Response of Boreal forest tree canopy cover to chronic gamma irradiation

International Nuclear Information System (INIS)

Amiro, B.D.

1994-01-01

A section of the Canadian Boreal forest was irradiated chronically by a point source of 137 Cs from 1973 to 1986. Tree canopy cover was measured at permanently marked locations during the pre-irradiation, irradiation and post-irradiation phases, spanning a period of two decades. The tree canopy was severely affected at dose rates greater than 10 mGy/h delivered chronically. The canopy of sensitive coniferous tree species, such as Abies balsamea and Picea Mariana, decreased at dose rates greater than 2 mGy/h, but in some cases the tree canopy was replaced by more resistant species, such as Populus tremuloides and Salix bebbiana. Effects on canopy cover could not be detected at dose rates less than 0.1 mGy/h. Even at dose rates of 5 mGy/h, the forest canopy is recovering six years after irradiation stopped. (author)

Researchin chronic low-level gamma -irradiation on laboratory populations of Lemna minor

International Nuclear Information System (INIS)

Rasskazova, M.M.; Berestina, A.V.

2012-01-01

Researching carried out on the laboratory population of Lemna minor showed that the chronically γ-irradiated plants significantly reduced specific rate of population growth, accelerating the process of withering away of the fronds. Chronic irradiation with dose of 5,0 mGy/h stimulates the growth of the roots, and irradiation with a capacity of 50 mGy/h significantly increases the percentage of damage fronds. Found out independent of dose effect on the criterion of the number of deaths of individuals in the range of absorbed dose between 0,01 - 1 Gy. (authors)

Modeling analysis of the lymphocytopoiesis dynamics in chronically irradiated residents of Techa riverside villages

Energy Technology Data Exchange (ETDEWEB)

Smirnova, Olga A. [Federal State Unitary Enterprise Research and Technical Center of Radiation-Chemical Safety and Hygiene, Moscow (Russian Federation); Akleyev, Alexander V. [Urals Research Center for Radiation Medicine (URCRM), Chelyabinsk (Russian Federation); Chelyabinsk State University, Chelyabinsk (Russian Federation); Dimov, Georgy P. [Urals Research Center for Radiation Medicine (URCRM), Chelyabinsk (Russian Federation)

2014-08-15

A biologically motivated dynamical model of the lymphocytopoietic system in irradiated humans is applied here to analyze the data obtained under hematological examinations of residents of Techa riverside villages. Those people were exposed to chronic irradiation with varying dose rates, due to the radioactive contamination of the river basin by the Mayak Production Association. Modeling studies revealed the relationship between the dynamics of the lymphocytopoietic system in the examined individuals and the variation of dose rate over the considered period of time. It is found that the developed model is capable of reproducing the decreased level of blood lymphocyte concentration observed during the period of maximum radiation exposure, the recovery processes in the system observed during the period of decreasing dose rate, as well as the enhanced mitotic activity of bone marrow precursor cells in this hematopoietic lineage observed during the entire period under consideration. Mechanisms of these effects of chronic irradiation on the human lymphocytopoietic system are elucidated based on the applied model. The results obtained demonstrate the efficiency of the developed model in the analysis, investigation, and prediction of effects of chronic irradiation with varying dose rate on the human lymphocytopoietic system. In particular, the developed model can be used for predicting any radiation injury of this vital system in people exposed to chronic irradiation due to environmental radiological events, such as anthropogenic radiation accidents or radiological terroristic attacks. (orig.)

Studies on the chronic effect of lower dose level irradiation

International Nuclear Information System (INIS)

Yun, T.G.; Yun, E.S.; Chung, I.Y.; Yun, M.S.; Chae, H.S.; Lee, J.Y.

1982-01-01

This experiment was carried out to evaluate the chronic hazard of Co-60 low dose radiation on ICR mice. There is now considerable evidence from human studies that age, both at exposure to radiation and at observation for risk, can be major determinant of radiation induced cancer risk. For this reason, ICR mice at different ages such as below were exposed to 60m rads/week, 500m rads/week and 60 rads/biweek whole body Co-60 radiation at a dose rate of 3.6 rads/min. ICR mice were irradiated during pregnant period, from 1st week to 3rd week, from 3rd week to 52nd week, from 6th week to 52nd week, and from 22nd week to 52nd week after the birth. All experimental mice were autopsied immediately after being sacrificed at 52nd week. All major organs were examined grossly and weighed. After fixation histo-pathological preparations were made for microscopical study. Blood cells W.B.C., R.B.C., Hb-from eye's vein were counted by hemocytometer and hemometer. (Author)

Lifespan studies on different strains of mice exposed chronically to low levels of whole body gamma irradiation

International Nuclear Information System (INIS)

Fox, L.A.; Klein, A.K.; Cain, G.R.; Rosenblatt, L.S.

1982-01-01

Several strains of mice, chosen for their predisposition to immunohematological disorders, were exposed to low levels of 60 irradiation continuously for four weeks. All individuals were subsequently followed throughout their lifetimes. W/W/sup v/ mice, which are tyically subject to a stem cell deficiency, had a lower cumulative survival rate for the irradiated group than for the unirradiated controls. Irradiated RF/sub j/ mice had a dramatically lower cumulative survival rate than their unirradiated controls. Conversely, BXSB mice, which have a lumphoproliferative autoimmune disorder, had a higher cumulative survival rate after chronic irradiation than did unirradiated BXSBs. Irradiation had no effect upon the survival rate curves of the NZB strain, the murine model for Lupus Erythematosus

Changes in oil composition after chronic irradiation of winter and spring zero-erucic rape hybrids

International Nuclear Information System (INIS)

Fabry, A.; Cerny, J.

1980-01-01

Hybrid plants of the F1 generation of erucic-free spring Canadian rape and some winter rape cultivars containing erucic acid were irradiated in a gamma field with doses ranging between 5973 and 329 R during vegetation. Chronic irradiation increased significantly the frequency of zero- or low-erucic genotypes in the segregating F2 generation. Chronic irradiation disturbed the correlations between the contents of the studied fatty acids in the hybrid F1, F2 and F3 progenies. Lines of zero- and low-erucic winter rapes with a reduced content of linolenic acid and increased content of linoleic acid were obtained by selection. (author)

Thymic irradiation and chronic myelogenous leukemia

International Nuclear Information System (INIS)

Shimaoka, K.; Sokal, J.E.

1977-01-01

Two cases of Ph positive chronic myelogenous leukemia with a history of thymic irradiation are presented. Both patients received radiation therapy from low voltage x-ray equipment at two to three months of age. Leukemia developed 18 and 22 years later. Presentation, response to antileukemic therapy, and clinical course did not differ from that of other patients with this disease treated in our department

Chronic gamma irradiation of ornamental and landscaping plants at gamma greenhouse

International Nuclear Information System (INIS)

Shuhaimi Shamsudin; Zaiton Ahmad; Affrida Abu Hassan

2011-01-01

Activities on chronic gamma irradiation of ornamental and landscaping plants have started since April 2010. Among plants which have been irradiated were landscaping plants such as hibiscus, canna, turnera, plumeria, amaryllis, and ornamental plants such as orchid, heliconia, cucurma and sanseviera, as well as vanilla. The main objectives at the initial stage were to develop database for optimum chronic irradiation dose and suitable experimental design for each species. The ultimate aim is to obtain new varieties of ornamental plants with flower and horticultural traits of commercial values and landscaping plants suitable for Malaysian landscape such as large and colourful flower, longer bloom period and frequent flowering. This paper discusses irradiation activities for ornamental plants in Gamma Greenhouse including preparation of samples, growing medium and screening plots, selection/determination of optimum dose and dose rate, collection of data and selection of mutants. (author)

Dynamics of genetic processes in chronically irradiated populations of small mammals

International Nuclear Information System (INIS)

Ryabokon', N.I.; Goncharova, R.I.; Smolich, I.I.; Kapitanova, N.P.; Nikitchenko, N.V.

2000-01-01

The distinctive features of dynamics of mutagenesis in mammalian populations under chronic low-intensive irradiation were first revealed. The main of them is gradual increase in mutability in somatic cells and embryonal lethality during series of irradiated generations of animals (bank vole - Clethrionomys glareolus). The data obtained strongly suggest that there are oppositely directed processes in natural populations after irradiation of more than 20 generations of animals: on the one hand, accumulation of mutations (genetic load of populations) and pre-mutation events which increase genome instability of germ and somatic cells in consecutive generations of animals, and on the other, formation of genetic radio adaptation through better functioning protection systems. In this period of micro evolution in chronically irradiated populations, the frequencies of genetic damages could be higher if the radiation adaptation doesn't form. (authors)

Service factor calculated from an experimental simulation of chronic occupational irradiation

International Nuclear Information System (INIS)

Berikashvili, V.Sh.

1975-01-01

A correlation has been studied between the body weight, basal metabolism, lifespan, the period of water exchange, average life of erythrocytes and average rate of pulse-beat, and values LDsub(50/30-60), half-recovery period after irradiation and time of leucopenia occurrence in different species of laboratory animals and man. An authentic degree-interrelation of these indices has been revealed, and the dependency of radiobiological effects on the body weight of animals has been estimated. Similarity conditions of dose accumulation upon chronic irradiation of animals and man have been obtained on the basis of Blair's and Davidson's equations for an effective dose of a single exposure. Service factor and coefficients of intensity and duration of irradiation of various animals have been calculated, simulating professional irradiation with 5 rad/a within 20 years

Adaptation dynamics of laboratory populations of Drosophila Melanogaster to low dose chronic ionizing irradiation

International Nuclear Information System (INIS)

Zajnullin, V.G.; Yushkova, E.A.

2008-01-01

In genetically non-uniform populations D. melanogaster in conditions of a chronic irradiation in a doze 10-11 about sGy/generation dynamics parameters of populations was investigated. It is established, that number of individuals in irradiated populations is lower, than in control. It is revealed, that viability of populations undergone to a chronic irradiation depends on their genotype. The gradual increase in fruitfulness, viability of individuals and decrease in a level of lethal mutations in a number of generations after of an irradiation in low doses is caused by adaptable opportunities of populations. (authors)

Effects of low-level chronic irradiation on aquatic organisms

Energy Technology Data Exchange (ETDEWEB)

Etoh, H. (National Inst. of Radiological Sciences, Chiba (Japan))

1980-10-01

Effects of continual irradiation for a long term on fishes and aquatic invertebrates were outlined. Effects of low-level chronic irradiation on aquatic organisms were less than acute effects induced when the same dose was irradiated once. The radiosensitivity of the genital organ to continual irradiation was high. There was a difference in radiosensitivity of the genital organ between female and male, and the degree of the difference varied according to kinds of animals. In an experiment on continual irradiation of adult killifishes, ova recovered from radiation damage, but spermatozoa did not recover. Incubation rates of eggs obtained from aquatic organisms which lived in water where radioactive sewage flowed into decreased significantly, and the frequency of reverse position of salivary gland chromosomes which were peculiar to exposed organisms increased in larvae of Chironomus tentans.

Enlargement of induced variations by combined method of chronic irradiations with callus culture in sugarcane

International Nuclear Information System (INIS)

Nagatomi, Shigeki

1993-01-01

The present study was conducted to elucidate the effects of gamma ray irradiation and callus culture upon induced variation of the regeneratives. The populations regenerated from young leaf tissue of chronic irradiated plnats grown under a gamma field receiving a total dose of 300 and 100 Gy, showed rather wider variation on quantitative characters than plants from populations of the non-irradiated. This variation extended in both negative and positive directions. Analysis of variance also revealed that variation and heritability in broad sense of most agronomic characters increased significantly among the subclones as the irradiation done rose. Principal component analysis also indicated that the subclones from the irradiated population were more variable than the non-irradiated. Such variation with higher heritability could be transmitted to the following generations by clonal propagation and utilized as genetic sources in mutation breeding. The combined method with chronic irradiation followed by tissue culture is evaluated as an effective method of widening mutation spectrum and increasing mutation frequency in regenerated plants. In addition, this method is valid to improve any crop species which can regenerate plants through callus culture. (author)

Melanin is Effective Radioprotector against Chronic Irradiation and Low Radiation Doses

International Nuclear Information System (INIS)

Mosse, I.; Plotnikova, S.; Kostrova, L.; Molophei, V.; Dubovic, B.

2001-01-01

Full text: Earlier we found pigment melanin ability to reduce significantly genetic consequences of acute irradiation in animals (drosophila, mice) and cultured human cells and to decrease strongly 'genetic load' accumulated in irradiated populations. The influence of melanin isolated from human hair on genetic effects of chronic irradiation in mice has been investigated. Melanin suspension or distilled water were injected every day into stomach of animals during 1-3 Gy g-irradiation with dose rate 0.007Gy/h. Levels of reciprocal translocations in germ cells were analysed cytologically. Melanin influence on genetic effect of chronic irradiation was shown to be even more effective than that of acute one. Radioadaptive response was used in order to study melanin influence on low radiation dose effect. We have demonstrated adaptive response in mice germ cells and bone marrow cells frequency of chromosomal aberrations in these cells after 0.2+1.5 Gy was about half as much as 1.7 Gy effect. Melanin injection 2 hours before the conditioning dose of 0.2 Gy resulted in the same mutation level as before 1.7 Gy adaptive response was not found. If melanin was applied between the first and second doses, both adaptive reaction and protection led to 4-fold decrease in aberration level. Thus melanin is able to remove completely low radiation dose effect. Complete toxicological tests have been conducted. The pigment melanin is not toxic and does not possess a mutagenic, teratogenic or carcinogenic activity. Melanin could be used in medicine for people protection against genetic consequences of long-term irradiation at low doses. (author)

A change in radioresistance of barley under chronic irradiation

International Nuclear Information System (INIS)

Kal'chenko, V.A.; Shevchenko, V.A.; Fedotov, I.S.

1981-01-01

Mutation process and radioresistance of barley growing in an area with increased radiation background (beta radiation doss -0.6 R/day) have been analyzed. Experimental material is given with 250 kindred families where aberration level of chromosomes was analyzed in mitosis and meiosis during 4 years. It is shown that the first generations (M 1 -M 2 ) in experimental material demonstrate an increased level of structural mutations of chromosomes, while the subsequent generations (M 3 -M 4 ) demonstrate the level reduced to control. A higher radioresistance is observed in M 5 plants of chronically irradiated version as compared to nonirradiated version. It is suggested that increase in radioresistance results from the stimulation of repair systems with low doses of chronic irradiation as well as from the selection of a more radioresistant forms out of the population [ru

Relative genetic radiosensitivity of mammalian species to acute and chronic gamma irradiation

International Nuclear Information System (INIS)

Vyglenov, A.K.

1985-01-01

Comparative studies of genetic radiosensitivity were carried out in a group of mammals - mouse, rat, Syrian hamster, and rabbit - in an effort to improve the predictive value of estimates derived from the experimental model in extrapolating from animals to man. Investigations concerned the ratio between principal quadrivalent (ring-tochain) configurations translating reciprocal translocation induction in premeiotic spermatogenic cells from the above mammals. Frequencies of univalents and of fragments recorded in diakinesis-metaphase 1 spermatocytes showed neither dose nor dose-rate dependence but had species-specific characteristics. Yields of reciprocal translocations from spermatogonial irradiation were examined under acute and chronic exposure conditions. From the linear regression coefficients, genetic susceptibility was found to increase in the following sequences. With acute irradiation: hamster -4 reciprocal translocations per cell per cGy. For chronic gamma-radiation exposure conditions, a correction coefficient of 0.5 is recommended

Cytogenetic investigations of persons exposed to professional chronic low-dose irradiation

International Nuclear Information System (INIS)

Rangelov, V.; Mitev, L.; Petrunov, P.; Vesselinova, L.

2005-01-01

The problem of long term influence of low-doses occupational irradiation is connected with the real assessment of their consequences. The current cytogenetic investigations were done on persons working under occupational chronic external partial irradiation. Accumulated doses of external irradiation are surveyed. Data give ground for suggestion about the relationship between accumulated dose and chromosomal aberrations. The additional damage factors (diagnostic investigations, chemical substances, tobacco addict) have done the more significant influence upon aberrations appearance increasing

The effects of chronic low dose irradiation on drosophila melanogaster

International Nuclear Information System (INIS)

Zajnullin, V.G.; Moskalev, A.A.; Shaposhnikov, M.V.; Yuraneva, I.N.; Taskaev, A.I.

2001-01-01

It was investigated the influence of the chronic gamma-irradiation in the dose rate of 0.17 cGy/h on the rate of genetic variability and on the life-span in the laboratory strains of Drosophila melanogaster with genotypic distinguishes in mobile genetic elements and defects in the DNA repair processes. It is shown that the radiation-induced alteration of the traits under study depends from genotype of investigated strains. In the different strains we have observed an increase as well as a decrease of the mutation rate and life-span. Also it was established that irradiation leads to the frequencies of the GD-sterility and mutability of the snw and h(w+) in the P-M and H-E dysgenic crosses. The obtained results suggest that mobile genetic elements play an important role in the forming of genetic effects in response to low dose irradiation. (author)

Suprachiasmic and infundibular parts of the third cerebral ventricle of sheep following chronic irradiation

International Nuclear Information System (INIS)

Rajtova, V.; Stanikova, A.; Arendarcik, J.; Lustik, J.; Briancin, J.

1983-01-01

The suprachiasmic and infundibular regions of the ependyma of the third cerebral ventricle were studied in Merino sheep in the anoestral phase of their sexual cycle. Test ewes were irradiated in the gamma field with 60 Co for seven days with a total exposure to 6.7 Gy (700 R). After sacrificing the brains of the test and control ewes were perfused with 2% to 4% paraformaldehyde and the samples were placed in 3% glutaraldehyde in 0.2 M cacodyl buffer (the pH of.all solutions was 7.4 and temperature 4 degC). The samples were further treated by the methods after Murakami et al. and Kelly et al., which require no subsequent metallization. After dehydration in alcohol the samples were dried in a desiccator and under vacuum. For viewing and imaging the TESLA BS 300 scanning electron microscope at 14 kV was used. The microscopic study after chronic irradiation showed a reduction in cilia deposits and an increase in the nubers of characteristic specific formations which were not present in the control ewes, or were only present in small numbers. ''Open spaces'' of different size were left from the released nuclei and the cell contents of ependymal cells in the infundibulum region over the hypophysis. A weakening or total disappearance of ''blebbing phenomenon'' in the typical infundibular region of tanycytes can be observed after chronic irradiation. On the other hand, in the regions with less damaged tanycytes chronic irradiation caused local hypersecretion, as indicated by the multiplication of ''miniblebs''. (author)

[Study of genome instability using DNA fingerprinting of the offspring of male mice subjected to chronic low dose gamma irradiation].

Science.gov (United States)

Bezlepkin, V G; Vasil'eva, G V; Lomaeva, M G; Sirota, N P; Gaziev, A I

2000-01-01

By a polymerase chain reaction with an arbitrary primer (AP-PCR), the possibility of transmission of genome instability to somatic cells of the offspring (F1 generation) from male parents of mice exposed to chronic low-level gamma-radiation was studied. Male BALB/c mice 15 days after exposure to 10-50 cGy were mated with unirradiated females. Biopsies were taken from tale tips of two month-old offspring mice and DNA was isolated. The primer in the AP-PCR was a 20-mer oligonucleotide flanking the microsatellite locus Atp1b2 on chromosome 11 of the mouse. A comparative analysis of individual fingerprints of AP-PCR products on DNA-templates from the offspring of irradiated and unirradiated male mice revealed an increased variability of microsatellite-associated sequences in the genome of the offspring of the males exposed to 25 and 50 cGy. The DNA-fingerprints of the offspring of male mice exposed to chronic irradiation with the doses 10 and 25 cGy 15 days before fertilization (at the post-meiotic stage of spermatogenesis) showed an increased frequency of "non-parent bands". The results of the study point to the possibility of transmission to the offspring somatic cells of changes increasing genome instability from male parents exposed to chronic low-level radiation prior to fertilization.

Monitoring of gluconeogenesis in rats following chronic irradiation

Energy Technology Data Exchange (ETDEWEB)

Paulikova, E.; Sedlakova, A.; Praslicka, M. (Univerzita P.J. Safarika, Kosice (Czechoslovakia). Katedra Vseobecnej Biologie)

1984-01-01

A dose dependent cumulation of liver glycogen with the maximum on the day 120 was observed as was an increased incorporation of /sup 14/C-alanine in liver glycogen (statistically nonsignificant changes). The contribution of /sup 14/C-acetate to gluconeogenesis was negligible. The results showed increased gluconeogenesis in rats following chronic gamma irradiation with small daily dose rates (0.0957 Gy).

Monitoring of gluconeogenesis in rats following chronic irradiation

International Nuclear Information System (INIS)

Paulikova, E.; Sedlakova, A.; Praslicka, M.

1984-01-01

A dose dependent cumulation of liver glycogen with the maximum on the day 120 was observed as was an increased incorporation of 14 C-alanine in liver glycogen (statistically nonsignificant changes). The contribution of 14 C-acetate to gluconeogenesis was negligible. The results showed increased gluconeogenesis in rats following chronic gamma irradiation with small daily dose rates (0.0957 Gy)

Effect of Acute and Chronic Gamma Irradiation on in vitro Growth of Stevia rebaudiana Bertoni

International Nuclear Information System (INIS)

Norazlina Noordin; Rusli Ibrahim; Nur Hidayah Mohd Sajahan; Salmah Moosa; Sobri Hussein

2014-01-01

Stevia rebaudiana Bertoni is a perennial herb that belongs to the family of Asteraceae. It is a natural sweetener plant known as sweet leaf, which is estimated to be 300 times sweeter than cane sugar. In this study, micropropagation and in vitro mutagenesis of this natural herb was successfully conducted. It was found that shoot tips on MS medium supplemented with 1 mg/l Kinetin showed the highest shoot induction and multiplication after 3 weeks of culture. Radiosensitivity test was conducted to identify the LD50 for in vitro stevia shoots and to select effective doses to be used for the in vitro mutagenesis. Shoot tips were irradiated with acute and chronic gamma radiation at 0, 10.00, 20.00, 30.00, 40.00, 60.00, and 80.00 Gy. At 60 Gy and 80 Gy, the shoot tips demonstrated 0 % survival, all were killed. LD 50 for stevia (the dose that killed 50 % of the irradiated explants) was at 29 Gy. In this study, LD 50 for the stevia (the dose that killed 50 % of the irradiated explants) was at 29 Gy for acute irradiation and was at 45 Gy for chronic irradiation. The effective doses were selected at 10, 20 and 30 Gy. These three selected doses were applied for the in vitro mutagenesis of the stevia shoots. (author)

Comparative radioresistance of chronically irradiated populations of Arabidopsis thaliana (L.) Heynh

International Nuclear Information System (INIS)

Dineva, S.B.; Abramov, V.I.; Shevchenko, V.A.

1994-01-01

The radioresistance of seeds of populations of Arabidopsis thaliana (L.) Heynh. growing for 5 years in the regions with different levels of radioactive contamination within 30 km zone of Chernobyl NPP was studied. The analysis of comparative radiosensitivity by root test was performed. It has been shown that plants from arabidopsis population growing under chronic irradiation did not gain an increased radioresistance. The data obtained shown that they are more radiosensitive

Lipid metabolism in rat tissues exposed to the chronic effects of γ-irradiation and ubiquinone Q9

International Nuclear Information System (INIS)

Novoselova, E.G.

1992-01-01

Chronic γ-irradiation of rats with the daily dose of 0.129 Gy activates the synthesis of various classes of lipids in the thymus, spleen and bone marrow cells and induces lipid accumulation in these tissues. Feeding of rats with the antioxidant, ubiquinone Q-9, under conditions of chronic irradiation causes a considerable normalization of lipogenesis and levels of the lipid concentration in the tissues of animals irradiated with the dose of 20 Gy

Paramecium tetraurelia growth stimulation under low-level chronic irradiation: investigations on a possible mechanism

International Nuclear Information System (INIS)

Croute, F.; Soleilhavoup, J.P.; Vidal, S.; Dupouy, D.; Planel, H.

1982-01-01

Experiments were carried out to demonstrate the effects of low-level chronic irradiation on Paramecium tetraurelia proliferation. Biological effects were strongly dependent on the bacterial density of culture medium and more exactly on the catalase content of the medium. Significant growth stimulation was found under 60 Co chronic irradiation at a dose rate of 2 rad/year when paramecia were grown in a medium containing a high bacterial concentration (2.5 x 10 2 cells/m) or supplemented with catalase (300 U/ml). In a medium with a low bacterial density (1 x 10 6 cell/ml) or supplemented with a catalase activity inhibitor, growth simulation was preceded by a transitory inhibiting effect which could be correlated with extracellularly radioproduced H 2 O 2 . H 2 O 2 addition appeared to be able to simulate the biological effects of chronic irradiation. A possible mechanism is discussed.We proposed that the stimulating effects were the result of intracellular enzymatic scavenging of radioproduced H 2 O 2

Chronic irradiation as an ecological factor affecting genetic population structure

International Nuclear Information System (INIS)

Kal'chenko, V.A.; Kalabushkin, B.A.; Rubanovich, A.V.

1991-01-01

Genetic structure of two Centaurea scabiosa L. populations was studied by frequency distribution of leucine aminopeptidase (LAP) locus genotypes. The experimental population has been growing under conditions of chronic irradiation, with the dose per generation amounting to 1.2 to 25.5 Gy. In it, mutational variants are observed with a frequency of 5.4.10(-3)-4.5.10(-2) per generation (as compared to control population frequency at 5.4.10(-4)). Indexes for heterozygosity, mean number of genotypes, and effective number of alleles were higher in the experimental population. Segregation analysis revealed no differences in viability in the control population, and all genotypic combinations were found to be nearly neutral. In the experimental population, however, significant differences in relative viability of the genotypes were disclosed. The relative viability of heterozygotes for mutant allele C' was nearly maximum, while heterozygotes for other mutant alleles showed minimum viability. We reach the conclusion that the differences in genetic structure of the populations under investigation can be explained by the chronic irradiation factor that brought out differences in adaptability of both normal and mutant genotypes. The suggestion is that intra-locus interactions of the C' allele with normal alleles determine plant resistance to a wide range of unfavorable environmental conditions

Changing patterns of radiosensitivity of hematopoietic progenitors from chronically irradiated dogs prone either to aplastic anemia or to myeloproliferative disease

International Nuclear Information System (INIS)

Seed, T.M.; Kaspar, L.V.

1990-01-01

Hematopoietic patterns have been assessed in chronic 60 Co gamma irradiated dogs during preclinical phases of evolving aplastic anemia (AA) or myeloproliferative disease (MPD), principally myeloid leukemia. The results support the concept that acquired radioresistance of vital granulocyte/monocyte lineage-committed hematopoietic progenitors is temporally, perhaps causally, linked to the processes mediating hematopoietic recovery and accommodation under chronic irradiation, and in turn to preclinical events of evolving MPD. In addition, the marked differential responses of progenitors to gamma and neutron irradiation in vitro might suggest differences in the nature of cellular lesions elicited by chronic gamma irradiation, in vivo. (author)

Changing patterns of radiosensitivity of hematopoietic progenitors from chronically irradiated dogs prone either to aplastic anemia or to myeloproliferative disease

Energy Technology Data Exchange (ETDEWEB)

Seed, T.M.; Kaspar, L.V. (Oak Ridge National Lab., TN (USA))

1990-01-01

Hematopoietic patterns have been assessed in chronic {sup 60}Co gamma irradiated dogs during preclinical phases of evolving aplastic anemia (AA) or myeloproliferative disease (MPD), principally myeloid leukemia. The results support the concept that acquired radioresistance of vital granulocyte/monocyte lineage-committed hematopoietic progenitors is temporally, perhaps causally, linked to the processes mediating hematopoietic recovery and accommodation under chronic irradiation, and in turn to preclinical events of evolving MPD. In addition, the marked differential responses of progenitors to gamma and neutron irradiation in vitro might suggest differences in the nature of cellular lesions elicited by chronic gamma irradiation, in vivo. (author).

Effect of chronic irradiation combined with other damaging factors on some morphological systems of mice

International Nuclear Information System (INIS)

Ponomareva, T.V.; Merkushev, G.N.; Pil'shchuk, E.M.; Bikkulov, R.I.

1978-01-01

A model experiment on mice is carried out to study morphofunctional changes that occur in mammals chronically exposed to radiation in doses close to those in occupational exposures of a man. Mice have been exposed to gamma-radiation at dose rates of 6, 16, 40, 120, and 300 mr/day from the time of birth onward throughout lifetime. It is concluded that, where a chronic purulent infection is present, chronic irradiation at the above dose rates, with the exception of 6 mr/day, accelerates the onset of irreversible pathologic changes, in particular of amyloidosis, in immunocompetent organs

Rat behaviour reactions and brain synaptic membrane lipids under the chronical gamma-irradiation

International Nuclear Information System (INIS)

Semenova, T.P.; Medvinskaya, N.I.; Potekhina, N.I.; Kolomijtseva, I.K.

1997-01-01

The effects of low level chronical ionising irradiation (12.9 cGy/day on the sensory attention to the stimuli of different modalities (somatosensor, visual, odor) of Wistar rats were studied. Analysis of animals behaviour was made after they had received the different doses of irradiation: 4, 6, 8, 10, 15 and 20 Gy. It was founded, that the attention and exploratory activity of rats is significantly decreased up to 20-30% after 4-6 Gy. The irradiation doses 8 Gy did not change animal behaviour as compared to control animals, but doses 10, 15 and 20 Gy decreased the exploratory activity as well as sensory attention of rats to 3-5-times as compared to previous dose. Such a wave-like way of behaviour reflects the functioning of an adaptive mechanism. Biochemical data indicated that after 5 months of the irradiation (dose 20 Gy) the level of phospholipids, lysophosphatidylcholine, phosphatdylethanolamine, phosphatidylcholine, cholesterol were decreased

Use of chronic irradiation in formation of new rape genotypes

International Nuclear Information System (INIS)

Fabry, A.; Zukalova, H.; Cerny, J.; Folk, A.

1980-01-01

Chronic irradiation of hybrid plants of F 1 generation obtained by crossing the Canadian rape without erucic acid with European winter varieties containg this acid, doubled the frequency of winter genotypes and increased significantly the frequency of required recombinations of winter character and absence of erucic acid in F 2 -M 2 . Genotypes with a more favourable ratio between linoleic and linolenic acids were obtained in the irradiated F 2 -M 2 population. The obtained radio-induced mutants are used for the production of new varieties of winter rape without erucic acid at the Slapy Breeding Station. (author)

Efficacy of total lymphoid irradiation for chronic allograft rejection following double lung transplantation

International Nuclear Information System (INIS)

Diamond, David A.; Michalski, Jeff M.; Trulock, Elbert M.; Lynch, John P.

1997-01-01

Purpose: The purpose of this study was to assess the safety and efficacy of total lymphoid irradiation in a series of patients experiencing chronic rejection following bilateral lung transplantation. Patients and Materials: Eleven patients (10 males, 1 female) received total lymphoid irradiation for chronic allograft rejection (bronchiolitis obliterans syndrome) refractory to conventional treatment modalities. Treatment was delivered between March, 1995, and September, 1996. Mean patient age was 33 years (range 15-51). Indications for transplantation included cystic fibrosis (7 patients), alpha 1 anti-trypsin deficiency (2 patients), primary pulmonary hypertension (1 patient), and emphysema (1 patient). Radiation therapy was prescribed as 800 cGy delivered in ten 80 cGy fractions, 2 fractions per week, via AP/PA mantle and inverted-Y fields. Radiation was withheld for total wbc count 3 , absolute neutrophil count 3 , or platelets 3 . Serial pre- and post-radiation therapy pulmonary function values, complete blood counts, and immunosuppressive augmentation requirements (use of methylprednisolone, azathioprine, mycophenolate mofetil, OKT3, and FK506) were monitored. Results: In the 3 months preceding total lymphoid irradiation, the average decrease in FEV 1 was 34% (range 0-75%) and the median number of immunosuppression augmentations was 3 (range 0-5). At initiation of radiation therapy, the average FEV 1 was 1.4 liters (range 0.77-2.28). Only (4(11)) patients completed all 10 treatment fractions. Reasons for discontinuation included unabated rejection (4 patients), worsening pulmonary infection (2 patients), and persistent thrombocytopenia (1 patient). No treatment course was discontinued because of persistent neutropenia or leukopenia. Seven of the 11 patients failed within 8 weeks of treatment cessation. One patient had unabated rejection and received bilateral living related donor transplants. He is alive and well. Six patients died. Two of these deaths were due

Cytogenetic analysis of the effect of chronic irradiation on natural Vicia Cracca L. populations

International Nuclear Information System (INIS)

Bondar', L.M.; Popova, O.N.; AN SSSR, Syktyvkar

1989-01-01

The study of microsporogenesis in Vicia cracca L. from chronically irradiated natural populations has demonstrated an increased number of wholly or partially sterile buds and reduced and damaged anthers. Both the number and the spectrum of chromosome and cell pathology increasing radiation dose, the exposed plants exhibiting meiosis disturbances that are not found in the controls

The influence of chronic gamma-irradiation on the structure of follicular system of animal ovaries

International Nuclear Information System (INIS)

Banetskaya, N.B.; Amvros'ev, A.P.

1994-01-01

The influence of a chronic gamma - irradiation in a low doze (0.5 Gy, capacity of a doze 1.8 * 10 -7 Gy / s) on follicular apparatus of ovary of young white female rats was investigated. Quantity of the follicles on the all stages of development was calculated. It is detected that the chronic irradiation by a low doze of young rats causes to morphological changes in ovaries. At once after an irradiation is marked the ovulation stimulation, it can be connected with change of the hormone balance in a body of the animals. In one month after an irradiation quantity of follicles on the all stages of development is reduced and number of atretic bodies is increased. The similar disorders can be connected as with direct influence of ionizing radiation on oocytes and them follicular cells, and also with action through change in bodies of the endocrine system. 14 refs., 2 tabs

Gamma greenhouse for chronic irradiation in plant mutation breeding

International Nuclear Information System (INIS)

Azhar Mohamad; Rusli Ibrahim; Sobri Hussein

2009-01-01

The gamma greenhouse makes use of chronic irradiation from a 137 Cs source (double encapsulated 800 Ci caesium-137 pencil) producing a low dose rate, which is considered to be more effective in recovering and producing useful mutants in comparison to acute irradiation. The irradiation facility comprises an open topped irradiation area 30 m in diameter, protected by a partial concrete wall with entry maze and site topography. For safety, the facility is protected by a sophisticated interlock system, which only allows the source to be exposed when all the prerequisite safety conditions are met, and automatically returns the source to the safe storage position if any safety device is compromised. The main irradiation area is further protected by a 300 m diameter exclusion zone that is also protected by the safety interlock circuit. The facility can accommodate a wide range of plant materials such as seeds, seedlings in pots, cuttings, callus, somatic embryos and suspension cell cultures. Plant samples will be exposed to low dose gamma radiation over long periods of time (hours, weeks, months), depending on their nature and sensitivity. There was evidence whereby exposure of tissue culture materials to continuous low dose gamma irradiation resulting in considerably elevated somaclonal variation frequency without negative effects on culture response. It is not surprising that in vitro culture generating somaclonal variation together with in vitro mutagenesis inducing mutation lead to a higher variation frequency due to possible addition of mutagenic effect by in vitro mutagenesis to somaclonal variability arising from in vitro culture as well as the interaction between them. (Author)

Dose-response relations for dicentric yields in G0 lymphocytes of man and crab-eating monkey following acute and chronic γ-irradiations

International Nuclear Information System (INIS)

Takahashi, E.; Hirai, M.; Tobari, I.; Nakai, S.A.

1979-01-01

A comparison has been made of dicentric yields in G 0 lymphocytes between man and crab-eating monkey, Macaca fascicularis, after acute and chronic γ-irradiations. With acute irradiation (49.6 rad/min) there was no significant difference between them, but for the chronic irradiation (17.1 rad/h) a significant difference was observed between the species. When the dose-response relations were fitted to the linear-quadratic model (Y = αD + βD 2 ), the species-difference observed for chronic irradiation was almost entirely due to change in the value of β. In addition, after chronic irradiation the β-value for monkey was almost negligible, but that for man was significant. Post-irradiation incubation experiment showed that cells with dicentrics were partly eliminated during the course of chronic irradiation, because there were appreciable reductions of dicentric yields (ca. 25% for both man and monkey at 400 rad) together with mitotic indices (ca. 30% and 60% for man and monkey, respectively, at 400 rad). Accordingly, it would be reasonable to postulate that G 0 repair for dicentrics other than selection mechanism must play a major role in the effects of low dose rate. It can be further suggested that G 0 -repair capacity for chromosal damages leading to dicentrics may be different among different primate species. (Auth.)

Effect of Chronic Gamma Irradiation on Kenaf (Hibiscus cannabinus. L) Variety V36

International Nuclear Information System (INIS)

Mohd Zulmadi Sani; Faiz Ahmad; Mustapha Akil; Zaiton Ahmad; Affrida Abu Hassan; Abdul Rahim Harun

2016-01-01

Kenaf (Hibiscus cannabinus) is originated from Africa and used in making various products such as animal food pallet, clothes, particle board, bio-plastics, paper and many other fibre related products. Due to its commercial value in various industries, research has been carried out to obtain kenaf with improved traits. Mutation breeding using ionizing radiation has been used widely and proven to be effective as an alternative method in plant improvement. In this study, chronic gamma irradiation on kenaf (Hibiscus cannabinus. L) Variety V36 was carried out at Gamma Greenhouse (GGH) facility at Malaysia Nuclear Agency. Kenaf seeds were planted in pots at the shade house and transferred to GGH after 7 days. These seedlings were subjected to various dose rates of 0.3 Gy/ hour, 0.17 Gy/ hour, 0.11 Gy /hour, 0.05 Gy/ hour, 0.03 Gy/ hour, 0.02 Gy/ hour, and 0 Gy/ hour (control). Plant survival and morphological data such as plant height and stem girth, were observed. From the result obtain, at accumulated dose of 230 Gy (Ring 4), plant showed the highest average plant height, stem girth and highest morphological changes. The finding of this study is useful in determining the most suitable dose rate for chronic gamma irradiation in the future. (author)

Pathomorphologic aftereffects of chronic irradiation with γ-neutron source incorporated in the abdominal cavity (communication 2)

International Nuclear Information System (INIS)

Ivanov, A.E.; Vasilenko, V.T.; Kiselev, Yu.M.; Mosidze, T.G.; Krylova, A.I.; Suskova, V.S.

1992-01-01

The results were presented of radiometric and morphological studies of the viscera of dogs and sheep who lived 5 to 7 years with the Hertz-IR type γ-neutron standard radiation sources, implanted in the abdominal cavity. The most coarse dystrophic and sclerotic changes were found in the visceral sites adjacent to the radiation source or near it. It was suggested that spermatogenesis disorders resulting from chronic low-dose irradiation were due to not only the immediate action of ionizing radiation, but to total disorders of the trophicity of irradiated body as well

Response change in winter-wheat types to the pathogen complex under chronic gamma-irradiation

International Nuclear Information System (INIS)

Budanov, V.E.; Lysenkov, V.I.; Shcherbakov, V.K.

1975-01-01

Disease reactions in plants that have been gamma-irradiated are discussed. Damage to different types of soft winter wheat, due to pathogenic fungi, is evaluated. The Mironovski Jubilee variety showed high resistance to the leaf form of powdery mildew, along with the opposite phenomenon of a high susceptibility to the stem form of this disease. Chronic gamma irradiation of plants of this variety increased the susceptibility to this disease

Specific features of the hemorrhagic syndrome manifestation under chronic, prolonged and acute irradiation

International Nuclear Information System (INIS)

Arlashchenko, N.I.; Gorlov, V.G.; Maksimova, E.N.

1978-01-01

To make the hemorrhagic syndrome manifest itself, two phenomena are necessary to coincide in time, they are: a fall in the elasticity of the vascular wall and reduction in the amount of thrombocytes in blood. Depending upon the radiation dose, the vascular wall and the thrombocytic function may be either simultaneously impaired after acute exposure) or dissociated (following prolonged irradiation). Chronic irradiation at small (subliminal) dose rates fails to induce hemorrhagic disorders and death of rats caused by pathologic hemophilia

Total Body Irradiation for Allogeneic Bone Marrow Transplantation in Chronic Myelogenous Leukemia

Energy Technology Data Exchange (ETDEWEB)

Chung, Su Mi; Choi, Ihl Bohng; Kang, Ki Mun; Kim, In Ah; Shinn, Kyung Sub; Kim, Choon Choo; Kim, Dong Jip [Catholic University College of Medicine, Seoul (Korea, Republic of)

1994-06-15

Between July 1987 and December 1992, we treated 22 patients with chromic myelogenous leukemia; 14 in the chronic phase and 8 with more advanced disease. All were received with allogeneic bone marrow transplantation from HLA-identical sibling donors after a total body irradiation (TBI) cyclophosphamide conditioning regimen. Patients were non-randomly assigned to either 1200 cGy/6 fractions/3 days (6 patients) or 1320 cGy/8 fractions/4 days (16 patients) by dose of TBI. Of the 22 patients, 8 were prepared with cyclophosphamide alone, 14 were conditioned with additional adriamycin or daunorubicin. To prevent graft versus host disease, cyclosporine was given either alone or in conjunction with methotrexate. The actuarial survival and leukemic-free survival at four years were 58.5% and 41.2%, respectively, and the relapse rate was 36% among 22 patients. There was a statistically significant difference in survival between the patients in chronic phase and more advanced phase (76% vs 33%, p=0.05). The relapse rate of patients receiving splenectomy was higher than that of patients receiving splenic irradiation (50% vs 0%, p=0.04). We conclude that the probability of cure is highest if transplantation is performed while the patient remains in the chronic phase.

Total Body Irradiation for Allogeneic Bone Marrow Transplantation in Chronic Myelogenous Leukemia

International Nuclear Information System (INIS)

Chung, Su Mi; Choi, Ihl Bohng; Kang, Ki Mun; Kim, In Ah; Shinn, Kyung Sub; Kim, Choon Choo; Kim, Dong Jip

1994-01-01

Between July 1987 and December 1992, we treated 22 patients with chromic myelogenous leukemia; 14 in the chronic phase and 8 with more advanced disease. All were received with allogeneic bone marrow transplantation from HLA-identical sibling donors after a total body irradiation (TBI) cyclophosphamide conditioning regimen. Patients were non-randomly assigned to either 1200 cGy/6 fractions/3 days (6 patients) or 1320 cGy/8 fractions/4 days (16 patients) by dose of TBI. Of the 22 patients, 8 were prepared with cyclophosphamide alone, 14 were conditioned with additional adriamycin or daunorubicin. To prevent graft versus host disease, cyclosporine was given either alone or in conjunction with methotrexate. The actuarial survival and leukemic-free survival at four years were 58.5% and 41.2%, respectively, and the relapse rate was 36% among 22 patients. There was a statistically significant difference in survival between the patients in chronic phase and more advanced phase (76% vs 33%, p=0.05). The relapse rate of patients receiving splenectomy was higher than that of patients receiving splenic irradiation (50% vs 0%, p=0.04). We conclude that the probability of cure is highest if transplantation is performed while the patient remains in the chronic phase

Pathological consequences of chronic low daily dose gamma irradiation

Energy Technology Data Exchange (ETDEWEB)

Seed, T.M.; Miller, A.C.; Ramakrishnan, N. [Armed Forces Radiobiology Research Inst., Bethesda, MD (United States); Fritz, T.E.

2000-07-01

The quantitative relationships between the chronic radiation exposure parameters of dose-rate and total dose in relation to associated health risks was examined in dogs. At a dose-rate of 75, 128, and 263 mGy/d the incidence of acute lymphohematopoietic suppression (aplastic anemia) and associated septic complications was 73%, 87%, and 100%, respectively, and it increased in dose-dependent manner. By contrast, at dose-rates below 75 mGy/d, late cancers contributed significantly to the death of relatively long-lived animals, whose mean survival time was 1800 days. Myeloproliferative disease (MPD), mainly myeloid leukemia, was the dominant pathology seen at the higher daily dose-rates (18.8-75 mGy/d). When daily exposure was carried out continuously, the incidence of MPD was quite high. It should be noted that the induction radiation-induced MPD in this study was highly significant, because spontaneous MPD is exceedingly rare in the dog. However, when the daily dose-rate was reduced further or exposure was discontinued, the incidence of MPD declined significantly. At these lower dose-rates, solid tumors contributed heavily to the life-shortening effects of chronic irradiation. The induction and progression of these survival-compromising, late forms of pathology appeared to be driven by the degree of hematopoietic suppression that occurred early during the exposure phase, and in turn by the capacity of hematopoietic system to repair itself, recover, and to accommodate under chronic radiation stress. (K.H.)

Genomic instability in mutation induction on normal human fibroblasts irradiated with chronic low-dose radiations in heavy-ion radiation field

International Nuclear Information System (INIS)

Suzuki, M.; Tsuruoka, C.; Uchihori, Y.; Yasuda, H.; Fujitaka, K.

2003-01-01

Full text: At a time when manned space exploration is more a reality with the planned the International Space Station (ISS) underway, the potential exposure of crews in a spacecraft to chronic low-dose radiations in the field of low-flux galactic cosmic rays (GCR) and the subsequent biological effects have become one of the major concerns of space science. We have studied both in vitro life span and genomic instability in cellular effects in normal human skin fibroblasts irradiated with chronic low-dose radiations in heavy-ion radiation field. Cells were cultured in a CO2 incubator, which was set in the irradiation room for the biological study of heavy ions in the Heavy Ion Medical Accelerator in Chiba (HIMAC) at National Institute of Radiological Sciences (NIRS), and irradiated with scattered radiations produced from heavy ions. Absorbed dose measured using a thermoluminescence dosimeter (TLD) and a Si-semiconductor detector was to be around 1.4 mGy per day when operating the HIMAC machine for biological experiments. The total population doubling number (tPDN) of low-dose irradiated cells was significantly smaller (79-93%) than that of unirradiated cells. The results indicate that the life span of the cell population shortens by irradiating with low-dose scattered radiations in the heavy-ion irradiation field. Genomic instability in cellular responses was examined to measure either cell killing or mutation induction in low-dose accumulated cells after exposing to X-ray challenging doses. The results showed that there was no enhanced effect on cell killing between low-dose accumulated and unirradiated cells after exposing to defined challenging doses of 200kV X rays. On the contrary, the mutation frequency on hprt locus of low-dose accumulated cells was much higher than that of unirradiated cells. The results suggested that genomic instability was induced in mutagenesis by the chronic low-dose irradiations in heavy-ion radiation field

Chronic low-dose UVA irradiation induces local suppression of contact hypersensitivity, Langerhans cell depletion and suppressor cell activation in C3H/HeJ mice

International Nuclear Information System (INIS)

Bestak, Rosa; Halliday, G.M.

1996-01-01

It has previously been demonstrated that chronic low-dose solar-simulated UV radiation could induce both local and systemic immunosuppression as well as tolerance to a topically applied hapten. In this study, we have used a chronic low-dose UV-irradiation protocol to investigate the effects of UVA on the skin immune system of C3H/HeJ mice. Irradiation with UVA+B significantly suppressed the local and systemic primary contact hypersensitivity (CHS) response to the hapten 2,4,6-trinitrochlorobenzene. Furthermore, UVA+B reduced Langerhans cell (LC) and dendritic epidermal T cell (DETC) densities in chronically UV-irradiated mice. Ultraviolet A irradiation induced local, but not systemic, immunosuppression and reduced LC (32%) but not DETC from the epidermis compared to the shaved control animals. Treatment of mice with both UVA+B and UVA radiation also induced an impaired secondary CHS response, and this tolerance was transferable with spleen cells. (Author)

Effect of long-term chronic irradiation on gluconeogenesis in rats

International Nuclear Information System (INIS)

Paulikova, E.; Ahlers, I.; Praslicka, M.

1982-01-01

The incorporation of 14 C-acetate in glucose in the blood and in glycogen in the liver of rats chronically irradiated with gamma radiation was observed in vivo. During the period of observation the concentration of glycogen in the liver was increased. Increased acetate incorporation in glycogen was, however, observed only on day 30 of exposure. No changes in glucose concentration and acetate incorporation in glucose in the blood were observed. (M.D.)

Trypsin inhibitory activity in blood and cervical mucus of sheep following chronic gamma irradiation

International Nuclear Information System (INIS)

Molnarova, M.; Arendarcik, J.; Pastorova, B.

1982-01-01

The effect was investigated of chronic gamma irradiation for a period of 7 days to a total dose of 6.7 Gy. A decrease was found in TIA (trypsin inhibition activity) of blood plasma to 73.6% of the value prior to irradiation. The low-molecular fraction of TIA increased to 194.6%. Later in the experiment the values decreased. The TIA dynamics of the cervical mucus had the reverse character. The values increased; at the 16th day after irradiation they increased up to 392% of the initial values. A comparison with previous experiments shows that acute local irradiation with an almost three-fold dose of the hypothalamo-pituitary area and of the ovaries does not induce significant changes in the blood plasma TIA. (M.D.)

Hematopoietic tissue repair under chronic low daily dose irradiation

International Nuclear Information System (INIS)

Seed, T.M.

1994-01-01

The capacity of the hematopoietic system to repair constantly accruing cellular damage under chronic, low daily dose gamma irradiation is essential for the maintenance of a functional hematopoietic system, and, in turn, long term survival. In certain individuals, however, such continuous cycles of damage and repair provide an essential inductive environment for selected types of hematopathologies, e.g., myeloid leukemia (ML). We have been studying temporal and causal relationships between hematopoietic capacity, associated repair functions, and propensities for hematologic disease in canines under variable levels of chronic radiation stress (0.3-26.3 cGy d -1 ). Results indicate that the maximum exposure rate tolerated by the hematopoietic system is highly individual-specific and is based largely on the degree to which repair capacity, and, in turn, hematopoietic restoration, is augmented under chronic exposure. In low-tolerance individuals (prone to aplastic anemia, subgroup (1), the failure to augment basic m-pair functions seemingly results in a progressive accumulation of genetic and cellular damage within vital progenitorial marrow compartments particularly marked within erythroid compartments. that results in loss of reproductive capacity and ultimately in collapse of the hematopoietic system. The high-tolerance individuals (radioaccomodated and either prone- or not prone to ML, subgroup 2 ampersand 3 appear to minimize the accumulating damage effect of daily exposures by extending repair functions, which preserves reproductive integrity and fosters regenerative hematopoietic responses. As the strength of the regenerative response manifests the extent of repair augmentation, the relatively strong response of high- tolerance individuals progressing to patent ML suggests an insufficiency of repair quality rather than repair quantity

Chronic radiation exposure as an ecological factor: Hypermethylation and genetic differentiation in irradiated Scots pine populations

International Nuclear Information System (INIS)

Volkova, P.Yu.; Geras'kin, S.A.; Horemans, N.; Makarenko, E.S.; Saenen, E.; Duarte, G.T.; Nauts, R.; Bondarenko, V.S.; Jacobs, G.; Voorspoels, S.; Kudin, M.

2018-01-01

Genetic and epigenetic changes were investigated in chronically irradiated Scots pine (Pinus sylvestris L.) populations from territories that were heavily contaminated by radionuclides as result of the Chernobyl Nuclear Power Plant accident. In comparison to the reference site, the genetic diversity revealed by electrophoretic mobility of AFLPs was found to be significantly higher at the radioactively contaminated areas. In addition, the genome of pine trees was significantly hypermethylated at 4 of the 7 affected sites. - Highlights: • Chronic radiation exposure changes the genetic structure of plant populations. • Genomes of irradiated pines are hypermethylated. • The level of hypermethylation does not depend on annual dose. - These results indicate that even relatively low levels of chronic radiation exposure can influence on the genetic characteristics and the methylation status of natural pine populations and that it should be considered as an important ecological factor reflecting the anthropogenic impact on ecosystems.

High Levels of Dietary Supplement Vitamins A, C and E are Absorbed in the Small Intestine and Protect Nutrient Transport Against Chronic Gamma Irradiation

Science.gov (United States)

Azzam, Edouard I.; Ferraris, Ronaldo P.; Howell, Roger W.

2015-01-01

We examined nutrient transport in the intestines of mice exposed to chronic low-LET 137Cs gamma rays. The mice were whole-body irradiated for 3 days at dose rates of 0, 0.13 and 0.20 Gy/h, for total dose delivery of 0, 9.6 or 14.4 Gy, respectively. The mice were fed either a control diet or a diet supplemented with high levels of vitamins A, C and E. Our results showed that nutrient transport was perturbed by the chronic irradiation conditions. However, no apparent alteration of the macroscopic intestinal structures of the small intestine were observed up to day 10 after initiating irradiation. Jejunal fructose uptake measured in vitro was strongly affected by the chronic irradiation, whereas uptake of proline, carnosine and the bile acid taurocholate in the ileum was less affected. D-glucose transport did not appear to be inhibited significantly by either 9.6 or 14.4 Gy exposure. In the 14.4 Gy irradiated groups, the diet supplemented with high levels of vitamins A, C and E increased intestinal transport of fructose compared to the control diet (day 10; t test, P = 0.032), which correlated with elevated levels of vitamins A, C and E in the plasma and jejunal enterocytes. Our earlier studies with mice exposed acutely to 137Cs gamma rays demonstrated significant protection for transport of fructose, glucose, proline and carnosine. Taken together, these results suggest that high levels of vitamins A, C and E dietary supplements help preserve intestinal nutrient transport when intestines are irradiated chronically or acutely with low-LET gamma rays. PMID:26484399

The two strategies of plants to cope with chronic low dose irradiation

International Nuclear Information System (INIS)

Grodzinsky, D.M.

