Studies on the curing behaviour and mechanical properties of styrene/methyl methacrylate grafted deproteinized natural rubber latex

The graft copolymerization of styrene/methyl methacrylate (MMA) onto deproteinized natural rubber (DPNR) latex was carried out using ammonium peroxy disulfate (N2H8O8S2) as the initiator. The presence of the grafted polystyrene (PS) and polymethyl methacrylate (PMMA) on the rubber backbone was confirmed by FTIR spectroscopy. The effects of monomer concentrations on curing characteristics and mechanical properties were studied. It was found that the cure time and scorch time were increased with increasing monomer concentration whereas the torque max-min value was slightly decreased. It was also noted that the increase in the monomer concentration resulted in stiffer rubber with increased modulus and reduced elongation at break

Bursaphelenchus xylophilus and B. mucronatus secretomes: a comparative proteomic analysis

The pinewood nematode, Bursaphelenchus xylophilus, recognized as a worldwide major forest pest, is a migratory endoparasitic nematode with capacity to feed on pine tissues and also on fungi colonizing the trees. Bursaphelenchus mucronatus, the closest related species, differs from B. xylophilus on its pathogenicity, making this nematode a good candidate for comparative analyses. Secretome profiles of B. xylophilus and B. mucronatus were obtained and proteomic differences were evaluated by quantitative SWATH-MS. From the 681 proteins initially identified, 422 were quantified and compared between B. xylophilus and B. mucronatus secretomes and from these, 243 proteins were found differentially regulated: 158 and 85 proteins were increased in B. xylophilus and B. mucronatus secretomes, respectively. While increased proteins in B. xylophilus secretome revealed a strong enrichment in proteins with peptidase activity, the increased proteins in B. mucronatus secretome were mainly related to oxidative stress responses. The changes in peptidases were evaluated at the transcription level by RT-qPCR, revealing a correlation between the mRNA levels of four cysteine peptidases with secretion levels. The analysis presented expands our knowledge about molecular basis of B. xylophilus and B. mucronatus hosts interaction and supports the hypothesis of a key role of secreted peptidases in B. xylophilus pathogenicity