A simple and sensitive electroanalytical determination of anxiolytic buspirone hydrochloride drug based on multiwalled carbon nanotubes modified electrode

In the present study, a simple and sensitive buspirone hydrochloride (BPH) sensor was developed based on multiwalled carbon nanotubes (MWCNT) modified electrode. The modified electrode was characterized using transmission electron microscopy and electrochemical impedance spectroscopy. The MWCNT modified electrode showed an enhanced oxidation peak current response toward BPH than unmodified electrode. The oxidation peak potential of BPH at modified electrode was 0.85, which was quite lower than that of bare electrode (0.88 V). The BPH was successfully determined at modified electrode using different electrochemical methods, such as cyclic voltammetry (CV), differential pulse voltammetry (DPV), and amperometry. The good sensitivity and linear range response of BPH were obtained using amperometry when compared with other methods employed in this study (CV and DPV). The modified electrode displayed the electro-oxidation of BPH in the linear response from 0.5 to 99.5 μM with the sensitivity of 16.49 μA μM^?1 cm^?2. The limit of detection was calculated as 0.22 μM. In addition, the modified electrode exhibited a good repeatability and repeatability with acceptable stability.     

Enhanced fluorescence and time resolved fluorescence properties of p-terphenyl crystal grown by selective self seeded vertical Bridgman technique

The fluorescence and fluorescence decay time of a modified Bridgman grown p-terphenyl single crystals have been studied. The fluorescence spectra of selective self seeded vertical Bridgman technique (SSVBT) grown p-terphenyl single crystals exhibit intense peak at 372 nm and a hump at 388 nm. Fluorescence lifetime measured by Time Correlated Single Photon Counting (TCSPC) method for p-terphenyl crystal showed a very short fluorescence decay time (τ) of 3.3 ns.     

One Pot Synthesis and Characterization of Cesium Doped SnO2 Nanocrystals via a Hydrothermal Process

The physico-chemical properties of cesium doped SnO2 nanocrystals synthesized by wet chemical method have been investigated. Scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray analysis (EDAX), inductively coupled plasma (ICP), atomic absorption spectroscopic (AAS) analyses, UV-vis-NIR spectral studies and dielectric studies were carried out for both pure SnO2 and cesium doped SnO2 nano-samples. All samples of SnO2 did not show any metallic cluster, but the sample containing cesium as a dopant displayed significant activity. The products formed were chloride and water representing a competitive advantage from the stand point of environmental protection.     

Effect of microwave sintering on the structural, optical and electrical properties of BaTiO3 nanoparticles

BaTiO₃ nanoparticles were prepared by high energy ball milling and subjected to conventional and microwave post sintering at 1,000 °C. From the powder X-ray diffraction results, the synthesized material exhibits strong tetragonality with large c/a ratio. Scanning electron microscope results show the formation of tetragonal shaped BaTiO₃ crystals in the nanometer scale and a significant reduction in the particle size for the microwave sintered sample. The reduced d-spacing of 1.741 Å with high crystallinity for the microwave sintered material is revealed by high resolution transmission electron microscopy analysis. Ultraviolet–visible spectroscopy studies confirm the higher optical band gap (E_g) of 4.157 eV for the microwave sintered sample. Microwave sintered sample shows a very high dielectric constant of ε_r = 4,445 with a low dielectric loss as tan δ = 0.0961. Microwave sintered sample exhibit a high polarization maximum of 73 μC/mm² with reduced coercivity to be 0.293 kV/mm.     

Growth and Characterization of Organic NLO Crystal:β-Naphthol

Single crystals of β-Naphthol(βN),an organic nonlinear optical(NLO) material was successfully grown by temperature lowering method using chloroform as solvent.The initial compound was purified by repeated recrystallization process.As-grown crystals were characterized by single crystal X-ray diffraction(XRD) studies to ascertain that βN crystal crystallized in the monoclinic system with a noncemtrosymmetric space group.Vibrational frequencies of various functional groups in the crystals were derived from Fourier transform infrared(FTIR) spectroscopy and proton nuclear magnetic resonance(NMR) spectrum.Optical characterization was done using UV-Visible near-infrared(NIR) spectroscopy.The thermal behaviour of the material was studied by thermo gravimetric and differential thermal plots.Scanning electron microscopy(SEM) study was carried out on the surface of the grown crystals to investigate the nature of defects in the crystal surface and the NLO property of the crystal was tested by Nd:YAG laser as a source.     

