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Sample records for 54mn 60co 85sr

  1. Soil-to-plant transfer of 54Mn, 60Co, 85Sr and 137Cs deposited during the growing season of potato

    To measure the soil-to-plant transfer factors (TFa, m2 kg-1-fresh) of radionuclides deposited during the growing season of potato, a radioactive solution containing 54Mn, 60Co, 85Sr and 137Cs was applied to the soil surfaces in soil boxes 2 d before seeding and three different times during the plant growth. For the Pre-Seeding Application (PSA), radionuclides were mixed with the topsoil (loamy sand and 5.2 in pH). The plant parts investigated were leaves, stems, tuber skin and tuber flesh. The TFa values of 54Mn, 60Co, 85Sr and 137Cs from the PSA were in the ranges of 1.9 x 10-4∼1.5 x 10-2, 1.8 x 10-4∼7.5 x 10-4, 4.0 x 10-4∼1.6 x 10-2, 1.5 x 10-4∼3.9 x 10-4, respectively, for different plant parts. The TFa values from the growing-time applications were on the whole a few times lower than those from the PSA. For 54Mn, 85Sr and 137Cs, the TFa values from the early- or middle-growth-stage application were higher than those from the late-growth-stage application, whereas the opposite was true for 60Co. Leaves and tuber flesh had the highest and lowest TFa values, respectively, in most cases. The total uptake from soil by the four plant parts was in the range of 0.05∼3.16%. In the third year following the PSA, the TFa values of 54Mn, 60Co and 137Cs were 11∼25%, 21∼25% and 38∼67% of those in the first year, respectively, depending on the plant parts. The present results can be used for estimating the radiological impact of an acute radioactive deposition during the growing season of potato and for testing the validity of relevant food-chain models

  2. Distribution of 60Co and 54Mn in graphite material of irradiated HTGR fuel assemblies

    Distribution of 60Co and 54Mn was measured in the graphite sleeves and blocks of the third and fourth HTGR fuel assemblies irradiated in the Oarai Gas Loop-1 (OGL-1), which is a high temperature inpile gas loop installed in the Japan Materials Testing Reactor (JMTR) of Japan Atomic Energy Research Institute (JAERI). Axial and circumferential profiles were obtained by gamma spectrometry, and radial profiles by lathe sectioning with gamma spectrometry. Distribution of 60Co is in good agreement with that of thermal neutron flux, and the Co content in the graphite is estimated to be -- 1 x 10-9 in weight fraction. Concentration of 54Mn decreases toward the axial center in its axial profile, and radially is almost uniform inside and appreciably higher at free surfaces. An estimated Fe content of --10-8 in wight fraction is smaller by two orders of magnitude than that from chemical analysis. Higher concentraion of 60Co and 54Mn at the free surfaces suggests the importance of transportation process of these nuclides in the coolant loop. (author)

  3. Retention of 60Co, 85Sr and 137Cs on inorganic ion exchangers

    The aim of the study is the treatment of radioactive wastes produced in plutonium fuel fabrication or in spent fuel reprocessing by inorganic ion exchangers for ultimate storage. This rapport, gives the distribution coefficients of 60Co, 85Sr, 137Cs (in sodium nitrate medium at different concentration of sodium: .23g/l, 1 g/l, 10 g/l) obtained with different inorganic exchangers: titanium oxyde, sodium titanate, sodium zirconate, sodium niobate, sodium tantalate, titanium phosphate, zirconium phosphate, ammonium phosphotungstate in zirconium phosphate, polyantimonic acid amorphous aluminosilicate and several zeolites (ZBS 15 from OXYMIN, ZEOLON 400, ZEOLON 500, ZEOLON 900 from Norton, IE 96, A 51, 13 X from Union Carbide)

  4. The use of ion exchange chromatography in the cyclotron production of the radioisotopes 85Sr, 54Mn, 57Co and 109Cd

    This dissertation shows the successful application of ion exchange chromatography to the isolation of carrier free cyclotron produced radioisotopes. A simple method is presented for the isolation of 85Sr from a 10 g rubidium chloride target. Cation exchange with AG50-X12 is used to retain 85Sr from a bombarded target dissolved in 0.1 mol/dm3 hydrochloric acid. Rubidium is effectively eluted with 0.5 mol/dm3 hydrochloric acid and trace impurities such as copper, iron and 65Zn are eluted with 0.5 mol/dm3 hydrochloric acid/φ=0.95 acetone (where φ is the volume fraction of acetone). Strontium-85 is eluted in nearly 100% yield with 3.0 mol/dm3 nitric acid. The isolation of 54Mn, 57Co and 109Cd from a composite iron-silver target is performed with AG50-X4 cation exchange resin in a hydrochloric acid-acetone medium subsequent to the removal of silver by reduction with hydrazine hydrate. Cadmium-109 is eluted with 0.1 mol/dm3 hydrochloric acid/φ=0.80 acetone and is further refined by absorption onto a AG1-X8 anion exchange column and subsequent washing with 0.25 mol/dm3 nitric acid/0.1 mol/dm3 hydrobromic acid. The elution of copper, iron, 65Zn and other impurities from the cation exhanger is performed with 0.5 mol/dm3 hydrochloric acid/φ=0.83 acetone. Cobalt-57 is quantitively eluted with 0.35 mol/dm3 hydrochloric acid/φ=0.90 acetone, and 54Mn, the remaining element on the column, is recovered with 3.0 mol/dm3 hydrochloric acid

  5. Evaluation of small scale laboratory and pot experiments to determine realistic transfer factors for the radionuclides 90Sr, 137Cs, 60Co and 54Mn

    Transfer factors for the root uptake of 90Sr, 137Cs, 60Co and 54Mn were compared using outdoor lysimeters, Kick-Brauckmann experimental pots under greenhouse conditions and Neubauer cups under growth chamber conditions. The uptake was studied in barley, potatoes, sugar beet and salad vegetables grown on either podsolic or loess soil. The transfer factors for these radionuclides under the specific conditions of the small scale Neubauer cup experiments differed greatly from those obtained from the outdoor lysimeter. In the pot experiments, the transfer factors for 90Sr, 137Cs and 54Mn showed less deviation from the lysimeter results especially in crops grown on podsolic soil. For 60Co, the transfer factors varied for the different crops grown. Transfer factors obtained in pot experiments can only be applicable to a limited extent to field conditions; factors influencing the transfer factors in pot experiments include soil volume, root density, root/shoot ratio, water supply and fertilizer application rate. (UK)

  6. Transport of 85Sr, 60Co, 65Zn and 109Cd in two forest soils as observed in undisturbed soil columns

    Undisturbed soil columns of 20 cm in diameter and about 40 cm length were taken in a spruce stand (podsolic parabrown earth) and in a pine stand (podsol). In the laboratory the transport of 85Sr, 60Co, 65Zn and 109Cd was investigated under unsaturated conditions by periodical irrigation of the columns with rainwater and observation of the resulting depth profiles with a scanner technique as a function of time for three years. From the activity distributions obtained, the residence half-times and mean rates of migration of the radionuclides in the various soil horizons were evaluated with a compartment model. - In the top layer of the soil from the spruce stand (consisting of organic material only) the mean migration rate of 85Sr, 65Zn and 109Cd was 2.0 ± 0.05 cm/y and thus rather similar to that of 60Co (1.7 ± 0.3 cm/y). In the corresponding layer from the pine stand the mean migration rate of 85Sr, 65Zn and 109Cd was only 0.87 ± 0.06 cm/y (60Co:0.5 ± 0.10 cm/y). Since the water flux in the columns from the pine stand was even higher than in those from the spruce stand, the radionuclides seem to be sorbed stronger by organic material derived from pine needles than from spruce needles (the pH was about 3 in both soils). In the underlaying mineral soil the migration rate of the radionuclides was considerably faster than in the organic layer (between 2.5 and 10 cm/y), but a statistical difference between the values observed in the two stands or between the radionuclides was not apparent. (orig.)

  7. In situ determination of the distribution of 110Agm, 58Co, 60Co and 54Mn between fresh water and suspended matter

    In order to obtain data on the equilibrium conditions and the exchange kinetics of radionuclides between water and suspended matter in natural conditions, an in situ experiment was carried out in the nuclear power plant of Golfech (France). In this plant, an experimental physical model of river systems, represented by a channel, was built. Before being discharged into the Garonne river, part of the radioactive effluents, previously mixed with water originating from the cooling system, are diverted to a channel where different phenomena generally occurring in a river can be simulated. The experiment presented in the paper was undertaken during a scheduled discharge of low activity wastes; the suspended matter was sampled at four points along the channel using sequential filtration. The results give information about: (1) The influence of the particle size on the process of radionuclide adsorption by suspended matter. The uptake of radioactivity is generally higher for the smallest particles (size 110Agm, size 58Co, 60Co and 54Mn). (2) The exchange kinetics between water and suspended matter. Generally, radioactive equilibrium is rapidly attained. Consequently, it is possible to calculate the global distribution coefficient (Kd) value of each radionuclide (110Agm, 58Co, 60Co and 54Mn) and to determine exactly the specific Kd value for each granulometric class (class 1 > 10 μm; 10 μm < class 2 < 2.5 μm; 2.5 μm < class 3 < 0.5 μm). (author). 11 refs, 3 figs, 1 tab

  8. Cosmic ray half life of 54Mn

    A search for the β+ decay of 54Mn has established an upper limit of 4.4 x 10-8 for this branching ratio, and a lower limit of 13.3 for the log ft value for this second forbidden unique transition. Assuming that the β- decay branch has the same log ft value, then its partial half life must be greater than 4 x 104 years. Experiments to directly measure the β- decay rate of 54Mn are now in progress. 6 refs., 2 figs

  9. Internal bremsstrahlung endpoint energy of 54Mn

    For 54Mn there is a discrepancy between the QEC obtained from the endpoint energy of the internal bremsstrahlung (IB) spectrum which accompanies the electron capture decay (QEC=1353±8 keV) and that obtained from the accepted mass differences (QEC=1377±1 keV). This Q value is needed to deduce the partial-half life of the astrophysically interesting β- decay of 54Mn from the recently measured β+ partial half-life. To resolve this discrepancy, we have remeasured the endpoint energy of the IB spectrum, by recording coincidences between the IB and the 835-keV γ ray, both detected in Compton-suppressed Ge detectors. The QEC we deduce is 1379±8 keV, in agreement with the accepted mass differences. (c) 2000 The American Physical Society

  10. Search for the β+ decay of 54Mn

    We have performed a search for the β+ decay of 54Mn by looking for back-to-back 511-keV γ rays in two high-purity Ge detectors. No excess of events above background was observed, and a limit of 5.7x10-7% has been established for the β+ branch. The significance of this result for the use of 54Mn as a cosmic ray chronometer is discussed

  11. Lifetimes of excited states in 54Mn and 53Cr

    The recoil-distance method has been used in conjection with the 51V(α, n) and 50Ti(α, n) reactions to investigate the lifetimes of four levels in 54Mn and four in 53Cr. The mean lives obtained are as follows: 53Cr(Esub(x)= 1006 keV), tau 53Cr(Esub(x) = 1537 keV), tau = 33.2 +- 1.6 ps; 53Cr(Esub(x) = 2173 keV), tau = 13.9 +- 1.1 ps; 53Cr(Esub(x) = 2707 keV), tau = 3.4 +-1.4 ps; 54Mn(Esub(x) = 156 keV), tau = 302 +- 24 ps; 54Mn(Esub(x) = 368 keV), tau = 8.9 +- 1.9 ps; 54Mn(Esub(x) = 408 keV), tau = 2.7 +- 0.8 ps; 54Mn(1073 keV), tau = 321 +- 13 ps. In addition, the Doppler-shift attenuation method has been used to investigate ten lifetimes in 53Cr and fourteen in 54Mn. The results extracted are discussed, and compared with previous experiments and with theoretical predictions. (author)

  12. Internal bremsstrahlung endpoint energy of {sup 54}Mn

    Hindi, M. M. [Physics Department, Tennessee Technological University, Cookeville, Tennessee 38505 (United States); Larimer, R.-M. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Norman, E. B. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Rech, G. A. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    2000-05-01

    For {sup 54}Mn there is a discrepancy between the Q{sub EC} obtained from the endpoint energy of the internal bremsstrahlung (IB) spectrum which accompanies the electron capture decay (Q{sub EC}=1353{+-}8 keV) and that obtained from the accepted mass differences (Q{sub EC}=1377{+-}1 keV). This Q value is needed to deduce the partial-half life of the astrophysically interesting {beta}{sup -} decay of {sup 54}Mn from the recently measured {beta}{sup +} partial half-life. To resolve this discrepancy, we have remeasured the endpoint energy of the IB spectrum, by recording coincidences between the IB and the 835-keV {gamma} ray, both detected in Compton-suppressed Ge detectors. The Q{sub EC} we deduce is 1379{+-}8 keV, in agreement with the accepted mass differences. (c) 2000 The American Physical Society.

  13. Soil radiochromatography using 22Na, 85Sr, and 58Co

    A laboratory study of radionuclide movement and adsorption in soil has been performed. A commercial, high-performance, liquid chromatography system, employing an ultraviolet adsorption detector, was supplemented with a real-time radiation monitor of the column effluent. Columns packed with various soils and their size separates were injected with 22Na, 85Sr, and 58Co using various CaCl2 solutions for eluting solvents to simulate groundwater. The near identical behavior of 85Sr and Ca allowed the elution volumes of the Sr peaks to be used for the calculation of the cation retention capacities of the soils which agreed with their measured cation exchange capacities. Treatment with NaOH increased the cation exchange capacity of one column by 50%. Acetone or sodium benzoate proved useful for measuring column void volumes using the ultraviolet detector because they eluted at exactly the calculated void volumes for all soil columns. Methods to measure a soil's retardation factor (R/sub d/) and distribution coefficient (K/sub d/) for each isotope from the experimental elution patterns were developed. Excellent simulations of the elution peaks were attained using the Lapidus-Amundson equation, which required inputs of flow rate, K/sub d/, bulk density, porosity, the dispersion coefficient, and column length. The factors determining the elution volume of either 22Na or 85Sr were the cation exchange capacity of the column and the concentration of Ca in the eluting solution. Elution of these isotopes was not affected by the presence of complexing organic acids, EDTA, or acidic and basic soil organic matter extracts. On the other hand, 58Co exhibited enhanced mobility when complexed with EDTA but not with other organic acids or soil extracts. A significant amount of 58Co was strongly adsorbed by the soils and could be removed only by washing with strong mineral acid

  14. Double K-shell ionization probability in 54Mn

    We have measured the probability of double K-shell vacancy production in the electron capture decay of 54Mn to the 835-keV level of 54Cr. The probability was deduced from the number of triple coincidences among the Cr hypersatellite and satellite x rays emitted in filling the double vacancy and the 835-keV γ ray. The probability of double K-shell vacancy production per K-shell electron capture (PKK) was found to be (2.3-0.5+0.8)x10-4. Comparisons to previous experimental results and theoretical calculations are discussed

  15. STABLE SR VS 85SR SORPTION FROM SIMULATED WASTE SOLUTIONS BY MST AND MMST

    Taylor-Pashow, K.; Hobbs, D.

    2012-04-02

    A series of tests were performed to examine the sorption of stable Sr versus the sorption of {sup 85}Sr by monosodium titanate (MST) and modified monosodium titanate (mMST) from simulated waste solutions. Earlier testing indicated a discrepancy between the decontamination factors (DFs) obtained by measuring the stable Sr concentrations by inductively coupled plasma - mass spectroscopy (ICP-MS) and the {sup 85}Sr activities by gamma spectroscopy. One hypothesis to explain this discrepancy was that the stable Sr and {sup 85}Sr were in different chemical forms in the simulated solutions. Several simulants were prepared using different methods for adding the Sr and performance tests were carried out using MST and mMST to determine the Sr and {sup 85}Sr DFs with the various simulants. Testing indicated no discrepancy between the Sr and {sup 85}Sr DFs in tests with these simulants.

  16. Age influence on retention, distribution and internal doses of 85Sr in rat

    After I.V. 85Sr, the whole body 85Sr-retentions in rats were fit to two compartment exponential equations. The equation parameters showed a significantly difference between the young group and both the adult and old groups (p 2) for 85Sr in the slow compartment decreased in regular order from the young to the old groups. In the bone 85Sr-retention equations Tb2 of the slow compartment for 85Sr in the young group was significantly lower than the adult and old groups. The doses of the whole body and red-marrow for young rats were 4.2 times as much as those of adult rats, and 6.2 and 5.9 times as much as those old rats. The dose-cumulative speeds was most quick in the young groups and similar in the adult and the old

  17. Comparison of transfer factors of 85Sr and 134Cs for some Greek soils and crops

    The 'soil-plant' transfer factors (TF) of 85Sr and 134Cs was studied in two successive and similar in design glasshouse experiments. Plant species of wheat, alfalfa, radish, string bean, cucumber, lettuce (only for 85Sr) and endive (only for 134Cs) were grown in pots on eight Greek soils differing significantly in their physical and chemical properties. After the necessary measurements and analysis, big differences were detected in the transfer factors of both radionuclides for the soil types. The TFs of 85Sr were higher than those of 134Cs and for the tested crops and soils ranged between 0.3 and 36.5 for 85Sr and between 0.01 and 1.72 - for 134Cs. For 85Sr the TFs of the edible parts were much lower than those of the rest plant material, while this difference was not so high for 134Cs. The correlation between TFs and pH, negative in all cases, was significant or highly significant for all tested crops or plant parts (for 85Sr r=-0.89, for 134Cs r=-0.82). The values of TRs indicated a trend towards negative correlation with other soil properties (cation exchange capacity - CEC, clay %). The exchangeable (Ca+Mg) cations as well as exchangeable bases, expressed as percentages of CEC, gave a significant or highly significant correlation with TFs of both radionuclides. (author)

  18. Preparatory on manganose salts of carboxilic acids labelled with 54Mn and comparison with 54MnCl2 in liquid scintillation counting

    Procedures for scintillation sample preparation of manganose dimethylbutirate, decanoate and palmitate, labelled with 54Mn are described. Their quenching effect, spectral evolution and counting stability along several weeks are analysed in liquid scintillation measurements with Toluene, HlSafe II, PCS, Instagel, Dioxane-naphtalene and Toluene-alcohol. For comparison, inorganic 54MnCl2 samples are also studied, resulting in acceptable counting stability but showing greater quenching and signs of little spectral degradation against the organic samples. (author) 14 fig. 15 ref

  19. Galactic Confinement Time of Iron-Group Cosmic Rays Derived from the {sup 54}Mn Chronometer

    Zaerpoor, K.; Dragowsky, M.R.; Krane, K.S. [Physics Department, Oregon State University, Corvallis, Oregon 97331 (United States); Chan, Y.D.; Isaac, M.C.; Larimer, R.M.; Macchiavelli, A.O.; Macleod, R.W.; Norman, E.B. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); DiGregorio, D.E. [Laboratorio TANDAR-Comision Nacional de Energia Atomica, Buenos Aires, 1429 (Argentina); Hindi, M.M. [Physics Department, Tennessee Technological University, Cookeville, Tennessee 38505 (United States); Miocinovic, P. [Physics Department, University of California, Berkeley, California 94720 (United States)

    1997-12-01

    The {beta} -decay half-life of {sup 54}Mn is needed to employ this isotope as a cosmic ray chronometer. We have determined the partial half-life of {sup 54}Mn for positron emission by counting a highly purified 35-{mu}Ci source of {sup 54}Mn in GAMMASPHERE to search for the astrophysically interesting {beta}{sup +} decay branch through the observation of coincident positron-annihilation {gamma} rays. A careful analysis of 97hours of source counting and 61hours of background shows a net signal of 24{plus_minus}10 back-to-back 511-511keV coincident events. Based on this result, the branch for this decay mode is (2.2{plus_minus}0.9){times}10{sup {minus}7}{percent} . The implications of this result for the {sup 54}Mn cosmic-ray chronometer problem are discussed. {copyright} {ital 1997} {ital The American Physical Society}

  20. Separation of 54Mn from Irradiated Natural Fe2O3 Using Anion Exchange Resin

    Preparation of radioisotope from natural target has an advantage namely the production is cheaper, but the produced radioisotope may content radionuclidic impurities. Preparation of 54Mn from irradiated natural Fe2O3 has a problem due to 59Fe impurity. The separation of 54Mn from irradiated natural Fe2O3 has been carried out by means of solving irradiated target using HCl and dowex resin 1 x 8 Cl form. The separation of 54Mn from irradiated natural Fe2O3 showed a good result by 8 N HCl concentration and 90 minute contact time and efficiency was 7.55 % 54Mn and 94.13 % for 59Fe. (author)

  1. Galactic Confinement Time of Iron-Group Cosmic Rays Derived from the 54Mn Chronometer

    The β -decay half-life of 54Mn is needed to employ this isotope as a cosmic ray chronometer. We have determined the partial half-life of 54Mn for positron emission by counting a highly purified 35-μCi source of 54Mn in GAMMASPHERE to search for the astrophysically interesting β+ decay branch through the observation of coincident positron-annihilation γ rays. A careful analysis of 97hours of source counting and 61hours of background shows a net signal of 24±10 back-to-back 511-511keV coincident events. Based on this result, the branch for this decay mode is (2.2±0.9)x10-7% . The implications of this result for the 54Mn cosmic-ray chronometer problem are discussed. copyright 1997 The American Physical Society

  2. Comparative kinetics of 47Ca, 85Sr and 226Ra in the freshwater turtle, Trachemys scripta

    The kinetics of 47Ca, 85Sr and 226Ra were compared in the yellow-bellied slider, a common freshwater turtle of the southeastern USA. The absorption and elimination processes were examined as a function of stable dietary Ca, season, age and sex of the animals. Turtles were gavaged with radionuclides and serial whole-body analyses were performed on the live animals for up to 480 days. Only in the juvenile age class did reduced dietary Ca cause a significant increase in 85Sr absorption. The absorption of 85Sr and 226Ra in the adult male, adult female and hatchling groups was unaffected by dietary Ca. Mean absorption was greater than that which has been reported for other organisms and significantly differed among isotopes. The high absorption values were not restricted to immatures, but continued into maturity. Elimination rates were not affected by the dietary treatment, nor were isotopic differences in elimination observed. Annual mean elimination rate constants pooled among animal groups, were 0.22 ± 0.07 for 85Sr and 0.26 ± 0.18 for 226Ra. Retention was strongly affected by season with the greatest elimination occurring in the summer and declining to levels that were not distinguishable from zero in the winter. Elimination rate constants for hatchlings were greater than for the other age groups. (author)

  3. The transfer parameter of environmental 85Sr radiostrontium trough soil - spinach plant (Amaranthus sp.) Pathway

    The radionuclide transfer from soil to crop is a pathway of the radionuclide to contaminate human body. Soil plant interaction can be examined by several parameter such as transfer factor (Ft) and transfer rate coefficient (k12). An experiment about radiostrontium transfer from soil to crop had been conducted to determine the plant ability in radiostrontium accumulation for human internal doses assessment. Crop represented by commonly consumed by people, spinach (Amaranthus sp.), was cultivated in soil contaminated with 85Sr for about 2 months. Every five days the soil and plants were sampled, dried, and the 85Sr activities were measured using gamma spectrometer. The measurement results showed that the spinach crop were able to absorb and accumulate 85Sr. The Ft value obtained from this experiment is about 3, whereas the k12 values are 9.99 x 10-3 day-1 and 9.98 x 10-3 day-1, for 041 days, respectively. The 85Sr soil - plant transfer parameter is expected to be used for radiological impact assessment in the case of Sr radionuclide contamination in soil. The obtained Ft and k12 can be use for predicting Sr radioactivities in edible parts of plants in certain period after soil contamination with radiostrontium. (author)

  4. Effect of plant species on the specific activity of 65Zn and 54Mn

    The effect of five plant species on the specific activity of 65Zn and 54Mn is studied. Soybean (Glycine max (L.) Merril), bean (Phaseolus vulgaris, L.), rice (Oryza sativa, L.), wheat (Triticum aestivum, L.) and tomato (Lycopersium esculentum Mill) were grown in PV and TE soils labelled with 65Zn and 54Mn. The plants were harvested 30 days after seeding and specific activities of zinco and manganese were determined in the above ground part and in the roots. (M.A.C.)

  5. Cosmic-ray history derived from the 54Mn, 56Ni and 144Pm chronometers

    Sources of 54Mn, 56Ni, and 144Pm were placed at the center of the Gammasphere array and searches were made for the astrophysically interesting β+ decay modes of these isotopes. The results of these searches are presented and the implications for cosmic-ray physics are discussed

  6. 54Mn absorption and excretion in rats fed soy protein and casein diets

    Rats were fed diets containing either soy protein or casein and different levels of manganese, methionine, phytic acid, or arginine for 7 days and then fed test meals labeled with 2 microCi of 54Mn after an overnight fast. Retention of 54Mn in each rat was measured every other day for 21 days using a whole-body counter. Liver manganese was higher (P less than 0.0001) in soy protein-fed rats (8.8 micrograms/g) than in casein-fed rats (5.2 micrograms/g); manganese superoxide dismutase activity also was higher in soy protein-fed rats than in casein-fed rats (P less than 0.01). There was a significant interaction between manganese and protein which affected manganese absorption and biologic half-life of 54Mn. In a second experiment, rats fed soy protein-test meals retained more 54Mn (P less than 0.001) than casein-fed rats. Liver manganese (8.3 micrograms/g) in the soy protein group was also higher than that (5.7 micrograms/g) in the casein group (P less than 0.0001), but manganese superoxide dismutase activity was unaffected by protein. Supplementation with methionine increased 54Mn retention from both soy and casein diets (P less than 0.06); activity of manganese superoxide dismutase increased (P less than 0.05) but liver manganese did not change. The addition of arginine to casein diets had little effect on manganese bioavailability. Phytic acid affected neither manganese absorption nor biologic half-life in two experiments, but it depressed liver manganese in one experiment. These results suggest that neither arginine nor phytic acid was the component in soy protein which made manganese more available from soy protein diets than casein diets

  7. Removal of 54Mn from the mouse body by dilution with stable manganese and by chelation with DTPA

    54Mn is one of the activation products generated in nuclear reactors. This study was carried out to find a method appropriate for the removal of 54Mn. Intraperitoneal administration of stable manganese effectively promoted the excretion of 54Mn from the mouse body. The efficacy for removing 54Mn was estimated to be 56, 67, 77 and 82% for manganese doses of 0.3, 1, 3 and 10 mg/kg, respectively. Oral administration of stable manganese was also effective for the removal of 54Mn, but the efficacy was inferior to that obtained by intraperitoneal administration because of low gastrointestinal absorption of manganese. Ca-DTPA and Zn-DTPA promoted the excretion of 54Mn when administered 1 h after administration of 54Mn, but these chelating agents had little effect when administered after 3 h or more. Zn-DTPA was less effective than Ca-DTPA. These results demonstrate that dilution with stable manganese is more effective than chelation with DTPA for the removal of 54Mn from the body. (author)

  8. Transfer of 226Ra, 85Sr and 137Cs from milk to milk products

    Transfer of 226Ra, 85Sr and 137Cs from cow and sheep milk to various Syrian dairy products has been evaluated. Dairy products include Kashkivan cheese, braided cheese, Haloom cheese, Sircassian cheese, liquid cheese, native cheese, cottage, thick yogurt, butter and milk cream. The results showed that the percentage of 226Ra, 85Sr and 137Cs transferred from cow milk to milk cream (Pt = food processing retention factor x processing efficiency x 100%) has reached 32%, 16% and 7%, respectively. Butter and liquid cheese were found to have the lowest percentage of transferred 226Ra, 85Sr and 137Cs. Most of the obtained Pt values of the studied radionuclides in thick yogurt were relatively low in spite of the high processing efficiencies of thick yogurt. Moreover, the transfer, Pt, of the studied radionuclides from cow milk to the prepared cheese was higher than those values determined for sheep milk. This is due to differences in chemical compositions of each type of milk. On the other hand, the treatment of Native cheese, most commonly consumed cheese in Syria, with different concentrations of NaCl solutions showed that 137Cs was completely removed from cheese soaking in 5% NaCl solution (soaking time of 48 hours), while 40% of 226Ra and 80% of 85Sr were also decontaminated using 0-2.5% NaCl solutions and soaking time of 48 hours. Based on the obtained results, industrialization processes of the dairy products that resulted the removal of radionuclides have been identified. (author)

  9. Transfer Factors of 137Cs and 85Sr by Freshwater Fish in Tropical Environment

    The experiment was set up to determine the radionuclide transfer factors (T.F.) of 137Cs and 85Sr by tropical freshwater fish. Mixed breeding catfish between Thai catfish (Clarias acrocephalus) and African catfish (Clarias garispinus African sharptooth) were exposed to 137Cs and 85Sr in two 1000-L tanks for 42 days during uptake phase. The calculated T.F. at equilibrium, in flesh, bone, skin plus fin and head were 3.2, 2.6, 1.6 and 1.5 L.kg-1 for 137Cs and 0.1, 4, 1 and 17 L.kg-1 for 90Sr, respectively. These results revealed a much lower values than reported elsewhere for temperate environment, however were in accordance with the tropical values as observed by others. The biological half-lives of 137Cs and 85Sr in flesh part were 41 and 4 days respectively. It is then imperative that suitable T.F. values are employed in the models to predict the transport of radionuclides within the particular ecosystem and the potential dose to man. Thus the relationship between routine release of radionuclides and resulting dose to man can be established and corresponding release limits stipulated for that particular nuclear site

  10. Chelation in metal intoxication X: influence of different polyaminocarboxylic acids and thiol chelators in the excretion and tissue distribution of 54Mn in rat

    The influence of some selected polyaminocarboxylic acids and thiol metal binding agents on the urinary and faecal excretions of 54Mn and on the tissue distribution of 54Mn in 54MnC12 administered rats was studied to find a suitable chelating drug for Mn poisoning. HEDTA, CDTA, DTPA and TTHA were highly successful in enhancing the excretion of 54Mn and reducing the tissue levels of 54Mn in rats. The thiol chelators viz. D L-penicillamine, N-acetyl D L-penicillamine and DMS could neither influence the excretion nor the tissue distribution of 54Mn suggesting poor affinity of the metal towards sulfhydryl groups

  11. Metabolism of 60Co in mollusca

    After mollusca were bred in 60Co-labeled sea water or were given 60Co-labeled feed for certain hours, their tissues including the liver were removed as experimental samples. 60Co metabolism was observed by the Sephadex gel filtration profile. A gel chromatogram of the liver in gastropoda showed a marked peak of 60Co on the high-molecular side. Although the peak was observed on both high- and low-molecular sides in pelecypoda, it was more marked on the high-molecular side than on the low-molecular side. In cephalopoda, the peak pattern was similar to that in the other mollusca, but the proportion of low-molecular components was comparatively large. The gel filtration profile of 60Co in various tissues of cephalopoda revealed the incorporation of 60Co into the high-molecular components in blood, three peaks in the kidneys, and the incorporation of 60Co into the low-molecular components in the branchial heart. The metabolism of 60Co was dependent upon the chemical form of Co in gastropoda, and organic 60Co was specifically observed in the high-molecular components. (Namekawa, K.)

  12. 60Co levels in the seawater regions

    In order to assess the contribution from nuclear power facilities to the 60Co levels in seawater regions, it is essential to grasp the background values of 60Co. The following matters are described: 60Co sources and the respective inputs; nuclear test fallout and nuclear power plants; the 60Co levels in overseas countries; the 60Co levels in Japan; the 60Co levels from nuclear power plants in Fukui prefecture. In the seawater regions around Japan, there have been numerous instances of 60Co detection; several pCi/kg of dry earth in sea bottom earth and about 1 pCi/kg of raw material in marine life can be considered as the background levels due to nuclear test fallout and nuclear-powered submarines. In the seawater regions of Fukui prefecture, the 60Co levels appreciably exceeded the above background due to the nuclear power plants, which are insignificant concerning the radiation exposure of the local people. (Mori, K.)

  13. Comparison of histomorphometry and 85Sr uptake in induced heterotopic bone in rats

    Heterotopic bone formation in the abdominal muscle of 45 male 8-week-old Wistar rats induced by implantation of 5, 10, or 15 mg demineralized bone (DBM) powder was evaluated at 4 weeks by 85Sr uptake of the implants and area histomorphometry of the induced bone. Two indices of 85Sr uptake were calculated: the osteogenic index [(counts/min/mg implant)/(counts/min/mg os ilium)] and an index that we have called the osteoquantum index in which the weight of the implant is disregarded [(counts/min implant)/counts/min/mg os ilium)]. The osteoquantum index showed a linear relationship to the area of the induced bone with a correlation coefficient (r) of 0.90. Only weak linear relationships were found between the osteogenic index and the area of the bone (r = 0.32) and between the osteogenic index and the osteoquantum index (r = 0.33). The osteoquantum index and the area of the induced bone both increased with increasing mass of implanted DBM, whereas the osteogenic index did not change. (au)

  14. Comparison of histomorphometry and [sup 85]Sr uptake in induced heterotopic bone in rats

    Solheim, E.; Pinholt, E.M. (Institute for Surgical Research, Rikshospitalet, University of Oslo (Norway)); Bang, G. (Department of Oral Pathology and Forensic Odontology, University of Bergen (Norway)); Sudmann, E. (Hagavik Orthopedic Hospital, University of Bergen (Norway))

    1992-01-01

    Heterotopic bone formation in the abdominal muscle of 45 male 8-week-old Wistar rats induced by implantation of 5, 10, or 15 mg demineralized bone (DBM) powder was evaluated at 4 weeks by [sup 85]Sr uptake of the implants and area histomorphometry of the induced bone. Two indices of [sup 85]Sr uptake were calculated: the osteogenic index [(counts/min/mg implant)/(counts/min/mg os ilium)] and an index that we have called the osteoquantum index in which the weight of the implant is disregarded [(counts/min implant)/(counts/min/mg os ilium)]. The osteoquantum index showed a linear relationship to the area of the induced bone with a correlation coefficient (r) of 0.90. Only weak linear relationships were found between the osteogenic index and the area of the bone (r = 0.32) and between the osteogenic index and the osteoquantum index (r = 0.33). The osteoquantum index and the area of the induced bone both increased with increasing mass of implanted DBM, whereas the osteogenic index did not change. (au).

  15. Curing time effect on the fraction of 60Co from cement matrix

    Cement has been successfully used in Radioactive Waste Management to immobilize a wide range of waste including filter sludges, ion-exchange resins and evaporator concentrates produced in nuclear power plants. In any assessment of cement-immobilized radwaste composites, leach of radionuclides (60Co, 137Cs, 54Mn) is an important factor, for it must be assumed that the composite material will eventually come into contact with leachant solutions. Cement and concrete are widely used in low-level waste management both as a means of solidifying waste and for containment of dry or liquid wastes.At present there is also widespread interest in the use of near-surface concrete trench system for the disposal of radwaste materials.Typical concrete is a mixture of cement, sand, water in various proportions,that together determine the structural properties and tightness of the poured material

  16. Heavy metal effect on uptake and translocation of 134Cs and 85Sr in aubergine plants

    Aubergine plants were treated either with radionuclides or with heavy metals and subsequently (24 h after) with radionuclides, in order to determine the effects of heavy metals (Zn, Cd and Ni) on the behaviour of radiocesium and radiostrontium in plants; the treatments were carried out at anthesis and when fruits were present. It was observed that the treatment of leaves and fruits with heavy metals did not influence the direct uptake of radionuclides and their translocation. 134Cs deposited on the surface of the leaves is transferred to the edible parts of plants to the extent of 0.70% (anthesis) and 0.45% (with covered fruits), while the translocation of 85Sr was found to be negligible, as compared with radiocesium (0.007 and 0.001%, respectively). Strontium activity in fruits is more largely due to direct uptake, while cesium activity in fruits is due to both direct uptake and translocation from leaves

  17. Suppression of the stellar enhancement factor and the reaction 85Rb(p,n)85Sr

    Rauscher, T; Gyürky, Gy; Simon, A; Fülöp, Z; Somorjai, E

    2009-01-01

    It is shown that a Coulomb suppression of the stellar enhancement factor occurs in many endothermic reactions at and far from stability. Contrary to common assumptions, reaction measurements for astrophysics with minimal impact of stellar enhancement should be preferably performed for those reactions instead of their reverses, despite of their negative reaction Q-value. As a demonstration, the cross section of the astrophysically relevant 85Rb(p,n)85Sr reaction has been measured by activation between 2.16<=E_{c.m.}<= 3.96 MeV and the astrophysical reaction rates at p-process temperatures for (p,n) as well as (n,p) are directly inferred from the data. Additionally, our results confirm a previously derived modification of a global optical proton potential. The presented arguments are also relevant for other alpha- and proton-induced reactions in the p-, rp-, and nu-p-processes.

  18. Response of orange plants to foliar application for manganese using 54Mn

    The greenhouse experiment was designed using MnSO4 as a single element or in a mixture of Mn-Fe-Zn sulphate at rates of 0.5 and 1.0%. The solutions were adjusted to pH6.0, and Tween 20 at 0.5% (vol./vol.) was added. The prepared solutions were labelled with carrier free 54Mn. Two year old orange seedlings were arranged in a complete randomized block design to study the foliar absorption, translocation and percentage use of 54Mn. A field experiment was also carried out on 40 year old Balady orange trees (Citrus sinensis, Osbeck) grown in sandy clay loam soil. These trees were suffering from micronutrient deficiencies, in particular Mn. Their response to foliar application of MnSO4 or a mixture of Mn, Fe and Zn sulphates at 0.5 and 1.0% was studied. The vegetative growth, nutritional status and productivity of the treated trees were estimated. The total absorption, translocation and percentage use of 54Mn were greatly affected, depending on the spraying treatment. The percentage use of MnSO4 at 0.5% was more than that at 1.0%, and its value for MnSO4 was twice as high as that of the mixture. The growth parameter were significantly increased by spraying the orange trees with MnSO4 or a mixture of MnSO4 + FeSO4 + ZnSO4; the highest response was found with MnSO4 alone at 1.0%. The leaf N, P and K levels were slightly affected by all the spraying treatments. However, the Mn level in the orange leaves was markedly increased and MnSO4 was more effective in supplying the orange trees with Mn than the mixture. The orange yield increased significantly with all the treatments as a result of spraying the trees, but the rate of increase varied according to the spraying solution. In general, from the nutritional point of view, spraying orange trees suffering from Mn deficiency with MnSO4 at 0.5% could be recommended for correcting this deficiency within a few days and for improving the productivity of the trees. (author). 17 refs, 4 tabs

  19. Sorption of 60 Co on inorganic solids

    The behavior of sorption of the 60 Co in aqueous solution under static conditions to different values of pH of the aqueous solution (1, 3, 5, 7, and 10) on MgO, MnO2, SnO, TiO2, activated carbon and calcinate hydrotalcite was investigated. It was found that the best sorbents of the 60 Co was the MnO2, activated carbon and TiO2 whose sorption was incremented when increasing the pH value of the aqueous solutions, in the one case of the hydrated oxides, the 60 Co interacted with the electrically charged surface of the sorbents that depends on the pH of the solution and of the point of zero charge (zpc) of the sorbent. (Author)

  20. Variations in soil-to-red pepper transfer factors of radionuclides with time of their application and fruit harvest

    A mixed solution of 54Mn, 60Co, 85Sr and 137Cs was applied to the soil of culture boxes in a greenhouse 2 days before transplanting red pepper and at 3 different times during its growth for investigating transfer factors (m2/kg-dry) for its green and red fruits. Transfer factors varied with radionuclide, application time and harvest time by factors of about 20-100. They decreased mostly radionuclide, application time and harvest time by factors of about 20-100. They decreased mostly in the order of 85Sr>54Mn>60Co>137Cs while 54Mn and 60Co was higher than 85Sr when time lapse between application and harvest was short. Transfer factors of 85Sr and 137Cs at the last application were lower than those at the previous one by factors of 3-20 depending on harvest time. Variations in 54Mn and 60Co transfer factors with application time after transplanting were comparatively low. Transfer factors of 54Mn, 60Co and 85Sr mixed with topsoil before transplanting were up to 3-9 times higher than those for the application onto soil surface 2 days after transplanting root-uptake concentrations of the radionuclides in red pepper fruit and taking proper measures for its harvest and consumption at the event of an accidental release during the growing season of red pepper

  1. Evidence for correlations between fluctuations in 54Mn decay rates and solar storms

    Mohsinally, T.; Fancher, S.; Czerny, M.; Fischbach, E.; Gruenwald, J. T.; Heim, J.; Jenkins, J. H.; Nistor, J.; O'Keefe, D.

    2016-02-01

    Following recent indications that several radioactive isotopes show fluctuating decay rates which may be influenced by solar activity, we present findings from a 2 year period of data collection on 54Mn. Measurements were recorded hourly from a 1 μCi sample of 54Mn monitored from January 2010-December 2011. A series of signal-detection algorithms determine regions of statistically significant fluctuations in decay behaviour from the expected exponential form. The 239 decay flags identified during this interval were compared to daily distributions of multiple solar indices, generated by NOAA, which are associated with heightened solar activity. The indices were filtered to provide a list of the 413 strongest events during a coincident period. We find that 49% of the strongest solar events are preceded by at least 1 decay flag within a 48 h interval, and 37% of decay flags are followed by a reported solar event within 48 h. These results are significant at the 0.9σ and 2.8σ levels respectively, based on a comparison to results obtained from a shuffle test, in which the decay measurements were randomly shuffled in time 10,000 times. We also present results from a simulation combining constructed data reflecting 10 sites which compared and filtered decay flags generated from all sites. The results indicate a potential 35% reduction in the false positive rate in going from 1 to 10 sites. By implication, the improved statistics attest to the benefit of analysing data from a larger number of geographically distributed sites in parallel.

  2. Absorption and biological half-life in humans of intrinsic and extrinsic 54Mn tracers from foods of plant origin

    Absorption and biological half-life of 54Mn were measured in adult men and women fed foods labeled intrinsically or extrinsically with 54Mn. Each subject consumed a series of three test meals consisting of a food labeled intrinsically, a food labeled extrinsically or MnCl2 (control) served in random order. The foods tested were lettuce, spinach, wheat and sunflower seeds. Lettuce meals and their controls contained 9.65 mumol Mn; other meals contained 22.50 mumol Mn. In addition to the test food or MnCl2, each meal consisted of vegetable oil (5 g), salt (NaCl, 0.15 g) and crackers (10 g), which provided 0.55 mumol Mn. There were no differences in percentage of Mn absorption or biological half-life of 54Mn for any of the intrinsically/extrinsically labeled food pairs. Absorption of 54Mn from MnCl2 (8.90%) was greater than from lettuce (5.20%), spinach (3.81%), wheat (2.16%) or sunflower seeds (1.71%), but the biological half-life did not vary with the source of Mn. Absorption of 54Mn from lettuce was significantly (P less than 0.05) greater than from wheat or sunflower seeds. Although the Mn dose in the test meal was less for lettuce than for the other foods, there was no difference in Mn absorption from MnCl2 between the subjects fed lettuce and subjects fed other foods. There was no correlation of either 54Mn absorption or biological half-life with whole blood or plasma Mn

  3. Bioaccumulation of 137Cs and 85Sr by an Australian sub-tropical freshwater teleost (Bidyanus bidyanus)

    Adult Silver Perch (Bidyanus bidyanus) were exposed to 137Cs and 85Sr for 8 weeks to determine radionuclide concentration factors (CFs) for use in a dose assessment model database for sub-tropical and tropical ecosystems. At equilibrium, the fresh weight CFs for 137Cs and 85Sr in the flesh of B. bidyanus were 12.6±5.2 kg l-1 (mean±S.E.) and 0.73±0.21 kg l-1, respectively. The mean CFs were considerably lower than those expected for temperate freshwater fish, but were consistent with recently reported values for other sub-tropical and tropical freshwater fish. The results indicate that the use of recommended CFs for radiological dose assessment models, based on temperate freshwater fish, may provide overestimates of dose when applied to sub-tropical and tropical fish. The biological half-lives of 137Cs (19±2 days) and 85Sr (5±1 days) in the flesh of B. bidyanus, estimated from a one-compartment exponential uptake model, were lower than reported values for four other species of sub-tropical and tropical freshwater fish. Cesium-137 was distributed in B. bidyanus as follows: flesh (63%)>skin/scales (22%)>bone (15%). Conversely, 85Sr showed similar activities in the bone and skin/scales that were still increasing after eight weeks, while the levels in the flesh remained relatively low. Analysis of the skin/scales component showed that the majority of 85Sr (=94%) was located in the scales

  4. Regional alterations in long bone 85Sr clearance produced by internal fixation devices. Part II. Histomorphometry

    The effects of each of the surgical stages involved in compression plating on the development of cortical thinning and porosity were assessed in the intact midshaft, stress-shielded femoral segments of adult mongrel dogs 6 months postoperatively. The data were evaluated in terms of a postsurgical tetracycline-based measure of remodeling and terminal 85Sr clearance (SrC) values for the plated segments of bone. Drilling had no effect on any parameter. Screw application was associated with minimal cortical thinning (p less than 0.05), while plate fixation clearly promoted thinning (p less than 0.01) and porosity (p less than 0.05). The percentage of labeled osteons, a measure of remodeling activity, increased only after plate fixation (p less than 0.05), and the labeling patterns suggested that most osteons had formed during the first 4 postsurgical months. That none of these changes were correlated with the 6-month SrC values suggests that the development of plate-induced osteopenia involves disparate histomorphometric time constants, rather than lack of any association

  5. Loss of 51Cr, 54Mn, 57Co, 59Fe, 65Zn and 134Cs by the mussel Mytilus

    The loss of 51Cr, 54Mn, 57Co, 59Fe, 65Zn and 134Cs from naturally growing mussels (Mytilus edulis) was followed in a temperate estuarine environment -a Danish fjord - by individual whole-body countings on a Ge(Li) detector. The mussels accumulated the radionuclides in the laboratory from food and water and were brought back to their natural environment in small plastic cages. The loss curves for 12 animals from July - August 1979 until November 1979 (20-50C) were resolved in a slow compartment with 140-215 d biological half-life for 57Co, 54Mn, 51Cr and 59Fe, and 87 d for 65Zn, and a medium compartment with a biological half-life of 4-7 d for all nuclides. The long-lived compartments of 65Zn, 57Co and 54Mn were followed in four individual animals from August 1979 to August 1980. For 65Zn a seasonal effect was clearly demonstrated as the biological half-life was prolonged from 87 d during autumn 1979 to 347 d in the cold period (0-50C), whereas it decreased again during the summer of 1980. For 57Co and 54Mn the long-term excretion study revealed an extra-slow compartment, as the long half-life in the cold period (approximately 600 d) persisted during the summer of 1980. This is explained by association with the shell. (author)

  6. Cosmic-ray history derived from the {sup 54}Mn, {sup 56}Ni and {sup 144}Pm chronometers

    Zaerpoor, K.; Chan, Y.D.; DiGregorio, D.E.; Dragowsky, M.R.; Hindi, M.M.; Isaac, M.C.P.; Krane, K.S.; Larimer, R.-M.; Macchiavelli, A.O.; Macleod, R. W.; Miocinovic, P.; Norman, E.B.; Robinson, S.J

    1999-07-26

    Sources of {sup 54}Mn, {sup 56}Ni, and {sup 144}Pm were placed at the center of the Gammasphere array and searches were made for the astrophysically interesting {beta}{sup +} decay modes of these isotopes. The results of these searches are presented and the implications for cosmic-ray physics are discussed.

  7. Development of irradiator {sup 60}Co sources

    Mosca, Rodrigo C.; Moura, Eduardo S.; Zeituni, Carlos A.; Mathor, Monica B., E-mail: rcmosca@usp.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    According to a recent report by the International Agency for Research on Cancer (IARC) / WHO (2008-2010), the global impact of cancer more than doubled in 30 years. In this report, it was estimated that occurred about 12 million new cancer cases and 7 million deaths. In Brazil in 2010, with estimates for the year 2011, point to the occurrence of 489,270 new cases of cancer. Among the possibilities for cancer treatment, radiotherapy is one of the most important therapeutic and resources used to combat it. However, inherent complications of treatment can occur such as tiredness, loss of appetite, radiodermatitis and in more extreme cases late radionecrosis. In order to reproduce a point of radionecrosis in the vicinity of radiodermatitis to mimic these effects in animals, producing a model for assessment of tissue repair, we propose the setting up of an irradiator source of collimated {sup 60}Co. The development of was based on 11 sources of {sup 60}Co with 1 mm thickness that were inserted by inference in stainless steel 'gate-source' screw (patent pending) and later adjusted in a cross-shaped arrangement reinforced so that the beam radiation is directed to a target point, saving for other regions around this target point. The main use of this irradiator with sources of {sup 60}Co is just one cause radionecrosis point (target point) of approximately 5 mm{sup 2} with a surrounding and adjacent area of radiodermatitis around about 8 to 10 mm{sup 2} in laboratory animals for subsequent coating with epidermal-dermal matrix populated by a cell culture of human fibroblasts, keratinocytes and mesenchymal stem cells. With that said, its use will be valuable for evaluation of curative treatments against the bone and radionecrosis or palliative treatment rather than as it is currently assumed. (author)

  8. Development of irradiator 60Co sources

    According to a recent report by the International Agency for Research on Cancer (IARC) / WHO (2008-2010), the global impact of cancer more than doubled in 30 years. In this report, it was estimated that occurred about 12 million new cancer cases and 7 million deaths. In Brazil in 2010, with estimates for the year 2011, point to the occurrence of 489,270 new cases of cancer. Among the possibilities for cancer treatment, radiotherapy is one of the most important therapeutic and resources used to combat it. However, inherent complications of treatment can occur such as tiredness, loss of appetite, radiodermatitis and in more extreme cases late radionecrosis. In order to reproduce a point of radionecrosis in the vicinity of radiodermatitis to mimic these effects in animals, producing a model for assessment of tissue repair, we propose the setting up of an irradiator source of collimated 60Co. The development of was based on 11 sources of 60Co with 1 mm thickness that were inserted by inference in stainless steel 'gate-source' screw (patent pending) and later adjusted in a cross-shaped arrangement reinforced so that the beam radiation is directed to a target point, saving for other regions around this target point. The main use of this irradiator with sources of 60Co is just one cause radionecrosis point (target point) of approximately 5 mm2 with a surrounding and adjacent area of radiodermatitis around about 8 to 10 mm2 in laboratory animals for subsequent coating with epidermal-dermal matrix populated by a cell culture of human fibroblasts, keratinocytes and mesenchymal stem cells. With that said, its use will be valuable for evaluation of curative treatments against the bone and radionecrosis or palliative treatment rather than as it is currently assumed. (author)

  9. Loss of 60 Co, 134 Cs and 137 Cs during the leaching test in the conditioned ion exchanger block

    The goal of this work is the study on immobilization of spent ion exchangers during the treatment of liquid radioactive wastes from Decontamination Center as a monolithic block, so that the safety of the environment be ensured during final disposal, according to international standards, all along the required time for radionuclide decay until an acceptable level is attained. The spent resin contains a lot of radionuclides (54 Mn, 57 Co, 58 Co, 60 Co, 134 Cs and 137 Cs) requiring the finding of a matrix suitable for all these radionuclides. As a result of experiments performed on the simulated waste containing the same radionuclides (immobilization in cement, bitumen and organic polymers), it was determined that the most suitable matrix is industrial bitumen, I 60-70, made in Romania. (authors)

  10. Measurement of Ca channel activity of isolated adult rat heart cells using 54Mn

    Isolated adult rat heart cells incubated with 5 microM Mn in a medium with 1 mM Ca showed a rapid phase of Mn binding plus a slow phase of Mn uptake. The rapid phase was extracellular binding, as judged by its temperature-insensitive removal by ethylene glycol bis(beta-aminoethyl ether) N, N'-tetraacetic acid. The slow linear phase represented cellular uptake, as judged by its release with digitonin plus the ionophore A23187. Isoproterenol increased the linear rate of Mn uptake and induced spontaneous beating activity in some cells. Both effects were inhibited by nitrendipine. Electrical stimulation of the cells in suspension increased the linear rate of cellular Mn uptake. The increase was potentiated by isoproterenol, and inhibited by nitrendipine or verapamil. Stimulation-dependent Mn uptake (per milligram protein) was greater for cells from 5- to 6-week-old rats than for 8- to 9-month-old female retired breeder rats, in the presence of isoproterenol. Ryanodine increased the stimulation-dependent Mn uptake in the presence of isoproterenol, but not in its absence. We conclude: (i) that cellular uptake of 54Mn is a good probe of Ca channel function; (ii) that isoproterenol promotes Mn influx by the channel in isolated heart cells; (iii) that cells from young rats (5-6 weeks) have a higher beta-adrenergically induced Ca channel activity than cells from mature rats (8-9 months); and (iv) that ryanodine promotes Ca channel activity (perhaps indirectly) in the presence of isoproterenol

  11. Vehicle mobile 60Co container inspection system

    This paper presents a mobile 60Co container inspection system (CIS) and its performance. With all devices including industrial 60Co source, high sensitive gas-ionized array detector, image treatment and control system, inspection driving device on a vehicle, the vehicle mobile CIS has advantages of high agility and climate resistance, and it can complete emergent inspection. The mobile CIS contains equipment-vehicle and control-vehicle. Equipment-vehicle and object-container are still, while a folding detector gantry is moving through a folding rail on the equipment-vehicle and completes the inspection. the mobile CIS has the inspection characteristics similar to the fixed system and it can be used in worse circumstances. Its CI (Contrast Indicator) and IQI (Image Quality Indicator) for 100 mm steel plate attain to 0.5% and 2.5% respectively, and the SP (Space Penetration) is about 240 mm (Fe). Maximum dose per scanning is about 5 μGy, scanning speed is varied from 6 to 18 m/min, and maximum transformational speed is 90 km/h

  12. Sorption of {sup 60} Co on inorganic solids; Sorcion de {sup 60} Co en solidos inorganicos

    Granados C, F.; Bulbulian G, S. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Mardel V, B. [UAM-I, 09340 Mexico D.F. (Mexico)

    2003-07-01

    The behavior of sorption of the {sup 60} Co in aqueous solution under static conditions to different values of pH of the aqueous solution (1, 3, 5, 7, and 10) on MgO, MnO{sub 2}, SnO, TiO{sub 2}, activated carbon and calcinate hydrotalcite was investigated. It was found that the best sorbents of the {sup 60} Co was the MnO{sub 2}, activated carbon and TiO{sub 2} whose sorption was incremented when increasing the pH value of the aqueous solutions, in the one case of the hydrated oxides, the {sup 60} Co interacted with the electrically charged surface of the sorbents that depends on the pH of the solution and of the point of zero charge (zpc) of the sorbent. (Author)

  13. Accumulation of radioactive corrosion products on steel surfaces of VVER-type nuclear reactors. II. 60Co

    In the case of intact fuel claddings, the predominant source of radioactivity in the primary circuits of water-cooled nuclear reactors is the activation of corrosion products in the core. The most important corrosion product radionuclides in the primary coolant of pressurized water reactors (PWRs) are 60Co, 58Co, 51Cr, 54Mn, 59Fe (as well as 110mAg in some Soviet-made VVER-type reactor). The second part of this series is focused on the complex studies of the formation and build-up of 60Co-containing species on an austenitic stainless steel type 08X18H10T (GOST 5632-61) and magnetite-covered carbon steel often to be used in Soviet-planned VVERs. The kinetics and mechanism of the cobalt accumulation were studied by a combination (coupling) of an in situ radiotracer method and voltammetry in a model solution of the primary circuit coolant. In addition, independent techniques such as X-ray photoelectron spectroscopic (XPS) and ICP-OES are also used to analyze the chemical state of Co species in the passive layer formed on stainless steel as well as the chemical composition of model solution. The experimental results have revealed that: (i) The passive behavior of the austenitic stainless steel at open-circuit conditions, the slightly alkaline pH and the reducing water chemistry can be considered to be optimal to minimize the 60Co contamination. (ii) The highly potential dependent deposition of various Co-oxides at E>1.10 V (vs. RHE) offers a unique possibility to elaborate a novel electrochemical method for the decrease or removal of cobalt traces from borate-containing coolants contaminated with 60Co and/or 58Co radionuclides

  14. Time-dependent transfer of 137Cs, 85Sr and 65Zn to earthworms in highly contaminated soils.

    Keum, Dong-Kwon; Jun, In; Lim, Kwang-Muk; Choi, Yong-Ho; Howard, Brenda J

    2013-12-01

    The transfer characteristics of (137)Cs, (85)Sr and (65)Zn to earthworms (Eisenia andrei) in soils with different amounts of the radionuclides have been investigated. The time-dependent whole-body concentration ratios (CR) were derived for worms in artificially contaminated soils with three different activity concentrations. Two parameters of a first order kinetic model, the equilibrium concentration ratio (CR(eq)) and the effective loss rate constant (k), were estimated by a comparison of experimental CR results with model predictions. The estimated CR(eq) (Bq/kg fresh worm per Bq/kg dry soil) ranged from 3.9 × 10(-4) to 4.1 × 10(-3) for (137)Cs, 1.39 × 10(-3) to 2.94 × 10(-2) for (85)Sr, and 1.39 × 10(-3) to 5.0 × 10(-2) for (65)Zn, and consistently decreased with increasing soil activity concentration but the trend was not statistically significant. The CR(eq) for (137)Cs was one to two orders of magnitude lower than previously reported CR(wo-soil) values (based on field data with much less contaminated soil), that for (85)Sr was comparable with other reported values and for (65)Zn was less two to three orders of magnitude lower than CR(wo-soil) values for stable zinc. The estimated k (d(-1)) values ranged from 9 × 10(-2) to 1.4 × 10(-1) for (137)Cs, 7 × 10(-2) to 2 × 10(-1) for (85)Sr, and 6 × 10(-2) to 1.8 × 10(-1) for (65)Zn, and did not show a relationship with soil activity concentration. The effect of CR(eq) on the total dose rate was insignificant for (137)Cs or (65)Zn because external dose rates to the soil dwelling earthworms due to these radionuclides were much greater than the internal dose rate. In contrast, the total dose from (90)Sr was determined by the internal dose rate and therefore proportional to the CR(eq). PMID:22948029

  15. Contamination of Chinese cabbage with 85Sr, 103Ru and 134Cs related to time of foliar application

    A solution containing 85Sr, 103Ru and 134Cs was applied to Chinese cabbage in a greenhouse via foliar spraying at 5 different times during its growth. Interception of the applied activity by plant showed no difference among radionuclides and increased with decreasing time interval between application and harvest. The maximum interception factor observed was 0.87. Percentages of the intercepted activity remaining in the whole leaves at harvest varied 16-58 % for 85Sr, 15-73 % for 103Ru and 33-64 % for 134Cs, with application time and those for the inner leaves (without 6 outmost leaves) varied 2-35 %, 0.4-46 % and 14-40 %, respectively. It was demonstrated that rain plays an important role in weathering loss of the activity. Tying the upper end of the plant prior to the last application lowered interception and remaining activity in the inner leaves by factors of 3-4. Present results can be referred to in predicting the radionuclide concentration in Chinese cabbage and deciding counter-measures at the time of an accidental release from the nuclear installation

  16. Accumulation and excretion of 60Co by marine organisms

    The biological half-life of 60Co accumulated from seawater by marine fish was 20-50 days. It was slightly longer in the liver and muscles than in the whole body. Feed including natural feed organisms contributed more to the total body burden of 60Co than environmental waters. The total body burden of 60Co via feed varied according to the organism species, kinds of feed and the root of incorporation. Transfer ratio of 60Co from the water into the organisms was higher than that from the marine sediments having high affinity of Co into the organisms. The elevated water temperature promoted the biological activity, resulting in the increased bioaccumulation of radioactive Co. Concentration coefficients of 60Co by mollusca and seaweeds were generally high. In particular, organic 60Co was more likely to be accumulated than inorganic 60Co. The biological half-life of organic 60Co was longer than inorganic 60Co in mollusca, while it was the same as or shorter than inorganic 60Co in the other organisms. (Namekawa, K.)

  17. Foliar and root uptake of {sup 134}Cs, {sup 85}Sr and {sup 65}Zn in processing tomato plants (Lycopersicon esculentum Mill.)

    Brambilla, M. E-mail: radlab@pc.unicatt.it; Fortunati, P.; Carini, F

    2002-07-01

    The results of an experimental study on the behaviour of {sup 134}Cs, {sup 85}Sr and {sup 65}Zn in processing tomato plants grown in peat substrate are presented. Plants were contaminated by wet deposition of {sup 134}Cs, {sup 85}Sr and {sup 65}Zn, either by sprinkling the above ground part at two phenological stages or by administering {sup 134}Cs, {sup 85}Sr and {sup 65}Zn to the soil. The plants contaminated at the second phenological stage intercepted 38.3% less than those contaminated at the first stage, although leaf area increased by more than double. Transfer coefficients from peat soil to ripe fruit for {sup 134}Cs are significantly higher than those for {sup 85}Sr and {sup 65}Zn. Leaf to fruit transfer coefficients for {sup 134}Cs are one order of magnitude higher than for {sup 65}Zn and two orders higher than for {sup 85}Sr. Only when deposition affects fruits, as at the second phenological stage, are transfer coefficients to fruits similar for the three radionuclides.

  18. Bioelimination of 51Cr and 85Sr by cockroaches, Gromphadorhina portentosa (orthoptera: blaberidae), as affected by mites, Gromphadorholaelaps schaeferi (parasitiformes: laelapidae)

    The rates of Chromium-51 and Strontium-85 assimilation and bioelimination by the hissing cockroach, Gromphadorhina portentosa (Schaum) are described when the symbiotic mite, Gromphadorholaelaps schaeferi Till, was present or removed. Mite-infested cockroaches had significantly higher rates of 51Cr elimination relative to mite-free cockroaches, implying more rapid gut clearance times. The authors did not find a significant mite effect on 85Sr elimination by the host, but mite effects could have been masked by the apparently unique process of nutrient assimilation and elimination by G. portentosa. Conventional models of radioactive tracer bioelimination predict a rapid initial loss of tracer due to gut clearance, followed by a slower loss due to excretion of assimilated tracer. The results indicated that assimilated 85Sr was eliminated earlier than unassimilated 85Sr, which was lost by defecation

  19. Bioelimination of 51Cr and 85Sr by cockroaches, Gromphadorhina portentosa (Orthoptera: Blaberidae), as affected by mites, Gromphadorholaelaps schaeferi (parasitiformes: laelapidae)

    This paper describes rates of Chromium-51 and Strontium-85 assimilation and bioelimination by the hissing cockroach, Gromphadorhina portentosa (Schaum), when the symbiotic mite, Gromphadorholaelaps schaeferi Till, was present or removed. Mite-infested cockroaches had significantly higher rates of 51Cr elimination relative to mite-free cockroaches, implying more rapid gut clearance times. We did not find a significant mite effect on 85Sr elimination by the host, but mite effects could have been masked by the apparently unique process of nutrient assimilation and elimination by G. portentosa. Conventional models of radioactive tracer bioelimination predict a rapid initial loss of tracer due to gut clearance, followed by a slower loss due to excretion of assimilated tracer. Our results indicated that assimilated 85Sr was eliminated earlier than unassimilated 85Sr was lost by defecation

  20. Transfer of 60Co from midwater squid to sperm whales

    Sperm whales are notable squid-eaters. They feed mainly on medium to large-sized cephalopods at midwater levels and defecate near the surface. This suggests the existence of an upward transport of 60Co by sperm whales from the mesopelagic zone (150-1,200m). To elucidate this squid-whale route for this artificial radionuclide, 60Co content was determined in squid and in predator whales captured by commercial whaling. In the Cephalopoda livers 60Co levels of 30-500 mBq kg-1 wet were found and in the viscera of Odontoceti (toothed whales) 15-40 mBq kg-1 wet. About 0.3% of 60Co ingested was estimated to be retained in a 23-year-old male sperm whale. In the livers of Bryde's whales, 60Co levels of 40-80 mBq kg-1 wet were detected, but not in euphausiids and sardines, their possible prey. The level of Co in sperm whales was nearly the same as in Bryde's whales. Specific radioactivity 60Co/59Co in mBq μg-1 was several times higher in sperm whale (1.1-1.6) than in cephalopods (0.19-0.77). Eating prey with a high content of 60Co in the 1960's may have contributed to the present body burden in sperm whales with a long-life span. However, the origin of 60Co in Bryde's whales is unknown. (author)

  1. Research and construction of 60Co container inspection system

    The author presents a special kind of container inspection system, in which the radiation source is a 60Co industrial radiography source of 100-300 Ci. By the adoption of special high sensitivity array detector and other technical solutions, this 60Co container inspection system possesses nice properties. Its 'image quality indicator (IQI)' and 'contrast indicator (CI)' for 100 mm steel plate are equal to 0.7% and 2.5% respectively. Its 'steel penetration (SP)' is about 240 mm. The 60Co container inspection system is much cheaper and more reliable than the accelerator inspection system, and the area for its installation and operation is much smaller. The 'Steel Penetration (SP)' of 60Co system is much higher than that of X-ray machine inspection system. The another merit of 60Co system is the feasibility of designing and constructing a movable type

  2. Optimisation by mathematical modeling of physicochemical characteristics of concrete containers in radioactive waste management

    Plećaš Ilija

    2013-01-01

    Full Text Available A method for obtaining an optimal concrete container composition used for storing radioactive waste from nuclear power plants is developed. It is applied to the radionuclides 60Co, 137Cs, 85Sr, and 54Mn. A set of recipes for concrete composition leading to an optimal solution is given.

