Analysis of Giant-nucleated Cell Formation Following X-ray and Proton Irradiations

Science.gov (United States)

Almahwasi, Ashraf Abdu

Radiation-induced genetic instability has been observed in survivors of irradiated cancerous and normal cells in vitro and in vivo and has been determined in different forms, such as delayed cell death, chromosomal aberration or mutation. A well defined and characterized normal human-diploid AG1522 fibroblast cell line was used to study giant-nucleated cell (GCs) formation as the ultimate endpoint of this research. The average nuclear cross-sectional areas of the AG1522 cells were measured in mum2. The doubling time required by the AG1522 cells to divide was measured. The potential toxicity of the Hoechst dye at a working concentration on the live AG1522 cells was assessed. The yield of giant cells was determined at 7, 14 and 21 days after exposure to equivalent clinical doses of 0.2, 1 or 2 Gy of X-ray or proton irradiation. Significant differences were found to exist between X-ray or proton irradiation when compared with sham-irradiated control populations. The frequency of GCs induced by X-rays was also compared to those formed in proton irradiated cultures. The results confirm that 1 Gy X-rays are shown to induce higher rates of mitotically arrested GCs, increasing continually over time up to 21 days post-irradiation. The yield of GCs was significantly greater (10%) compared to those formed in proton populations (2%) 21 days postirradiation. The GCs can undergo a prolonged mitotic arrest that significantly increases the length of cell cycle. The arrest of GCs at the mitotic phase for longer periods of time might be indicative of a strategy for cell survival, as it increases the time available for DNA repair and enables an alternative route to division for the cells. However, the reduction in their formation 21 days after both types of radiation might favour GCs formation, ultimately contributing to carcinogenesis or cancer therapy resistance. The X-ray experiments revealed a dose-dependent increase in the GCs up to 14 days after irradiation. Although the proton

The occurrence of recruitment supported from the finding of an increase in radiosensitivity of quiescent cells in solid tumors after fractionated irradiation with X-rays

International Nuclear Information System (INIS)

Masunaga, Shinichiro; Ono, Koji; Kinashi, Yuko; Suzuki, Minoru; Akaboshi, Mitsuhiko

1998-01-01

We examined the behavior of quiescent cells in solid tumors irradiated twice at various intervals with X-rays, using our recently developed method for selectively detecting the response of quiescent cells in solid tumors. To determine the labeling indices of tumors at the second irradiation, each mouse group included mice that were continuously administered BrdU until just before the second irradiation using mini-osmotic pumps which had been implanted before the first irradiation. Radiosensitivity of total tumor cells at the second irradiation decreased in proportion to the increase in interval time. However, radiosensitivity of quiescent cells was raised with increase in the interval time. In addition, the labeling index at the second irradiation was higher than that at the first irradiation. These findings supported the occurrence of recruitment from quiescent to proliferating state during fractionated irradiation. (author)

The influence of fractionation on cell survival and premature differentiation after carbon ion irradiation

International Nuclear Information System (INIS)

Wang Jufang; Li Renming; Guo Chuanling; Fournier, C.; K-Weyrather, W.

2008-01-01

To investigate the influence of fractionation on cell survival and radiation induced premature differentiation as markers for early and late effects after X-rays and carbon irradiation. Normal human fibroblasts NHDF, AG1522B and WI-38 were irradiated with 250 kV X-rays, or 266 MeV/u, 195 MeV/u and 11 MeV/u carbon ions. Cytotoxicity was measured by a clonogenic survival assay or by determination of the differentiation pattern. Experiments with high-energy carbon ions show that fractionation induced repair effects are similar to photon irradiation. The relative biological effective (RBE) 10 values for clonogenic survival are 1.3 and 1.6 for irradiation in one or two fractions for NHDF cells and around 1.2 for AG1522B cells regardless of the fractionation scheme. The RBE for a doubling of post mitotic fibroblasts (PMF) in the population is 1 for both single and two fractionated irradiation of NHDF cells. Using 11 MeV/u carbon ions, no repair effect can be seen in WI-38 cells. The RBE 10 for clonogenic survival is 3.2 for single irradiation and 4.9 for two fractionated irradiations. The RBE for a doubling of PMF is 3.1 and 5.0 for single and two fractionated irradiations, respectively. For both cell lines the effects of high-energy carbon ions representing the irradiation of the skin and the normal tissue in the entrance channel are similar to the effects of X-rays. The fractionation effects are maintained. For the lower energy, which is representative for the irradiation of the tumor region, RBE is enhanced for clonogenic survival as well as for premature terminal differentiation. Fractionation effects are not detectable. Consequently, the therapeutic ratio is significantly enhanced by fractionated irradiation with carbon ions. (author)

Levels of 2-dodecylcyclobutanone in ground beef patties irradiated by low-energy X-ray and gamma rays.

Science.gov (United States)

Hijaz, Faraj M; Smith, J Scott

2010-01-01

Food irradiation improves food safety and maintains food quality by controlling microorganisms and extending shelf life. However, acceptance and commercial adoption of food irradiation is still low. Consumer groups such as Public Citizen and the Food and Water Watch have opposed irradiation because of the formation of 2-alkylcyclobutanones (2-ACBs) in irradiated, lipid-containing foods. The objectives of this study were to measure and to compare the level of 2-dodecylcyclobutanone (2-DCB) in ground beef irradiated by low-energy X-rays and gamma rays. Beef patties were irradiated by low-energy X-rays and gamma rays (Cs-137) at 3 targeted absorbed doses of 1.5, 3.0, and 5.0 kGy. The samples were extracted with n-hexane using a Soxhlet apparatus, and the 2-DCB concentration was determined with gas chromatography-mass spectrometry. The 2-DCB concentration increased linearly (P irradiation dose for gamma-ray and low-energy X-ray irradiated patties. There was no significant difference in 2-DCB concentration between gamma-ray and low-energy X-ray irradiated patties (P > 0.05) at all targeted doses. © 2010 Institute of Food Technologists®

Effect of localized intraoperative x-rays irradiation followed by intermittent external exposure on certain histochemical parameters related to pancreatic function

International Nuclear Information System (INIS)

Abdel-Azeem, M.G.

2005-01-01

The present study was carried out to evaluate the pancreatic enzyme activities in rabbits, whose splenic part of pancreas was exposed to local intraoperative radiation therapy (IORT) at level of 30 Gy X-rays followed by fractionated external radiation therapy (ERT) at a total dose of 40 Gy (2 Gy day after day) starting from the 15th day following the local intraoperative irradiation. The control pancreas was that received only external X-rays radiation without local irradiation. The exocrine pancreatic functions were assessed by determination of insulin hormone and enzyme activity of lipase as well as alkaline and acid phosphatases. After local X-rays irradiation on days 2 and 10 and after external X-rays irradiation on days 23 , 33 , 43 and 53, technovit-8100 plastic embedding (Kulzer and Heraeus) was used to prepare the cold blocks. The quantitative morphometric method was used to evaluate the histochemical pancreatic activity of the irradiated and control pancreas of each rabbit. Most of the studied parameters recorded non-significant changes as a result of the applied different levels of X-rays irradiation, which would give the chance to use this type of irradiation in pancreatic radiotherapy without any hazards to the pancreas

Luteolin as reactive oxygen generator by X-ray and UV irradiation

Science.gov (United States)

Toyama, Michiru; Mori, Takashi; Takahashi, Junko; Iwahashi, Hitoshi

2018-05-01

Non-toxic X-ray-responsive substances can be used in the radiosensitization of cancer, like porphyrin mediated radiotherapy. However, most X-ray-responsive substances are toxic. To find novel non-toxic X-ray-responsive substances, we studied the X-ray and UV reactivity of 40 non-toxic compounds extracted from plants. Dihydroethidium was used as an indicator to detect reactive oxygen species (ROS) generated by the compounds under X-ray or UV irradiation. We found that 13 of the investigated compounds generated ROS under X-ray irradiation and 17 generated ROS under UV irradiation. Only 4 substances generated ROS under both X-ray and UV. In particular, luteolin exhibited the highest activity among the investigated compounds; therefore, the ROS generated by luteolin were thoroughly characterized. To identify the ROS, we employed a combination of ROS detection reagents and their quenchers. O2·- generation by luteolin was monitored using dihydroethidium and superoxide dismutase (as an O2·- quencher). OH· and 1O2 generation was determined using aminophenyl fluorescein with ethanol (OH· quencher) and Singlet Oxygen Sensor Green® with NaN3 (1O2 quencher), respectively. Generation of O2·- under X-ray and UV irradiation was observed; however, no OH· or 1O2 was detected. The production of ROS from luteolin is surprising, because luteolin is a well-known antioxidant.

Time-resolved x-ray spectra of laser irradiated high-Z targets

International Nuclear Information System (INIS)

Lee, P.H.Y.; Attwood, D.T.; Boyle, M.J.; Campbell, E.M.; Coleman, L.C.; Kornblum, H.N.

1977-01-01

Recent results obtained by using the Livermore 15 psec x-ray streak camera to record x-ray emission from laser-irradiated high-z targets in the 1-20 keV range are reported. Nine to eleven K-edge filter channels were used for the measurements. In the lower energy channels, a dynamic range of x-ray emission intensity of better than three orders of magnitude have been recorded. Data will be presented which describe temporally and spectrally resolved x-ray spectra of gold disk targets irradiated by laser pulses from the Argus facility, including the temporal evolution of the superthermal x-ray tail

The effect of fractionating 100 R hard X-ray doses on the hemogram and proteinogram of the rabbit

International Nuclear Information System (INIS)

Alix, D.

1965-01-01

Eighty one rabbits 'Fauve de Bourgogne' received total exposure of 100 R X-rays, by fractional doses of 5 - 10 - 25 - 50 and 100 R per irradiation. Blood count and protein dosage were practised before, during and after the irradiation session. Seventeen controls were subjected to the same investigations with the same periodicity. Statistical analysis of experimental data permitted to infer from the exposures of X-rays, that irradiation induces drop in leucocytes count, resulting from a drop in mononuclear cells. On the other hand, it is more difficult to clear up its action on the protein profiles, because the observed changes were likewise observed on the controls, although at a lesser degree. Nevertheless, the authors think that it may be concluded to an increase of albumin concentration and to some instability of the gamma-globulins concentration. Then they discuss the possible mechanisms of X-rays effects: either perturbations of protean metabolism following loss of mitotic activity or histolysis. (author) [fr

Changes of surface electron states of InP under soft X-rays irradiation

International Nuclear Information System (INIS)

Yang Zhian; Yang Zushen; Jin Tao; Qui Rexi; Cui Mingqi; Liu Fengqin

1999-01-01

Changes of surface electronic states of InP under 1 keV X-ray irradiation is studied by X-ray photoelectron spectroscopy (XPS) and ultraviolet ray energy spectroscopy (UPS). The results show that the soft X-ray irradiation has little effect on In atoms but much on P atoms. The authors analysed the mechanism of irradiation and explained the major effect

The increase of metallothionein content in rat liver induced by x-ray irradiation and its physiological function

International Nuclear Information System (INIS)

Shiraishi, Noriyuki; Miyahara, Masanobu; Utsumi, Kozo; Aono, Kaname; Inoue, Bunji.

1982-01-01

Whether or not stress promotes peroxidase reaction of lipids in vivo influences the biosynthesis of metallothionein (MT) was studied. After X-ray irradiation rats were exposed to oxygen, and the liver supernatant was examined. The Zn distribution in the liver supernatant fraction of 10,000 in molecular weight, which was attributed to MT in origin, was small in the control group, but was great in the stress group. The amount of Cd found to the 10,000 fraction (Zn in MT is relatively easily replaced by Cd) was extremely smaller in the control group than in the stress group. These data indicate that the amount of Zn is small, with no appreciable presence of MT, in the 10,000 fraction of the control group. The X-ray irradiated group showed a marked increase of Zn 5 and 7 days later, indicating a definite increase of MT, and the group exposed to O 2 showed similar phenomena, suggesting induction of MT synthesis in the rat liver. (Chiba, N.)

Interspecific transfer of only part of genome by fusion between non-irradiated protoplasts of Nicotiana glauca and X-ray irradiated protoplasts of N. Langsdorffii

International Nuclear Information System (INIS)

Itoh, K.; Futsuhara, Y.

1983-01-01

To transfer only part of genome, X-ray irradiated suspension cell protoplasts of N. langsdorffii were fused with suspension cell protoplasts of N. glauca by polyethylene glycol. Somatic hybrid calli were selected by the growth in the hormone-free medium. Some of somatic hybrid calli from fusion with irradiated protoplasts indicated the loss of small subunit polypeptide of fraction 1 protein which was coded by N. langsdorffii nuclear DNA. Cytological analysis provided an information on significant decrease of chromosomes in somatic hybrid calli from fusion with irradiated protoplasts, compared with the somatic hybrid calli from fusion with non-irradiated protoplasts. In addition, isozyme analysis revealed that somatic hybrid calli from fusion with irradiated protoplasts lost particular bands of N. langsdorffli. These results demonstrate the tranfer of only part of genome from N, langsdorffii to N, glauca by fusion with X-ray irradiated protoplasts

X-ray irradiation on blood products for the purpose of prevention of PT-GVHD

International Nuclear Information System (INIS)

Tayama, Tatsuya; Naohara, Tooru; Haneda, Kenji; Juji, Takeo.

1990-01-01

X-ray irradiation on blood products is a common method to prevent the risk of inducing PT-GVHD, and has recently become to be used in Japan. We have tried X-ray irradiation on WB, CRC and PC using HITACHI X-ray Irradiation Apparatus MBR1520R, and studied its practical usefulness. In case of irradiation on blood bags as the minimum dose of 1,500 rads, these conditions are thought to be practical: 1) the use of 1.0 mm Al filter, 2) the distance of 550 nm from X-ray source, and 3) irradiation on 4 bags at the same time. But, it has also been noticed that total doses and qualities of X-ray absorbed into blood were different between upper and lower side of the bag. Bloods on upper side absorbed much doses and a wide range of X-ray, on the other hand, bloods on lower side absorbed less doses and hard X-ray. In these conditions, irradiated lymphocytes showed a complete inhibition of thymidine uptake in MLC test, still had 15% of activity in PHA stimulation. The qualities of other blood components have not changed before and after irradiation. X-ray irradiation is useful in a routine work of blood center, but problems of proper doses and a uniformity of irradiation are remained to be solved. (author)

Positron trap centers in x-ray and γ-ray irradiated SiO2

International Nuclear Information System (INIS)

Khatri, R.; Asoka-Kumar, P.; Nielsen, B.; Roellig, L.O.; Lynn, K.G.

1993-01-01

Using Doppler broadening annihilation spectroscopy, we investigated the properties of irradiated samples of SiO 2 /Si(100) with 117 nm thick oxide layer, grown in dry O 2 on p- and n-type substrates. These samples were irradiated with γ rays and x rays at doses in the range of 7x10 4 --9x10 6 rad and 50--2000 mJ/cm 2 , respectively. The changes observed in the Doppler broadening line shape parameter after irradiation and its recovery during isochronal annealing were used to obtain an activation energy of 1.48--1.61 eV required for annealing the defects

Building lab-scale x-ray tube based irradiators

International Nuclear Information System (INIS)

Haff, Ron; Jackson, Eric; Gomez, Joseph; Light, Doug; Follett, Peter; Simmons, Greg; Higbee, Brad

2016-01-01

Here we report the use of x-ray tube based irradiators as alternatives to gamma sources for laboratory scale irradiation. Irradiators were designed with sample placement in closest possible proximity to the source, allowing high dose rates for small samples. Designs using 1000 W x-ray tubes in single tube, double tube, and four tube configurations are described, as well as various cabinet construction techniques. Relatively high dose rates were achieved for small samples, demonstrating feasibility for laboratory based irradiators for research purposes. Dose rates of 9.76, 5.45, and 1.7 Gy/min/tube were measured at the center of a 12.7 cm container of instant rice at 100 keV, 70 keV, and 40 keV, respectively. Dose uniformity varies dramatically as the distance from source to container. For 2.54 cm diameter sample containers containing adult Navel Orangeworm, dose rates of 50–60 Gy/min were measured in the four tube system. - Highlights: • X-ray is demonstrated as an alternative to gamma for lab-based irradiation. • Cabinets using one, two, and four 1000 W tubes are reported. • Dose rate of 9.8 Gy/min/tube at the center of a 12.7 cm container of instant rice. • Dose uniformity varies dramatically as the distance from source to container.

SOFT X-RAY IRRADIATION OF PURE CARBON MONOXIDE INTERSTELLAR ICE ANALOGUES

Energy Technology Data Exchange (ETDEWEB)

Ciaravella, A.; Candia, R.; Collura, A. [INAF-Osservatorio Astronomico di Palermo, P.za Parlamento 1, 90134 Palermo (Italy); Jimenez-Escobar, A.; Munoz Caro, G. M. [Centro de Astrobiologia (CSIC-INTA), Carretera de Ajalvir, km 4, Torrejon de Ardoz, 28850 Madrid (Spain); Cecchi-Pestellini, C. [INAF-Osservatorio Astronomico di Cagliari, Strada n.54, Loc. Poggio dei Pini, I-09012 Capoterra (Italy); Giarrusso, S. [INAF-Istituto di Astrofisica Spaziale e Fisica Cosmica, Via U. La Malfa 153, I-90146 Palermo (Italy); Barbera, M., E-mail: aciaravella@astropa.unipa.it [Dipartimento di Scienze Fisiche and Astronomiche, Universita di Palermo, Sezione di Astronomia, Piazza del Parlamento 1, I-90134 Palermo (Italy)

2012-02-10

There is an increasing evidence for the existence of large organic molecules in the interstellar and circumstellar medium. Very few among such species are readily formed in conventional gas-phase chemistry under typical conditions of interstellar clouds. Attention has therefore focused on interstellar ices as a potential source of these relatively complex species. Laboratory experiments show that irradiation of interstellar ice analogues by fast particles or ultraviolet radiation can induce significant chemical complexity. However, stars are sources of intense X-rays at almost every stage of their formation and evolution. Such radiation may thus provide chemical changes in regions where ultraviolet radiation is severely inhibited. After H{sub 2}O, CO is often the most abundant component of icy grain mantles in dense interstellar clouds and circumstellar disks. In this work we present irradiation of a pure carbon monoxide ice using a soft X-ray spectrum peaked at 0.3 keV. Analysis of irradiated samples shows formation of CO{sub 2}, C{sub 2}O, C{sub 3}O{sub 2}, C{sub 3}, C{sub 4}O, and CO{sub 3}/C{sub 5}. Comparison of X-rays and ultraviolet irradiation experiments, of the same energy dose, shows that X-rays are more efficient than ultraviolet radiation in producing new species. With the exception of CO{sub 2}, X-ray photolysis induces formation of a larger number of products with higher abundances, e.g., C{sub 3}O{sub 2} column density is about one order of magnitude higher in the X-ray experiment. To our knowledge this is the first report on X-ray photolysis of CO ices. The present results show that X-ray irradiation represents an efficient photo-chemical way to convert simple ices to more complex species.

Study on the inactivation of intracellular enzyme molecules by X-ray irradiation

International Nuclear Information System (INIS)

Lee, S.B.

1977-01-01

Inactivation of the glutamic acid dehydrogenase and glucose-6-phosphate dehydrogenase enzyme molecules in the Ehrlich ascites tumor cells of the mouse were studied. The above mentioned intracellular enzyme molecules were irradiated by the X-ray radiation under the condition of 65 kV, 1 Amp under the atmosphere of nitrogen gases and by 4 0 C. Thereby, irradiation doses were 580 KR/min(error: +-3%). After irradiation, the cell homogentes were prepared through liquid air techniques. There after, the activities of the enzymes were measured with photometric method given by O. Warburg and W. Christian. The dose effect curves of the activities of the two enzymes by the X-ray irradiation showed both exponential and the inactivation doses were 6.5x10 6 and 5.0x10 6 R respectively. These results showed one side that the inactivation process of the intracellular enzyme molecules was one hit reaction after target theory, and the other side that this inactivation process could not be the primary causes of the death through X-ray irradiation of the vertebrate animals, because of the high resistance of the intracellular protein molecules against X-ray irradiation. The one hit reaction by the inactivation process of the irradiated intracellular enzyme molecules was discussed. (author)

Linear luminescence for thin plastic scintillator under intense soft X-ray irradiation

International Nuclear Information System (INIS)

Ning Jiamin; Jiang Shilun; Xu Rongkun; Guo Cun

2006-01-01

The basic principle of soft X-ray power meter is introduced in the paper and the experimental process and the result of thin plastic scintillator linear luminescence under intense soft X-ray irradiation are described. A range of flux density of energy for thin plastic scintillator linear luminescence under intense soft X-ray irradiation is included. The upper limit of the flux density is 1.47 x 10 5 W/cm 2 . (authors)

Intestinal complications following accelerated fractionated X-irradiation

International Nuclear Information System (INIS)

Hauer-Jensen, M.; Poulakos, L.; Osborne, J.W.

1990-01-01

Due to paucity of suitable animal models, it has been difficult to study the development of long-term intestinal complications following fractionated irradiation. We recently developed a model which allows multiple radiation exposures of a short segment of rat ileum without the need for repeated surgery. In the present series, this model was used to study the influence of shortening the total treatment time (accelerated fractionation) on development of radiation enteropathy. Male rats were orchiectomized and a short segment of distal ileum was transposed to the scrotum. Starting 3 weeks after surgery, the scrotum containing the intestinal segment was X-irradiated with 20 fractions of 2.8 Gy (total dose 56 Gy). Two fractionation schedules were compared: one fraction per day (total treatment time 26 days) and 3 fractions per day (total treatment time 7 days). Actuarial survival curves were obtained, and the degree of radiation injury was assessed 2, 8 and 26 weeks after the last radiation exposure using a semiquantitative histopathologic scoring system. There was no mortality from acute radiation injury in either treatment group. All animals of the 1-fraction/day group survived the observation period (26 weeks). In the 3-fraction/day group, there was significant mortality due to intestinal obstruction, and cumulative mortality at 26 weeks was 100%. Radiation injury, as assessed by the histopathologic scoring system, was also more pronounced in this group than in the 1-fraction/day group. We conclude that shortening the total treatment time significantly increases the severity of late intestinal complications. Our data are suggestive of an association between acute mucosal damage and chronic radiation injury of the small intestine. (orig.)

Supercrystallization of KCl from solution irradiated by soft X-rays

Science.gov (United States)

Janavičius, A. J.; Rinkūnas, R.; Purlys, R.

2016-10-01

The X-rays influence on KCl crystallization in a saturated water solution has been investigated for the aim of comparing it with previously considered NaCl crystallization. The rate of crystallization has been measured in the drying drop in the solution activated by the irradiation. We have measured the influence of the irradiation time of the solution on the rates of KCl crystallization as well as the beginning of the crystallization processes on drying drops. For a longer irradiation time of the solution early crystallization in the drops occurs. A saturated water solution of KCl was irradiated with the diffractometer DRON-3M (Russian device) and this had a great influence on the two-step processes of crystallization. The ionization of the solution by soft X-rays can produce ions, metastable radicals in water, excited crystals' seeds and vacancies in growing crystals by Auger's effect. The X-rays generate a very fast crystallization in the drying drop.

Effect of x-ray irradiation on the dentin matrix formation

Energy Technology Data Exchange (ETDEWEB)

You, Dong Soo [Dept. of Radiology, College of Dentistry, Seoul National University, Seoul (Korea, Republic of); Chang, Won Sik [Dept. of Prosthodontics, College of Dentistry, Seoul National University, Seoul (Korea, Republic of); Whang, Sung Myung [Dept. of Oral Antomy, College of Dentistry, Seoul National University, Seoul (Korea, Republic of)

1976-11-15

The authors has observed the effect of X-ray irradiation on the dentin matrix formation of the albino rat fetuses. The lower abdomen of the pregnant rats were exposed to X-ray on the 9 1/2th day of gestation, respectively 150, 250 and 350 rads. The fetuses of the right side of the same pregnant rats which were not exposed to X-ray were as controls. The results were as follows: 1) In the 150 rads irradiated fetuses, predentin formation was identical with control groups, but the arrangement of od ontoblasts was distorted, subodontoblastic layer was condensed with pulp cells, and blood capillaries were enlarged. 2) In the 250 rads irradiation, dentin matrix was imperfect or osteodentin was occurred. Short columnar or cuboidal od ontoblasts were presented and pulp cells were dispersed. Blood capillaries were congested. 3) 350 rads irradiated fetuses showed osteodentin matrix and numerous degenerated odontoblasts. Their dental papilla sh owed reticular atrophy and enlarged capillary.

X-ray microbeam stand-alone facility for cultured cells irradiation

Energy Technology Data Exchange (ETDEWEB)

Bożek, Sebastian, E-mail: sebastian.bozek@yahoo.com [Jagiellonian University Medical College, Department of Pharmaceutical Biophysics, Krakow (Poland); Bielecki, Jakub; Wiecheć, Anna; Lekki, Janusz; Stachura, Zbigniew; Pogoda, Katarzyna; Lipiec, Ewelina; Tkocz, Konrad; Kwiatek, Wojciech M. [Institute of Nuclear Physics Polish Academy of Sciences, PL-31342 Krakow (Poland)

2017-03-01

Highlights: • An X-ray microbeam line for irradiation of living cultured cells was constructed. • A step by step explanation of working principles with engineering details, procedures and calculations is presented. • A model of beam and cell interaction is presented. • A method of uniform irradiation of living cells with an exact dose per a cell is presented. • Results of preliminary experiments are presented. - Abstract: The article describes an X-ray microbeam standalone facility dedicated for irradiation of living cultured cells. The article can serve as an advice for such facilities construction, as it begins from engineering details, through mathematical modeling and experimental procedures, ending up with preliminary experimental results and conclusions. The presented system consists of an open type X-ray tube with microfocusing down to about 2 μm, an X-ray focusing system with optical elements arranged in the nested Kirckpatrick-Baez (or Montel) geometry, a sample stand and an optical microscope with a scientific digital CCD camera. For the beam visualisation an X-ray sensitive CCD camera and a spectral detector are used, as well as a scintillator screen combined with the microscope. A method of precise one by one irradiation of previously chosen cells is presented, as well as a fast method of uniform irradiation of a chosen sample area. Mathematical models of beam and cell with calculations of kerma and dose are presented. The experiments on dose-effect relationship, kinetics of DNA double strand breaks repair, as well as micronuclei observation were performed on PC-3 (Prostate Cancer) cultured cells. The cells were seeded and irradiated on Mylar foil, which covered a hole drilled in the Petri dish. DNA lesions were visualised with γ-H2AX marker combined with Alexa Fluor 488 fluorescent dye.

Effects of x-ray and neutron irradiation on spherical colonies

International Nuclear Information System (INIS)

Aramaki, Ryoji

1980-01-01

Responses of in vitro cultured mammalian cells in spherical colonies to 200 kVp x-rays and D-T neutrons were studied using reproductive capacity as a criterion for survival. Cell lines used were FM3A, L5 and Chinese hamster V79. The spherical colonies exposed to x-rays exhibited two-component survival curves. All cells used were more radio-resistant in spherical colonies than in single cell suspensions. It was suggested that this difference in response was attributable to the presence of hypoxic cells in spherical colonies. Dose-modifying Factor (DMF), the ratios of D 0 of the second slopes of the curves for spherical colonies to those for single cells, were 1.6 for FM3A, 1.8 for L5, and 1.7 for Chinese hamster V79. The hypoxic cell fractions in spherical colonies for FM3A, L5, and Chinese hamster V79, were 0.1, 0.6 and 0.4, respectively, resulting in variations in cell survival in spherical colonies following x-radiation. No significant difference was observed between responses of spherical colonies and single cell suspensions to D-T neutrons. FM3A and Chinese hamster V79 showed two-component survival curves when irradiated with neutrons at 37 0 C, but not at 25 0 C. The repair of potentially lethal and sub-lethal damage was also investigated using FM3A in spherical colonies. No detectable repair of potentially lethal damage was observed for x-rays and D-T neutrons. The effect of neutron fractionation was considerably smaller for spherical colonies as compared to single cells. (author)

The clinical research on fractionated irradiation treatment with X knife in patients of PD

International Nuclear Information System (INIS)

Wei Pengxiang; Chen Xu; Ai Quanshan; Xia Jiyong; Yang Jiongda; Chen Binghuan

2003-01-01

Objective: To explore X knife treatment methods and to seek a new effective way for PD therapy. Methods: Sixteen patients of PD were treated by performing VIM with 2 times of X knife fractionated irradiation (interval, 24 h) to a total dose of 140 Gy, and 8 patients of PD were treated by performing VIM with 3 times of X knife fractionated irradiation (interval, 24 h) to a total of dose of 165 Gy. Results: During 3-24 months follow-up after X knife treatment, tremor was stopped in 19 patients and was relived significantly in 5 patients. Rigidity and bradykinesia of PD were relieved slightly. No complications were observed. Conclusion: To perform VIM with X knife fractionated irradiation can be safely and effectively used to treat PD. The tremor of PD can be relieved slightly

Radioprotection of mice by lactoferrin against irradiation with sublethal X-rays

International Nuclear Information System (INIS)

Nishimura, Yoshikazu; Homma-Takeda, Shino; Kim, Hee-Sun; Kakuta, Izuru

2014-01-01

The influence of a host defense protein, lactoferrin (LF), contained in exocrine secretions such as milk, on radiation disorder was investigated. A total of 25 C3H/He mice in each of two groups were maintained with 0.1% LF-added and LF-free diets, respectively, for one month. The mice were then treated with single whole-body X-ray irradiation at a sublethal dose (6.8 Gy), and the survival rate after irradiation was investigated. The survival rate at 30 d after irradiation was relatively higher in the LF group than in the control group (LF-free), (85 and 62%, respectively). The body weight 15 d after X-ray irradiation was also significantly greater in the LF group than in the control group. The hemoglobin level and hematocrit value were higher in the LF group at 5 d before X-ray irradiation. Another 52 mice underwent whole-body X-ray irradiation at the sublethal dose (6.8 Gy), and then LF was intraperitoneally injected once at 4 mg/animal to half of them. The survival rate in LF-treated mice 30 d after irradiation was 92%, significantly higher than in mice treated with saline (50%) (P = 0.0012). In addition, LF showed hydroxyl radical scavenger activity in vitro. These findings suggest that LF may inhibit radiation damage. (author)

Prenatal death and malformations after irradiation of mouse zygotes with neutrons or X-rays

International Nuclear Information System (INIS)

Pampfer, S.; Streffer, C.

1988-01-01

Female mice (strain: Heiligenberger Stamm) were irradiated with neutrons (7 MeV) or X-rays when embryos were at the early zygote stage; uterine contents were examined on gestation day 19 for prenatal mortality and malformed fetuses. For both radiation qualities, the dose-dependent survival curve fitted well to a simple exponential equation; the neutron relative biological efficiency (RBE) value was 2.3. The major fraction of deaths induced by exposure to neutrons or X-rays occurred before implantation. Aside from dead embryos, malformed fetuses were observed 19 days p.c. (postconception). The number of malformed fetuses increased with a linear-quadratic function of neutron or X-ray dose. Malformations were mainly gastroschisis, although omphaloceles and anencephalies were also observed. The neutron RBE value for the induction of malformations varied from 2.0 to 2.8 in the dose range tested. Except after 75-cGy neutrons, no significant increase in the proportion of stunted or skeletally malformed fetuses was noted. Our results indicated that the reaction of preimplantation embryos to irradiation could be more complex than the simple all-or-none response considered so far

Comparison of x-ray output of inverter-type x-ray equipment

International Nuclear Information System (INIS)

Asano, Hiroshi; Miyake, Hiroyuki; Yamamoto, Keiichi

2000-01-01

The x-ray output of 54 inverter-type x-ray apparatuses used at 18 institutions was investigated. The reproducibility and linearity of x-ray output and variations among the x-ray equipment were evaluated using the same fluorescence meter. In addition, the x-ray apparatuses were re-measured using the same non-invasive instrument to check for variations in tube voltage, tube current, and irradiation time. The non-invasive instrument was calibrated by simultaneously obtaining measurements with an invasive instrument, employing the tube voltage and current used for the invasive instrument, and the difference was calculated. Reproducibility of x-ray output was satisfactory for all x-ray apparatuses. The coefficient of variation was 0.04 or less for irradiation times of 5 ms or longer. In 84.3% of all x-ray equipment, variation in the linearity of x-ray output was 15% or less for an irradiation time of 5 ms. However, for all the apparatuses, the figure was 50% when irradiation time was the shortest (1 to 3 ms). Variation in x-ray output increased as irradiation time decreased. Variation in x-ray output ranged between 1.8 and 2.5 compared with the maximum and minimum values, excluding those obtained at the shortest irradiation time. The relative standard deviation ranged from ±15.5% to ±21.0%. The largest variation in x-ray output was confirmed in regions irradiated for the shortest time, with smaller variations observed for longer irradiation times. The major factor responsible for variation in x-ray output in regions irradiated for 10 ms or longer, which is a relatively long irradiation time, was variation in tube current. Variation in tube current was slightly greater than 30% at maximum, with an average value of 7% compared with the preset tube current. Variations in x-ray output in regions irradiated for the shortest time were due to photographic effects related to the rise and fall times of the tube voltage waveform. Accordingly, in order to obtain constant x-ray

Destroying the photoelectret in Bi12SiO20 by X-ray irradiation

International Nuclear Information System (INIS)

Vavrek, A. F.; Khristova, K. K.

1987-01-01

The destroying of the classical photoelectret state (PES) in bismuth silicon oxide (BSO) monocrystals during X-ray irradiation is investigated and the reciprocity law (RL) is examined. The sample is irradiated by nonfiltered X-rays with continuous spectrum and maximum energy of the photons 70 keV. The polaryzing voltage used is 85 V. The dependence of the destroyed PE charge on the time of X-ray irradiation of the sample with equal X-ray exposure in each point shows that the exposure rates higher than a certain 'critical' value cause a larger destroyed charge that is RL during X-ray irradiation. The 'critical' value is about 3x10 -5 A/kg. The dependence of the destroyed photoelectric (PE) charge on the irradiation time generally shows that the destroyed PE charge increases with the increase of the X-ray exposure. After some time the distruction of the charge is terminated and the sample seems to lose its X-ray sensitivity although a considerable PE charge (30-40% of the initial one) remains in it. At higher exposure rates (above the critical one for the RL) the maxmimum destroyed charge is smaller. According to the dependencies of the linear coefficients of X-ray attenuation in the investigated energy range the photoelectric absorption is dominating. The radiation is absorbed only in the near-surface region. Part of the sample remains nonexited and the PE charge which has been initially barrier distributed is destroyed as a result of the redistribution of the charges in the excitation region only. At sufficiently long irradiation time this redistribution is terminated, notwithstanding the fact that out of the excitation region the sample still remains polarized. The maximum destroyed PE charge during nonhomogeneous excitation under nonquasi-stationary conditions is smaller at higher exposure rates because of the lower values of the diffusion and drift length

Sensitivity of P-Channel MOSFET to X- and Gamma-Ray Irradiation

Directory of Open Access Journals (Sweden)

Milić Pejović

2013-01-01

Full Text Available Investigation of Al-gate p-channel MOSFETs sensitivity following irradiation using 200 and 280 kV X-ray beams as well as gamma-ray irradiation of 60Co in the dose range from 1 to 5 Gy was performed in this paper. The response followed on the basis of threshold voltage shift and was studied as a function of absorbed dose. It was shown that the most significant change in threshold voltage was in the case of MOSFET irradiation in X-ray fields of 200 kV and when the gate voltage was +5 V. For practical applications in dosimetry, the sensitivity of the investigated MOSFETs was also satisfactory for X-ray tube voltage of 280 kV and for gamma rays. Possible processes in gate oxide caused by radiation and its impact on the response of MOSFETs were also analyzed in this paper.

Luminescence imaging of water during irradiation of X-ray photons lower energy than Cerenkov- light threshold

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, Seiichi; Koyama, Shuji; Komori, Masataka [Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine (Japan); Toshito, Toshiyuki [Department of Proton Therapy Physics, Nagoya Proton Therapy Center, Nagoya City West Medical Center (Japan)

2016-10-01

Luminescence imaging of water using X-ray photon irradiation at energy lower than maximum energy of ~200 keV is thought to be impossible because the secondary electrons produced in this energy range do not emit Cerenkov- light. Contrary to this consensus assumption, we show that the luminescence imaging of water can be achieved by X-ray irradiation at energy lower than 120 keV. We placed water phantoms on a table with a conventional X-ray imaging system, and luminescence images of these phantoms were measured with a high-sensitivity, cooled charge coupled device (CCD) camera during X-ray photon irradiation at energy below 120 keV. We also carried out such imaging of an acrylic block and plastic scintillator. The luminescence images of water phantoms taken during X-ray photon irradiation clearly showed X-ray photon distribution. The intensity of the X-ray photon images of the phantom increased almost proportionally to the number of X-ray irradiations. Lower-energy X-ray photon irradiation showed lower-intensity luminescence at the deeper parts of the phantom due to the higher X-ray absorption in the water phantom. Furthermore, lower-intensity luminescence also appeared at the deeper parts of the acrylic phantom due to its higher density than water. The intensity of the luminescence for water was 0.005% of that for plastic scintillator. Luminescence imaging of water during X-ray photon irradiation at energy lower than 120 keV was possible. This luminescence imaging method is promising for dose estimation in X-ray imaging systems.

Luminescence imaging of water during irradiation of X-ray photons lower energy than Cerenkov- light threshold

Science.gov (United States)

Yamamoto, Seiichi; Koyama, Shuji; Komori, Masataka; Toshito, Toshiyuki

2016-10-01

Luminescence imaging of water using X-ray photon irradiation at energy lower than maximum energy of 200 keV is thought to be impossible because the secondary electrons produced in this energy range do not emit Cerenkov- light. Contrary to this consensus assumption, we show that the luminescence imaging of water can be achieved by X-ray irradiation at energy lower than 120 keV. We placed water phantoms on a table with a conventional X-ray imaging system, and luminescence images of these phantoms were measured with a high-sensitivity, cooled charge coupled device (CCD) camera during X-ray photon irradiation at energy below 120 keV. We also carried out such imaging of an acrylic block and plastic scintillator. The luminescence images of water phantoms taken during X-ray photon irradiation clearly showed X-ray photon distribution. The intensity of the X-ray photon images of the phantom increased almost proportionally to the number of X-ray irradiations. Lower-energy X-ray photon irradiation showed lower-intensity luminescence at the deeper parts of the phantom due to the higher X-ray absorption in the water phantom. Furthermore, lower-intensity luminescence also appeared at the deeper parts of the acrylic phantom due to its higher density than water. The intensity of the luminescence for water was 0.005% of that for plastic scintillator. Luminescence imaging of water during X-ray photon irradiation at energy lower than 120 keV was possible. This luminescence imaging method is promising for dose estimation in X-ray imaging systems.

Long-term storage method for soft X-ray irradiated 'Hyuganatsu' pollen

International Nuclear Information System (INIS)

Yano, S.; Tanaka, M.; Ohara, N.

2008-01-01

The long-term storage conditions for 'Hyuganatsu ' pollen that had been irradiated with soft X-rays was examined. This study, was aimed at production of 'Tosa-buntan' without formation of nuclear fruit. 1. We evaluated the germination rate of pollen that had been irradiated with soft X-ray (500 or 1,000 Gy) and stored at 3 deg C, -20 deg C, and -40 deg C. The germination rate was the same as that of unirradiated pollen, even after storage for 1 year. Soft X-ray irradiation did not influence the storage attributes of pollen. 2. In unirradiated pollen and pollen that had been irradiated with soft X-ray (500 or 1,000 Gy), temperature conditions necessary for storing from 3 months to 1 year were -20 deg C or less, and pollen stored at -40 deg C had a higher germination rate after 1 year. 3. The germination rate was 1% or less in 4 months if silica gel was sealed into a gas barrier bag with 1,000 Gy-irradiated pollen at a rate of 10:1 (w/w). The ability to germinate was completely lost after 1 year in these conditions. 4. We evaluated the effect of sealing methods on 1,000 Gy-irradiated pollen stored at -20 deg C. There was no difference in germination rates among pollen stored in gas-barrier bags, vacuum-packaged pollen, and pollen stored with nitrogen in gas-barrier bags. Moreover, the germination rate of 750 Gy-irradiated pollen stored at -20 deg C decreased from 3 months onwards when pollen was stored with a free-oxygen absorber (Ageless ZP). 5. Pollen that was treated with acetone before or after soft X-ray irradiation (750 Gy) withstood long-term storage of 1 year. Long-term storage was possible if pollen was stored at -20 deg C, as is the case for rough pollen

X-ray photoelectron microscope with a compact x-ray source generated by line-focused laser irradiation

International Nuclear Information System (INIS)

Yamaguchi, N.; Okamoto, Y.; Hara, T.; Takahashi, Z.; Nishimura, Y.; Sakata, A.; Watanabe, K.; Azuma, H.

2004-01-01

Full text: A laboratory-sized microscopic system of x-ray photoelectrons has been developing using a compact x-ray source produced by line-focused laser irradiation. The system is a scanning type photoelectron microscope where x-ray beam is micro-focused via a Schwartzschild optics. A compact laser-plasma x-ray source has been developed with a YAG laser system, a line-focus lens system, a tape-target driving system and a debris prevention system, that was operated at repetition rate of 10 Hz or 50 Hz. X-rays were delivered along line plasma whose length was 0.6 to 11 mm with higher intensity than that from a point-focused source. Because the transition line of Al V (13.1 nm) was prominent in the soft x-ray spectrum when the Al tape target irradiated at the lower power density of 10 11 W/cm 2 , the 13.1 nm x-ray was used as an excitation source. The Schwartzschild optics was set on the beamline at a distance about 1 m from the source, which was coated with Mo/Si multilayers for 13.1 nm x-ray. The designed demagnification is 224 that was confirmed in the previous experiment. Therefore, an x-ray micro spot of sub-micron size can be formed on a sample surface when the source size is less than about 0.2 mm. Samples were set on a two-axis high-precision piezo stage mounted to a four-axis manipulator. The electron energy analyzer was a spherical capacitor analyzer with mean diameter of 279.4 mm. The electron detector was a microchannel plate (MCP) with a phosphor screen and the optical image of electrons on the exit plane of the analyzer was taken and recorded by using an ultra low dark noise CCD camera, that was suited for detection of vast photoelectrons excited by x-ray pulse of ns-order duration. We performed spatial resolution test measurements by using a GaAs wafer coated with photo-resist that formed a stripe pattern. The spatial resolution less than 3 micron has been obtained from the variation of As 3d electron intensity along the position of the GaAs sample

Characterization of the multiple drug resistance phenotype expressed by tumour cells following in vitro exposure to fractionated X-irradiation

International Nuclear Information System (INIS)

Hill, B.T.; McClean, S.; Hosking, L.; Shellard, S.; Dempke, W.; Whelan, R.

1992-01-01

The major clinical problem of the emergence of drug resistant tumor cell populations is recognized in patients previously treated with antitumor drugs and with radiotherapy. It is proposed that, although radiation-induced vascular fibrosis may limit drug delivery to the tumor, exposure to radiation may 'induce' or 'select for' drug resistance. This hypothesis was examined by establishing in vitro model systems to investigate the resistance phenotype of tumor cells following exposure to X-rays. Characteristically tumor cells surviving exposure to a series of fractions of X-irradiation are shown to have consistently expressed resistance to multiple drugs, including the Vinca alkaloids and the epipodophyllotoxins. Currently this research is aimed at determining whether distinctive resistance mechanisms operate depending on whether resistance results following drug or X-ray exposure. Initial results indicate that whilst some common mechanisms operate, drug resistant tumor cells identified following exposure to X-irradiation appear to exhibit a novel multidrug resistance phenotype. (author). 13 refs., 1 tab

Fractionated irradiation and haematopoiesis. Pt. 3

International Nuclear Information System (INIS)

Ninkov, V.; Karanovic, D.; Savovski, K.

1982-01-01

The effect of total single fractionated irradiation with short time interval on heamatopoietic regeneration of the bone marrow and spleen was investigated. Also, the importance of first dose, when dose of 600 R was divided in two unequal fractions with time interval of 300 s was studied. The investigation was performed on 25 day old rats. The dose of 600 R (X-rays) was divided on: 500 + 100, 400 + 200, 300 + 300, 200 + 400 or 100 + 500 R with time interval of 150, 300 or 600 s. Ten days after irradiation the changes in blood, bone marrow and spleen were observed. After unequal fractionated dose with interval of 600 s slight effect was found. The results after intervals of 600 s and 300 s were significant, when the total dose was divided in two equal doses. The first dose has no promoting role in haematopoietic regeneration when total dose was unequally fractionated. (orig.) [de

Hard X-ray irradiation of cosmic silicate analogs: structural evolution and astrophysical implications

Science.gov (United States)

Gavilan, L.; Jäger, C.; Simionovici, A.; Lemaire, J. L.; Sabri, T.; Foy, E.; Yagoubi, S.; Henning, T.; Salomon, D.; Martinez-Criado, G.

2016-03-01

Context. Protoplanetary disks, interstellar clouds, and active galactic nuclei contain X-ray-dominated regions. X-rays interact with the dust and gas present in such environments. While a few laboratory X-ray irradiation experiments have been performed on ices, X-ray irradiation experiments on bare cosmic dust analogs have been scarce up to now. Aims: Our goal is to study the effects of hard X-rays on cosmic dust analogs via in situ X-ray diffraction. By using a hard X-ray synchrotron nanobeam, we seek to simulate cumulative X-ray exposure on dust grains during their lifetime in these astrophysical environments and provide an upper limit on the effect of hard X-rays on dust grain structure. Methods: We prepared enstatite (MgSiO3) nanograins, which are analogs to cosmic silicates, via the melting-quenching technique. These amorphous grains were then annealed to obtain polycrystalline grains. These were characterized via scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) before irradiation. Powder samples were prepared in X-ray transparent substrates and were irradiated with hard X-rays nanobeams (29.4 keV) provided by beamline ID16B of the European Synchrotron Radiation Facility (Grenoble). X-ray diffraction images were recorded in transmission mode, and the ensuing diffractograms were analyzed as a function of the total X-ray exposure time. Results: We detected the amorphization of polycrystalline silicates embedded in an organic matrix after an accumulated X-ray exposure of 6.4 × 1027 eV cm-2. Pure crystalline silicate grains (without resin) do not exhibit amorphization. None of the amorphous silicate samples (pure and embedded in resin) underwent crystallization. We analyze the evolution of the polycrystalline sample embedded in an organic matrix as a function of X-ray exposure. Conclusions: Loss of diffraction peak intensity, peak broadening, and the disappearance of discrete spots and arcs reveal the amorphization

Chromosome aberrations in human peripheral lymphocytes induced by single or fractionated X-irradiation

International Nuclear Information System (INIS)

Ivanov, B.; Leonard, A.; Deknyudt, G.

1980-01-01

Investigated is the effect of single (125 and 250 R) and fractionated (2x125 R) irradiation on the output of chromosome aberrations in lymphocytes of human peripheral blood kept between irradiations at the temperature of 5 deg C. The single irradiation is carried out immediately after vein-puncture. In the case of fractionated irradiation the first dose of 125R is given after vein-puncture, the second, in the interval of 2, 8 and 24 hours. Blood is cultivated immediately after two irradiations in order to prepare metaphase plates for cytogenic analysis. Repair processes in cell heritage structures are not realised in blood irradiated by fractions which is kept at 5 deg C between irradiations. On the contrary, chromosome fragments, interstitial deletions, aberrant cells and cell breaks are found in a large amount in blood irradiated by fractions. They have appeared with the authentically high statistic difference as compared with the cells irradiated one time with the same dose. This effect is probably attained due to blood preservation

Radiological safety research of food irradiation with 7.5 MeV X-rays

International Nuclear Information System (INIS)

Yang Bin; Tang Weidong; Zhang Yue; Xu Tao; Jin Jianqiao; Ye Mingyang

2012-01-01

China and America both have 7.5 MeV high energy X-ray accelerator. The radiological safety of food irradiated with 7.5 MeV X-rays (bremsstrahlung) has been investigated. Samples of meat and meat ash were located in a large volume of fresh meat at the position of the highest photoneutron fluence and irradiated to an X-ray dose of 15 kGy, twice the maximum dose allowed by the US FDA for meat irradiation. An evaluation of the corresponding radiation exposure from ingestion of the irradiated product has been compared to natural background radiation. The paper concludes that the risk to individuals from intake of food irradiated with X-rays from 7.5 MeV electrons, even with a broad energy spectrum, would be trivial. The common target materials are Au, Ta and W. The U.S, requires only Au and Ta can be used as food irradiation target materials and China has not yet relevant provisions. The first 7.5 MeV accelerator for food irradiation in China is under built, and will do the explore research for the choice of target material. (authors)

Ac-electrical conductivity of poly(propylene) before and after X-ray irradiation

International Nuclear Information System (INIS)

Gaafar, M.

2001-01-01

Study on the ac-electrical conductivity of poly(propylene), before and after X-ray irradiation within the temperature range 300-360 K are reported. The measurements have been performed in a wide range of frequencies (from 0 to 10 5 Hz) and under the effect of different X-ray irradiation doses (from 0 to 15 Gy). Cole-Cole diagrams have been used to show the frequency dependence of the complex impedance at different temperatures. The results exhibit semicircles which are consistent with existing equivalent circuit model. Analysis of the results reveal semiconducting features based mainly on a hopping mechanism. The study shows a pronounced effect of X-ray irradiation on the electrical conductivity at zero frequency σ DC . At the early stage of irradiation, σ DC increased as a result of free radical formation. As the irradiation progressed, it decreased as a result of crosslinking, then it increased again due to irradiation induced degradation, which motivates the generation of mobile free radicals. The study shows that this polymer is one among other polymers which its electrical conductivity is modified by irradiation

Ac-electrical conductivity of poly(propylene) before and after X-ray irradiation

Science.gov (United States)

Gaafar, M.

2001-05-01

Study on the ac-electrical conductivity of poly(propylene), before and after X-ray irradiation within the temperature range 300-360 K are reported. The measurements have been performed in a wide range of frequencies (from 0 to 10 5 Hz) and under the effect of different X-ray irradiation doses (from 0 to 15 Gy). Cole-Cole diagrams have been used to show the frequency dependence of the complex impedance at different temperatures. The results exhibit semicircles which are consistent with existing equivalent circuit model. Analysis of the results reveal semiconducting features based mainly on a hopping mechanism. The study shows a pronounced effect of X-ray irradiation on the electrical conductivity at zero frequency σDC. At the early stage of irradiation, σDC increased as a result of free radical formation. As the irradiation progressed, it decreased as a result of crosslinking, then it increased again due to irradiation induced degradation, which motivates the generation of mobile free radicals. The study shows that this polymer is one among other polymers which its electrical conductivity is modified by irradiation.

Sparing effect of x-ray fractionation in mammary tumours and skin reactions of mice

International Nuclear Information System (INIS)

Fowler, J.F.; Denekamp, J.; Sheldon, P.W.; Smith, A.M.; Begg, A.C.; Harris, S.R.; Page, A.L.

1975-01-01

The increase in total dose with number of fractions of x-rays between 2 and 15 was found to be similar for local control of tumours (TCD 50 ) and for skin reactions. This result could be explained if the gain from reoxygenation of hypoxic tumour cells was the same for two fractions as for larger numbers, and the dose-sparing effect of repair and repopulation was similar for the tumour and for skin. In addition, a split-dose experiment was carried out with the tumours clamped off to make them acutely hypoxic during irradiation. The resulting value of (D 2 -D 1 )sub(24h) was not significantly smaller than the value previously found for skin reactions. 1290 rad was found in anoxic conditions, corresponding to a dose increment for repair in oxygenated conditions of 430 to 520 rad, assuming an oxygen enhancement ratio of 3 to 2.5. Reduced values have been found from regrowth experiments on two other types of tumour in mice. These results are consistent with no significant difference in the sparing effect of x-ray fractionation on skin or C 3 H mammary tumours in mice for up to 15 equal fractions given in 18 days; but reduced repair plus more proliferation in tumours than in skin cannot be excluded. (author)

Effects of x-ray irradiation on mast cells and mastocalcergy in the connective tissue

Energy Technology Data Exchange (ETDEWEB)

Song, H. Y.; Rhee, S. J.; Son, M. H.; Choi, K. C. [Chonbuk National University College of Medicine, Jeonju (Korea, Republic of)

1982-09-15

Experiments were performed to observe the influence of x-ray irradiation on mast cells and mastocalcergy in rats. Animals were irradiated single dose of x-ray. X-ray irradiation was applied to the whole body in doses either 100 rads or 150 rads (Cobalt-60 Teletherapy Unit). One day after irradiation the rats were injected lead acetate intravenously, followed by injection of compound 48/80 in the back subcutaneously. Animals were killed by decapitation at intervals, 1 hour, 5 hours, 1 day and 6 day after subcutaneous injection. Specimens of the abdominal and back skin were fixed in alcohol formol solution and stained with the following methods; H-E for observation of pathological changes of tissues, toluidine blue for demonstration of mast cells, von Kossa-azure A for demonstration of carbonate and phosphate, and chloranilic acid for demonstration of calcium. The following conclusions were obtained. Calciphylatic wheals are large size in the control group, medium size in 100 rads irradiation group and small size in 150 rads irradiation group. In x-ray irradiation groups the number of mast cells decreases more in the 150 rads than in the 100 rads irradiation. In the 100 rads x-ray irradiation group, histochemical study of the injection sites showed that calcium impregnated to mast cell granules and connective tissue fibers in 1 days after subcutaneous injection. The morphogenesis of this calcinosis was the same in the rat of 5 hour after subcutaneous injection of the control group. Whereas, 1 day after subcutaneous injection in 150 rads x-ray irradiation group calcium deposited more slightly than other groups.