Electrochemical Impedance Spectroscopic Analysis of ZnS Nanorod Fabricated Using Butterfly Wings as Biotemplate

This article describes the growth of zinc sulfide(ZnS) nanorod on glass/aluminum foil by employing butterfly wings as biotemplate. Upon calcinating(at 400 °C), the butterfly wings soaked in ZnS nanoparticle suspension, with uniform cage-like nanostructures in nanodimensions, were found on glass/aluminum surface. The transverse and longitudinal dimensions of the nanorods were evaluated from scanning electron microscopy micrographs as 132 and 159 nm,respectively. Purity of the ZnS nanorod found on the specimen was checked by recording XRD(28.877°, 48.038°, and57.174°) and Fourier transform infrared spectrometer spectra(663.7 and 551.68 cm-1). Luminescence natures of the nanorods were examined using photoluminescence spectral studies. The characteristic emission peak is shown in the visible region with strong intensity, while the excitation peak is shown at 267 nm. Electrochemical impedance spectroscopic analysis of ZnS nanorod exhibits double-layer capacitance value(Cdl= 6.7 nF), and the Bode plot explains the stability of ZnS nanorod under the influence of electrical field.     

Multilayered electrode materials based on polyaniline/activated carbon composites for supercapacitor applications

The supercapacitor multilayered electrode materials were prepared potentiodynamically based on polyaniline/activated carbon composite materials. The multilayers comprised of various combinations of activated carbon and doped polyaniline layers using three dopants such as sulphuric acid, camphor-10-sulphonic acid and p-toluene sulphonic acid. These composite materials were characterized using SEM, BET Surface area and FTIR. The supercapacitive properties of the fabricated symmetrical supercapacitors were analyzed by cyclic voltammetry, ac impedance and galvanostatic charge–discharge techniques. Based on the electrochemical results best one was chosen for fabricating the symmetrical supercapacitor and it showed the highest specific capacitance of 549.5 F/g. Further, it was found that these multilayered electrode materials gave higher capacitance than their single layered counter parts.     

Ballistic behaviour of gun powder and flash powder for firework chemicals as a function of particle sizes

In this paper, analysis of ballistic behaviour of gun powder and flash powder of firework chemicals with different particle size have been carried out in a closed vessel to find out the maximum pressure when ignited. The experiment was carried out by changing the variables like sample composition, particle size, vessel volume. Works were carried out to synthesis of nanoflash powders and the particle sizes are 139.7 nm for KNO₃, 94.5 nm for Al and 92.36 nm for S. The nanoflash powders are mixed with micron powders in different ratios and crackers are manufactured. The maximum pressure during the combustion of different samples and explosivity of the crackers are analysed. Results show that peak pressure is increased by 21.6% and explosive impulse is increased by 60% when burning of 100% nfp compared to 10% nfp cracker.     

LCK-phosphorylated human killer cell-inhibitory receptors recruit and activate phosphatidylinositol 3-kinase

HLA-specific killer cell inhibitory receptors (KIR) are thought to impede natural killer (NK) and T cell activation programs through recruitment of the SH2 domain-containing tyrosine phosphatases, SHP-1 and SHP-2, to their cytoplasmic tails (CYT). To identify other SH2 domain-containing proteins that bind KIR CYT, we used the recently described yeast two-bait interaction trap and a modified version of this system, both of which permit tyrosine phosphorylation of bait proteins. Using these systems, we show that KIR CYT, once phosphorylated by the src-family tyrosine kinase LCK, additionally bind the p85alpha regulatory subunit of phosphatidylinositol (PI) 3-kinase. Furthermore, we show that in an NK cell line, NK3.3, cross-linking of KIR results in recruitment of p85alpha to KIR and activation of PI 3-kinase lipid kinase activity. One consequence of KIR coupling to PI 3-kinase is downstream activation of the antiapoptotic protein kinase AKT. Therefore, in addition to providing negative signals, KIR may also contribute positive signals for NK and T cell growth and/or survival.