  3. Investigation of the transfer of 90Sr, 137Cs, 60Co, and 54Mn from soil to plant, and of the main soil parameters that have influence on the transfer process

    In lysimetric field experiments with 2 soil types most common in the Federal Republic of Germany the effects of a continuous contamination as well as of a temporary contamination of the soil caused by a possible accident were simulated to allow forecastings on the resorption of radionuclides by farm plants. Parallel pot experiments (8 kg of soil) in greenhouses and in the field and small pot experiments under reproducible climatic chamber conditions were to examine wether or not transfer data from laboratory and pot experiments can be applied to field conditions. In addition to this, soil types representative according to soil mapping were taken from the locations of the nuclear power plants Biblis and Stade, and their properties were determined. In large-scale comparative pot experiments the relative transfer factors were determined. (orig./DG)

  4. Areal distribution of 60Co, 137Cs, and 90Sr in streambed gravels of White Oak Creek Watershed, Oak Ridge, Tennessee

    The concentrations of 90Sr, 60Co, and 137Cs in streambed gravels from contaminated drainages in White Oak Creek Watershed were determined. Methods to determine the relative contributions of various sources to the total discharge from the watershed were developed. Principal sources of 90Sr were: ORNL plant effluents (50%), leaching from solid waste disposal area (SWDA) 4 (30%), and leaching from SWDA 5 (10%). Minor sources included SWDA 3, the Molten Salt Reactor Facility, and intermediate-level liquid waste pit 1 with each representing 4% or less of the total basin discharge. The cooling water effluent from the High-Flux Isotope Reactor was the dominant source of 60Co contamination in the watershed. ORNL plant effluents accounted for almost all the 137Cs discharge from White Oak Creek basin. Downstream radionuclide concentrations were constant until significant dilution by other tributaries occurred. Any future activities giving rise to additional contamination can now be identified. Distribution coefficients between streambed gravels and streamwater for 85Sr, 60Co, and 137Cs were 50, 560, and 8460 ml/g, respectively. An abridged radiochemical fractionation developed for 90Sr was found to be as accurate and precise for these samples as the standard 90Sr method above levels of 2 dpm/g

  5. Radioecological studies of 90Sr in limnological ecosystems. Accumulation and excretion of 85Sr in goldfish, Carassius auratus auratus, rearing in the radioactive freshwater

    Accumulation and excretion of 85Sr in goldfish, Carassius auratus auratus, rearing in the radioactive freshwater were investigated in order to elucidate the accumulation mechanism of 90Sr in naturally living fishes. The accumulation of 85Sr, expressed in concentration ratio (CR) between fish and water, in whole body of the fish showed a increasing tendency with the rearing time, and the CR value reached 5.4±0.4 (mean±standard error) at 7th day. On the other hand, the excretion of 85Sr, expressed in retention rate, in whole body rearing in non-radioactive freshwater following the accumulation above the 7 days demonstrated a rapid decreasing at first few days, and then a gradual decreasing tendency indicating the biological half lives about 4 days and 205 days, respectively. The retention rate resulted in nearly 75% of initial radioactivity, i.e. 25% of excretion, at 25th day. As for the tissues and organs, the CR values of 85Sr reared in the radioactive freshwater for 7 days were 62.3 (vertebra: bone), 31.1 (scale), 12.5 (gill), 0.6 (viscera) and 0.4 (muscle). On the other hand, higher excretion was found in the viscera and the muscle than that in the bone, the scale and the gill. It is so suggested that the metabolic turnover rate of this radionuclide is different among these tissues and organs particularly characterizing higher accumulation and lower excretion in the vertebra (bone) and scale. (author)

  6. 60Co retention by a freshwater planktonic alga Scenedesmus obliquus

    This paper presents the results of various decontamination experiments aimed at evaluating 60Co retention by Scenedesmus obliquus, and the respective role played by absorption and adsorption in the contamination of the alga by this radionuclide. The physiological condition of cells is not involved in radiocobalt desorption, which seems to indicate that the phenomenon is of a passive nature. When the precontamination time is extended, the proportion of adsorbed 60Co decreases, and the final percentage of radionuclide retained increases. These results are confirmed by bringing cells into contact with a strong chelating agent. The elimination of 60Co in the presence of EDTA undergoes a sharp decrease which is correlated with the increase in the duration of the precontamination phase. The use of a weaker complexing agent, such as NaCl, leads to the hypothesis of there being 2 types of 60Co receptor on cell membranes. (author)

  7. A sorption study of 85Sr, 137Cs and 227Th onto glacial sand as part of an interlaboratory exercise

    A number of radionuclide batch sorption tests have been carried out on core material from boreholes on the BNFL Drigg site, Cumbria, as part of an intercomparison exercise with BNFL, Sellafield. This report describes the nature of the materials used, the method and the results of the BGS side of the interlaboratory exercise. Another report will describe the intercomparison. These experiments formed part of a wider programme of laboratory tests by BGS to ascertain the sorption properties of the Drigg sands and silts as an information base for designing artificial in-situ radionuclide migration experiments on site at Drigg. Three radionuclides were used, 85Sr, 137Cs, and 227Th. Interestingly, although sorption of strontium was about 15 times less than for thorium, the pattern of sorption as a function of borehole depth i.e. mineralogical composition, was very similar. Sorption of 137Cs was found to be non-linear, depending strongly on caesium concentration in the groundwater. Isotherm fits were used to determine the energy of sorption in the ion exchange process, the mechanism responsible for uptake. There is a need for a standard batch sorption method to be in common use. (author)

  8. Studies of radioactivity of vegetables: determination of transfer factors 85Sr and 134Cs in some vegetables

    The radioisotope uptake of potato and culinary dry bean was studied in field experiments on meadow soil enriched with vermiculite and humanite by artificial soil contamination. The isotope uptake from the soil was characterized by a transfer factor (TF). Based on the results of the potato experiment it was found that the TF value characterizing the 134Cs contamination of the crop, changed between 1.31 - 0.77*10-4 m2 (kg dry matter)-1 on high humus content soil (treated with humanite) and on soil treated with vermiculite, while it was 22-45 % higher in plants grown on the radioactive control plots. lt was 1.69*10-4 m2 (kg dry matter)2-1 in average. The TF values of 85Sr uptake of potato are several times higher than those of experiments treated by isotope 134Cs. The TF values fluctuated between 5.30-7.33*10-4 m2 (kg dry matter)-1 in soils treated with the additives, while on the plots with radioactive contamination it was 8.42*10-4 m2 (kg dry matter)-1. Based on the results of 134Cs studies of edible part of dry bean, it could be stated that after the soil contamination the TF value was 0.99*10-4 m2 (kg dry matter)-1 in average. According to the activity results of the experiments there was significant difference between the contamination of the plant parts. Refs. 6 (author)

  9. Effect of hydrocortisone on total body calcium in rats. [/sup 47/Ca and /sup 85/Sr tracer techniques

    Yasumura, S.; Ellis, K.J.; Cohn, S.H.

    1976-11-01

    Administration of 5 mg. of hydrocortisone acetate to rats every other day for 2 weeks resulted in growth retardation and weight loss as indicated by body weights of experimental animals, which averaged 33 percent lower than those of the controls, and a significant decrease in the length of the tibiae and femurs (p less than 0.01 for treated vs controls). However, despite the smaller size of the treated animals, the values for total body calcium (TBCa) and the calcium in the tibia and femur did not differ significantly from control values. Thus, there was more calcium per unit length of bone, resulting in an increase in the skeletal density of treated rats. This finding was confirmed by x-ray examination of these bones. The net intestinal absorption of calcium (rate of initial entry) calculated from plasma levels following an oral and intravenous dose of /sup 47/Ca and /sup 85/Sr, respectively, was not significantly different in hydrocortisone-treated rats compared to controls. This would indicate that the rate of intestinal absorption of calcium is unimpaired despite the administration of massive doses of corticosteroids. When the animals were placed on a calcium-deficient diet, both TBCa and tibia and femur calcium levels were decreased. Subsequent administration of hydrocortisone did not alter the calcium values. The results of this study are compatible with the hypothesis that hydrocortisone promotes weight loss, retards growth, but inhibits the rate of bone resorption.

  10. Treatment of boundary conditions in through-diffusion: A case study of (85)Sr(2+) diffusion in compacted illite.

    Glaus, M A; Aertsens, M; Maes, N; Van Laer, L; Van Loon, L R

    2015-01-01

    Valuable techniques to measure effective diffusion coefficients in porous media are an indispensable prerequisite for a proper understanding of the migration of chemical-toxic and radioactive micropollutants in the subsurface and geosphere. The present article discusses possible pitfalls and difficulties in the classical through-diffusion technique applied to situations where large diffusive fluxes of cations in compacted clay minerals or clay rocks occur. The results obtained from a benchmark study, in which the diffusion of (85)Sr(2+) tracer in compacted illite has been studied using different experimental techniques, are presented. It is shown that these techniques may yield valuable results provided that an appropriate model is used for numerical simulations. It is further shown that effective diffusion coefficients may be systematically underestimated when the concentration at the downstream boundary is not taken adequately into account in modelling, even for very low concentrations. A criterion is derived for quasi steady-state situations, by which it can be decided whether the simplifying assumption of a zero-concentration at the downstream boundary in through-diffusion is justified or not. The application of the criterion requires, however, knowledge of the effective diffusion coefficient of the clay sample. Such knowledge is often absent or only approximately available during the planning phase of a diffusion experiment. PMID:26004771

  11. Treatment of boundary conditions in through-diffusion: A case study of 85Sr2 + diffusion in compacted illite

    Glaus, M. A.; Aertsens, M.; Maes, N.; Van Laer, L.; Van Loon, L. R.

    2015-06-01

    Valuable techniques to measure effective diffusion coefficients in porous media are an indispensable prerequisite for a proper understanding of the migration of chemical-toxic and radioactive micropollutants in the subsurface and geosphere. The present article discusses possible pitfalls and difficulties in the classical through-diffusion technique applied to situations where large diffusive fluxes of cations in compacted clay minerals or clay rocks occur. The results obtained from a benchmark study, in which the diffusion of 85Sr2 + tracer in compacted illite has been studied using different experimental techniques, are presented. It is shown that these techniques may yield valuable results provided that an appropriate model is used for numerical simulations. It is further shown that effective diffusion coefficients may be systematically underestimated when the concentration at the downstream boundary is not taken adequately into account in modelling, even for very low concentrations. A criterion is derived for quasi steady-state situations, by which it can be decided whether the simplifying assumption of a zero-concentration at the downstream boundary in through-diffusion is justified or not. The application of the criterion requires, however, knowledge of the effective diffusion coefficient of the clay sample. Such knowledge is often absent or only approximately available during the planning phase of a diffusion experiment.

  12. Uptake and translocation of 54Mn and 65Zn applied on foliage and bark surfaces on balsam fir (Abies balsamea (L.) Mill.) seedlings

    Uptake and translocation of 54Mn and 65Zn in balsam fir [Abies balsamea (L.) Mill.] seedlings were studied with the radioisotopes applied directly on shoot or main-stem surfaces in a growth chamber. Concentration and distribution of the absorbed radioisotopes in different plant parts depended on distances between source (the application site) and sink (the rest of the seedling), as well as on tissue growth activity. Acidic wetness significantly enhanced radioisotope absorption. 54Mn and 65Zn were found to be concentrated primarily in 1-year old needles at the middle and top levels of the seedling crown. There were significant (P < 0.05) differences in accumulation (Bq g−1) between 54Mn and 65Zn in needles and twigs from foliar uptake. The absorption by seedlings (including the washed application shoot) 70 days after application was 24–32% of the remaining activities for 54Mn and 25–30% for 65Zn. Less than 1% of the absorbed isotopes was translocated from the bark application sites to other plant organs, whereas more than 54% of the activity absorbed at 1-year old shoots moved to the rest of the seedling. (author)

  13. A comparison of pdd for 60Co teletherapy units

    Although BJR supplement No 17 provides TAR and PDD tables for 60Co gamma rays, due to inherent differences hat exists among individual teletherapy machine and their source it is essential to measure TAR and PDD that are applicable for user's teletherapy unit. TAR and PDD values for different field sizes at 80 cm SSD, open field, gantry angle 0o, collimator angle 0o were determined in CIRUS 60Co teletherapy unit by ionization chamber NE2570/1B Farmer type. PDD for a standard field size 10 10 cm2, open field, gantry angle 0o,Collimate angle 0o were determined in MEDNIF FYC 2600H 60Co teletherapy unit by using ionization chamber RT101. That experimentally measured PDD values for both units were compared with published values in BJR supplement No 17. The experimentally measured values for CIRUS 60Co showed up to 0.8% deviation at maximum and that for MEDNIF 60Co showed up to 4.5% deviation at maximum. This study investigated the discrepancy between the BJR values and experimentally determined values for two teletherapy units in Nepal

  14. Concentration of 60Co by marine organisms through sediments

    Uptake of 60Co absorbed on sea sands by benthic marine organisms was observed in laboratory experiments, since the radioactive cobalt released from nuclear power plants or other establishments into coastal seawater trends to be absorbed on sea sediments and also various kinds of marine organisms live in bottom sediments. Few kinds of flatfishes (Limanda spp.) and shrimp (Trachypenaeus curvirostris) were reared in aquariums contained seawater and sea sands which were highly contaminated with 60Co previously, and whole body retention and distribution of radioactivity were measured on the organisms taken up from the aquariums occasionally by a scintillation counter. Uptake of 60Co from ingested sea sands was also observed on the flatfishes administrating the contaminated sands orally. Concentration of 60Co by the flatfishes reared in the sands was not significant while the shrimp showed high retention of the radioactivity. The food habit of shrimp which usually feeds on organic detritus with other small benthic organisms is different from that of flatfishes, one of the carnivorous, and considered to bring the difference on the pathway of radionuclides concentration. Assimilation of 60Co via the digestive tract of flatfishes through the sands was estimated as about 10 per cent of the administrated radioactivity. (auth.)

  15. On the Spirulina platensis - 60 Co2+ bioaccumulation system

    Radiochemical studies, IR spectrometry and electron microscopy studies have been carried out with the purpose of establishing the mechanisms involved in the bioaccumulation of 60 Co2+ in the blue alga Spirulina platensis. By measuring the radioactivity it was determined that, without ionic competition, an one week old culture of Spirulina platensis can retain up to 65% of the 60 Co2+ ions from a slightly radioactive solution. Sodium carbonate is involved in the mechanism of the bioaccumulation of these β + γ - radiocations (a phenomenon evidenced by IR spectrometry). Electronic microscopy studies point out that the compounds resulted from the interaction between the exopolysaccharides and 60 Co2+ disperse in the solution. Thus, even though the radiocobalt is completely blocked up in complex compounds, it is not completely retained on the surface and inside of the alga. (authors)

  16. Decontamination of fermented chicken feet by 60Co irradiation

    Fermented chicken feet was treated by 60Co irradiation, and the aerobic plate count, enumeration of coliforms, pathogens and TBARS value were measured during storage. The results showed that, aerobic plate count of all irradiated samples was lower than control, and enumeration of coliforms, and pathogens of Staphylococcus aureus, Shigella, Salmonella were not detected. TBARS value of all treatments was stable during 60 d storage. It could be concluded that 60Co irradiation of chicken feet was an effective method to prolong its shelf life. (authors)

  17. Dosimetric evaluation of Radiotherapy units wit 60Co

    The SSDL network of the IAEA performs, every year, quality audit tests for radiotherapy services (60 Co units and linear accelerators), and for national SSDL as well. Because of the SSDL-Mexico results in these tests and due to our enthusiasm and confidence in our work, a parallel test has been done , which is described in this talk as well as the results. Nowadays, a second parallel test goes up, which could confirm our optimism and open the possibility to our country to start a national dosimetric audit of 60 Co radiotherapy units. (Author)

  18. Metal-insulator transition in the spin-glass system La0.85Sr0.15CoO3

    Electrical resistivity measurements (20-300 K) show a metal-insulator transition in low-temperature-sintered samples of the spin-glass insulating composition La0.85Sr0.15CoO3. Insulating behaviour is observed only for samples sintered at high temperatures. The results can explain the widely differing electrical resistivity behaviour reported for different compositions in the La1-xSrxCoO3 system. (author). Letter-to-the-editor

  19. Structure, non-stoichiometry and thermodynamic properties of Bi1.85Sr2Co1.85O7.7−δ ceramics

    Highlights: • Cobaltite Bi1.85Sr2Co1.85O7.7−δ was prepared and its structure was refined. • Oxygen non-stoichiometry of Bi1.85Sr2Co1.85O7.7−δ was determined by TG. • Thermodynamic properties were measured by PPMS, DSC and drop calorimetry. • The heat capacity was analyzed using combined Debye–Einstein model. - Abstract: The structure and oxygen non-stoichiometry of misfit layered cobaltite Bi1.85Sr2Co1.85O7.7−δ was determined by Rietveld analysis and by thermogravimetric measurements. The heat capacity and enthalpy increments of pseudo-ternary oxide Bi1.85Sr2Co1.85O7.7−δ was measured by the relaxation time method (PPMS) from 2 K to 256 K, by differential scanning calorimetry (DSC) from 258 K to 355 K and by the drop calorimetry from 573 K to 1153 K. Above room temperature the temperature dependence of the molar heat capacity in the form Cpm = (305.8 + 0.07325 · T − 4702536 · T−2) J K−1 mol−1 was derived by the least-squares method from the experimental data. The heat capacity was analyzed in terms of a combined Debye–Einstein model. The molar entropy Sm∘(298.15)=317.7 J mol−1 K−1 was evaluated from the low temperature heat capacity measurements

  20. Interface Resistance between FeCr Interconnects and La0.85Sr0.15Mn1.1O3

    Mikkelsen, Lars; Neufeld, Kai; Hendriksen, Peter Vang

    2009-01-01

    The long term oxidation behaviour and the electrical interface resistance between FeCr interconnects and La0,85Sr0,15Mn1,1O3 plates was studied by a DC four-point method in air at 750{degree sign}C for 10000 h. The tested FeCr alloys were: Crofer 22 APU, Sanergy HT, Plansee IT10, Plansee IT11...

  1. Comparative analysis of 60Co intensity-modulated radiation therapy

    Fox, Christopher; Romeijn, H. Edwin; Lynch, Bart; Men, Chunhua; Aleman, Dionne M.; Dempsey, James F.

    2008-06-01

    In this study, we perform a scientific comparative analysis of using 60Co beams in intensity-modulated radiation therapy (IMRT). In particular, we evaluate the treatment plan quality obtained with (i) 6 MV, 18 MV and 60Co IMRT; (ii) different numbers of static multileaf collimator (MLC) delivered 60Co beams and (iii) a helical tomotherapy 60Co beam geometry. We employ a convex fluence map optimization (FMO) model, which allows for the comparison of plan quality between different beam energies and configurations for a given case. A total of 25 clinical patient cases that each contain volumetric CT studies, primary and secondary delineated targets, and contoured structures were studied: 5 head-and-neck (H&N), 5 prostate, 5 central nervous system (CNS), 5 breast and 5 lung cases. The DICOM plan data were anonymized and exported to the University of Florida optimized radiation therapy (UFORT) treatment planning system. The FMO problem was solved for each case for 5-71 equidistant beams as well as a helical geometry for H&N, prostate, CNS and lung cases, and for 3-7 equidistant beams in the upper hemisphere for breast cases, all with 6 MV, 18 MV and 60Co dose models. In all cases, 95% of the target volumes received at least the prescribed dose with clinical sparing criteria for critical organs being met for all structures that were not wholly or partially contained within the target volume. Improvements in critical organ sparing were found with an increasing number of equidistant 60Co beams, yet were marginal above 9 beams for H&N, prostate, CNS and lung. Breast cases produced similar plans for 3-7 beams. A helical 60Co beam geometry achieved similar plan quality as static plans with 11 equidistant 60Co beams. Furthermore, 18 MV plans were initially found not to provide the same target coverage as 6 MV and 60Co plans; however, adjusting the trade-offs in the optimization model allowed equivalent target coverage for 18 MV. For plans with comparable target coverage

  2. Dosimetric evaluation of Radiotherapy units wit {sup 60}Co; Evaluacion dosimetrica de unidades de radioterapia con {sup 60}Co

    Leon, B. Salinas de; Tovar M, V.; Becerril V, A. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2000-07-01

    The SSDL network of the IAEA performs, every year, quality audit tests for radiotherapy services ({sup 60} Co units and linear accelerators), and for national SSDL as well. Because of the SSDL-Mexico results in these tests and due to our enthusiasm and confidence in our work, a parallel test has been done , which is described in this talk as well as the results. Nowadays, a second parallel test goes up, which could confirm our optimism and open the possibility to our country to start a national dosimetric audit of {sup 60} Co radiotherapy units. (Author)

  3. The data correction algorithms in 60Co train inspection system

    Because of the physical characteristics of the 60Co train inspection system and the application of high-speed data collection system based on current integral, the original images have been distorted in a certain degree. Authors investigate into the reasons why the distortion comes into being, and accordingly present the data correction algorithm

  4. Development of 60Co cargo train inspection system

    The author introduces the research and development of 60Co cargo train inspection system. With the use of radiography principle, every car image is acquired when the cargo train runs through the inspection channel. It is evaluated whether the cargo in car matches the corresponding customs declaration information with digital image processing techniques. The system has been installed in railway port at Manzhouli Customs

  5. The influence of antibiotics on the adsorption kinetics of 54-Mn and 59-Fe on suspended particles in river Elbe water

    Many pollutants in river water are mainly transported by suspended particles. It depends on many physical and chemical parameters how these pollutants are distributed between water and suspended particles. Much effort has been made for measuring this distribution. Our examination has dealt with the determination of influences on the adsorption kinetics of some metal ions from water to suspended particles. We used 54-MnCl2 and 59-FeCl3 as tracers. (orig.)

  6. Distribution of 60Co in steel samples from Hiroshima

    This paper describes ultra low-level gamma-ray spectrometry measurements of the 60Co activity distribution inside one 52 mm and one 41 mm thick steel sample. The samples had been exposed to the Hiroshima atomic bomb and were from the Aioi bridge and the Yokogawa bridge. Both samples were measured in a recent study aiming to back up model calculation of Hiroshima dosimetry. The 60Co activity distributions found in this study support the assumptions made in the previous study. - Highlights: ► The Co-60 activity distribution within two thick steel samples from Hiroshima was measured. ► Activities down to 0.1 mBq were measured using underground gamma-ray spectrometry systems. ► The distribution confirms assumptions made in previous studies. ► Further support to the Dosimetry System 02 is provided.

  7. Radiolytic degradation scheme for 60Co-irradiated corticosteroids

    Kane, M.P.; Tsuji, K.

    1983-01-01

    The cobalt 60 radiolytic degradation products have been identified in the following corticosteroids: cortisone, cortisone acetate, hydrocortisone, hydrocortisone acetate, hydrocortisone sodium succinate, isoflupredone acetate, methylprednisolone, methylprednisolone acetate, prednisolone, prednisolone acetate, and prednisone. Two major types of degradation processes have been identified: loss of the corticoid side chain on the D-ring to produce the C-17 ketone and conversion of the C-11 alcohol, if present, to the C-11 ketone. Minor degradation products derived from other changes affecting the side chain are also identified in several corticosteroids. These compounds are frequently associated in corticosteroids as process impurities or degradation compounds. No new radiolytic compounds unique to 60Co-irradiation have been found. The majority of corticosteroids have been shown to be stable to 60Co-irradiation. The rates of radiolytic degradation ranged from 0.2 to 1.4%/Mrad.

  8. Software program in 60Co container inspection system

    The author analyzes the features and limits of the present container inspection system in the world, and puts forward a new inspection apparatus with 60Co as radiography source and microcomputer network to complete inspecting image's acquisition, transmission, assignment, process, inspection, control and information management etc. The author emphasizes on task analysis and technical request in the system, discusses the software running environment and developing environment, the tasks logical division, and makes clear the design's idea, object and style

  9. Effects of 60Co administration on early placental cells

    The effects of 60Co administration on early placental cells were studied. Placental tissue and embryo obtained by induced abortion (6 - 13 weeks gestational age) were placed in the minimal essential medium (MEM) and irradiated with various doses of 60Co. After irradiation, the villi were cultured in a CO2 incubater at 370C. Cell growth process was observed every day with the phase-contrast microscope. Between 1 and 5 days epitheloid cells were dominant, but from about 7th day on fibroblastic cells dominated the culture. In placental tissue irradiated with 100, 200, 500 rad, fibroblastic cells began to grow earlier than in non-treated. Over 3000 rad 60Co inhibited the growth of cells and a culture was impossible. For each dose, the tissue was incubated for various periods of time, exposed to tritiated thymidine for the last hour and autoradiogram was prepared by the dipping method. The labeling index of irradiated trophoblasts showed a significant decrease compared with controls. A chromosome study was made in irradiated in vitro cell lines of fetus and placenta. There was no significant difference between the two cell lines concerning the frequency of chromosome aberration, which tended to increase as the chromosome becomes longer. It is concluded that the trophoblast is highly radiosensitive and that irradiation early in pregnancy may damage DNA synthesis in the trophoblast, and induce abortion. (author)

  10. Fabrication, qualification and calibration of 60 Co sealed sources

    Argentina produces about 5% of the worldwide production of 60 Co radioisotope (3,000,000 of Ci/year) whose main application is the radio sterilization of disposable medical consumables, the radiating therapy, and the food preservation for human consumption. From 1985 to the present 56,000,000 Ci were produced. At first all the generated 60 Co was exported in bulk to the sealed sources producers, but now the local production of sources has been consolidated and 100% of the 60 Co is used to manufacture sealed sources. That is a successful production of around 400 sealed sources, 70% of which have been made during the last three years. Mainly 95% of the sealed sources for industrial applications were exported to the United States, Europe, Japan and China. These countries are the main importation centers. The local and regional markets are the most important users of the sources for x-ray radiography. At present 8% of the total sources that were produced are used as x-ray sources. The present work describes the development of the sequence of manufacture of simple and double encapsulated radioactive sources, which includes the in-process inspection, the certification of the sealed sources according the designation E66646 (5,7) of the ISO 2919:1999(E) standard and a statistical quality control analysis of the penetration of the seam weld of the end caps. (author)

  11. Local blood flow, 99mTc-MDP retention and 85Sr retention in femur and tibia of rats: local differentiation and inter-relations

    Variations were studied in blood flow, retention of 99mTc-methylenediphosphonate (MDP) and 85SrCl2 in the femur and in the tibia of rats. The objective of the experiments was to assert local differences in the blood flow and similar patterns, if any, in the retention of both radionuclides in the long bones of the hind leg of the rat. The results showed a significant differentiation in the blood flow in both the femur and the tibia, with high levels in the growth-active parts and low levels in the diaphyses. The lowest levels were found in the distal terminal part of the tibia. A marked similarity was observed in the patterns of blood flow distribution and 99mTc-MDP retention, this both in quality and in quantity. The retention was found to be significantly higher in the growth-active parts, i.e., in the distal methaphysis of the femur and in the proximal metaphysis os the tibia, while several times lower values were found for the other parts of the bones. However, age dependence was observed in the distribution and some other factors may play a role. Thus, a quantitative relationship was excluded. The initial retention of 85Sr showed a similar pattern with high levels in the growth-active parts of the bones. However, the values quickly decreased with time, which may have been associated with the metabolism of minerals. In the other parts of the bones, the differences in 85Sr retention were insignificant. It is believed that local blood flow may affect the behavior of both osteotropic materials as a common regulating factor. (L.O.). 3 figs., 1 tab., 22 refs

  12. Optical properties of La0.85(Sr,Ba)0.15MnO3 single crystals in infrared spectral range

    The optical spectra (reflection and absorption) of La0.85Sr0.15MnO3 (LSM) and La0.85Ba0.15MnO3 (LBM) single crystals are studied in the infrared range, where the interaction of charge carriers with light dominates. In paramagnetic state, the small lattice polarons dominate the optical properties of LBM single crystal but in the optical spectra of LSM crystal the polarons manifest themselves weaker. The activation energy of polaron hopping E a is determined

  13. ESR phase competition study of Pr0.5(Ca0.85Sr0.15)0.5MnO3

    We report an electron spin resonance (ESR) study of the competing phases at the crossover from localized to itinerant behaviour on the polycrystalline Pr0.5(Ca0.85Sr0.15)0.5MnO3 compounds. From the temperature dependence of the ESR intensity, we derived the transition temperatures to charge order (TCO=230 K), and antiferromagnetic (TN=150 K) states. In addition, at T<200 K, a ferromagnetic minority phase was found, that coexists with the paramagnetic and antiferromagnetic phases. We perform simulations of the ESR spectra that reproduce the behaviour found at different temperatures

  14. Sorption and desorption of 85Sr, 125I and 152,154Eu on columns of crushed crystalline rocks under dynamic conditions

    A comparison of transport parameters from breakthrough curves has shown that the transport of 85Sr is retarded moderately and increases in order: diorite-I + sorption appears to be reversible and 85Sr can be desorbed (displaced) from the crushed rocks with groundwater. Sorption of l25I- is almost negligible and radioiodide was transported by groundwater with any distinct retardation. Retardation of l52,154Eu3+ is extensive due to its very strong sorption by rocks. Desorption with groundwater is little effective, but Eu can be displaced with an acid mixture almost completely, the retardation coefficient increasing in order: granite ≅ gabbro < tonalite < diorite-II < diorite-I. It is reasonable to assume that acid rains stimulate significantly mobilization of the Sr and Eu (Am) radionuclides. The integral form of an 1-D ADE equation proved useful in fitting the experimental values and modelling the breakthrough curves. A good agreement was obtained between the observed and calculated values by using a simple theoretical relation. The static method was also found to give considerably higher values of the distribution and retardation coefficients of radionuclides in crushed crystalline rocks

  15. Study of La1.85Sr0.15CuO4 superconducting phase synthesis by ion beam mixtures

    In order to synthesize the superconducting phase La1.85Sr0.15CuO4 powders of La2O3, CuO, and SrCO3 are usually ground together and annealed at high temperature. We studied another original way: the possibility of using accelerated ions in order to mix the atomic species of thin multilayered films of La(OH)3, Sr(OH)2, and Cu and to synthesize crystalline La1.85Sr0.15CuO4. In the first part of this work, we present a review of ion beam mixing in relation to particle-matter interactions. The second part is devoted to a description of our implementation of ion beam analysis techniques and to the determination of experimental uncertainties. The use of X ray diffraction in order to study the films structures is also presented. In the third part, we show that irradiation does not generally lead to very large mixing ratios in our films but induces partial or total desorption of O and H. This is presumably related to the thermodynamic properties of the various coexisting ceramic phases. We do however find evidence of cristalline La2CuO4 formation under irradiation for a specific multilayer configuration. The critical parameters of this method are shown to be the initial configuration of the multilayer and the irradiation temperature. 64 refs

  16. Processing and properties of superconducting La[sub 1. 85]Sr[sub 0. 15]CuO[sub 4] powder by double-step calcining

    Alconchel, Silvia A. (Instituto de Investigaciones en Catalisis y Petroquimica, INCAPE (FIQ,UNL-CONICET), Santiago del Estero 2829, 3000 Santa Fe (Argentina)); Ulla, Maria A. (Instituto de Investigaciones en Catalisis y Petroquimica, INCAPE (FIQ,UNL-CONICET), Santiago del Estero 2829, 3000 Santa Fe (Argentina)); Lombardo, Eduardo A. (Instituto de Investigaciones en Catalisis y Petroquimica, INCAPE (FIQ,UNL-CONICET), Santiago del Estero 2829, 3000 Santa Fe (Argentina))

    1994-11-01

    The preparation of single-phase tetragonal La[sub 1.85]Sr[sub 0.15]CuO[sub 4] powder using two consecutive thermal cycles is described. Freeze-dried or evaporated lanthanum, strontium and copper acetates were used as precursor materials. The effect of the reaction temperature (in the second cycle) on the characteristics of high-T[sub c] superconductor was studied by X-ray diffraction, idometric titration, temperature-programmed reduction, scanning electron microscopy and electrical resistivity measurements.Monophasic powder was obtained by reacting freeze-dried precursors at a final temperature of 1253 K for 8 h. The reduction of La[sub 1.85]Sr[sub 0.15]CuO[sub 4] occurred in one step at 744 K. Thermal treatments in either N[sub 2] or O[sub 2] strongly affect the hydrogen consumption profile.Monophasic sintered pellets were obtained from freeze-dried precursors calcined at final temperatures between 973 and 1253 K. The microstructure of sintered bodies was characterized by equiaxed grains of about 0.5 [mu]m. Evaporated precursors did not yield powder or single phase sintered material, and gave a grain size of about 1 [mu]m. The critical temperature ranged between 36.7 and 37.3 K and [Delta]T[sub c] between 2.8 and 4.8 K. ((orig.))

  17. Application of 65Zn and 54Mn isotopic dilution for evaluation of available soil manganese and zinc fractions in Western Slovak region

    This paper mapped the accumulation and availability of zinc and manganese in young wheatgrass plants (Triticum aestivum L.) grown in typical agricultural soil (Calcic Phaenozem) of Western Slovakia. For estimation of zinc and manganese availability the biological, chemical and radiochemical methods with application of 65Zn and 54Mn isotopic dilution and gamma spectrometry were used. Radiochemical and statistical analyses of obtained metal concentrations in plant tissues, soil samples, soil extracts and isotopically exchangeable fractions (E-values) confirmed the significant correlations mainly between wheatgrass concentrations and E-values. Results showed the important role of isotopic dilution methods for quantification of available metal fractions. (author)

  18. Sorption of 60 Co in natural zeolite (clinoptilolite)

    A Mexican zeolite (clinoptilolite) from Taxco, Guerrero, was partially stabilized with sodium cations. Radioactive Cobalt (60 Co) was used to study the Co 2+ sorption in the stabilized zeolite (Na+). It was found that sorption in general does not favour the diffusion of cobalt between framework, it explains because of it is a natural zeolite and its composition heterogeneous decrease its exchange capacity by the generated competence to the existence other type of exchange ions. The cobalt retention reached the highest level, around 0.408 m eq Co2+ /g in the Na-Clinoptilolite. The crystallinity of the aluminosilicates was maintained during experiments, it was verified by XRD patterns. (Author)

  19. Determination of 60Co sorption in natural clinoptilolite

    It was studied the clinoptilolite behavior coming from a deposit in Taxco, Guerrero in hydration and stabilization conditions with sodium for determining its sorption properties. The ion exchange process was carried out through gamma spectrometry using a CoCl2 solution marked with 60 Co at p H 6.5 in different contact times. It was observed a maximum sorption of 0.408 m eq Co+2/g mineral, from 0.314 m eq Co+2/g mineral correspond at ion exchange. (Author)

  20. Influence of plant roots upon the mobility of radionuclides in soil, with respect to location of contamination below the surface

    The movement of 85Sr, 137Cs, 54Mn and 60Co in the 50 cm soil profile was studied with and without the presence of plant roots (triticum aestivum) in order to investigate the influence of roots and depth contamination upon the migration of radionuclides. The water table was maintained manually at 3 cm from the bottom. The physicochemical characteristics (Eh Fe-2, NH4+, pH and moisture content) as well as the total and extractable radioactivity were investigated. In the discrete contamination, where the location of contamination varied within the soil profile (0-5, 25-30 or 45-50 cm from the top), the influence of location upon the movement of these radionuclides was also studied. It was found that the changes in the soil physicochemical characteristics influenced the mobility of the four radionuclides. The extractability of 54Mn and 60Co was significantly increased in the reducing region of the soil, whereas that of 85Sr, 137Cs was not. Plant roots excerted significant effects upon the soil characteristics, via, reducing the Eh pH and moisture content of the soil; increasing the extractability of both 54Mn and 60Co from the depth of 35 cm downwards. Radionuclide migration occurred via physicochemical and biological transport. The biological transport via plant roots was of particular importance for 137Cs. Location of contamination had a significant influence upon the mobility of radionuclides. The migration of radionuclides was in the sequence of contamination in middle > bottom > top. The degree of the influence varied with radionuclides concerned. In the top layer contamination, the rank of the migration from the contamination layers, on the other hand 54Mn, 60Co and 137Cs were more mobile and the movement was: 85Sr54Mn60Co > 137Cs. In the middle and bottom contamination layers, on the other hand, 54Mn and 60Co and 137Cs were more mobile and the movement was 85Sr54Mn60Co ∼ 137Cs. (author)

  1. Study of {sup 60}Co as gamma source in backscatter gamma densitometers

    Gholipour Peyvandi, R.; Taheri, A.; Rahmanzadeh Tootkaleh, S.; Askari Lehdarboni, M. [Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of); Islami Rad, S.Z. [Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of); Univ. of Qom (Iran, Islamic Republic of). Dept. of Physic

    2015-07-15

    In this work the performance of backscatter gamma densitometer is studied using {sup 60}Co as gamma source. The ability of the densitometer to determine the liquid's interfaces in multi-phase flows was assessed. The aim mainly was to investigate the possibility of using {sup 60}Co in this system. Furthermore, a comparison between {sup 60}Co and was done. The obtained results indicate that {sup 60}Co can be advantageous in this regard.

  2. Study of 60Co as gamma source in backscatter gamma densitometers

    In this work the performance of backscatter gamma densitometer is studied using 60Co as gamma source. The ability of the densitometer to determine the liquid's interfaces in multi-phase flows was assessed. The aim mainly was to investigate the possibility of using 60Co in this system. Furthermore, a comparison between 60Co and was done. The obtained results indicate that 60Co can be advantageous in this regard.

  3. Effect of 60 Co gamma radiation on crystalline proteins

    In order to study the effects of 60 Co gamma radiation on crystalline proteins an in vitro system was set up. For that, aqueous solutions from bovine crystalline were used irradiated with 0, 5.000, 10.000, 15.000, 20.000 and 25.000 Gy. The treatment led to protein alterations determined by different methods. By turbidimetry the formation of aggregates that increased with the radiation dose was revealed. The same observation was done from viscosity data and from the UV spectrum of the samples. From amino acid analysis and fluorimetry determinations, tryptophan appeared as the most sensitive amino acid. An increase in the free-S H-groups was also observed. After the standardization of the method, the radio modifier capability of glutathione, amino ethyl thiourea, mercapto ethyl alanine and dimethyl sulfoxide was tested. The results showed that in the presence of those substances the radiation effect was diminished. (author)

  4. Fieldbus: technology application in a 60Co sterilization plant

    Process instrumentation was made by pressure signals in the 1940s. In the 1960s, 4-20 mA analogue signals were introduced. The development of digital processors in the 1970s sparked the use of computers to monitor and control instruments from a central point. In the 1980s smart sensors were developed and implemented in digital control, microprocessor environments. Fieldbus is a generic-term that describes a new digital communications network. The network is a digital, bi-directional, multidrop, serial-bus, and communications network used to link isolated field devices, such as controllers, transducers, actuators and sensors. Fieldbus technology may improve quality, reduce costs and increase efficiency because information is transmitted digitally without analog to digital or digital to analog converters, which also minimizes hardware errors. Fieldbus communication is based on two-wire communication, interconnecting all the components in the system. This paper introduces Fieldbus technology in a 60Co sterilization plant

  5. Retention of ingested (60)Co by a freshwater fish

    The experiment was carried out on a group of 10 carp receiving the soft tissue of previously contaminated lymnaea as food. Ingestion by carp of 45 daily rations, distributed over a 63-day period, resulted in a low retention of the radionuclide. The contamination kinetics showed that the steady state should be reached after only 225 days. The 60Co transfer factor was approximately 10−2 and the retention factor about 3.3 x 10−3. During the depuration phase, radiocobalt elimination by the carp developed in accordance with an exponential model based on the existence of two biological half-lives of 1.5 and 35 days which indicate a high Co turnover. During both phases of the experiment, urinary and branchial excretion appeared to be higher than faecal excretion

  6. Seed germination of peanuts irradiated with cobalt (60CO)

    This work was realized to evaluate the effect of gamma irradiation (60Co) at doses 0, 0.50, 1.00, 1.50, 2.00, 2.50, 3.00 and 4.00 kGy, on germination of seeds of peanut, cultivar BR1. Irradiation Department of Nuclear, UFPE, where he received after the irradiation, they were stored in packing of PET and polyethylene braided with a time of 90 days. Through the results, obtained monthly, concluded that the dose of 0.5 kGy was effective in the germination of seeds of peanut, not affecting its power of germination and overcoming the witness within 30 to 60 days. (author)

  7. Planning a 60Co Irradiation Facility for Fruit Preservation

    A conceptual design for a conveyor system is proposed for use in fruit irradiation. The seasonal nature of the fruit harvest requires that the 60Co source inventory should be sufficient to meet the demand at peak season, but this would be excessive at the beginning and towards the end of the harvest. Because of the short crop period the possibility of other irradiation services should be exploited to ensure full utilization of the facility. For successful extension of fruit shelf-life rigid practices in pre-irradiation treatment are essential and careful packaging is indispensable to the operation of the irradiator. Based on the time required for construction and equipment supply, a period of 18 months should be assumed for completion of the project. (author)

  8. Planning a 60Co irradiation facility for fruit preservation

    A conceptual design for a conveyor system is proposed for use in fruit irradiation. The seasonal nature of the fruit harvest requires that the 60Co source inventory should be sufficient to meet the demand at peak season, but this would be excessive at the beginning and towards the end of the harvest. Because of the short crop period the possibility of other irradiation services should be exploited to ensure full utilization of the facility. For successful extension of fruit shelf-life rigid practices in pre-irradiation treatment are essential and careful packaging is indispensable to the operation of the irradiator. Based on the time required for construction and equipment supply, a period of 18 months should be assumed for completion of the project. (author)

  9. Effect of 60Co radiation on peritoneal cells

    This work deals with the effect of 60Co gamma irradiation on the levels and quality of peritoneal cells of albino mice. The cells were obtained from peritoneal exudate, fixed and stained in 30% glacial acetic acid containing 0,5% cristal violet. Os exudates from irradiated and control animals the qualitative analysis and the counting of different cell populations were performed one hour, three days and six days after irradiation with 9 Gy. All the cell populations from the peritoneal exudate shown a decrease 3 days after the irradiation with 9.0. Gy but the different cellular populations dimished in unlike proportions. The data reaffirm the discrepance in radiosensivity of the diverse peritoneal cell populations. (author)

  10. Thickness dependence of superconductivity and resistivity in La{sub 1.85}Sr{sub 0.15}CuO{sub 4} films

    Sato, Hisashi [NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi-shi, Kanagawa 243-0198 (Japan)], E-mail: hisashi@will.brl.ntt.co.jp

    2008-07-01

    The temperature dependence of resistivity was measured for (0 0 1), (1 0 0) and (1 1 0)-oriented La{sub 1.85}Sr{sub 0.15}Cu{sub 4} (LSCO) thin films with thickness between 1 and 90 nm on LaSrAlO{sub 4} (LSAO) substrates. As thickness increases, superconductivity appears for (0 0 1) films at 3 nm, whereas it appears for (1 0 0) and (1 1 0) films at 23 nm. The difference is explained by compressive strain in the c-axis direction for (1 0 0) and (1 1 0) films caused by a smaller c-axis length in LSAO than in LSCO. It is suggested that small lengths of Cu-O bonds perpendicular to CuO{sub 2} planes degrade superconductivity in this system.

  11. Current induced degradation of the La0.85Sr0.15MnO3+/YSZ8 and Pt/YSZ8 interfaces

    Knudsen, Tine; Jacobsen, Torben; Skou, Eivind

    Electrochemical reduction of oxygen by the use of both a cone shaped La0.85Sr0.15MnO3+δ electrode and Platinum electrodes together with the solid electrolyte YSZ8, induced significant changes in the materials. The cone was after use no longer homogenous (EDX analysis in figure), and the cone top...... electrode set-up with three identical Pt-electrodes. The cathode was polarized –0.1V at 1000oC in air in 85 days. The current through the anode and cathode was measured and is displayed in figure (). The current increased the first 50 days, where after is became approximately constant. Inspection showed...

  12. EPR study of Fe-doped La sub 1. 85 Sr sub. 15 CuO sub 4. [La-Sr-Cu-Fe-O

    Sienkiewicz, A.; Cieplak, M.Z. (Inst. of Physics, Polish Academy of Sciences, Warsaw (Poland)); Gang Xiao (Dept. of Physics, Brown Univ., Providence, RI (USA)); Chien, C.L. (Dept. of Physics and Astronomy, Johns Hopkins Univ., Baltimore, MD (USA))

    1990-10-15

    We study EPR of Fe-doped La{sub 1.85}Sr{sub 0.15}CuO{sub 4} for the dopant content from 0 to 10 at.%. The g-factor of the Fe{sup 3+} resonance line decreases rapidly in the low temperature region and then remains constant. Depending on temperature and impurity content the linewidth displays two distinct behaviors. We associate the low temperature behavior with the occurrence of a spin-glass phase due to Fe-Fe dipole-dipole interactions. Correlation of the EPR and transport properties at high temperatures suggests the presence of RKKY mechanism which is strongly influenced by localization of free carriers. (orig.).

  13. Strain Relaxation in Thin Films of La1.85Sr0.15CuO4 Grown by Pulsed Laser Deposition

    Zaytseva, I.; Cieplak, M. Z.; Abal'Oshev, A.; Berkowski, M.; Domukhovski, V.; Paszkowicz, W.; Shalimov, A.

    2007-01-01

    X-ray diffraction, resistivity, and susceptibility measurements are used to examine the effects of film thickness d (from 17 to 250 nm) on the structural and superconducting properties of La1.85Sr0.15CuO4 films grown by pulsed laser deposition on SrLaAlO4 substrates. For each d the film sgrow with a variable strain, ranging from a large compressive strain in the thinnest films to a negligible or tensile strain in thick films. Our results indicate that the tensile strain is not caused by the off-stoichiometric layer at the substrate-film interface. Instead, it may be caused by the extreme oxygen deficiency in some of the films.

  14. Superconductivity and the metal-insulator transition in La sub 1. 85 Sr sub 0. 15 CuO sub 4

    Cieplak, M.Z.; Guha, S.; Kojima, H.; Lindenfeld, P. (Serin Physics Lab., Rutgers Univ., Piscataway, NJ (United States)); Gang Xiao (Serin Physics Lab., Rutgers Univ., Piscataway, NJ (United States) Dept. of Physics, Brown Univ., Providence, RI (United States)); Xiao, J.Q.; Chien, C.L. (Serin Physics Lab., Rutgers Univ., Piscataway, NJ (United States) Dept. of Physics, Johns Hopkins Univ., Baltimore, MD (United States))

    1991-12-01

    Measurements on La{sub 1.85}Sr{sub 0.15}CuO{sub 4} with five different substitutions for the Cu show that the M-I transition occurs in each case at an impurity concentration x{sub MI} higher than the value x{sub c} at which superconductivity disappears. While x{sub c} correlates with the magnitude of the local magnetic moment, we show that the M-I transition is the result of the superposition of the disorder and of the change in carrier concentration as obtained from the Hall effect. On the metallic side the normal-state conductivity changes linearly with {radical}T over a wide range of temperature. The normal-state conductivity extrapolated to zero temperature exhibits a critical exponent close to one as the M-I transition is approached. (orig.).

  15. Metallic Nonsuperconducting Phase and D -Wave Superconductivity in Zn-Substituted La{sub 1.85}Sr{sub 0.15}CuO{sub 4}

    Karpinska, K. [Institute of Physics, Polish Academy of Sciences, 02 668 Warsaw, (Poland); Cieplak, Marta Z. [Institute of Physics, Polish Academy of Sciences, 02 668 Warsaw, (Poland); Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854-8019 (United States); Guha, S. [Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854-8019 (United States); Malinowski, A. [Institute of Physics, Polish Academy of Sciences, 02 668 Warsaw, (Poland); Skoskiewicz, T. [Institute of Physics, Polish Academy of Sciences, 02 668 Warsaw, (Poland); Plesiewicz, W. [Institute of Physics, Polish Academy of Sciences, 02 668 Warsaw, (Poland); Berkowski, M. [Institute of Physics, Polish Academy of Sciences, 02 668 Warsaw, (Poland); Boyce, B. [Department of Physics, The Ohio State University, Columbus, Ohio 43210-1106 (United States); Lemberger, Thomas R. [Department of Physics, The Ohio State University, Columbus, Ohio 43210-1106 (United States); Lindenfeld, P. [Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854-8019 (United States)

    2000-01-03

    Measurements of the resistivity, magnetoresistance, and penetration depth were made on films of La{sub 1.85} Sr{sub 0.15} CuO{sub 4} , with up to 12 at. % of Zn substituted for the Cu. The results show that the quadratic temperature dependence of the inverse square of the penetration depth, indicative of d -wave superconductivity, is not affected by doping. The suppression of superconductivity leads to a metallic nonsuperconducting phase, as expected for a pairing mechanism related to spin fluctuations. The metal-insulator transition occurs in the vicinity of k{sub F}l{approx_equal}1 , and appears to be disorder driven, with the carrier concentration unaffected by doping. (c) 1999 The American Physical Society.

  16. Transport properties of Ru-doped La1.85Sr0.15CuO4 and the effect of carrier concentration compensation

    This paper is a study of the structure and transport properties of Ru-doped La1.85Sr0.15CuO4. It is found that Ru substitution for Cu has two effects. (1) Ru doping introduces disorder into the system, which causes a metal-insulator transition with high localization. (2) There is a hole-filling effect due to the valence of the Ru ion being higher than that of the Cu ion. Increase of the strontium content could compensate for the imbalance of valence caused by doping with the high-valence Ru ion. A universal curve for Tc versus the number of holes per Cu site is observed for the La2-ySryCu1-xRuxO4 system, indicating that a rigid-band model holds and Tc correlates with features in the density of states, such as a Van Hove singularity

  17. Assessment of bone formation and bone resorption in osteoporosis: a comparison between tetracycline-based iliac histomorphometry and whole body 85Sr kinetics

    Bone formation and resorption have been measured in patients with idiopathic osteoporosis by histomorphometry of 7.5-mm trephine biopsies and in the whole body by 85Sr radiotracer methodology and calcium balances. The studies were synchronized and most were preceded by double in vivo tetracycline labeling. Correlations between histological and kinetic bone formation indices were better when better when based on the extent of double tetracycline labels than on measurements of osteoid by visible light microscopy. Correction of the kinetic data for long-term exchange, using 5 months' serial whole body counting of retained 85Sr, improved the fit of the kinetic to the histological data. A statistical analysis of the measurement uncertainties showed that the residual scatter in the best correlations (between exchange-corrected bone formation rates and double-labeled osteoid surface indices) could be attributed to measurement imprecision alone. The exchange-corrected resorption rate correlated fairly well with iliac trabecular resorption surfaces, and using a volume referent rather than a surface referent for the histological index improved the statistical fit when patients with therapeutically accelerated bone turnover were included. A much better correlation was obtained by including osteoid volume acting as an independent predictor of bone resorption in a bivariate regression with a resorption surface index. The residual errors could then be accounted for by known measurement uncertainties. Whereas osteoid taking a double label closely predicted the kinetic rate of bone formation, further analysis suggested that osteoid that took no label or a single label was more closely related to bone resorption, presumably as a secondary result of the coupling of bone formation to bone resorption

  18. Uptake, distribution and metabolic fate of 59Fe, 58Co, 54Mn and 65Zn in plants and their mobility and availability to crops in typical black and laterite soils

    Studies were undertaken on typical soils of India. Nutrient culture experiments indicated that with identical plant growth periods the accumulation in aerial tissues of 65Zn and 54Mn was greater than that of 58Co and 59Fe. The distribution of 59Fe, 58Co and 65Zn in the various aerial organs of bean plants was generally uniform whereas the distribution of 54Mn followed an acropetal gradient. The chemical association of 59Fe, 58Co and 65Zn in the edible bean pods was predominantly with lipids and ionic forms whereas 54Mn association was mainly with ionic forms. The plant uptake of these radionuclides from typical black and laterite soils showed maximum accumulation of 54Mn followed by 65Zn, 59Fe and 58Co in both soil types and the uptake was greater from the laterite soil than from the black soil. Flooding treatment of rice, while showing a reduction of 59Fe uptake, showed an increase in plant uptake of 58Co, 54Mn and 65Zn in both soil types. Organic matter addition resulted in a significant reduction of 59Fe and 58Co in the laterite soil and of 65Zn in the black soil. All the four nuclides were completely immobile in the two soil types when leached with rain water or irrigation waters or when treated with organic matter. However, leaching with 10-2 M EDTA solution induced a rapid breakthrough of all the four radionuclides. (author)

  19. Establishment of a production line for the fabrication of mega-curie sealed 60Co sources

    In order to change the status that highly radioactive 60Co sources in China are de- pendent on imports, the fabrication technology of sealed 60Co sources was successfully developed and a mega Curie production line was established. This paper describes the hot cell facilities for the 60Co source encapsulation and quality control, the model and main technical parameters of the sealed 60Co source, the fabrication process, some key techniques in the re- search and development of the sealed 60Co source, etc. (authors)

  20. Transference kinetics of 60Co in an aquatic-terrestrial ecosystem

    The dynamics of transportation, accumulation, disappearance and distribution of 60Co in a simulated aquatic-terrestrial ecosystem was studied by isotope-tracer technique. In the aquatic system, 60Co was transported and transformed via depositing, coupling with ions and adsorption. The absorption resulted in the redistribution and accumulation of 60Co in each compartment of the system. Specific activities of 60Co in water started sharply and gently decreased. The sediment accumulated a large amount of 60Co by adsorption and ion exchange. The hornwort (Ceralophyllum demersum) could also adsorb a large amount of 60Co in a short time, because of its large specific surface area. Fish (Carassius auratus) and snail (Bellamya purificata) had a poor capacity of adsorbing 60Co. The distribution of 60Co in the fish was mainly in the viscera, and the amount of 60Co in the snail flesh was greater than that in the shell. The amount of 60Co in individual compartment in the system was changed with time. The highest specific activity of 60Co in the bean of the terrestrial system remained in the root nodule. (authors)

  1. Accumulation, Toxicity And Elimination Of 60Co In Some Aquatic Bivalves

    The present study was undertaken to evaluate the importance of some common bivalve oysters namely Caelatura teretiusculua and Caelatura companyoi as new radiobioindicators for 60Co in Egyptian aquatic environment.The uptake and accumulation of 60Co in water were followed for four weeks to evaluate the following:1-Maximum uptake as concentration factor values.2-The rate of survival of bivalves at different activity levels of 60Co to estimate its toxic effect.3-The lethal dose (LD50) of 60Co.4-The effect of ph of 60Co polluted water on survival of biota.5-The competitive effects of Zn+2 and Fe+3 with 60Co on the uptake and accumulation.6-The effect of biota weight on the uptake of 60Co.7-Elimination of the accumulated 60Co by such biota in water and in 10-4M ethylene diamine tetra acetic acid (EDTA) as chelating agent that enhance the bivalve to release the accumulated radioisotope.The results showed that 60Co was highly taken up by the investigated biota with high concentration factor values and that EDTA enhanced the decontamination of 60Co than water. It could be concluded that the investigated bivalves can be used as good radiobioindicators for pollution of water with 60Co.

  2. Influence of pH-buffer action on desorption behavior of 60Co adsorbed on sand

    In order to clarify influence of pH-buffer action of soil on desorption behavior of radionuclides absorbed on a soil, a batch type desorption experiment, in which a coastal sand adsorbed 60Co was contacted with an aqueous solution of 4, 7 or 10 in pH, was performed. When pH of the solution became higher, the desorption ratio of 60Co from the sand to the solution decreased, while the abundance ratio of non-cationic 60Co species increased. Relationship between the pH of solution and the desorption ratio of 60Co could been explained by a pH dependency of negative charge density on the sand surface. It was found that the non-cationic 60Co species in the solution was colloidal {60Co (OH)2}n, which was formed by hydrolysis of 60Co2+ at buffered pH. (author)

  3. Transfer factors of radionuclides from Andsols to some selected crops

    In order to obtain the applicable transfer factor for Japanese environment, we performed radiotracer experiments on the uptake of 137Cs, 85Sr, 54Mn, 60Co and 65Zn by leaf vegetables (two cabbages, komatsuna, spinach and lettuce), root vegetables (radish and carrot) and other crops (wheat, soy bean sweet potato and tomato) using the Andosol (Kuroboku soil), the most common of Japanese arable soils. The ranges of TFs (on a dry weight basis) of 137Cs, 85Sr, 60Co, 54Mn and 65Zn for edible parts of crops (leaf vegetables, root vegetables, wheat and soy bean) were 0.09 - 1.42, 0.24 - 3.7, 0.019 - 1.5, 0.31 - 12 and 0.68 - 14, respectively. TFs were, in most cases in the order Mn, Zn, Sr > Cs > Co. (author)

  4. ONE CASE OF LEUKEMIA INDUCED BY 60Co ACCIDENT

    邵松生; 冯嘉林; 等

    1995-01-01

    The peripheral blood lymphocyte chromosomes in a case of 60Co γ rays accident were examined at 2.5h after exposure.The frequency of the dicentrics plus centric rings was 89% and exposure dose was estimated to be 4.78 (4.53-4.88)GY.The examinations of lymphocyte chromosome aberration within follow-up 12a showed that the incidence of Dic+R reduced with lg regrssion(r=-0.9895).While the number of ceels with stable aberration remained unchanged and showed a tendency to increase.During the period of leukemia,bone marrow cell chromosome aberrations were studied by method of G-banding.Of 13 cells observed,4 cells belonged to normal karyotypes.Among 9 aberration cells,12 aberrations were detected.The majority of which were classified as translocation,deletion and inversion,Numeric aberrations were-9,12,20-,22,-y.This case suggested that acute lymphocytic leukemia was induced after radiation accident.

  5. Determination of Absorbed Dose in Large 60-Co Fields Radiotherapy

    Radiation in radiotherapy has selective impact on ill and healthy tissue. During the therapy the healthy tissue receives certain amount of dose. Therefore dose calculations in outer radiotherapy must be accurate because too high doses produce damage in healthy tissue and too low doses cannot ensure efficient treatment of cancer cells. A requirement on accuracy in the dose calculations has lead to improvement of detectors, and development of absolute and relative dosimetry. Determination of the dose distribution with use of computer is based on data provided by the relative dosimetry. This paper compares the percentage depth doses in cubic water phantoms of various dimensions with percentage depth doses calculated with use of Mayneord factor from the experimental depth doses measured in water phantom of large dimension. Depth doses in water phantoms were calculated by the model of empirical dosimetrical functions. The calculations were based on the assumption that large 60Co photon field exceeds the phantom's limits. The experimental basis for dose calculations by the model of empirical dosimetrical functions were exposure doses measured in air and dose reduction factors because of finite phantom dimensions. Calculations were performed by fortran 90 software. It was found that the deviation of dosimetric model was small in comparison to the experimental data. (author)

  6. Qualities of Patin Fishball Irradiated by Gamma Rays (60Co)

    An experiment on patin fishball quality using gamma irradiation (60Co) has been conducted. Samples were irradiated at 0, 1, 3 and 5 kGy and stored in refrigerator at temperature 10 oC for sixty days. Samples were analysed every fifteen days, except content of fat and protein that analysed only at the beginning and the end of storage. The purpose of this experiment is to know the quality changes of patin fishball irradiated during storage, by measuring of chemical (content of fat, protein, water, TVB value, pH value) and microbiology (TPC aerobic and anaerobic bacteria) changes. The results showed that irradiation did not affect macro nutrient contents (content of fat, protein and water) of patin fishball during storage but irradiation can affect TVB and pH values. Irradiation at 1 kGy can reduce one logarithmic cycle of total aerobic and anaerobic bacteria. The storage life of irradiated patin fishball treated at 1, 3 and 5 kGy could be extended up to 15, 30 and 60 days, respectively. Control samples the storage life could be extended less than 15 days. (author)

  7. Response of adrenal gland to whole body 60Co irradiation

    Whole body of the adult albino rates was exposed to 60Co radiation in a single dose of 600 R. Following irradiation the adrenal serotonin level was found higher till the end of 8th week except a fall on 14th day, whereas the blood 5HT level remained lower than the normal except a slight rise at the end of 1st week and dropped down at 14 days followed by a further rise. The blood catecholamine level was found increased at the end of 14th day followed by a fall at 4th and 8th weeks, but the levels were moving round the normal value. The histological studies of adrenal gland showed degranulation and hypertrophy of adrenal cortex and medullary cells at various intervals of post-irradiation. On the whole it is observed that maximum changes in the level of biogenic amines take place within 14 days after irradiation, and maximum rate of mortality also coincide with this period. Thus bringing out the fact that adrenal bioamines play an important role in the vital activities of the animals. (author)

  8. Disturbed tooth formation by 60Co-gamma-ray radiation

    The molar of guinea pigs was irradiated with 60Co-#betta# ray for daily observations of the manifestation of disturbed tooth formation by microradiography and the time registration by tetracycline-labelling. Irradiation first injured young blast cells of the dentin in the growth phase, dental pulp cells, and cells of the enamel. The portion composed of injured cells formed a depressed ''constriction'' from the dental pulp side toward the border between the enamel and dentin. The cells of the enamel injured by irradiation in the growth phase later formed a very thin irregular stroma. In contrast, cells in the differentiation or subsequent phase at the time of irradiation and cells probably having started to grow after irradiation proceeded with formation of a normal stroma and calcification. No uniform relation was obtained between the histological staining of the organic stroma of normal or abnormal dentin and calcification. Labelling with tetracycline revealed that the irradiation conditions in the present study provoked hardly any changes in the speed of tooth eruption. (Chiba, N.)

  9. 60Co γ-irradiation induced mutation breeding of ginger

    Sprout rhizome and plumelet rhizome of Laiwu ginger were irradiated by 60Co γ-rays at different doses (20, 25, 30 and 35 Gy), and the variations at the VM1, VM2, and VM3 generations were studied. The results showed that the inhibition effect of irradiation on the VM1 generation was found to be increased as the dose increased, and the sprout rhizome was more sensitive to γ-irradiation than the plumelet rhizome. The LD50 and LD60 dose of plumelet rhizomes were 20 and 25 Gy, respectively, and the optimum irradiation dose was 25Gy. The LD50 and LD60 dose of sprout rhizomes were below 20 Gy. Seven types of mutants were found and selected in VM2 generation. The induced mutation characters were unstable in the VM3 generation. Three mutant lines (GDC2531, PZC3026, ZLX2007) selected from VM3 generation showed high yield, and fresh weight of rhizomes increased 33.5%, 27.5% and 24.9%, respectively compared to control. (authors)

  10. Effect of 60CO radiation processing in mate (Ilex paraguariensis)

    The mate (Ilex paraguariensis), a native species from South America, is mainly consumed as typical beverage called chimarrao and terere. An important problem that has been afflicting this product since a long time is its natural fungal contamination responsible to affect its physical, health and nutritional qualities. In order to improve this product quality, radiation processing can be effective in reducing pathogens levels, with minimal nutritional and sensory changes. The aim of this study was to evaluate the effectiveness of gamma radiation from 60Co at doses 0, 3, 5, 7 and 10kGy in reducing fungal contamination in mate, as well as analyze its nutritional and sensory characteristics. The following methodologies were applied: analysis of yeast and mold, total phenolic compounds analysis, antioxidant analysis, quantification of phenolic compounds and xanthines by liquid chromatography and sensory analysis. Microbiological analysis showed a decreasing molds and yeasts growth with increasing radiation doses. Regardless of the radiation dose applied there were no decrease of total phenolic compounds in both infusions. Chimarrao samples irradiated with 7 and 10kGy showed a decrease in the DPPH radical-scavenger activity, nevertheless for terere samples, there were no significant difference. Chimarrao chromatographic profile did not show a variation on xanthines quantification, however a 10kGy radiation dose caused a change to phenolic compounds quantitative profile. Terere samples did not show any significant difference to any analyzed compounds. Sensory analysis did not exhibit a significant difference between irradiated and non irradiated chimarrao samples, as well as between irradiated and non irradiated terere samples. It could be concluded that gamma radiation processing of mate may be a feasible alternative to industry, since there was a reduction on fungal contamination, without changes in sensory qualities and with minimum alterations in quantitative and

  11. Effect of 60Co radiation processing in mate (Ilex paraguariensis)

    The mate (Ilex paraguariensis), a native species from South America, is mainly consumed as typical beverage called chimarrao and terere. An important problem that has been afflicting this product since a long time is its natural fungal contamination responsible to affect its physical, health and nutritional qualities. In order to improve this product quality, radiation processing can be effective in reducing pathogens levels, with minimal nutritional and sensory changes. The aim of this study was to evaluate the effectiveness of gamma radiation from 60Co at doses 0, 3, 5, 7 and 10 kGy in reducing fungal contamination in mate, as well as analyze its nutritional and sensory characteristics. The following methodologies were applied: analysis of yeast and mold, total phenolic compounds analysis, antioxidant analysis, quantification of phenolic compounds and xanthines by liquid chromatography and sensory analysis. Microbiological analysis showed a decreasing molds and yeasts growth with increasing radiation doses. Regardless of the radiation dose applied there were no decrease of total phenolic compounds in both infusions. Chimarrao samples irradiated with 7 and 10 kGy showed a decrease in the DPPH radical-scavenger activity, nevertheless for terere samples, there were no significant difference. Chimarrao chromatographic profile did not show a variation on xanthines quantification, however a 10 kGy radiation dose caused a change to phenolic compounds quantitative profile. Terere samples did not show any significant difference to any analyzed compounds. Sensory analysis did not exhibit a significant difference between irradiated and non irradiated chimarrao samples, as well as between irradiated and non irradiated terere samples. It could be concluded that gamma radiation processing of mate may be a feasible alternative to industry, since there was a reduction on fungal contamination, without changes in sensory qualities and with minimum alterations in quantitative and

  12. Placental transfer of 60Co as a function of gestation age

    The transfer of 60Co from mother to foetus in relation to the time of gestation was examined 24 hrs after injecting 5 μCi of 60CoCl2 to the pregnant rat on 15th - 21st day of gestation. The radioactivity of foetuses, placentae as well as liver, kidney and femur of mother was determined. It was found that activity of 60Co transferred to the foetus body increased with the time of gestation. (author)

  13. Bioaccumulation and elimination of 60 Co and 137 Cs by Anomalocardia brasiliana (Gmelin, 1791) (Mollusca bivalvia). Remobilization of 60 Co, retained in marine sediment by microbial activity

    It was studied the capacity of a bi valve mollusc Anomalocardia brasiliana, which lives in the local bottom sediment, to remobilize 60 Co previously sorbed in the sediment. Laboratory experiments demonstrated that the transference of 60 Co from the sediment to the animal was insignificant (bioaccumulation factor (BF) of the order of 10-3). At the same time, the capacity of microorganisms, present in the bottom sediment, to remobilize 60 Co was studied. The results showed that this via of transference was important, considering the much greater microorganism biomass in relation to the biomass of bentonic organisms, as a whole. For 137 Cs the determined BF from water to the animal was 2.2. and, as in the case of 60 Co, the soft tissues concentrated more 137 Cs than shell. Remaining viscera showed the highest BFs. In another series of experiments, the loss of 60 Co or 137 Cs, previously accumulated by A. brasiliana, was followed in aquaria with or without sediment and the respective biological half-lives were calculated. Soft tissues retained 60 Co longer (biological half-life = 117 days) than shells, whereas for 137 Cs the opposite was observed and shells showed a biological half life of 38.5 days. The low values of 60 Co and 137 Cs BFS do not allow to classify A. brasiliana as good biological indicator for pollution by there radionuclides. However since A brasiliana is consumed by the local population and is commercialized to other areas, it was recommended that its contamination by 60 Co or 137 Cs should be monitored. (author)

  14. Studies on the transportation dynamics of 60Co in simulated ecosystem

    The isotope tracer techniques were applied to study the transportation, accumulation and distribution of 60Co in the pot-cultivated tomato-soil, aquatic and terrestrial ecosystems. Based on the principle of tracer dynamic compartment models, the mathematical formulae were established via computer simulation to describe the 60Co behavior patterns in ecosystems and thus provided some basic information for elucidating the behavior of 60Co in the environment. The results are as follows: (1) When 60Co was introduced into the tomato-soil system, 60Co was transported and accumulated in the soil and adsorbed by tomato root quickly, then transported to the above-ground plant. (2) The behavior patterns of 60Co in the tomato-soil system could be described using the opened two-compartment model. (3) When 60Co was introduced into aquatic system in the form of 60Co-CoCl2, it was transported and transformed via deposit, complexation with other ions, adsorption and absorption by aquatic living things and led to the distribution and accumulation in individual part of the living things. (4) The behavior pattern of 60Co in the aquatic-terrestrial ecosystem could be described by using opened five-compartment model

  15. Ionic Liquid Type Crown Ether as a Novel Medium for Liquid-Liquid Extraction of the Radioactive Metal Ion 85Sr2+

    1,13-dichloro-4,7,10-trioxatridecane (2-[2-(1-chloro-2-ethoxy)ethoxy]ethyl chloride) was synthesized by chlorination of 1,13-dihydroxy-4,7,10-trioxatridecane (triethylene glycol). Treatment with imidazole and sodium ethoxide provided 1N,1N'- tris(oxoethylene)-diimidazole, which was then converted to an ionic liquid type crown ether (ILCE) with reaction with 1,9-dichloro-3,6-trioxaoctane. The anion of the ILCE was then exchanged by an anion exchange method. Ultimately, a very efficient synthetic pathway was developed for the preparation of ILCEs having various physical and chemical characteristics by a modification of the polyethylene glycol chain length and anions. The 85Sr2+ was successfully extracted into the [(3,2)OEtIm][Cl] phase, but was not extracted into the [(2,2)OEtIm][Cl], [(3,3)OEtIm][Cl] and [(4,3)OEtIm][Cl] phases. (author)

  16. Ionic liquid-type crown ether as a novel medium for a liquid/liquid extraction of radioactive metal ion 85Sr2+

    1,13-Dichloro-4,7,10-trioxatridecane (2-[2-(1-chloro-2-ethoxy)ethoxy] ethyl chloride) (3a) was synthesized by a chlorination of 1,13-dihydroxy-4,7,10-trioxatridecane (triethylene glycol). And it was treated with imidazole and sodium ethoxide to give the 1N, 1N'-tris(oxoethylene)-diimidazole (3b), which was then converted to ionic liquid-type crown ether (ILCE) 3 with a reaction with 1,9-dichloro-3,6-trioxaoctane (2a). Further, the anion of ILCE was exchanged by an anion-exchange method. Ultimately, we developed a very efficient synthetic pathway for ILCEs 1-4 which have various physical and chemical characteristics by a modification of the polyethylene glycol chain length and anions. 85Sr2+ was successfully extracted into the [(3,2)OEtIm][Cl] (3) phase, but it was not extracted into the [(2,2)OEtIm][Cl] (1), [(3,3)OEtIm][Cl] (2), and [(4,3)OEtIm][Cl] (4) phases. (author)

  17. Critical fields and the critical current density of La/sub 1.85/Sr/sub 0.15/CuO4

    A detailed investigation of the magnetic and transport properties of La/sub 1.85/Sr/sub 0.15/CuO4 in the superconducting state is presented. It is concluded that the magnetic and transport behavior is that of a granular type-II superconductor in which strongly superconducting grains are coupled via weak superconducting links. Five characteristic fields are identified. H/sub c/1/sup w/ (≅1 Oe at 4 K) is the field at which the first vortex line penetrates the weak links. At H = H/sup w/ (≅11 Oe at 4.2 K) the London penetration depth in the weak links is very large compared to their dimensions. H/sub c/1/sup g/ (≅300 Oe at 4.2 K) defines the first flux thread entering the grains themselves. H/sup g/ is the value above which the magnetic behavior of the grain is thought to be governed by Abrikosov's negative surface energy model. The critical current density measured by the resistivity technique is about 8 A cm2 and is imposed by the sample size and compositional inhomogeneities and by H/sub c/1/sup w/, whereas the bulk (or intragrain) critical density could attain 105--106 A/cm2

  18. Critical fields and the critical current density of La/sub 1. 85/Sr/sub 0. 15/CuO/sub 4/

    Senoussi, S.; Oussena, M.; Ribault, M.; Collin, G.