Differential effects of fractionated X irradiation on mouse spermatogonial stem cells

NARCIS (Netherlands)

van der Meer, Y.; Huiskamp, R.; Davids, J. A.; de rooij, D. G.

1993-01-01

The response of spermatogonial stem cells to fractionated X irradiation was studied in the various stages of the spermatogenic cycle of the CBA mouse. Fractionated doses of 2 + 2, 1 + 3, and 3 + 1 Gy with a 24-h interval between the doses were compared with a single dose of 4 Gy. The numbers of

A study on relation between nitroxyl radical reduction potency and X-ray irradiation on mouse lung using L-band electron spin resonance

International Nuclear Information System (INIS)

Taneike, Makoto; Sho, Keizen; Morita, Rikushi

1999-01-01

Changes in nitroxy radical reduction potency (''reduction potency''), caused by different doses and different number of fractions of X-ray irradiation were studied using a L-band electron spin resonance system on mouse lungs into which 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (hydroxy-TEMPO) was introduced through the trachea. The ''reduction potency'' lineally decreased as the irradiation dose increased from 1.0 to 5.0 Gy, but no further decrease was observed at higher doses of 7.5 and 10 Gy. The reduction potency'' dropped at 20 min after each irradiation, but it recovered to the control levels after 1 week in all 3 groups of single dose of 10 Gy, 3 fractions and 5 fractions in a similar manner. Although the levels of the ''reduction potency'' were kept high in the groups of fractionated irradiation through 1-4 weeks after irradiation, the levels dropped again in the single dose group at 1 week and the levels were kept significantly low until 4 weeks after irradiation. suggesting that the fractionation of X-ray irradiation would also be effective to prevent the deterioration of the ''reduction potency''. Pre-treatment with sufficient ascorbic acid inhibited the lowering effects of radiation on the ''reduction potency'' in a dose dependent manner. Furthermore the levels of the reduction potency'' ever elevated higher than those of controls with the large amount of ascorbic acid of 750 mg/kg or more, suggesting that the large amounts of ascorbic acid could prevent the adverse effects associated with radiation therapy for the lung malignancy. (author)

Cell kinetic changes in the follicular epithelium of pig skin after irradiation with single and fractionated doses of X rays

International Nuclear Information System (INIS)

Morris, G.M.; Hopewell, J.W.

1989-01-01

Changes in cell kinetics of the follicular epithelium of the pig were studied after x-irradiation with single and fractionated doses (30 fractions/39 days) and compared with previous epidermal data. In the follicular epithelium there was an initial degenerative phase, when the rate of cell depletion was independent of radiation dose and mode of administration. Repopulation was seen between the 14th and 18th days after single doses (15 or 20 Gy) and by the 28th day after the start of irradiation with fractionated doses (52.3-80.0 Gy). The degree of cell depletion and subsequent rate of repopulation were independent of dose. The regenerative phase was characterized by an increased cell proliferation. Islands of cells with appearance similar to cells in the normal follicular epithelium, were seen 18 days after a single dose of 20 Gy and 42 days after the start of fractionated irradiation. Compared with the epidermis, the follicular epithelium exhibited considerably less evidence of damage after both single and fractionated doses. There was a lower incidence of degenerate cells and reduced levels of cell depletion in the follicular epithelium. (author)

The response of mouse skin to re-irradiation with x-rays or fast neutrons

International Nuclear Information System (INIS)

Tsukiyama, Iwao; Egawa, Sunao; Kumazawa, Akiyoshi; Iino, Yuu.

1986-01-01

Effects of neutrons and x-rays on mouse skin which had been previously irradiated with x-rays were investigated. Two tattoo marks were placed in the hairless legs of mice at intervals of 15 mm. The legs were exposed to various doses of x-ray and neutrons to determine the relative biological effectiveness (RBE) using the contraction of the skin as an index. The RBE was 0.93 - 1.73. The legs of the mice were preexposed to 25 Gy of x-ray, and exposed 4 months later. The contraction of the skin began earlier than after the first irradiation. RBE was 2.18 - 2.47. This RBE was higher than that in untreated mice. These results suggest that previously irradiated normal tissues are much more sensitive to neutrons than to x-rays. (author)

Simulation of X-ray irradiation on human hand

International Nuclear Information System (INIS)

Amaya, Fabiola; Montoya, Modesto

2001-01-01

Using the Monte Carlo code MCNP we simulate a human hand X-rays irradiation with radiodiagnostic energies to find the better range energy to make radiographs with the lowest dose and an optimal contrast. We calculate bone doses by considering a soft tissue - water - and calcium bone hand, which is irradiated with a million of X-rays photons from a punctual source. These photons are directed inside a conic angle on the hand. Afterwards, we simulate elements which normally compose bones (C, H, O, N, Mg, P, Ca, and S). We estimate bone dose considering: a) bone material (water, calcium and bone tissue); b) bone thickness (0.01; 0.1; 0.5; 1.0; 1.5 and 3.0 cm); and c) source-hand distance (30, 50, 70 and 90 cm). We calculate photon transmission percent through soft tissue and bone tissue and the statistics from the number of photons that reach the radiographic film after passing through soft tissue or bone tissue for our geometric configuration. We found that we can obtain a good image contrast by using X-rays with energies in the range of 20 to 40 keV. (author)

Electrophysiologic and cellular characteristics of cardiomyocytes after X-ray irradiation

Energy Technology Data Exchange (ETDEWEB)

Frieß, Johannes L., E-mail: johannes.friess@h-ab.de [University for Applied Sciences Aschaffenburg, biomems lab, Würzburger Straße 45, 63743 Aschaffenburg (Germany); Heselich, Anja [Technische Universität Darmstadt, Developmental Biology and Neurogenetics, Schnittspahnstraße 13, 64287 Darmstadt (Germany); Ritter, Sylvia [Helmholtz Institute for Heavy Ion Research (GSI), Biophysics Department, Planckstraße 1, 64291 Darmstadt (Germany); Haber, Angelina; Kaiser, Nicole; Layer, Paul G. [Technische Universität Darmstadt, Developmental Biology and Neurogenetics, Schnittspahnstraße 13, 64287 Darmstadt (Germany); Thielemann, Christiane [University for Applied Sciences Aschaffenburg, biomems lab, Würzburger Straße 45, 63743 Aschaffenburg (Germany)

2015-07-15

Highlights: • Electrophysiologic and cellular effects of X-rays on primary cardiac cell cultures. • X-ray doses between 0.5 and 7 Gy. • Higher beat rate at reduced field action potential durations 7 days after exposure. • More increased cell cycle checkpoint arrest in G2/M than in G1/S phase. • Induced DSBs were mostly repaired within 24 h after irradiation. - Abstract: The aim of this study was to investigate possible effects of ionizing irradiation on the electrophysiological functionality of cardiac myocytes in vitro. Primary chicken cardiomyocytes with spontaneous beating activity were irradiated with X-rays (dose range of 0.5–7 Gy). Functional alterations of cardiac cell cultures were evaluated up to 7 days after irradiation using microelectrode arrays. As examined endpoints, cell proliferation, apoptosis, reactive oxygen species (ROS) and DNA damage were evaluated. The beat rate of the cardiac networks increased in a dose-dependent manner over one week. The duration of single action potentials was slightly shortened. Additionally, we observed lower numbers of mitotic and S-phase cells at certain time points after irradiation. Also, the number of cells with γH2AX foci increased as a function of the dose. No significant changes in the level of ROS were detected. Induction of apoptosis was generally negligibly low. This is the first report to directly show alterations in cardiac electrophysiology caused by ionizing radiation, which were detectable up to one week after irradiation.

Electrophysiologic and cellular characteristics of cardiomyocytes after X-ray irradiation

International Nuclear Information System (INIS)

Frieß, Johannes L.; Heselich, Anja; Ritter, Sylvia; Haber, Angelina; Kaiser, Nicole; Layer, Paul G.; Thielemann, Christiane

2015-01-01

Highlights: • Electrophysiologic and cellular effects of X-rays on primary cardiac cell cultures. • X-ray doses between 0.5 and 7 Gy. • Higher beat rate at reduced field action potential durations 7 days after exposure. • More increased cell cycle checkpoint arrest in G2/M than in G1/S phase. • Induced DSBs were mostly repaired within 24 h after irradiation. - Abstract: The aim of this study was to investigate possible effects of ionizing irradiation on the electrophysiological functionality of cardiac myocytes in vitro. Primary chicken cardiomyocytes with spontaneous beating activity were irradiated with X-rays (dose range of 0.5–7 Gy). Functional alterations of cardiac cell cultures were evaluated up to 7 days after irradiation using microelectrode arrays. As examined endpoints, cell proliferation, apoptosis, reactive oxygen species (ROS) and DNA damage were evaluated. The beat rate of the cardiac networks increased in a dose-dependent manner over one week. The duration of single action potentials was slightly shortened. Additionally, we observed lower numbers of mitotic and S-phase cells at certain time points after irradiation. Also, the number of cells with γH2AX foci increased as a function of the dose. No significant changes in the level of ROS were detected. Induction of apoptosis was generally negligibly low. This is the first report to directly show alterations in cardiac electrophysiology caused by ionizing radiation, which were detectable up to one week after irradiation

Effects of local single and fractionated X-ray doses on rat bone marrow blood flow and red blood cell volume

International Nuclear Information System (INIS)

Pitkaenen, M.A.; Hopewell, J.W.

1985-01-01

Time and dose dependent changes in blood flow and red blood cell volume were studied in the locally irradiated bone marrow of the rat femur after single and fractionated doses of X-rays. With the single dose of 10 Gy the bone marrow blood flow although initially reduced returned to the control levels by seven months after irradiation. With doses >=15 Gy the blood flow was still significantly reduced at seven months. The total dose levels predicted by the nominal standard dose equation for treatments in three, six or nine fractions produced approximately the same degree of reduction in the bone marrow blood flow seven months after the irradiation. However, the fall in the red blood cell volume was from 23 to 37% greater in the three fractions groups compared with that in the nine fractions groups. Using the red blood cell volume as a parameter the nominal standard dose formula underestimated the severity of radiation damage in rat bone marrow at seven months for irradiation with small numbers of large dose fractions. (orig.) [de

Repair of skin damage during fractionated irradiation with gamma rays and low-LET carbon ions

International Nuclear Information System (INIS)

Ando, Koichi; Koike, Sachiko; Uzawa, Akiko; Takai, Nobuhiko; Fukawa, Takeshi; Furusawa, Yoshiya; Aoki, Mizuho; Hirayama, Ryoichi

2006-01-01

In clinical use of carbon-ion beams, a deep-seated tumor is irradiated with a Spread-Out Bragg peak (SOBP) with a high-linear energy transfer (LET) feature, whereas surface skin is irradiated with an entrance plateau, the LET of which is lower than that of the peak. The repair kinetics of murine skin damage caused by an entrance plateau of carbon ions was compared with that caused by photons using a scheme of daily fractionated doses followed by a top-up dose. Right hind legs received local irradiations with either 20 keV/μm carbon ions or γ rays. The skin reaction of the irradiated legs was scored every other day up to Day 35 using a scoring scale that consisted of 10 steps, ranging from 0.5 to 5.0. An isoeffect dose to produce a skin reaction score of 3.0 was used to obtain a total dose and a top-up dose for each fractionation. Dependence on a preceding dose and on the time interval of a top-up dose was examined using γ rays. For fractionated γ rays, the total dose linearly increased while the top-up dose linearly decreased with an increase in the number of fractions. The magnitude of damage repair depended on the size of dose per fraction, and was larger for 5.2 Gy than 12.5 Gy. The total dose of carbon ions with 5.2 Gy per fraction did not change till 2 fractions, but abruptly increased at the 3rd fraction. Factors such as rapid repopulation, induced repair and cell cycle synchronization are possible explanations for the abrupt increase. As an abrupt increase/decrease of normal tissue damage could be caused by changing the number of fractions in carbon-ion radiotherapy, we conclude that, unlike photon therapy, skin damage should be carefully studied when the number of fractions is changed in new clinical trials. (author)

Effect of laser-plasma X-ray irradiation on crystallization of amorphous silicon film by excimer laser annealing

International Nuclear Information System (INIS)

Matsuo, Naoto; Uejukkoku, Kazuya; Heya, Akira; Takanashi, Yasuyuki; Amano, Sho; Miyamoto, Shuji; Mochizuki, Takayasu

2007-01-01

The effect of laser plasma soft X-ray (LPX) irradiation on crystallization by excimer laser annealing (ELA) was investigated at low ELA energy densities. The crystalline fraction at energy densities of 50 and 60 mJ/cm 2 for LPX followed by ELA is nearly equal to that at 80 to 100 mJ/cm 2 for the ELA method with non-LPX irradiation. The results obtained indicate that LPX irradiation before ELA reduces the critical energy density for the start of crystallization. The combined method of LPX irradiation and ELA will enable us to realize a low-temperature process for ELA crystallization. (author)

Studies on the ability of irradiated Escherichia coli bacteria to reactivate X-ray inactivated bacteriophages

International Nuclear Information System (INIS)

Kiessling, W.

1980-01-01

The Weigle Reactivation phenomenon ie. the observation that low UV-flow irradiated bacteria increase the survival rate of UV-irradiated phages has not, to date, been studied with other forms of irradiation as inducers. In the studies reported here lambda-phages and E. coli cells in LB-medium were treated with X-rays. Host cells treated with an X-ray dose from 85 to 765 Gy showed a reactivation factor of 1.3 to 3.0 for X-ray inactivated phages. The capacity of the bacteria for phage reproduction did not appear to be markedly diminished. A reactivation factor of 1.3 only was found for X-irradiated phages when host cells were treated with UV-irradiation. The low Weigle reactivation of X-ray treated phages compared to UV-treatment was found to be due to a diminished absorption capacity, as demonstrated by the determination of free non-absorbed phages by filtration of radioactive-labelled phage-host-complexes. Reactivation studies on X-irradiated phages with various host bacteria of different radiation sensitivities confirm this finding. (orig.) [de

Effects of ginger extract on testis enzymes of X-ray irradiated mice

International Nuclear Information System (INIS)

Zhao Shuhua; Li Jingshun; Wang Chunhua; Pan Qin; Yang Qiong

2005-01-01

Objective: To research the effects of extract of ginger on testis enzymes of X-ray irradiated mice. Methods: Mice were treated with three different doses of extract of ginger: high dose (9.3 mL·kg -1 ), middle dose (4.7 mL·kg -1 ), and low dose (2.3 mL·kg -1 ). All mice were irradiated once with 2.0 Gy X-ray. At the same time, the negative group (treated with vegetable oil only) and positive one (irradiated as well as extract of ginger groups after treated with vegetable oil) were set up. The changes of activities of enzymes in testes of mice were observed. Results: After irradiated, in the group of high dose the activity of G-6-PD was decreased but the activity of LDH was increased (P 0.05). In every group, SDH had no significant difference (P>0.05). Conclusion: The proper dose of extract of ginger has significant effects on stabilization of testis enzymes of X-ray irradiated mice. (authors)

Yeast cell metabolism investigated by CO{_2} production and soft X-ray irradiation

Science.gov (United States)

Masini, A.; Batani, D.; Previdi, F.; Milani, M.; Pozzi, A.; Turcu, E.; Huntington, S.; Takeyasu, H.

1999-01-01

Results obtained using a new technique for studying cell metabolism are presented. The technique, consisting in CO2 production monitoring, has been applied to Saccharomyces cerevisiae yeast cells. Also the cells were irradiated using the soft X-ray laser-plasma source at Rutherford Appleton Laboratory with the aim of producing a damage of metabolic processes at the wall level, responsible for fermentation, without great interference with respiration, taking place in mitochondria, and DNA activity. The source was calibrated with PIN diodes and X-ray spectrometers and used Teflon stripes as target, emitting X-rays at about 0.9 keV, with a very low penetration in biological material. X-ray doses delivered to the different cell compartments were calculated following a Lambert-Bouguet-Beer law. Immediately after irradiation, the damage to metabolic activity was measured again by monitoring CO2 production. Results showed a general reduction in gas production by irradiated samples, together with non-linear and non-monotone response to dose. There was also evidence of oscillations in cell metabolic activity and of X-ray induced changes in oscillation frequency.

Investigations of X-ray irradiation of marine fish aboard

International Nuclear Information System (INIS)

Karnop, G.; Reinacher, E.; Antonacopoulos, N.; Meyer, V.

1976-01-01

Studies on X-ray irradiation of ocean perch, cod and coley (at doses of 50-150 krad) are described. The results show that irradiation within this dose range has no significant effect on the shelf-life of fish stored in ice. Although irradiation positively influenced bacteriological and chemical characteristics (e.g. reduction of total aerobic count, and inhibition of decomposition of N-containing compounds), the organoleptically-limited shelf-life of irradiated specimens was similar to that of non-irradiated specimens. Organoleptic changes in irradiated and in non-irradiated samples differed; this is attributed to the abnormal spoilage flora (mainly radiation-resistant Moraxella spp.) in the irradiated samples. (orig./HP) [de

Effect of single and fractionated x-irradiation on maze learning ability of mice

International Nuclear Information System (INIS)

Aoyama, Takashi; Norimura, Toshiyuki; Nakamura, Takeshi; Yoshikawa, Isao

1976-01-01

Fifty-six-day-old male ddk mice at the starting of the investigation were used as subjects through the experiment for 64 weeks. After 15 days' preliminary training, and 16 times of weekly trial training using complete maze, 15 mice received a single 224 rads of x-rays (S group), another 15 mice received two 112 rads spaced two weeks apart (F group) and another 15 mice were sham-irradiated (Control group). Then those mice were tested on the multiple T-maze with nine-choice points and change of performance was observed in terms of errorchoices by giving one test trial a week. We introduced the concept of ''confusional trials'' as an index for surmising to what extent mice failed to exhibit good maze learning habits. In the results, the F group showed significantly worse performance than the two other groups at early stages, opposite to it the S group exhibited the same, but at late stages after irradiation. The worse performance of F group should be considered to be due to the psychological after-effect to fractionated irradiation and that for S group could be assumed to be due to the acceleration of aging by the irradiation. (auth.)

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.

Determination of fission products in irradiated fuel by X-ray fluorescence

International Nuclear Information System (INIS)

Mogensen, M.; Als-Nielsen, J.; Hessel Andersen, N.

1986-08-01

X-ray fluorescence is a well established analytical tool for measuring elemental composition of fairly large (approximately 5 cm 2 ) ''cold'' samples. A version of this technique has been developed for analysis of radial distribution of fission products Xe, Cs and Ba in irradiated UO 2 fuel samples. About 0.1 mm thin slices of fuel pellets (full cross sections) are irradiated by 50 keV X-rays. The intensity of the Xe (Cs, Ba) K α fluorescence radiation generated is measured by means of a Ge detector fitted with a collimator. The slit is 0.5 mm wide in the scanning direction and 2 mm long. The measured Xe K α X-ray intensities are converted to absolute concentrations by comparing to the intensity from a Xe gas standard. In the case of Cs and Ba solid standards may be used. The X-ray fluorescence analysis is compared to other techniques used to obtain radial fission product profiles. It is shown how a combination of X-ray fluorescence and electron probe micro analysis is able to reveal the amount of Xe in the grain boundary porosities. (author)

Gold nanoparticles: BSA (Bovine Serum Albumin) coating and X-ray irradiation produce variable-spectrum photoluminescence

Energy Technology Data Exchange (ETDEWEB)

Lee, Kuo-Hao [Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan (China); Institute of Physics, Academia Sinica, Taipei 115, Taiwan (China); Lai, Sheng-Feng [Institute of Physics, Academia Sinica, Taipei 115, Taiwan (China); Department of Engineering Science, National Cheng Kung University, Tainan 701, Taiwan (China); Lin, Yan-Cheng; Chou, Wu-Ching [Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan (China); Ong, Edwin B.L. [Institute of Physics, Academia Sinica, Taipei 115, Taiwan (China); Tan, Hui-Ru [Institute of Materials Research and Engineering, 3 Research Link, 117602 (Singapore); Tok, Eng Soon [Physics Department, National University of Singapore, 117542 (Singapore); Yang, C.S. [Center for Nanomedicine, National Health Research Institutes, Miaoli 350, Taiwan (China); Margaritondo, G. [Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland); Hwu, Y., E-mail: phhwu@sinica.edu.tw [Institute of Physics, Academia Sinica, Taipei 115, Taiwan (China); Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 701, Taiwan (China); Institute of Optoelectronic Sciences, National Taiwan Ocean University, Keelung 202, Taiwan (China)

2015-01-15

We show that by using different x-ray irradiation times of BSA-coated Au nanoparticles (NPs) we can change their ultraviolet-stimulated photoluminescence and shift the spectral weight over the visible spectral range. This is due to the interplay of two emission bands, one due to BSA and the other related to gold. The emission properties did not change with time over a period of several months. - Highlights: • Gold nanoparticles (Au NPs) coated with Bovine Serum Albumin (BSA) are synthesized by x-ray irradiation. • BSA coated AuNPs with ∼1 nm size show strong photoluminescence in red by UV excitation. • The blue photoluminescence of BSA increase with x-ray irradiation. • Increase x-ray irradiation time during the synthesis shift the color of the colloid from red to blue.

Gold nanoparticles: BSA (Bovine Serum Albumin) coating and X-ray irradiation produce variable-spectrum photoluminescence

International Nuclear Information System (INIS)

Lee, Kuo-Hao; Lai, Sheng-Feng; Lin, Yan-Cheng; Chou, Wu-Ching; Ong, Edwin B.L.; Tan, Hui-Ru; Tok, Eng Soon; Yang, C.S.; Margaritondo, G.; Hwu, Y.

2015-01-01

We show that by using different x-ray irradiation times of BSA-coated Au nanoparticles (NPs) we can change their ultraviolet-stimulated photoluminescence and shift the spectral weight over the visible spectral range. This is due to the interplay of two emission bands, one due to BSA and the other related to gold. The emission properties did not change with time over a period of several months. - Highlights: • Gold nanoparticles (Au NPs) coated with Bovine Serum Albumin (BSA) are synthesized by x-ray irradiation. • BSA coated AuNPs with ∼1 nm size show strong photoluminescence in red by UV excitation. • The blue photoluminescence of BSA increase with x-ray irradiation. • Increase x-ray irradiation time during the synthesis shift the color of the colloid from red to blue

Charge yield for cobalt-60 and 10-keV x-ray irradiations of MOS devices

International Nuclear Information System (INIS)

Shaneyfelt, M.R.; Fleetwood, D.M.; Schwank, J.R.; Hughes, K.L.

1991-01-01

In this paper the radiation response of MOS devices exposed to 60 Co and low-energy (∼10 keV) x-ray irradiation is evaluated as a function of electric field during exposure. Improved charge yield estimates are obtained for 60 Co irradiations at fields below 1 MV/cm by matching voltage shifts due to oxide-trap and interface-trap charge to an E -0.55 electric field dependence. Combining these improved charge yield estimates and calculated dose enhancement factors, the relative response of x-ray to 60 Co irradiations is accurately predicted for oxide electric fields from 0.03 MV/cm to 5.0 MV/cm. The ability to predict the relative response of x-ray to 60 Co irradiations should speed acceptance of x-ray testers as a hardness assurance tool

Skin response to X-irradiation in the guinea-pig

Energy Technology Data Exchange (ETDEWEB)

Berry, R J; Mole, R H; Barnes, D W.H. [Medical Research Council, Harwell (UK). Radiobiological Research Unit

1976-12-01

Skin reaction to X-irradiation has been studied in the albino quinea-pig; early response in limited-field irradiations of the flank was comparable to that commonly seen in rodents, swine and man, and was dose-dependent with a dynamic range from mild erythema to moist desquamation. The peak early skin reaction was seen between 14 and 21 days after irradiation, and declined before 30 days except at the highest doses used. Fractionation of the X-ray dose at 24 hours resulted in a 'sparing' of about 340 rad. Permanent partial epilation was detectable at doses in excess of 1400 rad, and complete epilation at 1 year occurred in 50 per cent of irradiated fields at 1740 rad. Twenty-four hour two-dose fractionation resulted in a 'sparing' of about 500 rad for epilation. Palpable dermal 'fibrosis' was detectable at 3 months after irradiation in fields given more than 2070 rad, and at 1 year after irradiation in fields given more than 1800 rad; 50 per cent of fields showed palpable 'fibrosis' at 1 year at 1930 rad. Unlike domestic swine and man, skin fields in the quinea-pig showed no dimensional contraction after X-ray doses which produced gross early skin damage.

Relative Biologic Effectiveness (RBE) of 50 kV X-rays Measured in a Phantom for Intraoperative Tumor-Bed Irradiation

Energy Technology Data Exchange (ETDEWEB)

Liu, Qi; Schneider, Frank; Ma, Lin; Wenz, Frederik [Department of Radiation Oncology, Universitätsmedizin Mannheim, Medical Faculty Mannheim, University of Heidelberg, Mannheim (Germany); Herskind, Carsten, E-mail: carsten.herskind@medma.uni-heidelberg.de [Department of Radiation Oncology, Universitätsmedizin Mannheim, Medical Faculty Mannheim, University of Heidelberg, Mannheim (Germany)

2013-03-15

Purpose: Intraoperative radiation therapy (IORT) with low-energy x-rays is used to treat the tumor bed during breast-conserving surgery. The purpose was to determine the relative biologic effectiveness (RBE) of 50-kV x-rays for inactivation of cells irradiated in a tumor-bed phantom. Methods and Materials: The RBE was determined for clonogenic inactivation of human tumor and normal cells (MCF7, human umbilical vein endothelial cells, normal skin fibroblasts), and hamster V79 cells. The 50-kV x-rays from the Intrabeam machine (Carl Zeiss Surgical) with a spherical 4-cm applicator were used. Cells were irradiated in a water-equivalent phantom at defined distances (8.1-22.9 mm) from the applicator surface. The 50-kV x-rays from a surface therapy machine (Dermopan, Siemens) were included for comparison; 6-MV x-rays were used as reference radiation. Results: At 8.1-mm depth in the phantom (dose rate 15.1 Gy/h), mean RBE values of 50-kV x-rays from Intrabeam were 1.26 to 1.42 for the 4 cell types at doses yielding surviving fractions in the range of 0.01 to 0.5. Confidence intervals were in the range of 1.2 and 1.5. Similar RBE values were found for 50-kV x-rays from Dermopan for V79 (1.30, CI 1.25-1.36, P=.74) and GS4 (1.42, CI 1.30-1.54, P=.67). No significant dependence of RBE on dose was found for Intrabeam, but RBE decreased at a larger distance (12.7 mm; 9.8 Gy/h). Conclusions: An increased clinically relevant RBE was found for cell irradiation with Intrabeam at depths in the tumor bed targeted by IORT. The reduced RBE values at larger distances may be related to increased repair of sublethal damage during protracted irradiation or to hardening of the photon beam energy.

Optically stimulated luminescence in x-ray irradiated xSnO-(25-x)SrO-75B2O3 glass

Science.gov (United States)

Nanto, H.; Nakagawa, R.; Takei, Y.; Hirasawa, K.; Miyamoto, Y.; Masai, H.; Kurobori, T.; Yanagida, T.; Fujimoto, Y.

2015-06-01

An intense optically stimulated luminescence (OSL) was observed, for the first time, in x-ray irradiated xSnO-(25-x)SrO-75B2O3 glass. It was found that the peak wavelength of OSL emission spectrum and its stimulation spectrum is about 400 nm and 600 nm, respectively. The OSL intensity is depended on the SnO contents (x=0.05-1.5) and the most intense OSL was observed in 1.0 mol% SnO doped glass. It was found that the OSL intensity is increased with increasing x-ray absorbed dose. Fairly good fading characteristics were observed in the x-ray irradiated glass, showing that this glass is useful as a candidate for OSL sensor materials for ionizing radiation monitoring.

DNA Damage Induction and Repair Evaluated in Human Lymphocytes Irradiated with X-Rays an Neutrons

International Nuclear Information System (INIS)

Niedzwiedz, W.; Cebulska-Wasilewska, A.

2000-12-01

The objective of this study was to evaluate the kinetic of the DNA damage induction and their subsequent repair in human lymphocytes exposed to various types of radiation. PBLs cells were isolated from the whole blood of two young healthy male subjects and one skin cancer patient, and than exposed to various doses of low LET X-rays and high LET neutrons from 252 Cf source. To evaluate the DNA damage we have applied the single cell get electrophoresis technique (SCGE) also known as the comet assay. In order to estimate the repair efficiency, cells, which had been irradiated with a certain dose, were incubated at 37 o C for various periods of time (0 to 60 min). The kinetic of DNA damage recovery was investigated by an estimation of residual DNA damage persisted at cells after various times of post-irradiation incubation (5, 10, 15, 30 and 60 min). We observed an increase of the DNA damage (reported as a Tail DNA and Tail moment parameters) in linear and linear-quadratic manner, with increasing doses of X-rays and 252 Cf neutrons, respectively. Moreover, for skin cancer patient (Code 3) at whole studied dose ranges the higher level of the DNA damage was observed comparing to health subjects (Code 1 and 2), however statistically insignificant (for Tail DNA p=0.056; for Tail moment p=0.065). In case of the efficiency of the DNA damage repair it was observed that after 1 h of post-irradiation incubation the DNA damage induced with both, neutrons and X-rays had been significantly reduced (from 65% to 100 %). Furthermore, in case of skin cancer patient we observed lover repair efficiency of X-rays induced DNA damage. After irradiation with neutrons within first 30 min, the Tail DNA and Tail moment decreased of about 50%. One hour after irradiation, almost 70% of residual and new formed DNA damage was still observed. In this case, the level of unrepaired DNA damage may represent the fraction of the double strand breaks as well as more complex DNA damage (i.e.-DNA or DNA

Effects of soft x-ray irradiation on cell ultrastructure

International Nuclear Information System (INIS)

Ford, T.W.; Page, A.M.; Stead, A.D.; Foster, G.F.

1993-01-01

The future of X-ray microscopy lies mainly in its potential for imaging fresh, hydrated biological material at a resolution superior to that of light microscopy. For the image to be accepted as representing the cellular organization of the living cell, it is essential that artifacts are not introduced as a result of the image collection system. One possible source of artifacts is cellular damage resulting from the irradiation of the material with soft X-rays. Cells of the unicellular alga Chlorella have been examined by transmission electron microscopy (TEM) following exposure to different doses of monochromatic (380eV) soft X-rays. Extreme ultrastructural damage has been detected following doses of 10 3 -10 4 Gy, in particular loss of cellular membranes such as the internal thylakoid membranes of the chloroplast. This is discussed in relation to dosage commonly used for imaging by soft X-ray microscopy

Development of X-ray photoelectron microscope with a compact X-ray source generated by line-focused laser irradiation

International Nuclear Information System (INIS)

Yamaguchi, N.; Takahashi, Z.; Nishimura, Y.; Watanabe, K.; Okamoto, Y.; Sakata, A.; Azuma, H.; Hara, T.

2005-01-01

A laboratory-sized X-ray photoelectron microscope was constructed using a compact X-ray source produced by line-focused laser irradiation. The system is a scanning type photoelectron microscope where X-ray beam is micro-focused via Schwarzschild optics. A compact laser-plasma X-ray source has been developed with a YAG laser, a line-focus lens assembly, an Al tape-target driver and a debris prevention system. The 13.1 nm X-ray was delivered along line plasma whose length was 0.6 or 11 mm with higher intensity than that from a point-focused source. The Schwarzschild optics having the designed demagnification of 224, which was coated with Mo/Si multilayers for 13.1 nm X-ray, was set on the beamline 1 m distant from the source. The electron energy analyser was a spherical capacitor analyser with the photoelectron image detection system that was suited for detection of vast photoelectrons excited by an X-ray pulse of ns-order duration. The spatial resolution less than 5 μm has been confirmed from the variation of As 3d electron intensity along the position of the GaAs sample coated with a photo-resist test pattern

Acute skin reactions observed in fractionated proton irradiation

International Nuclear Information System (INIS)

Arimoto, Takuro; Maruhashi, Noboru; Takada, Yoshihisa; Hayakawa, Yoshinori; Inada, Tetsuo; Kitagawa, Toshio

1989-01-01

Between May 1985 and July 1987, 49 skin reactions of 43 patients treated by proton irradiation were observed at the Particle Radiation Medical Science Center (PARMS), the University of Tsukuba. Taking the peak skin score as an endpoint, the radiobiological effects [relative biological effectiveness (RBE) and time-dose relationship] of the proton beam in multi-fractionated treatments were estimated. Factors influencing the skin dose, such as the prescribed tumor dose, tumor site, and number of applied fields, were also analyzed. The following conclusions regarding acute skin reactions to the clinical use of proton irradiation were obtained: 1) the physical skin-sparing effect of proton irradiation in single-field irradiation, especially in superficial regions, is not large compared with that of high-energy photon irradiation; 2) multidirectional proton irradiation significantly reduced the skin dose and severity of acute reasons; 3) the radiobiological effects of the proton beam, RBE and the time factor, estimated in human skin in multi-fractional treatment were slightly smaller than those of X-rays, i.e., 0.92 and -0.25±0.09, respectively. (author)

Characterization of X-ray irradiator RS-2000; Caracterizacao do irradiador de raios X RS-2000

Energy Technology Data Exchange (ETDEWEB)

Mazaro, Sarah Jessica; Pavoni, Juliana Fernandes [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Departamento de Fisica; Silva, Maelson do Nascimento; Bianchini, Adriano L.B.; Amaral, Leonardo Lira do, E-mail: sarahmazaro@yahoo.com.br [Universidade de Sao Paulo (HC/FMRP/USP), Ribeirao Preto, SP (Brazil). Hospital das Clinicas. Faculdade de Medicina. Servico de Radioterapia

2014-04-15

Gamma irradiators are being replaced by the x - rays ones which are more economical and have greater safety benefits compared to the radionuclide irradiators. Some tests are usually performed to ensure quality control while working with radiation, as constancy, linearity, repeatability, reproducibility, radiometric survey and security tests. Evaluating the technical parameters and the instrument and equipment performance quickly. The irradiator characterization determines its operation, by ensuring that the deposited dose is the one desired. This study aims to characterize x-rays irradiators through dosimetric tests. The equipment used in this study stable in dose rate free space and regularity for safety test. Furthermore, the measurements were reproducible with a maximum variation of 10% and the radiometric survey showed that the results are consistent with the exemption requirements of radiological protection described in regulatory position 3.01/001:2011. (author)

Evaluation of components of X-ray irradiated 7-valent pneumococcal conjugate vaccine and pneumococcal vaccine polyvalent and X-ray and gamma-ray irradiated acellular pertussis component of DTaP vaccine products

International Nuclear Information System (INIS)

May, J.C.; Rey, L.; Lee, C.-J.; Arciniega, Juan

2004-01-01

Samples of pneumococcal vaccine polyvalent, 7-valent pneumococcal conjugate vaccine, and two different diphtheria and tetanus toxoids and acellular pertussis vaccines adsorbed were irradiated with X-rays and/or gamma-rays (Co-60). Mouse IgG and IgM antibody responses (ELISA) for types 9V, 14, 18C, and 19F pneumococcal polysaccharides and conjugates indicated that the polysaccharides were more tolerant of the radiation than the conjugates. The mouse antibody response for the detoxified pertussis toxin (PT) antigen, filamentous hemagglutinin antigen (FHA), pertactin (PRN), and fimbriae types 2 and 3 (FIM) antigens for the appropriate vaccine type indicated that the antibody response was not significantly changed in the 25 kGy X-ray irradiated vaccines frozen in liquid nitrogen compared to the control vaccine

Evaluation of components of X-ray irradiated 7-valent pneumococcal conjugate vaccine and pneumococcal vaccine polyvalent and X-ray and gamma-ray irradiated acellular pertussis component of DTaP vaccine products

Energy Technology Data Exchange (ETDEWEB)

May, J.C. E-mail: may@cber.fda.gov; Rey, L. E-mail: louis.rey@bluewin.ch; Lee, C.-J.; Arciniega, Juan

2004-10-01

Samples of pneumococcal vaccine polyvalent, 7-valent pneumococcal conjugate vaccine, and two different diphtheria and tetanus toxoids and acellular pertussis vaccines adsorbed were irradiated with X-rays and/or gamma-rays (Co-60). Mouse IgG and IgM antibody responses (ELISA) for types 9V, 14, 18C, and 19F pneumococcal polysaccharides and conjugates indicated that the polysaccharides were more tolerant of the radiation than the conjugates. The mouse antibody response for the detoxified pertussis toxin (PT) antigen, filamentous hemagglutinin antigen (FHA), pertactin (PRN), and fimbriae types 2 and 3 (FIM) antigens for the appropriate vaccine type indicated that the antibody response was not significantly changed in the 25 kGy X-ray irradiated vaccines frozen in liquid nitrogen compared to the control vaccine.

X-ray photoelectron spectra of γ-irradiated perfluorobenzene

International Nuclear Information System (INIS)

Sunder, S.; Sagert, N.H.; Wood, D.D.; Miller, N.H.

1990-01-01

The effect of γ-radiolysis on perfluorobenzene (PFB) was investigated using low-temperature X-ray photoelectron spectroscopy (XPS). PFB was irradiated in fluorine-passivated nickel cells using Co 60 γ-rays in an Atomic Energy of Canada Limited Gammacell at a dose rate of about 2.6 Gy·s -1 and for a total dose of about 50 kGy. The γ-radiolysis of PFB not only results in cross-linkage but also in the formation of saturated carbon centers in the PFB, as indicated by the presence of CF 2 and CF 3 groups. The relative abundance of CF, CF 2 and CF 3 groups, in the irradiated PFB, was estimated to be about 86, 9 and 5%, respectively

Effects of X-ray irradiation to genetic transformation of Eruca sativa Mill mediated by agrobacterium rhizogenes

International Nuclear Information System (INIS)

Wu Zhenhua; Zhang Hong; Liu Bin; Li Ning; Niu Bingtao; Wang Genxuan; Li Sha; Sun Peng

2008-01-01

To investigate the effects of X-ray irradiation to the hairy root induction of Eruca sativa Mill, and to provide basic experimental data for concerted reaction of irradiation to the Genetic transformation technology. The aseptic cotyledons of Eruca sativa Mill were jointly treated with the X-ray at dose of 5, 10, 15, 20 Gy respectively and the different infected time, then the influence of explant age, pre-culturing time, dose of X-ray and infected time were studied. Furthermore, the hairy roots were testified in molecular level by the polymerase chain reaction(PCR). The irradiation of X-ray at dose of 15 Gy can improve the frequency of Eruca sativa Mill hairy root induction in a dose-dependent manner. Moreover, the transformation frequency in pre-infection plus irradiation group is higher than that in pre-irradiation plus infection group at the same irradiation dose. In addition, the PCR analysis also demonstrated that rolB gene of T-DNA from Ri plasmid had been integrated into the genome of the transformed roots. The irradiation of X-ray has some positive effects on the hairy root induction of Eruca sativa Mill, and the optimal revulsive dose is 15 Gy ora little bit more. (authors)

X-ray luminescence computed tomography imaging via multiple intensity weighted narrow beam irradiation

Science.gov (United States)

Feng, Bo; Gao, Feng; Zhao, Huijuan; Zhang, Limin; Li, Jiao; Zhou, Zhongxing

2018-02-01

The purpose of this work is to introduce and study a novel x-ray beam irradiation pattern for X-ray Luminescence Computed Tomography (XLCT), termed multiple intensity-weighted narrow-beam irradiation. The proposed XLCT imaging method is studied through simulations of x-ray and diffuse lights propagation. The emitted optical photons from X-ray excitable nanophosphors were collected by optical fiber bundles from the right-side surface of the phantom. The implementation of image reconstruction is based on the simulated measurements from 6 or 12 angular projections in terms of 3 or 5 x-ray beams scanning mode. The proposed XLCT imaging method is compared against the constant intensity weighted narrow-beam XLCT. From the reconstructed XLCT images, we found that the Dice similarity and quantitative ratio of targets have a certain degree of improvement. The results demonstrated that the proposed method can offer simultaneously high image quality and fast image acquisition.

In vitro X-ray irradiation of human peripheral blood T lymphocytes enhances suppressor function

International Nuclear Information System (INIS)

Ogawa, H.; Tsunematsu, T.

1983-01-01

The effect of in vitro X-ray irradiation on human peripheral blood T lymphocytes was studied with regard to their suppressor activity related to the concanavalin A (Con A)-induced suppressor system. To generate suppressor T lymphocytes, purified human T lymphocytes were incubated for 3 days in the first culture, with or without Con A. These lymphocytes were irradiated with various doses of X-ray before, mid or after the culture. After doing a second culture for 6 days, the suppressive influence of these cells on T lymphocyte proliferation rates stimulated with allogeneic mononuclear cells, and B lymphocyte proliferation rates stimulated with pokeweed mitogen was measured. Irradiation of cultures to which Con A had not been added induced much the same level of suppressor activity as seen in the cultures with Con A. The suppressor activity gradually increased with time from the irradiation to the suppressor cell assay. Suppressor T lymphocytes were resistant to X-ray irradiation and independent of DNA synthesis. However, irradiation-induced enhancement was minimal in cultures incubated with con A, regardless of the irradiation time. (author)

Modeling of finite systems irradiated by intense ultrashort hard X-ray pulses

Energy Technology Data Exchange (ETDEWEB)

Jurek, Zoltan [Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron, Notkestrasse 85, D-22607 Hamburg (Germany); Ziaja, Beata [Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron, Notkestrasse 85, D-22607 Hamburg (Germany); Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342 Krakow (Poland); Santra, Robin [Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron, Notkestrasse 85, D-22607 Hamburg (Germany); Department of Physics, University of Hamburg, Jungiusstrasse 9, 20355 Hamburg (Germany)

2013-07-01

Large number of experiments have already been carried out at the existing hard X-Ray Free-Electron Laser facilities (LCLS, SACLA) during the recent years. Their great success generates even higher anticipation for the forthcoming X-ray sources (European XFEL). Single molecule imaging and nanoplasma formation are the challenging projects with XFELs that investigate the interaction of finite, small objects, e.g. single molecules, atomic clusters with intense X-ray radiation. Accurate modelling of the time evolution of such irradiated systems is required in order to understand the current experiments and to inspire new directions of experimental investigation. In this presentation we report on our theoretical molecular-dynamics tool able to follow non-equilibrium dynamics within finite systems irradiated by intense X-ray pulses. We introduce the relevant physical processes, present computational methods used, discuss their limitations and also the specific constraints on calculations imposed by experimental conditions. Finally, we conclude with a few simulation examples.

Radiation-Induced Bystander Effects in A549 Cells Exposed to 6 MV X-rays.

Science.gov (United States)

Yang, Shuning; Xu, Jing; Shao, Weixian; Geng, Chong; Li, Jia; Guo, Feng; Miao, Hui; Shen, Wenbin; Ye, Tao; Liu, Yazhou; Xu, Haiting; Zhang, Xuguang

2015-07-01

The aim of the study is to explore the bystander effects in A549 cells that have been exposed to 6MV X-ray. Control group, irradiated group, irradiated conditioned medium (ICM)-received group, and fresh medium group were designed in this study. A549 cells in the logarithmic growth phase were irradiated with 6MV X-ray at 0, 0.5, 1, 1.5, and 2. In ICM-received group, post-irradiation A549 cells were cultured for 3 h and were transferred into non-irradiated A549 cells for further cultivation. Clone forming test was applied to detect the survival fraction of cells. Annexin V-FITC/PI double-staining assay was used to detect the apoptosis of A549 cells 24, 48, 72, and 96 h after 2-Gy 6MV X-ray irradiation, and the curves of apoptosis were drawn. The changes in the cell cycles 4, 48, 72, and 96 h after 2-Gy 6MV X-ray irradiation were detected using PI staining flow cytometry. With the increase of irradiation dose, the survival fraction of A549 cells after the application of 0.5 Gy irradiation was decreasing continuously. In comparison to the control group, the apoptosis rate of the ICM-received group was increased in a time-dependent pattern, with the highest apoptosis rate observed at 72 h (p X-ray irradiation can induce bystander effect on A549 cells, which reaches a peak at 72 h.

Mucosal pathology of an experimental otitis media with effusion after X-ray irradiation

International Nuclear Information System (INIS)

Ohashi, Y.; Nakai, Y.; Ikeoka, H.; Esaki, Y.; Koshimo, H.; Onoyama, Y.

1987-01-01

Ten guinea pigs were irradiated with 30 Gy of x-radiation. Five were killed on the eighth day after irradiation, and the remainder were killed at the sixteenth day after irradiation. At the time of death, examination was made of the ciliary activity and the fine structure of the middle ear mucosa. Serous effusion was found in each tympanic cavity of all animals. It was shown also that the guinea pig, when irradiated with 30 Gy of x-radiation, exhibits pathologic abnormalities similar to those in humans with otitis media with effusion: degeneration of cilia or ciliated cells and changes in the vascular system (capillary injury and increased capillary permeability). Functional examinations showed that x-ray irradiation has delayed effects on ciliary activity, and the effects are much greater at the sixteenth day than at the eighth day. We speculate that the accumulation of effusion can be, at least partially, a consequence of ciliary dysfunction. The induction of sterile effusion by the use of x-ray irradiation provides a unique animal model for chronic otitis media with effusion of the serous type

Elimination of radical on the x-ray irradiated hydroxyapatite compounds

International Nuclear Information System (INIS)

Ohta, M.; Yasuda, M.; Miyazawa, C.; Okamura, H.; Suzuki, Y.

2002-01-01

We investigate the elimination of radical produced in a human tooth and synthetic calcium-deficient hydroxyapatite compounds after X-ray irradiation. Used samples were enamel and dentine of a human tooth and synthetic calcium-deficient hydroxyapatite (DAp), and stoichiometric hydroxyapatite (HAp). The ESR signal intensities at nearly g = 2 in the samples after X-ray irradiation were proportional to the absorbed dose in the range from 6 to 39 Gy. And these ESR signal intensities of the samples soaked in various ion containing fluids decreased with soaking time. Especially, the decrease in these ESR signal intensities was remarkably large in the samples soaked in Na 2 HPO 4 aqueous solution. This fact suggests that the surface layer of the samples easily dissolves in ion containing fluids

Effect of propolis feeding on rat tissues damaged by X-ray irradiation

Energy Technology Data Exchange (ETDEWEB)

Lee, Ji Hoon; Seo, Eul Won [Andong National Univ., Andong (Korea, Republic of); Ji, Tae Jeong [Kaya Univ., Goryeong (Korea, Republic of)

2007-06-15

Present study aimed to investigate the radioprotective effects of propolis feeding on rat tissues damaged by X-ray irradiation. It was shown that the number of white blood cell in X-ray irradiated group supplemented with propolis increased as much to those of the control group and also the GOT activities among the blood components were decreased after propolis feeding. The mineral contents such as Mg, Fe, Ca, Mn, Cu, Mo, Ni, As in liver were increased as compared with those of the control group but maintained lower level than those of only irradiated groups, implying that the propolis feeding elevated the recovery capability of white blood cell effectively and propolis have a potential resistance to cell damage by X-ray. According to histological observations of the testis, intestine and liver tissues which are irradiated after feeding propolis, the numbers of damaged undifferentiated cells were decreased in testis and the shape of the goblet cells and inner and outer muscular layers in intestine were restored to the original state and the hepatocytes and interlobular veins were shown intact in liver, suggesting that propolis has a potential capacity to restore cell shapes or resist deformation of cell.

High linolenic acid mutant in soybean induced by X-ray irradiation

Energy Technology Data Exchange (ETDEWEB)

Takagi, Y. [Saga Univ. (Japan); Hossain, A. B.M.M.; Yanagita, T.; Kusaba, S.

1989-12-15

Soybean [Glycine max (L.) Merr. cv. Bay] seeds were irradiated with X-rays (25kR) and the M{sub 2} progeny was screened for changes in the fatty acid composition of seed oil. X-ray irradiation remarkably increased the variability of the fatty acid composition in the oil of the Bay cultivar. A mutant in which linolenic acid accounted for 18.4 per cent of the total oil cornpared with 9.4 per cent in the Bay cultivar was identified among 2006 M{sub 2} plants. The M{sub 3} generation of the mutant also showed a linolenic acid content approximately two times higher than that of the original variety.

High linolenic acid mutant in soybean induced by X-ray irradiation

International Nuclear Information System (INIS)

Takagi, Y.; Hossain, A.B.M.M.; Yanagita, T.; Kusaba, S.

1989-01-01

Soybean [Glycine max (L.) Merr. cv. Bay] seeds were irradiated with X-rays (25kR) and the M 2 progeny was screened for changes in the fatty acid composition of seed oil. X-ray irradiation remarkably increased the variability of the fatty acid composition in the oil of the Bay cultivar. A mutant in which linolenic acid accounted for 18.4 per cent of the total oil cornpared with 9.4 per cent in the Bay cultivar was identified among 2006 M 2 plants. The M 3 generation of the mutant also showed a linolenic acid content approximately two times higher than that of the original variety

Effects of proton irradiation on structure of NdFeB permanent magnets studied by X-ray diffraction and X-ray absorption fine structure

International Nuclear Information System (INIS)

Yang, L.; Zhen, L.; Xu, C.Y.; Sun, X.Y.; Shao, W.Z.

2011-01-01

The effects of proton irradiation on the structure of NdFeB permanent magnet were investigated by X-ray diffraction and X-ray absorption fine structure (XAFS). The results reveal that proton irradiation has no effect on the long-range structure, but significantly affects the atomic local structure of the NdFeB magnet. The alignment degree of the magnet decreases and the internal stress of the lattice increases after proton irradiation. XAFS results show that the coordination number of Fe-Nd in the first neighboring coordination shell of the Fe atoms decreases and the disorder degree increases.

Effects of proton irradiation on structure of NdFeB permanent magnets studied by X-ray diffraction and X-ray absorption fine structure

Energy Technology Data Exchange (ETDEWEB)

Yang, L. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Zhen, L., E-mail: lzhen@hit.edu.c [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Xu, C.Y.; Sun, X.Y.; Shao, W.Z. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China)

2011-01-15

The effects of proton irradiation on the structure of NdFeB permanent magnet were investigated by X-ray diffraction and X-ray absorption fine structure (XAFS). The results reveal that proton irradiation has no effect on the long-range structure, but significantly affects the atomic local structure of the NdFeB magnet. The alignment degree of the magnet decreases and the internal stress of the lattice increases after proton irradiation. XAFS results show that the coordination number of Fe-Nd in the first neighboring coordination shell of the Fe atoms decreases and the disorder degree increases.

Influence of fractionation of dose on 3 year results of X-ray therapy of skin cancer

International Nuclear Information System (INIS)

Szymczyk, W.; Radziszewska, J.; Cyplik, I.; Glinska, H.

1985-01-01

Three-year results of X-ray therapy of skin cancer in 345 patients are presented. The dependence of results on the size of irradiated field and the method of dose fractionation is analysed. The clinical usefulness of a cumulative radiation effect (CRE) is evaluated. 96.5% of three-year cures were obtained. Recurrences amounted to 1.6% and necroses to 1.9% of treated lesions. It has been shown that treatment of small fields with 8-fractions gave equally positive results as with 15-fractions whereas in the treatment of large lesions the selection of CRE value, a number of fractions and dose should let the value of CRE minimally exceeds the level of tolerance of healthy tissues. The regard to CRE value in the treatment of large lesions or the introduction of additional dosimetric acts seems to be useful. 10 refs., 1 fig., 5 tabs. (author)

Analysis of microstress in neutron irradiated polyester fibre by X-ray ...

Indian Academy of Sciences (India)

Unknown

Abstract. Microstresses developed in the crystallites of polymeric material due to irradiation of high-energy particle causes peak broadening and shifting of X-ray diffraction lines to lower angle. Neutron irradiation significantly changes the material properties by displacement of lattice atoms and the generation of helium.

Proliferation and clonal survival of human lung cancer cells treated with fractionated irradiation in combination with paclitaxel

International Nuclear Information System (INIS)

Rijn, Johannes van; Berg, Jaap van den; Meijer, Otto W.M.

