When Nereis eggs are exposed to radiations from a tube of radium emanation, the walls of which absorb all the alpha-rays, the resulting physiological change is produced by rays having a coefficient of absorption of the order of 23.9 cm.(-1) This fact indicates that the physiological effect is due almost exclusively to beta-rays. The gamma-rays alone can produce the reaction. To produce equivale...

objective: in this study, we aimed to validate the accuracy of computed tomography-based attenuation correction (ctac) using the bilinear scaling method.methods: the measured attenuation coefficient (μm) was compared to a theoretical attenuation coefficient (μt ) using four different ct scanners and an rmi 467 phantom. the effective energy of the ct beam x-rays was calculated, using the aluminu...

the systematics, morphology, distribution, biology, economic importance and conservation of the sticklebacks and pipefishes of iran are described, the species are illustrated, and a bibliography on these fishes is provided. there are two sticklebacks ( gasterosteus aculeatus , an exotic, and pungitius platygaster , a native) and one native pipefish ( syngnathus caspius ), the natives found in t...

background: lymphocytes of fanconi anemia (fa) show an increased sensitivity to the alkylating agents such as mitomycin c (mmc), but their responses to gamma-irradiation is controversial. the extent of dna damage in leukocytes of fa patients following irradiation and mmc treatment was studied at cellular and single chromosome level. methods: dna damage induced by gamma-rays and mmc was measured...