    1987-09-01

    A detailed investigation of the magnetic and transport properties of La/sub 1.85/Sr/sub 0.15/CuO/sub 4/ in the superconducting state is presented. It is concluded that the magnetic and transport behavior is that of a granular type-II superconductor in which strongly superconducting grains are coupled via weak superconducting links. Five characteristic fields are identified. H/sub c//sub 1//sup w/ (approx. =1 Oe at 4 K) is the field at which the first vortex line penetrates the weak links. At H = H/sup w/ (approx. =11 Oe at 4.2 K) the London penetration depth in the weak links is very large compared to their dimensions. H/sub c//sub 1//sup g/ (approx. =300 Oe at 4.2 K) defines the first flux thread entering the grains themselves. H/sup g/ is the value above which the magnetic behavior of the grain is thought to be governed by Abrikosov's negative surface energy model. The critical current density measured by the resistivity technique is about 8 A cm/sup 2/ and is imposed by the sample size and compositional inhomogeneities and by H/sub c//sub 1//sup w/, whereas the bulk (or intragrain) critical density could attain 10/sup 5/--10/sup 6/ A/cm/sup 2/.

  19. Bioremediation of {sup 60}Co from simulated spent decontamination solutions

    Rashmi, K.; Naga Sowjanya, T.; Maruthi Mohan, P.; Balaji, V.; Venkateswaran, G

    2004-07-26

    Bioremediation of {sup 60}Co from simulated spent decontamination solutions by utilizing different biomass of (Neurospora crassa, Trichoderma viridae, Mucor recemosus, Rhizopus chinensis, Penicillium citrinum, Aspergillus niger and, Aspergillus flavus) fungi is reported. Various fungal species were screened to evaluate their potential for removing cobalt from very low concentrations (0.03-0.16 {mu}M) in presence of a high background of iron (9.33 mM) and nickel (0.93 mM) complexed with EDTA (10.3 mM). The different fungal isolates employed in this study showed a pickup of cobalt in the range 8-500 ng/g of dry biomass. The [Fe]/[Co] and [Ni]/[Co] ratios in the solutions before and after exposure to the fungi were also determined. At micromolar level the cobalt pickup by many fungi especially the mutants of N. crassa is seen to be proportional to the initial cobalt concentration taken in the solution. However, R. chinensis exhibits a low but iron concentration dependent cobalt pickup. Prior saturating the fungi with excess of iron during their growth showed the presence of selective cobalt pickup sites. The existence of cobalt specific sorption sites is shown by a model experiment with R. chinensis wherein at a constant cobalt concentration (0.034 {mu}M) and varying iron concentrations so as to yield [Fe/Co]{sub initial} ratios in solution of 10, 100, 1000 and 287 000 have all yielded a definite Co pickup capacity in the range 8-47 ng/g. The presence of Cr(III)EDTA (3 mM) in solution along with complexed Fe and Ni has not influenced the cobalt removal. The significant feature of this study is that even when cobalt is present in trace level (sub-micromolar) in a matrix of high concentration (millimolar levels) of iron, nickel and chromium, a situation typically encountered in spent decontamination solutions arising from stainless steel based primary systems of nuclear reactors, a number of fungi studied in this work showed a good sensitivity for cobalt pickup.

  20. The effect of 60Co-γ ray on fertilized eggs and growing change in chicken

    The fertilized eggs were stimulated by 60Co-γ ray of different doses. The experimental results show that the rate of hatching of different fertilized eggs reaches the maximum when the dose of 60Co-γ ray is 300rad. And, the higher the dose of 60Co-γ ray is used, the lower the rate of breeding and hatching are obtained. It is concluded that it is beneficial to growing of cock and the fertilized eggs are stimulated by the 60Co-γ ray of low doses. However, the growing of hen is inhibited and eggs are early produced with the low dose treatment of 60Co-γ ray

  1. Sensitivity and uncertainty analysis of the simulation of 123I and 54Mn gamma and X-ray emissions in a liquid scintillation vial

    Radiation transport simulations of the most probable gamma- and X-ray emissions of 123I and 54Mn in a three photomultiplier tube liquid scintillation detector have been carried out. A Geant4 simulation was used to acquire energy deposition spectra and interaction probabilities with the scintillant, as required for absolute activity measurement using the triple to double coincidence ratio (TDCR) method. A sensitivity and uncertainty analysis of the simulation model is presented here. The uncertainty in the Monte Carlo simulation results due to the input parameter uncertainties was found to be more significant than the statistical uncertainty component for a typical number of simulated decay events. The model was most sensitive to changes in the volume of the scintillant. Estimates of the relative uncertainty associated with the simulation outputs due to the combined stochastic and input uncertainties are provided. A Monte Carlo uncertainty analysis of an 123I TDCR measurement indicated that accounting for the simulation uncertainties increases the uncertainty of efficiency of the logical sum of double coincidence by 5.1%.

  2. Sensitivity and uncertainty analysis of the simulation of 123I and 54Mn gamma and X-ray emissions in a liquid scintillation vial.

    Bignell, L J; Mo, L; Alexiev, D; Hashemi-Nezhad, S R

    2010-01-01

    Radiation transport simulations of the most probable gamma- and X-ray emissions of (123)I and (54)Mn in a three photomultiplier tube liquid scintillation detector have been carried out. A Geant4 simulation was used to acquire energy deposition spectra and interaction probabilities with the scintillant, as required for absolute activity measurement using the triple to double coincidence ratio (TDCR) method. A sensitivity and uncertainty analysis of the simulation model is presented here. The uncertainty in the Monte Carlo simulation results due to the input parameter uncertainties was found to be more significant than the statistical uncertainty component for a typical number of simulated decay events. The model was most sensitive to changes in the volume of the scintillant. Estimates of the relative uncertainty associated with the simulation outputs due to the combined stochastic and input uncertainties are provided. A Monte Carlo uncertainty analysis of an (123)I TDCR measurement indicated that accounting for the simulation uncertainties increases the uncertainty of efficiency of the logical sum of double coincidence by 5.1%. PMID:20036571

  3. Strain accommodation through facet matching in La1.85Sr0.15CuO4/Nd1.85Ce0.15CuO4 ramp-edge junctions

    M. Hoek

    2015-08-01

    Full Text Available Scanning nano-focused X-ray diffraction and high-angle annular dark-field scanning transmission electron microscopy are used to investigate the crystal structure of ramp-edge junctions between superconducting electron-doped Nd1.85Ce0.15CuO4 and superconducting hole-doped La1.85Sr0.15CuO4 thin films, the latter being the top layer. On the ramp, a new growth mode of La1.85Sr0.15CuO4 with a 3.3° tilt of the c-axis is found. We explain the tilt by developing a strain accommodation model that relies on facet matching, dictated by the ramp angle, indicating that a coherent domain boundary is formed at the interface. The possible implications of this growth mode for the creation of artificial domains in morphotropic materials are discussed.

  4. Gamma 60Co DL50/30 of Biomphalaria glabrata (Say, 1818) DL50/30 raios gama de 60Co em Biomphalaria glabrata (Say, 1818)

    Elaine Barros da Costa CARVALHO; Melo, Ana Maria Mendonça de Albuquerque; Mauricy Alves da MOTTA

    1999-01-01

    The variation of resistance to 60Co gamma-rays of Biomphalaria glabrata was studied. A population of 480 mollusks was observed during 30 days - distributed in 8 groups of snails isolated and 8 groups of snails in colonies - after exposure (30 snails per group per dose) to increasing doses of gamma radiation. Doses of 10, 20, 40, 60, 80, 160, 320 and 640 Gy from a Gamma-cell 60Co irradiator, were applied to the test groups and two groups control (non-irradiated) of snails - isolated and colony...

  5. In Vivo Internal Decontamination of 134Cs and 60Co from Male Albino Rats

    The Present work aimed to evaluate the therapeutic role of prussian blue (PB), vermiculite and calcium trisodium salt of diethylenetriaminepentaacetic acid (DTPA) as internal de contaminants of radio-active cesium and/ or cobalt in adult male albino rats. Radionuclides were given as a single doses; 60Co was introduced orally, subcutaneously or intraperitoneally (ip) while 134Cs was taken orally or in combination with ip injection of 60Co. The de contaminants were supplied daily for three weeks immediately after 60Co or 134Cs intake; oral dose of PB + vermiculite treated the oral 134Cs group, oral and subcutaneous 60Co groups and combined 60Co and 134Cs groups. Rats receiving ip dose of 60Co were treated with daily ip dose of DTPA while the three de contaminants were added to the combined 60Co and 134Cs groups.Haemoglobin concentration (Hb), haematocrite percentage (Ht), red blood cells count (RBC's), as well as liver function tests (total bilirubine, total protein, albumin, globulin, A/ G ratio, alanine transaminase (ALT), spartic transaminase (AST) and alkaline phosphatase (ALP)) were analyzed in all groups. The data obtained revealed that internal contamination by radioactive materials causes a significant decrease in the RBC's counts, Hb concentration, haematocrit value, serum total proteins and albumin. On the other hand, the therapeutic agents caused a significant amelioration in the changes produced by internal contamination with variable degree. Thus, it could be concluded that the therapeutic agents might provide a protection against internal contamination hazards

  6. Retention and translocation of foliar applied {sup 239,240}Pu and {sup 241}Am, as compared to {sup 137}Cs and {sup 85}Sr, into bean plants (Phaseolus vulgaris)

    Henner, P. [Institute for Radioprotection and Nuclear Safety, Environment and Emergency Operations Division, Department for the Study of Radionuclides Behaviour in Ecosystems, Laboratory of Radioecology and Ecotoxicology, IRSN/DPRE/SECRE/LRE, Cadarache Centre, Building 186, BP 3, 13115 Saint-Paul-lez-Durance (France)]. E-mail: pascale.henner@irsn.fr; Colle, C. [Institute for Radioprotection and Nuclear Safety, Environment and Emergency Operations Division, Department for the Study of Radionuclides Behaviour in Ecosystems, Laboratory of Radioecology and Ecotoxicology, IRSN/DPRE/SECRE/LRE, Cadarache Centre, Building 186, BP 3, 13115 Saint-Paul-lez-Durance (France); Morello, M. [Institute for Radioprotection and Nuclear Safety, Environment and Emergency Operations Division, Department for the Study of Radionuclides Behaviour in Ecosystems, Laboratory of Radioecology and Ecotoxicology, IRSN/DPRE/SECRE/LRE, Cadarache Centre, Building 186, BP 3, 13115 Saint-Paul-lez-Durance (France)

    2005-07-01

    Foliar transfer of {sup 241}Am, {sup 239,240}Pu, {sup 137}Cs and {sup 85}Sr was evaluated after contamination of bean plants (Phaseolus vulgaris) at the flowering development stage, by soaking their first two trifoliate leaves into contaminated solutions. Initial retentions of {sup 241}Am (27%) and {sup 239,240}Pu (37%) were higher than those of {sup 137}Cs and {sup 85}Sr (10-15%). Mean fraction of retained activity redistributed among bean organs was higher for {sup 137}Cs (20.3%) than for {sup 239,240}Pu (2.2%), {sup 241}Am (1%) or {sup 85}Sr (0.1%). Mean leaf-to-pod translocation factors (Bq kg{sup -1}dry weight pod/Bq kg{sup -1}dry weight contaminated leaves) were 5.0 x 10{sup -4} for {sup 241}Am, 2.7 x 10{sup -6} for {sup 239,240}Pu, 5.4 x 10{sup -2} for {sup 137}Cs and 3.6 x 10{sup -4} for {sup 85}Sr. Caesium was mainly recovered in pods (12.8%). Americium and strontium were uniformly redistributed among leaves, stems and pods. Plutonium showed preferential redistribution in oldest bean organs, leaves and stems, and very little redistribution in forming pods. Results for americium and plutonium were compared to those of strontium and caesium to evaluate the consistency of the attribution of behaviour of strontium to transuranium elements towards foliar transfer, based on translocation factors, as stated in two radioecological models, ECOSYS-87 and ASTRAL.

  7. Superconductivity in bulk and thin films of La/sub 1.85/Sr/sub 0.15/CuO/sub 4-//sub δ/ and Ba2YCu3O/sub 7-//sub δ/

    A laser-ablation technique was used to deposit thin films from the bulk oxides La/sub 1.85/Sr/sub 0.15/CuO/sub 4-//sub δ/ and Ba2YCu3O/sub 7-//sub δ/, whose superconductivity properties were investigated by dc resistivity, complex ac susceptibility, and microwave response. The latter technique was employed to establish that the thin films have superconducting regions with properties similiar to the bulk materials

  8. Development of technology for the large-scale preparation of 60Co polymer film source

    60Co sources (∼37 kBq) in the form of a thin film are widely used in position identification of perforation in offshore oil-well explorations. This paper describes the large-scale preparation of such sources using a radioactive polymer containing 60Co. 60Co was extracted into chloroform containing 8-hydroxyquinoline. The chloroform layer was mixed with polymethyl methacrylate (PMMA) polymer. A large film was prepared using the polymer solution containing the complex. The polymer film was then cut into circular sources, mounted on a source holder and supplied to various users

  9. Development and evaluation of a technique for in vivo monitoring of 60Co in human lungs

    de Mello, J. Q.; Lucena, E. A.; Dantas, A. L. A.; Dantas, B. M.

    2016-07-01

    60Co is a fission product of 235U and represents a risk of internal exposure of workers in nuclear power plants, especially those involved in the maintenance of potentially contaminated parts and equipment. The control of 60Co intake by inhalation can be performed through in vivo monitoring. This work describes the evaluation of a technique through the minimum detectable activity and the corresponding minimum detectable effective doses, based on biokinetic and dosimetric models of 60Co in the human body. The results allow to state that the technique is suitable either for monitoring of occupational exposures or evaluation of accidental intake.

  10. Effects of some chelating agents on the uptake and distribution of 54Mn(II) in the brown trout (Salmo trutta)

    The effects of humic acids, which are natural metal-complexing compounds, and potassium ethylxanthate, sodium diethyldithiophosphate, sodium dimethyldithicarbamate, which are sulphur-containing man-made chelating agents, on the uptake and tissue distribution of 54Mn(II) were studied in brown trout (Salmo trutta). Fish were exposed for 7 days to 0.1 μg Mn(II)x.-2 as NmCl2 (l μCia 54Mnxl-1) with or without chelat agents. Examination of the partition of Mn between octanol and a Tris-HCl buffer in the presence of these compounds was also performed. Humic acids had only small effects on Mn uptake and distribution in trout, probably because of the low stability of Mn-humate complexes. Partition of Mn in the presence of potassium ethylxanthate, sodium diethyldithiophosphate, sodium dimethyldithiocarbamate, and sodium diethyldithiocarbamate between octanol and Tris-HCl buffer showed formation of lipophilic complex with the latter two compounds, but not with the former. However, these four chelating agents all decreased Mn uptake in the trout by 40-45%. These substances also changed the distribution of Mn within the fish, with a higher proportion of the metal being present in some visceral organs and a smaller proportion being localized in some non-parenchymateous tissues, such as skin, fins and bones. The mechanisms underlying these effects are not known. however, the interaction of chelating agents with the Mn, although weak, may have partially withdrawn the metal from the uptake process inthe gills. The redistribution of Mn in the fish may be due to the binding of the metal to complexing compounds which have reached the intestinal lumen. Previous studies with other metals have shown increased or unchanged metal levels in tissues of fish at exposure together with potasium ethylxanthate, sodium diethyldithiophosphate, sodium dimethyldithiocarbamate, and sodium diethyldithiocarbamate, but decreased metal levels have not been observed before. (au) (37 refs.)

  11. Soil-water distribution coefficients and plant transfer factors for 134Cs, 85Sr and 65Zn under field conditions in tropical Australia

    Measurements of soil-to-plant transfer of 134Cs, 85Sr and 65Zn from two tropical red earth soils ('Blain' and 'Tippera') to sorghum and mung crops have been undertaken in the north of Australia. The aim of the study was to identify factors that control bioaccumulation of these radionuclides in tropical regions, for which few previous data are available. Batch sorption experiments were conducted to determine the distribution coefficient (Kd) of the selected radionuclides at pH values similar to natural pH values, which ranged from about 5.5 to 6.7. In addition, Kd values were obtained at one pH unit above and below the soil-water equilibrium pH values to determine the effect of pH. The adsorption of Cs showed no pH dependence, but the Kd values for the Tippera soils (2300-4100 ml/g) exceeded those for the Blain soils (800-1200 ml/g) at equilibrium pH. This was related to the greater clay content of the Tippera soil. Both Sr and Zn were more strongly adsorbed at higher pH values, but the Kd values showed less dependence on the soil type. Strontium Kds were 30-60 ml/g whilst Zn ranged from 160 to 1630 ml/g for the two soils at equilibrium pH. With the possible exception of Sr, there was no evidence for downward movement of radionuclides through the soils during the course of the growing season. There was some evidence of surface movement of labelled soil particles. Soil-to-plant transfer factors varied slightly between the soils. The average results for sorghum were 0.1-0.3 g/g for Cs, 0.4-0.8 g/g for Sr and 18-26 g/g for Zn (dry weight) with the initial values relating to Blain and the following values to Tippera. Similar values were observed for the mung bean samples. The transfer factors for Cs and Sr were not substantially different from the typical values observed in temperate studies. However, Zn transfer factors for plants grown on both these tropical soils were greater than for soils in temperate climates (by more than an order of magnitude). This may be

  12. Transfer and translocation of {sup 241}Am, {sup 239}Pu, {sup 137}Cs and {sup 85}Sr after partial foliar contamination of bean plants

    Henner, P.; Colle, C.; Morello, M. [CEA Cadarache (DEI/SECRE/LRE), Laboratory of Radioecology and Ecotoxicology, Institute for Radioprotection and Nuclear Safety, 13 - Saint-Paul-lez-Durance (France)

    2004-07-01

    Bean plants at the flowering development stage were contaminated by soaking their two first leaves for 3 hours in a solution containing one of the actinides {sup 241}Am or {sup 239}Pu, or both {sup 137}Cs and {sup 85}Sr. The aim of the study was to assess the adequacy of using the values of Cs/Sr for the foliar transfer parameters of transuranic actinides, as used for example in the ASTRAL code to calculate the contamination of agricultural products after a nuclear accident. Secondly, these experiments were launched to tentatively determine specific values for the foliar transfer parameters for Am and Pu, despite technical limitations due to high radiotoxicity of these isotopes which prevented the contamination of the whole foliage of bean plants. Cs and Sr were used to compare the results with those obtained with other modes of contamination, by dry deposition of aerosols for example. Results showed that the soaking protocol was adequate to compare the foliar transfer of various radionuclides, although it should be difficult to provide specific values because of partial contamination of the foliage. Foliar transfer factors, expressed as Bq.kg{sup -1}{sub dw} {sub pods}/Bq.L{sup -1}{sub solution} (2.5x10{sup -2}) and translocation factors, dimensionless, (2.3x10{sup -3}) for Am and for Pu (1.5x10{sup -3} and 7.5x10{sup -5} respectively), compared to those for Sr (respectively 3.6x10{sup -3} and 5.9x10{sup -4}) and for Cs (respectively 2.9x10{sup -1} and 1.3x10{sup -1}), were studied using this procedure. Transfer and translocation factors for Am were significantly higher than those for Sr, but were smaller than those for Cs. Therefore, Am can be classified as a medium mobile radionuclide in plant. Transfer and translocation of Pu were significantly lower than these for Sr and for Am. Besides, the transfer and translocation factors of Am and Pu only differed from one order of magnitude or less from the one of Sr, which could be in the usual range of variation

  13. Effect of 60Co-gamma whole-body irradiation on serum amylase level

    Changes of serum amylase activity in rats, after several doses of acut 60Co-gamma irradiation as a function of time were investigated. These changes proved to be of no diagnostic value in early radiation damage. (author)

  14. Monte Carlo calculation of 60Co γ-ray's albedo-dose rate from the air

    The Monte Carlo calculation of 60Co γ-ray's albedo-dose rate from the air is reported. A formula is presented with which the relations of the albedo-doserate with some parameters are simulated and fitted

  15. Bioremediation of 60Co from simulated spent decontamination solutions of nuclear power reactors by bacteria

    The spent decontamination solutions generated from nuclear power reactors contain radionuclides of cobalt (60Co, 56Co and 57Co) along with a large excess (105) of non-radioactive metal ions (Fe, Ni and Cr). Our previous studies demonstrated that bioremediation of 60Co from simulated effluents using fungal biomass can provide an alternative to conventional ion exchangers. In this study, we used several bacteria to further improve the process of bioremediation by decreasing biomass requirement and treatment period. Further, metabolite activation in specific bacterial species resulted in enhanced bioremediation of 60Co from simulated effluent. Optimization of conditions in simulated effluent for the eight bacterial species to accomplish maximum 60Co removal is discussed. (author)

  16. Manufacture of 60Co source irradiation facility and measurement of radiation filed

    60Co source radiation facility is an important equipment to produce reference radiation filed, according to national standard, the scattered dose rate must be less than 5% of the total dose rate in the reference radiation filed. Scattered radiation contribution and uniformity of reference radiation field are important parameters to describe the radiation performance of 60CO source irradiation device, Monte Carlo method was used to study the scattered radiation and uniformity of the reference radiation filed to provide theoretical basis for the design of 60CO source irradiating device in order to avoid economic losses caused by design mistakes. When 60CO source irradiating device was manufactured, PTW ionization chamber was used to measure the irradiation field. The results showed that the scattered radiation and uniformity of the radiation filed were in good agreement with the simulation results. The radiation performance met the design requirements. (authors)

  17. Histological variations in liver of freshwater fish Oreochromis mossambicus exposed to 60Co gamma irradiation

    The irradiation effect of 60Co at the three dose level of 3 mGy, 30 mGy and 300 mGy on the histology of liver of the freshwater fish Oreochromis mossambicus was investigated. The liver of O. mossambicus was dissected out and processed for light microscopy studies. 60Co exposed O. mossambicus were found to result in several alterations in the histoarchitecture of liver. The alterations included mild congestion of blood vessels, structural alteration, cellular swelling, vacuolation and necrotic liver cells, indicating a definite response to 60Co irradiation. The results suggest that the liver of O. mossambicus exposed to 60Co were structurally altered with increasing dose levels. It is to record that alteration in the liver does not affect the physiology, behaviour or lethality of the individuals. Self regulating mechanisms would have influenced the liver to remain sustained. To confirm the same further studies in the direction by increasing dose level is required. - Highlights: ► Fish Oreochromis mossambicus irradiated to the dose of 3 mGy, 30 mGy and 300 mGy. ► Histoarchitecture of liver altered with increasing dose levels of 60Co. ► Alteration in the liver does not affect the physiology, behaviour or lethality. ► Self regulating mechanisms might have prevented from Lethality. ► HSI index value for exposed group reported (60Co.

  18. Mechanisms of60Co uptake and loss by Scenedesmus obliquus and transfer to two benthic organisms

    The affinity of Scenedesmus obliquus for 60Co has been confirmed under various experimental conditions allowing for the age of cultures, the physiological state of the cells, the radioactivity level and stable cobalt concentration in the medium, and the acute or periodic nature of the contamination. The dry weight 60Co concentration factor may reach 4x104 in LCO culture medium and is about 104 in natural water. 60Co uptake by algae is a 95% passive phenomenon, initiated by radionuclide absorption on the cell walls and followed by intracellular diffusion in accordance with Fick's law. From the initial cationic form, radiocobalt develops anion forms at a rate proportional to the algal biomass, resulting in lower contamination of old and dense cultures. After transfer in natural or artificial nonradioctive medium, 60Co is eliminated by Scenedesmus obliquus, mainly as Co2+ ions, according to a two-phase exponential process with two biological half-lives. The study of radioactive cobalt transfer from algae to gammarids and to midge larvae reveals the extend to which phytoplankton predominate over water and sediment in contaminating these two organisms. The total 60Co uptake depends significantly on whether the cells are incorporated in or deposited on the sediment. No biomagnification phenomenon of the radionuclide was found in any case, as the transfer factor was less than 1. Depuration of 60Co by organisms involved a two-phase exponential process regardless of whether uptake occured directly or from food. The presence of sediment appears to reduce the 60Co desorption rate, but from 85 to 95% of the initial quantity is eliminated. This percentage does not depend on the transfer pathway or the presence of organic matter, and indicates very slight assimilation of radiocobalt ingested with algal cells

  19. Comparative uptake from sea water and tissue distribution of 60Co in marine mollusks

    Five different species of marine mollusks, Mytilus galloprovincialis Lmk., Tapes decussatus L., Cerastoderma (Cardium) edule (L.), Donax vittatus (da Costa) and Patella vulgata L., were exposed to 60Co-labelled sea water under laboratory conditions. After a 1-mo exposure, tested species reached different whole-body 60Co concentration factors (CF) over radioactive sea water of 73 +/- 27, 22 +/- 10, 84 +/- 25, 6.3 +/- 1.4 and 31 +/- 10, respectively, which are not dependent upon the size of mollusks. Equations for the experimental uptake curves, obtained using a multi-exponential model, indicate that 60Co uptake by mollusks involves two or three compartments, according to the species. In all species, the larger compartments turn over with long biological half-lives, dependent upon species. At the beginning of the experiment, 60CoCl2 added to sea water was mainly in cationic forms. These forms were progressively converted into anionic plus neutral forms most likely due to complex formation with organic ligands. With time this physico-chemical evolution had a lowering effect on 60Co bioaccumulation by mollusks. Analysis of 60Co in tissues revealed that Donax shell and mantle do not accumulate the radionuclide in great quantities, generating the low whole-body concentration factor found. In contrast, shell and mantle from all other species displayed variable but high CFs. Shell by itself accounts for more than half of the 60Co whole-body burden. Among soft tissues, gills and viscera displayed the highest CF and muscle the lowest. From these experiments, one may conclude that significant differences among species do exist regarding Co bioaccumulation potential

  20. Comparative uptake from sea water and tissue distribution of 60Co in marine mollusks

    Carvalho, F.P.

    1987-07-01

    Five different species of marine mollusks, Mytilus galloprovincialis Lmk., Tapes decussatus L., Cerastoderma (Cardium) edule (L.), Donax vittatus (da Costa) and Patella vulgata L., were exposed to /sup 60/Co-labelled sea water under laboratory conditions. After a 1-mo exposure, tested species reached different whole-body /sup 60/Co concentration factors (CF) over radioactive sea water of 73 +/- 27, 22 +/- 10, 84 +/- 25, 6.3 +/- 1.4 and 31 +/- 10, respectively, which are not dependent upon the size of mollusks. Equations for the experimental uptake curves, obtained using a multi-exponential model, indicate that /sup 60/Co uptake by mollusks involves two or three compartments, according to the species. In all species, the larger compartments turn over with long biological half-lives, dependent upon species. At the beginning of the experiment, /sup 60/CoCl2 added to sea water was mainly in cationic forms. These forms were progressively converted into anionic plus neutral forms most likely due to complex formation with organic ligands. With time this physico-chemical evolution had a lowering effect on /sup 60/Co bioaccumulation by mollusks. Analysis of /sup 60/Co in tissues revealed that Donax shell and mantle do not accumulate the radionuclide in great quantities, generating the low whole-body concentration factor found. In contrast, shell and mantle from all other species displayed variable but high CFs. Shell by itself accounts for more than half of the /sup 60/Co whole-body burden. Among soft tissues, gills and viscera displayed the highest CF and muscle the lowest. From these experiments, one may conclude that significant differences among species do exist regarding Co bioaccumulation potential.

  1. 60Co deposition on carbon-steel structural materials after seawater infiltration in BWR plant

    Seawater infiltration occurred during shutdown of the Hamaoka Unit 5 (H-5). Chloride ion (Cl-) is known to affect the corrosion behavior of carbon steel, and it may change the properties of the oxide film formed on the surface. 60Co deposition in high-temperature water is strongly related to the oxide film properties, and any change in the properties may affect the 60Co deposition after the plant is restarted. This paper shows the results of 60Co deposition tests of carbon steels under simulated H-5 water conditions. Specimens for the 60Co deposition tests were prepared in three steps, which simulated the conditions of normal plant operation, seawater infiltration, and chemical decontamination after the infiltration. The first step was a prefilming step under Normal Water Condition (NWC). The second step included two different conditions: seawater infiltration and keeping after infiltration. Prefilmed specimens were immersed in 450 ppm Cl- diluted artificial seawater at 513 K for 24 hours. Following that, the specimens were immersed in 50 ppm Cl- diluted artificial seawater at 323 K for 100-500 hours. During the second step, the prefilming oxide (NiFe2O4) flaked off in spots. In the third step, the oxide remaining on some specimens after the second step was removed chemically. The three types of prepared specimens, that is, a prefilmed specimen, an exposed specimen, and an oxide-removed specimen, were used for the 60Co deposition tests using 0.015 Bq/cm3 60Co solution for 500 or 1000 hours under NWC conditions. After the deposition tests, the 60Co activity was measured with a Ge detector. From the results of the deposition test, at the spots where flaking occurred in the second step, only loose hematite was formed, and generation of a new protective film was not observed. The amount of 60Co deposited on the exposed specimen was more than that on the prefilmed and oxide-removed specimens. The simulated infiltrating conditions inhibited the regeneration of a

  2. Adsorption kinetic regime of cocrystallization. The system ZnC/sub 2/O/sub 4/x2H/sub 2/O-/sup 54/MnC/sub 2/O/sub 4/x2H/sub 2/0. 1. Adsorption and surface cocrystallization of /sup 54/Mn

    Melikhov, I.V.; Berdonosova, D.G.; Pencheva, Zh.

    1984-01-01

    The ZnC/sub 2/O/sub 4/x2H/sub 2/O finely divided deposit surface properties have been investigated by the methods of electron microscopy, gas adsorption and isotopic exchange in /sup 65/Zn /sup 54/Mn adsorption from aqueous solutions with Mn/sup 2 +/ initial concentration of 4x10/sup -6/ - 5x10/sup -4/ mol/l has been studied using the same deposit. Characteristic frequencies of Zn/sup 2 +/ and Mn/sup 2 +/ transitions between layers, zinc and manganese oxalates masses in the first and second layers and local coefficients of cocrystallization of manganese and zinc oxalates in near-surface layers (lambda=0.38+-0.05 and lambda/sub 2/=0.17+-0.04) have been calculated using representation on successive Zn/sup 2 +/ and Mn/sup 2 +/ transition to three near-surface monolayers and on reverse translation motion. A formula for the connection of lambda sub(..gamma..) coefficients (is a number of the surface layer) with a layer-to-surface distance has been derived. A possibility of the forecast of a dependence of effective cocrystallization coefficient of impurity with growing crystals on crystal growth rate has been revealed.

  3. Monte Carlo dosimetry for 125I and 60Co in eye plaque therapy

    Monte Carlo calculations of radiation dosimetry using morse code are performed for 125I and 60Co point sources in a cylindrical head phantom that simulates the geometry of eye plaque therapy for choroidal melanoma. We obtain the dose variation in the eye at submillimeter intervals over distances as close as 1 mm and up to 2.5 cm from the source. The calculations for 125I are performed for the phantom media of water, protein, and a homogenized protein--water mixture simulating the composition of the eye. Relative dose functions for 125I for these phantom media are fitted to second-degree polynomials. Agreement is found with published results. The relative dose function for 60Co at eye position in the water head phantom is fitted to a third-degree polynomial and compared with that for 60Co at the center of a large water sphere. A boundary effect due to the head phantom--air interface on the dose distribution for 60Co is demonstrated. The dose falloff with distance is faster for the eye geometry compared with the bulk geometry. We also show that the relative dose distributions within the tumor are comparable for 125I and 60Co by comparing their relative dose functions. This result is consistent with the success of clinical trials of large melanoma treatments with 125I plaques

  4. Different gamma ray (60 Co) dose effects on Sorghum genotype germination

    In agriculture, applying irradiation is a very valuable way of obtaining vegetable products for human and animal consumption. Cobalt-60, one of the main sources of gamma-rays, is considered an important tool in plant breeding programs, which have the objective of promoting genetic variability of cultivars with resistance to adverse environments. In this research, the effects of different 60Co doses on germination vigor and seed germination velocity of forage sorghum genotypes were evaluated. The study was carried out at the IPA (Empresa Pernambucana de Pesquisa Agropecuaria) in Recife, Pernambuco, Brazil. The work was installed in germination boxes, following laboratory recommendations. Thus, a experiment involving three sorghum genotypes (IPA 467-4-2, IPA 02-03-01, and Sudan 4202), five 60Co doses (Zero, 150, 300, 350, and 400 Gy), was set up. The sees were irradiated before the beginning of the experiment being exposed to gamma rays from a 60Co-source (cobalt irradiator) at DEN (Nuclear Engineering Department) of the UFPE (Pernambuco Federal University), Brazil. The work also had the objective of evaluating the sorghum genotypes x 60Co dose interaction. The main results obtained showed that the sorghum genotype IPA 02-03-01 presented the greatest values of germination and vigor percentages, and seed germination velocity, when compared to the others evaluated, on 350 and 400 Gy of 60Co doses. (author)

  5. Atomic-resolution studies of epitaxial strain release mechanisms in La_(1.85)Sr_(0.15)CuO_(4)/La_(0.67)Ca_(0.33)MnO_(3) superlattices

    Biskup Zaja, Nevenko; Das, S.; González-Calbet, J. M.; Bernhard, C.; Varela del Arco, María

    2015-01-01

    In this paper we present an atomic-resolution electron microscopy study of superlattices (SLs) where the colossal magnetoresistant manganite La_(0.67)Ca_(0.33)MnO_(3) (LCMO) and the high critical temperature superconducting cuprate La_(1.85)Sr_(0.15)CuO_(4 (LSCO) are combined. Although good quality epitaxial growth can be achieved, both the choice of substrate and the relatively large lattice mismatch between these materials (around 2%) have a significant impact on the system properties...

  6. Superconductivity in bulk and thin films of La/sub 1. 85/Sr/sub 0. 15/CuO/sub 4-//sub delta/ and Ba/sub 2/YCu/sub 3/O/sub 7-//sub delta/

    Moorjani, K.; Bohandy, J.; Adrian, F.J.; Kim, B.F.; Shull, R.D.; Chiang, C.K.; Swartzendruber, L.J.; Bennett, L.H.

    1987-09-01

    A laser-ablation technique was used to deposit thin films from the bulk oxides La/sub 1.85/Sr/sub 0.15/CuO/sub 4-//sub delta/ and Ba/sub 2/YCu/sub 3/O/sub 7-//sub delta/, whose superconductivity properties were investigated by dc resistivity, complex ac susceptibility, and microwave response. The latter technique was employed to establish that the thin films have superconducting regions with properties similiar to the bulk materials.

  7. Magnetic pair-breaking effects: Moment formation and critical doping level in superconducting La1.85Sr0.15Cu1-xAxO4 systems (A=Fe,Co,Ni,Zn,Ga,Al)

    We have conducted a systematic study on the effect of Cu-site doping in La1.85Sr0.15CuO4 system. The relations between Tc and doping level as well as the critical doping levels xc have been determined accurately for the Fe-, Co-, Ni-, Zn-, Ga-, and Al-doped systems. Every dopant either carries an intrinsic magnetic moment or induces a net moment on the Cu-O2 plane. The size of the moment is correlated with the suppression of superconductivity, consistent with the magnetic-pair-breaking effect. The ground states of the dopants have also been determined

  8. Characterization of 60Co dose distribution using BEAMnrc Monte Carlo code

    In this study BEAMnrc based on EGSnrc as Monte Carlo code has been used for modeling and simulating 60Co machine in radioisotope centre of Khartoum (RICK), Two fields size ( 5 cm x 5 cm and 35 cm x 35 cm), were been studied, to define the characterization of 60Co machine and to investigate the effect of increasing the surface to skin distance (SSD) on the 60Co machine properties, e.g.; beam profile and percentage depth dose (Pdd). For the narrow field size there is a small change observed in the curves representing beam profile and the percentage depth dose when increasing the distance by 5 cm, for the wide fi ld size there relatively clear different in curves. The study results been compared with other previous studies and clear consistence observed. (Author)

  9. Changes of collagen metabolism induced by 60Co γ-ray external irradiation

    Objective: To study the changes and molecular mechanism of collagen metabolism induced by 60Co γ-ray external irradiation of local tissues. Methods: After the hip skin of rabbits was irradiated with 60Co γ-rays, the changes of collagen metabolism and collagen contents of the rabbits' skin of different sex groups were determined. Results: The γ-rays decreased the soluble collagen contents (especially type III) and increased the activity of MMPs in local tissues. Although the radiation affected the contents of serum SOD, 5-HT, and LPO, its influence on the contents in local tissues was not remarkable. There were changes of collagen metabolism in local tissues after radiation injury, but no differences were found in SOD, 5-HT, LPO, and glucosamine of tissues. Conclusion: The main mechanism of skin burn induced by 60Co γ-rays may be that the changes of collagen metabolism bring about the pathological effect

  10. Soil to plant transfer of 137Cs and 60Co in Ferralsol, Nitisol and Acrisol

    In this study, soil to plant transfer factor values were determined for 137Cs and 60Co in radish (Raphanus sativus), maize (Zea mays L.) and cabbage (Brassica oleracea L. var. capitata) growing in gibbsite-, kaolinite- and iron-oxide-rich soils. After 3 years of experiment in lysimeters it was possible to identify the main soil properties able to modify the soil to plant transfer processes, e.g. exchangeable K and pH, for 137Cs, and organic matter for 60Co. Results of sequential chemical extraction were coherent with root uptake and allowed the recognition of the role of iron oxides on 137Cs behaviour and of Mn oxides on 60Co behaviour. This information should provide support for adequate choices of countermeasures to be applied on tropical soils in case of accident or for remediation purposes

  11. Quality control and calibration of the ZEUS forward and rear calorimeters with 60Co sources

    We present the motivation for and the design of a mobile 60Co source system used as part of the quality control and calibration monitoring scheme for the ZEUS calorimeters. A 2 mCi 60Co source is pushed by a computer controlled drive mechanism through guide tubes which extend into the calorimeter. Measurements of induced photocurrents as a function of the source position allow checks on the calorimeter response. We present results obtained during the initial scan of all 1024 towers of the forward and rear calorimeter modules. (orig.)

  12. Phonon, magnon and electron contributions to low temperature specific heat in metallic state of La0.85Sr0.15MnO3 and Er0.8Y0.2MnO3 manganites

    Dinesh Varshney; Irfan Mansuri; E Khan

    2013-12-01

    The reported specific heat \\ () data of the perovskite manganites, La0.85Sr0.15MnO3 and Er0.8Y0.2MnO3, is theoretically investigated in the temperature domain 3 ≤ ≤ 50 K. Calculations of \\ () have been made within the three-component scheme: one is the fermion and the others are boson (phonon and magnon) contributions.Lattice specific heat is well estimated fromthe Debye temperature for La0.85Sr0.15MnO3 and Er0.8Y0.2MnO3 manganites. Fermion component as the electronic specific heat coefficient is deduced using the band structure calculations. Later on, following double-exchange mechanism the role of magnon is assessed towards specific heat and found that at much low temperature, specific heat shows almost T3/2 dependence on the temperature. The present investigation allows us to believe that electron correlations are essential to enhance the density of states over simple Fermi-liquid approximation in the metallic phase of both the manganite systems. The present numerical analysis of specific heat shows similar results as those revealed from experiments.

  13. Effect of 60Co γ-ray irradiation on salmonella in high immunity egg yolk

    Salmonella were inoculated into the yolk and irradiated with different dose of 60Co γ-ray. The results show that 3 kGy irradiation dose can kill all Salmonella in the yolk and D10 value of Salmonella in the yolk is 0.36-0.46 kGy

  14. A description of 60Co gamma irradiation facilities in the Radiation Biology and Health Physics branch

    The Radiation Biology and Health Physics Branch manages three 60Co irradiation facilities, to (Gammabeam 150C, Gammacell 200 and Gammacell 220) provide a range of dose rates suitable for variety of applications. This report describes the physical characteristics of the facilities, a description of the dosimetry and operating procedures. (author). 6 refs., tabs., figs

  15. The measurement of some signals for control system of 60Co scan system for freight train

    The 60Co Scan system for Freight Train has an automatic inspection flow, so it is very crucial that the measurement of the signals for the automatic control system. In this paper, we mainly introduce the identification of the intervals between two freight train carriage, the measurement of the train speed, and identification of freight train

  16. Design and realization of the review station of 60Co train inspection system

    The author illustrates design and realization of the review station software of 60Co train inspection system (TCT-SCAN). The software have two remarkable functions: processing images of carriages and accessing information of inspection, which are provided by two processes respectively. The communication between processes is realized by memory-mapped file

  17. Mutant in tobacco anther culture induced by 60Co γ-rays

    The tobacco anthers at uninucleate eccentric stage were irradiated by 60Co γ-rays for the purpose of inducing desirable mutants. The results showed that the induction frequency of plantlets increased following 1kR of 60Co γ-rays treatment. However, the time of plantlet induction was delayed and the percentage of responding anthers as well as the number of plantlets induced per anther significantly decreased after 3kR of 60Co γ-ray radiation which was considered as a semilethal exposure. The plantlet numbers induced per anther were extremely low following 6kR of 60Co γ-ray radiation. A white flower mutant appeared in the induced progenies. The tobacco leaf quality of this mutant were significantly improved as compared with its parental line. The mutant line has been tested and proved to have commercial value though the resistance to the black shank of tobacco slightly decreased as compared with the parental line

  18. Monte Carlo Dosimetry of the 60Co BEBIG High Dose Rate for Brachytherapy.

    Luciana Tourinho Campos

    Full Text Available The use of high-dose-rate brachytherapy is currently a widespread practice worldwide. The most common isotope source is 192Ir, but 60Co is also becoming available for HDR. One of main advantages of 60Co compared to 192Ir is the economic and practical benefit because of its longer half-live, which is 5.27 years. Recently, Eckert & Ziegler BEBIG, Germany, introduced a new afterloading brachytherapy machine (MultiSource®; it has the option to use either the 60Co or 192Ir HDR source. The source for the Monte Carlo calculations is the new 60Co source (model Co0.A86, which is referred to as the new BEBIG 60Co HDR source and is a modified version of the 60Co source (model GK60M21, which is also from BEBIG.The purpose of this work is to obtain the dosimetry parameters in accordance with the AAPM TG-43U1 formalism with Monte Carlo calculations regarding the BEBIG 60Co high-dose-rate brachytherapy to investigate the required treatment-planning parameters. The geometric design and material details of the source was provided by the manufacturer and was used to define the Monte Carlo geometry. To validate the source geometry, a few dosimetry parameters had to be calculated according to the AAPM TG-43U1 formalism. The dosimetry studies included the calculation of the air kerma strength Sk, collision kerma in water along the transverse axis with an unbounded phantom, dose rate constant and radial dose function. The Monte Carlo code system that was used was EGSnrc with a new cavity code, which is a part of EGS++ that allows calculating the radial dose function around the source. The spectrum to simulate 60Co was composed of two photon energies, 1.17 and 1.33 MeV. Only the gamma part of the spectrum was used; the contribution of the electrons to the dose is negligible because of the full absorption by the stainless-steel wall around the metallic 60Co. The XCOM photon cross-section library was used in subsequent simulations, and the photoelectric effect, pair

  19. Systematic study of (La sub 1 minus x Gd sub x ) sub 1. 85 Sr sub 0. 15 CuO sub 4 (0 le x le 1): Structure, superconductivity, resistivity, and magnetic properties

    Xiao, G.; Cieplak, M.Z.; Chien, C.L. (Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218 (US))

    1989-09-01

    A room-temperature structural phase diagram has been determined in (La{sub 1{minus}{ital x}}Gd{sub {ital x}}){sub 1.85}Sr{sub 0.15}CuO{sub 4} system (0{le}{ital x}{le}1). There exist three stable phases ({ital T}, {ital T}{sup *} and {ital T}{prime}), in which the local Cu-O unit is an octahedron, a pyramid, and a square, respectively. The Jahn-Teller distortion is reduced in the order of {ital T}, {ital T}{sup *}, and {ital T}{prime}. For each phase, there is a solubility region. No magnetic ordering is found in the {ital T} and {ital T}{sup *} phase, both of which exhibit paramagnetism with a constant Gd magnetic moment consistent with that of Gd{sup 3+}. In Gd{sub 2}CuO{sub 4} and Gd{sub 1.85}Sr{sub 0.15}CuO{sub 4}, the initial susceptibility indicates a Neel state in the Cu-O{sub 2} plane at {ital T}{sub {ital N}}=285 K and another magnetic transition at low temperature. {ital T}{sub {ital N}} is not sensitive to the Sr doping at all, indicating that extra holes cannot be doped onto the Cu-O{sub 2} plane. While the {ital T}{sup *} and {ital T}{prime} phases are insulating, exhibiting a variable-range hopping behavior, the Gd-doped (La{sub 1{minus}{ital x}}Gd{sub {ital x}}){sub 1.85}Sr{sub 0.15}CuO{sub 4} ({ital x}{le}0.1) is superconducting with {ital T}{sub {ital c}} reducing with increasing Gd concentration. The suppression of {ital T}{sub {ital c}} is not due to a variation of the electron-boson coupling strength which remains unchanged in the system, but correlates closely with the low-temperature resistivity anomaly. Such an anomaly can be best described by a logarithmic temperature dependence.

  20. Comparison of dosimetric standards of Canada and France for photons at 60Co and higher energies

    We report the results of a comparison of the dosimetric standards of Canada and France for photon beams at 60Co and a few higher energies. The present primary standard of absorbed dose to water for NRC, Canada is based on measurements made with a sealed water calorimeter. The corresponding standard of the LNHB, France is based on measurements made with a graphite calorimeter at 60Co energy and transferred to absorbed dose to water for 60Co and higher-energy photon beams using both ion chambers and Fricke dosemeters as transfer instruments. To make this comparison, we used three graphite-walled NE2571 Farmer chambers. The absorbed dose to water determined by the LNHB was greater than that determined by NRC by 0.20% at 60Co energy. This difference is not significant given the uncertainties on the standards. In order to do the comparison for higher-energy photons, we interpolated the NRC data set at the beam qualities used at the LNHB. When %dd(10)x is used as the method of specifying beam quality, the determination of absorbed dose to water by the LNHB is about 0.2% greater than that determined by NRC and consistent with the results at 60Co. However, when using TPR20,10 as the beam quality specifier, the LNHB determination is greater than the NRC's determination by 0.8% and 1.2% at 12 and 20 MV respectively. This discrepancy, which systematically increases with increasing energy, eventually exceeds the uncertainties in the ratio of the standards, estimated to be 0.7%. This underscores the importance of selecting the method of specifying beam quality, either %dd(10)x or TPR20,10, at least for the 'soft' beams used by NRC in this comparison. In the case of the air kerma standards, which were also compared at 60Co energy, the LNHB determination was greater than NRC's by 0.14%, which is not significant given the uncertainties on the standards. (author)

  1. Seed germination of peanuts irradiated with cobalt ({sup 60}CO); Germinacao de sementes de amendoim irradiadas com cobalto ({sup 60}Co)

    Alves, Niedja Marrize C.; Almeida, Francisco de Assis C.; Gomes, Josivanda P.; Pessoa, Elvira B., E-mail: niedjamarizze@yahoo.com.b, E-mail: josivanda@deag.ufcg.edu.b, E-mail: elvirabe@gmail.co [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Dept. de Engenharia Agricola; Leal, Artur S. Cavalcanti, E-mail: arturcleal@yahoo.com.b [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Dept. de Engenharia de Materiais

    2010-07-01

    This work was realized to evaluate the effect of gamma irradiation ({sup 60}Co) at doses 0, 0.50, 1.00, 1.50, 2.00, 2.50, 3.00 and 4.00 kGy, on germination of seeds of peanut, cultivar BR1. Irradiation Department of Nuclear, UFPE, where he received after the irradiation, they were stored in packing of PET and polyethylene braided with a time of 90 days. Through the results, obtained monthly, concluded that the dose of 0.5 kGy was effective in the germination of seeds of peanut, not affecting its power of germination and overcoming the witness within 30 to 60 days. (author)

  2. Cataract production in mice by fractionated doses of 12C particles or 60Co gamma radiation

    The objective of our study was to evaluate the sparing effects of long-term dose fractionation with high LET 12C ions and 60Co gamma radiation. Because cataract examinations could be performed nondestructively, mice dedicated to studies of life shortening and carcinogenic response to photons and heavy charged particles were available for study. The project's staffing was such that slit-lamp biomicroscopic examinations could be performed only on CB6F1 male mice that received single or fractionated doses of 225 MeV/amu 12C ions and animals that received a single or fractionated dose of 60Co gamma radiation of 4.17 Gy. A total of 24 fractionated doses were administered weekly. Using a semiquantitative scoring system, the severity of cataract response was evaluated at three sample times following the single dose or first fractionated dose

  3. Analysis of the microbial growth in {sup 60}Co {gamma}-irradiated foods by calorimetry

    Furuta, Masakazu; Hayashi, Toshio [Osaka Pref. Univ., Research Institute for Advanced Science Technology, Sakai, Osaka (Japan); Hamasaki, Koji; Wirkner, Sandra; Constantinoiu, Elena; Takahashi, Katsutada [Osaka Pref. Univ., College of Agriculture, Sakai, Osaka (Japan)

    2002-09-01

    Using a heat conduction calorimeter equipped with 24 sample units the heat evolutions from growing {sup 60}Co {gamma}-irradiated bioburden of black pepper seeds and frozen beef were detected in the form of growth thermograms. {sup 60}Co {gamma}-irradiation affected the growth pattern in which a dose-dependent reduction of the growth rate constant was observed together with the retardation in growth, indicating a combination of bactericidal and bacteriostatic effects. We successfully determined the minimal inactivation doses for the two food samples using the relationship between the irradiation dose and the retardation in growth t{sub {alpha}}, or the growth rate constant {mu} obtained from the growth thermograms. These results strongly suggested the possibility of calorimetry as measure of predictive microbiology in food irradiation. (author)

  4. Effect of 60Co-γ ray irradiation on green coffee beans, 1

    Green coffee beans were irradiated with 60Co-γ rays at doses of 0, 0.05, 0.5, 5.0 and 10.0 Mrad and the changes of general components in green and roast coffee beans were investigated together with those of the organoleptic properties of roast beans during storage according to the cup testing. In case of Brazil santos beans, irradiation of some 0.05 Mrad 60Co-γ ray gave rather favourable mild flavour and no harmful influence on the quality of coffee, and moreover, would tend to extend the shelf life of roast beans. But influence of irradiation on the quality of coffee differed somewhat between two cultivars, Brazil santos and Colombia. (auth.)

  5. Removal of 60Co and 134Cs from radioactive process waste water by flotation

    The removal of 134Cs and 60Co from radioactive process waste water using cetyl pyridinium chloride (CPC) as a collector and cobalt(II) hexacyanoferrate(II) as a precipitant for 60Co and sorbent (ion exchanger) for 13'4Cs was intensively investigated and the best removal conditions could be established. The results indicate that under the optimum conditions removals higher than 96% and 97% could be achieved for Co(II) and Cs(I), respectively. Cobalt(II) hexacyanoferrate(II) was found to have high affinity for cesium and can preferentially remove it in presence of relatively high amounts of other alkali or alkaline earth cations. A two-stage flotation process was successfully tested for the removal of both Cs(I) and Co(II) from waters containing both cations. (author) 59 refs.; 8 figs.; 2 tabs

  6. National comparison of activity measurements of 131I, 60Co, and 133Ba in Indonesia

    National comparisons of radioactivity measurements of 131I and 60Co (in 2010) and of 133Ba (in 2011) were carried out within the framework of the National Radiation Metrology Laboratory Program of Indonesia, coordinated by PTKMR-BATAN. Eleven laboratories took part in the comparison, and all measurements were made using gamma spectrometry, on point sources with an activity between 2000 Bq and 6000 Bq. Several laboratories reported values which were more than 10% different from the reference value for 131I and 133Ba. Possible reasons for these differences are discussed. This program will be continued with other radionuclides to maintain and control quality assurance for the local laboratories. - Highlights: • PTKMR-BATAN coordinated national comparison of 131I, 60Co and 133Ba. • Eleven laboratories took part in the comparison. • All measurements were done using gamma spectrometry methods. • For 131I and 133Ba, 3 laboratories have more than 10% difference from reference laboratory value

  7. Dosimetric response of united, commercially available CTA foils for 60Co gamma rays

    The usefulness of two kinds of untinted CTA foils: Fuji CTR-125 dosimetric foil and technical CTA-T foil, produced by 'Zaklady Chemiczne, 'Gorzow Wielkopolski' as support for light-sensitive layers of amateur photo-films, for 60Co gamma ray dosimetry was investigated. In spite of rather bad physical parameters of the technical foil (spread of foil thickness, high and different initial absorbance) the dosimetric response of both foils for 60Co gamma rays was similar. The CTA-T foil can be used for routine dosimetry providing that dosimetric signals have to be calculated exactly as recommended by the ASTM (American Society for Testing and Materials) standard, i.e. as the difference of absorbance of irradiated and (the same) non-irradiated foil. Any other approach may lead to high errors of dose evaluation. The last is true also for other CTA foils, especially after long self-life. (author)

  8. The teratogenic effects of low dose 60Co γ-rays on the early pregnant rats

    The pregnant Wistar rats were exposed to 0.5 Gy and 1.0 Gy 60Co γ-rays at the 9th day after conception. The results: 60Co γ-rays at dose of 1.0 Gy could induced many defects: excenphaly, hydrocephalus, gastroschisis, cleft palate and cleft lip, anophthalmia, microphthalmia, shorten tail and absent tail in surviving fetuses. The growth retardation was found from the parameters of fetal weight, height, head circle and development of skeleton. In the group of radiation dose 0.5 Gy, only hydrocephalus, absent tail and growth retardation of skeleton appeared. The results suggest that low-dose exposure in the early pregnant rats can induce fetal defects and growth retardation. The probable mechanism of teratogen and growth retardation was discussed. The cAMP levels of brain and liver of rat fetuses were reported

  9. SV40 DNA amplification and reintegration in surviving hamster cells after 60Co γ-irradiation

    SV40-transformed Chinese hamster embryo cells were exposed to 60Co γ-irradiation and the fate of the integrated SV40 sequences was pursued over a period of 20 days following radiation exposure. As shown by colony hybridization, integrated SV40 sequences were amplified in surviving and non-surviving cells. At later times, however, clonal sublines of surviving cells grown for 20-30 cell generations after irradiation had lost most of their amplified SV40 copies but showed altered restriction fragment patterns indicating reintegration of SV40 sequences at new sites of the hamster genome. This suggest that 60Co γ-irradiation can generate mutations by inducing over-replication of chromosome segments that are then substrates of enzymatic rearrangements. (author)

  10. Long-term clearance of accidentally inhaled 60Co aerosols in humans

    Long-term body retention was measured on six workers inhaling 60Co aerosols incidentally during manipulation with a high activity 60Co source. An improved whole body counter technique and calibration provided good conditions to follow the body clearance over 4 years. A two-detector profile scanning arrangement was used to measure the activity distribution 'in vivo' over the lung region. The observed whole body retention followed a two-exponential time function between 10-1500 days. The consistency of the measured retention pattern with ICRP inhalation model was investigated assuming different aerosol size distributions. A possible extension of ICRP lung model is proposed to take into account the actual pulmonary lung clearance determined individually. (R.P.) 29 refs.; 15 figs.; 6 tabs

  11. Experiments for inactivation of mycoplasms and bacteria in calf sera, using 60Co irradiation

    The use of 60Co gamma radiation to inactivate mycoplasms in calf serum, newborn calf serum, and fetal calf serum is reported. A dose of 3 kGy, independent of dose rate, was found to be sufficient for inactivation in the above sera of several mycoplasms, including Acholeplasma laidlawii, Mycoplasma orale, M. arginini, M. hyorhinis, and M. bovis. The critical dose proved to be at 2 kGy. No difference was found to exist between the above species in susceptibility to irradiation in diluted sera (50% and 10% in Eagle MEM). Sensibility of wild mycoplasm strains was found to be identical with that of laboratory strains. Hence, 60Co gamma irradiation of sera appears to be a safe method by which to make sera free of mycoplasms. Bacillus subtilis in calf serum was inactivated by doses above 18 kGy, with the critical dose being 15 kGy. (author)

  12. The realization of 60Co container inspection system's check-in station

    The functional design and realizing mode of the check-in station software of 60Co container inspection system are illustrated. Check-in station plays an important role in 60Co container inspection system. It undertakes the tasks of inputting the container's relative information, flow control of containers waiting for inspections and the information transfer. Of all the information of check-in station inputs, the customs declaration or the encasement declaration is the main information to be input. In this software, they are input by scanner and the control module of scanner is programmed according to Twain criterion. As Twain criterion is generally followed by image industry, this software has high generality and facility independence

  13. The effect of 60Co gamma radiation on human serum gamma-globulin

    The effect of 60Co gamma radiation on human serum gamma-globulin was studied in vitro experiments. Solutions of 0.5 percent gamma-globulin were exposed to 0.2, 0.5, 1.0 and 1.9 Mrad doses 60Co gamma irradiation. Experiments showed that electrophoretic mobility of serum gamma-globulin decreased after gamma irradiation. No significant change in gamma-globulin UV absorption spectrum was observed at 0.2, 0.5, 1.0 and 1.9 Mrad doses. Gamma-globulin becomes progressively less soluble in water as the radiation doses is increased. Radiation induced transformation into insoluble gamma-globulin agregates and scission products. (author)

  14. Doses in sensitive organs during prostate treatment with a 60Co unit

    Using thermoluminiscent dosimeters the absorbed dose in the bladder, rectum and thyroid have been evaluated when 200 cGy was applied to the prostate. The treatment was applied with a 60Co unit. A water phantom was built and thermoluminiscent dosimeters were located in the position where the prostate, bladder, rectum and thyroid are located. The therapeutic beam was applied in 4 irradiations at 0, 90, 180 and 270° with the prostate at the isocenter. The TLDs readouts were used to evaluate the absorbed dose in each organ. The absorbed doses were used to estimate the effective doses and the probability of developing secondary malignacies in thyroid, rectum and bladder. - Highlights: • The absorbed doses in the bladder, rectum and thyroid were measured. • Measurements were done during prostate treatment with a 60Co unit. • TLD100s in a water phantom were used. • The effective doses were also estimated

  15. Comparison of the electrodynamic properties of sintered YBa2Cu3O/sub 7-//sub y/ and La/sub 1.85/Sr/sub 0.15/CuO/sub 4-//sub y/

    The reflectivity in the superconducting and normal states of YBa2Cu3O/sub 7-//sub y/ has been reproduced with the effective-medium theory plus an anisotropic dielectric function and the Mattis-Bardeen conductivity with a gap value 2Δ/k/sub B/T/sub c/ = 2.5 to 2.7. We find that the lowest ir-active phonon polarized in the high-conductivity plane produces structure in the superconducting gap, the lowest-frequency phonon perpendicular to the plane is overdamped, and that the electronic susceptibility is more isotropic for YBa2Cu3O/sub 7-//sub y/ than for La/sub 1.85/Sr/sub 0.15/CuO/sub 4-//sub y/

  16. Monte Carlo simulation of a digital coincidence system applied to 60Co standardization

    The Laboratorio de Metrologia Nuclear (LMN) at the Instituto de Pesquisas Energeticas e Nucleares (IPEN) is developing a Digital Coincidence System (DCS), including the design of the proper acquisition electronics and analysis software. A brief discussion about the measurement methodology and the electronics operation is presented. This work is focused on the results of the designed software (the Monte Carlo simulation of 60Co decay data and the Coincidence Data Analysis), which are in good agreement with the experimental data. (author)

  17. Studies on bioaccumulation of 152Eu, 137Cs, 60Co by different algal genera

    In the present paper, the bioaccumulation of a mixture of potentially hazardous, long lived radionuclides 152Eu, 137Cs and 60Co by five algal genera of three different family, viz.: Lyngbya and Phormidium from cyanophyceae; Phizoclonium and Chaetomorpha from chlorophyceae and Catenella from rhodophyceae have been studied. Because of the long half life and high solubility, these radionuclides are considered the most hazardous in the nuclear spent fuel

  18. A positron 1D-ACAR spectrometer for the study of 60Co containing materials

    In order to study some micro-structural changes in irradiated nuclear reactor-pressure vessel steels using a positron annihilation technique, a new three-detector set-up, suitable for a positron 1-dimensional angular correlation of annihilation radiation (1D-ACAR) study of 60Co-containing materials, was developed. The design of the equipment as well as results from test measurements are described. (orig.)

  19. Image acquisition, transmission and assignment in 60Co container inspection system

    The author describes the data acquisition mode and image reconstruction method in 60Co container inspection system, analyzes the relationship between line pick period and geometry distortion, makes clear the demand to data transmitting rate. It discusses several data communication methods, draws up a plan for network, realizes automatic direction and reasonable assignment of data in the system, cooperation of multi-computer and parallel processing, thus greatly improves the systems inspection efficiency

  20. Immobilization of 60Co and 90Sr ions using red mud from aluminum industry

    Milenković Aleksandra S.; Smičiklas Ivana D.; Marković Jelena P.; Vukelić Nikola S.

