Low Doses of Very Low-Dose-Rate Low-LET Radiation Suppress Radiation-Induced Neoplastic TransformationIn Vitroand Induce an Adaptive Response

2008 ◽  
Vol 169 (3) ◽  
pp. 311-318 ◽  
Author(s):  
E. Elmore ◽  
X-Y. Lao ◽  
R. Kapadia ◽  
E. Giedzinski ◽  
C. Limoli ◽  
...  
Keyword(s):  
Dose Rate ◽  
Adaptive Response ◽  
Low Dose ◽  
Low Doses ◽  
Low Dose Rate ◽  
Radiation Induced

The Progress of ICRP New Recommendations

2010 ◽  
Author(s):  
Aiguo Shang ◽  
Changjie Lu ◽  
Jin Qin
Keyword(s):  
Comparative Analysis ◽  
Dose Rate ◽  
Low Dose ◽  
System Analysis ◽  
Weighting Factor ◽  
Radiological Protection ◽  
Stochastic Effects ◽  
Risk Coefficient ◽  
Low Dose Rate ◽  
Radiation Induced

In order to probe into the usage of the Recommendations of the ICRP, through comparative analysis of low-dose-rate radiation-induced stochastic effects of a nominal risk coefficient, radiation weighting factor, tissue weighting factor as well as the the implementation of changes on the radiological protection system, analysis of the international on Radiological Protection fundamental recommendations of the Committee on the latest changes in radiological protection and development, and that these changes can not affect the existing radiation protection of China’s basic policy and standards.

Radiation-Induced Segregation in 316 and 304 Stainless Steels Irradiated at Low Dose Rate

2000 ◽  
Vol 650 ◽  
Author(s):  
T. R. Allen ◽  
J. I. Cole ◽  
J. Ohta ◽  
K. Dohi ◽  
H. Kusanagi ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Grain Boundary ◽  
Dose Rate ◽  
Stainless Steels ◽  
Low Dose ◽  
Bulk Composition ◽  
304 Stainless Steel ◽  
316 Stainless Steel ◽  
Low Dose Rate ◽  
Radiation Induced

ABSTRACTAs part of the shutdown of the EBR-II reactor, structural materials were retrieved to analyze the effects of long-term irradiation on mechanical properties and microstructure. In this work, the effect of low dose rate irradiation (10−7 to 10−8 dpa/s) on grain boundary composition in 316 and 304 stainless steels was analyzed. Samples were taken from surveillance specimens and subassemblies irradiated in the reflector region of EBR-II at temperatures from 371-390°C to maximum doses of 30 dpa. The effects of dose, dose rate, and bulk composition on radiation- induced segregation are analyzed. In 316 stainless steel, changes in grain boundary chromium and nickel concentrations occur faster than changes in iron and molybdenum concentrations. In 304 stainless steel, decreasing the dose rate increases the amount of grain boundary segregation. For a dose of 20 dpa, chromium depletion and nickel enrichment are greater in 304 stainless steel than in 316 stainless steel, the difference most likely due to dose rate. In both 304 and 316 stainless steels, the presence of a grain boundary precipitate significantly changes the composition of the adjacent grain boundary.

scholarly journals Modeling of Molecular Mechanisms of Radiation Adaptive Response Formation

2021 ◽  
Keyword(s):  
Adaptive Response ◽  
Molecular Mechanisms ◽  
Low Dose ◽  
Low Doses ◽  
Radiation Hormesis ◽  
Biological Objects ◽  
Mechanisms Of Formation ◽  
Radiation Induced ◽  
High Doses ◽  
Lnt Model

The phenomenon of adaptive response is expressed in the increase of resistance of a biological object to high doses of mutagens under the conditions of previous exposure to these (or other) mutagens in low doses. Low doses of mutagen activate a number of protective mechanisms in a living object, which are called hormetic. Thus, the adaptive response and hormesis are links in the same chain. Radiation hormesis refers to the generally positive effect of low doses of low LET radiation on biological objects. The phenomenology of radiation-induced adaptive response and radiation hormesis for biological objects of different levels of organization is considered; the review of existing theories describing the dose-effect relationship has been reviewed. The hypothesis proposing one of the mechanisms of formation of radiation adaptive response of cells taking into account the conformational structure of chromatin has been submitted. The analysis of modern concepts of the phenomenon of hormesis on the basis of modeling of molecular mechanisms of formation of hormetic reactions to low-dose low LET radiation has been carried out. The parameters that can be used for quantitative and graphical evaluation of the phenomenon of hormesis was considered, and a formula for calculating the coefficient of radiation-induced adaptive response has been proposed. A review of mathematical models describing the radiation relative risk of gene mutations and neoplastic transformations at low-dose irradiation of cohorts has been performed. The following conclusions have been made: radiation hormesis and adaptive response are generally recognized as real and reproducible biological phenomena, which should be considered as very important phenomena of evolutionarily formed biological protection of living organisms from ionizing radiation. The hormesis model of dose-response relationship makes much more accurate predictions of a living object's response to radiation (or other stressors) in the low-dose range than the linear threshold (LNT) model does. The LNT model can adequately describe reactions only in the region of high doses of radiation, and, therefore, extrapolation modeling of biological object’s reactions from the zone of high doses to low doses is not correct.

Radiation-induced attenuation in polarization maintaining fibers: low dose rate response, stress, and materials effects

1989 ◽  
Vol 28 (23) ◽  
pp. 5138 ◽  
Author(s):  
E. Joseph Friebele ◽  
Louise A. Brambani ◽  
Michael E. Gingerich ◽  
Steven J. Hickey ◽  
James R. Onstott
Keyword(s):  
Dose Rate ◽  
Low Dose ◽  
Low Dose Rate ◽  
Radiation Induced ◽  
Polarization Maintaining

scholarly journals Cytogenetic Adaptive Response and Genetic Instability Induced by Low-Dose Rate High-LET Radiation in Mice

2008 ◽  
Vol 43 (5) ◽  
Author(s):  
S. Sorokina ◽  
S. Zaichkina ◽  
O. Rozanova ◽  
G. Aptikaeva ◽  
A. Akhmadieva ◽  
...  
Keyword(s):  
Dose Rate ◽  
Adaptive Response ◽  
Genetic Instability ◽  
Low Dose ◽  
Low Dose Rate ◽  
High Let Radiation ◽  
High Let
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