1995-01-01

Purpose: This study was performed to determine the effects of a continuous exposure to paclitaxel (taxol) in combination with fractionated irradiation on cell proliferation and survival. Methods and Materials: Human lung carcinoma cells (SW1573) were given a daily treatment with 3 Gy of x-rays during 5 days in the continuous presence of 5 nM taxol. The surviving fraction and the total number of cells were determined every 24 h before and immediately after irradiation. Results: Irradiation with 5 x 3 Gy and 5 nM taxol cause approximately the same inhibition of cell proliferation. In combination these treatments have an additional effect and the cell population increases no further after the first 24 h. Whereas the cells become more resistant to taxol after the first 24 h with a minimum survival of 42%, taxol progressively reduces the population of surviving cells in combination with x-rays when the number of fractions increases, up to 25-fold relative to irradiation alone. The enhancement effect of 5 nM taxol is likely to be attributed to an inhibition of the repopulation during fractionated irradiation and not to an increased radiosensitivity. Only after treatment with 10 or 100 nM taxol for 24 h, which is attended with a high cytotoxicity, is moderate radiosensitization observed. Conclusion: Taxol, continuously present at a low concentration with little cytotoxicity, causes a progressive reduction of the surviving cell population in combination with fractionated irradiation, mainly by an inhibition of the repopulation of surviving cells between the dose fractions

Radioprotective effect of chitosan in sub-lethally X-ray irradiated mice

Energy Technology Data Exchange (ETDEWEB)

Nishimura, Yoshikazu; Ikota, Nobuo; Arima, Hiromi; Watanabe, Yoshito; Yukawa, Masae; Ozawa, Toshihiko [National Inst. of Radiological Sciences, Chiba (Japan); Kim, Hee-Sun [Korea Hydro and Nuclear Power Corp., Seoul (Korea, Republic of). Radiation Health Research Inst.; Bom, Hee-Seung; Kim, Young-Ho [Chonnam Univ., Kwangju (Korea, Republic of). Hospital

2003-03-01

The radioprotective effect of chitosan was studied in mice following whole-body X-ray irradiation. C3H/He mice were exposed to 7 Gy, and their survival rates were examined. The survival rates of chitosan-diet mice were about 20% higher than those of mice on a standard diet, and the rates dropped sharply to a plateau at day 10 after X-ray irradiation. The chitosan-diet mice had an increased weight ratio of spleen to body within the experimental period. The leukocyte, thrombocyte, and erythrocyte counts as well as the hematocrit and hemoglobin levels were recovered significantly and more rapidly in the chitosan-diet mice than the standard-diet mice at day 14 after irradiation. The scavenging abilities of chitosan were evaluated by the electron spin resonance (ESR) spin-trapping method. These observations suggested that chitosan led to hematopoetic activation and leuko-cytogenesis in mice after sub-lethal dose irradiation, and that the biological response might be caused by radical trapping or scavenging. (author)

X-ray geometrical smoothing effect in indirect x-ray-drive implosion

International Nuclear Information System (INIS)

Mochizuki, Takayasu; Sakabe, Shuji; Yamanaka, Chiyoe

1983-01-01

X-ray geometrical smoothing effect in indirect X-ray drive pellet implosion for inertial confinement fusion has been numerically analyzed. Attainable X-ray driven ablation pressure has been found to be coupled with X-ray irradiation uniformity. (author)

In-situ measurement of the strain relaxation of GaN nanograins during X-ray irradiation

International Nuclear Information System (INIS)

Choe, Hyeokmin; Lee, Sanghwa; Sohn, Yuri; Kim, Chinkyo

2008-01-01

GaN nanograins were grown on a c-plane sapphire substrate and their strain relaxation due to X-ray irradiation was investigated in-situ by utilizing synchrotron xray scattering. The GaN nanograins were constantly exposed to the synchrotron X-ray and θ-2θ scans through the (002) Bragg peak of GaN were repeatedly carried out during the irradiation. The Bragg peak of the compressively strained GaN nanograins gradually shifted toward higher angle, which implies that the GaN nanograins in compressive strain experienced strain relaxation during X-ray irradiation. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Skin reactions of rat feet exposed to multiple fractions of X rays per day

International Nuclear Information System (INIS)

Rongen, E. van

1983-01-01

The right hind feet of female WAG/Rij rats were irradiated with multiple fractions per day (4 x 2 Gy daily), with daily fractions of 3 Gy and with single doses of 300 kV X-rays. Acute reactions were scored 5 times per week until the reactions disappeared. Mean scores were derived from the 7-day period encompassing the peak reaction. The mean scores for the acute reactions are presented. Tolerance doses, defined as the total doses resulting in one small area of moist desquamation in 50% of the animals, as calculated by probit analysis are 55.7 +- 0.7 Gy for the 4 x 2 Gy per day scheme and 67.3 +- 2.9 Gy for the 3 Gy per day scheme. It can be seen that, when increasing the total dose above the tolerance dose, the mean reaction to the 3 Gy per day regimen reaches a plateau (corresponding to 10 to 40% moist desquamation of the sole of the foot), while the reaction to the 4 x 2 Gy per day regimen increases to the maximum, i.e., moist desquamation of the entire foot. These differences can be attributed to differences in repair of sublethal damage and repopulation. (Auth.)

Mathematical modeling predicts enhanced growth of X-ray irradiated pigmented fungi.

Directory of Open Access Journals (Sweden)

Igor Shuryak

Full Text Available Ionizing radiation is known for its cytotoxic and mutagenic properties. However, recent evidence suggests that chronic sub-lethal irradiation stimulates the growth of melanin-pigmented (melanized fungi, supporting the hypothesis that interactions between melanin and ionizing photons generate energy useful for fungal growth, and/or regulate growth-promoting genes. There are no quantitative models of how fungal proliferation is affected by ionizing photon energy, dose rate, and presence versus absence of melanin on the same genetic background. Here we present such a model, which we test using experimental data on melanin-modulated radiation-induced proliferation enhancement in the fungus Cryptococcus neoformans, exposed to two different peak energies (150 and 320 kVp over a wide range of X-ray dose rates. Our analysis demonstrates that radiation-induced proliferation enhancement in C. neoformans behaves as a binary "on/off" phenomenon, which is triggered by dose rates 5000 mGy/h. Proliferation enhancement of irradiated cells compared with unirradiated controls occurs at both X-ray peak energies, but its magnitude is modulated by X-ray peak energy and cell melanization. At dose rates <5000 mGy/h, both melanized and non-melanized cells exposed to 150 kVp X-rays, and non-melanized cells exposed to 320 kVp X-rays, all exhibit the same proliferation enhancement: on average, chronic irradiation stimulates each founder cell to produce 100 (95% CI: 83, 116 extra descendants over 48 hours. Interactions between melanin and 320 kVp X-rays result in a significant (2-tailed p-value = 4.8 × 10(-5 additional increase in the number of radiation-induced descendants per founder cell: by 55 (95% CI: 29, 81. These results show that both melanin-dependent and melanin-independent mechanisms are involved in radiation-induced fungal growth enhancement, and implicate direct and/or indirect interactions of melanin with high energy ionizing photons as an important pro

The influence of x-ray energy on lung dose uniformity in total-body irradiation

International Nuclear Information System (INIS)

Ekstrand, Kenneth; Greven, Kathryn; Wu Qingrong

1997-01-01

Purpose: In this study we examine the influence of x-ray energy on the uniformity of the dose within the lung in total-body irradiation treatments in which partial transmission blocks are used to control the lung dose. Methods and Materials: A solid water phantom with a cork insert to simulate a lung was irradiated by x-rays with energies of either 6, 10, or 18 MV. The source to phantom distance was 3.9 meters. The cork insert was either 10 cm wide or 6 cm wide. Partial transmission blocks with transmission factors of 50% were placed anterior to the cork insert. The blocks were either 8 or 4 cm in width. Kodak XV-2 film was placed in the midline of the phantom to record the dose. Midplane dose profiles were measured with a densitometer. Results: For the 10 cm wide cork insert the uniformity of the dose over 80% of the block width varied from 6.6% for the 6 MV x-rays to 12.2% for the 18 MV x-rays. For the 6 cm wide cork insert the uniformity was comparable for all three x-ray energies, but for 18 MV the central dose increased by 9.4% compared to the 10 cm wide insert. Conclusion: Many factors must be considered in optimizing the dose for total-body irradiation. This study suggests that for AP/PA techniques lung dose uniformity is superior with 6 MV irradiation. The blanket recommendation that the highest x-ray energy be used in TBI is not valid for all situations

Effect of x-ray irradiation on maize inbred line B73 tissue cultures and regenerated plants

International Nuclear Information System (INIS)

Wang, A.S.; Cheng, D.S.K.; Milcic, J.B.; Yang, T.C.

1988-01-01

In order to enhance variation induced by the tissue culture process and to obtain agronomically desirable mutants, friable embryogenic tissue cultures of maize (Zea mays L.) inbred line B73 were x-ray irradiated with 11 doses [0-8.4 kilorads (kR)]. Reductions in callus growth rate and embryogenic callus formation occurred with increasing x-ray doses 20 d and 3 months after irradiation. Callus irradiated with 0.8 kR showed a significant increase in growth rate and a 20% increase in embryogenic callus 9 months after irradiation. A total of 230 R 0 plants were regenerated for evaluation. Pollen fertility and seed set of R 0 plants decreased with increasing x-ray dosage. Days to anthesis and plant height of R 0 plants varied among x-ray treatments but were generally reduced with higher dosages. The number of chromosomal aberrations increased with x-ray dosage. The R 1 seeds taken from R 0 plants were also grown and tested for mutant segregation. Plants regenerated from irradiated calli had a two- to 10-fold increase in mutations over plants regenerated from unirradiated control callus. Germination frequency of seeds from R 0 plants decreased with increasing x-ray dosage. Although chlorophyll mutants were most frequently observed, a number of vigorous plants with earlier anthesis date were also recovered

Radioprotective effects of melatonin on carbon-ion and X ray irradiation in mice

International Nuclear Information System (INIS)

Saito, Masayoshi; Kawata, Tetsuya; Liu, C.; Sakurai, Akiko; Ito, Hisao; Ando, Koichi

2004-01-01

The radioprotective ability of melatonin was investigated in C3H mice irradiated to a whole-body X-ray (150 Kv, 20 mA) and carbon-ion (290 MeV/u). Mice exposed to X-ray, 13 KeV/μm and 50 KeV/μm carbon-ion dose of 7.0-7.5 Gy, 6.5-7.25 Gy and 6.0-6.5 Gy, respectively. One hour before the irradiation, mice were given an intraperitoneal injection of 0.2 ml of either solvent (soybean oil) or melatonin (250 mg/kg, uniform suspension in soybean oil). Mice were observed for mortality over a period of 30 days following irradiation. Results obtained the first year are as follows. The toxicity of melatonin (at a dose 250 mg/kg) intraperitoneal administered to mice could not be observed. A pretreatment of melatonin is effective in protecting mice from lethal damage of low-linear energy transfer (LET) irradiation (X-ray and 13 KeV/μm carbon-ion). In the high-LET irradiated mice with 50 KeV/μm carbon-ion, melatonin exhibited a slight increase in their survival. (author)

The performance of the anthraquinone/p-Si and the pyridine/p-Si rectifying device under X-ray irradiation

International Nuclear Information System (INIS)

Şahin, Yılmaz; Aydoğan, Şakir; Ekinci, Duygu; Turut, Abdulmecit

2016-01-01

Some X-ray irradiation-induced electrical characteristics of the Au/anthraquinone/p-Si and the Au/pyridine/p-Si junction devices have been investigated. The experimental ideality factors increased for both devices with increasing irradiation dose from 25 Gy to 150 Gy. These values ranged from 1.10 to 1.52 for Au/anthraquinone/p-Si and from 1.46 to 1.77 for Au/pyridine/p-Si, respectively. Furthermore, the barrier height of Au/anthraquinone/p-Si increased with increasing irradiation dose from 0.75 to 0.91 eV, whereas it displayed about a constant value for Au/pyridine/p-Si. In addition, the series resistance of both devices increased with x-ray dose too. The increase in the series resistance with x-ray irradiation has been attributed to the decrease in the active dopant densities. It was seen that the ionization damage is effective on most of the junction characteristics. The leakage current of the Au/anthraquinone/p-Si device decreased with x-ray irradiation since the irradiation induced the formation of electron-hole pairs and hydroquinone structure, and thus some of them are trapped by the interface states. The degradation of the I-V curves of Au/pyridine/p-Si/Al device is attributed to the variation of the surface or interface states distribution for the devices. The reverse and forward bias currents relatively increased after x-ray irradiation because of the decrease in bulk lifetime. In addition, ATR-FTIR spectra of anthraquinone and pyridine films showed that pyridine is more stable than anthraquinone under x-ray irradiation. - Highlights: • Two junction devices based on organic materials were fabricated. • The effect of the x-ray irradiation on devices were examined. • Both devices showed x-irradiation-dependence.

The performance of the anthraquinone/p-Si and the pyridine/p-Si rectifying device under X-ray irradiation

Energy Technology Data Exchange (ETDEWEB)

Şahin, Yılmaz [Department of Physics, Faculty of Sciences, University of Atatürk, 25240 Erzurum (Turkey); Aydoğan, Şakir, E-mail: saydogan@atauni.edu.tr [Department of Physics, Faculty of Sciences, University of Atatürk, 25240 Erzurum (Turkey); Ekinci, Duygu [Department of Chemistry, Faculty of Sciences, University of Atatürk, 25240 Erzurum (Turkey); Turut, Abdulmecit [Department of Engineering Physics, Faculty of Sciences, Istanbul Medeniyet University (Turkey)

2016-11-01

Some X-ray irradiation-induced electrical characteristics of the Au/anthraquinone/p-Si and the Au/pyridine/p-Si junction devices have been investigated. The experimental ideality factors increased for both devices with increasing irradiation dose from 25 Gy to 150 Gy. These values ranged from 1.10 to 1.52 for Au/anthraquinone/p-Si and from 1.46 to 1.77 for Au/pyridine/p-Si, respectively. Furthermore, the barrier height of Au/anthraquinone/p-Si increased with increasing irradiation dose from 0.75 to 0.91 eV, whereas it displayed about a constant value for Au/pyridine/p-Si. In addition, the series resistance of both devices increased with x-ray dose too. The increase in the series resistance with x-ray irradiation has been attributed to the decrease in the active dopant densities. It was seen that the ionization damage is effective on most of the junction characteristics. The leakage current of the Au/anthraquinone/p-Si device decreased with x-ray irradiation since the irradiation induced the formation of electron-hole pairs and hydroquinone structure, and thus some of them are trapped by the interface states. The degradation of the I-V curves of Au/pyridine/p-Si/Al device is attributed to the variation of the surface or interface states distribution for the devices. The reverse and forward bias currents relatively increased after x-ray irradiation because of the decrease in bulk lifetime. In addition, ATR-FTIR spectra of anthraquinone and pyridine films showed that pyridine is more stable than anthraquinone under x-ray irradiation. - Highlights: • Two junction devices based on organic materials were fabricated. • The effect of the x-ray irradiation on devices were examined. • Both devices showed x-irradiation-dependence.

Effect of X-ray irradiation on the physical and chemical quality of ...

African Journals Online (AJOL)

The use of irradiation as a phytosanitary treatment has expanded in recent years. It plays important roles in developed and developing countries, facilitating international trade in irradiated fresh fruit. To evaluate the potential of X-ray irradiation as a quarantine treatment for America red globe grapes, we investigated the ...

Feasibility of using continuous X-ray to simulate cable response under X-ray environment

International Nuclear Information System (INIS)

Ma Liang; Zhou Hui; Cheng Yinhui; Wu Wei; Li Jinxi; Zhao Mo; Guo Jinghai

2014-01-01

The mechanism and simulating method of cable response induced by X-ray were researched, and the relationship of cable response irradiated by continuous and pulsed X-ray was analyzed. A one-dimension model of strip line irradiation response of X-ray was given, which includes the gap between cable shield and dielectric, and induced conductivity in cable dielectric. The calculation result using the model indicates that the cable responses of continuous and rectangular-pulsed X-ray have the similar current waveform and the same gap voltages. Therefore, continuous X-ray can be used to research some cable responses of pulsed X-ray irradiation under the mechanism described in the one-dimension model. (authors)

Larval x-ray irradiation influences protein expression in pupae of the Oriental fruit fly, Bactrocera Dorsalis

Science.gov (United States)

Third instar larvae were exposed to X-ray treatment of the Oriental fruit fly, Bactrocera dorsalis. Irradiated pupae were collected daily. Biological performance parameters of pupae and adults of larvae treated with X-ray irradiation were evaluated. Standard proteomics procedures such as densitometr...

Relationship between X-ray irradiation and chromosomal damage in bone marrow tissue of mice

International Nuclear Information System (INIS)

Chaubey, R.C.; George, K.P.; Sundaram, K.

1976-01-01

X-ray induced chromosomal damage in bone-marrow tissue of male mice was studied using micronucleus technique. Dose response relationship was evaluated. Male Swiss mice received whole body x-ray irradiation at different doses from 25-1000 rads. Animals were sacrificed at the end of 24 hours, bone-marrow smears were made and stained in May-Grunwald-Giemsa. The preparatians were scored for the following types of aberrations: micronuclei in young erythocytes-polychromatic cells and in the mature erythrocytes-normechromatic cells. A dose dependent increase in the frequency of micronuclei in polychromatic cells up to a dose of 100 rads was observed. In addition the effect of post-irradiation duration on the frequency of micronuclei in polychromatic and normochromatic cells were studied. Male Swiss mice were exposed to 200 rads x-rays and were then sacrificed at different time intervals after irradiation and bone-marrow preparations were made and scored. Maximum polychromatic cells with micronuclei were observed in 24 hours post-irradiated animals, thereafter a decrease in the frequency of polychromatic cells with micronuclei was observed in 40 hours post irradiated animals. (author

Electron and photon emissions from gold nanoparticles irradiated by X-ray photons

Energy Technology Data Exchange (ETDEWEB)

Casta, R., E-mail: castaromain@gmail.com, E-mail: romain.casta@irsamc.ups-tlse.fr; Champeaux, J.-P.; Moretto-Capelle, P.; Sence, M.; Cafarelli, P. [Université de Toulouse, UPS, Laboratoire Collisions Agrégats Réactivité, IRSAMC, CNRS, UMR 5589 (France)

2015-01-15

In this paper, we develop a totally new probabilistic model for the electron and photon emission of gold nanoparticles irradiated by X-ray photons. This model allows direct applications to recent researches about the radiotherapy enhancement by gold nanoparticles in the context of cancer treatment. Our model uses, in a complete original way, simulated Auger cascade and stopping power to compute electron emission spectra, photon emission spectra and released energy inside the material of gold nanoparticles. It allows us to present new results about the electron and photon emission of gold nanoparticle irradiated by hard X-rays.

Non-destructive test for irradiated fuels using X-ray CT system in hot-laboratory

International Nuclear Information System (INIS)

Kim, Heemoon; Kim, Gil-Soo; Yoo, Boung-Ok; Tahk, Young-Wook; Cho, Moon-Sung; Ahn, Sang-Bok

2015-01-01

To inspect inside of irradiated fuel rod for PIE in hotcell, neutron beam and X-ray have been used. Many hot laboratories in the world have shown the results for NDT by 2-D film data. Currently, computed image processing technology instead of film has been developed and CT was applied to the X-ray and neutron beam system. In this trend, our facility needed to set up X-ray system for irradiated fuel inspection and installed in hotcell with consideration of radiation damage. In this study, X-ray system was tested to be operated with radioactive samples and was performed to inspect fuel rods and observe internal damage and dimensional change. 450kV X-ray CT system was installed in hotcell with modification and tested to check image resolution and radiation damage. The image data were analyzed by 3-D computer software. 8 fuel plates and VHTR rods were inspected and measured internal shape and dimension

SOFT X-RAY IRRADIATION OF SILICATES: IMPLICATIONS FOR DUST EVOLUTION IN PROTOPLANETARY DISKS

Energy Technology Data Exchange (ETDEWEB)

Ciaravella, A.; Cecchi-Pestellini, C.; Jiménez-Escobar, A. [INAF—Osservatorio Astronomico di Palermo, P.za Parlamento 1, I-90134 Palermo (Italy); Chen, Y.-J.; Huang, C.-H. [Department of Physics, National Central University, Jhongli City, Taoyuan County 32054, Taiwan (China); Muñoz Caro, G. M. [Centro de Astrobiología (INTA-CSIC), Carretera de Ajalvir, km 4, Torrejón de Ardoz, E-28850 Madrid (Spain); Venezia, A. M., E-mail: aciaravella@astropa.unipa.it [ISMN—CNR, Via Ugo La Malfa 153, I-90146 Palermo (Italy)

2016-09-01

The processing of energetic photons on bare silicate grains was simulated experimentally on silicate films submitted to soft X-rays of energies up to 1.25 keV. The silicate material was prepared by means of a microwave assisted sol–gel technique. Its chemical composition reflects the Mg{sub 2}SiO{sub 4} stoichiometry with residual impurities due to the synthesis method. The experiments were performed using the spherical grating monochromator beamline at the National Synchrotron Radiation Research Center in Taiwan. We found that soft X-ray irradiation induces structural changes that can be interpreted as an amorphization of the processed silicate material. The present results may have relevant implications in the evolution of silicate materials in X-ray-irradiated protoplanetary disks.

MeV single-ion beam irradiation of mammalian cells using the Surrey vertical nanobeam, compared with broad proton beam and X-ray irradiations

Energy Technology Data Exchange (ETDEWEB)

Prakrajang, K. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Faculty of Science, Maejo University, Chiang Mai 50290 (Thailand); Jeynes, J.C.G.; Merchant, M.J.; Kirkby, K.; Kirkby, N. [Surrey Ion Beam Center, Faculty of Engineering and Physical Science, University of Surrey, Guildford Surrey, GU2 7XH (United Kingdom); Thopan, P. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, L.D., E-mail: yuld@fnrf.science.cmu.ac.th [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

2013-07-15

Highlights: •Recently completed nanobeam at the Surrey Ion Beam Centre was used. •3.8-MeV single and broad proton beams irradiated Chinese hamster cells. •Cell survival curves were measured and compared with 300-kV X-ray irradiation. •Single ion irradiation had a lower survival part at ultra-low dose. •It implies hypersensitivity, bystander effect and cell cycle phase of cell death. -- Abstract: As a part of a systematic study on mechanisms involved in physical cancer therapies, this work investigated response of mammalian cells to ultra-low-dose ion beam irradiation. The ion beam irradiation was performed using the recently completed nanobeam facility at the Surrey Ion Beam Centre. A scanning focused vertical ion nano-beam was applied to irradiate Chinese hamster V79 cells. The V79 cells were irradiated in two different beam modes, namely, focused single ion beam and defocused scanning broad ion beam of 3.8-MeV protons. The single ion beam was capable of irradiating a single cell with a precisely controlled number of the ions to extremely low doses. After irradiation and cell incubation, the number of surviving colonies as a function of the number of the irradiating ions was measured for the cell survival fraction curve. A lower survival for the single ion beam irradiation than that of the broad beam case implied the hypersensitivity and bystander effect. The ion-beam-induced cell survival curves were compared with that from 300-kV X-ray irradiation. Theoretical studies indicated that the cell death in single ion irradiation mainly occurred in the cell cycle phases of cell division and intervals between the cell division and the DNA replication. The success in the experiment demonstrated the Surrey vertical nanobeam successfully completed.

Activation and inactivation of Bacillus pumilus spores by kiloelectron volt X-ray irradiation.

Directory of Open Access Journals (Sweden)

Thi Mai Hoa Ha

Full Text Available In this study, we investigated the inactivation efficacy of endospore-forming bacteria, Bacillus pumilus, irradiated by low-energy X-rays of different beam qualities. The different low-energy X-rays studied had cut-off energies of 50, 100 and 150 keV. Bacillus pumilus spores (in biological indicator strips were irradiated at step doses between 6.5 to 390 Gy. The resulting bacteria populations were then quantified by a pour plate method. Results showed that X-rays of lower energies were more effective in inactivating bacterial spores. In addition, an increment in bacterial population was observed at doses below 13Gy. We attributed this increase to a radiation-induced activation of bacterial spores. Four kinetic models were then evaluated for their prediction of bacterial spore behavior under irradiation. This included: (i first-order kinetics model; (ii Shull model; (iii Sapru model; and (iv probabilistic model. From R2 and AIC analyses, we noted that the probabilistic model performed the best, followed by the Sapru model. We highlighted that for simplicity in curve fitting the Sapru model should be used instead of the probabilistic model. A 12-log reduction in bacterial population (corresponding to a sterility assurance level of 10-6 as required in the sterilization of medical devices was computed to be achievable at doses of 1000, 1600 and 2300 Gy for the three different X-ray cut-off energies respectively. These doses are an order in magnitude lesser than that required in gamma irradiation. This highlights the applicability of cheaper and safer table-top X-ray sources for sterilization application.

Micronucleus formation compared to the survival rate of human melanoma cells after X-ray and neutron irradiation and hyperthermia

Energy Technology Data Exchange (ETDEWEB)

van Beuningen, D.; Streffer, C.; Bertholdt, G.

1981-09-01

After neutron and X-ray irradiation and combined X-ray irradiation and hyperthermia (3 hours, 42/sup 0/C), the survival rate of human melanoma cells was measured by means of the colony formation test and compared to the formation of micronuclei. Neutrons had a stronger effect on the formation of micronuclei than the combination of X-rays and hyperthermia. X-rays had the lowest effect. The dose effect curve showed a break at that dose level at which a reduction of cells was observed in the cultures. A good relation between survival rate and formation of micronuclei was found for the X-ray irradiation, but not for the neutron irradiation and the combined treatment. These observations are discussed. At least for X-rays, the micronucleus test has turned out to be a good screening method for the radiosensitivity of a biologic system.

Low-dose X-irradiation of adjuvant-induced arthritis in rats. Efficacy of different fractionation schedules

International Nuclear Information System (INIS)

Liebmann, A.; Hindemith, M.; Jahns, J.; Kamprad, F.; Hildebrandt, G.; Madaj-Sterba, P.; Weisheit, S.

2004-01-01

Background and purpose: low-dose radiotherapy is widely accepted as a very effective treatment option for inflammatory symptoms associated with painful degenerative joint disorders. Radiation doses and fractionation schedules in practical use are empirical and mainly based on clinical observations. Experimental data are rare. The efficacy of low-dose X-irradiation on adjuvant induced arthritis in rats using different fractionation schemes was investigated in vivo, in order to explore whether there is a dose and fractionation dependence. Material and methods: adjuvant arthritis in female lewis rats (n = 128) was induced by intradermal injection of heat-inactivated Mycobacterium tuberculosis on day 0. Both arthritic hind paws were sham-irradiated (group 1: days 10-14; group 2: days 15-19; group 3: days 22-26) or X-irradiated with either 5 x 1.0 Gy (group 4: days 10-14; group 6: days 15-19; group 8: days 22-26; group 10: days 10, 12, 14, 16, and 18) or 5 x 0.5 Gy (group 5: days 10-14; group 7: days 15-19; group 9: days 22-26; group 11: days 10, 12, 14, 16, and 18; group 12: days 10-14 and 22-26). The clinical parameters arthritis score (AS), hind paw volume (HPV), and body weight were determined. Results: a significant decrease of the clinical arthritis parameters was observed following 5 x 0.5 Gy or 5 x 1.0 Gy during the acute maximum of the inflammatory response (days 15-19). The most pronounced treatment effect was reached after two daily fractionated series of 5 x 0.5 Gy with an early treatment onset (days 10-14) and repetition in interval (days 22-26). After the application of 5 x 1.0 Gy on days 10-14 or in a protracted scheme (days 10, 12, 14, 16, and 18), only a nonsignificant positive trend could be detected. Daily fractionated X-irradiation in the chronic phase of adjuvant arthritis (days 22-26) did not show any positive clinical effect. Conclusion: low-dose radiotherapy is able to prevent a full-blown arthritic reaction if given during the florid phase of

Carbon-ion beam irradiation kills X-ray-resistant p53-null cancer cells by inducing mitotic catastrophe.

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Napapat Amornwichet

Full Text Available BACKGROUND AND PURPOSE: To understand the mechanisms involved in the strong killing effect of carbon-ion beam irradiation on cancer cells with TP53 tumor suppressor gene deficiencies. MATERIALS AND METHODS: DNA damage responses after carbon-ion beam or X-ray irradiation in isogenic HCT116 colorectal cancer cell lines with and without TP53 (p53+/+ and p53-/-, respectively were analyzed as follows: cell survival by clonogenic assay, cell death modes by morphologic observation of DAPI-stained nuclei, DNA double-strand breaks (DSBs by immunostaining of phosphorylated H2AX (γH2AX, and cell cycle by flow cytometry and immunostaining of Ser10-phosphorylated histone H3. RESULTS: The p53-/- cells were more resistant than the p53+/+ cells to X-ray irradiation, while the sensitivities of the p53+/+ and p53-/- cells to carbon-ion beam irradiation were comparable. X-ray and carbon-ion beam irradiations predominantly induced apoptosis of the p53+/+ cells but not the p53-/- cells. In the p53-/- cells, carbon-ion beam irradiation, but not X-ray irradiation, markedly induced mitotic catastrophe that was associated with premature mitotic entry with harboring long-retained DSBs at 24 h post-irradiation. CONCLUSIONS: Efficient induction of mitotic catastrophe in apoptosis-resistant p53-deficient cells implies a strong cancer cell-killing effect of carbon-ion beam irradiation that is independent of the p53 status, suggesting its biological advantage over X-ray treatment.

Radiobiological effect of different irradiation fractionated regimens in human brain glioma

International Nuclear Information System (INIS)

Gai Xue; Yang Weizhi; Gao Li; Jiang Heng; Wang Mianrong; Shi Huizhen

2010-01-01

Objective: To evaluate the radiobiological effect of different irradiation fractionated regimens in human glioma cells (BT 325 cell line). Methods: The xenografts in Balb/c-nude mice were irradiated with different single and fractionated regimens. The single fraction dose was 10, 20, 30, 40 and 60 Gy, respectively. The fractionated regimens were 2 Gy x 5 fractions ( irradiated every day), and 3 Gy x 3 fractions (irradiated every other day), 3 Gy x 5 fractions (irradiated every day) and 4 Gy x 3 fractions (irradiated every other day), with total doses of 125 Gy, 114 Gy, 126 Gy and 112 Gy, respectively. The growth curve was used to evaluate the tumor doubling time. clonogenic assays was performed to draw the cell survival curve and analyze the radiobiological parameters with doses of 1, 2, 4, 6, 8 and 10 Gy. T 1/2 was measured by comet assay. Results: Tumor regression were not observed by single fraction irradiation, 2 Gy x 5 fractions and 3 Gy x 3 fractions irradiation regimens. The tumor regress was more significant with the increas of fraction dose. The 4 Gy x 3 fractions inhibited tumor more though not curing tumor. The cell doubling time of the BT 325 cell was 30. 16 h and the tumor doubling time of the xenograft was 43 days.When fitted with L-Q model, α was 0. 36 Gy -1 and β was 0. 057 Gy -2 . When fitted with the single-hit multi target model, D 0 was 1. 394 Gy, Dq was 2. 127 Gy and SF 2 was 0.714, respectively. The T 1/2 was 9.999 min. Conclusions: Glioma is a radioresistant tumor. Increase of the fraction dose improves recent effect.Further study is needed to control the tumor stem cells. (authors)

Accelerated repopulation of mouse tongue epithelium during fractionated irradiations or following single doses

International Nuclear Information System (INIS)

Doerr, W.; Kummermehr, J.

1990-01-01

Mouse tongue mucosa was established as an animal model to study repopulation after large single doses or during continuous irradiation. A top-up irradiation technique was used employing priming doses or fractionated treatment to the whole snout (300 kV X-rays) followed by local test doses (25 kV X-rays) to elicit denudation in a confined field of the inferior tongue surface. Clearcut quantal dose-response curves of ulcer incidence were obtained to all protocols; animal morbidity, i.e. body weight loss was minimal. Repopulation following priming doses of 10 and 13 Gy started with a delay of at least 3 days and then progressed rapidly to nearly restore original tissue tolerance by day 11. During continuous fractionation over 1 to 3 weeks with 5 fractions/week and doses per fraction of 2.5, 3 and 3.5 Gy, repopulation was small in week one but subsequently increased to fully compensate the weekly dose at all dose levels. Additional measurements of cell density during a 4 weeks course of 5 x 3 Gy or 5 x 4 Gy per week showed only moderate depletion to 67% of the control figures. The fact that rapid repopulation is achieved at relatively moderate damage levels should be taken into account when the timing of a treatment split is considered. (author). 18 refs.; 7 figs.; 1 tab

Rib necrosis after postoperative irradiation with 6MeV x-ray to breast cancer

Energy Technology Data Exchange (ETDEWEB)

Asakawa, H; Watarai, J; Otawa, H [Miyagi Prefectural Adult Disease Center, Natori (Japan)

1975-04-01

In order to examine quality of rays in radiation injury in the rib by high energy x-ray, radiation injury in the rib was roentgenologically followed up in the subjects that received postoperative irradiation only with 6 MeV x-ray to breast cancer. The subjects consisted of 79 patients with the age of 30 to 78 and were irradiated with 200 rads of 6 MeV x-ray 5 times a week delivered in 5 to 6 weeks postoperatively. Two fields were irradiated in a day and the total dose reached more than 5,000 rads. Roentgenologic follow up for more than 12 months revealed that rib necrosis occurred in 9 (11%) of 79 patients and that there was no relation to the age of patient. The necrosis was most likely to develop in the right second rib 10 to 23 months after the irradiation and the mean was 16 months. To the rib region where necrosis occurred, 1,880 to 2,230 ret were irradiated and the mean was 2,014 ret. There found no relation between the irradiation dose and occurrence of rib necrosis in the extent of 4,000 to 6,000 rads for tumor doses. Radiation injury in the lung was complicated in 8 (89%) of 9 patients with rib necrosis, indicating high incidence.

Quantitative measurements of oxidative stress in mouse skin induced by X-ray irradiation

International Nuclear Information System (INIS)

Chi, Cuiping; Tanaka, Ryoko; Okuda, Yohei; Ikota, Nobuo; Ozawa, Toshihiko; Anzai, Kazunori; Yamamoto, Haruhiko; Urano, Shiro

2005-01-01

To find efficient methods to evaluate oxidative stress in mouse skin caused by X-ray irradiation, several markers and methodologies were examined. Hairless mice were irradiated with 50 Gy X-rays and skin homogenates or skin strips were prepared. Lipid peroxidation was measured using the skin homogenate as the level of thiobarbituric acid reactive substances. The level of lipid peroxidation increased with time after irradiation and was twice that of the control at 78 h. Electron spin resonance (ESR) spectra of skin strips showed a clear signal for the ascorbyl radical, which increased with time after irradiation in a manner similar to that of lipid peroxidation. To measure levels of glutathione (GSH) and its oxidized forms (GSSG) simultaneously, two high performance liquid chromatography (HPLC) methods, sample derivatization with 1-fluoro-2,4-dinitrobenzene and detection with a UV detector (method A) and no derivatization and detection with an electrochemical detector (method B), were compared and the latter was found to be better. No significant change was observed within 24 h after irradiation in the levels of GSH and GSSG measured by method B. The GSH/GSSG ratio may be a less sensitive parameter for the evaluation of acute oxidative stress caused by X-ray irradiation in the skin. Monitoring the ascorbyl radical seems to be a good way to evaluate oxidative stress in skin in vivo. (author)

Soft x-ray irradiation effects of Li₂O₂, Li₂CO₃ and Li₂O revealed by absorption spectroscopy.

Directory of Open Access Journals (Sweden)

Ruimin Qiao

Full Text Available Li(2O(2, Li(2CO(3, and Li(2O are three critical compounds in lithium-air and lithium-ion energy storage systems. Extensive measurements have been carried out to study the chemical species and their evolutions at difference stages of the device operation. While x-ray spectroscopy has been demonstrated to be one of the most powerful tools for such purpose, no systematic study on the irradiation effects have been reported. Here we carry out extensive time, position, and irradiation dependent Li K-edge soft x-ray absorption spectroscopy on these compounds with so far the best energy resolution. The ultra-high resolution in the current study allows the features in the absorption spectra to be well-resolved. The spectral lineshape thus serves as the fingerprints of these compounds, enabling the tracking of their evolution under x-ray irradiation. We found that both Li(2O(2 and Li(2CO(3 evidently evolve towards Li(2O under the soft x-ray irradiation with Li(2CO(3 exhibiting a surprisingly higher sensitivity to x-rays than Li(2O(2. On the other hand, Li(2O remains the most stable compound despite experiencing substantial irradiation dose. We thus conclude that high resolution soft x-ray spectroscopy could unambiguously fingerprint different chemical species, but special cautions on irradiation effects would be needed in performing the experiments and interpreting the data properly.

Regularity of wound healing in rats irradiated locally with different doses of soft X-rays

International Nuclear Information System (INIS)

Liu Jianzhong; Zhou Yuanguo; Cheng Tianmin; Zhou Ping; Liu Xia; Li Ping

2002-01-01

Objective: To study the regular patter of wound healing in rats irradiated locally with different doses of soft X-rays. Methods: Rats were locally irradiated, and wounded immediately thereafter. Gross observation, histopathology and immunohistochemistry examinations, and image analysis were used to study the wound healing process. Results: The authors found that the delayed time of wound healing induced by soft X-ray irradiation of 0.50, 1.01, 1.96, 3,26, 4.00, 5.21 Gy was 1.6, 4.2, 5.4, 6.6, 8.2 and 9.4 days, respectively. Irradiation with 7.0 and 10.0 Gy caused failure of wound healing (up to 40 days). Compared to the non-irradiated wounds, the healing rates of irradiation-impaired wounds were lower during the whole healing process. From day 3 to day 9 after irradiation, the healing rates decreased along with increasing of the radiation dose, indicating the key phase of wound healing was delayed. After irradiation, the collagen synthesis was decreased, its arrangement was disordered, and the structure of granulation tissue was irregular. Conclusion: Soft X-rays irradiation may cause a delay of wound healing in a dose-dependent manner, and irradiation with 7.0 and 10.0 Gy cause failure of wound healing

Effect of combined treatment of x-rays and ACNU on rat glioma cells in monolayer and multicellular spheroids

International Nuclear Information System (INIS)

Sugiyama, Satoru; Mori, Teruaki; Suzuki, Jiro; Sasaki, Takehito

1985-01-01

Spheroids of rat glioma clone-6 cells having a central necrosis were used to determine the effect of combined treatment of x-rays and 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU), where the optimum time intervals and doses in the combination were analyzed. The treatment with ACNU 2 to 6 hours prior to x-ray irradiation was most effective for cells in both monolayers and in spheroids. The dose survival curves with x-ray irradiation indicated that the hypoxic cell fraction in spheroids disappeared with a prior treatment by ACNU. The enhancement ratio in spheroids was thus larger for larger x-ray doses, and was always larger than that in monolayer cells. The survival curves versus concentration of ACNU indicated that the enhancement ratio in spheroids was more than 1.2 in all concentrations with the combined x-ray irradiation, and exceeded that in monolayer cells with a surviving fraction of less than 0.4. (author)

Defect analysis of BaSrFBr:Eu irradiated by X-ray

International Nuclear Information System (INIS)

Lee, C. Y.; Jeong, J. M.; Kim, J. H.

2010-01-01

The mechanical property of the BaSrFBr:Eu phosphor layer of X-ray image plates was investigated by using image quality (IQ), resolution (LP/mm), and coincidence Doppler broadening (CDB) positron annihilation. The screen samples of BaSrFBr:Eu phosphors were irradiated with hospital X-rays in the course of diagnostic radiography at an average rate of 20,000 times per year and were used for various periods of time. The LP/mm values of the irradiated BaSrFBr:Eu image plates varied between 2.4 and 2.0 for three years while the IQ values varied between 35 and 11 over the same period. CDB positron annihilation spectroscopy was used to analyze the defect structures in the phosphor layer. The S parameter values increased in correlation with increased exposure time, which indicated that more defects were generated. There was a positive relationship between the IQ and S parameters. Measurements of the defects indicate that most of the defects were likely to have been generated by the X-ray radiation.

Short irradiation time characteristics of the inverter type X-ray generator

International Nuclear Information System (INIS)

Miyazaki, Shigeru; Hara, Takamitu; Matutani, Kazuo; Saito, Kazuhiko.

1994-01-01

The linearity of the X-ray output is an important factor in radiography. It is a composite of the linearities of the X-ray tube voltage, the X-ray tube current, and the exposure time. This paper focuses on the linearity of exposure time. Non-linearity of the X-ray output for short-time exposure became a problem when the three-phase X-ray generator was introduced. This paper describes the inverter-type X-ray generator, which is expected to become predominant in the future. Previously, we investigated X-ray output linearity during short-time exposure using the technique of dynamic study. In this paper, we describe the application of a digital memory and a personal computer to further investigation. The non-linearity of the X-ray output was caused by irregular waveforms of the X-ray tube voltage found at the rise time and the fall time. When the rise time was about 0.6 ms, the non-linearity was about 2%, which is negligibly small. The non-linearity due to the fall time of the X-ray tube varied greatly according to the X-ray tube current. For the minimum irradiation time of 1 ms, 4% to 27% of the non-linearity was attributable to the fall time. The main cause was the stray capacitance of the X-ray high-voltage cables. When the X-ray tube current exceeded 400 mA, the rise time was almost equal to the fall time, and the problem did not occur. Consequently, the ideal generator should have a fall time which is equal to the rise time of the X-ray tube voltage. Strictly speaking, such a generator should have rectangular waveforms. (author)

Forming a structure of the CoNiFe alloys by X-ray irradiation

Science.gov (United States)

Valko, Natalia; Kasperovich, Andrey; Koltunowicz, Tomasz N.

The experimental data of electrodeposition kinetics researches and structure formation of ternary CoNiFe alloys deposited onto low-carbon steel 08kp in the presence of X-rays are presented. Relations of deposit rate, current efficiencies, element and phase compositions of CoNiFe coatings formed from sulfate baths with respect to cathode current densities (0.5-3A/dm2), electrolyte composition and irradiation were obtained. It is shown that, the CoNiFe coatings deposited by the electrochemical method involving exposure of the X-rays are characterized by more perfect morphology surfaces with less developed surface geometry than reference coatings. The effect of the X-ray irradiation on the electrodeposition of CoNiFe coatings promotes formatting of alloys with increased electropositive component and modified phase composition.

The effect of cepharanthin on the hemopoietic suppression by X-ray irradiation

International Nuclear Information System (INIS)

Mori, Masaharu; Kawasaki, Seiji; Sacho, Masanori; Awai, Michiyasu; Ono, Minoru; Sadahira, Yoshito.

1989-01-01

The effects of cepharanthin on the suppression of hemopoiesis by X-ray irradiation were studied. A whole body X-irradiation (3 Gy) induced decrease of leucocyte count, nucleated cell count of bone marrow, myeloid stem cell count (CFU-C), and spleen weight. Oral administration of cepharanthin (25 mg/kg BW or 50 mg/kg BW) tended to decrease these damage on hemopoiesis, and increased spleen weight on 5th day after irradiation. Histological examinations revealed that the administration of cepharanthin accerelated the hemopoietic recovery in the red pulp of spleen. (author)

An evaluation of low-energy x-ray and cobalt-60 irradiations of MOS transistors

International Nuclear Information System (INIS)

Dozier, C.M.; Fleetwood, D.M.

1987-01-01

An evaluation of methodologies for irradiating MOS transistors with low-energy x-ray and Co-60 sources has been performed. The authors find that comparisons of voltage shifts produced by bulk trapped charge and interface states in MOS transistors irradiated using two different low energy x-ray sources (an ARACOR 10 keV W source and an 8 keV Cu source) agree to within better than 30 percent. This quality of agreement is similar in magnitude to that between MOS devices irradiated by different Co-60 sources. In contrast, the measurements indicate that interlaboratory comparisons of ratios of shifts produced by x-ray and Co-60 sources can lead to differences in ratios as large as a factor of --1.7. Improved electron-hole recombination data for oxides is presented. This recombination correction, in conjunction with a correction for interface dose enhancement, is used to predict the ratios of shifts produced by x-ray and Co-60 sources. However, the results show that corrections for electron-hole recombination and interface does enhancement do not, by themselves, adequately predict the field dependent behavior of these transistors

Low-temperature crystallization of amorphous silicon and amorphous germanium by soft X-ray irradiation

Energy Technology Data Exchange (ETDEWEB)

Heya, Akira, E-mail: heya@eng.u-hyogo.ac.jp [Department of Materials Science and Chemistry, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671–2280 (Japan); Kanda, Kazuhiro [Laboratory of Advanced Science and Technology for Industry (LASTI), University of Hyogo, 3-2-1 Koto, Kamigori, Hyogo 678–1205 (Japan); Toko, Kaoru; Sadoh, Taizoh [Department of Electronics, Kyushu University, 744 Nishi-ku, Motooka, Fukuoka 819–0395 (Japan); Amano, Sho [Laboratory of Advanced Science and Technology for Industry (LASTI), University of Hyogo, 3-2-1 Koto, Kamigori, Hyogo 678–1205 (Japan); Matsuo, Naoto [Department of Materials Science and Chemistry, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671–2280 (Japan); Miyamoto, Shuji [Laboratory of Advanced Science and Technology for Industry (LASTI), University of Hyogo, 3-2-1 Koto, Kamigori, Hyogo 678–1205 (Japan); Miyao, Masanobu [Department of Electronics, Kyushu University, 744 Nishi-ku, Motooka, Fukuoka 819–0395 (Japan); Mochizuki, Takayasu [Laboratory of Advanced Science and Technology for Industry (LASTI), University of Hyogo, 3-2-1 Koto, Kamigori, Hyogo 678–1205 (Japan)

2013-05-01

The low-temperature-crystallization effects of soft X-ray irradiation on the structural properties of amorphous Si and amorphous Ge films were investigated. From the differences in crystallization between Si and Ge, it was found that the effects of soft X-ray irradiation on the crystallization strongly depended on the energy band gap and energy level. The crystallization temperatures of the amorphous Si and amorphous Ge films decreased from 953 K to 853 K and 773 K to 663 K, respectively. The decrease in crystallization temperature was also related to atoms transitioning into a quasi-nucleic phase in the films. The ratio of electron excitation and migration effects to thermal effects was controlled using the storage-ring current (photon flux density). Therefore, we believe that low-temperature crystallization can be realized by controlling atomic migration through electron excitation. - Highlights: • This work investigates the crystallization mechanism for soft X-ray irradiation. • The soft X-ray crystallization depended on the energy band gap and energy level. • The decrease in the crystallization temperature for Si and Ge films was 100 K. • This decrement was related to atoms transitioning into a quasi-nucleic phase.

Fractionated dose studies with X-rays and various alkylating agents in P388 mouse lymphoma cells

International Nuclear Information System (INIS)

Anderson, D.

1981-01-01

The fractionated dose technique has been used in P388F cells to examine the effects of X-rays and four alkylating agents on survival and induction of 5-iodo-2-deoxyuridine (IudR) resistant variants. Fractionation intervals up to 5 1/2 h were used for X-rays and for the alkylating agents up to 192 h. Fractionation of the X-ray dose resulted in a sparing effect for survival and variant induction. A sparing effect was also observed for survival after treatment with alkylating agents. However, variant frequencies were observed as large as or greater than those produced by the full doses of alkylating agents. For such agents this would suggest that survival and variant induction are independent events. Differences in the effects of X-rays and alkylating agents cannot be explained by differences in growth rate or the recovery of viability after treatment

Fractionated dose studies with X-rays and various alkylating agents in P388 mouse lymphoma cells

International Nuclear Information System (INIS)

Anderson, D.

1981-01-01

The fractionated dose technique was used in P388F cells to examine the effects of X-rays and four alkylating agents on survival and induction of 5-iodo-2-deoxyuridine (IudR) resistant variants. Fractionation intervals up to 51/2 h were used for X-rays and for the alkylating agents up to 192 h. Fractionation of the X-ray dose resulted in a sparing effect for survival and variant induction. A sparing effect was also observed for survival after treatment with alkylating agents. However, variant frequencies were observed as large as or greater than those produced by the full doses of alkylating agents. For such agents this would suggest that survival and variant induction are independent events. Differences in the effects of X-rays and alkylating agents cannot be explained by differences in growth rate or the recovery of viability after treatment. (author)

Scintillation properties and X-ray irradiation hardness of Ce3+-doped Gd2O3-based scintillation glass

International Nuclear Information System (INIS)

Liu, Liwan; Shao, Chongyun; Zhang, Yu; Liao, Xili; Yang, Qiuhong; Hu, Lili; Chen, Danping

2016-01-01

Ce 3+ -doped Gd 2 O 3 -based scintillation glasses are prepared within an air or CO atmosphere. The effects of fluorine, lutetium, barium, and the melting atmosphere on the optical properties, scintillation properties and irradiation hardness are studied. Absorption spectra, luminescence spectra under UV and X-ray excitation, and the X-ray radiation-induced spectra are presented. The results show that the density can be increased by doping with fluorine, lutetium and barium. The luminescence intensity decreases after X-ray irradiation. Because of charge transfer quenching, fluorine and lutetium enhance the UV-excited and X-ray excited luminescence intensity, but barium decreases. Moreover, fluorine and lutetium are advantageous to irradiation hardness while barium is not. In addition, a non-reducing atmosphere provides a higher irradiation hardness than a reducing atmosphere. Fluorine-doped glass is promising to enhance luminescence intensity, promote irradiation hardness, and increase the density.

Postharvest quality of dragon fruit (Hylocereus spp.) after x-ray irradiation quarantine treatment

Science.gov (United States)

The quality of three dragon fruit clones (Hylocereus sp.) was determined following x-ray irradiation for disinfestation of quarantine pests. Fruit were treated with irradiation doses of 0, 200, 400, 600, or 800 Gy and stored for 12 days at 10 °C. Irradiation did not affect soluble solids content, ti...

Clastogenic effects in human lymphocytes exposed to low and high dose rate X-ray irradiation and vitamin C

International Nuclear Information System (INIS)

Konopacka, M; Rogolinski, J.

2011-01-01

In the present work we investigated the ability of vitamin C to modulate clastogenic effects induced in cultured human lymphocytes by X-irradiation delivered at either high (1 Gy/min) or low dose rate (0.24 Gy/min). Biological effects of the irradiation were estimated by cytokinesis-block micronucleus assay including the analysis of the frequency of micronuclei (MN) and apoptotic cells as well as calculation of nuclear division index (NDI). The numbers of micronucleated binucleate lymphocytes (MN-CBL) were 24.85 ± 2.67% and 32.56 ± 3.17% in cultures exposed to X-rays (2 Gy) delivered at low and high dose rates, respectively. Addition of vitamin C (1-20 μg/ml) to the medium of cultures irradiated with the low dose rate reduced the frequency of micronucleated lymphocytes with multiple MN in a concentration-dependent manner. Lymphocytes exposed to the high dose rate radiation showed a U-shape response: low concentration of vitamin C significantly reduced the number of MN, whereas high concentration influenced the radiation-induced total number of micronucleated cells insignificantly, although it increased the number of cells with multiple MN. Addition of vitamin C significantly reduced the fraction of apoptotic cells, irrespective of the X-ray dose rate. These results indicate that radiation dose rate is an important exposure factor, not only in terms of biological cell response to irradiation, but also with respect to the modulating effects of antioxidants. (authors)

Multifrequency EPR study on freeze-dried fruits before and after X-ray irradiation

Science.gov (United States)

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

2006-09-01

X-, K- and Q-band EPR studies on lyophilized whole pulp parts of blue plum, apricot, peach, melon as well as achens and pulp separately of strawberry before and after X-ray irradiation are reported. Before irradiation all samples show in X band a weak singlet EPR line with g=2.0030±0.0005, except melon, which is EPR silent. Immediately after irradiation all samples exhibit complex fruit-depending spectra, which decay with time and change to give, in ca. 50 days, an asymmetric singlet EPR line with g=2.0041±0.0005. Only apricot pulp gave a typical "sugar-like" EPR spectrum. Singlet EPR lines recorded after irradiation in X -band are K- and Q-band resolved as typical anisotropic EPR spectra with g=2.0023±0.0003 and g⊥=2.0041±0.0005. In addition, K- and Q-band EPR spectra of all samples show a superposition with the six EPR lines of Mn 2+ naturally present in the fruits. The saturation behavior of the EPR spectra of achens of lyophilized and fresh strawberry is also studied. The differences in g factors of samples before and after X-ray irradiation might be used for the identification of radiation processing of fruits in the case of pulp and the differences in the EPR saturation behavior might be used for the achens of strawberry.

New Solar Irradiance Measurements from the Miniature X-Ray Solar Spectrometer Cubesat

Energy Technology Data Exchange (ETDEWEB)

Woods, Thomas N.; Jones, Andrew; Kohnert, Richard; Mason, James Paul; Moore, Christopher S.; Palo, Scott; Rouleau, Colden [University of Colorado, Boulder, CO (United States); Caspi, Amir [Southwest Research Institute, Boulder, CO (United States); Chamberlin, Phillip C. [NASA Goddard Space Flight Center, Greenbelt, MD (United States); Solomon, Stanley C. [National Center for Atmospheric Research, Boulder, CO (United States); Machol, Janet; Viereck, Rodney [NOAA Space Weather Prediction Center, Boulder, CO (United States)

2017-02-01

The goal of the Miniature X-ray Solar Spectrometer ( MinXSS ) CubeSat is to explore the energy distribution of soft X-ray (SXR) emissions from the quiescent Sun, active regions, and during solar flares and to model the impact on Earth's ionosphere and thermosphere. The energy emitted in the SXR range (0.1–10 keV) can vary by more than a factor of 100, yet we have limited spectral measurements in the SXRs to accurately quantify the spectral dependence of this variability. The MinXSS primary science instrument is an Amptek, Inc. X123 X-ray spectrometer that has an energy range of 0.5–30 keV with a nominal 0.15 keV energy resolution. Two flight models have been built. The first, MinXSS -1, has been making science observations since 2016 June 9 and has observed numerous flares, including more than 40 C-class and 7 M-class flares. These SXR spectral measurements have advantages over broadband SXR observations, such as providing the capability to derive multiple-temperature components and elemental abundances of coronal plasma, improved irradiance accuracy, and higher resolution spectral irradiance as input to planetary ionosphere simulations. MinXSS spectra obtained during the M5.0 flare on 2016 July 23 highlight these advantages and indicate how the elemental abundance appears to change from primarily coronal to more photospheric during the flare. MinXSS -1 observations are compared to the Geostationary Operational Environmental Satellite ( GOES ) X-ray Sensor (XRS) measurements of SXR irradiance and estimated corona temperature. Additionally, a suggested improvement to the calibration of the GOES XRS data is presented.