    2014-01-01

    The removal of 60Co and 90Sr from the aqueous phase was tested using red mud - the fine grained residue from bauxite ore processing. This industrial waste represents a mixture of numerous minerals, mainly oxides and hydroxides of Fe, Al, Si, and Ti. Experiments were conducted as a function of contact time, pH, and pollutant concentrations. Kinetic data were well fitted with a pseudo-second order equation. The calculated rate constants and initial sorption r...

  1. A case study of medical intervention following intake of 60Co

    The present study is based on the follow up study of a case of 60Co internal contamination using whole body counting and bioassay analysis. The effect of medical intervention applied on the subject is studied. Medical intervention with D-penicillamine (250 mg x 4 daily) orally was administered from thirteenth day of initial exposure for about a fortnight, which showed reduction of activity present by 33.4% through urine. (author)

  2. Study on the possibility of using a 60 Co therapeutical unity in Intensity Modulated Radiotherapy (IMRT)

    With the increasing advances in complex treatment techniques, there is a tendency to obtain more sophisticated equipment to deliver the dose. The use of 3D conformal radiotherapy is now routine in many radiotherapy facilities as well as the utilization of intensity modulated radiotherapy (IMRT). Both are usually implemented using linear accelerators equipped with multi leaves collimators, which create the conformity and the fluence distributions required. However, the complexity of increasingly sophisticated equipment, such as linear accelerators, requires a frequent quality control of their operation, as well as a detailed and constant maintenance. Even carrying out these procedures, the accelerators may present technical problems interrupting for a long time a treatment using the IMRT technique. Despite the clear practical and technological advantages that linear accelerators have on 60Co irradiators, these devices occupy an important place in radiotherapy, mainly due to the low cost of equipment installation and maintenance when compared to those required by accelerators. Many radiotherapy facilities that work with IMRT have tele therapeutic isocentric 60Co units. In principle, such equipment would be able to be used for treatment with IMRT using compensating blocks to modulate the beam. This study investigates this possibility and shows that it is feasible. The comparison of treatment plans of a head-and-neck cancer and other of a cancer of the central nervous system, based on a 60Co irradiator and a Linac 2300 C/D, presented advantages for the 60Co irradiator. Furthermore; the delivery of dose obtained with the two systems showed themselves equivalent when compared to their respective plans. (author)

  3. Superconducting and normal-state properties of La/sub 1. 85/Sr/sub 0. 15/Cu/sub 1-//sub x/Ga/sub x/BO/sub 4/

    Cieplak, M.Z.; Xiao, G.; Bakhshai, A.; Chien, C.L.

    1989-03-01

    We have studied the superconducting and normal-state properties of La/sub 1.85/Sr/sub 0.15/(CU/sub 1-//sub x/Ga/sub x/)O/sub 4/ (085/Sr/sub 0.15/(Cu/sub 1-//sub x/Zn/sub x/)O/sub 4/ system. The disappearance of superconductivity is most likely due to the complete filling of the Cu local 3d band and not due to the pair-breaking effect induced by nonmagnetic disorder. The Ga doping induces localization of the Cu 3d holes as evidenced from the susceptibility measurements. The normal-state resistivity exhibits a minimum followed by a logarithmic increase as the temperature is lowered. The temperature of the minimum increases linearly with the Ga content. The logarithmic upturn in the resistivity indicates that neither an activation process nor variable range hopping is responsible for the low-temperature electronic transport. Among two other possible mechanisms, the Kondo effect and effect of localization and correlation, the Kondo effect gives a much better description of the temperature dependence of the resisitivity in the whole temperature range (4--300 K) and for all of the samples.

  4. Decontamination of salmonella from the coastal fish meals by 60Co γ ray irradiation

    The decontamination fo salmonellae from fish meal samples by irradiation which 60Co γ ray was examined. Sixteen strains of Salmonella were used. A composite fish meal sample was prepared by mixing with different coastal meals, and after radiation sterilization at a dose of 20 kGy 60Co γ ray, which was employed as the salmonella-free meal sample. D10 values of test strains determined in buffered saline were found to range from 0.08 to 0.36 kGy, and inactivation factors at a dose of 1 kGy ranged from 102.8 to 1013. D10 values of test strains determined in the salmonella-free meal sample ranged from 0.59 to 1.64 kGy, and the inactivation factors at a dose of 10 kGy were found to range from 106.1 to 1017. Interestingly the D10 values of salmonellae determined in fish meal samples were 10 times as much compared with those determined in buffered saline. From the commercial aspects of coastal fish meal production, destruction of salmonellae in fish meals by 60Co γ ray irradiation was found to be much more practical than other methods such as dry heating and ethylene oxide fumigation. (author)

  5. Development and characterization of a new graphite ionization chamber for dosimetry of 60Co beams

    Ionization chambers are the most employed dosimeters for precise measurements, as those required in radiotherapy. In this work, a new graphite ionization chamber was developed and characterized in order to compose a primary standard system for the beam dosimetry of the 60Co sources. This dosimeter is a cylindrical type ionization chamber, with walls and collecting electrode made of high-purity graphite, and the insulators and stem made of Teflon®. The walls are 3.0 mm thick, and it has a sensitive volume of 1.40 cm3. The characterization was divided in two steps: experimental and Monte Carlo evaluations. This new dosimeter was evaluated in relation to its saturation curve, ion collection efficiency, polarity effect, short- and medium-term stabilities, leakage current, stabilization time, linearity of response and angular dependence. All results presented values within the established limits. The second part of the characterization process involved the determination of the correction factors, obtained by Monte Carlo simulations. Comparing these correction factors values with those from other primary standard laboratories, the highest differences were those for the wall and stem correction factors. The air-kerma rate of the 60Co source was determined with this new dosimeter and with the IPEN standard system, presenting a difference of 1.7%. These results indicate that this new dosimeter may be used as a primary standard system for 60Co gamma beams. (author)

  6. Responses of commercial broiler chicks to 60Co gamma-rays

    A total of 360 chicks of Nichols line at one-day old were used in this study. Within each sex, the chicks were divided into three exposure treatments (non-irradiated, 400 rads and 800 rads). The source of irradiation was 60Co gamma-rays. The results can be summarized as follows: Of the 360 chicks used in this study, only 10 chicks died during the experimental period. Radiation induced a reduction in body weight in both sexes during the growth period. Gamma-rays reduce the feed intake in both sexes. Moreover, the feed conversion ratio for the irradiated chicks was higher than that the non-irradiated birds. While red blood cells and hemoglobin content were higher in the irradiated chicks, white blood cells count and especially lymphocytes did not affect by 60Co gamma-rays. Gamma-rays had no effect on carcass, bone, meat and giblets as fractions of body weight in both sexes. Moreover, meat water content decreased and meat fat content increased in irradiated chicks. The total length and the total weight of the GI tract decreased due to 60Co gamma-rays. The response of the different regions of the GI tract to this rays is different. Moreover, the effect of this radiation on the GI tract is dependent upon the body weight irrespective of the sex. (orig./MG)

  7. 60Co accumulation from sediment and planktonic algae by midge larvae (Chironomus luridus)

    This paper reports the results of several experiments carried out to evaluate uptake and retention by a limicolous midge larva of 60Co retained in sediment, either adsorbed on mineral particles or bound to planktonic algae. In order to determine their relative contributions in radionuclide accumulation, the different vectors (water, algae and sediment) were first labelled individually and then simultaneously. 60Co accumulation from water and from algae results in a maximum concentration factor of 30 and in a mean trophic transfer factor of 4·5 × 10−3. The level of contamination of midge larvae from sediment is markedly influenced by the presence of endogenous organic matter. Thus the radionuclide transfer factor is about twice as high for larvae placed in labelled raw sediment than for larvae placed in labelled incinerated sediment, in the presence as in the absence of contaminated planktonic algae. Irrespective of the contamination conditions, 60Co depuration from midge larvae is a very rapid phenomenon that corresponds, in all cases, to a radionuclide half-life of only a few days

  8. Decoloration Kinetics of Waste Cooking Oil by 60Co γ-ray/H2O2

    Xiang, Yulin; Xiang, Yuxiu; Wang, Lipeng

    2016-03-01

    In order to decolorize, waste cooking oil, a dark red close to black solution from homes and restaurants, was subjected to 60Co γ-ray/H2O2 treatment. By virtue of UV/Vis spectrophotometric method, the influence of Gamma irradiation to decoloration kinetics and rate constants of the waste cooking oil in the presence of H2O2 was researched. In addition, the influence of different factors such as H2O2 concentration and irradiation dose on the decoloration rate of waste cooking oil was investigated. Results indicated that the decoloration kinetics of waste cooking oil conformed to the first-order reaction. The decoloration rate increased with the increase of irradiation dose and H2O2 concentration. Saponification analysis and sensory evaluation showed that the sample by 60Co γ-ray/H2O2 treatment presented better saponification performance and sensory score. Furthermore, according to cost estimate, the cost of the 60Co γ-ray/H2O2 was lower and more feasible than the H2O2 alone for decoloration of waste cooking oil.

  9. A new parallel-plate graphite ionization chamber as a 60Co gamma radiation reference instrument

    The calibration procedure in radiotherapy treatments is very important and a sensitive task due to the high doses delivered to the patients. Generally, the air-kerma cavity standards for 60Co gamma rays are graphite cavity ionization chambers. In this work a new parallel-plate graphite ionization chamber was studied to analyze its potential use as a reference instrument. In order to evaluate its performance in 60Co beams, it was submitted to several characterization tests. Moreover, Monte Carlo simulations were undertaken using the EGSnrc code to study the influence of the chamber components on its response. The results obtained showed that this new ionization chamber presented a satisfactory performance in all evaluated tests. - Highlights: ► A new ionization chamber was characterized as a reference dosimeter for 60Co beams. ► The EGSnrc code was used to determine the influence of the chamber components. ► The characterization test results were within the recommended limits. ► The results showed that this dosimeter may be used as a reference dosimeter

  10. Transfer and mobility of 137 Cs and 60 Co in oxisol and alfisol

    One manner to assess potential mobility of radionuclides in soils is the use of sequential extraction procedures. These procedures intend to provide the radionuclide partitioning in geochemical phases of soil affected by changes in physico-chemical conditions. In this study a new sequential chemical extraction protocol was choose to evaluate 60 Co and 137 Cs mobility under a large range of physico-chemical soil properties. The results of sequential procedure was further compared with soil to plant transfer factors data for maize and radish and with soil properties, showing rather consistent results. The 137 Cs distribution in soil showed that Fe oxides are the main sink for this element and after 14 years after contamination the 137 Cs was still available for plants. The 60 Co distribution showed that Mn oxides are the main sink for this element in Alfisol and 5 years after contamination no 60 Co was detected as bioavailable neither detectable in maize. The knowledge of the bio-geochemical behavior of radionuclides in soil system can be useful for risk assessment studies, to be applied in the case of nuclear accident or contamination scenarios. (author)

  11. Leaching of 60Co, 137Cs and 226Ra in lysimeter experiments

    The present report describes the first results obtained from lysimeter experiments started in 1990. The lysimeter plant consists of twelve soil monoliths from four different sites (three replicates each). Since 1990 the following agricultural crops were grown: endive, corn, winter wheat, mustard, sugar beet and potato. Gravitational water ranged from 3.9 % to 18.3 % of precipitation plus irrigation water, calculated as half years average values excluding the first six months of operation. The two Cambisols on sediments exhibited a mean percentage of approx. 10 %. The Dystric Cambisol on silicate rock and the Gleysol showed average values of 20 %. In 1990 the top layers (20 cm) were contaminated with three radionuclides. The leaching of the contaminants 60Co, 137Cs and 226Ra differed distinctly between the elements. The lowest leaching rates were observed for 137Cs, followed by 60Co. The 226Ra-concentrations in the gravitational water were clearly highest of all. However, the comparison of the 226Ra/2228Ra ratios in deep soil layers and in gravitational water showed that the 226Ra measured in the leachate originates from the natural contents in the subsoil and not from the artificial 226Ra contamination of the topsoil. The mobility of the artificial radionuclides decreased therefore in the following order: 60Co > (226Ra) > 137Cs. (author)

  12. Effects of 60Co γ-radiation on the embryo development of goldfish

    The effects of 60Co γ-radiation on the development of goldfish embryos were investigated by different doses and different dose rate. The results showed that 0.5-1.0 Gy 60Co γ-radiation could speed up the development of embryos, but did not cause higher hatching rate. 0.5-1.0 Gy 60Co γ-radiation caused hyperradiosensitivity on goldfish embryos, whereas 2.0-4.0 Gy caused increased radioresistance. Embryos at 4-8 cell stage showed higher survival rate and lower abnormal embryo rate than embryos at multicellular stage or early gastrula stage when radiated at the same dose and dose rate. The results also showed that the radiation at low dose rate (lower than 1.0 Gy/min) could cause more serious damage than the relative higher dose rate (1.0 Gy/min). Early embryos radiated at 1.0 Gy/min dose rate and lower than 2.5 Gy were suggested for the breeding. (authors)

  13. Behavior of 60Co and 134Cs in a Canadian Shield lake over 5 years

    Radionuclides were added to the anoxic hypolimnion of a Canadian Shield lake to simulate the nuclear fuel waste disposal scenario where radionuclides might enter the bottom waters of a lake. The radionuclides remained in the hypolimnion until lake mixing at autumn turnover after which 60Co was rapidly lost and 134Cs was slowly lost from the water. Only 0.4% of the 60Co and 0.6% of the 134Cs remained in the water at year 5. Highest concentrations occurred in periphyton and filter feeders, Holopedium gibberum and clams (Anodonata grandis grandis). From maximum annual concentrations in clam tissues, it was estimated that the availability of 60Co for uptake had a half-time (t1/2) of 835 days in the lake, whereas that for 134Cs was 780 days. Loss rate coefficients, k, for the radionuclides from taxa ranged from 0.0008 to 0.0043 day-1 (t1/2=161-866 days) for 60Co and from 0.0009 to 0.005 day-1 (t1/2=139-770 days) for 134Cs. Cobalt-60 concentrations in forage fish were low, whereas 134Cs concentrations increased over the first year or two, then slowly declined. On the basis of k values measured for forage fish, the biological half-time of 134Cs in forage fish ranged from 428 to 630 days. Maximum 134Cs concentrations in forage fish were higher following hypolimnetic addition than epilimnetic addition. Relatively high 134Cs concentrations in periphyton at year 5 point to the importance of benthic pathways in the recycling of contaminants to higher trophic levels. The presence of 134Cs in biota 5 years after the addition, long after concentrations were no longer detectable in surface waters, is evidence of the persistence of Cs in aquatic systems. The k values (or t1/2 values) for the loss of 60Co and 134Cs from water and their uptake and loss from biota can be used to establish parameter values for assessment models. The results demonstrate that assessment models should account for the release of radionuclides from sediment and their subsequent recycling in the food chain

  14. Gamma 60Co DL50/30 of Biomphalaria glabrata (Say, 1818 DL50/30 raios gama de 60Co em Biomphalaria glabrata (Say, 1818

    Elaine Barros da Costa CARVALHO

    1999-11-01

    Full Text Available The variation of resistance to 60Co gamma-rays of Biomphalaria glabrata was studied. A population of 480 mollusks was observed during 30 days - distributed in 8 groups of snails isolated and 8 groups of snails in colonies - after exposure (30 snails per group per dose to increasing doses of gamma radiation. Doses of 10, 20, 40, 60, 80, 160, 320 and 640 Gy from a Gamma-cell 60Co irradiator, were applied to the test groups and two groups control (non-irradiated of snails - isolated and colony - were kept apart. After have been exposed, the snails were drew back to the aquaria where they were maintained before. The survival was estimated on a daily score of the alive animals in each group-dose, starting after the irradiation exposure day. As a result, the survival self-fertilization forms (DL50/30 = 218.2 Gy was found greater than in cross-fecundation forms. These data point to a low radio-resistance on the cross-fertilization forms - the sexual reproductive form - which is most found in nature. The lower radio-resistance of the cross-fertilization forms suggests the presence of some sex-linked hormonal factor related to this phenomenon.A variação da resistência entre indivíduos em autofecundação e fecundação cruzada de Biomphalaria glabrata foram estudadas. Uma população de 480 moluscos foi observada durante 29 dias, distribuída em 8 grupos de caramujos isolados e 8 grupos em colônias após a exposição (30 caramujos por grupo-dose a doses crescentes de radiação gama. Foram usadas doses de 10, 20, 40, 60, 80, 160, 320 e 640 Gy de um irradiador Gamma-Cell 60Co. Dois grupos não irradiados - isolado e colônia - foram separados como controle e após a irradiação todos os caramujos voltaram para aquários onde viviam antes. A sobrevida foi estimada pela contagem diária dos animais vivos em cada grupo-dose, a partir do dia da irradiação. O resultado mostrou maior sobrevivência nos grupos isolados (DL50/30 = 218.2 Gy que nos grupos

  15. 60 Co 放射源运输容器屏蔽性能检测%Shielding Performance Measurements on Container for 60 Co Radioactive Sources Transport

    孙洪超; 李国强; 闫峰; 庄大杰; 孙树堂; 王学新

    2015-01-01

    工业及医疗用放射源主要包括60 Co、137 Cs、131 I、32 P、153 Sm、99 Mo、90 Sr、89 Sr等核素,射线形式有α、β、γ、中子等。本文针对运输活动中γ辐射,使用现有的60 Co放射源运输容器,开展辐射屏蔽性能检测技术研究。通过模拟计算和实验测量,得到运输容器最大装载活动情况下外部辐射水平,并对计算和实验结果进行了比较。针对放射源在屏蔽容器中安放位置发生偏移和放射源在容器中安放方式不同对容器外部的辐射水平影响进行了相关研究。研究结果可对今后完善放射性物质运输容器的辐射屏蔽性能检测提供一定的借鉴。%Some radioactive sources are often used in irradiation industry and radiothera‐py ,such as 60Co ,137Cs ,131I ,32P ,153Sm ,99Mo ,90Sr ,89Sr and so on .The radiation includeα、β、γ and n .The radiation from γ sources are the mostly concerned during the transporting of radioactive sources .The shielding performance measurements on con‐tainer for 60Co radioactive sources transport were discussed by using both Monte Carlo method simulation calculation and experiment measurement . Some important factors w as discussed w hich could affect the results of shielding performance measurements . The layout of radioactive sources had a important impact on the monitoring results of the external radiation levels of radiation sources transport container .The results affor‐ded the contribution to the improvement of the radiation monitoring and management of radioactive material transportation package .

  16. Detection and temporal variation of 60Co in the digestive glands of the common octopus, Octopus vulgaris, in the East China Sea

    60Co were detected in common octopus specimens collected in the East China Sea in 1996-2005. The source of 60Co has remained unclear yet. Stable isotope analyses showed that there was no difference in stable Co concentrations between octopus samples with 60Co and without 60Co. This result showed that the stable Co in the digestive gland of octopus potentially did not include a trace amount of 60Co and the source of 60Co existed independently. Furthermore, investigations of octopus in other area and other species indicated that the origin of the source of 60Co occurred locally in the restricted area in the East China Sea and not in the coastal area of Japan. Concentrations of 60Co have annually decreased with shorter half-life than the physical half-life. This decrease tendency suggests that the sources of 60Co were identical and were temporary dumped into the East China Sea as a solid waste.

  17. Behavior of the sorption of 60 Co in aqueous solution on inorganic materials as function of p H

    The sorption of the 60 Co is evaluated in aqueous solution on Mg O, MnO2, TiO2, Sn O, activated carbon and hydrotalcite calcined as a function of the p H, using the method for lots and quantifying at the 60 Co for gamma spectrometry. Likewise it was explained the one behavior of the sorption of the 60 Co in the materials with base in the chemical species of this radioactive isotope in aqueous solution. The chemical species of the 60 Co in solution were identified by electrophoresis of high voltage for the different p H values. It was found that under the experimental conditions, the 60 Co showed a significant sorption on MnO2, TiO2 and activated carbon. On the other hand, in Mg O, Sn O and calcined hydrotalcite also was observed a sorption, although in smaller quantities. The studied hydrated metallic oxides retained the 60 Co for ion exchange via. It was found that the 60 Co was present as a cationic specie to p H 1, 3, 5 and 7 and like a neutral specie to alkaline p H. (Author)

  18. Assessment of the mobility and bioavailability of 60 Co and 137 Cs in contaminated soils

    Results of a classical sequential chemical extraction procedure for 137 Cs in an acid Oxisol showed that after 3 years of contamination radiocesium remains potentially available for transfer processes: 40% bio-available, 20% mobile under oxidizing conditions and 40% bound to Fe and Mn oxides (available under reducing conditions). At this time, the transfer factor obtained in this soil was higher than values obtained in basic Oxisol and was higher than values obtained in soils from temperate climate areas. Seven years after the contamination, the 137 Cs distribution in this acid Oxisol have been changed as consequence of changes in soil properties: 8% bioavailable, 16% mobile under oxidizing conditions, 43% bound to Fe and Mn oxides and 33% strongly bound to soil compounds. Changes in the 137 Cs distribution in this soil were followed by reductions in soil to plant transfer factor. Between 1996 and 2000, the 137 Cs distribution, 137 Cs soil to plant transfer factor and soil properties in the basic Oxisol remained almost the same. The 60 Co distribution showed that Mn oxides is the main sink for this element and four years after contamination no 60 Co was detected as bioavailable or detectable in plants. In this study the use of an alternative sequential chemical extraction protocol to evaluate 60 Co and 137 Cs mobility under a large range of physico-chemical soil properties has shown to be very consistent with soil to plant transfer factors data for maize. The knowledge of bio-geochemical behavior of radionuclides in soil system can be used for the risk assessment in the case of nuclear accident or contamination scenarios. (author)

  19. Comparison of treatment in soybean grains between 60Co and e-beans applications

    Soybean is the most important oleaginous cultivated in Brazil, who is the second largest exported in the world, and generates high incomes, direct and indirectly, its oils could be used since to cook even to machine's fuel and the nutrients become basic for the feeding human being, beyond its by-products, that offer great diversities of products for the nourishing industry. Between the main factors that limit the attainment of high incomes, are the illnesses caused by microorganism like fungi, bacteria, and viruses that, in general, are difficult to control and cause damages on harvest of billions of dollar every year. An alternative to minimize the losses is preserving the grains through the irradiation that can come today from two different main sources: e-beam and 60Co. Beyond power to be off when it will not be in use, the source of e-beams machines does not need to be recharged, is easily available, possess high tax of dose and low energy. However the 60Co have low dose rate, high energy and the photons emission is continuous. This work aims to compare the effects of the radiation through viscosimetry, DNA Comet Assay and Cooking time techniques in soybean grains at doses 0, 1.0, 3.0 and 5.0kGy irradiated in ambient temperature at 60Co source Gammacell 220 (A.E.C. Ltda) and in e-beam accelerator - Radiation Dynamics (Radiation Dynamics Co. model JOB, New York, USA), 1.5 MeV- 25mA with the lower dose. (author)

  20. 60Co-γ Irradiation Affects the Enzymatic Antioxidant System of the Citrus Red Mite Panonychus citri (Acari: Tetranychidae)

    Ke Zhang; Zhibin Li; Shaowen Zhu; Qunfang Weng

    2014-01-01

    Radio-(60Co), which emits γ rays, has been used worldwide in pest control. The aim of the present study was to analyze the effect of effective-low-power 60Co-γ irradiation on the enzymatic antioxidant system of the citrus red mite Panonychus citri. One day old female adults were exposed to 0.4 kGy 60Co-γ irradiation and on the, 6th h, 1st day, 2nd day, and 5th day post treatment, the mites were euthanized for biochemical analysis. The activity of superoxide dismutase (SOD), catalase (CAT), p...

  1. The transfer of 60Co from feed into vitamin B12 in cow liver, milk and beef

    The transfer of the radionuclide 60Co from feed to milk, meat and the organs of a cow and its incorporation into vitamin B12 were studied in order to determine the transfer coefficient of 60Co into vitamin B12 in cattle. Upper limits of transfer coefficients for 60Co organically complexed into vitamin B12 were determined to be 6.0 x 10-5 days/litre in milk and 3.9 x 10-5 days/kg in meat, based on values measured after 140 days in bovine liver. (author)

  2. Effects of 60Co-γ ray irradiation on antioxidant enzyme activities in tobacco

    Effects of 300Gy 60Co-γ ray irradiation on the activities of 3 antioxidant enzymes in tobacco were studied in this paper. The results showed that the activities of superoxide dismutase (SOD), peroxidas (POD) and catalse (CAT) in tobacco were gradually increased. All the activities of SOD POD and CAT reached the maximums at 12 h and then gradually decreased. Similar results were also observed in the expression of sod, pod and cat genes. These results indicated that the activities of antioxidant enzymes could play an important role in tobacco tolerance against irradiation

  3. Assessing deposition levels of 55Fe, 60Co and 63Ni in the Ignalina NPP environment

    Two RBMK-1500 reactor units operated in Lithuania in the 1987-2004 period (one of them was stopped for decommissioning in 2004). This study presents a preliminary investigation of surface deposition density levels of 55Fe and 63Ni in moss samples collected in the close vicinity of the Ignalina NPP. Non-destructive analysis by the HPGe gamma-spectrometry was followed by radiochemical separation. Radiochemical analysis was based on anion-exchange and extraction chromatography. 55Fe and 63Ni activities were measured by liquid scintillation counting (LSC). The results indicate that the deposition values of 55Fe are generally higher than those of 60Co and 63Ni.

  4. Infection of tissue-culture cells with 60Co gamma-irradiated malaria sporozoites

    Plasmodium berghei sporozoites, attenuated by radiation from a 60Co source (8 or 15 krads) retain the ability to enter WI38 human embryonic lung cells in vitro. During the first 24 hours of incubation, the sporozoites appear to undergo normal development into exoerythrocytic trophozoites. Further development appears abnormal, although the trophozoites persist in culture cells for at least 48 hours. Parasite reactivities to fluorescent-labelled, sporozoite-specific antisera are normal up to 48 hours in culture. These observations suggest that sporozoites used in vaccine preparations may enter host cells and transform into exoerythrocytic trophozoites in vivo, but that maturation of the exoerythrocytic stage may be incomplete. (author)

  5. Study on Several Characteristics of Agaricus blazei Murril Strain J3 Irradiated by 60Co

    WENG Bo-qi; JIANG Zhi-he; HUANG Ting-jun; CHEN Jian; ZHENG Wei-wen

    2003-01-01

    A new mutant strain J3 from Agaricus blazei Murril was obtained by 60Co irradiation. The yields of successive generations were increased more than 70% to compare with their original strain. The component analysis on amino acids and fatty acid illuminated that the nutrient value of strain J3 fruiting body was better than the original strain. The apparent nodule structure was found in the hyphea of J3 strain through the observation by scanning electron microscope. RAPD analysis showed the great difference of PCR fingerprints between J3 and its original strain. It is a promising mutant strain for further commercial development in the future.

  6. Effect of 60Co γ irradiation and GA3 treatment on mutation of Carica papaya L

    The seeds of Carica papaya L. were irradiated by 60Co γ-rays of 10-40 Gy and treated by GA3 of 10-50 mg/L after irradiation. The results showed that small nuclear cell percentage, chromosome variation percentage and leaf variability of papaya seedling increased with increase of irradiation dose, the pollen fertility and fruit quality decreased. GA3 of 10-50 mg/L treatment after irradiation could alleviate the irradiation harm, and the effect of lower concentration of GA3 was better than higher concentration with lower dose irradiation, however, the effect of higher concentration of GA3 was better with higher dose irradiation

  7. The studies on apple preservation by 60Co-γ irradiation

    Studies on 60Co-γ irradiation of Golden Delicious apple have been carried out. The results showed that the optimum irradiation dosage for stored apple was ranged from 0.3-0.5 kGy. With this dosage, the contents of vitamin C and titratable acidity in these apples had no significant change compared with unirradiated apples. The respiratory rate and the amount of ethylene release were decreased after irradiation. The mortality of the verticillate pathogenic fungi was 97% at the dose of 0.5 kGy

  8. Sensitivity of watermelon variety Bojura to mutant agents 60Co and EMS

    Nikolay Velkov; Nasya Tomlekova; Fatma Sarsu

    2016-01-01

    A study on the sensitivity of watermelon variety Bojura to mutagenic agents was carried out in 2013-2014. The goal was to establish effective doses for mutagenic treatment of dry seeds with 60Co gamma rays (80, 100, 200, 250, 350 and 450 Gy) and swollen seeds with water for 24 hours were treated with ethyl methanesulfonate (EMS) at a concentration of 2%. Dominant mutations were not observed in the M1 generation. Morphological changes in 14 of 1395 M2 plants were observed. Phenotypic variation...

  9. The influence of 60Co gamma irradiation for downy mildew infection on corn

    Corn seeds of Genjah kertas variety were irradiated with 60Co gamma in the range of 0 rad - 40.000 rads, at interval of 2000 rads, as preliminary investigation to obtain possibilities of corn mutation. Several agronomical effects of radiation on the seedling-plant such as seed germination, height of the seedling, ages of flowering, ages of harvesting, length and circle of the cob, 100U dry seeds weight, number and diameter of stomata, and percentage of downy mildew infection have been observed. The exact conclusion can be obtained only after testing the results of M2 and M3. (author)

  10. The 1998 calibration of Australian secondary standards of exposure and absorbed dose at 60Co

    New calibration factors are reported for several of the ionization chambers maintained at the Australian Radiation Laboratory (ARL) and at the Australian Nuclear Science and Technology Organisation (ANSTO) as Australian secondary standards of exposure/air kerma and absorbed dose at 60Co. These calibration factors supplement or replace the calibration factors given in earlier reports. Updated 90Sr reference source data are given for the ARL chambers, and for two of the ANSTO chambers. These results confirm the stability of the secondary standards. A re-calibration of the ANSTO reference electrometer is reported. This was carried out using an improved method, which is fully described

  11. Effect of 60Co-irradiation on penicillin G procaine in veterinary mastitis products

    The effect of 60Co-irradation on penicillin G procaine in a peanut oil-based veterinary mastitis product was examined by reversed-phase high-performance liquid chromatography (HPLC). The HPLC method is capable of separating and quantifiying procaine, penicillin G, and various degradation compounds. Values obtained by the HPLC method on the product irradiated and stored at various temperatures correlated well with those of the microbiological assay. No significant decrease in the procaine was detected even after 4.0-Mrad irradiation. The HPLC method is applicable for analysis of other beta-lactam antibiotics

  12. Effects of 60Co gamma radiation on Biomphalaria glabrata (Say, 1818) Embryo, I. Mortality

    A study was conducted on the radiosensitivity of Biomphalaria glabrata embryos submitted to doses of 5, 10,15,20 and 25 Gy of 60Co during the cleavage, blastula, gastrula, young trochophore and trochophore stages. Mortality was the parameter used to evaluated the damage induced by ionizing radiation. Susceptibility decreased with increasing embryo age and with decreased radiation dose. Estimated LD50 values (15 days) showed that the cleavage stage (4.3 Gy) was approximately four times more radiosensitive than the trochophore stage (17.0 Gy). The survival curves obtained for each embryo stage are discussed on the basis of the multitarget theory. (author)

  13. Dominant lethal mutation induced by continuous irradiation of 60Co gamma rays in mice

    Female and male mice were exposed to 60Co gamma rays for 10 days, the accumulative doses were 0.396-2.024 and 0.462-2.552 Gy respectively. The number of dominant lethal mutations was calculated as follows: PRE = CL - (ED + LD + VIA). The results showed that Preimplantation Loss (PRE) ranged from 1.222 to 3.714 for female mice and 0.0345 to 2.2308 for male mice. In both cases a linear dose-effect relationship was observed. The PRE of oocytes is 1.66 times higher than that of spermatids

  14. Radiation effects of polyolefin elastomer by 60Co γ-rays

    Polyolefin elastomer was irradiated in air or N2 to different doses by 60Co γ-rays. Gel fraction, mechanic performance and flame retarding property of the irradiated POE were investigated. G value of the POE crosslinked in air or N2 is 0.13 and 0.14, respectively. Gel fraction of the irradiated POE increased with both absorbed dose and sensitizer content, and the value of tensile strength and oxygen index (OI) increased to some extent after irradiation. The value of break at elongation decreased slightly after irradiation. (authors)

  15. Impact of 60Co-γ-ray Sterilization of Tetracycline Hydrochloride Raw Materials%60Co-γ射线对盐酸四环素原料灭菌的研究

    黄波; 赵全如; 刘莉萍

    2014-01-01

    Different doses of 60Co-γ rays were compared for radiation sterilization on raw materials of tetracycline hydrochloride. By checking stability data, the optimal radiation dose of 60Co-γ rays on tetracycline hydrochloride raw materials was 9 kGy, at which its physical and chemical detection indicators were in line with the requirements of USP, and the sterility test results met the requirements..%采用不同剂量的60Co-γ射线对盐酸四环素原料进行辐射灭菌,结合稳定性考察数据,最终确定盐酸四环素原料的60Co-γ射线的辐射剂量为9 kGy时,其理化检测指标符合USP的要求,且无菌检查符合要求。

  16. Viabilidade e micoflora de sementes de amendoim irradiadas com cobalto (60Co Viability and mycoflora of irradiated seeds of peanut with cobalt (60Co

    Niédja M. C. Alves

    2011-03-01

    Full Text Available Estudou-se o efeito de diferentes doses da irradiação gama na germinação e percentagem de infecção fúngica em sementes de amendoim cultivar BR1. Inicialmente, as sementes foram avaliadas quanto à micoflora, utilizando-se o método de papel de filtro umedecido, a germinação em substrato de papel germitest e determinação do teor de umidade em estufa, a 105 ± 2 ºC. Posteriormente, as sementes foram submetidas à irradiação com uma fonte de 60Co, tipo gammacell, onde se estudou o efeito de 8 doses de irradiação na micoflora e germinação das sementes acondicionadas em embalagem de PET e polietileno trançado durante 60 dias de armazenamento, sem controle de temperatura e umidade relativa do ar. Os fatores estudados (doses em kGy, embalagens e tempo de armazenamento foram analisados em um delineamento inteiramente casualizado, dispostos em fatorial. Com base nos resultados, observou-se que a irradiação gama afetou negativamente a germinação das sementes de amendoim e que doses acima de 3,0 kGy comprometem a germinação das sementes. A radiação a partir da dose 1,5 kGy eliminou os fungos Aspergillus niger e, Penicillium a partir da dose de 2,5 kGy.The effect of different doses of the gamma irradiation was studied on germination and percentage of fungal infection in peanut seeds cultivar BR1. Initially the seeds were evaluated for the mycoflora using the method of humidified filter paper, the germination in paper substratum germitest and determination of the moisture content in oven at 105 ± 2 ºC. Later on the seeds were submitted to irradiation with a source of 60Co, type gammacell, where the effect was studied of 8 doses of irradiation in the mycoflora and germination of the seeds conditioned in PET packing and polyethylene tressed during 60 days of storage, without control of temperature and relative humidity of the air. The studied factors (doses in kGy, packing and time of storage were analyzed in a completely

  17. Effects of 60Co γ-rays irradiation on seed growth of ground-cover chrysanthemum

    The seeds of ground-cover chrysanthemum were used to study the effects of different doses of 60Co γ-rays irradiation(10-50 Gy) on seed germination and physiological characteristics. The results showed that the rate of seed germination and seedling survival decreased significantly with the irradiation doses. With the increase of irradiation dose to above 20 Gy, the content of malondialdehyde (MDA) and activity of peroxidase (POD) in seedlings significantly increased. The similar trends were found in the activities of superoxide dismutase (SOD) and glutathione reductase (GR). Catalase (CAT) activity increased at doses lower than 20 Gy, and then decreased at the higher doses, whereas ascorbate peroxidase (APX) activity did not alter except for 40 Gy. It is concluded that the suitable irradiation dose of mutation breeding is 20 Gy for the seeds of ground-cover chrysanthemum. Although 60Co γ-rays irradiation resulted in damage of membrane lipid peroxidation in the survival seedlings, the increased activity of CAT and POD could protect them against the damage. (authors)

  18. Gamma 60 Co D L 50/30 of Biomphalaria glabrata (Say, 1818)

    The variation of resistance to 60 Co gamma-rays of Biomphalaria glabrata was studied. A population of 480 mollusks was observed during 30 days - distributed in 8 groups of snails isolated and 8 groups of snails in colonies - after exposure (30 snails per group per dose) to increasing doses of gamma radiation. Doses of 10, 20 40, 60, 80, 160, 320 and 640 Gy from a Gamma-cell 60 Co irradiator, were applied to the test groups and two groups control (non-irradiated) of snails - isolated and colony - were kept apart. After have been exposed, the snails were drew back to the aquaria where they were maintained before. The survival was estimated on a daily score of the alive animals in each group-dose, starting after the irradiation exposure day. As a result, the survival self-fertilization forms (DL50/30=218.2 Gy) was found greater than in cross-fecundation forms. These data point to allow radio-resistance on the cross-fertilization forms - the sexual reproductive form - which is most found in nature. The lower radio-resistance of the cross-fertilization forms suggests the presence of some sex-linked hormonal factor related to this phenomenon. (author)

  19. Ferrous sulphate (Fricke) dosimetry in a fast neutron and a 60Co radiotherapeutical beams

    Ferrous sulphate (Fricke) dosimetry was performed in the fast neutron beam produced at the U-120 cyclotron of the Institute of Nuclear Physics and in a 60Co gamma-ray therapeutical beam at the Centre of Oncology in Krakow. The G-value was measured for the neutron component in the mixed (neutron + gamma) field of the fast neutron beam, where the mean neutron energy is 5.6 MeV. This value is Gn = 8.1 ± 0.8. Track structure theory calculations were made using energy spectra of charged secondary particles generated in water by the MRC Hammersmith fast neutron beam (mean neutron energy 7.6 MeV, measured value of Gn = 9.4 ± 0.6), yielding the calculated value of Gn = 8.61. Fricke dosimetry of the 60Co beam indicates that the absolute value of gamma-ray dose at the Centre of Oncology may be underestimated by about 3% . 19 refs., 1 tab. (author)

  20. Gamma {sup 60} Co D L {sub 50/30} of Biomphalaria glabrata (Say, 1818)

    Carvalho, Elaine Barros da Costa; Melo, Ana Maria Mendonca de Albuquerque; Motta, Mauricy Alves da [Pernambuco Univ., Recife, PE (Brazil). Dept. de Biofisica e Radiobiologia

    1999-12-01

    The variation of resistance to {sup 60} Co gamma-rays of Biomphalaria glabrata was studied. A population of 480 mollusks was observed during 30 days - distributed in 8 groups of snails isolated and 8 groups of snails in colonies - after exposure (30 snails per group per dose) to increasing doses of gamma radiation. Doses of 10, 20 40, 60, 80, 160, 320 and 640 Gy from a Gamma-cell {sup 60} Co irradiator, were applied to the test groups and two groups control (non-irradiated) of snails - isolated and colony - were kept apart. After have been exposed, the snails were drew back to the aquaria where they were maintained before. The survival was estimated on a daily score of the alive animals in each group-dose, starting after the irradiation exposure day. As a result, the survival self-fertilization forms (DL{sub 50/30}=218.2 Gy) was found greater than in cross-fecundation forms. These data point to allow radio-resistance on the cross-fertilization forms - the sexual reproductive form - which is most found in nature. The lower radio-resistance of the cross-fertilization forms suggests the presence of some sex-linked hormonal factor related to this phenomenon. (author)

  1. Effects of 60Co γ-rays on PWM and LPS induced lymphocytes

    The relationship between lymphocytes induced by PWM and LPS was investigated by means of 3H-TdR and 14C-UR incorporation. The study showed that in votro, PWM-induced cells were able to promote the stimulating effect of LPS to B lymphocyte. The stimulating effect of PWM-induced cells was obviously weakened after PWM cells being irradiated with γ-rays. When PWM-induced cells and LPS-induced cells were incubated together, with one kind of cells exposed to 60Co γ-rays, incorporation value of 3H-TdR became much smaller and the synergetic function disappeared, especially, when PWM-induced cells were irradiated. For patients suffering from carcinoma of nasopharynx, when treated with 60Co γ-rays, the incorporation value in LPS-induced cells approached normal level, while the incorporation value in PWM-induced cells reduced significantly and the stimulating effect of PWM-induced cells on LPS-induced cells became much weaker. The fact described above demonstrated that PWM-induced cells have the function of T-helper cells and play a more important role in the synergy than LPS induced cells

  2. Effect of 60Co γ-rays on PWM and LPS induced lymphocytes

    The relationship between lymphocytes induced by PWM (pokeweed mitogen) and LPS (lipopolysaccharide) was investigated by means of 3H-TdR incorporation. The study showed that, in vitro, PWM-induced cells were able to promote the stimulating effect of LPS to B lymphocytes. The stimulating effect of PWM-induced cells was obviously weakened after PWM cells being irradiated with γ-rays. When PWM-induced cells and LPS-induced cells were incubated together, with one kind of cells exposed to 60Co γ-ray, incorporation value of 3H-TdR became much smaller and the synergetic function disappeared, especially, when PWM-induced cells were irradiated. For patients suffering from carcinoma of nasopharynx, while treated with 60Co γ-rays, the incorporation value in LPS-induced cells approached normal level, meanwhile, the incorporation value in PEM-induced cells reduced significantly and the stimulating effect of PWM-induced cells on LPS-induced cells became much weaker. The facts described above demonstrated that PWM-induced cells have the function of T-helper cells and play more important role in the synergy than LPS-induced cells

  3. Effects of testicular irradiation with 60Co in guinea pigs CAVIA PORCELLUS

    Improvements were made in restaint systems and in the technique of electroejaculation in guinea pigs, emphasizing safety, effectiveness and repetition. Arrangements for simultaneous testicular irradiation with 60Co in 5 animals and a phantom to test dose levels in the target region and scattering were also made. Effects of single and fractionated exposures on sperm were studied. A collimated point-shaped 60Co-machine calibrated to 7 R/min was used as radiation source. Groups of five 12 month aged male guinea pigs were exposed to either single testicular irradiation of 50, 100, 200 and 400 R or fractionated weekly testicular irradiation of 2, 5, 10 and 20 R, during 10 weeks. A last group was exposed to 4 fractionated testicular irradiations of 20 R at time intervals of 21 days and a group of 8 animals was used as control. Semen samples evaluations were made during 5 weeks before irradiation and in the subsequent 11 weeks. Abnormalities in sperm morphology were studied by William's method and phase contrast microscopy. Mean percentages of semen normal espermatzoons and spermatic abnormalities are shown in figures and photomicrographs. Marked differences on concentration, sperm motility and sperm abnormalities were found, but not on volume, in favour of 100 and 200 R single doses levels, as compared to fractionated 10 and 20 R. (Author)

  4. Humoral immune response against native or 60Co irradiated venom and mucus from stingray Paratrygon aiereba

    Poisonings and traumas caused by poisonous freshwater fish such as rays are considered a major public health problem and draw attention because of accidents involving these animals cause serious local symptoms and are disabling, keeping the victim away from work. The therapy of these cases is based only on the symptoms of patients, which implies in its low efficiency, causing suffering for the victims. This study aims to evaluate and compare the humoral immune response in animals inoculated with native or 60Co irradiated Paratrygon aiereba venom and mucus. Ionizing radiation has proven to be an excellent tool to decrease the toxicity of venoms and isolated toxins. The mucus and venom samples of P. aiereba were irradiated using gamma rays from a 60Co source. Animals models were immunized with the native or irradiated mucus or venom. The assays were conducted to assess the production of antibodies by the immunized animals using enzyme immunoassay and western blotting. Preliminary results show the production of antibodies by the immunized animals. The resulting sera were also checked for antigenic cross- reactivity between venom and mucus, demonstrating the potential of mucus as an antigen for serum production for the specific treatment for accidents by stingrays. However, it is essential to carry out further tests in order to verify the neutralization of the toxin by antibodies formed by animals. (author)

  5. Biochemical and hematological study of goats envenomed with natural and 60Co-irradiated bothropic venom

    Lucas de Oliveira, P.C.; Madruga, R.A.; Barbosa, N.P.U. [Uberaba School of Veterinary Medicine (UNIUBE), MG (Brazil)]. E-mail: pedrolucaso@uol.com.br; Sakate, M. [UNESP, Botucatu, SP (Brazil). School of Veterinary Medicine and Animal Husbandry

    2007-07-01

    Venoms from snakes of the Bothrops genus are proteolytic, coagulant, hemorrhagic and nephrotoxic, causing edema, necrosis, hemorrhage and intense pain at the bite site, besides systemic alterations. Many adjuvants have been added to the venom used in the sensitization of antiserum-producer animals to increase antigenic induction and reduce the envenomation pathological effects. Gamma radiation from {sup 60}Co has been used as an attenuating agent of the venoms toxic properties. The main objective was to study, comparatively, clinical and laboratory aspects of goats inoculated with bothropic (Bothrops jararaca) venom, natural and irradiated from a {sup 60}Co source. Twelve goats were divided into two groups of six animals: GINV, inoculated with 0.5 mg/kg of natural venom; and GIIV, inoculated with 0.5 mg/kg of irradiated venom. Blood samples were collected immediately before and one, two, seven, and thirty days after venom injection. Local lesions were daily evaluated. The following exams were carried out: blood tests; biochemical tests of urea, creatinine, creatine kinase, aspartate amino-transferase and alanine amino-transferase; clotting time; platelets count; and total serum immunoglobulin measurement. In the conditions of the present experiment, irradiated venom was less aggressive and more immunogenic than natural venom. (author)

  6. Biochemical and hematological study of goats envenomed with natural and 60Co-irradiated bothropic venom

    Venoms from snakes of the Bothrops genus are proteolytic, coagulant, hemorrhagic and nephrotoxic, causing edema, necrosis, hemorrhage and intense pain at the bite site, besides systemic alterations. Many adjuvants have been added to the venom used in the sensitization of antiserum-producer animals to increase antigenic induction and reduce the envenomation pathological effects. Gamma radiation from 60Co has been used as an attenuating agent of the venoms toxic properties. The main objective was to study, comparatively, clinical and laboratory aspects of goats inoculated with bothropic (Bothrops jararaca) venom, natural and irradiated from a 60Co source. Twelve goats were divided into two groups of six animals: GINV, inoculated with 0.5 mg/kg of natural venom; and GIIV, inoculated with 0.5 mg/kg of irradiated venom. Blood samples were collected immediately before and one, two, seven, and thirty days after venom injection. Local lesions were daily evaluated. The following exams were carried out: blood tests; biochemical tests of urea, creatinine, creatine kinase, aspartate amino-transferase and alanine amino-transferase; clotting time; platelets count; and total serum immunoglobulin measurement. In the conditions of the present experiment, irradiated venom was less aggressive and more immunogenic than natural venom. (author)

  7. Effect of 60Co γ-rays on the lymphocyte subsets with monoclonal antibodies

    Three kinds of monoclonal antibodies (McAb), OkT4 McAb, OkT3 McAb and HI43, were used to identify T helper (Th). T suppresser (Ts) and B lymphocytes respectively. After lympbocytes were immediately exposed to 0.1 Gy, 0.25 Gy and 4 Gy 60Co γ-rays, 200 cells were counted to obtain the percentage of immunofluorescence positive cells. The results show that when the Th, Ts and B lymphocytes were irradiated by 0.1 Gy 60Co γ-rays, their abilities to combine with McAb decreased significantly. The radiation effect was more remarkable with increasing radiation dosage. Three kinds of the immunofluorescence positive cells percentages were analysed with weighted linear regression method. The relational coefficients (r) of Th, Ts and B lymphocytes were 0.8131, 0.8832 and 0.9086. The significant tests of regression coefficient showed that the radiosensitivities of Ts and B lymphocytes were higher than that of Th lymphocytes

  8. The transfer of 137Cs and 60Co from feed to pork

    The transfer of 137Cs and 60Co from fodder to meat and other organs was studied in growing pigs. The influence of two different feeding methods (potato and grain) commonly used in Germany was investigated. The radionuclides were transferred into plants by root uptake and these were fed once a day, all at once, to young pigs until they reached maturity. In this manner, the radioactivity was administered to the pigs in a similar chemical form as would occur after radioactive contamination of soil. It is demonstrated that the two feeding practices have only a minor influence on transfer coefficients, which were determined to be ≤0.002 days/kg for 60Co in meat and in the ranges 0.18-0.26 (potato-feeding) and 0.17-0.33 days/kg (grain-feeding), respectively, for 137Cs in different components of the meat; the transfer coefficients for 137Cs into different organs range from 0.06 to 0.24 days/kg after potato-feeding and from 0.12 to 0.29 after grain-feeding. (author)

  9. Scattering factor evaluation and study of medical intervention following intake of 60Co

    Guidelines for the assessment of internal doses from monitoring suggest default measurement of uncertainties (i.e. lognormal scattering factor, SF) to be used for different types of monitoring data. In this paper, SF values have been evaluated for internal contamination due to 60Co in two cases using whole body counting data. SF values of 1.04 and 1.03 were obtained for case I and II, respectively while SF value of 1.03 was obtained using bioassay data for case I. SF evaluated is in good agreement with the default values given by IDEAS guidelines. The present study also presents the follow up study of a case I of 60Co internal contamination using whole body counting and bioassay analysis. The effect of medical intervention applied on the subject is studied. Medical intervention of d-Penicillamine (250 mg x 4 daily) was orally administered from 13th day of initial exposure for about a fortnight, which showed reduction of activity present by 33.4% through urine. (author)

  10. Grafting of HEMA onto dopamine coated stainless steel by 60Co-γ irradiation method

    A novel method for grafting of 2-hydroxyethyl methacrylate (HEMA) onto the surface of stainless steel (SS) was explored by using 60Co-γ irradiation. The surface of SS was modified by coating of dopamine before radiation grafting. The grafting reaction was performed in a simultaneous irradiation condition. The chemical structures change of the surface before and after grafting was demonstrated by Fourier transform infrared (FTIR) spectrometer. The hydrophilicity of the samples was determined by water contact angle measurement in the comparison of the stainless steel in the conditions of pristine, dopamine coated and HEMA grafted. Surface morphology of the samples was characterized by atomic force microscope (AFM) and scanning electron microscope (SEM). The corrosion resistance properties of the samples were evaluated by Tafel polarization curve. The hemocompatibility of the samples were tested by platelet adhesion assay. - Highlights: • Poly-HEMA was grafted onto the surface of SS by 60Co-γ-ray irradiation. • Pristine SS was coated by dopamine to form a dense poly-dopamine film before radiation grafting. • The biocompatibility and hydrophility of SS were improved after the grafting of HEMA

  11. Sensitivity of watermelon variety Bojura to mutant agents 60Co and EMS

    Nikolay Velkov

    2016-04-01

    Full Text Available A study on the sensitivity of watermelon variety Bojura to mutagenic agents was carried out in 2013-2014. The goal was to establish effective doses for mutagenic treatment of dry seeds with 60Co gamma rays (80, 100, 200, 250, 350 and 450 Gy and swollen seeds with water for 24 hours were treated with ethyl methanesulfonate (EMS at a concentration of 2%. Dominant mutations were not observed in the M1 generation. Morphological changes in 14 of 1395 M2 plants were observed. Phenotypic variations changes were the colour of the seed coat, chlorophyll disorders of cotyledons, leaves, petals, and alterations of the location of the fruit set in the central stem. Visible changes of the morphological characteristics of the fruit were not observed. The doses induced certain morphological changes, however, higher doses or combined gamma rays 60Co and EMS treatments would induce mutations more efficiently. Subsequent experiments are required to obtain mutants with changes that affect flowers and fruits. The results are important for increasing mutation efficiency in watermelon breeding.

  12. Effect of 60 Co gamma radiation on Biomphalaria Glabrata (Mollusca, Gastropoda) embryos: mortality, malformation and hatching

    A study was carried out on the radiosensitivity of Biomphalaria glabrata embryos submitted to doses of 5, 10, 15, 20 and 25 Gy of 60 Co during the cleavage, blastula, gastrula, young trochophore and trochophore stages. Mortality, malformation and hatching were the parameters used to evaluate the damage induced by ionizing radiation. Estimated L D50 values (15 days) showed that the cleavage stage (4.3 Gy) was approximately four times more radiosensitive than the trochophore stage (17.0 Gy). Susceptibility to malformation induction was higher in the blastula, gastrula and young trochophore stages. Several types of morphogenetic malformations were observed, such as head malformations, exogastrulas, shell malformations, and embryos with everted stomodeum, with nonspecific malformations being the most frequent. The types of malformation induced by radiation probably are not radiation-specific and do not depend on the dose applied. The dose of 15 Gy was sufficient to greatly reduce the number of hatching snails regardless of the embryonic stage irradiated. We conclude that the effect of 60 Co gamma radiation on B. glabrata embryos presented a specific pattern. (author)

  13. The effect of 60Co γ-rays on Con A and LPS induced lymphocytes

    The effect to 60Co γ-rays on lymphocytes induced by Con A and LPS and the relationship between these two groups of cells were investigated by means of 3H-TdR incorporation. The study showed that in vitro, Con A cells were able to promote the inducing effect of LPS to B cells. When Con A cells were irradiated by 10 Gy γ-rays, the 3H-TdR incroporation value reduced significanly and the stimulating effect of Con A cells on LPS cells disappeared. Having been irradiated by γ-rays, LPS cells were not able to be stimulated by normal Con A cells. When the groups of cells were incubated together after irradiation, the synergistic function disappeared, furthermore the suppressive effect of Con A cells on LPS cells emerged. When these two groups of cells were investigated by means of agar culture, the suppressive effect of 10 Gy-γ-rays on lymphocytes colony formation was more obvious. Tests on 8 patients who were suffering from carcinoma of nasopharynx showed that after a course of teatment with 60Co γ-rays, the incorporation value in Con A cells became much smaller, the stimulating effect of Con A cells on LPS cells disappeared. LPS cells could not be stimulated by normal Con A cells. The study demonstrated that the radiosensitivity of Con A cells was higher than that of LPS cells

  14. Residual 152Eu and 60Co activities induced by neutrons from the Hiroshima atomic bomb

    Specific activities of 152Eu:Eu in stone samples exposed to the Hiroshima atomic bomb were determined for 70 samples up to a 1,500-m slant range from the epicenter. The specific activities of 60Co:Co were also determined for six samples near the Hiroshima hypocenter. First, the 152Eu data were investigated to find out the directional dependence of neutron activation. Directional anisotropy was not definite; however, there was an indication that the activation in the west-southwest was lower than in other directions. Second, measured 152Eu and 60Co radioactivity data were compared with activation calculations based on DS86 neutrons. It is clearly shown that the measured data are lower than the calculation near the hypocenter and vice versa at long distances beyond 1,000 m. The calculated-to-measured ratios of 152Eu are 1.6 at the hypocenter, 1.0 at approximately 900 m, and 0.05 at a 1,500-m slant range. Present results indicate that systematic errors exist in the DS86 neutrons concerning the source-term spectrum, neutron transport calculations in air, and/or activation measurements

  15. The effect of 60Co γ-rays on con A and LPS induced lymphocytes

    The effect of 60Co γ-rays on lymphocytes induced by Con A and LPS and the relationship between these two groups of cells were investigated by means of 3H-TdR incorporation. The study showed that in vitro, Con A cells were able to promote the inducing effect of LPS to B cells. When Con A cells were irradiated by 10 Gy γ-rays, the 3H-TdR incorporation value reduced significantly and the stimulating effect of Con A cells on LPS cells disappeared. Having been irradiated by γ-rays, LPS cells were not be able to be stimulated by normal Con A cells. When the groups of cells were incubated together after irradiation, the synergistic function disappeared, furthermore the suppressive effect of Con A cells on LPS cells emerged. When these two groups of cells were investigated by means of agar culture, the suppressive effect of 10 Gy γ-rays on lymphocytes colony formation was more obvious. Tests on 7 patients who were suffering from carcinoma of nasoparynx showed that after a course of treatment with 60Co γ-rays, the incorporation value in Con A cells became much smaller, the stimulating effect of Con A cells on LPS cells disappeared. LPS cells could not be stimulated by normal Con A cells. The study demonstrated that the radiosensitivity of Con A cells is higher than that of LPS cells

  16. Radiation quality of tritium: A comparison with 60Co gamma rays

    In a previous study, microdosimetric simulations were performed for tritium uniformly distributed in a medium, and for tritium bound to biologically critical sites of dimensions from 10 nm to 2 μm. Results of local energy density, i.e. energy deposition in microscopic regions, are different for these two cases. Based on the spatial distribution of energy deposition, dose mean lineal energies are calculated for tritium in the forms of tritiated water (HTO) and organically bound tritium (OBT). The dose mean lineal energies of OBT are about a factor of 1.7 higher than those of HTO in a wide range of target dimensions of biological interest. The results are consistent with radiobiological findings that OBT is about twice as effective as HTO. In this study, the same calculations were performed for 60Co gamma rays in a wide range of target dimensions of biological interest (10 nm to 2 μm). Compared with 60Co gamma rays, the estimated relative biological effectiveness could vary from 1.3 to 3.5 for HTO, and 2.3 to 5.6 for OBT. The results are consistent with radiobiological findings for various biological endpoints in different biological systems that OBT is about twice as effective as HTO. (authors)

  17. Sorption behavior of human bone powder towards 60 Co and 65 Zn

    Human bone powder 30-40 Μ in diameter was prepared from human bone femurs as fat-free (FFB), protein-free (PFB) or left untreated as raw bone powder (RB). The sorption behavior of human bone powder towards60 Co and 65 Zn was studied. The uptake changed with the type of bone powder to be : PFB>FFB>RB. The increase in the concentration of cobalt(from 10-6 to 10-1 Mole/litre)and of zinc (from 10-7 to 10-4 M/1) increased the uptake of 60 Co and 65 Zn. Freunclich-type isotherm was successfully applied on the uptake data of both ions and the slopes of these isotherms were, nearly, directly proportional to their uptake values. The uptake was found to be less influenced by the PH. In case of cobalt the uptake increased till PH 4, followed by a plateau till PH 8 while in case of zinc the PH effect is much less pronounced

  18. Mathematical Modelling of Immobilization of Radionuclides 137Cs and 60Co in Concrete Matrix

    Transport phenomena involved in the leaching of a radioactive material from a cement composite matrix are investigated using an empirical method employing a polynomial equation. To assess the safety for disposal of radioactive waste-cement composition, the leaching of 137Cs and 60Co, from a waste composite into a surrounding fluid has been studied. Leaching tests were carried out in accordance with a method recommended by IAEA . Determination of retardation factors, KF and coefficients of distribution, kd, using a simplified mathematical model for analyzing the migration of radionuclides, has been developed. Transport phenomena involved in the leaching of a radioactive material from a cement composite matrix are investigated using an empirical method employing a polynomial equation. In our experiment we have analyzed mechanism of 137Cs and 60Co leaching values during a period of 60 days. Results presented in this paper are examples of results obtained in a 25 year mortar and concrete testing project, which will influence the design of the engineered trenches system for a future central Serbian radioactive waste storage center.(author).

  19. Detection and thermoluminescence of coriander (Coriandrum sativum L.) irradiated with {sup 60}Co; Deteccion y termoluminiscencia del cilantro (Coriandrum sativum L.) irradiado con {sup 60}Co

    Ruiz G, B. [Departamento de Agricultura y Ganaderia, Universidad de Sonora, 083190 Hermosillo, Sonora (Mexico); Cruz Z, E. [Unidad de Irradiacion y Seguridad Radiologica, Instituto de Ciencias Nucleares, UNAM, A. P. 70-543, 04510 Mexico D. F. (Mexico); Barboza F, M. [Centro de Investigacion en Fisica, Universidad de Sonora, A. P. 5-088, 083190 Hermosillo, Sonora (Mexico)

    2009-10-15

    The fresh and dried coriander (Coriandrum sativum L.) is a spice of high commercial value as food for consumption in Mexico. Their hygienic quality is often poor due to some factors: contaminants present in irrigation water and the cultivation atmosphere, harvesting and post harvest handling, mainly. The process by radiation is an alternative to achieve the sterilization to adequate dose for the hygienic quality for its consumption. However, irradiation also involves food detection exposed to radiation. This paper presents detected results on the dried coriander that was obtained from fresh samples and thermoluminescent properties such as glow curves structure from low doses (0.5 Gy) to high (15 kGy), the dose response, thermoluminescent signal decay, in order to determine the loss of stability during the storage of the poly mineral fraction. We obtained the inorganic fraction separation of the organic part of particle sizes of 10 {mu}m by the Zimmerman method. The samples were exposed at two dose ranges; 0.5-400 Gy and 0.5-15 kGy of gamma radiation with {sup 60}Co. The limit of thermoluminescent detection of the irradiated coriander samples was from 1 Gy. The glow curves were at a broad band of 35-400 C, with a maximum thermoluminescence around 182-196 C, and run at 164 C for high doses of 15 kGy. The range of linear response to dose was 4-25 Gy, whereas higher doses than the kGy order the response increase with the dose. The thermoluminescent properties of the coriander poly mineral fraction, show it can be used to identify irradiated food at gamma doses relatively low and even in doses of commercial interest due to the high stability of thermoluminescent signals. (Author)

  20. Effect of {sup 60}Co radiation processing in mate (Ilex paraguariensis); Efeito do processamento por radiacao de {sup 60}Co na erva-mate (llex paraguariensis)

    Furgeri, Camilo

    2009-07-01

    The mate (Ilex paraguariensis), a native species from South America, is mainly consumed as typical beverage called chimarrao and terere. An important problem that has been afflicting this product since a long time is its natural fungal contamination responsible to affect its physical, health and nutritional qualities. In order to improve this product quality, radiation processing can be effective in reducing pathogens levels, with minimal nutritional and sensory changes. The aim of this study was to evaluate the effectiveness of gamma radiation from {sup 60}Co at doses 0, 3, 5, 7 and 10 kGy in reducing fungal contamination in mate, as well as analyze its nutritional and sensory characteristics. The following methodologies were applied: analysis of yeast and mold, total phenolic compounds analysis, antioxidant analysis, quantification of phenolic compounds and xanthines by liquid chromatography and sensory analysis. Microbiological analysis showed a decreasing molds and yeasts growth with increasing radiation doses. Regardless of the radiation dose applied there were no decrease of total phenolic compounds in both infusions. Chimarrao samples irradiated with 7 and 10 kGy showed a decrease in the DPPH radical-scavenger activity, nevertheless for terere samples, there were no significant difference. Chimarrao chromatographic profile did not show a variation on xanthines quantification, however a 10 kGy radiation dose caused a change to phenolic compounds quantitative profile. Terere samples did not show any significant difference to any analyzed compounds. Sensory analysis did not exhibit a significant difference between irradiated and non irradiated chimarrao samples, as well as between irradiated and non irradiated terere samples. It could be concluded that gamma radiation processing of mate may be a feasible alternative to industry, since there was a reduction on fungal contamination, without changes in sensory qualities and with minimum alterations in quantitative

  1. Biochemical and pharmacological characterization of irradiated crotamine by gamma rays of {sup 60}Co; Caracterizacao bioquimica e farmacologica da crotamina irradiada por raios gama de {sup 60}Co

    Oliveira, Karina Corleto

    2014-07-01

    The serum production in Brazil, the only effective treatment in cases of snakebites, uses horses that although large size, have reduced l lifespan compared with horses not immunized. Ionizing radiation has been shown as an excellent tool in reducing the toxicity of venoms and toxins isolated, and promote the achievement of better immunogens for serum production, and contributing to the welfare of serum-producing animals. It is known, however, that the effects of ionizing radiation on protein are characterized by various chemical modifications, such as fragmentation, cross-linking due to aggregation and oxidation products generated by water radiolysis. However, the action of gamma radiation on toxins is not yet fully understood structurally and pharmacologically, a fact that prevents the application of this methodology in the serum production process. So we proposed in this paper the characterization of crotamine, an important protein from the venom of Crotalus durissus terrificus species, irradiated with {sup 60}Co gamma rays. After isolating the toxin by chromatographic techniques and testing to prove the obtaining of pure crotamine, it was irradiated with gamma rays and subjected to structural analysis, Fluorescence and Circular Dichroism. Using high hydrostatic pressure tests were also conducted in order to verify that the conformational changes caused by radiation suffer modifications under high pressures. From the pharmacological point of view, muscle contraction tests were conducted with the objective of limiting the action of crotamine in smooth muscle as well as the change in the action of toxin caused structural changes to the front. Analysis of Circular Dichroism and Fluorescence showed changes in structural conformation of crotamine when subjected to gamma radiation and that such changes possibly occurring in the secondary and tertiary structure of the protein. The observed in pharmacological tests showed that the irradiated crotamine was less effective

  2. Inhibition of MAPK and PKC pathways by 60Co γ-radiation in cultured vascular smooth muscle cells

    Objective: To investigate the signal transduction pathways inhibited by 60Co γ-radiation in cultured vascular smooth muscle cells (VSMC). Methods: The cultured VSMC were irradiated with 60Co γ-radiation of 3.5, 7.0 and 14 Gy respectively. VSMC proliferation was measured by 3H-TdR incorporation, while PKC, MAPK activities were determined by radioactivity assay. Results: Proliferation of VSMC was inhibited by 7.0, 14 Gy 60Co γ-irradiation and the activities of PKC, MAPK were decreased significantly. Conclusion: Inhibitory effect of 7.0, 14 Gy 60Co γ-irradiation on proliferation of VSMC might be resulted from decrease of the activity of PKC, MAPK

  3. Ramp-edge junctions between superconducting Nd1.85Ce0.15CuO4 and La1.85Sr0.15CuO4

    Hoek, M.; Coneri, F.; Renshaw Wang, X.; Hilgenkamp, H.

    2016-03-01

    We have fabricated in-plane ramp-edge junctions between Nd1.85Ce0.15CuO4 (NCCO) and La1.85Sr0.15CuO4 (LSCO) where both layers are superconducting. At the interface, we find an insulating barrier in electronic transport. The barrier is shown to be a tunneling barrier with a combination of inelastic and elastic tunneling, the former is indicated by the appearance of the LSCO phonon density of states in {{{d}}}2I/{{d}}{V}2 measurements and the latter is inferred from the temperature dependence of the conductance. The energy scale of the barrier is smaller than would be expected from band alignment found by considering the cuprates as degenerate semiconductors. It is closest to the scenario where hybridization of the O 2p valence band states dictate band alignment. Additional experiments with overdoped interlayers of Nd1.8Ce0.2CuO4 and La1.75Sr0.25CuO4 show that the origin of the barrier is most likely a combination of electronic depletion mainly in the NCCO and a strain effect in the LSCO.

