A feasibility study of the post-irradiation dose estimation with SPECT technique for BNCT

In the (n, γ)-reaction in cristalline dibenzene chromium(0) the retention is 11,8%. This value increases to 19,4% if the irradiated sample is sublimated or if it is heated for about 30 minutes to 110°C. It is shown, that the increase of the retention by annealing is not caused only by a reaction of electrones on the skeleton of dibenzene chromium. Beside this, benzene, added as a solvens, cannot replace the recombination-components of 51Cr in the post irradiation process. From these facts and from the independence of the annealing effete of the irradiation-dose can be concluded, that the mechanism of the fast annealing is not a recombination of separated fragments, but taken place between reaction-components, which are correlated from the very beginning.

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Zur Induktion prototropher Saccharomyces-Mutanten durch ultraviolettes Licht in Abhängigkeit von Dosis und Nachbehandlung

Zeitschrift für Naturforschung B ◽

10.1515/znb-1963-0409 ◽

1963 ◽

Vol 18 (4) ◽

pp. 301-309 ◽

Cited By ~ 6

Author(s):

Klaus Haefner ◽

Wolfgang Laskowski

Keyword(s):

Irradiation Dose ◽

Mutation Rates ◽

Recessive Lethal ◽

Induced Mutation ◽

Post Irradiation ◽

Yeast Strains ◽

Ultraviolettes Licht ◽

Strain Dependent

A formula for the determination of UV induced mutation rates in haploid yeast strains is given. In a Saccharomyces strain dependent on adenine, uracil and histidine the mutation rates of functional backmutants depending on irradiation dose and certain post-irradiation treatments are determined. The results obtained are compared with certain mutation rates previously obtained for recessive lethal alleles.

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Study of Solving the Bottleneck Problem of the Estimation of Biological Dose in the Window of Time of Medical Emergency in Large-scale Nuclear Radiation Accidents

10.21203/rs.3.rs-120520/v1 ◽

2020 ◽

Author(s):

Gang Liu

Keyword(s):

Dose Rate ◽

Irradiation Dose ◽

Large Scale ◽

Peripheral Blood Lymphocytes ◽

Nuclear Radiation ◽

Dicentric Chromosome ◽

Medical Emergency ◽

Dose Estimation ◽

Standard Curve ◽

Biological Dose

Abstract Purpose In order to achieve the goal of rapid response, effective disposal and protection of life of large-scale radiation events, how to establish the uniform standard curve of biological dose estimation for chromosome aberration analysis becomes an urgent need. Methods Chromosomal aberrations with different irradiation dose rates were used to analyze the biological dose curve and the share of the “dicentric + ring” caused by the dose rate at each dose point. The dose-rate effect of 60Co-rays on peripheral blood lymphocytes was analyzed by statistical method . Results Irradiation dose is dominant ; At each dose point, “(dicentric chromosome + centric rings) /cell” is proportional to "dose rate", that is, Y = k X + b;Between 1-5Gy dose, “(dicentric chromosome + centric rings) /Cell ” holds a quadratic linear relationship with dose rate, that is,y = ax2 + bx + c. Conclusion The fraction of “dicentric + ring” caused by dose rate was calculated, if “Dose rate” is Z Gy•min− 1, it corresponds to an increase in linear relationships. Biological dose estimation curve :Y = 3.318 × 10− 3+2.0541 × 10− 2 x + 7.1721 × 10− 2x2(1.16Gy•min− 1༛R2 = 0.9997)(3).Dose rate :Y Dose rate = 1.2534 × 10− 2 x 2+6.6164 × 10− 2 x -2.732 × 10− 3༈0.01Gy•min− 1༛R2 = 0.999༉(1).The estimated dose is formula (3) – (1.16-Z) × formula (1).