2005-01-01

Full text: The adaptive responses of plants to an increase in radioactivity of environment were established in radiobiological researches carried out in the Zone of the Chernobyl Nuclear Power Station. It has been shown that there are two types of adaptive strategies to the environment contaminated with radionuclides, namely ontogenetic and phylogenetic strategies. The ontogenetic adaptive strategy is attained by induction of DNA reparation. Increasing of the genetic variability in irradiated population performs the phylogenetic adaptive strategy. The mechanism of this strategy is associated with induction of genetic instability. Rise in the frequency of genetic recombination as well as heterozygosity is at the time essential components of phylogenetic adaptation. Ontogenetic and phylogenetic adaptation strategies are an important feature in coping of plants to the elevated chronic irradiation. Most likely plant cells as a stress signal into adaptive responses perceive the low doses of irradiation. (author)

Effects of a turmeric extract (Curcuma longa) on chronic ultraviolet B irradiation-induced skin damage in melanin-possessing hairless mice.

Science.gov (United States)

Sumiyoshi, Maho; Kimura, Yoshiyuki

2009-12-01

Turmeric (the rhizomes of Curcuma longa L., Zingiberacease) is widely used as a dietary pigment and spice, and has been traditionally used for the treatment of inflammation, skin wounds and hepatic disorders in Ayurvedic, Unani and Chinese medicine. Although the topical application or oral administration of turmeric is used to improve skin trouble, there is no evidence to support this effect. The aim of this study was to clarify whether turmeric prevents chronic ultraviolet B (UVB)-irradiated skin damage. We examined the effects of a turmeric extract on skin damage including changes in skin thickness and elasticity, pigmentation and wrinkling caused by long-term, low-dose ultraviolet B irradiation in melanin-possessing hairless mice. The extract (at 300 or 1000 mg/kg, twice daily) prevented an increase in skin thickness and a reduction in skin elasticity induced by chronic UVB exposure. It also prevented the formation of wrinkles and melanin (at 1000 mg/kg, twice daily) as well as increases in the diameter and length of skin blood vessels and in the expression of matrix metalloproteinase-2 (MMP-2). Prevention of UVB-induced skin aging by turmeric may be due to the inhibition of increases in MMP-2 expression caused by chronic irradiation.

The development and characterization of two types of chronic responses in irradiated mouse colon

International Nuclear Information System (INIS)

Followill, D.S.

1991-01-01

The hypothesis to be tested is that there are two distinct types of chronic responses in irradiated normal tissues, each resulting from damage to different cell populations in the tissue. The first is a sequela of chronic epithelial depletion in which the tissue's integrity cannot be maintained. The other response is due to cell loss in the connective tissue and/or vascular stroma, i.e. a 'primary' chronic response. The purpose of this study was to test the hypothesis in the murine colon by first, establishing a model of each chronic response and then, by determining whether the responses differed in timing of expression, histology, and expression of specific collagen types. The model of late damage used was colonic obstructions/strictures induced by a single dose of 27 Gy ('consequential' response) and two equal doses of 14.75 Gy (t = 10 days) ('primary' response). 'Consequential' lesions appeared as early as 5 weeks after 27 Gy and were characterized by a deep mucosal ulceration and a thickened fibrotic serosa containing excessive accumulations of collagen types I and III. Both types were commingled in the scar at the base of the ulcer. Fibroblasts were synthesizing pro-collagen types I and III mRNA 10 weeks prior to measurable increases in collagen. A significant decrease in the ratio of collagen types I:III was associated with the 'consequential' response at 4-5 months post-irradiation. The 'primary' response, on the other hand, did not appear until 40 weeks after the split dose even though the total dose delivered was approximately the same as that for the 'consequential' response. The 'primary' response was characterized with an intact mucosa and a thickened fibrotic submucosa which contained excessive amounts of only collagen type I. An increased number of fibroblasts were synthesizing pro-collagen type I mRNA nearly 25 weeks before collage type I levels were increased

Effects of chronic γ-irradiation on growth and survival of the Tohoku hynobiid salamander, Hynobius lichenatus

Energy Technology Data Exchange (ETDEWEB)

Fuma, Shoichi [Project for Environmental Dynamics and Radiation Effects, Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 Japan (Japan); Une, Yumi [Laboratory of Veterinary Pathology, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Sagamihara, Kanagawa 252-5201 (Japan); Ihara, Sadao [Hokkaido University of Education Kushiro Campus, 1-15-55 Shiroyama, Kushiro, Hokkaido 085-8580 Japan (Japan); Matsui, Kumi [Laboratory of Veterinary Physiology 1, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Sagamihara, Kanagawa 252-5201 (Japan); Kudo, Tomoo; Tokiwa, Toshihiro [Laboratory of Veterinary Pathology, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Sagamihara, Kanagawa 252-5201 (Japan); Kubota, Yoshihisa; Soeda, Haruhi [Project for Environmental Dynamics and Radiation Effects, Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 Japan (Japan); Ishikawa, Takahiro [Department of Technical Support and Development, Research, Development and Support Centre, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 Japan (Japan); Doi, Kazutaka [Project for Human Health, Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 Japan (Japan); Watanabe, Yoshito; Yoshida, Satoshi [Project for Environmental Dynamics and Radiation Effects, Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 Japan (Japan)

2014-09-15

The Tohoku hynobiid salamanders, Hynobius lichenatus, were chronically irradiated with γ-rays from embryonic to juvenile stages for 450 days. At 490 μGy h{sup −1} or lower dose rates, growth and survival were not significantly affected by irradiation, and any morphological aberrations and histological damages were not observed. At 4600 μGy h{sup −1}, growth was severely inhibited, and all the individuals died mostly at the juvenile stage. Chronic LD{sub 50} was 42 Gy as a total dose. In the liver, the number of hematopoietic cells was significantly reduced in the living juveniles, and these cells disappeared in the dead juveniles. In the spleen, mature lymphocytes were depleted in the living larvae, and almost all the heamtopoietic cells disappeared in the dead juveniles. These results suggest that this salamander died due to acute radiation syndrome, i.e., hematopoietic damage and subsequent sepsis caused by immune depression. The death would be also attributed to skin damage inducing infection. At 18,000 μGy h{sup −1}, morphological aberrations and severe growth inhibition were observed. All the individuals died at the larval stage due to a multiple organ failure. Chronic LD{sub 50} was 28 Gy as a total dose. Assuming that chronic LD{sub 50} was 42 Gy at lower dose rates than 4600 μGy h{sup −1}, a chronic median lethal dose rate could be estimated to be <340 μGy h{sup −1} for the whole life (>14 years). These results suggest that, among guidance dose rates, i.e., 4–400 μGy h{sup −1}, proposed by various organisations and research programmes for protection of amphibians and taxonomic groups or ecosystems including amphibians, most of them would protect this salamander but the highest value may not on the whole life scale. - Highlights: • The salamanders, Hynobius lichenatus, were chronically γ-irradiated for 450 days. • At 490 μGy h{sup −1} or lower, irradiation did not significantly affect growth and survival. • All the individuals

Biological effect of 60Co chronic irradiation on different development stage in common wheat (T. aestivum L.)

International Nuclear Information System (INIS)

Chen Youliang; Yang Pinghua; Xie Yukang

1991-01-01

Common wheats were irradiated in 60 Co garden at the stages of plant mature sporophyte, gametophyte and zygote-young embryo during the growing cycle. The biological effects of M 1 and M 2 was significantly related to the development stage of irradiation. When irradiated in the phase of zygote-young embryo, the emergence rate of M 2 was greatly influenced, but the irradiation had a little effect on the fertility of M 1 . The rate of seedling emergence in M 2 can be used for determining optimal dose of irradiation. The rate of micro-nuclei cells were low in the root tip cells of M 1 and seedling cells of M 2 . The M 1 is the major generation of irradiation injury. The irradiation injury of M 2 is minor. M 2 is the first generation for mutant selection. The generation gradation of chronic irradiation was discussed

The field-irradiator gamma study: Fourteen years of irradiation of the boreal forest

International Nuclear Information System (INIS)

Amiro, B.D.; Hawkins, J.L.; Laverock, M.J.; Sheppard, S.C.

1996-01-01

The Field-Irradiator Gamma (FIG) project is a long-term experiment on the response of boreal forest vegetation to chronic ionizing radiation. The forest was irradiated from 1973 to 1986 by a 370 TBq point source of 137 Cs placed at a height of 20 m. The forest is now in the recovery phase. The irradiated forest included several different community types, and each of these was affected differently by the radiation stress. New vegetation zones have now been created because of the selective tolerance to radiation along a gradient from background dose rates to a maximum of 65 mGy h -1 . One of the easiest measured indicators of the radiation stress has been photographic documentation of changes in forest communities over time. Measured changes in species composition and the decrease in tree canopy cover at dose rates >2 Gy h -1 have also helped quantify radiation effects. Indicators such as trends in annual growth rings have been less satisfactory. Our experiment suggests that there are no visible impacts at chronic dose rates less than 0.1 mGy h -1 and the threshold for effects likely is between 0.1 and 1 mGy h -1 . The experimental area has been preserved to allow measurements of long-term recovery of the site

Irradiation-induced hypoxia in bones and soft tissues: an experimental study

International Nuclear Information System (INIS)

Aitasalo, K.; Aro, H.

1986-01-01

Bone marrow and subcutaneous tissue pO 2 and pCO 2 were measured by means of implanted tissue tonometers in irradiated and nonirradiated rabbit hind limbs. The x-ray dose was 500, 1000, 1500, 2000, and 3000 rads. Tissue gas tensions were measured 1 day and 5 and 11 weeks after radiation. The pCO 2 changes in both tissues were slight but not statistically significant. The subcutaneous tissue pO 2 decreased during the acute phase of irradiation injury, and the effect of irradiation was dose-dependent. Later on, irradiation had no significant effects on the subcutaneous pO 2 , although light microscopy of the affected tissues showed fibrosis and blood vessel changes. The response of the subcutaneous pO 2 to systemic hyperoxia also increased in the chronic phase of irradiation injury as a sign of improved microcirculation. The bone marrow showed a high radiosensitivity. Irradiation caused a rapid dose-dependent decrease of the marrow pO 2 , and the marrow pO 2 decreased with time during the chronic phase of irradiation injury. The marrow pO 2 responded slowly and marginally to an increment of arterial pO 2 during breathing 100% oxygen as further evidence of impaired vascular pattern. The results showed that irradiation causes only a transient impairment of tissue perfusion in the skin. However, irradiation-damaged marrow was characterized by progressive tissue hypoxia

Revascularization of autogenous skin grafts placed on irradiated tissue

International Nuclear Information System (INIS)

Ueda, M.; Torii, S.; Kaneda, T.; Oka, T.

1982-01-01

Vascular changes in rat skin after irradiation were examined microangiographically. Revascularization of the skin transplanted during the chronic stage after irradiation was also studied. The results obtained through these examinations revealed higher vascular densities at the acute and the subacute stages, and low values at the chronic stages compared with those of the control. Furthermore, when the skin grafts were transplanted to the irradiated beds in the chronic stage, primary revascularization was scant, and the inhibited capillary proliferation in the recipient sites prevented new vessel penetration. This explains why grafts transplanted to previously irradiated beds fail to survive

Effects of Linear-Polarized Near-Infrared Light Irradiation on Chronic Pain

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Dong Huang

2012-01-01

Full Text Available In order to study the efficacy of linear-polarized near-infrared light irradiation (LPNIR on relieving chronic pain in conjunction with nerve block (NB or local block (LB, a 3-week prospective, randomized, double-blind, controlled study was conducted to evaluate the pre- and post-therapy pain intensity. Visual analogue scales (VASs were measured in all patients before and 6 months after therapy visiting the pain clinic during the period of August 2007 to January 2008. A total of 52 patients with either shoulder periarthritis or myofascial pain syndrome or lateral epicondylitis were randomly assigned into two groups by drawing lots. Patients in Group I were treated with NB or LB plus LPNIR; Group II patients, for their part, were treated with the same procedures as in Group I, but not using LPNIR. In both groups, the pain intensity (VAS score decreased significantly immediately after therapy as compared to therapy. There was a significant difference between the test and control groups immediately after therapy (P<0.05, while no effect 6 months later. No side effects were observed. It is concluded that LPNIR is an effective and safe modality to treat various chronic pains, which has synergic effects with NB or LB.

INTRACELLULAR COPPER ACCUMULATION ENHANCES THE GROWTH OF KINEOCOCCUS RADIOTOLERANS DURING CHRONIC IRRADIATION

International Nuclear Information System (INIS)

Bagwell, C; Charles Milliken, C

2007-01-01

The actinobacteria Kineococcus radiotolerans is highly resistant to ionizing radiation, desiccation, and oxidative stress; though the underlying biochemical mechanisms are unknown. The purpose of this study was to explore a possible linkage between the uptake of transition metals and extreme resistance to ionizing radiation and oxidative stress. The effects of 6 different divalent cationic metals on growth were examined in the absence of ionizing radiation. None of the metals tested were stimulatory, though cobalt was inhibitory to growth. In contrast, copper supplementation dramatically increased cell growth during chronic irradiation. K. radiotolerans exhibited specific uptake and intracellular accumulation of copper compared to only a weak response to both iron and manganese supplementation. Copper accumulation sensitized cells to hydrogen peroxide. Acute irradiation induced DNA damage was similar between the copper-loaded culture as the age-synchronized no copper control culture, though low molecular weight DNA was more persistent during post-irradiation recovery in the Cu-loaded culture. Still, the estimated times for genome restoration differed by only 1 hr between treatments. While we cannot discount the possibility that copper fulfills an unexpectedly important biochemical role in a radioactive environment; K. radiotolerans has a high capacity for intracellular copper sequestration, and presumably efficiently coordinated oxidative stress defenses and detoxification systems, which confers cross-protection from the damaging affects ionizing radiation

Genetic variability in chronic irradiated plant populations - Polymorphism and activity of antioxidant enzymes in chronic irradiated plant populations

Energy Technology Data Exchange (ETDEWEB)

Volkova, Polina Y.; Geras' kin, Stanislav A. [Russian Institute of Agricultural Radiology and Agroecology, 249030, Obninsk, Kievskoe shosse 109 km (Russian Federation)

2014-07-01

Introduction: The gene pool of natural population is constantly changing in order to provide the greatest fitness at this time. Ability of population to adapt to changing environmental conditions depends on genetic polymorphism of traits which are operates by selection. Chronic stress exposure can change amount or structure intra-population variability. Therefore, it is necessary to analyze the relationships between genetic polymorphism and stress factors, such as radiation exposure. This studies my assist in the development of new bio-indication methods. Materials and methods: Studying sites: Bryansk region is the most contaminated region of Russia as a result of Chernobyl accident. The initial activity by {sup 137}Cs on this territory reached 1 MBq/m{sup 2} above surface. Our study conducted in several districts of Bryansk region, which are characterized the most dose rate. Experimental sites similar to climate characteristics, stand of trees is homogeneous, pine trees take up a significant part of phytocenosis. Heavy metals content in soils and cones be within background. Dose rates vary from 0.14 to 130 mGy/year. Object: Pinus sylvestris L.,the dominant tree species in North European and Asian boreal forests. Scots pine has a long maturation period (18-20 month), which means that significant DNA damage may accumulate in the undifferentiated stem cells, even at low doses (or dose rates) during exposure to low concentrations of contaminants Isozyme analysis: We evaluated isozyme polymorphism of three antioxidant enzymes: superoxide dismutase, glutatione reductase and glutatione peroxidase. Analysis of enzymes activities: We chose key enzymes of antioxidant system for this experiment: superoxide dismutase, catalase and peroxidase. Results and conclusions: We estimated frequency of each allele in reference and experimental populations. based It was showed that frequency of rare alleles increase in chronic irradiated populations, i.e. increase the sampling variance

Hemopoiesis in monkeys in the course of and after total chronic irradiation

International Nuclear Information System (INIS)

Dzhikikidze, Eh.E.; Kosichenko, L.P.; Kuksova, M.I.

1992-01-01

Morphological and cytogenetic changes in blood-formation system of 2 types of monkeys were studied following chronic prolonged irradiation with low daily doses and considerable integral radiation load. Peak decrease of total leukocyte number of 1 mkl in both groups of monkeys at the expense of neutrophils was observed at integral dose of 10.78 Gy and was caused by decrease of index of neutrophil maturation. Violations of hereditary structures of bone marrow cells and peripheric blood lymphocytes were stable. Structural chromosomal aberrations remained in monkeys of both groups up to natural animal death. Quantitative and qualitative violations were less pronounced in macaca rhesus than in hamadryas baboons. This fact revealed high radiosensitivity of the baboons

The dynamics of immunologic reactions in rats affected by repeated external γ-irradiation and internal irradiation with radionuclides

International Nuclear Information System (INIS)

Shubik, V.M.; Livshits, R.E.

1975-01-01

Nonspecific factors of immunity and formation of autoantibodies in rats exposed to comparable doses of repeated external γ-irradiation and of internal irradiation with Cs 137 , Sr 90 and I 131 chronically administered to animals have been studied comparatively. No essential variations have been found in changes induced in the immunologic reactions by chronic external and even internal γ-irradiation. Certain peculiarities have been revealed in the character of changes in the immunologic reactions depending on biophysical properties of the radionuclides used in the experiments

Wholesomeness studies of irradiated salted and dried mackerel, using rats. Part of a coordinated programme on the wholesomeness of the process of food irradiation

International Nuclear Information System (INIS)

Anukarahanonta, T.

1978-04-01

Chronic toxicity of irradiated salted and dried mackerel was evaluated by multi-generation rat feeding studies. Salted and dried mackerel samples were irradiated with 200krad, ground and mixed with a standard laboratory animal diet at 28% w/w. Wistar strain rats were used in the experiment and were divided into 3 groups and fed their respective diets, i.e. stock ration, diet containing 28% of non-irradiated salted and dried mackerel and diet containing 28% of irradiated salted and dried mackerel. The test was carried out for 3 generations. The results revealed no significant difference that would impose a hazard attributable to consumption of irradiated salted and dried mackerel with respect to longevity, carcinogenicity, teratogenicity, dominant lethal, reproductive function and biophysiological function in animals tested

Selective brain responses to acute and chronic low-dose X-ray irradiation in males and females

International Nuclear Information System (INIS)

Silasi, Greg; Diaz-Heijtz, Rochellys; Besplug, Jill; Rodriguez-Juarez, Rocio; Titov, Viktor; Kolb, Bryan; Kovalchuk, Olga

2004-01-01

Radiation exposure is known to have profound effects on the brain, leading to precursor cell dysfunction and debilitating cognitive declines [Nat. Med. 8 (2002) 955]. Although a plethora of data exist on the effects of high radiation doses, the effects of low-dose irradiation, such as ones received during repetitive diagnostic and therapeutic exposures, are still under-investigated [Am. J. Otolaryngol. 23 (2002) 215; Proc. Natl. Acad. Sci. USA 97 (2000) 889; Curr. Opin. Neurol. 16 (2003) 129]. Furthermore, most studies of the biological effects of ionizing radiation have been performed using a single acute dose, while clinically and environmentally relevant exposures occur predominantly under chronic/repetitive conditions. Here, we have used a mouse model to compare the effects of chronic/repetitive and acute low-dose radiation (LDR) exposure (0.5 Gy) to ionizing radiation on the brain in vivo. We examined the LDR effects on p42/44 MAPK (ERK1/ERK2), CaMKII, and AKT signaling-the interconnected pathways that have been previously shown to be crucial for neuronal survival upon irradiation. We report perturbations in ERK1/2, AKT, and CREB upon acute and chronic/repetitive low-dose exposure in the hippocampus and frontal cortex of mice. These studies were paralleled by the analysis of radiation effects on neurogenesis and cellular proliferation. Repetitive exposure had a much more pronounced effect on cellular signaling and neurogenesis than acute exposure. These results suggest that studies of single acute exposures might be limited in terms of their predictive value. We also present the first evidence of sex differences in radiation-induced signaling in the hippocampus and frontal cortex. We show the role of estrogens in brain radiation responses and discuss the implications of the observed changes

Role of NO in adrenergic regulation of the heart after chronic gamma irradiation in 1 Gy dose

International Nuclear Information System (INIS)

Suvorova, T.A.; Lobanok, L.M.

2005-01-01

Chronic irradiation in 1 Gy dose significantly decreased adrenoreactivity of the heart. Modification of NO-mediated mechanisms plays an important role in radiation-induced changes of adrenergic control of heart functional activity and coronary flow. (authors)

Efficacy of total lymphoid irradiation for chronic allograft rejection following bilateral lung transplantation

International Nuclear Information System (INIS)

Diamond, David A.; Michalski, Jeff M.; Lynch, John P.; Trulock, Elbert P.

1998-01-01

Purpose: To assess the safety and efficacy of total lymphoid irradiation (TLI) in patients experiencing chronic rejection following bilateral lung transplantation (BLT). Patients and Materials: Eleven patients received TLI for chronic allograft rejection (bronchiolitis obliterans syndrome) refractory to conventional treatment modalities. Radiation therapy (RT) was prescribed as 8 Gy delivered in 10 0.8-Gy fractions, 2 fractions/week, via mantle, paraaortic, and inverted-Y fields. Serial pre- and post-RT pulmonary function values, complete blood counts, and immunosuppressive augmentation requirements [use of methylprednisolone, murine anti-human mature T-cell monoclonal antibody (OKT3), polyclonal antithymocyte globulin (ATG), and tacrolimus] were monitored. Results: In the 3 months preceding TLI, the average decrease in forced expiratory volume in 1 s (FEV 1 ) was 34% (range 0-75%) and the median number of immunosuppression augmentations was 3 (range 0-5). Only 4 of 11 patients completed all 10 TLI treatment fractions. Reasons for discontinuation included progressive pulmonary decline (four patients), worsening pulmonary infection (two patients), and persistent thrombocytopenia (one patient). Seven of the 11 patients failed within 8 weeks of treatment cessation. One patient had unabated rejection and received bilateral living related-donor transplants; he is alive and well. Six patients died. Two of these deaths were due to pulmonary infection from organisms isolated prior to the start of RT; the other four deaths were from progressive pulmonary decline. The four remaining patients had durable positive responses to TLI (mean follow-up of 47 weeks; range 24-72). Comparing the 3 months preceding RT to the 3 months following treatment, these four patients had improvements in average FEV 1 (40% decline vs. 1% improvement) and fewer median number of immunosuppressive augmentations (3.5 vs. 0). None of these patients has developed lymphoproliferative disease or has died

A Biomathematical Model of Lymphopoiesis and Its Application to Acute and Chronic Irradiation Assessment

Science.gov (United States)

Hu, Shaowen; Cucinotta, Francis A.

2010-01-01

After the events of September 11, 2001, there is an increasing concern of the occurrence of radiological terrorism that may result in significant casualties in densely populated areas. Much effort has been made to establish various biomarkers to rapidly assess radiation dose in mass-casualty and population-monitoring scenarios, which are demanded for effective medical management and treatment of the exposed victims. Among these the count of lymphocytes in peripheral blood and their depletion kinetics are the most important early indicators of the severity of the radiation injury. In this study, we examine a biomathematical model of lymphopoiesis which has been successfully utilized to simulate and interpret experimental data of acute and chronic irradiations on rodents [1]. With revised parameters for humans, we find this model can reproduce several sets of clinical lymphocyte data of accident victims over a wide range of absorbed doses. In addition, the absolute lymphocyte counts and the depletion rate constants calculated by this model also show good correlation with the Guskova formula and the Goans model, the two empirical tools which have been widely recognized for early estimation of the exposed dose after radiation accidents [2]. We also use the model to analyze the hematological data of the Techa River residents which were exposed to chronic low-dose irradiation during 1950-1956 [3]. This model can serve as a computational tool in radiation accident management, military operations involving nuclear warfare, radiation therapy, and space radiation risk assessment.

Dose-response relationship for translocation induction in spermatogonia of the crab-eating monkey (Macaca fascicularis) by chronic γ-ray-irradiation

International Nuclear Information System (INIS)

Tobari, Izuo; Matsuda, Yoichi; Xiaohung, Gu; Yamagiwa, Junju; Utsugi, Toyoko; Kitazume, Masayuki; Okamoto, Masanori

1988-01-01

The induction of reciprocal translocations in spermatogonia of the crab-eating monkey (Macaca fascicularis) by chronic γ-irradiation was examined. The frequencies of translocation per cell were 0.15% at 0.3 Gy, 0.27% at 1.0 Gy and 0.33% at 1.5 Gy. The dose-response relationship for translocation yield was a linear one with a regression coefficient (b) of 0.16 · 10 -2 . When the slope (b) of the regression line was compared with that at a high dose rate (0.25 Gy/min, b = 1.79 · 10 -2 , it was clear that the induction rate of translocations after chronic γ-irradiation was only about one-tenth of that after high-dose-rate irradiation. Thus, there was evidence for a pronounced dose-rate effect in the crab-eating monkey. (author). 27 refs.; 2 figs.; 3 tabs

Chronic low-dose γ-irradiation of Drosophila melanogaster larvae induces gene expression changes and enhances locomotive behavior

International Nuclear Information System (INIS)

Kim, Cha Soon; Lee, Byung Sub; Lee, In Kyung; Yang, Kwang Hee; Kim, Ji-Young; Nam, Seon Young; Seong, Ki Moon

2015-01-01

Although radiation effects have been extensively studied, the biological effects of low-dose radiation (LDR) are controversial. This study investigates LDR-induced alterations in locomotive behavior and gene expression profiles of Drosophila melanogaster. We measured locomotive behavior using larval pupation height and the rapid iterative negative geotaxis (RING) assay after exposure to 0.1 Gy γ-radiation (dose rate of 16.7 mGy/h). We also observed chronic LDR effects on development (pupation and eclosion rates) and longevity (life span). To identify chronic LDR effects on gene expression, we performed whole-genome expression analysis using gene-expression microarrays, and confirmed the results using quantitative real-time PCR. The pupation height of the LDR-treated group at the first larval instar was significantly higher (∼2-fold increase in PHI value, P < 0.05). The locomotive behavior of LDR-treated male flies (∼3 − 5 weeks of age) was significantly increased by 7.7%, 29% and 138%, respectively (P < 0.01), but pupation and eclosion rates and life spans were not significantly altered. Genome-wide expression analysis identified 344 genes that were differentially expressed in irradiated larvae compared with in control larvae. We identified several genes belonging to larval behavior functional groups such as locomotion (1.1%), oxidation reduction (8.0%), and genes involved in conventional functional groups modulated by irradiation such as defense response (4.9%), and sensory and perception (2.5%). Four candidate genes were confirmed as differentially expressed genes in irradiated larvae using qRT-PCR (>2-fold change). These data suggest that LDR stimulates locomotion-related genes, and these genes can be used as potential markers for LDR. (author)

On the development of neoplasma in dogs after chronic gamma-irradiation at a low dose rate

International Nuclear Information System (INIS)

Yakovleva, V.I.

1978-01-01

In order to estimate end effects of chronic prolonged gamma irradiation of dogs, an exposure of 80 animals to irradiation was terminated and they were followed up closely. Out of 80 animals 30 dogs (Ist series) were irradiated for 3 years and 50 dogs (2 series) for 6 years. The dogs were exposed to irradiation at doses of 21 to 190 rad per year. Out of the total number of animals 22 dogs died. Post-mortem examinations showed neoplasms in 13 animals (7 malignant and 12 benign neoplasms). The highest number of tumors developed in dogs of the 2 series (10 out of 11) one-two years after irradiation (6 malignant tumors-malignant pheochro--mocytoma of adrenals; malignant adenoma of the hypophysis: polymorphocellular sarcoma of the liver; leucomyosarcoma of the uterus; blader cancer; breast cancer; and 10 benign tumors-pancreatic adenoma; liver angioma; 2 papillary adenomas of the prostate; 3 renal adenomas; lipoma; polyps of the gall-bladder). Animals of the 1-st series displayed 3 neoplasms (1 malignant tumor-bladder tumor and 2 benign tumors-liver hepatoma and spleen angioma) 4-5 years after irradiation

Chronic irradiation effects on variability of maize and teosinte hybrids

International Nuclear Information System (INIS)

Cerny, J.; Ledecky, J.; Holas, J.

1981-01-01

The plants of the F 1 generation of the back-crosses of maize and teosinte, radiomutant RTZM no. 1 (B1 and B2), were exposed to chronic irradiation with doses from 1000 to 2000 R in a gamma field during their growing season. In the M 4 to F 4 progenies of the B1 hybrid, the correlation between lateness and a higher number of cobs, typical of teosinte, line RTZM no. 1, was significantly distorted. M 4 to F 4 generation lines, characterized by the required higher number of cobs and earliness and by a medium to good combining ability in silage mass yield, were selected from both back-cross hybrids. (author)

Assessment of testicular function after acute and chronic irradiation: Further evidence for an influence of late spermatids on Sertoli cell function in the adult rat

International Nuclear Information System (INIS)

Pineau, C.; Velez de la Calle, J.F.; Pinon-Lataillade, G.; Jegou, B.

1989-01-01

To study cell to cell communications within the testis of adult Sprague-Dawley rats, we used acute whole body neutron plus gamma-irradiation over 7-121 days postirradiation and chronic whole body gamma-irradiation over 14-84 days of irradiation and 7-86 days postirradiation. Neither irradiation protocol had an effect on the body weight of the animals. Neutron plus gamma-rays induced dramatic damages to spermatogonia, preleptotene spermatocytes, spermatozoa, and, to a lesser extent, pachytene spermatocytes. In contrast, gamma-rays induced a selective destruction of spermatogonia. Subsequently, in both experiments a maturation-depletion process led to a marked decrease in all germ cell types. A complete or near complete recovery of the different germ cell types and spermatozoa took place during the two postirradiation periods. Under both irradiation protocols Sertoli cells number was unchanged. Androgen-binding protein and FSH levels were normal in spite of the disappearance of most germ cells from spermatogonia to early spermatids. However, the decline of androgen-binding protein as well as the rise of FSH and their subsequent recovery were highly correlated to the number of late spermatids and spermatozoa. Moreover, it appeared that spermatocytes may also interfere with the production of inhibin (Exp B). With neither irradiation was Leydig cell function altered, except in Exp B in which elevated LH levels were temporarily observed. Correlation analysis suggested a relationship between preleptotene spermatocytes and Leydig cell function. In conclusion, this study establishes that chronic gamma-irradiation is particularly useful in the study of intratesticular paracrine regulation in vivo and provides further support to the concept that late spermatids play a major role in controlling some aspects of Sertoli cell function in the adult rat

Total lymphoid irradiation preceding bone marrow transplantation for chronic myeloid leukaemia

Energy Technology Data Exchange (ETDEWEB)

James, N D; Apperley, J F; Kam, K C; Mackinnon, S; Goldman, J M; Goolden, A W.G.; Sikora, K [Royal Postgraduate Medical School, London (UK)

1989-03-01

Between August 1985 and October 1987 35 patients with chronic myeloid leukaemia (CML) were treated by high dose chemotherapy, total body irradiation (TBI) (1000 or 1200 cGy, n=31) and total lymphoid irradiation (TLI) (800 or 600 cGy, n=35) preceding allogeneic bone marrow transplantation (BMT). Both TBI and TLI were given at 200 cGy/fraction. Twenty-three patients had HLA-identical sibling donors, nine patients had HLA-matched but unrelated donors, and three partially HLA-mismatched donors. Twenty-two patients received T-cell depleted marrow. TLI did not add greatly to the toxicity. Four patients had recurrent leukaemia before engraftment was evaluable. The other 31 patients engrafted and no graft failed. Twenty-two patients survive at a median time from transplant of 305 days (range 81-586 days). Fourteen have no evidence of disease; eight have or had only cytogenetic evidence of leukaemia. It is concluded that addition of TLI to pretransplant immunosuppression increases the probability of reliable engraftment in patients receiving T-cell depleted marrow. This is not associated with significantly increased toxicity. (author).

Total lymphoid irradiation preceding bone marrow transplantation for chronic myeloid leukaemia

International Nuclear Information System (INIS)

James, N.D.; Apperley, J.F.; Kam, K.C.; Mackinnon, S.; Goldman, J.M.; Goolden, A.W.G.; Sikora, K.

1989-01-01

Between August 1985 and October 1987 35 patients with chronic myeloid leukaemia (CML) were treated by high dose chemotherapy, total body irradiation (TBI) (1000 or 1200 cGy, n=31) and total lymphoid irradiation (TLI) (800 or 600 cGy, n=35) preceding allogeneic bone marrow transplantation (BMT). Both TBI and TLI were given at 200 cGy/fraction. Twenty-three patients had HLA-identical sibling donors, nine patients had HLA-matched but unrelated donors, and three partially HLA-mismatched donors. Twenty-two patients received T-cell depleted marrow. TLI did not add greatly to the toxicity. Four patients had recurrent leukaemia before engraftment was evaluable. The other 31 patients engrafted and no graft failed. Twenty-two patients survive at a median time from transplant of 305 days (range 81-586 days). Fourteen have no evidence of disease; eight have or had only cytogenetic evidence of leukaemia. It is concluded that addition of TLI to pretransplant immunosuppression increases the probability of reliable engraftment in patients receiving T-cell depleted marrow. This is not associated with significantly increased toxicity. (author)

Caffeine-induced hematological changes after whole-body irradiation in rat

Energy Technology Data Exchange (ETDEWEB)

Kim, Jin Kyu [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); Kim, Ji Hyang; Yoon Yong Dal [Hanyang University, Seoul (Korea, Republic of)

2004-07-01

Recent research indicated dietary antioxidants were useful radioprotectors to protect organisms against radiation-induced tissue lethality and other deleterious effects. Radioprotective effects of vitamin C have been demonstrated in certain cells and animals, which would result from scavenging free radicals. Moreover, the previous studies indicated that caffeine had been shown to potently act the radioprotector in irradiated mice. However it is not clear exactly about effects of caffeine treatments chronically after irradiation. So the present studies were designed to identify the hematological effect of caffeine treatments chronically one month after whole-body gamma irradiation.

Acute and chronic response of articular cartilage to Ho:YAG laser irradiation

Science.gov (United States)

Trauner, Kenneth B.; Nishioka, Norman S.; Flotte, Thomas J.; Patel, Dinesh K.

1992-06-01

A Ho:YAG laser system operating at a wavelength of 2.1 microns has recently been introduced for use in arthroscopic surgery. The acceptability of this new tool will be determined not only by its ability to resect tissue, but also by its long term effects on articular surfaces. In order to investigate these issues further, we performed two studies to evaluate the acute and chronic effects of the laser on cartilaginous tissue. We evaluated the acute, in vitro effects of 2.1 micron laser irradiation on articular and fibrocartilage. This included the measurement of ablation efficiency, ablation threshold and thermal damage in both meniscus and articular cartilage. To document the chronic effects on articular cartilage in vivo, we next performed a ten week healing study. Eight sheep weighing 30 - 40 kg underwent bilateral arthrotomy procedures. Multiple full thickness and partial thickness defects were created. Animals were sacrificed at 0, 2, 4, and 10 weeks. The healing study demonstrated: (1) no healing of full or partial thickness defects at 10 weeks with hyaline cartilage; (2) fibrocartilaginous granulation tissue filling full thickness defects at two and four weeks, but no longer evident at ten weeks; (3) chondrocyte necrosis extending to greater than 900 microns distal to ablation craters at four weeks with no evidence of repair at later dates; and (4) chondrocyte hyperplasia at the borders of the damage zone at two weeks but no longer evident at later sacrifice dates.

Compensative-rehabilitative responses of blood-forming tissue cells after chronic irradiation.; Kompensatorno-vosstanovitel`nye reaktsii kletok krovetvornoj tkani pri khronicheskom obluchenii.

Energy Technology Data Exchange (ETDEWEB)

Nosova, L I; Ryasenko, V I [Yinstitut Zoologyiyi, Natsyional` na Akademyiya Nauk Ukrayini, Kyiv (Ukraine); [Nauchno-Proizvodstvennoe Ob` ` edinenie Pripyat` , Chernobyl (Ukraine)

1994-12-31

The bone marrow eosinophils of minks and wild rats subjected to chronical irradiation are able of secreting a peroxidase system obtained by neutrophils. As a result heterophilic granulocytes appear in the peripheral blood. Intercellular transgranulation, emperiopolesis into megakaryocytes and eosinophils as peroxidase donors for neutrophils are regarded as cellular and subcellular adaptations in the mammalian bone marrow after irradiation.

Pre-irradiation at a low dose-rate blunted p53 response

International Nuclear Information System (INIS)

Takahashi, A.; Ohnishi, K.; Asakawa, I.; Tamamoto, T.; Yasumoto, J.; Yuki, K.; Ohnishi, T.; Tachibana, A.

2003-01-01

Full text: We have studied whether the p53-centered signal transduction pathway induced by acute radiation is interfered with chronic pre-irradiation at a low dose-rate in human cultured cells and whole body of mice. In squamous cell carcinoma cells, we found that a challenge irradiation with X-ray immediately after chronic irradiation resulted in lower levels of p53 than those observed after the challenge irradiation alone. In addition, the induction of p53-centered apoptosis and the accumulation of its related proteins after the challenge irradiation were strongly correlated with the above-mentioned phenomena. In mouse spleen, the induction of apoptosis and the accumulation of p53 and Bax were observed dose-dependently at 12 h after a challenge irradiation. In contrast, we found significant suppression of them induced by challenge irradiation at a high dose-rate when mice were pre-irradiated with chronic irradiation at a low dose-rate. These findings suggest that chronic pre-irradiation suppressed the p53 function through radiation-induced p53-dependent signal transduction processes. There are numerous papers about p53 functions in apoptosis, radiosensitivity, genomic instability and cancer incidence in cultured cells or animals. According to our data and other findings, since p53 can prevent carcinogenesis, pre-irradiation at a low dose-rate might enhance the predisposition to cancer. Therefore, it is possible that different maximal permissible dose equivalents for the public populations are appropriate. Furthermore, concerning health of human beings, studies of the adaptive responses to radiation are quite important, because the radiation response strongly depends on experience of prior exposure to radiation

Studies on chronic effect on radiation

International Nuclear Information System (INIS)

Yun, T.K.; Kang, T.U.; Yun, Y.S.; Chung, I.Y.; Koh, J. W.; Kim, J.W.; Ryu, Y.W.

1983-01-01

This experiment was carried out to evaluate the chronic harzard of Co-60 low dose irradiation on ICR mice. There is now considerable evidence from human studies that age, both at exposure to radiation and at observation for risk, can be a major determinant of radiation induced cancer risk. For this reason, ICR mice at different ages as specified below were exposed to 60 m rads/week, 500 m rads/biweek of whole body Co-60 radiation at a dose rate of 3.6 rads/min. ICR mice were irradiated during pregnant period and each period from the 1st week to the 3rd week to the 52nd week, from the 6th week to the 52nd week and from the 22nd week to the 52nd week after the birth. All the experimental mice were autopsied immediately after sacrificed at the 52nd week. And all of their major organs were examined grossly and weighed. After fixation histo-pathological preparations were made for microscopical study. Blood cells-W.B.C., R.B.C., Hb-from eye's vein were counted by hemocytometer and hemometer. (Author)

Antioxidant Approaches to Management of Ionizing Irradiation Injury

Directory of Open Access Journals (Sweden)

Joel Greenberger

2015-01-01

Full Text Available Ionizing irradiation induces acute and chronic injury to tissues and organs. Applications of antioxidant therapies for the management of ionizing irradiation injury fall into three categories: (1 radiation counter measures against total or partial body irradiation; (2 normal tissue protection against acute organ specific ionizing irradiation injury; and (3 prevention of chronic/late radiation tissue and organ injury. The development of antioxidant therapies to ameliorate ionizing irradiation injury began with initial studies on gene therapy using Manganese Superoxide Dismutase (MnSOD transgene approaches and evolved into applications of small molecule radiation protectors and mitigators. The understanding of the multiple steps in ionizing radiation-induced cellular, tissue, and organ injury, as well as total body effects is required to optimize the use of antioxidant therapies, and to sequence such approaches with targeted therapies for the multiple steps in the irradiation damage response.

Value of subtyping in studies of irradiation and human leukaemia

Energy Technology Data Exchange (ETDEWEB)

Darby, S C

1985-01-01

The two largest studies of the effects of irradiation on humans in postnatal life are described. These are 1) the Ankylosing Spondylitis Study(ASS) carried out on patients given X-ray therapy as treatment for spondylitis in the UK and 2) the Life Span Study(LSS) carried out on the survivors of the atomic bombings of Hiroshima and Nagasaki. From these studies, a limited degree of subtyping of leukemias is indicated. Chronic lymphatic leukemia is much less readily induced by radiation than the other major subtypes. The inducibility of acute myeloid leukemia increases with age at exposure.

Low dose irradiation and risk of leukaemia: A case-control study

International Nuclear Information System (INIS)

Chobanova, N.; Bayrakova, A.

1997-01-01

The effect of low dose irradiation (medical X-ray diagnostic) on the developing of leukaemias in adults is investigated. The influence of non-radiation agents (occupational exposure to chemical carcinogens, past viral infections, family aggregations) to leukaemias are considered also. During this retrospective study 228 patients have been examined with the following diagnosis: acute myeloid leukaemia, chronic myelogenous leukaemias, myelodisplastic syndrome and non-Hodgkin lymphoma (diagnosed between 1991-1993). Each case has been matched with two controls. Statistically significant increase has been found in the risk of developing leukaemias after X-ray diagnostic irradiation (OR = 1.98, 95% CI = 1.14 ./. 3.46). Exposure to chemical agents is also associated with significant increase in the risk (OR = 1.98, 95% CI = 1.25 ./. 2.86). (author)

Vitamin D Status in Chronic Kidney Disease - UVB Irradiation Is Superior to Oral Supplementation.

Science.gov (United States)

Krause, Rolfdieter; Roth, Heinz Jürgen; Kaase, Heinrich; Stange, Rainer; Holick, Michael F

2016-03-01

In chronic kidney disease (CKD) a deficiency of 1,25-dihydroxyvitamin D is common. The aim of this review was to compare vitamin D status after oral supplementation of vitamin D3 to that of serial suberythemal irradiation in end-stage kidney disease (ESKD) patients. Ninety-five patients, with a mean age of 62 (range=35-82) years, were treated with a mean dose of 35,000 (20,000-60,000) IU vitamin D3 per week for a period of 18 months. Fourteen patients, with a mean age of 51 (range=41-57) years, were whole-body UVB irradiated for over 6 months. From 3 hemodialysis patients skin biopsies were performed. With oral supplementation 25(OH)D3 increased by 60%. With UV irradiation 25(OH)D3 increased by 400%. Gene expression analysis demonstrated an improvement in the vitamin D receptor (VDR) by 0.65 fold, in 1-alpha-hydroxylase (CYP27B1) by 1.0 fold, and in 25-hydroxylase (CYP2R) by 1.2 fold. Serial suberythemal UVB irradiation of patients with CKD on dialysis is capable to improve serum 25(OH)D3 and 1,25(OH)2D3 by enhancing the skin's ability to activate vitamin D. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Evaluation of acute and chronic toxicity of DSS and LAS surfactants undergoing the irradiation with electron beam

International Nuclear Information System (INIS)

Romanelli, Maria Fernanda

2004-01-01

Surfactants are synthetic organic compounds widely used in cosmetic, food, textile, dyers and paper production industries and in particular detergents and others cleaning products industries. The world consumption is nearly 8 million tons per year. One of the main environmental issues coming from the use of these compounds is their toxicity that compromises the biological treatment of effluents and the quality of receiving waters. The objective of this work was the application of ionizing radiation by electron beam in the degradation and reduction of acute and chronic toxicities of surfactants sodium dodecylsulfate (SDS), dodecyl p-benzenesulfonate acid (LAS) and sodium dodecyl p-benzenesulfonate (LAS). This treatment technology has been studied as a pre-treatment for effluents containing toxic and non-biodegradable compounds, before the biological treatment. Two acute toxicity assays were employed, one with the micro-crustacean Daphnia similis and the other with the luminescent bacterium Vibrio fischeri along with a chronic toxicity assay with the micro-crustacean Ceriodaphnia dubia (just for SDS and acid LAS) for the non-irradiated and irradiated samples and radiation doses 3.0 kGy, 6.0 kGy, 9.0 kGy and 12.0 kGy. Physical-chemical parameters were evaluated for the following up the degradation of the surfactant molecules. The reductions of acute toxicity varied between 72.49% and 90.98% for SDS, 18.22% and 78.98% for acid LAS and 82.66% and 94.26% for sodium LAS. For the chronic toxicity, the reduction percentages varied between 64.03% and 83.01% for SDS and 47.48% and 64.91% for acid LAS. When one considers the application of the electron beam as a pre-treatment of effluents containing high concentrations of surfactants, the toxicity is an essential parameter allowing the further biological treatment of these effluents. (author)

Effects of chronic gamma irradiation on adventitious plantlet formation of Saintpaulia ionantha (African violet) detached leaves

International Nuclear Information System (INIS)

Arunee Wongpiyasatid; Peeranuch Jompuk; Katarat Chusreeaeom; Thanya Taychasinpitak

2007-01-01

Formation of adventitious plantlets on unrootedly detached leaves of two African violet (Saintpaulia ionantha) cultivars, pink and violet flowers, chronically gamma-irradiated in gamma room at The Gamma Irradiation Service and Nuclear Technology Research Center, Kasetsart University was compared. Detached leaves were immediately planted after detachment in plastic trays containing peat moss, 18 leaves per treatment with 3 replications. Three dose rates (rad/h) with 3 doses (rad)/dose rate, were applied to the irradiated samples while the controls were placed outside the gamma room. Three months after irradiation, the number of survived leaves, the number of leaves producing adventitious plantlets and the number of plantlets per leaf were recorded. After that, the young plantlets were transferred to the new pots for further observation on plant growth and mutation characters. The results revealed that the number of survived leaves, the number of leaves producing adventitious plantlets and the number of plantlets per leaf varied slightly with radiation doses but were not significantly different at different dose rates. Radiosensitivity was noticed to be higher in pink flower cultivar than the violet one. M 1 V 1 plantlets will be followed up for growth and mutation character observations

Squamous cell carcinoma in situ after irradiation

International Nuclear Information System (INIS)

Kambara, Takeshi; Nishiyama, Takafumi; Yamada, Rie; Nagatani, Tetsuo; Nakajima, Hiroshi; Sugiyama, Asami

1997-01-01

We report two cases with Squamous Cell Carcinoma (SCC) in situ caused by irradiation to hand eczemas, resistant to any topical therapies. Both of our cases clinically show palmer sclerosis and flexor restriction of the fingers, compatible to chronic radiation dermatitis. Although SCC arising in chronic radiation dermatitis is usually developed ten to twenty years after irradiation, in our cases SCC were found more than forty years after irradiation. (author)

Toxicological studies on irradiated food and food constituents

International Nuclear Information System (INIS)

Schubert, J.

1978-01-01

Selected aspects of the genotoxicology and chemistry of irradiated foods and food components are critically examined and compared with other food processing operations such as cooking, and intentional use of food additives. For example, it is estimated that if 10% of an average daily diet contained irradiated (<1.0Mrad) foods, the daily consumption of radiolytic products would be 2-20mg/d compared with a total of approximately 4000mg/d of intentional food additives and approximately 80mg/d of toxic inorganic and organic environmentally derived contaminants. Several recommendations for the genotoxicological testing of irradiated foods are given, including: (1) that feeding tests include a control diet consisting of food processed by one of the standard methods such as thermalization; (2) that more use be made of positive controls so as to have a 'built-in' measure of sensitivity and responsiveness; (3) that a battery of in vitro and in vivo short-term mutagenicity tests be performed prior to the carrying out of the long-term feeding tests; and (4) that an irradiated food be tested after it is cooked in the manner normally consumed, which may, of course, include the raw or uncooked state as well. An outline of current genetic-toxicological testing schemes is provided and examined. Emphasis is given to a modification in the protocols for the Ames mutagenicity tests leading to a reduction in the evidence of false positives and false negatives. Also described is a procedure for systematically studying combined or interactive effects, acute or chronic, which requires no more effort than that needed for testing a single agent and which yields complete dose-response curves. It is concluded that food irradiation, as a physical process, appears more advantageous from the genotoxicological, chemical, and pollution aspects than well-accepted, but actually rarely tested, physical processes such as canning. (author)

Effects of chronic gamma irradiation: a multigenerational study using Caenorhabditis elegans

International Nuclear Information System (INIS)

Buisset-Goussen, Adeline; Goussen, Benoit; Della-Vedova, Claire; Galas, Simon; Adam-Guillermin, Christelle; Lecomte-Pradines, Catherine

2014-01-01

The effects of chronic exposure to 137 Cs gamma radiation (dose rate ranging from 6.6 to 42.7 mGy h −1 ) on growth and reproductive ability were carried out over three generations of Caenorhabditis elegans (F0, F1, and F2). Exposure began at the egg stage for the first generation and was stopped at the end of laying of third-generation eggs (F2). At the same time, the two subsequent generations from parental exposure were returned to the control conditions (F1’ and F2’). There was no radiation-induced significant effect on growth, hatchability, and cumulative number of larvae within generations. Moreover, no significant differences were found in growth parameters (hatching length, maximal length, and a constant related to growth rate) among the generations. However, a decrease in the cumulative number of larvae across exposed generations was observed between F0 and F2 at the highest dose rate (238.8 ± 15.4 and 171.2 ± 13.1 number of larvae per individual, respectively). Besides, the F1′ generation was found to lay significantly fewer eggs than the F1 generation for tested dose rates 6.6, 8.1, 19.4, and 28.1 mGy h −1 . Our results confirmed that reproduction (here, cumulative number of larvae) is the most sensitive endpoint affected by chronic exposure to ionizing radiation. The results obtained revealed transgenerational effects from parental exposure in the second generation, and the second non-exposed generation was indeed more affected than the second exposed generation. - Highlights: • Chronic exposure to γ-radiation is studied using 3 generations of Caenorhabditis elegans. • Reproduction is the most sensitive endpoint affected by exposure to gamma radiation. • The results obtained revealed transgenerational effects from parental exposure

Plants experiencing chronic internal exposure to ionizing radiation exhibit higher frequency of homologous recombination than acutely irradiated plants

Energy Technology Data Exchange (ETDEWEB)

Kovalchuk, O.; Kovalchuk, I.; Hohn, B. [Friedrich Miescher Institute, P.O. Box 2543, CH-4002 Basel (Switzerland); Arkhipov, A. [Chernobyl Scientific and Technical Center of International Research, Shkolnaya Str. 6, 255620 Chernobyl (Ukraine); Barylyak, I.; Karachov, I. [Ukrainian Scientific Genetics Center, Popudrenko Str. 50, 253660 Kiev (Ukraine); Titov, V. [Ivano-Frankivsk State Medical Academy, Galitska Str.2, 284000 Ivano-Frankivsk (Ukraine)

2000-04-03

Ionizing radiation (IR) is a known mutagen responsible for causing DNA strand breaks in all living organisms. Strand breaks thus created can be repaired by different mechanisms, including homologous recombination (HR), one of the key mechanisms maintaining genome stability [A. Britt, DNA damage and repair in plants, Annu. Rev. Plant. Phys. Plant Mol. Biol., 45 (1996) 75-100; H. Puchta, B. Hohn, From centiMorgans to basepairs: homologous recombination in plants, Trends Plant Sci., 1 (1996) 340-348.]. Acute or chronic exposure to IR may have different influences on the genome integrity. Although in a radioactively contaminated environment plants are mostly exposed to chronic pollution, evaluation of both kinds of influences is important. Estimation of the frequency of HR in the exposed plants may serve as an indication of genome stability. We used previously generated Arabidopsis thaliana and Nicotiana tabacum plants, transgenic for non-active versions of the {beta}-glucoronidase gene (uidA) [P. Swoboda, S. Gal, B. Hohn, H. Puchta, Intrachromosomal homologous recombination in whole plants, EMBO J., 13 (1994) 484-489; H. Puchta, P. Swoboda, B. Hohn, Induction of homologous DNA recombination in whole plants, Plant, 7 (1995) 203-210.] serving as a recombination substrate, to study the influence of acute and chronic exposure to IR on the level of HR as example of genome stability in plants. Exposure of seeds and seedlings to 0.1 to 10.0 Gy 60Co resulted in increased HR frequency, although the effect was more pronounced in seedlings. For the study of the influence of chronic exposure to IR, plants were grown on two chemically different types of soils, each artificially contaminated with equal amounts of 137Cs. We observed a strong and significant correlation between the frequency of HR in plants, the radioactivity of the soil samples and the doses of radiation absorbed by plants (in all cases r0.9, n=6, P<0.05). In addition, we noted that plants grown in soils with

Detection of TT Virus Among Thalassaemic Children With Chronic Viral Hepatitis B and C Receiving Irradiated and Non Irradiated RBCs

International Nuclear Information System (INIS)

El-Maghraby, D.F.; EL-Shafie, A.I.; El-Sayed, S.A.; Alkady, M.M.

