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Abstract Perovskite-related materials of composition LaFe1−xCoxO3 have been prepared by conventional calcination methods and by mechanical milling methods. The reduction properties in a flowing mixture of hydrogen and nitrogen have been monitored by temperature programmed reduction techniques and the nature of the reduced phases characterised by X-ray powder diffraction, X-ray absorption spectroscopy and 57Fe Mossbauer spectroscopy. The smaller particle materials made by mechanical milling methods are more susceptible to reduction than their counterparts made by conventional solid state methods. The presence of cobalt enhances the reducibility of iron in the perovskite-related structures. In iron-rich systems more limited reduction of iron and cobalt leads to the segregation of discrete metallic phases without destruction of the perovskite-related structure at temperatures up to 1200°C whereas in cobalt-rich systems the reduction of Fe3+ and Co3+ leads to significant segregation of alloy and metallic phases and is accompanied by destruction of the perovskite-related structure. [ABSTRACT FROM AUTHOR]

Nitride microcavities offer an exceptional platform for the investigation of light–matter interactions as well as the development of devices such as high efficiency light emitting diodes (LEDs) and low-threshold nanolasers. Microdisk geometries in particular are attractive for low-threshold lasing applications due to their ability to support high finesse whispering gallery modes (WGMs) and small modal volumes. In this article we review the effect of defects on the properties of nitride microdisk cavities fabricated using photoelectrochemical etching of an InGaN sacrificial superlattice (SSL). Threading dislocations originating from either the original GaN pseudosubstrate are shown to hinder the undercutting of microdisk cavities during the photoelectric chemical etching process resulting in whiskers of unetched material on the underside of microdisks. The unetched whiskers provide a pathway for light to escape, reducing microdisk Q-factor if located in the region occupied by the WGMs. Additionally, dislocations can affect the spectral stability of quantum dot emitters, thus hindering their effective integration in microdisk cavities. Though dislocations are clearly undesirable, the limiting factor on nitride microdisk Q-factor is expected to be internal absorption, indicating that the further optimisation of nitride microdisk cavities must incorporate both the elimination of dislocations and careful tailoring of the active region emission wavelength and background doping levels. [ABSTRACT FROM AUTHOR]

Recently, direct inkjet printing of conductive solutions has received much attention in the microfluidics and lab-on-a-chip community because of its low-cost and mask-free deposition of electrodes on various substrates. However, the investigation of micro-scale direct inkjet printing on the polydimethylsiloxane (PDMS) substrate has not been completed. Here we present a direct inkjet printing technique to produce narrow (40–90 µm) silver microelectrodes on PDMS. Extensive experimental characterization studies on the pattern uniformity and electrical properties of the printed silver lines are presented. The effect of major printing parameters such as drop spacing, sintering temperature and duration, platen temperature, and nozzle temperature have been thoroughly investigated. We also investigated multiple layer printing as well as the effects of thermal expansion and mechanical bending. In order to demonstrate the utility of the inkjet-printed silver microelectrode, we fabricated both quadruple and castellated electrodes, and conducted dielectrophoretic manipulation of microbeads. The results clearly show that the printed silver electrodes can be used for electrokinetic applications in PDMS microchip devices. We believe that the direct inkjet printing of silver ink on PDMS presented here can provide a very convenient way of creating microelectrodes on PDMS devices for a variety of applications in the MEMS, microfluidics, and lab-on-a-chip communities. [ABSTRACT FROM AUTHOR]

An abstract of the conference paper "Fusion of CTA and CTB gene to immunogen significantly enhances the immunogenicity of DNA vaccine" by X. Ren and colleagues is presented.

Large-area free-standing arrays of TiO2 nanorods and nanotubes were selectively synthesized on transparent conducting indium tin oxide substrates using sol-gel electrophoresis and anodic alumina (AAO) thin film templates. The effect of sol-gel ageing on the growth of TiO2 was explained, providing a tailored ability to produce nanotubes and nanorods. An annular tungsten base electrode, stemming from the anodization of the AAO template, was found to be crucial to the growth of nanotubes. This was supported by a study of substrate annealing in a reducing atmosphere. The work can be readily adapted for the fabrication of free-standing arrays of other metal, metal oxide, and complex oxide nanorod and nanotube arrays on conducting substrates. [ABSTRACT FROM AUTHOR]

Copolymers of an N-halamine siloxane and a quaternary ammonium salt siloxane were prepared using 5,5-dimethylhydantoin and trimethylamine as functional groups. The solubility of this siloxane copolymer in water was dramatically improved over that of a hydantoinyl siloxane homopolymer developed earlier. The biocidal activity of cotton swatches coated with the copolymer was evaluated against S. aureusand E. coliO157:H7; the antimicrobial fabric with 0.23%−0.26% chlorine loading could inactivate 107colony forming units (CFU) of bacteria within 1−5 min of contact. It was observed that a 1 wt % coating bath could provide a coating that could be chlorinated to greater than a 0.20% chlorine loading for a copolymer having a 9:1 ratio of hydantoin to quat moieties. The stability of the oxidative chlorine loading on the cotton swatches was not affected by the presence of the very hydrophilic quat functional group. Use of the copolymer in an antimicrobial coating application will be desirable because no organic solvent is needed for the preparation of a coating bath for textile materials. [ABSTRACT FROM AUTHOR]