  4. Fabrication of SiO2-doped Ba0.85Sr0.15TiO3 glass-ceramic films and the measurement of their pyroelectric coefficient

    SiO2-doped Ba0.85Sr0.15TiO3 (SBST) glass-ceramic (g-c) films with perovskite structure have been prepared on Pt/Ti/SiO2/Si substrates by sol-gel technique. Differential thermal analysis (DTA), X-ray diffraction (XRD) and atomic force microscopy (AFM) are employed to analyze the synthesize process and microstructure of SBST g-c films. The ferroelectricity and crystallization behavior of SBST films are discussed. It is found that the starting synthesize temperature of SBST15 film is larger than that of pure barium strontium titanate (BST) film for about 60 deg. C. The grain sizes decrease and the ferroelectricity of SBST g-c films is degenerated, but their loss tangent and leakage current density decrease with increasing SiO2 contents. The temperature coefficient of dielectric (TCD) and the pyroelectric coefficient γ of the films are measured. The results show that TCD and the pyroelectric coefficient γ of SBST5 film at 20-25 deg. C are, respectively, 4.6% deg. C-1 and 8.1x10-8 C cm-2 K-1, which is about 2/3 value of the pure BST films. BST g-c film with 5 mol% SiO2 dopant is hopeful to be the advanced candidate material for uncooled infrared focal plane arrays (UFPAs) applied at near room temperature

  5. Correlation between superconductivity and normal-state properties in the La/sub 1. 85/Sr/sub 0. 15/ (Cu/sub 1-//sub x/Zn/sub x/)O/sub 4/ system

    Xiao, G.; Bakhshai, A.; Cieplak, M.Z.; Tesanovic, Z.; Chien, C.L.

    1989-01-01

    Superconducting and normal-state properties have been studied in the La/sub 1-85/Sr/sub 0.15/ (Cu/sub 1-//sub x/Zn/sub x/)O/sub 4/ system with 0less than or equal toxless than or equal to0.06. The value of T/sub c/ decreases rapidly with the Zn content and vanishes as 2.1 at. % of Zn is doped into the Cu sublattice. Metallic resistivity is observed when superconductivity disappears at x = 0.02. The suppression of T/sub c/ is not caused by the reduction of carrier concentration which should remian constant in the Zn-doped samples, but rather due to the filling of the local Cu d/sub x//sub <2/-y/sup =/ state. The residual resistivity scales linearly with the Zn content as expected from the impurity scattering due to disorder. Quantitative analysis of the residual resistivity indicates that the mean free path due to disorder is about twice as large as the coherence length when T/sub c/ is suppressed to zero. The implication of this finding on the disorder pair-breaking effect will be discussed. The value of T/sub c/ is found to strongly correlate with the slope of the resistivity in relation to temperature. Qualitative analysis is carried out in both inelastic and elastic scattering process between carriers and other excitations.

  6. Superconducting and normal-state properties of La/sub 1.85/Sr/sub 0.15/Cu/sub 1-//sub x/Ga/sub x/BO4

    We have studied the superconducting and normal-state properties of La/sub 1.85/Sr/sub 0.15/(CU/sub 1-//sub x/Ga/sub x/)O4 (04 system. The disappearance of superconductivity is most likely due to the complete filling of the Cu local 3d band and not due to the pair-breaking effect induced by nonmagnetic disorder. The Ga doping induces localization of the Cu 3d holes as evidenced from the susceptibility measurements. The normal-state resistivity exhibits a minimum followed by a logarithmic increase as the temperature is lowered. The temperature of the minimum increases linearly with the Ga content. The logarithmic upturn in the resistivity indicates that neither an activation process nor variable range hopping is responsible for the low-temperature electronic transport. Among two other possible mechanisms, the Kondo effect and effect of localization and correlation, the Kondo effect gives a much better description of the temperature dependence of the resisitivity in the whole temperature range (4--300 K) and for all of the samples

  7. Correlation between superconductivity and normal-state properties in the La/sub 1.85/Sr/sub 0.15/ (Cu/sub 1-//sub x/Zn/sub x/)O4 system

    Superconducting and normal-state properties have been studied in the La/sub 1-85/Sr/sub 0.15/ (Cu/sub 1-//sub x/Zn/sub x/)O4 system with 0≤x≤0.06. The value of T/sub c/ decreases rapidly with the Zn content and vanishes as 2.1 at. % of Zn is doped into the Cu sublattice. Metallic resistivity is observed when superconductivity disappears at x = 0.02. The suppression of T/sub c/ is not caused by the reduction of carrier concentration which should remian constant in the Zn-doped samples, but rather due to the filling of the local Cu d/sub x//sub <2/-y/sup =/ state. The residual resistivity scales linearly with the Zn content as expected from the impurity scattering due to disorder. Quantitative analysis of the residual resistivity indicates that the mean free path due to disorder is about twice as large as the coherence length when T/sub c/ is suppressed to zero. The implication of this finding on the disorder pair-breaking effect will be discussed. The value of T/sub c/ is found to strongly correlate with the slope of the resistivity in relation to temperature. Qualitative analysis is carried out in both inelastic and elastic scattering process between carriers and other excitations

  8. Temperature and depth dependence of positron annihilation parameters in YBa/sub 2/Cu/sub 3/O/sub 7-. / and La/sub 1. 85/Sr/sub 0. 15/CuO/sub 4/

    Lynn, K.G.; Usmar, S.G.; Nielsen, B.; van der Kolk, G.J.; Kanazawa, I.; Sferlazzo, P.; Moodenbaugh, A.R.

    1987-01-01

    The temperature dependence of the positron annihilation parameters for YBa/sub 2/Cu/sub 3/O/sub 7-x/ x = 0.7, 0.4 and 0.0 and La/sub 1.85/Sr/0.15/CuO/sub 4/ were measured. The depth dependence of the YBa/sub 2/Cu/sub 3/O/sub 7/ was studied using a variable-energy positron beam showing a strong depth dependence in the Doppler line-shape extending up to an average depth of approx.5.0 ..mu..m. It was found that a transition in the Doppler line-shape parameter, ''S'', was associated with the superconducting transition temperature (T/sub c/) in YBa/sub 2/Cu/sub 3/O/sub 7-x/ x = 0.4 and 0.0 while no transition was observed in the superconducting YBa/sub 2/Cu/sub 3/O/sub 6.3/. Positron lifetime parameters in YBa/sub 2/Cu/sub 3/O/sub 7/ were found to be consistent with positrons localized at open volume regions (probably unoccupied crystallographic sites) in this material with a lifetime of 210 psec at 300 K. These results indicate that the electron density at these unoccupied sites increases, using a free electron model, approximately 9% between 100 and 12 K. 15 refs., 4 figs.

  9. Temperature and depth dependence of positron annihilation parameters in YBa/sub 2/Cu/sub 3/O/sub 7-x/ and La/sub 1. 85/Sr/sub 0. 15/CuO/sub 4/

    Lynn, K.G.; Usmar, S.G.; Nielsen, B.; van der Kolk, G.; Kanazawa, I.; Sferlazzo, P.; Moodenbaugh, A.R.

    1988-02-25

    The temperature dependence of the positron annihilation parameters for YBa/sub 2/Cu/sub 3/O/sub 7-//sub x/ x = 0.7, 0.4 and 0.0 and La/sub 1.85/Sr/sub 0.15/CuO/sub 4/ were measured. The depth dependence of the YBa/sub 2/Cu/sub 3/O/sub 7/ was studied using a variable-energy positron beam showing a strong depth dependence in the Doppler line-shape extending up to an average depth of approx.5.0 ..mu..m. It was found that a transition in the Doppler line-shape parameter, ''S'', was associated with the superconducting transition temperature (T/sub c/) in YBa/sub 2/Cu/sub 3/O/sub 7-x/ x = 0.4 and 0.0 while no transition was observed in the nonsuperconducting YBa/sub 2/Cu/sub 3/O/sub 6.3/. Positron lifetime parameters in YBa/sub 2/Cu/sub 3/O/sub 7/ were found to be consistent with positrons localized at open volume regions (probably unoccupied crystallographic sites) in this material with a lifetime of 210 psec at 300 K. These results indicate that the electron density at these unoccupied sites increases, using a free electron model, approximately 9% between 100 and 12 K.

  10. Modulation of transport properties of optimally doped La{sub 1.85}Sr{sub 0.15}CuO{sub 4} thin films via electric field modification of the grain boundaries

    Hassan, Muhammad Umair [Center for Micro and Nano Devices, Department of Physics, COMSATS Institute of Information Technology, Islamabad (Pakistan); Cavendish Laboratory, Cambridge (United Kingdom); Wimbush, Stuart C. [The MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington (New Zealand)

    2015-09-15

    Modulation of the transport properties of a superconducting La{sub 1.85}Sr{sub 0.15}CuO{sub 4}-based ionic-liquid gated transistor has been achieved. For an applied gate bias V{sub g} ≥ 2 V, the characteristic sheet resistivity vs. temperature (R{sub s}-T) curves exhibit a fully reversible foot feature below the superconducting transition temperature (T{sub c}). In contrast to the behaviour expected from the large charge carrier density of this high-T{sub c} superconductor material, the normal state conductance above T{sub c} also exhibits a large modulation, indicating a larger charge screening length than that predicted from a simple Thomas-Fermi model. We regard these changes as due to electrostatic modification of the charge density at structural imperfections such as grain boundaries present within the sample. Such modification alters the coupling between superconducting domains and dictates the overall R{sub s}-T trend of the gated film. To explain our findings, we employ Mannhart's model of electronic band bending at the grain boundaries and propose that this band bending can be modulated by large electric fields resulting in the observed modulation of the transport properties of the device. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Bio-geochemical behavior of 90Sr, 137Cs and 60Co in tropical soil

    One manner to assess the bio-geochemical behavior of radionuclides in soils is the integration of experimental methods results obtained in the laboratory with results obtained in field experiments. In this work was used an alternative sequential chemical extraction protocol to evaluate mobility of radionuclides as a function of some physico-chemical conditions operationally defined: Slightly acidic phase: CH3COOH + CH3COONa 1:1, pH 4.7, shacked at room temperature; Easily reducible phase: NH2OH.HCl (0.1 M), pH 2, shacked at room temperature;Oxidizable phase: H2O2 (30%) + HNO3, pH 2, CH3COONH4 (1 M);shacked at room temperature; Alkaline phase: NaOH (0.1 M), pH 12, shacked at room temperature; Resistant phase: Aqua regia heated to 50 deg C / 30 min. The results obtained experimentally indicate the vulnerability of some Brazilian soils due to the higher radionuclide transfer to plant. Although it seems clear that it is difficult to identify which soil property will determine a given TF, the results of geochemical partition for 137Cs, 90Sr and 60Co obtained in slightly acidic phase were very consistent with the TF data for reference plants or with some of the soil properties recognized in the specialized literature as related with mechanisms of sorption of Cs (e.g. exchangeable K, organic matter and iron oxides content), Co (e.g. manganese oxide) and Sr (pH and exchangeable Ca). The 137Cs distribution in soil showed that Fe oxides are the main sink for this element in all type of soil and 16 years after contamination the 137Cs the TF remains almost the same in Goiania soil. The 60Co distribution in soil showed that Mn oxides are the main sink for this element in all type of soils and in the Nitisol, 5 years after contamination, the 60Co was not detected as bioavailable (in the slightly acidic phase) neither detected in plant or were detectable with values very close to the detection limit. In the Nitisol, it is possible that reduction in 137Cs transfer is also

  12. Evaluation of fruit productivity and quality in Hass avocado submitted to 60Co gamma radiation

    Evaluation of productivity, postharvest behavior and fruit quality was performed on four years Hass avocado trees irradiated with 60 Co gamma rays in doses of 5, 10, 15, 20 and 25 Gy, established in the ''La Labor'' Experimental Center of the Centro de Investigaciones Cientificas y Tecnologias del Aguacate en el Estado de Mexico (CICTAMEX) at Temascaltepec Mexico. Productivity had a significant increase in the dose of 15 Gy being the average number of fruits nearly 400 % more than the control at fruit setting, being such difference reduced at fruit harvesting to 300 %. In regard to postharvest performance, the respiration index (mg CO2/kg/hr) did not show significant differences among treatments. Also others variables such as physiological weight losses, texture, maturity pattern, and sensorial tests (color, flavor, aroma, texture) were not different in regard to the control. This mean that radiation has altered productivity but not the quality and postharvest behavior of fruits. (Author)

  13. EVALUATION OF THE MIGRATION POTENTIAL FOR 60Co AND 137Cs AT THE MAINE YANKEE SITE

    The objective of this report is to discuss the degree of sorption and desorption of 137Cs and 60Co that may be associated with the granite bedrock and the ''popcorn'' cement drain system that underlie the Maine Yankee Containment Foundation. The purpose is to estimate how much retardation of these two radionuclides takes place in groundwater that flows in the near-field of the Containment Foundation, specifically with respect to contamination originating at the PAB Test Pit. Specific concerns revolve around the potential for the contamination originating near the PAB to create a radioactive dose to a hypothetical ''resident farmer'' using a well intercepting this water to exceed 4 millirems/yr

  14. Radiation esophagitis in the opossum: radioprotection with indomethacin. [/sup 60/Co

    Northway, M.G.; Libshitz, H.I.; Osborne, B.M.; Feldman, M.S.; Mamel, J.J.; West, J.H.; Szwarc, I.A.

    1980-05-01

    Twenty-five opossums were evaluated before irradiation by fiberoptic endoscopy and air-contrast barium esophagram examination. All animals received 2250 rad /sup 60/Co-irradiated in a single exposure to the entire esophagus and lower exophageal sphincter. Animals received treatment with indomethacin. Acute esophagitis occurred 7 to 10 days postirradiation in control animals and was characterized by erythema, ulceration, and sloughing of esophageal mucosa as determined by air-contrast barium esophagram, endoscopy, and histology. Prostaglandin-treated animals showed more severe evidence of esophagitis than control animals. Indomethacin-treated animals showed no signs or only mild esophagitis posttreatment. It is concluded that indomethacin treatment may significantly reduce the severity of radiation esophagitis perhaps by blockade of prostaglandin synthesis.

  15. The study of mildew proof effect of 60Co γ irradiation on leather shoes

    Leather products occupy an important place in the national economy. In order to prevent from mildewing of leather products in storage, transportation and sale, the packed shoes were irradiated with 60Co γ ray. Test materials are cattle, sheep and pig leather shoes. The results shows that: 1. There are 11 types of molds which make leather shoes mildewed: Oospora sp, Rhizopus oryzae Went and Grrelings, Aspergillus flavus Link, Aspergillus terreus thom, Monilia sp, Botrytis sp, Aspergillus niger V. Tiegh, Penicillum Lividum Westling, Penicillum Corylophilum Dieckx, Penicillum Cyaneum (B. and S.) Biourge and Penicillum Verrulosum Peeyrone. 2. The three types of shoes packed with polyethylene film can be prevented from mildewing after irradiation at level of 12 kGy. 3. The irradiation at 30 kGy does not change the physical properties of the shoes. 4. The irradiated shoes packed with polyethylene film can prevent mildewing, but unpacked ones would be mildewed again

  16. Measurements of (60)Co in massive steel samples exposed to the Hiroshima atomic bomb explosion.

    Gasparro, Joël; Hult, Mikael; Marissens, Gerd; Hoshi, Masaharu; Tanaka, Kenichi; Endo, Satoru; Laubenstein, Matthias; Dombrowski, Harald; Arnold, Dirk

    2012-04-01

    To study discrepancies in retrospective Hiroshima dosimetry, the specific activity of (60)Co in 16 steel samples from Hiroshima was measured using gamma-ray spectrometry in underground laboratories. There is general agreement between these new activity measurements and the specific activities derived from previously calculated dose values on the one hand and former measurements of samples gathered at distances less than 1,000 m from the center of the explosion ( 1,300 m slant range) were mainly cosmogenically induced. Furthermore, at long range, these results are in disagreement with older measurements whose specific activity values were 10 to 100 times higher than predicted by computer model calculations in DS86 and DS02. As a consequence, the previously reported discrepancy is not confirmed. PMID:22378201

  17. 3D visualization design and implementation in 60Co container CT inspection system

    60Co γ-ray container inspection system (TC-Scan), developed at Institute of Nuclear and New Energy Technology (INET) of Tsinghua University, is installed at the customs for air-cargo or mega-object inspection against smuggling and prohibited objects. With the development of computer science and technology, 3D visualization technology applied to CT inspection system becomes a hotspot. In this paper, a volume rendering visualization system is designed and implemented for TC-Scan, based on ray-casting algorithm. In order to keep flexibility and compatibility for further development, the 3D rendering subsystem is independent from acquisition and reconstruction subsystems. Final rendering results demonstrate legible and distinct 3D vision for container inspection, which improves inspection validity. (authors)

  18. A preliminary study on doses of 60Co-γ ray for mutation breeding of roegneria

    Six groups from three species of Roegneria were radiated with eight ladders of 60Co-γ ray for finding the most suitable absorbed dose. The dose ladders were CK (O Gy), 50 Gy, 100 Gy, 150 Gy, 200 Gy, 250 Gy, 300 Gy and 400 Gy. The half-lethal dose of six groups, generated by multi-Target Single Hit Model Equation, were from 59.6 Gy to 172.8 Gy. Germination percentage of seeds, height of seeding, plant survival percentage and setting percentage were investigated. The most suitable absorbed doses of each species primarily were deduced from these data. The research provide a valuable reference for Roegneria mutation breeding on choosing the absorbed does. (authors)

  19. The specific absorbed dose constant: comparison of values published for 60Co photons

    For the specific absorbed dose constant for 60Co photons, three values quoted directly in the literature and two derived indirectly from published information are reported. The three publications giving the direct values mention no medium of absorption, whereas the other two specify tissue. A database of the specific absorbed dose constant is generated for each of 14 media namely air, water, bone and 11 types of soft tissue. These values are consistent with the three directly quoted values plus one of the indirectly obtained values. Air is found to be unlikely as the medium for the first three; and appropriate media for these are suggested. For the other two values, the generated database suggests that one is too small to be accurate; while the other is correct for tissue (as stated in the publication). An apparent error of 103 is identified in one of the values directly quoted. (author)

  20. Cell survival of human tumor cells compared with normal fibroblasts following 60Co gamma irradiation

    Three tumor cell lines, two of which were shown to be HeLa cells, were irradiated with 60Co gamma irradiation, together with two cell cultures of normal human diploid fibroblasts. Cell survival was studied in three different experiments over a dose range of 2 to 14 gray. All the tumor cell lines showed a very wide shoulder in the dose response curves in contrast to the extremely narrow shoulder of the normal fibroblasts. In addition, the D/sub o/ values for the tumor cell lines were somewhat greater. These two characteristics of the dose response curves resulted in up to 2 orders of magnitude less sensitivity for cell inactivation of HeLa cells when compared with normal cells at high doses (10 gray). Because of these large differences, the extrapolation of results from the irradiation of HeLa cells concerning the mechanisms of normal cell killing should be interpreted with great caution

  1. 60Co gamma radiation effect on AlGaN//AlN/GaN HEMT devices

    The testing techniques and experimental methods of the 60Co gamma irradiation effect on AlGaN/AlN/GaN high electron mobility transistors (HEMTs) are established. The degradation of the electrical properties of the device under the actual radiation environment are analyzed theoretically, and studies of the total dose effects of gamma radiation on AlGaN/AlN/GaN HEMTs at three different radiation bias conditions are carried out. The degradation patterns of the main parameters of the AlGaN/AlN/GaN HEMTs at different doses are then investigated, and the device parameters that were sensitive to the gamma radiation induced damage and the total dose level induced device damage are obtained. (authors)

  2. A case of radiation gastroduodenitis caused by 60Co-irradiation therapy for hepatoma

    A 56-year-old man with hepatoma, who had been treated with total 3,960 rad of 60Co-irradiation 2 months previously, was readmitted to the hospital because of fever and anemia. Following admission, he passed tarry stools every day. Barium meal examination revealed esophageal varices and erosive gastritis of the antrum. At endoscopy, many hemorrhagic erosions were found in the gastric antrum and the first part of duodenum, which were located in the irradiation area. Since repeated blood transfusion failed to improve anemia, a complete fasting with intravenous hyperalimentation and antacid therapy were started. Two months later, feeding was started and thereafter continued without any appreciable GI bleeding or worsening of anemia. Endoscopic examination at this time revealed only a few erosions scattered over the edematous antral mucosa as well as the proximal duodenum. IVH, antacids and abstinence from food seem to be an effective measure in the treatment of radiation injury of the gut. (author)

  3. 60Co gamma radiation effect on AlGaN/AlN/GaN HEMT devices

    WANG Yan-Ping; LUO Yin-Hong; WANG Wei; ZHANG Ke-Ying; GUO Hong-Xia; GUO Xiao-Qiang; WANG Yuan-Ming

    2013-01-01

    The testing techniques and experimental methods of the 60Co gamma irradiation effect on AlGaN/AlN/GaN high electron mobility transistors (HEMTs) are established.The degradation of the electrical properties of the device under the actual radiation environment are analyzed theoretically,and studies of the total dose effects of gamma radiation on AlGaN/AlN/GaN HEMTs at three different radiation bias conditions are carried out.The degradation patterns of the main parameters of the AlGaN/AlN/GaN HEMTs at different doses are then investigated,and the device parameters that were sensitive to the gamma radiation induced damage and the total dose level induced device damage are obtained.

  4. Effects of 60Co γ-ray irradiation on growth characters of Chamaecrista seeds

    The seeds of 5 Chamaecrista varieties were irradiated by 60Co γ-ray of 300 Gy and the effects on M1 generation were studied. The results showed that the emergence of 5 Chamaecrista varieties decreased in some degree ; the stem-length of variety 34721 was significantly decreased, the stem-diameter of variety 2219 and the leaf-width of variety 2219 were significantly increased. The number of branch, leaf and leaf-length had no significant difference, but there were many black blots in the leaf during early period; the dry-weight of aerial part changed in two directions, either increased (92985) or decreased (34721). The total N of variety 2217 were significantly increased and the total P of variety 92985 were significantly decreased. The squaring stage, initiate flower stage, full bloom stage, pod-bearing stage, peak pod setting stage and maturing stage had changed in two direction, either early, or late

  5. Effect of 60Co γ-irradiation on the infectivity of toxoplasma gondii bradyzoites

    Homogenates of mouse brains harboring toxoplasma NT strain cysts were irradiated at various doses of 60Co γ ray and digested with 0.4% trypsin buffer to release bradyzoites from cysts. The suspensions containing various number bradyzoites were obtained through a serial 10-fold dilution in saline solution and inoculated intraperitoneally into mice separately. Infectivity of toxoplasma bradyzoites was determined by bioassay of mice. A group of mice inoculated with non-irradiated bradyzoites was used as control. Results showed that the minimal effective dose of γ rays controlling infectivity of toxoplasma NT strain bradyzoites was 0.55 kGy. Effect of 0.1 kGy γ rays on infectivity of toxoplasma bradyzoites was not significant. Infectivity of bradyzoites irradiated at 0.45 kGy had 104 fold reduction in comparison with that of 0.1 kGy

  6. Effects of 60Co irradiation on virulent Toxoplasma gondii and its use in experimental immunization

    The effects of 60Co irradiation on the virulence and immunogenicity of the RG strain of Toxoplasma gondii was studied by infecting batches of mice with graded inocula of tachyzoites that had been exposed to radiation doses ranging from 0 to 20 000 rad. While doses of 15 000 and 20 000 rads appeared to be effective, and 10 000 rad nearly effective in annulling the virulence, irradiation at 5000 rad was only partially effective in rendering the organisms avirulent and could achieve only a prolongation of survival time of the inoculated mice. The survivors of higher irradiation inocula showed no evidence of the development of the parasite in them, but could resist a limited virulent challenge. The use of a booster inoculation improved both the quality and the duration of protective effect. (author)

  7. Biological effects of 60Co γ-irradiation on Laiwu ginger VM1 growth

    Rhizome of Laiwu ginger were treated with γ-irradiation at the doses of 0, 20, 40 and 60 Gy. The results showed that 60Co γ-irradiation inhibited the rhizome burgeoning, and decreased the survival rate of the seedlings, rate of leaf- expansion and the growth of plants (VM1). The inhibition effects became stronger with the increase of the irradiation dose. Different bands were found through the analysis of POD, EST isozymes and RAPD of VM1 plants, which showed that variation on molecular level occurred in VM1 plants. LD30-40 was appropriate for the irradiation of rhizomes of Laiwu ginger and the optimal irradiation dose was about 20- 30 Gy. (authors)

  8. Study on change of free radicals of bamboo with 60Co γ radiation

    Bamboo samples collected in mountain areas of Fujian province were mechanically pulverized into saw dust. This breaks the covalent bonds of bamboo molecules and free radicals are formed. ESR characterization of the bamboo saw dust samples of 20, 200 and 500 mesh showed that the relative intensity of the 500 mesh saw dust was the highest, and that of the 20 mesh was the lowest(g=2.0033). After 60Co γ-ray irradiation,the intensity of free radicals increased sharply. At>100 kGy, the free radicals tended to be saturated at about 40 times of the free radicals produced mechanically. The intensity of free radicals increased exponentially with the dose below 100 kGy, and decay coefficients of the free radicals in the three samples were different. (authors)

  9. Effect of dosage on property and structure of gelatin irradiated by 60Co γ-ray

    The gelatin was irradiated for 0-60 kGy dosages by 60Co γ-ray. The relationship of dosage and properties including viscosity, gel strength, mechanical property, molecular weight and protein component was discussed. The results show that there is a negative correlation between the dosage and intrinsic viscosity, relative viscosity, gel strength and molecular weight. With the increase of irradiation dosage, the γ, β, α chain content of gelatin decreases but the small molecules content increases, and relative molecular weight distribution changes wider. The elongation decreases but tensile strength of gelatin film increases. Compared with no irradiation one, the irradiation gelatin has more compact and smooth surface texture. It is assumed that when the limited water and oxygen exist during the irradiation process, cross-linking and degradation of gelatin molecular produce simultaneously and the main reaction is cross-linking. The reaction degree increases with the dosage. (authors)

  10. Reliability of planar silicon transistors exposed to 60Co γ rays

    This report gives an account of results obtained during investigations on the reliability of silicon Planar Transistors, irradiated by the 60Co γ rays. We consider in a first part the variation of the average values of the parameters of the lots under test. Then, a more complete statistical study is carried out (distribution of the values of the parameters within the lots; research of correlations, etc. ). It is clearly stated and shown that evaluation of the degradation of the gain of transistors depends on: the conditions of measurement (voltage, current), after irradiation; the polarisation of the elements during irradiation; the origin of manufacture of the lots under test (4 manufacturers). We show then the difficulties met to predict the behaviour of the transistors under radiation stress, and attempt is made to define practical rules for design engineers. (author)

  11. Determination of the sterilizing gamma radiation dose of 60Co to ACANTHOSCELIDES OBTECTUS imagos (col. bruchidae)

    This paper relates the results of experiments dealing with irradiation of adults of Acanthoscelides obtectus (Say, 1831). The insects were irradiated with doses of 0 (control), 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 and 20 krad gamma radiation of a 60Co source. After irradiation, the adults were kept for observation on beans (Phaseolus vulgaris) var. Jalo, in a controlled environmen t chamber at 30 +- 10C and 70 +- 5% relative humidity. Continuous weighing at weekly intervals was done 22 times, showing, by weight loss in percent, that the sterilizing dose for adults was 10,65 krad. It could also be observed that losses of less than 0,5% occured at 9 krad. For a possible employment on commercial scale, the ideal radiation dose for bean desinfestation would be 10 krad, after which no weight loss occurrence. (Author)

  12. The degradation of p-chloronitrobenzene in aqueous solution by 60Co-γ irradiation

    The degradation of p-Chloronitrobenzene (p-CNB) in aqueous solution was investigated by 60Co-γ irradiation. The concentrations of p-CNB and inorganic ions generated during the irradiation process were measured by HPLC and Ion Chromatography technology. And also, the factors affecting degradation degree, such as absorbed dose, radiation aura, were studied in detail. It was found that the degradation degree of p-CNB and the concentrations of ions increased with absorbed dose. The presence of O2 was more favorable to the degradation of p-CNB. Furthermore, the experimental results showed that both hydrated electron and hydroxyl radical generated from water radiolysis could degrade p- CNB effectively and produce Cl-, NO3-, NH4- in the solutions. (authors)

  13. Study for optimization of a 60 Co industrial irradiator of 250 k Ci

    This work presents results of a benchmark between calculated and experimental absorbed dose values for a typical product, in a 60 Co industrial irradiator, located at ININ, Mexico. The goal of this work is to reach a ± 10 % approximation between both values. ININ 60 Co industrial irradiator is a two level, two layer system with overlapping product configuration, 56 irradiation positions with an activity of around 250 k Ci. Calculated values were obtained by QAD-CGGP code. This code uses a point kernel technique, build-up factors fitting was done by geometrical progression and combinatorial geometry was used for 3 D system description. Main code modifications were related with source simulation by punctual sources and energy spectrum (16 energy groups) and anisotropic emission were also considered. Experimental data were obtained from routine dosimetry which was done with red acrylic pellets; they were irradiated together the product in predetermined positions, for 36 maximum and minimum absorbed dose values. Typical product was polypropylene Petri dish packages, apparent density 0.13 g/cm3. It was chosen because regular geometry (2 packages per full irradiator container) and enough amount for considering homogeneous loading inside irradiation chamber. Required minimum dose was 15 kGy. Results showed a 8% variation between calculated and experimental values for maximum absorbed dose (18.2 kGy vs 16.8 kGy) and 3 % variation for minimum absorbed dose (13.8 kGy vs 14.3 kGy); these results fixed with the original proposal. (Author)

  14. Polymer microcapsules prepared in inverse emulsion by 60Co γ-ray induced interfacial polymerization

    Inverse emulsion was usually applied to polymerization of hydrophilic monomers, such as acrylamide, acrylic acid, salt of acrylic acid, and N-isopropylacrylamide. However, there have been few reports of one-step synthesis hydrophobic polymer hollow spheres or microcapsules in inverse emulsion system via an interfacial polymerization approach under mild reaction conditions. The motivation of this work is to explore the formation mechanism of polymer microcapsules via γ-ray irradiation in W/O inverse emulsion system. Utilizing the strong reducing radical (OH, hydrated electron) and oxidant radical (eaq-, hydroxyl radical) produced in aqueous phase by 60Co γ-ray irradiation, two interfacial redox initiation systems were proposed and applied to the preparation of polymer microcapsules. In this work, BPO (benzoyl peroxide)-eaq- and DMA (N, N-dimethyl aniline)-OH were used to control the polymerization position at the water-oil interface. High viscosity of external oil phase, high inner phase emulsion and polymeric surfactant were employed to depress the homogeneous nuclei and enhance stability of the inverse emulsion during polymerization. A typical inverse emulsion of water : Span80: kerosene : styrene = 20ml : 2.0g :10ml/4ml (including 0.050g BPO) was irradiated to 20 kGy by 60Co γ-rays at a dose rate of 65 Gy/min. Finally, polystyrene microcapsules were synthesized successfully with an average diameter of 400 nm and shell thickness of 50 nm. The productivity of micro-capsules decreased with the increasing of styrene content due to the homogeneous nuclei. When cyclohexane was used as the oil phase, porous polymer materials can be successfully obtained. Because of the multiplicity in choosing oil-soluble monomers and substances being dissolved in the aqueous phase, this approach revealed interests in encapsulation of bioactive materials or drugs. (authors)

  15. 60Co irradiation for sterilization of veterinary mastitis products containing antibiotics and steroids

    Tsuji, K.; Kane, M. P.; Rahn, P. D.; Steindler, K. A.

    Effects of 60Co irradiation for sterilization of veterinary mastitis products were evaluated. The mastitis products which were examined contained various combinations of antibiotics and steroids suspended in peanut oil vehicle. Bioburden data indicated that the unirradiated products were only occasionally contaminated with microorganisms. The D-values of the nonsterile product and environmental isolates were 0.028, 0.15, 0.017, and 0.018 Mrads for Aspergillus fumigatus, Penicillium oxalicum, Pseudomonas aeruginosa, and Pseudomonas maltophilia, respectively. The D-value of the biological indicator organism, Bacillus pumilus spores, in the vehicle was 0.27 Mrads. Thus, an irradiation dose of 1.6 Mrads would be sufficient to achieve six log cycles of destruction of the biological indicator organism. The minimum absorbed irradiation dose of 2.5 Mrads preferred by many countries for sterilization would achieve 9.3 log cycle destruction of the indicator organism and guarantee a probability of 1 × 10 -15 assurance for the most radio-resistant product isolate, Penicillium oxalicum. In order to examine short and long term chemical stabilities of active components, stability indicating high-performance liquid chromatographic (HPLC) methods for the determination of the following antibiotics and steroids were developed. They were: dihydrostreptomycin, neomycin, novobiocin, penicillin G, hydrocortisone acetate, hydrocortisone sodium succinate, and prednisolone. The rates of degradation and radiolytic degradation schemes for the majority of these compounds were elucidated. Formation of new compounds was not observed in these antibiotics and steroids upon 60Co irradiation. The compounds that increased by irradiation were inherently present in commercially available non-irradiated lots and/or can easily be formed by either acidic, basic, or thermal treatment.

  16. Analysis of the frequency of unstable chromosome aberrations in human lymphocytes irradiated with 60Co

    The aim of this study was to analyze the frequency of unstable chromosomal aberrations induced by gamma radiation from a 60Co source at two different doses. Samples were obtained from a healthy donor and exposed to 60Co source (Gammacel 220 ) located in the Department of Nuclear Energy of Pernambuco Federal University (DEN/UFPe/Brazil) with a rate of air Kerma to 3,277 Gy/h. Exposures resulted in absorbed dose 0.51 Gy and 0.77 Gy. Mitotic metaphases were obtained by culturing lymphocytes for chromosome analysis and the slides were stained with 5% Giemsa. Among the unstable chromosomal aberrations the dicentric chromosomes, ring chromosomes and acentric fragments were analyzed. To calculate the significance level the chi - square test was used, considering relevant differences between the frequencies when the value of p < 0.05. To calculate the significance level of the chi - square test was used, considering relevant differences between the frequencies when the value of p < 0.05. The results showed that there was significant difference of the frequencies of dicentric chromosomes (from 0.18 to 0.51 to 0.37 Gy to 0.77 Gy), however there was no statistically significant difference between the frequencies of acentric fragments ( 0.054 to 0, 51 Gy to 0.063 to 0.77 Gy) and ring chromosomes (0.001 to 0.51 Gy to 0.003 to 0.77 Gy). The low number of rings is found justified, considering that in irradiated human lymphocytes, its appearance is rare relative to dicentrics. The results confirm that dicentrics are the most reliable biomarkers in estimating dose after exposure to gamma radiation. These two points will make the calibration curve dose-response being built for Biological Dosimetry Laboratory of CRCN-NE/CNEN

  17. Phenotype and molecular analysis of M1 generation of stylosanthes irradiated by 60Co

    The seeds of Stylosanthes guianensis SW. ‘Reyan No.13’ were irradiated by 60Co at 0, 325, 487 and 974 Gy. Phenotype and molecular variations of Stylosanthes M1 generations were studied. Germination percentage, plant height, leaf length and stem diameter of M1 seedlings were determined using SRAP-PCR. Results showed that biological character indices of treatments were significantly lower than that of control (CK). Irradiation inhibited plant growth. Growth indices of 974 Gy treatment, except leaf length, were significantly lower than CK and other two treatments. Eight effective primers selected from 24 primers combination were used for SRAP-PCR. SRAP analysis revealed that the 57 of 88 DNA fragments were amplified showing polymorphisms. The average percentage of polymorphic bands was 64.77%. The effects of 60Coγ irradiation on DNA variation of seedlings were varied from different treatments. Numbers of polymorphic bands changed after irradiation. Coefficient of variation was in direct proportion to irradiation doses. Variation rates of 325 Gy, 487 Gy and 974 Gy treatments were 22.0%, 38.1% and 41.5%, respectively. The Nei’s genetic similarity coefficient of all treatments was ranged from 0.585 to 0.780 by software NTSYSpc 2.1 based on SRAP results and the average Nei's coefficient was 0.678. The Nei’s genetic similarity coefficient of 974 Gy treatment was 0.585 and variation degree was highest among all treatments, 487 Gy treatment was second and 325 Gy treatment was the lowest one. Based on present bands, four irradiated treatments were classified into two major groups by UPGMA cluster analysis. Group 1 included CK, 325 Gy and 487 Gy treatment and group 2 included 974 Gy. SRAP analysis determined variation of Stylosanthes after irradiation and the results of SRAP analysis were consistent with their biological indexes in some extent

  18. Adsorption kinetic regime of cocrystallization. The system ZnC2O4x2H2O-54MnC2O4x2H20

    The ZnC2O4x2H2O finely divided deposit surface properties have been investigated by the methods of electron microscopy, gas adsorption and isotopic exchange in 65Zn 54Mn adsorption from aqueous solutions with Mn2+ initial concentration of 4x10-6 - 5x10-4 mol/l has been studied using the same deposit. Characteristic frequencies of Zn2+ and Mn2+ transitions between layers, zinc and manganese oxalates masses in the first and second layers and local coefficients of cocrystallization of manganese and zinc oxalates in near-surface layers (lambda=0.38+-0.05 and lambda2=0.17+-0.04) have been calculated using representation on successive Zn2+ and Mn2+ transition to three near-surface monolayers and on reverse translation motion. A formula for the connection of lambda sub(γ) coefficients ( is a number of the surface layer) with a layer-to-surface distance has been depived. A possibility of the forecast of a dependence of effective cocrystallization coefficient of impurity with growing crystals on crystal growth rate has been revealed

  19. The accumulation and distribution of 60Co in carp (Cyprinus carpio) in water-fish compartment system

    In relation with nuclear safety assessment, the parameter of radionuclide transfer in the environment is significantly needed for internal doses estimation received by public trough environment - food product - human pathways. International Atomic Energy Agency (IAEA) has published the transfer parameter data for temperate zone in Technical Report Series 472. In order to complete the IAEA data, especially for tropical region, the accumulation and distribution of 60Co in carp (Cyprinus carpio) was experimentally studied based on the water-fish compartment system. The carp were cultured in 500L water containing 60Co of about 30 Bq.mL-1 in a water tank. The 60Co concentration in fish and water were measured using gamma spectrometer. The 60Co was accumulated and distributed in the fish tissues with the concentration ratio (CR) of 3.08 mL.g-1 1.55 mL.g-1 and 1.14 mL.g-1 for internal organs, bones, and muscle, respectively. The CR of 60Co in the fish will be useful in internal radiation dose estimation to human trough water-fish-human pathway, and will also complete the IAEA transfer parameter data for tropical region. (author)

  20. Preliminary Study on the Quantitative Value Transfer Method of Absorbed Dose to Water in 60Co γ Radiation

    SONG Ming-zhe

    2015-01-01

    Full Text Available Absorbed dose to water in 60Co γ radiation is the basic physics quantity in the quantitative value system of radiation therapy, it is very necessary for radiation therapy. The study on the quantitative value transfer method of absorbed dose to water in 60Co γ Radiation could provide important technical support to the establishment of Chinese absorbed dose to water quantity system. Based on PTW-30013 ionization chamber, PMMA water phantom and 3D mobile platform, quantitative value transfer standard instrument was established, combined with the requirement of IAEA-TRS398, developed preliminary study of 60Co absorbed dose to water quantity value transfer method. After the quantity value transfer, the expanded uncertainty of absorbed dose to water calibration factor of PTW-30013 was 0.90% (k=2, the expanded uncertainty of absorbed dose to water of 60Co γ reference radiation in Radiation Metrology Center (SSDL of IAEA was 1.4% (k=2. The results showed that, this value transfer method can reduce the uncertainty of 60Co absorbed dose to water effectively in Secondary Standard Dosimetry Laboratory.

  1. 60 Co accumulation by scenedesnus obliquus. Mechanism of uptake and relative contribution of radionuclide adsorption and absorption

    In this paper are presented the results of various 60Co accumulation and depuration experiments, carried out to assess the respective contributions of passive and active processes in the radionuclide uptake by Scenedesmus obliquus. The experiments were conduced on living illuminated cells, living cells maintained in darkness and dead cells. Exposure study shows that living illuminated cells and dead cells incorporated the same amount of available 60Co, in the order of 65%. In contrast, the radionuclide uptake by cells in darkness was very lower. Depuration experiments show that radiocobalt release by living illuminated cells and dead cells is an exponential process including two phases. The first, during which the decrease of the radioactivity was about 80%, corresponds to elimination of the 60Co adsorbed on the cell walls. During the second phase, the slight decrease of the radioactivity results from the intracellular 60Co desorption. The addition of EDTA in the depuration culture medium results in an almost instantaneous loss of 80% of the accumulated radionuclide. The results clearly indicate that 60Co uptake is mainly a passive phenomenon, since adsorption accounts for 80% of the accumulation and passive diffusion for about 10%. Metabolic assimilation contributes for a weak part

  2. Study on the effectiveness of some decontamination agents against skin contamination of {sup 137}Cs and {sup 60}Co

    Chon, Je Keun; Ji, Pyung Kook; Kwak, Sang Soo; Kim, Byung Tae; Park, Chong Mook [Nuclear Environment Technology Institute, Taejon (Korea, Republic of)

    1998-03-01

    In order to evaluate the effectiveness of some decontamination agents against skin contamination of {sup 60}Co and {sup 137}Cs, the experiments were carried out in this study. In the experiments, pig skin was used instead of human skin, {sup 60}CoCl{sub 2} and {sup 137}CsCl were used the liquid sources of skin contamination. To examine the effectiveness of decontamination agents, skin decontamination was tried using soup, EDTA, DAERICON which was developed for decontamination of radionuclides on the surface of building structure, and new decontamination agents such as IOCON, TRICON, and CHARCON, which were developed in this study. The absorption of radionuclides through the skin was evaluated by the gamma-ray detection on the surface of sample skin after radionuclides were penetrated into the skin during 16 hour soiling time. The results of this absorption experiment indicated that 11.5% and 3.2% of initial amounts of {sup 137}Cs and {sup 60}Co, respectively, were penetrated into the skin. In the experiment to remove the residual radioactivity fixed on the skin, KAERICON showed the decontamination rates up to 52.1%(decontamination factor of 2.1) and IOCON showed the equivalent decontamination rate (decontamination factor 1.9) for {sup 137}Cs. However, IOCON and CHARCON showed the poor decontamination rates of less than 20%(decontamination factor of 1.2) for {sup 60}Co, and KAERICON showed the poor decontamination rate (decontamination factor 1.1) for {sup 60}Co.

  3. Study on the effectiveness of some decontamination agents against skin contamination of 137Cs and 60Co

    In order to evaluate the effectiveness of some decontamination agents against skin contamination of 60Co and 137Cs, the experiments were carried out in this study. In the experiments, pig skin was used instead of human skin, 60CoCl2 and 137CsCl were used the liquid sources of skin contamination. To examine the effectiveness of decontamination agents, skin decontamination was tried using soup, EDTA, DAERICON which was developed for decontamination of radionuclides on the surface of building structure, and new decontamination agents such as IOCON, TRICON, and CHARCON, which were developed in this study. The absorption of radionuclides through the skin was evaluated by the gamma-ray detection on the surface of sample skin after radionuclides were penetrated into the skin during 16 hour soiling time. The results of this absorption experiment indicated that 11.5% and 3.2% of initial amounts of 137Cs and 60Co, respectively, were penetrated into the skin. In the experiment to remove the residual radioactivity fixed on the skin, KAERICON showed the decontamination rates up to 52.1%(decontamination factor of 2.1) and IOCON showed the equivalent decontamination rate (decontamination factor 1.9) for 137Cs. However, IOCON and CHARCON showed the poor decontamination rates of less than 20%(decontamination factor of 1.2) for 60Co, and KAERICON showed the poor decontamination rate (decontamination factor 1.1) for 60Co

  4. Evaluation of the effect of various mechanisms on the magnetoresistance of lanthanum manganites La{sub 0.85}Sr{sub 0.15}MnO{sub 3} with activation-type conductivity

    Gudin, S. A., E-mail: gudin@imp.uran.ru; Kurkin, M. I.; Neifel’d, E. A.; Korolev, A. V.; Gapontseva, N. N.; Ugryumova, N. A. [Russian Academy of Sciences, Institute of Metal Physics, Ural Branch (Russian Federation)

    2015-11-15

    A method is proposed that allows one to divide the magnetoresistance (MR) observed in manganites into three mechanisms: dimensional, orientational, and magnetic. The first two mechanisms are associated with the stratification of a substance into ferromagnetic and nonferromagnetic phases, which significantly differ in electric resistivity. The dimensional mechanism of MR is attributed to the effect of a magnetic field on the size of magnetic inclusions. The orientational mechanism of MR is determined by the dependence of electric resistivity on the mutual orientation of the magnetizations of magnetic inclusions. The magnetic mechanism of MR is determined by the properties of the magnetization of a ferromagnet, in particular, by the Curie–Weiss singularity on the temperature dependence of magnetic susceptibility at the Curie point. This mechanism exists in homogeneous substances, although its value may depend on the magnetic properties of inhomogeneities. The method is developed for substances with activation-type conductivity and is applied to the analysis of MR of La{sub 0.85}Sr{sub 0.15}MnO{sub 3} manganite near the Curie point, where the MR attains its maximum. The dimensional mechanism turns out to be dominant in magnetic fields H greater than the saturation field H{sub s} (H > H{sub s}). The orientational, dimensional, and magnetic mechanisms have a comparable effect on the MR for H < H{sub s}. The effect of the orientational mechanism on MR is relatively weak (does not exceed the third part of the total MR), although this mechanism determines the giant MR in multilayered metal films. The possibility of application of the method to the analysis of MR near the insulator–metal transition is analyzed.

  5. Effects of 60Co-γ-ray and cyclophosphamide on the contents of monoamine neurotransmitters in hypothalamus of rats

    The model of rats irradiated by 60Co-γ-ray(60Co) or injected by cyclophosphamide (Cy) was studied. It was found that the contents of monoamine neurotransmitters change greatly in the hypothalamus in both kinds of model. The contents of noradrenaline (NA) and dopamine (DA), and the ratio of DA to DOPAC increased significantly in hypothalamus of rats irradiated by 60Co. The contents of NA and the ratio of 5-hydroxyamine (5-HT) to 5-hychoxyindole acetic acid (5-HIAA) decreased markedly in lamus of rats injected by Cy. The author thinks that there is a certain relation between the monoamine neurotransmitters and the activity of methylation of NA and monoamine oxidase

  6. The effect of organic amendment on potential mobility and bioavailability of 137Cs and 60Co in tropical soils

    In this work the role of organic matter in the potential mobility and bioavailability of 137Cs and 60Co in Brazilian soil was investigated. Radish was cultivated in pots containing the top layer (0-20 cm) of a Histosol, Ferralsol and Nitisol spiked with 137Cs and 60Co. In the case of the Ferralsol and Nitisol samples, besides the control, two different rates of organic amendments were used. In these soils, a sequential extraction protocol was used to identify the main soil compartments that could be responsible for the variation of transfer factor values. Our results indicate that organic amendment could be suggested as a practical countermeasure for 137Cs and 60Co contamination, since it reduces bioavailability of radionuclides and, consequently, soil to plant transfer factor values by almost one order of magnitude in a short period of time

  7. Measurement of residual 60Co activity induced by atomic-bomb neutrons in Nagasaki and background contribution by environmental neutrons

    Residual 60Co activity in five steel samples induced by neutrons from the Nagasaki atomic bomb has been measured within about 1000 m from the hypocenter. The chemical separation of cobalt and nickel from steel samples was performed, and cobalt-enriched samples were prepared for all samples. Gamma-ray measurements were carried out with a low-background well-type germanium detector. The gamma-ray spectra for five samples were compared with the spectrum of a control sample to ensure that the observed 60Co was actually induced by A-bomb neutrons. The activation of cobalt by environmental neutrons was also investigated. It has been shown that the present 60Co data are consistent with earlier Hashizume's data. (author)

  8. Effects on agronomic traits of M1 by pollen of upland cotton irradiated by 60Co-γ ray

    [Objective] The aim was to provide reference for research on radiation and breeding of cotton pollen through irradiating common ripe pollen grain of upland cotton by 60Co-? Ray of varied doses. [Method] Ripe pollen grains of upland cotton were irradiated by 60Co-γ Ray with doses of 5, 10, 15, and 20 Gy, respectively, to learn radiation effect and select appropriate dose. [Result] Most properties of M1 obviously showed variation when dose was over 10 Gy; vitality, growth, and fertility were greatly inhibited when dose was 15 Gy which was almost semi-lethal concentration, and variation species were richest at the same time, which provided materials for practical breeding. [Conclusion] 60Co-γ Ray of 15 Gy was more suitable for inducing research for ripe pollen grains of upland cotton

  9. Study on the radiation research of differentiation state oxalis triaggularis purpurea regeneration system by 60Co γ-rays

    To study the mutation method of Oxalis triangularis purpurea, the Oxalis triangularis purpurea regeneration system generated from the leaf was irradiated by 60Co γ-rays. It shows that the number of adventitious bud and root induced from the differentiation state Oxalis triangularis purpurea regeneration system are cut down with the increment of absorbed doses. After growth seedling length has not distinctly reduced while the absorbed dose is 10 Gy. And it has reduced at 25 Gy and 50 Gy of 60Co γ-rays irradiation with the differentiation state tissue of Oxalis triangularis purpurea. The mutation, such as leaf number, leaf colour and leaf shape mutation, mainly the leaf number mutation (76% of the total mutation) occur in the 60Co γ-rays irradiated group. The M2 mutation rate is 2.9%, and the main mutations are leaf number mutations. (authors)

  10. Effect of 60Co γ-rays irradiation on antioxidant enzymes activities in transgenic and non-transgenic tobacco seedlings

    Changes of activities of antioxidant enzymes in pprI-transgenic tobacco seedlings and non-transgenic tobacco seedlings after different doses 60Co γ-rays irradiation were studied. The results showed that the activity of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) in pprI-transgenic tobacco seedlings and non-transgenic tobacco seedlings were gradually increased after different doses 60Co γ-rays irradiation. The activity of SOD was to the maximum at 100 Gy treatment, but the activity of POD and CAT at 300 Gy treatment, and then these three antioxidant enzymes gradually decreased with the increase of irradiation dose. Quantitative real-time PCR analysis also revealed that the over-express of these antioxidant enzymes were induced after different doses 60Co γ-rays irradiation and were consistent with the variance of their enzymic activities, which enhanced the tolerance of tobacco against irradiation. (authors)

  11. Measurement of residual 60Co activity induced by atomic-bomb neutrons in Nagasaki and background contribution by environmental neutrons.

    Shizuma, Kiyoshi; Endo, Satoru; Hoshi, Masaharu; Takada, Jun; Iwatani, Kazuo; Hasai, Hiromi; Oka, Takamitsu; Shimazaki, Tatsuya; Okumura, Yutaka; Fujita, Shoichiro; Watanabe, Tadaaki; Imanaka, Tetsuji

    2002-12-01

    Residual 60Co activity in five steel samples induced by neutrons from the Nagasaki atomic bomb has been measured within about 1000 m from the hypocenter. The chemical separation of cobalt and nickel from steel samples was performed, and cobalt-enriched samples were prepared for all samples. Gamma-ray measurements were carried out with a low-background well-type germanium detector. The gamma-ray spectra for five samples were compared with the spectrum of a control sample to ensure that the observed 60Co was actually induced by A-bomb neutrons. The activation of cobalt by environmental neutrons was also investigated. It has been shown that the present 60Co data are consistent with earlier Hashizume's data. PMID:12674203

  12. Protective effect of gingerol on leucocyte and bone marrow DNA of 60Co γ-rays irradiated mice

    In this article, the effect of gingerol on peripheral leucocyte and bone marrow DNA of 60Co γ-rays irradiated mice was developed., Twenty-four healthy healthy female Kunming mice were randomly divided into 4 groups: control, gingerol, irradiation and gingerol + irradiation group. Gingerol group and gingerol + irradiation group were given gingerol intragastrically once a day for five days. Irradiation group and gingerol + irradiation group were suffered from 5 Gy 60Co γ-rays irradiation at the rate of 1.2 Gy/min on the 6th day. Blood samples, spleens, livers and thigh bones were collected to be measured after 48 h. The results showed that, compared with irradiation group, gingerol + irradiation group had significantly higher spleen index (p60Co γ-rays irradiated mice. (authors)

  13. Soil to plant transfer of {sup 137}Cs and {sup 60}Co in Ferralsol, Nitisol and Acrisol

    Wasserman, M.A. [Instituto de Radioprotecao e Dosimetria, CNEN, Av. Salvador Allende s/no, Recreio, CEP: 22780-160, Rio de Janeiro, RJ (Brazil)], E-mail: angelica@ird.gov.br; Bartoly, F.; Viana, A.G.; Silva, M.M.; Rochedo, E.R.R. [Instituto de Radioprotecao e Dosimetria, CNEN, Av. Salvador Allende s/no, Recreio, CEP: 22780-160, Rio de Janeiro, RJ (Brazil); Perez, D.V. [Centro Nacional de Pesquisa de Solos, EMBRAPA, R. Jardim Botanico 1024, CEP: 22460-000, Rio de Janeiro, RJ (Brazil); Conti, C.C. [Instituto de Radioprotecao e Dosimetria, CNEN, Av. Salvador Allende s/no, Recreio, CEP: 22780-160, Rio de Janeiro, RJ (Brazil)

    2008-03-15

    In this study, soil to plant transfer factor values were determined for {sup 137}Cs and {sup 60}Co in radish (Raphanus sativus), maize (Zea mays L.) and cabbage (Brassica oleracea L. var. capitata) growing in gibbsite-, kaolinite- and iron-oxide-rich soils. After 3 years of experiment in lysimeters it was possible to identify the main soil properties able to modify the soil to plant transfer processes, e.g. exchangeable K and pH, for {sup 137}Cs, and organic matter for {sup 60}Co. Results of sequential chemical extraction were coherent with root uptake and allowed the recognition of the role of iron oxides on {sup 137}Cs behaviour and of Mn oxides on {sup 60}Co behaviour. This information should provide support for adequate choices of countermeasures to be applied on tropical soils in case of accident or for remediation purposes.

  14. HeLa cell tumor response to 60Co, Cs-137, Cf-252 radiations and cisplatin chemotherapy in nude mice

    HeLa cells were implanted into athymic nude mice from tissue culture and solid tumors established (HeLa cell tumor or HCT). Large cell numbers of 1 X 107 were required to obtain consistent and progressive growth, and tumor growth followed a Gompertzian mode. Irradiation studies were carried out using acute Cobalt-60 (60Co), low-dose-rate (LDR) Cs-137 and LDR Cf-252. Cf-252, a neutron-emitting radioisotope, produced an immediate tumor shrinkage and regression response after a dose of 279 cGy. Acute 60Co or LDR Cs-137 irradiation with 1000 cGy had little effect on the HCT. After a dose of 2000 cGy of 60Co radiation tumor shrinkage followed a latent period of approximately 5 days. Cisplatin had no effect on the HCT in nude mice in stationary or late exponential growth

  15. Effects of 2.0 Gy of 60Co gamma rays irradiation on rat embryos

    Pregnant rats of Donryu strain were exposed to a whole-body 60Co γ ray irradiation of a single dose of 2.0 Gy (Dose rate: 0.5 Gy/min) on day 7, 8, 9, 10 or 11 of gestation (sperm day = day 0). The rats were sacrificed on day 18 and the offspring were examined for external and visceral malformations. Malformed embryos occurred between days 7 and 11 with the highest incidence occurring on day 9. Dose with 2.0 Gy increased the rate of resorption or death (52.1 %), in the survivors, caused congenital malformation in a majority of embryos (86.5 %) on day 8 of gestation. There is an increase in malformation (93.3 %) and growth retardation, but no increase in mortality (42.9 %) on day 9 of gestation. Relatively few anomalies resulted from irradiation on day 7 of gestation. The peak day for cardiovascular anomalies occurred on day 9 (88.3 % of all survival embryos) with high levels also occurring on day 8 (86.5 %). Cardiovascular anomalies consisted of VSD, hypoplasia of the pulmonary trunk, coarctation of the aorta, double aortic arch, right aortic arch, riding aorta, complete transposition of the aorta, persistent atrioventricular canal, vascular ring, aberrant right subclavian artery and others. Similar anomalies, but at a lower incidence, were produced by 60Co γ ray at dose levels of 2.0 Gy on day 10 or 11 of gestation. Cases of cleft lip and cleft palate or facial cleft were observed seventeen fetuses on day 9 of gestation (31 %). Exencephaly occurred in nine embryos treated on day 9 (16.1 %) and in one embryos treated on day 10. Tail defects appeared with treatment on day 9 with the latter predominating on day 11. The present study show that maximum resorption (52.1 %) was seen with treatment on day 8 whereas the highest rate of malformation (93.3 %) was observed with treatment on day 9. (J.P.N.)

  16. Biochemical and pharmacological studies of native and irradiated crotamine with gamma radiation of 60Co

    Ionizing radiation can change the molecular structure and affect the biological properties of biomolecules. This has been employed to attenuate animal toxins. Crotamine is a strongly basic polypeptide from the South American rattlesnake venom, composed of 42 amino acid residues. It induces skeletal muscle spasms leading to a spastic paralysis of hind limbs in mice. The objective of this thesis was carry out biochemical and pharmacological studies of native and irradiated crotamine with 60 Co. Crotamine was purified from Crotalus durissus terrificus venom by Sephadex G-100 gel filtration followed by ion exchange chromatography, using a Fast Performance Liquid Chromatography (FPLC) system. It was irradiated at 2 mg/ml in 0.15 M Na Cl with 2.0 kGy gamma radiation emitted by a 60 Co source. The native and irradiated crotamine were evaluated by biochemical characterization, toxic activity (LD50 and biodistribution. The native and irradiated crotamine were labelled with 29.6 MBq of 125 I using chloramine T method, and separated in a Sephadex G-50 column. Male Swiss mice (35± 5 g), were injected i.p. with o.1 mL (2.4 x 106 cpm/mouse) of 125 I native crotamine or with 0.4 mL (1.3 x 106 cpm/mouse) of 125 I irradiated crotamine. At 0.08; 0.25; 0.5; 1; 2; 4; 8; 12 and 24 hours the animal were killed by ether inhalation. Blood, spleen, liver, kidneys, brain, lungs, heart, and skeletal muscle were collected in order to determine radioactivity content. The results showed that gamma radiation did not change the protein concentration, the electroforetic profile or the primary structure of the protein, although differences were shown by spectroscopic techniques. The gamma radiation diminished the toxicity of crotamine, but it did not abolish bioactivity. Biodistribution studies showed that native and irradiated crotamine have hepatic metabolism and renal elimination. The native and irradiated crotamine have affinity by skeletal muscle and they did not pass the blood - brain

  17. Biological dosimetry in radiological protection: dose response curves elaboration for 60Co and 137Cs

    Ionizing radiation sources for pacific uses are being extensively utilized by modern society and the applications of these sources have raised the probability of the occurrence of accidents. The accidental exposition to radiation creates a necessity of the development of methods to evaluate dose quantity. This data could be obtained by the measurement of damage caused by radiation in the exposed person. The radiation dose can be estimated in exposed persons through physical methods (physical dosimetry) but the biological methods can't be dispensed, and among them, the cytogenetic one that makes use of chromosome aberrations (dicentric and centric ring) formed in peripheral blood lymphocytes (PBL) exposed to ionizing radiation. This method correlates the frequency of radioinduced aberrations with the estimated absorbed dose, as in vitro as in vivo, which is called cytogenetic dosimetry. By the introduction of improved new techniques in culture, in the interpretation of aberrations in the different analysers of slides and by the adoption of different statistical programs to analyse the data, significant differences are observed among laboratories in dose-response curves (calibration curves). The estimation of absorbed dose utilizing other laboratory calibration curves may introduce some uncertainties, so the International Atomic Energy Agency (IAEA) advises that each laboratory elaborates your own dose-response curve for cytogenetic dosimetry. The results were obtained from peripheral blood lymphocytes of the healthy and no-smoking donors exposed to 60Co and 137Cs radiation, with dose rate of 5 cGy.min.-1. Six points of dose were determined 20,50,100,200,300,400 cGy and the control not irradiated. The analysed aberrations were of chromosomic type, dicentric and centric ring. The dose response curve for dicentrics were obtained by frequencies weighted in liner-quadratic mathematic model and the equation resulted were for 60Co: Y = (3 46 +- 2.14)10-4 cGy-1 + (3.45 +- 0

  18. Studies on influence of biological factors on concentration of radionuclides

    Biological factors influencing the concentration of radionuclides were studied from the points of uptake through digestive tract, food as pathways, and metabolic activities. The uptake of radionuclides by marine fishes through digestive tract was determined by whole body counter. 137Cs, 65Zn, 131I, 54Mn, 60Co, 85Sr, and 144Ce were used as tracers and was given with solid feed. The feed given was excreated 24 to 48 hours later in small of middle sized fishes, and 20 to 48 hours later in large sized fishes. The uptake rate of 137Cs and 65Zn was high absorption of 20 to 80 per cent, that of 131I, 60Co and 54Mn was not remarkable, and that of 85Sr and 144Ce was low absorption. The biological concentration of 137Cs through pathways of food. In fishes taking up radionuclides through contaminated food, concentration factor increased in accordance with contamination level. In addition, radionuclides with small uptake but delayed excretion and those with high concentration rate could be the factors to decide the concentration factors of marine organisms. In order to study the relationship between metabolic activities and concentration, the uptake of one-year old fishes and adult fishes, and fishes fed and those non-fed were compared. One-year fishes took up large amount of 85Sr during short period, however, concentration by metabolism in adult fishes was slow. Comparing feeding group and non-feeding group, the former showed 85Sr concentration factor of 1.5 to 2 times that of the later, and the later showed 137Cs concentration factor of 2 to 4 times that of the former. However, both uptake and excretion were rapid suggesting that taking food activated the metabolism of substances. (Kanao, N.)

  19. Quality of Intensity Modulated Radiation Therapy Treatment Plans Using a (60)Co Magnetic Resonance Image Guidance Radiation Therapy System

    Wooten, H Omar; Green, Olga; Yang, Min;

    2015-01-01

    PURPOSE: This work describes a commercial treatment planning system, its technical features, and its capabilities for creating (60)Co intensity modulated radiation therapy (IMRT) treatment plans for a magnetic resonance image guidance radiation therapy (MR-IGRT) system. METHODS AND MATERIALS: The...... clinical tolerances. CONCLUSIONS: A commercial (60)Co MR-IGRT device can produce highly conformal IMRT treatment plans similar in quality to linac IMRT for a variety of disease sites. Additional work is in progress to evaluate the clinical benefit of other novel features of this MR-IGRT system....

  20. Effect of mixed 60Co γ-rays and rare earth elements on sugar content and yield of beet

    The effect on sugar content and yield of beet was studied by using 60Co γ-ray and rare earth elements (REE) to treat seeds of beet. The results indicated that 60Co γ-ray of 50 Gy and seed-soaking in 750 g/hm2 of farm REE could improve the root growth of beet, raise the sugar content of beetroot by 11.9% and yield by 13.5% compared to that of CK. The differences reached the significant level

  1. Effect of mixed 60Co γ-rays and rare earth elements on sugar content and yield of beet

    The effect on sugar content and yield of beet was studied by using 60Co γ-ray and rare earth elements (REE) to treat seeds of beet. The results indicated that 60Co γ-ray of 50 Gy and seed-soaking in 750 g/hm2 of farm REE could improve the root growth of beet, raise the sugar content of beetroot by 11.9% and yield by 13.5% compared to that of CK. The differences reached the significant level. (authors)

  2. 129I, 60Co, and 106Ru measurements on water samples from the Hanford project environs

    Groundwater flow and contamination patterns beneath the Hanford project reservation have been studied since the early days of the project. The measurement of radioactive materials at concentrations much below those required for radiation protection are useful for tracing groundwater movement and detection of potential contamination problems before they are apt to occur. Groundwater samples from a number of wells on or near the Hanford reservation have been analyzed for 129I by neutron activation analysis and for gamma radioactivity by low-level coincidence gamma-ray spectrometry. The major radionuclides in addition to natural radioactivity detected in the underground waters by gamma-ray spectrometry were 106Ru and 60Co. Local river and rain water samples were also analyzed for 129I and long-lived radionuclides. Special sample collection methods were developed to prevent contamination of the water samples during collection. Anions travel farther than cations in underground water systems since soils are primarily cation exchangers and retain the cations. Anion exchange techniques were used in the field and the laboratory to recover the desired radionuclides. Sample sizes ranged up to several thousand liters. This paper discusses the sample collection methods,analysis methods, and results obtained. The methods used were found to provide high sensitivity for groundwater studies. (auth)

  3. Irradiation effect on enzymatic activity of papain with {sup 60}Co-{gamma} rays

    Furuta, Masakazu; Ohashi, Isao; Oka, Masahito; Hayashi, Toshio [Osaka Prefecture Univ., Sakai (Japan). Research Inst. for Advanced Science and Technology

    1998-12-31

    An investigation was made on the durability of enzyme activity against {sup 60}Co-{gamma} irradiation at a dose up to 55 kGy/h using dry powder and aqueous solution of papain preparations on the market. Hybrid materials including bioactive molecules combined with biocompatible synthetic polymers are expected to have biocompatible properties and also biomimetic functions as a component of artificial organs for human body. The activity of papain in an aqueous solution was rapidly decreased at the early stage of irradiation through oxidation of SH group at its active site with active oxygen produced by the irradiation and then, partially recovered since SH group was reproduced in an anoxic state after O{sub 2} consumption in the solution irradiated at a high dose. A usual radiation method for sterilization was found applicable to decontamination of dry and frozen preparations of papain. When suitable conditions for radiation were chosen and N{sub 2} gas was purged to suppress the formation of free radicals, it was possible to keep the enzyme activity at more than 50% of the initial activity after radiation at 30 kGy. (M.N.)