2010-01-01

TTV was first identified in the serum of a patient with post transfusion hepatitis of unknown etiology in 1997.As a consequence of the high prevalence of TTV in blood donors, thalassemia patients frequently acquire various genotypes of this virus through therapeutic blood transfusions.TTV as a cause of chronic hepatitis has not yet determined . Ten healthy and twenty-eight poly-transfused thalassemia children were evolved in this study where ten patients were receiving irradiated RBCs and eighteen receiving non irradiated ones.TTV was detected in serum samples by semi-nested polymerase chain reaction (PCR) using TTV-specific primer. Transaminases levels, hepatitis B and C virus markers were interpreted for possible association with TTV infection. As a result, TTV was found in 50% of thalassemia patients and in 20 % of the controls. Among thalassemia patients, isolated HBsAG, isolated HCV-AB, HBsAG and TTV-DNA and HCV-AB and TTV-DNA distributions were: 6 (21.43%) ,8 ( 28.57%) , 4 ( 14.29%) and 10 (35.7%) respectively. Regarding thalassemia patients receiving irradiated RBCs, the frequency of viral infections were 8(80%), 2(20%) and 0% for TTV co-infections, isolated HBV and isolated HCV, respectively. On the other hand, the prevalence of viral infections among patients receiving non irradiated RBCs were 6(33.3%), 4(22.2%) and 8(44.5%) for TTV co-infection, isolated HBV and isolated HCV, respectively. These data may give evidence that radiation raises the levels of blood safety especially regarding HCV. Furthermore, liver transaminase levels were significantly higher in all patients versus the controls, meanwhile, transaminase values were not different in HBsAG-positive subjects as compared with subjects who had both HBsAG and TTV-DNA positive. Also, there was no significant difference between isolated HCV infection and HCV and TTV co-infection. So, no convincing evidence was found to support TTV involvement in the D. F. EL-MAGHRABY, et al. / J. Rad. Res. Appl. Sci

Total body irradiation: what schedule(s). Les irradiations corporelles totales: quel(s) schema(s)

Energy Technology Data Exchange (ETDEWEB)

Cosset, J M [Institut Curie, 75 - Paris (France)

1993-01-01

In this article, the author explains why a whole-body irradiation is still an essential step before a bone marrow graft. He presents irradiation protocols for acute myeloid leukemia and chronic myeloid leukemia. 14 refs.

Kinetics of lymphohematopoiesis and leukemia induction in chronically whole-body irradiated RF/J mice

International Nuclear Information System (INIS)

Cain, G.R.; Stitzel, K.A.; Fox, L.A.; Klein, A.K.; Dyck, J.A.; Shimizu, J.A.; Rosenblatt, L.S.

1982-01-01

Lymphohematopoietic progenitor cell populations (bone marrow CFU-GM, splenic CFU-BL) were quantitated in unirradiated and in chronically irradiated (17.5 R/day for 4 weeks) RF/J mice and control CAF 1 mice. RF/J mice were found capable of making substantial numbers of bone marrow CFU-GM but less so than the control strain CAF 1 . Significant strain differences were also seen in ability to form splinic B lymphocyte progenitor cells (CFU-BL). Unirradiated and irradiated RF mice produced over three times as many CFU-BL as CAF 1 mice. Throughout the period of protracted irradiation, followed by a twelve week recovery period, CFU-BL and CFU-GM were depressed less in the RF strain than the CAF 1 strain. This was due to an overcompensatory regenerative response which surpassed homostatic baseline levels. Despite strain and strain x dose differences in CFU-BL and CFU-GM, no significant strain x dose relationships were seen in circulati leukocyte counts. The increased susceptibility of RF mice to radiation-induced leukemia may be related to either inherent depressed regulatory control or the persistence of progenitor cell compartments. An apparent increased cell turnover rate in both CFU-BL and CFU-GM in RF mice following radiation damage may likewise play a contributory role

Effects of chronic whole-body gamma irradiation on cell mediated immunity

International Nuclear Information System (INIS)

Shifrine, M.; Taylor, N.J.; Wilson, F.D.; DeRock, E.W.; Wiger, N.

1979-01-01

The whole blood lymphocyte stimulation test has been used to estimate the effects of chronic, whole-body, gamma irradiation in the dog. At lower dose levels, 0.07 and 0.33 R/day to cumulative dose of about 50 and 250 R, there was no change in cell mediated immunity. Dogs at high dose levels were affected. Dogs which succumbed to aplastic anemia at high doses had reduced immunological responses. Dogs which survived these high doses showed a temporary depression. When aplastic anemia was initially noted, there was a differential response to PHA and Con-A stimulation. The response to the former mitogen was profoundly reduced, but Con-A stimulated cells were unaffected, indicative of the development of radioresistant cell lines. As the dogs progressed toward aplastic anemia, all T lympocytes were negatively affected

Granzyme B mediates both direct and indirect cleavage of extracellular matrix in skin after chronic low-dose ultraviolet light irradiation.

Science.gov (United States)

Parkinson, Leigh G; Toro, Ana; Zhao, Hongyan; Brown, Keddie; Tebbutt, Scott J; Granville, David J

2015-02-01

Extracellular matrix (ECM) degradation is a hallmark of many chronic inflammatory diseases that can lead to a loss of function, aging, and disease progression. Ultraviolet light (UV) irradiation from the sun is widely considered as the major cause of visible human skin aging, causing increased inflammation and enhanced ECM degradation. Granzyme B (GzmB), a serine protease that is expressed by a variety of cells, accumulates in the extracellular milieu during chronic inflammation and cleaves a number of ECM proteins. We hypothesized that GzmB contributes to ECM degradation in the skin after UV irradiation through both direct cleavage of ECM proteins and indirectly through the induction of other proteinases. Wild-type and GzmB-knockout mice were repeatedly exposed to minimal erythemal doses of solar-simulated UV irradiation for 20 weeks. GzmB expression was significantly increased in wild-type treated skin compared to nonirradiated controls, colocalizing to keratinocytes and to an increased mast cell population. GzmB deficiency significantly protected against the formation of wrinkles and the loss of dermal collagen density, which was related to the cleavage of decorin, an abundant proteoglycan involved in collagen fibrillogenesis and integrity. GzmB also cleaved fibronectin, and GzmB-mediated fibronectin fragments increased the expression of collagen-degrading matrix metalloproteinase-1 (MMP-1) in fibroblasts. Collectively, these findings indicate a significant role for GzmB in ECM degradation that may have implications in many age-related chronic inflammatory diseases. © 2014 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

Evolution of microbial activity in a mediterranean ecosystem submitted to chronic gamma irradiation. Investigation of nitrogen transfer with isotopic tracers

International Nuclear Information System (INIS)

Castet, R.

1987-07-01

A mediterranean ecosystem located on the site of Cadarache (France) has been experimentally by irradiated over the past fifteen years. The potential effects of ionizing radiations for different doses of its ecological system has been studied. The objective of the work was to demonstrate the level of soil microbial population and its activity. Chronic exposures reduced the biomass and the dehydrogenase activity by a factor of 50% and increased the amount of nitrate in the soil. To measure the direct impact of irradiations on soil microorganisms, we have irradiated soil sample in laboratory at 0.1; 0.5; 1 kGy, and observed its evolution during a period of six weeks thereafter. We have a reduction of the dehydrogenase activity and an increase of nitrate being proportionaly to the dose delivered. Using nitrogen labelled, we state that this high rate of nitrate production is due to an inhibition of the organization of this form of nitrogen. Conversely, the ammonification and the nitrification are not affected. Also, for anaerobic conditions created by glucose, the nitrate labelled (15N) permitted us to show that in untreated soil, 45% of nitrate was reduced to nitrogen gas by denitrification and 24% of nitrate was reduced to ammonium by dissimilation in the irradiated soil. These experiments show that gamma irradiations are of great interest for studying soil microorganisms. As of now, very little is known on the effects of this kind of stress for attention and need to be pursued on such ecosystems. Further investigations call [fr

Studies of blood irradiator application

International Nuclear Information System (INIS)

Li Wenhong; Lu Yangqiao

2004-01-01

Transfusion is an important means for medical treatment, but it has many syndromes such as transfusion-associated graft-versus-host disease, it's occurrence rate of 5% and above 90% death-rate. Now many experts think the only proven method is using blood irradiator to prevent this disease. It can make lymphocyte of blood product inactive, so that it can not attack human body. Therefore, using irradiation blood is a trend, and blood irradiator may play an important role in medical field. This article summarized study of blood irradiator application, including the meaning of blood irradiation, selection of the dose for blood irradiation and so on

Blood responses under chronic low daily dose gamma irradiation: Pt.1

International Nuclear Information System (INIS)

Seed, T.M.; Carnes, B.A.; Tolle, D.V.; Fritz, T.E.

1989-01-01

Male beagles chronically exposed to low daily doses of 60 Co γ rays show one of three hematopoietic patterns, which reflect three different distinctly responding subgroups: (1) low radioresistance with progressing aplastic anemia and shortened survival ( -S -AA subgroup); (2) high radioresistance with a complex of progressing myeloproliferative disorders ( + R-MPD group); or (3) high radioresistance with other nonMPD syndromes ( + R-nonMPD group). Blood cell levels (granulocytes, monocytes, erythrocytes, lymphocytes, and platelets) were assessed and fitted to a flexible polynomial spline model. Results showed that relative to the overall magnitude of blood cell loss as well as to the maximum rate of suppression during the initial phase, the subgroups were generally ranked - S-AA >> + R-MPD > + R-nonMPD. Relative to the overall strength of the recovery response, the subgroups were generally ranked + R-MPD > + R-nonMPD >>> - S-AA. In terms of overall maintenance levels of circulating blood cells during the recovery phase, however, the + R-nonMPD subgroup consistently exhibited stronger responses than the + R-MPD subgroup. These results support our contention that selected subgroups of dogs have strong propensities to specific hematopathologies (i.e. aplastic anemia and myeloid leukemia) under chronic irradiation and that these pathology-prone animals exhibit a series of marked differential hematopoietic responses during early preclinical phases, which serve effectively to prognosticate subsequent pathological progression. (author)

Chronic radiation exposure as an ecological factor: Hypermethylation and genetic differentiation in irradiated Scots pine populations.

Science.gov (United States)

Volkova, P Yu; Geras'kin, S A; Horemans, N; Makarenko, E S; Saenen, E; Duarte, G T; Nauts, R; Bondarenko, V S; Jacobs, G; Voorspoels, S; Kudin, M

2018-01-01

Genetic and epigenetic changes were investigated in chronically irradiated Scots pine (Pinus sylvestris L.) populations from territories that were heavily contaminated by radionuclides as result of the Chernobyl Nuclear Power Plant accident. In comparison to the reference site, the genetic diversity revealed by electrophoretic mobility of AFLPs was found to be significantly higher at the radioactively contaminated areas. In addition, the genome of pine trees was significantly hypermethylated at 4 of the 7 affected sites. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mutagenic effect of cyclophosphan on bone marrow cells of irradiated rats

International Nuclear Information System (INIS)

Barkan, R.S.; Yakovleva, T.K.

1979-01-01

The frequency of chromosome aberrations in bone marrow cells of male rats was studied 24 hours after the intraperitoneal injection of cyclophosphane (25 mg/kg weight). Cyclophosphane (CP) was injected to animals that had been earlier (15 days before, 1, 3, 4, 6 and 9 months earlier) exposed to X-ray and γ-irradiation at the dose of 400 rad. It has been shown that the preliminary irradiation of animals results in a higher mutagenic CP effect as against its effect for non irradiated rats. The effect was recorded during four months following the acute single x-irradiation (dose rate of 70 rad/min) and within one month following chronic γ-irradiation (dose rate of 100 rad/day). At later periods, the above effect fully disappeared. Chronic irradiation was less effective with regard to the subsequent mutagenic CP action than the acute irradiation. In most experiments with acute irradiation an increase in mutagenic CP efficiency revealed itself both in an increase in the frequency of cells with chromosome aberrations and in the cell damage rate. The possible mechanisms of the effect of preliminary irradiation on the subsequent mutagenic effect of chemical compounds are discussed

Long-term follow-up observation of patients with chronic radiation sickness due to external irradiation treated with thymopeptide

International Nuclear Information System (INIS)

Gao Shenyong; Sun Wenji; Zhang Aizhen; Ye Anfang

1998-01-01

Objective: To provide the clinical data and prognosis judgement, the authors observed the results and progression of 11 cases of chronic radiation sickness due to external irradiation treated with thymopeptide. Methods: The clinical symptoms, hematopoiesis, T lymphocyte percentage and chromosome aberration rate were used as the judgement indexes for recovery from the chronic radiation sickness. Results: Thymopeptide treatment greatly improved the neurasthenic syndrome and increased the T lymphocyte percentage (P 0.05), and improvement of neurasthenic syndrome occurred 3.5 years after they left radiation work or diminished the exposure level. 5 to 8 years after, bone marrow hematopoiesis also restored to the normal level. However, the chromosome aberration rate restored to the normal level 10 years after. Conclusion: According to the judgement criteria, the chronic radiation sickness due to external radiation exposure can recover and thymopeptide is a helpful and simple means to treat it

Health condition of children irradiated in utero

Energy Technology Data Exchange (ETDEWEB)

Stepanova, E [Research Center for Radiation Medicine, Kiev (Ukraine)

1997-09-01

Among the children exposed to ionizing radiation, the ones irradiated in utero constitute a group under special surveillance. The greatest sensitivity of the organism to the effects of radiative factors occurs in the neonatal period of development and the forthcoming life span with irradiation effects is the longest for these children. Children with acute exposure, with chronic exposure and control group were encompassed by this study - 1144 children altogether. 9 figs, 2 tabs.

Health condition of children irradiated in utero

International Nuclear Information System (INIS)

Stepanova, E.

1997-01-01

Among the children exposed to ionizing radiation, the ones irradiated in utero constitute a group under special surveillance. The greatest sensitivity of the organism to the effects of radiative factors occurs in the neonatal period of development and the forthcoming life span with irradiation effects is the longest for these children. Children with acute exposure, with chronic exposure and control group were encompassed by this study - 1144 children altogether. 9 figs, 2 tabs

Reproductive function of monkeys subjected to chronic irradiation

International Nuclear Information System (INIS)

Artem'eva, N.S.; Kosichenko, L.P.; Andreeva, A.V.; Zvereva, G.A.

1976-01-01

Marked functional disorders have been detected in reproductive glands of eight female monkeys (as compared to twelve control animals) subjected to protracted (up to eight years) irradiation (cumulative doses 826-3282 R). Irradiated monkeys exhibited a drastically decreased reproductive capacity, early menopause and sterility. Irradiation of preadolescent animals inhibited, in most cases, the puberty processes and disturbed sex cycles. Structural disorders in sex glands, inhibition of the processes of maturation and ovulation of folloculi, death of the mass of germ cells, atypical vegetations of the integmentary epithelium, sclerosing and cystic degeneration of the glandular tissue have been revealed

The role of blood flow in chronic duodenal ulcer

Energy Technology Data Exchange (ETDEWEB)

Gompertz, R.H.K.; Mathie, R.T.; Michalowski, A.S.; Spencer, J.; Baron, J.H.; Williamson, R.C.N.

1996-01-01

Changes in gastroduodenal blood flow have been implicated in the pathogenesis of duodenal ulcer. The authors have studied duodenal blood flow during the development of an acute to chronic duodenal ulcer by using the abscopal model, in which ulcers are generated as an indirect effect of lower mediastinal irradiation. Female CFLP mice were randomly allocated to one of three groups. Irradiated ``controls`` received 18 Gy 250 kV X-rays to the upper mediastinum. The lower mediastinum group received the same dose of irradiation, which has been shown to induce typical chronic duodenal ulcers in 45% of animals so treated. Animals were studied by means of radiolabelled microspheres 3 or 7 days later. Proximal duodenal blood flow specifically was reduced by 32% in the lower mediastinum group compared with irradiated controls at 7 days. There was no significant difference in blood flow to the stomach and to the distal duodenum. The decrease in proximal duodenal blood flow in the lower mediastinum group did not differ in the five animals that developed ulcer compared with the seven that did not. Although, there is an overall decrease in duodenal blood flow associated with chronic duodenal ulcer, reduced blood flow may not explain individual susceptibility to ulceration. 21 refs., 1 fig., 2 tabs.

Effects of chronic postnatal opioid receptor blockade by naltrexone upon proliferation capacity in the prenatally x-irradiated brain of the rat

International Nuclear Information System (INIS)

Schmahl, W.; Miaskowski, U.

1991-01-01

We recently reported that in rats prenatally x-irradiated on gestation day 14 with 1 Gy, postnatal chronic application of the opioid antagonist naltrexone (Nx) led to a remarkable growth spurt of the microencephalic brain. In the present study we present histological and autoradiographic results found in the subependymal layer (SEL) of the forebrain lateral ventricles. Nx led to an intermittent augmentation of the mitotic index of the x-irradiated brains within a postnatal observation period of 24 weeks. The most conspicuous finding was transient hyperplasia of the SEL at 4-6 weeks of age which occurred in close proximity to an intact ependymal lining. Districts of the lateral ventricles which were denuded from ependyme and where the rest of the ependymal layer (EL) was dislocated peripherally showed upon Nx treatment a long-lasting SEL hyperplasia with a tendency towards dysplasia. These results revealed that repair proliferation of embryotoxic x-irradiation is normally under strong control by the opioid system. If that system, which exerts a suppressing effect upon glial growth, is blocked by Nx, prominent hyperplastic reactions occur which may be useful for repairing the lesion pattern

Effects of chronic postnatal opioid receptor blockade by naltrexone upon proliferation capacity in the prenatally x-irradiated brain of the rat

Energy Technology Data Exchange (ETDEWEB)

Schmahl, W.; Miaskowski, U. (Department of Pathology, Gesellschaft fuer Strahlen-und Umweltforschung mbh Muechen, Neuherberg (West Germany))

1991-01-01

We recently reported that in rats prenatally x-irradiated on gestation day 14 with 1 Gy, postnatal chronic application of the opioid antagonist naltrexone (Nx) led to a remarkable growth spurt of the microencephalic brain. In the present study we present histological and autoradiographic results found in the subependymal layer (SEL) of the forebrain lateral ventricles. Nx led to an intermittent augmentation of the mitotic index of the x-irradiated brains within a postnatal observation period of 24 weeks. The most conspicuous finding was transient hyperplasia of the SEL at 4-6 weeks of age which occurred in close proximity to an intact ependymal lining. Districts of the lateral ventricles which were denuded from ependyme and where the rest of the ependymal layer (EL) was dislocated peripherally showed upon Nx treatment a long-lasting SEL hyperplasia with a tendency towards dysplasia. These results revealed that repair proliferation of embryotoxic x-irradiation is normally under strong control by the opioid system. If that system, which exerts a suppressing effect upon glial growth, is blocked by Nx, prominent hyperplastic reactions occur which may be useful for repairing the lesion pattern.

Chronic progressive multiple sclerosis

International Nuclear Information System (INIS)

Buffoli, A.; Micheletti, E.; Capra, R.; Mattioli, F.; Marciano', N.

1991-01-01

A long-lasting immunological suppression action seems to be produced by total lymphoid irradiation; some authors emphasize the favorable effect of this treatment on chronic progressive multiple sclerosis. In order to evaluate the actual role of TLI, 6 patients affected with chronic progressive multiple sclerosis were submitted to TLI with shaped and personalized fields at the Istituto del Radio, University of Brescia, Italy. The total dose delivered was 19.8 Gy in 4 weeks, 1.8 Gy/day, 5d/w; a week elapsed between the first and the second irradiation course. Disability according to Kurtzke scale was evaluated, together with blood lymphocyte count and irradiation side-effects, over a mean follow-up period of 20.8 months (range: 13-24). Our findings indicate that: a) disease progression was not markedly reduced by TLI; b) steroid hormones responsivity was restored after irradiation, and c) side-effects were mild and tolerable

Pre-irradiation at a low dose-rate blunted p53 response

International Nuclear Information System (INIS)

Takahashi, Akihisa

2002-01-01

We investigated whether chronic irradiation at a low dose-rate interferes with the p53-centered signal transduction pathyway induced by radiation in human cultured cells and C57BL/6N mice. In in vitro experiments, we found that a challenge with X-ray irradiation immediately after chronic irradiation resulted in lower levels of p53 than those observed after the challenge alone in glioblastoma cells (A-172). In addition, the levels of p53-centered apoptosis and its related proteins after the challenge were strongly correlated with the above-mentioned phenomena in squamous cell carcinoma cells (SAS/neo). In in vivo experiments, the accumulation of p53 and Bax, and the induction of apoptosis were observed dose-dependently in mouse spleen at 12 h after a challenge with X-rays (3.0 Gy). However, we found significant suppression of p53 and Bax accumulation and the induction of apoptosis 12 h after challenge irradiation at 3.0 Gy with a high doses-rate following chronic pre-irradiation (1.5 Gy, 0.001 Gy/min). These findings suggest that chronic pre-irradiation suppressed the p53 function through radiation-induced signaling and/or p53 stability. (author)

A study on UV irradiated HDPE

International Nuclear Information System (INIS)

Sang Haibo; Liu Zimin; Wu Shishan; Shen Jian

2006-01-01

The structure and properties of HDPE irradiated by ultraviolet (UV) in ozone atmosphere were studied by FT-IR, XPS, gel, and water contact angle test. The oxygen-containing groups such as C=O, C-O and C(=O)O were introduced onto high density polyethylene (HDPE) chains through ultraviolet irradiation in ozone atmosphere, their content increased with the UV irradiation time. Under the same UV irradiation conditions, amount of the oxygen-containing groups introduced in ozone atmosphere was more than that in air atmosphere, indicating that the speed of oxygen-containing groups introduced through UV irradiation in ozone atmosphere was faster than that in air. Therefore, HDPE could be quickly functionalized through UV irradiation in ozone atmosphere. There was no gel formed in the HDPE irradiated in ozone atmosphere. After UV irradiation, the water contact angle of HDPE decreased, and its hydrophilicity was improved, suggesting that the compatibility between the irradiated HDPE and polar polymer or inorganic fillers may be better. Compared with HDPE, the temperature of initial weight loss for irradiated HDPE decreased. The structure and properties of irradiated HDPE/CaCO 3 blend were also investigated. The results showed that the compatibility and interfacial action of the irradiated HDPE/CaCO 3 blend were improved compared to that of HDPE/CaCO 3 blend. The mechanical properties of irradiated HDPE/CaCO 3 blend increased with increasing irradiation time. (authors)

Study of the recrystallisation of irradiated uranium; Etude sur l'uranium irradie

Energy Technology Data Exchange (ETDEWEB)

Bloch, J; Mustelier, J P; Bussy, P; Blin, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

1- Study of the recrystallisation of irradiated uranium. The recrystallisation of uranium irradiated to a burnup level of 220 MWj/t, at a temperature of the order of 350 deg. C, has been investigated. The observations were made chiefly by means of micrography an hardness measurements. If the irradiated metal is compared with a cold-drawn metal showing the same shearing of the twinned crystals, and therefore the same rate of plastic deformation, as the irradiated metal, it is noted that the restoring of the irradiated metal takes place at a considerably higher temperature than that of the cold-drawn metal. Pre-crystallisation is very much delayed. Only, a passage of the {alpha}-{beta} transformation point quickly wipes out irradiation effect. 2- Hardening of uranium by irradiation. Using hardness measurements we have studied more especially the effect of very weak irradiations on uranium (integrated flux < 10{sup 16} nvt). The hardness does not increase linearly with the flux, but a period of incubation is observed probably representing the time necessary for saturation of the dislocations. (author)Fren. [French] 1- Etude de la recristallisation de l'uranium irradie. On a etudie la recristallisation d'uranium irradie jusqu'a un taux de combustion de 220 MWj/t a une temperature de l'ordre de 350 deg. C. Les observations ont ete faites principalement a l'aide de la micrographie et de la durete. Si l'on compare le metal irradie avec un metal ecroui presentant le meme cisaillement des macles, donc le meme taux de deformation plastique que le metal irradie, on constate que la restauration du metal irradie se fait a une temperature notablement superieure a celle du metal ecroui. La recristallisation est tres retardee. Seul, un passage du point de transformation {alpha}-{beta} efface rapidement l'effet de l'irradiation. 2- Durcissement de l'uranium par irradiation. Nous avons, a l'aide de la durete, etudie plus particulierement l'effet de tres faibles irrtions sur l

Blood responses under chronic low daily dose gamma irradiation: Pt. 2; Differential preclinical responses of irradiated female dogs in progression to either aplastic anemia or myeloproliferative disease

Energy Technology Data Exchange (ETDEWEB)

Seed, T.; Carnes, B.; Tolle, D.; Fritz, T. (Argonne National Lab., IL (United States). Biological and Medical Research Div.)

1993-05-01

Female beagle dogs were chronically exposed to low daily doses of [sup 60]Co gamma rays and responded in one of three distinct hemopathological patterns. These patterns, reflective of distinct subgroups, were characterized by (a) low radioresistance resulting in progressive hematopoietic suppression, terminal aplastic anemia (AA), and relatively short (<400 days) survival ([sup -]S-AA subgroups); (b) high radioresistance, initially coupled with strong but aberrant regenerative hematopoiesis, and later with the development of myeloproliferative disease (MPD) ([sup +]-R-MPD subgroup); and (c) high radioresistance, coupled with an early phase of strong regenerative hematopoiesis, but later with no myeloproliferative disease ([sup +]R-nonMPD subgroup). In this study, the changes in circulating blood cells levels (granulocytes, monotcytes, erythrocytes, lymphocytes and platelets) were sequentially assessed in time and fitted to a flexible, quadratic-linear-type response model previously developed. The results are consistent with our earlier observations of blood responses of chronically irradiated male dogs, in the subgroups of female dogs prone to specific radiogenic hematopathologies (i.e. AA and MPD) can be readily identified and staged in specific preclinical periods by a series of marked differential blood responses. (Author).

In situ transmission electron microscope studies of ion irradiation-induced and irradiation-enhanced phase changes

International Nuclear Information System (INIS)

Allen, C.W.

1992-01-01

Motivated at least initially by materials needs for nuclear reactor development, extensive irradiation effects studies employing transmission electron microscopes (TEM) have been performed for several decades, involving irradiation-induced and irradiation-enhanced microstructural changes, including phase transformations such as precipitation, dissolution, crystallization, amorphization, and order-disorder phenomena. From the introduction of commercial high voltage electron microscopes (HVEM) in the mid-1960s, studies of electron irradiation effects have constituted a major aspect of HVEM application in materials science. For irradiation effects studies two additional developments have had particularly significant impact; the development of TEM specimen holder sin which specimen temperature can be controlled in the range 10-2200 K and the interfacing of ion accelerators which allows in situ TEM studies of irradiation effects and the ion beam modification of materials within this broad temperature range. This paper treats several aspects of in situ studies of electron and ion beam-induced and enhanced phase changes and presents two case studies involving in situ experiments performed in an HVEM to illustrate the strategies of such an approach of the materials research of irradiation effects

Total body irradiation: current indications; L`irradiation corporelle totale: les indications actuelles

Energy Technology Data Exchange (ETDEWEB)

Giraud, P.; Danhier, S.; Dubray, B.; Cosset, J.M. [Institut Curie, 75 - Paris (France)

1998-05-01

The choice of dose and fractionation for total body irradiation is made difficult by the large number of considerations to be taken into account. The outcome of bone marrow transplantation after total body irradiation can be understood in terms of tumor cell killing, engraftment, and normal tissue damage, each of these endpoints being influenced by irradiation-, disease-, transplant-, and patient- related factors. Interpretation of clinical data is further hampered by the overwhelming influence of logistic constraints, the small numbers of randomized studies, and the concomitant variations in total dose and fraction size or dose rate. So far, three cautious conclusions can be drawn in order to tentatively adapt the total body irradiation schedule to clinically-relevant situations. Firstly, the organs at risk for normal tissue damage (lung, liver, lens, kidney) are protected by delivering small doses per fraction at low dose rate. This suggests that, when toxicity is at stake (e.g. in children), fractionated irradiation should be preferred, provided that inter-fraction intervals are long enough. Secondly, fractionated irradiation should be avoided in case of T-cell depleted transplant, given the high risk of graft rejection in this setting. An alternative would be to increase total (or fractional) dose of fractionated total body irradiation, but this approach is likely to induce more normal tissue toxicity. Thirdly, clinical data have shown higher relapse rates in chronic myeloid leukemia after fractionated or low dose rate total body irradiation, suggesting that fractionated irradiation should not be recommended, unless total (or fractional) dose is increased. Total body irradiation-containing regimens, primarily cyclophosphamide / total body irradiation, are either equivalent to or better than the chemotherapy-only regimens, primarily busulfan / cyclophosphamide. Busulfan / cyclophosphamide certainly represents a reasonable alternative, especially in patients who

Study of the recrystallisation of irradiated uranium

International Nuclear Information System (INIS)

Bloch, J.; Mustelier, J.P.; Bussy, P.; Blin, J.

1958-01-01

1- Study of the recrystallisation of irradiated uranium. The recrystallisation of uranium irradiated to a burnup level of 220 MWj/t, at a temperature of the order of 350 deg. C, has been investigated. The observations were made chiefly by means of micrography an hardness measurements. If the irradiated metal is compared with a cold-drawn metal showing the same shearing of the twinned crystals, and therefore the same rate of plastic deformation, as the irradiated metal, it is noted that the restoring of the irradiated metal takes place at a considerably higher temperature than that of the cold-drawn metal. Pre-crystallisation is very much delayed. Only, a passage of the α-β transformation point quickly wipes out irradiation effect. 2- Hardening of uranium by irradiation. Using hardness measurements we have studied more especially the effect of very weak irradiations on uranium (integrated flux 16 nvt). The hardness does not increase linearly with the flux, but a period of incubation is observed probably representing the time necessary for saturation of the dislocations. (author) [fr

Effect of total lymphoid irradiation on functional status in chronic multiple sclerosis: importance of lymphopenia early after treatment--the pros

International Nuclear Information System (INIS)

Devereux, C.; Troiano, R.; Zito, G.

1988-01-01

To determine whether immunosuppression by total lymphoid irradiation (TLI) slowed deterioration of chronic progressive multiple sclerosis (MS), functional impairment score and blood lymphocyte counts were compared at 6-month intervals through 4 years following treatment of MS patients by either TLI (n = 27) or sham irradiation (n = 21). At each interval, 20 to 30% fewer TLI-treated patients had deteriorated (p less than 0.05 at 6, 12, and 18 months), and the difference in mean functional impairment score between groups became progressively greater (p less than 0.01 at 42 and 48 months). Benefit accrued principally to the 17 TLI-treated patients with absolute blood lymphocyte counts less than 900/mm3 3 months after treatment, whose mean functional impairment score remained within 0.6 units of baseline (p = NS), whereas the ten TLI patients with higher post-treatment lymphocyte counts had progressive deterioration (p less than 0.05 to p less than 0.001 versus TLI-treated patients with lower lymphocyte counts at all intervals except 30 months) and had deteriorated by more than 5 functional scale units by 42 and 48 months. Side effects were minor and complications rare in TLI-treated patients, but one TLI-treated patient developed staphylococcal sepsis. Thus, TLI slows deterioration of chronic progressive MS, with what appears to be enduring benefit through 4 years compartmented to patients with greater induced lymphopenia. Modification of lymphoid irradiation regimens to increase the proportion of MS patients who achieve a favorable degree of lymphopenia and to avert functional hyposplenism may further improve the benefit/risk ratio

Monte Carlo studies for irradiation process planning at the Portuguese gamma irradiation facility

International Nuclear Information System (INIS)

Oliveira, C.; Salgado, J.; Botelho, M.L.M. Luisa; Ferreira, L.M.

2000-01-01

The paper describes a Monte Carlo study for planning the irradiation of test samples for microbiological validation of distinct products in the Portuguese Gamma Irradiation Facility. Three different irradiation geometries have been used. Simulated and experimental results are compared and good agreement is observed. It is shown that Monte Carlo simulation improves process understanding, predicts absorbed dose distributions and calculates dose uniformity in different products. Based on these results, irradiation planning of the product can be performed

Thermoluminescent and impedimetric studies on irradiated foodstuffs

International Nuclear Information System (INIS)

Mamoon, A.M.

2000-01-01

Several brands of different spices and milk powders were irradiated with relatively high doses of gamma radiation. Glow curves were produced upon heating these irradiated foodstuffs only. Study of the obtained spices glow curves revealed that the magnitude of these curves depends upon the dose received while the shape of the curves remains generally the same for the different doses and for the different spices. Previous studies had shown that the obtained thermoluminescence (TL) is due to dust particles carried by the spices. The TL studies show, furthermore, that different brands of the same spice are apparently contaminated with different amounts of dust or soil. The obtained TL from irradiated milk powders is apparently due to its mineral content. Different milk powders gave TL curves of different magnitudes for the same dose depending upon the milk brand. Impedimetric studies carried out irradiated potatoes show changes in impedance amplitude and phase angle. The results support earlier work on the use of TL to differentiate between irradiated and control foodstuffs, to assess the extent of spices contamination with soil-which perhaps reflects hygienic care-and that impedimetric measurements can distinguish irradiated from control potatoes

Study of irradiation effect on curcuma polyphenols

International Nuclear Information System (INIS)

Rejeb, Imen

2008-01-01

The present study was carried out to evaluate the effect of gamma irradiation on curcumin (Curcuma Longa rhizome) component, particularly the polyphenolic fraction. Powdered rhizome was irradiated at 0, 5, 10 and 15 KGy (dose rate of 6 KGy / H). Polyphenolics were extracted and total polyphenols conent (TPC) was quantified using the Folin-Ciocalteau method. The irradiation effect was also evaluated by the HPLC technique. The chromatographic analysis showed that the irradiated and non-irradiated curcumin spectrum gave similar data. The antioxidant and antibacterial activities of the phenolic extracts were also assessed. the anti oxidative potential of the sample was evaluated using two radical scavenging methods with DPPH and ABTS. The antimicrobial analysis showed that the phenolic extracts of curcumin inhibited the growth of the studied microorganisms. Our results showed that irradiated samples were not affected in terms of polyphenols content and characteristics. (Author)

Clinical effects of chronic low doses irradiation (11 years after Chernobyl accident)

International Nuclear Information System (INIS)

Romanenko, A.Y.; Bebeshko, V.G.

1997-01-01

Estimation of clinical effects of influence low doses of irradiation as the result of the Chernobyl accident on the human organism is presented in this report. The results of the investigations are concerning to changings in different organs and systems of inhabitants of the contamination territories and among clean-up workers. Increasing of morbidity of digestive and nervous systems is notified. Increase of thyroid cancer, chronic thyroidities and hypothyreouses is resisted in clean-up workers in dynamic observation. Highly morbidity of bronchopulmonal system and blood circulation system is revealed. High level of compensative and adaptive reactions of immune and hemopoietic systems is notified. Excesses of leukemias and lymphomas in inhabitants of the contamination territories is not demonstrated but tendency for increasing quantity cases of oncohematological diseases (leukemias, lymphomas, MDS) among clean-up workers IV-VII 1986 are absent. A dynamic of health state of children injured as a result of Chernobyl accident is characterized with continues negative tendencies. (author)

Irradiation-induced mutation experiments with eiploid and tetraploid tomato plants

International Nuclear Information System (INIS)

Boda, J.

1979-01-01

Tomato mutation experiments are described. The tomatoes used in the experiment were the diploid Reziszta and its autotetraploid variety. The experimental plants were exposed to an irradiation of 5000 rsd for 1-2 days, and after transplantation into the gamma field, to chronic irradiation during the whole growing season. The chronic treatment heavily reduced fertility in the generations of tetraploid tomato plants. Recurrent treatment of tetraploid led to further deterioration in fertility. Several berries were formed with few seeds or with no seeds at all. After three irradiations, the chlorophyll mutation frequency increased in the diploid and tetraploid tomato plants. For diploids, treatment applied at the seedling stage gave a lower chlorophyll mutation frequency. With tetraploids the same treatment induced similar chlorophyll mutation frequency. As regards to phenotypic variability of quantitative characteristics in diploid and tetraploid tomatoes, the single and repeated chronic irradiation induced no increase in the variability of properties like flowering time, weight, height etc. (author)

Medium-Level Laser in Chronic Tinnitus Treatment

OpenAIRE

Dejakum, K.; Piegger, J.; Plewka, C.; Gunkel, A.; Thumfart, W.; Kudaibergenova, S.; Goebel, G.; Kral, F.; Freysinger, W.

2013-01-01

The purpose of this study was to evaluate the effect of medium-level laser therapy in chronic tinnitus treatment. In a prospective double-blind placebo-controlled trial, either active laser (450 mW, 830 nm combined Ga-Al-As diode laser) or placebo irradiation was applied through the external acoustic meatus of the affected ear towards the cochlea. Fourty-eight patients with chronic tinnitus were studied. The main outcome was measured using the Goebel tinnitus questionnaire, visual analogue sc...

Influence of thymogene on the repair of lymphocyte DNA in the spleen of minks under the influence of chronic irradiation.; Vpliv timogehu na reparatsyiyu DNK lyimfotsityiv selezyinki norok za umov khronyichnogo opromyinennya.

Energy Technology Data Exchange (ETDEWEB)

Tkhorzhevs` kij, B M; Demidov, S V; Ryasenko, V Yi; Khrapunov, S M [Kievskij Gosudarstvennyj Univ., Kiev (Ukraine); [Nauchno-Proizvodstvennoe Ob` ` edinenie Pripyat` , Chernobyl (Ukraine)

1994-12-31

Results of own investigations of the authors as to the thymogene influence on correction of the repair system under the effect of chronic irradiation are discussed in the article. The influence of thymogene on the repair of DNA in lymphocytes of the spleen of minks has been investigated. Changes in the correlation between single- and double stranded DNA forms in a cell were determinated. It has been found that the quantity of DNA with single stranded breaks has considerably increased in animals under conditions of chronic irradiation. The use of thymogene promotes activation of repair processes in a cell.

Production and standing crop of litter and humus in a forest exposed to chronic gamma irradiation for twelve years

International Nuclear Information System (INIS)

Armentano, T.V.; Woodwell, G.M.

1976-01-01

Continuous exposure since 1961 of an oak-pine forest at Brookhaven National Laboratory to chronic gamma irradiation has shown: (1) progressive reduction in litter production from the first year through 1965; (2) greater litter production in 1973 compared to 1965 at exposure rates below 9 R/day primarily because of the prolific sprouting of the oaks, especially Quercus alba; (3) further reduction in litter production in intermediate zones (14-49 R/day) from 1965 to 1973 as a result of replacement of the forest by a Carex pensylvanica mat; (4) increased litter production in the high exposure zone (125 R/day) in 1973 as a result of colonization by adventive species; (5) reduction in the standing crop of litter by 1973 at the lowest exposure rate studied (3.5 R/day) although in 1965 there was no reduction at exposure rates up to 15 R/day; (6) decline in humus content at 4.6 R/day and above with the standing crop in the Carex zone exceeding that of the shrub and damaged forest zones of lower exposures. Both further losses and partial recovery in the production and storage of organic matter have occurred since 1965. These changes constitute a portion of the long-term response of the forest to chronic disturbance. The pattern of response is the result of ecosystem processes that are still not in equilibrium with the chronic disturbance and which were not predictable from short-term studies, even those spanning as much as 4 yr

A study of positron irradiated porous silicon

International Nuclear Information System (INIS)

Huang Yuanming; Xue Qing; Zhai Baogai; Xu Aijun; Liu Shewen; Yu Weizhong

1998-01-01

The effect of positron irradiation on photoluminescence (PL) of porous silicon has been studied. After four hour positron irradiation, the red PL spectrum of porous silicon blue shifts into greenish spectral region, and a higher energy luminescence band is introduced into this blueshifted spectrum. The fourier transform infrared absorption experiment shows that the positron irradiation can cause further oxidization of porous silicon. A possible mechanism causing this change of PL spectra after positron irradiation is suggested

Heavy ions amorphous semiconductors irradiation study

International Nuclear Information System (INIS)

Benmalek, M.

1978-01-01

The behavior of amorphous semiconductors (germanium and germanium and arsenic tellurides) under ion bombardment at energies up to 2 MeV was studied. The irradiation induced modifications were followed using electrical parameter changes (resistivity and activation energy) and by means of the transmission electron microscopy observations. The electrical conductivity enhancement of the irradiated samples was interpreted using the late conduction theories in amorphous compounds. In amorphous germanium, Electron Microscopy showed the formations of 'globules', these defects are similar to voids observed in irradiated metals. The displacement cascade theory was used for the interpretation of the irradiation induced defects formation and a coalescence mechanism of growth was pointed out for the vacancy agglomeration [fr

Studies on some irradiated food products

International Nuclear Information System (INIS)

Mohammed, H.M.B.

1998-01-01

The aim of this investigation was to study the possibility of using some doses of gamma irradiation and cold storage (4+1 C) for improving the hygienic quality and shelf-life of some meat products ( beef luncheon, processed minced beef and fresh beef sausage). luncheon meat samples were irradiated at doses of 4,6,8,10 and 12 k Gy, while beef and sausage samples were subjected to 4,6 and 8 KGy gamma rays doses and the effects of irradiation on the organoleptic properties, microbiological aspects and the chemical composition were studied during cold storage (4+1 C) of samples. Attention was focussed on the changes occurred in the organoleptic properties of these products by the evaluation of sensory scores for appearance, color and odor of samples post irradiation and during cold storage (4+1 C). In addition, the effects of treatments and cold storage on the microbiological quality by the determination of total bacterial count, total psychropilic bacteria, total coliforms, total molds and yeasts, staphylococcus aureus, streptococcus faecalis as well as the detection of salmonellae were studied

Study of irradiation creep of vanadium alloys

Energy Technology Data Exchange (ETDEWEB)

Tsai, H.; Strain, R.V.; Smith, D.L. [Argonne National Lab., IL (United States)] [and others

1997-08-01

Thin-wall tubing was produced from the 832665 (500 kg) heat of V-4 wt.% Cr-4 wt.% Ti to study its irradiation creep behavior. The specimens, in the form of pressurized capsules, were irradiated in Advanced Test Reactor and High Flux Isotope Reactor experiments (ATR-A1 and HFIR RB-12J, respectively). The ATR-A1 irradiation has been completed and specimens from it will soon be available for postirradiation examination. The RB-12J irradiation is not yet complete.

Comparative study on disinfection potency of spore forming bacteria by electron-beam irradiation and gamma-ray irradiation

International Nuclear Information System (INIS)

Takizawa, Hironobu; Suzuki, Satoru; Suzuki, Tetsuya; Takama, Kozo; Hayashi, Toru; Yasumoto, Kyoden.

1990-01-01

Along with gamma-ray irradiation, electron-beam irradiation (EB) is a method to disinfect microorganisms which cause food decomposition and food-poisoning. The present study was undertaken to compare sterilization efficacy of EB and gamma-ray irradiation on bacterial spores and vegetative cells under various conditions. Spores of Bacillus pumilus, a marker strain for irradiation study, and Bacillus stearothermophilus known as a thermophilic bacteria were irradiated by electron-beam and gamma-ray separately at irradiation dose of 0 to 10 kGy on combination of wet/dry and aerobic/anaerobic conditions. Sterilization effect of irradiation on spores was evaluated by colony counting on agar plates. Results showed that both EB and gamma-ray irradiation gave sufficient sterilization effect on spores, and the sterilization effect increased exponentially with irradiation dose. The sterilization effect of gamma-ray irradiation was higher than that of EB in all cases. Higher disinfection effect was observed under aerobic condition. The present study suggests that oxygen supply in EB is more important than gamma-ray irradiation. No results suggesting that chlorine ion at 0.1 ppm (as available chlorine concentration) enhanced the sterilization efficacy of either EB or gamma-ray irradiation was obtained under any conditions examined. (author)

Comparative study on disinfection potency of spore forming bacteria by electron-beam irradiation and gamma-ray irradiation

Energy Technology Data Exchange (ETDEWEB)

Takizawa, Hironobu; Suzuki, Satoru; Suzuki, Tetsuya; Takama, Kozo [Hokkaido Univ., Hakodate (Japan). Faculty of Fisheries; Hayashi, Toru; Yasumoto, Kyoden

1990-10-01

Along with gamma-ray irradiation, electron-beam irradiation (EB) is a method to disinfect microorganisms which cause food decomposition and food-poisoning. The present study was undertaken to compare sterilization efficacy of EB and gamma-ray irradiation on bacterial spores and vegetative cells under various conditions. Spores of Bacillus pumilus, a marker strain for irradiation study, and Bacillus stearothermophilus known as a thermophilic bacteria were irradiated by electron-beam and gamma-ray separately at irradiation dose of 0 to 10 kGy on combination of wet/dry and aerobic/anaerobic conditions. Sterilization effect of irradiation on spores was evaluated by colony counting on agar plates. Results showed that both EB and gamma-ray irradiation gave sufficient sterilization effect on spores, and the sterilization effect increased exponentially with irradiation dose. The sterilization effect of gamma-ray irradiation was higher than that of EB in all cases. Higher disinfection effect was observed under aerobic condition. The present study suggests that oxygen supply in EB is more important than gamma-ray irradiation. No results suggesting that chlorine ion at 0.1 ppm (as available chlorine concentration) enhanced the sterilization efficacy of either EB or gamma-ray irradiation was obtained under any conditions examined. (author).

Chronic radiation injury with mice and dogs exposed to external whole-body irradiation at the Argonne National Laboratory

International Nuclear Information System (INIS)

Grahn, D.; Fritz, T.E.

1986-01-01

This document describes studies on chronic radiation injury in experimental animals and the extrapolation of derived injury parameters to man. Most of the large studies have used mice given single, weekly, or continuous exposure to cobalt-60 gamma rays, or, more recently, single or weekly exposure to fission neutrons from the JANUS reactor. Primary measures of injury have been life shortening and the associated major pathological changes, particularly neoplastic diseases. Recent and ongoing studies compare the effects of extremely low neutron exposures with gamma irradiations delivered as a single dose or in 60 equal weekly increments. Total neutron doses range from 1 to 40 rads; gamma-ray doses range from 22.5 to 600 rads. Selected genetic studies are performed concurrently to provide a nearly complete matrix of somatic and genetic effects of these low exposures. Studies with the beagle have complemented those with mice and have shown a strong parallelism in the responses of the two species. Present exposures are at 0.3, 0.75, and 1.88 rads per day of continuous gamma irradiation to test a model for the prediction of life shortening in man which has evolved from Argonne's long-term studies. The dog offers the opportunity for longitudinal clinical evaluations that are not possible in the mouse, to develop a broader view of the neoplastic disease spectrum, and to study the mechanisms of radiation induction of leukemia. Diverse statistical approaches have been used to measure excess risk, dose-response functions, and rates of injury and repair. Actuarial statistical methods have been favored since they permit a more direct means of extrapolation to man. 50 refs., 4 figs

Irradiation preservation processing study of strawberry

International Nuclear Information System (INIS)

Xu Shihong; Zhu Zhaodi

1992-01-01

Radiation preservation processing of strawberry was studied. The results show that single seal processing or combining with irradiation processing under given doses is of no practical value, but only combining with chill processing can promote lengthening period of fresh keeping. Single irradiation processing under given doses provides not only good initial state, but also the beginning of bad development at top speed on microorganism. The composite processing of irradiation, chill and seal can supply extended shelf lifetime with optimum value of dual synergetic effect

Effect of chronic radiation on rape genotype formation

International Nuclear Information System (INIS)

Fabry, A.; Hannich, K.; Cerny, J.; Vyvadilova, M.

1975-01-01

The F 1 generation of hybrid plants of the Canadian erucic acid-free rape cross-bred with some European winter rape varieties with a high content of erucic acid were chronically irradiated in a gamma-field with doses ranging from 5978 to 329 R er vegetation. In segregating F 2 generations, the irradiation significantly increased the proportion of winter genotypes; a matroclinous influence on the developmental characteristics of plants occurred in irradiated segregating F 2 hybrid populations. As against spring rape, winter rape varieties used as the maternal form during hybridization caused a statistically significant increase in the frequency of winter genotypes. The segregation of half-winter forms in irradiated segregating hybrid populations of the F 2 generation proved the incomplete dominance of the spring habit of oil rape. Chronic irradiation significantly increased erucic-free (0 - 10% of erucic acid) and low-erucic (10 - 20% of erucic acid) genotype frequencies in segregating F 2 generations. Chronic irradiation of the hybrid plants of erucic-free spring rapes and erucic winter rapes with doses ranging from 5978 to 329 R per vegetation, together with the temperature screening of winter forms and with the determination of the fatty acid content, may be considered as an effective method of creating non-erucic and low-erucic winter forms of oil rape. (author)

Facilities for studying radiation damage in nonmetals during irradiation

International Nuclear Information System (INIS)

Levy, P.W.

1984-08-01

Two facilities have been developed for making optical absorption, luminescence and other measurements on a single sample before, during and after irradiation. One facility uses 60 Co gamma rays and the other 0.5 to 3 MeV electrons from an accelerator. Optical relays function as spectrophotometers, luminescenc detectors, etc. All radiation sensitive components are outside of walk-in irradiation chambers; all measurement control and data recording is computerized. Irradiations are made at controlled temperatures between 5K and 900 0 C. The materials studied include glasses, quartz, alkali halides (especially natural rock salt), organic crystals, etc. As determined from color center measurements the damage formation rate in all materials studied at 25 0 C or above is strongly temperature dependent. The defect concentration during irradiation is usually much greater than that measured after irradiation. The fraction of defects annealing after irradiation and the annealing rate usually increases as the irradiation temperature increases. The completed studies demonstrate that, in most cases, the extent of maximum damage and the damage formation and annealing kinetics can be determined only by making measurements during irradiation

Wholesomeness studies in the International Food Irradiation Project

Energy Technology Data Exchange (ETDEWEB)

Elias, P S [International Food Irradiation Project, Federal Research Centre for Nutrition

1980-01-01

Despite more than 25 years of history as an effective food preservation method, food irradiation is still subject to strict legislative control in many countries and scientific investigations are required to provide reassurance as to the safety of irradiated food. The International Food Irradiation Project was set up on October 14, 1970 to facilitate the objective evaluation of the wholesomeness of irradiated foodstuffs. Its major activities are; (1) wholesomeness testing of irradiated foods, (2) research on and investigations into the methodology of wholesomeness testing, (3) dissemination of information, and (4) assisting national and international authorities in their consideration of acceptance of irradiated food. In particular, the project over the past nine years had been devoted to the provision of data to national health authorities and international bodies. Up to now, 23 studies were and are being carried out for the project under contract. Subjects for the studies include wheat, wheat flour, potatoes, fish, rice, mango, spices, dried dates, onions and cocoa beans.

Wholesomeness studies in the International Food Irradiation Project

International Nuclear Information System (INIS)

Elias, P.S.

1980-01-01

Despite more than 25 years history as an effective food preservation method, food irradiation is still subject to strict legislative control in many countries and it is required to carry out scientific investigations to reassure the safety of irradiated food. The International Food Irradiation Project was set up on October 14, 1970 to facilitate the objective evaluation of the wholesomeness of irradiated foodstuffs. Its major activities are; (1) wholesomeness testing of irradiated foods, (2) research on and investigations into the methodology of wholesomeness testing, (3) dissemination of information, and (4) assisting national and international authorities in their consideration of acceptance of irradiated food. In particular, the project over the past nine years had been devoted to the provision of data to national health authorities and international bodies. Up to now, 23 studies were and are being carried out for the project under contract. Subject to the studies include wheat, wheat flour, potatoes, fish, rice, mango, spices, dried dates, onions and cocoa beans. (Kitajima, A.)

Study for the identification of irradiated carbohydrate containing food

International Nuclear Information System (INIS)

Scherz, H.

1991-01-01

The study was undertaken to find radiation specific substances of carbohydrates and methods to detect those ones in irradiated food. Deoxycompounds have been found by irradiation of carbohydrates. It could be stated, that the formation of these substances was radiation specific. The irradiation of wheat for desinfestation was high actual at the moment of this study and therefore it was tried to find these deoxycompounds in irradiated potato starch and wheat flour. These substances were isolated and one of them was identified as w-hydroxymaltol. This substance was also found in irradiated wheat flour. The dependence between the amount of w-hydroxymaltol and the irradiation dosage was determined for both materials. (7 refs, 2 figs)

E-submission Format for Sub-chronic and Chronic Studies

Science.gov (United States)

The purpose of this document is to suggest the format for final reports and to provide instructions for creation of Adobe PDF electronic submission documents for electronic submission of sub-chronic and chronic studies for pesticides.

Electron microscope study of irradiated beryllium oxide

International Nuclear Information System (INIS)

Bisson, A.A.

1965-06-01

The beryllium oxide is studied first by fractography, before and after irradiation, using sintered samples. The fractures are examined under different aspects. The higher density sintered samples, with transgranular fractures are the most interesting for a microscopic study. It is possible to mark the difference between the 'pores' left by the sintering process and the 'bubbles' of gases that can be produced by former thermal treatments. After irradiation, the grain boundaries are very much weakened. By annealing, it is possible to observe the evolution of the gases produced by the reaction (n, 2n) and (n. α) and gathered on the grain boundaries. The irradiated beryllium oxide is afterwards studied by transmission. For that, a simple method has been used: little chips of the crushed material are examined. Clusters of point defects produced by neutrons are thus detected in crystals irradiated at the three following doses: 6 x 10 19 , 9 x 10 19 and 2 x 10 20 n f cm -2 at a temperature below 100 deg. C. For the irradiation at 6 x 10 19 n f cm -2 , the defects are merely visible, but at 2 x l0 20 n f cm -2 the crystals an crowded with clusters and the Kikuchi lines have disappeared from the micro-diffraction diagrams. The evolution of the clusters into dislocation loops is studied by a series of annealings. The activation energy (0,37 eV) calculated from the annealing curves suggests that it must be interstitials that condense into dislocation loops. Samples irradiated at high temperatures (650, 900 and 1100 deg. C) are also studied. In those specimens the size of the loops is not the same as the equilibrium size obtained after out of pile annealing at the same temperature. Those former loops are more specifically studied and their Burgers vector is determined by micro-diffraction. (author) [fr

Study of inhibition on lipid oxidation of irradiated pork

International Nuclear Information System (INIS)

Ha Yiming

2006-03-01

It was studied that the effect factors of irradiation dose, preservation temperature, oxygen content and antioxidant on lipid oxidation of irradiated pork. A mechanism was explained on lipid oxidation of irradiated pork. The results showed that irradiation might aggravate lipid oxidation of pork and that decreased preservation temperature and oxygen content of the packaging, added antioxidant also could effectively inhibit lipid oxidation of irradiated pork. (authors)

Effect of irradiation on the canine exocrine pancreas

International Nuclear Information System (INIS)

Pieroni, P.L.; Rudick, J.; Adler, M.; Nacchiero, M.; Rybak, B.J.