COSMIC-RAY AND X-RAY HEATING OF INTERSTELLAR CLOUDS AND PROTOPLANETARY DISKS

International Nuclear Information System (INIS)

Glassgold, Alfred E.; Galli, Daniele; Padovani, Marco

2012-01-01

Cosmic-ray and X-ray heating are derived from the electron energy-loss calculations of Dalgarno, Yan, and Liu for hydrogen-helium gas mixtures. These authors treated the heating from elastic scattering and collisional de-excitation of rotationally excited hydrogen molecules. Here we consider the heating that can arise from all ionization and excitation processes, with particular emphasis on the reactions of cosmic-ray and X-ray generated ions with the heavy neutral species, which we refer to as chemical heating. In molecular regions, chemical heating dominates and can account for 50% of the energy expended in the creation of an ion pair. The heating per ion pair ranges in the limit of negligible electron fraction from ∼4.3 eV for diffuse atomic gas to ∼13 eV for the moderately dense regions of molecular clouds and to ∼18 eV for the very dense regions of protoplanetary disks. An important general conclusion of this study is that cosmic-ray and X-ray heating depends on the physical properties of the medium, i.e., on the molecular and electron fractions, the total density of hydrogen nuclei, and, to a lesser extent, on the temperature. It is also noted that chemical heating, the dominant process for cosmic-ray and X-ray heating, plays a role in UV irradiated molecular gas.

Prolonged survival of isolated rat islet allografts pre-irradiated with X-rays

Energy Technology Data Exchange (ETDEWEB)

Kimura, Toshihisa; Note, Masayuki; Nakagawara, Gizo (Fukui Medical School, Matsuoka (Japan)); Kojima, Yasuhiko

1994-04-01

Prior to transplantation of islets, pre-incubation, or pre-irradiation may suppress the immunogenicity of islet cells without suppressing islet function. In the presently described experiments we investigated the use of X-ray irradiation prior to transplantation to reduce islet immunogenicity. To determine whether or not the islet function was reduced after irradiation, ACI rat islets were transplanted into the subrenal capsules of isogeneic rats which had been diabetic and examined the blood glucose level over a period of 40 days. The results indicated that irradiation injury was dose-dependent and that islets irradiated with over 80 Gy lost their function. Next, allogeneic transplantation was performed using the model of ACI rats to Lewis rats without the use of any immunosuppressive agent. Non-irradiated islets were rejected within 7 days. However 20 Gy or 40 Gy irradiated islets prolonged survival (18.7[+-]5.8 days (n=6) and 26.7[+-]10.0 days (n=6), respectively). To determine the basis for this effect, MHC expression of islets was examined by the immunoperoxidase technique. Immunohistologic studies showed that 40 Gy-irradiated islets were depleted of Class II antigen positive cells while Class I antigen expression was unchanged. These results suggest that the prolongation of islets survival by X-ray irradiation may possibly be due to, in part, the depletion of donor Class II antigen positive cells. (author).

Action of 50 R X-ray doses on the breeding function of C3H strain mice - effect of splitting the dose, action of repeated irradiations on successive generations

International Nuclear Information System (INIS)

Alix, D.

1965-01-01

X-rays exposure effect was studied on C3H strain mice, at the standpoint of the effects produced on breeding function. The method used with this purpose was the following: single doses 20 - 30 - 40 and 50 R/dose, fractional doses: 50 R/total dose, divided in 2 - 5 - 10 or 25 irradiations distributed in one month duration. The offsprings were irradiated at the same doses than the parents, consanguinity being maintained. Statistical treatment of results was carried out, that led at the following conclusions: 1) Couples receiving single exposure of 50 R or two exposures of 25 R at one month interval give comparable results. Fractional doses do not involve the slightest diminution of X-rays effect. 2) 30 R exposure brings about a decrease in fertility, with an increase in abortions. Fertility of 20 R irradiated couples remains below controls. 3) After ten times 5 R and twenty-five 2 R, the number of abortions is the largest. Ovarian function is particularly sensitive to X-rays; one may think that twenty-five 2 R give injuries conditioning non-viability of conception products, smaller doses should produce mutations and yield births of altered genotype individuals. (author) [fr

X-ray diffraction studies of sucrose and sucrose irradiated with γ-radiation

International Nuclear Information System (INIS)

Prasad, Mahendra

1981-01-01

In order to understand and solve numerous problems related to sugar quality and its storage life, X-ray diffraction studies of sucrose and sucrose irradiated with γ-radiation have been made. It is observed that the interplanar spacing 'd' in irradiated sucrose is reduced indicating the partial damage of sucrose lattice. (author)

Effect of X-rays combined with ACNU and O sup 6 -ethylguanine on rat subcutaneous gliomas

Energy Technology Data Exchange (ETDEWEB)

Takahashi, Kou; Katakura, Rhuichi; Mashiyama, Shoji; Yoshimoto, Takashi; Suzuki, Jiro (Tohoku Univ., Sendai (Japan). School of Medicine); Sasaki, Takehito

1991-06-01

Rat gliomas of subcutaneously transplanted RGc-6 cells were irradiated with X-ray either alone, or combined with ACNU, and the cell-survival was assayed in vitro. Cell-survival curve composed of two components by X-irradiation alone indicated the presence of a hypoxic cell fraction. We have previously shown that combined treatment with ACNU apparently made the effect of X-ray on spheroids in vitro of the same cell line of RGc-6 more powerful. Although treatment of rat gliomas with ACNU administered at 2 hrs prior to X-irradiation was most effective, it resulted in only the additive effect of the independent action of the two agents. Further treatment by O{sup 6}-ethylguanine prior to ACNU administration and X-irradiation apparently increased the strength of the effect of ACNU combined with X-ray to the dose-modifying factor for X-ray of 1.8. The result indicated that the combination of O{sup 6}-ethylguanine prior to ACNU administration and X-irradiation may clinically enhance the effect of X-ray against apparent ACNU-resistant glioma cells such as RGc-6 cells. (author).

Dosimetric characteristics of ultraviolet and x-ray-irradiated KBr:Eu2+ thermoluminescence crystals

International Nuclear Information System (INIS)

Melendrez, R.; Perez-Salas, R.; Aceves, R.; Piters, T.M.; Barboza-Flores, M.

1996-01-01

Thermoluminescence (TL) characteristics of KBr:Eu 2+ (150 ppm) previously exposed to ultraviolet (UV) light (200 endash 300 nm) and x-ray radiation at room temperature have been determined. The TL glow curve of UV-irradiated samples is composed of six peaks located at 337, 384, 402, 435, 475, and 510 K. The TL glow curves of x-irradiated samples show mainly a TL peak around 384 K. The TL intensities of UV-irradiated (402 and 510 K glow peaks) and x-irradiated specimens present a linear dependence as a function of radiation dose as well as fading stability 300 s after irradiation. These results further enhance the possibilities of using europium-doped materials in nonionizing (actinic region) and ionizing radiation detection and dosimetry applications. copyright 1996 American Institute of Physics

Enhancement of the effect of X-irradiation against cultured human glioblastoma cells by pretreatment with ACNU

Energy Technology Data Exchange (ETDEWEB)

Mashiyama, Shoji; Katakura, Ryuichi; Takahashi, Kou; Kitahara, Masakazu; Suzuki, Jiro [Tohoku Univ., Sendai (Japan). Inst. of Brain Diseases; Sasaki, Takehito

1989-12-01

Human glioblastoma A-7 (GB A-7) cells can apparently recover from potentially lethal X-irradiation. The authors, using a colony-forming assay, studied the influence of pretreatment with 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3- (2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) on the effectiveness of X-irradiation against GB A-7 cells grown in monolayers and as multicellular spheroids. Pre-exposure to ACNU inhibited the recovery of irradiated GB A-7 cells. In monolayer cells, the combination treatment was most effective when ACNU was applied 2 to 8 hours prior to irradiation, and the larger the X-ray dose, the more potent the effect. ACNU pretreatment was more effective against large spheroids (enhancement ratio 1.86) than against small ones (1.34). Large spheroids showed necrosis, whereas small ones did not. Isobolographic analysis disclosed that the effect of combining X-irradiation and ACNU is within an additive envelope at the surviving fraction of 10{sup -2}, while supra-additive at the surviving fraction of 10{sup -3}. These results suggest that the potency of X-irradiation is augmented by ACNU pretreatment through an interactive mechanism. Further, suppression of recovery from X-ray induced potentially lethal damage was influenced by the presence of necrosis. (author).

Enhancement of the effect of X-irradiation against cultured human glioblastoma cells by pretreatment with ACNU

International Nuclear Information System (INIS)

Mashiyama, Shoji; Katakura, Ryuichi; Takahashi, Kou; Kitahara, Masakazu; Suzuki, Jiro; Sasaki, Takehito.

1989-01-01

Human glioblastoma A-7 (GB A-7) cells can apparently recover from potentially lethal X-irradiation. The authors, using a colony-forming assay, studied the influence of pretreatment with 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3- (2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) on the effectiveness of X-irradiation against GB A-7 cells grown in monolayers and as multicellular spheroids. Pre-exposure to ACNU inhibited the recovery of irradiated GB A-7 cells. In monolayer cells, the combination treatment was most effective when ACNU was applied 2 to 8 hours prior to irradiation, and the larger the X-ray dose, the more potent the effect. ACNU pretreatment was more effective against large spheroids (enhancement ratio 1.86) than against small ones (1.34). Large spheroids showed necrosis, whereas small ones did not. Isobolographic analysis disclosed that the effect of combining X-irradiation and ACNU is within an additive envelope at the surviving fraction of 10 -2 , while supra-additive at the surviving fraction of 10 -3 . These results suggest that the potency of X-irradiation is augmented by ACNU pretreatment through an interactive mechanism. Further, suppression of recovery from X-ray induced potentially lethal damage was influenced by the presence of necrosis. (author)

Aqueous gold nanosols stabilized by electrostatic protection generated by X-ray irradiation assisted radical reduction

International Nuclear Information System (INIS)

Wang, C.-H.; Hua, Tzu-En; Chien, C.-C.; Yu, Y.-L.; Yang, T.-Y.; Liu, C.-J.; Leng, W.-H.; Hwu, Y.; Yang, Y.-C.; Kim, Chong-Cook; Je, Jung-Ho; Chen, C.-H.; Lin, H.-M.; Margaritondo, G.

2007-01-01

Reductant, stabilizer-free colloidal gold solutions were fabricated by a new room-temperature synchrotron X-ray irradiation method. The influence of process parameters such as the pH value and the exposure time on the structure of gold nanoparticles was investigated. The mechanisms underlying the X-ray-triggered reduction of gold ions and the formation of gold clusters are discussed in detail. The X-ray irradiation derived highly concentrated gold nanoparticles are readily to be re-dispersed and possess suitable colloidal stability within cellular environment. The characterization included a study of the possible cytotoxicity for the EMT-6 tumor cell line: the negative results indicate that the gold clusters produced with our approach are biocompatible

Multifrequency EPR study on freeze-dried fruits before and after X-ray irradiation

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); Dimitrova, A. [Laboratory EPR, Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Georgieva, L. [Institute of Cryobiology and Food Technologies, 1162 Sofia (Bulgaria); Tzvetkova, E. [Institute of Cryobiology and Food Technologies, 1162 Sofia (Bulgaria)

2006-09-15

X-, K- and Q-band EPR studies on lyophilized whole pulp parts of blue plum, apricot, peach, melon as well as achens and pulp separately of strawberry before and after X-ray irradiation are reported. Before irradiation all samples show in X band a weak singlet EPR line with g=2.0030+/-0.0005, except melon, which is EPR silent. Immediately after irradiation all samples exhibit complex fruit-depending spectra, which decay with time and change to give, in ca. 50days, an asymmetric singlet EPR line with g=2.0041+/-0.0005. Only apricot pulp gave a typical ''sugar-like'' EPR spectrum. Singlet EPR lines recorded after irradiation in X -band are K- and Q-band resolved as typical anisotropic EPR spectra with g{sub ||}=2.0023+/-0.0003 and g{sub -}bar =2.0041+/-0.0005. In addition, K- and Q-band EPR spectra of all samples show a superposition with the six EPR lines of Mn{sup 2+} naturally present in the fruits. The saturation behavior of the EPR spectra of achens of lyophilized and fresh strawberry is also studied. The differences in g factors of samples before and after X-ray irradiation might be used for the identification of radiation processing of fruits in the case of pulp and the differences in the EPR saturation behavior might be used for the achens of strawberry.

Void fraction measurements by means of flash x-ray radiography

International Nuclear Information System (INIS)

Angelini, S.; Theofanous, T.G.

1998-01-01

In this paper we discuss X-ray radiography as a means of obtaining quantitative space distributions of void fractions in highly-transient, multiphase flows. The technique and the calibration of the instrument are discussed in detail, and its application in the MAGICO-2000 experiments is used to illustrate its potential in providing unique information about the interactions. (author)

X-ray emission from stainless steel foils irradiated by femtosecond petawatt laser pulses

Science.gov (United States)

Alkhimova, M. A.; Faenov, A. Ya; Pikuz, T. A.; Skobelev, I. Yu; Pikuz, S. A.; Nishiuchi, M.; Sakaki, H.; Pirozhkov, A. S.; Sagisaka, S.; Dover, N. P.; Kondo, Ko; Ogura, K.; Fukuda, Y.; Kiriyama, H.; Esirkepov, T.; Bulanov, S. V.; Andreev, A.; Kando, M.; Zhidkov, A.; Nishitani, K.; Miyahara, T.; Watanabe, Y.; Kodama, R.; Kondo, K.

2018-01-01

We report about nonlinear growth of x-ray emission intensity emitted from plasma generated by femtosecond petawatt laser pulses irradiating stainless steel foils. X-ray emission intensity increases as ˜ I 4.5 with laser intensity I on a target. High spectrally resolved x-ray emission from front and rear surfaces of 5 μm thickness stainless steel targets were obtained at the wavelength range 1.7-2.1 Å, for the first time in experiments at femtosecond petawatt laser facility J-KAREN-P. Total intensity of front x-ray spectra three times dominates to rear side spectra for maximum laser intensity I ≈ 3.2×1021 W/cm2. Growth of x-ray emission is mostly determined by contribution of bremsstrahlung radiation that allowed estimating bulk electron plasma temperature for various magnitude of laser intensity on target.

Soft X-ray variability and the covering fraction of active galactic nuclei

International Nuclear Information System (INIS)

Wachter, K.W.; Strauss, M.A.; Filippenko, A.V.

1988-01-01

A model to explain the observed soft X-ray variability to some low-luminosity Seyfert 1 galaxies is developed. The variability is due to changes in the covering fraction of the central source as broad-line clouds move across our line of sight. A formalism is developed which is used to demonstrate how analysis of a soft X-ray light curve can provide three important quantities: the radius of the X-ray emitting region, the radius of a typical broad-line cloud, and the electron density in the cloud. It is shown that the results are rather insensitive to the assumed radial dependence of the surface brightness of the source, but are quite sensitive to a large dispersion in cloud sizes. 55 references

Concept development of X-ray mass thickness detection for irradiated items upon electron beam irradiation processing

Science.gov (United States)

Qin, Huaili; Yang, Guang; Kuang, Shan; Wang, Qiang; Liu, Jingjing; Zhang, Xiaomin; Li, Cancan; Han, Zhiwei; Li, Yuanjing

2018-02-01

The present project will adopt the principle and technology of X-ray imaging to quickly measure the mass thickness (wherein the mass thickness of the item =density of the item × thickness of the item) of the irradiated items and thus to determine whether the packaging size and inside location of the item will meet the requirements for treating thickness upon electron beam irradiation processing. The development of algorithm of X-ray mass thickness detector as well as the prediction of dose distribution have been completed. The development of the algorithm was based on the X-ray attenuation. 4 standard modules, Al sheet, Al ladders, PMMA sheet and PMMA ladders, were selected for the algorithm development. The algorithm was optimized until the error between tested mass thickness and standard mass thickness was less than 5%. Dose distribution of all energy (1-10 MeV) for each mass thickness was obtained using Monte-carlo method and used for the analysis of dose distribution, which provides the information of whether the item will be penetrated or not, as well as the Max. dose, Min. dose and DUR of the whole item.

ROS enhancement by silicon nanoparticles in X-ray irradiated aqueous suspensions and in glioma C6 cells

International Nuclear Information System (INIS)

David Gara, Pedro M.; Garabano, Natalia I.; Llansola Portoles, Manuel J.; Moreno, M. Sergio; Dodat, Diego; Casas, Oscar R.; Gonzalez, Mónica C.; Kotler, Mónica L.

2012-01-01

The capability of silicon nanoparticles to increase the yield of reactive species upon 4 MeV X-ray irradiation of aqueous suspensions and C6 glioma cell cultures was investigated. ROS generation was detected and quantified using several specific probes. The particles were characterized by FTIR, XPS, TEM, DLS, luminescence, and adsorption spectroscopy before and after irradiation to evaluate the effect of high energy radiation on their structure. The total concentration of O 2 •− /HO 2 • , HO • , and H 2 O 2 generated upon 4-MeV X-ray irradiation of 6.4 μM silicon nanoparticle aqueous suspensions were on the order of 10 μM per Gy, ten times higher than that obtained in similar experiments but in the absence of particles. Cytotoxic 1 O 2 was generated only in irradiation experiments containing the particles. The particle surface became oxidized to SiO 2 and the luminescence yield reduced with the irradiation dose. Changes in the surface morphology did not affect, within the experimental error, the yields of ROS generated per Gy. X-ray irradiation of glioma C6 cell cultures with incorporated silicon nanoparticles showed a marked production of ROS proportional to the radiation dose received. In the absence of nanoparticles, the cells showed no irradiation-enhanced ROS generation. The obtained results indicate that silicon nanoparticles of 1 O 2 upon X-ray irradiation opens novel approaches in the design of therapy strategies.

Thermally and optically stimulated luminescence correlated processes in X-ray irradiated KCl:Eu2+

International Nuclear Information System (INIS)

Chernov, V.; Melendrez Ao, R.; Piters, T.M.; Barboza-Flores, M.

2001-01-01

The effect of optical bleaching on thermoluminescence (TL) and thermal bleaching on optically stimulated luminescence (OSL) outputs in X-ray irradiated KCl : Eu 2+ have been investigated. The X-ray induced glow curves reveal three main peaks located at 370, 410 and 470 K. Illumination with 560 nm light leads to a drastic change of the TL glow curve. The 470 K peak is destroyed during bleaching. The other peaks initially increase in intensity and only after sufficiently long bleaching begin to decrease. After long-time bleaching, the TL peaks in X-ray irradiated crystals look like the TL peaks found in UV irradiated crystals. The effect of thermal bleaching on OSL is also very pronounced. The temperature dependencies show a step-by-step decrease of the OSL intensity correlated with the positions of the TL peaks. The result obtained shows that centers responsible for the TL peaks participate in OSL, but this participation seems not to be direct and is complicated by processes accompanying the F center bleaching

Two cases of fibrosarcoma occurring in the x-ray irradiated site

International Nuclear Information System (INIS)

Wakamatsu, Katsuo; Mochizuki, Masako.

1975-01-01

The histological examination was carried out on the following 2 cases: One case was a 46-year-old man with psoriasis vulgaris who received x-ray irradiation continually for about 10 years on the gluteal regions and the extensive sides of both elbows. An ulcer appeared on the irradiated site and about 2 weeks later a tumor appeared. The other case was a 77-year-old man with prurigo in the pudendal region. Although the dose and duration of irradiation are unknown, the tumors appeared in the irradiated site 6-7 years after the start of irradiation. The histological examination of these cases revealed the clinical findings of fibrosarcoma. In the review of literature, 8 cases of irradiation sarcoma in Japan were discussed. (Kanao, N.)

Partial body irradiation of small laboratory animals with an industrial X-ray tube

International Nuclear Information System (INIS)

Frenzel, Thorsten; Kruell, Andreas; Grohmann, Carsten; Schumacher, Udo

2014-01-01

Dedicated precise small laboratory animal irradiation sources are needed for basic cancer research and to meet this need expensive high precision radiation devices have been developed. To avoid such expenses a cost efficient way is presented to construct a device for partial body irradiation of small laboratory animals by adding specific components to an industrial X-ray tube. A custom made radiation field tube was added to an industrial 200 kV X-ray tube. A light field display as well as a monitor ionization chamber were implemented. The field size can rapidly be changed by individual inserts of MCP96 that are used for secondary collimation of the beam. Depth dose curves and cross sectional profiles were determined with the use of a custom made water phantom. More components like positioning lasers, a custom made treatment couch, and a commercial isoflurane anesthesia unit were added to complete the system. With the accessories described secondary small field sizes down to 10 by 10 mm 2 (secondary collimator size) could be achieved. The dosimetry of the beam was constructed like those for conventional stereotactical clinical linear accelerators. The water phantom created showed an accuracy of 1 mm and was well suited for all measurements. With the anesthesia unit attached to the custom made treatment couch the system is ideal for the radiation treatment of small laboratory animals like mice. It was feasible to shrink the field size of an industrial X-ray tube from whole animal irradiation to precise partial body irradiation of small laboratory animals. Even smaller secondary collimator sizes than 10 by 10 mm 2 are feasible with adequate secondary collimator inserts. Our custom made water phantom was well suited for the basic dosimetry of the X-ray tube.

Histological examination of the effect of differently fractionated irradiations in rat and mouse organs. Pt. 3

International Nuclear Information System (INIS)

Unger, E.

1984-01-01

The spleen of rats was irradiated with 50 Gy dose local X-rays in two different fractionation rhythms, i.e. twice a week given high and daily applied lower fractions of radiation. According to the results of 3 H-thymidine autoradiography made after the last irradiation 24 hours later both in the white and the red pulp the labelling index was less on the effect of twice in a week applied high radiation fractions than in case of daily given lower fractions. This indicate in correlation with the results of earlier analogous histological experiments that the damaging effect of rarely given higher fractions of radiation in the spleen is especially obvious. (orig.) [de

Thermoluminescence properties of undoped and Tb3+ and Ce3+ doped YAG nanophosphor under UV-, X- and β-ray irradiation

International Nuclear Information System (INIS)

Rosa, E. de la; Rodriguez, R.A.; Melendrez, R.; Salas, P.; Diaz-Torres, L.A.; Barboza-Flores, M.

2007-01-01

The thermoluminescence (TL) properties of undoped, Ce 3+ and Tb 3+ doped Y 3 Al 5 O 12 (YAG) nanocrystals under UV-, X- and β-rays irradiation is reported. The TL signal of undoped and doped samples indicates a high sensitivity to UV-, X- and β-ray irradiation. The introduction of the doping ions induces changes in the trapping processes and the TL efficiency. The results show that both undoped and doped YAG nanocrystalline phosphor present good TL efficiency as well as good dose response which qualify them as a potential UV-, X- and β-ray dosimeter. A linear response under X-ray irradiation is observed for low doses level in the 0.02-1.02 μGy range and for relatively high doses level of β-ray irradiation in the range from 10 to 600 Gy

Heterogeneous response to X-ray and ultraviolet light irradiations of cultured skin fibroblasts in two families with Gardner's Syndrome

International Nuclear Information System (INIS)

Kinsella, T.J.; Little, J.B.; Nove, J.; Weichselbaum, R.R.; Li, F.P.; Meyer, R.J.; Marchetto, D.J.; Patterson, W.B.

1982-01-01

A heterogeneous response to X-ray and far UV (254 nm) light irradiations was found in cultured skin fibroblast lines from 2 separate families with Gardner's syndrome. When compared to 2 normal control cultures and cultures from 2 patients with nonfamilial colon cancer, cultures from 4 clinically affected members of family 1 showed increased sensitivity to the lethal effects of both X-ray and UV light irradiations. These cells also showed a delayed pattern of X-ray potentially lethal damage repair (PLDR) and absent UV PLDR. In contrast, cultures from 3 members of family 2 (2 of whom were clinically affected) showed a normal response of survival and PLDR to both X-ray and UV light irradiations. Thus increased sensitivity of cultured skin fibroblasts to X-ray and UV light irradiations was not a consistent in vitro finding in patients with Gardner's syndrome. However, in families with Gardner's syndrome who demonstrate in vitro radiosensitivity, additional studies are needed to assess the usefulness of these techniques in detecting affected individuals prior to the development of colon carcinoma and other manifestations

A low-energy x-ray irradiator for electrophysiological studies

International Nuclear Information System (INIS)

Schauer, D.A.; Zeman, G.H.; Pellmar, T.C.

1989-01-01

A 50 kVp molybdenum target/filter x-ray tube has been installed inside a lead-shielded Faraday cage. High-dose rates of up to 1.54 Gy min -1 (17.4 keV weighted average photons) have been used to conduct local in vitro irradiations of the hippocampal region of guinea pig brains. Electrophysiological recordings of subtle changes in neuronal activity indicate this system is suitable for this application. (author)

Experimental investigations of the dosimetric features of x-ray radiation used in x-ray diagnosis

Energy Technology Data Exchange (ETDEWEB)

Prostyakova, M A

1975-10-01

For radiation hygiene estimates of the extent of the irradiation of various organs and tissues in roentgenological investigations, the quality and quantity of the primary radiation beam and its behaviour in the irradiated medium are assessed. It is shown that the effective energy of x-rays generated at 50-100 kV and with different radiation field dimensions at different depths in a tissue-equivalent irradiated medium is more or less constant, varying within the range 25 to 32 keV. The constancy of effective x-ray energies in a tissue-equivalent medium enables one to use, for different x-ray tube regimes, constant values of the roentgen-rad conversion factor for soft tissue and bone tissue. The investigations confirm the desirability of using high voltages across the x-ray tube in practical x-ray work.

X-ray diffraction and thermal analysis of kaolins particle size fractions

Directory of Open Access Journals (Sweden)

Patricia dos Santos

2013-09-01

Full Text Available Kaolins are common geological materials and have high concentrations of kaolinite as well as the clay fraction of tropical and subtropical soils of Brazil. The characterization of kaolin is a proxy of assessing the contribution of kaolinite to important soil chemical and mineralogical attributes. This study evaluated four kaolins (commercial kaolin A (CCA, commercial kaolin B (CCB, pink sandy kaolin A (CRA and green sandy kaolin A (CVA in the original form and after particle size separation into: sand (200-53 mm, coarse silt (53-20 m, fine silt (20-2 m, large clay (2-1m, medium clay (1-0.5 m and fine clay (<0.5m fractions. The minerals were identified by X-ray diffraction (XRD and evaluated for crystallinity (kaolinite and halloysite through indexes Hughes and Brown, Amigó, Bramão and the dehydroxylation temperature. The physical fractionation was efficient to concentrate minerals in specific size fractions which were not identified in the original material. In CCA kaolin was concentrated one mineral which remains unidentified in fine fractions, in kaolin CRA, zircon was concentrated in the coarse silt and different silicates in the fine fractions, in kaolin CCB were concentrated kaolinite and a silicate in the medium and coarse clay fractions. The estimate by X-ray diffraction overestimated the amount of kaolinite and halloysite underestimated when compared to quantification by thermal gravimetric analysis The crystallinity index exhibit different behaviors depending on the mineralogy of each material, thus the correlation between the crystallinity of kaolinite and / or halloysite and other variables, may be compromised, especially in materials with distinct geological origins.

The enhancing effect of fractionated whole-body x-irradiation on replication of endogenous leukemia viruses in BALB/c mice

International Nuclear Information System (INIS)

Takamori, Yasuhiko; Okumoto, Masaaki; Iwai, Mineko; Iwai, Yoshiaki

1976-01-01

The incidence of leukemia, changes in the tissue weight of spleen and thymus, and the expression of endogenous viruses were examined with BALB/c mice following 4 weekly fractionated whole-body x-irradiation of 170 R each, starting at 4 weeks of age. The leukemia incidence was quite low for the unirradiated controls, while 60% of the irradiated male mice developed thymic lymphoma. The virus-positive cells appeared earlier in the spleen than in the thymus and bone marrow, and increased with aging. The time of appearance of virus-positive cells in these tissues was remarkably promoted by the fractionated x-irradiation, and its frequency was also enhanced. (auth.)

A biosafety evaluation of synchrotron radiation X-ray to skin and bone marrow: single dose irradiation study of rats and macaques.

Science.gov (United States)

Lu, Yifan; Tang, Guanghui; Lin, Hui; Lin, Xiaojie; Jiang, Lu; Yang, Guo-Yuan; Wang, Yongting

2017-06-01

Very limited experimental data is available regarding the safe dosages related to synchrotron radiation (SR) procedures. We used young rats and macaques to address bone marrow and skin tolerance to various doses of synchrotron radiation. Rats were subjected to 0, 0.5, 2.5, 5, 25 or 100 Gy local SR X-ray irradiation at left hind limb. Rat blood samples were analyzed at 2-90 days after irradiation. The SR X-ray irradiated skin and tibia were sectioned for morphological examination. For non-human primate study, three male macaques were subjected to 0.5 or 2.5 Gy SR X-ray on crus. Skin responses of macaques were observed. All rats that received SR X-ray irradiation doses greater than 2.5 Gy experienced hair loss and bone-growth inhibition, which were accompanied by decreased number of follicles, thickened epidermal layer, and decreased density of bone marrow cells (p X-ray but showed significant hair loss when the dose was raised above 2.5 Gy. The safety threshold doses of SR X-ray for rat skin, bone marrow and macaque skin are between 0.5 and 2.5 Gy. Our study provided essential information regarding the biosafety of SR X-ray irradiation.

Effects of Ru(CO)3Cl-glycinate on the developmental toxicities induced by X-ray and carbon-ion irradiation in zebrafish embryos

Energy Technology Data Exchange (ETDEWEB)

Zhou, Rong [Department of Radiation Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Basic Research on Heavy Ion Radiation Application in Medicine, Gansu Province, Lanzhou 730000 (China); Song, Jing’e [School/Hospital of stomatology, Lanzhou University, Lanzhou 730000 (China); Si, Jing [Department of Radiation Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Basic Research on Heavy Ion Radiation Application in Medicine, Gansu Province, Lanzhou 730000 (China); Zhang, Hong, E-mail: zhangh@impcas.ac.cn [Department of Radiation Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Basic Research on Heavy Ion Radiation Application in Medicine, Gansu Province, Lanzhou 730000 (China); Liu, Bin [School/Hospital of stomatology, Lanzhou University, Lanzhou 730000 (China); Gan, Lu; Zhou, Xin [Department of Radiation Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Basic Research on Heavy Ion Radiation Application in Medicine, Gansu Province, Lanzhou 730000 (China); and others

2016-11-15

Highlights: • CORM-3 pretreatment could significantly inhibit the X-ray irradiation-induced developmental toxicity and apoptosis with ROS generation. • CORM-3 pretreatment showed little effect on carbon-ion irradiation-induced developmental toxicity and apoptosis without ROS generation. • CORM-3 could inhibit apoptosis induced by ionizing radiation with low-LET as an effective ROS scavenger. • CORM-3 could suppress apoptosis and DNA damage by inhibiting the activation of P53 and the mitochondrial apoptotic pathway. - Abstract: The inhibitory effects of carbon monoxide (CO), generated by Ru(CO){sub 3}Cl-glycinate [CO-releasing molecule (CORM-3)], on developmental toxicity in zebrafish embryos induced by ionizing radiation with different linear energy transfer (LET) were studied. Zebrafish embryos at 5 h post-fertilization were irradiated with X-ray (low-LET) and carbon-ion (high-LET) with or without pretreatment of CORM-3 1 h before irradiation. CORM-3 pre-treatment showed a significant inhibitory effect on X-ray irradiation-induced developmental toxicity, but had little effect on carbon-ion irradiation-induced developmental toxicity. X-ray irradiation-induced significant increase in ROS levels and cell apoptosis could be modified by CORM-3 pretreatment. However, embryos exposed to carbon-ion irradiation showed significantly increase of cell apoptosis without obvious ROS generation, which could not be attenuated by CORM-3 pretreatment. CORM-3 could inhibit apoptosis induced by ionizing radiation with low-LET as an effective ROS scavenger. The expression of pro-apoptotic genes increased significantly after X-ray irradiation, but increased expression was reduced markedly when CORM-3 was applied before irradiation. Moreover, the protein levels of P53 and γ-H2AX increased markedly after X-ray irradiation, which could be modified by the presence of CORM-3. The protective effect of CORM-3 on X-ray irradiation occurred mainly by suppressing ROS generation and DNA

The effect of fractionating 100 R hard X-ray doses on the hemogram and proteinogram of the rabbit; Action du fractionnement de 100 R de rayons X sur l'hemogramme et le proteinogramme du lapin

Energy Technology Data Exchange (ETDEWEB)

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

1965-07-01

Eighty one rabbits 'Fauve de Bourgogne' received total exposure of 100 R X-rays, by fractional doses of 5 - 10 - 25 - 50 and 100 R per irradiation. Blood count and protein dosage were practised before, during and after the irradiation session. Seventeen controls were subjected to the same investigations with the same periodicity. Statistical analysis of experimental data permitted to infer from the exposures of X-rays, that irradiation induces drop in leucocytes count, resulting from a drop in mononuclear cells. On the other hand, it is more difficult to clear up its action on the protein profiles, because the observed changes were likewise observed on the controls, although at a lesser degree. Nevertheless, the authors think that it may be concluded to an increase of albumin concentration and to some instability of the gamma-globulins concentration. Then they discuss the possible mechanisms of X-rays effects: either perturbations of protean metabolism following loss of mitotic activity or histolysis. (author) [French] 81 lapins de race fauve de Bourgogne ont ete irradies in toto aux rayons X a la dose totale de 100 R aux fractionnements suivants: 5 - 10 - 25 - 50 et 100 R par seance. Des examens hematologiques et des dosages de proteines ont ete pratiques avant et apres irradiation et au cours de la periode d'irradiation; 17 temoins non irradies ont ete soumis aux memes examens avec la meme frequence. L'irradiation provoque une chute des leucocytes totaux, due surtout a la chute des elements mononuclees. Par contre, on ne peut pas mettre en evidenre une action propre a l'irradiation sur la formule proteique car les variations rencontrees s'observent egalement dans le lot temoin non irradie. (auteur)

Neutron and X-ray diffraction analysis of the effect of irradiation dose and temperature on microstructure of irradiated HT-9 steel

International Nuclear Information System (INIS)

Mosbrucker, P.L.; Brown, D.W.; Anderoglu, O.; Balogh, L.; Maloy, S.A.; Sisneros, T.A.; Almer, J.; Tulk, E.F.; Morgenroth, W.; Dippel, A.C.

2013-01-01

Material harvested from several positions within a nuclear fuel duct (the ACO-3 duct) used in a 6-year irradiation of a fuel assembly in the Fast Flux Test Reactor Facility (FFTF) was examined using neutron and high-energy X-ray diffraction. Samples with a wide range of irradiation dose and irradiation temperature history, reaching doses of up to 147 dpa and temperatures of up to 777 K, were examined. The response of various microstructural characteristics such as the weight fraction of M 23 C 6 carbides, the dislocation density and character, and the crystallographic texture were determined using whole profile analysis of the diffraction data and related to the macroscopic mechanical behavior. For instance, the dislocation density was observed to be intimately linked with observed flow strength of the irradiated materials, following the Taylor law. In general, at the high doses studied in this work, the irradiation temperature is the predominant controlling factor of the dislocation density and, thus, the flow strength of the irradiated material. The results, representing some of the first diffraction work done on samples exposed to such a high received dose, demonstrate how non-destructive and stand-off diffraction techniques can be used to characterize irradiation induced microstructure and at least estimate mechanical properties in irradiated materials without exposing workers to radiation hazards

The irradiation action on human dental tissue by X-rays and electrons. A nanoindenter study

Energy Technology Data Exchange (ETDEWEB)

Fraenzel, Wolfgang [Halle-Wittenberg Univ., Halle (Germany). Dept. of Physics; Gerlach, Reinhard [Halle-Wittenberg Univ., Halle (Germany). Clinic of Radiation Therapy

2009-07-01

It is known that ionizing radiation is used in medicine for Roentgen diagnostics and for radiation therapy. The radiation interacts with matter, in particular with biological one, essentially by scattering, photoelectric effect, Compton effect and pair production. To what extent the biological material is changed thereby, depends on the type and the amount of radiation energy, on the dose and on the tissue constitution. In modern radiation therapy two different kinds of radiation are used: high energy X-rays and electron radiation. In the case of head-neck tumors the general practice is an irradiation with high energy X-rays with absorbed dose to water up to 70 Gy. Teeth destruction has been identified as a side effect during irradiation. In addition, damage to the salivary glands is often observed which leads to a decrease or even the complete loss of the salivary secretion (xerostomia). This study shows how the different energy and radiation types damage the tooth tissue. The effects of both, high X-ray energy and high energy electrons, on the mechanical properties hardness and elasticity of the human dental tissue are measured by the nanoindentation technique. We compare these results with the effect of the irradiation of low X-ray energy on the dental tissue. (orig.)

The irradiation action on human dental tissue by X-rays and electrons. A nanoindenter study

International Nuclear Information System (INIS)

Fraenzel, Wolfgang; Gerlach, Reinhard

2009-01-01

It is known that ionizing radiation is used in medicine for Roentgen diagnostics and for radiation therapy. The radiation interacts with matter, in particular with biological one, essentially by scattering, photoelectric effect, Compton effect and pair production. To what extent the biological material is changed thereby, depends on the type and the amount of radiation energy, on the dose and on the tissue constitution. In modern radiation therapy two different kinds of radiation are used: high energy X-rays and electron radiation. In the case of head-neck tumors the general practice is an irradiation with high energy X-rays with absorbed dose to water up to 70 Gy. Teeth destruction has been identified as a side effect during irradiation. In addition, damage to the salivary glands is often observed which leads to a decrease or even the complete loss of the salivary secretion (xerostomia). This study shows how the different energy and radiation types damage the tooth tissue. The effects of both, high X-ray energy and high energy electrons, on the mechanical properties hardness and elasticity of the human dental tissue are measured by the nanoindentation technique. We compare these results with the effect of the irradiation of low X-ray energy on the dental tissue. (orig.)

Thermoluminescent response of Y2O3:Ce,Eu irradiated with X-rays

International Nuclear Information System (INIS)

Sanchez J, F. del R.; Sosa A, M. A.

2017-10-01

The thermoluminescent response of various materials has been studied when irradiated with X-rays, and the parameters that characterize the order of the kinetics of the material, depth of traps and frequency have been determined. The objective of this project was to characterize the thermoluminescent response of dosimeters based on yttrium oxide (Y 2 O 3 ) irradiated with X-rays. To do this, the thermoluminescent response of the Y 2 O 3 :Ce,Eu dosimeter was measured and exposed to an X-ray radiation field; five levels of radiation were used: in the first, a potential of 53.5 kv was used and a working load of 5.6 m As, in the second: 70.0 kv, 12.5 m As; in the third: 81.0 kv, 20.0 m As; in the fourth: 109 kv, 32 m As, in the fifth: 121 kv, 80.0 m As, applying an exposure range between 17.7 and 40 R. The irradiation was performed exposing the sample at 104 cm from the focus of the X-ray tube. To obtain the readings of the thermoluminescent response, a Harshaw TLD 3500 reader was used. The data captured by the reader was processed using the WinREMS software. The deletion protocol was as follows: the dosimeters already read were placed, one hour in the Terlab MA12D muffle at a temperature of (400 ± 1) degrees centigrade, the dosimeters were removed and left at room temperature of 20 degrees centigrade for 20 minutes. Then they were placed in the Binder high temperature oven ED23 at 100 ± 1 centigrade degrees for 2 hours. The brightness curves were de convolved using the WebPlotDigitizer v 3.8 software and the individual peaks of the brightness curves were obtained. We found that: the synthesized materials presented a good thermoluminescent response when irradiated with X-rays. However, only one of the dosimeters, of Yttrium oxide doped with 0.5% Cerium, showed a relatively linear response in the applied dose range. The analysis made to the brightness curve of the Yttrium oxide doped with Cerium at 0.5%, applying the method of the three points for the parameters

X-rays and photocarcinogenesis in hairless mice.

Science.gov (United States)

Lerche, Catharina M; Philipsen, Peter A; Wulf, Hans Christian

2013-08-01

It is well known that excessive X-ray radiation can cause non-melanoma skin cancers. With the increased incidence of sun-related skin cancer there is a need to investigate the combination of sunlight and X-rays. Immunocompetent C3.Cg/TifBomTac mice (n = 298) were divided into 12 groups. Mice were irradiated with 12, 29 or 50 kV X-rays. The mice received a total dose of 45 Gy. They were irradiated with 3 SED simulated solar radiation (SSR) either before or after irradiation with X-rays. The groups irradiated with X-rays alone, 0, 3, 9 and 10 mice (0, 12, 29 and 50 kV, respectively) developed squamous cell carcinoma. In the groups irradiated with SSR after X-rays the development of tumours was significantly faster in the 50 kV group than in the corresponding control group (175 vs. 194 days, p X-ray radiation the development of tumours was significantly faster in the 29 and the 50 kV groups than in the corresponding control group (175 vs. 202 days, p X-ray radiation alone is a weak carcinogen in hairless mice. There is an added carcinogenic effect if X-ray radiation is given on prior sun-exposed skin or if the skin is sun-exposed after X-rays. We still believe that X-ray radiation is a safe and effective therapy for various dermatological diseases but caution should be observed if a patient has severely sun-damaged skin or has a high-risk sun behaviour.

Improvement of mungbean by X-ray and thermal neutron irradiation

International Nuclear Information System (INIS)

Kwon, S.H.; Oh, J.H.

1983-01-01

With the aim of improving yield, resistance to Cercospora leaf spot and pod shattering, mungbean varieties Kyunggi No. 5 and M-317 were irradiated with X-rays and thermal neutrons. High yielding mutant lines are generally characterized by a higher number of pods per plant. Better Cercospora resistance appears often associated with later maturity. Satisfactory shattering resistance was not yet obtained. (author)

X-ray irradiation induced reversible resistance change in Pt/TiO2/Pt cells.

Science.gov (United States)

Chang, Seo Hyoung; Kim, Jungho; Phatak, Charudatta; D'Aquila, Kenneth; Kim, Seong Keun; Kim, Jiyoon; Song, Seul Ji; Hwang, Cheol Seong; Eastman, Jeffrey A; Freeland, John W; Hong, Seungbum

2014-02-25

The interaction between X-rays and matter is an intriguing topic for both fundamental science and possible applications. In particular, synchrotron-based brilliant X-ray beams have been used as a powerful diagnostic tool to unveil nanoscale phenomena in functional materials. However, it has not been widely investigated how functional materials respond to the brilliant X-rays. Here, we report the X-ray-induced reversible resistance change in 40-nm-thick TiO2 films sandwiched by Pt top and bottom electrodes, and propose the physical mechanism behind the emergent phenomenon. Our findings indicate that there exists a photovoltaic-like effect, which modulates the resistance reversibly by a few orders of magnitude, depending on the intensity of impinging X-rays. We found that this effect, combined with the X-ray irradiation induced phase transition confirmed by transmission electron microscopy, triggers a nonvolatile reversible resistance change. Understanding X-ray-controlled reversible resistance changes can provide possibilities to control initial resistance states of functional materials, which could be useful for future information and energy storage devices.

X-ray imaging of targets irradiated by the Nike KrF laser

International Nuclear Information System (INIS)

Brown, C.; Seely, J.; Feldman, U.; Obenschain, S.; Bodner, S.; Pawley, C.; Gerber, K.; Serlin, V.; Sethian, J.; Aglitskiy, Y.; Lehecka, T.; Holland, G.

1997-01-01

Foil targets irradiated by the Naval Research Laboratory Nike KrF laser were imaged in the x-ray region with two-dimensional spatial resolution in the 2 endash 10 μm range. The images revealed the smoothness of the emission from target and backlighter foils, the acceleration of the target foils, and the growth of Rayleigh endash Taylor instabilities that were seeded by patterns on the irradiated sides of CH foils

Effect of γ- Ray Irradiation on the Solid Ionic Conductor of (Cul)x(Na3PO4)1-X Materials (x= 0.1 and x= 0.3)

International Nuclear Information System (INIS)

Purwanto, P.

2008-01-01

Study on the effect of γ- ray irradiation on solid state conductor (Cul) x (Na 3 PO 4 ) 1-X have been done. The solid ionic conductor of (Cul) x (Na 3 PO 4 ) 1-X (x= 0.1 and x= 0.3) had been made by mixing Cul with Na 3 PO 4 by formula of (Cul) x (Na 3 PO 4 ) 1-X where x= 0.1 and x= 0.3 then pressed with 48.26 x 10 6 N/m 2 into pellete in diametre 1.5 x 10 - 2 m. The solid ionic conductor was then γ- ray irradiated with dose of 5 to 30 kGy. The result showed that the structure of (Cul) x (Na 3 PO 4 ) 1-X was Cul and Na 3 PO 4 . Crystall lattice strain of (Cul) x (Na 3 PO 4 ) 1-X were measured stable against the influence of radiation. The conductivity measurement of (Cul) x (Na 3 PO 4 ) 1-X was carried out by LCR at the frequence of 0.1 Hz to 100 kHz. The result showed that the conductivities of (Cul) x (Na 3 PO 4 ) 1-X after irradiation were increasing with radiation dose. (author)

ROS enhancement by silicon nanoparticles in X-ray irradiated aqueous suspensions and in glioma C6 cells

Energy Technology Data Exchange (ETDEWEB)

David Gara, Pedro M. [CITOMA, Fundacion Avanzar, Instituto de Terapia Radiante S.A., CIO La Plata (Argentina); Garabano, Natalia I. [University of Buenos Aires, Departamento de Quimica Biologica, Facultad de Ciencias Exactas y Naturales, UBA (Argentina); Llansola Portoles, Manuel J. [UNLP, INIFTA, Departamento de Quimica, Facultad de Ciencias Exactas (Argentina); Moreno, M. Sergio [Centro Atomico Bariloche (Argentina); Dodat, Diego; Casas, Oscar R. [CITOMA, Fundacion Avanzar, Instituto de Terapia Radiante S.A., CIO La Plata (Argentina); Gonzalez, Monica C., E-mail: gonzalez@inifta.unlp.edu.ar [UNLP, INIFTA, Departamento de Quimica, Facultad de Ciencias Exactas (Argentina); Kotler, Monica L., E-mail: kotler@qb.fcen.uba.ar [University of Buenos Aires, Departamento de Quimica Biologica, Facultad de Ciencias Exactas y Naturales, UBA (Argentina)

2012-03-15

The capability of silicon nanoparticles to increase the yield of reactive species upon 4 MeV X-ray irradiation of aqueous suspensions and C6 glioma cell cultures was investigated. ROS generation was detected and quantified using several specific probes. The particles were characterized by FTIR, XPS, TEM, DLS, luminescence, and adsorption spectroscopy before and after irradiation to evaluate the effect of high energy radiation on their structure. The total concentration of O{sub 2}{sup Bullet -}/HO{sub 2}{sup Bullet}, HO{sup Bullet}, and H{sub 2}O{sub 2} generated upon 4-MeV X-ray irradiation of 6.4 {mu}M silicon nanoparticle aqueous suspensions were on the order of 10 {mu}M per Gy, ten times higher than that obtained in similar experiments but in the absence of particles. Cytotoxic {sup 1}O{sub 2} was generated only in irradiation experiments containing the particles. The particle surface became oxidized to SiO{sub 2} and the luminescence yield reduced with the irradiation dose. Changes in the surface morphology did not affect, within the experimental error, the yields of ROS generated per Gy. X-ray irradiation of glioma C6 cell cultures with incorporated silicon nanoparticles showed a marked production of ROS proportional to the radiation dose received. In the absence of nanoparticles, the cells showed no irradiation-enhanced ROS generation. The obtained results indicate that silicon nanoparticles of <5 nm size have the potential to be used as radiosensitizers for improving the outcomes of cancer radiotherapy. Their capability of producing {sup 1}O{sub 2} upon X-ray irradiation opens novel approaches in the design of therapy strategies.

Spermatogenesis in adult rhesus monkeys following irradiation with X-rays or fission neutrons

International Nuclear Information System (INIS)

Rooij, D.G. de; Sonneveld, P.; Bekkum, D.W. van

A group of male rhesus monkeys was exposed to total body irradiation followed by autologous bone marrow transplantation. The animals were irradiated in the period between 1965 and 1976 and received a dose of 8.5 Gy of X-rays (300 KVP) or 3.6 Gy of 1 MeV fission neutrons. Of this group, a total of 11 male monkeys proved to be evaluable for studying the effects of irradiation on spermatogenesis. (Auth.)

Estimation of dependence between mean of fractionation of photons and neutrons dose and intensity of post-irradiation reaction of mouse large intestine

International Nuclear Information System (INIS)

Gasinska, A.

1995-01-01

The aim of the work was verification of mouse large intestine tolerance on fractionated 250 kV X-rays and 2.3 MeV neutrons doses. Two cm of large intestine of mouse CBA/HT strain were irradiated with various fraction doses: from 0.25 to 35 Gy of X-rays and 0.05-12 Gy of neutrons. The measure of injury was handicap of intestine function. Early post-irradiation reaction was measured by loss of body weight (2-3 weeks after irradiation) and mouse mortality (till 2 months after irradiation, LD50/2). The late reaction was measured on the base of maximal body weight in 1 year period after irradiation, deformation of excrements (after 10 months) and death of animals (till 12. month after irradiation, LD50/12). Fractionation of X-ray dose influenced on decrease of intensification of late irradiation effects. After fractionation of neutrons this effect has not been observed. α/β coefficient for X-rays was 19.9 Gy [15.2; 27.0] for body weight nadir, 13.4 Gy [9.3; 19.5] for early mortality (LD50/2), 6.4 Gy [3.6;11.0] for maximal body weight and 6.9 [4.2; 10.8] for late mortality (LD50/12). Analysis of influence of low doses of photons 90.25-4 Gy) and neutrons (0.05-0.8 Gy) showed trend to reduction α/β for photons only (LD50/2=5.4 Gy; LD50/12=4.6 Gy). α/β coefficient for neutrons was defined by LQ model only for maximal body weight and was 19.9 Gy [9.5; 61.0]. In application of graphic method α/β for neutrons was 230 Gy for early and 48 Gy for late effects. Lower values of α/β coefficient for late irradiation effects for photon radiation demonstrate the big influence of fractionation of photons dose on large intestine tolerance (decrease intensity in all biological effects). Author did not observe increase of intestine tolerance in fractionation of neutrons dose. Effect of irradiation damages repair in interfraction pauses, measured by percent of regenerated dose (F r ) was much bigger for photons. For X-rays it was 50% for early and 63% for late effects. In case of

Influence of X-ray irradiation on metabolic effects of adrenaline

International Nuclear Information System (INIS)

Szyszko, A.

1976-01-01

Effects of X-ray irradiation in the whole-body dose of 650 R on changes in glycogen levels in liver, and in either diaphragm and skeletal muscles, and on blood glucose levels, induced in 10 min by adrenaline, were investigated in starved mice. One day after the exposure, the drops in liver glycogen levels due to starvation were found to be highly reduced by previous irradiation. This resulted in an over dozen-fold relative elevation of liver glycogen content in relation to starved not irradiated mice. The post-irradiation accumulation of liver glycogen was found to disappear after administration of adrenaline. Also in diaphragm and skeletal muscles, the changes in muscle glycogen content, induced by irradiation of starved mice, have turned out to be abolished or even reversed by adrenaline, what reflected in reduction of elevated levels and elevation of those reduced. In starved mice during first three days following irradition, adrenaline was found to be ineffective in increasing blood sugar levels, whereas this its effects was noted in either not irradiated mice or on the fourth day after irradiation. (author)

X-ray emission, ablation pressure, and preheating for foils irradiated at 0. 26. mu. m wavelength

Energy Technology Data Exchange (ETDEWEB)

Pepin, H.; Fabbro, R.; Faral, B.; Amiranoff, F.; Virmont, J.; Cottet, F.; Romain, J.P.

1985-11-01

The x-ray emission, ablation pressure, and preheating for foils irradiated with a 0.26 ..mu..m laser at intensities approx.10/sup 15/ W cm/sup -2/ are studied. The foils are Al with various thicknesses, coated or uncoated with CH or Au. The x-ray emission and conversion efficiency are obtained with a multichannel x-ray diode spectrometer, the ablation pressures are deduced from shock transit times, and the rear temperatures are inferred from x-ray pyrometry. For thin foils (<<12 ..mu..m), the rear temperatures can be predicted reasonably well with the use of the front x-ray spectra. For thick foils shock preheating is dominant.

X-ray emission, ablation pressure, and preheating for foils irradiated at 0.26 μm wavelength

International Nuclear Information System (INIS)

Pepin, H.; Fabbro, R.; Faral, B.; Amiranoff, F.; Virmont, J.; Cottet, F.; Romain, J.P.

1985-01-01

The x-ray emission, ablation pressure, and preheating for foils irradiated with a 0.26 μm laser at intensities approx.10 15 W cm -2 are studied. The foils are Al with various thicknesses, coated or uncoated with CH or Au. The x-ray emission and conversion efficiency are obtained with a multichannel x-ray diode spectrometer, the ablation pressures are deduced from shock transit times, and the rear temperatures are inferred from x-ray pyrometry. For thin foils (<<12 μm), the rear temperatures can be predicted reasonably well with the use of the front x-ray spectra. For thick foils shock preheating is dominant

Influence of UV Photo-Transfer on Post Irradiated Double Sulphate Poly-Crystals By Gamma And X-rays

International Nuclear Information System (INIS)

El-kolaly, M.A.