  4. Mutant strain screening by 60Co γ-rays irradiation and its cellulase enzyme produce condition

    A mutant strain A50 with high cellulase activity was induced and isolated by using 60Co γ-rays irradiation from the initial Penicillium decumbens A10. The optimum fermentation conditions of A50 were investigated through orthogonal designing experiment, the major carbon resource 5%, the ratio between wheat bran and corn straw 1:1, the concentration of glucose as supplemental carbon 0.1%, the concentration of (NH4)2HPO4 as supplemental nitrogen resource 0.2%, the initial pH of liquid medium 5.0, the inoculated amount for fermentation 10% and the concentration of Tween-80 0.1%, 30 ml initial media filled in the 300 ml flask with culture condition of 32 degree C and 200 r/min. Under the optimum conditions mentioned above, the highest activities of cellulase and filter paper enzyme were 27.28 and 1.98IU/ml at 60 h fermentation, respectively, which was 33.2% and 45.59% higher than those of the initial strain. (authors)

  5. Primary Observations on the Influence of 60Co Local Irradiation on Free Skin Flaps

    杨建荣; 张园

    2002-01-01

    Objective To study the effect of postoperative radiation on free skin flaps.Methods Twenty-nine patients with free skin flaps applied to the plerosis of the postoperative defectwere followed up. Twenty-eight out of 29 patients received forearm free flaps while 1 had anterolater-al femoris skin flaps in a size ranging from 14 cm× 6 cm to 8 cm× 4 cm. These flaps were exposedto 60Co radiation ranging 40-69 Gy. Results Observation during irradiation: no visible changes ofskin flaps and oral mucous membrane were detected when irradiation dose was within 40 Gy; somechanges may be detected over 40 Gy. Observation 1 - 4 months after irradiation: pigmentations werefound in areas of erosion epidermis; skin flaps got dark but without evidence of necrosis. Observation2 years after irradiation: no necrosis happened in 29 skin flaps. Hairs were found on 15 of 29flaps. Sensation occurred within the margin of 1 cm. Conclusion Free skin flap can endure irradi-ation at the dose of 60 Gy.

  6. Serum asparate aminotransferase levels following cadmium and/or 60Co radiation

    A total of 216 young adult male Sprague‐Dawley rats were used. Animals were injected intraperitoneally (IP) every 3 days for 29 days for a total of 9 injections with 0, 1.0, or 2.5 mg Cd/kg body wt. Twenty‐four hrs after the last Cd injection (day 30), each animal was subjected to an acute sublethal total‐body exposure of 0, 3.62 or 5.43 gray of gamma (60Co) radiation at a dose rate of 3.04 gray/min. Eight rats from each of the 9 groups were sacrificed by cardiac exsanguination on post‐irradiation day 1, 7, or 21. A significant high‐dose cadmium‐induced increase in AST enzyme was observed at days 1 and 7; however, by day 21 levels had returned to normal. The results suggest that high‐dose cadmium increases were dose and time‐dependent. No significant differences in AST values were observed between radiation only groups, days, or doses. However, significant dose‐related differences were observed between high‐dose cadmium and means, as well as between high and low‐dose cadmium doses at days 1, 7, and 21. When the co‐insult was used, significant differences were seen between the high cadmium‐high radiation group and the mean at day one

  7. Evaluation of gamma-sterilization (60Co) by RT-PCR by DHFR expression detection

    The improvement of techniques to detect pathogen agents in blood had reduced significantly the contamination mechanisms by hemocomponents in blood transfusion procedures. Ionizing radiation is a method that has presented several applications on medicine and in currently days has been showing special attention on blood banks which has been applied to avoid TA-GVHD development. DHFR is an enzyme constitutive in Plasmodium protozoa and has an important role in folate metabolism on these parasites. Detecting the expression of RNAm coder for this enzyme is possible to evaluate the viability of this parasite in blood samples. Plasmodium chabaudi AJ is a parasite that induces lethal malaria in rodents similar to human malaria In this work, the objective was to detect the presence of plasmodium protozoa in irradiated blood samples, infected experimentally, through the application of a RT-PCR using primers for the coder sequence of DHFR's mRNA. We studied doses of ionizing radiation between 0 and 75 Gy. The irradiation procedures were accomplished in Center of Radiation Technology of IPEN-CNEN in a 60Co panoramic source. Our results had demonstrated that RT-PCR is a sensible method to evaluate the viability of plasmodium in blood samples because the technique could detect low parasite burden in all tested samples. (author)

  8. Proteomics study of progeny of normal human liver cells irradiated by 60Co γ-rays

    Objective: To characterize the differential protein expression in the progeny of human liver cells surviving from ionizing radiation by the proteomic analysis. Methods: Two-dimensional electrophoresis gel coupled with mass spectrometry was used to explore the specific protein expression in the progeny of 7702 human liver cells surviving from ionizing radiation. Alterations in expression level of protein spots between the control and the progeny groups were statistically analyzed by ImageMaster 2D Platinum software and mass spectrometry was used to identify the protein spots with significantly altered expression-level. Results: The progeny of irradiated ceils were derived from human liver cell line exposed to 0, 2, 4, 6 Gy of 60Co γ-irradiation. A total of 42 differentially expressed proteins between the control and the progeny of the irradiated cells groups were screened, of which 17 were identified by matrix assistant laser desorption ion-top off light-mass spectrometry (MALDI-TOF MS) analysis, including 4 up-regulated and 13 down-regnlated proteins. Conclusions: The differentially expressed proteins profile could be significantly altered in the progeny of irradiated cells. The proteomics approach has the potential to detect the protein changes relevant to radiatian-induced genomic instability (RIGI). Further study of differentially expressed proteins would likely reveal the molecular mechanisms of gene expression in RIGI. (authors)

  9. Perna perna (LINNAEUS, 1758) mussels irradiated by 60CO gamma rays cytotoxicity evaluation

    The aim of the present work was the study of ionizing radiation effects on aquatic biota regarding the location of nuclear facilities nearby coastal areas assuming the risk of leaks and nuclear accidents. Bivalve mollusks have been widely used in the monitoring of aquatic environment studies mainly for their sessile habit and pollutants bioconcentration ability. So marine mussel Perna perna (Bivalvia: Mytilidae) was used as organism test in this study. The study of radioactive toxicity was performed by cytotoxicity test exposing the organisms to 11Gy gamma radiation dose. After radiation the neutral red retention assay evaluated the lysosomal membrane integrity in the mussel hemocytes. 50% lethal dose assay (LD50) of gamma radiation on Perna perna mussels was carried out by exposure the organisms to 60Co gamma rays at doses ranging from 0 to 3000 Gy. The result of gamma radiation LD50 for these mussels was 1068 Gy and the neutral red retention time of irradiated organisms was about 47% lower than the control, non irradiated organisms. With the obtained results is expected to contribute in the study to identify the range of ionizing radiation doses which can cause toxic effects in marine invertebrates. (author)

  10. Effects of flavonoids of Astragali Complanali against damage induced by 60Co γ-ray irradiation

    Objective: To study on the radioprotective effect of flavonoids of Astragali Complanali on γ-ray induced injury. Methods: Female mice were fed with FAC at different doses for 17 days, positive control were administered with Leucogen Tablets, irradiation and negative control were administered with distilled water only, then all mice except the negative control group were exposed to 6 Gy 60Co γ-ray for whole-body-irradiation at the 7th day, observe the protective effect of FAC against damage of irradiation and its effects on antioxidant system and immune function. Results: The 21-day survival rate of FAC-protected mice were higher than that in the control group, blood cell counts of FAC-protected mice were higher than those in the control group such as WBC, RBC, PLT, HGB and LY counts; superoxide dismutase and lymphocyte proliferation index of FAC-protected mice were much higher than those in the control group and malondiadehyde counts lower. Conclusion: These results suggest that FAC can alleviate irradiation damage induced by gamma-ray, might be associated with ameliorating antioxidant level and immune function. (authors)

  11. /sup 60/Co irradiation for sterilization of veterinary mastitis products containing antibiotics and steroids

    Tsuji, K.; Kane, M.P.; Rahn, P.D.; Steindler, K.A. (Upjohn Co., Kalamazoo, MI (USA))

    1981-01-01

    Effects of /sup 60/Co irradiation for sterilization of veterinary mastitis products were evaluated. The mastitis products which were examined contained various combinations of antibiotics and steroids suspended in peanut oil vehicle. Bioburden data indicated that the unirradiated products were only occasionally contaminated with microorganisms. The D-values of the nonsterile product and environmental isolates were 0.028, 0.15, 0.017, and 0.018 Mrads for Aspergillus fumigatus, Penicillium oxalicum, Pseudomonas aeruginosa, and Pseudomonas maltophilia, respectively. The D-value of the biological indicator organism, Bacillus pumilus spores, in the vehicle was 0.27 Mrads. Thus, an irradiation dose of 1.6 Mrads would be sufficient to achieve six log cycles of destruction of the biological indicator organism. The minimum absorbed irradiation dose of 2.5 Mrads preferred by many countries for sterilization would achieve 9.3 log cycle destruction of the indicator organism and guarantee a probability of 1 x 10/sup -15/ assurance for the most radio-resistant product isolate, Penicillium oxalicum. In order to examine short and long term chemical stabilities of active components, stability indicating high-performance liquid chromatographic (HPLC) methods for the determination of several of the antibiotics and steroids were developed. The rates of degradation and radiolytic degradation schemes for the majority of the compounds were elucidated.

  12. Onset of behavioral effects in mice exposed to 10-Gy 60Co radiation

    Maier, D.M.; Landauer, M.R.

    1990-10-01

    The effects of 10 Gray (Gy)60Co radiation on social behavior, locomotor activity, and body weight were assessed in individually housed male Swiss-Webster mice. In Experiment 1, aggressive behavior was evaluated prior to irradiation and for 7 d postirradiation by placing an untreated intruder in the irradiated or sham-irradiated resident's home cage for 5 min. Offensive aggressive behavior was not affected significantly by radiation until day 7 postirradiation, when attack latency increased, the frequency and duration of fighting decreased, and the frequency of bites, lunges, and chases decreased. Untreated intruder mice paired with irradiated resident mice showed a decrease in the duration of defensive upright postures, squeaks, and escapes on day 7 postirradiation. In Experiment 2, locomotor activity and body weight were monitored for 7 d postirradiation. Body weight was decreased in irradiated mice beginning 4 d postirradiation. Locomotor activity was suppressed in irradiated animals 90 min after irradiation and remained depressed throughout the 7-d testing period.

  13. Some gamma radiation (60Co) effects on Chrysomya megacephala (Fabricius, 1794) (Diptira-Calliphoridae)

    The effect of different gama radiation (60Co) doses on Chrysomya megcephala (Fabricius) have been studied under laboratory conditions, in the Entomology Section of Centro de Energia Nuclear na Agricultura (CENA-USP), Piracicaba, SP, Brasil. The insects were collected close to sucking animals brooding areas, identified and reared on artificial diet, being kept in a temperature (26 +- 20C) and humidity (66 +- 9%) controlled room, with 12L:12D photopheriod. A Gammabeam type 650 Cobalt-60 gamma irradiation source was used, with 28, 196x1010 Bq activity at the beginning of the experiment. The pupae were submitted to increasing gamma radiation doses. To determine lethal doses, treatments were carried out at four different ages and to determine the sterilizing doses two-three day pupae were used. It was noted pupae radiosensitivity decreased with age, LD50 varying from 14 - 513 Gy. The sterilizing dose for males was 40 Gy and for females 30 Gy. During the individuals life cycle, it was noted that there was a decrease in life expectancy (exo) of adults when the gamma radiation dose was increased. Treated males were more sensitive than females (Crossed with ''normals''), there occurring a marked reduction in the number of eggs and their viability when the used gamma radiation dose was increased. (author)

  14. Studying the Effect of Ionization Radiation of 60Co on the Spirulina

    Ai, Weidang; Guo, Shuang-Sheng; Ai, Weidang; Dong, Wen-Ping; Qin, Li-Feng; Tang, Yong-Kang

    It studied the effect of ionization radiation on the Spirulina plastensis(No.6) by using the γ-rays of 60 Co. In the experiment, Spirulina were irradiated, and the dose of the ionization radiation covered 0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0kGy. After irradiating, these Spirulina were cultured under the same conditions. During the course of the experiment, the growth rate, photosynthetic efficiency and nutrition quality of the Spirulina, were analyzed. From the results, low dose of γ-rays (less than 1.5kGy) could improve the content of phycobilin and protein of Spirulina. Only small changes in the morphology of algae filament were found at dose less than 1.0kGy. But with the increase of the dose of γ-rays (more than 1.5kGy), the filaments would break up or even disintegrate. Spirulina had stronger ionization radiation proof and self-rehabilitation capacity, but the growth of Spirulina was stagnated. The LD50 (i.e. the dose resulted in 50% death of the Spirulina) of the colony was 2.0kGy. Considering the capacity of being resistant to γ-rays irradiation, Spirulina can be considered as one of the key biological components in the Controlled Ecological Life Support System (CELSS) for future long-term space missions. Keywords: Controlled Ecological Life Support System (CELSS); Spirulina; ionization radiation; biological component

  15. Microbiological analysis of peach palm in natura submitted to {sup 60}Co radiation

    Silva, Priscila V.; Araujo, Michel M.; Nunes, Thaise C.F.; Costa, Helbert S.F.; Villavicencio, Anna Lucia C.H. [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil)], e-mail: priscilavsilva@gmail.com, e-mail: villavic@ipen.br; Hojeije, Khalil Y. [Floresta Industria e Comercio Ltda., Sao Paulo, SP (Brazil)

    2009-07-01

    The palm tree (Bactris gasipaes Kunth) is a species with high potential benefits, because of the nutritional value of its fruits that could be used both in human and animals feeding and mainly for peach palm extraction. It represents a great source of dietary fiber and a moderate source of magnesium and iron. Food irradiation is a worldwide technology that aims to improve the product quality, in order to eliminate diverse microorganisms that can spoil the food. Radiation processing, in the recommended doses, causes very few chemical alterations and nutritional losses in foods, being considered insignificant and/or similar to other food treatments. The objective of this study was to evaluate the effect of irradiation on microbiological counts of mesophilic aerobic in the peach palm in natura. Samples were irradiated with 1.0 and 1.5 kGy using a {sup 60}Co multipurpose irradiator. Radiation treatment appeared to be a useful alternative to reduce microbial contamination in the samples analyzed. (author)

  16. Modification of polyethersulfone films by grafting hydrophilic monomers with 60Co γ-rays

    Polyethersulfone (PES), with its high strength, high temperature resistance, corrosion- resistance, oxidation resistance and applicability under wide pH range, is used extensively as ultrafiltration and nanofiltration membrane. However, PES membranes foul easily in such an application because of hydrophobic nature of PES raw materials. Improving the hydrophilicity of PES by grafting hydrophilic monomers onto it is of potential to solve the problem. At present, common approaches to improve hydrophilicity of PES membranes are UV grafting modification, plasma modification, and chemical modification, whereas grafting and modifying PES films by 60Co γ-rays has rarely been reported. Studies have been carried out in our laboratory to graft hydrophilic monomers onto PES membranes directly or PES powders via simultaneous radiation grafting with the rays. Acrylic acid, methyl acrylic acid or acrylamide was used to study effects of the monomer concentration, irradiation dose and dose rate, solvent, inhibitor and pH of the grafting solution on the degree of grafting. The results showed that hydrophilicity of all the PES membranes could be improved, with the extent of improvement being dependent on the grafting conditions. (authors)

  17. A study on the irradiation effect of 60Co gamma ray on dental polymethylmethacrylate bonded parts

    In this paper we describe an experimental study on the irradiation effect of 60Co gamma ray on dental polymethylmethacrylate (P.M.M.A.) welding part, hot and cold polymerizing adhesion part. It was found that from the result of tension test, no remarkable change of mechanical property is found with any of the bonded parts by the irradiation dose up to 107 r., and no deterioration by irradiation is observed. And then, according to the results of bending test, it is found that, although the three different bonded parts have different features, the strength of the welded part and of the part adhered by hot polymerizing adhesive becomes lower by irradiation, and bending strength of the three parts converges on 6 kg/mm2 after irradiation within a range of 106 - 107 r.. Joint efficiency (= bonded part strength/base material strength) of 65 - 75% in tension and 50 - 62% in bending can be adopted. Fracture of the base material and of the Welded part are similar, and prove high bonding strength. (author)

  18. Changes in membrane receptors of B and T human lymphocytes exposed to 60Co gamma rays

    The present report describes the effect of 50 to 2500 rad of 60Co gamma rays on the membrane receptors of B and T lymphocytes. Surface membrane immunoglobulins and Fc receptors were used as markers for B cells, while the formation of rosettes with sheep red blood cells was used as a marker for T cells. The effect of radiation is expressed as the percentage of viable cells that bear membrane receptors. The radiation effects were studied after 2, 24, 36 hr of culture. For B lymphocytes no reduction in SmIg and Fc receptors was seen 2 hr after radiation, whereas a dose-related reduction was observed after 24 and 36 hr. A dose-related inhibition of the ''capping'' of SmIg was observed. For T lymphocytes a reduction of E rosette formation was seen starting 2 hr after irradiation. Electron microscopy of separated B and T cells showed a higher sensitivity of T cells as well as a different structural arrangement of the chromatin as a consequence of radiation damage. These data suggest differentiated behavior of B and T lymphocyte membrane receptors after exposure to radiation

  19. Mechanism of INF-γ antagonizing pulmonary fibroblast proliferation stimulated by 60Co γ-rays

    Objective: To explore the mechanism of IFN-γ antagonizing human pulmonary fibroblasts (HLF) proliferation stimulated by 60Co γ-rays. Methods: The time- and dose-effect of HLF proliferation promoted by TGF-β1 and rat serum after radiation as well as effect of IFN-γ on proliferation were observed by MTT colorimetric methods. Content of TGF-β1 in rat serum and pulmonary tissues after irradiation as well as the effect of IFN-γ on rat serum after radiation promoting HLF to synthesize TGF-β1 were determined by ELISA. Results: TGF-β1 played a role in promoting HLF proliferation. The sera of irradiated rats could promote HLF proliferation and TGF-β1 synthesis, but the effect was inhibited by IFN-γ significantly (P<0.05). The level of TGF-β1 in rat serum and lung tissues gradually increased from 1 to 4 weeks after irradiation. Conclusions: TGF-β1 is involved in the process of γ-rays stimulating HLF proliferation, while IFN-γ can inhibit HLF from synthesizing TGF-β1 and antagonize its role of promoting HLF proliferation. (authors)

  20. Dose-response for bone regeneration after single doses of 60Co irradiation

    The Bone Growth Chamber (BGC) methodology was used to establish a dose-response relationship for regeneration of mature bone tissue after irradiation of 5, 8, 11, 15 and 25 Gy single dose 60Co. The BGC, which is a titanium implant, was inserted in the proximal tibial metaphyses, bilaterally, of a rabbit immediately following local irradiation to one tibia. Each animal thus served as its own control. During a healing period of 4 weeks, the two canals penetrating the implant became filled with more or less newly formed bone. At the end of the healing period, the implants were removed and taken apart and the newly formed bone was collected and its volume measured by microradiography and microdensitometry. It was found that in the dose range of 5 to 8 Gy bone regeneration was reduced by about 20% as compared to non-irradiated controls. Between 8 and 11 Gy, there was a critical range in that a small increase in dose resulted in a greatly reduced bone formation. At 11 Gy and above, the depression in bone formation, as compared to non-irradiated controls, was about 65 to 75%

  1. Perna perna (LINNAEUS, 1758) mussels irradiated by {sup 60}CO gamma rays cytotoxicity evaluation

    Martini, Gisela A.; Pusceddu, Fabio H.; Rogero, Sizue O.; Rogero, Jose Roberto, E-mail: gisela.martini@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    The aim of the present work was the study of ionizing radiation effects on aquatic biota regarding the location of nuclear facilities nearby coastal areas assuming the risk of leaks and nuclear accidents. Bivalve mollusks have been widely used in the monitoring of aquatic environment studies mainly for their sessile habit and pollutants bioconcentration ability. So marine mussel Perna perna (Bivalvia: Mytilidae) was used as organism test in this study. The study of radioactive toxicity was performed by cytotoxicity test exposing the organisms to 11Gy gamma radiation dose. After radiation the neutral red retention assay evaluated the lysosomal membrane integrity in the mussel hemocytes. 50% lethal dose assay (LD50) of gamma radiation on Perna perna mussels was carried out by exposure the organisms to {sup 60}Co gamma rays at doses ranging from 0 to 3000 Gy. The result of gamma radiation LD50 for these mussels was 1068 Gy and the neutral red retention time of irradiated organisms was about 47% lower than the control, non irradiated organisms. With the obtained results is expected to contribute in the study to identify the range of ionizing radiation doses which can cause toxic effects in marine invertebrates. (author)

  2. Studies on mutagenic activity of 60Co γ-ray irradiated rape pollen

    In the present study on disinfection, the rape pollen was irradiated with 2.5 kGy 60Co γ-ray. Micronuclei, sister chromatid exchanges (SCE) of bone marrow cells and chromosomal aberrations of meiotic cells in mice were used as an indicater of chromosomal damage to study the mutagenicity of irradiated rape pollen. The results are as follows: (1) The frequency of micronuclei in polychromatic erythrocytes is 2.00 per mille; nucleated cells is 0.8 per mille in control group. In the numbers of polychromatic erythrocytes and nucleated cells with micronuclei, there is no obviously difference in irradiated and unirradiated groups. (2) SCE incidence of control group is 2.01 ± 0.12/cell. No significant difference in the frequency of SCE exists between non-irradiated rape pollen and the control groups. But the frequency of SCE in irradiated rape pollen group (3000 mg/kg/day x 7) is 2.36 ± 0.12/cell; high dose group (6000 mg/kg/day x 7) is 2.96 ± 0.14/cell. In comparison with control group, there is a significant difference. (3) The chromatid breaks, fragments, and univalents in primary spermatocytes have been obseved. The frequencies of chromosomal aberration showed no obviously difference among irradiated and non-irradiated rape pollen groups

  3. Effect of 60Co gamma-ray irradiation on dilute aqueous solutions of surfactants

    Present work deals with the effects of gamma irradiation from 60Co γ-ray source upon aqueous solutions of three kinds of surfactants. When dilute aqueous solutions of sodium dodecyl sulfate (SDS, anionic), cethyl trimethyl ammonium chloride (CTAC, cationic), and polyoxyethylene lauryl ether (POE, non-ionic) were irradiated with γ-rays at a room temperature, the residual concentration, products, surface tension, and forming power were examined by colorimetric method, IR spectrophotometric method, gaschromatography, Ross-Miles method, and Traube's stalagmometer etc. These surfactants were decomposed by the irradiation and thus the surface tension increased and the forming power, on the contrary, decreased with dose. Radiation chemical yields (G-value) of the degradation were about 1 for the solutions of SDS and CTAC, and about 0.3 for the POE solution. From the experimental results, it was found that following chemical reactions seem to occur followed by the radiolysis of water: a) bond cleavage of ester for SDS, of CN for CTAC, and of oxyethylene for POE, b) hydrogen abstraction from the surfactants, c) production of CO bond in the presence of dissolved oxygen. (auth.)

  4. Suitable dose of 60Co γ-ray for mutation in Roegneria seeds

    Seeds from six accessions of three species of Roegneria were radiated with 60Co γ-ray at different doses (50, 100, 150, 200, 250, 300 and 400 Gy). Following these treatments, germination energy, germination rate, seedling height, plant height, plant survival, and seed set were observed. Plant survival was highly correlated with seedling height (R2 > 0.91, P 2 > 0.82, P < 0.01). The semi-lethal dose of each accession, calculated using a 'Multi-target single-hit' model, ranged from 60 to 173 Gy. The most suitable absorbed doses for each accession were deduced from these data. The suitable doses for Roegneria kamoji, Roegneria ciliaris and Roegneria japonensis were 65-100 Gy, 63-150 Gy and 80-170 Gy, respectively. According to the range of suitable doses, R. kamoji (Pr87-88-353) was the most sensitive to radiation, and R. japonensis (88-89-267) was the most resistant to radiation. Suitable doses of R. ciliaris were close to that of R. kamoji (ZY1007). This research provides preliminary guidelines for radiation induced mutagenesis in Roegneria. (author)

  5. 100 Gy 60Co γ-Ray Induced Novel Mutations in Tetraploid Wheat

    Chuntao Yang

    2014-01-01

    Full Text Available 10 accessions of tetraploid wheat were radiated with 100 Gy 60Co γ-ray. The germination energy, germination rate, special characters (secondary tillering, stalk with wax powder, and dwarf, meiotic process, and high-molecular-weight glutenin subunits (HMW-GSs were observed. Different species has different radiation sensibility. With 1 seed germinated (5%, T. dicoccum (PI434999 is the most sensitive to this dose of radiation. With a seed germination rate of 35% and 40%, this dose also affected T. polonicum (As304 and T. carthlicum (As293. Two mutant dwarf plants, T. turgidum (As2255 253-10 and T. polonicum (As302 224-14, were detected. Abnormal chromosome pairings were observed in pollen mother cells of both T. dicoccoides (As835 237-9 and T. dicoccoides (As838 239-8 with HMW-GS 1Ax silent in seeds from them. Compared with the unirradiated seed of T. polonicum (As304 CK, a novel HMW-GS was detected in seed of T. polonicum (As304 230-7 and its electrophoretic mobility was between 1By8 and 1Dy12 which were the HMW-GSs of Chinese Spring. These mutant materials would be resources for wheat breeding.

  6. A review of the (60)Co internal dosimetry at Devonport Royal Dockyard.

    Vickers, J M A; Collison, R; Collision, R

    2010-03-01

    The physico-chemical properties of (60)Co contaminants arising from the UK Naval Nuclear Propulsion Programme (NNPP) pressurised water reactor (PWR) plants have been investigated in order to review individual monitoring requirements at Devonport Royal Dockyard (DRD). This has been achieved through laboratory tests on NNPP primary component samples and interpretation of direct bioassay measurements using internal dosimetry modelling software. Interpretation of lung measurements was completed for two inhalation events involving material originating from a PWR plant and post-primary circuit decontamination. Initial estimates of intake and dose were calculated using International Commission on Radiological Protection default parameter values. However, a good fit could only be achieved by fitting the data to alternative absorption parameters where 90-95% of the material dissolved and absorbed rapidly at a rate of 1 day(-1). As a consequence of this review, a number of improvements have been made to monitoring arrangements at DRD. A minimum of three direct measurements are now taken during the 0-30 day period after an intake, the capability of the Canberra Accuscan has been enhanced and dissolution tests are being carried out by the Health Protection Agency (HPA) on samples taken from PWR plants. PMID:20220215

  7. Evaluation of gamma-sterilization ({sup 60}Co) by RT-PCR by DHFR expression detection

    Converso, Ana Paula G.; Andrade Junior, Heitor F. de [Instituto de Medicina Tropical de Sao Paulo, Sao Paulo, SP (Brazil)]. E-mail: anapaulagconverso@gmail.com; hfandrad@usp.br; Vieira, Daniel P. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Instituto de Medicina Tropical de Sao Paulo, Sao Paulo, SP (Brazil); E-mail: dperezv@usp.br

    2007-07-01

    The improvement of techniques to detect pathogen agents in blood had reduced significantly the contamination mechanisms by hemocomponents in blood transfusion procedures. Ionizing radiation is a method that has presented several applications on medicine and in currently days has been showing special attention on blood banks which has been applied to avoid TA-GVHD development. DHFR is an enzyme constitutive in Plasmodium protozoa and has an important role in folate metabolism on these parasites. Detecting the expression of RNAm coder for this enzyme is possible to evaluate the viability of this parasite in blood samples. Plasmodium chabaudi AJ is a parasite that induces lethal malaria in rodents similar to human malaria In this work, the objective was to detect the presence of plasmodium protozoa in irradiated blood samples, infected experimentally, through the application of a RT-PCR using primers for the coder sequence of DHFR's mRNA. We studied doses of ionizing radiation between 0 and 75 Gy. The irradiation procedures were accomplished in Center of Radiation Technology of IPEN-CNEN in a {sup 60}Co panoramic source. Our results had demonstrated that RT-PCR is a sensible method to evaluate the viability of plasmodium in blood samples because the technique could detect low parasite burden in all tested samples. (author)

  8. Microbiological analysis of peach palm in natura submitted to 60Co radiation

    The palm tree (Bactris gasipaes Kunth) is a species with high potential benefits, because of the nutritional value of its fruits that could be used both in human and animals feeding and mainly for peach palm extraction. It represents a great source of dietary fiber and a moderate source of magnesium and iron. Food irradiation is a worldwide technology that aims to improve the product quality, in order to eliminate diverse microorganisms that can spoil the food. Radiation processing, in the recommended doses, causes very few chemical alterations and nutritional losses in foods, being considered insignificant and/or similar to other food treatments. The objective of this study was to evaluate the effect of irradiation on microbiological counts of mesophilic aerobic in the peach palm in natura. Samples were irradiated with 1.0 and 1.5 kGy using a 60Co multipurpose irradiator. Radiation treatment appeared to be a useful alternative to reduce microbial contamination in the samples analyzed. (author)

  9. Effects of 60Co γ rays on the cell cycle progress of MCF-7 cells

    To investigate the effects of ionizing radiation on cell cycle progress of tumor cell lines, the human breast cancer MCF-7 cell line cultured in vitro was exposed to 60Co γ rays and the alterations in cell cycle progress after irradiation were measured by flow cytometry. The results indicated that the MCF-7 cells showed a transient S arrest continuing for about 6 h and an obvious G2 arrest continuing for about 63 h after irradiation with 5.0 Gy γ rays. S and G2 arrest culminated at 9 h and 18 h respectively after irradiation and the peak values of S and G2 arrest reached respectively 1.6 times and 6.2 times as many as normal value. The dose-effect curve examined 9 h after irradiation was quite different from that examined 18 h after irradiation. Both of the S arrest at 9 h after irradiation and the G2 arrest at 18 h after irradiation presented significant relationship with irradiation dose

  10. Chemical changes in the chloroform-paraffin system irradiated by 60Co gamma-rays, 1

    It has been reported that the chloroform-paraffin-dye system have excellent sensitivity for radiation as a solid chemical dosimeter or a phantom. However, the chemical changes in the irradiated system are not examined in detail. In the present study, the effect of paraffin on changes in the above system of a liquid state irradiated by 60Co γ-rays was examined by using various normal paraffin, and the other variable factors on the changes were done. When the chloroform solution and the solution containing 25 per cent of paraffin by volume with 5.0 x 15-5 mol/liter of Methyl Yellow as a dye were irradiated by 2000 R, G values for the formation of hydrogen chloride in the both solutions were 8.4 and 10.8, respectively, and were little affected by the kind of those, from C6 (hexane) to C36 (hexatria-contane). These results suggest that chlorine radical formed by radiolysis of chloroform may react with hydrogen atom from paraffin, thereby increasing the amount of hydrogen chloride. Presence of oxygen increased G value of the chloroform solution from 7.6 to 8.4, but did little that of the solution containing paraffin. (author)

  11. Decomposition of ρ-nonylphenols in water by 60Co γ-ray irradiation

    ρ-Nonylphenols (NPs), one of endocrine disrupting chemicals, are used as plastic flexibilizers or nonionic surfactants, and widely released into the water environment. Hydroxyl radicals produced from water molecules by γ-ray irradiation have high oxidation reactivity. Recently, treatments with the hydroxyl radicals have drawn much attention to conserve the water environment. In this study, decompositions of NPs in water were investigated using hydroxyl radicals by 60Co γ-rays irradiation. The concentrations of the NPs at initial concentration from 45 to 1000 nM were decomposed by γ-ray irradiation. Qualitative and quantitative analyses of NPs were carried out by high performance liquid chromatography. The decomposition curves of NPs at each initial concentration were analyzed as single exponential functions. Alkylphenol activity of aqueous NPs solution, which was estimated by enzyme-linked immunosorbent assay, implies the irradiation products have alkylphenol activity. Two products having molecular weight of 236 were investigated by liquid chromatography-mass spectrometry, and were considered to be ρ-nonylcatechol and 1-(ρ-hydroxyphenyl)-1-nonanol on the basis of the oxidation mechanisms of ρ-cresol and 4-ethylphenol. (author)

  12. A review of the {sup 60}Co internal dosimetry at Devonport Royal Dockyard

    Vickers, J M A; Collision, R [Babcock Marine, Devonport Royal Dockyard, Plymouth PL1 4SG (United Kingdom)], E-mail: Jenny.Vickers@babcock.co.uk, E-mail: Roger.Collison@babcock.co.uk

    2010-03-01

    The physico-chemical properties of {sup 60}Co contaminants arising from the UK Naval Nuclear Propulsion Programme (NNPP) pressurised water reactor (PWR) plants have been investigated in order to review individual monitoring requirements at Devonport Royal Dockyard (DRD). This has been achieved through laboratory tests on NNPP primary component samples and interpretation of direct bioassay measurements using internal dosimetry modelling software. Interpretation of lung measurements was completed for two inhalation events involving material originating from a PWR plant and post-primary circuit decontamination. Initial estimates of intake and dose were calculated using International Commission on Radiological Protection default parameter values. However, a good fit could only be achieved by fitting the data to alternative absorption parameters where 90-95% of the material dissolved and absorbed rapidly at a rate of 1 day{sup -1}. As a consequence of this review, a number of improvements have been made to monitoring arrangements at DRD. A minimum of three direct measurements are now taken during the 0-30 day period after an intake, the capability of the Canberra Accuscan has been enhanced and dissolution tests are being carried out by the Health Protection Agency (HPA) on samples taken from PWR plants.

  13. Effect of 60Co radiation-induced grafting of methyl methacrylate on mechanical properties of bamboo

    In order to investigate the effect of radiation grafting on mechanical properties of bamboo, the original and carbonized bamboo soaked with monomer MMA were radiation grafted by 60Co γ rays with the doses of 60-220 kGy. The results showed that compared with original blanks, treated with MMA and irradiated with the dose of 180 kGy the specific gravity, bending strength modulus of elasticity of original bamboo increased by 6.7%, 4.4%, and 28%, meanwhile its oven-dried radial, tangential and volumetric shrinkage decreased by 38.9%, 47.4%, and 32.9%, respectively. What is more, treated with MMA and irradiated with the doses of 140 kGy the specific gravity and modulus of elasticity of carbonized bamboo increased by 6.8% and 20%, while its oven-dried radial, tangential, volumetric shrinkage decreased by 11%, 4.6% and 12%, respectively. The study reveals that mechanical properties of original and carbonized bamboo can be enhanced by radiation grafting copolymerization with suitable absorbed doses, which may be valuable for the further research of developing new bamboo plastic composites. (authors)

  14. Evaluation by EPR of potential antioxidant components of 60Co-irradiated varieties of soybean

    Brazil is today the second main producer of soybean in the world with a planted ground of about 21 million hectares and an annual production of 60 million tons in 2008, being slight more than a fourth of the annual production. The presence of flavonoids, particularly isoflavones in soybean products has been related as important for human health. It has been suggested that flavonoids play a role in the protection of plants by screening vital cellular components from damaging UV radiation. Electron paramagnetic resonance (EPR) spectroscopy can measure free radicals produced by dissociation molecules resulting from irradiation. It has been successfully employed for the detection of some irradiated food products. Twenty one Brazilian soybean cultivars from two crops were gamma-irradiated with a 60Co source and evaluated by EPR. Correlation coefficients were made among the central EPR signal (g = 2.0039) and the total and partial isoflavones contents. There was no correlation with total contents, though glicitein and acetyl-daidzin showed a negative correlation. Even 7 months after irradiation the intensity of central EPR signal were high enough to distinguish the irradiated samples. EPR measurements of separated parts of the grain were more efficient for that purpose, particularly from hilum and coat. The radiation did not change substantially the total isoflavone contents, although there were some evidences suggesting some conversion of glycosides to aglycones. (author)

  15. Effects of 60Co gamma radiation on defense function of human polymorphonuclear leukocytes

    The effects of radiation on defense function of polymorphonuclear leukocytes (PMN) were studied following irradiation with 60Co γ radiation (30 - 3,000 rad) using PMN separated from the peripheral blood of healthy volunteers. The migration distances for all three measures of chemotaxis to fMet-Leu-Phe (10-8 M), chemokinesis induced by fMet-Leu-Phe, and random migration tended to decrease with increasing dose, showing 0.0054 μm/rad (p -5 M) in conjunction with cytochalasin B (CB, 5 μg/ml) there was a significant dose trend, showing the dose effects of decreasing 0.0022 % release/rad for BGL and 0.0030 % release/rad for LYZ with increasing dose. In superoxide anion (O2-) production, a slight and marginally significant linear dose trend was found. These results suggest that the defense function of PMN is not so resistant to radiation as predicted from the fact that PMN in the peripheral blood are differentiated and mature. It is thought that radiation inflicts substantially harmful effects on the defense function of peripheral PMN. (author)

  16. Analysis of 60Co gamma-ray transport through air by discrete-ordinates transport codes

    An assessment of the calculational accuracy of the discrete-ordinates codes, PALLAS-2DCY and DOT-III, has been performed for gamma-ray transport through air from a 60Co point isotropic source. The first collision source technique was used in the calculations. The results were compared with the measured exposure dose rates near the ground surface. Also, the ratio of the dose rates by gamma rays incident on and reflected from the ground was compared between the calculations. In addition, the calculated angular fluxes were examined. It is shown that the use of a truncated Legendre polynomial expansion implemented on DOT-III is not sufficient for calculations of gamma-ray scattering in air, while the direct application of the Klein-Nishina formula on PALLAS-2DCY is adequate to the calculatons. Both two-dimensional tranport codes, however, are useful for calculating the gamma-ray transport through air with a practical accuracy. PALLAS-2DCY requires one-fifth the central processor unit time as DOT-III

  17. Characteristic evaluation of papain irradiated with 60Co γ-rays for the purpose of sterilization

    To establish irradiation sterilization method for hybrid biomedical materials containing bioactive molecules together with artificial polymers, we employed dry powder and aqueous solution of papain as a model and examined radiation tolerance with 60Co γ-rays. The dry powder and frozen aqueous solution showed significant resistance after 30-kGy irradiation, indicating that commercial irradiation sterilization method for disposable medical supplies was applicable. Unfrozen aqueous solutions (10mg/ml), in contrast, showed significant drop of enzymatic activity within the early period of irradiation (ca. 0.5kGy) but 40% of the activity was recovered at ca. 3-kGy before total inactivation at 15kGy. Taking various conditions including dose rate, concentration of enzyme, oxygen and nitrogen bubbling into irradiation inactivation experiments, we demonstrated that inactivation of papain could be controlled under anoxic condition, such as nitrogen bubbling, increasing sample volume at high dose rates and high concentration of enzyme where dissolved oxygen was consumed rapidly. It is suggested that radiation inactivation of papain in the aqueous solution was occurred through reversible oxidation of the sulfhydryl group at the active site by free radicals derived from radiolysis of water and dissolved oxygen. (author)

  18. Irradiation effect on enzymatic activity of papain with 60Co-γ rays

    An investigation was made on the durability of enzyme activity against 60Co-γ irradiation at a dose up to 55 kGy/h using dry powder and aqueous solution of papain preparations on the market. Hybrid materials including bioactive molecules combined with biocompatible synthetic polymers are expected to have biocompatible properties and also biomimetic functions as a component of artificial organs for human body. The activity of papain in an aqueous solution was rapidly decreased at the early stage of irradiation through oxidation of SH group at its active site with active oxygen produced by the irradiation and then, partially recovered since SH group was reproduced in an anoxic state after O2 consumption in the solution irradiated at a high dose. A usual radiation method for sterilization was found applicable to decontamination of dry and frozen preparations of papain. When suitable conditions for radiation were chosen and N2 gas was purged to suppress the formation of free radicals, it was possible to keep the enzyme activity at more than 50% of the initial activity after radiation at 30 kGy. (M.N.)

  19. Effects of 60Co irradiation on the genetics of indian meal moth

    4 ∼ 5 days old male pupae of Indian meal moth, Plodia interpunctella Hubner were irradiated with 1, 3, 5, 7 and 10 krad of 60Co γ-ray. The male moths developed from treated pupae and their F1 generation were put together with normal female moths for copulation separately. The genetic effects of irradiation was studied and the results showed that the effects of irradiation were significant, which related to the irradiation dosage, on both parental and filial generations. Only 40% of the pupae was emerged, when they were irradiated at 10 krad. The effects on deformation rates, survival rates, copulation abilities, fecundities, hatching rates and genetic sterilities varied with different irradiation dosage treatment. With consideration of the total irradiation effect, the dosage lower than 5 krad is desirable for inducing the sterility of adults and sex chain recessive lethal gene. With 1, 5 and 7 krad of irradiation, a mutant of P. interpunctella with transparent wings was induced, which provides a marking feature in control of Indian meal moth by sex chain recessive lethal gene

  20. The effect of 60Co-γ ray on the culture cell of Leymus chinensis

    The chromosomal variation and the growth and differentiation of the calli of Leymus chinensis irradiated by 60Co-γ rays at different dose and dose rate were investigated. It was shown that γ-rays in the range of 30∼100 Gy induced a lot of structural variations of chromosome, such as fragmentation, ring formation etc. and led to chromosomal elimination and inhibition of mitosis of the cells. The rate of chromosomal variation and the degree of inhibition in growth and differentiation of the callus were in relation to the dose and dose rate of γ-rays. The sensitivity of the cell to γ-rays is depended on the time of subculture. After two-day's subculture the calli were most sensitive. The results provide the cytological evidence of the effect of γ-rays on the cultured cell of Leymus chinensis and may be valuable for asymmetrical cell hybridization of L. chinensis, which plays a role as a donor

  1. Diffusion of strongly sorbing cations (60Co and 152Eu) in compacted FEBEX bentonite

    Diffusion experiments in compacted FEBEX bentonite were performed with strongly sorbing radionuclides, 60Co and 152Eu. Diffusion experiments with these radionuclides present several difficulties: first of all these tests are very time consuming because of the high sorption on the clays, secondly these elements not only present high sorption onto clays but also on diffusion cells, tubing, filters and reservoirs, typically used in the classical through-diffusion or in-diffusion methods, which makes difficult the interpretation of the results. In this study, the experiments were performed using the instantaneous planar source method, where a paper filter tagged with a tracer is placed between two tablets of compacted bentonite. The apparent diffusion coefficient (Da) is obtained analysing the tracer concentration profile in the samples at the end of the experiment, both with an analytical and a numerical approach. The ranges of Da values obtained from these experiments in the FEBEX clay compacted at 1.65 g/cm3 are (0.5-2.3) x 10-13 m2/s for Co and (0.8-2.5) x 10-14 m2/s for Eu. Results showed that the analytical solution is able to fit reasonably well the Eu concentration profiles, whereas Co concentration profiles show a different behavior, not straightforward to explain, which was also analyzed by numerical methods. (authors)

  2. Change of free radicals and chemical structure of Moso bamboo with 60Co γ radiation

    After 60Co γ radiation, absolutely dry bamboo powder produced free radicals and its chemical composition and structure changed. Electron spin resonance (ESR) and X-ray photoelectron spectroscopy (XPS) techniques were used to measure the spectrum of the free radicals and X-ray photoelectron spectroscopy of the γ-ray radiated bamboo powder. The test results reveal that when the spectral splitting factor (g) of the bamboo free radicals is 2.0033, and the intensity of free radicals increase with the absorbed dosage of irradiation according to exponential law. After irradiation of 200 kGy, the O/C atomic number ratio in the bamboo surface increases slightly, C-C and C-H content increases, C-O and C=O content decreases, and -O-C=O content increases to 1.5 times over that of the original, which indicates some oxygen-containing functional groups occur and oxidation state of carbon increases in the bamboo surface. (authors)

  3. Bioaccumulation of 137Cs and 60Co by a tropical marine teleost Epinephelus sp

    As part of a project on behavior of radionuclides released by Angra Nuclear Power Station in the marine environment, laboratory experiments were performed to study cesium and cobalt accumulation by juvenile groupers (Epinephelus sp.). The fishes were kept in aquariums equipped with gravel-bed filters spiked with 60C0 (150 KBq/l) and 137Cs (75 KBq/l). Uptake was only via water since the fishes received only non- radioactive food during 4 months of experiment. Cesium accumulation in muscle was higher than in any other organ, reaching CFs (concentration factors) of 5 (fresh weight basis). Cobalt, in contrast, concentrated mostly in the liver, gut and skin and scales. Cobalt CF in muscle tissue was 8x10-2, lower than any previously reported figure. Chromatographic analysis of the water at the beginning and end of the experiment showed that cobalt had been completely converted from 60CoCl2 to non-cationic forms, most probably through complexation with organic ligands, mediated by the intense microbial activity of the filter bed. This conversion apparently enhanced cobalt bio-availability since a second experiment performed with this aged seawater yielded CFs for muscle tissue higher by a factor of 2.5. (author). 20 refs.; 2 figs.; 2 tabs

  4. 60Co irradiation for sterilization of veterinary mastitis products containing antibiotics and steroids

    Effects of 60Co irradiation for sterilization of veterinary mastitis products were evaluated. The mastitis products which were examined contained various combinations of antibiotics and steroids suspended in peanut oil vehicle. Bioburden data indicated that the unirradiated products were only occasionally contaminated with microorganisms. The D-values of the nonsterile product and environmental isolates were 0.028, 0.15, 0.017, and 0.018 Mrads for Aspergillus fumigatus, Penicillium oxalicum, Pseudomonas aeruginosa, and Pseudomonas maltophilia, respectively. The D-value of the biological indicator organism, Bacillus pumilus spores, in the vehicle was 0.27 Mrads. Thus, an irradiation dose of 1.6 Mrads would be sufficient to achieve six log cycles of destruction of the biological indicator organism. The minimum absorbed irradiation dose of 2.5 Mrads preferred by many countries for sterilization would achieve 9.3 log cycle destruction of the indicator organism and guarantee a probability of 1 x 10-15 assurance for the most radio-resistant product isolate, Penicillium oxalicum. In order to examine short and long term chemical stabilities of active components, stability indicating high-performance liquid chromatographic (HPLC) methods for the determination of several of the antibiotics and steroids were developed. The rates of degradation and radiolytic degradation schemes for the majority of the compounds were elucidated. (author)

  5. Protective effect of catecholestrogens against 60Co γ-ray radiation injury in mice

    When 10-week-old male BALB/c mice received whole-body irradiation with a single dose of 8 Gy 60Co γ-ray and catecholestrogen 2-hydroxyestradiol (2-OHE2) was subcutaneously injected 3 hours before and after the irradiation, 30-day survival rate of the mice was 70%, while the survival rate of the mice administered the other test samples was as follows; 2-hydroxyestrone, 20%; 2-hydroxyestriol, 20%; 4-hydroxyestradiol, 0%; 2-methoxyestrone, 0%; 2-methoxyestradiol, 0%; 2-methoxyestriol, 0%; estrone, 0%; estradiol, 5%; estriol, 0%; control, 5%. Lipid peroxide level in the liver of mice markedly increased on the 4th day after the irradiation. However, this increase in the lipid peroxide level was significantly suppressed by the administration of 2-OHE2. The radiation-induced anemia, leukopenia, and atrophy of the thymus were significantly protected by the administration of 2-OHE2. These results indicate that 2-OHE2 had a potent inhibitory effect on radiation injury. (author)

  6. Influence of rhTPO on hematopoiesis in mice irradiated with 60Co γ-ray

    Objective: Thrombopoietin, a major physiological regulator of megakaryocytopoiesis, has potent effects on megakaryocytopoiesis. With a view to finding a new therapeutic modality for bone marrow injury-induced thrombocytopenia, the authors studied the biological activity of rhTPO in vivo. Methods: The authors recombined hTPO by means of RT-PCR and eukaryotic expression. The rhPTO was administered to 5.0 Gy 60Co γ-ray irradiated male mice, once per day for 20 consecutive days. Peripheral blood counts were monitored and bone marrow was assayed for clonogenic activity. Results: Circulating platelet counts and CFU-MK of the rhTPO-treated mice increased significantly in contrast with the control group. Conclusion: These results show that rhTPO can restore platelets and CFU-MK of irradiated mice in vivo. Clearly, the growing understanding of the biology of TPO will lead to important new in-sights into megakaryocytopoiesis and to improvement in clinical treatment of bone marrow failure

  7. Study on the energy dependence of gamma radiation detectors for {sup 137}Cs and {sup 60}Co; Estudo da dependencia energetica de detectores de radiacao gama para {sup 137}Cs e {sup 60}Co

    Nonato, Fernanda B.C.; Diniz, Raphael E.; Carvalho, Valdir S.; Vivolo, Vitor; Caldas, Linda V.E., E-mail: fbnonato@ipen.b, E-mail: rediniz@ipen.b, E-mail: vcsouza@ipen.b, E-mail: vivolo@ipen.b, E-mail: lcaldas@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    38 Geiger-Mueller radiation detectors and 9 ionization chambers were calibrated, viewing to study the energy dependence of the monitor response for gamma radiation fields ({sup 137}Cs and {sup 60}Co). The results were considered satisfactory only for ionization chambers and for some Geiger-Mueller detectors

  8. C-V characteristics of Pt/PbZr0.53Ti0.47O3/LaAlO3/Si and Pt/PbZr0.53Ti0.47O3/La0.85Sr0.15CoO3/LaAlO3/Si structures for ferroelectric gate FET memory

    Pt/PbZr0.53Ti0.47O3 (PZT)/LaAlO3 (LAO)/Si and Pt/PbZr0.53Ti0.47O3/La0.85Sr0.15CoO3 (LSCO)/LaAlO3/Si structures for ferroelectric field effect memory applications were fabricated on n-type Si substrate by pulsed laser deposition (PLD). The Auger electron spectrometry (AES) analysis shows that a LaAlO3 buffer layer can effectively prevent Si and Ti, Pb interdiffusion between PZT and Si substrate. For both of the structure, the current density-voltage measurement shows a typical leakage current density of about 10-7 A/cm2 at 8 V applied voltage. Furthermore, it has been demonstrated that the PbZr0.53Ti0.47O3/LaAlO3/Si structures and Pt/PbZr0.53Ti0.47O3/La0.85Sr0.15CoO3/LaAlO3/Si structures exhibit ferroelectric switching properties, showing a memory window as large as 2 and 2.9 V, respectively, under a ramp rate of 200 mV/s from -6 to +6 V driving voltage at 1 MHz. It is believed that the La0.85Sr0.15CoO3 buffer layer deposited on LaAlO3 layer can improve the crystalline properties of PZT films, and then result in lager polarization of PZT and lager memory windows for Pt/PbZr0.53Ti0.47O3/La0.85Sr0.15CoO3/LaAlO3/Si structures

  9. Comparison of the standards of absorbed dose to water of the OMH and the BIPM for 60Co γ rays

    A comparison of the standards of absorbed dose to water of the Orszagos Meresugyi Hivatal (OMH), Budapest, Hungary and of the Bureau International des Poids et Mesures (BIPM) has been made in 60Co radiation. The results show that the OMH and the BIPM standards for absorbed dose to water are in close agreement, the difference being within the estimated uncertainty. (authors)

  10. Determination of the mean energy necessary for the production of an ion pair in air by 60Co gamma radiation

    On the basis of an ionometric and a calorimetric method for determining the absorbed dose in graphite the following values of the mean energy for ion pair production by 60Co gamma radiation has been obtained in dry air: (33.87 +- 0.34) J/C. The errors of the method are discussed. The result is compared with recently published values. (author)

  11. Preparation of low molecular weight chitosan by a combination of chemical treatment and 60Co gamma radiation

    A low molecular weight chitosan finds potential applications in agriculture, medicine, personal health care, cosmetics etc. Chitosan undergoes depolymerization when exposed to ionizing radiation, therefore 60 Co gamma rays or electron beam irradiation appears to be the most promising way to prepare a low molecular weight chitosan

  12. The evaluation of 59Co(n,γ)60Co reaction cross section and its covariance data

    59Co(n,γ)60Co reaction cross section is of importance for dosimetry application. The evaluation of cross section and its covariance data is studied. The resonance parameter sets are modified in this evaluation. The value of evaluated cross section and its covariance are presented. The cross section of thermal energy region is 37.18 +- 0.6b

  13. Whole-body retetion of 60CoCl2 and 58Co-cyanocobalamin in young and adult rats

    Whole-body retention of 60CoCl2 and 58Co-cyanocobalamin after oral and intravenous administration was investigated in young and adult rats. Whole-body retention of 58Co-cyanocobalamin was considerably higher than that of 60CoCl2 in rats of all age groups. Younger rats showed higher retention of both CoCl2 and cyanocobalamin than did the adult rats. The biological half life in the slowly decreasing phase after oral administration of 60CoCl2 and 58Co-cyanocobalamin was approximately equal in all age groups and was estimated to be about 10 and 25 days, respectively. These results suggested that the whole-body retention of orally administered 60CoCl2 and 58Co-cyanocobalamin in rats of various ages depends mainly on intestinal absorption rather than endogenous excretion rate. The excretion pattern of 58Co-cyanocobalamin, i.e., F/U ratio etc., is very different from that of inorganic cobalt, and it is therefore assumed that 58Co-cyanocobalamin is rather stable in the body. (auth.)

  14. High dose internal radiotherapy of bile duct carcinoma with sup(60)Co wire placed inside a percutaneous transhepatic drainage catheter

    A new method for relieving biliary obstruction due to malignant tumours is described. The procedure consists of percutaneous transhepatic cannulation of the obstructed bile duct by means of a Ring biliary drainage catheter and sup(60)Co wire built in a nylon tube, placed inside the catheter for 23 hours. First results are reported. (author)

  15. Microdosimetric spread for cell-sized targets exposed to 60Co, 192Ir and 125I sources

    The magnitude of the spread in specific energy deposition per cell may be a confounding factor in dose- response analysis motivating derivation of explicit data for the most common brachytherapy isotopes 125I and 192Ir, and for 60Co radiation frequently used as reference in RBE studies. The aim of this study is to analyse the microdosimetric spread as given by the frequency distribution of specific energy for a range of doses imparted by 125I, 192Ir and 60Co sources. An upgraded version of the Monte Carlo code PENELOPE was used for scoring energy deposition distributions in liquid water for each of the radiation qualities. Frequency distributions of specific energy were calculated according to the formalism of Kellerer and Chmelevsky. Results indicate that the magnitude of the microdosimetric spread increases with decreasing target size and decreasing energy of the radiation quality. Within the clinical relevant dose range (1 to 100 Gy), the spread does not exceed 4 % for 60Co, 5 % for 192Ir and 6 % for 125I. The frequency distributions can be accurately approximated with symmetrical normal distributions at doses down to 0.2 Gy for 60Co, 0.1 Gy for 192Ir and 0.08 Gy for 125I. (authors)

  16. Use of the bleeding sap for investigation of radionuclide transfer to crops through root and translocation of the nuclide in the crops

    Adsorption and translocation characteristics of radionuclides in the root of tomato plant were investigated. Mature tomato plant was transplanted to culture solution containing 85Sr, 137Cs, 131I, 54Mn, 60Co and 65Zn. Immediately after transplantation, the tomato plant was cut at 10 cm above the surface of the culture solution in order to collect bleeding sap solution (Experiment-1). Another mature tomato plant was cultured for 3 days in culture solution containing radionuclides as mentioned above and then transplanted to fresh culture solution. Bleeding sap solution was also collected in the same way as shown in Experiment-1 (Experiment-2). Activity ratios of bleeding sap to culture solution were measured for several hours. Adsorption and removement of those radionuclides in tomato plant were summarized as follows; 137Cs was taken up by the root almost at the same speed as that of water and accumulated in the lowest among the six nuclides used in the experiments. The concentrations of 85Sr, 54Mn and 65Zn in the bleeding sap of 3 days' uptake experiment were higher than the initial concentrations of the culture solution for several hours even after the tomato plant was transplanted to fresh culture solution. 131I and 60Co were accumulated much in the root and found extremely low in the bleeding sap during the experiment, suggesting that the nuclide were absorbed on the surface of the roots and scarcely moved. (author)

  17. Comparison of two standard dosimetry protocols for output calibration of 60Co teletherapy machines

    Two protocols for output calibration of 60Co teletherapy machines were studied in two steps. In the first step, two methods for timer error determination were studied both in air and in water: the two-exposure method with the short exposure time ranging in value form ts=0.1tL to ts=0.7tL, where tL is the long exposure time; and the single/multiple exposure method with the number of exposures ranging from n=2 to n=9. The results showed better precision for the two-exposure method with smaller ratios of ts to tL and for the single/multiple exposure method with the greater n, and also showed better precision for in-air than in-water measurements in both protocols. A comparison was made between the two-exposure protocol with ts=0.2tL, 0.3tL and 0.5tL and the single/multiple exposure protocol with n=6. In-air measurements showed the best results with ts=0.2tL in terms of both precision and decay constants estimated from the regression of exposure rate against time. In the second step, the protocol with n=6 was used in comparing the output value measured in air with that measured in water. The dose rates at 5 cm depth in water determined by these two methods of measurement were comparable to within ±0.5%. (author). 8 refs, 3 figs, 2 tabs

  18. The radiation effect of 60Co gamma rays on polycarbonate detector

    The irradiation of polymeric materials with ionizing radiation (gamma rays, X rays, accelerated electrons, ion beams) leads to the formation of very reactive intermediates products (excited states, ions and free radicals), which result in rearrangements and/or formation of new bonds. The effects of these reactions are formation of oxidized products, grafts, scission of main chain (degradation) or cross-linking. Often the two processes (degradation - cross- linking) occur simultaneously, and the outcome of the process is determined by a competition between the reactions. Polycarbonate detectors are used as a particle track detector for neutrons and alpha particles detection. This work aims to study the ionizing radiation dose response of polycarbonate samples using spectrophotometric technique. A commercially available polycarbonate was analysed and its dosimetric characteristics were studied: radiation-induced absorption spectra, ambient light, temperature and humidity influence, pre- and post-irradiation stability, reproducibility and dose range useful response. Samples of polycarbonate (3 x 1 cm2) were irradiated with 60Co gamma radiation in free air at electronic equilibrium with absorbed doses between 1 and 95 kGy. When exposed to gamma radiation the polycarbonate detectors undergoes changes in their optical response, the colour variation is used for determining the absorbed dose. A Shimadzu UV-2101PC spectrophotometer was used for scanning the absorption spectra and measuring the optical density of film detectors irradiated with different radiation doses. Polycarbonate film detector are easy to prepare and to analyse, of good optical quality, inexpensive and of small size. The dosimetric accuracy can be affect by environmental conditions so, the detectors must be stored in appropriate conditions. The reproducibility of the detectors response can be improved by careful monitoring of optical densities before irradiation. The dose response curve presents linear

  19. Evaluation of myotoxic activity of Bothropstoxin-1 irradiated with 60Co gamma rays

    Ionizing radiation has been successfully employed to modify the immunological properties of biomolecules and has been proven to be a powerful tool to attenuate snake venoms toxicity without affecting their immunogenic properties. Snake venoms and their isolated toxins showed structural modifications after gamma radiation process, in aqueous solution, mainly by water radiolysis sub products. Free radical scavengers, such as NaNO3 and t-butanol, present selective effects on specific radical from water radiolysis. The NaNO3 has affinity by aqueous electron, while the t-butanol has affinity by hydroxyl radical. At the present work, we have investigated the myotoxic activity of Bothropstoxin-1 (BTHX-1), a K49 phospholipase, present in Bothrops jararacussu crude venom, before and after irradiation process, with or without scavenger substances presence. BTHX-1 was irradiated with 2 kGy of 60Co gamma rays, in aqueous solution and in the presence of oxygen. BALB/c mice were inoculated with either native or irradiated toxin, with or without scavenger substances. After 3 hours, blood samples were collected and the myotoxic activity was evaluated by LDH (lactate dehydrogenase) release. The muscular tissue damage was directly related to the LDH amounts released. Irradiated Bothropstoxin-1, with or without NaNO3 substance, caused less damage than their native counterpart. But irradiated toxin, in the presence of t-butanol, was so myotoxic as the native BTHX-1. These results indicate that irradiation of toxic proteins can promote significant modifications on their structures, but still retaining many of the original biological properties of their native counterparts. Additionally, some scavengers substances can change these gamma radiation effects. (author)

  20. Immobilization of 60Co and 90Sr ions using red mud from aluminum industry

    Milenković Aleksandra S.

    2014-01-01

    Full Text Available The removal of 60Co and 90Sr from the aqueous phase was tested using red mud - the fine grained residue from bauxite ore processing. This industrial waste represents a mixture of numerous minerals, mainly oxides and hydroxides of Fe, Al, Si, and Ti. Experiments were conducted as a function of contact time, pH, and pollutant concentrations. Kinetic data were well fitted with a pseudo-second order equation. The calculated rate constants and initial sorption rates indicated faster sorption of Sr2+ ions. Removal of both cations rapidly increased with the initial pH increase from 2.5 to 3.5. With the further increase of pH, Co2+ sorption was nearly constant (98%-100%, whereas Sr2+ removal remained at the same level to initial pH ~8 and gradually increased to 100% at pH 12. Equilibrium sorption data followed the Langmuir model, with the maximum sorption capacities of 0.52 mmol/g for Co2+ and 0.31 mmol/g for Sr2+. Sorbed cations exhibited high stability in distilled water. Desorption of Co2+ was also negligible in the presence of the competing Ca2+ cation, while 42%-25% of Sr2+ ions were desorbed depending on the previously sorbed amount. The results indicate that red mud is of potential significance as Co2+ and Sr2+ immobilization agent due to its high efficiency, abundance, and low-cost. [Projekat Ministarstva nauke Republike Srbije, br. 43009

  1. Use of {sup 60}Co panoramic source in the induction of oral mucositis in rats

    Andrade, Maira F.; Benetti, Carolina; Zezell, Denise M., E-mail: mairandrade@yahoo.com, E-mail: zezell@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Correa, Luciana, E-mail: lcorrea@usp.br [Universidade de Sao Paulo (FO/USP), Sao Paulo, SP (Brazil). Fac. de Odontologia

    2013-07-01

    Oral Mucositis is a well-known side effect of chemo-radiotherapy in cancer patients or transplant recipients that could induce hospitalization or impairs therapy in different levels of severity. This study is devoted to define the first steps in the research of low level laser treatments in oral mucositis, proposing a {sup 60}Co radiation to experimentally induce oral mucositis in rats using Panoramic gamma irradiator, simulating usual radiotherapy of head and neck cancer. Fifteen male Wistar rats, above 250g, were irradiated at Centro de Tecnologia das Radiacoes (IPEN - CNEN/SP) and divided in three experimental groups, with different single doses of radiation (30 Gy, 25 Gy and 20 Gy). The animals were observed for a 20 days period. Animals that received 30 Gy and 25 Gy developed greater severity of mucositis and premature euthanasia was performed in these groups on the 7th and 11th day after the irradiation, respectively. The 20 Gy group developed oral mucositis grading from moderated to severe between the days 7 and 11 after irradiation, with progressive body mass loss and decrease in the intake of food and water. These animals recovered from oral mucositis around the 18th day and clinical remission at the 20th day. The single dose of 20 Gy Gamma radiation proved to be efficient way for inducing oral mucositis in rats, allowing the establishment of an experimental model for oral mucositis in rats for future use on interventions of this serious aspect of radiation therapy, such as laser therapy using different wave lengths and power densities. (author)

  2. Whole-body retention of 60Co emitted in the environment

    In order to calculate whole-body retention of radioactive Co incorporated into man through food chain, the in vivo fate of Co was examined using rats. When 60CoCl2 (Co A) and 58Co-cyanocobalamin (Co B) were compared in terms of in vivo metabolism, biological half life of Co A, irrespective of age, was approximately 10 days, and that of Co B was 25 days. Eighty percent of Co A was excreted into the urine, and 9 % into the feces; whereas, 5 % of Co B was excreted into the urine, and 14 % into the feces. According to the organs, relative concentration rate of Co A was 2 - 3 % in the lungs and kidneys. The uptake of Co B into the kidneys was approximately 10 times higher than that into the liver. The fetal uptake of Co A was independent of gestation periods. However, much more dose of Co B was incorporated into the placenta when administered at more progressed gestation period. Much dose of Co B was incorporated into the sucklings through breast milk. A study on incorporation of Co A using a food model showed that cyanocobalamin analogues are synthesized from Co A. Because the absorption rate of Co A was dependent on the age in the experiment with rats, the digestive absorption rate in infants was estimated to be 10 times higher than that in adults. Effective dose commitment of Co B was 230 mrem, which was more than 20 times higher than that of Co A (10 mrem). When metabolic parameters of Co B were applied to infants, effective dose commitment was approximately 70 times higher than that in ICRP standard populations. (Namekawa, K.)

