scholarly journals Incorporation of 5-substituted uracil derivatives into nucleic acids. The isolation and γ-radiation-sensitivity of bacteriophage T3 containing the thymine analogue 5-vinyluracil

1980 ◽  
Vol 187 (1) ◽  
pp. 257-260 ◽  
Author(s):  
E T J Chelton ◽  
M Duggan ◽  
R N Hunston ◽  
A S Jones ◽  
M K O'Leary ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Nucleic Acids ◽  
Gamma Radiation ◽  
Radiation Sensitivity ◽  
Γ Radiation ◽  
Uracil Derivatives ◽  
Phage Dna

Bacteriophage T3 was produced in a form that contained 32% of its normal DNA thymine residues replaced with 5-vinyluracil residues by infecting a thymine-requiring strain of Escherichia coli with phage T3 in a medium containing 5-vinyluracil. When 2′-deoxy-5-vinyluridine was added to the medium instead, no incorporation was observed into the phage DNA, and the presence of the deoxyribonucleoside severely decreased the number of viable phage particles produced. The analogue-containing phage, although initially viable, rapidly lost viability when stored, but it was no more sensitive than was normal phage T3 to the effect of gamma-radiation.

DETECTION OF GAMMA RADIATION EFFECT INDUCED BY COBELT-60 ON ESCHERICHIA COLI CELLS

2010 ◽  
Vol 13 (3) ◽  
pp. 129-133
Author(s):  
Ghusoon Ali Abdul Hasan Al-Sudany ◽  
◽  
Wasan Zuheir Majeed ◽  
Hind Jabbar Abdul Rhman Akram Al-Aubeidi ◽  
◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Gamma Radiation ◽  
Radiation Effect ◽  
Escherichia Coli Cells

scholarly journals Facile preparation of new polystyrene leucomalachite green thick films and study of their radiochromic behavior for low doses of gamma radiation

2017 ◽  
Vol 5 (2) ◽  
pp. 80
Author(s):  
Anuradha Bera ◽  
Shatrughan Malav ◽  
Bajrang Lal Tiwari ◽  
Shyam Govind Vaijapurkar
Keyword(s):  
Film Thickness ◽  
Gamma Radiation ◽  
Thick Films ◽  
Radiation Processing ◽  
Γ Radiation ◽  
Dye Loading ◽  
Leucomalachite Green ◽  
Colour Development ◽  
Green Coloration ◽  
Potential Use

Colourless polystyrene-leucomalachite green (PS-LMG) thick films containing a suitable chloroalkane were prepared by a fast and facile casting method, and were investigated for their radio chromic response behavior under the influence of 1.25 MeV γ-radiation. Their gamma response was studied in the 0.05 kGy to 10 kGy range to evaluate their suitability for potential use as the dosimeter in the radiation processing industries. The films were found to undergo a visibly distinct green coloration in the studied range, with the colour intensity increasing with an increase in the total dose. The radiochromic response of these films when investigated as a function of film thickness showed that the colour development as well as the linearity of the response was markedly affected by the thickness of the films. The effect of dye loading and the chloroalkane concentration on the radiochromic response of these films were also investigated. Depending upon the film thickness and reactant concentrations, the films were found to be capable of visually detecting gamma radiation doses as low as few tens of grays.

Effect of Gamma Radiation on the Reduction of Salmonella strains, Listeria monocytogenes, and Shiga Toxin–Producing Escherichia coli and Sensory Evaluation of Minimally Processed Spinach (Tetragonia expansa)

2014 ◽  
Vol 77 (10) ◽  
pp. 1768-1772 ◽  
Author(s):  
ANA CAROLINA B. REZENDE ◽  
MARIA CRYSTINA IGARASHI ◽  
MARIA TERESA DESTRO ◽  
BERNADETTE D. G. M. FRANCO ◽  
MARIZA LANDGRAF
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Gamma Radiation ◽  
Shiga Toxin ◽  
Radiation Doses ◽  
Minimally Processed ◽  
Tetragonia Expansa ◽  
Effects Of Irradiation On ◽  
Spinach Leaves

This study evaluated the effects of irradiation on the reduction of Shiga toxin–producing Escherichia coli (STEC), Salmonella strains, and Listeria monocytogenes, as well as on the sensory characteristics of minimally processed spinach. Spinach samples were inoculated with a cocktail of three strains each of STEC, Salmonella strains, and L. monocytogenes, separately, and were exposed to gamma radiation doses of 0, 0.2, 0.4, 0.6, 0.8, and 1.0 kGy. Samples that were exposed to 0.0, 1.0, and 1.5 kGy and kept under refrigeration (4°C) for 12 days were submitted to sensory analysis. D10-values ranged from 0.19 to 0.20 kGy for Salmonella and from 0.20 to 0.21 for L. monocytogenes; for STEC, the value was 0.17 kGy. Spinach showed good acceptability, even after exposure to 1.5 kGy. Because gamma radiation reduced the selected pathogens without causing significant changes in the quality of spinach leaves, it may be a useful method to improve safety in the fresh produce industry.

scholarly journals exrB: amalB-linked gene inEscherichia coliB involved in sensitivity to radiation and filament formation