2000-01-01

Solid state thermoluminescence (TL) dosimetry has for many years been the pre-eminent method for quantifying ionizing radiation dose. In this work, thermoluminescence characteristics of the double sulphate (Li Cs So 4 ) poly-crystals have been studied after exposure to different doses from X and gamma radiation. The glue curves showed TL response of three peaks at 75,125,250 degree. The structure of the glue peaks due to X-rays is quite different from that due to gamma rays. UV exposure yields a regeneration of the TL peaks for the post irradiated samples for X or gamma radiation with some changes in the peaks structure especially the third peak. For the post X-ray irradiated crystals, the area under the third glow peak (III) increased linearly with the integrated time of UV exposures till about 30 min. after which no changes were observed; while , for the post gamma-irradiated crystals two linear regions were observed

X-ray studies of irradiation induced dislocation loops in metals

International Nuclear Information System (INIS)

Larson, B.C.

1975-01-01

Theoretical and experimental progress has resulted in the increased use of x-rays for the study of defects and defect clusters in crystals. An outline of the theoretical framework associated with Huang, Stokes-Wilson and integral diffuse scattering from dislocation loops is presented, and an account of recent experiments on radiation induced loops is given. These studies include low temperature, ambient temperature, and elevated temperature irradiations of metals with electrons, neutrons, and accelerated ions, and pertain to the study of the thermal annealing characteristics as well as the as-produced damage structure. The information obtained by x-rays as to the type, size and concentrations of dislocation loops is contrasted with existing electron microscopy, electrical resistivity, and lattice parameter data in order to establish correlations and identify areas of disagreement

Effects of gamma-ray irradiation on the optical properties of amorphous Se100-xHgx thin films

Science.gov (United States)

Ahmad, Shabir; Islam, Shama; Nasir, Mohd.; Asokan, K.; Zulfequar, M.

2018-06-01

In this study, the thermal quenching technique was employed to prepare bulk samples of Se100-xHgx (x = 0, 5, 10, 15). Thin films with a thickness of ∼250 nm were deposited on glass substrates using the thermal evaporation technique. These films were irradiated with gamma rays at doses of 25-100 kGy. The elemental compositions of the as-deposited thin films were confirmed by energy dispersive X-ray analysis and Rutherford backscattering spectrometry. X-ray diffraction analysis confirmed the crystalline nature of these thin films upto the dose of 75 kGy. Fourier transform-infrared spectroscopy showed that the concentration of defects decreased after gamma irradiation. Microstructural analysis by field emission scanning electron microscopy indicated that the grain size increases after irradiation. Optical study based on spectrophotometry showed that the optical band gap values of these films increase after the addition of Hg whereas they decrease after gamma irradiation. We found that the absorption coefficient increases with doses up to 75 kGy but decreases at higher doses. These remarkable shifts in the optical band gap and absorption coefficient values are interpreted in terms of the creation and annihilation of defects, which are the main effects produced by gamma irradiation.

Effects of X-ray irradiation on the microbial growth and quality of flue-cured tobacco during aging

International Nuclear Information System (INIS)

Wang, J.J.; Xu, Z.C.; Fan, J.L.; Wang, Y.; Tian, Z.J.; Chen, Y.T.

2015-01-01

X-ray irradiation was evaluated for improving microbial safety and the quality of flue-cured tobacco during aging. Tobacco samples were irradiated at doses of 0, 1, 2, 3 and 5 kGy and stored for 12 months under normal storage conditions or in a high-humidity (RH>70%) room. Microbiological data indicated that the population of total aerobic bacteria was significantly decreased with increasing irradiation doses. In particular, a dose of 2 kGy was effective for the decontamination of fungi from the tested samples, with a 0.93 log CFU/g reduction for bacteria. The control and 1 kGy X-ray treated tobacco samples were became rotted and moldy after the 12th month, whereas those treated with 2, 3 and 5 kGy had no detectable mold during 12 months of storage at high humidity. Chemical measurements showed that irradiation up to 3 kGy did not affect the total nitrogen, nicotine, reducing and total sugars, ratio of total nitrogen to nicotine and sugar-to-nicotine ratio. Furthermore, sensory evaluation results also showed that X-ray irradiation did not affect sensory scores with irradiation at a dose <3 kGy. Based on these results, X-ray irradiation dose in the range of 2–3 kGy is recommended for the decontamination of fungi from flue-cured tobacco. - Highlights: • 2 kGy dose improved sufficiently the microbial safety of flue-cured tobacco. • The doses up to 3 kGy did not affect the chemical components. • A dose <3 kGy had no effect on sensory scores. • The recommended dose to irradiated flue-cured tobacco is the range of 2–3 kGy

Impact of gold nanoparticles combined to X-Ray irradiation on bacteria

International Nuclear Information System (INIS)

Simon-Deckers, A.; Gouget, B.; Carriere, M.; Brun, E.; Sicard-Roselli, C.

2008-01-01

Recent increase of multi drug-resistant bacteria represents a crucial issue of public health. As innovative approaches are required to face that problem, those emerging from nano-technology are of great interest. In that context we propose the possibility to use gold nano-particles combined with ionising radiation to destroy pathogenic bacteria. For that, we investigated the potential X-Rays enhanced reduction of bacterial cell viability, following nanoparticle exposure, on a bacterial model, Escherichia coli. Our first concern was to confirm the absence of toxicity of the colloidal solution used. Then, we developed an X-Ray irradiation system and showed that gold nanoparticles increased the efficiency of ionising radiation to induce bacteria cell death. (authors)

Luminescence yield in irradiating gases by X-rays and alpha particles

International Nuclear Information System (INIS)

Combecher, D.

1973-01-01

In this paper, the measurable light emission in the irradiation of gases as modle substances has been quantitatively determined. The gases Ar, H 2 , N 2 , air, and C 3 H 8 were irradiated with X-rays and α-particles at a pressure of 730 torr. The emitted light was measured in the spectral range between the short-wave absorption edge of the gases and 6000 A (spectral resolution: 20 A). The spectral light yield was determined from the efficiency of the apparatus and from the total energy absorbed in the gases. (HK) [de

Effects of genistein following fractionated lung irradiation in mice

International Nuclear Information System (INIS)

Para, Andrea E.; Bezjak, Andrea; Yeung, Ivan W.T.; Van Dyk, Jake; Hill, Richard P.

2009-01-01

Background and purpose: This study investigated protection of lung injury by genistein following fractionated doses of radiation and its effect on tumor response. Material and methods: C3H/HeJ mice were irradiated (100 kVp X-rays) with 9 fractions of 3.1 Gy over 30 days (approximately equivalent to 10 Gy single dose) and were maintained on a genistein diet (∼10 mg/kg). Damage was assessed over 28 weeks in lung cells by a cytokinesis block micronucleus (MN) assay and by changes in breathing rate and histology. Tumor protection was assessed using a colony assay to determine cell survival following in situ irradiation of small lung nodules (KHT fibrosarcoma). Results: Genistein caused about a 50% reduction in the MN damage observed during the fractionated radiation treatment and this damage continued to decrease at later times to background levels by 16 weeks. In mice not receiving Genistein MN levels remained well above background out to 28 weeks after irradiation. Genistein reduced macrophage accumulation by 22% and reduced collagen deposition by 28%. There was minimal protection against increases in breathing rate or severe morbidity during pneumonitis. No tumor protection by genistein treatment was observed. Conclusions: Genistein at the dose levels used in this study partially reduced the extent of fibrosis developing in mouse lung caused by irradiation but gave minimal protection against pneumonitis. There was no evidence that genistein caused protection of small tumors growing in the lung.

X-ray masks

International Nuclear Information System (INIS)

Greenwood, J.C.; Satchell, D.W.

1984-01-01

In semiconductor manufacture, where X-ray irradiation is used, a thin silicon membrane can be used as an X-ray mask. This membrane has areas on which are patterns to define the regions to be irradiated. These regions are of antireflection material. With the thin, in the order of 3 microns, membranes used, fragility is a problem. Hence a number of ribs of silicon are formed integral with the membrane, and which are relatively thick, 5 to 10 microns. The ribs may be formed by localised deeper boron deposition followed by a selective etch. (author)

Biological X-ray irradiator characterization for use with small animals and cells.

Science.gov (United States)

Bruno, A Colello; Mazaro, S J; Amaral, L L; Rego, E M; Oliveira, H F; Pavoni, J F

2017-03-02

This study presents the characterization of an X-ray irradiator through dosimetric tests, which confirms the actual dose rate that small animals and cells will be exposed to during radiobiological experiments. We evaluated the linearity, consistency, repeatability, and dose distribution in the positions in which the animals or cells are placed during irradiation. In addition, we evaluated the performance of the X-ray tube (voltage and tube operating current), the radiometric survey (leakage radiation) and safety devices. The irradiator default setting was established as 160 kV and 25 mA. Tests showed that the dose rate was linear overtime (R2=1) and remained stable for long (constant) and short (repeatability) intervals between readings. The mean dose rate inside the animal cages was 1.27±0.06 Gy/min with a uniform beam of 95.40% (above the minimum threshold guaranteed by the manufacturer). The mean dose rate inside the cell plates was 0.92±0.19 Gy/min. The dose rate dependence with tube voltage and current presented a quadratic and linear relationship, respectively. There was no observed mechanical failure during evaluation of the irradiator safety devices and the radiometric survey obtained a maximum ambient equivalent dose rate of 0.26 mSv/h, which exempts it from the radiological protection requirements of the International Atomic Energy Agency. The irradiator characterization enables us to perform radiobiological experiments, and assists or even replaces traditional therapy equipment (e.g., linear accelerators) for cells and small animal irradiation, especially in early research stages.

Biological X-ray irradiator characterization for use with small animals and cells

Directory of Open Access Journals (Sweden)

A. Colello Bruno

Full Text Available This study presents the characterization of an X-ray irradiator through dosimetric tests, which confirms the actual dose rate that small animals and cells will be exposed to during radiobiological experiments. We evaluated the linearity, consistency, repeatability, and dose distribution in the positions in which the animals or cells are placed during irradiation. In addition, we evaluated the performance of the X-ray tube (voltage and tube operating current, the radiometric survey (leakage radiation and safety devices. The irradiator default setting was established as 160 kV and 25 mA. Tests showed that the dose rate was linear overtime (R2=1 and remained stable for long (constant and short (repeatability intervals between readings. The mean dose rate inside the animal cages was 1.27±0.06 Gy/min with a uniform beam of 95.40% (above the minimum threshold guaranteed by the manufacturer. The mean dose rate inside the cell plates was 0.92±0.19 Gy/min. The dose rate dependence with tube voltage and current presented a quadratic and linear relationship, respectively. There was no observed mechanical failure during evaluation of the irradiator safety devices and the radiometric survey obtained a maximum ambient equivalent dose rate of 0.26 mSv/h, which exempts it from the radiological protection requirements of the International Atomic Energy Agency. The irradiator characterization enables us to perform radiobiological experiments, and assists or even replaces traditional therapy equipment (e.g., linear accelerators for cells and small animal irradiation, especially in early research stages.

Radiation induced muscositis as space flight risk. Model studies on X-ray and heavy ion irradiated typical oral mucosa models

International Nuclear Information System (INIS)

Tschachojan, Viktoria

2014-01-01

Humans in exomagnetospheric space are exposed to highly energetic heavy ion radiation which can be hardly shielded. Since radiation-induced mucositis constitutes a severe complication of heavy ion radiotherapy, it would also implicate a serious medical safety risk for the crew members during prolonged space flights such as missions to Moon or Mars. For assessment of risk developing radiation-induced mucositis, three-dimensional organotypic cultures of immortalized human keratinocytes and fibroblasts were irradiated with a 12 C particle beam at high energies or X-Rays. Immunofluorescence stainings were done from cryosections and radiation induced release of cytokines and chemokines was quantified by ELISA from culture supernatants. The major focuses of this study were on 4, 8, 24 and 48 hours after irradiation. The conducted analyses of our mucosa model showed many structural similarities with the native oral mucosa and authentic immunological responses to radiation exposure. Quantification of the DNA damage in irradiated mucosa models revealed about twice as many DSB after heavy-ion irradiation compared to X-rays at definite doses and time points, suggesting a higher gene toxicity of heavy ions. Nuclear factor κB activation was observed after treatment with X-rays or 12 C particles. An activation of NF κB p65 in irradiated samples could not be detected. ELISA analyses showed significantly higher interleukin 6 and interleukin 8 levels after irradiation with X-rays and 12 C particles compared to non-irradiated controls. However, only X-rays induced significantly higher levels of interleukin 1β. Analyses of TNF-α and IFN-γ showed no radiation-induced effects. Further analyses revealed a radiation-induced reduction in proliferation and loss of compactness in irradiated oral mucosa model, which would lead to local lesions in vivo. In this study we revealed that several pro-inflammatory markers and structural changes are induced by X-rays and heavy-ion irradiation

Reactions of the intracellular NADpool in the yeast S. cerevisiae after UV-C- or X-ray irradiation

International Nuclear Information System (INIS)

Winckler, K.; Herfurth, E.

1988-01-01

The reaction of the intracellular NADpool after irradiation of cells either with UV-C light or with X-rays was studied in four different strains of the yeast S. cerevisiae. We found neither in wildtype strains nor in radiation sensitive mutants remarkable changes in the NADpool within 2 h after irradiation. Preculture of cells in medium enriched with nicotinic acid, a precursor of NAD, influenced the intracellular NAD concentration only to a small extent in all strains, but enhanced the radiation resistance against UV-C significantly in one rad6 mutant strain. The uptake of NAD and NAC by all strains before and after irradiation with UV-C and X-ray was tested also. NAD generally is taken up by the cells to a very low extent before and after irradiation without irradiation-dose dependency. NAC is taken up by all strains before and after irradiation. Only the rad6 mutant exhibited an irradiation-dose dependent NAC-uptake after UV-C irradiation. (orig.)

X-ray excited optical luminescence, photoluminescence, photostimulated luminescence and x-ray photoemission spectroscopy studies on BaFBr:Eu

CERN Document Server

Subramanian, N; Govinda-Rajan, K; Mohammad-Yousuf; Santanu-Bera; Narasimhan, S V

1997-01-01

The results of x-ray excited optical luminescence (XEOL), photoluminescence (PL), photostimulated luminescence (PSL) and x-ray photoemission spectroscopy (XPS) studies on the x-ray storage phosphor BaFBr:Eu are presented in this paper. Analyses of XEOL, PL and PSL spectra reveal features corresponding to the transitions from 4f sup 6 td sup 1 to 4f sup 7 configurations in different site symmetries of Eu sup 2 sup +. Increasing x-ray dose is seen to lead to a red shift in the maximum of the PL excitation spectrum for the 391 nm emission. The XEOL and XPS spectra do not show any signature of Eu sup 3 sup + in the samples studied by us, directly raising doubts about the model of Takahashi et al in which Eu sup 2 sup + is expected to ionize to Eu sup 3 sup + upon x-ray irradiation and remain stable until photostimulation. XEOL and PSL experiments with simultaneous x-ray irradiation and He - Ne laser excitation as well as those with sequential x-ray irradiation and laser stimulation bring out the competition betwe...

Response of the upper atmosphere to variations in the solar soft x-ray irradiance. Ph.D. Thesis

Science.gov (United States)

Bailey, Scott Martin

1995-01-01

Terrestrial far ultraviolet (FUV) airglow emissions have been suggested as a means for remote sensing the structure of the upper atmosphere. The energy which leads to the excitation of FUV airglow emissions is solar irradiance at extreme ultraviolet (EUV) and soft x-ray wavelengths. Solar irradiance at these wavelengths is known to be highly variable; studies of nitric oxide (NO) in the lower thermosphere have suggested a variability of more than an order of magnitude in the solar soft x-ray irradiance. To properly interpret the FUV airflow, the magnitude of the solar energy deposition must be known. Previous analyses have used the electron impact excited Lyman-Birge-Hopfield (LBH) bands of N2 to infer the flux of photoelectrons in the atmosphere and thus to infer the magnitude of the solar irradiance. This dissertation presents the first simultaneous measurements of the FUV airglow, the major atmospheric constituent densities, and the solar EUV and soft x-ray irradiances. The measurements were made on three flights of an identical sounding rocket payload at different levels of solar activity. The linear response in brightness of the LBH bands to variations in solar irradiance is demonstrated. In addition to the N2 LBH bands, atomic oxygen lines at 135.6 and 130.4 nm are also studied. Unlike the LBH bands, these emissions undergo radiative transfer effects in the atmosphere. The OI emission at 135.6 nm is found to be well modeled using a radiative transfer calculation and the known excitation processes. Unfortunately, the assumed processes leading to OI 130.4 nm excitation are found to be insufficient to reproduce the observed variability of this emission. Production of NO in the atmosphere is examined; it is shown that a lower than previously reported variability in the solar soft x-ray irradiance is required to explain the variability of NO.

X-ray diffraction studies of 145MeV proton-irradiated AlBeMet 162

Directory of Open Access Journals (Sweden)

Mohamed Elbakhshwan

2016-08-01

Full Text Available AlBeMet 162 (Materion Co., formerly Brush Wellman has been irradiated with 145MeV protons up to 1.2×1020cm−2 fluence, with irradiation temperatures in the range of 100–220°C. Macroscopic post-irradiation evaluation on the evolution of mechanical and thermal properties was integrated with a comprehensive X-ray- diffraction study using high-energy monochromatic and polychromatic X-ray beams, which offered a microscopic view of the irradiation damage effects on AlBeMet. The study confirmed the stability of the metal–matrix composite, its resistance to proton damage, and the continuing separation of the two distinct phases, fcc aluminum and hcp beryllium, following irradiation. Furthermore, based on the absence of inter-planar distance change during proton irradiation, it was confirmed that the stacking faults and clusters on the Al (111 planes are stable, and thus can migrate from the cascade region and be absorbed at various sinks. XRD analysis of the unirradiated AlBeMet 162 showed clear change in the texture of the fcc phase with orientation especially in the Al (111 reflection which exhibits a “non-perfect” six-fold symmetry, implying lack of isotropy in the composite.

Effects of X-ray irradiation on the expression of Pokemon gene in human lung adenocarcinoma cell line

International Nuclear Information System (INIS)

Liang Xiaofang; Zou Yue; Wang Lu; Jiang Qisheng; Li Fengsheng

2012-01-01

Objective: To study the dose and time effects of X-ray radiation on the expression of Pokemon gene and protein in human lung adenocarcinoma cell line A 549 . Methods: A 549 cells was exposed to different doses of X-ray (2, 4, 6 and 8 Gy), and the expression of Pokemon mRNA and protein of the cells was detected by using Quantitative real-time PCR and western-blotting at 2, 4, 8, 12, 24, and 48 h after irradiation. 3-( 4, 5-Dimethylthiazole-2-yl )-2, 5-diphenyltetrazolium bromide was used to detect the proliferation of A 549 cells at 1, 2, 3, 4, and 5 d after 2 Gy X-ray irradiation. The mock treated A 549 cells were used as the control. Results: The expression of Pokemon mRNA trended to decrease after irradiated with 4, 6 and 8 Gy in the earlier period and increased in the later period with statistical difference at the most time points (t =3.40 -154.76, P =0.000 -0.041). The expression of Pokemon protein trended to increase and reached the peak at 8 h after irradiated of 2, 4, 6 and 8 Gy with statistical difference at the most time points (t =4.18 - 89.64, P =0.000 - 0.039). Compared with the control, the proliferation of A 549 cells was significantly inhibited during 3 to 5 d after irradiation of 2 Gy (t =2.34 - 18.19, P =0.000 -0.040). Conclusions: X-ray irradiation may increase the expression of Pokemon mRNA and protein in A 549 cells, which might be correlated with radiation-resistance of A 549 cells. (authors)

Repair of lesions provoked by X-rays in embryos of Drosophila (D. melanogaster Meig)

International Nuclear Information System (INIS)

Ghelelovitch, S.

1975-01-01

The sensitivity of Drosophila eggs to the lethal action of X-rays did not remain constant during embryogenesis. The X-ray doses used in the present investigation may have retarded the hatching of the larvae but did not block development immediately after irradiation. A fraction of the damage induced in young embryos was repaired during gastrulation. The amount of repair was independent of the X-ray dose but was influenced by the temperature. The damage could be repaired even after the cells of the embryo had undergone many mitotic cycles. (author)

Expression and localization of Smad4 protein in mouse testis after whole-body X-ray irradiation

International Nuclear Information System (INIS)

Zhu Huaping; Zhang Yuanqiang; Zhao Jie; Zhao Yong; Ma Jing; Hou Wugang; Qi Yuhong

2005-01-01

The work is to determine whether and where Transforming growth factor-betas downstream Signaling molecule Smad4 is expressed in the testes after whole-body X-ray irradiation and shed light on the mechanisms of Transforming growth factor-betas/Smad signal pathway mediates cell fate decisions following X-ray exposure. Five groups of adult BALB/c mice, with ten mice in each group, received whole-body of X-ray at dose levels of 0.1 Gy, 0.5 Gy, 1.0 Gy, 1.5 Gy and 2.0 Gy. They were sacrificed at 16 hour, 1 week, 2 weeks, 3 weeks and 4 weeks after the irradiation. Cellular localization and expression changes were examined by immunohistochemical ABC method. Quantitative analysis of the immunostaining was made by an image analysis system. In the seminiferous tubules, the expression of Smad4 was modulated by irradiation. The immunostaining showed that 16 hour post-irradiation, there was a significant decline in the Leydig cell, and it was dose and time depended. In addition, the immunolocalization showed that Smad4 was not exclusively localized in the cytoplasm of Leydig cells, but also localized in various Stages of spermatogenesis after the exposure, especially in premeiotic spermatogonia and primary spermatocytes. There was just a little expression in the 2.0 Gy group 16 h after the irradiation and the 1.0 Gy and 1.5 Gy groups at 2 weeks after the irradiation. Therefore in the 0.1 Gy to 2.0 Gy groups at 3 weeks after the irradiation, the immunostaining positive cells were significantly increased in spermatogonia and primary spermatocytes. There was no significant change in sertoli cells with different doses and different times after the exposure. The different expression patterns and change by dose and time of Smad4, suggest that TGF-β/Smad signal pathway may affect aspect after X-ray impairment and Smad4 may play an important role during these periods. (authors)

Survivin and chromosome instability induced by X-irradiation

International Nuclear Information System (INIS)

Shen Bo; Ju Guizhi; Liu Yang

2006-01-01

Objective: To explore the biological effect of survivin on chromosome instability induced by X-ray irradiation. Methods: Immunocytochemistry was used to detect the expression of sutvivin in HeLa cells. Carrier pSUPER-SVV was transfected into HeLa cells to interfere the expression of survivin. Flow cytometry assay was applied to detect the occurrence of polyploid at 0 h, 4 h, 12 h, and 48 h after the HeLa cells transfected with pSUPER-SVV and irradiated with 4 Gy X-rays irradiation, and compared with the group irradiated with 4 Gy X-rays but no transfection. Results: The expression of survivin was down-regulated by transfecting with small hair RNA, its depression rate was estimated to be about 32.16% at 48 h after transfection. The occurrence of polyploid giant cells was higher in the 4 Gy X-ray irradiated group at 48 h after the irradiation than the control groups (P<0.001). Being expression of survivin interfered, the occurrence at 12 h or 48 h after irradiation, however, was about two times higher than that in the control group. Conclusion: X-ray irradiation can induce chromosome instability in HeLa cells and the effect could be enhanced by interfering the expression of surviving. It was suggested that survivin plays an important role in maintaining the stability of chromosome. (authors)

PFGE analysis of DNA double-strand breaks and DNA repair process in human osteosarcoma cells irradiated by X-ray

International Nuclear Information System (INIS)

Cao Jianping; Majima, H.; Yamaguchi, C.

2000-01-01

Objective: To study the induction of DNA double-strand breaks (DSBs) in human osteosarcoma cells irradiated by X-ray, the DNA DSBs repair process and the tumour cell radiosensitivity. Methods: Two cell lines of human osteosarcoma, Rho0 and 143. B were used. Initial DNA damage of DSBs by X-ray irradiation was measured using clamped homogeneous electrical field (CHEF) electrophoresis. Results: X-ray-induced DNA DSBs of human osteosarcoma cells after CHEF-electrophoresis increased linearly with the irradiation dose between 0 and 50 Gy. The repair of DNA DSBs in human osteosarcoma cells increased with the post-irradiation incubation time. In contrast to 14.3B cell line at the same dose point, much more DNA DSBs were induced in Rho0 cell line after X-ray irradiation. Conclusion: CHEF pulsed-field gel electrophoresis (PEGE) is a sensitive method for the determination of radiation-induced DNA DSBs in high molecular weight DNA of human osteosarcoma cells. Radiation-induced DNA DSBs of osteosarcoma increase with the dose in a linear manner. After incubation, both Rho0 cell line and 143. B cell line can repair the DNA DSBs. Between two cell lines of human osteosarcoma, Rho0 and 143.B, Rho0 cell line is more sensitive to ionizing radiation than 143.B line

Three-dimensional Invasion of Human Glioblastoma Cells Remains Unchanged by X-ray and Carbon Ion Irradiation In Vitro

Energy Technology Data Exchange (ETDEWEB)

Eke, Iris; Storch, Katja; Kaestner, Ina; Vehlow, Anne [OncoRay-National Center for Radiation Research in Oncology, Medical Faculty Carl Gustav Carus, Dresden University of Technology, Dresden (Germany); Faethe, Christina; Mueller-Klieser, Wolfgang [Institute of Physiology and Pathophysiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz (Germany); Taucher-Scholz, Gisela [Department of Biophysics, GSI Helmholtz Center for Heavy Ion Research, Darmstadt (Germany); Temme, Achim; Schackert, Gabriele [Section of Experimental Neurosurgery/Tumor Immunology, Department of Neurosurgery, University Hospital Carl Gustav Carus, Dresden University of Technology, Dresden (Germany); Cordes, Nils, E-mail: Nils.Cordes@Oncoray.de [OncoRay-National Center for Radiation Research in Oncology, Medical Faculty Carl Gustav Carus, Dresden University of Technology, Dresden (Germany); Department of Radiation Oncology, Medical Faculty Carl Gustav Carus, Dresden University of Technology, Dresden (Germany)

2012-11-15

Purpose: Cell invasion represents one of the major determinants that treatment has failed for patients suffering from glioblastoma. Contrary findings have been reported for cell migration upon exposure to ionizing radiation. Here, the migration and invasion capability of glioblastoma cells on and in collagen type I were evaluated upon irradiation with X-rays or carbon ions. Methods and Materials: Migration on and invasion in collagen type I were evaluated in four established human glioblastoma cell lines exposed to either X-rays or carbon ions. Furthermore, clonogenic radiation survival, proliferation (5-bromo-2-deoxyuridine positivity), DNA double-strand breaks ({gamma}H2AX/53BP1-positive foci), and expression of invasion-relevant proteins (eg, {beta}1 integrin, FAK, MMP2, and MMP9) were explored. Migration and invasion assays for primary glioblastoma cells also were carried out with X-ray irradiation. Results: Neither X-ray nor carbon ion irradiation affected glioblastoma cell migration and invasion, a finding similarly observed in primary glioblastoma cells. Intriguingly, irradiated cells migrated unhampered, despite DNA double-strand breaks and reduced proliferation. Clonogenic radiation survival was increased when cells had contact with extracellular matrix. Specific inhibition of the {beta}1 integrin or proliferation-associated signaling molecules revealed a critical function of JNK, PI3K, and p38 MAPK in glioblastoma cell invasion. Conclusions: These findings indicate that X-rays and carbon ion irradiation effectively reduce proliferation and clonogenic survival without modifying the migration and invasion ability of glioblastoma cells in a collagen type I environment. Addition of targeted agents against members of the MAPK and PI3K signaling axis to conventional chemoradiation therapy seems potentially useful to optimize glioblastoma therapy.

Long-term effects of x-ray irradiation on reproductive function in male rats

International Nuclear Information System (INIS)

Varga, S.V.; Demchenko, V.N.; Chajkovskaya, L.V.; Reznikov, A.G.

1994-01-01

Reproductive function in male rats was studied in 1, 3 and 6 months after x-ray irradiation at doses of 2 and 3 Gy. It was been established that long-term effects of irradiation at a dose of 3 Gy are manifested through decrease in spermatozoa content in the epididymis and reduction of nucleie acid and protein content in the testes. Fertility of male rats under study significantly lowered shortly after irradiation and full recovery of fecundating ability was observed 6 months later. The effect of irradiation with a dose of 2 Gy was less pronounced

Radiation Safety of Gamma, Electron and X Ray Irradiation Facilities. Specific Safety Guide (Spanish Edition)

International Nuclear Information System (INIS)

2015-01-01

The objective of this Safety Guide is to provide recommendations on how to meet the requirements of the BSS with regard to irradiation facilities. This Safety Guide provides specific, practical recommendations on the safe design and operation of gamma, electron and X ray irradiators for use by operating organizations and the designers of these facilities, and by regulatory bodies. SCOPE. The facilities considered in this publication include five types of irradiator, whether operated on a commercial basis or for research and development purposes. This publication is concerned with radiation safety issues and not with the uses of irradiators, nor does it cover the irradiation of product or its quality management. The five types of irradiator are: - Panoramic dry source storage irradiators; - Underwater irradiators, in which both the source and the product being irradiated are under water; - Panoramic wet source storage irradiators; - Electron beam irradiation facilities, in which irradiation is performed in an area that is potentially accessible to personnel, but that is kept inaccessible during the irradiation process; - X ray irradiation facilities, in which irradiation is performed in an area that is potentially accessible to personnel, but that is kept inaccessible during the irradiation process. Consideration of non-radiation-related risks and of the benefits resulting from the operation of irradiators is outside the scope of this Safety Guide. The practices of radiotherapy and radiography are also outside the scope of this Safety Guide. Category I gamma irradiators (i.e. 'self-shielded' irradiators) are outside the scope of this Safety Guide

Techunique to depress seeds formation in small sized watermelon [Citrullus lanatus] by using pollen irradiated with soft X-rays

International Nuclear Information System (INIS)

Tajiri, K.; Ishida, T.

2005-01-01

Pollen irradiated soft X-rays is effective to depress seed formation in fruits of watermelon. In this investigation, it's effect are disucussed on some varieties of small sized water melon on semi-focing and retarding culture. Results are followed; The radiation of soft X-rays to pollen gave less seeds formation in fruits of wide varieties on both cropping season. The fruit setting was normal on the case of using irradiated pollen, and the growth and quality of fruits were equal or better than that of triploid variety of watermelon. The size of emty seeds remained in fruit was big in the variety whitch had originally big size seeds. On variety comparison under two cropping season. 'hitorijime' , 'summerkids' and ' himekannsen' showed excellent quality and less-formation of residual seeds in their fruits. To determine optimum level of soft X-rays irradiation, three levels of irradiation intensity were te sted. Irradiation intensity to pollen did not affect to the furit setting and the growth of fruit. B ut sugarcontent in fruit was generally higher than that of no-treatment. The effect of radiation int ensity to formation of seeds was different on cropping season. The optimum intensity was 1600Gy on r etarding culture. On semi-forcing culture, depressive effect on seeds formation by soft X-rays irrad iation was incresed as the increment of irradiation intensity between 0 to 800Gy, but irradiation av obe 1600Gy gave opposite result. Then optimum irradiation level is 800-1200Gy

The development for small scale soft X-ray spectrometer

International Nuclear Information System (INIS)

Sun Kexu; Jiang Shaoen; Yi Rongqing; Cui Yanli

2004-12-01

For the development of small-scale soft X-ray spectrometer, first, some small-scale soft X-ray detection elements are developed, it is included GaAs irradiated with neutron, GaAs irradiated with proton, multi-layer mirror, plane mirror and small scale X-ray diode et al. Soft X-ray spectrometers built of multi-layer mirror-GaAs (with neutron irradiation), and plane mirror-small-scale XRD, and plane mirror-GaAs (with proton irradiation) are prepared. These spectrometers are examined in Shen Guang-II laser facility, and some external estimation are given. (authors)

Irradiation with X-rays phase-advances the molecular clockwork in liver, adrenal gland and pancreas.

Science.gov (United States)

Müller, Mareike Hildegard; Rödel, Franz; Rüb, Udo; Korf, Horst-Werner

2015-02-01

The circadian clock of man and mammals shows a hierarchic organization. The master clock, located in the suprachiasmatic nuclei (SCN), controls peripheral oscillators distributed throughout the body. Rhythm generation depends on molecular clockworks based on transcriptional/translational interaction of clock genes. Numerous studies have shown that the clockwork in peripheral oscillators is capable to maintain circadian rhythms for several cycles in vitro, i.e. in the absence of signals from the SCN. The aim of the present study is to analyze the effects of irradiation with X-rays on the clockwork of liver, adrenal and pancreas. To this end organotypic slice cultures of liver (OLSC) and organotypic explant cultures of adrenal glands (OAEC) and pancreas (OPEC) were prepared from transgenic mPer2(luc) mice which express luciferase under the control of the promoter of an important clock gene, Per2, and allow to study the dynamics of the molecular clockwork by bioluminometry. The preparations were cultured in a membrane-based liquid-air interface culturing system and irradiated with X-rays at doses of 10 Gy and 50 Gy or left untreated. Bioluminometric real-time recordings show a stable oscillation of all OLSC, OAEC and OPEC for up to 12 days in vitro. Oscillations persist after irradiation with X-rays. However, a dose of 50 Gy caused a phase advance in the rhythm of the OLSC by 5 h, in the OPEC by 7 h and in the OAEC by 6 h. Our study shows that X-rays affect the molecular clockwork in liver, pancreas and adrenal leading to phase advances. Our results confirm and extend previous studies showing a phase-advancing effect of X-rays at the level of the whole animal and single cells.

Converging stereotactic radiotherapy using kilovoltage X-rays: experimental irradiation of normal rabbit lung and dose-volume analysis with Monte Carlo simulation.

Science.gov (United States)

Kawase, Takatsugu; Kunieda, Etsuo; Deloar, Hossain M; Tsunoo, Takanori; Seki, Satoshi; Oku, Yohei; Saitoh, Hidetoshi; Saito, Kimiaki; Ogawa, Eileen N; Ishizaka, Akitoshi; Kameyama, Kaori; Kubo, Atsushi

2009-10-01

To validate the feasibility of developing a radiotherapy unit with kilovoltage X-rays through actual irradiation of live rabbit lungs, and to explore the practical issues anticipated in future clinical application to humans through Monte Carlo dose simulation. A converging stereotactic irradiation unit was developed, consisting of a modified diagnostic computed tomography (CT) scanner. A tiny cylindrical volume in 13 normal rabbit lungs was individually irradiated with single fractional absorbed doses of 15, 30, 45, and 60 Gy. Observational CT scanning of the whole lung was performed every 2 weeks for 30 weeks after irradiation. After 30 weeks, histopathologic specimens of the lungs were examined. Dose distribution was simulated using the Monte Carlo method, and dose-volume histograms were calculated according to the data. A trial estimation of the effect of respiratory movement on dose distribution was made. A localized hypodense change and subsequent reticular opacity around the planning target volume (PTV) were observed in CT images of rabbit lungs. Dose-volume histograms of the PTVs and organs at risk showed a focused dose distribution to the target and sufficient dose lowering in the organs at risk. Our estimate of the dose distribution, taking respiratory movement into account, revealed dose reduction in the PTV. A converging stereotactic irradiation unit using kilovoltage X-rays was able to generate a focused radiobiologic reaction in rabbit lungs. Dose-volume histogram analysis and estimated sagittal dose distribution, considering respiratory movement, clarified the characteristics of the irradiation received from this type of unit.

Converging Stereotactic Radiotherapy Using Kilovoltage X-Rays: Experimental Irradiation of Normal Rabbit Lung and Dose-Volume Analysis With Monte Carlo Simulation

International Nuclear Information System (INIS)

Kawase, Takatsugu; Kunieda, Etsuo; Deloar, Hossain M.; Tsunoo, Takanori; Seki, Satoshi; Oku, Yohei; Saitoh, Hidetoshi; Saito, Kimiaki; Ogawa, Eileen N.; Ishizaka, Akitoshi; Kameyama, Kaori; Kubo, Atsushi

2009-01-01

Purpose: To validate the feasibility of developing a radiotherapy unit with kilovoltage X-rays through actual irradiation of live rabbit lungs, and to explore the practical issues anticipated in future clinical application to humans through Monte Carlo dose simulation. Methods and Materials: A converging stereotactic irradiation unit was developed, consisting of a modified diagnostic computed tomography (CT) scanner. A tiny cylindrical volume in 13 normal rabbit lungs was individually irradiated with single fractional absorbed doses of 15, 30, 45, and 60 Gy. Observational CT scanning of the whole lung was performed every 2 weeks for 30 weeks after irradiation. After 30 weeks, histopathologic specimens of the lungs were examined. Dose distribution was simulated using the Monte Carlo method, and dose-volume histograms were calculated according to the data. A trial estimation of the effect of respiratory movement on dose distribution was made. Results: A localized hypodense change and subsequent reticular opacity around the planning target volume (PTV) were observed in CT images of rabbit lungs. Dose-volume histograms of the PTVs and organs at risk showed a focused dose distribution to the target and sufficient dose lowering in the organs at risk. Our estimate of the dose distribution, taking respiratory movement into account, revealed dose reduction in the PTV. Conclusions: A converging stereotactic irradiation unit using kilovoltage X-rays was able to generate a focused radiobiologic reaction in rabbit lungs. Dose-volume histogram analysis and estimated sagittal dose distribution, considering respiratory movement, clarified the characteristics of the irradiation received from this type of unit.

Response of mesenchymal stem cells in mice to 3.5 Gy X-ray irradiation

International Nuclear Information System (INIS)

Su Wenxia; Liu Huimin; Chen Yonghong; Zeng Wen; Liu Wenli; Sun Hanying

2011-01-01

Objective: To investigate the response of mesenchymal stem cells in mice to medium-dose X-ray irradiation in vitro. Methods: The mouse mesenchymal stem cell line C3H10T1/2 was submitted to 3.5 Gy X-ray irradiation. Hoechst33258 staining of adherent cells and Annexin V-FITC staining and flow cytometry analysis of suspension cells were performed respectively to assess cellular apoptosis at 3, 6, 12, 24, 48, 72 h and 1 week after irradiation. SA-β-gal staining was performed to analyze the cellular senescence at 24, 48, 72 h and 1 week after irradiation. The mRNA level of both Fas with its ligand FasL and p53 with its downstream target p21 WAF1 were measured by Real-Time PCR analysis. The expression of Fas protein was determined by immunofluorescence staining. Results: An increased apoptosis was observed at 3 h after irradiation with apoptosis rate 11.72% ± 1.61% (t=9.01, P<0.01), the apoptosis rate reached the peak level at 12 h 20.52% ± 1.96% (t=16.27, P<0.01), and then declined progressively to normal level at 48 h 4.93% ±0.46% (t=2.26, P>0.05). The SA-β-gal positive rate of post-radiation cells at 72 h was 53.33% ± 5.62%, significantly higher than that of normal control 3.24% ± 0.39% (t=17.77, P<0.01). The level of Fas, FasL mRNA was found to be elevated 3 h after irradiation with a peak at 12 h, and no differences were found l week later. The level of Fas protein was observed to reach the peak at 12 h after irradiation. The occurrence of peak level of Fas/FasL mRNA and protein was consistent with that of apoptosis of C3H10T1/2 cell. A transient up-regulation of p53, p21 WAF1 mRNA expression was found at 12 h after irradiation followed by a significant increase later at 72 h after irradiation. The occurrence of the two peaks of p53, p21 WAF1 mRNA expression were coincident with that of cellular apoptosis and senescence, respectively. The levels of p53, p21 WAF1 mRNA in senescence group were significantly higher than those of apoptosis group (t=17.85, 13

Meiotic chromosomal translocations in male mice induced by X-irradiation

Energy Technology Data Exchange (ETDEWEB)

Savkovic, N.; Pecevski; Vuksanovic, L.; Radivojevic, D.; Alavantic, D.

1983-01-01

The dose-response curve for reciprocal translocations induced by acute exposure of spermatogonial stem cells to X-rays in treated mice and their F-1 sons was examined. Male mice were totally irradiated with doses of 1Gy;5x1Gy and 5Gy. The obtained results show that frequency of the chromosomal translocations in directly treated animals is dose dependent. The percentage of animals irradiated with 1Gy which had the chromosomal translocations was 60, while this percentage in animals irradiated with single and fractionated dose of 5Gy was 100. The frequency of chromosomal translocations varies from 1.5% to 8.0%. Multivalent configurations in F-1 males were observed after exposure to 5Gy only. The incidence of F-1 translocated males was 17.5%.

Irradiated ISM : Discriminating between cosmic rays and X-rays

NARCIS (Netherlands)

Meijerink, R.; Spaans, M.; Israel, F. P.

2006-01-01

The interstellar medium ( ISM) at the centers of active galaxies is exposed to a combination of cosmic-ray, far-ultraviolet (FUV), and X-ray radiation. We apply photodissociation region (PDR) models to this ISM with both "normal" and highly elevated (5 x 10(-15) s(-1)) cosmic- ray (CR) rates and

Numerical simulation of SPH for dynamics effect of multilayer discontinuous structure irradiated by impulse X-ray

International Nuclear Information System (INIS)

Xu Binbin; Tang Wenhui; Ran Xianwen; Xu Zhihong; Chen Hua

2012-01-01

When high energy X-ray irradiates material, it will cause energy deposition in materials, and generates thermal shock wave. At present, finite difference method is used to the numerical simulation of thermal shock usually, but if considering the inter-space between the multilayer materials, the difference method will be more difficult. This paper used the SPH method to simulate multilayer discontinuous structure irradiated by high energy X-ray, and the results show that the gap between the materials of each layer has a certain influence on the thermal shock wave intensity, but doesn't have any affect to gasification impulse. (authors)

Action of caffeine on x-irradiated HeLa cells. III. enhancement of x-ray-induced killing during G2 arrest

International Nuclear Information System (INIS)

Busse, P.M.; Bose, S.K.; Jones, R.W.; Tolmach, L.J.

1978-01-01

The ability of caffeine to enhance the expression of potentially lethal x-ray damage in HeLa S3 cells was examined as a function of the age of the cells in the generation cycle. Synchronous populations were irradiated at different times after mitotic collection and treated for various intervals with 1 mM caffeiene, which causes negligible killing of unirradiated cells. The response was thereby determined as a function of cell age at both the time of irradiation and the time of exposure to caffeine. The amount of cell killing depends strongly on when in the cycle caffeine is present and only weakly on when the cells are irradiated. If cells are irradiated in early G 1 , caffeine treatment enhances killing for 2 to 3 hr. No additional enhancement is observed until 16 to 17 hr postcollection, corresponding to G 2 ; here they enter a second period of much greater sensitivity. Similarly, fluorodeoxyuridine resynchronized cells irradiated during S and treated with caffeine suffer no enhanced killing until they pass into this sensitive phase in G 2 , approximately 7 hr after release from the fluorodeoxyuridine block. The sensitive period appears to coincide with G 2 arrest. The rate and extent of killing during this period are dependent upon the x-ray dose and the caffeine concentration. In the absence of caffeine, cells irradiated in G 1 lose sensitivity to caffeine in about 9 hr; they do so faster in G 2 . It is concluded that the potentially lethal x-ray damage expressed on treatment with caffeine is retained for many hours in the presence of caffeine and is maximally manifested by G 2 -arrested cells

X-ray photoelectron spectroscopy study of synchrotron radiation irradiation of a polytetrafluoroethylene surface

CERN Document Server

Haruyama, Y; Matsui, S; Ideta, T; Ishigaki, H

2003-01-01

The effect of synchrotron radiation (SR) irradiation of a polytetrafluoroethylene (PTFE) surface was investigated using X-ray photoelectron spectroscopy (XPS). After the SR irradiation, the relative intensity of the F ls peak to the C ls peak decreased markedly. The chemical composition ratio to the F atoms to C atoms was estimated to be 0.29. From the curve fitting analysis of C ls and F ls XPS spectra, the chemical components and their intensity ratio were determined. The reason for the chemical composition change by the SR irradiation was discussed. (author)

The effect of caffeine on p53-dependent radioresponses in undifferentiated mouse embryonal carcinoma cells after X-ray and UV-irradiations

International Nuclear Information System (INIS)

Taga, Masataka; Shiraishi, Kazunori; Shimura, Tsutomu; Uematsu, Norio; Kato, Tomohisa; Niwa, Ohtsura; Nishimune, Yoshitake; Aizawa, Shinichi; Oshimura, Mitsuo

2000-01-01

The effect of caffeine was studied on the radioresponses of undifferentiated mouse embryonal carcinoma cells (EC cells) with or without the functional p53. The radioresponses studied included radiosensitivity, the activation of p53, apoptosis with characteristic DNA ladder formation and cell cycle progression. An undifferentiated mouse EC cell line, ECA2, and a newly established p53-deficient EC cell line, p53δ, were used in the present study. The status of the p53 gene did not significantly affect the colony survivals of undifferentiated EC cells to X-rays and UV. Although a post-irradiation treatment with caffeine sensitized both lines to X-rays marginally, the sensitization was prominent for UV regardless of the p53 status of the cells. The activation of a p53 responsible lacZ reporter construct was observed in stably transfected ECA2 cells after X-ray and UV irradiations. Caffeine suppressed the X-ray induced activation of the lacZ reporter, while it drastically enhanced the activation after UV irradiation. X-rays and UV readily triggered the apoptosis of ECA2 cells with the characteristic DNA ladder. Although UV-induced DNA ladder formation was enhanced by caffeine, that induced by X-rays was unaffected. Therefore, the effects of caffeine on the p53-dependent radioresponses were found to be agent specific: suppression for the X-ray induced and augmentation for the UV induced. In contrast to p53-proficient ECA2 cells, smear-like DNA degradation was observed for irradiated p53δ cells, suggesting the presence of a mode of cell death without DNA ladder formation. UV induction of the smear-like DNA degradation was enhanced in the presence of caffeine. Regardless of the state of the p53 gene, G1/S arrest was not observed in X-ray and UV irradiated EC cells. X-rays induced G2/M arrest in both lines, which was abrogated by caffeine, while G2/M arrest after UV was unaffected by a caffeine treatment. These results indicate that the radioresponses of undifferentiated

The effect of caffeine on p53-dependent radioresponses in undifferentiated mouse embryonal carcinoma cells after X-ray and UV-irradiations

Energy Technology Data Exchange (ETDEWEB)

Taga, Masataka; Shiraishi, Kazunori; Shimura, Tsutomu; Uematsu, Norio; Kato, Tomohisa; Niwa, Ohtsura [Kyoto Univ. (Japan). Radiation Biology Center; Nishimune, Yoshitake; Aizawa, Shinichi; Oshimura, Mitsuo

2000-09-01

The effect of caffeine was studied on the radioresponses of undifferentiated mouse embryonal carcinoma cells (EC cells) with or without the functional p53. The radioresponses studied included radiosensitivity, the activation of p53, apoptosis with characteristic DNA ladder formation and cell cycle progression. An undifferentiated mouse EC cell line, ECA2, and a newly established p53-deficient EC cell line, p53{delta}, were used in the present study. The status of the p53 gene did not significantly affect the colony survivals of undifferentiated EC cells to X-rays and UV. Although a post-irradiation treatment with caffeine sensitized both lines to X-rays marginally, the sensitization was prominent for UV regardless of the p53 status of the cells. The activation of a p53 responsible lacZ reporter construct was observed in stably transfected ECA2 cells after X-ray and UV irradiations. Caffeine suppressed the X-ray induced activation of the lacZ reporter, while it drastically enhanced the activation after UV irradiation. X-rays and UV readily triggered the apoptosis of ECA2 cells with the characteristic DNA ladder. Although UV-induced DNA ladder formation was enhanced by caffeine, that induced by X-rays was unaffected. Therefore, the effects of caffeine on the p53-dependent radioresponses were found to be agent specific: suppression for the X-ray induced and augmentation for the UV induced. In contrast to p53-proficient ECA2 cells, smear-like DNA degradation was observed for irradiated p53{delta} cells, suggesting the presence of a mode of cell death without DNA ladder formation. UV induction of the smear-like DNA degradation was enhanced in the presence of caffeine. Regardless of the state of the p53 gene, G1/S arrest was not observed in X-ray and UV irradiated EC cells. X-rays induced G2/M arrest in both lines, which was abrogated by caffeine, while G2/M arrest after UV was unaffected by a caffeine treatment. These results indicate that the radioresponses of

Arrangement for X-ray shield

International Nuclear Information System (INIS)

1980-01-01

X-ray screen unit consisting of a light transmissive carrier onto which scintillation material is deposited, which is able to generate light under the influence of incident X-ray irradiation, characterised in that the X-ray screen comprises a number of sectors, wherein the surface with respect to the incident X-radiation is maintained at an acute angle. (G.C.)

Persistent genetic instability induced by synergistic interaction between x-irradiation and 6-thioguanine

International Nuclear Information System (INIS)

Grosovsky, A.J.; Nelson, S.L.; Smith, L.E.

1995-01-01

Clonal karyotypic analysis was performed using G-banding on four groups of clones derived from TK6 human lymphoblasts: 25 HPRT - total gene deletion mutants induced by exposure to 2 Gy of x-rays; 8 spontaneous HPRT - total gene deletion mutants; 25 clones irradiated with 2 Gy, not selected with 6-thioguanine. Ten to twenty metaphases were examined for each clone. Extensive karyotypic heterogeneity was observed among x-ray induced HPRT - mutants involving translocations, deletions, duplications and aneuploidy; recovery of chromosomal aberrations and karyotypic heterogeneity was greater than the additive effects of clones treated with x-irradiation or 6-thioguanine alone. This synergistic interaction between x-irradiation and 6-thioguanine was observed despite a 7 day phenotypic expression interval between exposure to the two agents. Thus, x-irradiated TK6 cells appear to be persistently hypersensitive to the induction of genetic instability. Several mutants appeared to exhibit evidence of clonal evolution since aberrant chromosomes observed in one metaphase, were found to be further modified in other metaphases. In order to determine if genetic instability, identified by clonal karyotypic heterogeneity, affected specific locus mutation rates, we utilized the heterozygous thymidine kinase (tk) locus as a genetic marker. Four x-ray induced HPRT - mutants with extensive karyotypic heterogeneity, exhibited mutation rates at tk ranging from 5 to 8 fold higher than the parental TK6 cells. Further analysis, using fractionated low dose radiation exposure, is currently in progress

Intestinal metaplasia induced by x-irradiation in rat

International Nuclear Information System (INIS)

Watanabe, Hiromitsu; Terada, Yoritaka; Fujii, Isao; Yamamoto, Yukiko; Takizawa, Shoichi

1978-01-01

Total 400 rad of x-ray was given in 100 or 150 rad doses to the whole body of rats at intervals of one week, and one year and a half later, rats were killed. Disaccharidase was formed in most of animals, intestinal metaplasia only with goblet cells occurred in 65% of animals, and that with intestinal type of lacuna occurred in 36% of them. When 500 rad of x-ray was irradiated to each part of stomach day after day up to the total dose of 3,000 rad, biochemical intestinal metaplasia already occurred one week after the irradiation, and intestinal type lacuna occurred 2 months after the irradiation. Intestinal type lacuna was recognized in all animals killed 499 days after the irradiation, and intestinal metaplasia with Paneth's cells occurred in 6 out of 11 cases (56%). When a dose of 1,000 rad was irradiated to stomach three times at intervals of 2 days up to the total of 3,000 rad, much intestinal type lacuna was recognized 2 months after the irradiation, gastric adenoid cancerous changes appeared 4 months after, and gastric adenoid cancer occurred 6 months after. The above-mentioned results clarified that even if x-ray of a small dose was irradiated, intestinal metaplasia occurred, and that the period from the irradiation to occurrence of intestinal metaplasia was shortened by increasing a dose of x-ray. It was also clarified that not only intestinal metaplasia but also gastric adenoic cancer occurred due to a great amount of x-ray irradiation. (Ueda, J.)

Intestinal metaplasia induced by x-irradiation in rat

Energy Technology Data Exchange (ETDEWEB)

Watanabe, H; Terada, Y; Fujii, I; Yamamoto, Y; Takizawa, S [Hiroshima Univ. (Japan). Research Inst. for Nuclear Medicine and Biology

1978-04-01

Total 400 rad of x-ray was given in 100 or 150 rad doses to the whole body of rats at intervals of one week, and one year and a half later, rats were killed. Disaccharidase was formed in most of animals, intestinal metaplasia only with goblet cells occurred in 65% of animals, and that with intestinal type of lacuna occurred in 36% of them. When 500 rad of x-ray was irradiated to each part of stomach day after day up to the total dose of 3,000 rad, biochemical intestinal metaplasia already occurred one week after the irradiation, and intestinal type lacuna occurred 2 months after the irradiation. Intestinal type lacuna was recognized in all animals killed 499 days after the irradiation, and intestinal metaplasia with Paneth's cells occurred in 6 out of 11 cases (56%). When a dose of 1,000 rad was irradiated to stomach three times at intervals of 2 days up to the total of 3,000 rad, much intestinal type lacuna was recognized 2 months after the irradiation, gastric adenoid cancerous changes appeared 4 months after, and gastric adenoid cancer occurred 6 months after. The above-mentioned results clarified that even if x-ray of a small dose was irradiated, intestinal metaplasia occurred, and that the period from the irradiation to occurrence of intestinal metaplasia was shortened by increasing a dose of x-ray. It was also clarified that not only intestinal metaplasia but also gastric adenoic cancer occurred due to a great amount of x-ray irradiation.

