Endpoints

included clonogenic survival, micronucleus formation and foci formation at histone 2AX over doses ranging from 10-100 cGy.

Results: The results showed no evidence of a low-LET radiation-induced bystander response for the endpoints of clonogenic survival and induction of DNA damage. Nor did we see evidence of a high-LET, Fe ion radiation (1 GeV/n) induced bystander effect. However, direct comparison for 3.2 McV alpha-particle exposures showed a statistically significant medium transfer bystander effect for this high-LET radiation.

Conclusions: From our results, it is evident that there are many confounding factors influencing bystander responses as reported in the literature. Our observations reflect the inherent variability in biological systems and the difficulties in extrapolating from in vitro models to radiation risks in humans.”
“Hot phonon effects are of interest for heterostructure Fer-1 cell line field effect

transistors where CDK inhibitor heat dissipation depends on the lifetime of the longitudinal optical mode. Previous treatments have ignored the coupling of plasmon and phonons. Here, a bulk-phonon model is used to examine the effects of hot phonon-plasmon coupled modes based on the random-phase Lindhard dielectric function with nondegenerate statistics and a nonparabolic conduction band. Comparison of the results concerning power dissipation and drift velocity with those for bare phonons assuming a constant phonon lifetime indicate no striking differences. The phonon lifetime is known to exhibit a temperature and electron density dependence in GaN. Incorporating the observed dependence of lifetime on electron density profoundly affects the hot phonon effect. We find that the drift velocity, as expected, becomes limited by the production of hot phonons at high electric fields as the electron density is increased but this reduction in velocity is ameliorated by the concomitant

reduction in the phonon lifetime with increasing density. The result is that hot phonon effects become insensitive to electron density at high fields. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3500329]“
“The selleck inhibitor synthesis and antiproliferative activity of new coumarin-based benzopyranone derivatives containing basic amino side chain are described. The cytotoxicities against A549 and MCF-7 human cancerous cell lines were determined after 24, 48, 72h drug exposure employing MTT assay at concentrations ranging from 0-100 mu M. The antiproliferative activities of these compounds were compared to tamoxifen (TAM), 4-hydroxytamoxifen (4-OHT), raloxifene (RAL), 17 beta-estradiol (E2) and Diethylstilbestrol (DES). In vitro results indicated that compounds 10 and 12 were the most potent showing significant inhibitory activities against these cell lines. Furthermore, their antiproliferative activity against MCF-7 human breast cancer cell line is comparable to that of TAM, RAL and 4-OHT.