1976-01-01

Effects of irradiation on the pancreas was studied in 6 dogs receiving a dose equivalent to the biologic effect of 4000 R/6 weeks (with a nominal standard dose of 1175 rets) given to patients with Hodgkins disease. After control secretory, histologic and pancreatographic studies, 6 Thomas fistula dogs were subjected to 2400 R tumor dose over two weeks. There was a biphasic response to secretin alone or secretin with cholecystokininpancreozymin. An initial hypersecretion occurred at 2 weeks--volume was increased, but bicarbonate and enzyme output remained unchanged. Thereafter there was a progressive reduction in volume, bicarbonate and enzyme outputs (greater than 90 percent after 3 months). Histology showed early ductal reduplication but with progressive fibrosis, features compatible with chronic pancreatitis. Pancreatic insufficiency may contribute to post-irradiation gastrointestinal symptomatology. Close field irradiation of the pancreas results in actual destruction of the parenchyma

Biochemical and Tissue Studies on Post Irradiation Recovery in Mammals

International Nuclear Information System (INIS)

Abdou, M.I.M.

2004-01-01

three main studies were performed in this thesis, namely, mortality and survival study, biochemical studies, and studies on tissue alterations cobalt-60 gamma irradiation for low let was used for the external whole body irradiation of the irradiated animal groups. a total number of animals of 722 virgin female adult wister rats of approximately the same age and weight were used for the three studies that were performed, including the control and irradiated animal groups. the animals were housed and kept with special care at fixed temperature, humidity and diet. the study on mortality and survival included 370 animals divided into control and groups irradiated with 4,5,6,7,8 and 9 Gy. this study was followed up for one year to record the number and date of animal deaths for the different irradiated groups. for the 8 and 9 Gy irradiated groups the follow up ended after 12 weeks and 11 days respectively when animal mortality reached 100%. the maximum percent mortality was noted at the second week (3.3,8,14 and 29%) for the 4,5,6 and 7 Gy irradiated groups respectively. for the 8 and 9 Gy irradiated groups, the maximum percent mortality was noted at the first week (42.9 and 90% respectively). regression equations were applied for the percent of mortality of the 5-8 Gy irradiated groups to estimate the LD 50/30, which was found to be 6.4 Gy

Consumer acceptance of irradiated food products: an apple marketing study

International Nuclear Information System (INIS)

Terry, D.E.; Tabor, R.L.

1990-01-01

This study was exploratory in nature, with emphasis on initial purchases and not repeat purchases or long-term loyalties to either irradiated or non-irradiated produce. The investigation involved the actual sale of irradiated and non-irradiated apples to consumers. Limited information about the process was provided, and apples were sold at roadside stands. Prices for the irradiated apples were varied while the price for the non-irradiated apples was held constant. Of these 228 West-Central Missouri shoppers, 101 (44%) bought no irradiated apples, 86 (38%) bought only irradiated apples, and 41 (18%) bought some of both types, Results of probit regressions indicated three significant independent variables. There was an inverse relationship between the price of irradiated apples and the probability of purchasing irradiated apples. There was a positive relationship between the purchasers’ educational level and the probability of purchasing irradiated apples. Predicted probabilities for belonging to categories in probit models were computed. Depending on particular equation specification, correctly placed were approximately 70 percent of the purchasers of the two categories--bought only non-irradiated apples, or bought some of both irradiated and non-irradiated apples or only irradiated apples. This study suggests that consumers may be interested in food irradiation as a possible alternative or supplement to current preservation techniques

In-situ high temperature irradiation setup for temperature dependent structural studies of materials under swift heavy ion irradiation

International Nuclear Information System (INIS)

Kulriya, P.K.; Kumari, Renu; Kumar, Rajesh; Grover, V.; Shukla, R.; Tyagi, A.K.; Avasthi, D.K.

2015-01-01

An in-situ high temperature (1000 K) setup is designed and installed in the materials science beam line of superconducting linear accelerator at the Inter-University Accelerator Centre (IUAC) for temperature dependent ion irradiation studies on the materials exposed with swift heavy ion (SHI) irradiation. The Gd 2 Ti 2 O 7 pyrochlore is irradiated using 120 MeV Au ion at 1000 K using the high temperature irradiation facility and characterized by ex-situ X-ray diffraction (XRD). Another set of Gd 2 Ti 2 O 7 samples are irradiated with the same ion beam parameter at 300 K and simultaneously characterized using in-situ XRD available in same beam line. The XRD studies along with the Raman spectroscopic investigations reveal that the structural modification induced by the ion irradiation is strongly dependent on the temperature of the sample. The Gd 2 Ti 2 O 7 is readily amorphized at an ion fluence 6 × 10 12 ions/cm 2 on irradiation at 300 K, whereas it is transformed to a radiation-resistant anion-deficient fluorite structure on high temperature irradiation, that amorphized at ion fluence higher than 1 × 10 13 ions/cm 2 . The temperature dependent ion irradiation studies showed that the ion fluence required to cause amorphization at 1000 K irradiation is significantly higher than that required at room temperature irradiation. In addition to testing the efficiency of the in-situ high temperature irradiation facility, the present study establishes that the radiation stability of the pyrochlore is enhanced at higher temperatures

Cell-kinetics of the human uterine cervical carcinoma cells during radium irradiation

International Nuclear Information System (INIS)

Iwata, Masaharu; Sasaki, Hiroshi

1983-01-01

HeLa cells grown in a monolayer culture and in nude mice were exposed to graded dose rates (37, 55 or 200 rad/hour) and doses (500-2,000 rad) of radiation and analyzed in terms of their cell cycle distribution using flow-microfluorometry. In the case of the cultured HeLa cells, dose-survival curves were constructed using colony formation as the end-point. The HeLa cells, both in vitro and in vivo, accumulated in G2-M phases after both acute and chronic irradiation. The dose rate of 37 rad/hour proved to be the most effective in producing G2-M accumulation, which is the sensitive phase of the cell cycle. In comparing the G2-M accumulation to the irradiation time, 55 and 37 rad/hour proved to be similarly efficient in producing G2-M accumulation, both in vitro and in vivo. When survival of HeLa cells in vitro was studied, the radiation-induced changes in cell distribution correlated with cell survival and accounted for the change in the dose rate effect above 1,000 rads. In the case of in vivo HeLa cells, the decrease in the number of G0+G1 stage cells was demonstrated during chronic irradiation (37 and 55 rad/hour). The two low dose rates were equally efficient in producing a decrease in the number of G0+G1 cells. These data indicate that chronic irradiation induces redistribution and recruitment more effectively than acute irradiation. (author)

Chronic pyelonephritis: Modulation of host defenses by cyclosporin A

International Nuclear Information System (INIS)

Findon, G.; Miller, T.E.

1989-01-01

Chronic experimental pyelonephritis is characterized by a stable level of infection, which persists for many months. Administration of cyclosporin A (CsA) reactivated previously healed renal lesions and caused a marked increase in bacterial numbers in the kidney. Studies were then carried out to compare the effects of CsA, and the nonselective cytodepletive agents irradiation and cyclophosphamide, on both host defenses and the bacteriologic status of chronically infected kidneys. Two different responses were observed. In animals treated with CsA, bacterial numbers increased markedly, although circulating neutrophil numbers were relatively unaffected. This observation was in contrast to the severe ablation of leukocyte numbers and competence needed to achieve an equivalent effect when irradiation and cyclophosphamide were used. One possible explanation for the adverse effect of CsA on the host-parasite balance in chronic pyelonephritis is that CsA affects mediators that control the inflammatory response or induces a qualitative change in a critical cellular defense compartment

Chronic exposure of Sk-1 hairless mice to narrow-band ultraviolet A (320-355 nm)

International Nuclear Information System (INIS)

Menter, J.M.; Sayre, R.M.; Etemadi, A.A.; Agin, P.P.; Wills, I.

1996-01-01

Several recent investigations collectively suggest that the role of ultraviolet A (UVA) in chronic actinic skin damage may be greater than originally thought. In the present work, the output of a xenon-arc solar-simulator passed through a Bausch and Lomb monochromator in conjunction with a 2-mm Schott WG-320 filter produced narrow-band UVA centered at 338 nm, half-band width 24 nm, I 0 =3.4±0.3 mW/cm 2 . We chronically irradiated 10 SK-1 albino hairless mice 5 times per week for 18 weeks, starting with 1.25 J/cm 2 , for 33 irradiation days, sequentially followed by 1.50 J/cm 2 (34 days), 1.8 J/cm 2 (10 days), 2.0 J/cm 2 (22 days) to afford a total UVA dose of 154.3 J/cm 2 over 99 irradiation days. Erythema was noted clinically by day 6, which persisted throughout the irradiation. During the irradiation period, some scaling, consistent with mild epidermal hyperplasia was noted during irradiation days 37-56. This response later regressed despite continued chronic irradiation. Hematoxylin and eosin examination immediately after the final irradiation revealed a mild inflammatory response, with some dermal restructuring. At the end of the experiment, no significant signs of epidermal hyperplasia or (pre)malignant lesions were seen, although some stratum corneum thickening was noted. Marked dermal collagen damage and moderate elastosis was also evident. We believe that the observed differences in results reported in previous studies are in large part due to differences in light sources and irradiation protocols. (au)

Effect of post-Chernobyl chronic irradiation on some important plant processes

International Nuclear Information System (INIS)

Goncharova, N.

1994-01-01

The efficiency of photosynthetic plant apparatus characterized by photochemical activity of chloroplasts (the Hill reaction), cyclic photophosphorylation and activity of ribulosebiphosphate carboxylase (RuBC) is investigated. These characteristics are used to show the state of plant growing under increased background radiation. There is a trend towards increase of chlorophyll content per unit wet weight of a leaf and reduction in the concentration of soluble protein in irradiated plants. However, the photochemical reactions, as indicated by RuBC activity, are similar. The low hydrolytic activity of chlorophyllase, an enzyme of chlorophyll degradation, indicates a high activity of the photosynthetic apparatus of plants growing under increased background radiation conditions. Thus, the observed resistance of photosynthetic apparatus to ionizing radiation and stimulation of pigment metabolism and activity of photochemical and enzyme reactions reveals a high adaptive ability of plants. Under conditions of elevated radiation background, the processes of photosynthesis in plants may become more active. This in turn may favour the accumulation of green mass and the crop raising. The prolonged chronic action of radionuclides on plants in contaminated zones will be determined by their specific accumulation in individual plant species, their radiosensitivity and factors connected with their growth - type of soil, kind of radionuclide fallout, chemical and physical effects. (author)

Flux and energy deposition distribution studies inside the irradiation room of the portuguese 60Co irradiation facility

International Nuclear Information System (INIS)

Portugal, Luis; Oliveira, Carlos

2008-01-01

Full text: In December 2003 the irradiator of the Portuguese 60 Co irradiation facility, UTR, was replenished. Eighteen new sources were loaded and the older ones (156) were rearranged. The result was an irradiator with about 10.2 P Bq of total activity. The active area of the irradiator has also increased. Now it uses twenty five of the thirty tubes of the source rack, nine more than in the previous geometry. This facility was designed mainly for sterilisation of medical devices. However it is also used for the irradiation of other products such as cork stoppers, plastics and a limited number of food and feed. The purpose of this work is to perform dosimetric studies inside the irradiation room of a 60 Co irradiation facility, particularly, the flux and energy deposition distributions. The MCNPX code was used for the simulation of the facility. The track average mesh tally capabilities of MCNPX were used to plot the photon flux and energy deposition distributions. This tool provides a fast way for flux and energy deposition mapping. The absorbed dose distribution near the walls of the irradiation room was also calculated. Instead of using meshtallys as before, the average absorbed dose inside boxes lined with the walls was determined and afterwards a plot of its distribution was made. The absorbed dose rates obtained ranged from 5 to 500 Gy.h -1 depending on material being irradiated in process and the location on the wall. These positions can be useful for fixed irradiation purposes. Both dosimetric studies were done considering two different materials being irradiated in the process: cork stoppers and water, materials with quite different densities (0.102 and 1 g.cm-3, respectively). These studies showed some important characteristics of the radiation fields inside the irradiation room, namely its spatial heterogeneity. Tunnelling and shadow effects were enhanced when the product boxes increases its density. Besides a deeper dosimetric understanding of the

Studies on potato irradiation in the G.D.R

International Nuclear Information System (INIS)

Luther, Th.; Huebner, G.; Grahn, Ch.; Doellstaedt, R.

1990-01-01

The studies of potato irradiation have been conducted in the framework of the National Food Irradiation Research Project for 4 years. Although in the G.D.R. the use of chemical sprout inhibitors is allowed, potato irradiation can be an alternative technique for potato processing. Before irradiation a wound healing period of approx. 2 weeks is absolutely necessary to protect the potatoes from Fusarium. The method that presents the minimum risk of damage is irradiation in containers. Economic evaluations for the irradiation of potatoes are also made. (author)

Cost/benefit study on date disinfestation by gamma irradiation in Algeria

International Nuclear Information System (INIS)

Mahlous, M.

2002-01-01

To establish the irradiation technology, one must have a holistic approach to the technology of food irradiation in order to assure a maximum utilization rate of the facility. The assumptions in this study are based on a free standing multipurpose irradiation facility, the throughput of which is expressed in t·kGy/year, and the unit cost of the treatment in US $/t·kGy. These values may then be applied for the calculation of the treatment cost of any food commodity, according to the irradiation dose needed. The study showed that irradiation treatment of dates is profitable and that the cost of irradiation does not exceed 1.6% of the selling price of the product. Post harvest losses may be considerably reduced thanks to irradiation treatment. A comparative study between irradiation and cold storage showed that irradiation will cost 30% less than cold storage. This study is completed by an evaluation of consumer acceptance of irradiated food products. (author)

Study on determination method of identifying irradiated chicken

International Nuclear Information System (INIS)

Guo Liping; Yu Xuejun; Yu Menghong; Fu Junjie; Zhang Shimin; Bao Jinsong

2003-01-01

The effects of gamma irradiation on the activities of aleipsis, peroxidase, perhydrol catalase and the peroxide values in chicken oil and effects of different storage time on self-oxidation of fat and lipa in irradiated chicken were studied. The results showed that the activities of aleipsis and perhydrol catalase in irradiated chicken decreased with increasing doses, and the peroxide activity and peroxide value of lipa increased with increase of doses. No significant effect of storage time on peroxide value was observed in the irradiated chicken

Some wholesomeness studies on irradiated Iraqi dates

International Nuclear Information System (INIS)

Al Rawi, A.M.; Hamoudi, H.I.

1981-01-01

Iraqi dates (Zahdi and Khestawi) were irradiated at different dose levels (0 to 1500 krad) to extend their shelf-lives. Samples irradiated at 150 krad showed no change in the behaviour studies of tested Swiss albino mice. Fungi were found to have a constant rate of growth on the syrup irradiated dates. Chemical products such as malondialdehyde, deoxy sugars, acids and reducing sugars were quantified. In conclusion, 150 krad is a convenient dose to extend the shelf-lives of the tested dates and is therefore recommended. (author)

[Alaskan commodities irradiation project: An options analysis study

International Nuclear Information System (INIS)

Zarling, J.P.; Swanson, R.B.; Logan, R.R.

1989-09-01

The ninety-ninth US Congress commissioned a six-state food irradiation research and development program to evaluate the commercial potential of this technology. Hawaii, Washington, Iowa, Oklahoma and Florida as well as Alaska have participated in the national program; various food products including fishery products, red meats, tropical and citrus fruits and vegetables have been studied. The purpose of the Alaskan study was to review and evaluate those factors related to the technical and economic feasibility of an irradiator in Alaska. This options analysis study will serve as a basis for determining the state's further involvement in the development of food irradiation technology

Treatment of blastic transformation of chronic granulocytic leukemia by chemotherapy, total body irradiation and infusion of cryopreserved autologous marrow

Energy Technology Data Exchange (ETDEWEB)

Buckner, C D; Stewart, P; Clift, R A; Fefer, A; Neiman, P E; Singer, J; Storb, R; Thomas, E D [Washington Univ., Seattle (USA). School of Medicine; The United States Public Health Service Hospital; Providence Medical Center, and the Fred Hutchinson Cancer Research Center, Seattle, Washington, USA)

1978-01-01

We have previously reported attempts to reestablish the chronic phase of chronic granulocytic leukemia (CGL), in two patients with blastic transrormation, utilizing intensive therapy followed by the infusion of cryopreserved autologous marrow. This approach has now been attempted in a total of seven patients. Marrow was harvested on single or multiple occasions during the chronic phase of CGL and cryopreserved in 10% dimethylsulfoxide. All patients were treated with cyclophosphamide, 120 mg/kg, plus 1,000 rad of total body irradiation followed by infusion of stored marrow. Two patients failed to achieve marrow repopulation and died of infection after 29 and 48 days. Three patients had partial marrow recovery. Two of these achieved repopulation of myeloid, erythroid, and lymphoid elements but did not recover platelet function; one died of hemorrhage on day 55, and one died of cytomegalovirus interstitial pneumonitis on day 58. A third patient had delayed engraftment of all cell elements, most prominently lymphocytes, and died after 84 days of an iodopathic interstitial pneumonitis. Two patients achieved prompt and complete reestablishment of the chronic phase of CGL. One died on day 72 with a fungal pheumonitis and one developed blastic transformation within 4 months. These preliminary results indicate that this approach to the treatment of blastic transformation of CGL is feasible but difficult. Improvements in results may be achieved by more frequent storage of marrow and pheripheral blood stem cells and lymphocytes and further advances in pretransplant therapy.

Soil nutrient content of old-field and agricultural ecosystems exposed to chronic gamma irradiation

International Nuclear Information System (INIS)

Armentano, T.V.; Holt, B.R.; Bottino, P.J.

1975-01-01

Soil nutrients (extractable P. and NO 3 -N, exchangeable Ca, Mg and K), exchangeable Al, pH and organic matter content were measured over the top six inches of the soils of the seven-year old-field portion and the cultivated portion of the Brookhaven gamma field. Although concentrations of all nutrient elements were higher in the agricultural soil, the distributions of Ca, P, Al, pH and organic matter were similar along the radiation gradient in both fields. There was also a regular reduction in the phosphorus with decreasing exposure, but distribution of other elements was not clearly related to radiation effects. The distribution of all elements except K was significantly correlated with pH in the agricultural soil. In the old-field only Ca, Mg and Al showed this relationship. The most conspicuous effects of nearly 25 yr of chronic irradiation of the site were a reduction in soil organic matter content and an increase in soil P in both fields. (author)

Study on silk yellowing induced by gamma-irradiation

International Nuclear Information System (INIS)

Tsukada, Masuhiro; Aoki, Akira

1985-01-01

The changes in the yellow color of silk threads with total dose of irradiation applied were described and studied by a colorimetric method and by monochrome photography. The change into a yellow color of the specimen in the course of irradiation was clearly detected in photographs using filters, 2B and SC 56 under light conditions at the wavelength of 366 nm. The b/L value measured by colorimetry in undegummed and degummed silk fibers sharply increased in the early stage of irradiation. Yellow color indices (b/L) of the specimen subjected to gamma-irradiation continued to increase and the yellow color of the silk threads became more pronounced above a total dose of irradiation of 21 Mrad. The b/L value of the undegummed silk fiber which had deen irradiated was about 2 times that of the degummed silk fiber. (author)

Basal cell carcinoma arising on the skin with chronic radiation dermatitis

International Nuclear Information System (INIS)

Tanaka, Yukiko; Ogusa, Yasuhiro; Tamura, Shinya

1986-01-01

In a 86-year-old woman, basal cell carcinoma (BCC) arose on the skin with chronic radiation dermatitis. She, at the age of 46, received irradiation to the abdomen for cancer of the uterine cervix. Radiation source and dose were unknown. A verrucous eruption appeared on the irradiated field of the right abdomen, and gradually expanded. Histological examination showed that proliferation of tumor cells with adenoid and cystose structure extended to the epidermis. Electron microscopic study showed both clear and dark tumor cells, although dark cells were few in number. A review of the literature showed that BCC arising on the skin with chronic radiation dermatitis is uncommon in Japan. (Namekawa, K.)

Experimental investigations on chronic irradiation damage of the heart

International Nuclear Information System (INIS)

Lauk, S.

1984-02-01

Irradiation of rat hearts induced the following clinical phenomena: increasingly severe dyspnea, associated flank respiration and deterioration of the general condition bordering on a prefinal syndrome. Dissection of the sick animals and thoracal x-rays taken regularly revealed extensive pesicardial and pleural effusions. The tissue of the pericardium was thickened and edematous. The most striking histological finding consisted in a focal degeneration and destruction of the myocardium without an increase in collagenous fibres. This damage to the heart muscle was quite severe and seen in all dose groups from 15 to 40 Gy. At the same time there was a reduction of the capillary density as a function of the radiation dose. Clinical symptoms were also observed in animals irradiated with 10 Gy only. All animals irradiated with at least 20 Gy, attained a state where death was imminent. Consequently, the LD-50 must be lower than 20 Gy. The latency period was over a year at 15 Gy but decreased considerably as the dose increased. (orig.) [de

Electron spin resonance studies of some irradiated pharmaceuticals

International Nuclear Information System (INIS)

Gibella, M.; Crucq, A-S.; Tilquin, B.; Stocker, P.; Lesgards, G.; Raffi, J.

2000-01-01

Five antibiotics belonging to the cephalosporins and penicillins groups have been irradiated: anhydrous ampicilline acid, amoxicilline acid trihydrate, cefuroxime sodium salt, cloxacilline sodium salt monohydrate and ceftazidime pentahydrate. ESR studies have been carried out, showing the influence of irradiation and storage parameters on the nature and concentration of the free radicals trapped. These results may be used to detect an irradiation treatment on such pharmaceuticals. (author)

Reparation in unicellular green algae during chronic exposure to the action of mutagenic factors. II. Restoration of single-stranded DNA breaks following exposure of Chlamydomonas reinchardii to gamma-irradiation

International Nuclear Information System (INIS)

Sergeeva, S.A.; Ptitsina, S.N.; Shevchenko, V.A.

1986-01-01

The restoration of single-stranded breaks in the DNA in different strains of unicellular green algae (chlamydomonads) during chronic exposure to the action of mutagenic factors following γ-irradiation was investigated. It was shown that the restoration of DNA breaks was most effective in the case of strain M γ/sup mt + /, which is resistant to radiation. Strains, that were sensitive to UV irradiation showed a similar order of DNA break restoration as the wild-type strain. Strain UVS-1 showed a higher level of restoration than the wild-type strain. The data indicated that chlamydomonads have different pathways of reparation, which lead to the restoration of breaks induced by γ-irradiation and UV-rays

Pristine and γ-irradiated halloysite reinforced epoxy nanocomposites - Insight study

Science.gov (United States)

Saif, Muhammad Jawwad; Naveed, Muhammad; Zia, Khalid Mahmood; Asif, Muhammad

2016-10-01

The present study focuses on development of epoxy system reinforced with naturally occurring halloysite nanotubes (HNTs). A comparative study is presented describing the performance of pristine and γ-irradiated HNTs in an epoxy matrix. The γ-irradiation treatment was used for structural modification of natural pristine HNTs under air sealed environment at different absorbed doses and subsequently these irradiated HNTs were incorporated in epoxy resin with various wt% loadings. The consequences of γ-irradiation on HNTs were studied by FTIR and X-ray diffraction analysis (XRD) in terms of changes in functional groups and crystalline characteristics. An improvement is observed in mechanical properties and crack resistance of composites reinforced with γ-irradiated HNTs. The irradiated HNTs imparted an improved flexural and tensile strength/modulus along with better thermal performance.

Study on biologically active substances in irradiated apple juice

International Nuclear Information System (INIS)

Tencheva, S.

1975-01-01

The radiochemical changes proceeding by irradiation of foodstuffs rich in carbohydrates are studied. For the purpose pure solutions of D-glucose, D-fructose and sucrose and fresh apple juice, irradiated with 0,5 and 1,0 Mrad are investigated. Changes set in UV-spectra of the irradiated foodstuffs, the specific reaction of malonic dialdehyde formation with 2-thiobarbituric acid and the formation of carbonyl compounds reacting with 2,4-dinitro phenylhydrazine are studied. Results show that in the irradiated sample solutions of sugars and apple juice two peaks are formed. The malonic dialdehyde formation depends on the dose of irradiation applied. The newly formed carbonyl compounds both in the sample solutions and in the juice are 8 to 9 in number. (author)

Study of boron carbide evolution under neutron irradiation

International Nuclear Information System (INIS)

Simeone, D.

1999-01-01

Owing to its high neutron efficiency, boron carbide (B 4 C) is used as a neutron absorber in control rods of nuclear plants. Its behaviour under irradiation has been extensively studied for many years. It now seems clear that brittleness of the material induced by the 10 B(n,α) 7 Li capture reaction is due to penny shaped helium bubbles associated to a high strain field around them. However, no model explains the behaviour of the material under neutron irradiation. In order to build such a model, this work uses different techniques: nuclear microprobe X-ray diffraction profile analysis and Raman and Nuclear Magnetic Resonance Spectroscopy to present an evolution model of B 4 C under neutron irradiation. The use of nuclear reactions produced by a nuclear microprobe such as the 7 Li(p,p'γ) 7 Li reaction, allows to measure lithium profile in B 4 C pellets irradiated either in Pressurised Water Reactors or in Fast Breeder Reactors. Examining such profiles enables us to describe the migration of lithium atoms out of B 4 C materials under neutron irradiation. The analysis of X-ray diffraction profiles of irradiated B 4 C samples allows us to quantify the concentrations of helium bubbles as well as the strain fields around such bubbles.Furthermore Raman spectroscopy studies of different B 4 C samples lead us to propose that under neutron irradiation. the CBC linear chain disappears. Such a vanishing of this CBC chain. validated by NMR analysis, may explain the penny shaped of helium bubbles inside irradiated B 4 C. (author)

Study of irradiation damage structures in austenitic stainless steels

Energy Technology Data Exchange (ETDEWEB)

Hamada, Shozo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1997-08-01

The irradiation damage microstructures in austenitic stainless steels, which have been proposed to be a candidate of structural materials of a fusion reactor, under ions and neutrons irradiation have been studied. In ion irradiation experiments, cross-sectional observation of the depth distribution of damage formed due to ion irradiation became available. Comparison and discussion between experimental results with TEM and the calculated ones in the depth profiles of irradiation damage microstructures. Further, dual-phase stainless steels, consisted of ferritic/austenitic phases, showed irradiation-induced/enhanced precipitation during ion irradiation. High Flux Isotope Reactor with high neutron fluxes was employed in neutron-irradiation experiments. Swelling of 316 steel showed irradiation temperature dependence and this had strong correlation with phase instability under heavy damage level. Swelling resistance of Ti-modified austenitic stainless steel, which has good swelling resistance, decreased during high damage level. This might be caused by the instability of Ti-carbide particles. The preparation method to reduce higher radioactivity of neutron-irradiated TEM specimen was developed. (author). 176 refs.

Study of irradiation damage structures in austenitic stainless steels

International Nuclear Information System (INIS)

Hamada, Shozo

1997-08-01

The irradiation damage microstructures in austenitic stainless steels, which have been proposed to be a candidate of structural materials of a fusion reactor, under ions and neutrons irradiation have been studied. In ion irradiation experiments, cross-sectional observation of the depth distribution of damage formed due to ion irradiation became available. Comparison and discussion between experimental results with TEM and the calculated ones in the depth profiles of irradiation damage microstructures. Further, dual-phase stainless steels, consisted of ferritic/austenitic phases, showed irradiation-induced/enhanced precipitation during ion irradiation. High Flux Isotope Reactor with high neutron fluxes was employed in neutron-irradiation experiments. Swelling of 316 steel showed irradiation temperature dependence and this had strong correlation with phase instability under heavy damage level. Swelling resistance of Ti-modified austenitic stainless steel, which has good swelling resistance, decreased during high damage level. This might be caused by the instability of Ti-carbide particles. The preparation method to reduce higher radioactivity of neutron-irradiated TEM specimen was developed. (author). 176 refs

Long term effects of exposure to ionizing irradiation on periodontal health status – the Tinea Capitis cohort study

Directory of Open Access Journals (Sweden)

Siegal eSadetzki

2015-10-01

Full Text Available Studies among long term survivors of childhood cancer who had received high dose irradiation therapy of 4-60 Gy, demonstrated acute and chronic dental effects including periodontal diseases. However, the possible effects of low to moderate doses of radiation on dental health are sparse. The aim of this study is to investigate the association between childhood exposure to low-moderate doses of ionizing radiation and periodontal health following 50 years from the exposure. The study population included 253 irradiated subjects (treated for Tinea Capitis in the 1950s and, 162 non-irradiated subjects, treated for Tinea Capitis in the 1950s. The estimated dose to the teeth was 0.2-0.4Gy. Dental examination was performed according to the Community Periodontal Index (CPI. Socio-economic and health behavior variables were obtained through a personal questionnaire. Periodontal disease was operationally defined as deep periodontal pockets. A multivariate logistic regression model was used for the association of irradiation status and other independent variables with periodontal status.The results showed that among the irradiated subjects, 23% (95% CI 18%-28% demonstrated complete edentulousness or insufficient teeth for CPI scoring as compared to 13% (95% CI 8%-19% among the non-irradiated subjects (p=0.01. Periodontal disease was detected among 54% of the irradiated subjects as compared to 40% of the non-irradiated (p=0.008. Controlling for education and smoking, the ORs for the association between radiation and periodontal disease were 1.61 (95% CI 1.01-2.57 and 1.95 (95% CI 1.1-3.5 for ever never and per 1 Gy absorbed in the salivary gland, respectively. In line with other studies, a protective effect for periodontal diseases among those with high education and an increased risk for ever smokers were observed. In conclusion, childhood exposure to low-moderate doses of ionizing radiation might be associated with later outcomes of dental health. The

The effect of total body irradiation dose and chronic graft-versus-host disease on leukaemic relapse after allogeneic bone marrow transplantation

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Frassoni, F; Bacigalupo, A [Ospedale San Martino (Italy). Centro Trapianti Midollo Osseo; Scarpati, D [Univ. di Genova (Italy). Ist. di Radiologia; and others

1989-10-01

One-hundred and five patients undergoing allo-geneic bone marrow transplantation (BMT) for acute myeloid leukaemia (AML) (n=61) and chronic myeloid leukaemia (n=44) were analysed for risk factors associated with relapse. All patients received marrow from an HLA identical sibling after preparation with cyclophosphamide 120 mg/kg and total body irradiation (TBI) 330 cGy on each of the three days prior to transplantation. A multivariate Cox analysis indicated that a lower TBI dose (less than 990 cGy) was the most significant factor associated with relapse and the second most important factor associated with recurrence of leukaemia was the absence of chronic graft-versus-host-disease (cGvHD). Actuarial relapse incidence was 62%, 28% and 18% for patients with no, limited or extensive chronic GvHD respectively. However, chronic GvHD had no significant impact on survival. Combined stratification for TBI dose and cGvHD showed that the dose effect of TBI on relapse was evident both in patients with and without cGvHD. Chronic GvHD influenced the risk of relapse only in patients receiving less than 990 cGy. These results suggest that a higher dose of TBI, within this schedule, produced long-term disease-free survival in the majority of AMLs and CMLs. Minor radiobiological side effects were experienced, but a small reduction of the dose may significantly increase the risk of relapse. (author).

The effect of total body irradiation dose and chronic graft-versus-host disease on leukaemic relapse after allogeneic bone marrow transplantation

International Nuclear Information System (INIS)

Frassoni, F.; Bacigalupo, A.; Scarpati, D.

1989-01-01

One-hundred and five patients undergoing allo-geneic bone marrow transplantation (BMT) for acute myeloid leukaemia (AML) (n=61) and chronic myeloid leukaemia (n=44) were analysed for risk factors associated with relapse. All patients received marrow from an HLA identical sibling after preparation with cyclophosphamide 120 mg/kg and total body irradiation (TBI) 330 cGy on each of the three days prior to transplantation. A multivariate Cox analysis indicated that a lower TBI dose (less than 990 cGy) was the most significant factor associated with relapse and the second most important factor associated with recurrence of leukaemia was the absence of chronic graft-versus-host-disease (cGvHD). Actuarial relapse incidence was 62%, 28% and 18% for patients with no, limited or extensive chronic GvHD respectively. However, chronic GvHD had no significant impact on survival. Combined stratification for TBI dose and cGvHD showed that the dose effect of TBI on relapse was evident both in patients with and without cGvHD. Chronic GvHD influenced the risk of relapse only in patients receiving less than 990 cGy. These results suggest that a higher dose of TBI, within this schedule, produced long-term disease-free survival in the majority of AMLs and CMLs. Minor radiobiological side effects were experienced, but a small reduction of the dose may significantly increase the risk of relapse. (author)

Splenic irradiation in the treatment of patients with chronic myelogenous leukemia or myelofibrosis with myeloid metaplasia. Results of daily and intermittent fractionation with and without concomitant hydroxyurea

International Nuclear Information System (INIS)

Wagner, H. Jr.; McKeough, P.G.; Desforges, J.; Madoc-Jones, H.

1986-01-01

Seventeen patients with either chronic myelogenous leukemia (CML) or myelofibrosis with myeloid metaplasia (MMM) received 24 courses of splenic irradiation at this institution from 1973 to 1982. Eleven of the 17 patients had received prior chemotherapy. Patients were treated with 60 Co gamma rays or 6 MV photons. The fraction size ranged from 15 to 100 rad and the total dose per treatment course from 15 to 650 rad, with the exception of one patient who received 1650 rad. Fourteen of 19 courses (71%) given for splenic pain yielded significant subjective relief while 17 of 26 courses given for splenomegaly obtained at least 50% regression of splenic size. Blood counts were carefully monitored before each treatment to limit hematologic toxicity. From this experience, the authors conclude that splenic irradiation effectively palliates splenic pain and reverses splenomegaly in the majority of patients with CML and MMM. Intermittent fractionation (twice or thrice weekly) is more convenient for the patient, appears to be as effective as daily treatment, and may be associated with less hematologic toxicity. Preliminary results of concurrent treatment with splenic irradiation and oral hydroxyurea show promise and warrant further study

Feeding Studies of Irradiated Foods with Insects

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Loaharanu, Srisan

1978-06-15

Insects are of value to man in many scientific studies. Microsomal detoxication systems exist in both insects and mammals. In the preliminary investigations it was found that irradiated cocoa beans and white and red kidney beans (Phaseolus spp.) did not significantly change the percentage of egg-hatch in the insects tested. In more detailed investigations food samples that are susceptible to insect spoilage and are representatives of widely consumed human foods were fed to various insect species. The development, sex distortion and reproductivity of the insects were investigated. Cytogenetic aberrations as related to dominant lethality were studied in insects with reasonably clear chromosomal patterns. The meiosis stage was examined, using the squash technique and Aceto-orcein staining. Black beans, Phaseolus spp., irradiated with up to 200 krad of gamma rays did not apparently change the percentage of survival and the sex ratio of the bean weevil, Zabrotes subfasciatus. Dominant lethality in the German cockroach, Blatella germanica, fed on irradiated black beans did not apparently occur when considering the results of cytological investigation and the number of offspring obtained. Dried sardine samples irradiated with up to 400 krad of gamma rays neither apparently affected the survival nor caused sex distortion in the cheese skipper, Piophila casei. This irradiated product apparently did not induce dominant lethality in the German cockroach as tested. Coffee processed from coffee beans that had been irradiated with up to 100 krad of gamma rays did not apparently cause adverse effects on the experimental insects. (author)

Feeding studies of irradiated foods with insects

International Nuclear Information System (INIS)

Loaharanu, S.

1978-01-01

Insects are of value to man in many scientific studies. Microsomal detoxication systems exist in both insects and mammals. In the preliminary investigations it was found that irradiated cocoa beans and white and red kidney beans (Phaseolus spp.) did not significantly change the percentage of egg-hatch in the insects tested. In more detailed investigations food samples that are susceptible to insect spoilage and are representatives of widely consumed human foods were fed to various insect species. The development, sex distortion and reproductivity of the insects were investigated. Cytogenetic aberrations as related to dominant lethality were studied in insects with reasonably clear chromosomal patterns. The meiosis stage was examined, using the squash technique and Aceto-orcein staining. Black beans, Phaseolus spp., irradiated with up to 200 krad of gamma rays did not apparently change the percentage of survival and the sex ratio of the bean weevil, Zabrotes subfasciatus. Dominant lethality in the German cockroach, Blatella germanica, fed on irradiated black beans did not apparently occur when considering the results of cytological investigation and the number of offspring obtained. Dried sardine samples irradiated with up to 400 krad of gamma rays neither apparently affected the survival nor caused sex distortion in the cheese skipper, Piophila casei. This irradiated product apparently did not induce dominant lethality in the German cockroach as tested. Coffee processed from coffee beans that had been irradiated with up to 100 krad of gamma rays did not apparently cause adverse effects on the experimental insects. (author)

Pristine and γ-irradiated halloysite reinforced epoxy nanocomposites – Insight study

International Nuclear Information System (INIS)

Saif, Muhammad Jawwad; Naveed, Muhammad; Zia, Khalid Mahmood; Asif, Muhammad

2016-01-01

The present study focuses on development of epoxy system reinforced with naturally occurring halloysite nanotubes (HNTs). A comparative study is presented describing the performance of pristine and γ-irradiated HNTs in an epoxy matrix. The γ-irradiation treatment was used for structural modification of natural pristine HNTs under air sealed environment at different absorbed doses and subsequently these irradiated HNTs were incorporated in epoxy resin with various wt% loadings. The consequences of γ-irradiation on HNTs were studied by FTIR and X-ray diffraction analysis (XRD) in terms of changes in functional groups and crystalline characteristics. An improvement is observed in mechanical properties and crack resistance of composites reinforced with γ-irradiated HNTs. The irradiated HNTs imparted an improved flexural and tensile strength/modulus along with better thermal performance. - Highlights: • The γ-irradiation was used for structural modification of halloysite nanotubes. • Composite materials with irradiated HNTs showed improved mechanical properties. • The γ-irradiation treatment is a promising surface modification method.

Onion irradiation - a case study

International Nuclear Information System (INIS)

Huebner, G.

1988-01-01

The irradiation of onions (Allium cepa L.) serves to prevent sprouting associated with long-term storage or transport and storage of onions in climatic conditions which stimulate sprouting. JECFI the Joint Expert Committee for Food Irradiation of FAO/IAEA/WHO, recommended the application of an irradiation dose of up to 150 Gy for sprout inhibition with onions. (author)

Repair of changes in peripheral blood count of rats after chronic irradiation

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Chlebovsky, O; Praslicka, M; Chlebovska, K [Univerzita P.J. Safarika, Kosice (Czechoslovakia). Katedra Vseobecnej Biologie

1980-01-01

Changes are described in the peripheral blood count of rats irradiated during 120 days with doses of 95.7, 191.4, 258.4, 344.5 and 507.2 mGy/day; during 15 days with a dose of 1004.8 mGy and examined till the 180th day after termination of irradiation. The course of repair can be divided into two phases, namely: phase 1 till the 40th day after termination of irradiation when leukocyte and platelet counts reach approximately 50% of control values; this phase lasts until the 100th day after cessation of irradiation; phase 2 from the 100th till the 180th day when these peripheral blood element counts attain the level of control values. Thus in the stated conditions of irradiation, 150 to 180 days are required for radiation damage to the hemopoietic system to repair.

Action of sulfured radioprotectors on spontaneous cerebral electric activity of implanted chronic non irradiated adult rabbit

International Nuclear Information System (INIS)

Fatome, M.

In a previous study, the radioprotective action of serotonin on central nervous system of lethal dose irradiated rabbit had been determined. In the present study, the possibilities of sulfured radioprotectors were considered in order to see if these products have by themselves an action on central nervous system of non irradiated animals [fr

Study of irradiation defects in GaAs

International Nuclear Information System (INIS)

Loualiche, S.

1982-11-01

Characterization techniques: C(V) differential capacity, DLTS deep level transient spectroscopy, DDLTS double deep level transient spectroscopy and DLOS deep level optical spectroscopy are studied and theoretical and experimental fundamentals are re-examined. In particular the centres created by ionic or electronic bombardment of p-type GaAs. New quantitative theoretical bases for the C(V) method are obtained. Study of the optical properties of traps due to irradiation using DLOS. The nature of irradiation defects are discussed [fr

Dosimetry of the portable blood irradiator

International Nuclear Information System (INIS)

Roberson, P.L.; Hungate, F.P.; Reece, W.D.; Tanner, J.E.

1985-08-01

A portable blood irradiator was developed at the Pacific Northwest Laboratory to evaluate the effects of chronic irradiation of the blood in suppressing graft rejection. The irradiator, designed to be worn on the arm or leg and be surgically connected in an arterio-venous shunt, uses beta radiation from activated thulium imbedded in a vitreous carbon matrix to reduce the number of lymphocytes circulating in the blood. The dose and energy spectra relative to the distance from and position around a prototype irradiator were measured by thermoluminescent dosimeters, ion chambers and photon spectroscopy. With computer simulations using those measurements, the shielding was redesigned to minimize the radiation dose to the patient and to the attending personnel and to minimize the weight of the irradiator. The new shielding design was incorporated into a new prototype, and the dose and spectral measurements were repeated, which confirmed the design improvements. 10 refs., 11 figs

Pharmacological approaches to the study of CHOLINO- and GABA-receptor states in nerve cells after irradiation with low intensity

International Nuclear Information System (INIS)

Anan'eva, T.V.; Dvoretskij, A.I.

2000-01-01

The peculiarities of functioning specific cholino- and GABA-receptors (ChR and GABA-R) by modeling the effect of synaptic neuromediators, correspondingly acetocholine (ACh) and gamma-aminobutyric acid (GABA), in low concentrations on the K + active transport in the rats cerebral cortex after single-time or chronical total irradiation with the dose of 0.25 Gy are studied. As a result of the study of both the acetocholine (10 -10 and 10 -6 mole/l) and gamma-aminobutyric avid (10 -9 and 10 -5 mole/l) effects on the K + active transport in the rats cerebral cortex slices in presence of any selective antagonists of the choline- and GABA-receptors, it is shown, that after the whole body irradiation with 25 c Gy (1.75 m Gy/min) the metabotropic muscarinic ChR and GABA B - receptors were involved into the processes of neurotransmitter modulation, whereas under ionotropic nicotinic choline- and GAB A - receptors. The observed changes are supposed to be of adaptive character. The post irradiation structural and functional disturbances may be considered as one of the causes of essential distortions in the processes of interneuronal metabolic communication in the central nerve system [ru

Studies on preservation of agricultural products by irradiation

International Nuclear Information System (INIS)

Chung, K.H.; Kwon, S.H.; Lee, Y.I.; Chae, J.C.; Shin, I.C.

1981-01-01

This study was attempted to develop and establish the preservation techniques of agricultural products by irradiation through ascertainment of the optimum irradiation doses for sprout inhibition of white potato and chestnut, and for disinfestation of rice insects during storage

Progresses in studies on 2-alkylcyclobutanones in irradiated lipid-containing foods

International Nuclear Information System (INIS)

Zhang Haiwei; Ha Yiming; Wang Feng

2007-01-01

When foods are irradiated, the free fatty acids and triacylglycerides in the food are decomposed to 2-alkylcyclobutanones (2-ACBs), which have been one of the focuses in food irradiation studies since they were dis- covered in irradiated lipid-containing foods. As specific markers, 2-ACBs could be used to detect irradiated food. The production and stability of 2-ACBs are affected strongly by the irradiation does and temperature and preservation conditions, etc. On the other hand, potential health hazard assessments of 2-ACBs have been studied extensively. Re- cent progresses in 2-ACBs detecting methods from irradiated food, toxicological studies on 2-ACBs, and factors affecting production and stability of 2-ACBs are reviewed in this paper. (authors)

Facts about food irradiation: Genetic studies

International Nuclear Information System (INIS)

1991-01-01

Results published in the mid-1970s from the National Institute of Nutrition (NIN) in India showed increased numbers of polyploid cells in rats, mice, monkeys and malnourished children fed irradiated wheat products. This fact sheet considers the validity of these results. A large number of independent studies have been subsequently performed, and in none of these have results been obtained that support the NIN findings. The conclusion is that there is no evidence to link the consumption of irradiated food with any mutagenic effect. 3 refs

A prospective study of whether radiation pneumonitis is influenced by low-dose irradiated lung volume in primary lung cancer with chronic pulmonary disease

International Nuclear Information System (INIS)

Niibe, Yuzuru; Hayakawa, Kazushige; Masuda, Noriyuki; Yoshimura, Hirokuni

2007-01-01

The current study prospectively investigated the optimal dose-volume condition in cases of lung cancer with chronic pulmonary disease compared to those without chronic pulmonary disease. Cases of primary lung cancer treated with intended curative radiation therapy were registered in the current study. Their fraction size was limited to 2-3 Gy, so-called standard fractionation. They were prescribed a total dose of 60 Gy for non-small cell lung cancer (NSCLC; n=17) and a total dose of 54 Gy for small cell lung cancer (SCLC; n=4). Of the 21 patients enrolled in this study, 4 had chronic pulmonary disease (study arm), and the others had no chronic pulmonary disease (control arm). Seven received chemotherapy. Symptomatic radiation pneumonitis occurred in 5. Of the four patients in the study arm, two (50%) experienced symptomatic radiation pneumonitis; only 3 of the 17 patients in the control arm (17.6%) experienced symptomatic radiation pneumonitis. Furthermore, the median V 20 of patients who experienced symptomatic radiation pneumonitis in the study arm was 14%, which was higher than that of patients with no symptomatic radiation pneumonitis in the study arm, 5.8%. On the other hand, in the control arm, the median V 20 of patients with symptomatic radiation pneumonitis was 14.2%, about the same as that of patients with no symptomatic radiation pneumonitis in the control arm, 15.1%. The current study suggested that, as much as 15% of V 20 , might play an important role in cases of lung cancer with chronic pulmonary disease. (author)

A model of hemo-immunopoietic system adaptation to chronic low and intermediate radiation doses

International Nuclear Information System (INIS)

Shibkova, D.Z.; Andreeva, O.G.; Efimova, N.V.; Akleev, A.V.

2003-01-01

In this paper radiobiological conformities to natural laws of mice's hemoimmunopoiesis systems (lines CBA and C 57 Bl/6) were investigated upon chronic internal with lowering power doses of β- irradiation 90 Sr and external γ-irradiation with constant power. It was shown that determinative effects of long chronic irradiation become apparent upon development of chronic radioactive effect for experimental animals were observed upon γ-irradiation with power 6 cGy/day and more or under internal with lowering power dose of β-irradiation 90 Sr introduced in concentration above 1.1 c Bq/g, that is correlated with appreciations of other author's made before, concerning 'critical' level of power doses for hemopoietic system. It was shown that reduction of medium length of animals' life correlates with dis-balance into a system and between systems' links of immuno- and hemopoiesis. Physiological balance of those systems was supplied genetically by determinative systems of sanogenesis, responded for forming adaptive processes in organism. Characteristics of positive and negative inter and outward systems' links, induced by additional radiation exposure and noticeably modified constitutive regulative mechanisms being before were made more exact. A model for adaptation of hemoimmunopoiesis system to chronic radiation exposure in a rate of low and intermediate power doses was modeled. A possibility of full or part regeneration of hemopoiesis depending on power dose and kind of irradiation was experimentally substantiated. (author)

Techno-economic studies on transportable moving-bed onion irradiator

International Nuclear Information System (INIS)

Krishnamurthy, K.; Sharma, K.S.S.; Deshmukh, V.P.; Bongirwar, D.R.; Nair, K.V.V.; Patil, K.B.

1984-01-01

The paper presents the optimisation studies and the design features of a transportable irradiator evolved to demonstrate the techno-economic advantage of the irradiation process at village level. A brief outline is also given of the computer programme generated and employed to optimise the source-target configuration based on a narrow plane source moving-bed irradiation concept that aimed at achieving a simplified product handling system and cost effective design of the biological shield and controls for the irradiator. The engineering features of the irradiator along with a summary of the analysis of the economics of the application of the process are also given. (author)

The Effect of Photoluminescence of Bioceramic Irradiation on Middle Cerebral Arterial Occlusion in Rats

Directory of Open Access Journals (Sweden)

Lei Zhang

2016-01-01

Full Text Available The purpose of this study is to determine the possible effect of photoluminescence of bioceramic (PLB on ischemic cerebral infarction (stroke, by using an animal model of transient middle cerebral artery occlusion (MCAO. Sprague-Dawley rats were used to induce MCAO to block the origin of the left MCAO; three months later, the positive chronic stroke rats were selected by running tunnel maze; the MCAO rats with significant chronic stroke and neurological defects were used for treadmill experiments with varying speed settings to test their capability for restoration after muscular fatigue under conditions of with and without PLB irradiation. As a result, PLB irradiation could improve exercise completion rate and average running speed during slow and fast treadmill settings. After PLB irradiation, the selected MCAO rats successfully completed all the second-round treadmill exercises at the maximum speed setting, and they had better restoration from muscular fatigue. An in vitro cell study on astrocytes of rats by bioceramic irradiation further demonstrated increased intracellular nitric oxide. To explain these results, we suggest that cortical brain stimulation of microcirculation and enhancement of peripheral muscular activity are the main causes of the improved exercise performance in MCAO rats by PLB.

Forecasting of the lethality in cases of nonuniform accidental irradiation (experimental studies at external gamma irradiation of rats)

International Nuclear Information System (INIS)

Ingilizova, K.

1983-01-01

A model is suggested that enables the prediction of death probability for the body (L) within the whole lethality dose range (DL 0 -DL 100 ), on the basis of predetermined physical characteristics: in cases of uneven external wholebody irradiation. Some biological effects of 4 variants of uneven irradiation have been studied, i.e. ventro-dorsal (V-D), dorso-ventral (D-V), cranio-caudal (Cr-Ca) and caudo-cranial (Ca-Cr). The following basic conclusions have been drawn: 1. The study of the biological effects of uneven irradiation, when estimated by the lethality factor, points out the lower efficiency of the former, if compared to even irradiation. 2. The even irradiation lethality in the conducted experiments, according to the ALE data and the postradiation mortality dynamics, is determined basically by the damage of the bloodforming tissue and the animals die of bone marrow syndrome. 3. The uneven irradiation, estimated by the total weight factor, is of lower efficiency than the even one. 4. The radiation-induced hypoplasia of the studied organs is exponential in character. 5. An original model for predicting radiation mortality in cases of uneven irradiation has been constructed. The model gives the possibility of relating the alterations in the index of biological efficiency reduction to the wholebody irradiation factor, as well as to the two systems with highest radiosensitivity: red bone marrow and the small intestine. The model helps determining the numerical value of death probability, depending on the average body irradiation doses and the integral unevenness factors for RBM. (author)

Chronic gamma irradiation and hypothalamo-pituitary system in sheep

International Nuclear Information System (INIS)

Arendarcik, J.; Praslicka, M.; Molnarova, M.

1982-01-01

After seven days of irradiation with gamma radiation to a total dose of 6.7 Gy the biochemical, morphological and hematological changes were observed in the bodies of sheep. A chromosomal analysis found a very low number of mitoses. A decrease was found in the total trypsin inhibition activity of the plasma. In the hypothalamus were found significant changes in the representation of catecholamines and a decrease was observed in the weight of ovaries and their follicular system was found to be damaged. This damage is more significant from the functional point of view than the damage caused by an acute local irradiation of the ovaries with doses of 4.7 and 9.5 Gy. (M.D.)

Cherry Irradiation Studies. 1984 annual report

International Nuclear Information System (INIS)

Eakin, D.E.; Hungate, F.P.; Tingey, G.L.; Olsen, K.L.; Fountain, J.B.; Burditt, A.K. Jr.; Moffit, H.R.; Johnson, D.A.; Lunden, J.D.