1974 ◽  
Vol 23 (2) ◽  
pp. 175-184 ◽  
Author(s):  
Joseph Greenberg ◽  
Leonard J. Berends ◽  
John Donch ◽  
Michael H. L. Green
Keyword(s):  
Escherichia Coli ◽  
Normal Growth ◽  
Filament Formation ◽  
Wild Type ◽  
Sensitive Mutant ◽  
Γ Radiation ◽  
Linked Gene ◽  
Derivatives Of

SUMMARYPAM 26, a radiation-sensitive mutant ofEscherichia colistrain B, is described. Its properties are attributable to a mutation in a gene,exrB, which is cotransducible withmalB. It differs fromuvrA(alsomalB-linked) derivatives of strain B in being sensitive to 1-methyl-3-nitro-1-nitroso-guanidine and γ-radiation, and in being able to reactivate UV-irradiated phage T3. It differs fromexrA(alsomalB-linked) derivatives of strain B in forming filaments during the course of normal growth as well as after irradiation. WhenexrBwas transduced into a K12 (lon+) strain, filaments did not form spontaneously. Three-point transductions established the order of markers asmet A malB exrB. Based on an analysis of the frequency of wild-type recombinants in a reciprocal transduction betweenexrAandexrBstrains, it was inferred that they are not isogenic and that the order of markers ismalB exrA exrB.

RELEASE OF ULTRAVIOLET-ABSORBING MATERIAL FROM ESCHERICHIA COLI AT SUBZERO TEMPERATURES

1963 ◽  
Vol 9 (4) ◽  
pp. 523-530 ◽  
Author(s):  
Gösta Lindeberg ◽  
Aaslaug Lode
Keyword(s):  
Escherichia Coli ◽  
Nucleic Acids ◽  
Cold Shock ◽  
Organic Phosphorus ◽  
Lethal Effect ◽  
Rapid Cooling ◽  
Pronounced Decrease ◽  
Subzero Temperatures ◽  
Absorbing Material ◽  
Freezing Seawater

When cells of Escherichia coli were suspended in dilute artificial seawater and cooled to various subzero temperatures, a maximum lethal effect occurred around −40 °C. In addition, rapid cooling to −26 °C of bacteria, suspended in concentrated, non-freezing seawater caused a pronounced decrease in viability ("cold shock"). The loss in viability was accompanied by a proportional release from the cells of ultraviolet-absorbing material and by an increase in the ribose and organic phosphorus contents of the suspending liquid. It seems possible that the released material, at least partly, consisted of nucleotides or nucleic acids.

scholarly journals Differential expression of NPM, GSTA3, and GNMT in mouse liver following long-term in vivo irradiation by means of uranium tailings

2018 ◽  
Vol 38 (5) ◽  
Author(s):  
Lan Yi ◽  
Hongxiang Mu ◽  
Nan Hu ◽  
Jing Sun ◽  
Jie Yin ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Radiation Exposure ◽  
Central Vein ◽  
Glutathione S Transferase ◽  
Γ Radiation ◽  
Dose Rates ◽  
Living Organisms ◽  
Uranium Tailings

Uranium tailings (UT) are formed as a byproduct of uranium mining and are of potential risk to living organisms. In the present study, we sought to identify potential biomarkers associated with chronic exposure to low dose rate γ radiation originating from UT. We exposed C57BL/6J mice to 30, 100, or 250 μGy/h of gamma radiation originating from UT samples. Nine animals were included in each treatment group. We observed that the liver central vein was significantly enlarged in mice exposed to dose rates of 100 and 250 μGy/h, when compared with nonirradiated controls. Using proteomic techniques, we identified 18 proteins that were differentially expressed (by a factor of at least 2.5-fold) in exposed animals, when compared with controls. We chose glycine N-methyltransferase (GNMT), glutathione S-transferase A3 (GSTA3), and nucleophosmin (NPM) for further investigations. Our data showed that GNMT (at 100 and 250 μGy/h) and NPM (at 250 μGy/h) were up-regulated, and GSTA3 was down-regulated in all of the irradiated groups, indicating that their expression is modulated by chronic gamma radiation exposure. GNMT, GSTA3, and NPM may therefore prove useful as biomarkers of gamma radiation exposure associated with UT. The mechanisms underlying those changes need to be further studied.

scholarly journals GAMMA-RADIATION SPECTRA OF 1200 MeV ELECTRONS IN THICK BERYLLIUM, SILICON AND TUNGSTEN SINGLE CRYSTALS

2019 ◽  
pp. 86-93
Author(s):  
G. L. Bochek ◽  
O. S. Deiev ◽  
V. I. Kulibaba ◽  
N. I. Maslov ◽  
V. D. Ovchinnik ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Single Crystals ◽  
Angular Distributions ◽  
Γ Radiation ◽  
Radiation Spectra ◽  
Solid Angles ◽  
Crystallographic Axes ◽  
And Tungsten

Gamma radiation spectra of 1200 MeV electrons from the single crystals of the beryllium 1.2 mm thick, silicon 1.5 mm and 15 mm thick and tungsten 1.18 mm thick along of the crystallographic axes were measured. Also spectral-angular distributions of gamma radiation from the silicon single crystals 1.5 mm thick along of the crystallographic axes < 100 >, < 110 > and < 111 > were measured. On the basis of these measurements the γ-radiation spectra for the different solid angles up to 6.97 × 10−6 sr were obtained.

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