The whitebacked planthopper (WBPH), Sogatella furcifera, and brown planthopper (BPH) Nilaparvata lugens Stål are important sucking insects of rice (Oryza sativa L.) crops throughout the world. Rice ‘B5’, which has derived its resistance genes from the wild rice O. officinalis Wall ex Watt, is a line that is highly resistant to both WBPH and BPH. Previously, two resistance genes against BPH, Qbp1, and Qbp2 in ‘B5’ had been mapped onto chromosome 3 and chromosome 4, respectively. In this study, we employed a mapping population composed of 187 recombinant inbred lines (RILs), produced from a cross between ‘B5’ and susceptible variety ‘Minghui63’, to locate the WBPH and BPH resistance genes. A RFLP survey of the bulked extremes from the RIL population identified two genomic regions, one on chromosome 3 and the other on chromosome 4, likely containing the resistance genes to planthoppers. QTL analysis of the RILs further confirmed that two WBPH resistance genes were mapped on the same loci as Qbp1 and Qbp2, using a linkage map with 242 molecular markers distributed on 12 rice chromosomes. Of the two WBPH resistance genes, one designated Wbph7(t) was located within a 1.1-cM region between R1925 and G1318 on chromosome 3, the other designated Wbph8(t) was within a 0.3-cM region flanked by R288 and S11182 on chromosome 4. A two-way analysis of variance showed that two loci acted independently with each other in determining WBPH resistance. The results have significant implications in studying the interactions between sucking insects and plants and in breeding programs of resistance to rice planthoppers.Heredity (2004) 92, 212-217, advance online publication, 10 December 2003; doi:10.1038/sj.hdy.6800398 [ABSTRACT FROM AUTHOR]

The aerodynamic loads of a wind turbine blade under complicated offshore wind conditions were analyzed using Davenport wind spectrum model, which represents the real working conditions closely. Finite element model of the blade was generated by using UG and ANSYS, and qualitative analysis and quantitative simulation were carried out to investigate the dynamic stability of the wind turbine blade. The numerical results indicate that the blade vibration diverges when the frequency of wind speed is close to the first-order natural frequency of the blade, which eventually leads to the occurrence of instability phenomena. It was also found that both waving amplitude and the maximum Mises stress of the blade increase nonlinearly with the average wind speed. However, the maximum Mises stress increases almost linearly with elastic modulus under vibration divergence. Finally, some characteristics for the critical values of the maximum Mises stress and the stable or/and unstable regions, due to variation of the elastic modulus and the horizontal distance between the blade and the tower frame, were further discussed. [ABSTRACT FROM AUTHOR]

Calcitonin gene-related peptide (CGRP) has been implicated in the pathogenesis of migraine. Early chemistry leads suffered from modest potency, significant CYP3A4 inhibition, and poor aqueous solubility. Herein, we describe the optimization of these leads to give 4(BMS-694153), a molecule with outstanding potency, a favorable predictive toxicology profile, and remarkable aqueous solubility. Compound 4has good intranasal bioavailablity in rabbits and shows dose-dependent activity in validated in vivo and ex vivo migraine models. [ABSTRACT FROM AUTHOR]

In the quiescent H-mode (QH-mode) regime, edge harmonic oscillations (EHOs) play an important role in avoiding transient edge localized mode (ELM) power fluxes by providing benign and continuous edge particle transport. A detailed theoretical, experimental and modeling comparison has been made of low-n (n  ⩽  5) EHO in DIII-D QH-mode plasmas. The calculated linear eigenmode structure from the extended magentoohydrodynamics (MHD) code M3D-C1 matches closely the coherent EHO properties from external magnetics data and internal measurements using the ECE, BES, ECE-Imaging and microwave imaging reflectometer (MIR) diagnostics, as well as the kink/peeling mode properties found by the ideal MHD code ELITE. Numerical investigations indicate that the low-n EHO-like solutions from M3D-C1 are destabilized by rotation and/or rotational shear while high-n modes are stabilized. This effect is independent of the rotation direction, suggesting that EHOs can be destabilized in principle with rotation in either direction. The modeling results are consistent with observations of EHO, support the proposed theory of the EHO as a low-n kink/peeling mode destabilized by edge E  ×  B rotational shear, and improve our understanding and confidence in creating and sustaining QH-mode in present and future devices. [ABSTRACT FROM AUTHOR]

We report a novel phenomenon in carbon nanotube based ultra-fast mechanical devices, the trans-phonon effect, which resembles the transonic effects in aerodynamics. It is caused by dissipative resonance of nanotube phonons similar to the radial breathing mode, and subsequent drastic surge of the dragging force on the sliding tube, and multiple phonon barriers are encountered as the intertube sliding velocity reaches critical values. It is found that the trans-phonon effects can be tuned by applying geometric constraints or varying chirality combinations of the nanotubes. [ABSTRACT FROM AUTHOR]