1985-04-01

Fresh cherries, cherry fruit fly larvae, and codling moth larvae were irradiated using the PNL cobalt-60 facility to determine the efficacy of irradiation treatment for insect disinfestation and potential shelf life extension. Irradiation is an effective disinfestation treatment with no significant degradation of fruit at doses well above those required for quarantine treatment. Sufficient codling moth control was achieved at projected doses of less than 25 krad; cherry fruit fly control, at projected doses of less than 15 krad. Dose levels up to 60 krad did not adversely affect cherry quality factors tested. Irradiation above 60 krad reduced the firmness of cherries but had no significant impact on other quality factors tested. Irradiation of cherries below 80 krad did not result in any significant differences in sensory evaluations (appearance, flavor, and firmness) in tests conducted at OSU. Irradiation up to 200 krad at a temperature of about 25 0 C (77 0 F) did not measurably extend shelf life. Irradiation at 500 krad at 25 0 C (77 0 F) increased mold and rotting of cherries tested. There is no apparent advantage of irradiation over low-temperature fumigation

Study on the sterilization of egg white powder by irradiation

International Nuclear Information System (INIS)

Fu Lixin; Meng Lifen; Zhao Xiaonan; Xu Dechun; Hu Shaoxin; Chen Changdong; Wang Zhidong

2013-01-01

The sterilizing effect, influence on main essential nutrient and sensory qualities of egg white powder treated with 60 Co γ-ray irradiation were studied. The microorganism index of egg white powder samples treated with 4 kGy irradiation could meet the government food sanitation standard, and the sterilization rate could reach 100%. The irradiation doses from 4 to 10 kGy had little influence on egg white powder protein, crude fiber and amino acidscontent, and the sensory quality such as color, luster, and scent changed little below 6 kGy irradiation. Considering the result of this study, the optimal irradiation dose for egg white powder sterilization was 4 to 6 kGy. (authors)

Neonatal irradiation nephropathy in the growing dog. I. Renal morphological and functional adaptations following neonatal, sublethal, whole-body irradiation

International Nuclear Information System (INIS)

Wilke, W.L.; Phemister, R.D.; Jaenke, R.S.

1979-01-01

Sixty beagles were used to study the effects of exposure to 330 R 60 Co γ radiation (bilateral, whole-body) at 2 days of age on renal functional and morphological development in the growing dog. A significant deficit in grams kidney per kilogram body weight was found in irradiated dogs at 50 days of age (P < 0.05), but not at 125 or 200 days of age. Glomerular filtration rate (GFR) per kilogram body weight and GFR per gram kidney were not significantly different between irradiated and nonirradiated dogs at 50, 125, or 200 days of age, but blood urea nitrogen (BUN) was significantly elevated in irradiated dogs throughout this period (P < 0.05). The fractional distribution of intracortical renal blood flow, as determined by radiolabeled microspheres, to the outermost cortex was found to be reduced in irradiated animals at all ages evaluated (P < 0.05). The fractional blood flow to the outermost renal cortex was negatively correlated with BUN in both irradiated (P < 0.05) and nonirradiated (P < 0.05) animals. Based on prior demonstrations of reductions in nephron numbers following similar irradiation, these data indicate increases in mean single nephron GFR and nephronal hypertrophy in the kidneys of the neonatally irradiated dog. The renal functional and morphological adaptations are sufficient to maintain adequate renal function in growing, neonatally irradiated dogs. The BUN elevations in irradiated dogs are believed to be related to changes in intracortical renal blood flow, rather than indicating renal insufficiency. The possible importance of the functional and morphological adaptations to the subsequent development of chronic renal failure in neonatally irradiated animals is discussed

Food irradiation nears commercial development

International Nuclear Information System (INIS)

1981-01-01

One person out of eight in the world today suffers from chronic undernourishment. This problem is likely to get worse as the world's population doubles during the next thirty to forty years. Since about 25% or more of our harvested food is lost due to various kinds of wastage and spoilage, food preservation is no less important than food production. To supply the world's demand for food, it is more reasonable to conserve what is produced than to produce more to compensate for subsequent losses. Thus, it is obvious that all methods of preserving food and agricultural produce should be examined to see if their use might alleviate the world's food shortage, and that to develop better and safer techniques of food preservation will improve food supplies. Food preservation is an ever greater problem for the developing countries, not only because of their chronic problems of undernourishment, but also because most of them are in tropical or sub-tropical regions where food spoilage is rapid. The IAEA and the Food and Agriculture Organization (FAO) held a symposium on food irradiation at Colombo in Sri Lanka. The symposium paid special attention to the use of food irradiation in preserving tropical fruits as well as fish and fish products. It also examined the cost of the food irradiation process and compared it with those of conventional processes. Food irradiation is one field in which advance is most likely to be achieved through international co-operation. This co-operation has been supported by the IAEA and FAO in a number of ways. During the last 15 years three previous symposia (Karlsruhe, 1966; Bombay, 1972; Wageningen, 1977), numerous panel meetings, and training courses, have been held on this subject and many nations' food irradiation projects have been supported by technical assistance and co-ordinated research programmes

Treatment of chronic granulocytic leukemia by chemotherapy, total body irradiation and allogeneic bone marrow transplantation

Energy Technology Data Exchange (ETDEWEB)

Doney, K; Buckner, C D; Sale, G E; Ramberg, R; Boyd, C; Thomas, E D [Fred Hutchinson Cancer Research Institute; Washington Univ., Seattle (USA). School of Medicine)

1978-01-01

Fourteen patients with chronic granulocytic leukemia received bone marrow grafts from HLA identical siblings. Ten patients were in blast crisis prior to grafting, three were in an accelerated phase of their disease, and one was aplastic secondary to chemotherapy. Prior to transplant all patients were conditioned with chemotherapy including cyclophosphamide plus 1,000 rad of total body irradiation. Ten patients achieved engraftment while four died 1 to 26 days after marrow infusion without functioning grafts. Two patients reveived a second infusion of donor marrow because of delayed engraftment. Neither marrow cell dose nor presence of myelofibrosis correlated with succesful engraftment. Three out of ten engrafted patients developed graft-versus-host disease. Interstitial pneumonia occurred in seven patients. The immediate cause of death was bacterial septicemia in six patients. All evidence of leukemia disappeared in nine out of ten evaluable patients. The median survival was 43 days. One patient had a complete remission of 16 months duration.

Treatment of chronic granulocytic leukemia by chemotherapy, total body irradiation and allogeneic bone marrow transplantation

International Nuclear Information System (INIS)

Doney, K.; Buckner, C.D.; Sale, G.E.; Ramberg, R.; Boyd, C.; Thomas, E.D.; Washington Univ., Seattle

1978-01-01

Fourteen patients with chronic granulocytic leukemia received bone marrow grafts from HLA identical siblings. Ten patients were in blast crisis prior to grafting, three were in an accelerated phase of their disease, and one was aplastic secondary to chemotherapy. Prior to transplant all patients were conditioned with chemotherapy including cyclophosphamide plus 1,000 rad of total body irradiation. Ten patients achieved engraftment while four died 1 to 26 days after marrow infusion without functioning grafts. Two patients reveived a second infusion of donor marrow because of delayed engraftment. Neither marrow cell dose nor presence of myelofibrosis correlated with succesful engraftment. Three out of ten engrafted patients developed graft-versus-host disease. Interstitial pneumonia occurred in seven patients. The immediate cause of death was bacterial septicemia in six patients. All evidence of leukemia disappeared in nine out of ten evaluable patients. The median survival was 43 days. One patient had a complete remission of 16 months duration. (Author)

Pathological study about two autopsy cases of bilateral irradiation pneumonitis induced by unilateral irradiation

International Nuclear Information System (INIS)

Yamauchi, Noriko; Tajima, Yo; Iio, Masaaki; Oshima, Takeo; Iino, Koichi.

1978-01-01

The first case is a 73-year-old man with left lung cancer. Seven days after completion of radiotherapy 7,000 rad, a chest roentgenogram showed diffuse bilateral pneumonia. The second case is a 61-year-old woman with right lung cancer and about one month after completion of radiotherapy 2,600 rad, a chest roentgenogram showed bilateral pneumonia. Pathological findings, all lobes of both lungs of these cases showed acute interstitial pneumonitis. The pathogenesis of irradiation pneumonitis is poorly understood. Several investigators thought that the pathogenesis of irradiation pneumonitis was caused by autoimmune mechanism, they carried out sero-pathological studies and demonstrated the bilateral pneumonia caused by unilateral irradiation. (author)

Cytologic studies on irradiated gestric cancer cells

Energy Technology Data Exchange (ETDEWEB)

Isono, S; Takeda, T; Amakasu, H; Asakawa, H; Yamada, S [Miyagi Prefectural Adult Disease Center, Natori (Japan)

1981-06-01

The smears of the biopsy and resected specimens obtained from 74 cases of irradiated gastric cancer were cytologically analyzed for effects of irradiation. Irradiation increased the amount of both necrotic materials and neutrophils in the smears. Cancer cells were decreased in number almost in inverse proportion to irradiation dose. Clusters of cancer cells shrank in size and cells were less stratified after irradiation. Irradiated cytoplasms were swollen, vacuolated and stained abnormally. Irradiation with less than 3,000 rads gave rise to swelling of cytoplasms in almost all cases. Nuclei became enlarged, multiple, pyknotic and/or stained pale after irradiation. Nuclear swelling was more remarkable in cancer cells of differentiated adenocarcinomas.

Ecotoxicological assays of Diethyltoluamide and Lemongrass Essencial Oil in irradiated and non-irradiated aquatic organisms

International Nuclear Information System (INIS)

Gimiliani, Giovana T.; Rogero, Sizue O.; Martini, Gisela A.; Rogero, Jose R.

2015-01-01

Aquatic invertebrates can be potentially exposed to nonradioactive contaminants in conjunction with ionizing radiation, especially in highly industrialized areas surrounding nuclear facilities, where radionuclides can accidentally be discharged in the aquatic environment containing stable chemicals. The aquatic organisms have continually been exposed to chemical contaminants like personal care products (PCPs) which have been found in various environmental matrices and may cause adverse effects to aquatic life and human health as radioactive products. In this study was used C. silvestrii as bioindicator organism in chronic ecotoxicity assays with lemongrass essencial oil (LEO) and Diethyltoluamide (DEET), both are insect repellent. In addition to exposition of the compounds, the organisms were irradiated with gamma rays from Co-60 source. Thus, the aim of this study was to evaluate the possible synergistic effect of gamma radiation and mosquito repellent products in the reproduction of Ceriodaphnia silvestrii utilizing standardized ecotoxicological tests. The C. silvestrii inhibition concentration (IC25; 7 days) result after DEET exposition was 16.4 ± 1.4 mg L -1 and for LEO was 3.1 ± 1.4 mg L -1 . In the irradiated (25 Gy) C. silvestrii exposed to DEET and LEO, the concentration that inhibited reproduction was 16.1 ± 0.9 mg L -1 and 2.4 ± 0.3 mg L -1 respectively. The results showed that the reproduction of irradiated C. silvestrii was not significantly affected when compared with non-irradiated organisms when exposed to DEET or LEO. (author)

Ecotoxicological assays of Diethyltoluamide and Lemongrass Essencial Oil in irradiated and non-irradiated aquatic organisms

Energy Technology Data Exchange (ETDEWEB)

Gimiliani, Giovana T.; Rogero, Sizue O.; Martini, Gisela A.; Rogero, Jose R., E-mail: sorogero@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

Aquatic invertebrates can be potentially exposed to nonradioactive contaminants in conjunction with ionizing radiation, especially in highly industrialized areas surrounding nuclear facilities, where radionuclides can accidentally be discharged in the aquatic environment containing stable chemicals. The aquatic organisms have continually been exposed to chemical contaminants like personal care products (PCPs) which have been found in various environmental matrices and may cause adverse effects to aquatic life and human health as radioactive products. In this study was used C. silvestrii as bioindicator organism in chronic ecotoxicity assays with lemongrass essencial oil (LEO) and Diethyltoluamide (DEET), both are insect repellent. In addition to exposition of the compounds, the organisms were irradiated with gamma rays from Co-60 source. Thus, the aim of this study was to evaluate the possible synergistic effect of gamma radiation and mosquito repellent products in the reproduction of Ceriodaphnia silvestrii utilizing standardized ecotoxicological tests. The C. silvestrii inhibition concentration (IC25; 7 days) result after DEET exposition was 16.4 ± 1.4 mg L{sup -1} and for LEO was 3.1 ± 1.4 mg L{sup -1}. In the irradiated (25 Gy) C. silvestrii exposed to DEET and LEO, the concentration that inhibited reproduction was 16.1 ± 0.9 mg L{sup -1} and 2.4 ± 0.3 mg L{sup -1} respectively. The results showed that the reproduction of irradiated C. silvestrii was not significantly affected when compared with non-irradiated organisms when exposed to DEET or LEO. (author)

NMR studies of defects created by irradiation in metals

International Nuclear Information System (INIS)

Minier, M.; Minier, C.

1983-06-01

Nuclear Magnetic Resonance has been rarely used to study point defects created by irradiation in metals. Information obtained in this field using N.M.R. are shown. Some results are also described: characterization of migrating defects in electron irradiated copper; mobility of the complex interstitial-impurity in Al with 150 ppm of chromium; interstitial structure in irradiated aluminum and autodiffusion in metals [fr

Surface study of irradiated sapphires from Phrae Province, Thailand using AFM

Science.gov (United States)

Monarumit, N.; Jivanantaka, P.; Mogmued, J.; Lhuaamporn, T.; Satitkune, S.

2017-09-01

The irradiation is one of the gemstone enhancements for improving the gem quality. Typically, there are many varieties of irradiated gemstones in the gem market such as diamond, topaz, and sapphire. However, it is hard to identify the gemstones before and after irradiation. The aim of this study is to analyze the surface morphology for classifying the pristine and irradiated sapphires using atomic force microscope (AFM). In this study, the sapphire samples were collected from Phrae Province, Thailand. The samples were irradiated by high energy electron beam for a dose of ionizing radiation at 40,000 kGy. As the results, the surface morphology of pristine sapphires shows regular atomic arrangement, whereas, the surface morphology of irradiated sapphires shows the nano-channel observed by the 2D and 3D AFM images. The atomic step height and root mean square roughness have changed after irradiation due to the micro-structural defect on the sapphire surface. Therefore, this study is a frontier application for sapphire identification before and after irradiation.

Spectroscopic study of gamma irradiated bovine hemoglobin

International Nuclear Information System (INIS)

Maghraby, Ahmed Mohamed; Ali, Maha Anwar

2007-01-01

In the present study, the effects of ionizing radiation of Cs-137 and Co-60 from 4.95 to 743.14 Gy and from 40 Gy to 300 kGy, respectively, on some bovine hemoglobin characteristics were studied. Such an effect was evaluated using electron paramagnetic resonance (EPR) spectroscopy, and infra-red (IR) spectroscopy. Bovine hemoglobin EPR spectra were recorded and analyzed before and after irradiation and changes were explained in detail. IR spectra of unirradiated and irradiated Bovine hemoglobin were recorded and analyzed also. It was found that ionizing radiation may lead to the increase of free radicals production, the decrease in α-helices contents, which reflects the degradation of hemoglobin molecular structure, or at least its incomplete performance. Results also show that the combined application of EPR and FTIR spectroscopy is a powerful tool for determining structural modification of bovine hemoglobin samples exposed to gamma irradiation

Study on irradiation preservation of frozen shelled shrimps

International Nuclear Information System (INIS)

Liu Chunquan; Zhu Jiating; Zhao Yongfu; Yu Gang; Zhang Weidong; Jin Yudong; Ji Ping

2004-01-01

The effect of irradiaiton preservation of frozen shelled shrimps for export was studied. The microbial indexd, nutritional ingredient, physico-chemical index for irradiation frozen shelled shrimps were detected. The results showed that 3-5 kGy irradiation dose could kill more than 99% of all kinds of microorganisms in frozen shelled shrimps, the content of most amino acids in shelled shrimps increased, after being irradiated by 1-9 kGy dose, the total amino acids had been obvisouly higher than CK, the increased range was 0.33%-24.6%, the content of the total volatile basic nitrogen (TVBN) decreased. Compared with the CK, the content of the heavy metal elements etc had no obvious change, the presrvation duration of irradiated shelled shrimp was twelve months longer than that of CK when storage temperature was under -7 degree C soft frozen, Compared with -18 degree C the effect of irradiation preservation had no obvious change. (authors)

Physiologic consequences of local heart irradiation in rats

International Nuclear Information System (INIS)

Geist, B.J.; Lauk, S.; Bornhausen, M.; Trott, K.R.

1990-01-01

Noninvasive methods have been used to study the long-term cardiovascular and pulmonary functional changes at rest and after exercise in adult rats following local heart irradiation with single x-ray doses of 15, 17.5 or 20 Gy, and in non-irradiated control animals. Rats that had undergone a chronic exercise program were compared with untrained cohorts. The earliest dysfunction detected was an increased respiratory rate (f) at 10 weeks after irradiation in the highest dose group. In contrast, both telemetric heart-rate (HR) and rhythm and indirect systolic blood pressure measurements performed at rest only revealed changes starting at 43 weeks after irradiation with 20 Gy, up to which point the rats showed no clinical signs of heart failure. However, the number of minutes required for the recovery of the HR to pre-exercise levels following the implementation of a standardized exercise challenge was elevated in untrained rats compared with their trained cohorts at 18 weeks after irradiation with 20 Gy. Increases in recovery times were required in the two lowest dose groups, starting at 26 weeks after irradiation. It was concluded that the reserve capacity of the cardiopulmonary system masks functional decrements at rest for many months following local heart irradiation, necessitating the use of techniques which reveal reductions in reserve capacities. Further, the influence of local irradiation to the heart and lungs deserves closer scrutiny due to mutual interactions

Studies on apple preservation by 60 -gamma irradiation

International Nuclear Information System (INIS)

Wang Chuanyao; Jiang Mengyue; Gao Meixu

1992-01-01

Studies on '60'Co-gamma 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 k Gy, with this dosage, the contents of vitamin c and titratalbe 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 k Gy

Studies on the safety and consumer acceptance of gamma irradiated meats

Energy Technology Data Exchange (ETDEWEB)

Kang, Il Jun [Hallym University, Kangwon (Korea); Lee, Cherl Ho [Korea University, Seoul (Korea); Kim, Jung Hee [Seoul Women' s University, Seoul (Korea)

1999-04-01

Gamma irradiation was applied to beefs (0-5 kGy) and porks (0-30 kGy) for evaluation of their possible genotoxicity, acute toxicity and four-week oral toxicity. The results were negative in the bacterial reversion assay with S. typhimurium TA98, TA100, TA1535, TA1537. Clastogenic effects of the irradiated samples tested were not shown in vivo mouse micronucleus assay. In an acute toxicity test, the maximal dose of 5,000 mg/kg did not change any toxic parameter examined in this study. In four-week oral toxicity study, no significant differences were found between the control and treatment groups. In the study of rat hepatocarcinogenesis, the consumption of gamma irradiated beef and pork not only does not affect the formation of lipid peroxide and membrane stability but also has a possibility to inhibit hepatocarcinogenesis. Also, the consumption of {gamma} - irradiated beef and pork does not affect antioxidative defense system. In the study of the biological safety of korean red pepper, no difference was found on microbial growth between pepper extract alone or irradiated pepper extract. In the preservation study of korean traditional rice-cake(garedok), irradiation dose below 10kGy had no influence on typical sensory characteristics. The shelf-life in rice-cakes with different conditions was the longest on 10kGy treatment than 5kGy. In investigation of the consumer attitude toward irradiated foods, the main reason for the concern about irradiated foods is that compounds in the products formed by irradiation. Therefore, regulatory authorities must be encouraged to permit the sale of irradiated items when wholesomeness is established. (author). 94 refs.,31 figs., 62 tabs.

Role of L-carnitine in Ameliorating the Cadmium Chloride and/or Irradiation-Induced Testicular Toxicity

International Nuclear Information System (INIS)

Ramadan, L.A.

2003-01-01

The role of oxidative stress in chronic administration of CdCl2 and/or irradiation toxicity and its prevention by pretreatment with L-carnitine was investigated. Adult male rats were administered with CdCl2 (3 mg/kg S.C. three times a week for three weeks) and /or irradiated at (2 Gy) dose level of gamma radiation. CdCl2 administration and/or irradiation induced cellular damage was indicated by significant decrease in lactate dehydrogenase isoenzyme (LDH-X), glutathione level (GSH) and glutathione peroxidase enzyme activity (GSH-PX) as well as significant increase in malonaldehyde (MDA) in testicular tissues. Administration of L-carnitine (200 mg/kg I.P.) 1 hr before CdCl2 and/or irradiation, ameliorated the decrease in LDH-X, GSH and GSH-PX and the increase in MDA induced by CdCl2 and/or irradiation indicating the prophylactic action of L-carnitine on CdCl2 and /or irradiation toxicity. Various studies have indicated that cadmium is a potent heavy metal carcinogen in experimental animals (Poirier et al., 1983 and Waalkes et al..,1988) and is possibly carcinogenic in human populations exposed either occupationally or environmentally (Bako et al., 1982). Target sites for cadmium carcinogenesis in rodents have been shown to include testes after parenteral exposure (Poirier et al., 1983 and Waalkes et al., 1988) and lung after chronic inhalation (Takenaka et al., 1983)

Medium-level laser in chronic tinnitus treatment.

Science.gov (United States)

Dejakum, K; Piegger, J; Plewka, C; Gunkel, A; Thumfart, W; Kudaibergenova, S; Goebel, G; Kral, F; Freysinger, W

2013-01-01

The purpose of this study was to evaluate the effect of medium-level laser therapy in chronic tinnitus treatment. In a prospective double-blind placebo-controlled trial, either active laser (450 mW, 830 nm combined Ga-Al-As diode laser) or placebo irradiation was applied through the external acoustic meatus of the affected ear towards the cochlea. Fourty-eight patients with chronic tinnitus were studied. The main outcome was measured using the Goebel tinnitus questionnaire, visual analogue scales measuring the perceived loudness of tinnitus, the annoyance associated with tinnitus, and the degree of attention paid to tinnitus as well as psycho-acoustical matches of tinnitus pitch and loudness. The results did show only very moderate temporary improvement of tinnitus. Moreover, no statistically relevant differences between laser and placebo group could be found. We conclude that medium-level laser therapy cannot be regarded as an effective treatment of chronic tinnitus in our therapy regime considering the limited number of patients included in our study.

Performance studies under high irradiation of resistive bulk-micromegas chambers at the CERN Gamma Irradiation Facility

CERN Document Server

Sidiropoulou, Ourania; Bortfeldt, J; Farina, E; Iengo, P; Longo, L; Sidiropoulou, O; Wotschack, J

2017-01-01

Radiation studies on several resistive bulk-Micromegas chambers produced at CERN will be viewed in this document. Two resistive bulk-Micromegas chambers have been installed at the CERN Gamma Irradiation Facility (GIF++) exposed to an intense gamma irradiation with the aim of evaluating the detector behaviour under high irradiation and carrying out a long-term age- ing study. The chambers under study have an active area of 10 x 10 cm 2 , a strip pitch of 400 m m , an ampli- fication gap of 128 m m , and a drift gap of 5 mm. The results on the detector performance as a function of the photon flux up to 44 MHz/cm 2 will be shown as well as the ageing properties as function of the integrated charge and the current intensity and its stability with time. In addition, the results of the efficiency measurements before, during, and after the irradiation will also be presented as a function of the amplification voltage at which the chambers are operated.

EPR study on gamma-irradiated fruits dehydrated via osmosis

International Nuclear Information System (INIS)

Yordanov, N.D.; Aleksieva, K.

2007-01-01

The shape and time stability of the electron paramagnetic resonance (EPR) spectra of non- and γ-irradiated papaya, melon, cherry and fig samples dehydrated via osmosis are reported. It is shown that non-irradiated samples are generally EPR silent whereas γ-irradiated exhibit 'sugar-like' EPR spectra. The recorded EPR spectra are monitored for a period of 7 months after irradiation (stored at low humidity and in the dark). The results suggest longer period of unambiguous identification of the radiation processing of osmose dehydrated fruits. Therefore, the Protocol EN 13708,2001 issued by CEN is fully applicable for the studied fruit samples

Stereophotogrammetric study of surface topography in ion irradiated silver

International Nuclear Information System (INIS)

Sokolov, V.N.; Fayazov, I.M.

1993-01-01

The irradiated surface topography of polycrystalline silver was studied using the stereophotogrammetric method. The surface of silver was irradiated with 30 keV argon ions at variation for the ion incidence angle in interval of 0-80 deg relative to a surface normal. The influence of the inclination angle of the sample in the SEM on the cone shape of a SEM-picture of the irradiated surface is discussed. The parameters of cones on the irradiated surface of silver were measured by the SEM-stereomethod. The measurements of the sample section perpendicular to the incidence plane are also carried out

EPR study on gamma-irradiated fruits dehydrated via osmosis

Science.gov (United States)

Yordanov, N. D.; Aleksieva, K.

2007-06-01

The shape and time stability of the electron paramagnetic resonance (EPR) spectra of non- and γ-irradiated papaya, melon, cherry and fig samples dehydrated via osmosis are reported. It is shown that non-irradiated samples are generally EPR silent whereas γ-irradiated exhibit "sugar-like" EPR spectra. The recorded EPR spectra are monitored for a period of 7 months after irradiation (stored at low humidity and in the dark). The results suggest longer period of unambiguous identification of the radiation processing of osmose dehydrated fruits. Therefore, the Protocol EN 13708,2001 issued by CEN is fully applicable for the studied fruit samples.

Modelling population-level consequences of chronic external gamma irradiation in aquatic invertebrates under laboratory conditions

Energy Technology Data Exchange (ETDEWEB)

Lance, Emilie [Laboratoire de modelisation pour l' expertise environnementale (LM2E) Institut de Radioprotection et de Surete Nucleaire (IRSN), PRP-ENV, SERIS, Cadarache (France); Alonzo, Frederic, E-mail: frederic.alonzo@irsn.fr [Laboratoire d' ecotoxicologie des radionucleides (LECO) Institut de Radioprotection et de Surete Nucleaire (IRSN), PRP-ENV, SERIS, Cadarache (France); Garcia-Sanchez, Laurent [Laboratoire de biogeochimie, biodisponibilite et transferts des radionucleides (L2BT) Institut de Radioprotection et de Surete Nucleaire (IRSN), PRP-ENV, SERIS, Cadarache (France); Beaugelin-Seiller, Karine; Garnier-Laplace, Jacqueline [Laboratoire de modelisation pour l' expertise environnementale (LM2E) Institut de Radioprotection et de Surete Nucleaire (IRSN), PRP-ENV, SERIS, Cadarache (France)

2012-07-01

We modelled population-level consequences of chronic external gamma irradiation in aquatic invertebrates under laboratory conditions. We used Leslie matrices to combine life-history characteristics (duration of life stages, survival and fecundity rates) and dose rate-response curves for hatching, survival and reproduction fitted on effect data from the FREDERICA database. Changes in net reproductive rate R{sub 0} (offspring per individual) and asymptotic population growth rate {lambda} (dimensionless) were calculated over a range of dose rates in two marine polychaetes (Neanthes arenaceodentata and Ophryotrocha diadema) and a freshwater gastropod (Physa heterostropha). Sensitivities in R{sub 0} and {lambda} to changes in life-history traits were analysed in each species. Results showed that fecundity has the strongest influence on R{sub 0}. A delay in age at first reproduction is most critical for {lambda} independent of the species. Fast growing species were proportionally more sensitive to changes in individual endpoints than slow growing species. Reduction of 10% in population {lambda} were predicted at dose rates of 6918, 5012 and 74,131 {mu}Gy{center_dot}h{sup -1} in N. arenaceodentata, O. diadema and P. heterostropha respectively, resulting from a combination of strong effects on several individual endpoints in each species. These observations made 10%-reduction in {lambda} a poor criterion for population protection. The lowest significant changes in R{sub 0} and {lambda} were respectively predicted at a same dose rate of 1412 {mu}Gy h{sup -1} in N. arenaceodentata, at 760 and 716 {mu}Gy h{sup -1} in O. diadema and at 12,767 and 13,759 {mu}Gy h{sup -1} in P. heterostropha. These values resulted from a combination of slight but significant changes in several measured endpoints and were lower than effective dose rates calculated for the individual level in O. diadema and P. heterostropha. The relevance of the experimental dataset (external irradiation rather

Preliminary study on sterilization effect of irradiation on dry vegetable

International Nuclear Information System (INIS)

Zhai Jianqing; Bao Jianzhong; Cao Hong; Wang Jinrong; Chen Xiulan

2004-01-01

The number of surviving germs relationship to irradiation dose for several species dry vegetable was studied, and the original value D 10 of the dry vegetable was given. The value will provide a theoretical reference to ascertain the appropriate irradiation dose in the irradiation process of the dry vegetable

A history of studies on safety of irradiated foods

International Nuclear Information System (INIS)

Miyahara, Makoto

2003-01-01

This report explained a history of studies on safety of irradiated foods in the United States. The army of USA had begun an experiment of irradiated foods in 1953. The toxic tests consisted of three phase, the phase I (1954 to 1959), phase II (1956 to 1965) and phase III (1971 to 1978). In the phase I, the short period toxic tests (90days) of 54 kinds of foods were carried out using high and low irradiation. The Swift and Company Laboratories reported detailed animal tests of 2685 albino rat, chickens and human. The animal tests showed many kinds of nutrition disorder, but the human test no problem. On phase II, 22 kinds of foods were tested for long period using rat, dog and mouse. Dog showed many kinds of symptom, for example, low birthrate, short life time, low growth rate, increasing spleen weight and thyroid disease. On phase III, two companies carried out the toxic test and Ralston Purina Company report is only data to be used now. Atomic Energy Commission (AEC) (1960 to 1970), Department of Commerce (1965 to 1976) and Department of Agriculture (1961 to 1966) studied safety of irradiated foods. Food and Drug Administration (FDA) determined that the irradiated foods belonged to under the category of food additive in 1958. FDA tests safety of irradiated foods using the determination tree and permitted many kinds of irradiated foods. (S.Y.)

Physic-chemical Study of Starch Extracted from Irradiated Corn Flour

International Nuclear Information System (INIS)

Pozo Sanchez, R. del; Alvarez Gil, M.

1986-01-01

The effects of gamma irradiation on starch extracted from irradiated samples of corn flour were studied in the range 0,6 kGy-1,0 kGy. Amylographic properties, solubility and swelling powder of starch samples were determined immediately after irradiation and at 75 days storage at environment conditions (16 0 C-31 0 C, 55%-97% H.R.). Diffraction patterns of crystalline starch were also obtained by X-rays. Gelatinization temperature, swelling powder and diffraction patterns did not change upon irradiation, but a decrease in viscosity and an increase in starch solubility were observed within the dose-range and storage time studied. (author)

Study on irradiation treatment to drunk crab

International Nuclear Information System (INIS)

Cao Hong; Chen Xiulan; Zhai Jianqing; Bao Jianzhong; Wang Jinrong

2002-01-01

For guaranteeing the quality of irradiated drunk crab, manufacture method of the dosimeter, sample setting and taking position, irradiation time, asymmetry degree of irradiation dose, contrast of the dosimeter are discussed and some reference datum to commercialization of drunk crab's irradiation are provided

Gamma greenhouse: A chronic facility for crops improvement and agrobiotechnology

Energy Technology Data Exchange (ETDEWEB)

Azhar, M., E-mail: azhar-m@nuclearmalaysia.gov.my; Ahsanulkhaliqin, A. W., E-mail: azhar-m@nuclearmalaysia.gov.my [Malaysian Nuclear Agency, Bangi, 43000 KAJANG, Selangor (Malaysia)

2014-02-12

Gamma irradiation is one of the most common procedures in plant mutagenesis and agrobiotechnology activities. The procedures consist of chronic and acute gamma radiation. Generally, {sup 60}Co and {sup 137}Cs are gamma radiation sources for radiation processing with relatively high energy (half-life 5.27 years for {sup 60}Co and 30.1 years for {sup 137}Cs). The energy associated with gamma radiation is high enough to break the molecular bonds and ionize atoms without affecting structure of the atomic nucleus (avoiding induction of radioactivity). The Gamma Green House (GGH) is the only chronic irradiation facility in Malaysia, located at Malaysian Nuclear Agency (Nuclear Malaysia). GGH is used for induction of mutation in plants and other biological samples at low dose radiation over period of time depending on the nature and sensitivity of the plant species. The GGH consist of circular green house with 30 meters radius, control room and irradiator with interlock system. The irradiator produces low dose gamma radiation derived from Caesium-137 radioactive source. The biological samples can be exposed to low dose radiation in days, weeks, months or years. The current irradiation rate for GGH is 2.67 Gy/hr at 1 meter from the source. Chronic gamma irradiation produces a wider mutation spectrum and useful for minimizing radiation damages towards obtaining new improved traits for research and commercial values. The prospect of the gamma greenhouse is its uses in research, educations and services on induced mutation techniques for the improvement of plant varieties and microbes. In generating awareness and attract users to the facility, Nuclear Malaysia provides wide range of irradiation services for plant species and mutagenesis consultancies to academicians, students scientists, and plant breeders, from local universities, other research institutes, and growers. Charges for irradiation and consultancy services are at nominal rates. The utilization activities of the

Gamma greenhouse: A chronic facility for crops improvement and agrobiotechnology

International Nuclear Information System (INIS)

Azhar, M.; Ahsanulkhaliqin, A. W.

2014-01-01

Gamma irradiation is one of the most common procedures in plant mutagenesis and agrobiotechnology activities. The procedures consist of chronic and acute gamma radiation. Generally, 60 Co and 137 Cs are gamma radiation sources for radiation processing with relatively high energy (half-life 5.27 years for 60 Co and 30.1 years for 137 Cs). The energy associated with gamma radiation is high enough to break the molecular bonds and ionize atoms without affecting structure of the atomic nucleus (avoiding induction of radioactivity). The Gamma Green House (GGH) is the only chronic irradiation facility in Malaysia, located at Malaysian Nuclear Agency (Nuclear Malaysia). GGH is used for induction of mutation in plants and other biological samples at low dose radiation over period of time depending on the nature and sensitivity of the plant species. The GGH consist of circular green house with 30 meters radius, control room and irradiator with interlock system. The irradiator produces low dose gamma radiation derived from Caesium-137 radioactive source. The biological samples can be exposed to low dose radiation in days, weeks, months or years. The current irradiation rate for GGH is 2.67 Gy/hr at 1 meter from the source. Chronic gamma irradiation produces a wider mutation spectrum and useful for minimizing radiation damages towards obtaining new improved traits for research and commercial values. The prospect of the gamma greenhouse is its uses in research, educations and services on induced mutation techniques for the improvement of plant varieties and microbes. In generating awareness and attract users to the facility, Nuclear Malaysia provides wide range of irradiation services for plant species and mutagenesis consultancies to academicians, students scientists, and plant breeders, from local universities, other research institutes, and growers. Charges for irradiation and consultancy services are at nominal rates. The utilization activities of the gamma greenhouse

Preliminary study on irradiation breeding of ornamental lotus

International Nuclear Information System (INIS)

Chen Xiulan; Bao Jianzhong; Liu Chungui; Cao Hong; Zhai Jianqing

2004-01-01

The effects of γ-ray irradiation on seeds and stems of ornamental lotus were studied. The results show that the mutation rate of seeds is higher than that of stems, and 30-60 Gy is the appropriate irradiation dose. The varieties with red or multi-color flower are more mutable than those with white flower. Two varieties were selected

Studies on Post-Irradiation DNA Degradation in Micrococcus Radiodurans, Strain RII51

DEFF Research Database (Denmark)

Auda, H.; Emborg, C.

1973-01-01

The influence of irradiation condition on post-irradiation DNA degradation was studied in a radiation resistant mutant of M. radiodurans, strain ${\\rm R}_{{\\rm II}}5$. After irradiation with 1 Mrad or higher more DNA is degraded in cells irradiated in wet condition than in cells irradiated with t...

Toxicological and radiological safety of chicken meat irradiated with 7.5 MeV X-rays

Science.gov (United States)

Song, Beom-Seok; Lee, Yunjong; Park, Jong-Heum; Kim, Jae-Kyung; Park, Ha-Young; Kim, Dong-Ho; Kim, Chang-Jong; Kang, Il-Jun

2018-03-01

This study was conducted to evaluate the toxicological and radiological safety of chicken meat that had been irradiated at 30 kGy with 7.5 MeV X-rays. In a sub-chronic toxicity study, ICR mice were fed X-ray-irradiated chicken meat at 2500 mg/kg body weight daily for 90 days, and no mortality or abnormal clinical signs were observed throughout the study period. However, several hematological and serum biochemical parameters of the ICR mice differed significantly from those in the control group; nevertheless, the observed values were all within the normal range for the respective parameters. In addition, no toxicological effects were determined in male or female mice. Furthermore, no differences in gamma-ray spectrometric patterns were detected between the non-irradiated and irradiated samples, indicating that the radioactivity induced by 7.5 MeV X-ray irradiation was below the detection limit. These results tentatively suggest that chicken meat irradiated with 7.5 MeV X-rays would be safe for human consumption in terms of toxicology and radiology.

EPR study on gamma-irradiated fruits dehydrated via osmosis

Energy Technology Data Exchange (ETDEWEB)

Yordanov, N.D. [Laboratory EPR, Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)]. E-mail: ndyepr@bas.bg; Aleksieva, K. [Laboratory EPR, Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)

2007-06-15

The shape and time stability of the electron paramagnetic resonance (EPR) spectra of non- and {gamma}-irradiated papaya, melon, cherry and fig samples dehydrated via osmosis are reported. It is shown that non-irradiated samples are generally EPR silent whereas {gamma}-irradiated exhibit 'sugar-like' EPR spectra. The recorded EPR spectra are monitored for a period of 7 months after irradiation (stored at low humidity and in the dark). The results suggest longer period of unambiguous identification of the radiation processing of osmose dehydrated fruits. Therefore, the Protocol EN 13708,2001 issued by CEN is fully applicable for the studied fruit samples.

Study on innocent irradiation treatment of Trichinella spiralis pork

International Nuclear Information System (INIS)

Zhao Guang; Guo Anxi; Xu Zhaomei

1992-01-01

The effects of 60 Co gamma rays on pork Trichinella spiralis and nutritional hygiene evaluation of irradiated Trichinella spiralis pork were studied by using animal infestation test and artificial gastric juice digestion method. The results showed that when mouse was infested by Trichinella spiralis pork irradiated with a dose of 0.04 kGy, the number of the second generation larvae and the parasitism in the muscle were reduced. 0.08 kGy irradiation could render the intestine Trichinella spiralis sterile. 0.1 kGy blocked the growth of Trichinella spiralis, which were excreted from the body four days after infestation. 0.2-0.8 kGy irradiation could severely block the growth of Trichinella spiralis, which were excreted completely from the body within forth-eight hours when irradiated with 7 kGy and 8 kGy, the Trichinella spiralis body was not found in the intestine within twenty-four hours. 0.3 kGy and 1 kGy irradiation had no harmful effect on nutrition and wholesomeness of Trichinella spiralis pork. Innocent irradiation treatment of Trichinella spiralis pork is practicable, and the lowest dose should be 0.3 kGy

Prospective study of nutritional support during pelvic irradiation

International Nuclear Information System (INIS)

Kinsella, T.J.; Malcolm, A.W.; Bothe, A. Jr.; Valerio, D.; Blackburn, G.L.

1981-01-01

A prospective study of nutritional support during pelvic irradiation was carried out in 32 patients with a primary pelvic malignancy and prior weight loss. Both curative and palliative patients were eligible for the study. Seventeen patients were randomized to receive intravenous hyperalimentation (IVH) and fifteen patients served as controls who were maintained on their regular diet. Patients were stratified by percent body weight loss. Tolerance to therapy was assessed by evaluation of functional status and by using nutritional parameters of body weight change, change in serum protein levels, and response to delayed hypersensitivity skin tests. The curative IVH group tolerated therapy well by both functional and nutritional measurements. All curative IVH patients completed the planned radiation therapy without a treatment break and were fully active following treatment. Patients gained an average of 4.0 kg body weight during irradiation, which was significantly different from the curative control patients. They demonstrated a significant increase in serum transferrin reflecting an improvement in visceral protein. In addition, all showed a positive response to delayed hypersensitivity skin tests at the completion of irradiation. The palliative IVH patients often did poorly because of progression of disease and demonstrated only an elevation of serum transferrin during treatment. The results in the curative IVH group suggest a potential adjunctive role for intravenous hyperalimentation in the malnourished cancer patient undergoing pelvic irradiation. Clearly, further study of nutritional support during pelvic irradiation is needed using curative patients with a single tumor type and significant prior weight loss

Study on identification of irradiated food containing cellulose by ESR

International Nuclear Information System (INIS)

Wan Xiaojuan; Dou Daying; Xu Gang; Jiao Zheng; Wang Jia; Zheng Jianfei; Jiao Zheng; Wu Minghong; Ding Guoji

2008-01-01

The fast development and application of food irradiation technology signify the necessity and urgency to research on effective detection method for irradiated food. In this paper, we report a preliminary study in this area with dried chili powder, peanuts and strawberry seeds. The food samples were irradiated to 0.5, 1.0, 3.0, 5.0 and 10.0 kGy by 60 Co gamma rays. The relation between ESR intensity and irradiation dose, and correlation R 2 , were studied. The results showed that the ESR signal intensity is positively related with the dose. ESR intensity of the strawberry increased the slowest with the dose, and the chili powder had the most accurate calculation. Accurate dose-effect curves, however, require repeating tests and further studies are needed to verify the ESR results. (authors)

An ESR study of radicals induced in irradiated fresh mango

International Nuclear Information System (INIS)

Kikuchi, Masahiro; Hussain, Mohammed S.; Morishita, Norio; Kobayashi, Yasuhiko; Ukai, Mitsuko; Shimoyama, Yuhei

2009-01-01

An electron spin resonance (ESR) spectroscopic study was performed on the radicals induced irradiated fresh mangoes. Fresh Philippine mangoes were irradiated by the γ-rays, lyophilized and powdered. The ESR spectrum of the dry specimen showed a strong main peak at g=2.004 and a pair of peaks at both magnetic fields of the main peak. The main peak detected from flesh and skin specimens faded away in a few days after the irradiation. On the other hand, the side peaks showed a well-defined dose response even 9 days after the irradiation. The side-peak is a useful mean to define the irradiation on fresh mangoes. (author)

Synthetic study of reactor irradiation for medical use

International Nuclear Information System (INIS)

An, Shigehiro; Furuhashi, Akira; Kanda, Keiji; Sumita, Kenji; Kakihana, Hidetake.

1978-01-01

This report is described on the results of the study on the reactor irradiation for medical use shared by the Nuclear Engineering Research Laboratory, Faculty of Engineering, University of Tokyo, and other seventeen facilities. Boron neutron-capturing therapy developed in Japan is extremely significant treating method for tumors by destroying tumor cells of encephaloma, etc. selectively. This is the synthetic study for promoting the above therapeutic method. Two existing reactors were reconstructed into the thermal neutron reactors for boron neutron-capturing therapy. The various preparatory and physical researches were made with the reconstruction, and the therapy was tried on eleven cases. Further experiments were made on the following points: (1) To promote treatment on encephaloma by boron neutron-capturing therapy. (2) To develop its application to malignant tumors other than encephaloma. (3) Animal irradiation experiments. (4) The basic experiments on the cellular level. (5) The study of remote controlled anesthesia. (6) To control irradiated dose. (7) To improve boron compounds. (8) To condense radioisotopes. (Kobatake, H.)

[Effect of irradiation on the degradation of rat thymocyte chromatin].

Science.gov (United States)

Tsudzevich, B O; Parkhomets', Iu P; Andriĭchuk, T R; Iurkina, V V

1998-01-01

Genome instability of adaptive nature is formed under the experimental influence on a cell. Under critical conditions, strategy of organism is to damage the cells that cannot be restored and controlled by including the program of apoptosis. The ordered internucleosomal DNA degradation is considered to be one of the proof attributes of immunocompetent cell apoptosis. We investigated the effects of various doses of irradiation on the thymocytes chromatine fragmentation in 1,2,3 hours after a single X-ray exposure or after chronic influence in conditions of Chernobyl research base. By the means of electrophoresis in agarose and judging by polydeoxyribonucleotides accumulation we observed the "ladder pattern" of degradation in 3 hr after single 1 Gr irradiation (the smallest dose displaying the effect). We suppose that the influence of both chronic low-intensity irradiation taking place in Chernobyl and single X-ray exposure result in intensifying of DNA fragmentation in the cells of immunocompetent organs.

Wholesomeness of irradiated foods, especially potatoes, in Japan

International Nuclear Information System (INIS)

Furuya, Tsuyoshi

1998-01-01

Food irradiation was established under the auspices of the Japan Atomic Energy Commission. In 1967, studies on the efficacy of food irradiation, irradiation techniques and wholesomeness of irradiated foods were begun on potatoes and 6 other items (onions, rice, wheat, vienna sausage, fish-paste products, and mandarin orange) by a project team consisting of scientists from various broad academic fields under the sponsorship of the Science and Technology Agency. Wholesomeness of irradiated foods generally includes the following three points. The first one is the toxicity consisting of chronic toxicity test which predicts the effect when food is continuously ingested for long time, e.g., carcinogenicity test, teratogenicity test which predicts the effect of reproduction and generation for multigeneration, and mutagenicity test which detects the cytogenic possibility. The second is the nutritional adequacy as evaluated by effect on growth, physiological function and nutritional contents. The last one is microbiological safety concerning to microorganic resistance and tolerance by irradiation. In 1972, on the basis of the reports on toxicological aspects that we mainly carried out, nutritional and other aspects, 0.15 kGy level for sprout inhibition of potato which was the first practical use for food irradiation in Japan was permitted by Food Sanitation Act. The safety of food contaminants and food additives, its object for use the same as food irradiation, is confirmed by toxicity test employed experimental animals. Limitation of food additives and residual limitation of food contaminants are decided by the results in toxicity test. And these insure humansafety. It is important and necessary to choose the irradiation or chemicals for food in view of human health. (author)

Absence of bile acid malabsorption as a late effect of pelvic irradiation

International Nuclear Information System (INIS)

Schuster, J.J.; Stryker, J.A.; Demers, L.M.; Mortel, R.

1986-01-01

The pathophysiology of chronic radiation-induced diarrhea was evaluated in 28 patients who had undergone pelvic irradiation for gynecologic neoplasms 2 to 7 years previously. Twenty-seven patients undergoing radiotherapy with techniques that did not require abdominal or pelvic irradiation served as controls. The glycine conjugates of cholic acid (GC) were measured in serum by radioimmunoassay. Fasting and 2 hr. pp GC levels for the pelvic irradiated patients were 11.0 +/- 11.1 (mean +/- SD) and 24.8 +/- 17.3 micrograms/dl. Fasting and 2 hr. pp GC levels for controls were 12.6 +/- 7.4 and 28.0 +/- 14.7. There were no significant differences in the post-prandial increases in serum GC between pelvic irradiated patients and controls (p = .23, Type II error probability = .13). There was also no significant difference in the 2 hr. pp and fasting GC ratio (p = .39). There was significant difference between the stool frequency (p less than .01) and the prevalence of diarrhea (p less than .02) between pelvic irradiated patients and controls. The data suggest that bile acid malabsorption due to ileal dysfunction is not an inevitable late complication of pelvic irradiation and is not the major determinant in the pathophysiology of chronic radiation-induced diarrhea

Color formation study of irradiated polymers by electron beam

International Nuclear Information System (INIS)

Nardi, Daniela Teves

2004-01-01

Color formation on national and commercial polymers (polymethyl methacrylate, polystyrene and polycarbonate) irradiated by electrons beam was investigated by colorimetry (CIELab), electron spectroscopy resonance (ESR), photoacoustic infrared spectroscopy (FTIR-PAS) and differential exploratory calorimetry (DSC). The heat effect on colorimetric properties was investigated after heating (110 deg C for 1 hour) of irradiated polymers at 150 kGy. The rule of oxygen in colorimetric properties of irradiated polycarbonate was investigated in the air presence and absence (p = 10 -3 mmHg). The visual aspect did not agree with colorimetric parameters only for polycarbonate. Yellow color and darkness were induced by radiation for all studied polymers varying only the intensity and behavior in function of post-irradiation time and heating. Polymethyl methacrylate and polystyrene ESR spectra showed that radicals could be responsible by yellow color centers. Wherever, in polycarbonate, color centers were not due radical species. The nature of color centers for any studied polymer was not study by FTIR-PAS because there were no changes in FTIR-PAS spectra neither in function of dose nor heating. Polycarbonate was the most radiosensible and polystyrene was the most radioresistant of all studied polymers in concern of colorimetric properties. (author)

Structural and functional changes in the intenstine of irradiated and hypothermic irradiated rats : a scanning and transmission electron microscopic study

International Nuclear Information System (INIS)

Chaudhuri, S.; Chaudhuri, Swapna; Roy, Bijon

1982-01-01

Severe destructive changes in the intestine of rats following whole body exposure to gamma rays (832 rads) were observed by light microscope, scanning and transmission electron microscope studies. Hypothermia (15deg C rectal temperature) induced prior to irradiation protected the intestinal mucosa from destruction. A simultaneous study showed that glucose absorption decreased significantly in irradiated rats, whereas it was increased in hypothermic irradiated animals. (author)

Alteration of T cell function in healthy persons with a history of thymic x irradiation

International Nuclear Information System (INIS)

Rieger, C.H.L.; Kraft, S.C.; Rothberg, R.M.

1975-01-01

The possible late effects of x irradiation to the infantile thymus were investigated by studying immune functions in 12 healthy persons with a history of thymic x irradiation and healthy control subjects. No differences were found in serum immunoglobulin values, humoral antibody levels, lymphocyte counts, and lymphocyte reactivity to phytohemagglutinin, vaccinia virus, purified protein derivative (PPD), and allogeneic cells. The irradiation group exhibited cellular hyperresponsiveness to streptokinase-streptodornase (SK-SD). In contrast, mean skin and in vitro lymphocyte responses to Candida albicans were depressed in the patients with thymic irradiation. A dissociation of these two Candida responses was found in only 1 of 14 healthy control subjects but in 7 of 12 irradiated individuals. While thymic irradiation did not result in impaired immunologic defenses leading to clinical disease, it caused alterations in T cell responses similar to those reported in patients with chronic mucocutaneous candidiasis

Alteration of T cell function in healthy persons with a history of thymic x irradiation

Energy Technology Data Exchange (ETDEWEB)

Rieger, C.H.L.; Kraft, S.C.; Rothberg, R.M.

1975-10-01

The possible late effects of x irradiation to the infantile thymus were investigated by studying immune functions in 12 healthy persons with a history of thymic x irradiation and healthy control subjects. No differences were found in serum immunoglobulin values, humoral antibody levels, lymphocyte counts, and lymphocyte reactivity to phytohemagglutinin, vaccinia virus, purified protein derivative (PPD), and allogeneic cells. The irradiation group exhibited cellular hyperresponsiveness to streptokinase-streptodornase (SK-SD). In contrast, mean skin and in vitro lymphocyte responses to Candida albicans were depressed in the patients with thymic irradiation. A dissociation of these two Candida responses was found in only 1 of 14 healthy control subjects but in 7 of 12 irradiated individuals. While thymic irradiation did not result in impaired immunologic defenses leading to clinical disease, it caused alterations in T cell responses similar to those reported in patients with chronic mucocutaneous candidiasis.

75 MeV boron ion irradiation studies on Si PIN photodiodes

Energy Technology Data Exchange (ETDEWEB)

Prabhakara Rao, Y.P.; Praveen, K.C. [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570006 (India); Rejeena Rani, Y. [Integrated Circuits Division, Bharat Electronics Limited, Bangalore 560013, Karnataka (India); Tripathi, Ambuj [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Gnana Prakash, A.P., E-mail: gnanap@hotmail.com [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570006 (India)

2013-12-01

The highly sensitive silicon PIN photodiodes were fabricated to use in radiation environments. The Si PIN photodiodes are coated with 150 nm silicon dioxide (SiO{sub 2}) as anti-reflective (AR) coating. The presence of AR coating on the performance of irradiated PIN photodiodes is studied up to a total dose of 10 Mrad. The effects of 75 MeV boron (B{sup 5+}) ions and {sup 60}Co gamma radiation on the I–V, C–V and spectral responses of PIN photodiodes were studied systematically to understand the radiation tolerance of the devices. The 75 MeV B{sup 5+} irradiation results are compared with {sup 60}Co gamma irradiated results in the same dose range for 1 mm × 1 mm and 10 mm × 10 mm active area PIN photodiodes. The irradiation results show that the ion irradiated PIN photodiodes show more degradation when compared {sup 60}Co gamma irradiated devices. The irradiation results are presented in this paper and the possible mechanism behind the degradation of photodiodes is also discussed in the paper.

Effects of irradiation on the anterior pituitary of young rats

International Nuclear Information System (INIS)

Kiriishi, Reijiro; Tsunoda, Shigeru; Sakaki, Toshisuke; Yoshimura, Hitoshi; Ohishi, Hajime; Okamoto, Shingo; Tsujii, Tadasu

1994-01-01

We examined irradiation-induced damage to the anterior pituitary of young rats, particularly to the folliculo-stellate (F-S) cells. The whole brain of 3-week-old Wistar rats (n=24), was irradiated once with a linear accelerator (Linac). The pituitary gland was removed after sacrifice and fixed in formalin. Pituitary specimens were stained with hematoxylin and eosin (H and E), or immunostained for S-100 protein, growth hormone (GH), and adrenocorticotropic hormone (ACTH) by the ABC technique. Angiogenesis in the chronic stage after irradiation was related to an increase of F-S cells in the subacute stage. The decrease in GH cells and ACTH cells after irradiation was dose-dependent, with more severe irradiation-induced damage being in GH cells than in ACTH cells. (author)

Gamma Greenhouse: A chronic facility for crops improvement and agro biotechnology

International Nuclear Information System (INIS)

Azhar Mohamad; Ahsanulkhaliqin Abdul Wahab

2013-01-01

Full-text: Gamma irradiation is one of the most common procedures in plant mutagenesis and agrobiotechnology activities. The procedures consist of chronic and acute gamma radiation. Generally, 60 Co and 137 Cs are gamma radiation sources for radiation processing with relatively high energy (half-life 5.27 years for 60 Co and 30.1 years for 137 Cs). The energy associated with gamma radiation is high enough to break the molecular bonds and ionize atoms without affecting structure of the atomic nucleus (avoiding induction of radioactivity). The Gamma Green House (GGH) is the only chronic irradiation facility in Malaysia, located at Malaysian Nuclear Agency (Nuclear Malaysia). GGH is used for induction of mutation in plants and other biological samples at low dose radiation over period of time depending on the nature and sensitivity of the plant species. The GGH consist of circular green house with 30 meters radius, control room and irradiator with interlock system. The irradiator produces low dose gamma radiation derived from Caesium-137 radioactive source. The biological samples can be exposed to low dose radiation in days, weeks, months or years. The current irradiation rate for GGH is 2.67 Gy/ hr at 1 meter from the source. Chronic gamma irradiation produces a wider mutation spectrum and useful for minimizing radiation damages towards obtaining new improved traits for research and commercial values. The prospect of the gamma greenhouse is its uses in research, educations and services on induced mutation techniques for the improvement of plant varieties and microbes. In generating awareness and attract users to the facility, Nuclear Malaysia provides wide range of irradiation services for plant species and mutagenesis consultancies to academicians, students scientists, and plant breeders, from local universities, other research institutes, and growers. Charges for irradiation and consultancy services are at nominal rates. The utilization activities of the gamma

Thermogravimetric study of γ-irradiated lanthanum oxalate

International Nuclear Information System (INIS)

Nayak, H.; Bhatta, D.

