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...

To the Editor, Microdosimetry is perhaps the most useful tool for intercomparing the different types of radiation that are used in radiotherapy; the relative effects of different radiations are controlled by the different initial energy deposition patterns in cellular targets—the subject matter of microdosimetry. It is therefore appropriate that many authors have measured microdosimetric spectr...

A microwave photonic filter with the highest reported quality factor (Q) value of 4895.31 is proposed and experimentally demonstrated by using two cascaded infinite impulse response (IIR) filters. Each IIR filter comprises both optical and electronic signals in a feedback loop and thus the loop length can be reduced without the need to consider the light coherence length. The Vernier effect ena...

We have designed and operated a superconducting tunnel junction circuit that behaves as a two-level atom: the "quantronium." An arbitrary evolution of its quantum state can be programmed with a series of microwave pulses, and a projective measurement of the state can be performed by a pulsed readout subcircuit. The measured quality factor of quantum coherence Qphi approximately 25,000 is suffic...

We investigate narrowband transmission filters based on subwavelength-grating reflectors at normal incidence. Computational results show that the filtering is realized through symmetry-protected mode coupling. The guided mode resonances introduced by the slab layer allow flexible control of the filter frequencies. The quality factor of the filters could exceed 106. Dielectric gratings can be us...

The "parameter-free", "local effects" theory of Scholz and Kraft is an extension to mammalian cells of the theory of RBE for dry enzymes and viruses of Butts and Katz. Its claim for parameter freedom has been challenged elsewhere. Here we examine its conceptual base and find errors in its use of the physical concept of cross section and its neglect of the radiobiological relationship between ta...

The National Council on Radiation Protection and Measurements (NCRP) has recently published a report (Report #137) that discusses various aspects of the concepts used in radiation protection and the difficulties in measuring the radiation environment in spacecraft for the estimation of radiation risk to space travelers. Two novel dosimetric methodologies, fluence-based and microdosimetric event...

A study was made on the loss of the reproductive capacity of HeLa S3 cells irradiated in vitro under both oxygenated and anoxic conditions with D-T neutrons (14 Mev) at 1, 20, 30, 150 and 400 rads/minute at 25•Ž and 37•Ž and with 180 kvp X-rays at 100 rads/minute at 37•Ž. 1) RBE of neutrons measured at a range of 2 to 10% survival was 2.67-2.62 under oxygenated conditions and 3.83.4.61 under an...

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...