How endogenous BR content and altered perception of BRs influence thermal tolerance is poorly understood. BR-induced thermotolerance in tomato seedlings with altered BR homeostasis was examined by assessing the survival, ion leakage and lipid peroxidation of seedlings
from a BR-deficient mutant (extreme dwarf d(x)), a partially BR-insensitive mutant curl3(-abs) allele (curl3 altered brassinolide sensitivity) and a line overexpressing the Dwarf, BR-biosynthesis gene (35SD). We confirmed that treatment with 1 mu M of epi-brassinolide (EBL) induces thermotolerance of wild type seedlings following a HS regime at 45 degrees C. The curl3(-abs) PF-03084014 price seedlings had the highest basal tolerance to heat, whereas the EBL-induced thermal tolerance of d(x) seedlings was greatest and responded to lower EBL concentrations. The d(x) and 35SD seedlings had similar thermal tolerance; however, they showed increased signs of oxidative stress. EBL reduced the induction of lipid peroxidation of seedlings after recovery from heat. Highest oxidative stress and peroxidase (POX) activity (EC 1.11.1.7) was in BR-deficient d(x) mutant seedlings. EBL was able of inducing POX activity but not other antioxidant enzymes; however, effects of HS on POX activity of seedlings were absent or less marked. Taking together, results indicate that thermal tolerance is independent of endogenous
BR content, but HS-mediated Bafilomycin A1 order oxidative stress depends on BR levels. (C) 2011 Elsevier Masson SAS. All rights reserved.”
“Subpercolated composites consisting of highly polar fillers in an insulating matrix have long been predicted to exhibit a large dielectric constant. In this study, we examine the feasibility of experimentally reproducing such an effect based on a multiwalled carbon nanotubes (MWNTs)-polydimethylsiloxane (PDMS) composite system. MWNTs of different diameters were subjected to high-power ultrasound. The sonication-induced scission of nanotubes shows saturation at a final length dependent on the tube diameter, in agreement with a theoretical model. Sonication allows us to produce MWNTs with a prescribed mean aspect ratio between
10 and 55. Composites were formed from these MWNTs with PDMS elastomer at a fixed 1 wt% doping level, using a common solution-processing method. Results from AC impedance spectroscopy indicate QNZ mouse that the tube length minimally affects the dielectric response of these composites when the doping level is below the percolation threshold. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3569596]“
“Background: Rotavirus gastroenteritis (RVGE) is a common cause of childhood hospitalizations and emergency department (ED) visits. In the Rotavirus Efficacy and Safety Trial (REST), the pentavalent rotavirus vaccine (RV5) significantly reduced RVGE-associated hospitalizations and ED visits for up to 2 years following the last vaccine dose.