2000-01-01

Thermogravimetric study of La 2 (C 2 O 4 ) 3 , exposed to different doses (5.0 - 50.0 x 10 -2 MGy) of γ-rays has been carried out. Marginal effect is observed at lower doses which is prominent at higher dose (5.0 x 10 -1 MGy). The radiolytic damaged entities, generated by irradiation favours the reaction by creating new potential nucleation centres in the lattice. The solid product, La 2 O 3 formed by irradiation also acts as a heterogeneous catalyst and brings out changes in the reactivity of the solid. (author)

Economic Feasibility Study for Using Irradiation Technology in Preservation of Animalism Foods

International Nuclear Information System (INIS)

El Gameel, E.A.

2011-01-01

The present study discus the economic feasibility for the preservation animalism foods by using irradiation technology. This study has included the technical data, regression foretelling for the throughput, determination of irradiators types and radiation sources activity. This study comprises the financial analysis for the establishment animalism foods irradiation facilities (types: tote box, pallet conveyor) and the national return

Study on process control and acceptability of irradiated seasonings

International Nuclear Information System (INIS)

Chen Qixun; Xu Peishu; Chen Hao; Chen Lihua; Dong Shaobin

1993-01-01

This paper studied the process control and quality control of irradiated seasonings for commercial purposes, market test and consumers' acceptability. The results showed that the rate of relative deviation of dose was less than 2 and the uniformity was better than 1.31 and the number of microbes decreased by 3-4 orders of magnitude after treatment with 8 kGy. No pathogenic bacteria were discovered and sensory evaluation as well as quality analysis were not changed. 110 tons of irradiated seasonings have been supplied to domestic markets and stores since 1990. The statistic data of 2045 consumers investigated showed that 67% of consumers heard about food irradiation. 72% of persons and 67% of families were willing to buy irradiated seasonings. (author)

Studies of electron-beam irradiation on ethylene-styrene interpolymers

CERN Document Server

Liu, I C

2002-01-01

Electron-beam irradiation-induced structural and properties changes on ethylene-styrene interpolymers (ESI) have been studied at electron doses ranging from 0 to 200 kGy. The amounts of species generated by irradiation such as hydroxyls, hydroperoxides, carbonyls and unsaturated double bonds have been analyzed using ATR-FTIR. While the structural changes are minimal for ESI69 comprising 69 wt.% styrene regardless of the dose level, the changes for ESI40 comprising 40 wt.% styrene are dose dependent and reaches a maximum at a dose of 100 kGy. Gel permeation chromatography analysis indicates that macromolecular chain scission occurs at low irradiation dose and crosslinking dominates at high irradiation doses. The average molecular weights between crosslinks, M sub C 's, have been calculated using the Flory-Rehner equation based on data collected from solvent extraction experiments. The M sub C 's of ESI40 samples are much smaller than those of ESI69 samples. Irradiated ESI samples have higher glass transition t...

Study on quality control of Chinese herb medicine irradiation

International Nuclear Information System (INIS)

Yang Dongqing; En Lihua; Deng Wenmin

2010-01-01

6-8 kGy γ-ray irradiation dosage treatment can reduce the bacteria, mildew effectively from 105 CFU/g to 102 CFU/g and eliminate the parasite in 4 kind of Chinese herb medicine, enhance their quality of sanitation observably. In the other hand, irradiation doesn't influence the medicinal component and therapy effect. Storage study has improved that the 4 kind of Chinese herb medicine treated by γ-ray irradiation can be preserved over one year in the room temperature with high quality of sanitation and steady medicinal component. (authors)

Study on the sterilization of egg white powder by irradiation

International Nuclear Information System (INIS)

Fu Lixin; Meng Lifen; Zhao Xiaonan; Xu Dechun; Hu Shaoxin; Chen Changdong; Pei Ying

2012-01-01

The article studied the killing microorganism result, the influence of main essential nutrient and sense organ of egg white powder by Co-60 γ-ray irradiation. The microorganism index of the egg white powder samples can meet the government food sanitation standard by 4 kGy irradiation, and the killing microorganism rare can reach 100%. The irradiation dose from 4 to 10 kGy has little influence to the egg white powder protein, crude fiber and amino acids contras ting to comparison, and the sensory quality such as color and luster, scent has little change below 6 kGy irradiation. Synthesizing the results of physical chemistry and sense organ, the optimal irradiation dose of egg white powder killing microorganism is 4 to 6 kGy. (authors)

Study on the sterilization of egg white powder by irradiation

International Nuclear Information System (INIS)

Fu Lixin; Meng Lifen; Zhao Xiaonan; Xu Dechun; Hu Shaoxin; Chen Changdong; Pei Ying

2011-01-01

The article studied the killing microorganism result, the influence of main essential nutrient and sense organ of egg white powder by Co-60 γ-ray irradiation. The microorganism index of the egg white powder samples can meet the government food 1 sanitation standard by 4 kGy irradiation, and the killing microorganism rare can reach 100%. The irradiation dose from 4 to 10 kGy has little influence to the egg white powder protein, crude fiber and amino acids contrasting to comparison, and the sensory quality such as color and luster, scent has little change below 6 kGy irradiation. Compositing the result of physical chemistry and sense organ, the optimal irradiation dose of egg white powder killing microorganism is 4 to 6 kGy. (authors)

Low doze γ-irradiation influence on drosophila life span in different genetics background

International Nuclear Information System (INIS)

Moskalev, A.

2007-01-01

Complete text of publication follows. The main goal of this work was to study in Drosophila melanogaster the contribution of DNA damage sensing and repair, apoptosis and heat shock defence into life span and physical activity alteration after gamma-irradiation at low doze rate. In our experiments, the strains were exposed to chronic gamma-irradiation from a 226Ra source (50 R/h) at doze rate 0.17 cGy/h at pre-imago development stages only. The absorbed radiation dose per generation (from embryo to imago, 12 days) was 60 cGy. Life span estimation was prepared in adult males and females separately. We compared the life span of apoptotic (p53, DIAP-1, dApaf-1, Dcp-1, reaper, grim and hid), heat shock defence (HSP70, HSP23, HSF), DNA damage sensing (ATR) and repair (XPF, XPC, PCNA, DSB repair helicase homologs) mutants after chronic irradiation with the control. On the basis of our investigation we have concluded: 1) Low doze irradiation alter the life span depending on genetic background (mutant alleles, heterozygosity level and sex); 2) Age dynamics of physical activity positively correlates with the life span; 3) Longevity potential forms at early development stages; 4) DNA damage sensing, DNA repair, heat shock defence and apoptosis as aging preventing mechanisms play crucial role in radiation-induced life span hormesis.

Medium-Level Laser in Chronic Tinnitus Treatment

Directory of Open Access Journals (Sweden)

K. Dejakum

2013-01-01

Full Text Available The purpose of this study was to evaluate the effect of medium-level laser therapy in chronic tinnitus treatment. In a prospective double-blind placebo-controlled trial, either active laser (450 mW, 830 nm combined Ga-Al-As diode laser or placebo irradiation was applied through the external acoustic meatus of the affected ear towards the cochlea. Fourty-eight patients with chronic tinnitus were studied. The main outcome was measured using the Goebel tinnitus questionnaire, visual analogue scales measuring the perceived loudness of tinnitus, the annoyance associated with tinnitus, and the degree of attention paid to tinnitus as well as psycho-acoustical matches of tinnitus pitch and loudness. The results did show only very moderate temporary improvement of tinnitus. Moreover, no statistically relevant differences between laser and placebo group could be found. We conclude that medium-level laser therapy cannot be regarded as an effective treatment of chronic tinnitus in our therapy regime considering the limited number of patients included in our study.

Moessbauer study of defects in molybdenum and chromium irradiated with ions

International Nuclear Information System (INIS)

Troyan, V.A.; Bogdanov, V.V.; Ivanyushkin, E.M.; Pen'kov, Yu.P.

1980-01-01

Effects of ion irradiation of monocrystalline molybdenum and polycrystalline chromium with Co-57 impurity were studied by Moessbauer effect. Molybdenum specimens were irradiated by He + ions at accelerators with 40 keV energy. Chromium specimens were irradiated by hydrogen ions with 1.2 MeV energy up to integral 2x10 17 -2x10 19 ion/cm 2 doses. It is shown, that defect introduction into the source matrix by irradiation results in change of gamma-resonance line form and effect value. The observed effects of defect influence on spectrum parameters are discussed. It is concluded, that study of Moessbauer spectra parameters of diluted Co-57 solutions in matrices of different metals permits to determine dynamics of movement of impurity atoms and defects in metals irradiated with ions [ru

Cytogenetic damages in peripheral blood of monkey lymphocytes under simulation of cosmonauts irradiation.

Science.gov (United States)

Petrov, Vladislav; Ivanov, Alexandr; Barteneva, Svetlana; Snigiryeva, Galina; Shafirkin, Alexandr

Earth modeling of crewmember exposure should be performed for correct estimating radiation hazard during the flight. Such modeling was planned in a monkey experiment for investigating consequences of exposure to a man during an interplanetary flight. It should reflect a chronic impact of galactic cosmic rays and acute and fractional irradiation specified for solar cosmic rays and radiation belts respectively. Due to the difficulty of modeling a chronic impact with the help of a charged particles accelerator it can be used the gamma source. While irradiating big animal groups during a long-term period of time it is preferably to replace chronic irradiation by an equal fractional one. In this case the chosen characteristics of fractional irradiation should ensure the appearances of radiobiological consequences equal to the ones caused by the modeled chronic exposure. So for developing an exposure scheme in the monkey experiment (with Macaca -Rhesus) the model of the acting residual dose, that takes into account repair and recovery processes in the exposed body was used. The total dose value was in the limits from 2.32 Gy up to 3.5 Gy depending on the exposure character. The acting residual dose in all versions of exposure was 2.0 Gy for every monkey. While performing the experiment all the requirements of bioethics for the work with animals were observed. The objects of interest were genomic damages in lymphocytes of monkey's peripheral blood. The data about the CAF during the exposure and at various time moments after exposure particularly directly after the completion of chronicle and fractional irradiation were analyzed. CAF -dose of acute single gamma-irradiation in the range 0 -1.5Gy relationship (calibration curve) was defined in vitro. In addition the rate of the aberrant cells elimination within three months after the irradiation completion was estimated. On the basis of the obtained CAF data we performed verification of applicability of cytogenetic analysis

Treatment of intractable rheumatoid arthritis with total lymphoid irradiation

International Nuclear Information System (INIS)

Kotzin, B.L.; Strober, S.; Engleman, E.G.; Calin, A.; Hoppe, R.T.; Kansas, G.S.; Terrell, C.P.; Kaplan, H.S.

1981-01-01

Eleven patients with intractable rheumatoid arthritis were treated with total lymphoid irradiation (total dose, 2000 rad) in an uncontrolled feasibility study, as an alternative to long-term therapy with cytotoxic drugs such as cyclophosphamide and azathioprine. During a follow-up period of five to 18 months after total lymphoid irradiation, there was a profound and sustained suppression of the absolute lymphocyte count and in vitro lymphocyte function, as well as an increase in the ratio of Leu-2 (suppressor/cytotoxic) to Leu-3 (helper) T cells in the blood. Persistent circulating suppressor cells of the mixed leukocyte response and of pokeweed mitogen-induced immunoglobulin secretion developed in most patients. In nine of the 11 patients, these changes in immune status were associated with relief of joint tenderness and swelling and with improvement in function scores. Maximum improvement occurred approximately six months after irradiation and continued for the remainder of the observation period. Few severe or chronic side effects were associated with the radiotherapy

Electron microscope study of irradiated beryllium oxide; Etude au microscope electronique de l'oxyde de beryllium irradie

Energy Technology Data Exchange (ETDEWEB)

Bisson, A A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1965-06-01

The beryllium oxide is studied first by fractography, before and after irradiation, using sintered samples. The fractures are examined under different aspects. The higher density sintered samples, with transgranular fractures are the most interesting for a microscopic study. It is possible to mark the difference between the 'pores' left by the sintering process and the 'bubbles' of gases that can be produced by former thermal treatments. After irradiation, the grain boundaries are very much weakened. By annealing, it is possible to observe the evolution of the gases produced by the reaction (n, 2n) and (n. {alpha}) and gathered on the grain boundaries. The irradiated beryllium oxide is afterwards studied by transmission. For that, a simple method has been used: little chips of the crushed material are examined. Clusters of point defects produced by neutrons are thus detected in crystals irradiated at the three following doses: 6 x 10{sup 19}, 9 x 10{sup 19} and 2 x 10{sup 20} n{sub f} cm{sup -2} at a temperature below 100 deg. C. For the irradiation at 6 x 10{sup 19} n{sub f} cm{sup -2}, the defects are merely visible, but at 2 x l0{sup 20} n{sub f} cm{sup -2} the crystals an crowded with clusters and the Kikuchi lines have disappeared from the micro-diffraction diagrams. The evolution of the clusters into dislocation loops is studied by a series of annealings. The activation energy (0,37 eV) calculated from the annealing curves suggests that it must be interstitials that condense into dislocation loops. Samples irradiated at high temperatures (650, 900 and 1100 deg. C) are also studied. In those specimens the size of the loops is not the same as the equilibrium size obtained after out of pile annealing at the same temperature. Those former loops are more specifically studied and their Burgers vector is determined by micro-diffraction. (author) [French] L'oxyde de beryllium est d'abord etudie, par une methode fractographique, avant et apres irradiation, en

Economic feasibility study of potato preservation by irradiation in saudi arabia

Energy Technology Data Exchange (ETDEWEB)

Kinsara, A A; Abulfaraj, W H; Mamoon, A M; Kamal, S E [Nuclear Engineering Department, Faculty of Engineering, King Abdulaziz University, Jeddah (Saudi Arabia)

1997-12-31

Comprehensive studies were carried out to investigate the economic feasibility of the preservation of potato crop by cobalt-60 gamma irradiation sprout inhibition by potato irradiation was approved by international organization and concerned authorities in many countries. The dose level range authorized for potato sprout inhibition extends from about 80-150 Gy depending on potato variety, time of irradiation after harvest, and post irradiation storage temperature. Sprout inhibition is most effective by irradiation after harvest, and after healing of any inflicted injuries, that when the potatoes are dormant. Irradiation at the recommended doses minimizes storage losses of potatoes that are refrigerated or stored on shelves. Despite the limited data available, an attempt was made to quantify the monetary value of preserving potato by irradiation. With economy scale taken in consideration, potato preservation by irradiation is economically feasible since at the local consumption rates there will be lot of potatoes that ned storage for off season use. 5 tabs.

Study on the storage properties of irradiated ginger

International Nuclear Information System (INIS)

Wang Shoujing; Yu Zihou; Sun Shouyi; Zou Jiwan; Zhang Qizhi; Sun Hongchun; Lv Tiexin; Liu Xiaoyong

2004-01-01

The γ-ray irradiation could cause the loss of Vc during the early stage of storage, however, after 150 days' storage there were no significant differences of Vc content between irradiated and non-irradiated samples. The content of reduced sugar was increased by irradiation especially with 150 and 250 Gy. When ginger were irradiated with 250 Gy and stored at room temperature for 120 days, the content of Met and Arg decreased obviously, but the contents of other 16 amino acids were not affected. The respiration rate of irradiated ginger reached its peak at 7-9 days of storage, and from then it kept lower level for the rest storage time. The electrolyte permeability increased slightly after γ-irradiation. Irradiation with 80-400 Gy had no effects on lipid isoenzyme zymogram

Study of the stability of the tragacanto rubber irradiated

International Nuclear Information System (INIS)

Rodriguez, M.; Romero, M.; Montes de Oca, N.

2001-01-01

Presently work was studied the processing by radiations of the tragacanto rubber powdered, with ends of achieving its sterilization. For the irradiation, the envelopes were placed in aluminum containers to reason of an envelope for container. The material underwent analysis of its viscosity and microbiological tests. They got ready solutions, according to the British pharmacopoeia, starting from the material irradiated with dose of D0-0, D1-5, D2-7.5, and D3-10 kGy. The smaller than the applied doses (5kGy) it produced a variation of 72% in the viscosity of the solutions, in comparison with the rubber without irradiating. They were carried out tests of sterility to the material irradiated with inferior dose of 5 kGy, being contaminated in all the cases

Studies On Quality Criteria For Irradiated Breaded Chicken Breast Fillets

International Nuclear Information System (INIS)

HASSAN, I.M.; IBRAHIM, M.T.; MAHMOUD, A.A.; SHAMS EL DIN, N.M.M.; MOHAMMAD, M.K.

2010-01-01

Quality criteria of irradiated breaded chicken breast fillets were studied. Fresh boneless and skinless breaded chicken breast meats samples were divided into four separate batches and packed in plastic bags and sealed by an impulse sealer. Samples in plastic bags were exposed to different doses of gamma irradiation (2.5, 5 and 7 kGy) at ambient temperature. Just after irradiation, the samples were stored at 4 ±1 0 C. All samples were evaluated for microbiological, chemical and sensorial properties after irradiation and throughout the storage periods. During storage, the total bacterial count was significantly increased (P<0.05) in all samples with higher rates of increase in non-irradiated samples. In all irradiated samples, Staphylococcus aureus did not detected up to 6 days then detected after 22 days in samples treated with 2.5 kGy as well as 31 days in samples treated with 5 kGy. On the other hand, Staphylococcus aureus was detected after 45 days in samples treated with 7 kGy. Salmonella sp., Listeria monocytogenes and Campylobacter jejuni could not detected in untreated and treated samples. The protein content showed significant decrease immediately after irradiation and during the refrigerated storage. The TVN values for non-irradiated samples were significantly higher (P<0.05) than irradiated samples. The present data showed significant decrease (P<0.05) in protein solubility percentages of irradiated samples at day 0 and 6 of refrigerated storage. The observed decrease was related to the increase of radiation dose. At the end of storage period (62 days), 2.5 kGy samples were significantly higher in TBA values than other irradiated samples. On the other hand, irradiation was significantly reduced (P<0.05) the amount of major mono unsaturated and poly unsaturated fatty acids. Sensory attributes of breaded chicken breast fillets did not affected by irradiation. It could be concluded that irradiation dose of 5 kGy can be used in chicken samples stored in

Total lymphoid irradiation for multiple sclerosis

International Nuclear Information System (INIS)

Devereux, C.K.; Vidaver, R.; Hafstein, M.P.; Zito, G.; Troiano, R.; Dowling, P.C.; Cook, S.D.

1988-01-01

Although chemical immunosuppression has been shown to benefit patients with chronic progressive multiple sclerosis (MS), it appears that chemotherapy has an appreciable oncogenic potential in patients with multiple sclerosis. Accordingly, we developed a modified total lymphoid irradiation (TLI) regimen designed to reduce toxicity and applied it to a randomized double blind trial of TLI or sham irradiation in MS. Standard TLI regimens were modified to reduce dose to 1,980 rad, lowering the superior mantle margin to midway between the thyroid cartilage and angle of the mandible (to avert xerostomia) and the lower margin of the mantle field to the inferior margin of L1 (to reduce gastrointestinal toxicity by dividing abdominal radiation between mantle and inverted Y), limiting spinal cord dose to 1,000 rad by custom-made spine blocks in the mantle and upper 2 cm of inverted Y fields, and also protecting the left kidney even if part of the spleen were shielded. Clinical efficacy was documented by the less frequent functional scale deterioration of 20 TLI treated patients with chronic progressive MS compared to to 20 sham-irradiated progressive MS patients after 12 months (16% versus 55%, p less than 0.03), 18 months (28% versus 63%, p less than 0.03), and 24 months (44% versus 74%, N.S.). Therapeutic benefit during 3 years follow-up was related to the reduction in lymphocyte count 3 months post-irradiation (p less than 0.02). Toxicity was generally mild and transient, with no instance of xerostomia, pericarditis, herpes zoster, or need to terminate treatment in TLI patients. However, menopause was induced in 2 patients and staphylococcal pneumonia in one

Positron annihilation studies on reactor irradiated and thermal annealed ferrocene

International Nuclear Information System (INIS)

Marques Netto, A.; Carvalho, R.S.; Magalhaes, W.F.; Sinisterra, R.D.

1996-01-01

Retention and thermal annealing following (n, γ) reaction in solid ferrocene, Fe(C 5 H 5 ) 2 , were studied by positron annihilation lifetime spectroscopy (PAL). Positronium (Ps) formation was observed in the non-irradiated compound with a probability or intensity (I 3 ) of 30%. Upon irradiation of the compound with thermal neutrons in a nuclear reactor, I 3 decreases with increasing irradiation time. Thermal treatment again increases I 3 values from 16% to 25%, revealing an important proportion of molecular reformation without variation of the ortho-positronium lifetime (τ 3 ). These results point out the major influence of the electronic structure as determining the Ps yields in the pure complex. In the irradiated and non irradiated complexes the results are satisfactorily explained on the basis of the spur model. (orig.)

Thermal Decompositon Studies Of Pre-Irradiated Nickel (II) Azides ...

African Journals Online (AJOL)

The effect of pre-irradiation on the thermal decomposition of three samples of nickel (II) azide was studied. It was found that the rates of thermal decomposition of Ni(OH)N3 increased substantially with increase in pre-irradiation dosage. The initial reaction rates change from time-dependant nucleation law for the unirradiated ...

Local graft irradiation in renal transplant rejection

International Nuclear Information System (INIS)

Kawamura, Masashi; Kataoka, Masaaki; Itoh, Hisao

1990-01-01

From 1977 to 1988, of 142 renal transplantations, seven recipients (4.9%) received local graft irradiation following rejective reaction refractory to antirejection medical managements. Concurrent with the administration of pulsed high dose methylprednisolone and other antirejection medical managements, the graft was irradiated with a total dose of 6.0 Gy-150 cGy per fraction every other day at the midplane of the graft using two opposing portals of 4MX Linac. The fields were defined by palpation and echography. All patients had improvements in serum creatinine on the 10th day after beginning the irradiation. Four patients with peripheral lymphocytosis during the irradiation combined with pulsed high dose methylprednisolone improved in renal functions. On the other hand, out of 3 patients with lymphcytopenic changes, in two the transplanted graft was removed due to deteriorations, and the other patient is currently suffering from chronic rejection. Local graft irradiation can be useful in maintaining a rejective graft and reversing its functions in some patients whose rejective reaction failed to respond to the antirejection medical managements. (author)

Spontaneous cell-mediated cytolysis by peripheral blood cells obtained from whole-body chronically irradiated beagle dogs

International Nuclear Information System (INIS)

Dyck, J.A.; Shifrine, M.; Klein, A.K.; Rosenblatt, L.S.; Kawakami, T.

1986-01-01

The level of natural killer (NK) activity of continuously gamma-irradiated (whole body) beagle dogs and their nonirradiated controls was studied. For analytical purposes, irradiated dogs were segregated into groups according to their clinical status: clinically normal, hypocellular, or with acute non-lymphocytic leukemia. Since unirradiated control animals exhibited a wide range of NK responses, the data from each irradiated animal were compared to its own age-matched or litter-matched unirradiated control. Of the eight clinically normal irradiated dogs (median = 146% activity of control) only one animal had a NK activity lower than that of its control. The hypocellular group (n = 5, median = 21.8% of control) and the leukemic group (n = 4, median = 52.5% of control) each contained one responder with higher activity than its control. The difference between the percentage of control of the clinically normal and clinically abnormal dogs was found to be significant (P less than 0.05). There is a negative correlation between the NK results obtained and the total accumulated dose of radiation at the time of sampling (correlation coefficient = -0.739, P less than 0.01), suggesting a radiation effect upon natural killer activity, which is evidence by enhancement at lower doses and depression at higher doses of irradiation

Experimental and theoretical study of solid solution stability under irradiation

International Nuclear Information System (INIS)

Cauvin, Richard.

1981-08-01

The behavior of dilute alloys (Al-Zn, Al-Ag, Al-Si, Al-Ge and Al-Mg) under 1 MeV electron irradiation has been studied in a high voltage electron microscope. A phenomenon of homogeneous precipitation induced by irradiation in undersaturated solid solutions (Al-Zn, Al-Ag and Al-Si) has been discovered; the observed precipitates are either coherent or incoherent, but never associated with point defect sinks. The solubility limit is a function of irradiation temperature and flux; but, under irradiation, it does not behave as a true thermal solubility limit (without irradiation). The existing theories (kinetic or strictly thermodynamic) do not account for this phenomenon. It is shown that the irreversibility of the mutual recombination between trapped vacancies and mixed interstitials is the driving force of this homogeneous precipitation. Using a dilute solid solution model, we show that, under irradiation, the homogeneous stationary state, stable from a strictly thermodynamic point of view, can be unstable when the recombination reaction is taken into account. The solubility limit under irradiation is calculated with a nucleation-growth model taking account for this effect; it is proportional to the thermal solubility limit without irradiation. This model explains all the experimental observations [fr

Damage studies on tungsten due to helium ion irradiation

International Nuclear Information System (INIS)

Dutta, N.J.; Buzarbaruah, N.; Mohanty, S.R.

2014-01-01

Highlights: • Used plasma focus helium ion source to study radiation induced damage on tungsten. • Surface analyses confirm formation of micro-crack, bubbles, blisters, pinholes, etc. • XRD patterns confirm development of compressive stress due to thermal load. • Reduction in hardness value is observed in the case of exposed sample. - Abstract: Energetic and high fluence helium ions emitted in a plasma focus device have been used successfully to study the radiation induced damage on tungsten. The reference and irradiated samples were characterized by optical microscopy, field emission scanning electron microscopy, X-ray diffraction and by hardness testers. The micrographs of the irradiated samples at lower magnification show uniform mesh of cracks of micrometer width. However at higher magnification, various types of crystalline defects such as voids, pinholes, bubbles, blisters and microcracks are distinctly noticed. The prominent peaks in X-ray diffraction spectrum of irradiated samples are seen shifted toward higher Bragg angles, thus indicating accumulation of compressive stress due to the heat load delivered by helium ions. A marginal reduction in hardness of the irradiated sample is also noticed

EPR study on non- and gamma-irradiated herbal pills

Energy Technology Data Exchange (ETDEWEB)

Aleksieva, K., E-mail: katerina_bas@abv.b [Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Lagunov, O. [Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Dimov, K. [Institute of Cryobiology and Food Technologies, 1162 Sofia (Bulgaria); Yordanov, N.D. [Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)

2011-06-15

The results of EPR studies on herbal pills of marigold, hawthorn, yarrow, common balm, tutsan, nettle and thyme before and after gamma-irradiation are reported. Before irradiation all samples exhibit one weak singlet EPR line with a g-factor of 2.0048{+-}0.0005. After irradiation herbal pills could be separated in two groups according to their EPR spectra. Radiation-induced free radicals in pills of marigold, yarrow, nettle, tutsan and thyme could be attributed mainly to saccharide excipients. Tablets of hawthorn and common balm show 'cellulose-like' EPR spectrum, superimposed on partly resolved carbohydrate spectrum, due to the active part (herb) and inulin, which is present in the pills as an excipient. Fading study of the radiation-induced EPR signals confirms that sugar radicals are more stable than cellulose species. The reported results show that the presence of characteristic EPR spectra of herbal pills due to excipients or active part can be used as unambiguous proof of radiation processing within 35 or more days after irradiation.

Experimental study on active specific immunotherapy modified with irradiation

International Nuclear Information System (INIS)

Imanaka, Kazufumi; Ogawa, Yasuhiro; Gose, Kyuhei; Imajo, Yoshinari; Kumura, Shuji

1982-01-01

We have already reported that the effectiveness of active specific immunotherapy using irradiated tumor cells and infiltrating mononuclear cells which were separated from the topical tumor tissue 7 days after irradiation of 2,000 rad in experimental study. The present study was designed to investigate the effect of non-specific immunopotentiator PS-K combined with active specific immunotherapy. Female C3H/He mice aged 12 weeks were inoculated 4 x 10 6 MM 46 tumor cells in the right hind paws and received local electron irradiation with the dose of 3,000 rad on the 5th day after irradiation. Active specific immunotherapy was performed on the 12th day, and daily dose of 200 mg/kg of PS-K was injected intraperitoneally from the 6th day to the 10th day. The inhibition of the tumor growth and the elongation of survival period were noted in the group which received active specific immunotherapy combined with non-specific immunopotentiator, PS-K compared with the active specific immunotherapy alone. (author)

EPR study on non- and gamma-irradiated herbal pills

International Nuclear Information System (INIS)

Aleksieva, K.; Lagunov, O.; Dimov, K.; Yordanov, N.D.

2011-01-01

The results of EPR studies on herbal pills of marigold, hawthorn, yarrow, common balm, tutsan, nettle and thyme before and after gamma-irradiation are reported. Before irradiation all samples exhibit one weak singlet EPR line with a g-factor of 2.0048±0.0005. After irradiation herbal pills could be separated in two groups according to their EPR spectra. Radiation-induced free radicals in pills of marigold, yarrow, nettle, tutsan and thyme could be attributed mainly to saccharide excipients. Tablets of hawthorn and common balm show 'cellulose-like' EPR spectrum, superimposed on partly resolved carbohydrate spectrum, due to the active part (herb) and inulin, which is present in the pills as an excipient. Fading study of the radiation-induced EPR signals confirms that sugar radicals are more stable than cellulose species. The reported results show that the presence of characteristic EPR spectra of herbal pills due to excipients or active part can be used as unambiguous proof of radiation processing within 35 or more days after irradiation.

EPR study on non- and gamma-irradiated herbal pills

Science.gov (United States)

Aleksieva, K.; Lagunov, O.; Dimov, K.; Yordanov, N. D.

2011-06-01

The results of EPR studies on herbal pills of marigold, hawthorn, yarrow, common balm, tutsan, nettle and thyme before and after gamma-irradiation are reported. Before irradiation all samples exhibit one weak singlet EPR line with a g-factor of 2.0048±0.0005. After irradiation herbal pills could be separated in two groups according to their EPR spectra. Radiation-induced free radicals in pills of marigold, yarrow, nettle, tutsan and thyme could be attributed mainly to saccharide excipients. Tablets of hawthorn and common balm show "cellulose-like" EPR spectrum, superimposed on partly resolved carbohydrate spectrum, due to the active part (herb) and inulin, which is present in the pills as an excipient. Fading study of the radiation-induced EPR signals confirms that sugar radicals are more stable than cellulose species. The reported results show that the presence of characteristic EPR spectra of herbal pills due to excipients or active part can be used as unambiguous proof of radiation processing within 35 or more days after irradiation.

Studies in mice fed a diet containing irradiated fish

International Nuclear Information System (INIS)

1979-01-01

Three groups of mice were observed in utero and for eighty (80) weeks thereafter to study growth, food consumption, hematology, blood chemistry and survival with particular interest in carcinogenic potential. Group I received only Purina Mouse Chow, Group II received a diet composed of 45% non-irradiated fish and 55% Purina Mouse Chow, and Group III received a diet composed of 45% gamma irradiated fish and 55% Purina Mouse Chow. Differences observed in body weights between control and fish treated diets were due to the incorporation of fish into the diet and not the results of fish being treated with gamma irradiation. Differences observed in food consumption between control and fish treated diets were due to the incorporation of fish into the diet and not the result of fish being treated with gamma irradiation. No daily observations were made which could be attributed to the treatment of fish with gamma irradiation. No observations were made at any time interval for hematology which could be attributed to the treatment of fish with gamma irradiation. No observations were made at any time interval for clinical chemistry which could be attributed to the treatment of fish with gamma irradiation. Palpable mass data did not reveal any trends which could be related to the treatment of fish with gamma irradiation. Gross observations at necropsy were limited to spontaneously occurring lesions or artifacts of necropsy technique commonly associated with animals of this species and age. Organ weight data did not reveal any trends which could be related to the treatment of fish with gamma irradiation. Pathological findings were limited to spontaneously occurring lesions or artifacts of necropsy technique commonly associated with animals of this species and age. (orig.)

Some conclusions of studies on irradiation of whole fish aboard fishing vessels

International Nuclear Information System (INIS)

Reinacher, E.; Ehlermann, D.A.E.

1978-01-01

Studies were conducted on irradiation of whole redfish and haddock (at 100 krad) and subsequent storage of the irradiated fish for up to approx. 30 days in ice. The fish were organoleptically evaluated at intervals during storage. The results show no significant difference in organoleptic quality between irradiated and non-irradiated samples during storage for [de

Study on neutron irradiation behavior of beryllium as neutron multiplier

Energy Technology Data Exchange (ETDEWEB)

Ishitsuka, Etsuo [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment

1998-03-01

More than 300 tons beryllium is expected to be used as a neutron multiplier in ITER, and study on the neutron irradiation behavior of beryllium as the neutron multiplier with Japan Materials Testing Reactor (JMTR) were performed to get the engineering data for fusion blanket design. This study started as the study on the tritium behavior in beryllium neutron reflector in order to make clear the generation mechanism on tritium of JMTR primary coolant since 1985. These experiences were handed over to beryllium studies for fusion study, and overall studies such as production technology of beryllium pebbles, irradiation behavior evaluation and reprocessing technology have been started since 1990. In this presentation, study on the neutron irradiation behavior of beryllium as the neutron multiplier with JMTR was reviewed from the point of tritium release, thermal properties, mechanical properties and reprocessing technology. (author)

Longitudinal study of the effects of chronic hypothyroidism on skeletal muscle in dogs.

Science.gov (United States)

Rossmeisl, John H; Duncan, Robert B; Inzana, Karen D; Panciera, David L; Shelton, G Diane

2009-07-01

To study the effects of experimentally induced hypothyroidism on skeletal muscle and characterize any observed myopathic abnormalities in dogs. 9 female, adult mixed-breed dogs; 6 with hypothyroidism induced with irradiation with 131 iodine and 3 untreated control dogs. Clinical examinations were performed monthly. Electromyographic examinations; measurement of plasma creatine kinase, alanine aminotransferase, aspartate aminotransferase, lactate, and lactate dehydrogenase isoenzyme activities; and skeletal muscle morphologic-morphometric examinations were performed prior to and every 6 months for 18 months after induction of hypothyroidism. Baseline, 6-month, and 18-month assessments of plasma, urine, and skeletal muscle carnitine concentrations were also performed. Hypothyroid dogs developed electromyographic and morphologic evidence of myopathy by 6 months after treatment, which persisted throughout the study, although these changes were subclinical at all times. Hypothyroid myopathy was associated with significant increases in plasma creatine kinase, aspartate aminotransferase, and lactate dehydrogenase 5 isoenzyme activities and was characterized by nemaline rod inclusions, substantial and progressive predominance of type I myofibers, decrease in mean type II fiber area, subsarcolemmal accumulations of abnormal mitochondria, and myofiber degeneration. Chronic hypothyroidism was associated with substantial depletion in skeletal muscle free carnitine. Chronic, experimentally induced hypothyroidism resulted in substantial but subclinical phenotypic myopathic changes indicative of altered muscle energy metabolism and depletion of skeletal muscle carnitine. These abnormalities may contribute to nonspecific clinical signs, such as lethargy and exercise intolerance, often reported in hypothyroid dogs.

Adaptive response after low level irradiation

Energy Technology Data Exchange (ETDEWEB)

Pelevina, I I; Afanasjev, G G; JaGotlib, V; Tereschenko, D G; Tronov, V A; Serebrjany, A M [Russian Academy of Sciences, Moscow (Russian Federation). Institute of Chemical Physics

1996-02-01

The experiments conducted on cultured HeLa (tissue culture) cells revealed that there is a limit of dose above which adaptive response was not observed and a limit of dose below which this response was not induced. The exposure of cells in the territories with elevated radiation background leads to genome instability which results in enhanced radiosensitivity. Investigations on the blood lymphocytes of people living in contaminated regions revealed that adaptive response was more significant in children whereas in adults there was slight increase. Acute irradiation serves as a tool revealing the changes that took place in DNA during chronic low level irradiations after Chernobyl disaster. (author).

The preliminary study on peculiar flavor from irradiated dried duck

International Nuclear Information System (INIS)

Li Zongju; Chen Zongdao; Xu Denyi

1992-01-01

Peculiar flavor may be induced from irradiative preservation of meat with higher dose. The study on the irradiation of dried duck indicated that peculiar flavor is produced by a threshold of 1.5 kGy and intensifies with the increase of dose. The flavor primarily comes from muscle of dried duck especially from its water soluble protein. With the increase of dose, volatile carbonyl compounds, amines and sulfur compounds increased significantly. Paper chromatography analysis shows that two new volatile carbonyl compounds (R f =0.23 and 0.28) and a new volatile amine-propamine are induced by irradiation. This compounds may be the source of peculiar flavor in irradiated dried duck

Age dependent effects of combined irradiation on lipid peroxidation in rat blood

International Nuclear Information System (INIS)

Mazhul', L.M.; Volykhina, V.E.; Gatsko, G.G.

2000-01-01

It was studied the effects of combined action of external acute gamma-irradiation in dose 1.0 Gy and chronic internal irradiation of cesium 137 (0.8 MBq/kg) on lipid peroxidation system in rat blood. Animals of two aged groups (2 and 6 months old) was investigated. The experiments were conducted on 10, 30, 90 and 180 days after the cessation of cesium 137 injection. Internal irradiation didn't exert influence on lipid peroxidation system in blood. Antioxidant system was activated on 10 days after acute irradiation at 2-months old animals and by 180 days at 6-months ones. In the case of combined irradiation activation of the antioxidant system in blood serum of 2-months old rats in early terms (10 days) possibly supports the invariable level of lipid peroxidation products. At 6-months old rats, on the contrary, the activation of the antioxidant system was not registered, however the content of malonic dialdehyde was increased. Possibly, at 2-months old rats the combined irradiation in early terms stimulates the protective systems of the organism in higher degree than at 6-months old ones

Blood responses under chronic low daily dose gamma irradiation: Pt. 1; Differential preclinical responses of irradiated male dogs in progression to either aplastic anemia or myeloproliferative disease

Energy Technology Data Exchange (ETDEWEB)

Seed, T.M.; Carnes, B.A.; Tolle, D.V.; Fritz, T.E. (Argonne National Lab., IL (USA))

1989-01-01

Male beagles chronically exposed to low daily doses of {sup 60}Co {gamma} rays show one of three hematopoietic patterns, which reflect three different distinctly responding subgroups: (1) low radioresistance with progressing aplastic anemia and shortened survival ({sup -S}-AA subgroup); (2) high radioresistance with a complex of progressing myeloproliferative disorders ({sup +}R-MPD group); or (3) high radioresistance with other nonMPD syndromes ({sup +}R-nonMPD group). Blood cell levels (granulocytes, monocytes, erythrocytes, lymphocytes, and platelets) were assessed and fitted to a flexible polynomial spline model. Results showed that relative to the overall magnitude of blood cell loss as well as to the maximum rate of suppression during the initial phase, the subgroups were generally ranked {sup -}S-AA >> {sup +}R-MPD > {sup +}R-nonMPD. Relative to the overall strength of the recovery response, the subgroups were generally ranked {sup +}R-MPD > {sup +}R-nonMPD >>> {sup -}S-AA. In terms of overall maintenance levels of circulating blood cells during the recovery phase, however, the {sup +}R-nonMPD subgroup consistently exhibited stronger responses than the {sup +}R-MPD subgroup. These results support our contention that selected subgroups of dogs have strong propensities to specific hematopathologies (i.e. aplastic anemia and myeloid leukemia) under chronic irradiation and that these pathology-prone animals exhibit a series of marked differential hematopoietic responses during early preclinical phases, which serve effectively to prognosticate subsequent pathological progression. (author).

Studies on irradiated BNFL culture medium for decontamination and longer storage

International Nuclear Information System (INIS)

Singh, Antaryami; Malodia, P.; Jain, S.K.; Ram Gopal

2001-01-01

The feasibility of gamma radiation for microbial decontamination and shelf-life extension of culture medium was studied. Changes in total viable count, coliform count and fungal count on exposure to 5, 10, 15, 20 and 25 kGy of gamma radiation were examined. The total viable counts were reduced on irradiation. Complete destruction of bacterial and fungal contamination was observed at 20 kGy. Studies were conducted to examine the changes in microbial contamination of the medium during storage. There was no post irradiation proliferation of microorganisms. Also, no significant change in the efficiency of the irradiated culture medium was observed. Thus, irradiation is extremely useful for longer storage and quality-assurance. (author)

Irradiation-related amorphization and crystallization: In situ transmission electron microscope studies

International Nuclear Information System (INIS)

Allen, C.W.

1994-01-01

Interfacing an ion accelerator to a transmission electron microscope (TEM) allows the analytical functions of TEM imaging and diffraction to be employed during ion-irradiation effects studies. At present there are twelve such installations in Japan, one in France and one in the US. This paper treats several aspects of in situ studies involving electron and ion beam induced and enhanced phase transformations and presents results of several in situ experiments to illustrate the dynamics of this approach in the materials science of irradiation effects. The paper describes the ion- and electron-induced amorphization of CuTi; the ion-irradiation-enhanced transformation of TiCr 2 ; and the ion- and electron-irradiation-enhanced crystallization of CoSi 2

Preliminary study on detection of irradiated foodstuffs from the Romanian market

International Nuclear Information System (INIS)

Cutrubinis, Mihalis; Chirita, Daniel; Savu, Diana; Elisabeta Secu, Corina; Mihai, Radu; Secu, Mihai; Ponta, Corneliu

2007-01-01

In order to fulfil the European task for market survey in food irradiation the first Romanian laboratory for detection of irradiated foodstuffs was established at IRASM Irradiation Centre. In this preliminary study, a wide range of Romanian food samples (spices, vegetables and meat) gamma irradiated at IRASM have been studied using different detection methods: (1) DNA comet assay, (2) thermoluminescence (TL) and (3) electron spin resonance (ESR) for foodstuffs containing bone or cellulose. The results suggest that there is no general available detection method and there is no perfect detection method. In conclusion, in order to carry out a correct identification of radiation treatment of a food sample it is recommended to use at least two standardised detection methods

Meiotic chromosome behaviours in M1 generation of bread wheat irradiated by gamma-rays

International Nuclear Information System (INIS)

Watanabe, Y.; Takato, S.

1982-01-01

Growing plants of bread wheat (Triticum aestivum L. 2 n=6x=42, AABBDD) were subjected to acute or chronic irradiation by gamma-rays from 60Co and meiotic chromosome behaviours of PMCS in M 1 generation were cytologically compared. Both acute and chronic irradiations produced different types of chromosomal aberrations at the meiotic stages. Among them, translocation type was the most frequent, followed by univalent type. A mixed type, i. e. translocation accompanying one or more univalents was often detected. Even normal type which lacked translocation and univalent included laggards and briclges without exception. Other meiotic abnormalities such as deletion, iso-chromosome and micronuclei were observed frequently in both treatments. Dose dependency of translocation frequency was not recognized in this experiment. In chronic irradiation, different chromosome numbers and meiotic behaviours were found not only among florets of a spike but also among anthers of a floret. A number of plants with aneuploid-like grass types occurred at a high frequency in M 1 , especially with low exposure

THE IMPACT OF ULTRAVIOLET IRRADIATION ON MORPHO-FUNCTIONAL STATE OF SKIN IN GUINEA PIGS.

Science.gov (United States)

Myronchenko, S; Naumova, O; Zvyagintseva, T

2016-11-01

The purpose of this study was to assess the impact of ultraviolet irradiation (UV) on morphological and functional condition of the skin in guinea pigs. The study involved 30 albino guinea pigs weighing 400-500 g subjected to local exposure to UV irradiation. Control group consisted of intact guinea pigs. Histological studies of the skin were carried out at different stages of the trial (2 hours, 4 hours, 3 days, 8 days following the exposure). Microscopic examination showed morphological signs of acute inflammation in the skin of animals within the first three days following the exposure to UV irradiation. Within 2 hours following the exposure to UV irradiation these changes were minimal with signs of mild exudative changes. In 4 hours after the exposure histological changes increased. The specimens were also found to contain altered apoptotic keratinocytes (sunburn cells). Histopathological changes persisted and reached maximum severity by the 3rd day. Within post-erythema period (the 8th day) proliferative, hyperplastic, degenerative and dystrophic changes in the skin persisted. The prolonged nature of the changes in the skin is suggestive of the development of chronic inflammation in the skin of guinea pigs subjected to local exposure to UV irradiation.

Positron lifetime study of copper irradiated by energetic protons or energetic neutrons

International Nuclear Information System (INIS)

Howell, R.H.

1979-03-01

Positron lifetime measurements of pure copper damaged by irradiation with energetic protons and neutrons are presented. Lifetime determinations of the bulk material and various traps were made, and the dependence of the trapping rate on dose and irradiation energy were investigated. The results from the neutron- and proton-irradiated samples point to the existence of traps with similar but distinct lifetime parameters, not varying greatly from values reported in deformation studies. Also, a trap with long lifetime is seen for some proton irradiations, but is never seen for the neutron irradiations. The trapping rate of the short-lifetime trap is a linear function of dose for proton-irradiated samples and nearly so for the neutron irradiation. 1 figure

Vacancy defects in electron irradiated RPV steels studied by positron lifetime

Energy Technology Data Exchange (ETDEWEB)

Moser, P; Li, X H [CEA Centre d` Etudes de Grenoble, 38 (France). Dept. de Recherche Fondamentale sur la Matiere Condensee; Akamatsu, M; Van Duysen, J C [Electricite de France (EDF), 77 - Ecuelles (France)

1994-12-31

Specimens of French RPV (reactor pressure vessels) steels at different rates of segregation have been irradiated at 150 and 288 deg C with 3 MeV electrons (irradiation dose: 4*10{sup 19} e-/cm{sup 2}). Vacancy defects are studied by positron lifetime measurements before and after irradiation and at each step of isochronal annealing. After 150 deg C irradiation, a recovery step is observed in both specimens, for annealing treatments in the range 220-370 deg C and is attributed to the dissociation of vacancy-impurity complexes. The size of vacancy clusters never overcome 10 empty atomic volumes. If ``fresh`` dislocations are created just before irradiation, big vacancy clusters could be formed. After 288 deg C irradiation, small vacancy cluster of 4-10 empty atomic volumes are observed. (authors). 3 figs., 7 refs.

Investigating the embryo/larval toxic and genotoxic effects of {gamma} irradiation on zebrafish eggs

Energy Technology Data Exchange (ETDEWEB)

Simon, O., E-mail: olivier.simon@irsn.fr [Laboratoire de Radioecologie et d' Ecotoxicologie, Institut de Radioprotection et de Surete Nucleaire, Cadarache, Bat 186, BP3, 13115 Saint-Paul-lez-Durance Cedex (France); Massarin, S. [Laboratoire de Modelisation Environnementale, Institut de Radioprotection et de Surete Nucleaire, Cadarache, Bat 159, BP3, 13115 Saint-Paul-lez-Durance Cedex (France); Coppin, F. [Laboratoire de Radioecologie et d' Ecotoxicologie, Institut de Radioprotection et de Surete Nucleaire, Cadarache, Bat 186, BP3, 13115 Saint-Paul-lez-Durance Cedex (France); Hinton, T.G. [Service d' Etude du Comportement des Radionucleides dans les Ecosystemes, Institut de Radioprotection et de Surete Nucleaire, Cadarache, Bat 159, BP3, 13115 Saint-Paul-lez-Durance Cedex (France); Gilbin, R. [Laboratoire de Radioecologie et d' Ecotoxicologie, Institut de Radioprotection et de Surete Nucleaire, Cadarache, Bat 186, BP3, 13115 Saint-Paul-lez-Durance Cedex (France)

2011-11-15

Eggs/larval of freshwater fish (Danio rerio) were exposed to low dose rates of external gamma radiation (from 1 to 1000 mGy d{sup -1}) over a 20-day period, with the objective of testing the appropriateness of the 10 mGy d{sup -1} guideline suggested by the IAEA. The present study examines different endpoints, mortality and hatching time and success of embryos as well as the genotoxicity of {gamma}-irradiations (after 48 h). The 20-day embryo-larval bioassay showed an enhanced larval resistance to starvation after chronic exposure to {gamma} irradiation (from low 1 mGy d{sup -1} to high dose rate 1000 mGy d{sup -1}) and an acceleration in hatching time. Gamma irradiation led to increased genotoxic damage Ito zebrafish egg (40-50% DNA in tail in Comet assay) from the lowest dose rate (1 mGy d{sup -1}). Possible mechanisms of {gamma} radiotoxicity and implications for radioprotection are discussed. - Highlights: > Relevant information on the {gamma} radiation impact on early life stage biota is scarce. > The eggs of zebrafish Danio rerio were selected as biological model. > We test the appropriateness of the 10 mGy d{sup -1} guideline (IAEA). > We observed effects measured at individual levels (starvation, hatching time). > Chronic gamma irradiation led to increased genotoxic damage to zebrafish egg. > {gamma} radiotoxicity mechanisms and implications for radioprotection are discussed.

Studies on mating competition of irradiated melon flies

International Nuclear Information System (INIS)

Limohpasmanee, W.

1994-01-01

Mating competition is the key factor for fruit flies control by using sterile insect technique project. Mass rearing and irradiation can reduce the mating competition of fruit flies. This experiment has purpose to evaluate the mating competition of the irradiated melon fly. The results show that mating competition values of irradiated melon flies were 0.36 and 0.24 when they mated with normal and irradiated females. Both normal male and female can mate more frequency than irradiated flies. (Z=1.322, P<0.05; Z=1.851, P<0.05). The results show that quality of mass rearing and irradiated melon fly was lower than the normal flies. So that quality of irradiated fly must be improved and the number of released flies as less must be higher than natural flies 6 time

Effect of gamma irradiation on nylon 6 films : swelling study

International Nuclear Information System (INIS)

Singh, L.P.; Chaudhuri, N.K.

1980-01-01

This paper reports on swelling studies of γ-irradiated nylon 6 films undertaken to investigate the effects of γ-irradiation in finer details. Benzyl alcohol has been used as the swelling agent. The kinetics of weight swelling of γ-irradiated nylon 6 films in benzyl alcohol was studied at different irradiation doses in the range 0 - 28.8 Mrad. It is observed that with increasing irradiation dose upto 14.4 Mrad the swelling, and hence the diffusion process are retarded; moreover, the sigmoidal nature of the percentage weight swelling vs (time)sup(1/2) plot is augmented. Above this critical dose the swelling and diffusion processes are accelerated. Besides, the sigmoidal behaviour recedes and is converted into linear behaviour at 28.8 Mrad. This behaviour indicates that a relaxation-controlled non-Fickian diffusion process is at work below 28.8 Mrad while at 28.8 Mrad a Fickian process is established. A significant effect on the equilibrium swelling in benzyl alcohol is observed. The plot of equilibrium weight swelling vs irradiation dose at 23deg C shows an initial decrease of swelling upto 3.6 Mrad at which swelling starts decreasing at accelerated rate in the dose range 3.6 - 7.6 Mrad. The rate slows down appreciably between 7.00 and 14.4 Mrad, above which there is a rapid fall. The results are correlated with scission and crosslinking processes through relative viscosity determination of formic acid solutions of the irradiated samples. It is established by combining viscosity data with kinetics and equilibrium swelling data that, besides scission, crosslinking processes are also at work in nylon 6 in the irradiation dose range 0 - 3.6 Mrad. It has been possible to bring out this point because the swelling technique seems to be preferentially sensitive towards crosslinking. (author)

Chronic effects of UV on human skin

International Nuclear Information System (INIS)

Cesarini, J.P.

