinated titanium dioxide nanocomposites in higher isolated yields. In addition, R_F‐(ACA)_n‐R_F/titanium dioxide composites are nanometer size‐controlled very fine nanoparticles (14–48 nm), and exhibited a good dispersibility not only in water but also in traditional organic solvents. Fluoroalkyl end‐capped oligomers/titanium dioxide nanocomposites were also applied to the surface modification of the common organic polymers such as poly(methyl methacrylate) to exhibit a good oleophobic and hydrophilic characteristics on the surface. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers.     

Characterization and functional properties of soybean high-molecular-mass polysaccharide complex

Soybean soluble polysaccharide (SSPS), extracted from the by-product obtained during isolation of soybean protein, is an anionic polysaccharide that stabilizes milk proteins under acidic conditions. We developed a high-molecular-mass complex of SSPS cross-linked via phosphate (SSPS-HC; absolute molecular weight = 2850 kg/mol, radius of gyration = 106 nm), and found that it has different protein stabilization properties when compared with the original SSPS (absolute molecular weight = 550 kg/mol, radius of gyration = 36 nm). The objective of this work was not only to study the rheological properties of SSPS-HC, but also clarify its protein-stabilizing properties in comparison with SSPS; if molecular mass or negative charge affected protein dispersion. Irrespective of high-molecular-mass, SSPS-HC possessed similar rheological properties to SSPS such as low viscosity in aqueous solution. The absolute negative charges of SSPS-HC measured by a zeta potential analyzer at pH range of 2.0–7.0 were higher than those of SSPS. Acidified milk drinks prepared with 8.4% non-fat milk solids and 0.4% SSPS-HC or SSPS showed low viscosity and small protein particle size, and did not aggregate for 14 days. The thickness of the hydrated layer, which was formed on the surface of protein particles by SSPS molecules measured after hemicellulase treatment with DLS (dynamic light scattering), was estimated to be about 89 nm for SSPS-HC and 33 nm for SSPS. These numerical values were in good relation to the molecular diameter of SSPS-HC and SSPS in aqueous solution measured by DLS and AFM image, and suggested that protein particles were dispersed and the hydrated monolayer made on the surface of protein particles by SSPS-HC or SSPS molecules prevented aggregation. However, stabilizing pH ranges were different with stability of SSPS-HC at pH range of 4.0–4.8 and stability for SSPS at pH range of 3.6–4.2. In addition to the difference in the molecular mass and absolute negative charge, the phosphate groups of SSPS-HC were possibly influenced on the protein-dispersing property approximately at isoelectric point of milk protein; SSPS-HC prevent aggregation of casein by accelerating solubility of calcium phosphate under acidic conditions as is already reported in the starches phosphorylated.