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Successive gamma-ray irradiation and corresponding post-irradiation annealing of pMOS dosimeters

Nuclear Technology and Radiation Protection ◽

10.2298/ntrp1204341p ◽

2012 ◽

Vol 27 (4) ◽

pp. 341-345 ◽

Cited By ~ 13

Author(s):

Milic Pejovic ◽

Momcilo Pejovic ◽

Aleksandar Jaksic ◽

Koviljka Stankovic ◽

Slavoljub Markovic

Keyword(s):

Threshold Voltage ◽

Irradiation Dose ◽

Elevated Temperatures ◽

Gamma Ray ◽

Threshold Voltage Shift ◽

Voltage Shift ◽

Post Irradiation ◽

Gamma Ray Irradiation ◽

Value Changes ◽

Dose Measurements

The paper investigates a possibility of pMOS dosimeter re-use for the measurement of gamma-ray irradiation. The dosimeters were irradiated to the dose of 35 Gy, annealed at room and elevated temperatures, after which they were irradiated again to the same dose value. Changes in the threshold voltage shift during those processes were followed, and it was shown that their re-use depends on a gate polarization during irradiation. For the gate polarization of 5 V during irradiation the pMOS dosimeters can be re-used for measurements of the irradiation dose after annealing without prior calibration. The pMOS dosimeters with the gate polarization during irradiation of 2.5 V can also be re-used for irradiation dose measurements but they require calibration. It is shown that for their re-use it is necessary to anneal the pMOS dosimeter so that the fading is higher than 50%.

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Post irradiation dose determination of 800 MeV proton irradiated aluminum from LAMPF experiment 407

10.2172/5398175 ◽

1980 ◽

Author(s):

W Sommer

Keyword(s):

Irradiation Dose ◽

Post Irradiation ◽

Dose Determination

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The Response of Testis Cells to Low Dose X-Irradiation

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100099155 ◽

1981 ◽

Vol 39 ◽

pp. 542-543

Author(s):

D. E. Philpott ◽

W. Sapp ◽

C. Williams ◽

Joann Stevenson ◽

S. Black

Keyword(s):

Electron Microscopy ◽

Stem Cell ◽

Light Microscopy ◽

Dose Level ◽

Cross Sections ◽

Low Dose ◽

Light And Electron Microscopy ◽

Cellular Responses ◽

Post Irradiation ◽

X Irradiation

The response of spermatogonial cells to X-irradiation is well documented. It has been shown that there is a radiation resistent stem cell (As) which, after irradiation, replenishes the seminiferous epithelium. Most investigations in this area have dealt with radiation dosages of 100R or more. This study was undertaken to observe cellular responses at doses less than 100R of X-irradiation utilizing a system in which the tissue can be used for light and electron microscopy.Brown B6D2F1 mice aged 16 weeks were exposed to X-irradiation (225KeV; 15mA; filter 0.35 Cu; 50-60 R/min). Four mice were irradiated at each dose level between 1 and 100 rads. Testes were removed 3 days post-irradiation, fixed, and embedded. Sections were cut at 2 microns for light microscopy. After staining, surviving spermatogonia were identified and counted in tubule cross sections. The surviving fraction of spermatogonia compared to control, S/S0, was plotted against dose to give the curve shown in Fig. 1.

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Crystallographic Characterization of Dislocation Loops in Irradiated Tungsten

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100101190 ◽

1968 ◽

Vol 26 ◽

pp. 290-291

Author(s):

Robert C. Rau

Keyword(s):

Electron Microscope ◽

Ambient Temperature ◽

Dislocation Loops ◽

Polycrystalline Specimen ◽

Post Irradiation ◽

Neutron Fluences

Previous work has shown that post-irradiation annealing, at temperatures near 1100°C, produces resolvable dislocation loops in tungsten irradiated to fast (E > 1 MeV) neutron fluences of about 4 x 1019 n/cm2 or greater. To crystallographically characterize these loops, tilting experiments were carried out in the electron microscope on a polycrystalline specimen which had been irradiated to 1.5 × 1021 n/cm2 at reactor ambient temperature (∼ 70°C), and subseouently annealed for 315 hours at 1100°C. This treatment produced large loops averaging 1000 Å in diameter, as shown in the micrographs of Fig. 1. The orientation of this grain was near (001), and tilting was carried out about axes near [100], [10] and [110].

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