1996-01-01

Chronic exposures and acute accidents of the skin to UV has been recognized as an important risk for skin cancers in human. Attempts have been made with mathematical models to correlate the ambient UV dose and occupational irradiations with the risk of skin cancers. Development of accurate global measurements of solar irradiance and personal dosimetry is expected in the future in order to reduce the exposure of the general population, to precise the measures to be taken for indoor and outdoor workers. (author)

Experimental studies on prevention of trichinosis by food irradiation (Co60)

International Nuclear Information System (INIS)

Shimazu, Kimitaka

1993-01-01

A systemic study was performed to elucidate the effects of 60 Co irradiation on maturation or fecundity of Trichinella spiralis by assessing from parasitological, morphological and immunological points of view. Pieces of muscle tissue of mice infected with T. spiralis were irradiated with 60 Co at doses of 50, 75, 100, 150 and 200 Gy. These irradiated tissue (Experimental group) and non-irradiated tissues (Control group) were fed to healthy mice. Half of the mice were sacrificed 6 days after the ingestion. The number of adult worms were counted and subjected to statistical analysis, which disclosed a good correlation between the dose of 60 Co irradiation and worm damage; the higher the dose the more damage parasites had, and no adults were recovered if the tissue had been irradiated with more than 150 Gy prior to infection. The same tendency was true for the histopathology of the intenstines of host mice; the higher the dose the less tissue damage. Circulating antigens of T. spiralis and antibodies against T. spiralis were detected in every serum examined by ELISA. The remaining mice were sacrificed 30 days after the ingestion. The numbers of muscle larvae were counted and subjected to statistical analysis, which disclosed a good correlation between th dose of 60 Co irradiation and worm damage, and no larvae were recovered if the tissue had been irradiated with more than 75Gy. Higher concentrations of circulating antigens of T. spiralis and antibodies against T. spiralis were detected in the serum samples taken with muscle larvae. Thus this study established that 60 Co irradiation of more than 150 Gy caused complete damage on maturation, and that irradiation of more than 75 Gy caused complete damage on the fecundity of T. spimalis. (author)

Preliminary Studies for the Application of Irradiated-Food to Food Service Industry

Energy Technology Data Exchange (ETDEWEB)

Lee, Ju-Woon; Byun, Myung-Woo; Kim, Jae-Hun; Choi, Jong-Il; Song, Beom-Seok; Kim, Dong-Ho; Seo, Min-Won

2008-04-15

This study is to investigate ways to improve the marketability of irradiated food materials, through examining reports on toxicological safety and public acceptance of irradiated food materials. Many studies have reaffirmed the mutagenic, genotoxicological, microbiological, and nutritional safety of food irradiation, and consider it an important tool to reduce loss of food due to spoilage and pests. Although food irradiation could provide an opportunity to replace certain pesticides and food additives, there is ambivalence among consumers on whether or not the technology provides a real benefit. An easy and inexpensive tool to identify irradiation trace residue in foods, public trust building in industry through educating consumers with the benefit and uses of irradiation process are thought to be key elements for a successful market for irradiated food. Gamma irradiation at 50 kGy was applied to food materials for institutional food-service to evaluate their possible genotoxicity. The genotoxicity of 12 kinds of food materials irradiated at 50 kGy for institutional food-service was evaluated by Salmonella typhimurium reversion assay, chromosomal aberration test and in vivo micronucleus assay. The results of bacterial reversion assay with S. typhimurium TA98, TA100, TA1535 and TA1537 were negative in the 12 kinds of food materials irradiated at 50 kGy. No mutagenicity was detected in the assay with and without metabolic activation. In chromosomal aberration tests with CHL cells and in vivo mouse micronucleus assay, no significant difference in the incidences of chromosomal aberration and micronuclei was observed between non-irradiated and 50 kGy-irradiated food materials. These results indicate that food materials irradiated at 50 kGy for institutional food-service did not show any genotoxic effects under these experimental conditions.

Preliminary Studies for the Application of Irradiated-Food to Food Service Industry

International Nuclear Information System (INIS)

Lee, Ju-Woon; Byun, Myung-Woo; Kim, Jae-Hun; Choi, Jong-Il; Song, Beom-Seok; Kim, Dong-Ho; Seo, Min-Won

2008-04-01

This study is to investigate ways to improve the marketability of irradiated food materials, through examining reports on toxicological safety and public acceptance of irradiated food materials. Many studies have reaffirmed the mutagenic, genotoxicological, microbiological, and nutritional safety of food irradiation, and consider it an important tool to reduce loss of food due to spoilage and pests. Although food irradiation could provide an opportunity to replace certain pesticides and food additives, there is ambivalence among consumers on whether or not the technology provides a real benefit. An easy and inexpensive tool to identify irradiation trace residue in foods, public trust building in industry through educating consumers with the benefit and uses of irradiation process are thought to be key elements for a successful market for irradiated food. Gamma irradiation at 50 kGy was applied to food materials for institutional food-service to evaluate their possible genotoxicity. The genotoxicity of 12 kinds of food materials irradiated at 50 kGy for institutional food-service was evaluated by Salmonella typhimurium reversion assay, chromosomal aberration test and in vivo micronucleus assay. The results of bacterial reversion assay with S. typhimurium TA98, TA100, TA1535 and TA1537 were negative in the 12 kinds of food materials irradiated at 50 kGy. No mutagenicity was detected in the assay with and without metabolic activation. In chromosomal aberration tests with CHL cells and in vivo mouse micronucleus assay, no significant difference in the incidences of chromosomal aberration and micronuclei was observed between non-irradiated and 50 kGy-irradiated food materials. These results indicate that food materials irradiated at 50 kGy for institutional food-service did not show any genotoxic effects under these experimental conditions

The preliminary study on peculiar flavor from irradiated dried duck

Energy Technology Data Exchange (ETDEWEB)

Zongju, Li; Zongdao, Chen; Denyi, Xu [Southwest Agricultural Univ., Chongqing, SC (China)

1992-11-01

Peculiar flavor may be induced from irradiative preservation of meat with higher dose. The study on the irradiation of dried duck indicated that peculiar flavor is produced by a threshold of 1.5 kGy and intensifies with the increase of dose. The flavor primarily comes from muscle of dried duck especially from its water soluble protein. With the increase of dose, volatile carbonyl compounds, amines and sulfur compounds increased significantly. Paper chromatography analysis shows that two new volatile carbonyl compounds (R[sub f] =0.23 and 0.28) and a new volatile amine-propamine are induced by irradiation. This compounds may be the source of peculiar flavor in irradiated dried duck.

Wholesomeness study of irradiated salted and dried mackerel in rats

International Nuclear Information System (INIS)

Anukarahanonta, T.; Temcharoen, P.; Nagara, B.N.; Chudhabuddhi, C.; Bhamarapravati, N.

1981-01-01

A long-term multigeneration study was performed of the wholesomeness of irradiated salted and dried mackerel fed to the rats of Wistar strain and revealed no significant evidence that would impose a hazard attributable to irradiation with respect to the longevity, carcinogenecity, teratogenicity, dominant lethal, reproductive function and biophysiological function. Some abnormalities that were noted could be explained on the basis of differences in food quality due to the addition of fish protein and minerals rather than the irradiation effect

Preliminary study of killing the larva of plodia interpunella by irradiation

International Nuclear Information System (INIS)

Wang Jide; Ma Xiaoping

1994-01-01

The results of killing the larva of plodia interpunella in the fruit by 60 Co γ-irradiation are described. The lowest effective dose for killing larva by irradiation is ca. 2000 Gy; the effective dose for immediately killing larva is 3000 Gy. The method is simple and easy and also suitable for the study of commercial irradiation of dry-fruit

Radioprotection by caffeine pre-treatment and post-treatment in the bone marrow chromosomes of mice given whole-body γ-irradiation

International Nuclear Information System (INIS)

Farooqi, Z.; Kesavan, P.C.

1992-01-01

The effect of caffeine given as pre- and post-treatment in mice exposed to whole-body γ-irradiation (1.5 Gy 60 Co γ-rays) was studied. The pre-treatment was either acute or chronic. The acute dose (5 mg/kg and 15 mg/kg body weight) was in the form of an injection given intraperitoneally, 30 min before irradiation. The chronic administration was in the form of caffeine solution (4.208x10 -3 M and 7.72x10 -4 M) contained in drinking water for 5 weeks prior to radiation exposure. The acute pre-treatment with caffeine reduced the radiation-induced frequency of chromosomal aberrations discernibly, whereas chronic pre-treatment afforded a much more significant degree of radioprotection. The caffeine post-treatment (5 mg/kg and 15 mg/kg body weight) was given in the form of an intraperitoneal injection to the mice immediately following whole-body γ-irradiation. It is noted that both post-treatment concentrations of caffeine also significantly reduced the frequency of chromosomal aberrations induced by γ-rays. These data are briefly discussed in terms of possible mechanistic considerations. (author). 33 refs.; 3 tabs

Radioprotection by caffeine pre-treatment and post-treatment in the bone marrow chromosomes of mice given whole-body [gamma]-irradiation

Energy Technology Data Exchange (ETDEWEB)

Farooqi, Z.; Kesavan, P.C. (Jawaharlal Nehru Univ., New Delhi (India). School of Life Sciences)

1992-10-01

The effect of caffeine given as pre- and post-treatment in mice exposed to whole-body [gamma]-irradiation (1.5 Gy [sup 60]Co [gamma]-rays) was studied. The pre-treatment was either acute or chronic. The acute dose (5 mg/kg and 15 mg/kg body weight) was in the form of an injection given intraperitoneally, 30 min before irradiation. The chronic administration was in the form of caffeine solution (4.208x10[sup -3] M and 7.72x10[sup -4] M) contained in drinking water for 5 weeks prior to radiation exposure. The acute pre-treatment with caffeine reduced the radiation-induced frequency of chromosomal aberrations discernibly, whereas chronic pre-treatment afforded a much more significant degree of radioprotection. The caffeine post-treatment (5 mg/kg and 15 mg/kg body weight) was given in the form of an intraperitoneal injection to the mice immediately following whole-body [gamma]-irradiation. It is noted that both post-treatment concentrations of caffeine also significantly reduced the frequency of chromosomal aberrations induced by [gamma]-rays. These data are briefly discussed in terms of possible mechanistic considerations. (author). 33 refs.; 3 tabs.

Studies on the irradiated solids

International Nuclear Information System (INIS)

Lesueur, D.

1988-01-01

The 1988 progress report of the Irradiated Solids laboratory (Polytechnic School, France), is presented. The Laboratory activities concern the investigations on disordered solids (chemical or structural disorder). The disorder itself, its effects on the material physical properties and the particle-matter interactions, are investigated. The research works are performed in the following fields: solid state physics, irradiation and stoechiometric defects, and nuclear materials. The scientific reviews, the congress communications and the thesis are listed [fr

Thermal studies on unirradiated and γ-irradiated polymer of allyl diglycol carbonate

International Nuclear Information System (INIS)

Kalsi, P.C.; Pandey, A.K.; Iyer, R.H.; Singh Mudher, K.D.

1995-01-01

The thermal decomposition of unirradiated and γ-irradiated (5.93-15.5 MRad dose range) allyl diglycol carbonate polymer (trade name, CR-39) was studied by thermogravimetry (TG) and differential thermal analysis (DTA). These studies indicate four main decomposition steps in CR-39 polymer in air. Assessment of the influence of radiation dose on the above range shows that while the 5.93 MRad γ-irradiated polymer CR-39 degrades in three steps, the 15.5 MRad γ-irradiated polymer degrades in only two steps. The kinetics of the different stages of degradation were also evaluated from the TG curves. Irradiation enhances the decomposition rate and the effect increases further with increasing radiation dose. The activation energy values calculated for all the decomposition stages decrease on irradiation

Study on the physiological activities of gamma-irradiated seafood cooking drips

International Nuclear Information System (INIS)

Jo, Eu Ri; Kim, Yeon Joo; Choi, Jong Il; Sung, Nak Yun; Jung, Pil Moon; Kim, Jae Hun; Song, Beom Seok; Yoon, Yo Han; Lee, Ju Woon; Lee, Ju Yeoun

2010-01-01

Cooking drips which were obtained as by-product after seafood processing in the food industries, still contain lost of proteins, carbohydrates, and other functional materials. This study was conducted to investigate the effect of gamma irradiation on the biological activities of seafood cooking drips. When the cooking drips of Hizikia fusiformis, Enteroctopus dofleini and Thunnus thynnus were irradiated, the antioxidant activities, whitening effect, and angiotensin I converting enzyme inhibition activity of the ethanol extract from seafood cooking drips were all increased by gamma irradiation. This was because of the increased extraction efficiency of available compounds by irradiation. These results suggested that the seafood cooking drips, wasted as by-products, can be used as functional compounds with gamma irradiation treatment

Study on the physiological activities of gamma-irradiated seafood cooking drips

Energy Technology Data Exchange (ETDEWEB)

Jo, Eu Ri; Kim, Yeon Joo; Choi, Jong Il; Sung, Nak Yun; Jung, Pil Moon; Kim, Jae Hun; Song, Beom Seok; Yoon, Yo Han; Lee, Ju Woon [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Lee, Ju Yeoun [Chonbuk National University, Jeonju (Korea, Republic of)

2010-03-15

Cooking drips which were obtained as by-product after seafood processing in the food industries, still contain lost of proteins, carbohydrates, and other functional materials. This study was conducted to investigate the effect of gamma irradiation on the biological activities of seafood cooking drips. When the cooking drips of Hizikia fusiformis, Enteroctopus dofleini and Thunnus thynnus were irradiated, the antioxidant activities, whitening effect, and angiotensin I converting enzyme inhibition activity of the ethanol extract from seafood cooking drips were all increased by gamma irradiation. This was because of the increased extraction efficiency of available compounds by irradiation. These results suggested that the seafood cooking drips, wasted as by-products, can be used as functional compounds with gamma irradiation treatment.

Study of gamma irradiation effect on commercial TiO2 photocatalyst

International Nuclear Information System (INIS)

Bello Lamo, M.P.; Williams, P.; Reece, P.; Lumpkin, G.R.; Sheppard, L.R.

2014-01-01

The aim of this work is to understand the effect of gamma irradiation on commercial TiO 2 photocatalyst for water treatment applications. Previous studies concluded that gamma-irradiation is able to modify the electronic properties of TiO 2 based photocatalysts and consequently their photocatalytic performance. However, there are some discrepancies in the literature where on one hand a significant enhancement of the material properties is reported and on the other hand only a weak effect is observed. In this study a surface effect on TiO 2 is confirmed by using low and medium gamma irradiation doses. - Highlights: • Gamma irradiated TiO 2 is investigated for photocatalytic water treatment. • By low gamma doses, no change in surface properties is observed. • However, a surface defect is found for gamma irradiated TiO 2 at higher doses. • XPS measurements showed an increase of hydroxyl groups. • That may cause a variation of its adsorption capacity

Multigeneration feeding studies with an irradiated whole diet

International Nuclear Information System (INIS)

Aravindakshan, M.; Chaubey, R.C.; Chauhan, P.S.; Sundaram, K.

1978-01-01

Multigeneration feeding studies have been carried out to investigate the effects of long-term feeding of an irradiated whole diet in Wistar rats. The parent and the four successive generations were fed on a nutritionally adequate test diet exposed to either 0.2 or 2.5Mrad gamma radiation and the effects, if any, on various parameters of animal health were assessed. In addition to an unirradiated test control, a historical control group fed on stock laboratory rations was also employed for comparison. The test diet consisted of various components including some of the basic ingredients of human diet in India. Exposure of the test diet to 0.2 or 2.5Mrad did not affect the food efficiency ratio and there were no significant differences in the growth rates of animals fed on unirradiated or irradiated diets. Reproductive performance of the rats fed on irradiated or unirradiated diets belonging to the parent, first, second or third generations were also comparable. Mortality rates and reproductive function in relation to age were also not altered due to feeding of irradiated whole diets. The haematological profile and the serum enzymes of the animals of all the generations fed irradiated diets were within normal limits. Though some differences were observed in the relative weights of some organs, these effects were limited to a particular generation, did not show any definite pattern and could not be related to the ingestion of irradiated diets. First-generation rats examined at 100-104 weeks for gross pathological manifestations including tumour incidence also did not indicate any significant differences among groups. (author)

Defect studies in electron-irradiated ZnO and GaN

International Nuclear Information System (INIS)

Tuomisto, F.; Look, D.C.; Farlow, G.C.

2007-01-01

We present experimental results obtained with positron annihilation spectroscopy in room-temperature electron-irradiated n-type ZnO and GaN. The cation vacancies act as important compensating centers in 2 MeV electron-irradiated samples, even though their introduction rates are different by 2 orders of magnitude. In addition, negatively charged non-open volume defects that also compensate the n-type conductivity are produced together with the cation vacancies at similar introduction rates. The low introduction rates of compensating defects in ZnO demonstrate the radiation hardness of the material. Isochronal thermal annealings were performed to study the dynamics of the irradiation-induced defects. In 2 MeV electron-irradiated ZnO, all the defects introduced in the irradiation disappear already at 600 K, while 1100 K is needed in GaN. Several separate annealing stages of the defects are observed in both materials, the first at 400 K

Defect studies in electron-irradiated ZnO and GaN

Energy Technology Data Exchange (ETDEWEB)

Tuomisto, F. [Laboratory of Physics, Helsinki University of Technology, 02015 TKK Espoo (Finland)], E-mail: filip.tuomisto@tkk.fi; Look, D.C. [Semiconductor Research Center, Wright State University, Dayton, OH 45435 (United States); Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, OH 45433 (United States); Farlow, G.C. [Physics Department, Wright State University, Dayton, OH 45435 (United States)

2007-12-15

We present experimental results obtained with positron annihilation spectroscopy in room-temperature electron-irradiated n-type ZnO and GaN. The cation vacancies act as important compensating centers in 2 MeV electron-irradiated samples, even though their introduction rates are different by 2 orders of magnitude. In addition, negatively charged non-open volume defects that also compensate the n-type conductivity are produced together with the cation vacancies at similar introduction rates. The low introduction rates of compensating defects in ZnO demonstrate the radiation hardness of the material. Isochronal thermal annealings were performed to study the dynamics of the irradiation-induced defects. In 2 MeV electron-irradiated ZnO, all the defects introduced in the irradiation disappear already at 600 K, while 1100 K is needed in GaN. Several separate annealing stages of the defects are observed in both materials, the first at 400 K.

Positron annihilation and Moessbauer studies of neutron irradiated reactor pressure vessel steels

International Nuclear Information System (INIS)

Brauer, G.; Matz, W.; Liszkay, L.; Molnar, B.

1990-11-01

Positron annihilation (lifetime, Doppler broadening) and Moessbauer studies on unirradiated, neutron irradiated and neutron irradiated plus annealed reactor pressure vessel steels (Soviet type 15Kh2NMFA) are presented. The role of microstructural properties and the formation of irradiation-induced precipitates is discussed. (orig.) [de

Comparative study of thermoluminescence detection methods for irradiated spices

International Nuclear Information System (INIS)

Kawamura, Y.; Kojima, K.; Sugita, T.; Yamada, T.; Saito, Y.

1995-01-01

The thermoluminescence (TL) detection methods for irradiated spices were compared using spice samples obtained on the Japanese market, irradiated at doses of 1, 5, 10 and 30 kGy and stored for 1 year before analysis. The TL intensities of irradiated spices were stable for 1 year after irradiation. Measurement with whole samples failed to identify irradiated samples. Minerals were separated from spices in sodium tungstate saturated solution and/or sodium polytungstate solution. The TL intensity of minerals which had undergone irradiation was significantly increased for all samples. However, the ranges of TL intensity of irradiated and unirradiated samples overlapped. Clear discrimination has been obtained between the TL ratios of irradiated and unirradiated spices by using normalized measurement with reirradiation. The detection limit in terms of irradiation dose is 1 kGy even in a sample that has been irradiated 1 year prior to analysis. Normalization is the best technique currently available for thermoluminescence analysis to identify irradiated spices

Acute and chronic radiation syndrome in domestic animals

International Nuclear Information System (INIS)

Nuessel, M.

1974-11-01

The paper reports on the incidence and the clinical picture of the radiation syndrome in domestic animals, especially in pigs which are often used in animal experiments. The following parameters which influence the radiation reaction are discussed: type of irradiation (whole-body, partial-body and local irradiation), mean lethal radiation dose, radiation quality and RBE, age and individual radiosensitivity. The auther then describes the various symptoms of the radiation syndrome and the lesions which lead to death (death due to intestinal lesions, death following changes in the central nervous system). The next few chapters treat the symptoms manifested after chronic and internal irradiation. The paper closes with some remarks on the usability of irradiated animals for human consumption. (MG/AK) [de

Study on the irradiation decontamination of traditional Chinese medicines

International Nuclear Information System (INIS)

Wang, B.; Shi, S.; Li, B.; Wang, G.

2005-01-01

Traditional Chinese Medicines (TCMs) are natural products prepared from plants, minerals and animals, it is easy for contamination by microorganisms to occur; thus causing problems in complying with the requirements laid down for passing microbial limit tests. We selected some kinds of TCMs, including unprocessed materia medica, traditional Chinese patent medicine (TCPMs) and chemical constituents for irradiation by 60 Co gamma ray and investigating the results in terms of microbiology, chemistry, pharmacology and toxicology. We found no evidence of changes in most of the tested items, which indicates that the irradiation method could be employed for decontamination of TCMs. However, some chemical constituents of unprocessed materia medica, such as gentiopicrin in Radix Gentianae Macrophyllae and 2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucoside in Radix Polygoni Multiflori, decomposed when these crude materials were irradiated with dose of 5kGy. Further study revealed that although the medicinal were altered by irradiation, the monomers of some of these chemical constituents were not affected. In addition to investigation of the items described above, the doses of irradiation were selected experimentally to ensure that, after irradiation, the TCMs passed the microbial limit tests described in the Chinese Pharmacopoeia. The lowest possible doses were used in order to avoid any impairment of the quality and clinical efficacy of the effective ingredients of the TCMs. (author)

Fundamental irradiation studies on vanadium alloys

International Nuclear Information System (INIS)

Loomis, B.A.; Garner, F.A.; Ermi, A.M.

1985-05-01

A joint experiment on the irradiation response of simple vanadium alloys has been initiated under the auspices of the DAFS and BES progams. Specimen fabrication is nearly complete and the alloys are expected to be irradiated in lithium in FFTF-MOTA Cycles 7 and 8

Studies on combination effects of peplomycin and x-ray irradiation

International Nuclear Information System (INIS)

Munenaga, Yasuichi

1984-01-01

In order to study effects and methods of combination of peplomycin (PEP) and x-ray irradiation, inhibitory effects on DNA synthesis were investigated with synchronized cells from the parotid gland of mice treated with isoproterenol (IPR) and inhibitory effects on cell proliferation were investigated with Ehrlich solid tumor cells. PEP had dose-dependent effects on the inhibition of DNA synthesis and on the prolongation of cell cycles in the IPR-treated mouse cells. When 3.0 and 5.0 mg/kg of PEP were combined with 200 rad of x-ray irradiation at the early phase of G 1 , synergistic effects on the inhibition of DNA synthesis were seen. This was most noted in the group with PEP 30 minutes before irradiation. PEP had also dose-dependent inhibitory effects on the proliferation of Ehrlich solid tumor cells. This was increased when x-ray irradiation was combined with PEP. Inhibitory effects on the proliferation of tumor cells were greater when PEP was given before x-ray irradiation than after x-ray irradiation, regardless of the amount. The greatest effect was seen in the group with PEP 30 minutes before irradiation, as well as in the experiment with IPR-treated mouse cells. (Namekawa, K.)

Effect of thermal treatment on the body temperature, respiration and pulse rate in dogs chronically irradiated with γ-rays

International Nuclear Information System (INIS)

Popova, N.A.; Petrovnin, M.G.

1975-01-01

Male dogs were chronically gamma-irradiated at different dose rates (0.06, 0.17, 0.34 rad/day) and subjected to heat treatment (raising of temperature from 22 0 C to 40 0 C) during winter and summer. Internal (rectal) temperature, respiration rate and heart rate were recorded. The respiration rate changed appreciably in all groups during all periods of temperature rise and fall in the chamber, but the variations were more pronounced in all groups during the winter experiment than during the summer experiment; no significant differences were found between the groups of animals while the respiration rate was changing, either in the winter or in the summer experiment. In both experiments, there were considerable heart rate variations only in the control group and in the group exposed to a dose rate of 0.06 rad/day. (V.A.P.)

Biophysical studies of irradiated thymocytes. 1. Surface changes

Energy Technology Data Exchange (ETDEWEB)

Sungurov, A Yu; Tokalov, S V; Petrov, Yu P; Sharlaeva, T M

1985-08-15

In order to study postirradiation changes in thymus lymphocyte surface, a number of biophysical analytical methods was used: the cell two-partition method, the physical adhesion method, fluorescence intensity and binding parameters of negatively charged ANS probe. Reduction of cell distribution factor in two-phase system and adhesion of thymocytes to cotton 1 hour after irradiation, as well as abrupt change in parameters of binding the probe in the interval of 3-4 hours after X-ray irradiation at the dose of 4 Gy are demonstrated.

About the study of irradiation effects on in-core instrumentation

International Nuclear Information System (INIS)

Angelino, G.

1972-01-01

The knowledge of in-core instrumentation performances is a very important item when irradiations of technological interest are concerned. When measurement of small changes in mechanical or thermal properties is of major importance, the effect of neutron and gamma irradiation on various transducers must be thoroughly evaluated. A rig mock-up was irradiated in the Triga Mark II Reactor of the Pavia University to assess the possibility of carrying out a study on irradiation effects on in-core instrumentation. Data on neutron flux distribution and γ-heating effect were collected from this preliminary experiment; at the same time a complete check was performed on rig assembling procedure, on the behaviour under operating conditions, and on the reactor loading and unloading operations. (author)

Irradiation of carbon nanotubes with carbon projectiles: A molecular dynamics study

Energy Technology Data Exchange (ETDEWEB)

Denton, Cristian D. [Departamento de Fisica Aplicada, Universidad de Alicante, 03080 Alicante (Spain); Heredia-Avalos, Santiago; Moreno-Marin, Juan Carlos [Departamento de Fisica, Ingenieria de Sistemas y Teoria de la Senal, Universidad de Alicante, 03080 Alicante (Spain)

2013-04-15

The irradiation of carbon based nanostructures with ions and electrons has been shown to be an appropriate tool to tailor their properties. The defects induced in the nanostructures during irradiation are able to modify their mechanical and electronic properties. Here we simulate the irradiation of carbon nanotubes with carbon ions using a molecular dynamics code. We use the Tersoff potential joined smoothly to the Universal Ziegler-Biersack-Littmark potential at short distances. We study the number of defects produced after irradiation with a single carbon ion finding a saturation with its energy at {proportional_to} 3 keV. We observe, after continuum irradiation with low energy ions, the formation of bumps in the irradiated region. For larger energy ions we find that the diameter of the nanotube shrinks as shown in previous works. (copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Monte Carlo studies of the Portuguese gamma irradiation facility. The irradiator geometry and its influence on process parameters

International Nuclear Information System (INIS)

Oliveira, C.; Ferreira, L.; Salgado, J.

2001-01-01

The paper describes a Monte Carlo study of dose distributions, minimum dose and uniformity ratio for the Portuguese Gamma Irradiation Facility. These process parameters are calculated using the MCNP code for several irradiator geometries. The comparison of the simulated results with the experimental results carried out using Amber Perspex dosimeters in a routine process of the gamma facility for a given material composition and density reveals good agreement. The results already obtained allow to conclude that the dose uniformity is not very sensitive to the irradiator geometry for density value ρ = 0.1 and for a dynamic process. (orig.)

Pilotscale studies of dried fish irradiation. Part of a coordinated programme in Asian Regional Cooperative Project on Food Irradiation

International Nuclear Information System (INIS)

Maha, M.

1983-03-01

Pilot scale experiments on irradiation of semi-dried mackerel with regard to shelf-life extension, packaging, transportation and cost-analysis were carried out. The results showed that dipping mackerel in saturated brine for 5 hours and then soaking it in 2% potassium sorbate before sun-drying to approximately 40% moisture content produced a good quality product. Sorbate treatment was effective in controlling mould growth while irradiation with 2 kGy was effective in reducing the bacterial load. Carton boxes were found most suitable as packaging material for irradiated dried fish from the point of view of strength, convenience for irradiation and better dose uniformity ratio than polypropylene bags which have ununiform configuration. Irradiation with doses up to 10 kGy has no significant effect on physical properties of the packaging materials tested. Carton boxes of 20 kg capacity provided with strapping bands are durable for land or sea transportation of dried fish. A radiation dose of 0.5 kGy was sufficient to control insect damage and reduce mould growth on dried fish. Irradiated dried fish can be marketed for 3-4 months at ambient conditions in Jakarta. Small scale consumer studies of irradiated samples using employees of the institute showed no negative reactions. Using the small pilot irradiator at CAIR and assuming 1 kGy minimum dose for dried fish, the total cost of irradiation and packaging was estimated to be approximately 10 U.S. cents/kg of fish, which is about 2-3% of the cost of the product

Experience with a pilot plant for the irradiation of sewage sludge: Bacteriological and parasitological studies after irradiation

International Nuclear Information System (INIS)

Wizigmann, I.; Wuersching, F.

1975-01-01

Comparative bacteriological studies of sewage sludge in a sewage plant have demonstrated that mechanical-biological sewage treatment reduced the total bacterial count and those of Enterococces by 2 log and the Enterobacteriaceae by 3-4 log. Frequently Salmonella could be isolated from sewage sludge. A further reduction of viable micro-organisms could be achieved by irradiation of sewage sludge ( 60 Co, gamma-radiation, 260 krad, 210 min). This reduction amounted to an average of 2 log with Enterococces and total bacterial count, and to 5 log with Enterobacteriaceae. Out of 40 samples investigated after irradiation, two contained Salmonella. The hygienic effects of the irradiation unit were demonstrated by means of a model experiment with bacterial pure cultures. Micro-organisms of different species as well as strains of the same species differ in their sensitivity to irradiation. Parasitological experiments with eggs of Ascaris suum were carried out to test the inhibitory or killing ability of the gamma rays on the developing stages of parasites

Transportation and storage studies on irradiated Alphonso mangoes

International Nuclear Information System (INIS)

Farkas, J.; Dharkar, S.D.; Sreenivasan, A.

1972-01-01

Control as well as skin coated (6% ''Myvacet'') and/or irradiated (25 to 35 krad) mangoes were packed in baskets in dry paddy straw and shipped by rail. After a storage at a temperature of 25 to 32 0 C for a period of 8 days, the baskets were shipped back. After receipt in the laboratory the fruits were kept under observation for 5 more days and then scored for ripening and marketability as assessed by appearance, skin gloss and typical flavour. 100 per cent of fruits skin-coated and irradiated were marketable at the end of the experiment. None of the unirradiated control fruits were saleable by this time, while 66%, of the irradiated fruits were in acceptable condition. In further experiments one dozen mangoes each from control, irradiated and skin-coated and irradiated groups were wrapped individually in tissue paper and packed tightly in a plyweed box. This consignment was air-lifted from Bombay to Budapest, a distance of about 5600 kilometers. The time interval between irradiation and their receipt in Hungary was 4 days. The mangoes were assessed for their storage characteristics by various parameters that included physiological loss in weight, puncture resistance of the skin, pulp texture, carotenoids, acidity and organoleptic attributes, at various periods during storage. It was found that ripening and senescence are strikingly delayed in mangoes by skin-coating and radiation treatment. The treated mangoes retained their skin-resistance while the disappearance of chlorophyl and formation of carotenoids were substantially delayed. Weight loss in storage was lower and reduction of acidity and formation of sugars in the fruit flesh took place later. Organoleptically, the fruits subjected to the combination treatment were good. These studies point to the feasibility of the combination treatment in prolonging the shelf life of fruits significantly to enable their transport to distant countries. (F.G.)

A study on the irradiation effect of reactor materials using a cyclotron

Energy Technology Data Exchange (ETDEWEB)

Hong, Joon Hwa; Ji, Se Hwan; Kang, Yung Hwan; Park, Duk Keun; Park, Jong Man; Lee, Bong Sang; Oh, Jong Myung [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1994-12-01

The objectives of the present study are to develop the simulation techniques of neutron irradiation through ion irradiation using a Cyclotron and small specimen techniques and to evaluate radiation effects of reactor materials. Effects of proton or neutron irradiation on domestic 12Cr-1MoV and SA508-3 steels were evaluated by small scale specimen test techniques, i.e, small punch and miniaturized tensile test. In order to study the radiation damage mechanism, irradiation effects of the steels were investigated by means of property change tests such as microstructure, physical and thermal properties. Feasibility study on application of a magnetic non-destructive methods to evaluate radiation effects on RPV materials was performed. 109 figs, 12 tabs, 102 refs. (Author).

A study on the irradiation effect of reactor materials using a cyclotron

International Nuclear Information System (INIS)

Hong, Joon Hwa; Ji, Se Hwan; Kang, Yung Hwan; Park, Duk Keun; Park, Jong Man; Lee, Bong Sang; Oh, Jong Myung

1994-12-01

The objectives of the present study are to develop the simulation techniques of neutron irradiation through ion irradiation using a Cyclotron and small specimen techniques and to evaluate radiation effects of reactor materials. Effects of proton or neutron irradiation on domestic 12Cr-1MoV and SA508-3 steels were evaluated by small scale specimen test techniques, i.e, small punch and miniaturized tensile test. In order to study the radiation damage mechanism, irradiation effects of the steels were investigated by means of property change tests such as microstructure, physical and thermal properties. Feasibility study on application of a magnetic non-destructive methods to evaluate radiation effects on RPV materials was performed. 109 figs, 12 tabs, 102 refs. (Author)

Swedish studies on irradiation effect in structural materials

Energy Technology Data Exchange (ETDEWEB)

Grounes, M; Myers, H P

1962-12-15

A brief description of work in hand at AB Atomenergi concerning the effects of neutron irradiation on structural materials is given. Some recent data is listed for the following pressure vessel steels 2103/R3 as used in the Aagesta reactor, SIS 142103, NO345, Fortiweld and weld metal OK 54 P. Zircaloy-2 has been studied regarding the combined effects of neutron irradiation and hydrogen content on tensile properties. The difficulties associated with determination of neutron dose and the correlation of damage with dose and neutron energy spectrum are discussed.

Swedish studies on irradiation effect in structural materials

International Nuclear Information System (INIS)

Grounes, M.; Myers, H.P.

1962-12-01

A brief description of work in hand at AB Atomenergi concerning the effects of neutron irradiation on structural materials is given. Some recent data is listed for the following pressure vessel steels 2103/R3 as used in the Aagesta reactor, SIS 142103, NO345, Fortiweld and weld metal OK 54 P. Zircaloy-2 has been studied regarding the combined effects of neutron irradiation and hydrogen content on tensile properties. The difficulties associated with determination of neutron dose and the correlation of damage with dose and neutron energy spectrum are discussed

Gamma Irradiation does not Cause Carcinogenesis of Irradiated Herbs

International Nuclear Information System (INIS)

Thongphasuk, Jarunee; Thongphasuk, Piyanuch; Eamsiri, Jarurut; Pongpat, Suchada

2009-07-01

Full text: Microbial contamination of medicinal herbs can be effectively reduced by gamma irradiation. Since irradiation may cause carcinogenicity of the irradiated herbs, the objective of this research is to study the effect of gamma irradiation (10 and 25 kGy) from cobalt-60 on carcinogenicity. The herbs studied were Pueraria candollei Grah., Curcuma longa Linn. Zingiber montanum, Senna alexandrina P. Miller, Eurycoma Longifolia Jack, Gymnostema pentaphylum Makino, Ginkgo biloba, Houttuynia cordata T., Andrographis paniculata, Thunbergia laurifolia L., Garcinia atroviridis G., and Cinnamomum verum J.S.Presl. The results showed that gamma irradiation at the dose of 10 and 25 kGy did not cause carcinogenicity of the irradiated herbs

Metabolism peculiarities at both children and teenagers irradiated after the Chernobyl accident

International Nuclear Information System (INIS)

Kaplieva, M.P.

1998-01-01

The lipid peroxidation intensity and the antioxidant system state reflect the organism's reaction to the irradiation. A reduction of the antioxidant system enzymes activity has been revealed in children and teenagers exposed by acute irradiation and evacuated during the first days after Chernobyl accident. The lipid peroxidation products levels were normal as compared to the control value. A significant inhibition of the antioxidant system protection indices activity and an increase of the lipid peroxidation toxic products concentration have been registered in children and teenagers living in condition of chronic irradiation

High-temperature annealing of proton irradiated beryllium – A dilatometry-based study

Energy Technology Data Exchange (ETDEWEB)

Simos, Nikolaos, E-mail: simos@bnl.gov [Brookhaven National Laboratory, Upton, NY, 11973 (United States); Elbakhshwan, Mohamed; Zhong, Zhong; Ghose, Sanjit [Brookhaven National Laboratory, Upton, NY, 11973 (United States); Savkliyildiz, Ilyas [Rutgers University (United States)

2016-08-15

S−200 F grade beryllium has been irradiated with 160 MeV protons up to 1.2 10{sup 20} cm{sup −2} peak fluence and irradiation temperatures in the range of 100–200 °C. To address the effect of proton irradiation on dimensional stability, an important parameter in its consideration in fusion reactor applications, and to simulate high temperature irradiation conditions, multi-stage annealing using high precision dilatometry to temperatures up to 740 °C were conducted in air. X-ray diffraction studies were also performed to compliment the macroscopic thermal study and offer a microscopic view of the irradiation effects on the crystal lattice. The primary objective was to qualify the competing dimensional change processes occurring at elevated temperatures namely manufacturing defect annealing, lattice parameter recovery, transmutation {sup 4}He and {sup 3}H diffusion and swelling and oxidation kinetics. Further, quantification of the effect of irradiation dose and annealing temperature and duration on dimensional changes is sought. The study revealed the presence of manufacturing porosity in the beryllium grade, the oxidation acceleration effect of irradiation including the discontinuous character of oxidation advancement, the effect of annealing duration on the recovery of lattice parameters recovery and the triggering temperature for transmutation gas diffusion leading to swelling.

Study of microstructural evolutions of the 6061-T6 aluminium alloy under irradiation

International Nuclear Information System (INIS)

Flament, Camille

2015-01-01

The 6061-T6 Aluminium alloy, whose microstructure contains Al(Fe,Mn,Cr)Si dispersoids and hardening needle-shaped β'' precipitates (Mg, Si), has been chosen as the structural material for the core vessel of the Material Testing Jules Horowitz Nuclear Reactor. Because it will be submitted to high neutron flux at a temperature around 50 C, it is necessary to study microstructural evolutions induced by irradiation and especially the stability of the second phase particles. In this work, an analytical study by in-situ and ex-situ electron and ion irradiations has been performed, as well as a study under neutron irradiation. The precipitate characterization by Transmission Electron Microscopy demonstrates that Al(Fe,Mn,Cr)Si dispersoids are driven under irradiation towards their equilibrium configuration, consisting of a core/shell structure, enhanced by irradiation, with a (Fe, Mn) enriched core surrounded by a Cr-enriched shell. In contrast, the (Mg,Si) β'' precipitates are destabilized by irradiation. They dissolve under ion irradiation in favor of a new precipitation of (Mg,Si,Cu,Cr,Al) rich clusters resulting in an increase of the alloy's hardness. β'' precipitates tend towards a transformation to cubic precipitates under neutron irradiation. (author) [fr

An ultrastructural and irradiation study of diffuse and localised kinetochore

International Nuclear Information System (INIS)

Bokhari, F.S.

1979-05-01

An electron microscope study of plant types Luzula nivea and Cyperus eragrostis with diffuse kinetochores and Crepis neglecta with localised kinetochore showed that Luzula has a rather different kinetochore organisation from Cyperus, with features approaching the localised type of Crepis. These studies included an examination of the ultrastructure of the kinetochore at metaphase at low magnification in control and irradiated material of Luzula; the chromosomal ultrastructure at high magnification at interphase and all stages of mitosis in Luzula, Cyperus and Crepis; and the ultrastructure of the nucleolus in Luzula, Cyperus and Crepis. Light microscopic studies were also performed showing the effects of irradiation on first mitotic division in Cyperus, Luzula and Crepis, mitotic aberrations in Cyperus and Crepis and meiosis in Cyperus. Finally, the survival with the diffuse as opposed to the localised kinetochore in M 1 and M 2 generations following seed irradiation was studied. (U.K.)

Study of irradiation induced defects and phase instability in β phase of Zr Excel alloy with in-situ heavy ion irradiation

International Nuclear Information System (INIS)

Yu, H.; Yao, Z.; Kirk, M.A.; Daymond, M.R.

2015-01-01

In situ heavy ion irradiation with 1 MeV Kr"2"+ was carried out to study irradiation induced phase change and atomic lattice defects in theβ phase of Zr Excel alloy. No decomposition of β-Zr was observed under irradiation at either 200 "oC or 450 "oC. However, ω-Zr particles experienced shape change and shrinkage associated enrichment of Fe in the β/ω interface at 200 "oC irradiation but not at 450 "oC. The defect evolution in the β-phase was examined with single phase Zr-20Nb alloy. It was found that dislocation loops with Burgers vector 1/2 and both present in β-Zr under room temperature irradiation. (author)

Experimental study of selective irradiation to the kidneys

Energy Technology Data Exchange (ETDEWEB)

Nishimori, I; Tsuda, N; Moriyama, N; Miyagawa, N; Fuzikawa, K [Nagasaki Univ. (Japan). School of Medicine

1976-03-01

In order to examine the effects of a massive irradiation on the kidney, 4,000 R of x-ray was irradiated to both kidneys of rats. Renal atrophy was observed 1, 2 and 3 weeks after the irradiation, and this alteration was severe especially in the left kidney. Light microscopic examination revealed dilatation of the renal tubules, swelling of the tubular epithelial cells, granular degeneration and cylindrialization 1 and 2 weeks after the irradiation. However, there was no remarkable alteration in the glomeruli. Lobulation of the glomeruli appeared in addition to alteration in the renal tubules 3 weeks after the irradiation. Hyalinosis of the glomeruli, degerenation of the renal tubules, cylindrialization, thickening of the vascular wall, fibroid necrosis, and proliferation of the interstitial cells appeared 25 weeks after the irradiation. Electron microscopic examination revealed reduction of the nuclei in the tubular epithelial cells, differentiation and thickening of dense bodies and the basement membrane, dilatation of capillaries and swelling of the endothelial cells 1 week after the irradiation. Obliteration of capillaries of the glomeruli, thickening of the basement membrane, deposit of collagen and swelling of the epithelial cells were observed 25 weeks after the irradiation. Cellular infiltration was observed in the interstitial tissue. The increase of blood pressure, vascular lesion and hyalinosis of the glomeruli, which appeased 25 weeks after the irradiation, are considered to be caused secondarily by an increase of the interstitial cells.

EPR study on tomatoes before and after gamma-irradiation

International Nuclear Information System (INIS)

Aleksieva, K.; Georgieva, L.; Tzvetkova, E.; Yordanov, N.D.

2009-01-01

The results from the EPR studies on fresh, air-dried and lyophilized tomato samples before and after gamma-irradiation are reported. Before irradiation fresh and air-dried tomatoes exhibit one singlet EPR line characterized with common g-factor of 2.0048±0.0005, whereas freeze-dried tomato does not show any EPR spectrum. After irradiation, a typical 'cellulose-like' triplet EPR spectrum appears in all samples, attributed to cellulose free radicals, generated by gamma-irradiation. It consists of intense central line with g=2.0048±0.0005 and two weak satellite lines separated ca. 3 mT left and right of it. In air-dried and lyophilized tomatoes the 'cellulose-like' EPR spectrum is superimposed by an additional partly resolved carbohydrate spectrum. Fading measurements of the radiation-induced EPR signals indicate that the intensity of the EPR spectra of air-dried and freeze-dried tomato are reduced to about 50% after 50 days, whereas those of fresh irradiated tomatoes kept at 4 o C fade completely in 15 days. The reported results unambiguously show that the presence of two satellite lines in the EPR 'cellulose-like' spectra of tomato samples can be used for identification of radiation processing.

Psychological Characteristics of Chronic Depression : A Longitudinal Cohort Study

NARCIS (Netherlands)

Wiersma, Jenneke E.; van Oppen, Patricia; van Schaik, Digna J. F.; van der Does, A. J. Willem; Beekman, Aartjan T. E.; Penninx, Brenda W. J. H.

Background: Few studies have investigated the importance of psychological characteristics for chronicity of depression. Knowledge about psychological differences between chronically depressed persons and nonchronically depressed persons may help to improve treatment of chronic depression. This is

Study on prediction model of irradiation embrittlement for reactor pressure vessel steel

International Nuclear Information System (INIS)

Wang Rongshan; Xu Chaoliang; Huang Ping; Liu Xiangbing; Ren Ai; Chen Jun; Li Chengliang

2014-01-01

The study on prediction model of irradiation embrittlement for reactor pres- sure vessel (RPV) steel is an important method for long term operation. According to the deep analysis of the previous prediction models developed worldwide, the drawbacks of these models were given and a new irradiation embrittlement prediction model PMIE-2012 was developed. A corresponding reliability assessment was carried out by irradiation surveillance data. The assessment results show that the PMIE-2012 have a high reliability and accuracy on irradiation embrittlement prediction. (authors)

Food irradiation for developing countries in Africa

International Nuclear Information System (INIS)

1990-12-01

The amount of post-harvest losses of food is considered to be highest on the African continent. As a result, increasing numbers of countries in Africa are suffering from problems of hunger and malnutrition, which range from chronic to acute. Food irradiation could play an important role in reducing the high rate of food losses especially in the case of food grain, root crops and dried food in this continent provided that proper infrastructure to employ this technique could be identified. Irradiation could contribute positively to the safety of food from microbiological and parasitic infection. A panel of experts participated at the round table discussion to assess the potential application of the technology in Africa. Some of the items for which technical feasibility has been established for food irradiation preservation include yams, onions, potatoes, maize, millet, sorghum, cowpeas and other pulses, cocoa beans, spices (pepper) and condiments, meat and poultry, fish and fishery products, animal feed, etc. In considered the local demand, a suitable choice of the type and size of the facility should be made. The design should allow up-grading in both size and automated operation to meet future expansion of the existing facility, but small commercial scale facilities, of low cost, should be considered to start with. Whatever type of equipment chosen, (whether Gamma or Electron Beam) safety, reliability, maintainability, and simplicity of operation should be of major consideration. It is recognized that for a project to be concluded on a reasonable schedule, technology transfer and training should be incorporated into the complete package. In addition back-up technical infrastructure in the country should be strengthened. The effective procedures demonstrated in a number of countries for performing consumer acceptance studies on irradiated foods, should be adopted in a slightly modified form adapted to the different target populations. Such studies should be

Psychological characteristics of chronic depression: a longitudinal cohort study.

Science.gov (United States)

Wiersma, Jenneke E; van Oppen, Patricia; van Schaik, Digna J F; van der Does, A J Willem; Beekman, Aartjan T F; Penninx, Brenda W J H

2011-03-01

Few studies have investigated the importance of psychological characteristics for chronicity of depression. Knowledge about psychological differences between chronically depressed persons and nonchronically depressed persons may help to improve treatment of chronic depression. This is the first study to simultaneously compare in large samples various psychological characteristics between chronically depressed and nonchronically depressed adults. Baseline data were drawn from the Netherlands Study of Depression and Anxiety (NESDA), an ongoing longitudinal cohort study aimed at examining the long-term course of depressive and anxiety disorders in different health care settings and phases of illness. Participants were aged 18 to 65 years at the baseline assessment in 2004-2007 and had a current diagnosis of DSM-IV major depressive disorder (N = 1,002). Chronicity of depression was defined as being depressed for 24 months or more in the past 4 to 5 years. The chronicity criterion was fulfilled by 31% (n = 312). The NEO Five-Factor Inventory measured the 5 personality domains, the Leiden Index of Depression Sensitivity-Revised was used to measure cognitive reactivity (eg, hopelessness, rumination), and the Mastery Scale measured external locus of control. Compared to the nonchronically depressed persons, the chronically depressed persons reported significantly higher levels of neuroticism (OR = 1.81; 95% CI, 1.55-2.12; P testing these variables multivariably, the odds of chronic depression were significantly increased among those with low extraversion (OR = 0.73; 95% CI, 0.61-0.88; P = .001), high rumination (OR = 1.24; 95% CI, 1.01-1.53; P = .04), and high external locus of control (OR = 1.48; 95% CI, 1.21-1.80; P psychological characteristics for chronicity of depression. These findings provide suggestions for more specific interventions, focused on extraversion, rumination, and external locus of control, in the treatment of chronic depression. © Copyright 2011

Experimental study associated to irradiation of FBR structural material, (4)

International Nuclear Information System (INIS)

1976-01-01

The study presents one of the bases to evaluate the results of the post-irradiation tests to conduct the thermal control tests related to the second JMTR irradiation (70M-61P) of the demestic austenitic stainless steels for the structural material of the FBR performed by Power Reactor and Nuclear Fuel Development Corporation. The thermal control specimens were given the temperature history which simulated that of the irradiation temperature in vacuum by the electrical furnance, and then the tensile, fatigue and Charpy impact tests were performed. The changes of the material properties caused by the thermal history were investigated. (auth.)

Crystallographic study of the tempering by irradiation of cold-worked uranium (1960); Etude cristallographique du revenu de l'uranium ecroui par irradiation (1960)

Energy Technology Data Exchange (ETDEWEB)

Tardivon, D [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

We have studied the phenomenon of the tempering of cold-worked uranium under the action of irradiation by observing the narrowing of the (114) and (133) X-ray diffraction lines as a function of the irradiation level. Simultaneously we have studied the broadening of the 114 line of a recrystallised uranium as a function of the irradiation level. The irradiation temperature was always less than 60 deg. C. Of these two processes, the first is the fastest. We have observed a saturation of the irradiation tempering for a flux of 10{sup 18} n/cm{sup 2}; we deduce from this the dimensions of the volume perturbed by one fission atom to be 10{sup -17} cm{sup 3}. (author) [French] Nous avons etudie le phenomene de revenu par irradiation d'echantillons d'uranium ecroui, en observant l'affinement des raies de diffraction de rayons X (114) et (133) en fonction du taux d'irradiation. Parallelement nous avons etudie l'elargissement de la raie (114 ) d'un uranium recristallise en fonction du taux d'irradiation. La temperature d'irradiation est toujours restee inferieure a 60 deg. C. De ces deux processus le premier est le plus rapide. Nous avons observe une saturation du revenu par irradiation pour un flux de 10{sup 18} n/cm{sup 2}; on en deduit une valeur du volume de la perturbation creee par un atome de fission egale a 10{sup -17} cm{sup 3}. (auteur)

Immunologic competence in adults following thymic irradiation in infancy

International Nuclear Information System (INIS)

Ammann, A.J.; Wara, W.M.; Wara, D.W.; Phillips, T.L.

1977-01-01

Removal of, or irradiation to, the thymus during the neonatal period in man has resulted in no reported adverse effects on cellular immunity, although thymectomy in neonatal experimental animals is known to produce profound immunological disturbances. Adverse effects in humans may not be recognized until several decades have passed. The immunological capabilities of 7 adults with histories of thymic irradiation as infants were evaluated; normal tests results indicated intact immune systems in all cases. The 3 women tested, however, had abnormal clinical histories, including 2 with multiple tumors and 1 with chronic mucocutaneous candidiasis

Immunologic competence in adults following thymic irradiation in infancy

Energy Technology Data Exchange (ETDEWEB)

Ammann, A.J.; Wara, W.M.; Wara, D.W.; Phillips, T.L.

1977-07-01

Removal of, or irradiation to, the thymus during the neonatal period in man has resulted in no reported adverse effects on cellular immunity, although thymectomy in neonatal experimental animals is known to produce profound immunological disturbances. Adverse effects in humans may not be recognized until several decades have passed. The immunological capabilities of 7 adults with histories of thymic irradiation as infants were evaluated; normal tests results indicated intact immune systems in all cases. The 3 women tested, however, had abnormal clinical histories, including 2 with multiple tumors and 1 with chronic mucocutaneous candidiasis.

Designing plasmas for chronic wound disinfection

International Nuclear Information System (INIS)

Nosenko, T; Shimizu, T; Morfill, G E

2009-01-01

Irradiation with low-temperature atmospheric-pressure plasma provides a promising method for chronic wound disinfection. To be efficient for this purpose, plasma should meet the following criteria: it should significantly reduce bacterial density in the wounded area, cause a long-term post-irradiation inhibition of bacterial growth, yet without causing any negative effect on human cells. In order to design plasmas that would satisfy these requirements, we assessed the relative contribution of different components with respect to bactericidal properties due to irradiation with argon plasma. We demonstrate that plasma-generated UV radiation is the main short-term sterilizing factor of argon plasma. On the other hand, plasma-generated reactive nitrogen species (RNS) and reactive oxygen species (ROS) cause a long-term 'after-irradiation' inhibition of bacterial growth and, therefore, are important for preventing wound recolonization with bacteria between two treatments. We also demonstrate that at certain concentrations plasma-generated RNS and ROS cause significant reduction of bacterial density, but have no adverse effect on human skin cells. Possible mechanisms of the different effects of plasma-generated reactive species on bacteria and human cells are discussed. The results of this study suggest that argon plasma for therapeutic purposes should be optimized in the direction of reducing the intensity of plasma-generated UV radiation and increasing the density of non-UV plasma products.

Designing plasmas for chronic wound disinfection

Energy Technology Data Exchange (ETDEWEB)

Nosenko, T; Shimizu, T; Morfill, G E [Max-Planck Institute for Extraterrestrial Physics, Garching (Germany)], E-mail: tnosenko@mpe.mpg.de

2009-11-15

Irradiation with low-temperature atmospheric-pressure plasma provides a promising method for chronic wound disinfection. To be efficient for this purpose, plasma should meet the following criteria: it should significantly reduce bacterial density in the wounded area, cause a long-term post-irradiation inhibition of bacterial growth, yet without causing any negative effect on human cells. In order to design plasmas that would satisfy these requirements, we assessed the relative contribution of different components with respect to bactericidal properties due to irradiation with argon plasma. We demonstrate that plasma-generated UV radiation is the main short-term sterilizing factor of argon plasma. On the other hand, plasma-generated reactive nitrogen species (RNS) and reactive oxygen species (ROS) cause a long-term 'after-irradiation' inhibition of bacterial growth and, therefore, are important for preventing wound recolonization with bacteria between two treatments. We also demonstrate that at certain concentrations plasma-generated RNS and ROS cause significant reduction of bacterial density, but have no adverse effect on human skin cells. Possible mechanisms of the different effects of plasma-generated reactive species on bacteria and human cells are discussed. The results of this study suggest that argon plasma for therapeutic purposes should be optimized in the direction of reducing the intensity of plasma-generated UV radiation and increasing the density of non-UV plasma products.