  3. Study of irradiated bothropstoxin-1 with {sup 60}Co gamma rays: immune system behavior

    Caproni, P.; Baptista, J.A.; Almeida, T.L. de; Nascimento, N. [Nuclear and Energy Research Institute (IPEN/CNEN-SP), SP (Brazil). Biotechnology Center; Passos, L.A.C. [State University of Campinas (UNICAMP), SP (Brazil). Lab. of Genetics and Embryo Cryopreservation

    2009-07-01

    Ionizing radiation has been successfully employed to modify the immunological properties of biomolecules. Very promising results were obtained when crude animal venoms, as well as isolated toxins, were treated with 60Co gamma rays, yielding toxoids with good immunogenicity. The achievement of modified antigens with lower toxicity and preserved or improved immunogenicity can be very useful. Ionizing radiation has already been proven to be a powerful tool to attenuate snake venom toxicity without affecting, and even increasing, their immunogenic properties. However, little is known about the modifications that irradiated molecules undergo and even less about the immunological response that such antigens elicit. In the present work, we investigated the immunological behavior of bothropstoxin-1, a K49 phospholipase, before and after irradiation. Structural modifications of the toxin were analyzed by SDS-PAGE. Isogenic mice were immunized with either the native or the irradiated toxin. The circulating antibodies were isotyped and titrated by ELISA. According to our data, irradiation promoted structural modifications in the toxin characterized by higher molecular weight forms of proteins (aggregates and oligomers). The results also indicated that irradiated toxins were immunogenic and antibodies elicited by them were able to recognize the native toxin in ELISA. These findings suggest that irradiation of toxic proteins can promote significant modifications in their structures; however they still retain many of the original antigenic and immunological properties of native proteins. Also, our data indicate that irradiated proteins induce higher titers of IgG2a and IgG2b, suggesting that Th1 cells are predominantly involved in the immune response. (author)

  4. Biochemical and immunological alterations of 60 Co irradiated Bothrops jararacussu venom

    Proteins irradiation leads to structural alterations resulting in activity and function loss. This process has been useful to detoxify animal venoms and toxins, resulting in low toxicity products which increased immunogenicity. The Bothrops jararacussu venom behaves as a weak immunogen and its lethal activity in not neutralized by either autologous, heterologous or bothropic polyvalent antisera. This venom is markedly myotoxic and and the commercial bothropic antiserum does not neutralize this activity, because of this low immunogenicity of the myotoxins. This present work was done in order to evaluate the possibility of irradiating Bothrops jararacussu, intending to increase the immunogenicity of the myotoxic components, leading to productions of myotoxins neutralizing antibodies. Bothrops jararacussu venom samples were irradiated with 500, 1000 and 2000 Gy of 60 Co gamma rays. A 2.3 folds decrease of toxicity was observed for the 1000 Gy irradiated samples while the 2000 Gy irradiated sample was at least 3.7 folds attenuated. On the other hand, the 500 Gy did not promote any detoxification. Electrophoresis and HPLC data indicate that the irradiation lead to the formation of high molecular weight products (aggregates). The proteolytic and phospholipasic activities decreased in a dose dependent manner, the phospholipases being more resistant than the proteases. Both the animals (rabbit) immunized with either native or 2000 Gy irradiated venom produced native venom binding antibodies, a slightly higher titer being obtained in the serum of the rabbit immunized with the irradiated samples. Western blot data indicate that the anti-irradiated venom Ig Gs recognised a greater amount of either autologous or heterologous venom bands, both sera behaving as genus specific. The anti-native serum did not neutralize the myotoxic activity of native venom, while the anti-irradiated one was able to neutralize this activity. (author)

  5. Biochemical and pharmacological characterization of irradiated crotamine by gamma rays of 60Co

    The serum production in Brazil, the only effective treatment in cases of snakebites, uses horses that although large size, have reduced l lifespan compared with horses not immunized. Ionizing radiation has been shown as an excellent tool in reducing the toxicity of venoms and toxins isolated, and promote the achievement of better immunogens for serum production, and contributing to the welfare of serum-producing animals. It is known, however, that the effects of ionizing radiation on protein are characterized by various chemical modifications, such as fragmentation, cross-linking due to aggregation and oxidation products generated by water radiolysis. However, the action of gamma radiation on toxins is not yet fully understood structurally and pharmacologically, a fact that prevents the application of this methodology in the serum production process. So we proposed in this paper the characterization of crotamine, an important protein from the venom of Crotalus durissus terrificus species, irradiated with 60Co gamma rays. After isolating the toxin by chromatographic techniques and testing to prove the obtaining of pure crotamine, it was irradiated with gamma rays and subjected to structural analysis, Fluorescence and Circular Dichroism. Using high hydrostatic pressure tests were also conducted in order to verify that the conformational changes caused by radiation suffer modifications under high pressures. From the pharmacological point of view, muscle contraction tests were conducted with the objective of limiting the action of crotamine in smooth muscle as well as the change in the action of toxin caused structural changes to the front. Analysis of Circular Dichroism and Fluorescence showed changes in structural conformation of crotamine when subjected to gamma radiation and that such changes possibly occurring in the secondary and tertiary structure of the protein. The observed in pharmacological tests showed that the irradiated crotamine was less effective in

  6. The radiation effect of 60Co gamma rays on polycarbonate detector

    The irradiation of polymeric materials with ionizing radiation (gamma rays, X rays, accelerated electrons, ion beams) leads to the formation of very reactive intermediates products (excited states, ions and free radicals), which result in rearrangements and/or formation of new bonds. The effects of these reactions are formation of oxidized products, grafts, scission of main chain (degradation) or cross-linking. Often the two processes (degradation - cross- linking) occur simultaneously, and the outcome of the process is determined by a competition between the reactions. Polycarbonate detectors are used as a particle track detector for neutrons and alpha particles detection. This work aims to study the ionizing radiation dose response of polycarbonate samples using spectrophotometric technique. A commercially available polycarbonate was analysed and its dosimetric characteristics were studied: radiation-induced absorption spectra, ambient light, temperature and humidity influence, pre- and post-irradiation stability, reproducibility and dose range useful response. Samples of polycarbonate (3 x 1 cm2) were irradiated with 60Co gamma radiation in free air at electronic equilibrium with absorbed doses between 1 and 95 kGy. When exposed to gamma radiation the polycarbonate detectors undergoes changes in their optical response, the colour variation is used for determining the absorbed dose. A Shimadzu UV- 2101PC spectrophotometer was used for scanning the absorption spectra and measuring the optical density of film detectors irradiated with different radiation doses. Polycarbonate film detector are easy to prepare and to analyse, of good optical quality, inexpensive and of small size. The dosimetric accuracy can be affect by environmental conditions so, the detectors must be stored in appropriate conditions. The reproducibility of the detectors response can be improved by careful monitoring of optical densities before irradiation. The dose response curve presents linear

  7. Use of 60Co panoramic source in the induction of oral mucositis in rats

    Oral Mucositis is a well-known side effect of chemo-radiotherapy in cancer patients or transplant recipients that could induce hospitalization or impairs therapy in different levels of severity. This study is devoted to define the first steps in the research of low level laser treatments in oral mucositis, proposing a 60Co radiation to experimentally induce oral mucositis in rats using Panoramic gamma irradiator, simulating usual radiotherapy of head and neck cancer. Fifteen male Wistar rats, above 250g, were irradiated at Centro de Tecnologia das Radiacoes (IPEN - CNEN/SP) and divided in three experimental groups, with different single doses of radiation (30 Gy, 25 Gy and 20 Gy). The animals were observed for a 20 days period. Animals that received 30 Gy and 25 Gy developed greater severity of mucositis and premature euthanasia was performed in these groups on the 7th and 11th day after the irradiation, respectively. The 20 Gy group developed oral mucositis grading from moderated to severe between the days 7 and 11 after irradiation, with progressive body mass loss and decrease in the intake of food and water. These animals recovered from oral mucositis around the 18th day and clinical remission at the 20th day. The single dose of 20 Gy Gamma radiation proved to be efficient way for inducing oral mucositis in rats, allowing the establishment of an experimental model for oral mucositis in rats for future use on interventions of this serious aspect of radiation therapy, such as laser therapy using different wave lengths and power densities. (author)

  8. Efficacy of a 60Co irradiated vaccine for experimentally infected calves with dictyocaulus viviparus

    Dictyocaulus viviparus larvae in non-infected stage (L.1) were cultured in vitro to their infective stage (L.3) and were irradiated with 40 Krad from 60Co and used as a vaccine. The oral experimental vaccine dose was 1000 L.3/animal. Three groups were formed with 8 calves in each one: group No. 1 and group No. 2 were vaccinated at 10 weeks of age. Four weeks later group No. 1 was infected with non-irradiated 60 L.3/Kg. of animal weight 'challenge dose'. After four weeks of post-vaccination group No. 2 was revaccinated and 4 weeks later it was infected with the 'challenge dose' as the previous group. Eight calves constituted group No. 3, four in each group; they were infected with only the challenge dose respectively. Information data on respiratory and cardiac frequency, temperature, weight, and L.1 count/g. of feces were obtained from each animal three times a week. After five weeks of post-challenge all animals were slaughtered to observe anatomopathologic lessions in the heart and lungs; the number of adult Dictyocaulus viviparus present in the respiratory tract were search 't'. Student test was used for the statistical analysis. The weight increment difference between animals of group No. 1 related control group was 7Kg.; and 11.25 Kg/animal in group No. 2 respectively. The percentage of protection confered by the vaccine to the subjects in group No. 1 relative to the respectivecontrol group, was 83.2; that for the group No. 2 was 88.5 per cent. Post-morten examination revealed severe anatomopathologic lessions in the control groups; only few lessions were observed in group No. 1 and practically none in group No. 2

  9. Influence of 60Co irradiation on the mandible of adult rabbit

    This study was performed in order to observe the effect of 60Co γ-ray irradiation (5000, 8000 and 10000R) on rabbits' mandible, for as long as possible, approximately 18 months. Radiographical and histopathological studies were done after irradiation. The upper anterior teeth of all experimental animals showed elongation, lateral flection and diasthema. The lower anterior teeth showed shortening or disappearance of the crowns and resorption of the root apex in all. These teeth were lost eventually. Molar teeth disclosed shortening of crowns and irregular and partial loss on the surface of the dentine. Pulp chambers were extremely narrowed. These changes were most conspicuous in the 10,000R irradiation group. Mandibular fractures occurred in 13 cases, which include 3 cases with 5,000R, 4 cases with 8,000R and 6 cases with 10,000R. The alveolar bones were resorped, and were replaced with mandibular bone trabeculae. Various types of ankylosis of root surface and mandibulars were seen. These changes were more frequently noted in the molar regions that the anterior regions and in the groups with higher doses and longer days after irradiation. Bone trabeculae and cortex of the mandibles were resorped in the 3 irradiation groups in the early stage, but regeneration and thickening of the bones occured later. The usual case was that the anterior bone marrow became more gelatinous and the molar marrow became more fibrous. Hyperemia and abscess formation were recognized in some cases. Although in the molar regions these pathological changes were conspicuous in proportion to the amount of dose, in the anterior regions, the same changes were more conspicuous in the 5,000R irradiation group than in the 8,000R group. (J.P.N.)

  10. Detection and thermoluminescence of coriander (Coriandrum sativum L.) irradiated with 60Co

    The fresh and dried coriander (Coriandrum sativum L.) is a spice of high commercial value as food for consumption in Mexico. Their hygienic quality is often poor due to some factors: contaminants present in irrigation water and the cultivation atmosphere, harvesting and post harvest handling, mainly. The process by radiation is an alternative to achieve the sterilization to adequate dose for the hygienic quality for its consumption. However, irradiation also involves food detection exposed to radiation. This paper presents detected results on the dried coriander that was obtained from fresh samples and thermoluminescent properties such as glow curves structure from low doses (0.5 Gy) to high (15 kGy), the dose response, thermoluminescent signal decay, in order to determine the loss of stability during the storage of the poly mineral fraction. We obtained the inorganic fraction separation of the organic part of particle sizes of 10 μm by the Zimmerman method. The samples were exposed at two dose ranges; 0.5-400 Gy and 0.5-15 kGy of gamma radiation with 60Co. The limit of thermoluminescent detection of the irradiated coriander samples was from 1 Gy. The glow curves were at a broad band of 35-400 C, with a maximum thermoluminescence around 182-196 C, and run at 164 C for high doses of 15 kGy. The range of linear response to dose was 4-25 Gy, whereas higher doses than the kGy order the response increase with the dose. The thermoluminescent properties of the coriander poly mineral fraction, show it can be used to identify irradiated food at gamma doses relatively low and even in doses of commercial interest due to the high stability of thermoluminescent signals. (Author)

  11. Preparation of Low Activity 60Co Sealed Source Based on Zirconyl Molybdo-Pyro phospate Inorganic Ion Exchanger for Radiometric Calibration Purposes

    Zirconyl Molybdo-pyrophosphate inorganic ion exchanger was prepared and used for preparation of a 60Co sealed source. The corresponding distribution coefficients of 60Co(II) ions on Zirconyl Molybdo-pyrophosphate were determined as a function of HCl acid concentration. The apparent capacity of Zirconyl Molybdo-pyrophosphate for 60Co(II) was determined by dynamic method and it was found to be 0.24 mmol/g. Zirconyl Molybdo-pyrophosphate was loaded with 60Co radionuclides by equilibrating of 60Co solution with 1g of it at ph 5 (HCl) for 48 h at 25±1 degree C. Sealed source of 1.0 8% μ Ci 60Co was prepared by packing 100 mg of the loaded matrix in the cylindrical cavity of a Chinese artelone capsule. The sealed source was submitted to quality control tests.

  12. Diffusion of strongly sorbing cations (60Co and 152Eu) in compacted Febex bentonite

    Document available in extended abstract form only. Compacted bentonite is used as an engineered barrier in high-level radioactive waste (HLRW) repositories because is a swelling clay of very low permeability and high sorption capability for many solutes. The transport of radionuclides through compacted bentonite is a diffusion-controlled process retarded by sorption. Performance assessment calculations of a repository need diffusion coefficients data of relevant radionuclides. Several studies on diffusion behaviour of neutral, anionic and weakly sorbing elements on clay exist while very few studies are available for moderately sorbing elements, and almost no studies for Eu, a highly sorbing element are reported. In this study, diffusion experiments with strongly sorbing radionuclides, as 60Co and 152Eu, have been performed through compacted FEBEX bentonite. Diffusion essays with these strongly sorbing radionuclides are not straightforward to carry out because they are very time consuming essays, but also because sorption on the diffusion cells, tubing, filters and reservoirs, typically used in the classical through-diffusion or in-diffusion methods make hard the interpretation of the experimental results and the calculation of the diffusion coefficients. FEBEX bentonite was selected as Spanish reference buffer materials, and used in many national and international projects. The clay comes from the Cortijo de Archidona deposit (Almeria, Spain), and has a smectite content greater than 90% (93 ± 2%), with quartz (2 ± 1%), plagioclase (3 ± 1%), cristobalite (2 ± 1%), potassic feldspar, calcite, and trydimite as accessory minerals. The specific weight of the FEBEX bentonite is 2.7 g/cm3. Diffusion experiments were performed using the instantaneous plane source method. In this setup, a paper filter tagged with a tracer is introduced between two compacted tablets, avoiding contact between the tracer and the experimental vessels. The tracer can diffuse into both

  13. (60)Co-γ irradiation affects the enzymatic antioxidant system of the citrus red mite Panonychus citri (Acari: Tetranychidae).

    Zhang, Ke; Li, Zhibin; Zhu, Shaowen; Weng, Qunfang

    2014-01-01

    Radio-(60Co), which emits γ rays, has been used worldwide in pest control. The aim of the present study was to analyze the effect of effective-low-power 60Co-γ irradiation on the enzymatic antioxidant system of the citrus red mite Panonychus citri. One day old female adults were exposed to 0.4 kGy 60Co-γ irradiation and on the, 6th h, 1st day, 2nd day, and 5th day post treatment, the mites were euthanized for biochemical analysis. The activity of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), phenoloxidase (PO) and acetylocholinesterase (AchE) were investigated. POD and CAT activities, as well as SOD were higher in the irradiated mites. We found that exposure to 60Co-γ radiation resulted in increased activities of SOD, CAT, POD and decreased AchE activity. When the recovery time lasted till the 5th day, the activities of POD and PO were significantly lower than the control, whereas the SOD, CAT and AchE activities returned to control levels. Cells possess protein repair pathways to rescue oxidized proteins and restore their functions, but if these repair processes fail, oxidized proteins may become cytotoxic. Our results confirm the hypothesis that low dosages of 60Co-γ irradiation increase the level of oxidative stress in P. citri adults in a short time, causing meanwhile damage and sterility. The results of this study also indicate that stress caused by exposure to irradiation could inhibit the cholinergic system in P. citri. PMID:24853454

  14. 60Co-γ Irradiation Affects the Enzymatic Antioxidant System of the Citrus Red Mite Panonychus citri (Acari: Tetranychidae

    Ke Zhang

    2014-05-01

    Full Text Available Radio-(60Co, which emits γ rays, has been used worldwide in pest control. The aim of the present study was to analyze the effect of effective-low-power 60Co-γ irradiation on the enzymatic antioxidant system of the citrus red mite Panonychus citri. One day old female adults were exposed to 0.4 kGy 60Co-γ irradiation and on the, 6th h, 1st day, 2nd day, and 5th day post treatment, the mites were euthanized for biochemical analysis. The activity of superoxide dismutase (SOD, catalase (CAT, peroxidase (POD, phenoloxidase (PO and acetylocholinesterase (AchE were investigated. POD and CAT activities, as well as SOD were higher in the irradiated mites. We found that exposure to 60Co-γ radiation resulted in increased activities of SOD, CAT, POD and decreased AchE activity. When the recovery time lasted till the 5th day, the activities of POD and PO were significantly lower than the control, whereas the SOD, CAT and AchE activities returned to control levels. Cells possess protein repair pathways to rescue oxidized proteins and restore their functions, but if these repair processes fail, oxidized proteins may become cytotoxic. Our results confirm the hypothesis that low dosages of 60Co-γ irradiation increase the level of oxidative stress in P. citri adults in a short time, causing meanwhile damage and sterility. The results of this study also indicate that stress caused by exposure to irradiation could inhibit the cholinergic system in P. citri.

  15. Effect of sterilization by gamma-irradiation on the sorption of 137Cs, 85Sr, 139Ce, 57Co, 109Cd, 65Zn, 103Ru, 95mTc and 131I by soils

    Six soils, two Sphagnum peat samples and a clay mineral were irradiated with 40 and 80 kGy (4 and 8 Mrad) from a 60Co source. As a result the microbial biomass, determined separately for each sample, decreased considerably. Depending on the radionuclide, the sorption, as characterised by the distribution coefficient, decreased, increased or remained unchanged. The effect of the irradiation on the sorption of the radionuclides depended, in general, also on the type of the sample, especially whether well humified soils, (e.g. crop soils), poorly humified samples (Sphagnum peat, O-horizon from woodland), or a clay mineral was employed. The data reveal that irradiation produces, besides sterilization, also other effects in soils, which can change their sorption properties. (orig.)

  16. Radiochemical separation of 55Fe, 63Ni from 60Co and estimation by triple-to-double coincidence ratio (TDCR) technique of liquid scintillation counting

    63Ni and 55Fe are long lived hard-to-detect (HTD) radionuclides associated with reactor wastes. Separation of 63Ni and 55Fe mutually from each other and from 60Co was achieved using simple precipitation steps, as an alternative for conventional ion-exchange and solvent extraction procedures. Liquid Scintillation Counting (LSC) using TDCR based system was used for activity estimation. The decontamination factor (DF) for 60Co from 63Ni was satisfactory to yield quantitative estimation of 63Ni by LSC. An improvement in the DF of 60Co may be required for accurate assessment of 55Fe activity in samples with high 60Co activity. (author)

  17. On-line 60Co monitor for reactor recirculation system piping in primary containment vessel during reactor operation

    Highlights: • We developed an on-line 60Co monitor for reactor recirculation system piping during reactor operation. • Energy resolution at 1.4 × 106 cps is 33 keV at 1332 keV using a pulse integral method. • A coincidence method is applied to reduce an effect of background gamma rays. • The coincidence counting of 60Co cascade gamma rays could be detected for a background dose rate of 4.8 mSv/h. - Abstract: Water chemistry control during reactor operation and installation of temporary radiation shielding prior to scheduled outages are carried out in order to reduce workers’ dose exposure caused by 60Co which is the main radiation source during scheduled outages of boiling water reactor (BWR) power plants. It is necessary to monitor the deposited 60Co on inner surfaces of reactor recirculation system (RRS) piping to evaluate effects of water chemistry control. We have developed an on-line 60Co monitor (OLCM) for this purpose. The OLCM applies a pulse integral method as a new method to measure gamma-ray counts of more than 1.0 × 106 counts per second (cps) and a coincidence counting method to reduce an effect of background gamma rays caused by 16N in the measurement of 60Co cascade gamma rays. Energy resolution at 1.4 × 106 cps is 33 keV using the pulse integral method and single LaBr3:Ce scintillation detector. The energy resolutions of this detector using the fast response photo multiplier tube (PMT) are 50 keV at 1.5 × 106 cps and 59 keV at 2.1 × 106 cps. Furthermore, we measured the energy spectra using the pulse integral method, the coincidence counting method and two LaBr3:Ce scintillation detectors and examined the transition of coincidence counting for 60Co detection under high dose rate during reactor operation at the Kyoto University Research Reactor (KUR). The coincidence counting of 60Co cascade gamma rays could be detected, and the result was average values of 47.9 counts per 40 min and standard deviations of 34%, 58.3 counts per 60 min

  18. Radiosensibilidad de semillas de soya a los rayos gamma 60Co

    C. de la Fé

    2000-01-01

    Full Text Available El presente estudio se desarrolló en las instalaciones del Instituto Nacional de Ciencias Agrícolas, con el objetivo de evaluar la radiosensibilidad de semillas de soya a los rayos gamma 60Co. Para su ejecución, se seleccionaron e irradiaron muestras de 50 semillas de la variedad Cubasoy-23, las que fueron sembradas en condiciones semicontroladas (macetas en la campaña de primavera, 1997. Las dosis de radiación fueron desde los 50 hasta los 480 Gy, con incrementos de 50 Gy entre las dosis de 50 y 200 Gy e incrementos de 40 Gy entre esta última y la dosis de 480 Gy. Las evaluaciones realizadas consistieron en porcentaje de semillas germinadas a los tres, seis y nueve días de la siembra, altura de las plantas a los 10, 20 y 50 días y número de pares de hojas emitidas a los 10 y 20 días de la siembra. El estudio realizado evidenció la ocurrencia de un efecto fuerte de las dosis aplicadas en el porcentaje de semillas germinadas, resultando las dosis próximas a los 280 Gy las de mayor efecto radioestimulador de la germinación. Desde el punto de vista de la altura de las plantas, el efecto de las dosis aplicadas se correspondió con el descrito para otros materiales biológicos irradiados, caracterizándose este por un aumento a dosis bajas seguido por una reducción cada vez mayor a medida que las dosis aplicadas se incrementaron. Por su parte, la emisión de hojas por las plantas mantuvo un comportamiento en correspondencia con la altura de las plantas. Los resultados del estudio permiten sugerir la aplicación de dosis próximas a los 360 Gy en los trabajos dirigidos a la creación de variabilidad genética en programas de mejora por inducción de mutaciones

  19. The 1997 determination of the Australian standards of exposure and absorbed dose at {sup 60}Co

    Huntley, R.B.; Boas, J.F. [Australian Radiation Laboratory, Yallambie, VIC (Australia); Van der Gaast, H. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    1998-05-01

    The arrangements for the maintenance of the Australian standards for {sup 60}Co are described in detail. The primary standards are a graphite cavity chamber for exposure/air kerma and a graphite calorimeter for absorbed dose. These secondary standards are described and their responses in corresponding {sup 90}Sr reference sources are reported. Accurate ratios between the Australian Radiation Laboratory (ARL) and Australian Nuclear Science and Technology (ANSTO) {sup 90}Sr reference sources are derived for use in future calibrations. The value of 28.8 years for the half-life of {sup 90}Sr is confirmed. The usefulness of {sup 90}Sr reference source measurements in quality assurance is discussed. The charge sensitivity and linearity of the ANSTO electrometers are reported by two different methods and are compared with previous results. Calibration factors for all the secondary standard ionization chambers are given, in terms of exposure, air kerma and absorbed dose to water. Calibration factors are also given for most of the chambers in terms of absorbed dose to graphite. The methods of deriving the calibration factors are explained in detail, including all the corrections applied to both the primary and secondary standard measurements. Three alternative methods of deriving the absorbed dose to water calibration factors are compared. The reported calibration factors are compared with previous results. Changes in the Australian units of exposure, air kerma and absorbed dose to graphite and water are derived from changes in the corresponding calibration factors. The Australian units of exposure and air kerma have not changed significantly since 1990. The Australian unit of absorbed dose to graphite is now 1.1 % smaller than in 1993 and 1.3 % smaller than in 1990. The Australian unit of absorbed dose to water is now 1.4 % smaller than in 1993, but is only 0.9 % smaller than in 1990. Comparisons of the Australian standards of exposure/air kerma and absorbed dose with

  20. Investigations on Pasteurization of Cold Marinades by 60Co Gamma Rays

    Marinated herring fillets are a fish product matured under the action of acetic acid and salt and marketed in a spiced brine containing about 3% salt and acetic acid (pH 4). Since the usual addition of the preservative hexamethylene-tetramine has been restricted to a limited period of time by the new German food law, investigations were made on pasteurization by means of ionizing rays, as a new method of preservation without the addition of other preservatives. Decay of this food product was caused by heterofermentative lactic-acid bacteria, which decarboxy- lated the amino acids set free from the protein; the decay was a result of carbon dioxide bombardment. The marinades were packed into flat tins holding about 125 g, and exposed to 60Co gamma rays from an under-water source, while being cooled. The shelf life of the tinned marinades was extended by the irradiation. The period up to bombardment at 15°C was three times as long as usual in cases of irradiation with 155 krad. The critical number of 1 million germs per ml at 15°C was also reached after a period three times as long as usual upon irradiation with 160 krad. The LD99 of three isolated strains of lactic-acid bacteria irradiated in a salt-peptone solution was 113, 165 and 144 krad, respectively. Since at 15°C the growth of the germs is retarded, while at 20°C it is practically unrestrained, the period of durability at a storage temperature of 18°C could only be doubled by irradiation with 280 krad. The organoleptic tests were based on preference analyses by means of the nine-step Hedonic scale, and on difference tests (triangle test) and were performed by a paneli At 70 kràd the taste is still acceptable at 140 krad there is a distinct taste of rays and at 280 krad the taste is disagreeable. A distinct improvement in taste is achieved by irradiation at low temperatures (-30°C) and by the addition of ascorbic acid, sorbitol and spices. The experiments are being continued. (author)

  1. Public knowledge and attitudes towards the 60Co incident in Qixian County, Henan Province

    Objective: To investigate radiation risk perception and nuclear acceptance after the 60Co stuck source incident in June 2009 in Qixian County, Henan Province. Methods: From March to April 2010, 23 hamlets and 2 schools from 5 towns in Qixian County were selected, while 3 hamlets and 2 schools from 3 towns were used as control in Huixian County, 135 km away where no any impact of the incident was found. Face-to-face questionnaire survey was conducted among three groups including mass public, elite public (representatives of public opinion, such as physicians, teachers, governmental officials, administrative personnel, private entrepreneurs), and middle school students (the third grade students in junior middle schools and the first grade students in senior middle schools). Results: A total of 1 340 valid questionnaires were collected. The public knowledge levels about radiation and nuclear power were low among all groups in two areas and public knowledge levels in Qixian County were higher than those in Huixian County. In both areas.the knowledge levels of the students were higher than those among the elite public, and that among the general public were the lowest. The knowledge levels of males and those with higher educational levels were higher than those of females and those with lower educational levels. More than 40.0% of the respondents supported the idea to build nuclear power plants in China, but only a small part of them supported to build nuclear power plants in their own areas. The percentages of opponents against local nuclear power plant construction were especially higher among the students and those with higher educational levels. More than 60% of the mass public and elite public believed the explanation of the government. More than 80% of the respondents held negative attitudes towards the performance of the Qixian County Government in dealing with this incident. The student gave the lowest evaluation of the credibility and the specific performance

  2. The 1997 determination of the Australian standards of exposure and absorbed dose at 60Co

    The arrangements for the maintenance of the Australian standards for 60Co are described in detail. The primary standards are a graphite cavity chamber for exposure/air kerma and a graphite calorimeter for absorbed dose. These secondary standards are described and their responses in corresponding 90Sr reference sources are reported. Accurate ratios between the Australian Radiation Laboratory (ARL) and Australian Nuclear Science and Technology (ANSTO) 90Sr reference sources are derived for use in future calibrations. The value of 28.8 years for the half-life of 90Sr is confirmed. The usefulness of 90Sr reference source measurements in quality assurance is discussed. The charge sensitivity and linearity of the ANSTO electrometers are reported by two different methods and are compared with previous results. Calibration factors for all the secondary standard ionization chambers are given, in terms of exposure, air kerma and absorbed dose to water. Calibration factors are also given for most of the chambers in terms of absorbed dose to graphite. The methods of deriving the calibration factors are explained in detail, including all the corrections applied to both the primary and secondary standard measurements. Three alternative methods of deriving the absorbed dose to water calibration factors are compared. The reported calibration factors are compared with previous results. Changes in the Australian units of exposure, air kerma and absorbed dose to graphite and water are derived from changes in the corresponding calibration factors. The Australian units of exposure and air kerma have not changed significantly since 1990. The Australian unit of absorbed dose to graphite is now 1.1 % smaller than in 1993 and 1.3 % smaller than in 1990. The Australian unit of absorbed dose to water is now 1.4 % smaller than in 1993, but is only 0.9 % smaller than in 1990. Comparisons of the Australian standards of exposure/air kerma and absorbed dose with those of the Bureau International

  3. Investigation of Chitosan for Decorporation of 60Co in the Rat

    Levitskaia, Tatiana G.; Creim, Jeffrey A.; Curry, Terry L.; Luders, Teresa; Morris, James E.; Sinkov, Sergey I.; Woodstock, Angela D.; Thrall, Karla D.

    2009-08-01

    Purpose: The reported investigation is a part of our on-going research aimed at identifying effective in vivo non-toxic decorporation agents and developing new therapies to treat internal contamination with radionuclides. The non-toxic nature of chitosan makes it an especially attractive candidate for unsupervised treatment of the general population in case of radiological/nuclear emergency. In this study, chemically unmodified water-soluble chitosan oligosaccharide of low molecular weight was tested for decorporation of cobalt-60 (Co-60) using a rodent model. Methods: Affinity of chitosan oligosaccharide for Co(II) was tested in vitro under conditions of physiological pH range and ionic strength using combined spectrophotometric and potentiometric titration techniques. Fisher F344 rat model was used for in vivo studies. To evaluate effect of chitosan on ingested Co-60, animals received single oral dose of Co-60 chloride (7 – 13.2 kBq per animal) followed by oral administration of chitosan material (288 – 366 mg per kg body weight); chitosan dosing was repeated in 24 hours. Chitosan was also tested for removal of internalized Co-60. In this study, Co-60 single intravenous injection (7 – 8 kBq per animal) was followed by repetitive oral (300 mg per kg body weight) or intravenous (195 mg per kg body weight) administration of the chitosan material once daily for 5 days. Control animal groups received a single dose of Co-60 without chelator treatment. Excreta was collected daily. Tissues were collected postmortem and analyzed for radioactivity by gamma counting technique. Results: In vitro experiments confirmed binding of Co(II) by chitosan oligosaccharide, formation of mixed cobalt-chitosan-hydroxide complex species was proposed, and stability constants was calculated. Control in vivo studies indicated that about 71% of ingested Co-60 was excreted in two days predominantly through the gastrointestinal tract. For intravenously administered Co-60, urinal excretion

  4. Investigation of Chitosan for Decorporation of 60Co in the Rat

    Purpose: The reported investigation is a part of our on-going research aimed at identifying effective in vivo non-toxic decorporation agents and developing new therapies to treat internal contamination with radionuclides. The non-toxic nature of chitosan makes it an especially attractive candidate for unsupervised treatment of the general population in case of radiological/nuclear emergency. In this study, chemically unmodified water-soluble chitosan oligosaccharide of low molecular weight was tested for decorporation of cobalt-60 (Co-60) using a rodent model. Methods: Affinity of chitosan oligosaccharide for Co(II) was tested in vitro under conditions of physiological pH range and ionic strength using combined spectrophotometric and potentiometric titration techniques. Fisher F344 rat model was used for in vivo studies. To evaluate effect of chitosan on ingested Co-60, animals received single oral dose of Co-60 chloride (7-13.2 kBq per animal) followed by oral administration of chitosan material (288-366 mg per kg body weight); chitosan dosing was repeated in 24 hours. Chitosan was also tested for removal of internalized Co-60. In this study, Co-60 single intravenous injection (7-8 kBq per animal) was followed by repetitive oral (300 mg per kg body weight) or intravenous (195 mg per kg body weight) administration of the chitosan material once daily for 5 days. Control animal groups received a single dose of Co-60 without chelator treatment. Excreta was collected daily. Tissues were collected postmortem and analyzed for radioactivity by gamma counting technique. Results: In vitro experiments confirmed binding of Co(II) by chitosan oligosaccharide, formation of mixed cobalt-chitosan-hydroxide complex species was proposed, and stability constants was calculated. Control in vivo studies indicated that about 71% of ingested Co-60 was excreted in two days predominantly through the gastrointestinal tract. For intravenously administered Co-60, urinal excretion was

  5. Study on the possibility of using a {sup 60} Co therapeutical unity in Intensity Modulated Radiotherapy (IMRT); Estudo sobre a possibilidade do uso de uma unidade terapeutica de {sup 60}Co em IMRT

    Dantas, Samuel Cesar

    2009-06-15

    With the increasing advances in complex treatment techniques, there is a tendency to obtain more sophisticated equipment to deliver the dose. The use of 3D conformal radiotherapy is now routine in many radiotherapy facilities as well as the utilization of intensity modulated radiotherapy (IMRT). Both are usually implemented using linear accelerators equipped with multi leaves collimators, which create the conformity and the fluence distributions required. However, the complexity of increasingly sophisticated equipment, such as linear accelerators, requires a frequent quality control of their operation, as well as a detailed and constant maintenance. Even carrying out these procedures, the accelerators may present technical problems interrupting for a long time a treatment using the IMRT technique. Despite the clear practical and technological advantages that linear accelerators have on {sup 60}Co irradiators, these devices occupy an important place in radiotherapy, mainly due to the low cost of equipment installation and maintenance when compared to those required by accelerators. Many radiotherapy facilities that work with IMRT have tele therapeutic isocentric {sup 60}Co units. In principle, such equipment would be able to be used for treatment with IMRT using compensating blocks to modulate the beam. This study investigates this possibility and shows that it is feasible. The comparison of treatment plans of a head-and-neck cancer and other of a cancer of the central nervous system, based on a {sup 60}Co irradiator and a Linac 2300 C/D, presented advantages for the {sup 60}Co irradiator. Furthermore; the delivery of dose obtained with the two systems showed themselves equivalent when compared to their respective plans. (author)

  6. Sorption of {sup 60}Co and {sup 137}Cs in sediments at Piraquara de Fora, Angra dos Reis, RJ, Brazil; Sorcao de {sup 60}Co e {sup 137}Cs em sedimentos do Saco de Piraquara de Fora - Angra dos Reis

    Carvalho, Franciane M.; Martins, Nadia S.F.; Lauria, Dejanira D., E-mail: francian@ird.gov.br, E-mail: nadia@ird.gov.br, E-mail: dejanira@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Ferreira, Ingryd M., E-mail: ingrydmarques@hotmail.com [Instituto Federal do Rio de Janeiro (IFRJ), RJ (Brazil); Azevedo, Izabella M.A.P., E-mail: izabella_azevedo@id.uff.br [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil)

    2013-07-01

    In this study, sediment of Piraquara de Fora, located near the launch area of the effluents of the Central Nuclear Almirante Alvaro Alberto - CNAAA Nuclear Power Plants, were collected. It were determined the parameters particle size and cationic exchange capacity (CTC). From the sorption curves of {sup 60}Co and {sup 137}Cs, obtained experimentally in the laboratory, were estimated preliminary values of Kd at equilibrium, for these radionuclides in order of magnitude of 10{sup 2}.

  7. Structure and magnetic entropy change of suck-cast Gd60Co26Al6Ge8 alloy

    The Gd60Co26Al6Ge8 alloy has been prepared by the copper-mold suck-casting and its phase component has been investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS). It is shown that this alloy consists of primary crystalline Gd5Ge3 phase and amorphous matrix. The glass transition temperature (Tg) and crystallization temperatures (Tx) occur at 292 and 320 deg. C, respectively. The maximal magnetic entropy change (ΔSM) under 0-5 T field is about 7.6 J (kg-1 K-1) at 155 K and the refrigeration capacity (RC) is about 768 J kg-1, which makes Gd60Co26Al6Ge8 bulk metallic glass matrix composite a promising candidate for magnetic refrigerant

  8. Differential gene expression in human fibroblasts after alpha-particle emitter (211)At compared with (60)Co irradiation

    Danielsson, Anna; Claesson, Kristina; Parris, Toshima Z; Helou, Khalil; Nemes, Szilárd; Elmroth, Kecke; Elgqvist, Jörgen; Jensen, Holger; Hultborn, Ragnar

    2013-01-01

    Purpose: The aim of this study was to identify gene expression profiles distinguishing alpha-particle (211)At and (60)Co irradiation. Materials and methods: Gene expression microarray profiling was performed using total RNA from confluent human fibroblasts 5 hours after exposure to (211)At labeled...... trastuzumab monoclonal antibody (0.25, 0.5, and 1 Gy) and (60)Co (1, 2, and 3 Gy). Results: We report gene expression profiles that distinguish the effect different radiation qualities and absorbed doses have on cellular functions in human fibroblasts. In addition, we identified commonly expressed transcripts...... transcription, cell cycle regulation, and cell cycle arrest, whereas mitosis, spindle assembly checkpoint, and apoptotic chromosome condensation were uniquely enriched for alpha particle irradiation. Conclusions: LET-dependent transcriptional modulations were observed in human fibroblasts 5 hours after...

  9. The design and manufacture of the automatic distance position-fixing system in 60Co γ-ray calibrator

    The author introduces the design principle and technical index of the automatic position-fixing system. This system consists of the PC computer control, loading vehicle and track. The authors used Pentium PC and Intel 8089 as an intelligent card to drive the stepping motor and to power the vehicle by rack, so as to realize the function of the automatic position control, demonstration and output online. The fixed position of the track vehicle has a basic point. In used scope (it is 0.5-6.2 m distant from 60Co source), the maximum deviation of the fixed position point is 0.5 mm , and the deviation of the fixed position point which is 1 m distant from 60Co source is 0.05%

  10. Fast timing study of a CeBr3 crystal: Time resolution below 120 ps at 60Co energies

    Fraile, L. M.; Mach, H.; Vedia, V.; Olaizola, B.; Paziy, V.; Picado, E.; Udías, J. M.

    2013-02-01

    We report on the time response of a novel inorganic scintillator, CeBr3. The measurements were performed using a cylindrical crystal of 1-in. in height and 1-in. in diameter at 22Na and 60Co photon energies. The time response was measured against a fast reference BaF2 detector. Hamamatsu R9779 and Photonis XP20D0 fast photomultipliers (PMTs) were used. The PMT bias voltages and Constant Fraction Discriminator settings were optimized with respect to the timing resolution. The Full Width at Half Maximum (FWHM) time resolution for an individual CeBr3 crystal coupled to Hamamatsu PMT is found here to be as low as 119 ps at 60Co energies, which is comparable to the resolution of 107 ps reported for LaBr3(Ce). For 511 keV photons the measured FWHM time resolution for CeBr3 coupled to the Hamamatsu PMT is 164 ps.

  11. Five detector set-up for positron 1D-ACAR study of 60Co containing materials

    Design of the five detector set-up, for 1-Dimensional Angular Correlation of Annihilation Radiation (1-ACAR) study of 60Co-containing materials as well as test measurements are described. The equipment is based on simultaneous registration of a starting positron (by detection of gamma-photon with energy 1274 keV) and its annihilation with an electron in the studied material (by detection of two annihilation gamma photons with the energy 511 keV emitted mainly at the 180o-angle). Through this triple coincidence the distributing 60Co-contribution (gamma-photons with energy of 1.17 and 1.33 MeV) can be effectively separated from the annihilation spectra of irradiated reactor pressure vessel steel specimens. (author). 8 refs, 2 figs

  12. Fast timing study of a CeBr3 crystal: Time resolution below 120 ps at 60Co energies

    We report on the time response of a novel inorganic scintillator, CeBr3. The measurements were performed using a cylindrical crystal of 1-in. in height and 1-in. in diameter at 22Na and 60Co photon energies. The time response was measured against a fast reference BaF2 detector. Hamamatsu R9779 and Photonis XP20D0 fast photomultipliers (PMTs) were used. The PMT bias voltages and Constant Fraction Discriminator settings were optimized with respect to the timing resolution. The Full Width at Half Maximum (FWHM) time resolution for an individual CeBr3 crystal coupled to Hamamatsu PMT is found here to be as low as 119 ps at 60Co energies, which is comparable to the resolution of 107 ps reported for LaBr3(Ce). For 511 keV photons the measured FWHM time resolution for CeBr3 coupled to the Hamamatsu PMT is 164 ps.

  13. Sorption of 60Co on a synthetic titanosilicate analogue of the mineral penkvilksite-2O and antimonysilicate

    The ability of two different types of synthetic inorganic ion-exchangers to sorb radioactive cobalt-60 using a batch-type method was studied. The two materials examined were the analogue of the natural titanosilicate penkvilksite-2O (AM-3) and a synthetic antimonysilicate. Ion-exchange experiments were performed with solutions labelled with radioactive cobalt (60Co). The sorption of 60Co onto the two samples materials were compared in terms of distribution coefficient (Kd), sorption percentage and cobalt quantity removed in mg per gram weight of the material. Several parameters were investigated viz. contact time, cobalt concentration, and sorbent concentration. It was found that the batch factor and cobalt concentration had a significant influence on the sorption of cobalt onto both of the materials. This was associated with the difference in pH generated by suspensions of the materials in water which was alkaline for the penkvilksite-2O analogue, and acid for the synthetic antimonysilicate. (author)

  14. Study on irradiation-induced-degradation of five fishery drugs in aqueous solution by 60Co γ-rays

    The degradation of five kinds of fishery drugs in aqueous solution irradiated by 60Co γ-rays at the absorbed dose of 0-10 kGy was investigated. The effects of acid/base, degassing and temperature on the degradation of fishery drugs were studied. The results show that fishery drugs can be degraded significantly with 60Co γ-rays irradiation,and the higher absorbed dose the higher degradation efficiency. The degradation percentage increases with the decrement of initial concentration of fishery drugs. More than 90% degradation of five fishery drugs has been achieved at absorbed dose of 8 kGy. The effects of acid/base and degassing environments on the degradation of fishery drugs are different. The lower temperature can inhibit remarkably the degradation of fishery drugs in aqueous solution. (authors)

  15. Identification of 63Ni and 60Co produced in a steel sample by thermal neutrons from the Hiroshima atomic bomb

    Shizuma, K.; Iwatani, K.; Hasai, H.; Oka, T.; Hoshi, M.; Shibata, S.; Imamura, M.; Shibata, T.

    1997-02-01

    Long-lived residual radioactivity 63Ni produced by the (n, γ) reaction was detected for the first time from a steel plate sampled at near the hypocenter of the Hiroshima atomic bomb. Nickel and cobalt were chemically separated and enriched from the steel sample. Low energy beta rays of 63Ni were measured with a low-background liquid scintillation counter and gamma-rays of 60Co were measured with a low background Ge detector. Specific activities were determined as 0.0063±0.0004 Bq mg -1 for {63Ni}/{Ni} and 8.70±0.46 Bq mg -1 for {60Co}/{Co} at the time of the bomb explosion. Comparisons with the calculated yield based on the current dosimetry system DS86 neutrons were also given.

  16. Identification of 63Ni and 60Co produced in a steel sample by thermal neutrons from the Hiroshima atomic bomb

    Long-lived residual radioactivity 63Ni produced by the (n,γ) reaction was detected for the first time from a steel plate sampled at near the hypocenter of the Hiroshima atomic bomb. Nickel and cobalt were chemically separated and enriched from the steel sample. Low energy beta rays of 63Ni were measured with a low-background liquid scintillation counter and gamma-rays of 60Co were measured with a low background Ge detector. Specific activities were determined as 0.0063±0.0004 Bq mg-1 for 63Ni/Ni and 8.70±0.46 Bq mg-1 for 60Co/Co at the time of the bomb explosion. Comparisons with the calculated yield based on the current dosimetry system DS86 neutrons were also given. (orig.)

  17. Regulation of Guzhen Fang on neuroendocrine and immune systems of rats irradiated with 60Co γ-rays

    Rats were singly irradiated with 6.8 Gy 60Co γ-rays. The changes of monoamine neurotransmitters in hypothalamus, luteinizing hormone (LH), estradiol (E2), testosterone (Ts) in serum, β-endorphin (β-EP) in plasma and the immunologic function of lymphocytes in spleen of rats were observed. The effects of Guzhen Fang (a traditional Chinese Medical prescription) composed of polygoni multiflori, cistanche salsa etc, were studied. The results were as follows: 1. After the rats were irradiated with 60Co γ-rays, the contents of monoamine neurotransmitters in hypothalamus decreased, β-EP in plasma increased, and the hyperfunction of hypothalamus-hypophysis-gonadal (HHG) axis and the hypofunction of lymphocytes appeared. The Guzhen Fang, however, could improve the above changes obviously. 2. Si Junzi Tang (also a traditional Chinese medical prescription) could also increase the immunologic function as Guzhen Fang did, but its effect on neuroendocrine system is not significant

  18. Effect of 60Co γ-rays irradiation pretreatment on callus inductivity and differentiation of strawberry anther

    Strawberry buds, in which a majority of pollen had single nuclear keeping to the side, were pretreated by 60Co γ-rays irradiation at different doses. The irradiation effect on the callus inductivity and plant differentiation rate of strawberry anther were studied. The results indicated that the pretreatment by 60Co γ-rays could increase the anther callus inductivity and plant differentiation rate significantly, and 20 Gy was the best dose. The callus inductivity of Akihime and Toyonoka increased by 39.09% and 35.68%, respectively, compared with the no-pretreatment materials. On the same media, the plant differentiation rate of Akihime and Toyonoka were also increased by 6.67%-6.72% and 4.73%-6.45%, respectively, compared with the two varieties of no-pretreatment. (authors)

  19. Radioprotective effects of sodium tungstate on hematopoietic injury by exposure to 60Co γ-rays in Wistar rats

    Radioprotective effects of sodium tungstate (ST) on 60Co γ-ray induced decrease in hematocrit value and in survival rate in Wistar strain male rats were examined. A long term administration of ST (less than 150 mg/kg body weight/day) for 60-300 day had no significant effects on body and organs weights and survival days. The LD50/60 in 20 weeks old rats was 220 mg/kg body weight/day. Daily administration of 38, 75 or 150 mg from 7 days before and after irradiation to 60 days significantly mitigated the decrease in hematocrit values, especially at 23 days after irradiation (P60Co γ-rays significantly. The dose-reduction factor for survival of 38 mg ST administered rats was 1.14. (author)

  20. Correction factors for Farmer-type chambers for absorbed dose determination in 60Co and 192Ir brachytherapy dosimetry

    This paper presents experimentally determined correction factors for Farmer-type chambers for absorbed dose determination in 60Co and 192Ir brachytherapy dosimetry. The correction factors were determined from measurements made in a PMMA phantom and calculation of ratios of measured charges. The ratios were corrected for the different volumes of the ionization chambers, determined in external high-energy electron beams. The correction factors for the central electrode effect and the wall material dependency in 60Co brachytherapy dosimetry agree with those used in external 60Co beam dosimetry. In 192Ir dosimetry, the central aluminium electrode increases the response of an NE2571 chamber compared with that of a chamber with a central graphite electrode. The increase is 1.1 and 2.1% at 1.5 and 5.0 g cm-2 distance, respectively. Similar values are obtained with an NE2577 chamber. The wall correction factor in 192Ir dosimetry for a chamber with an A-150 wall has been determined to be 1.018, independent of the measurement distance. For a graphite walled chamber, the correction factor is 0.996 and 1.001 at 1.5 and 5.0 g cm-2 distance, respectively. The values of the wall correction factors are evaluated by a theory presented. If the chamber is used according to the 'large cavity' principle, the correction factor to account for the replacement of the phantom material by the ionization chamber was determined to be 0.982 for an NE2571 chamber when used with a Delrin cap, and 0.978 for an NE2581 when used with a polystyrene cap. The correction factors for the 'large cavity' principle are valid at both 60Co and 192Ir qualities. (author)

  1. Sorption of 60Co and 137Cs in sediments at Piraquara de Fora, Angra dos Reis, RJ, Brazil

    In this study, sediment of Piraquara de Fora, located near the launch area of the effluents of the Central Nuclear Almirante Alvaro Alberto - CNAAA Nuclear Power Plants, were collected. It were determined the parameters particle size and cationic exchange capacity (CTC). From the sorption curves of 60Co and 137Cs, obtained experimentally in the laboratory, were estimated preliminary values of Kd at equilibrium, for these radionuclides in order of magnitude of 102

  2. The Lowest Spin and Parity Levels on Two Particle System for Odd-oddNuclei 60Co and 46K

    For obtaining the lowest spin and parity levels of odd-odd nuclei, theanalyzing of the nuclei 60Co and 46K has been done using delta forcemodel. The calculation is done by theoretically and compared with experiment.To get a result optimally, the data analyzed using least square method. It isshown that the lowest spin and parity level from calculation result and theexperiment result are similar. (author)

  3. Prevention and control of pneumonia induced by 60Co γ irradiation of thorax in rats of selenium-enriched Spirulina

    From the indicators including body weight, wet lung weight, percentage of T lymphocytes in peripheral blood, the cell count of broncho-alveolar lavage fluid and its chemoluminescence, contents of hydroxyproline and collagen mRNA synthesis in lung, and pathological changes in pulmonary tissue, the preventive and curative effects of selenium-enriched Spirulina on the pneumonia induced by 60Co γ irradiation of thorax in rats were demonstrated during 90 days of observation

  4. A primary study on mutation induction of in-vitro cultured garlic shoots by 60Co γ-ray irradiation

    In vitro cultured shoots of four garlic cultivars were used to estimate radio-sensitivities and mutation rate by 60Co γ-ray. LD50 of the tested materials was around 7∼9 Gy with a mutation rate of 5%. Two mutants, Tai-R1 and Cang R2 were proved to be genetical variants by the investigation on agronomic characters and the analysis of peroxidase isozyme

  5. Grafting of synthetic polyelectrolyte onto polymer surfaces--comparison of glow discharge and 60Co-gamma-irradiation method

    Water soluble polyelectrolyte synthesized from natural rubber contains sulfamate and carboxylate groups similar to that of heparin. It is observed that synthetic heparinoid polyelectrolyte is capable of inhibiting blood coagulation. In the present study, we attempted to graft the same onto polystyrene and polymethylmethacrylate surfaces using glow discharge technique and 60Co-gamma-irradiation method, and the surfaces were compared with respect to water contact angle and platelet adhesion parameters. Heparinized surfaces are also evaluated for relative comparison

  6. Comparison of the standards for air kerma of the NMIJ and the BIPM for 60Co γ rays

    A first comparison of the standards for air kerma of the National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology (NMIJ/AIST) and of the Bureau International des Poids et Mesures (BIPM) has been carried out in 60Co radiation. It shows that the NMIJ and BIPM standards differ by 0.72 % with a relative standard uncertainty of 2.4 x 10-3. (authors)

  7. PENELOPE-2008 Monte Carlo simulation of gamma exposure induced by 60Co and NORM-radionuclides in closed geometries

    We present Monte Carlo simulations of the gamma exposure in closed rooms made of steel or concrete and contaminated by 60Co or NORM radionuclides. The computer code PENELOPE-2008 (Salvat et al., 2009) was used. Our simulations for 60Co suggest considering detailed Monte Carlo simulations in future recommendations on clearance and exemption of materials with low radioactivity. For NORM nuclides our calculations suggest that Monte Carlo simulations are a possible alternative in case a material fails the dose rate criteria by using the RP 112 screening method. - Highlights: • PENELOPE-2008 was used for Monte Carlo simulations of gamma exposure in closed rooms made of steel or concrete. • Findings support introducing IAEA SR 44 activity concentration value of 0.1 Bq/g as exemption value for 60Co. • PENELOPE-2008 calculations show good agreement with a density corrected Berger model for dose rate calculations concerning NORM building materials. • Monte Carlo calculations or a density corrected Berger model could be used to modify the model suggested in RP 112

  8. The influence of whole body 60Co-irradiation on distribution of 67Ga in tumor-bearing mice

    Since the initial findings that 67Ga has a preferential affinity for soft tissue tumors, in humans numerous suggestions have been advanced for the basic mechanism involved. The effects produced by whole-body X-irradiation on the excretion and tissue distribution of 67Ga have been reported by Swartzendruber and others. Bradley and coworkers have shown that these irradiation effects were associated with an increase in serum iron. The present investigation was undertaken in order to study the relationships between the change in the serum iron concentration and 67Ga accumulation in the tumor and soft tissues in mice bearing Ehrlich's ascites tumor. The following results were obtained. (1) The serum iron concentration was significantly decreased between 3 and 6 hours after 10 Gy (1,000 rad) dose of whole-body 60Co-irradiation. Subsequently, the serum iron levels were slowly elevated. (2) The uptake of 67Ga in the tumor and soft tissues was increased if the serum iron concentration was decreased by whole-body 60Co-irradiation during the early phase. On the contrary, if the serum iron concentration was high, the uptake of 67Ga in the tumor was decreased. (3) The excretion of 67Ga from the body was delayed if the serum iron concentration was decreased by whole-body 60Co-irradiation. However, if the serum iron concentration was high, the excretion of 67Ga from the body significantly increased. (author)

  9. Studies on the function of pokeweed mitogen inducing lymphocytes and 60Co γ-ray irradiation effects

    T and B lymphocytes in human periphery blood were seperated by rosette procedure. After lymphocytes were labelled with T4+ McAB, T4+ and non-T4+ lymphocytes were isolated by cell affinity chromatography method. When parts of T, B, T4+ and non-T4+ cells were exposed to 10 Gy 60Co γ-rays, the function of poke weed mitogen (PWM) and 60Co-rays irradiation effect on lymphocytes were investigated by technique of 3H-TdR incorporation. The results showed that PWM can induce both T and B lymphocytes but B lymphocytes were more sensitive to PWM. The response of B lymphocytes to PWM was the same as that of non-T4+ cells, the response of T4+ cells to PWM was the lowest. DNA synthesis of both T and T4+ lymphocytes were synergistic to B lymphocytes. The synergistic effect in T and B lymphocytes were irradiated by 10 Gy 60Co γ-rays, the synergistic effect disappeared. Neither synergistic nor suppressive effect was found between non-T4+ and B lymphocytes. When T4+, B and non-T4+ lymphocytes had been exposed to 10 Gy irradiation, the percentage suppression of 3H-TdR incorporation between B and non-T4+ lymphocytes had no significant difference but was higher than that in T4+ lymphocytes

  10. Combined reactor neutron beam and {sup 60}Co γ-ray radiation effects on CMOS APS image sensors

    Wang, Zujun, E-mail: wangzujun@nint.ac.cn; Chen, Wei; Sheng, Jiangkun; Liu, Yan; Xiao, Zhigang; Huang, Shaoyan; Liu, Minbo [State Key Laboratory of Intense Pulsed Radiation Simulation and Effect, Northwest Institute of Nuclear Technology, P.O.Box 69-10, Xi’an, Shaanxi 710024 China (China)

    2015-02-15

    The combined reactor neutron beam and {sup 60}Co γ-ray radiation effects on complementary metal-oxide semiconductor (CMOS) active pixel sensors (APS) have been discussed and some new experimental phenomena are presented. The samples are manufactured in the standard 0.35-μm CMOS technology. Two samples were first exposed to {sup 60}Co γ-rays up to the total ionizing dose (TID) level of 200 krad(Si) at the dose rates of 50.0 and 0.2 rad(Si)/s, and then exposed to neutron fluence up to 1 × 10{sup 11} n/cm{sup 2} (1-MeV equivalent neutron fluence). One sample was first exposed to neutron fluence up to 1 × 10{sup 11} n/cm{sup 2} (1-MeV equivalent neutron fluence), and then exposed to {sup 60}Co γ-rays up to the TID level of 200 krad(Si) at the dose rate of 0.2 rad(Si)/s. The mean dark signal (K{sub D}), the dark signal non-uniformity (DSNU), and the noise (V{sub N}) versus the total dose and neutron fluence has been investigated. The degradation mechanisms of CMOS APS image sensors have been analyzed, especially for the interaction induced by neutron displacement damage and TID damage.

  11. Fate of 60Co and 134Cs added to the hypolimnion of a Canadian Shield lake: accumulation in biota

    The addition of 60Co and 134Cs to the anaerobic hypolimnion of a thermally stratified Canadian Shield lake in summer initially isolated the exposure of biota to only zooplankton that undergo vertical migration into this region of the lake. Once the radionuclides became mixed throughout the water column with autumn turnover, other biota were exposed to the radionuclides. In general, 60Co concentrations in biota were low because of the rapid loss to the sediments. Exceptions were for initial 60Co concentrations in filter-feeders (cladocerans and clams) during autumn turnover. Concentrations of 134CS were higher in biota the following spring and summer, reflecting the tendency of 134Cs to remain in the water column. Concentrations of 134Cs still continued to increase in forage fish 1 year following the radionuclide addition. The addition of radionuclides to the hypolimnion resulted in higher concentrations in forage fish than when added to the epilimnion. Radionuclide concentrations in biota varied with taxon and were greatest in periphyton. This study demonstrates that radionuclides that may enter the bottom waters of a lake as a result of nuclear fuel waste disposal will be available to biota and result in a radiation dose to aquatic biota and to humans via the water-fish-human pathway. (author)

  12. Combined reactor neutron beam and 60Co γ-ray radiation effects on CMOS APS image sensors

    Zujun Wang

    2015-02-01

    Full Text Available The combined reactor neutron beam and 60Co γ-ray radiation effects on complementary metal-oxide semiconductor (CMOS active pixel sensors (APS have been discussed and some new experimental phenomena are presented. The samples are manufactured in the standard 0.35-μm CMOS technology. Two samples were first exposed to 60Co γ-rays up to the total ionizing dose (TID level of 200 krad(Si at the dose rates of 50.0 and 0.2 rad(Si/s, and then exposed to neutron fluence up to 1 × 1011 n/cm2 (1-MeV equivalent neutron fluence. One sample was first exposed to neutron fluence up to 1 × 1011 n/cm2 (1-MeV equivalent neutron fluence, and then exposed to 60Co γ-rays up to the TID level of 200 krad(Si at the dose rate of 0.2 rad(Si/s. The mean dark signal (KD, the dark signal non-uniformity (DSNU, and the noise (VN versus the total dose and neutron fluence has been investigated. The degradation mechanisms of CMOS APS image sensors have been analyzed, especially for the interaction induced by neutron displacement damage and TID damage.

  13. Combined reactor neutron beam and 60Co γ-ray radiation effects on CMOS APS image sensors

    The combined reactor neutron beam and 60Co γ-ray radiation effects on complementary metal-oxide semiconductor (CMOS) active pixel sensors (APS) have been discussed and some new experimental phenomena are presented. The samples are manufactured in the standard 0.35-μm CMOS technology. Two samples were first exposed to 60Co γ-rays up to the total ionizing dose (TID) level of 200 krad(Si) at the dose rates of 50.0 and 0.2 rad(Si)/s, and then exposed to neutron fluence up to 1 × 1011 n/cm2 (1-MeV equivalent neutron fluence). One sample was first exposed to neutron fluence up to 1 × 1011 n/cm2 (1-MeV equivalent neutron fluence), and then exposed to 60Co γ-rays up to the TID level of 200 krad(Si) at the dose rate of 0.2 rad(Si)/s. The mean dark signal (KD), the dark signal non-uniformity (DSNU), and the noise (VN) versus the total dose and neutron fluence has been investigated. The degradation mechanisms of CMOS APS image sensors have been analyzed, especially for the interaction induced by neutron displacement damage and TID damage

  14. Leaching of 60Co and 137Cs from spent ion exchange resins in cement–bentonite clay matrix

    I B Plecas; R S Pavlovic; S D Pavlovic

    2003-12-01

    The leaching rate of 60Co and 137Cs from the spent cation exchange resins in cement–bentonite matrix has been studied. The solidification matrix was a standard Portland cement mixed with 290–350 (kg/m3) spent cation exchange resins, with or without 2–5% of bentonite clay. The leaching rates from the cement–bentonite matrix for 60Co: (4,2–7,0) × 10-5 (cm/d) and 137Cs: (3,2–6,6) × 10-4 (cm/d), after 125 days were measured. From the leaching data the apparent diffusivity of cobalt and cesium in cement–bentonite clay matrix with a waste load of 290–350 (kg/m3) spent cation exchange resins, was measured for 60Co: (1,1–4,0) × 10-6 (cm2/d) and 137Cs: (0,5–2,6) × 10-4 (cm2/d), after 125 days. The results presented in this paper are part of the results obtained in a 20-year mortar and concrete testing project which will influence the design of radioactive waste management for a future Serbian radioactive waste disposal centre.

  15. Study on the down-regulation of PKCα by tamoxifen combined with 60Co γ-irradiation in glioma cells

    The mechanism of radio-sensitizing effect of tamoxifen on the influence of PKCα expression has been explored by tamoxifen combined with 60Co γ-irradiation in human glioma cells. The protein expression of PKCα and CyclinD1 were detected by using Western-Blot. The level of DNA strand breaks was detected by the alkaline single-cell gel electrophoresis assay. The results demonstrated that the combination of tamoxifen and 60Co γ-irradiation could reduce expression of PKCα and CyclinD1. And it also enhanced the radiation-induced DNA damage and attenuated the repair of damaged DNA. The above results reveal that the combination of tamoxifen and 60Co γ-irradiation can enhance the downregulation of the expression of PKCα and the induction in the low expression of CyclinD1 as well at the delay of DNA repair. All these may be related to the impairment of the radioresistance of SHG-44 cells by tamoxifen. (authors)

  16. Radiation effects of 60Co γ-rays on expression of CDKN1A mRNA in human lymphocytoblast

    Objective: To study effect of 60Co γ-rays radiation with different doses on expression of CDKN1A gene mRNA in human lymphocytoblast cultured for different time. Methods: After human lymphocytoblasts were irradiated by the 60Co γ-rays with various doses of 0, 0.2, 1, 3, 5 and 10 Gy, and cells were separately cultured for sustaining survival during 0, 4, 24, 48, 72 and 96 h. The total RNA was extracted from each sample and the real-time PCR was conducted to observe the gene CDKN1A mRNA level changes in lymphocytoblasts exposed to various radiation doses for various cultured time. Results: Expressive levels of the CDKN1A mRNA in lymphocytoblasts gradually went up with increasing radiation doses, which showed γ-rays dose dependent from 0 Gy to 5 Gy (P<0.05), and reach the peak when cells were cultured for 24 h after exposing to radiation while displayed an expressive downtrend during the later stage of cell culture. Conclusion: Increase of the CDKN1A mRNA expression level in human lymphocytoblasts after exposing to 60Co γ-rays radiation within 24 hours of culture shows a dose dependent way, which may be used to evaluate the ionizing radiation dose. (authors)

  17. Optimization of point sources on thin films using a statistical design approach. Application to 60Co sources

    Radioactive point sources prepared by depositing weighed drops on thin membranes are commonly used in ionizing radiation metrology for 47πβ-γ coincidence counting or for low energy electrons spectrometry. The present study deals with the preparation of good quality sources having high detection yields. Some influential parameters on the source quality are studied using 60Co as radioactive tracer. An approach based on experimental statistical designs has been chosen. This approach allows us to obtain reliable results with a number of experiences lower than in the case of a systematic approach. Homogeneous 60Co sources with high metrological qualifies (Rβ> 96 %) can be prepared using a direct deposit of ∼ 5 mg drops of 60Co solution ([Co] = 12 μg/g), [HCl] = 0,5 mol/I) and dried at 60 deg C. The support of the radioactive spot is constituted with a gold coated (130 μg/cm2 of Au) Vyns films (thickness 45 μg/cm2) on which a pad (diameter = 7 - 8 mm) of polystyrene microspheres (Estapor K-007) is prepared by an electro-spraying technique under 7,5 kV during 10 minutes. The alcoholic solution used for the electro-spraying step has the following chemical composition [Estapor K-007] 2.5 10-2 wt % and [Tween 20] = 2.7 10-2 wt %. (authors)

  18. Absorbed dose response of Al2O3 dosimeter irradiated by 60Co γ spectrum source capture and collimators

    Objective: To investigated the absorbed dose response of Al2O3 dosimeter in water phantom irradiated by 60Co γ spectrum source. Methods: The EGSnrc simulation program code DOSRZnrc was used to calculate the absorbed dose of the Al2O3 dosimeter and that of the equivalent volume of water in the corresponding position, as well as the absorbed dose conversion factor, irradiated by 60Co photon beams in a water phantom. Simulations were done for a cylindrical geometry dosimeter (diameter 0.4 cm and height 0.1 cm) and the dosimeter was placed at the centre of the water phantom at different depths. Results: The average absorbed dose conversion factor is 1.143±0.006 and changes little with the depth of the dosimeter in the water phantom, and the deviation is less than 1.0%. Conclusion: The absorbed dose response of Al2O3 dosimeter irradiated by 60Co γ spectrum source is steady and is independent on the depth of the dosimeter in water phantom in this research. (authors)

  19. Dominant lethal effect of gamma radiation of 60Co in Biomphalaria glabrata (SAY, 1818)

    Germ cell mutations are used in ecotoxicological studies as biomarkers of population effects and indicators of ecological changes. Biomphalaria glabrata, a freshwater mollusk, is a good experimental model for biomonitoring studies due to its biological characteristics and the ecological importance of this invertebrate group. The dominant lethal test was established in B. glabrata for the detection of germ cell mutations. Results with chemical mutagens showed that this system is efficient, specific and sensitive in the evaluation of germ cell mutations induced by reference mutagens. In this work, the dominant lethal effects of gamma radiation of 60Co were studied. A preliminary experiment was done to establish the dose range and to estimate the chronology of spermatogenesis in B. glabrata. This estimate is possible because of the uniformity in response to ionizing radiation between germ cells at homologous stages of spermatogenesis in widely different species. In general, pre-meiotic germ cells are less sensitive to the induction of lethal dominant mutations than post-meiotic cells. This effect can be attributed to: young gametogenic cells - mitotically active - have greater repair ability from sub-lethal DNA damage and there is a selective elimination of the damaged cells. In our system: induction of lethal dominant mutations causes an increase in the frequency of malformations and, cytotoxic effect is displayed as a reduction in the crossing rates. Total duration of spermatogenesis was estimated in approximately 36 days, with the following distribution of stages: 1 to 13 days - spermatogonia, 14 to 20 days - spermatocytes, 21 to 36 days - spermatids and spermatozoa. Based on this chronology, irradiated wild-type snails with 2,5; 10 and 20Gy and crossed with non-irradiated albino snails after 7, 17, 23, 30 and 36 days. The frequencies of malformations in the heterozygous wild-type offspring of the nonirradiated albino snails were used as indicator of germ cell

  20. Effects of 60Co-γ Irradiation Intensity on Watermelon Seed Germination and Seedling Growth%60Co-γ辐射对西瓜种子萌发和幼苗生长的效应

    李玉明; 杨世梅; 纪海波; 方春媛; 潘从祥; 陈年来

    2013-01-01

    In order to investigate the effects of different doses of 60Co-γ radiation on watermelon seed germination and seedling growth, watermelon seeds with different qualities of 12 varieties were used as the test materials to investigate the effects of six different doses of radiation on emergence rate, surviving rate, emergence time, cotyledon area, plant height and stem diameter. The results showed that medium size seeds of watermelon demonstrated a promoting effect on seedling growth under the dose of 200 Gy and 400 Gy. When the radiation dose exceed 600 Gy, all watermelon seeds showed the extremely significant level (P small seed > medium seeds.%为了探讨60Co-γ辐射剂量对不同质量西瓜种子萌发和幼苗生长的影响,以不同质量的12个西瓜品种干种子为材料,通过6个剂量的辐射处理,研究辐射剂量对西瓜干种子出苗率、存活率、出苗时间、子叶面积、株高及茎粗等的影响.结果表明,200和400 Gy辐射对中等种子出苗有促进作用,超过600 Gy都具有显著(P<0.05)抑制作用;随着辐射剂量的增加,植株出苗时间延长,幼苗生长缓慢;根据半致死剂量确定西瓜种子适宜辐射剂量为600~800 Gy.不同大小西瓜种子对60Co-γ辐射的敏感性表现为大种子>小种子>中等种子.

