Development of a multiresidue method for the determination of multiclass pesticides in soil using GC

The principal objective of the present study was to develop a multiresidue analytical method for 62 pesticides in a soil matrix. Soil samples were fortified with known quantities of pesticides at two different concentration levels (0.1 and 0.01 μg/g) and the analytes were extracted via a liquid–solid extraction method. The pesticides were separated on an HP5 capillary column and were detected by gas chromatography coupled to an electron capture detector (GC‐ECD). The method was validated, considering its good linearities (r² = 0.978–0.999), specificity and recovery characteristics. Recoveries were found between 70.3 and 113.4% for all pesticides except edifenphos (67.5%) and dichlobenil (69.5%) spiked at a 0.1 μg/mL concentration level and 74.5–117% except ethalfluralin (63.3%) and dichlobenil (51.9%) spiked at a concentration of 0.01 μg/mL. The developed method could be utilized as a simple and cost‐effective method for the routine analysis of 62 pesticides in soil samples. Copyright © 2009 John Wiley & Sons, Ltd.     

Temperature‐dependent location of a weakly segregated block copolymer in binary blends of block copolymers

The phase behaviors of binary blends of poly(styrene‐b‐butadiene) block copolymers were investigated by a small‐angle X‐ray scattering technique. The blends were composed of weakly segregated one in a random micellar phase and the other in a cylindrical phase with similar molecular weights and complementary volume fractions. Morphologies, domain spacings, and order–disorder transition temperatures of the blends indicated that the junctions of the constituent block copolymers share the interface at low temperatures. The domain spacing decreased as temperature increased in a blend with a small amount of the weakly segregated block copolymer. In the cases of the blends with a large amount of the weakly segregated constituent, domain spacing increased with increasing temperature. These results implied that some of the weakly segregated block copolymer moved from the interface to one microdomain at higher temperatures. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52, 470–476     

K* Λ(1116) Photoproduction and Nucleon Resonances

We study the reaction mechanism of K* Λ(1116) photoproduction off the proton target near threshold considering the contributions from nucleon-resonances. Employing the effective Lagrangian method at the tree-level Born approximation, we investigate the role of the D ₁₃(2080) and the D ₁₅(2200). We found that the D ₁₃ plays a crucial role to reproduce the experimental data well in the forward scattering region at low energy. We also present theoretical predictions on the single photon-beam asymmetry (Σ) as well as the energy and angular dependence for the cross sections of this reaction.     

Mass spectrometry based cellular phosphoinositides profiling and phospholipid analysis: A brief review

Phospholipids are key components of cellular membrane and signaling. Among cellular phospholipids, phosphoinositides, phosphorylated derivatives of phosphatidylinositol are important as a participant in essential metabolic processes in animals. However, due to its low abundance in cells and tissues, it is difficult to identify the composition of phosphoinositides. Recent advances in mass spectrometric techniques, combined with established separation methods, have allowed the rapid and sensitive detection and quantification of a variety of lipid species including phosphoinositides. In this mini review, we briefly introduce progress in profiling of cellular phosphoinositides using mass spectrometry. We also summarize current progress of matrices development for the analysis of cellular phospholipids using matrix-assisted laser desorption/ionization mass spectrometry. The phosphoinositides profiling and phospholipids imaging will help us to understand how they function in a biological system and will provide a powerful tool for elucidating the mechanism of diseases such as diabetes, cancer and neurodegenerative diseases. The investigation of cellular phospholipids including phosphoinositides using electrospray ionization mass spectrometry and matrix-assisted laser desorption/ionization mass spectrometry will suggest new insights on human diseases, and on clinical application through drug development of lipid related diseases.     

Molecular dynamics study of effects of intertube gap on frequency-controlled carbon-nanotube oscillators

Model of frequency-controlled carbon-nanotube oscillators are proposed and their dynamic properties are investigated via classical molecular dynamic simulations. Their operation frequencies can be changed by engineering the intertube gap, which dominantly affects their operating frequencies in the improved bandwidths rather than those achieved by initial velocity engineering.     

Polishing behaviors of single crystalline ceria abrasives on silicon dioxide and silicon nitride CMP

The effects of single crystalline ceria (CeO₂) abrasives in chemical mechanical polishing (CMP) slurries were investigated for silicon dioxide (SiO₂) and silicon nitride (Si₃N₄) CMP process. The size of ceria abrasives was controlled by varying hydrothermal reaction conditions. Polishing removal rate was measured with four slurries, with different mean primary particle size of 62, 116, 163 and 232 nm. The polishing results showed that the single crystalline ceria abrasives were not easily broken-down by mechanical force during CMP process. It was found that the removal rate of oxide and nitride film strongly depend upon abrasive size, whereas the surface uniformity deteriorates as abrasive size increases. The observed polishing results confirmed that there exists an optimum abrasive size (163 nm) for maximum removal selectivity between oxide and nitride films. The polishing behavior of the single crystalline ceria abrasives was discussed in terms of morphological properties of the abrasive particle.     

Quantitative determination of sparfloxacin in rat plasma by liquid chromatography/tandem mass spectrometry

Sparfloxacin, a fluoroquinolone antibiotic, is used for the treatment of bacterial infection. A quantification method using mass spectrometry was developed for the determination of sparfloxacin in rat plasma. After simple protein precipitation with acetonitrile, the analytes were chromatographed on a reversed‐phase C₁₈ column and detected by liquid chromatography/tandem mass spectrometry with electrospray ionization. The accuracy and precision of the assay were in accordance with FDA regulations for validation of bioanalytical methods. This method was applied to measure the plasma sparfloxacin concentrations after a single oral administration of sparfloxacin in rats. Copyright © 2010 John Wiley & Sons, Ltd.     

Performance analysis of wide-band M-ary FSK systems in Rayleighfading channels

Performance analysis schemes for wide-band M-ary frequency-shift keying systems with a limiter-discriminator-integrator receiver are presented along with analysis and simulation results for 4-ary and 8-ary systems. The probability distribution of clicks is required for performance analysis and is determined for Rayleigh fading channels     

Oxide‐Supported IrNiOx Core–Shell Particles as Efficient,Cost‐Effective,and Stable Catalysts for Electrochemical Water Splitting

Active and highly stable oxide‐supported IrNiO_x core–shell catalysts for electrochemical water splitting are presented. IrNi_x@IrO_x nanoparticles supported on high‐surface‐area mesoporous antimony‐doped tin oxide (IrNiO_x /Meso‐ATO) were synthesized from bimetallic IrNi_x precursor alloys (PA‐IrNi_x /Meso‐ATO) using electrochemical Ni leaching and concomitant Ir oxidation. Special emphasis was placed on Ni/NiO surface segregation under thermal treatment of the PA‐IrNi_x /Meso‐ATO as well as on the surface chemical state of the particle/oxide support interface. Combining a wide array of characterization methods, we uncovered the detrimental effect of segregated NiO phases on the water splitting activity of core–shell particles. The core–shell IrNiO_x /Meso‐ATO catalyst displayed high water‐splitting activity and unprecedented stability in acidic electrolyte providing substantial progress in the development of PEM electrolyzer anode catalysts with drastically reduced Ir loading and significantly enhanced durability.