X-ray or UV-ray imaging sensor utilizing optically stimulated luminescence phenomenon in Eu-doped KCl phosphors

International Nuclear Information System (INIS)

Nanto, Hidehito; Murayama, Kazuhiko; Hirai, Yoshiaki; Taniguchi, Shin-ichi; Makamura, Shouichi; Takeuchi, Nozomu.

1993-01-01

An intense OSL with a peak at about 420 [nm] has been observed by stimulating an X-ray or UV-ray irradiated KCl: Eu crystal with F-band light whose wavelength is about 560 [um]. A possible excitation and emission mechanisms for the 420 [um] OSL peak X-ray or UV-ray irradiated sample is proposed. It is found that the OSL intensity is proportional to the X-ray absorbed dose or UV-ray irradiation dose. It is also found that X-ray or UV-ray irradiated KCl; Eu exhibited excellent fading characteristics. These results strongly suggest that the KCl: Eu is one of the most attractive candidates for two-dimensional X-ray or UV-ray imaging sensor utilizing the OSL phenomenon. (J.P.N.)

X-ray irradiation activates K+ channels via H2O2 signaling.

Science.gov (United States)

Gibhardt, Christine S; Roth, Bastian; Schroeder, Indra; Fuck, Sebastian; Becker, Patrick; Jakob, Burkhard; Fournier, Claudia; Moroni, Anna; Thiel, Gerhard

2015-09-09

Ionizing radiation is a universal tool in tumor therapy but may also cause secondary cancers or cell invasiveness. These negative side effects could be causally related to the human-intermediate-conductance Ca2+-activated-K+-channel (hIK), which is activated by X-ray irradiation and affects cell proliferation and migration. To analyze the signaling cascade downstream of ionizing radiation we use genetically encoded reporters for H2O2 (HyPer) and for the dominant redox-buffer glutathione (Grx1-roGFP2) to monitor with high spatial and temporal resolution, radiation-triggered excursions of H2O2 in A549 and HEK293 cells. The data show that challenging cells with ≥1 Gy X-rays or with UV-A laser micro-irradiation causes a rapid rise of H2O2 in the nucleus and in the cytosol. This rise, which is determined by the rate of H2O2 production and glutathione-buffering, is sufficient for triggering a signaling cascade that involves an elevation of cytosolic Ca2+ and eventually an activation of hIK channels.

Dose fractionation in synchrotron radiation x-ray phase micro-tomography

International Nuclear Information System (INIS)

Frachon, Thibaut; Weber, Loriane; Hesse, Bernhard; Rit, Simon; Dong, Pei; Olivier, Cecile; Peyrin, Françoise; Langer, Max

2015-01-01

Phase sensitive x-ray imaging expands the applicability of standard attenuation based techniques by offering several orders of magnitude of increase in sensitivity. Due to the short wavelength, x-ray phase is not directly measurable, but has to be put in evidence by the use of phase contrast techniques. The phase can then be reconstructed from one or several phase contrast images. In this study, we consider synchrotron x-ray phase micro-computed tomography (μCT) based on free space propagation for heterogeneous and strongly absorbing objects. This technique generally relies on acquiring several scans of the sample at different detector distances. It is also generally believed that multi-distance phase μCT needs a higher dose input than single distance phase μCT. The purpose of this work is to study the impact of different means of dose fractionation on the reconstructed image quality. We define different acquistion schemes in multi-distance in-line phase μCT. Previously, the exposure time at each sample-to-detector distance was usually kept the same. Here, we let not only the number of distances vary but also the fraction of exposure time at each distance, the total exposure time being kept constant. Phase retrieval is performed with the mixed approach algorithm. The reconstructed μCT images are compared in terms of accuracy, precision and resolution. In addition, we also compare the result of dose fractionated multi distance phase μCT to single distance phase μCT using the same total radiation dose. In the multi-distance approach, we find that using different exposure times on each distance improves the image quality in the reconstructed image. Further, we show that, despite having the same total dose delivery, the multi distance imaging method gives better image quality than the single distance method, at the cost of an additional overhead from camera displacements and reference images. We show that by optimizing the acquistion parameters in terms of

Study of serotonin effect on the yield of some damages in DNA after ultraviolet and x-ray irradiations

International Nuclear Information System (INIS)

Ivanova, Eh.V.; Frajkin, G.Ya.

1985-01-01

Using thin-layer two-dimensional chromatography serotonin effect on the yield of thymine dimers and appearance of n-glycoside strand breaks in DNA (thymine yield) after ultraviolet and X-ray irradiation is studied. It is shown that bound with DNA serotonin decreases formation of induced by ultraviolet thymine dimers but doesn't affect on the quantity of N-glycoside bond breaks in thymidine residues caused by X radiation. The obtained data are discussed in relation to the problem on mechanisms of realization of serotonin protective effect in the processes of yeast Saccharomyces photoprotection from ultraviolet and X-ray irradiation lethal effect

Binucleate cell formation correlates to loss of colony-forming ability in X-irradiated cultured mammalian cells

International Nuclear Information System (INIS)

Sasaki, H.; Yoshinaga, H.; Kura, S.

1986-01-01

The relationship between binucleate cell formation and the loss of colony-forming ability was examined in several cultured mammalian cell lines irradiated with X rays. The maximum fraction of binucleate cells after X irradiation increased dose-dependently within the range in which reproductive cell death might predominate over interphase cell death. When the logarithm of percentage survival was plotted against the percentage binucleate cells, a similar correlation was found for all cell lines tested, with the exception of mouse leukemia L5178Y cells, the most radiosensitive cells used. These observations suggest that the fraction of binucleate cells in the cell population can serve as a measure of cellular radiation damage

High-resolution x-ray imaging of planar foils irradiated by the Nike KrF laser

International Nuclear Information System (INIS)

Brown, C.; Seely, J.; Feldman, U.; Obenschain, S.; Bodner, S.; Pawley, C.; Gerber, K.; Sethian, J.; Mostovych, A.; Aglitskiy, Y.; Lehecka, T.; Holland, G.

1997-01-01

Thin plastic (CH) foils were irradiated by the Naval Research Laboratory Nike [Obenschain et al., Phys. Plasmas 3, 2098 (1996)] KrF laser and were imaged in the x-ray and extreme ultraviolet regions with two-dimensional spatial resolution in the 3 endash 10 μm range. The CH foils were backlit by a silicon plasma. A spherically curved quartz crystal produced monochromatic images of the Si +12 resonance line radiation with energy 1865 eV that was transmitted by the CH foils. Instabilities that were seeded by linear ripple patterns on the irradiated sides of CH foils were observed. The ripple patterns had periods in the 31 endash 125 μm range and amplitudes in the 0.25 endash 5.0 μm range. The silicon backlighter emission was recorded by an x-ray spectrometer, and the 1865 eV resonance line emission was recorded by a fast x-ray diode. The multilayer mirror telescope recorded images of the C +3 1550 Angstrom emission (energy 8.0 eV) from the backside of the CH foils. copyright 1997 American Institute of Physics

Study of the lattice parameter evolution of PWR irradiated MOX fuel by X-Ray diffraction

International Nuclear Information System (INIS)

Clavier, B.

1995-01-01

Fuel irradiation leads to a swelling resulting from the formation of gaseous (Kr, Xe) or solid fission products which are found either in solution or as solid inclusions in the matrix. This phenomena has to be evaluated to be taken into account in fuel cladding Interaction. Fuel swelling was studied as a function of burn up by measuring the corresponding cell constant evolution by X-Ray diffraction. This study was realized on Mixed Oxide Fuels (MOX) irradiated in a Pressurized Water Reactor (PWR) at different burn-up for 3 initial Pu contents. Lattice parameter evolutions were followed as a function of burn-up for the irradiated fuel with and without an annealing thermal treatment. These experimental evolutions are compared to the theoretical evolutions calculated from the hard sphere model, using the fission product concentrations determined by the APPOLO computer code. Contribution of varying parameters influencing the unit cell value is discussed. Thermal treatment effects were checked by metallography, X-Ray diffraction and microprobe analysis. After thermal treatment, no structural change was observed but a decrease of the lattice parameter was measured. This modification results essentially from self-irradiation defect annealing and not from stoichiometry variations. Microprobe analysis showed that about 15% of the formed Molybdenum is in solid solution In the oxide matrix. Micrographs showed the existence of Pu packs in the oxide matrix which induces a broadening of diffraction lines. The RIETVELD method used to analyze the X-Ray patterns did not allow to characterize independently the Pu packs and the oxide matrix lattice parameters. Nevertheless, with this method, the presence of micro-strains in the irradiated nuclear fuel could be confirmed. (author)

Proliferation kinetics of cultured cells after irradiation with X-rays and 14 MeV neutrons studied by time-lapse cinematography

Energy Technology Data Exchange (ETDEWEB)

Kooi, M.W.; Stap, J.; Barendsen, G.W. (Amsterdam Univ. (Netherlands). Lab. for Radiobiology)

1984-06-01

Exponentially growing cells of an established line derived from a mouse osteosarcoma (MOS) have been studied by time-lapse cinematography after irradiation with 3 Gy of 200 kV X- rays or 1.5 Gy of 14 MeV neutrons. The results show that the radiation doses applied cause an equal elongation of the mean cell cycle time Tsub(c), which is largest in the irradiated cells but persists in the three subsequent generations. After 3 Gy of X-rays, mitotic delay is largest in cells irradiated in later stages of the cycle, but this difference is not observed after 1.5 Gy of 14 MeV neutrons. In subsequent generations the Tsub(c) values show larger variations among descendents of cells treated in the same stage of the cycle as compared to controls but this variation is equal for the doses of X-rays and neutrons applied. Division probability was significantly reduced in irradiated cells as well as in subsequent generations, whereas with neutrons as compared to X-rays the damage is expressed in earlier generations, with less variation as a function of the cell cycle.

Proliferation kinetics of cultured cells after irradiation with X-rays and 14 MeV neutrons studied by time-lapse cinematography

International Nuclear Information System (INIS)

Kooi, M.W.; Stap, J.; Barendsen, G.W.

1984-01-01

Exponentially growing cells of an established line derived from a mouse osteosarcoma (MOS) have been studied by time-lapse cinematography after irradiation with 3 Gy of 200 kV X- rays or 1.5 Gy of 14 MeV neutrons. The results show that the radiation doses applied cause an equal elongation of the mean cell cycle time Tsub(c), which is largest in the irradiated cells but persists in the three subsequent generations. After 3 Gy of X-rays, mitotic delay is largest in cells irradiated in later stages of the cycle, but this difference is not observed after 1.5 Gy of 14 MeV neutrons. In subsequent generations the Tsub(c) values show larger variations among descendents of cells treated in the same stage of the cycle as compared to controls but this variation is equal for the doses of X-rays and neutrons applied. Division probability was significantly reduced in irradiated cells as well as in subsequent generations, whereas with neutrons as compared to X-rays the damage is expressed in earlier generations, with less variation as a function of the cell cycle. (author)

Pathomorphological studies of the radiation syndrome in sheep after whole-body irradiation with X-rays

International Nuclear Information System (INIS)

Johannsen, U.; Mehlhorn, G.; Koch, F.; Panndorf, H.

1978-01-01

Eight one-year-old Merino mutton sheep were irradiated with X-ray doses of 380 R. Five of the animals died between the 16th and 25th day after irradiation and were examined. In organs and tissues a great diversity of pathological changes was observed as for instance hematopoietic disorders, septic processes, hemorrhagic diatheses, and partial epilation

Analysis of electron-irradiated poly-ether ether ketone by X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Oyabu, Matashige; Kobayashi, Yoshinori; Seguchi, Tadao; Sasuga, Tsuneo; Kudoh, Hisaaki.

1995-01-01

Organic polymers used in atomic power plants or space are damaged by ionizing irradiation. Radicals produced by irradiation cause oxidation, chain scission and crosslinking, all of which lead to degradation of the material. In this paper, the surface of electron-irradiated poly-ether ether ketone (PEEK) was studied by X-ray photoelectron spectroscopy (XPS). The irradiation in air was found to oxidize the PEEK surface producing carboxyl groups, the content of which dependant on the dose. Carboxyl groups were not produced in helium gas. Quantitative spectral analysis indicated that the aromatic structure might be decomposed. Some comparison was made between the semicrystalline and amorphous samples. The oxygen content resulting from irradiation, of semicrystalline PEEK increased more than that of amorphous PEEK. (author)

DNA microarray analyses reveal a post-irradiation differential time-dependent gene expression profile in yeast cells exposed to X-rays and gamma-rays.

Science.gov (United States)

Kimura, Shinzo; Ishidou, Emi; Kurita, Sakiko; Suzuki, Yoshiteru; Shibato, Junko; Rakwal, Randeep; Iwahashi, Hitoshi

2006-07-21

Ionizing radiation (IR) is the most enigmatic of genotoxic stress inducers in our environment that has been around from the eons of time. IR is generally considered harmful, and has been the subject of numerous studies, mostly looking at the DNA damaging effects in cells and the repair mechanisms therein. Moreover, few studies have focused on large-scale identification of cellular responses to IR, and to this end, we describe here an initial study on the transcriptional responses of the unicellular genome model, yeast (Saccharomyces cerevisiae strain S288C), by cDNA microarray. The effect of two different IR, X-rays, and gamma (gamma)-rays, was investigated by irradiating the yeast cells cultured in YPD medium with 50 Gy doses of X- and gamma-rays, followed by resuspension of the cells in YPD for time-course experiments. The samples were collected for microarray analysis at 20, 40, and 80 min after irradiation. Microarray analysis revealed a time-course transcriptional profile of changed gene expressions. Up-regulated genes belonged to the functional categories mainly related to cell cycle and DNA processing, cell rescue defense and virulence, protein and cell fate, and metabolism (X- and gamma-rays). Similarly, for X- and gamma-rays, the down-regulated genes belonged to mostly transcription and protein synthesis, cell cycle and DNA processing, control of cellular organization, cell fate, and C-compound and carbohydrate metabolism categories, respectively. This study provides for the first time a snapshot of the genome-wide mRNA expression profiles in X- and gamma-ray post-irradiated yeast cells and comparatively interprets/discusses the changed gene functional categories as effects of these two radiations vis-à-vis their energy levels.

Secondary-source energy-dispersive x-ray spectrometer

International Nuclear Information System (INIS)

Larsen, R.P.; Tisue, G.T.

1975-01-01

A secondary-source energy-dispersive x-ray spectrometer has been built and tested. In this instrument the primary source of x rays is a tungsten-target tube powered by a high-voltage (75 kV), a high-power (3.7 kW) generator from a wavelength spectrometer (G.E. XRD-6). The primary polychromatic x rays irradiate an elemental foil, the secondary source. Its characteristic essentially monochromatic x rays are used to irradiate the sample. Fluorescent x rays from the sample are detected and resolved by a lithium-drifted silicon detector, multichannel-analyzer system. The design of the instrument provides a convenient means for changing the secondary, and hence, the energy of the excitation radiation

The effect of sex differences on induction of intestinal metaplasia in x-ray irradiated rats

International Nuclear Information System (INIS)

Watanabe, Hiromitsu; Takizawa, Shoichi; Terada, Yoritake; Naito, Masashi; Naito, Yukiko

1980-01-01

The effects of sex differences and ovarian resection on induction of intestinal metaplasia in x-ray irradiated mice were discussed. 1,000 rad of x-ray was irradiated to the stomach of female and male mice twice at intervals of 3 days. The range of intestinal metaplasia in male mice was wider than that in female mice. A total of 400 rad was irradiated to the whole body of mice which underwent ovarian resection (group 1), mice which underwent autotransplantation of the ovary after ovarian resection (group 2), and mice which underwent sham-ovarian resection (group 3). The incidence of intestinal metaplasia in the group 1 was significantly higher than that in the group 3. The weight of the uterus decreased gradually in order of the group 3, group 2, and group 1. It was suggested from above-mentioned results that disappearance or lowering of femal sex hormones, that is, male or androphacy, induced intestinal metaplasia. (Tsunoda, M.)

Effects of X-ray irradiation on expression of Pokemon gene in A549 cells of human lung adenocarcinoma

International Nuclear Information System (INIS)

Wang Lu; Zou Yue; Jiang Qisheng; Li Wei; Song Xiujun; Zhou Xiangyan; Wang Cuilan

2011-01-01

Objective: To study the dose-and time-effects of X-ray irradiation on the expression of Pokemon gene in A549 cells of human lung adenocarcinoma. Methods: A549 cells were cultured in vitro and exposed to X-rays with the doses of 2, 4, 6 and 8 Gy, respectively. Untreated A549 cells were used as control group. The relative levels of Pokemon mRNA expression in the cells were detected by using quantitative real-time PCR at 2, 4, 8, 12, 24, 48 and 72 h after irradiation. Results: The Pokemon mRNA expression levels decreased in the early period after irradiation (except 2 and 4 h after irradiation in 2 Gy group) and then increased in the later stage (48 h after irradiation) with significant statistical differences at the most time points in comparison with the control group (t=3.40-154.76, P<0.05). Conclusions: Higher doses of X-rays may degrade the expression of Pokemon mRNA in the human A549 cells and induce apoptosis in the early period, hut also may upgrade its expression in the later period, which might be correlated with the cell cycle regulation and DNA damage repair in the A549 cells. (authors)

Improving Soft X-Ray Spectral Irradiance Models for Use Throughout the Solar System

Science.gov (United States)

Eparvier, F. G.; Thiemann, E.; Woods, T. N.

2017-12-01

Understanding the effects of solar variability on planetary atmospheres has been hindered by the lack of accurate models and measurements of the soft x-ray (SXR) spectral irradiance (0-6 nm). Most measurements of the SXR have been broadband and are difficult to interpret due to changing spectral distribution under the pass band of the instruments. Models that use reference spectra for quiet sun, active region, and flaring contributions to irradiance have been made, but with limited success. The recent Miniature X-ray Solar Spectrometer (MinXSS) CubeSat made spectral measurements in the 0.04 - 3 nm range from June 2016 to May 2017, observing the Sun at many different levels of activity. In addition, the Solar Dynamics Observatory (SDO) EUV Variability Experiment (EVE) has observed the Sun since May 2010, in both broad bands (including a band at 0-7 nm) and spectrally resolved (6-105 nm at 0.1 nm resolution). We will present an improved model of the SXR based on new reference spectra from MinXSS and SDO-EVE. The non-flaring portion of the model is driven by broadband SXR measurements for determining activity level and relative contributions of quiet and active sun. Flares are modeled using flare temperatures from the GOES X-Ray Sensors. The improved SXR model can be driven by any sensors that provide a measure of activity level and flare temperature from any vantage point in the solar system. As an example, a version of the model is using the broadband solar irradiance measurements from the MAVEN EUV Monitor at Mars will be presented.

Reactivation of UV- and γ-irradiated herpes virus in UV- and X-irradiated CV-1 cells

International Nuclear Information System (INIS)

Takimoto, K.; Niwa, O.; Sugahara, T.

1982-01-01

Enhanced reactivation of UV- and γ-irradiated herpes virus was investigated by the plaque assay on CV-1 monkey kidney monolayer cells irradiated with UV light or X-rays. Both UV- and X-irradiated CV-1 cells showed enhancement of survival of UV-irradiated virus, while little or no enhancement was detected for γ-irradiated virus assayed on UV- or X-irradiated cells. The enhanced reactivation of UV-irradiated virus was greater when virus infection was delayed 24 or 48 h, than for infection immediately following the irradiation of cells. Thus the UV- or X-irradiated CV-1 cells are able to enhance the repair of UV damaged herpes virus DNA, but not of γ-ray damaged ones. (author)

Dosimetry for total body irradiation of rhesus monkeys with 300 kV X- rays

NARCIS (Netherlands)

Zoetelief, J.; Wagemaker, G.; Broerse, J.J.

1998-01-01

Purpose: To obtain more accurate information on the dose distribution in rhesus monkeys for total body irradiation with orthovoltage X-rays. Materials and methods: Dose measurements were performed with an ionization chamber inside homogeneous cylindrical and rectangular phantoms of various

Significance of Fractionated Administration of Thalidomide Combined With γ-Ray Irradiation in Terms of Local Tumor Response and Lung Metastasis

Science.gov (United States)

Masunaga, Shin-ichiro; Sanada, Yu; Moriwaki, Takahiro; Tano, Keizo; Sakurai, Yoshinori; Tanaka, Hiroki; Suzuki, Minoru; Kondo, Natsuko; Narabayashi, Masaru; Watanabe, Tsubasa; Nakagawa, Yosuke; Maruhashi, Akira; Ono, Koji

2014-01-01

Background The aim of this study was to evaluate the significance of fractionated administration of thalidomide combined with γ-ray irradiation in terms of local tumor response and lung metastatic potential, referring to the response of intratumor quiescent (Q) cells. Methods B16-BL6 melanoma tumor-bearing C57BL/6 mice were continuously given 5-bromo-2’-deoxyuridine (BrdU) to label all proliferating (P) cells. The tumor-bearing mice then received γ-ray irradiation after thalidomide treatment through a single or two consecutive daily intraperitoneal administrations up to a total dose of 400 mg/kg in combination with an acute hypoxia-releasing agent (nicotinamide) or mild temperature hyperthermia (MTH). Immediately after the irradiation, cells from some tumors were isolated and incubated with a cytokinesis blocker. The responses of the Q and total (= P + Q) cell populations were assessed based on the frequency of micronuclei using immunofluorescence staining for BrdU. In other tumor-bearing mice, 17 days after irradiation, macroscopic lung metastases were enumerated. Results Thalidomide raised the sensitivity of the total cell population more remarkably than Q cells in both single and daily administrations. Daily administration of thalidomide elevated the sensitivity of both the total and Q cell populations, but especially the total cell population, compared with single administration. Daily administration, especially combined with MTH, decreased the number of lung metastases. Conclusion Daily fractionated administration of thalidomide in combination with γ-ray irradiation was thought to be more promising than single administration because of its potential to enhance local tumor response and repress lung metastatic potential. PMID:29147396

X-ray diffraction in laser-irradiated epsomite crystals grown in presence of borax

International Nuclear Information System (INIS)

Zaitseva, E.V.; Portnov, V.N.; Faddeev, M.A.; Chuprunov, E.V.

1997-01-01

Relative changes in the intensities ΔI/I of the (220) and (440) X-ray diffraction reflection during laser irradiation of epsomite (MgSO 2 ·7H 2 O) crystals grown from an aqueous solution in the presence of borax (Na 2 B 4 O 7 ·10H 2 O) were measured using the CoK α , CuK α , MoK α radiations. The intensities measured depend on the real crystal structure dependent on the borax content in the solution. The dependence of ΔI/I is studied as a function of borax in the solution and X-ray-radiation wavelength

Influence of x-ray irradiation on the proliferative ability of the germinal layer cells of Echinococcus multilocularis

International Nuclear Information System (INIS)

Ohnishi, Kenji

1986-01-01

Influence of X-ray irradiation on the proliferative ability of the germinal layer cells of larval Echinococcus multilocularis was studied by using small sterile hydatids containing vesicles composed of a non-cellular laminated layer and a cellular germinal layer. The small sterile hydatids were irradiated by X-ray at dose levels of 5,000, 15,000, 25,000, 35,000, 45,000 or 55,000 R and implanted into the peritoneal cavity of Chinese hamsters. Fully developed hydatids were recognized in all cases irradiated at up to 35,000 R, when assessed 113 days after implantation. At 45,000 R, 2 out of 6 animals showed small, fully developed hydatids. No such hydatid was found in the other 4 animals nor in any of the animals implanted with hydatids irradiated at 55,000 R. No structural differences were observed between fully developed hydatids originating from the irradiated and non-irradiated small hydatids. These results indicate that the tolerance limit of the germinal layer cells is between 45,000 R and 55,000 R. (author)

Comparative study of radiation dose between digital panoramic X-ray unit and general panoramic X-ray unit

International Nuclear Information System (INIS)

Li Qingshan; Duan Tao; Wang Xiaoyun; Zhao Li; Dong Jian; Wei Lei

2010-01-01

Objective: To compare the actual dose of patients who receive the same medical practice by either digital panoramic X-ray unit and general panoramic X-ray unit and give evidence for better selection of oral X-ray examination method. Methods: Round sheet lithium fluoride (LiF) thermoluminescent dosimeters (TLD) were used. The experiment was divided into natural background contrast group, general panoramic X-ray children group, general panoramic X-ray adults group, digital panoramic X-ray children group and digital panoramic X-ray adults group. The dosimeter of natural background radiation was placed at the office of the doctor, the dosimeters of general panoramic X-ray children group and general panoramic X-ray adults group were irradiated by different conditions according to the clinical application of panoramic X-ray to children and adults, the dosimeters of digital panoramic X-ray children group and digital panoramic X-ray adults group were irradiated by different conditions according to the clinical application of digital panoramic X-ray to children and adults. The thermoluminescent dosimeter was used to count and calculate the exposure doses in various groups. Results: The dose of children exposed in general panoramic X-ray unit was 1.28 times of that in digital panoramic X-ray unit, there was significant difference (t=6.904, P<0.01). The dose of adults exposed in general panoramic X-ray unit was 1.55 times of that in the digital panoramic X-ray unit, there also was significant difference (t=-11.514. P< 0.01). Conclusion: The digital panoramic X-ray unit can reduce the dose of patients, so the digital panoramic X-ray unit should be used as far as possible. (authors)

X-ray generator for radiographs of seeds

International Nuclear Information System (INIS)

Suarez Canner, E.

1996-01-01

It is presented an X-ray generator which is destined to obtaining X-ray radiographs of seeds. It utilizes a low power X-ray tube with fine focal point. It consist of an electronic block and an irradiation chamber

Autoradiographic changes in the kidney of the whole-body sublethally x-ray irradiated rat

Energy Technology Data Exchange (ETDEWEB)

Olinic, A; Uray, Z

1977-01-01

203Hg-hydroxymersalyl uptake/gram of kidney (HU), renal autoradiographic and histologic aspect after 800 R x-ray whole-body rat irradiation was studied. Twenty-four to seventy-two hours after irradiation, HU increased, while tubular autoradiographic granularity decreased. Their return to the control levels occurred gradually within two weeks. The relations of these findings to the early circulatory and dystrophic changes, as well as to the subsequent postirradiation restoring renal process are discussed.

Combination of BMP-2-releasing gelatin/β-TCP sponges with autologous bone marrow for bone regeneration of X-ray-irradiated rabbit ulnar defects.

Science.gov (United States)

Yamamoto, Masaya; Hokugo, Akishige; Takahashi, Yoshitake; Nakano, Takayoshi; Hiraoka, Masahiro; Tabata, Yasuhiko

2015-07-01

The objective of this study is to evaluate the feasibility of gelatin sponges incorporating β-tricalcium phosphate (β-TCP) granules (gelatin/β-TCP sponges) to enhance bone regeneration at a segmental ulnar defect of rabbits with X-ray irradiation. After X-ray irradiation of the ulnar bone, segmental critical-sized defects of 20-mm length were created, and bone morphogenetic protein-2 (BMP-2)-releasing gelatin/β-TCP sponges with or without autologous bone marrow were applied to the defects to evaluate bone regeneration. Both gelatin/β-TCP sponges containing autologous bone marrow and BMP-2-releasing sponges enhanced bone regeneration at the ulna defect to a significantly greater extent than the empty sponges (control). However, in the X-ray-irradiated bone, the bone regeneration either by autologous bone marrow or BMP-2 was inhibited. When combined with autologous bone marrow, the BMP-2 exhibited significantly high osteoinductivity, irrespective of the X-ray irradiation. The bone mineral content at the ulna defect was similar to that of the intact bone. It is concluded that the combination of bone marrow with the BMP-2-releasing gelatin/β-TCP sponge is a promising technique to induce bone regeneration at segmental bone defects after X-ray irradiation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Spectral and temporal properties of the X-ray pulsar SMC X-1 at hard X-rays

Science.gov (United States)

Kunz, M.; Gruber, D. E.; Kendziorra, E .; Kretschmar, P.; Maisack, M.; Mony, B.; Staubert, R.; Doebereiner, S.; Englhauser, J.; Pietsch, W.

1993-01-01

The binary X-ray pulsar SMC X- 1 has been observed at hard X-rays with the High Energy X-Ray Experiment (HEXE) on nine occasions between Nov. 1987 and March 1989. A thin thermal bremsstrahlung fit to the phase averaged spectrum yields a plasma temperature (14.4 +/- 1.3) keV and a luminosity above (1.1 +/- 0.1) x 10 exp 38 erg/s in the 20-80 keV band. Pulse period values have been established for three observations, confirming the remarkably stable spin-up trend of SMC X-1. In one of the three observations the pulse profile was seen to deviate from a dominant double pulsation, while at the same time the pulsed fraction was unusually large. For one observation we determined for the first time the pulsed fraction in narrow energy bands. It increases with photon energy from about 20 percent up to over 60 percent in the energy range from 20 to 80 keV.

Extragalactic Hard X-ray Surveys: From INTEGRAL to Simbol-X

Science.gov (United States)

Paltani, S.; Dwelly, T.; Walter, R.; McHardy, I. M.; Courvoisier, T. J.-L.

2009-05-01

We present some results of the deepest extragalactic survey performed by the INTEGRAL satellite. The fraction of very absorbed AGN is quite large. The sharp decrease in the absorption fraction with X-ray luminosity observed at lower-energy X-rays is not observed. The current lack of truly Compton-thick objects, with an upper limit of 14% to the size of this population, is just compatible with recent modeling of the cosmic X-ray background. We also study the prospects for a future hard X-ray serendipitous survey with Simbol-X. We show that Simbol-X will easily detect a large number of serendipitous AGN, allowing us to study the evolution of AGN up to redshifts about 2, opening the door to the cosmological study of hard X-ray selected AGN, which is barely possible with existing satellites like Swift and INTEGRAL.

Synchrotron X-ray irradiation effects on the device characteristics and the resistance to hot-carrier damage of MOSFETs with 4 nm thick gate oxides

International Nuclear Information System (INIS)

Tanaka, Yuusuke; Tanabe, Akira; Suzuki, Katsumi

1998-01-01

The effects of synchrotron x-ray irradiation on the device characteristics and hot-carrier resistance of n- and p-channel metal oxide semiconductor field effect transistors (MOSFETs) with 4 nm thick gate oxides are investigated. In p-channel MOSFETs, device characteristics were significantly affected by the x-ray irradiation but completely recovered after annealing, while the device characteristics in n-channel MOSFETs were not noticeably affected by the irradiation. This difference appears to be due to a difference in interface-state generation. In p-channel MOSFETs, defects caused by boron-ion penetration through the gate oxides may be sensitive to x-ray irradiation, causing the generation of many interface states. These interface states are completely eliminated after annealing in hydrogen gas. The effects of irradiation on the resistance to hot-carrier degradation in annealed 4 nm thick gate-oxide MOSFETs were negligible even at an x-ray dose of 6,000 mJ/cm 2

Down-regulation of SMT3A gene expression in association with DNA synthesis induction after X-ray irradiation in nevoid basal cell carcinoma syndrome (NBCCS) cells

International Nuclear Information System (INIS)

Sugaya, Shigeru; Nakanishi, Hiroshi; Tanzawa, Hideki; Sugita, Katsuo; Kita, Kazuko; Suzuki, Nobuo

2005-01-01

Fibroblast cells derived from nevoid basal carcinoma syndrome (NBCCS) patients show increased levels of DNA synthesis after X-ray irradiation. Genes, whose expression is modulated in association with the DNA synthesis induction, were searched by using PCR-based mRNA differential display analysis in one of the NBCCS cell lines, NBCCS1 cells. Decreased levels of SMT3A gene expression were found in X-ray-irradiated NBCCS1 cells. This decrease was also shown by RT-PCR analysis in another cell line, NBCCS3 cells. In addition to NBCCS cells, normal fibroblast cells showed the DNA synthesis induction after X-ray irradiation when they were treated with antisense oligonucleotides (AO) for SMT3A. However, treatment of normal fibroblasts with the random oligonucleotides (RO) resulted in decreased levels of DNA synthesis after X-ray irradiation. Thus, down-regulation of SMT3A gene expression may be involved in the DNA synthesis induction after X-ray irradiation in the NBCCS cells at least tested

Down-regulation of SMT3A gene expression in association with DNA synthesis induction after X-ray irradiation in nevoid basal cell carcinoma syndrome (NBCCS) cells

Energy Technology Data Exchange (ETDEWEB)

Sugaya, Shigeru [Department of Environmental Biochemistry, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670 (Japan); Nakanishi, Hiroshi [Department of Clinical Molecular Biology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670 (Japan); Tanzawa, Hideki [Department of Clinical Molecular Biology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670 (Japan); Sugita, Katsuo [Department of Clinical Medicine, Faculty of Education, Chiba University, 1-33 Yayoi, Inage-ku, Chiba 263-8522 (Japan); Kita, Kazuko [Department of Environmental Biochemistry, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670 (Japan); Suzuki, Nobuo [Department of Environmental Biochemistry, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670 (Japan)]. E-mail: nobuo@faculty.chiba-u.jp

2005-10-15

Fibroblast cells derived from nevoid basal carcinoma syndrome (NBCCS) patients show increased levels of DNA synthesis after X-ray irradiation. Genes, whose expression is modulated in association with the DNA synthesis induction, were searched by using PCR-based mRNA differential display analysis in one of the NBCCS cell lines, NBCCS1 cells. Decreased levels of SMT3A gene expression were found in X-ray-irradiated NBCCS1 cells. This decrease was also shown by RT-PCR analysis in another cell line, NBCCS3 cells. In addition to NBCCS cells, normal fibroblast cells showed the DNA synthesis induction after X-ray irradiation when they were treated with antisense oligonucleotides (AO) for SMT3A. However, treatment of normal fibroblasts with the random oligonucleotides (RO) resulted in decreased levels of DNA synthesis after X-ray irradiation. Thus, down-regulation of SMT3A gene expression may be involved in the DNA synthesis induction after X-ray irradiation in the NBCCS cells at least tested.

Semisterility of the first male progeny of female rats given a fractionated x ray dose of 800 R with administration of cysteamine and cystamine

Energy Technology Data Exchange (ETDEWEB)

Baev, I; Bairakova, A

1975-01-01

A total of 107 male Wistar rats were obtained six months after the fractional irradiation of females at a total x ray dose of 800 R (40 R per day for 20 days). Part of the females were irradiated without protection, and the rest received 5 mg cysteamine and 20 mg cystamine per rat each day before irradiation. The irradiated females were crossed with intact males. Fifteen males obtained from unirradiated parents served as controls. Males obtained from irradiated mothers and the control males were each housed with 7 intact females on attaining reproductive age. The females were killed on the 18th day after fertilization, and the living and dead embryos and the yellow bodies in each female were determined. The embryonic lethality in the male progeny whose mothers were irradiated with a fractionated dose of 800 R was 11 percent preimplantation with 9 percent postimplantation for a total of 19 percent for irradiated mothers given no radioprotective agent compared with 7 percent preimplantation with 5.5 percent postimplantation for a total of 12.5 percent in the control rats. For the cystamine-protected mothers the corresponding embryonic lethalities were 16.1 percent preimplantation with 10.5 percent postimplantation for a total of 26.6 percent, and for the cysteamine protected mothers, 14.3 percent preimplantation with 14.2 percent postimplantation for a total of 28.5 percent. Abouthalf of the males from the first generation of irradiated females showed a lowered fertility. 10 refs.

Low-angle X-ray scattering properties of irradiated spices

International Nuclear Information System (INIS)

Almeida, A.P.G.; Braz, D.; Barroso, R.C.; Lopes, R.T.

2007-01-01

The scattering of X-rays at low angles (LAXS) is a technique dominated by the coherent scattering process. One characteristic observation of low-angle coherent scattering is the so-called molecular interference effect, being characterized by the presence of one or more peaks in the forward direction of scattering. In the present study, LAXS profiles from five different spices are carefully measured in order to establish characteristic scattering signatures. Samples of Ceylon cinnamon, cumin, nutmeg, paprika and black pepper were bought in local market in Rio de Janeiro, Brazil. The LAXS patterns were obtained using a Shimadzu DRX 6000 diffractometer in reflection geometry. Coherent scattering patterns are measured for the samples for θ=5-35 o . The data were collected in 0.05 o increments every 3 s. In order to evaluate the possible molecular structure changes caused to the irradiation procedure, the signatures obtained for control (non-irradiated) spices were compared with spice samples irradiated with different doses varying from 3 to 40 kGy. The LAXS patterns of all samples were obtained after 30, 60, 90, 120 days to evaluate the effect of storage period. Scattering profiles from spices irradiated with different irradiation doses were obtained and the results compared. For each spice, there is no considerable deviation in shape in function of the irradiation dose. It indicates that the molecular structure of each analyzed spices is preserved considering the dose range chosen. The results show that the molecular structure was found to be stable during storage at the ambient temperature for up to 4 months

Studies on the leukemogenic and immunologic effects of radiostrontium (90Sr) and x rays in mice

International Nuclear Information System (INIS)

Ito, K.; Nagao, K.; Kawamura, Y.; Yokoro, K.

1976-01-01

The leukemogenic effect of internal irradiation with radiostrontium ( 90 Sr) was compared with that of external irradiation with x rays in ICR/JCL mice. Immunological, hematological, and cytogenetical changes were also studied during the preleukemic period in mice treated with 90 Sr or with x rays. A single intraperitoneal injection of 1.0 μCi of 90 Sr per gram of body weight resulted in leukemia in 62 percent of the mice. Only one of the 90 Sr-induced leukemias was of thymic origin. The occurrence of the leukemia was not affected by thymectomy. A fractionated whole-body x-irradiation of 680 R induced leukemia in 77 percent of the mice; the majority of the leukemias were of thymic origin. Although x-irradiation over the thymic region was ineffective in eliciting leukemia, a combined treatment of 90 Sr and local x-irradiation of the thymus was effective in inducing thymic lymphomas. The single intraperitoneal administration of 90 Sr caused an enhancement of both direct and indirect splenic plaque-forming cell (PFC) responses to sheep red blood cells, lasting for 35 days after treatment. No changes were observed in delayed-type hypersensitivity to picryl chloride. Thymectomy caused no appreciable effect in these immune responses. The fractionated whole-body x-irradiation rapidly depressed both PFC and delayed-type hypersensitivity responses, which persisted for a long period, especially in thymectomized mice. An abrupt increase of chromosomally aberrant cells in the thymus 60 days after the last x-irradiation was preceded by an increase of aberrant population in the bone marrow. On the other hand, a long-lasting appearance of aberrant population in the bone marrow and lymph nodes was observed in 90 Sr-injected mice

Adaptive response of spermatogenic cell apoptosis selectively induced by low dose X-ray irradiation in mice

International Nuclear Information System (INIS)

Liu Guangwei; Dong Lihua; Liu Yang; Lv Zhe; Liu Shuchun; Gong Shouliang

2003-01-01

Objective: The adaptive response of spermatogenic cell apoptosis induced by whole-body X-ray irradiation at low doses was studied in mice. Methods: Kunming male mice were irradiated with an inductive dose (D1:75 mGy) and/or a challenging dose (D2:1.0, 2.0 or 3.0 Gy). Different kinds of spermatogenic cells were separated using density gradient centrifugation and their apoptotic percentages were analysed using flow cytometry (FCM). Results: When the mice were irradiated with D1 6 h before irradiation with D2, the apoptotic percentages of the spermatogonia and spermatocytes declined rapidly as compared with those in the groups irradiated with D2 only, and those of spermatids and spermatozoa showed no significant changes. When the interval times between D1 and D2 was 3, 6, 12 or 24 h, the apoptotic percentages in spermatogonia and spermatocytes reduced early, significantly and continued for a longer duration after smaller D2(1.0 and 2.0 Gy) irradiation, while the apoptotic percentages did not change after larger D2(3.0 Gy) irradiation. Conclusion: The adaptive response of apoptosis in spermatogonia and spermatocytes could be selectively induced by low dose X-ray irradiation. The adaptive response could be closely related to the D2 dose and interval time between D1 and D2

Assessment of differences between X and γ rays in order to validate a new generation of irradiators for insect sterilization

International Nuclear Information System (INIS)

Mastrangelo, Thiago; Walder, Julio M.M.; Parker, Andrew G.; Jessup, Andrew; Orozco-Davila, Dina; Islam, Amirul; Dammalage, Thilakasiri; Pereira, Rui

2009-01-01

Recent fears of terrorism provoked an increase in delays and denials of transboundary shipments of radioisotopes. This represents a serious constraint to sterile insect technique (SIT) programs around the world as they rely on the use of ionizing energy from radioisotopes for insect sterilization. In order to validate a novel Xray irradiator, a series of studies on Ceratitis capitata (Wiedemann) and Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae) were carried out, comparing the relative biological effectiveness (RBE) between X-rays and traditional γ radiation from 60 Co. Male C. capitata pupae and pupae of both sexes of A. fraterculus, both 24 to 48 h before adult emergence, were irradiated with doses ranging from 15 to 120 Gy and 10 to 70 Gy respectively. Estimated mean doses of 91.2 Gy of X and 124.9 Gy of γ radiation induced 99% sterility in C. capitata males. Irradiated A. fraterculus were 99% sterile at about 40-60 Gy for both radiation treatments. Standard quality control parameters were not significantly affected by the two types of radiation. There were no significant differences between X and γ radiation regarding mating indices. The RBE did not differ significantly between the tested X and γ radiation, and X-rays are as biologically effective for SIT purposes as γ rays are. This work confirms the suitability of this new generation of X-ray irradiators for pest control programs in UN Member States. (author)

Effect of X-ray irradiation on interaction between phenylobutazone and hexobarbital

International Nuclear Information System (INIS)

Wojciak, Z.; Nowakowska, E.; Godlewski, J.; Kozaryn, I.

1985-01-01

The effect of premedication with phenylobutazone (60 mg/kg i.p.) on the hypnotic activity of hexobarbital (100 mg/kg i.p.) in rats irradiated with X-rays (600 R) was examined. After premedication with phenylobutazone hexobarbital-induced sleep was significantly longer, especially on the 3rd day of postirradiation sickness. Prolonged biological half-life time of hexobarbital and higher level in brain could explain its longer hypnotic effect. 33 refs., 3 figs., 3 tabs. (author)

Interest of the grazing X ray diffraction to study the evolution of materials under irradiation: behaviour of zirconia under irradiation; Utilisation de la diffraction des rayons X en incidence rasante pour l'etude des solides irradies: application a la zircone

Energy Technology Data Exchange (ETDEWEB)

Simeone, D.; Gosset, D.; Bechade, J.L. [CEA Saclay, Dept. des Materiaux pour le Nucleaire DMN, 91 - Gif-sur-Yvette (France)

2001-07-01

This document was written to show that grazing X ray diffraction may be a powerful tool to study irradiation damages induced by ion beams in materials. Taking advantage of an asymmetric geometry and a curved detector, it is possible to analyse accurately diffraction diagrams at low angles by taking into account the specific effects induced by the grazing incidence. The interest of grazing incidence is to control the penetration depth of X rays. Such possibility allows to separate effects induced by damages (displacement cascades) and the implantation peak (elastic deformation of the lattice due to the insertion of projectile ions in the matrix). A Rietveld analysis on grazing X ray diagrams shows clearly that displacement cascades induce a phase transition on irradiated zirconia. (authors)

Interest of the grazing X ray diffraction to study the evolution of materials under irradiation: behaviour of zirconia under irradiation; Utilisation de la diffraction des rayons X en incidence rasante pour l'etude des solides irradies: application a la zircone

Energy Technology Data Exchange (ETDEWEB)

Simeone, D; Gosset, D; Bechade, J L [CEA Saclay, Dept. des Materiaux pour le Nucleaire DMN, 91 - Gif-sur-Yvette (France)

2001-07-01

This document was written to show that grazing X ray diffraction may be a powerful tool to study irradiation damages induced by ion beams in materials. Taking advantage of an asymmetric geometry and a curved detector, it is possible to analyse accurately diffraction diagrams at low angles by taking into account the specific effects induced by the grazing incidence. The interest of grazing incidence is to control the penetration depth of X rays. Such possibility allows to separate effects induced by damages (displacement cascades) and the implantation peak (elastic deformation of the lattice due to the insertion of projectile ions in the matrix). A Rietveld analysis on grazing X ray diagrams shows clearly that displacement cascades induce a phase transition on irradiated zirconia. (authors)

Biological effect of ultrasoft x-ray, 1

International Nuclear Information System (INIS)

Narita, Noboru

1985-01-01

Biological effect on Escherichia coli by ultrasoft X-ray have been studied by comparing with that by uv light (2537 A) and by soft X-ray (40 kVp, 5 mA). Ultrasoft X-ray is aluminium characteristic X-ray (about 1.5 keV) produced by low energy electron collision on aluminium foil target and is obtained from Lea-type transmission target discharge tube. Escherichia coli used here are AB1157, AB1886 (uvrA6), JC1569 (recA), AB2470 (recB) and AB2480 (uvr rec) for inactivation experiment and WP2, WP2uvrA, WP2pKM101 and WP2uvrApKM101 for mutation induction experiment. These strains are all irradiated in buffer. Results obtained are summerized as follows : (i) inactivation by ultrasoft X-ray is located between ones by uv light and by soft X-ray, or ultrasoft X-ray gives a lethal damage that uvrA6 gene seems to contribute, and (ii) ultrasoft X-ray does not show the remarkable mutation induction like that induced by low dose irradiation of uv light or soft X-ray. (author)

Sulfur transfer in the distillate fractions of Arabian crude oils under gamma-irradiation

International Nuclear Information System (INIS)

Basfar, Ahmed A.; Soliman, Yasser S.; Alkhuraiji, Turki S.

2017-01-01

Desulfurization of light distillation fractions including gasoline, kerosene and diesel obtained from the four Arabian crude oils (heavy, medium, light and extra light) upon γ-rays irradiation to different doses was investigated. In addition, yields vol%, FTIR analysis, kinematic viscosity and density of all distillation fractions of irradiated crude oils were evaluated. Limited radiation-induced desulfurization of those fractions was observed up to an irradiation dose of 200 kGy. FTIR analysis of those fractions indicates the absence of oxidized sulfur compounds, represented by S=O of sulfone group, indicating that γ-irradiation of the Arabian crude oils at normal conditions does not induce an oxidative desulfurization in those distillation fractions. Radiation-induced sulfur transfer decreases by 28.56% and increases in total sulfur by 16.8% in Arabian extra light oil and Arabian medium crude oil respectively. - Highlights: • Limited desulfurization in the light distillate fraction of Arabian crude oils using γ-rays was observed. • FTIR analysis confirms limited unchanged in density, viscosity and yields of Arabian crude oils. • In absence of oxidizer, radiation-induced sulfur transfer was observed in gasoline and diesel fractions of Arabian crude oils. • Radiation-induced oxidative desulfuration of the light distillate fractions depends on its characteristics.

Different mechanisms between premitotic apoptosis and postmitotic apoptosis in X-irradiated U937 cells

International Nuclear Information System (INIS)

Shinomiya, Nariyoshi; Kuno, Yukie; Yamamoto, Fuyumi; Fukasawa, Masashi; Okumura, Atsushi; Uefuji, Megumi; Rokutanda, Makoto

2000-01-01

Purpose: Apoptosis is currently being evaluated for its importance as a pathway of radiation-induced cell death. However, the difference in the mechanisms between premitotic and postmitotic apoptosis following X-irradiation remains not well understood. We show here that the human monoblastoid cell line U937 can be induced to undergo these two different types of apoptosis. Methods and Materials: U937 cells were irradiated at a dose of 5 or 20 Gy, and the DNA fragmentation rate was measured by both flow cytometric analysis and gel electrophoresis. Activation of caspase-3 was detected by Western blot analysis and fluorogenic assay using acetyl-Asp-Glu-Val-Asp-7-amino-4-methyl-coumarin (Ac-DEVD-AMC). Detection of mitochondrial transmembrane potential (no. DELTAno. no. PSIno. ) was performed by using Rho123. Chasing of S-phase fraction following X-irradiation was performed after labeling with 5-bromo-2'-deoxyuridine (BrdU). Thymidine was used for synchronization of the cells. Inhibition of caspase-3 activity was achieved by Acetyl-Asp-Glu-Val-Asp-aldehyde (Ac-DEVD-CHO). Results: Time courses of the apoptotic rates, caspase activation, and no. DELTAno. no. PSIno. indicated that two different types of cell death were induced by the different X-ray doses. High-dose X-ray (20 Gy) induced a rapid and strong apoptosis, whereas low-dose X-ray (5 Gy) induced a slow and mild apoptosis. Cell-cycle analyses revealed that there was cell death before cell division in the former apoptosis but the cells must be dying after cell division in the latter apoptosis. By means of cell-cycle synchronization, the S-phase cells proved to be the most sensitive fraction to premitotic apoptosis, but an obvious difference in the susceptibility to cell death among the cell-cycle phases was not observed in postmitotic apoptosis. Ac-DEVD-CHO treatment effectively blocked caspase activity and premitotic apoptosis, but it failed to block postmitotic apoptosis. Conclusions: Irradiation of U937 cells at

Intestinal metaplasia induced by x-irradiation in different strains of rats

International Nuclear Information System (INIS)

Watanabe, Hiromitsu; Naito, Masashi; Kawashima, Kengo; Ito, Akihiro

1985-01-01

Attempts were made to examine strain differences in the susceptibility of rats to intestinal metaplasia induced by X-irradiation. The gastric regions of 4 inbred male rats (SHR, F344, WKY, and LEW strains) in 5-week-old and 2 random bred male rats (SD, and WIS strains) were irradiated with a total dose of 20 Gy X-ray given in two equal fractions separated by three days. Upon sacrifice at 6 months after the last irradiation, the number of intestinal metaplastic crypts with positive reaction to alkaline phosphatase (ALP) appeared highest in the SHR and lowest in the WIS rats. Morphologically, the number of crypts with intestinal metaplasia in whole glandular stomachs of SHR, WIS, F344, and SD rats were higher than those in WKY and LEW rats. In the pyloric gland, it was highest in WIS rats, while in the fundic gland it was highest in SHR rats. The results show that the appearance and location of intestinal metaplasia by X-irradiation are greatly influenced by the strain of the rat. (author)

X-ray and optical study on point defect formation and interaction under irradiation adn doping of KCl

Energy Technology Data Exchange (ETDEWEB)

Braude, I S; Rogozyanskaya, L M [AN Ukrainskoj SSR, Kharkov. Fiziko-Tekhnicheskij Inst. Nizkikh Temperatur

1978-08-01

Optical and X-ray diffuse scattering methods have been applied to investigate structural changes, taking place in KCl crystals during irradiation with ..gamma..-quanta and doping with barium. It is shown that ..gamma..-irradiation of ''pure'' and doped KCl crystals mainly leads to formation of F-centers and spherical vacancy complexes. F-center concentration in irradiated addition crystals (3x10/sup -6/) has turned out to be 25% lower, than in irradiated pure ones (4x10/sup -6/), which is connected with interaction of radiation and addition defects. The type of defects, causing assymetry in the distribution of diffuse scattering has been determined. Appearance of scattering ability modulation over direction < 100 > during irradiation of KCl pure crystals has been found. Critical radius of spherical complexes formed during irradiation has been estimated, it appeared to be 2.5 a, where a is a lattice period.

The evaluation of the irradiation of medical team in critical X-ray diagnostic techniques

Energy Technology Data Exchange (ETDEWEB)

Markovic, S; Pavlovic, R [Inst. of Nuclear Science Vinca, Belgrade (Yugoslavia). Radiation and Environmental Protection Lab.; Boreli, F [Fac. of Electrical Engineering, Belgrade (Yugoslavia)

1996-12-31

A good realized assessment of the irradiation for any exposed group of population serves as the base for the radiation protection measures (emergency radiation preparedness, radiation protection optimization etc.). This is especially important, by the radiation protection point of view, in contrast X-ray diagnostic techniques - angiographies. This paper presents the way for the realization of the medical team irradiation assessment, based on originally derived simple equations for the scattered radiation field around patient. (author) 1 fig., 3 figs.

Study of the reactivation of X-ray inactivated lambda bacteriophages by irradiated Escherichia coli bacteria

International Nuclear Information System (INIS)

Kiessling, W.

1980-01-01

Bacteriophages lambda and E.coli cells were exposed to X-rays in LB medium. Host cells exposed to a dose of 85 to 765 Gy had a reactivation factor 1.3 to 3.0 for bacteriophages inactivated by X-rays. The capacity of the bacteria for bacteriophage mutliplication remained apparently unchanged in this dose range. After UV-irradiation of the host cells, only a reactivation factor of 1.3 was found for bacteriophages exposed to X-radiation. The comparatively low Weigle reactivation of bacteriophages exposed to X-radiation - as compared with bacteriophages exposed to UV radiation was analyzed by counting free, non-adsorbed bacteriophages determined by filtration of radioactively labelled bacteriophage-host complexes, it was found to be due to a reduced adsorptivity. Reactivation experiments with bacteriophages exposed to X-rays and host bacterias with different degrees of radiosensitivity proved this assumption to be correct. (orig.) [de

Tissue feature-based intra-fractional motion tracking for stereoscopic x-ray image guided radiotherapy

Science.gov (United States)

Xie, Yaoqin; Xing, Lei; Gu, Jia; Liu, Wu

2013-06-01

Real-time knowledge of tumor position during radiation therapy is essential to overcome the adverse effect of intra-fractional organ motion. The goal of this work is to develop a tumor tracking strategy by effectively utilizing the inherent image features of stereoscopic x-ray images acquired during dose delivery. In stereoscopic x-ray image guided radiation delivery, two orthogonal x-ray images are acquired either simultaneously or sequentially. The essence of markerless tumor tracking is the reliable identification of inherent points with distinct tissue features on each projection image and their association between two images. The identification of the feature points on a planar x-ray image is realized by searching for points with high intensity gradient. The feature points are associated by using the scale invariance features transform descriptor. The performance of the proposed technique is evaluated by using images of a motion phantom and four archived clinical cases acquired using either a CyberKnife equipped with a stereoscopic x-ray imaging system, or a LINAC equipped with an onboard kV imager and an electronic portal imaging device. In the phantom study, the results obtained using the proposed method agree with the measurements to within 2 mm in all three directions. In the clinical study, the mean error is 0.48 ± 0.46 mm for four patient data with 144 sequential images. In this work, a tissue feature-based tracking method for stereoscopic x-ray image guided radiation therapy is developed. The technique avoids the invasive procedure of fiducial implantation and may greatly facilitate the clinical workflow.