  1. Transfer of 137Cs and 60Co in a waste retention pond with emphasis on aquatic insects

    The objectives of this research were (1) to analyze the transfers of 137Cs and 60Co in a retention pond, with emphasis on aquatic insects and (2) to determine if detectable concentrations of these radionuclides are exported by emerging aquatic insects. We analyzed the radionuclide concentrations in the following components: water solution, bottom sediments, suspended particulate matter, plankton, floating mats of filamentous algae, benthic macroinvertebrates, and emerging aquatic insects. Samples were collected quarterly from June 1981 to April 1982. The lowest concentrations (in picocuries per milliliter) occurred in solution (range: 1.4 X 10(2) to 3.2 X 10(2) for 137Cs and 8.1 X 10(-1) to 2.2 X 10(0) for 60Co). The highest concentrations (in picocuries per gram dry weight) occurred in the sediments (range: 1.5 X 10(4) to 1.1 X 10(8) for 137Cs and 1.0 X 10(2) to 4.3 X 10(6) for 60Co). The primary producers and aquatic insect consumers had concentrations of both radionuclides that were two to four orders of magnitude higher than the respective concentrations dissolved in water but two to three orders of magnitude lower than the concentrations in the sediments. The concentrations of both radionuclides decreased successively at higher trophic levels. There were considerable temporal variations as the radionuclides cycled among the abiotic and biotic components of the pond. Emerging adult aquatic insects had lower concentrations of both radionuclides than the immature stages that lived in the pond (adult/immature ratio about 0.25). Because the emerging adult insects contain detectable concentrations of radionuclides, have relatively long life spans, and disperse away from the aquatic habitat, we conclude that adult aquatic insects would be effective biological monitors

  2. Expression of FHIT in AHH-1 cells irradiated by 60Co γ-ray and bystander effect cells

    Objective: To investigate the expression of FHIT gene in the 60Co gamma-ray irradiated human lymphocytoblast (AHH-1) cell and the bystander effect cell, and to explore the function of FHIT gene in the bystander effect of ionizing radiation. Method: Preparation of bystander effect cell model: after inadiated with different dose of 60Co gamma-ray (0, 2, 5 Gy), the directly irradiated AHH-1 cells were collected immediately by centrifugation and co-cultivated with non-irradiated cells in Transwell, forming the bystander effect group P1. In addition, some culture media supematant of directly irradiated cells were transferred to the non- irradiated cells culture medium, forming the group P2. Then cells were collected at 0, 6, 12, and 24 h after irradiation and the total RNA and protein were extracted. RT-PCR and Western blot were performed to determine the FHIT mRNA and protein level, respectively. Flow cytometry assay and cell counting were conducted to detect the alteration of cell cycle and cell proliferation, respectively at 0, 24 h after irradiation. Results: The mRNA level of FHIT gene among control cells, directly irradiated cells and bystander cells showed no obvious difference, while the FHIT protein level of the directly irradiated cells and bystander cells was significantly down-regulated compared with the control cells (F=102.45, P2 phase arrest and obviously inhibited the proliferation ability. Conclusions: 2 and 5 Gy of 60Co γ-ray irradiated AHH-1 cells can result in down regulation of the FHIT protein expression, which suggests that FHIT gene is involved in the process of bystander effect induced by irradiation. (authors)

  3. A prototype of an ionization chamber for gamma radiation beams of 60Co: Experimental and Monte Carlo preliminary results

    Ionization chambers are the most widely used instruments for dosimetry in radiotherapy. With the aim to test new configurations and materials using low-cost and easily-available components, verify the possibility of its application in the gamma radiation field of 60Co and fulfill the need of a chamber for scientific metrological purposes, in this paper the prototype of a plane-parallel ionization chamber has been designed and built, and its performance has been studied at the SSDL of KARAJ. The front wall and back wall of the chamber were made of graphite and Plexiglas respectively, as opposed to the one type of material in commercially available chambers. The collecting electrode has a diameter of 20 mm. The sensitive volume is 0.63 cm3. It was found that the Leakage current, the short-term stability and the polarity effect were within the international recommendations. The results were compared with those of a reference cylindrical chamber. The maximum difference observed in this comparison was 1.1%. The relative uncertainty was below 0.2%. Moreover, Monte Carlo simulation was undertaken using MCNP4C code and the relative difference of 1.9% was observed compared to the experiment. As a result the chamber presented a satisfactory performance in all evaluated tests in Gamma radiation field of 60Co. -- Highlights: • The prototype of a plane-parallel Ionization Chamber was designed. • Its performance was studied in Gamma radiation field of 60Co. • The response of the chamber was measured and compared with that of the cylindrical ionization chamber. • The chamber was simulated using the MCNP4C Monte Carlo code. • The Leakage current, the short-term stability and the polarity effect were within the international recommendations

  4. Morphological and histological studies on freshwater prawn Macrobrachium rosenbergii (de man) irradiated with 60Co gamma radiation

    Graphical abstract: -- Highlights: •Analyzing the impact of 60Co gamma radiation (low doses) in M. rosenbergii. •LD50 identified in 30 Gy; Irradiated exhibits morphological changes than control. •Significantly decreased HSI and histological changes in irradiated groups. •Aberration severities increased as increased of dose level. •Biomonitoring tool in determining low dose radiation pollution in aquatic ecosystem. -- Abstract: This study was framed to investigate the 60Co gamma radiation induced morphological and histological variations in freshwater prawn Macrobrachium rosenbergii. The LD50 value of 60Co gamma irradiated M. rosenbergii observed (by probit analysis) at 30 Gy. Prawns were irradiated to four different dose levels (3 mGy, 30 mGy, 300 mGy and 3000 mGy) using Theratron Phoenix TeleCobalt Unit [P-33] and one control group (without irradiation) maintained separately. Irradiated groups exhibited several morphological variations such as discoloration; damaged rostrum; opaque coloration in cephalothorax; black bands and dot formation in abdomen; deformed uropods and telson in tail regions when compared with control group. The Hepato Somatic Index reflected the severity of radiation on hepatopancreas. Histological variations in gills, hepatopancreas and muscles of irradiated groups were observed. In gills, structural changes such as swollen and fused lamellae, abnormal gill tips, hyperplasic, necrotic and clavate-globate lamellae were observed in gamma irradiated prawns. Accumulation of hemocytes in hemocoelic space, interstitial sinuses filled with abnormal infiltrated hemocytes, the tubular epithelium with ruptured basal laminae, abnormal and coagulated lumen, necrotic tubules, thickened basal laminae, tissue debris, necrotic hepatocytes were observed in irradiated prawn hepatopancreas. In muscle, shrinkage of muscular fiber and necrotic musculature were observed in irradiated prawns. These structural alterations of the organs it is felt could

  5. A comparative study on micronuclei production induced by carbon ion versus 60Co γ-rays in human peripheral blood lymphocytes

    Objective: To compare the effectiveness of carbon ion versus 60Co γ-rays in producing micronuclei in human peripheral blood lymphocytes. Method: Heparinized whole blood samples were exposed to carbon ion and 60Co γ-rays, respectively. Micronuclei in binuclear lymphocytes (CB method) were scored. Relative biological effectiveness (RBE) values were calculated. Results: RBE values of carbon ion decreased with increasing dose (ranged from 1.78 to 4.19 ). The average RBE value is 2.56. Conclusion: Carbon ion has higher biological effectiveness in inducing micronuclei than 60Co γ-rays do

  6. Study of the ionization of alkane-electron scavenger reactant mixtures irradiated by 60Co gamma rays

    This study deals with ionization of alkane-electron scavenger reactant mixtures, irradiated by 60Co γ-rays. It is shown that the extrapolated free-ion yields (extrapolated yield method) decrease with the reactant concentration. On the basis of ONSAGER model and theoretical treatment of MOZUMDER, the cross sections of epithermal electron attachment in hexane, cyclohexane, 2,2-dimethylbutane, cyclopentane, 2,2,4-trimethylpentane for CCl4, C7F14, C6H5Br, C6H5Cl, C6F14, (C6H5)2 are determined. A comparison between gas-phase and liquid-phase cross sections is established

  7. Influence of 60Co γ irradiation on fertility of Japanese pine sawyer beetle Monochamus alternatus hope (Coleoptera: Cerambycidae)

    The fertility of the Japanese pine sawyer beetle Monochamus alternatus (Coleoptera: Cerambycidae) irradiated with 60Co γ-rays was remarkable reduced at the doses of 30Gy, 35Gy and 40Gy, especially at 40Gy. When the non-irradiated females were coupled with the irradiated males first, and then coupled with non-irradiated males, the hatchability and the fertility had little higher but lower than the control. It explained that radiation has certain influence to the female gonad. It also has difference between the hatching rate and the amount of eggs in different match. (authors)

  8. Treatment of pituitaary dependent cushing's syndrome with closed stereotactic radiosurgery by means of 60Co gamma radiation

    Four patients with pituitary dependent Cushing's syndrome treated with external irradiation to the pituitary using 60Co gamma irradiation given with a stereotactic technique. The size of the sella turcica was normal or slightly enlarged in all patients. The doses given varied between 7000 and 10000 rad, and the observation time ranged between 14 and 20 months. Three of the patients showed complete clinical remission and one marked improvement. One patient developed ACTH insufficiency, while none developed insufficient secretion of other pituitary hormones. No complications of the irradiation were observed. (author)

  9. A new cane variety-Guitang No.22 bred by 60Co γ-ray induced mutation

    Guitang No.22 was developed through seed stems of Xintaitang No.1 exposed at a dosage of 80 Gy 60Co γ-radiation. In Guangxi regional variety test, the results show that the cane yield and the sugar yield are about 106.95 and 14.21 t/hm2 respectively. Moreover, the highest tonnage of biomass and fermentable carbohydrates reaches about 188.1 and 48.92 t/hm2, respectively. Guitang 22 is a new variety which has the characteristic of both sugar cane and energy cane. (authors)

  10. Electrical characteristics of 60Co gamma-ray irradiated pentacene-based organic thin film field effect transistors

    Preliminary studies of the 60Co γ-ray radiation effects on pentacene-based organic thin film transistors (OTFTs) with two kinds of gate insulators have been carried out. Negative threshold voltage shifts of OTFTs with a SiO2 gate insulator are consistent with positive charge trapping, and a rebound effect is observed. Threshold voltage of OTFTs with a polyimide gate insulator continuously decreased with increasing the total dose. When the total dose reached 1200 Gy (Si), the carrier mobility of OTFTs with the SiO2 gate insulator decreased by nearly 80%, while the carrier mobility of OTFTs with the polyimide gate insulator decreased by almost 40%. (author)

  11. INCASoy-36: soybean variety obtained in Cuba after the induction of mutations with 60Co gamma rays

    INCASoy-36 variety was obtained after irradiating seeds from INCASoy-15 at doses of 240 Gy 60Co gamma rays. This variety is adapted to summer and winter seedings; however, it can also be used in spring. Besides, its yields can reach up to 3,5-4,0 t.ha-1 grains in summer and spring seedings. It is tolerant to the main pests and diseases; it is especially resistant to Meloidogyne incognita attacks. During the adverse spring season, seeds have been damage tolerant. It can assure high productions with low inputs; therefore, it is feasible to Cuban agriculture. (Author)

  12. Effect of irradiation using 60Co on Trichinella spiralis larvae and on the eggs and protoscolices of Echinococcus granulosus

    The effect of irradiation using 60Co on Trichinella spiralis larvae and on the eggs and protoscolices of Echinococcus granulosus was studied. A dose of 30 Gy had no effect on T. spiralis larvae and on the eggs and protoscolices of E. granulosus. Irradiation of free T. spiralis larvae from muscle in normal saline exposed to 90 Gy and higher doses produced loss of infection in mice. There was reduction in the infectivity of eggs and protoscolices of E. granulosus by irradiation at a dose of 120 Gy, while there was complete loss of activity at a dose of 500 Gy. (author). 5 refs, 2 figs

  13. The regional genomic instability induced by 60Co γ-rays in B16 cells transfected by GFP

    Objective: To detect the regional genomic instability of B16 cells treated with 60Co γ-rays by a green fluorescence protein (GFP)-based genomic instability reporting system. Methods: Three groups were employed as non-transfection group, vector control group and transfection group. The GFP-marked reporter construct pCMV-EGFP2XhoI for regional genomic instability was successfully transfected into B16 cells using liposome. B16 cells were selected by screening of G418 with a series of concentrations and limiting dilution cultures to yield a single colony. B16 cells with the genomic instability report system were then irradiated by 60Co γ-rays at doses of 0, 2 and 4 Gy. The regional genomic instability of B16 cells was quantified by counting the number of cells with GFP expression. Results: B-16 cell strain steadily expressing the GFP-based genomic instability reporting system was established successfully. GFP-positive B16 cells were observed at 1 d after irradiation with 60Co γ-rays at doses of 2 and 4 Gy. Positive correlations between fluorescence intensity and dose and fluorescence intensity and time were also observed. The positive expression rate of GFP followed the increased of dose (F=36.55, 36.76, P<0.05) and time (t=-3.27, -3.16, -4.26, -6.11, -7.17, P<0.05), and differences between groups were significant. The positive expression rate of GFP increased significantly at 3 d, and maximum expression was observed at 5 d (2.46 ± 0.24 and 3.82 ± 0.35). The level was tending towards stability. Spontaneous GFP expression at a ratio of 1/600000 was observed in 0 Gy group after 2 weeks of culture. Conclusions: The regional genomic instability of B16 cells induced by 60Co γ-rays can be detected using a GFP-labelled genomic instability reporter system. (authors)

  14. Study about the sensibility in vitro of different strains of Vibrio cholera 01 exposed to 60 Co gamma radiation

    The presence of some microorganisms in food, or the metabolites originated during their own multiplication may bring several diseases to humans: intoxications and food borne infections. Among the agents that may cause those diseases, we find Vibrio cholerae 01. In this experiment, the studies are focused on the radiosensibility in vitro of four strains of V. cholerae 01, exposed to different doses of ionizing radiation of 60 Co. The results are compared with other data related to bacterial food borne diseases, including water. (author)

  15. The effect of 60Co γ-ray irradiation on the growth and regeneration of Cymbidium sinense rhizome

    The effect of 60Co γ-ray irradiation on growth of Cymbidium sinense rhizome and shoot regeneration were studied. The results showed that irradiation with low dose (2, 5 and 8 Gy) promoted the growth of Cymbidium sinense rhizome, while high dose (≥ 10 Gy) inhibited the growth. Shoot differentiation of rhizome was not affected by irradiation of low dose. Biochemical analyses indicated that the soluble protein content of rhizome irradiated with low dose was higher than that of CK, irradiated with 2 and 5 Gy seemed to reduce the activity of peroxidase, while irradiated with 8 Gy increased the activity of peroxidase

  16. COOMET.RI(I)-K1 comparison of national measurement standards of air kerma for 60Co γ radiation

    Results are presented of the COOMET key comparison of the national measurement standards of air kerma for 60Co γ radiation. Participants of the comparison were PTB (Germany, pilot institute), VNIIM (Russia), SMU (Slovakia), BelGIM (Belarus), CPHR (Cuba) and RMTC (Latvia). PTB, VNIIM and SMU had previously taken part in a key comparison with the Bureau International de Poids et Mesures (BIPM) and operated as link laboratories in order to evaluate the degree of equivalence of the participants' results with the key comparison reference value. These data form the basis of the results entered into the BIPM key comparison database for comparison COOMET.RI(I)-K1. (authors)

  17. Comparison of the standards of absorbed dose to water of the METAS and the BIPM for 60Co gamma radiation

    A comparison of the standards of absorbed dose to water of the Swiss Federal Office of Metrology and Accreditation (METAS), Switzerland and of the Bureau International des Poids et Mesures (BIPM) has been made in 60Co gamma radiation. The results show that the METAS and the BIPM standards for absorbed dose to water are in agreement, yielding a comparison result of 1.0001 for the mean ratio of the calibration coefficients for the transfer chambers, the difference from unity being within the combined standard uncertainty (0.0054). (authors)

  18. Improving the Content of Terpenoid Indole Alkaloids in Catharanthus roseus by 60Coγ Radiation%60Coγ射线辐射诱变提高长春花生物碱含量

    赵剑; 李建国

    2009-01-01

    本实验采用长春花种子为材料,用60Coγ射线不同剂量处理,统计处理萌发率和成株率,并观察当代表型变异率和进行回归模型分析.结果分析60Coγ射线辐照长春花种子的半致死剂量平均为174 Gy,照射长春花种子的较适宜剂量为200 Gy.我们观察到长春花M,代生长初期有明显的叶形不对称、叶缘卷曲等致变现象,各种畸形叶出现频率与辐照剂量大小有关.通过辐照,我们得到长春花高杆变异、矮杆变异等变异植株,并利用HPLC检测发现高杆变异株型长春花生物碱含量比未照射的CK多出24%.

  19. Development and characterization of a graphite-walled ionization chamber as a reference dosimeter for 60Co beams

    A graphite-walled ionization chamber with a sensitive volume of 6.4 cm3 was developed at the Calibration Laboratory of IPEN (LCI) to determine the air kerma rate of a 60Co source. This new prototype was developed to be a simple chamber, without significant nongraphite components and with a simple set-up, which allows the determination of its various required correction factors by Monte Carlo simulations. This new ionization chamber was characterized according to the IEC 60731 standard, and all results were obtained within its limits. Furthermore, Monte Carlo simulations were undertaken to obtain the correction factors involved with the air kerma determination. The air kerma rate obtained with the graphite-walled ionization chamber was compared with that from the reference dosimeter at the LCI, a PTW ionization chamber (model TN30002). The results obtained showed good agreement within the statistical uncertainties. - Author-Highlights: • A graphite ionization chamber was assembled and characterized as a reference dosimeter. • The characterization test results were within recommended limits. • Monte Carlo simulations were undertaken to obtain the correction factors. • The air kerma rate of a 60Co source was obtained with satisfactory results

  20. Multistep process of neoplastic transformation of normal human fibroblasts by 60Co gamma rays and Harvey sarcoma viruses

    Namba, M.; Nishitani, K.; Fukushima, F.; Kimoto, T.; Nose, K.

    1986-03-15

    As reported previously (Namba et al., 1985), normal human fibroblasts were transformed by 60Co gamma-ray irradiation into immortal cells with abnormal karyotypes. These transformed cells (KMST-6), however, showed a low cloning efficiency in soft agar and no transplantability. However, upon treatment with Harvey murine sarcoma virus (Ha-MSV), the cells acquired elevated clonability in soft agar and transplantability in nude mice. Ha-MSV alone, however, did not convert normal human fibroblasts into either immortal or tumorigenic cells. The Ha-MSV-transformed KMST-6 cells showed an enhanced expression of the ras oncogene, but normal and 60Co gamma-ray-transformed cells did not. Our current data suggest that gamma rays worked against normal human cells as an initiator, giving rise to chromosome aberrations and immortality, and that Ha-MSV, probably through its ras oncogene, played a role in the progression of the malignant cell population to a more malignant one showing enhanced colony formation in soft agar and tumorigenicity in nude mice.

  1. Study into the effect of 60Co γ-rays on the lymphocyte subests with monoclonal antibodies

    Three kinds of monoclonal antibodies, OKT4McAb, OKT8McAb and HI43McAb, were used in experiment to identify T helper (Th), T suppresser (Ts) and B lymphocytes respectively. After lymphocytes were exposed to 0.1 Gy, 0.25 Gy, 1 Gy and 4 Gy 60Co γ-rays, immediately, the author observed the radiation effect by means of the indirect immunofluorescence test. 200 cells were conted to obtain the percent of immunofluorescence positive cells. The results indicated that when the Th, Ts and B lymphocytes were irradiated by 0.1 Gy 60Co γ-rays, their abilities to combine with McAb decreased significantly. The radiation effect became more and more obvious with increasing radiation dosage. The percents of three kinds of the immunofluorescence positive cells were analysed with weighted linear regression methods. The correlation coefficients (r) of Th, Ts and B lymphocytes were 0.8131, 0.8832 and 0.9086 respectively. The significant tests of regression coefficient showed that the radiosensitivities of Ts and B lymphocytes had no significant difference and were higher than that of Th lymphocytes

  2. 60Co-irradiation as an alternate method for sterilization of penicillin G, neomycin, novobiocin, and dihydrostreptomycin

    Tsuji, K.; Rahn, P.D.; Steindler, K.A.

    1983-01-01

    The effects of the use of 60Co-irradiation to sterilize antibiotics were evaluated. The antibiotic powders were only occasionally contaminated with microorganisms. The D-values of the products and environmental isolates were 0.028, 0.027, 0.015, 0.046, 0.15, 0.018, and 0.19 Mrads for Aspergillus species (UC 7297, 7298), A. fumigatus (UC 7299), Rhodotorula species (UC 7300), Penicillium oxalicum (UC 7269), Pseudomonas maltophilia (UC 6855), and a biological indicator microorganism, Bacillus pumilus spores (ATCC 27142). An irradiation dose of 1.14 Mrads, therefore, was sufficient to achieve a six-log cycle destruction of B. pumilus spores. Based on the bioburden data, a minimum irradiation dose of 1.05 Mrads was calculated to be sufficient to obtain a 10(-6) probability of sterilizing the most radioresistant isolate, Pen. oxalicum. To determine the radiolytic degradation scheme and the stability of the antibiotics following irradiation, high-performance liquid chromatographic (HPLC) methods were developed. The resulting rates of degradation for the antibiotics were 0.6, 1.2, 2.3, and 0.95%/Mrad for penicillin G, neomycin, novobiocin, and dihydrostreptomycin, respectively. Furthermore, radiolytic degradation pathways for the antibiotics were identified and found to be similar to those commonly encountered when antibiotics are subjected to acidic, basic, hydrolytic, or oxidative treatments. No radiolytic compounds unique to 60Co-irradiation were found.

  3. 60Co-irradiation as an alternate method for sterilization of penicillin G, neomycin, novobiocin, and dihydrostreptomycin

    The effects of the use of 60Co-irradiation to sterilize antibiotics were evaluated. The antibiotic powders were only occasionally contaminated with microorganisms. The D-values of the products and environmental isolates were 0.028, 0.027, 0.015, 0.046, 0.15, 0.018, and 0.19 Mrads for Aspergillus species (UC 7297, 7298), A. fumigatus (UC 7299), Rhodotorula species (UC 7300), Penicillium oxalicum (UC 7269), Pseudomonas maltophilia (UC 6855), and a biological indicator microorganism, Bacillus pumilus spores (ATCC 27142). An irradiation dose of 1.14 Mrads, therefore, was sufficient to achieve a six-log cycle destruction of B. pumilus spores. Based on the bioburden data, a minimum irradiation dose of 1.05 Mrads was calculated to be sufficient to obtain a 10(-6) probability of sterilizing the most radioresistant isolate, Pen. oxalicum. To determine the radiolytic degradation scheme and the stability of the antibiotics following irradiation, high-performance liquid chromatographic (HPLC) methods were developed. The resulting rates of degradation for the antibiotics were 0.6, 1.2, 2.3, and 0.95%/Mrad for penicillin G, neomycin, novobiocin, and dihydrostreptomycin, respectively. Furthermore, radiolytic degradation pathways for the antibiotics were identified and found to be similar to those commonly encountered when antibiotics are subjected to acidic, basic, hydrolytic, or oxidative treatments. No radiolytic compounds unique to 60Co-irradiation were found

  4. Humoral immune response against native or {sup 60}Co irradiated venom and mucus from stingray Paratrygon aiereba

    Thomazi, Gabriela Ortega Coelho; Alves, Glaucie Jussilane; Aires, Raquel da Silva; Turibio, Thompson de Oliveira; Rocha, Andre Moreira; Spencer, Patrick Jack; Nascimento, Nanci do, E-mail: 0916@prof.itpacporto.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Seibert, Carla Simone, E-mail: carlaseibert@yahoo.com [Universidade Federal do Tocantins (UFT), Porto Nacional, TO (Brazil)

    2015-07-01

    Poisonings and traumas caused by poisonous freshwater fish such as rays are considered a major public health problem and draw attention because of accidents involving these animals cause serious local symptoms and are disabling, keeping the victim away from work. The therapy of these cases is based only on the symptoms of patients, which implies in its low efficiency, causing suffering for the victims. This study aims to evaluate and compare the humoral immune response in animals inoculated with native or {sup 60}Co irradiated Paratrygon aiereba venom and mucus. Ionizing radiation has proven to be an excellent tool to decrease the toxicity of venoms and isolated toxins. The mucus and venom samples of P. aiereba were irradiated using gamma rays from a {sup 60}Co source. Animals models were immunized with the native or irradiated mucus or venom. The assays were conducted to assess the production of antibodies by the immunized animals using enzyme immunoassay and western blotting. Preliminary results show the production of antibodies by the immunized animals. The resulting sera were also checked for antigenic cross- reactivity between venom and mucus, demonstrating the potential of mucus as an antigen for serum production for the specific treatment for accidents by stingrays. However, it is essential to carry out further tests in order to verify the neutralization of the toxin by antibodies formed by animals. (author)

  5. Determination of distribution coefficients for 134 Cs, 60 Co and 234 Th radionuclides in Pinheiro river sediment

    The distribution coefficients (K α) were determined in order to foresee the fate of the radionuclides discharged to the environment. Based upon the source-term released by IPEN's facilities in Pinheiros River during the year of 1988, three radionuclides were chosen as being the more critical, according to the radiation protection standards: 137 Cs, 60 Co and 232 Th. Their K α were determined experimentally in laboratory by using the corresponding radioactive tracers 134 Cs, 60 Co and 234 Th. Three different experimental methodologies were used: the static method, the shaken method and the dynamic method. The parameters studied were the effects of pH, aerobic condition and time of contact. The results obtained experimentally for the Kds confirm the predictions that: the cesium is slowly retained by the sediment along the Pinheiros River, the cobalt is an unstable element, therefore its retention by the sediment is affected by variations in the pH values, and finally, the thorium is almost completely retained in the vicinity of the discharge point. (author)

  6. Effect of combination of STAT3 RNAi and 60Co γ-irradiation on U251 cell proliferation

    Objective: To construct signal transduction and activators of transcription 3 (STAT3) small interference RNA (siRNA) expression vector and to study its effect on STAT3 expression and U251 cell line proliferation. Methods: STAT3 specific 19 bp oligonucleotides were designed and synthesized. These oligonucleotides were annealed to form the double strand DNA fragments and these fragments were cloned into Psilence2.1-U6-H1 vector. The recombinant of STAT3-siRNA expressing construction was confirmed by Hind III and BamH I double digestion and sequencing. The STAT3-siRNA was transfected into U251 cell. The inhibitory effect of STAT3-siRNA construction was tested by Western blot. Cellular proliferation activities were measured by tetrazolium bromide (MTT) colorimetry. Cloning efficiency and MTF were used to confirm the radiation dose. Results: STAT3-siRNA expression vector was successfully constructed, and it could effectively down-regulate the protein levels of STAT3 in transfected U251 cell line; and the radiation dose was confirmed to 2 Gy. U251 cells transfected with STAT3-siRNA expression vector showed lower cellular proliferation compared with non-transfected U251 cells (P60Co γ-irradiation showed lower cellular proliferation compared with non-irradiated U251 cells (P60Co γ irradiation can enhance the inhibitory efficiency. (authors)

  7. A case of metastatic carcinoma of the iris successfully treated by argon laser photocoagulation and 60Co therapy

    A 69-year-old female developed visual impairment and congestion in the right eye. She had been treated for small cell carcinoma in the left lung for the past 8 months with cytostatics and radiation. Three whitish gray nodules were located on the iris at 10-11 o'clock in the right eye. Three smaller nodules were present in the chamber angle in the same sector. The corrected visual activity of the affected eye was 0.3. The left eye was intact. We performed total iridectomy and sclerotomy to remove the tumors. The resected tissue showed the same cell type as in the lung. Two days after surgery, multiple nodules appeared on the entire iris surface and the chamber angle apparently due to dissemination of tumor cells by the surgical procedure. Repeated argon laser photocoagulation aimed on the cancer nodules was very effective in supressing the tumor and maintaining the visual acuity without severe side effects for the next 5 months, until intravitreal metastasis and death ensued. 60Co therapy was noticeably effective to extinguish the tumor mass in the anterior chamber and in the vitreous cavity. We recommend argon laser photocoagulation for metastatic iris tumor in the initial stage and 60Co therapy in the terminal stage. (author)

  8. Characterization and performance study of high-dose 60Co gamma-ray calibration laboratory for radiation processing

    The 60Co gamma-ray irradiation facility for high absorbed dose calibration at radiation processing dose level was originally designed and constructed in JAERI. Uncertainty in absorbed dose given at JAERI was estimated by reviewing its characteristics and dosimetry performance. Dosimeter calibration equipment consists of the two plaque 60Co gamma-ray radiation sources giving different dose rate range of 5-200 Gy/h and 400 Gy/h-20 kGy/h, a dosimeter holder stage with high-reproducible positioning, a parallel-plate ionization chamber for accurate measurement of exposure-rates, and an auxiliary temperature/humidity-controlled irradiation vessel for dosimeter calibration under specific irradiation condition. The characteristics of the irradiation field and dosimetry performance are sufficient to give a known dose to working dosimeters to be calibrated for absorbed doses in the range of 0.5 Gy to 160 kGy within a reasonable operation time, 8 h, with an uncertainty of ±2.2% at a 95% confidence level. Calibration of dosimeters giving known doses by transfer dosimetry employing alanine dosimeters calibrated at JAERI is also achievable with an uncertainty of ±3.4% at a 95% confidence level. (author)

  9. The effects of exposure of {sup 60}Co on the oxidant/antioxidant status among radiation victims

    Demir, Mustafa E-mail: mmdemir@e-kolay.net; Konukoglu, Dildar; Kabasakal, Levent; Yelke, Hakan Kadir; Ergen, Kadir; Ahmed, Sabbir

    2002-07-01

    This retrospective study has been performed with radiation victims who were accidentally exposed to a {sup 60}Co source and its release into the environment. The aim of the study was to assess the effects of elevated radiation exposures on plasma level, on erythrocyte thio barbituric acid reactive substance (TBARS) level and on erythrocyte glutathione (GSH) levels. Patients were treated in different hospitals with different symptoms such as nausea, vomiting, dizziness, along with severe anemia in some patients. Blood samples were collected 3-5 days following the radiation accident. Increases in plasma (6.25{+-}0.90 nmol ml{sup -1}) and erythrocyte TBARS levels (330.5{+-}30.5 {mu}mol gHb{sup -1}) were found in comparison to a healthy group (3.72{+-}0.68 nmol ml{sup -1} and 150.7{+-}20.5 {mu}mol gHb{sup -1}, respectively) at a significant level (p<0.001). Erythrocyte GSH levels (5.2{+-}0.30 {mu}mol gHb{sup -1}) were found to be decreased among the victims (healthy group: 10.2{+-}0.7 {mu}mol gHb{sup -1}) at the same significance level (p<0.001). These observations confirm a significant change induced by radiation in the oxidant/antioxidant status among the victims. It is suggested here that antioxidant supplementation therapy might be effective in preventing the harmful effects of {sup 60}Co radiation among radiation victims.

  10. Effects of accumulated 60Co γ-ray irradiation on the small molecular metabolites in rats urine

    Objective: To explore the effects of accumulated 60Co γ-ray irradiation on small molecular metabolites in rats urine. Methods: Ten healthy male SD rats were irradiated by 60Co γ-rays in 5 days and the accumulated doses were 0, 0.2, 0.4, 0.6, 0.8, 1.0 Gy, respectively. The metabolites in urine of different groups were measured with 1H-NMR combined with principal components analysis (PCA) and partial least square discriminate analysis (PLS-DA). Results: The metabolites in rat urine were obviously changed after irradiation. Compared with control group, the amount of acetoacetate decreased after irradiation (t=29.7-30.7, P<0.05), but its relative level was stable when the dose increased (P>0.05). Meanwhile,the relative level of hippuric acid increased (t=4.4-21.6, P<0.05) especially when the accumulated dose was higher than 1 Gy (t=21.6, P<0.05). The relative level of proline, taurine and trimethylamine-N-oxide increased after irradiation with the same trend(t=3.5-13.4, 4.7-11.5, 2.9-12.7, P<0.05). Conclusions: The acetoacetate, hippuric acid, proline, taurine, and trimethylamine-N-oxide may be applicable for biomarkers of accumulative irradiation on rat. (authors)

  11. Effects of 60Co γ-ray partial radiation on chromosome aberration in human peripheral blood in vitro

    Objective: To investigate the effects of 60Co γ-ray partial radiation on chromosome aberration in human peripheral blood in vitro. Methods: The samples of heparinized peripheral whole blood from 3 healthy persons were exposed to 60Co γ-rays at the doses between 0 and 8 Gy with the dose rate of 0.35 Gy/min at the temperature of 37 ℃ ,and then mixed with the unirradiated blood samples of the Microscopy was used to observe the chromosome aberration double (centromere + centromere) and the biological dose was estimated thereby. Results: The amounts of double centromere + centromere were increased along with the dose of irradiation in all groups. The estimated biological dose was higher than the 1/3 of the irradiation dose when the dose was between 0.5 to 2 Gy, and was close to the 1/3 of the irradiation dose when the dose was between 4 to 8 Gy. Conclusion: Chromosome aberration can be used as a biomarker in estimation of uneven irradiation. (authors)

  12. Study on the therapeutic effect of cytokine on acute radiation syndrome induced by 60Co γ ray exposure

    Objective: To examine the therapeutic effect of combined administration of rhIL-11 and rhG-CSF on acute radiation syndrome induced by 60Coγ ray exposure in beagles. Methods: Sixteen beagles were randomly divided into the control (n=5), symptomatic treatment group (n=5) and cytokine treatment group (n=6). All the beagles in the three groups were exposed to the whole-body irradiation of 60Co γ ray at a dose of 4.5 Gy. The animals in the second group accepted active symptomatic treatment. The animals in the cytokine treatment group were sub-cutaneously administered rhIL -11 and rhG -CSF besides active symptomatic treatment. Hemogram of peripheral blood, pristine apoptosis and necrosis ratio of nucleated cells, the content of IL-2 and IFN-γ in plasma and formation of bone marrow were used to evaluate the therapeutic effect. Results: In the cytokine treatment group, the animal' survival rate 45 days after exposure was increased and hemogram of peripheral blood was improved significantly. The rate of pristine apoptosis and necrosis of nucleated cell declined obviously. Early, the content of both IL-2 and IFN-γ in plasma was up significantly, then the content of IL-2 rapidly descended, but that of IFN-γ was relatively stable. Conclusion: The combined administration of rhIL-11 and rhG-CSF significantly improved the recovery of hematopoietic and immunological function. (authors)

  13. Intra-arterial administration of carboplatin plus lower dosage radiation of 60CO as induction treatment in advanced oral cancer

    Conventional pre-operative chemoradiotherapy often causes severe side effects, which may result in interruption of the treatment and delay of decided operation. Carboplatin (CBDCA) is one of the effective chemotherapeutants for head and neck cancer. We treated 23 patients with advanced oral cancers by a combination of intra-arterial administration of Carboplatin and 60CO radiotherapy. The dosage of Carboplatin was between 20 mg and 35 mg per square meter of body surface. The dosage of external 60CO irradiation was 2 Gy per day and 30 to 60 Gy in total. We evaluated clinical response, toxicity and survival of this therapy of all the patients. Histologic response was also evaluated in some of them. All cancers responded to the regional chemoradiotherapy and demonstrated remission. Two (8%) completed response rate (CR) and 16 (69%) partial response rate (PR) were achieved. The accumulated five-year overall survival rate by Kaplan-Meier method was 73.9%. Fourteen patients (60.8%) showed no evidence of disease (NED) within five years after the therapy. All patients had stomatitis, but most of them were not so severe. The major hematological toxicity was leukopenia, but it was from mild to moderate and reversible. Our study showed that this therapy provided low toxicity, high clinical and histological response rate. (author)

  14. Comparison of base substitutions in response to nitrogen ion implantation and 60Co-gamma ray irradiation in Escherichia coli

    Xie Chuan-Xiao

    2004-01-01

    Full Text Available To identify the specificity of base substitutions, a novel experimental system was established based on rifampicin-resistant (Rif r mutant screening and sequencing of the defined region of the rpoB gene in E. coli. We focused on comparing mutational spectra of base substitutions induced by either low energy nitrogen ion beam implantation or 60Co-gamma rays. The most significant difference in the frequency of specific kinds of mutations induced by low energy nitrogen ion beam was that CG ®TA transitions were significantly increased from 32 to 46, AT ®TA transversions were doubled from 7 to 15 in 50 mutants, respectively. The preferential base substitutions induced by nitrogen ion beam implantation were CG ®TA transitions, AT ®GC transitions, AT ®TA transversions, which account for 92.13% (82/89 of the total. The mutations induced by 60Co-gamma rays were preferentially GC ®AT and AT ®GC transitions, which totaled 84.31% (43/51.

  15. Decontamination of 60Co and 144Ce. low-activity liquid wastes with the Fe3+ /OH- /Ca2+ /PO-4-3- system

    The influence of reaction time, concentrations of Fe3+ and PO-4-3+, temperature and agitation velocity in the efficiency of decontamination of 60Co and 144Ce low-activity liquid wastes using the Fe3+ /OH-/Ca2+ /PO-4-3+ precipitator system was stud ied in this paper. The mathematical models of this process were obtained for 60Co and 144Ce. The best conditions for the decontamination we re calculated using the optimization program

  16. Resposta de sementes de amendoim a diferentes doses de radiação gama (60Co Response of peanut seeds to different levels of gamma radiation (60Co

    Tatiana da S. Santos

    2010-10-01

    Full Text Available A radiação gama, proveniente da fonte de 60Co, é bastante utilizada para esterilização, visando a prevenção da decomposição e a toxidez de origem microbiana em diversos produtos. O grau de radiossensibilidade de um embrião vegetal depende da espécie, do estágio de seu desenvolvimento durante a radiação, da dose empregada e do critério usado para medir o efeito biológico, sendo comumente utilizado o teste de germinação. Objetivou-se, com este trabalho, estudar a sensibilidade do amendoim a radiação gama e seus efeitos na germinação, no vigor e na micoflora das sementes da cultivar BRS Havana, irradiadas com uma fonte de 60Co, tipo gammacell, com taxa de dosagem de 12,5 kGy h-1. As doses testadas em kGy foram as seguintes: 0; 0,5; 1,0; 1,5; 2,0; 2,5; 3,0; 6,0; 9,0; 12,0; 15,0; 18,0; 21,0 e 24,0. Com os resultados obtidos, concluiu-se que as doses acima de 3,0 kGy prejudicaram a viabilidade das sementes e as doses acima de 12 kGy comprometeram totalmente o vigor e a germinação das sementes de amendoim. A radiação a partir da dose 2,0 kGy eliminou os fungos Aspergillus flavus e Aspergillus niger e, a partir da dose 3,0 kGy, eliminou o Aspergillus glaucus. O Penicilium spp. permaneceu em mais de 30% das sementes em todos os tratamentos com radiação, não sendo eliminado até a dose de 24 kGy.The gamma radiation from 60Co source is widely used for sterilization aiming at preventing decomposition and toxicity from microbes in several products. The degree of radiosensitvity of a plant embryo depends on the species, the development stage during radiation, doses used and the criteria used to measure the biological effect, the germination test, being commonly used.This work aimed to study the peanut sensitivity to gamma radiation and its effects in the germination, in the vigour and seeds microflora of cultivar BRS Havana, irradiated with 60Co source, type gammacell with rate of dosage of 12.5 kGy h-1. The tested doses were the

  17. Analysis of the frequency of unstable chromosome aberrations in human lymphocytes irradiated with {sup 60}Co; Analise da frequencia de alteracoes cromossomicas instaveis em linfocitos humanos irradiados com {sup 60}Co

    Mendonca, Julyanne C.G.; Mendes, Mariana E.; Lima, Fabiana F., E-mail: july_cgm@hotmail.com, E-mail: mendes_sb@hotmail.com [Centro Regional de Ciencias Nucleares (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Santos, Neide, E-mail: santos_neide@yahoo.com.br [Universidade Federal de Pernambuco (CCB/UFPE), Recife, PE (Brazil). Departamento de Genetica

    2013-07-01

    The aim of this study was to analyze the frequency of unstable chromosomal aberrations induced by gamma radiation from a {sup 60}Co source at two different doses. Samples were obtained from a healthy donor and exposed to {sup 60}Co source (Gammacel 220 ) located in the Department of Nuclear Energy of Pernambuco Federal University (DEN/UFPe/Brazil) with a rate of air Kerma to 3,277 Gy/h. Exposures resulted in absorbed dose 0.51 Gy and 0.77 Gy. Mitotic metaphases were obtained by culturing lymphocytes for chromosome analysis and the slides were stained with 5% Giemsa. Among the unstable chromosomal aberrations the dicentric chromosomes, ring chromosomes and acentric fragments were analyzed. To calculate the significance level the chi - square test was used, considering relevant differences between the frequencies when the value of p < 0.05. To calculate the significance level of the chi - square test was used, considering relevant differences between the frequencies when the value of p < 0.05. The results showed that there was significant difference of the frequencies of dicentric chromosomes (from 0.18 to 0.51 to 0.37 Gy to 0.77 Gy), however there was no statistically significant difference between the frequencies of acentric fragments ( 0.054 to 0, 51 Gy to 0.063 to 0.77 Gy) and ring chromosomes (0.001 to 0.51 Gy to 0.003 to 0.77 Gy). The low number of rings is found justified, considering that in irradiated human lymphocytes, its appearance is rare relative to dicentrics. The results confirm that dicentrics are the most reliable biomarkers in estimating dose after exposure to gamma radiation. These two points will make the calibration curve dose-response being built for Biological Dosimetry Laboratory of CRCN-NE/CNEN.

  18. Validation of dose-response curve of CRCN-NE - Regional Center for Nuclear Sciences from Northeast Brazil for {sup 60}Co: preliminary results; Validacao da curva dose-resposta do CRCN-NE para {sup 60}Co: resultados preliminares

    Mendonca, Julyanne C.G.; Mendes, Mariana E.; Hwang, Suy F.; Lima, Fabiana F. [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Santos, Neide, E-mail: july_cgm@yahoo.com.br [Universidade Federal de Pernambuco (CCB/UFPE), Recife, PE (Brazil). Departamento de Genetica

    2014-07-01

    The cytogenetic study has the chromosomal alterations as biomarkers in absorbed dose estimation by the body of individuals involved in exposure to ionizing radiation by interpreting a dose response calibration curve. Since the development of the technique to the analysis of data, you can see protocol characteristics, leading the International Atomic Energy Agency indicate that any laboratory with intention to carry out biological dosimetry establish their own calibration curves. The Biological Dosimetry Laboratory of the Centro Regional de Ciencias Nucleares (CRCN-NE/CNEN), Brazil, recently established the calibration curve related to gamma radiation ({sup 60}Co). Thus, this work aimed to start the validation of this calibration curve from samples of three different blood donors which were irradiated with an absorbed known single dose of 1 Gy. Samples were exposed to {sup 60}Co source (Glaucoma 220) located in the Department of Nuclear Energy (DEN/UFPE). After fixation with methanol and acetic acid and 5% Giemsa staining, the frequency of chromosomal alterations (dicentric chromosomes, acentric rings and fragments) were established from reading of 500 metaphases per sample and doses were estimated using Dose Estimate program. The results showed that, using the dose-response curve calibration for dicentrics, the dose absorbed estimated for the three individuals ranged from 0.891 - 1,089Gy, taking into account the range of confidence of 95%. By using the dose-response curve for dicentrics added to rings and for the same interval of confidence the doses ranged from 0,849 - 1,081Gy. Thus, the estimative encompassed known absorbed dose the three individuals in confidence interval of 95%. These preliminary results seems to demonstrate that dicentric dose-response curves and dicentrics plus rings established by CRCN-NE / CNEN are valid for dose estimation in exposed individuals. This validation will continue with samples from different individuals at different doses.

  19. Coefficients of leaf-fruit translocation for 60Co, 90Sr and 137Cs in bean plant (Phaseolus vulgaris)

    Due to the increasing use of nuclear fission for the generation of electrical energy, the safety aspects of power plants must be minutely appraised. In case of an accident, with liberation of radioactive material into the atmosphere, knowledge about the behavior of plant species when in contact with radionuclides is indispensable. An important route through which agricultural products are contaminated by radionuclides is leaf-fruit translocation. This phenomenon can be evaluated by simulating a fallout contamination in a controlled atmosphere using as a tracer man-made radionuclides. In order to quantity the leaf-fruit translocation coefficients for 60Co, 90Sr and 137Cs in the common bean (Phaseolus vulgaris), variety black diamond, an experiment was carried out in a greenhouse with completely randomized blocks design with six treatments and four blocks. A mixture of these three radionuclides was prepared and used to determine their translocation coefficients. The bean plants were contaminated inside a device especially designed to avoid environmental contamination. In each treatment four vases were sprinkled and one was used to estimate the initial activity of the other three vases. High-resolution gamma-ray spectrometry was used for 60Co and 137Cs activity determinations and chemical separation followed by beta counting of 90Y was used for 90Sr determinations. The number of treatments was reduced from six to four sprayings corresponding to 30, 45, 60 and 75 days after planting. This reduction was due to the attack of common and gold mosaic viroses. Symptoms were observed on the diseased bean plants 50 days after planting. It was possible, however, to verify a functional dependence between instant of tracer application and the level of physiological development of the bean plant. It was verified that the temporal relationship values for leaf-fruit translocation were similar for 60Co and 137Cs. For the 90Sr, the translocation was below 2,5 mBq kg-1/Bq kg-1, 0

  20. Morphological and histological studies on freshwater prawn Macrobrachium rosenbergii (de man) irradiated with {sup 60}Co gamma radiation

    Stalin, A.; Broos, K.V. [P.G. and Research Department of Zoology, Jamal Mohamed College (Autonomous), Tiruchirappalli 620020, Tamil Nadu (India); Sadiq Bukhari, A., E-mail: abjmc@yahoo.in [P.G. and Research Department of Zoology, Jamal Mohamed College (Autonomous), Tiruchirappalli 620020, Tamil Nadu (India); Syed Mohamed, H.E. [P.G. and Research Department of Zoology, Jamal Mohamed College (Autonomous), Tiruchirappalli 620020, Tamil Nadu (India); Singhal, R.K. [Analytical Spectroscopy Section, Analytical Chemistry Division, Bhabha Atomic Research Center, Trombay, Mumbai 4000085 (India); Venu-Babu, P. [Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Center, Trombay, Mumbai 4000085 (India)

    2013-11-15

    Graphical abstract: -- Highlights: •Analyzing the impact of {sup 60}Co gamma radiation (low doses) in M. rosenbergii. •LD{sub 50} identified in 30 Gy; Irradiated exhibits morphological changes than control. •Significantly decreased HSI and histological changes in irradiated groups. •Aberration severities increased as increased of dose level. •Biomonitoring tool in determining low dose radiation pollution in aquatic ecosystem. -- Abstract: This study was framed to investigate the {sup 60}Co gamma radiation induced morphological and histological variations in freshwater prawn Macrobrachium rosenbergii. The LD{sub 50} value of {sup 60}Co gamma irradiated M. rosenbergii observed (by probit analysis) at 30 Gy. Prawns were irradiated to four different dose levels (3 mGy, 30 mGy, 300 mGy and 3000 mGy) using Theratron Phoenix TeleCobalt Unit [P-33] and one control group (without irradiation) maintained separately. Irradiated groups exhibited several morphological variations such as discoloration; damaged rostrum; opaque coloration in cephalothorax; black bands and dot formation in abdomen; deformed uropods and telson in tail regions when compared with control group. The Hepato Somatic Index reflected the severity of radiation on hepatopancreas. Histological variations in gills, hepatopancreas and muscles of irradiated groups were observed. In gills, structural changes such as swollen and fused lamellae, abnormal gill tips, hyperplasic, necrotic and clavate-globate lamellae were observed in gamma irradiated prawns. Accumulation of hemocytes in hemocoelic space, interstitial sinuses filled with abnormal infiltrated hemocytes, the tubular epithelium with ruptured basal laminae, abnormal and coagulated lumen, necrotic tubules, thickened basal laminae, tissue debris, necrotic hepatocytes were observed in irradiated prawn hepatopancreas. In muscle, shrinkage of muscular fiber and necrotic musculature were observed in irradiated prawns. These structural alterations of

  1. Direct MC conversion of absorbed dose to graphite to absorbed dose to water for 60Co radiation.

    Lye, J E; Butler, D J; Franich, R D; Harty, P D; Oliver, C P; Ramanathan, G; Webb, D V; Wright, T

    2013-06-01

    The ARPANSA calibration service for (60)Co gamma rays is based on a primary standard graphite calorimeter that measures absorbed dose to graphite. Measurements with the calorimeter are converted to the absorbed dose to water using the calculation of the ratio of the absorbed dose in the calorimeter to the absorbed dose in a water phantom. ARPANSA has recently changed the basis of this calculation from a photon fluence scaling method to a direct Monte Carlo (MC) calculation. The MC conversion uses an EGSnrc model of the cobalt source that has been validated against water tank and graphite phantom measurements, a step that is required to quantify uncertainties in the underlying interaction coefficients in the MC code. A comparison with the Bureau International des Poids et Mesures (BIPM) as part of the key comparison BIPM.RI(I)-K4 showed an agreement of 0.9973 (53). PMID:23152147

  2. Destruction of Radiation-Resistant Micro-Organisms on Surgical Sutures by 60Co-Irradiation Under Manufacturing Conditions

    Any process adopted for producing sterile medical products must be demonstrated to produce sterility under reproducible manufacturing conditions. In addition, a margin of safety is required to guard against non-sterility due to undetected departures from standard operating practices. This study reports the results of exposure to 60Co γ-rays of surgical sutures intentionally contaminated with known radiation-resistant organisms, including St. faecalis, M. radiodurans and B. pumilus, under normal manufacturing conditions. Additionally, the results of over 20 000 sterility tests under prolonged incubation are reported to indicate that routine sterility testing of radiation-sterilized sutures is adequate to detect radiation survivors. The nature and level of the natural contaminants of surgical sutures before sterilization is tabulated and discussed from the standpoint of the safety factor inherent in the process. (author)

  3. Evaluation of 60Co radiation effect in the survival of different mouse strains. Radiomodifiers and celular response

    The radiomodifier capacity of proteose-peptone (PP), imidazole derivatives such as azomycin and levamisole against an 8 or 9 Gy single dose of 60Co irradiation of mice from IPEN animal house was evaluated, being the biological responses compared with other mouse strains. It is concluded that PP, azomycin and PP + azomycin behaved as radioprotectors, while lavamisole appeared as a radiossensitizer. The various strains showed differences in their survival indexes. The changes in body weight curves of mice from all the experiments were followed during 30 days. Qualitative and quantitative analysis 2 hours, 3 and 6 days after irradiation of typical macrophages, mononuclear cells (monocytes and lymphocytes), polimorphonuclear and mast cells from peritonium of test animals showed that radiation interfered in a differential way in the kinetics of peritoneal cells. (author)

  4. Determination of specific activity of 60Co in steel samples exposed to the atomic bomb in Hiroshima

    Specific activities 60Co/Co in a steel sample from Yokogawa Bridge, 1,295 m NNW, and three steel samples from the Atomic-Bomb Dome, 161 m NW from the hypocenter were measured by gamma-ray spectrometry and neutron activation analysis. The results expressed in a unit of dpm/mg Co were, 0.212±0.06 for Yokogawa Bridge, and 529±40, 561±38, and 524±74 for the Atomic Bomb Dome, at the time of bombing, which are consistent with previous data by Hashizume et al. for steel rings on the surface of roofs of buildings. The data are expected to serve for verification of the bomb neutron transport calculation. (author)

  5. Effect of 60Co-irradiation on the development and immunogenicity of Plasmodium berghei sporozoites in Anopheles stephensi mosquitoes

    Smrkovski, L.L.; McConnell, E.; Tubergen, T.A.

    1983-10-01

    Protection conferred to mice by Plasmodium berghei sporozoites increased significantly when the time interval between 60Co-irradiation of the infected mosquitoes and harvest of sporozoites increased. One thousand sporozoites conferred no protection against challenge if harvested on the day of irradiation, but protected 60% of recipient mice when harvested 28 days postirradiation. When the time between feeding of mosquitoes and irradiation was varied, sporozoites from mosquitoes irradiated 3 days after feeding were infective for mice. Sporozoites from mosquitoes irradiated on day 10 postfeeding were not infective, but were immunogenic. In all experiments a decline occurred in the number of recoverable sporozoites over a 28-day period postirradiation to less than 10% of the yield on the day of irradiation.

  6. Chromosome damage and clinical manifestation in a fetus and the mother after accidental 60Co exposure in Xinzhou

    The authors present the clinical effect and chromosome damage sustained by a fetus and the four months pregnant mother in an accidental 60Co exposure in November of 1992 in Xinzhou, Shanxi Province. The mother suffered from a moderate acute radiation sickness with ratardation of fetal development. After delivery, the infant's body length, body weight and head circumference were all lowered by three percentiles compared with the normals. Four months after the exposure, the assay of the mother's peripheral lymphocytes showed a chromosome aberration rate of 36%, while concomitant examination of the baby failed to reveal any chromosome abnormality although the sister chromatid exchange rate was remarkably higher than that of the mother and the normal control

  7. Suppression by ellagic acid of 60Co-irradiation-induced lipid peroxidation in placenta and fetus of rats

    The effect of ellagic acid, a component of Eucalyptus maculata, on lipid peroxidation was examined in placenta and fetus of pregnant rats irradiated with 60Co. The increase in lipid peroxide levels by the irradiation of the placenta and fetus brain as well as those of the serum and organs of mother was suppressed by treatment of the mother rats with ellagic acid. This suppressing effect found in placenta and fetus was significantly correlated with that found in mother rats. Moreover, ellagic acid suppressed the morphological changes such as degeneration in the endothelial cells of placenta and liver cells of fetus caused by the irradiation and improved the survival rate after the irradiation. These suppressing effects of ellagic acid were approximately the same as those of α-tocopherol. (author)

  8. Ten years medical follow-up of four persons accidentally exposed to 60Co γ-rays

    Four cases of acute radiation injury resulting from accidental exposure to a 60Co source in February, 1972, were subject to early medical examination, and followed-up for 10 years. Their whole body exposure doses were estimated to be 55-147 rads. The results showed that in the individuals who had received a single dose below 147 rads, the temporary clinical picture, and the injuries in hemopoietic function and male reproductive system were all recoverable, but the chromosome aberrations yield returned to normal slowly. Ten years after the accident, all these 4 cases were in good health, and no cataract or malignant diseases were observed. No obvious abnormalities were found in their children. (author)

  9. Radiolysis of D(+)-carnitine by /sup 60/Co-. gamma. -radiation and formation of L(+)-. beta. -methylcholine

    Loester, Heinz; Strack, Erich; Seim, Hermann

    1986-06-01

    The radiolysis of D(+)-carnitine by /sup 60/Co-..gamma..-radiation was examined to obtain optically active ..beta..-methylcholine. It was found that the radiolysis leads to a number of trimethylammonium bases but to no other betaines. (+)-..beta..-Methylcholine and acetonyltrimethylammonium could be identified by means of common analytical methods. The amounts of methylamines formed by irradiation were very small. Racemization of the D(+)-carnitine did not occur during irradiation, L(-)-carnitine was not found when an enzymatical determination method was used. The fact that (+)-..beta..-methylcholine was formed from D(+)-carnitine is pharmacologically important, because acetyl-L(+)-..beta..-methylcholine has a strong interaction with muscarinic receptors.

  10. Effects of total base of sophora alopecuroides on lipid peroxidation of 60Co γ-rays irradiated mice

    Objective: To study the effects of total base of Sophora alopecuroides on lipid peroxidation of irradiated mice. Methods: The mice were treated orally with different doses of total base of Sophora alopecuroides, after exposed to whole-body 60Co γ-rays at a dose of 5.0 Gy. The content of MDA in the liver and activities of Se-GSH-PX, SOD, GPT, GOT were measured. Results: After irradiation, the general status of the mice were changed such as hair deprivation, body weight reduction, blood spots appeared on the tail. Activities of Se-GSH-PX, SOD decreased remarkably, whereas those of GPT and GOT increased. MDA contents increased obviously. Oral administration of total base of Sophora alopecuroides could accelerate restoration of these indexes. Conclusion: Total base of Sophora alopecuroides has certain protective effects on irradiated mice, the mechanism of which may be related with antioxidation

  11. Effects of 60Co γ-ray irradiation on expression of surface antigens in endothelial cells of human umbilical veins

    Culture of endothelial cells of human umbilical veins and avidin-biotin peroxidase complex (ABC) immunochemical technique were used in the experiment to detect the surface antigens in endothelial cells. Endothelial cells separated from five umbilical cords in original culture were divided into two groups, irradiated and non-irradiated. The cells were irradiated with 15 Gy of 60Co γ-rays at dose rates of 21.78 cGy/min. Then antigens RBC A, HLA-ABC, HLA-DR, CD4 and CD8 were assayed for both groups by the method of ABC. The results showed that the values of integrated optical density (IOD) for the surface antigens in the irradiated cells were lower than those in the non-irradiated cells with the difference in antigen expression in endothelial cells being significant (P<0.05) between the two groups

  12. Radiation-induced micronucleus formation in mice bone marrow after exposure to different doses of 60Co gamma radiation

    The frequency of micronuclei formation in the polychromatic erythrocytes and normochromatic erythrocytes was studied at 12 and 24th post-irradiation in mice bone marrow whole-body exposed to 0, 0.5, 1.0, 2.0, 3.0 and 4.0 Gy of 60Co gamma radiation. It was observed that the frequency of MPCE (micronucleated polychromatic erythrocytes) and MNCE (micronucleated normochromatic erythrocytes) increased with increase in exposure dose in both intervals studied. The data analyzed using the linear quadratic (Y+C+αD+βD2) equation. It was found that the data for MPCE and MNCE fitted best for linear quadratic model. (The PCE/NCE ratio declined with increase in exposure dose in both intervals and this decline was dose related. (author). 28 refs., 1 tab

  13. Molecular analysis of 60Co gamma-ray-induced mutation at HPRT locus in human promyelocyte leukemia cells

    Objective: To explore the spectra and mechanism of human HPRT gene mutation induced by 60Co γ-rays and its relation with anti-tumor effect of radiation. Methods: Single cell clone culturing, two-way screening count, multiplex PCR amplification and electrophoresis technique were used. Results: (1) When doses were increasing, cell plating efficiency reduced and mutation frequency increased. (2) The most frequent spontaneous mutations were point mutation (92.3%) and gamma-ray-induced mutation, including mainly partial deletion and point mutation (61.7% and 38.3%, respectively). (3) There were deletion mutations in all 9 exons of HPRT gene and the most of gamma-ray-induced mutations were chain deletion with multiplex exons (97.9%). Conclusion: The spectra of spontaneous and gamma-ray-induced mutants were different. The bigger changes in genetic structure are related to the antitumor mechanism of radiation

  14. A study on the radiative mutation on the seeds of Adzuki bean by 60Co γ ray

    The seeds of Adzuki bean were irradiated by 60Co γ ray of 0-700 Gy. The results showed that: (1) The sub-lethal dose (LD50) was 389 Gy and the early seedling leaf at M1 showed incised, chlorotic, yellow, mosaic and curly edge. The absorbed dose was related with the rate of misshaped leaf. chromosomal aberration, chromosome bridge and fragment of M1 in the tip were observed. If the seed was irradiated with 400 Gy, the rate of abnormal cell at the root was more than 10%. The relationship between pollen fertility and irradiation dose was negative correlated. When the irradiation dose was 387 Gy, the pollen fertility was 50% in the seeds of Adzuki bean. (2) The optimum irradiation dose for the seed of Adzuki bean is 400 Gy in the M1 and M2

  15. Differential expression profile in the progeny of normal human liver cells irradiated by 60Co γ-rays

    Objective: To investigate the differential expression profile in the progeny of human liver cells surviving from ionizing radiation. Methods: Complemental DNA gene chip was used to measure the transcriptional profile in progeny of HL-7702 cells exposed to 0, 2, 4, and 6 Gy of 60Co γ-rays, and the differentially expressed genes HAVCR2 and RAN were further identified by real-time PCR. Results: The transcription level of 262 genes, 2746 genes and 3406 genes changed in the progeny of survival cells at 2, 4 and 6 Gy, respectively. A total of 71 common differentially expressed genes were screened, most of which were associated with transduction, cell cycle regulation, cellular immunity, cytoskeleton and movement, cell replication and repair mechanism. Conclusions: Ionizing radiation could induce the expression changes of many genes, which might reveal the molecular mechanisms of gene expression in radiation induced genomic instability. (authors)

  16. Radiolysis of D(+)-carnitine by 60Co-γ-radiation and formation of L(+)-β-methylcholine

    The radiolysis of D(+)-carnitine by 60Co-γ-radiation was examined to obtain optically active β-methylcholine. It was found that the radiolysis leads to a number of trimethylammonium bases but to no other betaines. (+)-β-Methylcholine and acetonyltrimethylammonium could be identified by means of common analytical methods. The amounts of methylamines formed by irradiation were very small. Racemization of the D(+)-carnitine did not occur during irradiation, L(-)-carnitine was not found when an enzymatical determination method was used. The fact that (+)-β-methylcholine was formed from D(+)-carnitine is pharmacologically important, because acetyl-L(+)-β-methylcholine has a strong interaction with muscarinic receptors. (author)

  17. Determination of 137Cs and 60Co pollution in the area of the Laguna Verde Nuclear Power Plant, Mexico

    The project 'Radiological Analysis of Environmental Samples in the Gulf of Mexico and the coast of Quintana Roo', had the aim of identifying and quantifying anthropogenic radionuclides in environmental samples consisting of silt, sand and sea water. This paper presents the results of the radiological analysis of these samples, which was made in the multichannel system for gamma spectrometry with hyper-pure germanium detector in the Laboratory of Radiological Analysis of Environmental Samples, located at the Physics Department, Faculty of Sciences, of the Autonomous National University of Mexico (UNAM). The sampled points are along the coast of the contiguous states of Tamaulipas, Veracruz, Tabasco, Campeche, Yucatan and Quintana Roo. This paper presents the qualitative and quantitative concentrations of the main identified anthropogenic radionuclides 60Co and 137Cs. (authors)

  18. Dose-rate effect on chromosomal aberrations induced by 60Co γ-rays irradiation in human peripheral blood lymphocyte

    To estimate exactly the biological dose of persons exposed to different dose rate, human peripheral blood was exposed to 60Co γ-rays in vitro at low, middle and high dose rates respectively and chromosome samples were prepared, then dose-response curves were established according to the dicentrics and ring frequencies. The result showed that the aberration frequency at same dose level increased with dose rate and there was an obvious dose-rate effect. Absorbed dose estimated with low dose-rate dose-response curve was higher markedly than that with high dose-rate dose-response curve. So, considering the effect of dose-rate, approximate dose-rate dose-response curve should be chosen when absorbed dose estimation and the result will be credible. (authors)

  19. Tl response of KMgF3 :Lu+PTFE depending on the dose of gamma radiation of 60Co

    Due to the great interest in Tl dosimetry for measuring the levels of radiation doses, as environmental as in the different medical radiation applications in different laboratories of the World it is continued in the searching of new Tl materials with optimum dosimetric characteristics and low cost. In this work the obtained results when irradiating Tl dosemeters of KMgF3 :Lu + PTFE with gamma radiation of 60 Co are presented. Such results showed that this material presents linearity of response depending on the dose between 0.016 to 100 Gy. Although it is continued with the characterization tests it is able to say that this Tl new material can be used for dosimetric aims. (Author)

  20. The sensitivity of the most common microorganisms of pig liquid manure to the effect of 60Co irradiation

    In model experiments the most common representatives of pathogens and facultative pathogens of pig liquid manure contaminating bacterial flora were examined for their sensitivity to different doses of 60Co, using liquid medium supplemented with 1% glucose, as well as Korthof-medium and different kinds of selective media. Erysipelothrix rhusiopathiea, Brucella suis, Mycoplasma hyorhinis and Pasteurella haemolytica proved to be the most senstive ones to irradiation, as they did not survive 100 krad dose. The highest resistances were observed in the cases of the following microorganisms: the spore containing Bacillus anthracis, killed by 700 krad irradiation dose, the saprophytic and pathogenic Mycobacteria and the spore containing Clostridium perfringens, killed by 1000-1500 krad irradiation. (author)