Comparative study of native and irradiated crotoxin. Biochemical and pharmacological effects

International Nuclear Information System (INIS)

Nascimento, N. do.

1991-01-01

Ionizing radiation is able to detoxify several venoms, including snake venom, without affecting significantly their antigenic and immunogenic properties. In order to elucidate this phenomena, we conceived a comparative biochemical and pharmacological study between native and gamma irradiated (2000Gy) crotoxin, main toxin of south american rattlesnake Crotalus durissus terrificus. Crotoxin was isolated and purified from crude venom by molecular exclusion chromatography, pI precipitation and then irradiated. Immunodiffusion, electrophoresis and gel filtration showed that the molecular integrity was preserved after irradiation with some higher molecular weight aggregate formation and maintenance of its antigenic capacity. The antibodies induced by irradiated toxin had a similar titer to the antibodies induced by native crotoxin; however with higher protective effects in mice. Crotoxin toxicity became 15 times lower after irradiation, as determined by LD sub(50) in mice. Native and irradiated crotoxin biodistribution occurred with a similar general pattern, with renal elimination. In contrast to irradiated crotoxin, the native crotoxin is initially retained in kidneys. A later concentration (2-3hs) occurs in phagocyticmononuclear cells rich organs (liver and spleen) and neural junctions rich organs (muscle and brain). (author)

Squamous cell carcinoma arising in previously burned or irradiated skin

International Nuclear Information System (INIS)

Edwards, M.J.; Hirsch, R.M.; Broadwater, J.R.; Netscher, D.T.; Ames, F.C.

1989-01-01

Squamous cell carcinoma (SCC) arising in previously burned or irradiated skin was reviewed in 66 patients treated between 1944 and 1986. Healing of the initial injury was complicated in 70% of patients. Mean interval from initial injury to diagnosis of SCC was 37 years. The overwhelming majority of patients presented with a chronic intractable ulcer in previously injured skin. The regional relapse rate after surgical excision was very high, 58% of all patients. Predominant patterns of recurrence were in local skin and regional lymph nodes (93% of recurrences). Survival rates at 5, 10, and 20 years were 52%, 34%, and 23%, respectively. Five-year survival rates in previously burned and irradiated patients were not significantly different (53% and 50%, respectively). This review, one of the largest reported series, better defines SCC arising in previously burned or irradiated skin as a locally aggressive disease that is distinct from SCC arising in sunlight-damaged skin. An increased awareness of the significance of chronic ulceration in scar tissue may allow earlier diagnosis. Regional disease control and survival depend on surgical resection of all known disease and may require radical lymph node dissection or amputation

Bone marrow transplantation in the patients with malignant tumor. Studies on supralethal total body irradiation

Energy Technology Data Exchange (ETDEWEB)

Tatsuno, Ikuro; Saito, Yasuo

1984-11-01

Based on evidence gained from ten patients of allogeneic bone marrow transplantation (BMT) and eight patients of autologous BMT, recent knowledge on literatures of BMT and total body irradiation (TBI) is summarized. Interstitial pneumonia after BMT has a strong correlation with TBI. Low dose-rate and fractionation of TBI are seemed to reduce the lung injury, thereby reducing the incidence of nonleukemia deaths. BMT is applied to not only acute leukemia, malignant lymphoma and solid tumors but also to chronic leukemia. It is emphasized that several of the important prognostic factors are within the control of the transplantation team.

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

International Nuclear Information System (INIS)

He Weishun; Liu Aihua; Lin Shiying; Xiong Xikun

1989-01-01

In the present study on disinfection, the rape pollen was irradiated with 2.5 kGy 60 Co 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

Study of irradiation induced defects and phase instability in β phase of Zr Excel alloy with in-situ heavy ion irradiation

Energy Technology Data Exchange (ETDEWEB)

Yu, H.; Yao, Z., E-mail: 12hy1@queensu.ca [Queen' s University, Department of Mechanical and Materials Engineering, Kingston, ON (Canada); Kirk, M.A. [Argonne National Laboratory, Materials Science Division, Argonne, IL (United States); Daymond, M.R. [Queen' s University, Department of Mechanical and Materials Engineering, Kingston, ON (Canada)

2015-07-01

In situ heavy ion irradiation with 1 MeV Kr{sup 2+} was carried out to study irradiation induced phase change and atomic lattice defects in theβ phase of Zr Excel alloy. No decomposition of β-Zr was observed under irradiation at either 200 {sup o}C or 450 {sup o}C. However, ω-Zr particles experienced shape change and shrinkage associated enrichment of Fe in the β/ω interface at 200 {sup o}C irradiation but not at 450 {sup o}C. The defect evolution in the β-phase was examined with single phase Zr-20Nb alloy. It was found that dislocation loops with Burgers vector 1/2<111> and <001> both present in β-Zr under room temperature irradiation. (author)

Evaluation of freshly irradiated wheat for dominant lethal mutations in Wistar rats

International Nuclear Information System (INIS)

Pawan, S.C.; Aravindakshan, M.; Kumar, N.S.; Subba Rao, V.; Aiyar, A.S.; Sundaram, K.

1977-01-01

Three independent, serially performed experiments involving acute and chronic feeding of freshly irradiated wheat (75 krad, gamma-irradiation) were carried out in Wistar rats. In the first experiment groups of 10 males were given wheat for 1 week; irradiated wheat was consumed by the animals within 24 h of irradiation. In the other two experiments feeding of males was continued for 6 (10 males per group) and 12 (13 males per group) weeks, respectively, and the irradiated wheat was fed within 7 days of irradiation. At the end of each treatment period each male was paired with 3 females for 7 days and sequentially at weekly intervals for 5 or 8 weeks. Females were killed and examined for live and dead implantations and corpora lutea. There were no differences between groups with regard to fertility nor was there any inter-group difference as regards pre- and post-implantation losses whether the rats were fed irradiated or non-irradiated wheat. This suggested that even feeding of freshly irradiated wheat does not induce any dominant lethal mutations in rats

Evaluation of freshly irradiated wheat for dominant lethal mutations in Wistar rats

Energy Technology Data Exchange (ETDEWEB)

Pawan, S C; Aravindakshan, M; Kumar, N S; Subba Rao, V; Aiyar, A S; Sundaram, K [Bhabha Atomic Research Centre, Bombay (India). Bio-medical Group

1977-01-01

Three independent, serially performed experiments involving acute and chronic feeding of freshly irradiated wheat (75 krad, gamma-irradiation) were carried out in Wistar rats. In the first experiment groups of 10 males were given wheat for 1 week; irradiated wheat was consumed by the animals within 24 h of irradiation. In the other two experiments feeding of males was continued for 6 (10 males per group) and 12 (13 males per group) weeks, respectively, and the irradiated wheat was fed within 7 days of irradiation. At the end of each treatment period each male was paired with 3 females for 7 days and sequentially at weekly intervals for 5 or 8 weeks. Females were killed and examined for live and dead implantations and corpora lutea. There were no differences between groups with regard to fertility nor was there any inter-group difference as regards pre- and post-implantation losses whether the rats were fed irradiated or non-irradiated wheat. This suggested that even feeding of freshly irradiated wheat does not induce any dominant lethal mutations in rats.

Mutants obtained by chronic gamma irradiation of soybean [Glycine Max (l.) Merrill]varieties

International Nuclear Information System (INIS)

Hajos Novak, M; Korosi, F.; Sipos, T.; Hodosne Kotvics, G.

2001-01-01

Soybean [Glycine max (L.) Merrill] is a wonder crop, containing about 20% oil and 40% high quality protein, having multiple uses such as food, fodder and industrial products. In Hungary in he last few years there has been a renewed interest in improving protein and oil content of the soybean crop. Selection for oil and/or protein content from segregating populations, derived from induced mutagenesis or hybridization, is known to be effective. Orf and Helms (1994) emphasized, that to fulfill demands of both sellers and purchasers, combined selection for yield components, yield, oil and/or protein content has to be carried out. For this purpose mutant soybean germplasm s were developed by pedigree method from a Carpathian-Ukrainian (KA) further more a Vietnamese (VL40) local variety adapted to Hungarian environmental conditions by 100-300 Gy chronic gamma irradiation. A function index was introduced to evaluate the genetic variability for the quality parameters and the most important agronomic traits. Chronic gamma irradiation increased the genetic variability of the oil content in the KA and of the protein content in the VL40 germplasm. Function index predicted up to 28% oil content in the KA mutant germplasm. Plants with 24.1 and 23.6% oil content were selected from the 150 Gy and the 100 Gy populations in the M4 generation. In the M5, progenies of a superior plant with 23.6% oil content were homozygous for this characteristics, while progenies of a superior plant with 24.1% oil content were segregating. Year can cause +-2.0-2.5% differences in the oil content of the seeds. Oil content had a moderate negative correlation with 1000-seed weight in both of the above mentioned generations .Seed samples with the highest oil content were analysed for fatty acid composition using gas-liquid chromatography. Their linoleic acid content ranged from 51.8 to 55.0%. Unfortunately, in M5 the linolenic acid content was higher than in M4, varying between 7.9% and 9.3%. The 200 Gy

Ergonomic Chair Explorative Intervention Study: Effect on Chronic ...

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Ergonomic Chair Explorative Intervention Study: Effect on Chronic Upper ... they are associated with a complex relationship between individual, work-related and ... in chronic upper quadrant musculoskeletal dysfunction and work productivity ...

Integrated studies of irradiated Philippine mangoes. Part of coordinated programme in Asian Regional Cooperative Project on Food Irradiation

International Nuclear Information System (INIS)

Manalo, J.A.

1985-09-01

Effects of combined treatment of hot water dip (50 deg. C for 5 min.) and irradiation (0.65 kGy) on technological and sensory qualities of Carabao mangoes were investigated. Mangoes that ripen to the yellow green stage during transport may be subjected to irradiation of combined hot water dip at 50 deg. C for 5 minutes and irradiation at 0.65 kGy. When stored at the low temperature of 12-15 deg. C, shelf life is extended further. Time interval between hot water dip and irradiation must be as short as possible and fruits must be stored at ambient temperature prior to irradiation to prevent discoloration. Shelf life studies show that green fruits subjected to combined treatment and stored at ambient temperature extended shelf life by 6 days, 50% of yellow green mangoes subjected to combined treatment exhibited shelf life extension by four days. Mangoes stored at cold temperature, whether immediately after irradiation or after ripening showed considerable reduction in bacterial decay, regardless of fruit maturity, thus extending their shelf life considerably. Results of sensory evaluation showed no marked differences in color, aroma, appearance, and acceptability were observed by the taste panelists and although controls were always rated higher than the treated samples, scores higher than 5 given to the treated samples showed that they were also generally acceptable

Study of homing patterns of x-irradiated murine lymphoid cells

International Nuclear Information System (INIS)

Crouse, D.A.

1974-01-01

Effects of in vitro x-ray exposure of murine lymphoid cells on their subsequent in vivo homing patterns were studied. The homing of lymphoid cells to various tissues and organs was followed by using radio-labeled cell preparations or by following the distribution of cells with a specific immunological memory. X irradiation of 51 Cr-labeled spleen, lymph node, bone marrow, or thymus cells was found to significantly alter their subsequent in vivo distribution. Irradiated cells demonstrated an increased distribution to the liver and a significantly lower retention in the lungs. Cells going to the lymph nodes of Peyer's patches showed a significant exposure dependent decrease in homing following irradiation. Irradiated lymph node cells homed in greater numbers to the spleen and bone marrow, while irradiated cells from other sources showed a decrease or no change indistribution to the same tissues. Lymph node cell suspensions from dinitrophenyl-bovine gamma globulin (DNP-BGG) immune LBN rats were prepared, irradiated (0 and 200 R) and injected into intermediate (LBN) hosts and controls. Irradiated memory cells provided a secondary antibody response, which was delayed but not suppressed when compared to unirradiated cells. Alteration in homing of lymphocytes caused by various physical and chemical agents was a result of effects on cell membrane characteristics which controlled some aspects of the phenomenon. Radiation (100 to 200 R) may have had a similar effect or it may have resulted in the selective elimination of a population of cells. (U.S.)

Solubility and IR studies of gamma-irradiated arabinoxylan

International Nuclear Information System (INIS)

Ebringerova, A.; Kacurakova, M.; Hromadkova, Z.; Pruzinec, J.

1989-01-01

The structural and solubility changes of a water-insoluble arabinoxylan with a low degree of branching was studied after γ-irradiation by IR spectroscopy and chemical analysis of the polysaccharide and its polymeric fractions. New functional groups like hydroperoxidic, carbonylic and endiolic ones were found after irradiation. The IR spectra shows that the structural changes involved by radiolytic treatment are reflected in the shape of the IR spectra of both polymeric fractions. The ratio of absorbance of the peaks at 1725 and 2920 cm -1 increased with radiation dose. (author) 17 refs.; 2 figs.; 2 tabs

Biochemical studies on irradiated onions, potatoes and mushrooms

International Nuclear Information System (INIS)

Matkovics, B.

1985-01-01

The activities of the antioxidant enzymes: superoxide dismutase, peroxidase and catalase and the quantitative values of some other important components of irradiated foodstuffs were studied. It was found that the activities of the examined antioxidant enzymes and the value of lipid peroxidation vary from species to species, but also depend on the variety within the species. Dynamic changes of the smaller molecules, lasting for various periods of time, can also be well observed following irradiation. This indicates that radiation treatment changes the physiological processes of the examined basic foodstuffs and give rise to new equilibria in these processes. (author)

Influence of chronic x-ray exposure on adrenal glucocorticoid function and adrenocorticocyte membrane potential

International Nuclear Information System (INIS)

Gorban', Je.M.; Topol'nikova, N.V.

1998-01-01

The peculiarities of adrenal glucocorticoid function and membrane potential (MP) of zona fasciculata adrenocorticocyte (ACC) in rats after chronic x-ray exposure was studied. The changes of adrenal glucocorticoid function caused by chronic x-ray exposure within a relatively small period of irradiation (1.5 months) are obscure and manifest themselves only at physiological load. With the prolongation of the period (8 and 15 months), more considerable inhibition of the adrenal glucocorticoid function and disturbances in the membrane mechanisms of ACC MP level regulation are revealed

The response of peripheral blood and bone marrow to combined irradiation

International Nuclear Information System (INIS)

Yakovleva, N.G.; Zhorno, L.Ya.

1975-01-01

Biological effects were examined in rats after X irradiation, oral administration of 90 Sr and 144 Ce as well as combined exposure to X radiation and internal contamination with both radionuclides. Morphological changes of the peripheral blood and the frequency of aberrant mitoses in bone marrow cells were used as criteria. In the case of combined radiation exposure three periods were observed with regard to blood changes. The first period was characterized by changes caused by external irradiation, the second one was a short-term period of normalization, and during the last period additive effects of external and internal irradiation were observed. Considering the changes of the frequency of aberrant mitoses only two periods could be detected according to the effects of external and internal irradiation. It is pointed out that in the case of combined irradiation the acute radiation syndrome caused by external irradiation gradually changes into a chronic stage associated with the long-term retention of radionuclides. (author)

The state of glutathion system of blood, brain and liver of white rats after chronic gamma-irradiation

International Nuclear Information System (INIS)

Petushok, N.Eh.; Lashak, L.K.; Trebukhina, R.V.

1999-01-01

The effects of 3-fold gamma-irradiation in total dose 0,75 Gy on the glutathion system in different periods after exposure (1 hour, 1 day, 1 and 4 weeks) in blood, brain and liver of white rats were studied. It was concluded that liver and brain have higher ability to maintain the stability of antioxidant system than blood has. After shot disturbances caused by irradiation in brain and liver the state of glutathion system of detoxication has normalized, while concentration of malonic dialdehyde was raised in all terms. The most pronounced changes of antioxidant system were registered in blood at early terms (1 hour) after irradiation that was manifested in increasing of reduced glutathion content, raising of glutathion reductase and catalase activity. In remote period the activity of this system in blood was exhausted

High-dose irradiation: Wholesomeness of food irradiated with doses above 10 kGy. Report of a joint FAO/IAEA/WHO study group

International Nuclear Information System (INIS)

1999-01-01

This report presents the recommendations of an international group of experts convened by the World Health Organization, in association with the Food and Agriculture Organization of the United Nations and the International Atomic Energy Agency, to consider the implications of food irradiated to doses higher than those recommended in 1980 by the Joint Expert Committee on the Wholesomeness of Irradiated Food. Irradiation ensures the hygienic quality of food and extends shelf-life. The public perception of the safety of food irradiation has generally precluded its widespread use. However, current applications of food irradiation to doses over 10 kGy have been in the development of high-quality shelf-stable convenience foods for specific target groups such as immunosuppressed individuals and those under medical care, astronauts and outdoor enthusiasts. The Study Group reviewed data relating to the toxicological, nutritional, radiation chemical and physical aspects of food irradiated to doses above 10kGy from a wide range and number of studies carried out over the last forty years. This report presents a comprehensive summary, along with references, of the effectiveness and safety of the irradiation process. It concludes that foods treated with doses greater than 10kGy can be considered safe and nutritionally adequate when produced under established Good Manufacturing Practice

Autoradiographic study of gamma-irradiated mouse spleen during primary immune response

International Nuclear Information System (INIS)

Gitsov, L.G.; Kyncheva, L.S.; Burneva, V.G.; Martinova, J.Sh.; Viklichka, S.

1978-01-01

Study on the kinetics of the cells in the mouse spleen during the primary immune response against thymusdependent antigen after sublethal irradiation was carried out. For this purpose the animals were immunized with sheep erythrocytes one day after their irradiation with 700 r gamma rays. On the 5th day after the immunization, tritium labelled thymidine was injected three times at two hourly intervals. Mice were killed two hours after the third injection for preparation of routine histological samples and autoradiographs. Immunized, but not irradiated mice were utilized as controls. Extensive zones of lymphocyte destruction were observed in the spleen of the irradiated mice - accumulation of picnotic lymphocyte nuclei, surrounded by reticulo-histocyte elements. The number of the labelled cells and the intensity of labelled are lower than that of the germinal centres in control animal. There is no marked cell destruction in the periarteriolar zone nor labelled cells, whereas in the controls there is a considerable number of labelled blast cells. In the red pulp of the irradiated animals islands of erythroblasts were found, whereas in the controls - parallely to the erythroblast islands, there are islands of proliferating lymphocytes and plasmocytes. The decrease of lymphocyte number in irradiated mice is connected with their destruction and with the altered lymphocytopoiesis in the red pulp. It is assumed that the observed preservation of the periarteriolar lymphatic sheaths in an expression of a higher radioresistance of the T-cells as compared to the B-cells in the white pulp. This study contributes for elucidation of the irradiation immunosuppressive effect. It points out also that the post-irradiation lymphopaenia is due not only to the cell death but also to the exclusion of part of the T-lymphocytes from the circulation and their selective deposition in the thymus-dependent zones of the peripheral lymphoid organs. (A.B.)

Study of the Effect of Swelling on Irradiation Assisted Stress Corrosion Cracking

Energy Technology Data Exchange (ETDEWEB)

Teysseyre, Sebastien Paul [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2016-09-01

This report describes the methodology used to study the effect of swelling on the crack growth rate of an irradiation-assisted stress corrosion crack that is propagating in highly irradiated stainless steel 304 material irradiated to 33 dpa in the Experimental Breeder Reactor-II. The material selection, specimens design, experimental apparatus and processes are described. The results of the current test are presented.

Experimental studies on anti-oxidants reducing lipid peroxidation of irradiated mice

International Nuclear Information System (INIS)

Du Zeji; Liu Keliang; Su Liaoyuan

1993-08-01

The free radical plays an important role in the irradiation damage. The irradiation damage would be reduced if anti-oxidants is used, because anti-oxidants can scavenge free radicals and suppress lipid peroxidation. In the study, a fluoro-spectrophotometer was used to determine the changes of MDA levels in mice tissues and serum after irradiation and the protective effect of anti-oxidants of Vit E and DMSO on damage caused by free radicals. The results are as follows: (1) The highest MDA level was at 12 to 24 hours after irradiation dose of 3.0 Gy. (2) The MDA level is increasing with the increasing of irradiation dose. It means the MDA level can indicate the extent of irradiation damage. (3) Both Vit E and DMSO had a powerful effect on reducing MDA level, but the effect of DMSO was stronger than Vit E. The optimum doses of them were 0.25 mg/g body weight and 10 mg/g body weight respectively. (4) The best effect obtained was to use Vit E and DMSO simultaneously

FTIR studies of swift silicon and oxygen ion irradiated porous silicon

International Nuclear Information System (INIS)

Bhave, Tejashree M.; Hullavarad, S.S.; Bhoraskar, S.V.; Hegde, S.G.; Kanjilal, D.

1999-01-01

Fourier Transform Infrared Spectroscopy has been used to study the bond restructuring in silicon and oxygen irradiated porous silicon. Boron doped p-type (1 1 1) porous silicon was irradiated with 10 MeV silicon and a 14 MeV oxygen ions at different doses ranging between 10 12 and 10 14 ions cm -2 . The yield of PL in porous silicon irradiated samples was observed to increase considerably while in oxygen irradiated samples it was seen to improve only by a small extent for lower doses whereas it decreased for higher doses. The results were interpreted in view of the relative intensities of the absorption peaks associated with O-Si-H and Si-H stretch bonds

The effect of low exposure-rate gamma irradiation on T and B lymphocyte function in the mouse

International Nuclear Information System (INIS)

McDermott, C.E.; Gengozian, N.

1980-01-01

The effect of chronic irradiation on T and B cell numbers and function was studied in mice. Cobalt 60 gamma radiation at 6 R/hour reduced the numbers of anti-SRBC PFC in the spleen, with minimal levels recorded after total exposures of 1000 to 2000 R. Recovery was incomplete after 1000 R, reaching only 40 to 50 per cent of normal in four months and remaining at that level for the animal's lifetime. The long-term deficiency in PFC formation was not due to a quantitative lack of T or B cells since normal cell numbers were observed in the spleen 60 to 144 days after 1000 R. Adoptive transfer studies with combinations of bone marrow and thymus cells, or of splenic T and B cells, from normal and irradiated mice, revealed functional defects in both cell compartments during the first two months. Normal and near normal function of T and B cells occurred 100 days postirradiation, a time when the splenic in vitro response was still only 50 per cent of the controls. The latter observation suggests that the microenvironment of the chronically irradiated spleen alters factors regulating T and B cell interactions in response to a T-dependent antigen. (author)

A history of study on safety of irradiated foods (2). Clostridium botulinum in irradiated seafood from the reports by the United States Atomic Energy Commission

International Nuclear Information System (INIS)

Miyahara, Makoto

2004-01-01

This review is a part of ''history of study on the wholesomeness of irradiated foods''. Clostridium botulinum in irradiated seafood have been of great concern at the beginning of development of irradiated food. This review describes the studies on Clostridium botulinum by US. Atomic Energy Commission in 1960's with their data and what they recognized it as a risk factor of irradiated foods. In 1999 FAO/IAEA/WHO reported that Clostridium botulinum type A and B spors are apparently the most resistant and thus of great concern in the radiation sterilization of food, whereas the less radiation-resistant type E spores are important in low dose irradiation of foods, particularly fishery products. This review also describes current break-through application by NASA and Canadian irradiator. (author)

Wholesomeness studies on irradiated foods. Past and future research within the Soviet Union

Energy Technology Data Exchange (ETDEWEB)

Zaytsev, A.N.; Shillinger, Yu.I.; Kamaldinova, Z.M.

1975-11-01

The concept of wholesomeness is based on the absence of induced radioactivity, conservation of the nutritive value of food, and absence of toxicological or mutagenic effects. The possible occurrence of Clostridium botulinum toxin in irradiated fish products is discussed. Evaluation of the nutritive value of irradiated food is discussed with regard to proteins and vitamins. Toxicity and mutagenicity studies are described. Feeding studies on the wholesomeness of irradiated food were conducted in the Soviet Union using potatoes, grain, dried fruits, meat, poultry, and fish. The need for further investigations on the biological value of irradiated foods is pointed out. (HLW)

Irradiation of Polystyrene and Polypropylene to study NIH 3T3 fibroblasts adhesion

International Nuclear Information System (INIS)

Arbeitman, C.R.; Grosso, M.F. del; Ibanez, I.; Garcia Bermudez, G.; Duran, H.; Chappa, V.C.; Mazzei, R.; Behar, M.

2010-01-01

When polymers are irradiated with heavy ions new chemical groups are created in a few microns of the material. The irradiation changed the polarity and wettability on the surface so that could enhance the biocompatibility of the modified polymer. The study of chemistry and nanoscale topography of the biomaterial is important in determining its potential applications in medicine and biotechnology, because their strong influence on cell function, adhesion and proliferation. In this study, thin films of Polystyrene and Polypropylene samples were modified by irradiation with low energy ion beams (30-150 keV) and swift heavy ions both with various fluences and energies. The changes were evaluated with different methods. Adhesion of NIH 3T3 fibroblasts onto unirradiated and irradiated surfaces has been studied by in vitro techniques. The correlations between physicochemical properties as a function of different irradiations parameters were compared with cell adhesion on the modified polymer surface.

The ageing kidney: biochemical and morphological study after irradiation

International Nuclear Information System (INIS)

Franciolini, F.; Becciolini, A.; Torcini, G.; Lanini, A.

1982-01-01

The behaviour of some activities of the kidney was studied both in young-adult and in adult rats exposed to an 8-Gy dose of γ-rays and killed at various intervals after irradiation (both in the morning and in the evening). Brush border and lysosomal enzymes did not show marked differences among control rats of the same age even if adult animals showed levels of maltase, alkaline phosphatase and LAP activities higher than the young-adult group. Moreover, irradiation did not induce typical modifications of the same enzyme activities in young-adult and adult rats. Adult animals showed a reduction in the brush border enzyme activities at 120 hours after irradiation while, at the same interval, lysosomal activities underwent an increase both in young and in adult animals. (orig.) [de

Kinetic study of UV-irradiated amorphous sulfur by EPR spectroscopy

International Nuclear Information System (INIS)

El Mkami, H.; Smith, G.M.

2005-01-01

Electron paramagnetic resonance (EPR) spectroscopy is used to investigate UV-irradiation damage in amorphous sulfur by examining post-irradiation kinetics as a function of UV-exposure time. The kinetic study is described by first-order concurrent reactions where the sulfur, as reactant, undergoes two parallel processes leading to the formation of two distinct defects called S 1 * and S 2 *. The temperature dependence of the EPR intensities of the signals, related to these defects, is used in the kinetic study

The protective effect of Sambucus ebulus against lung toxicity induced by gamma irradiation in mice

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Mohammad Karami

2015-01-01

Full Text Available The aim of present study was to investigate the potential antioxidant and lung protective activities of Sambucus ebulus (SE against toxicity induced by gamma irradiation. Hydroalcoholic extract of SE (20, 50 and 100 mg/kg was studied for its lung protective activity. Phenol and flavonoid contents of SE were determined. Male C57 mice were divided into ten groups with five mice per group. Only the first and second groups (as negative control received intraperitoneally normal saline fluid. Groups 3 to 5 received only SE extract at doses of 20 mg/kg, 50 mg/kg and 100 mg/kg intraperitoneally; three groups were repeatedly injected for 15 days as chronic group. Groups 6 to 8 received a single-dose of gamma irradiation just 2 hours before irradiation as acute group. The ninth and tenth groups (as positive control received only gamma rays. Animal was exposed whole-body to 6 Gy gamma radiation. After irradiation, tissue sections of lung parenchyma were examined by light microscope for any histopathologic changes. SE at doses 50 and 100 mg/kg improved markedly histopathological changes induced by gamma irradiation in lung. Lung protective effect of SE could be due to attention of lipid peroxidation. Our study demonstrated that SE as a natural product has a protective effect against lung toxicity induced by   gamma irradiation in animal.

Late radiation effects in animals surviving lethal irradiation

Energy Technology Data Exchange (ETDEWEB)

Dimitrov, L A

1974-01-01

Animals (rats, mice, dogs) survived lethal irradiation by means of prophylactic-therapeutic treatments or previously irradiated, were studied for late radiation effects: life span, cachexia and fat growing of hypophysical type, tissue or organ hypoplasia manifested by disturbed hemopoiesis, suppressed function of adrenal gland, etc., suppressed immune reactivity of the irradiated organism, atypical biochemical changes in DNA and protein metabolism, epilation, chronic dermatitis, ulcerations, reduced reproductivity or full sterility, damage of kidneys leading to nephrosclerosis, dishormonal states, cataracts, diffuse sclerotic processes, various kinds of malignant and non-malignant tumors. In these cases hemopoiesis compensated for a definite time peripheral blood composition, but during the late period it showed features of incompleteness: shorter life survival of erythrocytes and thrombocytes manifested by a decreased binding of labelled methionine in these blood elements, anemia and relative thrombocytopenia sometimes with an increased number of polychromatic erythrocytes in peripheral blood and a decreased number of reticulocytes at the same time; lymphopenia and relative leucopenia with an increased number of hypersegmented neutrophils. Decreased reproductivity and atypical biochemical changes available in the first generation of the irradiated animals showed the probable role of mutagenic factors in the emergency of some late radiation effects. A significant part of late radiation sequences were due to neuro-endocrine disintegrations. Some of the described late radiation effects were also observed in biological controls as features of ageing. After application of radioprotectors (AET, cysteamine, serotonin) a more marked protective effect is demonstrated in the early reactions (time survival till 30th day, DNA and protein metabolism, immune reactions) of the lethally irradiated animals.

Review of recent studies on neutron irradiation embrittlement in light water reactor pressure vessel steels

International Nuclear Information System (INIS)

Sudo, Akira; Miyazono, Shohachiro

1983-06-01

Recent studies in foreign countries (USA, France, FRG and UK) on neutron irradiation embrittlement have been reviewed. These studies are classified into four areas, such as 1) effect of chemical composition on irradiation embrittlement sensitivity, 2) postirradiation heat treatment for embrittlement relief, 3) fracture toughness evaluation of irradiated materials based on fracture mechanics analysis, and 4) effect of irradiation on fatigue crack propagation behavior. The first area mainly includes the studies related to the effects of copper, phosphorus impurities and nickel alloying and synergistic effect of these components, and furthermore, evaluation of Regulatory Guide 1.99 Rev.l. Studies in the second area show the effects of annealing condition (temperature and time) and metallugical condition on embrittlement relief, and evaluation of periodic annealing in the period of irradiation as a promising method for embrittlement control. Studies in the third area show the correlation between fracture toughness and Cv notch ductility changes with neutron irradiation, and J-R curves of irradiated materials based on the elasto-plastic fracture mechanics. In the forth area, most of studies are investigated in air condition but a few studies in reactor-grade water at high temperature and pressure. (author)

Radio protective effects of calcium channel blockers (Deltiazem) on survival of Saccharomyces cerevisiae cells irradiated with different doses of gamma rays

Energy Technology Data Exchange (ETDEWEB)

Alya, G; Shamma, M; Sharabi, N [Atomic Energy Commission, Damascus (Syrian Arab Republic), Dept. of Molecular Biology and Biotechnology

2007-03-15

Investigations of radioprotective effects of Deltiazem (as one of the commonly used calcium channel blockers, which is used in the treatment of acute and chronic angina and spasmo angina, in addition to the treatment of different types of essential hypertension) has been carried on Saccharomyces Cerevisiae cells. Cells cultures of the most famous yeast Saccharomyces Cerevisiae (bakers yeast) were irradiated with different doses of gamma rays. Results revealed that the necessary dose of gamma rays that leads to 10% of survived cellular population (D10 value) was about 256 Gy. This irradiation dose was used then in all irradiation experiments on culture of S. Cerevisiae cells in which different concentrations of Deltiazem (55, 110, 165 mg/Kg medium) were added before and after irradiation in order to study the radio protective effect of Deltiazem. Results showed that Deltiazem enhances survival percentage of irradiated S. Cerevisiae cultures in a concentration dependent manner. This study confirmed our previous works, which had demonstrated that Deltiazem protects lethally and supralethally irradiated rats, and enhances survival of pre-irradiated Deltiazem treated animals.(author)

Radio protective effects of calcium channel blockers (Deltiazem) on survival of Saccharomyces cerevisiae cells irradiated with different doses of gamma rays

International Nuclear Information System (INIS)

Alya, G.; Shamma, M.; Sharabi, N.

2007-03-01

Investigations of radioprotective effects of Deltiazem (as one of the commonly used calcium channel blockers, which is used in the treatment of acute and chronic angina and spasmo angina, in addition to the treatment of different types of essential hypertension) has been carried on Saccharomyces Cerevisiae cells. Cells cultures of the most famous yeast Saccharomyces Cerevisiae (bakers yeast) were irradiated with different doses of gamma rays. Results revealed that the necessary dose of gamma rays that leads to 10% of survived cellular population (D10 value) was about 256 Gy. This irradiation dose was used then in all irradiation experiments on culture of S. Cerevisiae cells in which different concentrations of Deltiazem (55, 110, 165 mg/Kg medium) were added before and after irradiation in order to study the radio protective effect of Deltiazem. Results showed that Deltiazem enhances survival percentage of irradiated S. Cerevisiae cultures in a concentration dependent manner. This study confirmed our previous works, which had demonstrated that Deltiazem protects lethally and supralethally irradiated rats, and enhances survival of pre-irradiated Deltiazem treated animals.(author)

Evaluation of irradiation hardening of proton irradiated stainless steels by nanoindentation

International Nuclear Information System (INIS)

Yabuuchi, Kiyohiro; Kuribayashi, Yutaka; Nogami, Shuhei; Kasada, Ryuta; Hasegawa, Akira

2014-01-01

Ion irradiation experiments are useful for investigating irradiation damage. However, estimating the irradiation hardening of ion-irradiated materials is challenging because of the shallow damage induced region. Therefore, the purpose of this study is to prove usefulness of nanoindentation technique for estimation of irradiation hardening for ion-irradiated materials. SUS316L austenitic stainless steel was used and it was irradiated by 1 MeV H + ions to a nominal displacement damage of 0.1, 0.3, 1, and 8 dpa at 573 K. The irradiation hardness of the irradiated specimens were measured and analyzed by Nix–Gao model. The indentation size effect was observed in both unirradiated and irradiated specimens. The hardness of the irradiated specimens changed significantly at certain indentation depths. The depth at which the hardness varied indicated that the region deformed by the indenter had reached the boundary between the irradiated and unirradiated regions. The hardness of the irradiated region was proportional to the inverse of the indentation depth in the Nix–Gao plot. The bulk hardness of the irradiated region, H 0 , estimated by the Nix–Gao plot and Vickers hardness were found to be related to each other, and the relationship could be described by the equation, HV = 0.76H 0 . Thus, the nanoindentation technique demonstrated in this study is valuable for measuring irradiation hardening in ion-irradiated materials

Spectroscopic studies of irradiated glasses: Application in nuclear dosimetry

International Nuclear Information System (INIS)

Farah, Khaled

2010-01-01

The present work aims to study the effects of ionizing radiation on silicate glasses in order to develop a new dosimetry system simple, precise, stable and inexpensive. Indeed, changes in mechanical properties, optical and paramagnetic glasses when subjected to ionizing radiation. The prediction of long-term behavior, physical aging under irradiation, the glass is paramount. many studies have brought many ways to avoid obscuring glass windows used in nuclear reactors or hot cells and optical devices. Recently, much work has concentrated on the application of the color induced by irradiation for developing a recyclable glass in the glass industry is of great interest economically and environmentally.

Food irradiation

International Nuclear Information System (INIS)

Sato, Tomotaro; Aoki, Shohei

1976-01-01

Definition and significance of food irradiation were described. The details of its development and present state were also described. The effect of the irradiation on Irish potatoes, onions, wiener sausages, kamaboko (boiled fish-paste), and mandarin oranges was evaluated; and healthiness of food irradiation was discussed. Studies of the irradiation equipment for Irish potatoes in a large-sized container, and the silo-typed irradiation equipment for rice and wheat were mentioned. Shihoro RI center in Hokkaido which was put to practical use for the irradiation of Irish potatoes was introduced. The state of permission of food irradiation in foreign countries in 1975 was introduced. As a view of the food irradiation in the future, its utilization for the prevention of epidemics due to imported foods was mentioned. (Serizawa, K.)

Gemstone color enhancement by electron beam irradiation-A preliminary study

International Nuclear Information System (INIS)

Sarada Idris; Zulkafli Ghazali; Shamshad Ahmad; Mohd Suhaimi Jusoh

2010-01-01

Treatment of gemstones has been going on for hundreds of years for enhancing color and clarity of gems devoid of these attributes. Whereas previous practices included fraudulent or otherwise processes to achieve the color enhancement, the ionizing radiation has proven to be a reliable and reproducible technique. Three types of irradiation processes include exposure to gamma radiation, electron beam irradiation and the nuclear power plants. Electron Beam Irradiation of Gemstone is a technique in which a gemstone is exposed to highly ionizing radiation electron beam to knock off electrons to generate color centers culminating in introduction of deeper colors. The color centers may be stable or unstable. Below 9 MeV, normally no radioactivity is introduced in the exposed gems. A study was conducted at Electron Beam Irradiation Centre (Alurtron) for gemstone color enhancement by using different kind of precious gemstones mined in Pakistan and elsewhere. The study shows that EB Irradiation not only enhances the color but also improves the clarity of the gemstones. The treated stones included kunzite tourmaline topaz quartz aquamarine and cultured pearls. Doses ranging from 25 kGy to 200 kGy were employed to assess the influence of doses on color and clarity and to select the optimum doses. The samples used included both the rough and the faceted gems. It is concluded that significant revenue generation is associated with the enhancement of the color in clarity of gemstones which are available at very cheap price in the world market. (author)

In vivo genetic toxicity studies in Chinese hamsters fed irradiated or unirradiated foodstuffs

International Nuclear Information System (INIS)

Altmann, H.

1982-01-01

Two in vivo genetic toxicity studies were performed in Chinese hamsters fed irradiated or unirradiated diets of chicken, fish or dates in order to detect possible mutagenic effects caused by irradiating these foodstuffs. The tests selected for study were: 1. Chromosomal analysis of bone narrow cells and 2. DNA metabolism in spleen cells. Chicken, fish and dates were irradiated with doses of 7, 2.5 and 1 kGy respectively. These investigations were subsequently extended to include the effects of irradiated dried onions, pulses and cocoa beans on DNA metabolism in Chinese hamster spleen cells only. Dried onions were irradiated with doses of 0.15, 9 and 15 kGy, pulses with 10 kGy and cocoa beans with 3.2 to 5 kGy. In addition, a fumigated cocoa bean group was included. No significant differences in chromosomal aberration rate were detected between groups fed irradiated or unirradiated diets. Dried dates, whether irradiated or not, showed some evidence of genetic toxicity in their effect on DNA metabolism in the spleen cells of Chinese hamsters. Both date diets caused more strand breaks DNA than are usual for Chinese hamster spleen cells, but DNA repair was not adversely affected. Chicken, both irradiated and unirradiated, was found to enhance replicative DNA synthesis but had no effect on the DNA repair process. Irradiated fish, however, caused enhanced DNA synthesis compared to unirradiated fish, but also had no adverse effect on DNA repair. Irradiated white beans also enhanced DNA synthesis compared to controls whereas unirradiated samples inhibited synthesis. (orig./MG)

A study of the physiological changes and the nutritional qualities of irradiated apples and the effect of irradiation on apples stored at room temperature

International Nuclear Information System (INIS)

Wang Chuanyao; Jiang Mengyue; Gao Meixu; Ma Xiuye; Zhang Shufen; Liu Shucheng

1993-01-01

The effects of γ-irradiation on the metabolism and nutritional qualities of Golden Delicious apples and on the lethality of pathogenic fungi have been studied. The storage effect of irradiation on apples at room temperature has been observed. Results showed that the respiratory intensity of irradiated apple at 0.3-0.5 kGy was near or lower than that of unirradiated apple after 15 days irradiation. The amount of ethylene release was obviously inhibited when fruits were irradiated with 0.3-0.7 kGy. The flesh firmness of apples irradiated with 0.3-0.9 kGy was higher than that of unirradiated apple with increased storage time. The negative correlations between the flesh firmness and the activities of pectinesterase (PE), polygalacturonase (PG) were observed when the dosage was lower than 1.5 kGy. The 2.0 kGy irradiation damaged the ultrastructure of cells, induced the softening of apple. When apples were irradiated with 0.7-2.0 kGy, the contents of 4 important volatile components of apple would be decreased. However, this dose had no effects on the pure chemicals. Studies showed that there was no significant effect of irradiation with 0.3-2.0 kGy on the nutritional qualities of apples and this dose range could effectively control the verticillate pathogenic fungi. The result of storage experiment showed that rotting of fruits decreased by 0.3-0.9 kGy irradiation. (author)

Systematic Study of the PbWO4 Crystal Short Term Instalibity Under Irradiation

CERN Document Server

Annenkov, Alexander; Chipaux, Rémi; Drobychev, Gleb; Fedorov, Andrey; Géléoc, Marie; Golubev, Nikolai; Korzhik, Mikhail; Lecoq, Paul; Ligun, A B; Missevitch, Oleg; Pavlenko, V B; Peigneux, Jean-Pierre; Singovsky, Alexander

1997-01-01

The effect of the irradiation on the lead tungstate ( PWO) scintillator properties has been studied at different irradiation facilities. Lead tungstate crystals grown with the tuning of oxides content in the melt to the stoichiometry of pure sheelite or sheelite-like type crystals and doped with heterovalent, trivalent and pentavalent impurities have been studied in order to optimize their resistance to irradiation. A combination of a selective cleaning of raw materials, a tuning of the melt from crystallization to crystallisation, and a destruction or compensation of the point structure defects has been used to minimize the short-term instability of PWO parameters under irradiation.

Irradiation-induced precipitates in a neutron irradiated 304 stainless steel studied by three-dimensional atom probe

Energy Technology Data Exchange (ETDEWEB)

Toyama, T., E-mail: ttoyama@imr.tohoku.ac.jp [International Research Center for Nuclear Materials Science, Institute for Materials Research, Tohoku University, Narita-cho 2145-2, Oarai, Ibaraki 311-1313 (Japan); Nozawa, Y. [International Research Center for Nuclear Materials Science, Institute for Materials Research, Tohoku University, Narita-cho 2145-2, Oarai, Ibaraki 311-1313 (Japan); Van Renterghem, W. [SCK-CEN, Nuclear Materials Science Institute, Boeretang 200, 2400 Mol (Belgium); Matsukawa, Y.; Hatakeyama, M.; Nagai, Y. [International Research Center for Nuclear Materials Science, Institute for Materials Research, Tohoku University, Narita-cho 2145-2, Oarai, Ibaraki 311-1313 (Japan); Al Mazouzi, A. [EDF R and D, Avenue des Renardieres Ecuelles, 77818 Moret sur Loing Cedex (France); Van Dyck, S. [SCK-CEN, Nuclear Materials Science Institute, Boeretang 200, 2400 Mol (Belgium)

2011-11-15

Highlights: > Irradiation-induced precipitates in a 304 stainless steel were investigated by three-dimensional atom probe. > The precipitates were found to be {gamma}' precipitates (Ni{sub 3}Si). > Post-irradiation annealing was performed to discuss the contribution of the precipitates to irradiation-hardening. - Abstract: Irradiation-induced precipitates in a 304 stainless steel, neutron-irradiated to a dose of 24 dpa at 300 deg. C in the fuel wrapper plates of a commercial pressurized water reactor, were investigated by laser-assisted three-dimensional atom probe. A high number density of 4 x 10{sup 23} m{sup -3} of Ni-Si rich precipitates was observed, which is one order of magnitude higher than that of Frank loops. The average diameter was {approx}10 nm and the average chemical composition was 40% Ni, 14% Si, 11% Cr and 32% Fe in atomic percent. Over a range of Si concentrations, the ratio of Ni to Si was {approx}3, close to that of {gamma}' precipitate (Ni{sub 3}Si). In some precipitates, Mn enrichment inside the precipitate and P segregation at the interface were observed. Post-irradiation annealing was performed to discuss the contribution of the precipitates to irradiation-hardening.

Irradiation probe and laboratory for irradiated material evaluation

International Nuclear Information System (INIS)

Smutny, S.; Kupca, L.; Beno, P.; Stubna, M.; Mrva, V.; Chmelo, P.

1975-09-01

The survey and assessment are given of the tasks carried out in the years 1971 to 1975 within the development of methods for structural materials irradiation and of a probe for the irradiation thereof in the A-1 reactor. The programme and implementation of laboratory tests of the irradiation probe are described. In the actual reactor irradiation, the pulse tube length between the pressure governor and the irradiation probe is approximately 20 m, the diameter is 2.2 mm. Temperature reaches 800 degC while the pressure control system operates at 20 degC. The laboratory tests (carried out at 20 degC) showed that the response time of the pressure control system to a stepwise pressure change in the irradiation probe from 0 to 22 at. is 0.5 s. Pressure changes were also studied in the irradiation probe and in the entire system resulting from temperature changes in the irradiation probe. Temperature distribution in the body of the irradiation probe heating furnace was determined. (B.S.)

Studies of Sterile Irradiation Effects on the White-striped Fruit Fly

International Nuclear Information System (INIS)

Limohpasmanee, Wanitch; Tannarin, Thodsapol; Khongratarpon, Titima; Segsarnviriya, Suchada

2011-06-01

Full text: In general, sterile irradiation can affect vigor and mating competitiveness of the fruit flies. The objective of the experiments was to study the effects of sterile irradiation on the white-striped oriental fruit fly, Bactrocera dorsalis (Hendel), developed for sterile fly detection. A day before adult emergence, the pupae were irradiated at the dose of 90 Grays. No effects on adult emergence and flight ability were observed. However, it induced complete sterility in both sexes. Also, it decreased male mating competitiveness significantly, while increasing sexual competitiveness significantly

Study of damages by neutron irradiation in lithium aluminates

International Nuclear Information System (INIS)

Palacios G, O.

1999-01-01

Lithium aluminates proposed to the production of tritium in fusion nuclear reactors, due to the thermal stability that they present as well as the behavior of the aluminium to the irradiation. As a neutron flux with profile (≅ 14 Mev) of a fusion reactor is not available. A irradiation experiment was designed in order to know the micro and nano structure damages produced by fast and thermal neutrons in two irradiation positions of the fusion nuclear reactor Triga Mark III: CT (Thermal Column) and SIFCA (System of Irradiation Fixed of Capsules). In this work samples of lithium aluminate were characterized by XRD (X-Ray Diffraction), TEM (Transmission Electron Microscopy) and SEM (Scanning Electron Microscopy). Two samples were prepared by two methods: a) coalition method and b) peroxide method. This characterization comprised original and irradiated samples. The irradiated sample amounted to 4 in total: one for each preparation method and one for each irradiation position. The object of this analysis was to correlate with the received neutron dose the damages suffered by the samples with the neutron irradiation during long periods (440 H), in their micro and nano structure aspects; in order to understand the changes as a function of the irradiation zone (with thermal and fast neutron flux) and the preparation methods of the samples and having as an antecedent the irradiation in SIFCA position by short times (2h). The obtained results are referred to the stability of γ -aluminate phase, under given conditions of irradiation and defined nano structure arrangement. They also refer to the proposals of growth mechanism and nucleation of new phases. The error associated with the measurement of neutron dose is also discussed. (Author)

Osteochondroma after total body irradiation in bone marrow transplant recipients. Report of two cases

International Nuclear Information System (INIS)

Maeda, Go; Yokoyama, Ryohei; Ohtomo, Katsuyuki; Takayama, Jun; Beppu, Yasuo; Fukuma, Hisatoshi; Ohira, Mutsuro

1996-01-01

We present two cases of osteochondroma after total body irradiation in bone marrow recipients, the first in a 6-year-old boy with juvenile chronic myelogenous leukemia and the second in a 13-year-old boy with acute myelogenous leukemia. The patients developed multiple osteochondromas three years and seven years, respectively, after 12 Gy of total body irradiation. Neither had a family history of hereditary multiple osteochondromatosis. A review of the English literature revealed only one report describing five cases of osteochondroma after 12 Gy of total body irradiation in bone marrow transplant recipients. Osteochondroma should be considered as an additional adverse effect of total body irradiation. (author)

Experimental studies on the effect of perfluorochemicals in tumor irradiation

International Nuclear Information System (INIS)

Shinoda, Jun; Iwai, Tomohiko; Hattori, Tatsuaki; Kondo, Hiroaki; Sakai, Noboru; Yamada, Hiroshi

1984-01-01

The effects of radiation therapy with Fluosol-DA on rat mammary tumors were studied. The tissue oxygen tension values of tumors in breathing mixed gas (5% carbon dioxide and 95% oxygen) with Fluosol-DA (25 ml/kg, i.v.) were significantly higher than those in room air without Fluosol-DA. The rats were divided into three groups: Group I received Fluosol-DA but no irradiation, Group II was treated with 1000 rads of irradiation using 60 Co without Fluosol-DA in room air and Group III received the same irradiation and Fluosol-DA in breathig mixed gas. In the latter group we observed a prolongation of the survival time and suppression of the tumor growth. (author)

Nucleotide diversity and gene expression of Catalase and Glutathione peroxidase in irradiated Scots pine (Pinus sylvestris L.) from the Chernobyl exclusion zone

International Nuclear Information System (INIS)

Vornam, Barbara; Arkhipov, Andrey; Finkeldey, Reiner

2012-01-01

In the Chernobyl exclusion zone forest trees have to tolerate and to adapt to ionizing radiation, therefore the molecular basis of their adaptive responses is of the utmost interest. Based on SNP analysis and real time PCR nucleotide diversity and expression profiles of gene fragments of catalase (Cat) and glutathione peroxidase (GPx), which are known as radical scavenging genes, were analysed in the needles of irradiated pine trees of the Chernobyl exclusion zone. In acutely and chronically irradiated trees (50 years old) planted before the accident a higher nucleotide diversity of Cat and more somatic mutations were found compared to their control. Chronically irradiated trees (20 years old) planted after the accident showed a similar nucleotide diversity of Cat compared to their control and in both collectives one somatic mutation was found. The nucleotide diversity of GPx was higher in all analysed trees compared to Cat. No somatic mutation events were found in GPx. For both gene fragments, no association between the received dose in a tree and the nucleotide diversity and mutation events was detected. The expression profiles of Cat and GPx in acutely and chronically and in chronically irradiated trees were similar. Compared to their corresponding control collectives, Cat was up-regulated and GPx slightly down-regulated.

Electron microscopic study of the spilt irradiation effects on the rat parotid ductal cells

International Nuclear Information System (INIS)

Kim, Sung Soo; Lee, Sang Rae

1988-01-01

This study was designed to investigate the effects of split irradiation on the salivary ductal cells, especially on the intercalated cells of the rat parotid glands. For this study, 24 Sprague-Dawley strain rats were irradiated on the head and neck region with two equal split doses of 9 Gy for a 4 hours interval by Co-60 teletherapy unit, Picker's mode l 4M 60. The conditions of irradiation were that field size, dose rate, SSD and depth were 12 X 5 cm, 222 cGy/min, 50 cm and 1 cm, respectively. The experimental animals were sacrificed 1, 2, 3, 6, 12, hours and 1, 3, 7, days after the irradiation and the changes of the irradiated intercalated cells of the parotid glands were examined under light and electron microscope. The results were as follows: 1. By the split irradiation, the degenerative changes of intercalated cells of the parotid glands appeared at 3 hours after irradiation and the most severe cellular degeneration observed at 6 hours after irradiation. The repair processes began from 12 hours after irradiation and have matured progressively. 2. Under electron microscope, loss of nuclear membrane, microvilli and secretory granules, derangement of chromosomes, degeneration of cytoplasm, atrophy or reduction of intracytoplasmic organelles were observed in the intercalated ductal cells after split irradiation. 3. Under light microscope, derangement of ductal cells, widening of cytoplasms and nuclei, hyperchromatism and proliferation of ductal cells were observed in intercalated ducts after split irradiation.

Studies on the preservation of Korean Ginseng by irradiation

International Nuclear Information System (INIS)

Sung, H.S.; Park, M.H.; Lee, K.S.; Cho, H.O.

1982-01-01

In order to evaluate the feasibility for the sterilization of Korean red and white ginseng powder by irradiation, red and white ginseng powder (120 mesh) was irradiated by 0.1, 0.3, 0.5, 0.7, 1.0 and 2.0 Mrad with 60 Co irradiator (dose rate: 4000 rad/h). Extraction rate of crude saponins by buthanol and by 50% ethanol were slightly increased according to the irradiation dose (buthanol ex. 1.7%, 50% ethanol ex. 2.6%) at 1.0 Mrad irradiation. There are no remarkable changes in HPLC patterns of crude saponins by radiation. It was found that irradiation up to 1 Mrad on Korean ginseng products have no significant effect on proximate component, reducing sugar and amino nitrogen of ginseng powder and on the color density of ginseng extract with 50% ethanol. Irradiation up to 1 Mrad could be utilized for the sterilization of Korean ginseng powder without changes of physicochemical properties. (Author)