Detection of four regulated grapevine viruses in a qualitative, single tube real-time PCR with melting curve analysis.

The detection of the four grapevine viruses (GLRaV-1, GLRaV-3, GFLV and ArMV) regulated in European Union plant material certification, requires sensitive and specific diagnostic tools. A strategy of simultaneous detection in a real-time single tube amplification was developed, based on the EvaGreen binding dye. The melting curve analysis (MCA) of the amplicons allows a qualitative detection of the four different virus targets in multiplex analysis. A plasmid dilution assay calculated an analytical sensitivity with an amplification threshold up to 100 copies of the target sequences. A small cohort of field grapevine samples, with a known status of infection by mixtures of the target viruses or free of them, respectively, was successfully tested for the evaluation of the amplicons Tm.

Copper catalysts for soot oxidation: alumina versus perovskite supports.

Copper catalysts prepared using four supports (Mg- and Sr-modified Al2O3 and MgTiO3 and SrTiO3 perovskites) have been tested for soot oxidation by 02 and NOx/O2. Among the catalysts studied, Cu/SrTiO3 is the most active for soot oxidation by NOx/O2 and the support affects positively copper activity. With this catalyst, and under the experimental conditions used, the soot combustion by NOx/O2 presents a considerable rate from 500 degrees C (100 degrees C below the uncatalysed reaction). The Cu/ SrTiO3 catalyst is also the most effective for NOx chemisorption around 425 degrees C. The best activity of Cu/SrTiO3 can be attributed to the improved redox properties of copper originated by Cu-support interactions. This seems to be related to the presence of weakly bound oxygen on this sample. The copper species present in the catalyst Cu/SrTiO3 can be reduced more easily than those in other supports, and for this reason, this catalyst seems to be the most effective to convert NO into NO2, which explains its highest activity for soot oxidation.