No abstract

The conducting polyaniline (PANI) and PANI doped with tungsten oxide (WO3) with varying wt% of WO3 are prepared by using in-situ chemical oxidative polymerization method. The X-ray diffraction it clearly reveals that pure PANI is amorphous whereas PANI/WO3 composites are in crystalline in nature. The electrical conductivity studied by four probe technique at 30–200°C. All the composites showed increase in conductivity values with the increase in WO3 content where the composite with 45% WO3 content showed highest value of 0.12 S/cm while the lowest conductivity of 0.06 S/cm was found in 5% WO3 content composite. The dielectric constant shows unusual response with respect to frequency with very high dielectric constant of 4.191X103 at 3X106 Hz for 45 wt% of WO3 in PANI, which attributes to the stronger localization of charge carriers and electrical relaxation processes.

Transposable elements constitute a large fraction of plant genomes, and changes due to TE mobilization have provided powerful genetic and molecular tools. Somaclonal variation is a common phenomena caused either by various extrinsic and intrinsic factors related to in vitro culture or transposon activity has been detected under cell culture or tissue culture milieu. In this study, variability among direct somatic embryogenesis (DSEM) and indirect somatic embryogenesis (ISEM) regenerants of sugarcane cv. CoC-671 was studied using Ac transposon insertion polymorphism. A total of 254 amplification products were obtained ranging from 0.5 Kb to 2 Kb. The DNA profile revealed genetic polymorphism among the ISEM regenerants compared to DSEM regenerants. There was n uniform insertion pattern of the Ac like transposons among the DSEM regenerants, whereas it was variable in case of ISEM regenerants. The results on the insertion polymorphism of Ac homologous regions among the ISEM regenerants indicate that the transposition occurred during in vitro culture and that this marker system could be useful in profiling of genetic variation.

The single cell gel electrophoresis technique (comet assay) has been adopted to demonstrate the DNA damage in human leukocytes of individuals who are habitual smokers. This technique allows the detection of single strand and double strand DNA breaks, which are indicative of the risk of cancer. The method followed is rapid, inexpensive, and a highly sensitive technique for the evaluation of DNA damage and risk assessment in smokers. This experiment should help students understand the effect of cigarette smoking.

Polyaniline is equipped by in-situ chemical oxidative polymerization method using ammonium persulphate as an oxidizing agent. The prepared Polyaniline is doped with the nano particles of WO3 at dissimilar weight percentage. The nano-compsites are characterized using XRD and SEM. The crystallite sizes are obtainvia Debye-Scherer relation from the XRD spectra for nano-composites of different weight percentages. The crystallite sizes of nano-particles decreased with increase in weight percentage of WO3 with the PANI. The dislocation density due to the defects in the crystals of nano-composites is obtained. The dislocation density increased as wt % of WO3 in PANI increased. Further, the strain produce at the grain boundary is obtained by FWHM of the XRD spectra. The strain of nano-composites at the grain boundary increased as dislocation density increased. Strain at the grain boundary is also increased as weight percent of WO3 increased in the nano-composites of PANI. Further, the surface morphology of the nano-composites of PANI/WO3 at different weight percentages were observed using SEM. The particles are appeared granular in shape and size. The agglomeration in the sizes of the nano-composites was observed as weight percent of WO3 with PANI increased.