Tissue feature-based intra-fractional motion tracking for stereoscopic x-ray image guided radiotherapy

International Nuclear Information System (INIS)

Xie Yaoqin; Gu Jia; Xing Lei; Liu Wu

2013-01-01

Real-time knowledge of tumor position during radiation therapy is essential to overcome the adverse effect of intra-fractional organ motion. The goal of this work is to develop a tumor tracking strategy by effectively utilizing the inherent image features of stereoscopic x-ray images acquired during dose delivery. In stereoscopic x-ray image guided radiation delivery, two orthogonal x-ray images are acquired either simultaneously or sequentially. The essence of markerless tumor tracking is the reliable identification of inherent points with distinct tissue features on each projection image and their association between two images. The identification of the feature points on a planar x-ray image is realized by searching for points with high intensity gradient. The feature points are associated by using the scale invariance features transform descriptor. The performance of the proposed technique is evaluated by using images of a motion phantom and four archived clinical cases acquired using either a CyberKnife equipped with a stereoscopic x-ray imaging system, or a LINAC equipped with an onboard kV imager and an electronic portal imaging device. In the phantom study, the results obtained using the proposed method agree with the measurements to within 2 mm in all three directions. In the clinical study, the mean error is 0.48 ± 0.46 mm for four patient data with 144 sequential images. In this work, a tissue feature-based tracking method for stereoscopic x-ray image guided radiation therapy is developed. The technique avoids the invasive procedure of fiducial implantation and may greatly facilitate the clinical workflow. (paper)

Usefulness of Daily Fractionated Administration of Wortmannin Combined With γ-Ray Irradiation in Terms of Local Tumor Response and Lung Metastasis

Science.gov (United States)

Masunaga, Shin-ichiro; Sakurai, Yoshinori; Tanaka, Hiroki; Suzuki, Minoru; Kondo, Natsuko; Narabayashi, Masaru; Tano, Keizo; Maruhashi, Akira; Ono, Koji

2013-01-01

Background To evaluate the usefulness of fractionated administration of wortmannin combined with γ-ray irradiation in terms of local tumor response and lung metastatic potential, referring to the response of intratumor quiescent (Q) cells. Methods B16-BL6 melanoma tumor-bearing C57BL/6 mice were continuously given 5-bromo-2’-deoxyuridine (BrdU) to label all proliferating (P) cells. The tumor-bearing mice then received γ-ray irradiation after wortmannin treatment through a single or 4 consecutive daily intraperitoneal administrations up to a total dose of 4 mg/kg in combination with an acute hypoxia-releasing agent (nicotinamide) or mild temperature hyperthermia (MTH). Immediately after the irradiation, cells from some tumors were isolated and incubated with a cytokinesis blocker. The responses of the Q and total (= P + Q) cell populations were assessed based on the frequency of micronuclei using immunofluorescence staining for BrdU. In other tumor-bearing mice, 17 days after irradiation, macroscopic lung metastases were enumerated. Results Wortmannin raised the sensitivity of Q cells more remarkably than the total cell population in both single and daily administrations. Daily administration of wortmannin elevated the sensitivity of both the total and Q cell populations, but especially the total cell population, compared with single administration. Daily administration, especially combined with MTH, decreased the number of lung metastases. Conclusion Daily fractionated administration of wortmannin in combination with γ-ray irradiation was thought to be more promising than single administration because of its potential to enhance local tumor response and repress lung metastatic potential. PMID:29147327

Repair of potentially lethal damage following irradiation with x rays or cyclotron neutrons: response of the EMT-6/UW tumor system treated under various growth conditions in vitro and in vivo

International Nuclear Information System (INIS)

Rasey, J.S.; Nelson, N.J.

1981-01-01

Postirradiation potentially lethal damage (PLD) repair was examined in the EMT-6/UW tumor system under a variety of in vitro and in vivo growth conditions. Following x irradiation, surviving fraction increased in fed and unfed plateau cultures if subculture and plating were delayed; in exponentially growing cultures if they were covered with depleted medium for the first 6 h postirradiation; and in tumors in vivo if excision for preparation of a cell suspension was delayed. Following irradiation with 21.5 meV (d + → Be) neutrons, PLD repair was measurable only in unfed plateau cultures when subculture was delayed and in exponentially growing cells exposed to depleted culture medium immediately after irradiation. In x-irradiated EMT-6/UW cells, the greatest repair capacity and the highest surviving fraction ratios were measured in unfed plateau cultures; the least repair was observed in exponentially growing cells exposed to depleted medium. Thus post-neutron repair was not limited to situations where the amount of repair of photon PLD is large. The demonstration of PLD repair in tumors irradiated in vivo with X rays and the absence of such repair after neutrons could have important implications in radiotherapy if this is a general phenomenon

A novel technique using DNA denaturation to detect multiply induced single-strand breaks in a hydrated plasmid DNA molecule by X-ray and 4He2+ ion irradiation

International Nuclear Information System (INIS)

Yokoya, A.; Shikazono, N.; Fujii, K.; Noguchi, M.; Urushibara, A.

2011-01-01

To detect multiple single-strand breaks (SSBs) produced in plasmid DNA molecules by direct energy deposition from radiation tracks, we have developed a novel technique using DNA denaturation by which irradiated DNA is analysed as single-strand DNA (SS-DNA). The multiple SSBs that arise in both strands of DNA, but do not induce a double-strand break, are quantified as loss of SS-DNA using agarose gel electrophoresis. We have applied this method to X-ray and 4 He 2+ ion-irradiated samples of fully hydrated pUC18 plasmid DNA. The fractions of both SS-DNA and closed circular DNA (CC-DNA) exponentially decrease with the increasing dose of X rays and 4 He 2+ ions. The efficiency of the loss of SS-DNA was half that of CC-DNA for both types of irradiation, indicating that one of two strands in DNA is not broken when one SSB is produced in CC-DNA by irradiation. Contrary to our initial expectation, these results indicate that SSBs are not multiply induced even by high linear energy transfer radiation distributed in both strands. (authors)

Cell survival after the combined action of manganese (MnCl2) and X-rays in synchronized Chinese hamster cells

International Nuclear Information System (INIS)

Skreb, Y.; Nagy, B.

1984-01-01

The interactions between the effects of manganese chloride and X-rays were studied in synchronized populations of V79 Chinese hamster fibroblasts. The cells were selected by shaking off asynchronous cultures for detachment of mitotic cells which were plated in petri dishes and exposed to various treatments. Irradiation was carried out with a Philips RT-100 X-ray unit. A final concentration of 0.25 mM MnCl 2 was used. The main parameter was the colony forming ability of the surviving cell fraction. When MnCl 2 was administered over 1 h, its toxicity was low regardless of the phase of the cell cycle. Administered separately, 2 Gy irradiation produced only a slight decrease in survival, less marked in the S phase. However, the two agents together induced a synergistic inhibition of the surviving fraction in the S phase when the metal was given immediately after irradiation. If manganese wad administered 3 h after irradiation the two inhibitory effects apparently remained only additive. It seems that MnCl 2 can impair some repair processes starting immediately after irradiation. (orig.)

Radiation Effect on Body Weight and Hematological Changes of Hybrid Mice by Conventional Fraction, Large Abdominal Field Irradiation

International Nuclear Information System (INIS)

Lee, Sung Heon; Shin, Sei One; Kim, Myung Se

1985-01-01

Radiation effect on mammals, especially on hematologic changes, has been studied since discovery of x-ray. Various experimental animals were tried for radiobiological studies. 72 hybrid mice with conventional fraction (5X/week), large abdominal field (2 x 3cm, from symphysis pubic to xyphoid process) were used. Body weight was declined gradually by increasing irradiation doses, nadir was about 29.7% in male ; 30.4% in female at 6000 rad irradiation group. Hemoglobin value was nearly normal throughout entire treatment. Significant dropping of WBC count was noted to 40-50% of pretreatment values by only 1000 rad irradiation. Change of differential count was interesting; lymphocyte proportion showed gradual reduction, instead of gradual increasing of segmented neutrophil. Those proportion were reversed after 6000 rad irradiation. Urinary protein tests showed + - +++, showing no correlation with dosage. Application. of our study in clinical combination therapy (radiation + chemotherapy) was discussed

Annual rate of hearing loss falls after fractionated stereotactic irradiation for vestibular schwannoma

International Nuclear Information System (INIS)

Sakamoto, Touru; Shirato, Hiroki; Takeichi, Norihito; Aoyama, Hidefumi; Fukuda, Satoshi; Miyasaka, Kazuo

2001-01-01

Purpose: The rate of hearing loss in a population before and after irradiation was investigated to determine the effect of irradiation on hearing impairment. Methods and materials: In 72 patients with vestibular schwannoma who received fractionated stereotactic irradiation from 1992 to 1999, 21 had had their hearing levels examined 3 months or more before the treatment. The mean time between the initial examination and treatment was 18.6 months (range: 3-89 months), and the mean time between treatment and the last follow-up was 24.2 months (12-69 months). Thirty-six to 50 Gy in 20-25 fractions over 5 to 6 weeks was given using an X-ray beam from a linear accelerator. Pure tone average (PTA) was measured using the mean hearing level at five frequencies, and the annual rate of hearing loss was defined as [(hearing loss in PTA(dB))/(follow-up period (months)x12)]. Results: The actual cumulative curve of decrease in tumor size of 2 mm or more was 38.3% at 2 years and 80.0% at 3 years. The mean of hearing loss in PTA was 11.6±10.3 dB (-1 to 35 dB) from the initial examination to the start of irradiation and 11.9±14.4 dB (-14 to 37 dB) from the start of irradiation to the last follow-up. The mean annual rates of hearing loss before irradiation and in the 1st, 2nd, 3rd and 4th years after irradiation were, respectively, 18.6, 11.2, 6.2, 5.1, and 5.0 dB/year. The annual rates of hearing loss in the 2nd year (P=0.025) and 3rd year (P=0.018) were significantly slower than the rate before irradiation. Conclusions: The mean annual rate of hearing loss was higher before irradiation than after irradiation, and hearing loss slowed rather than accelerated after irradiation. Although hearing loss after the treatment was usually permanent, fractionated stereotactic irradiation was suggested to be effective to lower the rate of hearing loss

Attempt at interpreting some optical absorption bands in X-ray irradiated fluorine

International Nuclear Information System (INIS)

Allain, Yves

1959-01-01

According to the results of one of our experiments, the 575 mμ absorption band of fluorine irradiated with X-Rays seams due to F - ion vacancies. Our goal has been to find a color centers model in fluorine colored in various conditions. Reprint of a paper published in Comptes rendus des seances de l'Academie des Sciences, t. 248, p. 2318-2320, sitting of Aril 20, 1959 [fr

Mutation induction in haploid yeast after split-dose radiation exposure. II. Combination of UV-irradiation and X-rays.

Science.gov (United States)

Keller, B; Zölzer, F; Kiefer, J

2004-01-01

Split-dose protocols can be used to investigate the kinetics of recovery from radiation damage and to elucidate the mechanisms of cell inactivation and mutation induction. In this study, a haploid strain of the yeast, Saccharomyces cerevisiae, wild-type with regard to radiation sensitivity, was irradiated with 254-nm ultraviolet (UV) light and then exposed to X-rays after incubation for 0-6 hr. The cells were incubated either on nutrient medium or salt agar between the treatments. Loss of reproductive ability and mutation to canavanine resistance were measured. When the X-ray exposure immediately followed UV-irradiation, the X-ray survival curves had the same slope irrespective of the pretreatment, while the X-ray mutation induction curves were changed from linear to linear quadratic with increasing UV fluence. Incubations up to about 3 hr on nutrient medium between the treatments led to synergism with respect to cell inactivation and antagonism with respect to mutation, but after 4-6 hr the two treatments acted independently. Incubation on salt agar did not cause any change in the survival curves, but there was a strong suppression of X-ray-induced mutation with increasing UV fluence. On the basis of these results, we suggest that mutation after combined UV and X-ray exposure is affected not only by the induction and suppression of DNA repair processes, but also by radiation-induced modifications of cell-cycle progression and changes in the expression of the mutant phenotype. Copyright 2004 Wiley-Liss, Inc.

Proliferation kinetics of cultured cells after irradiation with X-rays and 14 MeV neutrons studied by time-lapse cinematography.

Science.gov (United States)

Kooi, M W; Stap, J; Barendsen, G W

1984-06-01

Exponentially growing cells of an established line derived from a mouse osteosarcoma (MOS) have been studied by time-lapse cinematography after irradiation with 3 Gy of 200 kV X-rays or 1.5 Gy of 14 MeV neutrons. Cell cycle times (Tc) of individual cells and their progeny in three subsequent generations as well as the occurrence of aberrant mitosis have been determined to evaluate the variation in expression of damage in relation to the stage in the intermitotic cycle and the radiation quality. The results show that the radiation doses applied cause an equal elongation of the mean Tc, which is largest in the irradiated cells but persists in the three subsequent generations. After 3 Gy of X-rays, mitotic delay is largest in cells irradiated in later stages of the cycle, but this difference is not observed after 1.5 Gy of 14 MeV neutrons. In subsequent generations the Tc values show larger variations among descendents of cells treated in the same stage of the cycle as compared to controls but this variation is equal for the doses of X-rays and neutrons applied. Division probability was significantly reduced in irradiated cells as well as in subsequent generations, whereby with neutrons as compared to X-rays the damage is expressed in earlier generations, with less variation as a function of the cell cycle.

Untargeted viral mutagenesis is not found in X-irradiated monkey cells

International Nuclear Information System (INIS)

Lytle, C.D.; Carney, P.G.; Lee, W.; Bushar, H.F.

1988-01-01

The existence of untargeted viral mutagenesis in X-irradiated cells was investigated in a mammalian virus/cell system, where a low level of such viral mutagenesis can be demonstrated in UV-irradiated cells. In the positive control experiment UV-elicited mutagenesis was shown with cell exposures of 5, 10 and 15 J/m 2 and a delay of 24 h between cell irradiation and infection with unirradiated herpes simplex virus. Although X-ray doses of 1, 3 and 10 Gy elicit enhanced reactivation of UV-irradiated virus, no untargeted mutagenesis for any X-ray dose at post-irradiation infection times of 0, 24 or 72 h was observed in this study. Thus untargeted mutagenesis of herpes simplex virus was not demonstrated in X-irradiated monkey cells, under conditions where X-ray-enhanced reactivation occurs and where untargeted mutagenesis in UV-irradiated cells occurs. (author)

Effects of hyperthermia, x-ray irradiation and their combination on ascites tumor cells of mice

International Nuclear Information System (INIS)

Kaneko, Itsuo

1982-01-01

Fibrosarcoma ascites tumor cells (PB8) from NMRI mice were used to investigate cell loss by hyperthermia and/or x-ray irradiation. The tumor cells were labelled by an injection of 125 I-deoxyuridine to the abdominal cavity of the donors 2 days before the physical treatments. The labelled cells, transfered in test tubes, were heated at 44 0 C for 10-20 min and/or irradiated by x-ray at 250-1612 rad, and were transplanted in the recipient abdominal cavity as soon as possible after the treatments. The radioactivity of the tumor cells, as an indicator of cell loss, was measured with a gamma spectrometer. In the irradiated group, the ratio of cell loss increased in a dose-dependent manner, starting from the 4th day after the transplantation to the 9th day. In the heated group, the ratio of cell loss increased in proportion to the heating time, starting without delay after transplantation. In the combination group, the effect of the treatments was more marked than that by each single treatment. In the early stage of this group, cell loss was by heating and then, from the 4th day, the irradiation effect mostly dominated. It is concluded from the above results that cell loss by heating or irradiation is independent and that the effect of the combination is additive. (author)

The effect of mixed fractionation with X rays and neutrons on tumour growth delay and skin reactions in mice

International Nuclear Information System (INIS)

Carl, U.M.

1987-01-01

The authors have compared the effects of mixed fractionation schedules with X rays and neutrons on growth delay of a murine tumour and skin reactions in mice. The schedules were five daily fractions of X rays, neutrons or mixtures (NNXXX, XXXNN or NXXXN). For clamped tumours or skin all three mixed schedules had the same effect. In contrast, for unclamped tumours giving the neutrons first (NNXXX) was more effective than the other two mixed schedules. This represented a true therapeutic gain and implies that if neutrons are used clinically as only part of a course of fractionated radiotherapy, they should be given at the beginning rather than at the end of treatment. (author)

Hypothalamic-pituitary-testicular system following testicular X-irradiation

International Nuclear Information System (INIS)

Verjans, H.L.; Eik-Nes, K.B.

1976-01-01

Testes of adult, male rats were exposed to a total dose of 1500 R of X-irradiation. Testicular weight decreased from day 8 after X-ray treatment. This decrease was, however, precded by an increment of the testis weight on day 4 following treatment. X-ray treatment of testes was associated with significant increase in serum FSH. Testicular irradiation had, however, no effect on ventral prostate and seminal vesicles weights. Serum testosterone increased only on day 1, 2 and 4 after irradiation, while serum LH levels tended to increase from day 8 post-irradiation. These changes were not significant, however, when compared with non-irradiated controls. At 7, 13 and 20 days following 1500 R of bilateral, testicular X-irradiation, the hypothalamic-pituitary unit was still capable of responding to exogenous gonadotrophin releasing factor. Serum FSH may in male rats be regulated at least partly by circulating steroids of testicular origin and partly by an unknown factor of non-interstitial cell nature. (author)

Irradiation with x-rays of the energy 18 MV induces radioactivity in transfusion blood: Proposal of a safe method using 6 MV.

Science.gov (United States)

Frentzel, Katharina; Badakhshi, Harun

2016-12-01

To prevent a fatal transfusion-associated graft-versus-host disease, it is recommended to irradiate transfusion blood and blood components with ionizing radiation. Using x-rays from a linear accelerator of the radiotherapy department is an accepted alternative to gamma irradiation devices of the blood bank and to the orthovoltage units that are replacing the gamma irradiators today. However, the use of high energy x-rays may carry a potential risk of induced radioactivity. The objective of this study was to investigate the effect of two different energy levels, 6 and 18 MV, which are executed in routine clinical settings. The research question was if induced radioactivity occurs at one of these standard energy levels. The authors aimed to give a proposal for a blood irradiation procedure that certainly avoids induced radioactivity. For this study, the authors developed a blood bag phantom, irradiated it with x-ray energies of 6 and 18 MV, and measured the induced radioactivity in a well counter. Thereafter, the same irradiation and measuring procedure was performed with a unit of packed red blood cells. A feasible clinical procedure was developed using 6 MV and an acrylic box. With the irradiation planning system XiO, the authors generated an irradiation protocol for the linear accelerator Siemens ONCOR Anvant-Garde. Both measurement setups showed that there was induced radioactivity for 18 MV but not for 6 MV. The induced radioactivity for 18 MV was up to 190 times the background. This is significant and of clinical relevance especially since there are newborn and fetal blood recipients for whom every radiation exposure has to be strictly avoided. The irradiation of blood with x-rays from a linear accelerator of the radiotherapy department is safe and feasible, but by the current state of scientific knowledge, the authors recommend to use an x-ray energy of 6 MV or less to avoid induced radioactivity in transfusion blood.

G2 block in Chinese hamster cells induced by x-irradiation, hyperthermia, cycloheximide, or actinomycin-D

International Nuclear Information System (INIS)

Dewey, W.C.; Highfield, D.P.

1976-01-01

The entry of cells into mitosis was monitored by shaking off mitotic cells from monolayer cultures. The location in G 2 of the x-ray transition point (TP), beyond which the cells were not delayed by x irradiation moved closer to mitosis as the dose was increased, i.e., at 10 min before prophase for 100 to 200 rad, and at 19 min for 30 to 60 rad. Treatment with cycloheximide (CH, 20 μg/ml) at the time of irradiation (50 to 100 rad) shifted the TP for x irradiation by 5 to 9 min toward mitosis. Calculations from these shifts in TP with radiation dose indicated that the logarithm of both the fraction of cells in G 2 not delayed by irradiation and the fraction beyond the TP for CH (located at 26 min before phophase for 5 to 50 μg/ml) not delayed by irradiation decreased linearly with dose (anti D 0 of 30 rad). Furthermore, inhibition of protein synthesis by CH, with or without a simultaneous treatment with actinomycin D (AMD), prevented repair of damage causing mitotic delay for a period of time equal to the duration of the CH treatment

Acute skin reaction after fractionated irradiation

International Nuclear Information System (INIS)

Kozubek, S.

1983-01-01

Experimental data on acute mouse and pig skin reaction after fractionated γ or X irradiation have been analysed in terms of a new cell tissue kinetic model. The exponential-quadratic and generalized Huggett formulae have been used for cell lethality description. Fairly better results could be demonstrated with generalized Huggett formula. The speed of repopulation has been determined for fractionated regimes as well as for some irregular schedules. The repopulation is slower in the case of fractionated treatment. On considering the normal cell loss factor in the tissue, minimum cell cycle time has been calculated. Its value differs for various strains (Tsub(d)=28.8 hours for SAS/TO mice and Tsub(d) < or approximately 17 hours for WHT/Ht mice) and does not differ for plucked skin. The repopulation has been shown to follow exponential dependence after some latent period. Other factors influencing the effectiveness of radiation treatment (the length of the latent period or the changes of the survival curve during fractionated irradiation) have been considered, too

Restoring efficiency of hemopoietic cell transplantation in a mouse lethally irradiated by a total exposure to X rays

International Nuclear Information System (INIS)

Doria, Gino

1959-10-01

This research thesis reports the study of possibility of treatments (or restoration) of a mouse which has been submitted to a lethal dose of X rays. More particularly, the author compared the restoring efficiency of bone marrow and fetal liver injected in a mouse which had been lethally irradiated by a total exposure to X rays. He also studied the functional status of the hemopoietic graft, and the emergence of the secondary disease in mice which had been as well lethally irradiated and then restored by injection of bone marrow and fetal liver. The author then addressed the influence of the induction of immune tolerance of the host with respect to the donor on the survival of a mouse lethally irradiated and restored by homologue bone marrow [fr

X-ray emission from plasmas created by smoothed KrF laser irradiation

International Nuclear Information System (INIS)

Aglitskiy, Y.; Lehecka, T.; Deniz, A.; Hardgrove, J.; Seely, J.; Brown, C.; Feldman, U.; Pawley, C.; Gerber, K.; Bodner, S.; Obenschain, S.; Lehmberg, R.; McLean, E.; Pronko, M.; Sethian, J.; Stamper, J.; Schmitt, A.; Sullivan, C.; Holland, G.; Laming, M.

1996-01-01

The x-ray emission from plasmas created by the Naval Research Laboratory Nike KrF laser [Phys. Plasmas 3, 2098 (1996) ] was characterized using imaging and spectroscopic instruments. The laser wavelength was 1/4 μm, and the beams were smoothed by induced spatial incoherence (ISI). The targets were thin foils of CH, aluminum, titanium, and cobalt and were irradiated by laser energies in the range 100 endash 1500 J. A multilayer mirror microscope operating at an energy of 95 eV recorded images of the plasma with a spatial resolution of 2 μm. The variation of the 95 eV emission across the 800 μm focal spot was 1.3% rms. Using a curved crystal imager operating in the 1 endash 2 keV x-ray region, the density, temperature, and opacity of aluminum plasmas were determined with a spatial resolution of 10 μm perpendicular to the target surface. The spectral line ratios indicated that the aluminum plasmas were relatively dense, cool, and optically thick near the target surface. The absolute radiation flux was determined at 95 eV and in x-ray bandpasses covering the 1 endash 8 keV region. The electron temperature inferred from the slope of the x-ray flux versus energy data in the 5 endash 8 keV region was 900 eV for an incident laser energy of 200 J and an intensity of ≅10 13 W/cm 2

Measurements of void fraction in a water-molten tin system by X-ray absorption

International Nuclear Information System (INIS)

Baker, Michael C.; Bonazza, Riccardo; Corradini, Michael L.

1998-01-01

A facility has been developed to study the explosive interactions of gas-water injection into a molten tin pool. The experimental apparatus allows for variable nitrogen gas and water injection into the base of a steel tank containing up to 25 kg of molten tin. Due to the opaque nature of the molten metal-gas-water mixture and steel tank, a visualization and measurement technique using continuous high energy x-rays had to be developed. Visualization of the multiphase mixture can be done at 220 Hz with 256x256 pixel resolution or at 30 Hz with 480x1128 pixel resolution. These images are stored digitally and subsequently processed to obtain two dimensional mappings of the chordal average void fraction in the mixture. The image processing method has been used to measure void fraction in experiments that did not include water in the injection mixture. This work includes a comparison to previous studies of integral void fraction data in pools of molten metal with gas injection. (author)

Sister chromatid exchanges in X-ray irradiated blood lymphocytes from patients with hereditary diseases with radioresistant DNA synthesis

International Nuclear Information System (INIS)

Pleskach, N.M.; Andriadze, M.I.; Mikhel'son, V.M.; Zhestyanikov, V.D.

1988-01-01

X-ray irradiation induced sister chromatid exchanges (SCE) in blood lymphocytes from patient with Down's syndrome and adult progeria (in both the cases radioresistant DNA synthesis takes place). In normal lymphocytes (in which ionizing radiation inhibits the replicative synthesis of DNA) the rate of SCE rises with the rise of radiation dose. Thus, the rate of SCE in X-ray irradiated lymphocytes is in reverse dependence with radioresistance of replicative synthesis of DNA. The data obtained are explained in accordance with the replicative hypothesis of the SCE nature (Painter, 1980a): in cells of patients with Down's syndrome, xeroderma pigmentosum from 2 and progeria of adults the time of existence of partly replicated clusters of replicons is decreased due to radioresistant replicative synthesis of DNA, but the presence of partly replicated clusters of replicons in necessary for SCE formation. Therefore the rate of SCF in X-irradiated cells of these patients decreases

The effects of x-ray irradiation on the inner ear

International Nuclear Information System (INIS)

Kanagawa, Kiyoto

1983-01-01

Since the beginning of the 20th century, it has been known that the radiation can cause hearing loss, but the details of this process are not as well known as those of radiation effects on other organs. The author studied the effects of single dose of x-ray irradiation on the inner ear of guinea pigs by continuously measurement of cochlear microphonics (CM) and auditory brainstem responses (ABR) with permanent electrodes implanted on the round window and in the skull. With 2,000, 4,000, and 6,000 rad, slight conductive hearing impairment was observed in some guinea pigs. Severe sensorineural hearing loss was acutely induced by irradiation more than 8,000 rad. After 10,000 rad irradiation, both CM and ABR to air and bone conduction stimuli were usually enhanced by 20-50% above the pre-irradiation levels for one or two hours after completion of the irradiation, and they disappeared simultaneously about 6 hours after irradiation. Hearing impairment began earlier with increase in irradiation: about 10 hours at 8,000 rad, about 6 hours at 10,000 rad, and about 3 hours at 12,000 rad. Responses to high frequency sounds generally disappeared slightly earlier than those to low frequencies. The I-III interpeak latency of ABR didn't change after 10,000 rad irradiation. Endocochlear potential (EP) drop to about 30mV was observed about 7 hours after 10,000 rad irradiation. In the scanning electron micrographs, the sensory hairs in the outer and inner hair cells of every turn seemed to be normal 6 hours after 10,000 rad irradiation. In transmission electron microscopy, however, heavy damages were seen at the outer hair cells in the basal coil of the cochlea. (author)

Effect of x-ray irradiation ovary on interleukin 2 secretion in rats

International Nuclear Information System (INIS)

Huang Hui; Lin Yunlu; Zhang Haijun; Wang Hongfu

1993-01-01

The effects of interleukin 2 (IL-2) secretion were studied in a rat model by means of x-ray irradiated ovary. It was found that the reduction of estradiol (E 2 )in serum could promote lymphocyte blastogenesis and IL-2 secretion. There was also found a correlation between IL-2 production and the level of E 2 in serum (r = -0.952, P 2 might be associated with a decreased nonspecific immunity

Relative survival of hybrid x-ray-resistant, and normally sensitive mammalian cells exposed to x rays and protons under aerobic and hypoxic conditions

International Nuclear Information System (INIS)

Williams, J.R.; Gould, R.G.; Flynn, D.; Robertson, J.B.; Little, J.B.

1978-01-01

Survival of an x-ray-resistant hybrid cell line (HD 1 ) and a normally responsive cell line (H 4 ) have been compared when irradiated under induced hypoxia by both protons and X rays. The two cell lines are similarly protected when irradiated under hypoxic conditions with oxygen enhancement ratios of 2.8 and 2.7, respectively. The protection is consistent with a dose-modifying factor. No statistically significant difference is observed between cell inactivation by x rays and protons in either cell line, whether irradiated under aerobic or hypoxic conditions

Development, Beam characterization and chromosomal effectiveness of X-rays of RBC characteristic X-ray generator

International Nuclear Information System (INIS)

Endo, Satoru; Hoshi, Masaharu; Takada, Jun; Takatsuji, Toshihiro; Ejima, Yosuke; Saigusa, Shin; Tachibana, Akira; Sasaki, Masao S.

2006-01-01

A characteristic hot-filament type X-ray generator was constructed for irradiation of cultured cells. The source provides copper K, iron K, chromium K, molybdenum L, aluminium K and carbon K shell characteristic X-rays. When cultured mouse m5S cells were irradiated and frequencies of dicentrics were fitted to a linear-quadratic model, Y=αD+βD 2 , the chromosomal effectiveness was not a simple function of photon energy. The α-terms increased with the decrease of the photon energy and then decreased with further decrease of the energy with an inflection point at around 10 keV. The β-terms stayed constant for the photon energy down to 10 keV and then increased with further decrease of energy. Below 10 keV, the relative biological effectiveness (RBE) at low doses was proportional to the photon energy, which contrasted to that for high energy X- or γ-rays where the RBE was inversely related with the photon energy. The reversion of the energy dependency occurred at around 1-2 Gy, where the RBE of soft X-rays was insensitive to X-ray energy. The reversion of energy-RBE relation at a moderate dose may shed light on the controversy on energy dependency of RBE of ultrasoft X-rays in cell survival experiments. (author)

Near-surface density profiling of Fe ion irradiated Si (100) using extremely asymmetric x-ray diffraction by variation of the wavelength

Energy Technology Data Exchange (ETDEWEB)

Khanbabaee, B., E-mail: khanbabaee@physik.uni-siegen.de; Pietsch, U. [Solid State Physics, University of Siegen, D-57068 Siegen (Germany); Facsko, S. [Helmholtz-Zentrum Dresden-Rossendorf, 01314 Dresden (Germany); Doyle, S. [Synchrotron Light Source ANKA, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany)

2014-10-20

In this work, we report on correlations between surface density variations and ion parameters during ion beam-induced surface patterning process. The near-surface density variations of irradiated Si(100) surfaces were investigated after off-normal irradiation with 5 keV Fe ions at different fluences. In order to reduce the x-ray probing depth to a thickness below 5 nm, the extremely asymmetrical x-ray diffraction by variation of wavelength was applied, exploiting x-ray refraction at the air-sample interface. Depth profiling was achieved by measuring x-ray rocking curves as function of varying wavelengths providing incidence angles down to 0°. The density variation was extracted from the deviations from kinematical Bragg angle at grazing incidence angles due to refraction of the x-ray beam at the air-sample interface. The simulations based on the dynamical theory of x-ray diffraction revealed that while a net near-surface density decreases with increasing ion fluence which is accompanied by surface patterning, there is a certain threshold of ion fluence to surface density modulation. Our finding suggests that the surface density variation can be relevant with the mechanism of pattern formation.

Single Event Gate Rupture in 130-nm CMOS Transistor Arrays Subjected to X-Ray Irradiation

CERN Document Server

Silvestri, M; Gerardin, Simone; Faccio, Federico; Paccagnella, Alessandro

2010-01-01

We present new experimental results on heavy ion-induced gate rupture on deep submicron CMOS transistor arrays. Through the use of dedicated test structures, composed by a large number of 130-nm MOSFETs connected in parallel, we show the response to heavy ion irradiation under high stress voltages of devices previously irradiated with X-rays. We found only a slight impact on gate rupture critical voltage at a LET of 32 MeV cm(2) mg(-1) for devices previously irradiated up to 3 Mrad(SiO2), and practically no change for 100 Mrad(SiO2) irradiation, dose of interest for the future super large hadron collider (SLHC).

X-ray irradiation and Rho-kinase inhibitor additively induce invasiveness of the cells of the pancreatic cancer line, MIAPaCa-2, which exhibits mesenchymal and amoeboid motility

International Nuclear Information System (INIS)

Fujita, Mayumi; Otsuka, Yoshimi; Yamada, Shigeru; Iwakawa, Mayumi; Imai, Takashi

2011-01-01

Tumor cells can migrate and invade tissue by two modes of motility: mesenchymal and amoeboid. X-ray or γ-ray irradiation increases the invasiveness of tumor cells with mesenchymal motility through the induction of matrix metalloproteinases (MMP), and this increase is suppressed by MMP inhibitors (MMPI). However, the effects of X-ray or γ-ray irradiation on the invasiveness of tumor cells with amoeboid motility remain unclear. We investigated the effect of irradiation on amoeboid motility by using cells of the human pancreatic cancer line, MIAPaCa-2, which exhibits both modes of motility. The X-ray-induced invasiveness of MIAPaCa-2 cells was associated with the upregulation of MMP2 at both the RNA and protein levels and was inhibited by MMPI treatment. Amoeboid-mesenchymal transition was slightly induced after irradiation. The MMPI treatment caused mesenchymal-amoeboid transition without significant increase in invasiveness, while the ROCK inhibitor (ROCKI) stimulated amoeboid-mesenchymal transition and enhanced invasiveness under both non-irradiated and irradiated conditions. This ROCKI-induced transition was accompanied by the upregulation of MMP2 mRNA and protein. Exposure to both irradiation and ROCKI further enhanced MMP2 expression and had an additive effect on the invasiveness of MIAPaCa-2 cells. Additionally, exposure to MMPI led to significant suppression of both radiation-induced and the basal invasiveness of MIAPaCa-2 cells. This suggests that ROCKI treatment, especially with concomitant X-ray irradiation, can induce invasion of cancer cells and should be used only for certain types of cancer cells. Simultaneous use of inhibitors, ROCKI and MMPI may be effective in suppressing invasiveness under both X-ray-irradiated and non-irradiated conditions. (author)

Investigation of the internal electric field distribution under in situ x-ray irradiation and under low temperature conditions by the means of the Pockels effect

International Nuclear Information System (INIS)

Prekas, G; Sellin, P J; Veeramani, P; Davies, A W; Lohstroh, A; Oezsan, M E; Veale, M C

2010-01-01

The internal electric field distribution in cadmium zinc telluride (CdZnTe) x-ray and γ-ray detectors strongly affects their performance in terms of charge transport and charge collection properties. In CdZnTe detectors the electric field distribution is sensitively dependent on not only the nature of the metal contacts but also on the working conditions of the devices such as the temperature and the rate of external irradiation. Here we present direct measurements of the electric field profiles in CdZnTe detectors obtained using the Pockels electo-optic effect whilst under in situ x-ray irradiation. These data are also compared with alpha particle induced current pulses obtained by the transient current technique, and we discuss the influence of both low temperature and x-ray irradiation on the electric field evolution. Results from these studies reveal strong distortion of the electric field consistent with the build-up of space charge at temperatures below 250 K, even in the absence of external irradiation. Also, in the presence of x-ray irradiation levels a significant distortion in the electric field is observed even at room temperature which matches well the predicted theoretical model.

Characteristics of specifications of transportable inverter-type X-ray equipment

International Nuclear Information System (INIS)

Yamamoto, Keiichi; Miyazaki, Shigeru

2003-01-01

Our X-ray systems study group measured and examined the characteristics of four transportable inverter-type X-ray equipments. X-ray tube voltage and X-ray tube current were measured with the X-ray tube voltage and the X-ray tube current measurement terminals provided with the equipment. X-ray tube voltage, irradiation time, and dose were measured with a non-invasive X-ray tube voltage-measuring device, and X-ray output was measured by fluorescence meter. The items investigated were the reproducibility and linearity of X-ray output, error of pre-set X-ray tube voltage and X-ray tube current, and X-ray tube voltage ripple percentage. The waveforms of X-ray tube voltage, the X-ray tube current, and fluorescence intensity draw were analyzed using the oscilloscope gram and a personal computer. All of the equipment had a preset error of X-ray tube voltage and X-ray tube current that met Japanese Industrial Standards (JIS) standards. The X-ray tube voltage ripple percentage of each equipment conformed to the tendency to decrease when X-ray tube voltage increased. Although the X-ray output reproducibility of system A exceeded the JIS standard, the other systems were within the JIS standard. Equipment A required 40 ms for X-ray tube current to reach the target value, and there was some X-ray output loss because of a trough in X-ray tube current. Owing to the influence of the ripple in X-ray tube current, the strength of the fluorescence waveform rippled in equipments B and C. Waveform analysis could not be done by aliasing of the recording device in equipment D. The maximum X-ray tube current of transportable inverter-type X-ray equipment is as low as 10-20 mA, and the irradiation time of chest X-ray photography exceeds 0.1 sec. However, improvement of the radiophotographic technique is required for patients who cannot move their bodies or halt respiration. It is necessary to make the irradiation time of the equipments shorter for remote medical treatment. (author)

Effects of 2'-chlorothymidine on Chinese hamster cells irradiated with x-rays and ultraviolet light

Energy Technology Data Exchange (ETDEWEB)

Murai, T; Kuwabara, M; Sato, F; Kubo, K; Itoh, T; Yoshii, G

1985-06-01

Effects of 2'-chlorothymidine (2'-Cl-TdR) and its mother compound, thymidine (TdR), on cell killing induced by X- and UV-irradiation have been investigated. Chinse hamster V-79 (TK/sup +/) cells as well as thymidine kinase deficient (TK/sup -/) variant cells, which were isolated from parental V-79 cells following stepwise treatment with BUdR, were incubated in a medium containing 2'-Cl-TdR and TdR after X- and UV-irradiation. In the TK/sup +/ cells, both 2'-Cl-TdR and TdR enhanced the killing efficiency of X-rays and ultraviolet light. On the other hand, in the TK/sup -/ cells, only 2'-Cl-TdR enhanced the killing efficiency of X- and UV-irradiation, and no effect of TdR was observed. These results suggest that phosphorylation of TdR by the enzyme is essential for its ability to modify radiation response, while the enhancement of cell killing by 2'-Cl-TdR must be explained by a mechanism at least partly independent of phosphorylation. (author).

Relationship between the adaptive response and bystander effect produced by single cell irradiation using a focused ultrasoft x-ray microbeam

International Nuclear Information System (INIS)

Wu, L.; Schettino, G.; Folkard, M.; Yu, Z.; Prise, K.; Michael, B.; Wang, Y.

2003-01-01

Full text: Using the cell killing method and our newly developed focused carbon-K ultrasoft X-rays, we tested for an interaction between bystander responses and adaptive responses by irradiating only one V79 cell in a population with a dose of 0.2 or 1Gy, combined with a conventional 240kVp X irradiation (0, 0.01, 0.05, 0.2 or 1Gy) 2 hours before or after bystander treatment. The clonogenic survival of V79 cells was precisely measured by a single cell revisiting assay after incubation for 3 days. Our results clearly showed that the cell killing by the bystander treatment could be reduced by about 5% if we treated the cells with a very low dose of conventional 240kVp X-rays of 0.01 or 0.05Gy (at which dose they only kill 1 or 2% cells in a population), whether the conventional dose was given before or after bystander irradiation. When the conventional dose was increased to 0.2 or 1Gy (at which dose they could kill about 10 or 25% V79 cells), no adaptive response was found if we treated the cells with conventional irradiation first and bystander irradiation afterwards. However, the adaptive responses observed when we irradiated a single cell within the whole cell population before 0.2 or 1Gy conventional irradiation was given. This showed that the bystander-mediated adaptive response could increase the cell survival by 5 or 8% respectively compared with the cell killing by conventional irradiation of 0.2 or 1Gy only. We also tested the distribution of dead clones in the microbeam dishes either for bystander irradiation only or combined with conventional X-rays. We did not find any distance relationship between the irradiated cell and non-irradiated cells, which was consistent with our previous bystander irradiation studies showing an equal probability of finding damaged clones any where in the scanned area of the dish

Irradiation of Nd-Fe-B permanent magnets with APS bending magnet x-rays and 60Co γ-rays

International Nuclear Information System (INIS)

Alderman, J.; Job, P. K.; Puhl, J.

2000-01-01

The Advanced Photon Source (APS), as well as other third-generation synchrotron light sources, uses permanent magnets in the insertion devices to produce x-rays for scientific research. When placed in a high-energy storage ring, these permanent magnets are subjected to irradiation from synchrotron radiation, high-energy bremsstrahlung, and bremsstrahlung-produced photoneutrons. Previous investigations have exhibited varying degrees of degradation in the intensity of magnetization of these magnets due to irradiation from electron beams, 60 Co γrays, and high-energy neutrons. The APS specifically uses Nd-Fe-B permanent magnets in their insertion devices. Although no detectable radiation-induced demagnetization has been observed in the APS insertion devices so far, partial demagnetization has been observed in at least one insertion device at the European Synchrotron Radiation Facility (ESRF), where Nd-Fe-B permanent magnets are also used

A new device for X-ray Diffraction analyses of irradiated materials

International Nuclear Information System (INIS)

Valot, Christophe; Blay, Thierry; Caillot, Laurent; Ferroud-Plattet, Marie Pierre

2008-01-01

A new X-Ray Diffraction (XRD) equipment is being implemented in the LECA (Cea - Cadarache) hot laboratory. The device will be dedicated to structural characterization on irradiated fuels, as PWR fuels, transmutation targets and innovative fuels. The paper will present the specific design that was decided in order to reduce the number of components in contaminated volume and to make servicing easier. The analytical performances of this new equipment will be illustrated on some model samples: -) micro-diffraction capabilities will be detailed on heterogeneous material; -) strain and stress analyses on fresh uranium oxide pellets. (authors)

X-ray diffraction study of the Y{sub 2}Ti{sub 2}O{sub 7} pyrochlore disordering sequence under irradiation

Energy Technology Data Exchange (ETDEWEB)

Soulié, Aurélien, E-mail: aurelien.soulie@cea.fr [CEA, DEN, Service de Recherches de Métallurgie Physique, Université Paris-Saclay, F-91191 Gif sur Yvette (France); CEA, DEN, Service de Recherches de Métallurgie Appliqué, Université Paris-Saclay, F-91191 Gif sur Yvette (France); Menut, Denis [CEA, DEN, Service de Recherches de Métallurgie Appliqué, Université Paris-Saclay, F-91191 Gif sur Yvette (France); Crocombette, Jean-Paul [CEA, DEN, Service de Recherches de Métallurgie Physique, Université Paris-Saclay, F-91191 Gif sur Yvette (France); Chartier, Alain [CEA, DEN, Service de la Corrosion et du Comportement des Matériaux dans leur Environnement, Laboratoire de Modélisation, de Thermodynamique et de Thermochimie, Université Paris-Saclay, F-91191 Gif sur Yvette (France); Sellami, Neila [Univ. Paris Sud, ICMMO-SP2M, Bât. 410, F-91405 Orsay (France); Sattonnay, Gaël [Univ. Paris-Sud, CSNSM, CNRS, IN2P3, Bât. 108, F-91405 Orsay (France); Monnet, Isabelle [CIMAP, CEA, CNRS, Université de Caen, BP 5133, F-14070 Caen Cedex 5 (France); and others

2016-11-15

The disordering sequence of Y{sub 2}Ti{sub 2}O{sub 7} pyrochlore, a nano-oxide phase that strengthens ODS steels under irradiation is studied in the experimental and modeling framework. XRD analysis has been performed considering both swift heavy ion and low energy/low mass ion irradiations. The simulation within molecular dynamics of Frenkel pair accumulation proves able to reproduce the variation of the amorphization fluence with temperature. XRD patterns calculated from the simulations reproduce well the patterns observed experimentally in the literature. Both experiments and calculations point to a first transition from pyrochlore to fluorite before an eventual amorphization. For swift heavy ion irradiations with 93 MeV Xe ions, tracks of direct impact amorphization are visible by HRTEM. Advanced refinement shows that one third of the pyrochlore impacted by an ion transforms into fluorite, while two third are directly amorphized. - Highlights: • A comparison between swift heavy ion and low energy/low mass ion irradiation of Y{sub 2}Ti{sub 2}O{sub 7} pyrochlore is performed. • Simulations of the irradiation with Molecular dynamics reproduce the amorphization dose at low energy/mass ion irradiation. • Advanced refinement of X-ray diffraction patterns gives the evolution of phase fractions in pyrochlore under irradiation. • The disordering sequence a transition from pyrochlore to defect fluorite before an eventual amorphization.

Void fraction measurement in two-phase flow with X-rays

International Nuclear Information System (INIS)

Hufschmidt, W.; Clercq, E. de.

1984-01-01

The exact knowledge of the void fraction in two-phase flow systems with water and vapour is of great importance for water-reactors. A mesurement method not disturbing the fluid flow is the absorption technique X-rays. This method has been tested for the present case of small absorption lengths (about 16mm). In collaboration with the 'Lehrstuhl fuer elektronische Schaltungen' of the Ruhruniversitaet, Bochum (FRG), a rapid measurement device has been developed using ionization chambers. At present steady-state fluid in vertical tubes with homogeneous distribution of the two-phases water-vapour are tested at pressures in the range from 70 to 150 bars and rather good agreements with calculated values are found

Protective role of Aloe vera against X-ray induced testicular dysfunction.

Science.gov (United States)

Bala, S; Chugh, N A; Bansal, S C; Garg, M L; Koul, A

2017-09-01

The present investigation was carried out to evaluate the possible radioprotective potential of an Aloe vera extract against whole-body X-ray irradiation-induced testicular alterations in mice. Male balb/c mice were divided into four groups: control, A. vera, X-ray and A. vera pre-treated + X-ray irradiated. Histopathological examination revealed significant structural alterations in testes after X-ray exposure, which was also associated with the presence of apoptotic cells as assessed by TUNEL assay. X-ray irradiation resulted in elevation in the levels of reactive oxygen species, lipid peroxidation, a reduction in glutathione concentration and enhanced activities of antioxidant enzymes such as glutathione reductase, glutathione peroxidase, catalase, superoxide dismutase and glutathione-S-transferase. Sperm count/motility and testosterone levels were significantly decreased in the irradiated group. Irradiated animals pre-treated with A. vera extract revealed an improvement in antioxidant status, inhibition of lipid peroxides, apoptotic cell formation and enhanced testicular parameters when compared to the X-ray-exposed group. These findings suggest that A. vera extract could ameliorate X-ray-induced damage due to its free radical scavenging properties and its potential to boost cellular antioxidant defence machinery. © 2016 Blackwell Verlag GmbH.

Protease activation involved in resistance of human cells to x-ray cell killing

International Nuclear Information System (INIS)

Zhang, Hong-Chang; Takahashi, Shuji; Karata, Kiyonobu; Kita, Kazuko; Suzuki, Nobuo

2003-01-01

Little is known of proteases that play roles in the early steps of X-ray irradiation response. In the present study, we first searched for proteases whose activity is induced in human RSa-R cells after X-ray irradiation. The activity was identified as fibrinolytic, using 125 I-labeled fibrin as a substrate. Protease samples were prepared by lysation of cells with a buffer containing MEGA-8. RSa-R cells showed an increased level of protease activity 10 min after X-ray (up to 3 Gy) irradiation. We next examined whether this protease inducibility is causally related with the X-ray susceptibility of cells. Leupeptin, a serine-cysteine protease inhibitor, inhibited the protease activity in samples obtained from X-ray-irradiated RSa-R cells. Treatment of RSa-R cells with the inhibitor before and after X-ray irradiation resulted in an increased susceptibility of the cells to X-ray cell killing. However, the treatment of cells with other inhibitors tested did not modulate the X-ray susceptibility. These results suggest that leupeptin-sensitive proteases are involved in the resistance of human cells to X-ray cell killing. (author)

Characterization of neutron-irradiated HT-UPS steel by high-energy X-ray diffraction microscopy

Energy Technology Data Exchange (ETDEWEB)

Zhang, Xuan, E-mail: xuanzhang@anl.gov [Nuclear Engineering Division, Argonne National Laboratory, Lemont, IL 60439 (United States); Park, Jun-Sang; Almer, Jonathan [Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439 (United States); Li, Meimei [Nuclear Engineering Division, Argonne National Laboratory, Lemont, IL 60439 (United States)

2016-04-01

This paper presents the first measurement of neutron-irradiated microstructure using far-field high-energy X-ray diffraction microscopy (FF-HEDM) in a high-temperature ultrafine-precipitate-strengthened (HT-UPS) austenitic stainless steel. Grain center of mass, grain size distribution, crystallographic orientation (texture), diffraction spot broadening and lattice constant distributions of individual grains were obtained for samples in three different conditions: non-irradiated, neutron-irradiated (3dpa/500 °C), and irradiated + annealed (3dpa/500 °C + 600 °C/1 h). It was found that irradiation caused significant increase in grain-level diffraction spot broadening, modified the texture, reduced the grain-averaged lattice constant, but had nearly no effect on the average grain size and grain size distribution, as well as the grain size-dependent lattice constant variations. Post-irradiation annealing largely reversed the irradiation effects on texture and average lattice constant, but inadequately restored the microstrain.

Radiation and chemically induced potentially lethal lesions in noncycling mammalian cells: recovery analysis in terms of x-ray- and ultraviolet-like-systems

International Nuclear Information System (INIS)

Hahn, G.M.

1975-01-01

Recovery from and fixation of potentially lethal damage after exposure of Chinese hamster cells to uv and to x irradiation were investigated, as was recovery after exposure to chemotherapeutic agents. Recovery after uv radiation has a T/sub 1 / 2 / of about 20 hr; the fraction of cells able to undergo recovery depends upon nutritional factors both before and after exposure. After x irradiation, recovery proceeds with a T/sub 1 / 2 / of approximately 2 hr and is much less influenced by nutritional factors. Fixation after serum stimulation has a T/sub 1 / 2 / of 3 to 4 hr in uv-irradiated cells, a T/sub 1 / 2 / of 30 min in x-irradiated cells. Recovery kinetics after nitrogen mustard and bleomycin exposures mimic those for x-ray exposure; after methyl methane sulfonate the kinetics are mainly uv-like, though with an x-ray-like component. Recovery by cells with BUdR-substituted DNA and irradiated with visible light is primarily x-ray-like, though with a uv-like component. There is no recovery by cells exposed to adriamycin or to 1,3-bis(2-chloroethyl)-1-nitrosourea

X-ray scatter data for diagnostic radiology

International Nuclear Information System (INIS)

Dick, C.E.; Soares, C.G.; Motz, J.W.

1978-01-01

The ratio of the scattered to the total X-ray fluence (scatter fraction) at the centre of the image plane for X-rays transmitted through polystyrene phantoms has been measured for X-ray energies of 32 and 69 keV, X-ray beam diameters from 4 to 40 cm, phantom thicknesses from 5 to 30 cm and phantom-to-image-plane separations from 0.3 to 40 cm. The experimental values for this ratio have less than a 10% variation for these two X-ray energies and the experimental data show good agreement with Monte Carlo calculations and available experimental results for low atomic number materials. Based on these results, simple curves are generated which give estimates (+ - 10%) of the scatter fraction for all combinations of the geometric parameters encountered in diagnostic radiology. (author)

X-ray-induced changes in growth of Mozambique tilapia

International Nuclear Information System (INIS)

Jana, B.B.; Basu, M.

1995-01-01

Early fry (30 d postfertilization) and 7-8-week-old Mozambique tilapias (Tilapia mossambica) were exposed to X rays in dosages of 50, 100, 200, 300, 400 or 500 roentgens and reared in outdoor culture tanks between May 1981 and October 1988. Fish of either sex that were irradiated as fry grew faster than controls at all test X-ray doses. Among fish irradiated at 7-8 weeks, males grew significantly faster, but females grew significantly slower, than controls at all test doses. X-ray-induced changes in growth were dose-dependent: growth rates of fry (both sexes) and of juvenile males rose relative to those of controls with increased radiation dose. The growth increase per unit of radiation dose was higher for fry than for older juveniles. The length-weight regression was steeper for irradiated males than for controls. The average weights of F 1 offspring of irradiated fish were greatly reduced as compared with controls, which suggests the transfer of the detrimental effects of X rays from irradiated parents to their offspring. 39 refs., 3 figs., 3 tabs

Differential response of two cell lines sequentially irradiated with low X-ray doses.

