Bioactive Endophytic Actinomycetes of Cinnamomum sp.; Isolation, Identification, Activity Guided Purification and Process Optimization of Active Metabolite

Abstract

The dose-response of sintered MTS-N (LiF:Mg, Ti) thermoluminescent detectors in which the concentration of Mg was varied between 30 and 920 ppm and the Ti concentration varied between 13 and 260 ppm, has been studied after Cs-137 gamma-ray and fast proton irradiation (average energy 147 MeV) in the dose range between 0.5 and 37.5 Gy. Peak 4 and peak 5 were extracted from the TL glow curve by deconvolution, assuming first-order kinetics. We have observed a decrease in the supralinear response of LiF:Mg, Ti at increasing Mg concentration. The effect of varying the concentration of Ti on the dose response was less pronounced. No significant difference in the linearity index measured after Cs-137 gamma-ray and fast proton beam irradiation was observed at all the studied Mg and Ti concentration values. The data are discussed with reference to some models of TL supralinearity. The extended range of linearity of the high Mg-doped LiF:Mg, Ti materials may make them better suited for clinical dosimetry. © 2001 Elsevier Science Ltd. All rights reserved.