background: the trabecular bone changes in the tibia of c3h/hen mice were measured 12 weeks after whole body irradiation with various doses of fast neutrons (0-2.4 gy) or 137cs-generated gamma-rays (0-6 gy). materials and methods: serum calcium, phosphorus, estradiol concentration and alkaline phosphatase activity were measured. tibiae were analyzed using microcomputed tomography. biomechanical...

background: the assessment of rbe quantity in the treatment of cancer tumors with proton beams in treatment planning systems (tps) is of high significance. given the significance of the issue and the studies conducted in the literature, this quantity is fixed and is taken as equal to 1.1. objective: the main objective of this study was to assess rbe quantity of proton beams and their variations...

In this paper we review various information-theoretic characterizations of the approach to equilibrium in biological systems. The replicator equation, evolutionary game theory, Markov processes and chemical reaction networks all describe the dynamics of a population or probability distribution. Under suitable assumptions, the distribution will approach an equilibrium with the passage of time. R...

objective: to assess relative biological effectiveness (rbe) of 131i radiation relative to 60co gamma rays in glioblastoma spheroid cells. materials and methods: in this experimental study, glioblastoma spheroid cells were exposed to 131i radiation and 60co gamma rays. radiation induced dna damage was evaluated by alkaline comet assay. samples of spheroid cells were treated by radiation from 13...

We derive an expression for the lower bound of the phase-space beam quality factor M(2) of an ultrashort pulse. We show that the condition M(2)>or=1 does not, in general, hold for such pulsed beams. Rather, the minimum value of M(2) depends on the pulse spectrum. We also show that M(2) attains minimum only for pulsed beams whose spot size varies with frequency as omega(-1/2), and that the radia...