Detection and absolute quantification of betasatellites associated with okra yellow vein mosaic disease by qPCR.

Okra yellow vein mosaic disease (OYVMD) causes serious loss in okra production in Sri Lanka. Therefore, screening of resistant okra verities is an essential need to control the disease. As the available qualitative and semi-quantitative methods failed to detect latent infection the present study aimed to develop a quantitative PCR (qPCR) assay to detect and quantify one of the OYVMD causing agent, symptom modulating satellite molecules.

Defect properties of ZnO nanowires revealed from an optically detected magnetic resonance study.

Optically detected magnetic resonance (ODMR) complemented by photoluminescence measurements is used to evaluate optical and defect properties of ZnO nanowires (NWs) grown by rapid thermal chemical vapor deposition. By monitoring visible emissions, several grown-in defects are revealed and attributed to Zn vacancies, shallow (but not effective mass) donor and exchange-coupled pairs of Zn vacancies and Zn interstitials. It is also found that the intensity of the donor-related ODMR signals is substantially lower in the NWs compared with that in bulk ZnO.

Evidence for coupling between exciton emissions and surface plasmon in Ni-coated ZnO nanowires.

We show that coating ZnO nanowires (NWs) with a transition metal, such as Ni, can increase the efficiency of light emission at room temperature. Based on detailed structural and optical studies, this enhancement is attributed to energy transfer between near-band-edge emission in ZnO and surface plasmons in the Ni film which leads to an increased rate of the spontaneous emission. It is also shown that the Ni coating leads to an enhanced non-radiative recombination via surface states, which becomes increasingly important at low measurement temperatures and in annealed ZnO/Ni NWs.

Heteroepitaxial Si/ZnO hierarchical nanostructures for future optoelectronic devices.

The synthesis of highly-ordered ultra-dense heteroepitaxial Si/ZnO hierarchical nanostructures by a simple and cost-effective approach is demonstrated. We also show, based on the same approach, the synthesis of ZnO nanoparticle-decorated Si nanowire cores and Si/ZnO conformal core-shell hetero-nanostructures. The as-synthesized ZnO nanobranches on Si nanowire cores exhibit an epitaxial relationship as (111)Si/(100) ZnO.