Science.gov (United States)

Güerci, A M; Dulout, F N; Grillo, C A; Seoane, A I

2005-05-01

An experiment was designed to compare the effect of repeated low doses of X-rays in two different cell lines: one transformed, epithelial like and aneuploid Chinese hamster ovary K-1 (CHO-K1); the other originated from a human primary culture, fibroblast, diploid and non-transformed, MRC-5. CHO and MRC-5 cells were cultured for 14 or eight passages, respectively. Irradiation was performed once per passage when cells were in the quiescent state (90 - 95% in G1/G0). Cells were exposed to 10.0 mSv X-ray doses. Ionizing radiation did not induce apoptosis or necrosis in the exposed CHO cell population. Significant increases of low-level damaged cells (degrees 1 and 2) were found for the 14 cycles of radiation when compared with controls, except for the first irradiation cycle. No significant increases in the frequency of cells with severe damage were observed. The frequency of MRC-5 cells with low-level damage increased significantly when compared with controls for radiation cycles seven and eight. Significant increases of apoptosis, necrosis and severe damage were found only for the highest dose. Transformed and non-transformed cell types responded differently to direct and indirect damage using low-dose repeat exposures to ionizing radiation. Though more investigation is needed to understand the mechanisms of radiation effects in chronic low-dose-exposed cell populations, cellular type should be taken into account in the design of in vitro experiments for understanding low-dose-irradiation effects.

Sulfur transfer in the distillate fractions of Arabian crude oils under gamma-irradiation

Science.gov (United States)

Basfar, Ahmed A.; Soliman, Yasser S.; Alkhuraiji, Turki S.

2017-05-01

Desulfurization of light distillation fractions including gasoline, kerosene and diesel obtained from the four Arabian crude oils (heavy, medium, light and extra light) upon γ-rays irradiation to different doses was investigated. In addition, yields vol%, FTIR analysis, kinematic viscosity and density of all distillation fractions of irradiated crude oils were evaluated. Limited radiation-induced desulfurization of those fractions was observed up to an irradiation dose of 200 kGy. FTIR analysis of those fractions indicates the absence of oxidized sulfur compounds, represented by S=O of sulfone group, indicating that γ-irradiation of the Arabian crude oils at normal conditions does not induce an oxidative desulfurization in those distillation fractions. Radiation-induced sulfur transfer decreases by 28.56% and increases in total sulfur by 16.8% in Arabian extra light oil and Arabian medium crude oil respectively.

Synchrotron topographic evaluation of strain around craters generated by irradiation with X-ray pulses from free electron laser with different intensities

Czech Academy of Sciences Publication Activity Database

Wierzchowski, W.; Wieteska, K.; Sobierajski, R.; Klinger, D.; Pelka, J.; Zymierska, D.; Paulmann, C.; Hau-Riege, S.P.; London, R.A.; Graf, A.; Burian, Tomáš; Chalupský, Jaromír; Gaudin, J.; Krzywinski, J.; Moeller, S.; Messerschmidt, M.; Bozek, J.; Bostedt, C.

2015-01-01

Roč. 364, Dec (2015), s. 20-26 ISSN 0168-583X Institutional support: RVO:68378271 Keywords : x-ray free electron laser * soft x-ray lasers * irradiation with femtosecond pulses * silicon Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 1.389, year: 2015

AG, TL, and IRSL dosimetric properties in X-ray irradiated HPHT diamond crystals

Energy Technology Data Exchange (ETDEWEB)

Gil-Tolano, M.I. [Programa de Posgrado, Departamento de Investigacion en Fisica, Universidad de Sonora, A. P. 5-088, Hermosillo, Sonora, 83190, Mexico (Mexico); Melendrez, R.; Lancheros-Olmos, J.C.; Soto-Puebla, D.; Chernov, V.; Pedroza-Montero, M.; Barboza-Flores, M. [Departamento de Investigacion en Fisica, Universidad de Sonora, A. P. 5-088, Hermosillo, Sonora, 83190, Mexico (Mexico); Castaneda, B. [Departamento de Fisica, Universidad de Sonora, Blvd. Luis Encinas y Rosales S/N, Hermosillo, Sonora, 83000, Mexico (Mexico)

2014-10-15

HPHT diamonds have been studied for several years for their potential in different applications. In previous studies it has been found that the thermoluminescence (TL) glow curves of ''as-grown'' HPHT diamonds are non-reproducible. In this work, we study the afterglow (AG), thermoluminescent (TL), and optically stimulated luminescence (OSL) response of commercial samples of synthetic HPHT type-Ib diamond crystals exposed to X-ray irradiation (0.75 mA, 35 kV) at a dose rate of 0.624 Gy/s, after a high gamma ({sup 60}Co) dose irradiation of 500 kGy followed by a thermal treatment at 1073 K for 1 h in nitrogen atmosphere. Deconvolution of the TL glow curves shows four peaks, located around 379, 509, 561, and 609 K. The crystals exhibit evident AG recorded for 300 s immediately after X-ray irradiation, due to the thermal emptying of the traps responsible for the low-temperature TL peaks (below 400 K). The stimulation of irradiated crystals with 870-nm light, creates pronounced OSL and destroys all TL peaks with the exception of the high-temperature peak at 609 K. The dose responses of the integrated AG, TL, and OSL are linear in the range of 0.6-5 Gy and saturated at higher doses. The reproducibility of AG, TL, and OSL measurements is about 5%. The fading in the first hour of storage in dark conditions at RT of TL signal of HPHT diamond is mainly associated to the emptying of the traps responsible for the 379-K TL peaks. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Scatter fractions from linear accelerators with x-ray energies from 6 to 24 MV.

Science.gov (United States)

Taylor, P L; Rodgers, J E; Shobe, J

1999-08-01

Computation of shielding requirements for a linear accelerator must take into account the amount of radiation scattered from the patient to areas outside the primary beam. Currently, the most frequently used data are from NCRP 49 that only includes data for x-ray energies up to 6 MV and angles from 30 degrees to 135 degrees. In this work we have determined by Monte Carlo simulation the scattered fractions of dose for a wide range of energies and angles of clinical significance including 6, 10, 18, and 24 MV and scattering angles from 10 degrees to 150 degrees. Calculations were made for a 400 cm2 circular field size impinging onto a spherical phantom. Scattered fractions of dose were determined at 1 m from the phantom. Angles from 10 degrees to 30 degrees are of concern for higher energies where the scatter is primarily in the forward direction. An error in scatter fraction may result in too little secondary shielding near the junction with the primary barrier. The Monte Carlo code ITS (Version 3.0) developed at Sandia National Laboratory and NIST was used to simulate scatter from the patient to the barrier. Of significance was the variation of calculated scattered dose with depth of measurement within the barrier indicating that accurate values may be difficult to obtain. Mean energies of scatter x-ray spectra are presented.

Combination use of lentinan with x-ray therapy in mouse experimental tumor system, (1)

International Nuclear Information System (INIS)

Shiio, Tsuyoshi; Tsuchiya, Yoshiharu; Ohishi, Kazuo; Yoshihama, Takashi

1988-01-01

Apparent reduction of leukocyte counts was observed in mice irradiated with 1,500 ∼ 3,000 rads of X-ray on the left hind leg. This reduction of leukocyto counts was completely protected by the pre-treatment with lentinan before X-ray irradiation. Suppressive effect of X-ray on the antitumor function of lentinan seems to be weak. When treatment with X-ray irradiation and lentinan was applied for mice bearing solid type sarcoma 180, additive effect was obtained by the combination of lentinan before or after X-ray irradiation. (author)

Relationship between α/β and radiosensitivity and biologic effect of fractional irradiation of tumor cells

International Nuclear Information System (INIS)

Guo Chuanling; Chinese Academy of Sciences, Beijing; Wang Jufang; Jin Xiaodong; Li Wenjian

2006-01-01

Five kinds of malignant human tumor cells, i.e. SMMC-7721, HeLa, A549, HT29 and PC3 cell lines, were irradiated by 60 Co γ-rays to 1-6 Gy in a single irradiation or two irradiations of half dose. The radiosensitivity was compared with the dose-survival curves and D 50 and D 10 values. Differences in the D 50 and D 10 between the single and fractional irradiation groups showed the effect of fractional irradiation. Except for PC3 cells, all the cell lines showed obvious relationship between radiosensitivity and biologic effect of fractional irradiation and the α/β value. A cell line with bigger α/β was more radiation sensitive, with less obvious effect of fractional irradiation. The results indicate that there were obvious differences in radiosensitivity, repair ability and biologic effect of fractional irradiation between tumor cells from different tissues. To some tumor cell lines, the relationship between radiosensitivity, biologic effect of fractional irradiation and repair ability was attested. The α/β value of single irradiation can be regarded as a parameter to investigate the radiosensitivity and biologic effect of fractional irradiation of tumor cells. (authors)

Soft x rays for radiobiological studies

International Nuclear Information System (INIS)

Ban, Sadayuki; Iida, Shozo; Shimba, Hachiro; Awa, A.A.; Hamilton, H.B.; Clifton, K.H.

1986-04-01

Lethal effects and chromosome aberrations induced in cells exposed to low energy (soft) X rays demonstrated that these relatively low energy X rays are just as effective as those of higher energy for radiobiological studies, and even more effective for irradiating cultured mammalian cells than laboratory animals. (author)

Time-resolved suprathermal x-rays

International Nuclear Information System (INIS)

Lee, P.H.Y.; Rosen, M.D.

1978-01-01

Temporally resolved x-ray spectra in the range of 1 to 20 keV have been obtained from gold disk targets irradiated by 1.06 μm laser pulses from the Argus facility. The x-ray streak camera used for the measurement has been calibrated for streak speed and dynamic range by using an air-gap Fabry-Perot etalon, and the instrument response has been calibrated using a multi-range monoenergetic x-ray source. The experimental results indicate that we are able to observe the ''hot'' x-ray temperature evolve in time and that the experimentally observed values can be qualitatively predicted by LASNEX code computations when the inhibited transport model is used

Behavior of triterpenes from Maytenus aquifolium Martius ('espinheira santa') upon X- and gamma-rays irradiation

International Nuclear Information System (INIS)

Campos, P.; Vilegas, J.H.Y.; Lancas, F.M.

1997-01-01

The behavior of the triterpenes friedelin and friedelan-3-ol, contained on the leaves of Maytenus aquifolium Martius (Celastraceae), upon several doses of X- and γ-rays (10 to 100 kGy), was investigated by high resolution gas chromatography (HRGC) and high resolution gas chromatography -mass spectrometry (HRGC-MS). The friedelin content has not changed with γ-irradiation, but the content of friedelan-3-ol decreased around 17% at doses of 10, 20 and 40 kGy and around 27% at doses of 60, 80 and 100 kGy. The levels of both triterpenes remained unchanged even at higher X-ray doses. Lupen-3-one was detected by HRGC-MS. (author)

Effects of x-irradiation on lens reducing systems

International Nuclear Information System (INIS)

Giblin, F.J.; Chakrapani, B.; Reddy, V.N.

1978-01-01

Studies have been made of the effects of x ray on various lens reducing systems including the levels of NADPH and glutathione (GSH), the activity of the hexose monophosphate shunt (HMS), and the activities of certain enzymes including glutathion reductase, glutathione peroxidase, and glucose-6-phosphate dehydrogenase (G-6-PD). It was found that during several weeks following x irradiation but prior to cataract formation there was very little change in the number of reduced -SH groups per unit weight of lens protein but that, with the appearance of cataract, there was a sudden loss of protein -SH groups. In contrast, the concentration of GSH in the x-rayed lens decreased throughout the experimental period. Similarly, the concentration of NADPH in the x-rayed lens was found to decrease significantly relative to controls one week prior to cataract formation and the ratio of NADPH to NADP + in the lens shifted at this time period from a value greater than 1.0 in the control lens to less than 1.0 in the x-rayed lens. A corresponding decrease occurred in the activity of the HMS in x-rayed lenses as measured by culture in the presence of 1- 14 C-labelled glucose. G-6-PD was partially inactivated in the x-rayed lens. Of the eight enzymes studied, G-6-PD appeared to be the most sensitive to x-irradiation. The data indicate that x-irradiation results in a steady decrease in the effectiveness of lens reducing systems and that, when these systems reach a critically low point, sudden oxidation of protein -SH groups and formation of high molecular weight protein aggregates may be initiated

Ion, X-ray, UV and Neutron Microbeam Systems for Cell Irradiation.

Science.gov (United States)

Bigelow, A W; Randers-Pehrson, G; Garty, G; Geard, C R; Xu, Y; Harken, A D; Johnson, G W; Brenner, D J

2010-08-08

The array of microbeam cell-irradiation systems, available to users at the Radiological Research Accelerator Facility (RARAF), Center for Radiological Research, Columbia University, is expanding. The HVE 5MV Singletron particle accelerator at the facility provides particles to two focused ion microbeam lines: the sub-micron microbeam II and the permanent magnetic microbeam (PMM). Both the electrostatic quadrupole lenses on the microbeam II system and the magnetic quadrupole lenses on the PMM system are arranged as compound lenses consisting of two quadrupole triplets with "Russian" symmetry. Also, the RARAF accelerator is a source for a proton-induced x-ray microbeam (undergoing testing) and is projected to supply protons to a neutron microbeam based on the (7)Li(p, n)(7)Be nuclear reaction (under development). Leveraging from the multiphoton microscope technology integrated within the microbeam II endstation, a UV microspot irradiator - based on multiphoton excitation - is available for facility users. Highlights from radiation-biology demonstrations on single living mammalian cells are included in this review of microbeam systems for cell irradiation at RARAF.

Active and passive avoidance conditioning for rats which received x-ray irradiation in their embryonal period

International Nuclear Information System (INIS)

Tamaki, Yoshitaka; Inoue, Minoru; Kameyama, Yoshiro

1983-01-01

Fischer rats at 17 gestational days were given 200 R of x-ray, and their offsprings were subjected to conditioning of active and passive avoidance against a shuttle box stimulation. These rats irradiated in their embryonal period learned active avoidance reaction more rapidly than control rats, but it took time for them to gain passive avoidance reaction. This result seemed to suggest activated reactibility of the irradiated animals in avoiding the shuttle box stimulation. In the irradiated rats, frequency of the passive avoidance reaction increased gradually as they learned with training. (Ueda, J.)

Effect of x-irradiation on cell kinetics of esophageal membrane cells in mice

International Nuclear Information System (INIS)

Ando, Koichi; Tsunemoto, Hiroshi; Urano, Muneyasu; Koike, Sachiko

1977-01-01

Effect of x-irradiation on the cell kinetics of esophageal membrane cells was studied in C3Hf/He male mice. Experimental methods include; counting the number of basal and superficial cells, and pulse or continuous labelling by tritiated thymidine. Esophageal area was irradiated with 1000 rad of 200 kVp x-rays and cell kinetics were studied on the 5th post-irradiation day. Autoradiography revealed the shortening of the cell cycle time, specifically in G- and G- phases. Numbers of basal cells and of superficial cells were found to increase for 5 days after irradiation. Continuous labelling experiments using infusion technique demonstrated than growth fraction of irradiated basal cells was 1.0 as well as that of non-irradiated cells. It was of interest that the migration time, i.e., the time required for labelled cells to migrate from basal cell layer to superficial cell layer, was shortened approximately 1/3 of that of non-irradiated control after irradiation. Diurnal variation was observed not only in normal basal cells but also in irradiated ones, and the rate of increase of labelling index after continuous labelling was independent of the time when the labelling was started. (auth.)

Effect of x irradiation on cell kinetics of esophageal membrane cells in mice

Energy Technology Data Exchange (ETDEWEB)

Ando, K; Tsunemoto, H; Urano, M; Koike, S [National Inst. of Radiological Sciences, Chiba (Japan)

1977-05-01

Effect of x irradiation on the cell kinetics of esophageal membrane cells was studied in C3Hf/He male mice. Experimental methods include; counting the number of basal and superficial cells, and pulse or continuous labelling by tritiated thymidine. Esophageal area was irradiated with 1000 rad of 200 kVp x rays and cell kinetics were studied on the 5th post-irradiation day. Autoradiography revealed the shortening of the cell cycle time, specifically in G- and G- phases. Numbers of basal cells and of superficial cells were found to increase for 5 days after irradiation. Continuous labelling experiments using infusion technique demonstrated than growth fraction of irradiated basal cells was 1.0 as well as that of non-irradiated cells. It was of interest that the migration time, i.e., the time required for labelled cells to migrate from basal cell layer to superficial cell layer, was shortened approximately 1/3 of that of non-irradiated control after irradiation. Diurnal variation was observed not only in normal basal cells but also in irradiated ones, and the rate of increase of labelling index after continuous labelling was independent of the time when the labelling was started.

Effects of single doses of X-rays on renal function in the pig after the irradiation of both kidneys

International Nuclear Information System (INIS)

Robbins, M.E.C.; Hopewell, J.W.

1988-01-01

Irradiation of a single kidney in the pig with relatively low doses of X-rays, in the order of 8 Gy, produces a pronounced reduction in both glomerular filtration rate (GFR) and effective renal plasma flow (ERPF). This apparent high radiosensitivity may be due, in part, to the compensatory hypertrophy displayed by the contralateral unirradiated kidney. This could suppress any potential for recovery by the irradiated kidney. To test this hypothesis, both kidneys of 14-week-old Large White pigs were sequentially irradiated with single doses of 250 kV X-rays, in the range 8.8 to 12.6 Gy. Two weeks after irradiation, GFR and ERPF increased markedly in all irradiated kidneys; levels then declined in a dose-dependent manner. Following a dose of 8.8 Gy renal haemodynamics returned to control values within 4 weeks of irradiation. After higher doses, GFR and ERPF decreased markedly and remained below control values up to 24 weeks after irradiation. At all doses the mean functional status of irradiated kidneys in animals in which both kidneys were irradiated was significantly greater than that previously observed in the irradiated kidney of pigs in which only one kidney was irradiated. The findings support the above hypothesis, and indicate that individual kidneys in the same animal may differ in their response to a similar nephrotoxic insult. 35 refs.; 6 figs.; 2 tabs

Effect of X-ray irradiation on germination of rice and wheat at different temperatures and pH levels of water

International Nuclear Information System (INIS)

Rajput, T.B.S.; Singh, Jaswant

1981-01-01

An experiment was conducted on the germination of ''Jaya'' rice (Oryza sativa Linn.) and ''Sonalika'' wheat (Triticum aestivum Linn. emend. Thell.) to study the effects of low doses of X-ray irradiation at different temperatures and pH levels of water. The percentage of germination was more at pH 7, and decreased with an increase or decrease in pH level. In most of the cases irradiation delayed the germination and proved to be harmful. But at 20deg C, 4 KR X-ray irradiation promoted the germination of rice by more than 15% at pH levels of 5.5-8.5. But in wheat no significant increase in germination percentage was noted at any combination of the parameters. (auth.)

Long-term hematopoietic stem cell damage after external irradiation with X rays

International Nuclear Information System (INIS)

Grande, M.T.; Varas, F.; Bueren, J.A.

1997-01-01

We have investigated the functionality of the lympho-hematopoietic stem cells long-term (9 months) after the irradiation (X rays) of mice at different stages of development, by means of a competitive bone marrow repopulation assay. Our data revealed that a dose of 1 Gy was only capable of inducing significant long-term failures in the functionality of the primitive repopulating cells in mice irradiated at the young-adult stage (12 week-old), but not in mice irradiated at the late stages of foetus development (17 day-old fetuses) nor at the early development of the embryo (4 day-old embryos). The differential generation of long-term stem cell defects as a function of the age was confirmed in mice irradiated with 3 Gy. While no significant effects in the long-term repopulating cells were observed in 4 day-old embryos, significant repopulation deficiencies were observed in this population when mice were irradiated at the 17 day of foetus development, and more markedly at the adult stage of growth. These data offer new evidence about the influence of the developmental stage of the animal on the generation of residual hematopoietic dysfunctions by external irradiation, with particular relevance to the very primitive lympho-hematopoietic stem cells. (author)

X-ray diffraction studies of neutron irradiated beryllium oxide; Etude par diffraction des rayons X de glucine irradiee aux neutrons

Energy Technology Data Exchange (ETDEWEB)

Belbeoch, B; Rodot, J; Roulliay, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1966-07-01

X-ray diagrams of neutron irradiated sintered BeO (E > 1 MeV) can be classified into 3 types depending on the value of the c/a ratio, independently of the characteristics of the sinters, (hot pressed or cold pressed, material, variable density and grain size, pure BeO or BeO with additions). The anisotropic expansion of the BeO lattice caused by irradiation depends not only on the dose of irradiation, but also on the intergranular stresses of the samples. The sintered samples which resist most satisfactorily to irradiation consist of cold pressed high density and small grain size material for which the c/a ratio varies little with increasing dosage. The single crystal diagrams show the same classification as the polycrystalline material in respect with the c/a ratio. Furthermore, in addition to the Bragg reflections, X-ray diffusions are observed; the distribution of the defects is no longer isotropic; a description is given in particular of the scattering which occurs when 1.625 < c/a < 1.645. It appears that the defects start to congregate and cause pronounced distortion of the lattice. The defects are stabilized in the form of large aggregates only when a later irradiation stage is reached. (author) [French] Les diagrammes de rayons X obtenus a l'aide d'echantillons frittes de BeO irradies aux neutrons (E > 1 MeV) peuvent etre classes en trois types qui dependent de la valeur du rapport c/a, quelles que soient les caracteristiques du fritte (fritte sous charge ou fritte naturel, densite et taille de grains variables, BeO pur ou avec additions). La dilatation anisotrope de la maille de BeO observee par irradiation ne depend pas seulement de la dose recue, mais aussi des etats de contraintes intergranulaires des echantillons; ainsi les frittes qui resistent le mieux sous irradiation sont les frittes naturels a forte densite et a petits grains pour lesquels le rapport c/a varie peu en fonction de la dose d'irradiation. Les diagrammes de monocristaux presentent la

The Columbia University proton-induced soft x-ray microbeam.

Science.gov (United States)

Harken, Andrew D; Randers-Pehrson, Gerhard; Johnson, Gary W; Brenner, David J

2011-09-15

A soft x-ray microbeam using proton-induced x-ray emission (PIXE) of characteristic titanium (K(α) 4.5 keV) as the x-ray source has been developed at the Radiological Research Accelerator Facility (RARAF) at Columbia University. The proton beam is focused to a 120 μm × 50 μm spot on the titanium target using an electrostatic quadrupole quadruplet previously used for the charged particle microbeam studies at RARAF. The proton induced x-rays from this spot project a 50 μm round x-ray generation spot into the vertical direction. The x-rays are focused to a spot size of 5 μm in diameter using a Fresnel zone plate. The x-rays have an attenuation length of (1/e length of ~145 μm) allowing more consistent dose delivery across the depth of a single cell layer and penetration into tissue samples than previous ultra soft x-ray systems. The irradiation end station is based on our previous design to allow quick comparison to charged particle experiments and for mixed irradiation experiments.

Effects of X-ray irradiation combined with hyperthermia on human bone marrow cells

International Nuclear Information System (INIS)

Xie Huaijiang; Niu Rongjiu; Liu Xiaodong; Liu Huanqin

1996-01-01

The authors report on the effects of X-ray irradiation combined with hyperthermia on human bone marrow cells (BMC) in vitro. Observation was made on the morphology of treated cells under optic microscope and ultrastructural changes under electron microscope. The change was not obvious at first after treatment i,e, only the vacuolar degeneration was observed in a few cells under the EM. The survival of BMC alone after irradiation decreased with increase of the irradiation dose. The morphological changes included vacuolar degeneration of cells, swelling of mitochondria, and disintegration of nuclear membranes. The survival rate of BMC after irradiation combined with hyperthermia was significantly lower than that after treatment by either of them alone (P<0.01). The morphological changes were as follows: the cell structure was destroyed, the cell support system and cell organelles were destroyed, the cell membrane and nuclear membranes were destroyed, and the cell plasma and nuclear sap overflowed

Experimental and theoretical studies of the physical processes occurring in thin plane targets irradiated by intense X-ray pulses

International Nuclear Information System (INIS)

Bugrov, A. E.; Burdonskii, I. N.; Gavrilov, V. V.; Gol'tsov, A. Yu.; Grabovskii, E. V.; Efremov, V. P.; Zhuzhukalo, E. V.; Zurin, M. V.; Koval'skii, N. G.; Kondrashov, V. N.; Oleinik, G. M.; Potapenko, A. I.; Samokhin, A. A.; Smirnov, V. P.; Fortov, V. E.; Frolov, I. N.

2007-01-01

Results are presented from experimental and theoretical studies of the interaction of intense X-ray pulses with different types of plane targets, including low-density (∼10 mg/cm 3 ) ones, in the Angara-5-1 facility. It is found experimentally that a dense low-temperature plasma forms on the target surface before the arrival of the main heating X-ray pulse. It is demonstrated that the contrast of the X-ray pulse can be increased by placing a thin organic film between the target and the discharge gap. The expansion velocity of the plasma created on the target surface irradiated by Z-pinch-produced X rays was found to be (3-4) x 10 6 cm/s. A comparison between the simulation and experimental results confirms the validity of the physical-mathematical model used

Development of a guinea pig cutaneous radiation injury model using low penetrating X-rays.

Science.gov (United States)

Rodgers, Kathleen E; Tan, Alick; Kim, Lila; Espinoza, Theresa; Meeks, Christopher; Johnston, William; Maulhardt, Holly; Donald, Melissa; Hill, Colin; diZerega, Gere S

2016-08-01

A guinea pig skin model was developed to determine the dose-dependent response to soft X-ray radiation into the dermis. X-ray exposure (50 kVp) was defined to a 4.0 × 4.0 cm area on the lateral surface of a guinea pig using lead shielding. Guinea pigs were exposed to a single fraction of X-ray irradiation ranging from 25-79 Gy via an XRAD320ix Biological Irradiator with the collimator removed. Gross skin changes were measured using clinical assessments defined by the Kumar scale. Skin contracture was assessed, as well as histological evaluations. Loss of dermal integrity was shown after a single dose of soft X-ray radiation at or above 32 Gy with the central 2.0 × 2.0 cm of the exposed site being the most affected. Hallmarks of the skin injury included moist desquamation, ulceration and wound contracture, as well as alterations in epithelium, dermis, muscle and adipose. Changes in the skin were time- and radiation dose-dependent. Full-thickness injury occurred without animal mortality or gross changes in the underlying organs. The guinea pig is an appropriate small animal model for the short-term screening of countermeasures for cutaneous radiation injury (CRI).

Effects of various drugs on recovery of immunological function after x-ray irradiation

International Nuclear Information System (INIS)

Fukuda, Sakae; Komori, Shoichiro; Aramaki, Shojiro; Tamai, Kazunori; Fuyuno, Kikuo

1977-01-01

X-ray of 300 R was irradiation to the whole bodies of mice aged 6 to 8 weeks, and 0.2 mg of Cepharanthin, 0.2 mg of Leucon, 0.2 ml of Cytochrome-C, and 0.01 KE of Picibanil were given intraperitoneally for seven days from the next day of the irradiation. Three days after the administration of these drugs, 0.1 ml of 7% picrylchloride ethanol solution was painted on the shaven abdomen and its sensitization was examined. Next, 0.02 to 0.03 ml of 1% picrylchloride olive solution was painted on both ears 7 days after that, and swelling of them was measured with the thickness of ears 24 hours after the painting. Moreover, the sensitization was discussed from a viewpoint of the number of leukocyte and lymphocute. Delayed-type skin reaction which was an index of cellular immunity was influenced fairly by the whole body irradiation of x-ray, but it recovered from the damage 20 to 30 days after the irradiation, showing rebound-like phenomenon. Recovery of delayed-type skin reaction and the number of lymphocyte showed almost the same pattern. Accordingly, it was suspected that the number of lymphocyte was directly proportional to cellular immunological competence of the individual. Out of four drugs, there was not a drug particularly which activated delayed-type skin reaction. In contrast with this, Leucon and Cytochrome-C significantly inhibited the recovery. It was recognized that four drugs had a tendency to promote the recovery of the number of leucocyte, but they decreased it conversely from a viewpoint of percentage of lymphocyte. Therefore, it was suspected that the subject of this would be an increase of leukocyte except lymphocyte. (Ueda, J.)

Effects of mecobalamin on testicular dysfunction induced by X-ray irradiation in mice

International Nuclear Information System (INIS)

Oshio, Shigeru; Yazaki, Tsunetada; Umeda, Takashi; Ozaki, Satoru; Ohkawa, Isao; Tajima, Tetsuya; Yamada, Takeshi; Mohri, Hideo.

1991-01-01

Experimental testicular dysfunction was produced by X-ray irradiation to the testes in mice. Mecobalamin (CH 3 -B 12 ) was orally administered at a daily dose of 0.01, 0.1 or 1 mg/kg six times a week for 8 weeks from the next day after the irradiation. The control mice received physiological saline in the same manner. On 4th- and 6th-week after the irradiation, the weights of testes and epididymides were decreased, although those of the body and accessory sex glands (seminal vesicle, coagulating gland and prostate) were nearly equal to those of non-irradiated mice. At the same time, the diameter of seminiferous tubules decreased and sperm parameters (sperm count, sperm motility and sperm abnormality) deteriorated. When CH 3 -B 12 (1 mg/kg) was administered, the diameter of seminiferous tubules increased and sperm parameters improved as compared to those of the control. The results indicate that CH 3 -B 12 improved the experimental testicular dysfunction in mice induced by the irradiation. These results suggest that CH 3 -B 12 might accelerate testicular function. (author)

Determination of metal balance shift induced in small fresh water fish by X-ray irradiation using PIXE analysis

International Nuclear Information System (INIS)

Yukawa, M.; Aoki, K.; Iso, H.; Kodama, K.; Imaseki, H.; Ishikawa, Y.

2005-01-01

In the environmental pollution studies, it is very important to detect not only pollutants but also changes induced in organisms in the environment with various environmental stresses such as heavy metal toxicity radiation and agricultural chemicals. In the latter, monitoring is carried out using biological indicators to find out the changes, which have wide spectra from visible like deformity of the body to invisible such as changes in some enzyme activities. Changes of the balance of essential elements could occur in organisms to deal with the stresses. If we detect an elemental balance shift, we may see the environmental pollution in its early stages. Moreover, in the actual environment, combined effects, additive or reductive with coexistent elements or other stresses, is an important subject for investigation. Therefore, measurement of many elements in the biological indicator's simultaneously and determination of the distribution in the organisms are useful in clarifying the action of pollutants at sublethal levels. A small fresh water fish, Medaka can be used as one of the biological-indicators for determination of water quality. In the National Institute of Radiological Sciences (NIRS), an inbred strain of Medaka Orizias laptipes was established and has been maintained for the research purposes. Since the genetic background of inbred animals is almost uniform, the individual deviation among animals is very small. This characteristic is very useful to investigate the physiological effects of environmental stresses. We have continued to investigate the balance shift of essential elements induced in the bodies of Medaka by several stresses. In this paper, elemental content in various organs of the X-ray irradiated fish determined by PIXE method are reported in comparison with that of the control fish to observe the effect of the X-rays. Body size of Medaka is about 3 cm long, and the internal organs are very small (about l mm on average). PIXE is the most

Post-irradiation examination of a fuel pin using a microscopic X-ray system: Measurement of carbon deposition and pin metrology

International Nuclear Information System (INIS)

Gras, Ch.; Stanley, S.J.

2008-01-01

The paper presents some interesting aspects associated with X-ray imaging and its potential application in the nuclear industry. The feasibility of using X-ray technology for the post-irradiation examination of a fuel pin has been explored, more specifically pin metrology and carbon deposition measurement. The non-active sample was specially designed to mimic the structure of an AGR fuel pin whilst a carbon based material was applied to the mock up fuel rod in order to mimic carbon deposition. Short duration low energy (50 kV) 2D digital radiography was employed and provided encouraging results (with respect to carbon deposition thickness and structure measurements) for the mock up fuel pin with a spatial resolution of around 10 μm. Obtaining quantitative data from the resultant images is the principal added value associated with X-ray imaging. A higher intensity X-ray beam (≥90 kV) was also used in conjunction with the low energy set-up to produce a clear picture of the cladding as well as the interface between the lead (Pb mimics the uranium oxide) and stainless steel cladding. Spent fuel metrology and routine radiography are two additional tasks that X-ray imaging could perform for the post-irradiation examination programme. Therefore, when compared to other techniques developed to deliver information on one particular parameter, X-ray imaging offers the possibility to extract useful information on a range of parameters

Radiation processing with high-energy X-rays

International Nuclear Information System (INIS)

Cleland, Marshall R.; Stichelbaut, Frederic

2009-01-01

The physical, chemical or biological characteristics of selected commercial products and materials can be improved by radiation processing. The ionizing energy can be provided by accelerated electrons with energies between 75 keV and 10 MeV, gamma rays from cobalt-60 with average energies of 1.25 MeV or X-rays with maximum energies up to 7.5 MeV. Electron beams are preferred for thin products, which are processed at high speeds. Gamma rays are used for products that are too thick for treatment with electron beams. High-energy X-rays can also be used for these purposes because their penetration in solid materials is similar to or even slightly greater than that of gamma rays. Previously, the use of X-rays had been inhibited by their slower processing rates and higher costs when compared with gamma rays. Since then, the price of cobalt-60 sources has been increased and the radiation intensity from high-energy, high-power X-ray generators has also increased. For facilities requiring at least 2 MCi of cobalt-60, the capital and operating costs of X-ray facilities with equivalent processing rates can be less than that of gamma-ray irradiators. Several high-energy electron beam facilities have been equipped with removable X-ray targets so that irradiation processes can be done with either type of ionizing energy. A new facility is now being built which will be used exclusively in the X-ray mode to sterilize medical products. Operation of this facility will show that high-energy, high-power X-ray generators are practical alternatives to large gamma-ray sources. (author)

SOFT X-RAY IRRADIATION OF H{sub 2}S ICE AND THE PRESENCE OF S{sub 2} IN COMETS

Energy Technology Data Exchange (ETDEWEB)

Jimenez-Escobar, A.; Munoz Caro, G. M. [Centro de Astrobiologia (CSIC-INTA), Carretera de Ajalvir, km 4, Torrejon de Ardoz, 28850 Madrid (Spain); Ciaravella, A.; Candia, R.; Micela, G. [INAF-Osservatorio Astronomico di Palermo, P.za Parlamento 1, 90134 Palermo (Italy); Cecchi-Pestellini, C., E-mail: munozcg@cab.inta-csic.es [INAF-Osservatorio Astronomico di Cagliari, Strada n.54, Loc. Poggio dei Pini, I-09012 Capoterra (Canada) (Italy)

2012-06-01

Little is known about the effects of X-rays in interstellar ices. To understand the sulfur depletion in dense clouds and the presence of S{sub 2} in comets, we simulated experimentally the soft X-ray processing (0.3 keV) of H{sub 2}S ice for the first time. Experiments were performed under ultrahigh vacuum conditions at 8 K using infrared and quadrupole mass spectrometry to monitor the solid and gas phases, respectively. A UV irradiation experiment using a similar dose was made for comparison. After X-ray irradiation, an infrared absorption appears near 4.0 {mu}m which is attributed to H{sub 2}S{sub 2} formation in the ice. This identification is also supported by the desorption at 133 K of m/z 66, 65, 64, corresponding to the mass fragments of H{sub 2}S{sub 2}. The H{sub 2}S{sub 2} species is expected to be present in interstellar and cometary ices that were processed by X-rays. Further irradiation leads to dissociation of this molecule forming S{sub 2} and larger S-molecules up to S{sub 8}, which may explain the depletion of sulfur in dense clouds. CS{sub 2} was so far the parent molecule proposed for S{sub 2} formation in comets. But the abundance of H{sub 2}S{sub 2}, formed by irradiation of pure H{sub 2}S or H{sub 2}S in an H{sub 2}O-ice matrix, should be larger than that of CS{sub 2} in the ice, the latter requiring a carbon source for its formation. Based on our experimental results, we propose that S{sub 2} in comets could be formed by dissociation of H{sub 2}S{sub 2} in the ice.

Effects of X-rays and γ-rays on reconstitution of hematopoiesis and immunity after allogeneic bone marrow transplantation

International Nuclear Information System (INIS)

Pan Bin; Zeng Lingyu; Cheng Hai; Song Guoliang; Jia Lu; Yan Zhiling; Chen Chong; Xu Kailin

2011-01-01

Objective: To determine the conditioning regimen suitable for mice allogeneic hematopoietic stem cell transplantation (allo-HSCT). Methods: Twelve BALB/c mice were randomly divided into 2 equal groups to undergo X-ray irradiation by linear accelerator at the dose of 7.0 Gy (pure X-ray group) or 60 Co source irradiation at the dose of 7.0 Gy (pure γ-ray group). Thirty mice were randomly divided into 2 equal groups to undergo X-ray irradiation and then infusion of bone marrow from donor mice via caudal vein (X-ray + transplantation group) or γ-ray and then infusion of bone marrow via caudal vein (γ-ray + transplantation group). 3, 5, 7, 10, 15, 20, and 30 d later peripheral blood samples were collected to calculate the number of white blood cells (WBCs) and detect the chimeric rates of lymphocytes by flow cytometry. 5, 10, and 20 d after irradiation 15 mice were killed with their lung, liver, small intestine, spleen, and femurs taken out to undergo pathological examination. Results: The survival rates during the period 5-15 days of the γ-ray + transplantation group were all significantly higher than those of the X-ray + transplantation group. The pathological changes of organs of the X-ray + transplantation group were all more severe than those of the γ-ray + transplantation group. Since the fifth day after transplantation cells originating from the donor began to appear in the peripheral blood. The chimeric rate of the γ-ray + transplantation group 10 days after transplantation was (95.53± 2.57) %. The chimeric rates 5, 10, and 20 days after transplantation of the γ-ray + transplantation group were all significantly higher than those of the X-ray + transplantation group (t=15.263, 3.256, P<0.05). The WBC count of both irradiation groups decreased to the lowest level 5 d later and began to increase 10 days after transplantation and the WBC counts of the γ-ray + transplantation group 10 and 20 days after transplantation were both significantly higher than

JEM-X observations of the Be/X-ray binary EXO 2030+375

DEFF Research Database (Denmark)

Nunez, S.M.; Reig, P.; Blay, P.

2003-01-01

We have used data from the Joint European Monitor (JEM-X) to perform an X-ray spectral and timing analysis of the 42-s transient pulsar EXO 2030+375 during an X-ray outburst. X-ray pulsations are clearly detected with an average pulse period of 41.66+/-0.05 s and an average pulse fraction of 60...

Influence of X-ray irradiation on the mandible of ovariectomized rats

International Nuclear Information System (INIS)

Ikoma, Kazuyuki; Iwata, Hiroshi; Yosue, Takashi

2004-01-01

The aim of the present study was to investigate the influence of irradiation on the mandible of ovariectomized (OVX) rats. Female rats were subject to OVX or a sham operation (SHAM) at the age of 14 weeks. Ten Gy doses of X-ray were applied to the mandibles twelve weeks after the operation. The experimental animals were divided into four groups: the OVX non-irradiation group, the OVX irradiation group, SHAM non-irradiation group and SHAM irradiation group. Four, eight and twelve weeks after irradiation, the animals were sacrificed and the mandibles removed. The mandibles were investigated using μCT and pQCT, and from the images obtained, the rate of mineralized tissue in the bone as well as the bone mineral content (BMC) were evaluated. The rate of mineralized tissue in the bone as determined from the images of μCT was significantly (P<0.05) lower in the OVX non-irradiation group than in the SHAM non-irradiation group at four weeks after irradiation. Similarly, the rate in the OVX irradiation group was lower than that in the SHAM irradiation group at twelve weeks after irradiation. In both the SHAM and OVX groups, there was no difference between the non-irradiation and irradiation groups. From the pQCT images, the change in the BMC in the cortical bone was negligible when the BMC was measured in the mandibles. In the OVX non-irradiation group, the trabecular BMC of the mandibles was significantly lower than that in the SHAM non-irradiation group at four and twelve weeks after irradiation. The trabecular BMC of the mandibles in the SHAM and OVX irradiation groups were significantly lower than that of the SHAM and OVX non-irradiation groups respectively throughout the experimental period. In the rate of mineralized tissue in the mandibles, the influence of OVX was recognized, but the influence of irradiation was not. On the other hand, the BMC in the cortical bone was not significant through out the experiment. The influence of irradiation on the OVX group was

Effect of low dose X-ray irradiation on apoptosis in spermatogenic cells of mouse testes

International Nuclear Information System (INIS)

Liu Guangwei; Liu Shuchun; Lu Zhe; Gong Shouliang

2003-01-01

To study the effects of low dose radiation (LDR) with different doses of X-rays on the apoptosis in spermatogenic cells of male Kunming mouse testes. The time-effect and dose-effect of apoptosis in the different stages of spermatogenic cell cycles of mouse testis after LDR with different doses of X-rays were studied with light microscope using the methods of TdT-mediated dUTP nick end labeling (TUNEL) and HE staining. The apoptosis of spermatogenic cells induced by LDR had a remarkable regularity in cell types. When the dose was 0.025 Gy, spermatogonium apoptosis was taken as main. With the dose increase of irradiation (0.025-0.2 Gy), spermatocytes also showed an apoptotic change, but the apoptotic rate of spermatogonia was significantly higher than that of spermatocytes. Moreover, the apoptosis of spermatids and spermatozoa scarcely occurred after irradiation with low dose. The apoptosis of spermatogenic cells induced by LDR has a regular change, which provides a further experimental evidence for the mechanism study of hormesis by LDR

X-Ray-induced Deuterium Enrichment of N-rich Organics in Protoplanetary Disks: An Experimental Investigation Using Synchrotron Light

Energy Technology Data Exchange (ETDEWEB)

Gavilan, Lisseth; Carrasco, Nathalie [LATMOS, Université Versailles St Quentin, UPMC Université Paris 06, CNRS, 11 blvd d’Alembert, F-78280 Guyancourt (France); Remusat, Laurent; Roskosz, Mathieu [IMPMC, CNRS UMR 7590, Sorbonne Universités, UPMC Université Paris 06, IRD, Muséum National d’Histoire Naturelle, CP 52, 57 rue Cuvier, Paris F-75231 (France); Popescu, Horia; Jaouen, Nicolas [SEXTANTS beamline, SOLEIL synchrotron, L’Orme des Merisiers, F-91190 Saint-Aubin (France); Sandt, Christophe [SMIS beamline, SOLEIL synchrotron, L’Orme des Merisiers, F-91190 Saint-Aubin (France); Jäger, Cornelia [Laboratory Astrophysics and Cluster Physics Group of the Max Planck Institute for Astronomy at the Friedrich Schiller University and Institute of Solid State Physics, Helmholtzweg 3, D-07743 Jena (Germany); Henning, Thomas [Max-Planck Institute for Astronomy Königstuhl 17, D-69117 Heidelberg (Germany); Simionovici, Alexandre [Institut des Sciences de la Terre, Observatoire des Sciences de l’Univers de Grenoble, BP 53, F-38041 Grenoble (France); Lemaire, Jean Louis [Institut des Sciences Moléculaires d’Orsay (ISMO), CNRS, Univ. Paris Sud, Université Paris-Saclay, F-91405 Orsay (France); Mangin, Denis, E-mail: lisseth.gavilan@latmos.ipsl.fr [Institut Jean Lamour, CNRS, Université de Lorraine, F-54011 Nancy (France)

2017-05-01

The deuterium enrichment of organics in the interstellar medium, protoplanetary disks, and meteorites has been proposed to be the result of ionizing radiation. The goal of this study is to simulate and quantify the effects of soft X-rays (0.1–2 keV), an important component of stellar radiation fields illuminating protoplanetary disks, on the refractory organics present in the disks. We prepared tholins, nitrogen-rich organic analogs to solids found in several astrophysical environments, e.g., Titan’s atmosphere, cometary surfaces, and protoplanetary disks, via plasma deposition. Controlled irradiation experiments with soft X-rays at 0.5 and 1.3 keV were performed at the SEXTANTS beamline of the SOLEIL synchrotron, and were immediately followed by ex-situ infrared, Raman, and isotopic diagnostics. Infrared spectroscopy revealed the preferential loss of singly bonded groups (N–H, C–H, and R–N≡C) and the formation of sp{sup 3} carbon defects with signatures at ∼1250–1300 cm{sup −1}. Raman analysis revealed that, while the length of polyaromatic units is only slightly modified, the introduction of defects leads to structural amorphization. Finally, tholins were measured via secondary ion mass spectrometry to quantify the D, H, and C elemental abundances in the irradiated versus non-irradiated areas. Isotopic analysis revealed that significant D-enrichment is induced by X-ray irradiation. Our results are compared to previous experimental studies involving the thermal degradation and electron irradiation of organics. The penetration depth of soft X-rays in μ m-sized tholins leads to volume rather than surface modifications: lower-energy X-rays (0.5 keV) induce a larger D-enrichment than 1.3 keV X-rays, reaching a plateau for doses larger than 5 × 10{sup 27} eV cm{sup −3}. Synchrotron fluences fall within the expected soft X-ray fluences in protoplanetary disks, and thus provide evidence of a new non-thermal pathway to deuterium fractionation of

X-Ray-induced Deuterium Enrichment of N-rich Organics in Protoplanetary Disks: An Experimental Investigation Using Synchrotron Light

Science.gov (United States)

Gavilan, Lisseth; Remusat, Laurent; Roskosz, Mathieu; Popescu, Horia; Jaouen, Nicolas; Sandt, Christophe; Jäger, Cornelia; Henning, Thomas; Simionovici, Alexandre; Lemaire, Jean Louis; Mangin, Denis; Carrasco, Nathalie

2017-05-01

The deuterium enrichment of organics in the interstellar medium, protoplanetary disks, and meteorites has been proposed to be the result of ionizing radiation. The goal of this study is to simulate and quantify the effects of soft X-rays (0.1-2 keV), an important component of stellar radiation fields illuminating protoplanetary disks, on the refractory organics present in the disks. We prepared tholins, nitrogen-rich organic analogs to solids found in several astrophysical environments, e.g., Titan’s atmosphere, cometary surfaces, and protoplanetary disks, via plasma deposition. Controlled irradiation experiments with soft X-rays at 0.5 and 1.3 keV were performed at the SEXTANTS beamline of the SOLEIL synchrotron, and were immediately followed by ex-situ infrared, Raman, and isotopic diagnostics. Infrared spectroscopy revealed the preferential loss of singly bonded groups (N-H, C-H, and R-N≡C) and the formation of sp3 carbon defects with signatures at ˜1250-1300 cm-1. Raman analysis revealed that, while the length of polyaromatic units is only slightly modified, the introduction of defects leads to structural amorphization. Finally, tholins were measured via secondary ion mass spectrometry to quantify the D, H, and C elemental abundances in the irradiated versus non-irradiated areas. Isotopic analysis revealed that significant D-enrichment is induced by X-ray irradiation. Our results are compared to previous experimental studies involving the thermal degradation and electron irradiation of organics. The penetration depth of soft X-rays in μm-sized tholins leads to volume rather than surface modifications: lower-energy X-rays (0.5 keV) induce a larger D-enrichment than 1.3 keV X-rays, reaching a plateau for doses larger than 5 × 1027 eV cm-3. Synchrotron fluences fall within the expected soft X-ray fluences in protoplanetary disks, and thus provide evidence of a new non-thermal pathway to deuterium fractionation of organic matter.

Study on the effect of x-ray irradiation of seed on zinc uptake in maize (Zea Mays L.) plants

International Nuclear Information System (INIS)

Joshi, Gargi; Singh, K.P.; Joshi, G.C.

2007-01-01

The effects of irradiations by X-rays at the two dose levels (1.1 KR and 2.2 KR) of seeds on uptake of zinc ion in maize (Zea Mays L.) plants were studied. The uptake and internal distribution of zinc ion in the maize plants was carried out by incorporating radioactive zinc as zinc chloride (ZnCl 2 ) in the nutrient solution to the plants. The localization and translocation of radioactive zinc was studied employing phosphor imaging systems (FX). The radioactivity measurement has been carried out using solid scintillation counter. It was observed that zinc ions uptake was higher in plants out of 2.2 KR X-rays irradiated seeds. (author)

Clustering of DSB in DNA by X-Ray and a-particle irradiation in MCF-7 cells studied with anti γ-H2AX

International Nuclear Information System (INIS)

Tapia, O.; Soto, J.; Castro, F.A.; Berciano, Ma T; Lafarga, M.; Cos, S.; Sanchez-Barcelo, E.

2007-01-01

Among the effects produced by the ionizing radiations in cellular DNA, double strand breaks (DSB) are considered particularly important. These ruptures and their grouping in certain points, clustering, are acknowledged as the cause for mutagenic effects and cellular death. In this work we present the methodology and the results of the application of the DSB - DNA marking technique by using anti γ-H2AX, taking human cancerous cells MCF-7 as model and X-rays and a particles as irradiation agents. The obtained results are showed in a qualitative way like a set of figures. Are shows the effects of a dose of 2 Gy X-rays in the DSB - DNA after 30 minutes of the irradiation that responds to a certain pattern in which a spatially homogenous irradiation interacts with the DNA. As in previous case, the effects of X-rays in the DSB - DNA shows a different pattern affecting the cells that are in mitosis. Also, the effects of a dose of 2 Gy X-rays obtained after 24 hours of irradiation shows a number of DSB smaller, which is indicative of the repairing process. The results of the irradiation with a dose of 0.1 Gy originated from a particles cause a smaller number of DSB. Nevertheless, the existence of a bigger clustering with the appearance of clearly more intense points is appraised. Also, the effect of the irradiation is showed as an aligned trace of clusters that is possible to attribute to the passing of a a particle through the cellular nucleus. (Author)

Ultrastructural morphometry of parotid acinar cells following fractionated irradiation

International Nuclear Information System (INIS)

Grehn, A.-L.; Gustafsson, H.; Franzen, L.; Thornell, L.-E.; Henriksson, R.

1997-01-01

The aim of this study was to evaluate the long term effects on the ultrastructure of parotid glands after fractionated irradiation. The method implemented involved 5 x 6 Gy and 5 x 8 Gy, Monday to Friday 6 MV photons. By unilateral irradiation, the contralateral parotid gland served as a control. Although irradiation diminished the acinar cell density in light microscopic sections from 75 to 32% after 5 x 8 Gy of irradiation, ultrastructural morphometry could not detect any statistically significant differences in acinar cell size, nuclear size, nuclear density, granule area, mean granule size, or granule density. In general, greater differences were seen between rats receiving 30 or 40 Gy, on both the irradiated and the control side, than between the irradiated side and the control side. This was interpreted as due to differences in the nutritional state of the animals. This analysis concluded that individual acinar cells that survive irradiation seem not to be damaged in the long term when evaluated at the ultrastructural level. The study further stresses the importance of adequate sampling sizes and the use of adequate controls. (author)

Risks of fetus irradiation in X-ray and radioisotope examinations in early stages of pregnancy

International Nuclear Information System (INIS)

Husak, V.; Wiedermann, M.; Susila, M.; Ryznar, V.

1981-01-01

Radiation burden is discussed of the fetus in pregnancy. During organogenesis the fetus is not capable of repairs; irradiation causes growth inhibition and malformations. In the last trimestre, irradiation causes disturbances in the somatic growth, leukemia is found in greater incidence in newly-borns. Doses are tabulated from commonest X-ray examinations and the applications of radiopharmaceuticals. The said doses are only valid for the first five weeks of pregnancy; when the thyroid starts functioning, the total dose retained in the thyroid after the application of radiopharmaceuticals may be higher. (H.S.)

Irradiation effects and micro-structural changes in large grain uranium dioxide fuel investigated by micro-beam X-ray diffraction

Energy Technology Data Exchange (ETDEWEB)

Mieszczynski, C. [NES and SYN, Paul Scherrer Institute, 5232 Villigen PSI (Switzerland); Kuri, G., E-mail: goutam.kuri@psi.ch [NES and SYN, Paul Scherrer Institute, 5232 Villigen PSI (Switzerland); Degueldre, C.; Martin, M.; Bertsch, J.; Borca, C.N.; Grolimund, D. [NES and SYN, Paul Scherrer Institute, 5232 Villigen PSI (Switzerland); Delafoy, Ch. [AREVA NP, 10 Rue Juliette Récamier, 69456 Lyon Cedex 06 (France); Simoni, E. [Institut de Physique Nucléaire, Université Paris-Sud, 91406 Orsay (France)

2014-01-15

Microstructural changes in a set of commercial grade UO{sub 2} fuel samples have been investigated using synchrotron based micro-focused X-ray fluorescence (μ-XRF) and X-ray diffraction (μ-XRD) techniques. The results are associated with conventional UO{sub 2} materials and relatively larger grain chromia-doped UO{sub 2} fuels, irradiated in a commercial light water reactor plant (average burn-up: 40 MW d kg{sup −1}). The lattice parameters of UO{sub 2} in fresh and irradiated specimens have been measured and compared with theoretical predictions. In the pristine state, the doped fuel has a somewhat smaller lattice parameter than the standard UO{sub 2} as a result of chromia doping. Increase in micro-strain and lattice parameter in irradiated materials is highlighted. All irradiated samples behave in a similar manner with UO{sub 2} lattice expansion occurring upon irradiation, where any Cr induced effect seems insignificant and accumulated lattice defects prevail. Elastic strain energy densities in the irradiated fuels are also evaluated based on the UO{sub 2} crystal lattice strain and non-uniform strain. The μ-XRD patterns further allow the evaluation of the crystalline domain size and sub-grain formation at different locations of the irradiated UO{sub 2} pellets.

Induced mitotic gynogenesis in common carp (Cyprinus carpio L.), optimizing irradiation dose of X- and gamma-ray